watchdog: WatchDog Timer Driver Core - Add basic framework

The WatchDog Timer Driver Core is a framework
that contains the common code for all watchdog-driver's.
It also introduces a watchdog device structure and the
operations that go with it.

This is the introduction of this framework. This part
supports the minimal watchdog userspace API (or with
other words: the functionality to use /dev/watchdog's
open, release and write functionality as defined in
the simplest watchdog API). Extra functionality will
follow in the next set of patches.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
This commit is contained in:
Wim Van Sebroeck
2011-07-22 18:55:18 +00:00
parent 5efc7a6222
commit 43316044d4
8 changed files with 566 additions and 0 deletions

View File

@@ -59,6 +59,67 @@ struct watchdog_info {
#define WATCHDOG_NOWAYOUT 0
#endif
struct watchdog_ops;
struct watchdog_device;
/** struct watchdog_ops - The watchdog-devices operations
*
* @owner: The module owner.
* @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.
*
* The watchdog_ops structure contains a list of low-level operations
* that control a watchdog device. It also contains the module that owns
* these operations. The start and stop function are mandatory, all other
* functions are optonal.
*/
struct watchdog_ops {
struct module *owner;
/* mandatory operations */
int (*start)(struct watchdog_device *);
int (*stop)(struct watchdog_device *);
/* optional operations */
int (*ping)(struct watchdog_device *);
};
/** struct watchdog_device - The structure that defines a watchdog device
*
* @info: Pointer to a watchdog_info structure.
* @ops: Pointer to the list of watchdog operations.
* @driver-data:Pointer to the drivers private data.
* @status: Field that contains the devices internal status bits.
*
* The watchdog_device structure contains all information about a
* watchdog timer device.
*
* The driver-data field may not be accessed directly. It must be accessed
* via the watchdog_set_drvdata and watchdog_get_drvdata helpers.
*/
struct watchdog_device {
const struct watchdog_info *info;
const struct watchdog_ops *ops;
void *driver_data;
unsigned long status;
/* Bit numbers for status flags */
#define WDOG_DEV_OPEN 1 /* Opened via /dev/watchdog ? */
};
/* Use the following functions to manipulate watchdog driver specific data */
static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data)
{
wdd->driver_data = data;
}
static inline void *watchdog_get_drvdata(struct watchdog_device *wdd)
{
return wdd->driver_data;
}
/* drivers/watchdog/core/watchdog_core.c */
extern int watchdog_register_device(struct watchdog_device *);
extern void watchdog_unregister_device(struct watchdog_device *);
#endif /* __KERNEL__ */
#endif /* ifndef _LINUX_WATCHDOG_H */