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freebsd-nq/sys/dev/uart/uart_dev_ns8250.c

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Start each of the license/copyright comments with /*-, minor shuffle of lines
2005-01-06 01:43:34 +00:00
/*-
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
* Copyright (c) 2003 Marcel Moolenaar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
Add support for A10 uart. A10 uart is derived from Synopsys DesignWare uart and requires to read Uart Status Register when IIR_BUSY has detected. Also this change includes FDT check, where it checks device specific properties defined in dts and sets the busy_detect variable. broken_txfifo is also needed to be set in order to make it work for A10 uart case. Reviewed by: marcel@ Approved by: gonzo@
2013-03-01 01:42:31 +00:00
#include "opt_platform.h"
uart(4) - make the 8250 uart baudrate tolerance build time tweakable. It turns out on a 16550 w/ a 25MHz SoC reference clock you get a little over 3% error at 115200 baud, which causes this to fail. Just .. cope. Things cope these days. Default to 30 (3.0%) as before, but allow UART_DEV_TOLERANCE_PCT to be set at build time to change that.
2015-11-18 06:24:21 +00:00
#include "opt_uart.h"
Add support for A10 uart. A10 uart is derived from Synopsys DesignWare uart and requires to read Uart Status Register when IIR_BUSY has detected. Also this change includes FDT check, where it checks device specific properties defined in dts and sets the busy_detect variable. broken_txfifo is also needed to be set in order to make it work for A10 uart case. Reviewed by: marcel@ Approved by: gonzo@
2013-03-01 01:42:31 +00:00
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
Add a loader tunable "hw.broken_txfifo" which enables a workaround for a bug in old versions of QEMU (and Xen, and other places using QEMU code). On those buggy emulated UARTs, the "TX idle" interrupt gets lost; with this workaround, we spinwait for the TX to happen and then send ourselves the interrupt. It's ugly but it works, while minimizing the impact on the code for the !broken_txfifo case. MFC after: 2 weeks
2013-01-27 23:33:42 +00:00
#include <sys/kernel.h>
#include <sys/sysctl.h>
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
#include <machine/bus.h>
Add support for A10 uart. A10 uart is derived from Synopsys DesignWare uart and requires to read Uart Status Register when IIR_BUSY has detected. Also this change includes FDT check, where it checks device specific properties defined in dts and sets the busy_detect variable. broken_txfifo is also needed to be set in order to make it work for A10 uart case. Reviewed by: marcel@ Approved by: gonzo@
2013-03-01 01:42:31 +00:00
#ifdef FDT
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
#include <dev/uart/uart.h>
#include <dev/uart/uart_cpu.h>
Move the uart_class definitions and fdt compat data into the individual uart implementations, and export them using the new linker-set mechanism. Differential Revision: https://reviews.freebsd.org/D1993 Submitted by: Michal Meloun
2015-03-07 15:24:15 +00:00
#ifdef FDT
#include <dev/uart/uart_cpu_fdt.h>
#endif
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
#include <dev/uart/uart_bus.h>
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
#include <dev/uart/uart_dev_ns8250.h>
Restore uart PPS signal capture polarity to its historical norm, and add an option to invert the polarity in software. Also add an option to capture very narrow pulses by using the hardware's MSR delta-bit capability of latching line state changes. This effectively reverts the mistake I made in r286595 which was based on empirical measurements made on hardware using TTL-level signaling, in which the logic levels are inverted from RS-232. Thus, this re-syncs the polarity with the requirements of RFC 2783, which is writen in terms of RS-232 signaling. Narrow-pulse mode uses the ability of most ns8250 and similar chips to provide a delta indication in the modem status register. The hardware is able to notice and latch the change when the pulse width is shorter than interrupt latency, which results in the signal no longer being asserted by time the interrupt service code runs. When running in this mode we get notified only that "a pulse happened" so the driver synthesizes both an ASSERT and a CLEAR event (with the same timestamp for each). When the pulse width is about equal to the interrupt latency the driver may intermittantly see both edges of the pulse. To prevent generating spurious events, the driver implements a half-second lockout period after generating an event before it will generate another. Differential Revision: https://reviews.freebsd.org/D4477
2016-01-12 18:42:00 +00:00
#include <dev/uart/uart_ppstypes.h>
Include the common <dev/ic/ns16550.h> instead of the private <dev/uart_dev_ns8250.h>. The latter can be removed now.
2004-11-20 23:22:04 +00:00
#include <dev/ic/ns16550.h>
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
#include "uart_if.h"
#define DEFAULT_RCLK 1843200
uart(4) - make the 8250 uart baudrate tolerance build time tweakable. It turns out on a 16550 w/ a 25MHz SoC reference clock you get a little over 3% error at 115200 baud, which causes this to fail. Just .. cope. Things cope these days. Default to 30 (3.0%) as before, but allow UART_DEV_TOLERANCE_PCT to be set at build time to change that.
2015-11-18 06:24:21 +00:00
/*
* Set the default baudrate tolerance to 3.0%.
*
* Some embedded boards have odd reference clocks (eg 25MHz)
* and we need to handle higher variances in the target baud rate.
*/
#ifndef UART_DEV_TOLERANCE_PCT
#define UART_DEV_TOLERANCE_PCT 30
#endif /* UART_DEV_TOLERANCE_PCT */
Add support for A10 uart. A10 uart is derived from Synopsys DesignWare uart and requires to read Uart Status Register when IIR_BUSY has detected. Also this change includes FDT check, where it checks device specific properties defined in dts and sets the busy_detect variable. broken_txfifo is also needed to be set in order to make it work for A10 uart case. Reviewed by: marcel@ Approved by: gonzo@
2013-03-01 01:42:31 +00:00
static int broken_txfifo = 0;
Pull in r267961 and r267973 again. Fix for issues reported will follow.
2014-06-28 03:56:17 +00:00
SYSCTL_INT(_hw, OID_AUTO, broken_txfifo, CTLFLAG_RWTUN,
Add support for A10 uart. A10 uart is derived from Synopsys DesignWare uart and requires to read Uart Status Register when IIR_BUSY has detected. Also this change includes FDT check, where it checks device specific properties defined in dts and sets the busy_detect variable. broken_txfifo is also needed to be set in order to make it work for A10 uart case. Reviewed by: marcel@ Approved by: gonzo@
2013-03-01 01:42:31 +00:00
&broken_txfifo, 0, "UART FIFO has QEMU emulation bug");
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
/*
* Clear pending interrupts. THRE is cleared by reading IIR. Data
* that may have been received gets lost here.
*/
static void
ns8250_clrint(struct uart_bas *bas)
{
Fix hangs caused by hardware that signals receive errors (framing, parity, etc), but does not indicate characters being received. Since no chracters have been received, ignore the line errors. PR: 131006 MFC after: 3 days
2009-04-08 00:14:06 +00:00
uint8_t iir, lsr;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
iir = uart_getreg(bas, REG_IIR);
while ((iir & IIR_NOPEND) == 0) {
iir &= IIR_IMASK;
Fix hangs caused by hardware that signals receive errors (framing, parity, etc), but does not indicate characters being received. Since no chracters have been received, ignore the line errors. PR: 131006 MFC after: 3 days
2009-04-08 00:14:06 +00:00
if (iir == IIR_RLS) {
lsr = uart_getreg(bas, REG_LSR);
if (lsr & (LSR_BI|LSR_FE|LSR_PE))
(void)uart_getreg(bas, REG_DATA);
} else if (iir == IIR_RXRDY || iir == IIR_RXTOUT)
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
(void)uart_getreg(bas, REG_DATA);
else if (iir == IIR_MLSC)
(void)uart_getreg(bas, REG_MSR);
uart_barrier(bas);
iir = uart_getreg(bas, REG_IIR);
}
}
static int
ns8250_delay(struct uart_bas *bas)
{
int divisor;
u_char lcr;
lcr = uart_getreg(bas, REG_LCR);
uart_setreg(bas, REG_LCR, lcr | LCR_DLAB);
uart_barrier(bas);
Allow uart(4)'s ns8250 driver to work with devices whose regshift is > 0. - Rename REG_DL to REG_DLL and REG_DLH. - Always treat DLL and DLH as two separate 8-bit registers instead of one 16-bit register. Additionally, remove the probe for the high 4 bits of IER being 0 and don't assume we can always read/write 0 to/from those bits. These changes allow uart(4) to drive the UARTs on the Intel XScale PXA255. Reviewed by: marcel
2006-05-23 00:41:12 +00:00
divisor = uart_getreg(bas, REG_DLL) | (uart_getreg(bas, REG_DLH) << 8);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_barrier(bas);
uart_setreg(bas, REG_LCR, lcr);
uart_barrier(bas);
/* 1/10th the time to transmit 1 character (estimate). */
For embedded UARTs compatible with the ns8250 family it is possible that the driver clock is identical to the processor or bus clock. This is the case for the PowerQUICC processor. When the clock is high enough, overflows happen in the calculation of the time it takes to send 1/10 of a character, used in delay loops. Fix the overflows so as to fix bugs in the delay loops that can cause either insufficient delays or excessive delays.
2007-03-28 18:34:59 +00:00
if (divisor <= 134)
return (16000000 * divisor / bas->rclk);
return (16000 * divisor / (bas->rclk / 1000));
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
static int
ns8250_divisor(int rclk, int baudrate)
{
int actual_baud, divisor;
int error;
if (baudrate == 0)
return (0);
divisor = (rclk / (baudrate << 3) + 1) >> 1;
if (divisor == 0 || divisor >= 65536)
return (0);
actual_baud = rclk / (divisor << 4);
/* 10 times error in percent: */
error = ((actual_baud - baudrate) * 2000 / baudrate + 1) >> 1;
uart(4) - make the 8250 uart baudrate tolerance build time tweakable. It turns out on a 16550 w/ a 25MHz SoC reference clock you get a little over 3% error at 115200 baud, which causes this to fail. Just .. cope. Things cope these days. Default to 30 (3.0%) as before, but allow UART_DEV_TOLERANCE_PCT to be set at build time to change that.
2015-11-18 06:24:21 +00:00
/* enforce maximum error tolerance: */
if (error < -UART_DEV_TOLERANCE_PCT || error > UART_DEV_TOLERANCE_PCT)
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
return (0);
return (divisor);
}
static int
ns8250_drain(struct uart_bas *bas, int what)
{
int delay, limit;
delay = ns8250_delay(bas);
if (what & UART_DRAIN_TRANSMITTER) {
/*
* Pick an arbitrary high limit to avoid getting stuck in
* an infinite loop when the hardware is broken. Make the
* limit high enough to handle large FIFOs.
