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/*
* Generic watchdog defines. Derived from..
*
* Berkshire PC Watchdog Defines
* by Ken Hollis <khollis@bitgate.com>
*
*/
#ifndef _LINUX_WATCHDOG_H
#define _LINUX_WATCHDOG_H
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <uapi/linux/watchdog.h>
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.
* @status: The routine that shows the status of the watchdog device.
* @set_timeout:The routine for setting the watchdog devices timeout value (in seconds).
* @get_timeleft:The routine that gets the time left before a reset (in seconds).
* @ref: The ref operation for dyn. allocated watchdog_device structs
* @unref: The unref operation for dyn. allocated watchdog_device structs
* @ioctl: The routines that handles extra ioctl calls.
*
* 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 optional.
*/
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 *);
unsigned int (*status)(struct watchdog_device *);
int (*set_timeout)(struct watchdog_device *, unsigned int);
unsigned int (*get_timeleft)(struct watchdog_device *);
void (*ref)(struct watchdog_device *);
void (*unref)(struct watchdog_device *);
long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long);
};
/** struct watchdog_device - The structure that defines a watchdog device
*
* @id: The watchdog's ID. (Allocated by watchdog_register_device)
* @cdev: The watchdog's Character device.
* @dev: The device for our watchdog
* @parent: The parent bus device
* @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 (in seconds).
* @min_timeout:The watchdog devices minimum timeout value (in seconds).
* @max_timeout:The watchdog devices maximum timeout value (in seconds).
* @driver-data:Pointer to the drivers private data.
* @lock: Lock for watchdog core internal use only.
* @status: Field that contains the devices internal status bits.
* @deferred: entry in wtd_deferred_reg_list which is used to
* register early initialized watchdogs.
*
* 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.
*
* The lock field is for watchdog core internal use only and should not be
* touched.
*/
struct watchdog_device {
int id;
struct cdev cdev;
struct device *dev;
struct device *parent;
const struct watchdog_info *info;
const struct watchdog_ops *ops;
unsigned int bootstatus;
unsigned int timeout;
unsigned int min_timeout;
unsigned int max_timeout;
void *driver_data;
struct mutex lock;
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 ? */
#define WDOG_ALLOW_RELEASE 2 /* Did we receive the magic char ? */
#define WDOG_NO_WAY_OUT 3 /* Is 'nowayout' feature set ? */
#define WDOG_UNREGISTERED 4 /* Has the device been unregistered */
struct list_head deferred;
};
#define WATCHDOG_NOWAYOUT IS_BUILTIN(CONFIG_WATCHDOG_NOWAYOUT)
#define WATCHDOG_NOWAYOUT_INIT_STATUS (WATCHDOG_NOWAYOUT << WDOG_NO_WAY_OUT)
/* Use the following function to check whether or not the watchdog is active */
static inline bool watchdog_active(struct watchdog_device *wdd)
{
return test_bit(WDOG_ACTIVE, &wdd->status);
}
/* Use the following function to set the nowayout feature */
static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout)
{
if (nowayout)
set_bit(WDOG_NO_WAY_OUT, &wdd->status);
}
/* Use the following function to check if a timeout value is invalid */
static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t)
{
/*
* The timeout is invalid if
* - the requested value is smaller than the configured minimum timeout,
* or
* - a maximum timeout is configured, and the requested value is larger
* than the maximum timeout.
*/
return t < wdd->min_timeout ||
(wdd->max_timeout && t > wdd->max_timeout);
}
/* 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/watchdog_core.c */
extern int watchdog_init_timeout(struct watchdog_device *wdd,
unsigned int timeout_parm, struct device *dev);
extern int watchdog_register_device(struct watchdog_device *);
extern void watchdog_unregister_device(struct watchdog_device *);
#endif /* ifndef _LINUX_WATCHDOG_H */
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