Commit Graph

783 Commits

Author SHA1 Message Date
John Garry
a27d938251 serial: 8250_of: Fix for lack of interrupt support
In commit c58caaab3b ("serial: 8250: of: Defer probe on missing IRQ"), a
check was added for the UART driver being probed prior to the parent IRQ
controller.

Unfortunately this breaks certain boards which have no interrupt support,
like Huawei D03.

Indeed, the 8250 DT bindings state that interrupts should be supported -
not must.

To fix, switch from irq_of_parse_and_map() to of_irq_get(), which
does relay whether the IRQ host controller domain is not ready, i.e.
defer probe, instead of assuming it.

Fixes: c58caaab3b ("serial: 8250: of: Defer probe on missing IRQ")
Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18 16:07:25 +02:00
Lokesh Vutla
c886751465 serial: 8250_omap: Make 8250_omap driver driver depend on ARCH_K3
Allow 8250 omap serial driver to be used for K3 platforms.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18 16:07:24 +02:00
Sebastian Andrzej Siewior
9d7c249a1e serial: 8250: drop the printk from serial8250_interrupt()
The printk() in serial8250_interrupt() was once hidden behind a debug
macro in commit f4f653e987 ("serial: 8250, disable "too much work"
messages") and reverted back in commit 12de375ec4 ("Revert "serial:
8250, disable "too much work" messages"").

This was introduced first in 0.99.13k with the "serial" driver itself
(and called pass_number with a limit of 64 and no print). In 1.1.13 it
was renamed to pass_counter and the printk was behind #if 0. In 1.1.94
the limit of 64 was increased to 256 and hidden behind
RS_ISR_PASS_LIMIT. With this change the #if 0 turned into #if 1. It
slowly become what we have today with a loop limit of 512.

Usually, that printk isn't hit. However on KVM with a busy UART and
overloaded host it might happen. It is also likely with threaded
interrupts and a task which preempts the interrupt handler.

If the UART has (legitimate) work to do and we break out of the loop,
nothing changes: the interrupt is most likely already pending in the
interrupt controller and we end up in the handler anyway. This printk is
hardly helping.

Older kernels also had a comment saying that a bad configuration might
lead to this but I don't see how that should happen because a wrongly
configured interrupt number would let the handler leave "early" with
IRQ_NONE and the spurious detected will handle that (weill since 2.6.11,
before that we had no spurious detector). In that case, we would never
loop that often here.

This loop looks like an optimisation in order to pull the bytes from the
FIFO which were received while we were already here instead of waiting
for the interrupt. This might have been a good idea while the CPUs were
slow and FIFOs small.
There are other serial driver in tree, like the amba-pl*, which also
have this kind of a loop but without the printk (and were based on this
driver).

Remove the printk which might trigger in otherwise valid situtations.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18 16:07:23 +02:00
Linus Torvalds
d5acba26bf Char/Misc driver patches for 4.19-rc1
Here is the bit set of char/misc drivers for 4.19-rc1
 
 There is a lot here, much more than normal, seems like everyone is
 writing new driver subsystems these days...  Anyway, major things here
 are:
 	- new FSI driver subsystem, yet-another-powerpc low-level
 	  hardware bus
 	- gnss, finally an in-kernel GPS subsystem to try to tame all of
 	  the crazy out-of-tree drivers that have been floating around
 	  for years, combined with some really hacky userspace
 	  implementations.  This is only for GNSS receivers, but you
 	  have to start somewhere, and this is great to see.
 Other than that, there are new slimbus drivers, new coresight drivers,
 new fpga drivers, and loads of DT bindings for all of these and existing
 drivers.
 
 Full details of everything is in the shortlog.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 aC5jb20ACgkQMUfUDdst+ykfBgCeOG0RkSI92XVZe0hs/QYFW9kk8JYAnRBf3Qpm
 cvW7a+McOoKz/MGmEKsi
 =TNfn
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Merge tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the bit set of char/misc drivers for 4.19-rc1

  There is a lot here, much more than normal, seems like everyone is
  writing new driver subsystems these days... Anyway, major things here
  are:

   - new FSI driver subsystem, yet-another-powerpc low-level hardware
     bus

   - gnss, finally an in-kernel GPS subsystem to try to tame all of the
     crazy out-of-tree drivers that have been floating around for years,
     combined with some really hacky userspace implementations. This is
     only for GNSS receivers, but you have to start somewhere, and this
     is great to see.

