The TI uart hardware is ns16550-compatible, except that before it can
be used the clocks and power have to be enabled and a non-standard
mode control register has to be set to put the device in uart mode
(as opposed to irDa or other serial protocols). This adds the extra
code in an extension to the standard ns8250 probe routine, and the
rest of the driver is just the standard ns8250 code.
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.
device compatible with multiple drivers matches the more specific driver
first and doesn't overwrite it later with the more generic. Move the
generic ns16550 to the end of the list.
we call device-specific probe functions, which can (and typically will)
set the device description based on low-level device probe information.
In the end we never actually used the device description that we so
carefully maintained in the PCI match table. By setting the device
description after we call uart_probe(), we'll print the more user-
friendly description by default.
H/W not de-asserting the interrupt at all. On x86, and because of the
following conditions, this results in a hard hang with interrupts disabled:
1. The uart(4) driver uses a spin lock to protect against concurrent
access to the H/W. Spin locks disable and restore interrupts.
2. Restoring the interrupt on x86 always writes the flags register. Even
if we're restoring the interrupt from disabled to disabled.
3. The x86 CPU has a short window in which interrupts are enabled when the
flags register is written.
4. The uart(4) driver registers a fast interrupt by default.
To catch this case, we first try to clear any pending H/W interrupts and in
particular, before setting up the interrupt. This makes sure the interrupt
is masked on the PIC. The interrupt handler now has a limit set on the
number of iterations it'll go through to clear interrupt conditions. If the
limit is hit, the handler will return FILTER_SCHEDULE_THREAD. The attach
function will check for this return code and avoid setting up the interrupt
and foce polling in that case.
Obtained from: Juniper Networks, Inc.
1. Common headers for fdt.h and ofw_machdep.h under x86/include
with indirections under i386/include and amd64/include.
2. New modinfo for loader provided FDT blob.
3. Common x86_init_fdt() called from hammer_time() on amd64 and
init386() on i386.
4. Split-off FDT specific low-level console functions from FDT
bus methods for the uart(4) driver. The low-level console
logic has been moved to uart_cpu_fdt.c and is used for arm,
mips & powerpc only. The FDT bus methods are shared across
all architectures.
5. Add dev/fdt/fdt_x86.c to hold the fdt_fixup_table[] and the
fdt_pic_table[] arrays. Both are empty right now.
FDT addresses are I/O ports on x86. Since the core FDT code does
not handle different address spaces, adding support for both I/O
ports and memory addresses requires some thought and discussion.
It may be better to use a compile-time option that controls this.
Obtained from: Juniper Networks, Inc.
uart(4) allocates send and receiver buffers in attach() before it calls
the low-level driver's attach routine. Many low-level drivers set the
fifo sizes in their attach routine, which is too late. Other drivers set
them in the probe() routine, so that they're available when uart(4)
allocates buffers. This fixes the ones that were setting the values too
late by moving the code to probe().
to the same thing) by allocating the uart(4) rx buffer based on the
device's rxfifosz rather than using a hard-coded size of 384 bytes.
The historical 384 byte size is 3 times the largest hard-coded fifo
size in the tree, so use that ratio as a guide and allocate the buffer
as three times rxfifosz, but never smaller than the historical size.
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@
x86 buses
Otherwise the uart hardware could be in such a state after the resume
where IER is cleared and thus no interrupts are generated.
This behavior is observed and tested with QEMU, so I am comitting this
change to help with my debugging.
There has been no feedback from users of serial ports on real hardware.
MFC after: 20 days
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
PNP0510 and FUJ02E5 for a "Wacom Tablet at FuS Lifebook T"
PNP0502 and PNP0511 for some other generic devices.
PR: kern/173357
Submitted by: Andrey Zakharchenko <avz@jscc.ru>
Approved by: cperciva (implicit)
MFC after: 1 week
r233822:
Remove useless and wrong piece of code in fdt_get_range() which i
overwrites passed phandle_t node. Modify debug printf in fdt_reg_to_rl()
to be consistent (that is, print start and end *virtual* addresses).
r230560:
Handle "ranges;"
Make fdt_reg_to_rl() responsible for mapping the device memory, instead
on just hoping that there's only one simplebus, and using fdt_immr_va as
the base VA.
r230315
Add a function to get the PA from range, instead of (ab)using
fdt_immr_pa, and use it for the UART driver
used in polled-mode. The callout invokes uart_intr, which rearms the timeout.
