11  *	by all the watchdog timer drivers.
14  *	misc device: /dev/watchdog.
40 #include <linux/watchdog.h>	/* For watchdog specific items */
45 /* make sure we only register one /dev/watchdog device */
47 /* the watchdog device behind /dev/watchdog */
51  *	watchdog_ping: ping the watchdog.
52  *	@wddev: the watchdog device to ping
54  *	If the watchdog has no own ping operation then it needs to be
57  *	We only ping when the watchdog device is running.
64 			return wddev->ops->ping(wddev);  /* ping the watchdog */  in watchdog_ping()
66 			return wddev->ops->start(wddev); /* restart watchdog */  in watchdog_ping()
72  *	watchdog_start: wrapper to start the watchdog.
73  *	@wddev: the watchdog device to start
75  *	Start the watchdog if it is not active and mark it active.
95  *	watchdog_stop: wrapper to stop the watchdog.
96  *	@wddev: the watchdog device to stop
98  *	Stop the watchdog if it is still active and unmark it active.
101  *	If the 'nowayout' feature was set, the watchdog cannot be stopped.
109 		pr_info("%s: nowayout prevents watchdog to be stopped!\n",  in watchdog_stop()
125  *	watchdog_write: writes to the watchdog.
131  *	A write to a watchdog device is defined as a keepalive ping.
133  *	off the watchdog (if 'nowayout' is not set).
159 	/* someone wrote to us, so we send the watchdog a keepalive ping */  in watchdog_write()
166  *	watchdog_ioctl: handle the different ioctl's for the watchdog device.
168  *	@cmd: watchdog command
171  *	The watchdog API defines a common set of functions for all watchdogs
230 		/* If the watchdog is active then we send a keepalive ping  in watchdog_ioctl()
231 		 * to make sure that the watchdog keep's running (and if  in watchdog_ioctl()
246  *	watchdog_open: open the /dev/watchdog device.
250  *	When the /dev/watchdog device gets opened, we start the watchdog.
251  *	Watch out: the /dev/watchdog device is single open, so we make sure
259 	/* the watchdog is single open! */  in watchdog_open()
264 	 * If the /dev/watchdog device is open, we don't want the module  in watchdog_open()
274 	/* dev/watchdog is a virtual (and thus non-seekable) filesystem */  in watchdog_open()
285  *      watchdog_release: release the /dev/watchdog device.
289  *	This is the code for when /dev/watchdog gets closed. We will only
290  *	stop the watchdog when we have received the magic char (and nowayout
291  *	was not set), else the watchdog will keep running.
299 	 * We only stop the watchdog if we received the magic character  in watchdog_release()
307 	/* If the watchdog was not stopped, send a keepalive ping */  in watchdog_release()
309 		pr_crit("%s: watchdog did not stop!\n", wdd->info->identity);  in watchdog_release()
316 	/* make sure that /dev/watchdog can be re-opened */  in watchdog_release()
332 	.name		= "watchdog",
338  *	@watchdog: watchdog device
340  *	Register a watchdog device as /dev/watchdog. /dev/watchdog
344 int watchdog_dev_register(struct watchdog_device *watchdog)  in watchdog_dev_register()  argument
348 	/* Only one device can register for /dev/watchdog */  in watchdog_dev_register()
350 		pr_err("only one watchdog can use /dev/watchdog.\n");  in watchdog_dev_register()
354 	wdd = watchdog;  in watchdog_dev_register()
359 			watchdog->info->identity, WATCHDOG_MINOR, err);  in watchdog_dev_register()
373  *	@watchdog: watchdog device
375  *	Deregister the /dev/watchdog device.
378 int watchdog_dev_unregister(struct watchdog_device *watchdog)  in watchdog_dev_unregister()  argument
380 	/* Check that a watchdog device was registered in the past */  in watchdog_dev_unregister()
384 	/* We can only unregister the watchdog device that was registered */  in watchdog_dev_unregister()
385 	if (watchdog != wdd) {  in watchdog_dev_unregister()
386 		pr_err("%s: watchdog was not registered as /dev/watchdog.\n",  in watchdog_dev_unregister()
387 			watchdog->info->identity);  in watchdog_dev_unregister()