*/
limit = 10*1024;
while ((uart_getreg(bas, REG_LSR) & LSR_TEMT) == 0 && --limit)
DELAY(delay);
if (limit == 0) {
/* printf("ns8250: transmitter appears stuck... "); */
return (EIO);
}
}
if (what & UART_DRAIN_RECEIVER) {
/*
* Pick an arbitrary high limit to avoid getting stuck in
* an infinite loop when the hardware is broken. Make the
* limit high enough to handle large FIFOs and integrated
* UARTs. The HP rx2600 for example has 3 UARTs on the
* management board that tend to get a lot of data send
* to it when the UART is first activated.
*/
limit=10*4096;
while ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) && --limit) {
(void)uart_getreg(bas, REG_DATA);
uart_barrier(bas);
DELAY(delay << 2);
}
if (limit == 0) {
/* printf("ns8250: receiver appears broken... "); */
return (EIO);
}
}
return (0);
}
/*
* We can only flush UARTs with FIFOs. UARTs without FIFOs should be
* drained. WARNING: this function clobbers the FIFO setting!
*/
static void
ns8250_flush(struct uart_bas *bas, int what)
{
uint8_t fcr;
fcr = FCR_ENABLE;
if (what & UART_FLUSH_TRANSMITTER)
fcr |= FCR_XMT_RST;
if (what & UART_FLUSH_RECEIVER)
fcr |= FCR_RCV_RST;
uart_setreg(bas, REG_FCR, fcr);
uart_barrier(bas);
}
static int
ns8250_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,
int parity)
{
int divisor;
uint8_t lcr;
lcr = 0;
if (databits >= 8)
lcr |= LCR_8BITS;
else if (databits == 7)
lcr |= LCR_7BITS;
else if (databits == 6)
lcr |= LCR_6BITS;
else
lcr |= LCR_5BITS;
if (stopbits > 1)
lcr |= LCR_STOPB;
lcr |= parity << 3;
/* Set baudrate. */
if (baudrate > 0) {
divisor = ns8250_divisor(bas->rclk, baudrate);
if (divisor == 0)
return (EINVAL);
MFp4: Calculate the divisor before setting the DLAB bit. This prevents that there's a control flow that leaves the DLAB bit set.
2006-04-23 21:15:07 +00:00
uart_setreg(bas, REG_LCR, lcr | LCR_DLAB);
uart_barrier(bas);
Allow uart(4)'s ns8250 driver to work with devices whose regshift is > 0. - Rename REG_DL to REG_DLL and REG_DLH. - Always treat DLL and DLH as two separate 8-bit registers instead of one 16-bit register. Additionally, remove the probe for the high 4 bits of IER being 0 and don't assume we can always read/write 0 to/from those bits. These changes allow uart(4) to drive the UARTs on the Intel XScale PXA255. Reviewed by: marcel
2006-05-23 00:41:12 +00:00
uart_setreg(bas, REG_DLL, divisor & 0xff);
uart_setreg(bas, REG_DLH, (divisor >> 8) & 0xff);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_barrier(bas);
}
/* Set LCR and clear DLAB. */
uart_setreg(bas, REG_LCR, lcr);
uart_barrier(bas);
return (0);
}
/*
* Low-level UART interface.
*/
static int ns8250_probe(struct uart_bas *bas);
static void ns8250_init(struct uart_bas *bas, int, int, int, int);
static void ns8250_term(struct uart_bas *bas);
static void ns8250_putc(struct uart_bas *bas, int);
- Add a uart_rxready() and corresponding device-specific implementations that can be used to check whether receive data is ready, i.e. whether the subsequent call of uart_poll() should return a char, and unlike uart_poll() doesn't actually receive data. - Remove the device-specific implementations of uart_poll() and implement uart_poll() in terms of uart_getc() and the newly added uart_rxready() in order to minimize code duplication. - In sunkbd(4) take advantage of uart_rxready() and use it to implement the polled mode part of sunkbd_check() so we don't need to buffer a potentially read char in the softc. - Fix some mis-indentation in sunkbd_read_char(). Discussed with: marcel
2007-01-18 22:01:19 +00:00
static int ns8250_rxready(struct uart_bas *bas);
Don't hold the hardware mutex across getc(). It can wait indefinitely for a character to be received. Instead let getc() do any necesary locking.
2006-04-01 19:04:54 +00:00
static int ns8250_getc(struct uart_bas *bas, struct mtx *);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
struct uart_ops uart_ns8250_ops = {
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
.probe = ns8250_probe,
.init = ns8250_init,
.term = ns8250_term,
.putc = ns8250_putc,
- Add a uart_rxready() and corresponding device-specific implementations that can be used to check whether receive data is ready, i.e. whether the subsequent call of uart_poll() should return a char, and unlike uart_poll() doesn't actually receive data. - Remove the device-specific implementations of uart_poll() and implement uart_poll() in terms of uart_getc() and the newly added uart_rxready() in order to minimize code duplication. - In sunkbd(4) take advantage of uart_rxready() and use it to implement the polled mode part of sunkbd_check() so we don't need to buffer a potentially read char in the softc. - Fix some mis-indentation in sunkbd_read_char(). Discussed with: marcel
2007-01-18 22:01:19 +00:00
.rxready = ns8250_rxready,
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
.getc = ns8250_getc,
};
static int
ns8250_probe(struct uart_bas *bas)
{
The lcr variable in ns8250_probe is now unused. Remove it. Missed by: benno
2006-05-23 06:04:45 +00:00
u_char val;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
/* Check known 0 bits that don't depend on DLAB. */
val = uart_getreg(bas, REG_IIR);
if (val & 0x30)
return (ENXIO);
Ignore MCR[6] during the probe to fix a false negative. Bit 6 of the MCR register on the Sunix Sun1699 chip tends to be set but doesn't seem to have a function. That is, FreeBSD just works (provided the correct RCLK is used) regardless. PR: kern/129663 Diagnostics: Eygene Ryabinkin <rea-fbsd at codelabs.ru> MFC after: 3 days
2011-05-26 17:02:56 +00:00
/*
* Bit 6 of the MCR (= 0x40) appears to be 1 for the Sun1699
* chip, but otherwise doesn't seem to have a function. In
* other words, uart(4) works regardless. Ignore that bit so
* the probe succeeds.
*/
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
val = uart_getreg(bas, REG_MCR);
Ignore MCR[6] during the probe to fix a false negative. Bit 6 of the MCR register on the Sunix Sun1699 chip tends to be set but doesn't seem to have a function. That is, FreeBSD just works (provided the correct RCLK is used) regardless. PR: kern/129663 Diagnostics: Eygene Ryabinkin <rea-fbsd at codelabs.ru> MFC after: 3 days
2011-05-26 17:02:56 +00:00
if (val & 0xa0)
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
return (ENXIO);
return (0);
}
static void
ns8250_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
int parity)
{
Allow uart(4)'s ns8250 driver to work with devices whose regshift is > 0. - Rename REG_DL to REG_DLL and REG_DLH. - Always treat DLL and DLH as two separate 8-bit registers instead of one 16-bit register. Additionally, remove the probe for the high 4 bits of IER being 0 and don't assume we can always read/write 0 to/from those bits. These changes allow uart(4) to drive the UARTs on the Intel XScale PXA255. Reviewed by: marcel
2006-05-23 00:41:12 +00:00
u_char ier;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
if (bas->rclk == 0)
bas->rclk = DEFAULT_RCLK;
ns8250_param(bas, baudrate, databits, stopbits, parity);
/* Disable all interrupt sources. */
The XScale PXA255 has three generally ns16x50 compatible UARTs. One of the variations from normal 16x50 behaviour however is the the use of a normally unused bit of IER to control RX timeout interrupts independently of the generally used RXRDY bit. If this bit is not enabled, we only ever get interrupts when the FIFO is full, never before. This is not very useful when the UART is being used as a console. In order to support this without causing potential problems on more "normal" 16x50 variants, this change introduces two hints for the uart device, ier_mask and ier_rxbits. These can be used to override which bits get set and cleared when we're enabling and disabling RX interrupts. Reviewed by: marcel
2008-05-30 01:57:13 +00:00
/*
* We use 0xe0 instead of 0xf0 as the mask because the XScale PXA
* UARTs split the receive time-out interrupt bit out separately as
* 0x10. This gets handled by ier_mask and ier_rxbits below.
*/
ier = uart_getreg(bas, REG_IER) & 0xe0;
Allow uart(4)'s ns8250 driver to work with devices whose regshift is > 0. - Rename REG_DL to REG_DLL and REG_DLH. - Always treat DLL and DLH as two separate 8-bit registers instead of one 16-bit register. Additionally, remove the probe for the high 4 bits of IER being 0 and don't assume we can always read/write 0 to/from those bits. These changes allow uart(4) to drive the UARTs on the Intel XScale PXA255. Reviewed by: marcel
2006-05-23 00:41:12 +00:00
uart_setreg(bas, REG_IER, ier);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_barrier(bas);
/* Disable the FIFO (if present). */
uart_setreg(bas, REG_FCR, 0);
uart_barrier(bas);
/* Set RTS & DTR. */
uart_setreg(bas, REG_MCR, MCR_IE | MCR_RTS | MCR_DTR);
uart_barrier(bas);
ns8250_clrint(bas);
}
static void
ns8250_term(struct uart_bas *bas)
{
/* Clear RTS & DTR. */
uart_setreg(bas, REG_MCR, MCR_IE);
uart_barrier(bas);
}
static void
ns8250_putc(struct uart_bas *bas, int c)
{
Don't use a time-limiting loop that's defined in terms of the baudrate in the putc() method. Likewise, in the getc() method, don't check for received characters with an interval defined in terms of the baudrate. In both cases it works equally well to implement a fixed delay. More importantly, it avoids calculating a delay that's roughly 1/10th the time it takes to send/receive a character. The calculation is costly and happens for every character sent or received, affecting low-level console or debug port performance significantly. Secondly, when the RCLK is not available or unreliable, the delays could disrupt normal operation. The fixed delay is 1/10th the time it takes to send a character at 230400 bps.
2007-04-03 01:21:10 +00:00
int limit;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
Don't use a time-limiting loop that's defined in terms of the baudrate in the putc() method. Likewise, in the getc() method, don't check for received characters with an interval defined in terms of the baudrate. In both cases it works equally well to implement a fixed delay. More importantly, it avoids calculating a delay that's roughly 1/10th the time it takes to send/receive a character. The calculation is costly and happens for every character sent or received, affecting low-level console or debug port performance significantly. Secondly, when the RCLK is not available or unreliable, the delays could disrupt normal operation. The fixed delay is 1/10th the time it takes to send a character at 230400 bps.
2007-04-03 01:21:10 +00:00
limit = 250000;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
while ((uart_getreg(bas, REG_LSR) & LSR_THRE) == 0 && --limit)
Don't use a time-limiting loop that's defined in terms of the baudrate in the putc() method. Likewise, in the getc() method, don't check for received characters with an interval defined in terms of the baudrate. In both cases it works equally well to implement a fixed delay. More importantly, it avoids calculating a delay that's roughly 1/10th the time it takes to send/receive a character. The calculation is costly and happens for every character sent or received, affecting low-level console or debug port performance significantly. Secondly, when the RCLK is not available or unreliable, the delays could disrupt normal operation. The fixed delay is 1/10th the time it takes to send a character at 230400 bps.
