xref: /linux-6.15/include/linux/alarmtimer.h (revision 9d64fc08)
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 	/* Supported types end here */
14 	ALARM_NUMTYPE,
15 
16 	/* Used for tracing information. No usable types. */
17 	ALARM_REALTIME_FREEZER,
18 	ALARM_BOOTTIME_FREEZER,
19 };
20 
21 enum alarmtimer_restart {
22 	ALARMTIMER_NORESTART,
23 	ALARMTIMER_RESTART,
24 };
25 
26 
27 #define ALARMTIMER_STATE_INACTIVE	0x00
28 #define ALARMTIMER_STATE_ENQUEUED	0x01
29 
30 /**
31  * struct alarm - Alarm timer structure
32  * @node:	timerqueue node for adding to the event list this value
33  *		also includes the expiration time.
34  * @timer:	hrtimer used to schedule events while running
35  * @function:	Function pointer to be executed when the timer fires.
36  * @type:	Alarm type (BOOTTIME/REALTIME).
37  * @state:	Flag that represents if the alarm is set to fire or not.
38  * @data:	Internal data value.
39  */
40 struct alarm {
41 	struct timerqueue_node	node;
42 	struct hrtimer		timer;
43 	enum alarmtimer_restart	(*function)(struct alarm *, ktime_t now);
44 	enum alarmtimer_type	type;
45 	int			state;
46 	void			*data;
47 };
48 
49 void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
50 		enum alarmtimer_restart (*function)(struct alarm *, ktime_t));
51 void alarm_start(struct alarm *alarm, ktime_t start);
52 void alarm_start_relative(struct alarm *alarm, ktime_t start);
53 void alarm_restart(struct alarm *alarm);
54 int alarm_try_to_cancel(struct alarm *alarm);
55 int alarm_cancel(struct alarm *alarm);
56 
57 u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
58 u64 alarm_forward_now(struct alarm *alarm, ktime_t interval);
59 ktime_t alarm_expires_remaining(const struct alarm *alarm);
60 
61 /* Provide way to access the rtc device being used by alarmtimers */
62 struct rtc_device *alarmtimer_get_rtcdev(void);
63 
64 #endif
65