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
   9 struct rtc_device;
  10
  11 enum 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
  23 #define ALARMTIMER_STATE_INACTIVE       0x00
  24 #define ALARMTIMER_STATE_ENQUEUED       0x01
  25
  26 /**
  27  * struct alarm - Alarm timer structure
  28  * @node:       timerqueue node for adding to the event list this value
  29  *              also includes the expiration time.
  30  * @timer:      hrtimer used to schedule events while running
  31  * @function:   Function pointer to be executed when the timer fires.
  32  * @type:       Alarm type (BOOTTIME/REALTIME).
  33  * @state:      Flag that represents if the alarm is set to fire or not.
  34  * @data:       Internal data value.
  35  */
  36 struct alarm {
  37         struct timerqueue_node  node;
  38         struct hrtimer          timer;
  39         void                    (*function)(struct alarm *, ktime_t now);
  40         enum alarmtimer_type    type;
  41         int                     state;
  42         void                    *data;
  43 };
  44
  45 void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
  46                 void (*function)(struct alarm *, ktime_t));
  47 void alarm_start(struct alarm *alarm, ktime_t start);
  48 void alarm_start_relative(struct alarm *alarm, ktime_t start);
  49 void alarm_restart(struct alarm *alarm);
  50 int alarm_try_to_cancel(struct alarm *alarm);
  51 int alarm_cancel(struct alarm *alarm);
  52
  53 u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
  54 u64 alarm_forward_now(struct alarm *alarm, ktime_t interval);
  55 ktime_t alarm_expires_remaining(const struct alarm *alarm);
  56
  57 #ifdef CONFIG_RTC_CLASS
  58 /* Provide way to access the rtc device being used by alarmtimers */
  59 struct rtc_device *alarmtimer_get_rtcdev(void);
  60 #else
  61 static inline struct rtc_device *alarmtimer_get_rtcdev(void) { return NULL; }
  62 #endif
  63
  64 #endif