2007-04-03 01:21:10 +00:00
DELAY(4);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_setreg(bas, REG_DATA, c);
In ns8250_putc() insert a barrier between writing the character and checking for transmitter empty.
2004-04-02 07:37:28 +00:00
uart_barrier(bas);
Don't use a time-limiting loop that's defined in terms of the baudrate in the putc() method. Likewise, in the getc() method, don't check for received characters with an interval defined in terms of the baudrate. In both cases it works equally well to implement a fixed delay. More importantly, it avoids calculating a delay that's roughly 1/10th the time it takes to send/receive a character. The calculation is costly and happens for every character sent or received, affecting low-level console or debug port performance significantly. Secondly, when the RCLK is not available or unreliable, the delays could disrupt normal operation. The fixed delay is 1/10th the time it takes to send a character at 230400 bps.
2007-04-03 01:21:10 +00:00
limit = 250000;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
while ((uart_getreg(bas, REG_LSR) & LSR_TEMT) == 0 && --limit)
Don't use a time-limiting loop that's defined in terms of the baudrate in the putc() method. Likewise, in the getc() method, don't check for received characters with an interval defined in terms of the baudrate. In both cases it works equally well to implement a fixed delay. More importantly, it avoids calculating a delay that's roughly 1/10th the time it takes to send/receive a character. The calculation is costly and happens for every character sent or received, affecting low-level console or debug port performance significantly. Secondly, when the RCLK is not available or unreliable, the delays could disrupt normal operation. The fixed delay is 1/10th the time it takes to send a character at 230400 bps.
2007-04-03 01:21:10 +00:00
DELAY(4);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
static int
- Add a uart_rxready() and corresponding device-specific implementations that can be used to check whether receive data is ready, i.e. whether the subsequent call of uart_poll() should return a char, and unlike uart_poll() doesn't actually receive data. - Remove the device-specific implementations of uart_poll() and implement uart_poll() in terms of uart_getc() and the newly added uart_rxready() in order to minimize code duplication. - In sunkbd(4) take advantage of uart_rxready() and use it to implement the polled mode part of sunkbd_check() so we don't need to buffer a potentially read char in the softc. - Fix some mis-indentation in sunkbd_read_char(). Discussed with: marcel
2007-01-18 22:01:19 +00:00
ns8250_rxready(struct uart_bas *bas)
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
{
- Add a uart_rxready() and corresponding device-specific implementations that can be used to check whether receive data is ready, i.e. whether the subsequent call of uart_poll() should return a char, and unlike uart_poll() doesn't actually receive data. - Remove the device-specific implementations of uart_poll() and implement uart_poll() in terms of uart_getc() and the newly added uart_rxready() in order to minimize code duplication. - In sunkbd(4) take advantage of uart_rxready() and use it to implement the polled mode part of sunkbd_check() so we don't need to buffer a potentially read char in the softc. - Fix some mis-indentation in sunkbd_read_char(). Discussed with: marcel
2007-01-18 22:01:19 +00:00
return ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) != 0 ? 1 : 0);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
static int
Don't hold the hardware mutex across getc(). It can wait indefinitely for a character to be received. Instead let getc() do any necesary locking.
2006-04-01 19:04:54 +00:00
ns8250_getc(struct uart_bas *bas, struct mtx *hwmtx)
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
{
Don't use a time-limiting loop that's defined in terms of the baudrate in the putc() method. Likewise, in the getc() method, don't check for received characters with an interval defined in terms of the baudrate. In both cases it works equally well to implement a fixed delay. More importantly, it avoids calculating a delay that's roughly 1/10th the time it takes to send/receive a character. The calculation is costly and happens for every character sent or received, affecting low-level console or debug port performance significantly. Secondly, when the RCLK is not available or unreliable, the delays could disrupt normal operation. The fixed delay is 1/10th the time it takes to send a character at 230400 bps.
2007-04-03 01:21:10 +00:00
int c;
Don't hold the hardware mutex across getc(). It can wait indefinitely for a character to be received. Instead let getc() do any necesary locking.
2006-04-01 19:04:54 +00:00
uart_lock(hwmtx);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
Don't hold the hardware mutex across getc(). It can wait indefinitely for a character to be received. Instead let getc() do any necesary locking.
2006-04-01 19:04:54 +00:00
while ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) == 0) {
uart_unlock(hwmtx);
Don't use a time-limiting loop that's defined in terms of the baudrate in the putc() method. Likewise, in the getc() method, don't check for received characters with an interval defined in terms of the baudrate. In both cases it works equally well to implement a fixed delay. More importantly, it avoids calculating a delay that's roughly 1/10th the time it takes to send/receive a character. The calculation is costly and happens for every character sent or received, affecting low-level console or debug port performance significantly. Secondly, when the RCLK is not available or unreliable, the delays could disrupt normal operation. The fixed delay is 1/10th the time it takes to send a character at 230400 bps.
2007-04-03 01:21:10 +00:00
DELAY(4);
Don't hold the hardware mutex across getc(). It can wait indefinitely for a character to be received. Instead let getc() do any necesary locking.
2006-04-01 19:04:54 +00:00
uart_lock(hwmtx);
}
c = uart_getreg(bas, REG_DATA);
uart_unlock(hwmtx);
return (c);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
static kobj_method_t ns8250_methods[] = {
KOBJMETHOD(uart_attach, ns8250_bus_attach),
KOBJMETHOD(uart_detach, ns8250_bus_detach),
KOBJMETHOD(uart_flush, ns8250_bus_flush),
KOBJMETHOD(uart_getsig, ns8250_bus_getsig),
KOBJMETHOD(uart_ioctl, ns8250_bus_ioctl),
KOBJMETHOD(uart_ipend, ns8250_bus_ipend),
KOBJMETHOD(uart_param, ns8250_bus_param),
KOBJMETHOD(uart_probe, ns8250_bus_probe),
KOBJMETHOD(uart_receive, ns8250_bus_receive),
KOBJMETHOD(uart_setsig, ns8250_bus_setsig),
KOBJMETHOD(uart_transmit, ns8250_bus_transmit),
Introduce grab and ungrab upcalls. When the kernel desires to grab the console, it calls the grab functions. These functions should turn off the RX interrupts, and any others that interfere. This makes mountroot prompt work again. If there's more generalized need other than prompting, many of these routines should be expanded to do those new things. Should have been part of r260889, but waasn't due to command line typo. Reviewed by: bde (with reservations)
2014-01-19 19:39:13 +00:00
KOBJMETHOD(uart_grab, ns8250_bus_grab),
KOBJMETHOD(uart_ungrab, ns8250_bus_ungrab),
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
{ 0, 0 }
};
struct uart_class uart_ns8250_class = {
Don't expose the uart_ops structure directly, but instead have it obtained through the uart_class structure. This allows us to declare the uart_class structure as weak and as such allows us to reference it even when it's not compiled-in. It also allows is to get the uart_ops structure by name, which makes it possible to implement the dt tag handling in uart_getenv(). The side-effect of all this is that we're using the uart_class structure more consistently which means that we now also have access to the size of the bus space block needed by the hardware when we map the bus space, eliminating any hardcoding.
2007-04-02 22:00:22 +00:00
"ns8250",
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_methods,
sizeof(struct ns8250_softc),
Don't expose the uart_ops structure directly, but instead have it obtained through the uart_class structure. This allows us to declare the uart_class structure as weak and as such allows us to reference it even when it's not compiled-in. It also allows is to get the uart_ops structure by name, which makes it possible to implement the dt tag handling in uart_getenv(). The side-effect of all this is that we're using the uart_class structure more consistently which means that we now also have access to the size of the bus space block needed by the hardware when we map the bus space, eliminating any hardcoding.
2007-04-02 22:00:22 +00:00
.uc_ops = &uart_ns8250_ops,
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
.uc_range = 8,
Add support for the uart classes to set their default register shift value. This is needed with the pl011 driver. Before this change it would default to a shift of 0, however the hardware places the registers at 4-byte addresses meaning the value should be 2. This patch fixes this for the pl011 when configured using the fdt. The other drivers have a default value of 0 to keep this a no-op. MFC after: 1 week
2015-04-11 17:16:23 +00:00
.uc_rclk = DEFAULT_RCLK,
.uc_rshift = 0
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
};
Move the uart_class definitions and fdt compat data into the individual uart implementations, and export them using the new linker-set mechanism. Differential Revision: https://reviews.freebsd.org/D1993 Submitted by: Michal Meloun
2015-03-07 15:24:15 +00:00
#ifdef FDT
static struct ofw_compat_data compat_data[] = {
{"ns16550", (uintptr_t)&uart_ns8250_class},
Add ns16550a compatible string in UART 8250 driver Obtained from: Semihalf Submitted by: Michal Stanek <mst@semihalf.com> Sponsored by: Annapurna Labs Approved by: cognet (mentor) Reviewed by: imp, wma Differential revision: https://reviews.freebsd.org/D5404
2016-02-26 08:43:36 +00:00
{"ns16550a", (uintptr_t)&uart_ns8250_class},
Move the uart_class definitions and fdt compat data into the individual uart implementations, and export them using the new linker-set mechanism. Differential Revision: https://reviews.freebsd.org/D1993 Submitted by: Michal Meloun
2015-03-07 15:24:15 +00:00
{NULL, (uintptr_t)NULL},
};
UART_FDT_CLASS_AND_DEVICE(compat_data);
#endif
Restore uart PPS signal capture polarity to its historical norm, and add an option to invert the polarity in software. Also add an option to capture very narrow pulses by using the hardware's MSR delta-bit capability of latching line state changes. This effectively reverts the mistake I made in r286595 which was based on empirical measurements made on hardware using TTL-level signaling, in which the logic levels are inverted from RS-232. Thus, this re-syncs the polarity with the requirements of RFC 2783, which is writen in terms of RS-232 signaling. Narrow-pulse mode uses the ability of most ns8250 and similar chips to provide a delta indication in the modem status register. The hardware is able to notice and latch the change when the pulse width is shorter than interrupt latency, which results in the signal no longer being asserted by time the interrupt service code runs. When running in this mode we get notified only that "a pulse happened" so the driver synthesizes both an ASSERT and a CLEAR event (with the same timestamp for each). When the pulse width is about equal to the interrupt latency the driver may intermittantly see both edges of the pulse. To prevent generating spurious events, the driver implements a half-second lockout period after generating an event before it will generate another. Differential Revision: https://reviews.freebsd.org/D4477
2016-01-12 18:42:00 +00:00
/* Use token-pasting to form SER_ and MSR_ named constants. */
#define SER(sig) SER_##sig
#define SERD(sig) SER_D##sig
#define MSR(sig) MSR_##sig
#define MSRD(sig) MSR_D##sig
/*
* Detect signal changes using software delta detection. The previous state of
* the signals is in 'var' the new hardware state is in 'msr', and 'sig' is the
* short name (DCD, CTS, etc) of the signal bit being processed; 'var' gets the
* new state of both the signal and the delta bits.
