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 
9 struct rtc_device;
10 
11 enum alarmtimer_type {
12 	ALARM_REALTIME,
13 	ALARM_BOOTTIME,
14 
15 	/* Supported types end here */
16 	ALARM_NUMTYPE,
17 
18 	/* Used for tracing information. No usable types. */
19 	ALARM_REALTIME_FREEZER,
20 	ALARM_BOOTTIME_FREEZER,
21 };
22 
23 enum alarmtimer_restart {
24 	ALARMTIMER_NORESTART,
25 	ALARMTIMER_RESTART,
26 };
27 
28 
29 #define ALARMTIMER_STATE_INACTIVE	0x00
30 #define ALARMTIMER_STATE_ENQUEUED	0x01
31 
32 /**
33  * struct alarm - Alarm timer structure
34  * @node:	timerqueue node for adding to the event list this value
35  *		also includes the expiration time.
36  * @timer:	hrtimer used to schedule events while running
37  * @function:	Function pointer to be executed when the timer fires.
38  * @type:	Alarm type (BOOTTIME/REALTIME).
39  * @state:	Flag that represents if the alarm is set to fire or not.
40  * @data:	Internal data value.
41  */
42 struct alarm {
43 	struct timerqueue_node	node;
44 	struct hrtimer		timer;
45 	enum alarmtimer_restart	(*function)(struct alarm *, ktime_t now);
46 	enum alarmtimer_type	type;
47 	int			state;
48 	void			*data;
49 };
50 
51 void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
52 		enum alarmtimer_restart (*function)(struct alarm *, ktime_t));
53 void alarm_start(struct alarm *alarm, ktime_t start);
54 void alarm_start_relative(struct alarm *alarm, ktime_t start);
55 void alarm_restart(struct alarm *alarm);
56 int alarm_try_to_cancel(struct alarm *alarm);
57 int alarm_cancel(struct alarm *alarm);
58 
59 u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
60 u64 alarm_forward_now(struct alarm *alarm, ktime_t interval);
61 ktime_t alarm_expires_remaining(const struct alarm *alarm);
62 
63 #ifdef CONFIG_RTC_CLASS
64 /* Provide way to access the rtc device being used by alarmtimers */
65 struct rtc_device *alarmtimer_get_rtcdev(void);
66 #else
alarmtimer_get_rtcdev(void)67 static inline struct rtc_device *alarmtimer_get_rtcdev(void) { return NULL; }
68 #endif
69 
70 #endif
71