Implemented for bhyve, but generically useful for e.g. embedded bringup
when the interrupt controller hasn't been setup, or if it's not deemed
worthy to wire an interrupt line from a serial port.
Submitted by: neel
Reviewed by: marcel
Obtained from: NetApp
MFC after: 3 weeks
identical now that the bus spaces are unified under sys/x86.
Replace them with a single uart_cpu_x86.c.
o delete uart_cpu_i386.c
o move uart_cpu_amd64.c to uart_cpu_x86.c
o update files.amd64 and files.i386 accordingly.
It seems strchr() and strrchr() are used more often than index() and
rindex(). Therefore, simply migrate all kernel code to use it.
For the XFS code, remove an empty line to make the code identical to
the code in the Linux kernel.
At the moment grab and ungrab methods of all console drivers are no-ops.
Current intended meaning of the calls is that the kernel takes control of
console input. In the future the semantics may be extended to mean that
the calling thread takes full ownership of the console (e.g. console
output from other threads could be suspended).
Inspired by: bde
MFC after: 2 months
As C1X is close to being released, there is no need to wrap around a
feature that is already part of C90. Most of these files already use
`const' in different placed as well.
According to the open firmware standard, finddevice call has to return
a phandle with value of -1 in case of error.
This commit is to:
- Fix the FDT implementation of this interface (ofw_fdt_finddevice) to
return (phandle_t)-1 in case of error, instead of 0 as it does now.
- Fix up the callers of OF_finddevice() to compare the return value with
-1 instead of 0 to check for errors.
- Since phandle_t is unsigned, the return value of OF_finddevice should
be checked with '== -1' rather than '<= 0' or '> 0', fix up these cases
as well.
Reported by: nwhitehorn
Reviewed by: raj
Approved by: raj, nwhitehorn
improvements:
(1) Implement new model in previously missed at91 UART driver
(2) Move BREAK_TO_DEBUGGER and ALT_BREAK_TO_DEBUGGER from opt_comconsole.h
to opt_kdb.h (spotted by np)
(3) Garbage collect now-unused opt_comconsole.h
MFC after: 3 weeks
Approved by: re (bz)
accessible:
(1) Always compile in support for breaking into the debugger if options
KDB is present in the kernel.
(2) Disable both by default, but allow them to be enabled via tunables
and sysctls debug.kdb.break_to_debugger and
debug.kdb.alt_break_to_debugger.
(3) options BREAK_TO_DEBUGGER and options ALT_BREAK_TO_DEBUGGER continue
to behave as before -- only now instead of compiling in
break-to-debugger support, they change the default values of the
above sysctls to enable those features by default. Current kernel
configurations should, therefore, continue to behave as expected.
(4) Migrate alternative break-to-debugger state machine logic out of
individual device drivers into centralised KDB code. This has a
number of upsides, but also one downside: it's now tricky to release
sio spin locks when entering the debugger, so we don't. However,
similar logic does not exist in other device drivers, including uart.
(5) dcons requires some special handling; unlike other console types, it
allows overriding KDB's own debugger selection, so we need a new
interface to KDB to allow that to work.
GENERIC kernels in -CURRENT will now support break-to-debugger as long as
appropriate boot/run-time options are set, which should improve the
debuggability of BETA kernels significantly.
MFC after: 3 weeks
Reviewed by: kib, nwhitehorn
Approved by: re (bz)
Back in 2009 I changed the ABI of the GIO_KEYMAP and PIO_KEYMAP ioctls
to support wide characters. I created a patch to add ABI compatibility
for the old calls, but I didn't get any feedback to that.
It seems now people are upgrading from 8 to 9 they experience this
issue, so add it anyway.
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