*/
#define SIGCHGSW(var, msr, sig) \
if ((msr) & MSR(sig)) { \
if ((var & SER(sig)) == 0) \
var |= SERD(sig) | SER(sig); \
} else { \
if ((var & SER(sig)) != 0) \
var = SERD(sig) | (var & ~SER(sig)); \
}
/*
* Detect signal changes using the hardware msr delta bits. This is currently
* used only when PPS timing information is being captured using the "narrow
* pulse" option. With a narrow PPS pulse the signal may not still be asserted
* by time the interrupt handler is invoked. The hardware will latch the fact
* that it changed in the delta bits.
*/
#define SIGCHGHW(var, msr, sig) \
if ((msr) & MSRD(sig)) { \
if (((msr) & MSR(sig)) != 0) \
var |= SERD(sig) | SER(sig); \
else \
var = SERD(sig) | (var & ~SER(sig)); \
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
int
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_attach(struct uart_softc *sc)
{
struct ns8250_softc *ns8250 = (struct ns8250_softc*)sc;
struct uart_bas *bas;
add device hints to control the rx FIFO interrupt level on 16550A parts PR: kern/121421 Submitted by: UEMURA Tetsuya Reviewed by: marcel MFC after: 2 weeks
2008-03-12 19:09:20 +00:00
unsigned int ivar;
Add support for A10 uart. A10 uart is derived from Synopsys DesignWare uart and requires to read Uart Status Register when IIR_BUSY has detected. Also this change includes FDT check, where it checks device specific properties defined in dts and sets the busy_detect variable. broken_txfifo is also needed to be set in order to make it work for A10 uart case. Reviewed by: marcel@ Approved by: gonzo@
2013-03-01 01:42:31 +00:00
#ifdef FDT
phandle_t node;
pcell_t cell;
#endif
#ifdef FDT
Move support for Synopsys Designware APB UART out of ns8250 and into a separate driver. Add support for activating clock and hwreset resources for these devices when the EXT_RESOURCES option is present. Reviewed by: andrew, mmel, Emmanuel Vadot <manu@bidouilliste.com> Approved by: adrian (mentor) Differential Revision: https://reviews.freebsd.org/D5749
2016-04-01 20:26:45 +00:00
/* Check whether uart has a broken txfifo. */
Add support for A10 uart. A10 uart is derived from Synopsys DesignWare uart and requires to read Uart Status Register when IIR_BUSY has detected. Also this change includes FDT check, where it checks device specific properties defined in dts and sets the busy_detect variable. broken_txfifo is also needed to be set in order to make it work for A10 uart case. Reviewed by: marcel@ Approved by: gonzo@
2013-03-01 01:42:31 +00:00
node = ofw_bus_get_node(sc->sc_dev);
Actually check the DTS node value to enable the uart quirks. Without this fix, you cannot disable the quirks by setting it to 0, just the presence of the FDT node was enough to enable it.
2015-05-30 16:30:51 +00:00
if ((OF_getencprop(node, "broken-txfifo", &cell, sizeof(cell))) > 0)
broken_txfifo = cell ? 1 : 0;
Add support for A10 uart. A10 uart is derived from Synopsys DesignWare uart and requires to read Uart Status Register when IIR_BUSY has detected. Also this change includes FDT check, where it checks device specific properties defined in dts and sets the busy_detect variable. broken_txfifo is also needed to be set in order to make it work for A10 uart case. Reviewed by: marcel@ Approved by: gonzo@
2013-03-01 01:42:31 +00:00
#endif
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
bas = &sc->sc_bas;
ns8250->mcr = uart_getreg(bas, REG_MCR);
add device hints to control the rx FIFO interrupt level on 16550A parts PR: kern/121421 Submitted by: UEMURA Tetsuya Reviewed by: marcel MFC after: 2 weeks
2008-03-12 19:09:20 +00:00
ns8250->fcr = FCR_ENABLE;
if (!resource_int_value("uart", device_get_unit(sc->sc_dev), "flags",
&ivar)) {
if (UART_FLAGS_FCR_RX_LOW(ivar))
ns8250->fcr |= FCR_RX_LOW;
else if (UART_FLAGS_FCR_RX_MEDL(ivar))
ns8250->fcr |= FCR_RX_MEDL;
else if (UART_FLAGS_FCR_RX_HIGH(ivar))
ns8250->fcr |= FCR_RX_HIGH;
else
ns8250->fcr |= FCR_RX_MEDH;
} else
ns8250->fcr |= FCR_RX_MEDH;
The XScale PXA255 has three generally ns16x50 compatible UARTs. One of the variations from normal 16x50 behaviour however is the the use of a normally unused bit of IER to control RX timeout interrupts independently of the generally used RXRDY bit. If this bit is not enabled, we only ever get interrupts when the FIFO is full, never before. This is not very useful when the UART is being used as a console. In order to support this without causing potential problems on more "normal" 16x50 variants, this change introduces two hints for the uart device, ier_mask and ier_rxbits. These can be used to override which bits get set and cleared when we're enabling and disabling RX interrupts. Reviewed by: marcel
2008-05-30 01:57:13 +00:00
/* Get IER mask */
ivar = 0xf0;
resource_int_value("uart", device_get_unit(sc->sc_dev), "ier_mask",
&ivar);
ns8250->ier_mask = (uint8_t)(ivar & 0xff);
/* Get IER RX interrupt bits */
ivar = IER_EMSC | IER_ERLS | IER_ERXRDY;
resource_int_value("uart", device_get_unit(sc->sc_dev), "ier_rxbits",
&ivar);
ns8250->ier_rxbits = (uint8_t)(ivar & 0xff);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_setreg(bas, REG_FCR, ns8250->fcr);
uart_barrier(bas);
ns8250_bus_flush(sc, UART_FLUSH_RECEIVER|UART_FLUSH_TRANSMITTER);
if (ns8250->mcr & MCR_DTR)
Use the new serial port definitions for modemsignals.
2004-06-24 10:07:28 +00:00
sc->sc_hwsig |= SER_DTR;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
if (ns8250->mcr & MCR_RTS)
Use the new serial port definitions for modemsignals.
2004-06-24 10:07:28 +00:00
sc->sc_hwsig |= SER_RTS;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_getsig(sc);
ns8250_clrint(bas);
The XScale PXA255 has three generally ns16x50 compatible UARTs. One of the variations from normal 16x50 behaviour however is the the use of a normally unused bit of IER to control RX timeout interrupts independently of the generally used RXRDY bit. If this bit is not enabled, we only ever get interrupts when the FIFO is full, never before. This is not very useful when the UART is being used as a console. In order to support this without causing potential problems on more "normal" 16x50 variants, this change introduces two hints for the uart device, ier_mask and ier_rxbits. These can be used to override which bits get set and cleared when we're enabling and disabling RX interrupts. Reviewed by: marcel
2008-05-30 01:57:13 +00:00
ns8250->ier = uart_getreg(bas, REG_IER) & ns8250->ier_mask;
ns8250->ier |= ns8250->ier_rxbits;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_setreg(bas, REG_IER, ns8250->ier);
uart_barrier(bas);
Work-around a timing problem with the ITE IT8513E now that the core calls ns8250_bus_ipend() almost immediately after ns8250_bus_attach(). As it appears, a line break condition is being signalled for almost all received characters due to this. A delay of 150ms seems enough to allow the H/W to settle and to avoid the problem. More analysis is needed, but for now a regression has been addressed. Reported by: kevlo@ Tested by: kevlo@
2013-08-29 16:26:04 +00:00
/*
* Timing of the H/W access was changed with r253161 of uart_core.c
* It has been observed that an ITE IT8513E would signal a break
* condition with pretty much every character it received, unless
* it had enough time to settle between ns8250_bus_attach() and
* ns8250_bus_ipend() -- which it accidentally had before r253161.
* It's not understood why the UART chip behaves this way and it
* could very well be that the DELAY make the H/W work in the same
* accidental manner as before. More analysis is warranted, but
* at least now we fixed a known regression.
*/
A final test with unmodified code has shown that a delay of 150ms is not giving us a 100% success rate. Bump the delay to 200ms as that seems to do the trick. Note that during testing the delay was added to uart_bus_attach() in uart_core.c. While having the delay in a different place can change the behaviour, it was not expected. Having to bump the delay with another 50ms could therefore be an indication that the problem can not be solved with delays. Reported by: kevlo@ Tested by: kevlo@
2013-08-30 15:26:45 +00:00
DELAY(200);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
return (0);
}
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
int
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_detach(struct uart_softc *sc)
{
The XScale PXA255 has three generally ns16x50 compatible UARTs. One of the variations from normal 16x50 behaviour however is the the use of a normally unused bit of IER to control RX timeout interrupts independently of the generally used RXRDY bit. If this bit is not enabled, we only ever get interrupts when the FIFO is full, never before. This is not very useful when the UART is being used as a console. In order to support this without causing potential problems on more "normal" 16x50 variants, this change introduces two hints for the uart device, ier_mask and ier_rxbits. These can be used to override which bits get set and cleared when we're enabling and disabling RX interrupts. Reviewed by: marcel
2008-05-30 01:57:13 +00:00
struct ns8250_softc *ns8250;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
struct uart_bas *bas;
Allow uart(4)'s ns8250 driver to work with devices whose regshift is > 0. - Rename REG_DL to REG_DLL and REG_DLH. - Always treat DLL and DLH as two separate 8-bit registers instead of one 16-bit register. Additionally, remove the probe for the high 4 bits of IER being 0 and don't assume we can always read/write 0 to/from those bits. These changes allow uart(4) to drive the UARTs on the Intel XScale PXA255. Reviewed by: marcel
2006-05-23 00:41:12 +00:00
u_char ier;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
The XScale PXA255 has three generally ns16x50 compatible UARTs. One of the variations from normal 16x50 behaviour however is the the use of a normally unused bit of IER to control RX timeout interrupts independently of the generally used RXRDY bit. If this bit is not enabled, we only ever get interrupts when the FIFO is full, never before. This is not very useful when the UART is being used as a console. In order to support this without causing potential problems on more "normal" 16x50 variants, this change introduces two hints for the uart device, ier_mask and ier_rxbits. These can be used to override which bits get set and cleared when we're enabling and disabling RX interrupts. Reviewed by: marcel
2008-05-30 01:57:13 +00:00
ns8250 = (struct ns8250_softc *)sc;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
bas = &sc->sc_bas;
The XScale PXA255 has three generally ns16x50 compatible UARTs. One of the variations from normal 16x50 behaviour however is the the use of a normally unused bit of IER to control RX timeout interrupts independently of the generally used RXRDY bit. If this bit is not enabled, we only ever get interrupts when the FIFO is full, never before. This is not very useful when the UART is being used as a console. In order to support this without causing potential problems on more "normal" 16x50 variants, this change introduces two hints for the uart device, ier_mask and ier_rxbits. These can be used to override which bits get set and cleared when we're enabling and disabling RX interrupts. Reviewed by: marcel
2008-05-30 01:57:13 +00:00
ier = uart_getreg(bas, REG_IER) & ns8250->ier_mask;
Allow uart(4)'s ns8250 driver to work with devices whose regshift is > 0. - Rename REG_DL to REG_DLL and REG_DLH. - Always treat DLL and DLH as two separate 8-bit registers instead of one 16-bit register. Additionally, remove the probe for the high 4 bits of IER being 0 and don't assume we can always read/write 0 to/from those bits. These changes allow uart(4) to drive the UARTs on the Intel XScale PXA255. Reviewed by: marcel
2006-05-23 00:41:12 +00:00
uart_setreg(bas, REG_IER, ier);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_barrier(bas);
ns8250_clrint(bas);
return (0);
}
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
int
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_flush(struct uart_softc *sc, int what)
{
struct ns8250_softc *ns8250 = (struct ns8250_softc*)sc;
struct uart_bas *bas;
Add locking to the hardware drivers. I intended to figure out more precisely where locking would be needed before adding it, but it seems uart(4) draws slightly too much attention to have it without locking for too long. The lock added is a spinlock that protects access to the underlying hardware. As a first and obvious stab at this, each method of the hardware interface grabs the lock. Roughly speaking this serializes the methods. Exceptions are the probe, attach and detach methods.
