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path: root/drivers/watchdog/watchdog_core.c
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2017-11-17drivers/watchdog: make use of devm_register_reboot_notifier()Andrey Smirnov
Save a bit of cleanup code by leveraging newly added devm_register_reboot_notifier(). [akpm@linux-foundation.org: small cleanup: avoid 80-col tricks] Link: http://lkml.kernel.org/r/20170411160615.9784-1-andrew.smirnov@gmail.com Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Acked-by: Guenter Roeck <linux@roeck-us.net> Cc: Chris Healy <cphealy@gmail.com> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-23watchdog: core: Fix devres_alloc() allocation sizeGuenter Roeck
Coverity reports: Passing argument 152UL /* sizeof (*wdd) */ to function __devres_alloc_node and then casting the return value to struct watchdog_device ** is suspicious. Allocation size needs to be sizeof(*rcwdd), not sizeof(*wdd). Fixes: 83fbae5a148c ("watchdog: Add a device managed API for ...") Cc: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-07-17watchdog: skip min and max timeout validity check when max_hw_heartbeat_ms ↵Pratyush Anand
is defined When max_hw_heartbeat_ms has a none zero value, max_timeout is not used. So it's value can be 0. In such case if a driver uses min_timeout functionality, then check will always fail. This patch fixes above issue. Signed-off-by: Pratyush Anand <panand@redhat.com> Signed-off-by: Fu Wei <fu.wei@linaro.org> 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>
2016-07-17watchdog: Add a device managed API for watchdog_register_device()Neil Armstrong
This helps in reducing code in .remove callbacks and sometimes dropping .remove callbacks entirely. Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-05-25Merge git://www.linux-watchdog.org/linux-watchdogLinus Torvalds
Pull watchdog updates from Wim Van Sebroeck: - add support for Fintek F81865 Super-IO chip - add support for watchdogs (RWDT and SWDT) found on RCar Gen3 based SoCs from Renesas - octeon: Handle the FROZEN hot plug notifier actions - f71808e_wdt fixes and cleanups - some small improvements in code and documentation * git://www.linux-watchdog.org/linux-watchdog: MAINTAINERS: Add file patterns for watchdog device tree bindings Documentation: Add ebc-c384_wdt watchdog-parameters.txt entry watchdog: shwdt: Use setup_timer() watchdog: cpwd: Use setup_timer() arm64: defconfig: enable Renesas Watchdog Timer watchdog: renesas-wdt: add driver watchdog: remove error message when unable to allocate watchdog device watchdog: f71808e_wdt: Fix WDTMOUT_STS register read watchdog: f71808e_wdt: Fix typo watchdog: f71808e_wdt: Add F81865 support watchdog: sp5100_tco: properly check for new register layouts watchdog: core: Fix circular locking dependency watchdog: core: fix trivial typo in a comment watchdog: hpwdt: Adjust documentation to match latest kernel module parameters. watchdog: imx2_wdt: add external reset support via dt prop watchdog: octeon: Handle the FROZEN hot plug notifier actions. watchdog: qcom: Report reboot reason
2016-05-14watchdog: core: fix trivial typo in a commentWolfram Sang
Let's have balanced round brackets. 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@iguana.be>
2016-04-28treewide: Fix typos in printkMasanari Iida
This patch fix spelling typos in printk from various part of the codes. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-03-16watchdog: Make stop function optionalGuenter Roeck
Not all hardware watchdogs can be stopped. The driver for such watchdogs would typically only set the WATCHDOG_HW_RUNNING flag in its stop function. Make the stop function optional and set WATCHDOG_HW_RUNNING in the watchdog core if it is not provided. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-03-01watchdog: Add 'action' and 'data' parameters to restart handler callbackGuenter Roeck
The 'action' (or restart mode) and data parameters may be used by restart handlers, so they should be passed to the restart callback functions. Cc: Sylvain Lemieux <slemieux@tycoint.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-01-11watchdog: Drop pointer to watchdog device from struct watchdog_deviceGuenter Roeck
The lifetime of the watchdog device pointer is different from the lifetime of its character device. Remove it entirely to avoid race conditions. Signed-off-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>
2015-12-29watchdog: Separate and maintain variables based on variable lifetimeGuenter Roeck
