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 #include <linux/rtc.h>
9 
10 enum alarmtimer_type {
11 	ALARM_REALTIME,
12 	ALARM_BOOTTIME,
13 
14 	/* Supported types end here */
15 	ALARM_NUMTYPE,
16 
17 	/* Used for tracing information. No usable types. */
18 	ALARM_REALTIME_FREEZER,
19 	ALARM_BOOTTIME_FREEZER,
20 };
21 
22 enum alarmtimer_restart {
23 	ALARMTIMER_NORESTART,
24 	ALARMTIMER_RESTART,
25 };
26 
27 
28 #define ALARMTIMER_STATE_INACTIVE	0x00
29 #define ALARMTIMER_STATE_ENQUEUED	0x01
30 
31 /**
32  * struct alarm - Alarm timer structure
33  * @node:	timerqueue node for adding to the event list this value
34  *		also includes the expiration time.
35  * @timer:	hrtimer used to schedule events while running
36  * @function:	Function pointer to be executed when the timer fires.
37  * @type:	Alarm type (BOOTTIME/REALTIME).
38  * @state:	Flag that represents if the alarm is set to fire or not.
39  * @data:	Internal data value.
40  */
41 struct alarm {
42 	struct timerqueue_node	node;
43 	struct hrtimer		timer;
44 	enum alarmtimer_restart	(*function)(struct alarm *, ktime_t now);
45 	enum alarmtimer_type	type;
46 	int			state;
47 	void			*data;
48 };
49 
50 void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
51 		enum alarmtimer_restart (*function)(struct alarm *, ktime_t));
52 void alarm_start(struct alarm *alarm, ktime_t start);
53 void alarm_start_relative(struct alarm *alarm, ktime_t start);
54 void alarm_restart(struct alarm *alarm);
55 int alarm_try_to_cancel(struct alarm *alarm);
56 int alarm_cancel(struct alarm *alarm);
57 
58 u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
59 u64 alarm_forward_now(struct alarm *alarm, ktime_t interval);
60 ktime_t alarm_expires_remaining(const struct alarm *alarm);
61 
62 /* Provide way to access the rtc device being used by alarmtimers */
63 struct rtc_device *alarmtimer_get_rtcdev(void);
64 
65 #endif
66