2003-09-17 01:41:21 +00:00
int error;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
bas = &sc->sc_bas;
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_lock(sc->sc_hwmtx);
Eliminate the sc_hasfifo flag from the softc. It was only used by the NS8250 class driver. The UART has FIFOs if sc_rxfifosz>1, so test for that instead. While here properly initialize sc_rxfifosz and sc_txfifosz in the case the UART doesn't have FIFOs.
2006-04-02 21:45:54 +00:00
if (sc->sc_rxfifosz > 1) {
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_flush(bas, what);
uart_setreg(bas, REG_FCR, ns8250->fcr);
uart_barrier(bas);
Add locking to the hardware drivers. I intended to figure out more precisely where locking would be needed before adding it, but it seems uart(4) draws slightly too much attention to have it without locking for too long. The lock added is a spinlock that protects access to the underlying hardware. As a first and obvious stab at this, each method of the hardware interface grabs the lock. Roughly speaking this serializes the methods. Exceptions are the probe, attach and detach methods.
2003-09-17 01:41:21 +00:00
error = 0;
} else
error = ns8250_drain(bas, what);
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_unlock(sc->sc_hwmtx);
Add locking to the hardware drivers. I intended to figure out more precisely where locking would be needed before adding it, but it seems uart(4) draws slightly too much attention to have it without locking for too long. The lock added is a spinlock that protects access to the underlying hardware. As a first and obvious stab at this, each method of the hardware interface grabs the lock. Roughly speaking this serializes the methods. Exceptions are the probe, attach and detach methods.
2003-09-17 01:41:21 +00:00
return (error);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
int
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_getsig(struct uart_softc *sc)
{
Restore uart PPS signal capture polarity to its historical norm, and add an option to invert the polarity in software. Also add an option to capture very narrow pulses by using the hardware's MSR delta-bit capability of latching line state changes. This effectively reverts the mistake I made in r286595 which was based on empirical measurements made on hardware using TTL-level signaling, in which the logic levels are inverted from RS-232. Thus, this re-syncs the polarity with the requirements of RFC 2783, which is writen in terms of RS-232 signaling. Narrow-pulse mode uses the ability of most ns8250 and similar chips to provide a delta indication in the modem status register. The hardware is able to notice and latch the change when the pulse width is shorter than interrupt latency, which results in the signal no longer being asserted by time the interrupt service code runs. When running in this mode we get notified only that "a pulse happened" so the driver synthesizes both an ASSERT and a CLEAR event (with the same timestamp for each). When the pulse width is about equal to the interrupt latency the driver may intermittantly see both edges of the pulse. To prevent generating spurious events, the driver implements a half-second lockout period after generating an event before it will generate another. Differential Revision: https://reviews.freebsd.org/D4477
2016-01-12 18:42:00 +00:00
uint32_t old, sig;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uint8_t msr;
Restore uart PPS signal capture polarity to its historical norm, and add an option to invert the polarity in software. Also add an option to capture very narrow pulses by using the hardware's MSR delta-bit capability of latching line state changes. This effectively reverts the mistake I made in r286595 which was based on empirical measurements made on hardware using TTL-level signaling, in which the logic levels are inverted from RS-232. Thus, this re-syncs the polarity with the requirements of RFC 2783, which is writen in terms of RS-232 signaling. Narrow-pulse mode uses the ability of most ns8250 and similar chips to provide a delta indication in the modem status register. The hardware is able to notice and latch the change when the pulse width is shorter than interrupt latency, which results in the signal no longer being asserted by time the interrupt service code runs. When running in this mode we get notified only that "a pulse happened" so the driver synthesizes both an ASSERT and a CLEAR event (with the same timestamp for each). When the pulse width is about equal to the interrupt latency the driver may intermittantly see both edges of the pulse. To prevent generating spurious events, the driver implements a half-second lockout period after generating an event before it will generate another. Differential Revision: https://reviews.freebsd.org/D4477
2016-01-12 18:42:00 +00:00
/*
* The delta bits are reputed to be broken on some hardware, so use
* software delta detection by default. Use the hardware delta bits
* when capturing PPS pulses which are too narrow for software detection
* to see the edges. Hardware delta for RI doesn't work like the
* others, so always use software for it. Other threads may be changing
* other (non-MSR) bits in sc_hwsig, so loop until it can succesfully
* update without other changes happening. Note that the SIGCHGxx()
* macros carefully preserve the delta bits when we have to loop several
* times and a signal transitions between iterations.
*/
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
do {
old = sc->sc_hwsig;
sig = old;
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_lock(sc->sc_hwmtx);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
msr = uart_getreg(&sc->sc_bas, REG_MSR);
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_unlock(sc->sc_hwmtx);
Restore uart PPS signal capture polarity to its historical norm, and add an option to invert the polarity in software. Also add an option to capture very narrow pulses by using the hardware's MSR delta-bit capability of latching line state changes. This effectively reverts the mistake I made in r286595 which was based on empirical measurements made on hardware using TTL-level signaling, in which the logic levels are inverted from RS-232. Thus, this re-syncs the polarity with the requirements of RFC 2783, which is writen in terms of RS-232 signaling. Narrow-pulse mode uses the ability of most ns8250 and similar chips to provide a delta indication in the modem status register. The hardware is able to notice and latch the change when the pulse width is shorter than interrupt latency, which results in the signal no longer being asserted by time the interrupt service code runs. When running in this mode we get notified only that "a pulse happened" so the driver synthesizes both an ASSERT and a CLEAR event (with the same timestamp for each). When the pulse width is about equal to the interrupt latency the driver may intermittantly see both edges of the pulse. To prevent generating spurious events, the driver implements a half-second lockout period after generating an event before it will generate another. Differential Revision: https://reviews.freebsd.org/D4477
2016-01-12 18:42:00 +00:00
if (sc->sc_pps_mode & UART_PPS_NARROW_PULSE) {
SIGCHGHW(sig, msr, DSR);
SIGCHGHW(sig, msr, CTS);
SIGCHGHW(sig, msr, DCD);
} else {
SIGCHGSW(sig, msr, DSR);
SIGCHGSW(sig, msr, CTS);
SIGCHGSW(sig, msr, DCD);
}
SIGCHGSW(sig, msr, RI);
} while (!atomic_cmpset_32(&sc->sc_hwsig, old, sig & ~SER_MASK_DELTA));
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
return (sig);
}
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
int
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
{
struct uart_bas *bas;
Be slightly more paranoid about using the divisor in a division and the calculated baudrate. Neither should be 0.
2004-11-15 00:00:24 +00:00
int baudrate, divisor, error;
Add support for automatic hardware flow control for 16[679]50 UARTs. We simply use the detected FIFO size to determine whether we have a post 16550 UART or not. The support lacks proper serialization of hardware access for now.
2003-09-13 06:25:04 +00:00
uint8_t efr, lcr;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
bas = &sc->sc_bas;
Add locking to the hardware drivers. I intended to figure out more precisely where locking would be needed before adding it, but it seems uart(4) draws slightly too much attention to have it without locking for too long. The lock added is a spinlock that protects access to the underlying hardware. As a first and obvious stab at this, each method of the hardware interface grabs the lock. Roughly speaking this serializes the methods. Exceptions are the probe, attach and detach methods.
2003-09-17 01:41:21 +00:00
error = 0;
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_lock(sc->sc_hwmtx);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
switch (request) {
case UART_IOCTL_BREAK:
lcr = uart_getreg(bas, REG_LCR);
if (data)
lcr |= LCR_SBREAK;
else
lcr &= ~LCR_SBREAK;
uart_setreg(bas, REG_LCR, lcr);
uart_barrier(bas);
break;
Add support for automatic hardware flow control for 16[679]50 UARTs. We simply use the detected FIFO size to determine whether we have a post 16550 UART or not. The support lacks proper serialization of hardware access for now.
2003-09-13 06:25:04 +00:00
case UART_IOCTL_IFLOW:
lcr = uart_getreg(bas, REG_LCR);
uart_barrier(bas);
uart_setreg(bas, REG_LCR, 0xbf);
uart_barrier(bas);
efr = uart_getreg(bas, REG_EFR);
if (data)
efr |= EFR_RTS;
else
efr &= ~EFR_RTS;
uart_setreg(bas, REG_EFR, efr);
uart_barrier(bas);
uart_setreg(bas, REG_LCR, lcr);
uart_barrier(bas);
break;
case UART_IOCTL_OFLOW:
lcr = uart_getreg(bas, REG_LCR);
uart_barrier(bas);
uart_setreg(bas, REG_LCR, 0xbf);
uart_barrier(bas);
efr = uart_getreg(bas, REG_EFR);
if (data)
efr |= EFR_CTS;
else
efr &= ~EFR_CTS;
uart_setreg(bas, REG_EFR, efr);
uart_barrier(bas);
uart_setreg(bas, REG_LCR, lcr);
uart_barrier(bas);
break;
Implement UART_IOCTL_BAUD. Consequently, when the baudrate was unset for the console, we emit the actual baudrate during bus enumeration.