  Other than that, there are new slimbus drivers, new coresight drivers,
  new fpga drivers, and loads of DT bindings for all of these and
  existing drivers.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits)
  android: binder: Rate-limit debug and userspace triggered err msgs
  fsi: sbefifo: Bump max command length
  fsi: scom: Fix NULL dereference
  misc: mic: SCIF Fix scif_get_new_port() error handling
  misc: cxl: changed asterisk position
  genwqe: card_base: Use true and false for boolean values
  misc: eeprom: assignment outside the if statement
  uio: potential double frees if __uio_register_device() fails
  eeprom: idt_89hpesx: clean up an error pointer vs NULL inconsistency
  misc: ti-st: Fix memory leak in the error path of probe()
  android: binder: Show extra_buffers_size in trace
  firmware: vpd: Fix section enabled flag on vpd_section_destroy
  platform: goldfish: Retire pdev_bus
  goldfish: Use dedicated macros instead of manual bit shifting
  goldfish: Add missing includes to goldfish.h
  mux: adgs1408: new driver for Analog Devices ADGS1408/1409 mux
  dt-bindings: mux: add adi,adgs1408
  Drivers: hv: vmbus: Cleanup synic memory free path
  Drivers: hv: vmbus: Remove use of slow_virt_to_phys()
  Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind()
  ...
2018-08-18 11:04:51 -07:00
Mark
47ac76662c tty: serial: 8250: Revert NXP SC16C2552 workaround
Revert commit ecb988a3b7: tty: serial:
8250: 8250_core: NXP SC16C2552 workaround

The above commit causes userland application to no longer write
correctly its first write to a dumb terminal connected to /dev/ttyS0.
This commit seems to be the culprit. It's as though the TX FIFO is being
reset during that write. What should be displayed is:

PSW 80000000 INST 00000000                           HALT
//

What is displayed is some variation of:

T 00000000           HAL//

Reverting this commit via this patch fixes my problem.

Signed-off-by: Mark Hounschell <dmarkh@cfl.rr.com>
Fixes: ecb988a3b7 ("tty: serial: 8250: 8250_core: NXP SC16C2552 workaround")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-12 18:53:30 +02:00
Aaron Sierra
60ab0fafc4 serial: 8250_exar: Read INT0 from slave device, too
The sleep wake-up refactoring that I introduced in

  commit c7e1b40590 ("tty: serial: exar: Relocate sleep wake-up handling")

did not account for devices with a slave device on the expansion port.
This patch pokes the INT0 register in the slave device, if present, in
order to ensure that MSI interrupts don't get permanently "stuck"
because of a sleep wake-up interrupt as described here:

  commit 2c0ac5b48a ("serial: exar: Fix stuck MSIs")

This also converts an ioread8() to readb() in order to provide visual
consistency with the MMIO-only accessors used elsewhere in the driver.

Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Fixes: c7e1b40590 ("tty: serial: exar: Relocate sleep wake-up handling")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-02 10:11:35 +02:00
Srinath Mannam
784c29eda5 serial: 8250_dw: Add ACPI support for uart on Broadcom SoC
Add ACPI identifier HID for UART DW 8250 on Broadcom SoCs
to match the HID passed through ACPI tables to enable
UART controller.

Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
Reviewed-by: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>
Tested-by: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-02 10:11:32 +02:00
Chen Hu
dfcab6ba57 serial: 8250_dw: always set baud rate in dw8250_set_termios
dw8250_set_termios() doesn't set baud rate if the arg "old ktermios" is
NULL. This happens during resume.
Call Trace:
...
[   54.928108] dw8250_set_termios+0x162/0x170
[   54.928114] serial8250_set_termios+0x17/0x20
[   54.928117] uart_change_speed+0x64/0x160
[   54.928119] uart_resume_port
...

So the baud rate is not restored after S3 and breaks the apps who use
UART, for example, console and bluetooth etc.

We address this issue by setting the baud rate irrespective of arg
"old", just like the drivers for other 8250 IPs. This is tested with
Intel Broxton platform.

