alarmtimer.h

 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
 9struct rtc_device;
10
11enum 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#define ALARMTIMER_STATE_INACTIVE	0x00
24#define ALARMTIMER_STATE_ENQUEUED	0x01
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 * @timer:	hrtimer used to schedule events while running
31 * @function:	Function pointer to be executed when the timer fires.
32 * @type:	Alarm type (BOOTTIME/REALTIME).
33 * @state:	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	void			(*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		void (*function)(struct alarm *, ktime_t));
47void alarm_start(struct alarm *alarm, ktime_t start);
48void alarm_start_relative(struct alarm *alarm, ktime_t start);
49void alarm_restart(struct alarm *alarm);
50int alarm_try_to_cancel(struct alarm *alarm);
51int alarm_cancel(struct alarm *alarm);
52
53u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
54u64 alarm_forward_now(struct alarm *alarm, ktime_t interval);
55ktime_t alarm_expires_remaining(const struct alarm *alarm);
56
57#ifdef CONFIG_RTC_CLASS
58/* Provide way to access the rtc device being used by alarmtimers */
59struct rtc_device *alarmtimer_get_rtcdev(void);
60#else
61static inline struct rtc_device *alarmtimer_get_rtcdev(void) { return NULL; }
62#endif
63
64#endif