2004-11-14 23:31:19 +00:00
case UART_IOCTL_BAUD:
lcr = uart_getreg(bas, REG_LCR);
uart_setreg(bas, REG_LCR, lcr | LCR_DLAB);
uart_barrier(bas);
Allow uart(4)'s ns8250 driver to work with devices whose regshift is > 0. - Rename REG_DL to REG_DLL and REG_DLH. - Always treat DLL and DLH as two separate 8-bit registers instead of one 16-bit register. Additionally, remove the probe for the high 4 bits of IER being 0 and don't assume we can always read/write 0 to/from those bits. These changes allow uart(4) to drive the UARTs on the Intel XScale PXA255. Reviewed by: marcel
2006-05-23 00:41:12 +00:00
divisor = uart_getreg(bas, REG_DLL) |
(uart_getreg(bas, REG_DLH) << 8);
Implement UART_IOCTL_BAUD. Consequently, when the baudrate was unset for the console, we emit the actual baudrate during bus enumeration.
2004-11-14 23:31:19 +00:00
uart_barrier(bas);
uart_setreg(bas, REG_LCR, lcr);
uart_barrier(bas);
Be slightly more paranoid about using the divisor in a division and the calculated baudrate. Neither should be 0.
2004-11-15 00:00:24 +00:00
baudrate = (divisor > 0) ? bas->rclk / divisor / 16 : 0;
if (baudrate > 0)
*(int*)data = baudrate;
else
error = ENXIO;
Implement UART_IOCTL_BAUD. Consequently, when the baudrate was unset for the console, we emit the actual baudrate during bus enumeration.
2004-11-14 23:31:19 +00:00
break;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
default:
Add locking to the hardware drivers. I intended to figure out more precisely where locking would be needed before adding it, but it seems uart(4) draws slightly too much attention to have it without locking for too long. The lock added is a spinlock that protects access to the underlying hardware. As a first and obvious stab at this, each method of the hardware interface grabs the lock. Roughly speaking this serializes the methods. Exceptions are the probe, attach and detach methods.
2003-09-17 01:41:21 +00:00
error = EINVAL;
break;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_unlock(sc->sc_hwmtx);
Add locking to the hardware drivers. I intended to figure out more precisely where locking would be needed before adding it, but it seems uart(4) draws slightly too much attention to have it without locking for too long. The lock added is a spinlock that protects access to the underlying hardware. As a first and obvious stab at this, each method of the hardware interface grabs the lock. Roughly speaking this serializes the methods. Exceptions are the probe, attach and detach methods.
2003-09-17 01:41:21 +00:00
return (error);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
int
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_ipend(struct uart_softc *sc)
{
struct uart_bas *bas;
Disable the TX ready interrupts once we received one, some UART won't clear the IIR_TXRDY bit upon reading. Reviewed by: marcel
2011-11-02 20:45:44 +00:00
struct ns8250_softc *ns8250;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
int ipend;
uint8_t iir, lsr;
Disable the TX ready interrupts once we received one, some UART won't clear the IIR_TXRDY bit upon reading. Reviewed by: marcel
2011-11-02 20:45:44 +00:00
ns8250 = (struct ns8250_softc *)sc;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
bas = &sc->sc_bas;
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_lock(sc->sc_hwmtx);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
iir = uart_getreg(bas, REG_IIR);
Add support for A10 uart. A10 uart is derived from Synopsys DesignWare uart and requires to read Uart Status Register when IIR_BUSY has detected. Also this change includes FDT check, where it checks device specific properties defined in dts and sets the busy_detect variable. broken_txfifo is also needed to be set in order to make it work for A10 uart case. Reviewed by: marcel@ Approved by: gonzo@
2013-03-01 01:42:31 +00:00
if (ns8250->busy_detect && (iir & IIR_BUSY) == IIR_BUSY) {
(void)uart_getreg(bas, DW_REG_USR);
uart_unlock(sc->sc_hwmtx);
return (0);
}
Add locking to the hardware drivers. I intended to figure out more precisely where locking would be needed before adding it, but it seems uart(4) draws slightly too much attention to have it without locking for too long. The lock added is a spinlock that protects access to the underlying hardware. As a first and obvious stab at this, each method of the hardware interface grabs the lock. Roughly speaking this serializes the methods. Exceptions are the probe, attach and detach methods.
2003-09-17 01:41:21 +00:00
if (iir & IIR_NOPEND) {
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_unlock(sc->sc_hwmtx);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
return (0);
Add locking to the hardware drivers. I intended to figure out more precisely where locking would be needed before adding it, but it seems uart(4) draws slightly too much attention to have it without locking for too long. The lock added is a spinlock that protects access to the underlying hardware. As a first and obvious stab at this, each method of the hardware interface grabs the lock. Roughly speaking this serializes the methods. Exceptions are the probe, attach and detach methods.
2003-09-17 01:41:21 +00:00
}
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ipend = 0;
if (iir & IIR_RXRDY) {
lsr = uart_getreg(bas, REG_LSR);
if (lsr & LSR_OE)
MFp4: Stop using our local UART_IPEND_* and instead use the global SER_INT_* as defined in <sys/serial.h>.
2006-02-24 02:42:26 +00:00
ipend |= SER_INT_OVERRUN;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
if (lsr & LSR_BI)
MFp4: Stop using our local UART_IPEND_* and instead use the global SER_INT_* as defined in <sys/serial.h>.
2006-02-24 02:42:26 +00:00
ipend |= SER_INT_BREAK;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
if (lsr & LSR_RXRDY)
MFp4: Stop using our local UART_IPEND_* and instead use the global SER_INT_* as defined in <sys/serial.h>.
2006-02-24 02:42:26 +00:00
ipend |= SER_INT_RXREADY;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
} else {
Disable the TX ready interrupts once we received one, some UART won't clear the IIR_TXRDY bit upon reading. Reviewed by: marcel
2011-11-02 20:45:44 +00:00
if (iir & IIR_TXRDY) {
MFp4: Stop using our local UART_IPEND_* and instead use the global SER_INT_* as defined in <sys/serial.h>.
2006-02-24 02:42:26 +00:00
ipend |= SER_INT_TXIDLE;
Disable the TX ready interrupts once we received one, some UART won't clear the IIR_TXRDY bit upon reading. Reviewed by: marcel
2011-11-02 20:45:44 +00:00
uart_setreg(bas, REG_IER, ns8250->ier);
UART: Fix spurious interrupts generated by ns8250 and lpc drivers: - don't enable transmitter empty interrupt before filling TX FIFO. - add missing uart_barrier() call in interrupt service routine
2016-02-12 05:14:58 +00:00
uart_barrier(bas);
Disable the TX ready interrupts once we received one, some UART won't clear the IIR_TXRDY bit upon reading. Reviewed by: marcel
2011-11-02 20:45:44 +00:00
} else
MFp4: Stop using our local UART_IPEND_* and instead use the global SER_INT_* as defined in <sys/serial.h>.
2006-02-24 02:42:26 +00:00
ipend |= SER_INT_SIGCHG;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
Fix hangs caused by hardware that signals receive errors (framing, parity, etc), but does not indicate characters being received. Since no chracters have been received, ignore the line errors. PR: 131006 MFC after: 3 days
2009-04-08 00:14:06 +00:00
if (ipend == 0)
ns8250_clrint(bas);
uart_unlock(sc->sc_hwmtx);
Remove redundant checking of sc_leaving (uart_intr() already handles this). Approved by: marcel
2010-05-02 19:07:19 +00:00
return (ipend);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
int
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_param(struct uart_softc *sc, int baudrate, int databits,
int stopbits, int parity)
{
Wait for DesignWare UART transfers completion before accessing line control When using DW UART with BUSY detection it is necessary to wait until all serial transfers are finished before manipulating the line control. LCR will not be affected when UART is busy. In addition, if Divisor Latch Access Bit is being set in order to modify UART divisors: 1. We will get BUSY interrupt if interrupts are enabled. 2. Because LCR will not be affected the THR and (even worse) IER contents will be corrupted. This will lead to console hang. Approved by: cognet (mentor)
2013-10-26 17:24:59 +00:00
struct ns8250_softc *ns8250;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
struct uart_bas *bas;
Wait for DesignWare UART transfers completion before accessing line control When using DW UART with BUSY detection it is necessary to wait until all serial transfers are finished before manipulating the line control. LCR will not be affected when UART is busy. In addition, if Divisor Latch Access Bit is being set in order to modify UART divisors: 1. We will get BUSY interrupt if interrupts are enabled. 2. Because LCR will not be affected the THR and (even worse) IER contents will be corrupted. This will lead to console hang. Approved by: cognet (mentor)
2013-10-26 17:24:59 +00:00
int error, limit;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
Wait for DesignWare UART transfers completion before accessing line control When using DW UART with BUSY detection it is necessary to wait until all serial transfers are finished before manipulating the line control. LCR will not be affected when UART is busy. In addition, if Divisor Latch Access Bit is being set in order to modify UART divisors: 1. We will get BUSY interrupt if interrupts are enabled. 2. Because LCR will not be affected the THR and (even worse) IER contents will be corrupted. This will lead to console hang. Approved by: cognet (mentor)
2013-10-26 17:24:59 +00:00
ns8250 = (struct ns8250_softc*)sc;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
bas = &sc->sc_bas;
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_lock(sc->sc_hwmtx);
Wait for DesignWare UART transfers completion before accessing line control When using DW UART with BUSY detection it is necessary to wait until all serial transfers are finished before manipulating the line control. LCR will not be affected when UART is busy. In addition, if Divisor Latch Access Bit is being set in order to modify UART divisors: 1. We will get BUSY interrupt if interrupts are enabled. 2. Because LCR will not be affected the THR and (even worse) IER contents will be corrupted. This will lead to console hang. Approved by: cognet (mentor)
2013-10-26 17:24:59 +00:00
/*
* When using DW UART with BUSY detection it is necessary to wait
* until all serial transfers are finished before manipulating the
* line control. LCR will not be affected when UART is busy.
*/
if (ns8250->busy_detect != 0) {
/*
* Pick an arbitrary high limit to avoid getting stuck in
* an infinite loop in case when the hardware is broken.
*/
limit = 10 * 1024;
while (((uart_getreg(bas, DW_REG_USR) & USR_BUSY) != 0) &&
--limit)
DELAY(4);
if (limit <= 0) {
/* UART appears to be stuck */
uart_unlock(sc->sc_hwmtx);
return (EIO);
}
}
Add locking to the hardware drivers. I intended to figure out more precisely where locking would be needed before adding it, but it seems uart(4) draws slightly too much attention to have it without locking for too long. The lock added is a spinlock that protects access to the underlying hardware. As a first and obvious stab at this, each method of the hardware interface grabs the lock. Roughly speaking this serializes the methods. Exceptions are the probe, attach and detach methods.
2003-09-17 01:41:21 +00:00
error = ns8250_param(bas, baudrate, databits, stopbits, parity);
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_unlock(sc->sc_hwmtx);
Add locking to the hardware drivers. I intended to figure out more precisely where locking would be needed before adding it, but it seems uart(4) draws slightly too much attention to have it without locking for too long. The lock added is a spinlock that protects access to the underlying hardware. As a first and obvious stab at this, each method of the hardware interface grabs the lock. Roughly speaking this serializes the methods. Exceptions are the probe, attach and detach methods.
