LXR linux/include/linux/alarmtimer.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_ALARMTIMER_H
   3#define _LINUX_ALARMTIMER_H
   4
   5#include <linux/time.h>
   6#include <linux/hrtimer.h>
   7#include <linux/timerqueue.h>
   8
   9struct rtc_device;
  10
  11enum alarmtimer_type {
  12        ALARM_REALTIME,
  13        ALARM_BOOTTIME,
  14
  15        /* Supported types end here */
  16        ALARM_NUMTYPE,
  17
  18        /* Used for tracing information. No usable types. */
  19        ALARM_REALTIME_FREEZER,
  20        ALARM_BOOTTIME_FREEZER,
  21};
  22
  23enum alarmtimer_restart {
  24        ALARMTIMER_NORESTART,
  25        ALARMTIMER_RESTART,
  26};
  27
  28
  29#define ALARMTIMER_STATE_INACTIVE       0x00
  30#define ALARMTIMER_STATE_ENQUEUED       0x01
  31
  32/**
  33 * struct alarm - Alarm timer structure
  34 * @node:       timerqueue node for adding to the event list this value
  35 *              also includes the expiration time.
  36 * @timer:      hrtimer used to schedule events while running
  37 * @function:   Function pointer to be executed when the timer fires.
  38 * @type:       Alarm type (BOOTTIME/REALTIME).
  39 * @state:      Flag that represents if the alarm is set to fire or not.
  40 * @data:       Internal data value.
  41 */
  42struct alarm {
  43        struct timerqueue_node  node;
  44        struct hrtimer          timer;
  45        enum alarmtimer_restart (*function)(struct alarm *, ktime_t now);
  46        enum alarmtimer_type    type;
  47        int                     state;
  48        void                    *data;
  49};
  50
  51void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
  52                enum alarmtimer_restart (*function)(struct alarm *, ktime_t));
  53void alarm_start(struct alarm *alarm, ktime_t start);
  54void alarm_start_relative(struct alarm *alarm, ktime_t start);
  55void alarm_restart(struct alarm *alarm);
  56int alarm_try_to_cancel(struct alarm *alarm);
  57int alarm_cancel(struct alarm *alarm);
  58
  59u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
  60u64 alarm_forward_now(struct alarm *alarm, ktime_t interval);
  61ktime_t alarm_expires_remaining(const struct alarm *alarm);
  62
  63#ifdef CONFIG_RTC_CLASS
  64/* Provide way to access the rtc device being used by alarmtimers */
  65struct rtc_device *alarmtimer_get_rtcdev(void);
  66#else
  67static inline struct rtc_device *alarmtimer_get_rtcdev(void) { return NULL; }
  68#endif
  69
  70#endif
  71