Commit Graph

7 Commits

Author SHA1 Message Date
Yoshihiro Takahashi
81df65c311 Add the 2nd CCU and PnP devices support on pc98.
Reviewed by:	imp
Obtained from:	//depot/projects/uart with some fixes
2008-08-25 14:45:24 +00:00
Warner Losh
098ca2bda9 Start each of the license/copyright comments with /*-, minor shuffle of lines 2005-01-06 01:43:34 +00:00
Marius Strobl
37f37506de Remove the whole uart_cpu_identify() stuff again. Now that it's no longer
used on sparc64 they are only stubs on all architectures and it doesn't
look like if we would need it in the near future again.

Ok'ed by:	marcel
2004-11-17 20:01:43 +00:00
Marius Strobl
8f0882f544 Don't call uart_bus_probe() for non-matching PnP-devices. Trying to probe
the keyboard controller with uart_bus_probe() caused a hang here on an i386
machine.

Approved by:	marcel
2004-08-25 22:15:33 +00:00
Marius Strobl
efa79eb77e - Introduce an uart_cpu_identify() which is implemented in uart_cpu_<arch>.c
and that can be used as an identify function for all kinds of busses on a
  certain platform. Expect for sparc64 these are only stubs right now. [1]
- For sparc64, add code to its uart_cpu_identify() for registering the on-
  board ISA UARTs and their resources based on information obtained from
  Open Firmware.
  It would be better if this would be done in the OFW ISA code. However, due
  to the common FreeBSD ISA code and PNP-IDs not always being present in the
  properties of the ISA nodes there seems to be no good way to implement that.
  Therefore special casing UARTs as the sole really relevant ISA devices on
  sparc64 seemed reasonable. [2]

Approved by:	marcel
Discussed with:	marcel [1], tmm [2]
Tested by:	make universe
2004-08-14 23:54:27 +00:00
Marcel Moolenaar
875f70dba4 Revert the introduction of iobase in struct uart_bas. Both the SAB82532
and the Z8530 drivers used the I/O address as a quick and dirty way to
determine which channel they operated on, but formalizing this by
introducing iobase is not a solution. How for example would a driver
know which channel it controls for a multi-channel UART that only has a
single I/O range?

Instead, add an explicit field, called chan, to struct uart_bas that
holds the channel within a device, or 0 otherwise. The chan field is
initialized both by the system device probing (i.e. a system console)
or it is passed down to uart_bus_probe() by any of the bus front-ends.
As such, it impacts all platforms and bus drivers and makes it a rather
large commit.

Remove the use of iobase in uart_cpu_eqres() for pc98. It is expected
that platforms have the capability to compare tag and handle pairs for
equality; as to determine whether two pairs access the same device or
not. The use of iobase for pc98 makes it impossible to formalize this
and turn it into a real newbus function later. This commit reverts
uart_cpu_eqres() for pc98 to an unimplemented function. It has to be
reimplemented using only the tag and handle fields in struct uart_bas.

Rewrite the SAB82532 and Z8530 drivers to use the chan field in struct
uart_bas. Remove the IS_CHANNEL_A and IS_CHANNEL_B macros. We don't
need to abstract anything anymore.

Discussed with: nyan
Tested on: i386, ia64, sparc64
2003-09-26 05:14:56 +00:00
Marcel Moolenaar
27d5dc189c 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