All variables required by the watchdog core to manage a watchdog are currently stored in struct watchdog_device. The lifetime of those variables is determined by the watchdog driver. However, the lifetime of variables used by the watchdog core differs from the lifetime of struct watchdog_device. To remedy this situation, watchdog drivers can implement ref and unref callbacks, to be used by the watchdog core to lock struct watchdog_device in memory. While this solves the immediate problem, it depends on watchdog drivers to actually implement the ref/unref callbacks. This is error prone, often not implemented in the first place, or not implemented correctly. To solve the problem without requiring driver support, split the variables in struct watchdog_device into two data structures - one for variables associated with the watchdog driver, one for variables associated with the watchdog core. With this approach, the watchdog core can keep track of its variable lifetime and no longer depends on ref/unref callbacks in the driver. As a side effect, some of the variables originally in struct watchdog_driver are now private to the watchdog core and no longer visible in watchdog drivers. As a side effect of the changes made, an ioctl will now always fail with -ENODEV after a watchdog device was unregistered with the character device still open. Previously, it would only fail with -ENODEV in some situations. Also, ioctl operations are now atomic from driver perspective. With this change, it is now guaranteed that the driver will not unregister a watchdog between a timeout change and the subsequent ping. The 'ref' and 'unref' callbacks in struct watchdog_driver are no longer used and marked as deprecated. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-12-29watchdog: Create watchdog device in watchdog_dev.cGuenter Roeck
The watchdog character device is currently created in watchdog_dev.c, and the watchdog device in watchdog_core.c. This results in cross-dependencies, since device creation needs to know the watchdog character device number as well as the watchdog class, both of which reside in watchdog_dev.c. Create the watchdog device in watchdog_dev.c to simplify the code. Inspired by earlier patch set from Damien Riegel. Cc: Damien Riegel <damien.riegel@savoirfairelinux.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-12-27watchdog: Read device status through sysfs attributesPratyush Anand
This patch adds following attributes to watchdog device's sysfs interface to read its different status. * state - reads whether device is active or not * identity - reads Watchdog device's identity string. * timeout - reads current timeout. * timeleft - reads timeleft before watchdog generates a reset * bootstatus - reads status of the watchdog device at boot * status - reads watchdog device's internal status bits * nowayout - reads whether nowayout feature was set or not Testing with iTCO_wdt: # cd /sys/class/watchdog/watchdog1/ # ls bootstatus dev device identity nowayout power state subsystem timeleft timeout uevent # cat identity iTCO_wdt # cat timeout 30 # cat state inactive # echo > /dev/watchdog1 # cat timeleft 26 # cat state active # cat bootstatus 0 # cat nowayout 0 Signed-off-by: Pratyush Anand <panand@redhat.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>
2015-12-27watchdog: Use static struct class watchdog_class in stead of pointerPratyush Anand
We need few sysfs attributes to know different status of a watchdog device. To do that, we need to associate .dev_groups with watchdog_class. So convert it from pointer to static. Putting this static struct in watchdog_dev.c, so that static device attributes defined in that file can be attached to it. Signed-off-by: Pratyush Anand <panand@redhat.com> Suggested-by: Guenter Roeck <linux@roeck-us.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>
2015-12-13watchdog: core: add reboot notifier supportDamien Riegel
Many watchdog drivers register a reboot notifier in order to stop the watchdog on system reboot. Thus we can factorize this code in the watchdog core. For that purpose, a new notifier block is added in watchdog_device for internal use only, as well as a new watchdog_stop_on_reboot helper function. If this helper is called, watchdog core registers the related notifier block and will stop the watchdog when SYS_HALT or SYS_DOWN is received. Since this operation can be critical on some platforms, abort the device registration if the reboot notifier registration fails. Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com> Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-12-13watchdog: core: add restart handler supportDamien Riegel
Many watchdog drivers implement the same code to register a restart handler. This patch provides a generic way to set such a function. The patch adds a new restart watchdog operation. If a restart priority greater than 0 is needed, the driver can call watchdog_set_restart_priority to set it. Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-10-27watchdog: watchdog_dev: Use device tree alias for naming watchdogsJustin Chen
Currently there is no way to easily differentiate multiple watchdog devices. The watchdogs are named by the order they are probed. 1st probed watchdog: /dev/watchdog0 2nd probed watchdog: /dev/watchdog1 ... This change uses the alias of the watchdog device node for the name of the watchdog. aliases { watchdog0 = "/...../...." watchdog3 = "/..../....." watchdog2 = "/..../....." ... } This will translate to... /dev/watchdog0 /dev/watchdog3 /dev/watchdog2 v2 Assign alias number to id in watchdog_core instead of watchdog_dev. If failed to get id, fallback to original ida_simple_get call. Signed-off-by: Justin Chen <justinpopo6@gmail.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-06-29watchdog: watchdog_core: Add watchdog registration deferral mechanismJean-Baptiste Theou