Signed-off-by: Chen Hu <hu1.chen@intel.com>
Fixes: 4e26b134bd ("serial: 8250_dw: clock rate handling for all ACPI platforms")
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-02 10:11:32 +02:00
Andy Shevchenko
286d9b8c7d serial: 8250: Use cached port name directly in messages
Since we have port name stored in struct uart_port, we better to use
that one instead of open coding.

This will make it one place source for easier maintenance or
modifications.

While here, replace printk_ratelimited(KERN_INFO ) by pr_info_ratelimited().
It seems last printk() call in 8250_port.c.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 12:51:23 +02:00
Andy Shevchenko
b340cbbea5 serial: 8250_exar: Drop unused variable in pci_xr17v35x_setup()
After removal has_slave use the variable board becomes unused.
Remove it to avoid a warning:

drivers/tty/serial/8250/8250_exar.c: In function 'pci_xr17v35x_setup':
drivers/tty/serial/8250/8250_exar.c:380:31: warning: unused variable 'board' [-Wunused-variable]
  const struct exar8250_board *board = priv->board;
                               ^~~~~

Fixes: 328c11f24b ("serial: 8250_exar: Remove useless has_slave member")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-23 14:15:49 +02:00
Andy Shevchenko
26f22d5748 serial: 8250_exar: Describe all members in struct exar8250_board
Describe all memebers in struct exar8250_board, otherwise we get a warning:

drivers/tty/serial/8250/8250_exar.c:122: warning: Function parameter or member 'has_slave' not described in 'exar8250_board'
drivers/tty/serial/8250/8250_exar.c:122: warning: Function parameter or member 'setup' not described in 'exar8250_board'
drivers/tty/serial/8250/8250_exar.c:122: warning: Function parameter or member 'exit' not described in 'exar8250_board'

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-21 08:40:45 +02:00
Andy Shevchenko
328c11f24b serial: 8250_exar: Remove useless has_slave member
Exar UARTs by default supports only up to 8 channels,
all above go as extension. Thus, there is no need to have
an additional property to distinguish them from first ones.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-21 08:40:45 +02:00
Phil Edworthy
2ff5fa7f74 serial: 8250_dw: Add compatible string for Renesas RZ/N1 UART
The Renesas RZ/N1 UART is based on the Synopsys DW UART, but has additional
registers for DMA. This patch does not address the changes required for DMA
support, it simply adds the compatible string.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-21 08:39:25 +02:00
Alexander Sverdlin
c58caaab3b serial: 8250: of: Defer probe on missing IRQ
If the IRQ controller is not yet probed do not proceed with irq=0,
try to defer the probe.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-16 11:56:22 +02:00
Alexander Sverdlin
b29330d829 serial: 8250: of: Correct of_platform_serial_setup() error handling
Don't dispose IRQ mapping before it has been created.

Fixes: aa9594740 ("serial: 8250_of: Add IO space support")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-16 11:56:22 +02:00
Greg Kroah-Hartman
83cf9cd6d5 Merge 4.18-rc5 into char-misc-next
We want the char-misc fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-16 09:04:54 +02:00
Jisheng Zhang
701c5e73b2 serial: 8250_dw: add fractional divisor support
For Synopsys DesignWare 8250 uart which version >= 4.00a, there's a
valid divisor latch fraction register. The fractional divisor width is
4bits ~ 6bits.

Now the preparation is done, it's easy to add the feature support.
This patch firstly tries to get the fractional divisor width during
probe, then setups dw specific get_divisor() and set_divisor() hook.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-12 17:07:26 +02:00
Jisheng Zhang
6226e5f31a serial: 8250: export serial8250_do_set_divisor()
Some drivers could call serial8250_do_set_divisor() to complete its
own set_divisor routine. Export this symbol for code reusing.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-12 17:07:26 +02:00
Jisheng Zhang
0238d2b4a4 serial: 8250: introduce get_divisor() and set_divisor() hook
Add these two hooks so that they can be overridden with driver specific
implementations.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-12 17:07:26 +02:00
Randy Dunlap
ac3167257b headers: separate linux/mod_devicetable.h from linux/platform_device.h
At over 4000 #includes, <linux/platform_device.h> is the 9th most
#included header file in the Linux kernel.  It does not need
<linux/mod_devicetable.h>, so drop that header and explicitly add
<linux/mod_devicetable.h> to source files that need it.