2003-09-17 01:41:21 +00:00
return (error);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
int
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_probe(struct uart_softc *sc)
{
The XScale PXA255 has three generally ns16x50 compatible UARTs. One of the variations from normal 16x50 behaviour however is the the use of a normally unused bit of IER to control RX timeout interrupts independently of the generally used RXRDY bit. If this bit is not enabled, we only ever get interrupts when the FIFO is full, never before. This is not very useful when the UART is being used as a console. In order to support this without causing potential problems on more "normal" 16x50 variants, this change introduces two hints for the uart device, ier_mask and ier_rxbits. These can be used to override which bits get set and cleared when we're enabling and disabling RX interrupts. Reviewed by: marcel
2008-05-30 01:57:13 +00:00
struct ns8250_softc *ns8250;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
struct uart_bas *bas;
int count, delay, error, limit;
Allow uart(4)'s ns8250 driver to work with devices whose regshift is > 0. - Rename REG_DL to REG_DLL and REG_DLH. - Always treat DLL and DLH as two separate 8-bit registers instead of one 16-bit register. Additionally, remove the probe for the high 4 bits of IER being 0 and don't assume we can always read/write 0 to/from those bits. These changes allow uart(4) to drive the UARTs on the Intel XScale PXA255. Reviewed by: marcel
2006-05-23 00:41:12 +00:00
uint8_t lsr, mcr, ier;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
The XScale PXA255 has three generally ns16x50 compatible UARTs. One of the variations from normal 16x50 behaviour however is the the use of a normally unused bit of IER to control RX timeout interrupts independently of the generally used RXRDY bit. If this bit is not enabled, we only ever get interrupts when the FIFO is full, never before. This is not very useful when the UART is being used as a console. In order to support this without causing potential problems on more "normal" 16x50 variants, this change introduces two hints for the uart device, ier_mask and ier_rxbits. These can be used to override which bits get set and cleared when we're enabling and disabling RX interrupts. Reviewed by: marcel
2008-05-30 01:57:13 +00:00
ns8250 = (struct ns8250_softc *)sc;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
bas = &sc->sc_bas;
error = ns8250_probe(bas);
if (error)
return (error);
mcr = MCR_IE;
if (sc->sc_sysdev == NULL) {
/* By using ns8250_init() we also set DTR and RTS. */
Use 115200 and not 9600 as the initial baudrate. This speeds up detection of the FIFO size. Especially for large FIFOs.
2006-04-27 05:43:10 +00:00
ns8250_init(bas, 115200, 8, 1, UART_PARITY_NONE);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
} else
mcr |= MCR_DTR | MCR_RTS;
error = ns8250_drain(bas, UART_DRAIN_TRANSMITTER);
if (error)
return (error);
/*
* Set loopback mode. This avoids having garbage on the wire and
* also allows us send and receive data. We set DTR and RTS to
* avoid the possibility that automatic flow-control prevents
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
* any data from being sent.
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
*/
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
uart_setreg(bas, REG_MCR, MCR_LOOPBACK | MCR_IE | MCR_DTR | MCR_RTS);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_barrier(bas);
/*
* Enable FIFOs. And check that the UART has them. If not, we're
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
* done. Since this is the first time we enable the FIFOs, we reset
* them.
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
*/
uart_setreg(bas, REG_FCR, FCR_ENABLE);
uart_barrier(bas);
Eliminate the sc_hasfifo flag from the softc. It was only used by the NS8250 class driver. The UART has FIFOs if sc_rxfifosz>1, so test for that instead. While here properly initialize sc_rxfifosz and sc_txfifosz in the case the UART doesn't have FIFOs.
2006-04-02 21:45:54 +00:00
if (!(uart_getreg(bas, REG_IIR) & IIR_FIFO_MASK)) {
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
/*
* NS16450 or INS8250. We don't bother to differentiate
* between them. They're too old to be interesting.
*/
uart_setreg(bas, REG_MCR, mcr);
uart_barrier(bas);
Eliminate the sc_hasfifo flag from the softc. It was only used by the NS8250 class driver. The UART has FIFOs if sc_rxfifosz>1, so test for that instead. While here properly initialize sc_rxfifosz and sc_txfifosz in the case the UART doesn't have FIFOs.
2006-04-02 21:45:54 +00:00
sc->sc_rxfifosz = sc->sc_txfifosz = 1;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
device_set_desc(sc->sc_dev, "8250 or 16450 or compatible");
return (0);
}
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
uart_setreg(bas, REG_FCR, FCR_ENABLE | FCR_XMT_RST | FCR_RCV_RST);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_barrier(bas);
count = 0;
delay = ns8250_delay(bas);
/* We have FIFOs. Drain the transmitter and receiver. */
error = ns8250_drain(bas, UART_DRAIN_RECEIVER|UART_DRAIN_TRANSMITTER);
if (error) {
uart_setreg(bas, REG_MCR, mcr);
uart_setreg(bas, REG_FCR, 0);
uart_barrier(bas);
goto describe;
}
/*
* We should have a sufficiently clean "pipe" to determine the
* size of the FIFOs. We send as much characters as is reasonable
Fix typos - remove duplicate "the". PR: bin/154928 Submitted by: Eitan Adler <lists at eitanadler.com> MFC after: 3 days
2011-02-21 09:01:34 +00:00
* and wait for the overflow bit in the LSR register to be
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
* asserted, counting the characters as we send them. Based on
* that count we know the FIFO size.
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
*/
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
do {
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_setreg(bas, REG_DATA, 0);
uart_barrier(bas);
count++;
limit = 30;
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
lsr = 0;
/*
* LSR bits are cleared upon read, so we must accumulate
* them to be able to test LSR_OE below.
*/
while (((lsr |= uart_getreg(bas, REG_LSR)) & LSR_TEMT) == 0 &&
--limit)
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
DELAY(delay);
if (limit == 0) {
The XScale PXA255 has three generally ns16x50 compatible UARTs. One of the variations from normal 16x50 behaviour however is the the use of a normally unused bit of IER to control RX timeout interrupts independently of the generally used RXRDY bit. If this bit is not enabled, we only ever get interrupts when the FIFO is full, never before. This is not very useful when the UART is being used as a console. In order to support this without causing potential problems on more "normal" 16x50 variants, this change introduces two hints for the uart device, ier_mask and ier_rxbits. These can be used to override which bits get set and cleared when we're enabling and disabling RX interrupts. Reviewed by: marcel
2008-05-30 01:57:13 +00:00
ier = uart_getreg(bas, REG_IER) & ns8250->ier_mask;
Allow uart(4)'s ns8250 driver to work with devices whose regshift is > 0. - Rename REG_DL to REG_DLL and REG_DLH. - Always treat DLL and DLH as two separate 8-bit registers instead of one 16-bit register. Additionally, remove the probe for the high 4 bits of IER being 0 and don't assume we can always read/write 0 to/from those bits. These changes allow uart(4) to drive the UARTs on the Intel XScale PXA255. Reviewed by: marcel
2006-05-23 00:41:12 +00:00
uart_setreg(bas, REG_IER, ier);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_setreg(bas, REG_MCR, mcr);
uart_setreg(bas, REG_FCR, 0);
uart_barrier(bas);
count = 0;
goto describe;
}
When sizing the FIFO, don't count all the way up to 1030 if any FIFO size larger than 128 is considered an incompatible size. Stop counting when we reach 130 in the loop.
2004-07-26 03:54:40 +00:00
} while ((lsr & LSR_OE) == 0 && count < 130);
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
count--;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
uart_setreg(bas, REG_MCR, mcr);
/* Reset FIFOs. */
ns8250_flush(bas, UART_FLUSH_RECEIVER|UART_FLUSH_TRANSMITTER);
describe:
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
if (count >= 14 && count <= 16) {
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
sc->sc_rxfifosz = 16;
device_set_desc(sc->sc_dev, "16550 or compatible");
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
} else if (count >= 28 && count <= 32) {
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
sc->sc_rxfifosz = 32;
device_set_desc(sc->sc_dev, "16650 or compatible");
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
} else if (count >= 56 && count <= 64) {
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
sc->sc_rxfifosz = 64;
device_set_desc(sc->sc_dev, "16750 or compatible");
It seems that clearing the MCR_IE bit in the modem control register does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
2004-05-26 21:59:01 +00:00
} else if (count >= 112 && count <= 128) {
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
sc->sc_rxfifosz = 128;
device_set_desc(sc->sc_dev, "16950 or compatible");
} else {
If we failed to size the Rx FIFO, assume the worst. This however is not a size of 1. Since we already know there is a FIFO, we can safely assume that it is at least 16 bytes. Note that all this is mostly academic anyway. We don't use the size of the Rx FIFO currently. If we add support for hardware flow control, we only care about Rx FIFO sizes larger than 16.
2003-09-10 05:01:08 +00:00
sc->sc_rxfifosz = 16;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
device_set_desc(sc->sc_dev,
"Non-standard ns8250 class UART with FIFOs");
}
/*
* Force the Tx FIFO size to 16 bytes for now. We don't program the
* Tx trigger. Also, we assume that all data has been sent when the
* interrupt happens.
*/
sc->sc_txfifosz = 16;
Do not use hardware flow control for the moment. There are some issues with it that need to be understood better before they can be resolved. This takes time and time is already in short supply. Reported & tested by: glebius@
2004-08-06 15:51:31 +00:00
#if 0
/*
* XXX there are some issues related to hardware flow control and
* it's likely that uart(4) is the cause. This basicly needs more
* investigation, but we avoid using for hardware flow control
* until then.
*/
Add support for automatic hardware flow control for 16[679]50 UARTs. We simply use the detected FIFO size to determine whether we have a post 16550 UART or not. The support lacks proper serialization of hardware access for now.
2003-09-13 06:25:04 +00:00
/* 16650s or higher have automatic flow control. */
if (sc->sc_rxfifosz > 16) {
sc->sc_hwiflow = 1;
sc->sc_hwoflow = 1;
}
Do not use hardware flow control for the moment. There are some issues with it that need to be understood better before they can be resolved. This takes time and time is already in short supply. Reported & tested by: glebius@
2004-08-06 15:51:31 +00:00
#endif
Add support for automatic hardware flow control for 16[679]50 UARTs. We simply use the detected FIFO size to determine whether we have a post 16550 UART or not. The support lacks proper serialization of hardware access for now.
2003-09-13 06:25:04 +00:00
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
return (0);
}
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
int
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_receive(struct uart_softc *sc)
{
struct uart_bas *bas;
int xc;
uint8_t lsr;
bas = &sc->sc_bas;
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_lock(sc->sc_hwmtx);
In uart_intr() loop until all interrupts have been handled. Previously an UART interface could get stuck when a new interrupt condition arose while servicing a previous interrupt. Since an interrupt was already pending, no new interrupt would be triggered. Avoid infinite recursion by flushing the Rx FIFO and marking an overrun condition when we could not move the data from the Rx FIFO to the receive buffer in toto. Failure to flush the Rx FIFO would leave the Rx ready condition pending. Note that the SAB 82532 already did this due to the nature of the chip.
