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 struct hrtimer timer;
39 enum alarmtimer_restart (*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 enum alarmtimer_restart (*function)(struct alarm *, ktime_t));
47 int alarm_start(struct alarm *alarm, ktime_t start);
48 int 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 /*
58 * A alarmtimer is active, when it is enqueued into timerqueue or the
59 * callback function is running.
60 */
alarmtimer_active(const struct alarm * timer)61 static inline int alarmtimer_active(const struct alarm *timer)
62 {
63 return timer->state != ALARMTIMER_STATE_INACTIVE;
64 }
65
66 /*
67 * Helper function to check, whether the timer is on one of the queues
68 */
alarmtimer_is_queued(struct alarm * timer)69 static inline int alarmtimer_is_queued(struct alarm *timer)
70 {
71 return timer->state & ALARMTIMER_STATE_ENQUEUED;
72 }
73
74 /*
75 * Helper function to check, whether the timer is running the callback
76 * function
77 */
alarmtimer_callback_running(struct alarm * timer)78 static inline int alarmtimer_callback_running(struct alarm *timer)
79 {
80 return timer->state & ALARMTIMER_STATE_CALLBACK;
81 }
82
83
84 /* Provide way to access the rtc device being used by alarmtimers */
85 struct rtc_device *alarmtimer_get_rtcdev(void);
86
87 #endif
88