watchdog.h

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/*
 *  Generic watchdog defines. Derived from..
 *
 * Berkshire PC Watchdog Defines
 * by Ken Hollis <[email protected]>
 *
 */
#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 {
    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 {
    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 */
};

#ifdef CONFIG_WATCHDOG_NOWAYOUT
#define WATCHDOG_NOWAYOUT       1
#define WATCHDOG_NOWAYOUT_INIT_STATUS   (1 << WDOG_NO_WAY_OUT)
#else
#define WATCHDOG_NOWAYOUT       0
#define WATCHDOG_NOWAYOUT_INIT_STATUS   0
#endif

/* Use the following function to check wether 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 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  /* ifndef _LINUX_WATCHDOG_H */