alarmtimer.h revision dae373be9fec6f850159a05af3a1c36236a70d43 
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
9enum alarmtimer_type {
10	ALARM_REALTIME,
11	ALARM_BOOTTIME,
12
13	ALARM_NUMTYPE,
14};
15
16enum 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 */
36struct 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
45void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
46		enum alarmtimer_restart (*function)(struct alarm *, ktime_t));
47int alarm_start(struct alarm *alarm, ktime_t start);
48int alarm_try_to_cancel(struct alarm *alarm);
49int alarm_cancel(struct alarm *alarm);
50
51u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
52
53/*
54 * A alarmtimer is active, when it is enqueued into timerqueue or the
55 * callback function is running.
56 */
57static inline int alarmtimer_active(const struct alarm *timer)
58{
59	return timer->state != ALARMTIMER_STATE_INACTIVE;
60}
61
62/*
63 * Helper function to check, whether the timer is on one of the queues
64 */
65static inline int alarmtimer_is_queued(struct alarm *timer)
66{
67	return timer->state & ALARMTIMER_STATE_ENQUEUED;
68}
69
70/*
71 * Helper function to check, whether the timer is running the callback
72 * function
73 */
74static inline int alarmtimer_callback_running(struct alarm *timer)
75{
76	return timer->state & ALARMTIMER_STATE_CALLBACK;
77}
78
79
80/* Provide way to access the rtc device being used by alarmtimers */
81struct rtc_device *alarmtimer_get_rtcdev(void);
82
83#endif
84