root/include/linux/alarmtimer.h

INCLUDED FROM

#ifndef _LINUX_ALARMTIMER_H
#define _LINUX_ALARMTIMER_H

#include <linux/time.h>
#include <linux/hrtimer.h>
#include <linux/timerqueue.h>
#include <linux/rtc.h>

enum alarmtimer_type {
        ALARM_REALTIME,
        ALARM_BOOTTIME,

        ALARM_NUMTYPE,
};

enum alarmtimer_restart {
        ALARMTIMER_NORESTART,
        ALARMTIMER_RESTART,
};


#define ALARMTIMER_STATE_INACTIVE       0x00
#define ALARMTIMER_STATE_ENQUEUED       0x01

/**
 * struct alarm - Alarm timer structure
 * @node:       timerqueue node for adding to the event list this value
 *              also includes the expiration time.
 * @period:     Period for recuring alarms
 * @function:   Function pointer to be executed when the timer fires.
 * @type:       Alarm type (BOOTTIME/REALTIME)
 * @enabled:    Flag that represents if the alarm is set to fire or not
 * @data:       Internal data value.
 */
struct alarm {
        struct timerqueue_node  node;
        struct hrtimer          timer;
        enum alarmtimer_restart (*function)(struct alarm *, ktime_t now);
        enum alarmtimer_type    type;
        int                     state;
        void                    *data;
};

void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
                enum alarmtimer_restart (*function)(struct alarm *, ktime_t));
int alarm_start(struct alarm *alarm, ktime_t start);
int alarm_start_relative(struct alarm *alarm, ktime_t start);
void alarm_restart(struct alarm *alarm);
int alarm_try_to_cancel(struct alarm *alarm);
int alarm_cancel(struct alarm *alarm);

u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
u64 alarm_forward_now(struct alarm *alarm, ktime_t interval);
ktime_t alarm_expires_remaining(const struct alarm *alarm);

/* Provide way to access the rtc device being used by alarmtimers */
struct rtc_device *alarmtimer_get_rtcdev(void);

#endif