Some hardware implements reboot through its watchdog hardware,
for example by triggering a watchdog timeout. Platform specific
code starts to spread into watchdog drivers, typically by setting
pointers to a callback functions which is then called from the
platform reset handler.
To simplify code and provide a unified API to trigger reboots by
watchdog drivers, provide a single API to trigger such reboots
through the watchdog subsystem.
Acked-by: Maxime Ripard <maxime.rip...@free-electrons.com>
Acked-by: Arnd Bergmann <a...@arndb.de>
Tested-by: Jonas Jensen <jonas.jen...@gmail.com>
Acked-by: Heiko Stuebner <he...@sntech.de>
Signed-off-by: Guenter Roeck <li...@roeck-us.net>
---
v2: Remove unnecessary check for ops in reboot function
drivers/watchdog/watchdog_core.c | 15 +++++++++++++++
include/linux/watchdog.h | 11 +++++++++++
2 files changed, 26 insertions(+)
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index cec9b55..edfd9c5 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -43,6 +43,15 @@
static DEFINE_IDA(watchdog_ida);
static struct class *watchdog_class;
+static struct watchdog_device *wdd_reboot_dev;
+
+void watchdog_do_reboot(enum reboot_mode mode, const char *cmd)
+{
+ if (wdd_reboot_dev)
+ wdd_reboot_dev->ops->reboot(wdd_reboot_dev, mode, cmd);
+}
+EXPORT_SYMBOL(watchdog_do_reboot);
+
static void watchdog_check_min_max_timeout(struct watchdog_device *wdd)
{
/*
@@ -162,6 +171,9 @@ int watchdog_register_device(struct watchdog_device *wdd)
return ret;
}
+ if (wdd->ops->reboot)
+ wdd_reboot_dev = wdd;
+
return 0;
}
EXPORT_SYMBOL_GPL(watchdog_register_device);
@@ -181,6 +193,9 @@ void watchdog_unregister_device(struct watchdog_device *wdd)
if (wdd == NULL)
return;
+ if (wdd == wdd_reboot_dev)
+ wdd_reboot_dev = NULL;
+
devno = wdd->cdev.dev;
ret = watchdog_dev_unregister(wdd);
if (ret)
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index 2a3038e..0d204af 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -12,6 +12,7 @@
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/cdev.h>
+#include <linux/reboot.h>
#include <uapi/linux/watchdog.h>
struct watchdog_ops;
@@ -23,6 +24,7 @@ struct watchdog_device;
* @start: The routine for starting the watchdog device.
* @stop: The routine for stopping the watchdog device.
* @ping: The routine that sends a keepalive ping to the watchdog device.
+ * @reboot: The routine for rebooting the system
* @status: The routine that shows the status of the watchdog device.
* @set_timeout:The routine for setting the watchdog devices timeout value.
* @get_timeleft:The routine that get's the time that's left before a reset.
@@ -42,6 +44,8 @@ struct watchdog_ops {
int (*stop)(struct watchdog_device *);
/* optional operations */
int (*ping)(struct watchdog_device *);
+ void (*reboot)(struct watchdog_device *, enum reboot_mode,
+ const char *);
unsigned int (*status)(struct watchdog_device *);
int (*set_timeout)(struct watchdog_device *, unsigned int);
unsigned int (*get_timeleft)(struct watchdog_device *);
@@ -142,4 +146,11 @@ extern int watchdog_init_timeout(struct watchdog_device
*wdd,
extern int watchdog_register_device(struct watchdog_device *);
extern void watchdog_unregister_device(struct watchdog_device *);
+#ifdef CONFIG_WATCHDOG_CORE
+extern void watchdog_do_reboot(enum reboot_mode mode, const char *cmd);
+#else
+static inline void watchdog_do_reboot(enum reboot_mode mode,
+ const char *cmd) { }
+#endif
+
#endif /* ifndef _LINUX_WATCHDOG_H */
--
1.9.1
--
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