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