   4146 #include <linux/platform_device.h>

After this patch, there are 225 files that use <linux/mod_devicetable.h>,
for a reduction of around 3900 times that <linux/mod_devicetable.h>
does not have to be read & parsed.

    225 #include <linux/mod_devicetable.h>

This patch was build-tested on 20 different arch-es.

It also makes these drivers SubmitChecklist#1 compliant.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kbuild test robot <lkp@intel.com> # drivers/media/platform/vimc/
Reported-by: kbuild test robot <lkp@intel.com> # drivers/pinctrl/pinctrl-u300.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-07 17:52:26 +02:00
Andy Shevchenko
3ff10703c7 serial: 8250_dw: Introduce IO accessors to extended registers
There are several extended (in comparison to the traditional 16550)
registers are present in Synopsys DesignWare UART. All of them
are 32-bit ones.

Introduce helpers to simplify access to them and convert existing users.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-07 17:00:51 +02:00
Jisheng Zhang
6101be86cb serial: 8250: let serial8250_get_divisor() get uart_port * as param
Align serial8250_get_divisor() with serial8250_set_divisor() to accept
uart_port pointer as the first parameter. No functionality changes.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-06 16:45:38 +02:00
Greg Kroah-Hartman
16ecf49c10 Merge 4.18-rc3 into tty-next
We want ths tty core changes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-02 08:23:43 +02:00
Andy Shevchenko
20dcff436e serial: 8250_pci: Remove stalled entries in blacklist
After the commit

  7d8905d064 ("serial: 8250_pci: Enable device after we check black list")

pure serial multi-port cards, such as CH355, got blacklisted and thus
not being enumerated anymore. Previously, it seems, blacklisting them
was on purpose to shut up pciserial_init_one() about record duplication.

So, remove the entries from blacklist in order to get cards enumerated.

Fixes: 7d8905d064 ("serial: 8250_pci: Enable device after we check black list")
Reported-by: Matt Turner <mattst88@gmail.com>
Cc: Sergej Pupykin <ml@sergej.pp.ru>
Cc: Alexandr Petrenko <petrenkoas83@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-and-Tested-by: Matt Turner <mattst88@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-28 21:34:39 +09:00
Zhouyang Jia
85c634e919 drivers/tty: add error handling for pcmcia_loop_config
When pcmcia_loop_config fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling pcmcia_loop_config.

Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-28 21:23:44 +09:00
Nishanth Menon
be70874498 serial: 8250_omap: Add support for AM654 UART controller
AM654 uses a UART controller that is compatible (partially) with
existing 8250 UART, however, has a few differences with respect to DMA
support and control paths. Introduce a base definition that allows us
to build up the differences in follow on patches.

Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Vignesh R <vigneshr@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-28 21:23:44 +09:00
Daniel Golle
9d93989444 tty: serial: exar: generalize RS485 setup
Move the non-board-specific part of the RS485 initialization from
iot2040_rs485_config function to a new generic function used also for
other boards.
This allows using TIOCGRS485 and TIOCSRS485 on boards (such as mPCIe
serial IO modules) which are hard-wired to RS485 or have jumpers for
their configurations.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-28 21:07:55 +09:00
Phil Edworthy
d76c74387e serial: 8250_dw: Fix runtime PM handling
When using kgdb, you get an abort when accessing the UART registers.
This is because the driver has already entered runtime PM and so turned
off the bus clock needed to access the registers.

To fix this, set the capability indicating Runtime PM is active while idle.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 13:51:12 +02:00
Tony Lindgren
13dc04d0e5 serial: 8250: omap: Fix idling of clocks for unused uarts
I noticed that unused UARTs won't necessarily idle properly always
unless at least one byte tx transfer is done first.

After some debugging I narrowed down the problem to the scr register
dma configuration bits that need to be set before softreset for the
clocks to idle. Unless we do this, the module clkctrl idlest bits
may be set to 1 instead of 3 meaning the clock will never idle and
is blocking deeper idle states for the whole domain.

This might be related to the configuration done by the bootloader
or kexec booting where certain configurations cause the 8250 or
the clkctrl clock to jam in a way where setting of the scr bits
and reset is needed to clear it. I've tried diffing the 8250
registers for the various modes, but did not see anything specific.
So far I've only seen this on omap4 but I'm suspecting this might
also happen on the other clkctrl using SoCs considering they
already have a quirk enabled for UART_ERRATA_CLOCK_DISABLE.