2003-09-17 03:11:32 +00:00
lsr = uart_getreg(bas, REG_LSR);
while (lsr & LSR_RXRDY) {
if (uart_rx_full(sc)) {
sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
break;
In uart_intr() loop until all interrupts have been handled. Previously an UART interface could get stuck when a new interrupt condition arose while servicing a previous interrupt. Since an interrupt was already pending, no new interrupt would be triggered. Avoid infinite recursion by flushing the Rx FIFO and marking an overrun condition when we could not move the data from the Rx FIFO to the receive buffer in toto. Failure to flush the Rx FIFO would leave the Rx ready condition pending. Note that the SAB 82532 already did this due to the nature of the chip.
2003-09-17 03:11:32 +00:00
}
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
xc = uart_getreg(bas, REG_DATA);
if (lsr & LSR_FE)
xc |= UART_STAT_FRAMERR;
if (lsr & LSR_PE)
xc |= UART_STAT_PARERR;
uart_rx_put(sc, xc);
In uart_intr() loop until all interrupts have been handled. Previously an UART interface could get stuck when a new interrupt condition arose while servicing a previous interrupt. Since an interrupt was already pending, no new interrupt would be triggered. Avoid infinite recursion by flushing the Rx FIFO and marking an overrun condition when we could not move the data from the Rx FIFO to the receive buffer in toto. Failure to flush the Rx FIFO would leave the Rx ready condition pending. Note that the SAB 82532 already did this due to the nature of the chip.
2003-09-17 03:11:32 +00:00
lsr = uart_getreg(bas, REG_LSR);
}
/* Discard everything left in the Rx FIFO. */
while (lsr & LSR_RXRDY) {
(void)uart_getreg(bas, REG_DATA);
uart_barrier(bas);
lsr = uart_getreg(bas, REG_LSR);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_unlock(sc->sc_hwmtx);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
return (0);
}
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
int
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_setsig(struct uart_softc *sc, int sig)
{
struct ns8250_softc *ns8250 = (struct ns8250_softc*)sc;
struct uart_bas *bas;
uint32_t new, old;
bas = &sc->sc_bas;
do {
old = sc->sc_hwsig;
new = old;
Use the new serial port definitions for modemsignals.
2004-06-24 10:07:28 +00:00
if (sig & SER_DDTR) {
Restore uart PPS signal capture polarity to its historical norm, and add an option to invert the polarity in software. Also add an option to capture very narrow pulses by using the hardware's MSR delta-bit capability of latching line state changes. This effectively reverts the mistake I made in r286595 which was based on empirical measurements made on hardware using TTL-level signaling, in which the logic levels are inverted from RS-232. Thus, this re-syncs the polarity with the requirements of RFC 2783, which is writen in terms of RS-232 signaling. Narrow-pulse mode uses the ability of most ns8250 and similar chips to provide a delta indication in the modem status register. The hardware is able to notice and latch the change when the pulse width is shorter than interrupt latency, which results in the signal no longer being asserted by time the interrupt service code runs. When running in this mode we get notified only that "a pulse happened" so the driver synthesizes both an ASSERT and a CLEAR event (with the same timestamp for each). When the pulse width is about equal to the interrupt latency the driver may intermittantly see both edges of the pulse. To prevent generating spurious events, the driver implements a half-second lockout period after generating an event before it will generate another. Differential Revision: https://reviews.freebsd.org/D4477
2016-01-12 18:42:00 +00:00
new = (new & ~SER_DTR) | (sig & (SER_DTR | SER_DDTR));
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
Use the new serial port definitions for modemsignals.
2004-06-24 10:07:28 +00:00
if (sig & SER_DRTS) {
Restore uart PPS signal capture polarity to its historical norm, and add an option to invert the polarity in software. Also add an option to capture very narrow pulses by using the hardware's MSR delta-bit capability of latching line state changes. This effectively reverts the mistake I made in r286595 which was based on empirical measurements made on hardware using TTL-level signaling, in which the logic levels are inverted from RS-232. Thus, this re-syncs the polarity with the requirements of RFC 2783, which is writen in terms of RS-232 signaling. Narrow-pulse mode uses the ability of most ns8250 and similar chips to provide a delta indication in the modem status register. The hardware is able to notice and latch the change when the pulse width is shorter than interrupt latency, which results in the signal no longer being asserted by time the interrupt service code runs. When running in this mode we get notified only that "a pulse happened" so the driver synthesizes both an ASSERT and a CLEAR event (with the same timestamp for each). When the pulse width is about equal to the interrupt latency the driver may intermittantly see both edges of the pulse. To prevent generating spurious events, the driver implements a half-second lockout period after generating an event before it will generate another. Differential Revision: https://reviews.freebsd.org/D4477
2016-01-12 18:42:00 +00:00
new = (new & ~SER_RTS) | (sig & (SER_RTS | SER_DRTS));
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
}
} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_lock(sc->sc_hwmtx);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250->mcr &= ~(MCR_DTR|MCR_RTS);
Use the new serial port definitions for modemsignals.
2004-06-24 10:07:28 +00:00
if (new & SER_DTR)
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250->mcr |= MCR_DTR;
Use the new serial port definitions for modemsignals.
2004-06-24 10:07:28 +00:00
if (new & SER_RTS)
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250->mcr |= MCR_RTS;
uart_setreg(bas, REG_MCR, ns8250->mcr);
uart_barrier(bas);
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_unlock(sc->sc_hwmtx);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
return (0);
}
Make the uart ns8250 high-level interface public rather than static. This makes it easier to implement new drivers which are "mostly ns8250" but with some small difference such as needing to enable clocks or poke a non-standard register at probe or attach time.
2013-08-21 14:26:15 +00:00
int
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
ns8250_bus_transmit(struct uart_softc *sc)
{
struct ns8250_softc *ns8250 = (struct ns8250_softc*)sc;
struct uart_bas *bas;
int i;
bas = &sc->sc_bas;
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_lock(sc->sc_hwmtx);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
while ((uart_getreg(bas, REG_LSR) & LSR_THRE) == 0)
;
for (i = 0; i < sc->sc_txdatasz; i++) {
uart_setreg(bas, REG_DATA, sc->sc_txbuf[i]);
uart_barrier(bas);
}
UART: Fix spurious interrupts generated by ns8250 and lpc drivers: - don't enable transmitter empty interrupt before filling TX FIFO. - add missing uart_barrier() call in interrupt service routine
2016-02-12 05:14:58 +00:00
uart_setreg(bas, REG_IER, ns8250->ier | IER_ETXRDY);
uart_barrier(bas);
Add a loader tunable "hw.broken_txfifo" which enables a workaround for a bug in old versions of QEMU (and Xen, and other places using QEMU code). On those buggy emulated UARTs, the "TX idle" interrupt gets lost; with this workaround, we spinwait for the TX to happen and then send ourselves the interrupt. It's ugly but it works, while minimizing the impact on the code for the !broken_txfifo case. MFC after: 2 weeks
2013-01-27 23:33:42 +00:00
if (broken_txfifo)
ns8250_drain(bas, UART_DRAIN_TRANSMITTER);
else
sc->sc_txbusy = 1;
Add support for scc(4).
2006-03-30 18:37:03 +00:00
uart_unlock(sc->sc_hwmtx);
Add a loader tunable "hw.broken_txfifo" which enables a workaround for a bug in old versions of QEMU (and Xen, and other places using QEMU code). On those buggy emulated UARTs, the "TX idle" interrupt gets lost; with this workaround, we spinwait for the TX to happen and then send ourselves the interrupt. It's ugly but it works, while minimizing the impact on the code for the !broken_txfifo case. MFC after: 2 weeks
2013-01-27 23:33:42 +00:00
if (broken_txfifo)
uart_sched_softih(sc, SER_INT_TXIDLE);
The uart(4) driver is an universal driver for various UART hardware. It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
2003-09-06 23:13:47 +00:00
return (0);
}
Introduce grab and ungrab upcalls. When the kernel desires to grab the console, it calls the grab functions. These functions should turn off the RX interrupts, and any others that interfere. This makes mountroot prompt work again. If there's more generalized need other than prompting, many of these routines should be expanded to do those new things. Should have been part of r260889, but waasn't due to command line typo. Reviewed by: bde (with reservations)
2014-01-19 19:39:13 +00:00
void
ns8250_bus_grab(struct uart_softc *sc)
{
struct uart_bas *bas = &sc->sc_bas;
In the grab function, keep the bit 6 on in the IER, on XScale, using 0 turns the UART off, which is unfortunate if one want to use it as a console.
2014-05-29 19:57:51 +00:00
struct ns8250_softc *ns8250 = (struct ns8250_softc*)sc;
In uart_bus_grab(), use the ier_mask instead of a custom hack for XScale. Suggested by: jmg
2014-05-29 21:00:06 +00:00
u_char ier;
Introduce grab and ungrab upcalls. When the kernel desires to grab the console, it calls the grab functions. These functions should turn off the RX interrupts, and any others that interfere. This makes mountroot prompt work again. If there's more generalized need other than prompting, many of these routines should be expanded to do those new things. Should have been part of r260889, but waasn't due to command line typo. Reviewed by: bde (with reservations)
2014-01-19 19:39:13 +00:00
/*
* turn off all interrupts to enter polling mode. Leave the
* saved mask alone. We'll restore whatever it was in ungrab.
* All pending interupt signals are reset when IER is set to 0.
*/
uart_lock(sc->sc_hwmtx);
In uart_bus_grab(), use the ier_mask instead of a custom hack for XScale. Suggested by: jmg
2014-05-29 21:00:06 +00:00
ier = uart_getreg(bas, REG_IER);
uart_setreg(bas, REG_IER, ier & ns8250->ier_mask);
Introduce grab and ungrab upcalls. When the kernel desires to grab the console, it calls the grab functions. These functions should turn off the RX interrupts, and any others that interfere. This makes mountroot prompt work again. If there's more generalized need other than prompting, many of these routines should be expanded to do those new things. Should have been part of r260889, but waasn't due to command line typo. Reviewed by: bde (with reservations)
2014-01-19 19:39:13 +00:00
uart_barrier(bas);
uart_unlock(sc->sc_hwmtx);
}
void
ns8250_bus_ungrab(struct uart_softc *sc)
{
struct ns8250_softc *ns8250 = (struct ns8250_softc*)sc;
struct uart_bas *bas = &sc->sc_bas;
/*
* Restore previous interrupt mask
*/
uart_lock(sc->sc_hwmtx);
uart_setreg(bas, REG_IER, ns8250->ier);
uart_barrier(bas);
uart_unlock(sc->sc_hwmtx);
}
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