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Commit 234445b4 authored by Wim Van Sebroeck's avatar Wim Van Sebroeck
Browse files

watchdog: WatchDog Timer Driver Core - Add WDIOC_SETOPTIONS ioctl 



This part add's the WDIOC_SETOPTIONS ioctl functionality
to the WatchDog Timer Driver Core framework.

Signed-off-by: default avatarAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarWolfram Sang <w.sang@pengutronix.de>
parent c2dc00e4

Documentation/watchdog/watchdog-kernel-api.txt

+7 −2
Original line number Diff line number Diff line
@@ -56,8 +56,9 @@ It contains following fields: 
  This data should only be accessed via the watchdog_set_drvadata and

  watchdog_get_drvdata routines.

* status: this field contains a number of status bits that give extra

  information about the status of the device (Like: is the device opened via

  the /dev/watchdog interface or not, ...).

  information about the status of the device (Like: is the watchdog timer

  running/active, is the device opened via the /dev/watchdog interface or not,

  ...).



The list of watchdog operations is defined as:
@@ -109,6 +110,10 @@ they are supported. These optional routines/operations are: 


The status bits should (preferably) be set with the set_bit and clear_bit alike

bit-operations. The status bits that are defined are:

* WDOG_ACTIVE: this status bit indicates whether or not a watchdog timer device

  is active or not. When the watchdog is active after booting, then you should

  set this status bit (Note: when you register the watchdog timer device with

  this bit set, then opening /dev/watchdog will skip the start operation)

* WDOG_DEV_OPEN: this status bit shows whether or not the watchdog device

  was opened via /dev/watchdog.

  (This bit should only be used by the WatchDog Timer Driver Core).

drivers/watchdog/watchdog_dev.c

+72 −7
Original line number Diff line number Diff line
@@ -54,14 +54,64 @@ static struct watchdog_device *wdd; 
 *	If the watchdog has no own ping operation then it needs to be

 *	restarted via the start operation. This wrapper function does

 *	exactly that.

 *	We only ping when the watchdog device is running.

 */



static int watchdog_ping(struct watchdog_device *wddev)

{

	if (test_bit(WDOG_ACTIVE, &wdd->status)) {

		if (wddev->ops->ping)

			return wddev->ops->ping(wddev);  /* ping the watchdog */

		else

		return wddev->ops->start(wddev); /* restart the watchdog */

			return wddev->ops->start(wddev); /* restart watchdog */

	}

	return 0;

}



/*

 *	watchdog_start: wrapper to start the watchdog.

 *	@wddev: the watchdog device to start

 *

 *	Start the watchdog if it is not active and mark it active.

 *	This function returns zero on success or a negative errno code for

 *	failure.

 */



static int watchdog_start(struct watchdog_device *wddev)

{

	int err;



	if (!test_bit(WDOG_ACTIVE, &wdd->status)) {

		err = wddev->ops->start(wddev);

		if (err < 0)

			return err;



		set_bit(WDOG_ACTIVE, &wdd->status);

	}

	return 0;

}



/*

 *	watchdog_stop: wrapper to stop the watchdog.

 *	@wddev: the watchdog device to stop

 *

 *	Stop the watchdog if it is still active and unmark it active.

 *	This function returns zero on success or a negative errno code for

 *	failure.

 */



static int watchdog_stop(struct watchdog_device *wddev)

{

	int err;



	if (test_bit(WDOG_ACTIVE, &wdd->status)) {

		err = wddev->ops->stop(wddev);

		if (err < 0)

			return err;



		clear_bit(WDOG_ACTIVE, &wdd->status);

	}

	return 0;

}



/*
@@ -110,6 +160,7 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd, 
	void __user *argp = (void __user *)arg;

	int __user *p = argp;

	unsigned int val;

	int err;



	switch (cmd) {

	case WDIOC_GETSUPPORT:
@@ -120,6 +171,20 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd, 
		return put_user(val, p);

	case WDIOC_GETBOOTSTATUS:

		return put_user(wdd->bootstatus, p);

	case WDIOC_SETOPTIONS:

		if (get_user(val, p))

			return -EFAULT;

		if (val & WDIOS_DISABLECARD) {

			err = watchdog_stop(wdd);

			if (err < 0)

				return err;

		}

		if (val & WDIOS_ENABLECARD) {

			err = watchdog_start(wdd);

			if (err < 0)

				return err;

		}

		return 0;

	case WDIOC_KEEPALIVE:

		if (!(wdd->info->options & WDIOF_KEEPALIVEPING))

			return -EOPNOTSUPP;
@@ -155,7 +220,7 @@ static int watchdog_open(struct inode *inode, struct file *file) 
	if (!try_module_get(wdd->ops->owner))

		goto out;



	err = wdd->ops->start(wdd);

	err = watchdog_start(wdd);

	if (err < 0)

		goto out_mod;
@@ -181,8 +246,8 @@ static int watchdog_release(struct inode *inode, struct file *file) 
{

	int err;



	err = wdd->ops->stop(wdd);

	if (err != 0) {

	err = watchdog_stop(wdd);

	if (err < 0) {

		pr_crit("%s: watchdog did not stop!\n", wdd->info->identity);

		watchdog_ping(wdd);

	}

include/linux/watchdog.h

+1 −0
Original line number Diff line number Diff line
@@ -106,6 +106,7 @@ struct watchdog_device { 
	void *driver_data;

	unsigned long status;

/* Bit numbers for status flags */

#define WDOG_ACTIVE		0	/* Is the watchdog running/active */

#define WDOG_DEV_OPEN		1	/* Opened via /dev/watchdog ? */

};