Let's fix the issue by configuring scr before reset for basic dma
even if we don't use it. The scr register will be reset when we do
softreset few lines after, and we restore scr on resume. We should
do this for all the SoCs with UART_ERRATA_CLOCK_DISABLE quirk flag
set since the ones with UART_ERRATA_CLOCK_DISABLE are all based
using clkctrl similar to omap4.

Looks like both OMAP_UART_SCR_DMAMODE_1 | OMAP_UART_SCR_DMAMODE_CTL
bits are needed for the clkctrl to idle after a softreset.

And we need to add omap4 to also use the UART_ERRATA_CLOCK_DISABLE
for the related workaround to be enabled. This same compatible
value will also be used for omap5.

Fixes: cdb929e445 ("serial: 8250_omap: workaround errata around idling UART after using DMA")
Cc: Keerthy <j-keerthy@ti.com>
Cc: Matthijs van Duin <matthijsvanduin@gmail.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 13:51:12 +02:00
Marek Vasut
3ace822ad4 serial: 8250: Add missing rxtrig_bytes on Altera 16550 UART
The Altera 16550 UART core supports FCR Rx Trigger Level setting,
but the port definition in the driver is missing the rxtrig_bytes
array specifying the trigger levels. Add the array to make the Rx
Trigger Level setting available on this type of 16550 UART.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Thor Thayer <tthayer@opensource.altera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 13:51:11 +02:00
Dan Carpenter
a451debb41 serial/aspeed-vuart: fix a couple mod_timer() calls
The "unthrottle_timeout" is HZ/10 but mod_timer() takes a the actual
jiffie where you want it to timeout, not an offset.

Fixes: 5909c0bf9c ("serial/aspeed-vuart: Implement quick throttle mechanism")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 13:51:11 +02:00
John Garry
aa95947400 serial: 8250_of: Add IO space support
Currently the 8250_of driver only supports MEM IO type
accesses.

Some development boards (Huawei D03, specifically) require
IO space access for 8250-compatible OF driver support, so
add it.

The modification is quite simple: just set the port iotype
and associated flags depending on the device address
resource type.

Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 13:48:29 +02:00
Michal Simek
700ad5531b serial: 8250_early: Setup divider when uartclk is passed
device->baud is always non zero value because it is checked already in
early_serial8250_setup() before init_port is called.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-25 14:56:12 +02:00
Jeremy Kerr
5909c0bf9c serial/aspeed-vuart: Implement quick throttle mechanism
Although we populate the ->throttle and ->unthrottle UART operations,
these may not be called until the ldisc has had a chance to schedule and
check buffer space. This means that we may overflow the flip buffers
without ever hitting the ldisc's throttle threshold.

This change implements an interrupt-based throttle, where we check for
space in the flip buffers before reading characters from the UART's
FIFO. If there's no space available, we disable the RX interrupt and
schedule a timer to check for space later.

For this, we need an unlocked version of the set_throttle function to be
able to change throttle state from the irq_handler, which already holds
port->lock.

This prevents a case where we drop characters under heavy RX load.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Tested-by: Eddie James <eajames@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 10:16:50 +02:00
Jeremy Kerr
989983ea84 serial/aspeed-vuart: Implement rx throttling
The aspeed VUART runs at LPC bus frequency, rather than being restricted
to a typical UART baud rate. This means that the VUART can receive a lot
of data, which can overrun tty flip buffers, and/or cause a large amount
of interrupt traffic.

This change implements the uart_port->throttle & unthrottle callbacks,
implemented by disabling the receiver line status & received data
available IRQs.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Tested-by: Eddie James <eajames@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 10:16:50 +02:00
Jeremy Kerr
ebbaf9ab9e serial/8250: export serial8250_read_char
Currently, we export serial8250_rx_chars, which does a whole bunch of
reads from the 8250 data register, without any form of flow control
between reads.

An upcoming change to the aspeed vuart driver implements more
fine-grained flow control in the interrupt handler, requiring
character-at-a-time control over the rx path.