Currently, watchdog subsystem require the misc subsystem to register a watchdog. This may not be the case in case of an early registration of a watchdog, which can be required when the watchdog cannot be disabled. This patch introduces a deferral mechanism to remove this requirement. Signed-off-by: Jean-Baptiste Theou <jtheou@adeneo-embedded.us> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2014-01-28watchdog: core: Make dt "timeout-sec" property work on drivers w/out min/maxDoug Anderson
It is valid for a watchdog driver to have 0 for a "min" and "max" timeout if the driver doesn't need the core to enforce the concepts of min and max. The s3c2410_wdt driver is one such driver. Specifically it can be hard for that driver to come up with a static "max" on all platforms without a lot more information since the input clock on S3C2410 and S3C2440 can change with DVFS. As written, watchdog_init_timeout() will not ever read "timeout-sec" on these drivers since watchdog_timeout_invalid() will _never_ return true. Change to not consider a timeout_parm of 0 as valid even if min/max aren't specified by the driver. Also handle the case when there is no min/max and no "timeout-sec" property. Signed-off-by: Doug Anderson <dianders@chromium.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2013-11-17watchdog: watchdog_core: Fix a trivial typoSachin Kamat
Fixed a trivial typo. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2013-03-01watchdog: core: dt: add support for the timeout-sec dt propertyFabio Porcedda
Add support for watchdog drivers to initialize/set the timeout field of the watchdog_device structure. The timeout field is initialised either with the module timeout parameter value (if valid) or with the timeout-sec dt property (if valid). If both are invalid the initial value is unchanged. Signed-off-by: Fabio Porcedda <fabio.porcedda@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-09-10watchdog: move the dereference below the NULL testWei Yongjun
The dereference should be moved below the NULL test. spatch with a semantic match is used to found this. (http://coccinelle.lip6.fr/) Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: Add Locking supportHans de Goede
This patch fixes some potential multithreading issues, despite only allowing one process to open the /dev/watchdog device, we can still get called multiple times at the same time, since a program could be using thread, or could share the fd after a fork. This causes 2 potential problems: 1) watchdog_start / open do an unlocked test_n_set / test_n_clear, if these 2 race, the watchdog could be stopped while the active bit indicates it is running or visa versa. 2) Most watchdog_dev drivers probably assume that only one watchdog-op will get called at a time, this is not necessary true atm. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: create all the proper device filesAlan Cox
Create the watchdog class and it's associated devices. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: Add multiple device supportAlan Cox
We keep the old /dev/watchdog interface file for the first watchdog via miscdev. This is basically a cut and paste of the relevant interface code from the rtc driver layer tweaked for watchdog. Revised to fix problems noted by Hans de Goede Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: correct the name of the watchdog_core inlude fileWim Van Sebroeck
The watchdog_core include file should have been named watchdog_core.h and not watchdog_dev.h . Correct this. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27watchdog: Use pr_<fmt> and pr_<level>Joe Perches
Use the current logging styles. Make sure all output has a prefix. Add missing newlines. Remove now unnecessary PFX, NAME, and miscellaneous other #defines. Coalesce formats. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2011-07-28watchdog: WatchDog Timer Driver Core - Add minimum and max timeoutWim Van Sebroeck
Add min_timeout (minimum timeout) and max_timeout values so that the framework can check if the new timeout value is between the minimum and maximum timeout values. If both values are 0, then the framework will leave the check for the watchdog device driver itself. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-07-28watchdog: WatchDog Timer Driver Core - Add basic frameworkWim Van Sebroeck
The WatchDog Timer Driver Core is a framework that contains the common code for all watchdog-driver's. It also introduces a watchdog device structure and the operations that go with it. This is the introduction of this framework. This part supports the minimal watchdog userspace API (or with other words: the functionality to use /dev/watchdog's open, release and write functionality as defined in the simplest watchdog API). Extra functionality will follow in the next set of patches. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>