watchdog: rti_wdt: Drop runtime pm reference count when watchdog is unused

Call runtime_pm_put*() if watchdog is not already started during probe and re
enable it in watchdog start as required.

On K3 SoCs, watchdogs and their corresponding CPUs are under same
power-domain, so if the reference count of unused watchdogs aren't
dropped, it will lead to CPU hotplug failures as Device Management
firmware won't allow to turn off the power-domain due to dangling
reference count.

Fixes: 2d63908bdbfb ("watchdog: Add K3 RTI watchdog support")
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Tested-by: Manorit Chawdhry <m-chawdhry@ti.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20231213140110.938129-1-vigneshr@ti.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog:rit_wdt: Add support for WDIOF_CARDRESET

This patch adds the WDIOF_CARDRESET support for the platform watchdog
whose hardware does not support this feature, to know if the board
reboot is due to a watchdog reset.

This is done via reserved memory(RAM), which indicates if specific
info saved, triggering the watchdog reset in last boot.

Signed-off-by: Li Hua Qian <huaqian.li@siemens.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230718021007.1338761-4-huaqian.li@siemens.com
[groeck: vaddr == NULL --> !vaddr]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: rti: 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: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230303213716.2123717-28-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: rti-wdt:using the pm_runtime_resume_and_get to simplify the code

Using pm_runtime_resume_and_get() to instade of pm_runtime_get_sync
and pm_runtime_put_noidle.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220802074643.1648660-1-ye.xingchen@zte.com.cn
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: rti-wdt: Fix pm_runtime_get_sync() error checking

If the device is already in a runtime PM enabled state
pm_runtime_get_sync() will return 1, so a test for negative
value should be used to check for errors.

Fixes: 2d63908bdbfb ("watchdog: Add K3 RTI watchdog support")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220412070824.23708-1-linmq006@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: rti_wdt: Fix calculation and evaluation of preset heartbeat

This ensures that the same value is read back as was eventually
programmed when using seconds as accuracy. Even then, comparing the more
precise heartbeat_ms against heartbeat in seconds will almost never
provide a match and will needlessly raise a warning. Fix by comparing
apples to apples.

Tested in combination with U-Boot as watchdog starter.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/6a4b54ac-9588-e172-c4c7-b91d524a851e@siemens.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: rti-wdt: Add missing pm_runtime_disable() in probe function

If the probe fails, we should use pm_runtime_disable() to balance
pm_runtime_enable().

Fixes: 2d63908bdbfb ("watchdog: Add K3 RTI watchdog support")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220105092114.23932-1-linmq006@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: rti-wdt: Make use of the helper function devm_platform_ioremap_resource()

Use the devm_platform_ioremap_resource() helper instead of
calling platform_get_resource() and devm_ioremap_resource()
separately

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210907074237.2808-1-caihuoqing@baidu.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: rti-wdt: fix reference leak in rti_wdt_probe

pm_runtime_get_sync() will increment pm usage counter even it
failed. Forgetting to call pm_runtime_put_noidle will result
in reference leak in rti_wdt_probe, so we should fix it.

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20201030154909.100023-1-zhangqilong3@huawei.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: rti: Simplify with dev_err_probe()

Common pattern of handling deferred probe can be simplified with
dev_err_probe(). Less code and the error value gets printed.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200901153141.18960-3-krzk@kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: rti-wdt: balance pm runtime enable calls

PM runtime should be disabled in the fail path of probe and when
the driver is removed.

Fixes: 2d63908bdbfb ("watchdog: Add K3 RTI watchdog support")
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200717132958.14304-5-t-kristo@ti.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: rti-wdt: attach to running watchdog during probe

If the RTI watchdog is running already during probe, the driver must
configure itself to match the HW. Window size and timeout is probed from
hardware, and the last keepalive ping is adjusted to match it also.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200717132958.14304-4-t-kristo@ti.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: Add K3 RTI watchdog support

Texas Instruments K3 SoCs contain an RTI (Real Time Interrupt) module
which can be used as a watchdog. This IP provides a support for
windowed watchdog mode, in which the watchdog must be petted within
a certain time window. If it is petted either too soon, or too late,
a watchdog error will be triggered.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200312095808.19907-4-t-kristo@ti.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>