This change exports serial8250_read_char to allow this.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Tested-by: Eddie James <eajames@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 10:16:50 +02:00
Kurt Kanzenbach
54e53b2e80 tty: serial: 8250: pass IRQ shared flag to UART ports
On some systems IRQ lines between multiple UARTs might be shared. If so, the
irqflags have to be configured accordingly. The reason is: The 8250 port startup
code performs IRQ tests *before* the IRQ handler for that particular port is
registered. This is performed in serial8250_do_startup(). This function checks
whether IRQF_SHARED is configured and only then disables the IRQ line while
testing.

This test is performed upon each open() of the UART device. Imagine two UARTs
share the same IRQ line: On is already opened and the IRQ is active. When the
second UART is opened, the IRQ line has to be disabled while performing IRQ
tests. Otherwise an IRQ might handler might be invoked, but the the IRQ itself
cannot be handled, because the corresponding handler isn't registered,
yet. That's because the 8250 code uses a chain-handler and invokes the
corresponding port's IRQ handling rountines himself.

Unfortunately this IRQF_SHARED flag isn't configured for UARTs probed via device
tree even if the IRQs are shared. This way, the actual and shared IRQ line isn't
disabled while performing tests and the kernel correctly detects a spurious
IRQ. So, adding this flag to the DT probe solves the issue.

Note: The UPF_SHARE_IRQ flag is configured unconditionally. Therefore, the
IRQF_SHARED flag can be set unconditionally as well.

Example stacktrace by performing echo 1 > /dev/ttyS2 on a non-patched system:

|irq 85: nobody cared (try booting with the "irqpoll" option)
| [...]
|handlers:
|[<ffff0000080fc628>] irq_default_primary_handler threaded [<ffff00000855fbb8>] serial8250_interrupt
|Disabling IRQ #85

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 10:13:16 +02:00
Vignesh R
09d8b2bdbc serial: 8250: omap: Provide ability to enable/disable UART as wakeup source
Enable/Clear module level UART wakeup in UART_OMAP_WER register based on
return value of device_may_wakeup() in .suspend(). This allows
userspace to use sysfs to control the ability of UART to wakeup the
system from deep sleep state. Register is restored back in .startup()
call that happens as part of resume sequence.

With this patch, userspace can control UART wakeup capability via sysfs:
To enable wakeup capability:
echo enabled >  /sys/class/tty/ttyXX/device/power/wakeup
For disabling wakeup capability:
echo disabled > /sys/class/tty/ttyXX/device/power/wakeup

Note that the UART wakeup events configured in the 8250 hardware only
work for idle modes that do not cut off power for the UART. For deeper
idle states, dedicated padconf wakeirqs must be used. Or in some cases
the UART RX pin can be remuxed to GPIO input if the GPIO block stays
powered.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 10:12:14 +02:00
Joshua Scott
b7639b0b15 serial: 8250_dw: Limit dw8250_tx_wait_empty quirk to armada-38x devices
The previous implementation has had a detrimental effect on devices using
high bitrates (bluetooth), as the fifo being non-empty for a single check
would result in a 10 µs delay.

Limit the change to devices with the new "marvell,armada-38x-uart"
compatible string. Also update the code to allow the first 1000 retries
to not perform a delay.

The maximum duration of retries has been increased to cover a worst-case
seen on the Armada 385 SoC. "dmesg ; resize", will fill the buffer with
text to output before doing a resize. At 9600 baud this took up to 13 ms
to flush all characters and avoid some getting lost.

Signed-off-by: Joshua Scott <joshua.scott@alliedtelesis.co.nz>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 10:11:13 +02:00
Greg Kroah-Hartman
4958134df5 Merge 4.16-rc6 into tty-next
We want the serial/tty fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-20 11:27:18 +01:00
Michael Moese
e2fea54e45 8250-men-mcb: add support for 16z025 and 16z057
Add support for two MEN UARTs (16z025 and 16z057) to the
8250_men_mcb driver.
The 16z025 consists of up to four ports, the 16z057 has
exactly four ports. Apart from that, all of them share the
Port settings.

