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path: root/drivers/watchdog/watchdog_core.h
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2021-06-21watchdog: Add hrtimer-based pretimeout featureCurtis Klein1-0/+48
This adds the option to use a hrtimer to generate a watchdog pretimeout event for hardware watchdogs that do not natively support watchdog pretimeouts. With this enabled, all watchdogs will appear to have pretimeout support in userspace. If no pretimeout value is set, there will be no change in the watchdog's behavior. If a pretimeout value is set for a specific watchdog that does not have built-in pretimeout support, a timer will be started that should fire at the specified time before the watchdog timeout would occur. When the watchdog is successfully pinged, the timer will be restarted. If the timer is allowed to fire it will generate a pretimeout event. However because a software timer is used, it may not be able to fire in every circumstance. If the watchdog does support a pretimeout natively, that functionality will be used instead of the hrtimer. The general design of this feaure was inspired by the software watchdog, specifically its own pretimeout implementation. However the software watchdog and this feature are completely independent. They can be used together; with or without CONFIG_SOFT_WATCHDOG_PRETIMEOUT enabled. The main advantage of using the hrtimer pretimeout with a hardware watchdog, compared to running the software watchdog with a hardware watchdog, is that if the hardware watchdog driver is unable to ping the watchdog (e.g. due to a bus or communication error), then the hrtimer pretimeout would still fire whereas the software watchdog would not. Signed-off-by: Curtis Klein <curtis.klein@hpe.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/1612383090-27110-1-git-send-email-curtis.klein@hpe.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-07-08watchdog: convert remaining drivers to use SPDX license identifierGuenter Roeck1-5/+1
This gets rid of the unnecessary license boilerplate, and avoids having to deal with individual patches one by one. No functional changes. Reviewed-by: Jerry Hoemann <jerry.hoemann@hpe.com> Acked-by: Sylvain Lemieux <slemieux.tyco@gmail.com> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com> Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2015-12-29watchdog: Create watchdog device in watchdog_dev.cGuenter Roeck1-2/+2
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: Use static struct class watchdog_class in stead of pointerPratyush Anand1-1/+1
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>
2012-05-30watchdog: Add multiple device supportAlan Cox1-0/+4
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: watchdog_core.h: make functions externWim Van Sebroeck1-2/+2
Make the functions in watchdog_core.h extern like it should. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: correct the name of the watchdog_core inlude fileWim Van Sebroeck1-0/+33
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>