watchdog: wdat_wdt: Add timeout value as a param in ping method

According to the WDAT spec that states about WATCHDOG_ACTION_SET_COUNTDOWN_PERIOD:
"This action is required if WATCHDOG_ACTION_RESET does not explicitly write a new
countdown value to a register during a reset."
And that implies, WATCHDOG_ACTION_RESET may write a countdown value, thus may come
with a WATCHDOG_INSTRUCTION_WRITE_COUNTDOWN, thus need the timeout value as parameter
or would otherwise write 0.
The watchdog for SIONCT6126 need a entry WATCHDOG_INSTRUCTION_WRITE_COUNTDOWN for
WATCHDOG_ACTION_RESET action, I send this patch to support it.

Signed-off-by: Xing Tong Wu <xingtong.wu@siemens.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20231007082125.4699-1-xingtong_wu@163.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: wdat_wdt: Avoid unimplemented get_timeleft

As per the specification the action QUERY_COUNTDOWN_PERIOD is optional.
If the action is not implemented by the physical device the driver would
always report "0" from get_timeleft().
Avoid confusing userspace by only providing get_timeleft() when
implemented by the hardware.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20221221-wdat_wdt-timeleft-v1-1-8e8a314c36cc@weissschuh.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: wdat_wdt: Set the min and max timeout values properly

The wdat_wdt driver is misusing the min_hw_heartbeat_ms field. This
field should only be used when the hardware watchdog device should not
be pinged more frequently than a specific period. The ACPI WDAT
"Minimum Count" field, on the other hand, specifies the minimum
timeout value that can be set. This corresponds to the min_timeout
field in Linux's watchdog infrastructure.

Setting min_hw_heartbeat_ms instead can cause pings to the hardware
to be delayed when there is no reason for that, eventually leading to
unexpected firing of the watchdog timer (and thus unexpected reboot).

Since commit 6d72c7ac9fbe ("watchdog: wdat_wdt: Using the existing
function to check parameter timeout"), min_timeout is being set too,
but to the arbitrary value of 1 second, which doesn't make sense and
allows setting timeout values lower that the ACPI WDAT "Minimum
Count" field.

I'm also changing max_hw_heartbeat_ms to max_timeout for symmetry,
although the use of this one isn't fundamentally wrong, but there is
also no reason to enable the software-driven ping mechanism for the
wdat_wdt driver.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 058dfc767008 ("ACPI / watchdog: Add support for WDAT hardware watchdog")
Fixes: 6d72c7ac9fbe ("watchdog: wdat_wdt: Using the existing function to check parameter timeout")
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Liu Xinpeng <liuxp11@chinatelecom.cn>
Link: https://lore.kernel.org/r/20220823154713.023ee771@endymion.delvare
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: wdat_wdt: Remove #ifdef guards for PM related functions

Use the new NOIRQ_SYSTEM_SLEEP_PM_OPS() and pm_sleep_ptr() macros to
handle the .suspend/.resume callbacks.

These macros allow the suspend and resume functions to be automatically
dropped by the compiler when CONFIG_SUSPEND is disabled, without having
to use #ifdef guards. Not using #ifdef guards means that the code is
always compiled independently of any Kconfig option, and thanks to that
bugs and regressions are easier to catch.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220628193449.160585-9-paul@crapouillou.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: wdat_wdt: Stop watchdog when uninstalling module

Test shows that wachdog still reboots machine after the module
is removed. Use watchdog_stop_on_unregister to stop the watchdog
on removing.

Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn>
eviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1650984810-6247-4-git-send-email-liuxp11@chinatelecom.cn
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: wdat_wdt: Stop watchdog when rebooting the system

Executing reboot command several times on the machine "Dell
PowerEdge R740", UEFI security detection stopped machine
with the following prompt:

UEFI0082: The system was reset due to a timeout from the watchdog
timer. Check the System Event Log (SEL) or crash dumps from
Operating Sysstem to identify the source that triggered the
watchdog timer reset. Update the firmware or driver for the
identified device.

iDRAC has warning event: "The watchdog timer reset the system".

This patch fixes this issue by adding the reboot notifier.

Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1650984810-6247-3-git-send-email-liuxp11@chinatelecom.cn
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: wdat_wdt: Using the existing function to check parameter timeout

If max_hw_heartbeat_ms is provided, the configured maximum timeout is not
limited by it. The limit check in this driver therefore doesn't make much
sense. Similar, the watchdog core ensures that minimum timeout limits are
met if min_hw_heartbeat_ms is set. Using watchdog_timeout_invalid() makes
more sense because it takes this into account.

Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1650984810-6247-2-git-send-email-liuxp11@chinatelecom.cn
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: wdat_wdg: fix typo

Fix the following typo:

"recommeded" --> "recommended"
"firmare" --> "firmware"

Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210216141727.641224-1-f.suligoi@asem.it
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: wdat_wdt: Fix missing kerneldoc reported by W=1

Fix the following warning while compiling with W=1.

drivers/watchdog/wdat_wdt.c:48: warning: Function parameter or member 'instructions' not described in 'wdat_wdt'

Signed-off-by: Wong Vee Khee <vee.khee.wong@intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20201111172205.17215-1-vee.khee.wong@intel.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

ACPI: watchdog: Set default timeout in probe

If the BIOS default timeout for the watchdog is too small userspace may
not have enough time to configure new timeout after opening the device
before the system is already reset. For this reason program default
timeout of 30 seconds in the driver probe and allow userspace to change
this from command line or through module parameter (wdat_wdt.timeout).

Reported-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: watchdog: Fix gas->access_width usage

ACPI Generic Address Structure (GAS) access_width field is not in bytes
as the driver seems to expect in few places so fix this by using the
newly introduced macro ACPI_ACCESS_BYTE_WIDTH().

Fixes: b1abf6fc4982 ("ACPI / watchdog: Fix off-by-one error at resource assignment")
Fixes: 058dfc767008 ("ACPI / watchdog: Add support for WDAT hardware watchdog")
Reported-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Cc: 4.16+ <stable@vger.kernel.org> # 4.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

watchdog: wdat_wdt: Spelling s/configrable/configurable/

Fix misspelling of "configurable".

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20191024152856.30788-1-geert+renesas@glider.be
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

watchdog: wdat_wdt: Use 'dev' instead of dereferencing it repeatedly

Introduce local variable 'struct device *dev' and use it instead of
dereferencing it repeatedly.

The conversion was done automatically with coccinelle using the
following semantic patches. The semantic patches and the scripts
used to generate this commit log are available at
https://github.com/groeck/coccinelle-patches

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: wdat_wdt: fix get_timeleft call for wdat_wdt

The get_timeleft call for wdat_wdt was using ACPI_WDAT_GET_COUNTDOWN
when running an action on the device, which would return the configured
countdown, instead of ACPI_WDAT_GET_CURRENT_COUNTDOWN, which returns the
time left before the watchdog will fire. This change corrects that.

Signed-off-by: Bryan Tan <bryantan@vmware.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: simplify getting .drvdata

We should get drvdata from struct device directly. Going via
platform_device is an unneeded step back and forth.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

ACPI / watchdog: Fix off-by-one error at resource assignment

The resource allocation in WDAT watchdog has off-one-by error, it sets
one byte more than the actual end address. This may eventually lead
to unexpected resource conflicts.

Fixes: 058dfc767008 (ACPI / watchdog: Add support for WDAT hardware watchdog)
Cc: 4.9+ <stable@vger.kernel.org> # 4.9+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

watchdog: wdat_wdt: Ping the watchdog on resume

It turns out we need to ping the watchdog hardware on resume when we
re-program it. Otherwise this causes inadvertent reset to trigger
right after the resume is complete.

Fixes: 058dfc767008 (ACPI / watchdog: Add support for WDAT hardware watchdog)
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

watchdog: wdat_wdt: Fix warning for using 0 as NULL

Fixes the following sparse warnings:

drivers/watchdog/wdat_wdt.c:210:66: warning: Using plain integer as NULL pointer
drivers/watchdog/wdat_wdt.c:235:66: warning: Using plain integer as NULL pointer

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

watchdog: wdat_wdt: fix return value check in wdat_wdt_probe()

In case of error, the function devm_ioremap_resource() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check should
be replaced with IS_ERR().

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / watchdog: Add support for WDAT hardware watchdog

Starting from Intel Skylake the iTCO watchdog timer registers were moved to
reside in the same register space with SMBus host controller. Not all
needed registers are available though and we need to unhide P2SB (Primary
to Sideband) device briefly to be able to read status of required NO_REBOOT
bit. The i2c-i801.c SMBus driver used to handle this and creation of the
iTCO watchdog platform device.

Windows, on the other hand, does not use the iTCO watchdog hardware
directly even if it is available. Instead it relies on ACPI Watchdog Action
Table (WDAT) table to describe the watchdog hardware to the OS. This table
contains necessary information about the the hardware and also set of
actions which are executed by a driver as needed.

This patch implements a new watchdog driver that takes advantage of the
ACPI WDAT table. We split the functionality into two parts: first part
enumerates the WDAT table and if found, populates resources and creates
platform device for the actual driver. The second part is the driver
itself.

The reason for the split is that this way we can make the driver itself to
be a module and loaded automatically if the WDAT table is found. Otherwise
the module is not loaded.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>