Signed-off-by: Michael Moese <mmoese@suse.de>
Reported-by: Ben Turner <ben.turner@21net.com>
Tested-by: Ben Turner <ben.turner@21net.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-15 18:12:55 +01:00
Joel Stanley
f597fbce38 serial: 8250: Add Nuvoton NPCM UART
The Nuvoton UART is almost compatible with the 8250 driver when probed
via the 8250_of driver, however it requires some extra configuration
at startup.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09 11:01:19 -08:00
Andy Shevchenko
7d6e2143be serial: 8250_dw: Switch to use acpi_dev_present()
Special settings for APMC0D08 are applied when device is present
in the system. To check its presence we may use acpi_dev_present()
instead of current open coded variant.

Cc: Feng Kan <fkan@apm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09 10:24:38 -08:00
Andy Shevchenko
aad76f2c48 serial, pci_ids: Move duplicate IDs to PCI IDs database
PCI ID database is for IDs used across several drivers.
Here is the case for SUNIX combo cards.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28 15:33:04 +01:00
Nikola Ciprich
9f2068f357 serial: 8250_pci: Add Brainboxes UC-260 4 port serial device
Add PCI ids for two variants of Brainboxes UC-260 quad port
PCI serial cards.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28 13:48:21 +01:00
Andy Shevchenko
e7f3e99cb1 serial: 8250_pci: Don't fail on multiport card class
Do not fail on multiport cards in serial_pci_is_class_communication().

It restores behaviour for SUNIX multiport cards, that enumerated by
class and have a custom board data.

Moreover it allows users to reenumerate port-by-port from user space.

Fixes: 7d8905d064 ("serial: 8250_pci: Enable device after we check black list")
Reported-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28 13:48:21 +01:00
Joshua Scott
914eaf935e serial: 8250_dw: Allow TX FIFO to drain before writing to UART_LCR
An issue has been observed on the Marvell Armada 38x serial port.

Writes to UART_LCR can result in characters that are currently held in the
TX FIFO being lost rather than sent, even if the userspace process has
attempted to flush them.

This is most visible when using the "resize" command (tested on Busybox),
where we have observed the escape code for restoring cursor position
becoming mangled.

Signed-off-by: Joshua Scott <joshua.scott@alliedtelesis.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28 13:40:22 +01:00
Vignesh R
08fb00c64f serial: 8250: 8250_omap: Fix throttling when DMA is enabled
omap_8250_throttle() is called when tty RX buffer is about to overflow
and can no longer keep up with the rate at which UART is receiving data.
So, the expectation of this callback, is that UART stops RX and asserts
HW flow control to signal the sender to stop sending more data.
omap_8250_throttle() disables RX FIFO interrupts thus FIFO is no longer
serviced, leading to assertion of flow control once RX FIFO is full.
But, this does not work when DMA is enabled as driver keeps queuing new
RX DMA request in completion handler without brothering about throttling
request made by the higher layer.
This patch introduces a flag that can be used to determine whether or
not to queue next RX DMA request based on throttling request.

Without this patch, tty buffer overflows are reported at higher
baudrates.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28 13:40:22 +01:00
Vignesh R
2e9fe53910 serial: 8250: Don't service RX FIFO if interrupts are disabled
Currently, data in RX FIFO is read based on UART_LSR register state even
if RDI and RLSI interrupts are disabled in UART_IER register.
This is because when IRQ handler is called due to TX FIFO empty event,
RX FIFO is serviced based on UART_LSR register status instead of
UART_IIR status. This defeats the purpose of disabling UART RX
FIFO interrupts during throttling(see, omap_8250_throttle()) as IRQ
handler continues to drain UART RX FIFO resulting in overflow of buffer
at tty layer.
Fix this by making sure that driver drains UART RX FIFO only when
UART_IIR_RDI is set along with UART_LSR_BI or UART_LSR_DR bits.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28 13:40:22 +01:00
Aaron Sierra
c7e1b40590 tty: serial: exar: Relocate sleep wake-up handling
Exar sleep wake-up handling has been done on a per-channel basis by
virtue of INT0 being accessible from each channel's address space. I
believe this was initially done out of necessity, but now that Exar
devices have their own driver, we can do things more efficiently by
registering a dedicated INT0 handler at the PCI device level.

I see this change providing the following benefits:

    1. If more than one port is active, eliminates the redundant bus
       cycles for reading INT0 on every interrupt.
    2. This note associated with hooking in the per-channel handler in
       8250_port.c is resolved:
        /* Fixme: probably not the best place for this */

Cc: Matt Schulte <matts@commtech-fastcom.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-25 12:44:50 +01:00