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 enum 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  */
  42 struct 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
  51 void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
  52                 enum alarmtimer_restart (*function)(struct alarm *, ktime_t));
  53 void alarm_start(struct alarm *alarm, ktime_t start);
  54 void alarm_start_relative(struct alarm *alarm, ktime_t start);
  55 void alarm_restart(struct alarm *alarm);
  56 int alarm_try_to_cancel(struct alarm *alarm);
  57 int alarm_cancel(struct alarm *alarm);
  58
  59 u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
  60 u64 alarm_forward_now(struct alarm *alarm, ktime_t interval);
  61 ktime_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 */
  65 struct rtc_device *alarmtimer_get_rtcdev(void);
  66 #else
  67 static inline struct rtc_device *alarmtimer_get_rtcdev(void) { return NULL; }
  68 #endif
  69
  70 #endif