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Commit 014d694e authored by Wim Van Sebroeck's avatar Wim Van Sebroeck
Browse files

watchdog: WatchDog Timer Driver Core - Add WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT ioctl 



This part add's the WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT 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 234445b4

Documentation/watchdog/watchdog-kernel-api.txt

+10 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ struct watchdog_device { 
	const struct watchdog_info *info;

	const struct watchdog_ops *ops;

	unsigned int bootstatus;

	unsigned int timeout;

	void *driver_data;

	unsigned long status;

};
@@ -50,6 +51,7 @@ It contains following fields: 
* info: a pointer to a watchdog_info structure. This structure gives some

  additional information about the watchdog timer itself. (Like it's unique name)

* ops: a pointer to the list of watchdog operations that the watchdog supports.

* timeout: the watchdog timer's timeout value (in seconds).

* bootstatus: status of the device after booting (reported with watchdog

  WDIOF_* status bits).

* driver_data: a pointer to the drivers private data of a watchdog device.
@@ -70,6 +72,7 @@ struct watchdog_ops { 
	/* optional operations */

	int (*ping)(struct watchdog_device *);

	unsigned int (*status)(struct watchdog_device *);

	int (*set_timeout)(struct watchdog_device *, unsigned int);

};



It is important that you first define the module owner of the watchdog timer
@@ -107,6 +110,13 @@ they are supported. These optional routines/operations are: 
  info structure).

* status: this routine checks the status of the watchdog timer device. The

  status of the device is reported with watchdog WDIOF_* status flags/bits.

* set_timeout: this routine checks and changes the timeout of the watchdog

  timer device. It returns 0 on success, -EINVAL for "parameter out of range"

  and -EIO for "could not write value to the watchdog". On success the timeout

  value of the watchdog_device will be changed to the value that was just used

  to re-program the watchdog timer device.

  (Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the

  watchdog's info structure).



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

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

drivers/watchdog/watchdog_dev.c

+20 −0
Original line number Diff line number Diff line
@@ -190,6 +190,26 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd, 
			return -EOPNOTSUPP;

		watchdog_ping(wdd);

		return 0;

	case WDIOC_SETTIMEOUT:

		if ((wdd->ops->set_timeout == NULL) ||

		    !(wdd->info->options & WDIOF_SETTIMEOUT))

			return -EOPNOTSUPP;

		if (get_user(val, p))

			return -EFAULT;

		err = wdd->ops->set_timeout(wdd, val);

		if (err < 0)

			return err;

		wdd->timeout = val;

		/* If the watchdog is active then we send a keepalive ping

		 * to make sure that the watchdog keep's running (and if

		 * possible that it takes the new timeout) */

		watchdog_ping(wdd);

		/* Fall */

	case WDIOC_GETTIMEOUT:

		/* timeout == 0 means that we don't know the timeout */

		if (wdd->timeout == 0)

			return -EOPNOTSUPP;

		return put_user(wdd->timeout, p);

	default:

		return -ENOTTY;

	}

include/linux/watchdog.h

+4 −0
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ struct watchdog_device; 
 * @stop:	The routine for stopping the watchdog device.

 * @ping:	The routine that sends a keepalive ping to the watchdog device.

 * @status:	The routine that shows the status of the watchdog device.

 * @set_timeout:The routine for setting the watchdog devices timeout value.

 *

 * The watchdog_ops structure contains a list of low-level operations

 * that control a watchdog device. It also contains the module that owns
@@ -83,6 +84,7 @@ struct watchdog_ops { 
	/* optional operations */

	int (*ping)(struct watchdog_device *);

	unsigned int (*status)(struct watchdog_device *);

	int (*set_timeout)(struct watchdog_device *, unsigned int);

};



/** struct watchdog_device - The structure that defines a watchdog device
@@ -90,6 +92,7 @@ struct watchdog_ops { 
 * @info:	Pointer to a watchdog_info structure.

 * @ops:	Pointer to the list of watchdog operations.

 * @bootstatus:	Status of the watchdog device at boot.

 * @timeout:	The watchdog devices timeout value.

 * @driver-data:Pointer to the drivers private data.

 * @status:	Field that contains the devices internal status bits.

 *
@@ -103,6 +106,7 @@ struct watchdog_device { 
	const struct watchdog_info *info;

	const struct watchdog_ops *ops;

	unsigned int bootstatus;

	unsigned int timeout;

	void *driver_data;

	unsigned long status;

/* Bit numbers for status flags */