watchdog: bcm2835_wdt: Fix WDIOC_SETTIMEOUT handling

Users report about the unexpected behavior for setting timeouts above
15 sec on Raspberry Pi. According to watchdog-api.rst the ioctl
WDIOC_SETTIMEOUT shouldn't fail because of hardware limitations.
But looking at the code shows that max_timeout based on the
register value PM_WDOG_TIME_SET, which is the maximum.

Since 664a39236e71 ("watchdog: Introduce hardware maximum heartbeat
in watchdog core") the watchdog core is able to handle this problem.

This fix has been tested with watchdog-test from selftests.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217374
Fixes: 664a39236e71 ("watchdog: Introduce hardware maximum heartbeat in watchdog core")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20231112173251.4827-1-wahrenst@gmx.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: bcm2835: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230303213716.2123717-8-u.kleine-koenig@pengutronix.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: bcm2835_wdt: consider system-power-controller property

Until now all Raspberry Pi boards used the power off function of the SoC.
But the Raspberry Pi 400 uses gpio-poweroff for the whole board which
possibly cannot register the poweroff handler because the it's
already registered by this watchdog driver. So consider the
system-power-controller property for registering, which is already
defined in soc/bcm/brcm,bcm2835-pm.txt .

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1622981777-5023-3-git-send-email-stefan.wahren@i2se.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: bcm2835_wdt: Fix module autoload

The commit 5e6acc3e678e ("bcm2835-pm: Move bcm2835-watchdog's DT probe
to an MFD.") broke module autoloading on Raspberry Pi. So add a
module alias this fix this.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
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: bcm2835_wdt: drop warning after registering device

The core will print out details now.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: bcm2835_wdt: drop platform_set_drvdata

There is no call to platform_get_drvdata() in the driver,
so platform_set_drvdata() is unnecessary and can be dropped.

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

Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: Eric Anholt <eric@anholt.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

bcm2835-pm: Move bcm2835-watchdog's DT probe to an MFD.

The PM block that the wdt driver was binding to actually has multiple
features we want to expose (power domains, reset, watchdog). Move the
DT attachment to a MFD driver and make WDT probe against MFD.

Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>

watchdog: add SPDX identifiers for watchdog subsystem

- Add SPDX identifier
- Remove boiler plate license text
- If MODULE_LICENSE and boiler plate does not match, go for boiler plate
license

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Acked-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Mans Rullgard <mans@mansr.com>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
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>

scripts/spelling.txt: add "partiton" pattern and fix typo instances

Fix typos and add the following to the scripts/spelling.txt:

partiton||partition

Link: http://lkml.kernel.org/r/1481573103-11329-7-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

watchdog: bcm2835_wdt: Convert to use device managed functions and other improvements

Use device managed functions to simplify error handling, reduce
source code size, improve readability, and reduce the likelyhood of bugs.
Other improvements as listed below.

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

- Drop assignments to otherwise unused variables
- Replace of_iomap() with platform_get_resource() followed by
devm_ioremap_resource()
- Replace &pdev->dev with dev if 'struct device *dev' is a declared
variable
- Use devm_watchdog_register_driver() to register watchdog device
- Replace shutdown function with call to watchdog_stop_on_reboot()

Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Lee Jones <lee@kernel.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

watchdog: bcm2835_wdt: Use watchdog core to install restart handler

Use the infrastructure provided by the watchdog core to install
the restart handler.

Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

watchdog: bcm2835_wdt: set WDOG_HW_RUNNING bit when appropriate

A bootloader may start the watchdog device before handing control to
the kernel - in that case, we should tell the kernel about it so the
watchdog framework can keep it alive until userspace opens
/dev/watchdog0.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

watchdog: bcm2835_wdt: remove redundant ->set_timeout callback

bcm2835_wdt_set_timeout does exactly what the watchdog framework does
in the absence of a ->set_timeout callback (see watchdog_set_timeout
in watchdog_dev.c), so remove it.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: bcm2835_wdt: constify _ops and _info structures

These are never modified, so might as well be const.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: bcm2835_wdt: Drop log message if watchdog is stopped

Stopping a watchdog is a normal operation and does not warrant a log
message.

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

watchdog: bcm2835: Fix poweroff behaviour

Currently poweroff/halt results in a reboot on the Raspberry Pi.
The firmware uses the RSTS register to know which partiton to
boot from. The partiton value is spread into bits
0, 2, 4, 6, 8, 10. Partiton 63 is a special partition used by
the firmware to indicate halt.

The firmware made this change in 19 Aug 2013 and was matched
by the downstream commit:
Changes for new NOOBS multi partition booting from gsh

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Watchdog: Fix parent of watchdog_devices

/sys/class/watchdog/watchdogn/device/modalias can help to identify the
driver/module for a given watchdog node. However, many wdt devices do not
set their parent and so, we do not see an entry for device in sysfs for
such devices.

This patch fixes parent of watchdog_device so that
/sys/class/watchdog/watchdogn/device is populated.

Exceptions: booke, diag288, octeon, softdog and w83627hf -- They do not
have any parent. Not sure, how we can identify driver for these devices.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

ARM: bcm2835: Move the restart/power_off handling to the WDT driver

Since the WDT is what's used to drive restart and power off, it makes
more sense to keep it there, where the regs are already mapped and
definitions for them provided. Note that this means you may need to
add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

watchdog: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

watchdog: Remove unnecessary OOM messages

The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message. For example,
k.alloc and v.alloc failures use dump_stack().

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de> [for at32ap700x]
Acked-by: Lubomir Rintel <lkundrak@v3.sk> [for bcm2835]
Acked-by: Viresh Kumar <viresh.kumar@linaro.org> [for sp805_wdt]
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> [for ts72xx_wdt]
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: Drop unnecessary include of miscdevice.h

After commit 487722cf2 (watchdog: Get rid of MODULE_ALIAS_MISCDEV
statements) the affected drivers no longer need to include miscdevice.h.
Only exception is rt2880_wdt.c which never needed it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: Get rid of MODULE_ALIAS_MISCDEV statements

I just can't find any value in MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR)
and MODULE_ALIAS_MISCDEV(TEMP_MINOR) statements.

Either the device is enumerated and the driver already has a module
alias (e.g. PCI, USB etc.) that will get the right driver loaded
automatically.

Or the device is not enumerated and loading its driver will lead to
more or less intrusive hardware poking. Such hardware poking should be
limited to a bare minimum, so the user should really decide which
drivers should be tried and in what order. Trying them all in
arbitrary order can't do any good.

On top of that, loading that many drivers at once bloats the kernel
log. Also many drivers will stay loaded afterward, bloating the output
of "lsmod" and wasting memory. Some modules (cs5535_mfgpt which gets
loaded as a dependency) can't even be unloaded!

If defining char-major-10-130 is needed then it should happen in
user-space.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Cc: Jim Cromie <jim.cromie@gmail.com>

watchdog: Add Broadcom BCM2835 watchdog timer driver

This adds a driver for watchdog timer hardware present on Broadcom BCM2835 SoC,
used in Raspberry Pi and Roku 2 devices.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: linux-rpi-kernel@lists.infradead.org
Cc: linux-watchdog@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org