include/linux/alarmtimer.h

   1 #ifndef _LINUX_ALARMTIMER_H
   2 #define _LINUX_ALARMTIMER_H
   3
   4 #include <linux/time.h>
   5 #include <linux/hrtimer.h>
   6 #include <linux/timerqueue.h>
   7 #include <linux/rtc.h>
   8
   9 enum alarmtimer_type {
  10         ALARM_REALTIME,
  11         ALARM_BOOTTIME,
  12
  13         ALARM_NUMTYPE,
  14 };
  15
  16 enum alarmtimer_restart {
  17         ALARMTIMER_NORESTART,
  18         ALARMTIMER_RESTART,
  19 };
  20
  21
  22 #define ALARMTIMER_STATE_INACTIVE       0x00
  23 #define ALARMTIMER_STATE_ENQUEUED       0x01
  24 #define ALARMTIMER_STATE_CALLBACK       0x02
  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  * @period:     Period for recuring alarms
  31  * @function:   Function pointer to be executed when the timer fires.
  32  * @type:       Alarm type (BOOTTIME/REALTIME)
  33  * @enabled:    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         enum alarmtimer_restart (*function)(struct alarm *, ktime_t now);
  39         enum alarmtimer_type    type;
  40         int                     state;
  41         void                    *data;
  42 };
  43
  44 void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
  45                 enum alarmtimer_restart (*function)(struct alarm *, ktime_t));
  46 void alarm_start(struct alarm *alarm, ktime_t start);
  47 int alarm_try_to_cancel(struct alarm *alarm);
  48 int alarm_cancel(struct alarm *alarm);
  49
  50 u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
  51
  52 /*
  53  * A alarmtimer is active, when it is enqueued into timerqueue or the
  54  * callback function is running.
  55  */
  56 static inline int alarmtimer_active(const struct alarm *timer)
  57 {
  58         return timer->state != ALARMTIMER_STATE_INACTIVE;
  59 }
  60
  61 /*
  62  * Helper function to check, whether the timer is on one of the queues
  63  */
  64 static inline int alarmtimer_is_queued(struct alarm *timer)
  65 {
  66         return timer->state & ALARMTIMER_STATE_ENQUEUED;
  67 }
  68
  69 /*
  70  * Helper function to check, whether the timer is running the callback
  71  * function
  72  */
  73 static inline int alarmtimer_callback_running(struct alarm *timer)
  74 {
  75         return timer->state & ALARMTIMER_STATE_CALLBACK;
  76 }
  77
  78
  79 #endif