/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_ALARMTIMER_H
#define _LINUX_ALARMTIMER_H

#include <linux/time.h>
#include <linux/hrtimer.h>
#include <linux/timerqueue.h>

struct rtc_device;

enum alarmtimer_type {
        ALARM_REALTIME,
        ALARM_BOOTTIME,

        /* Supported types end here */
        ALARM_NUMTYPE,

        /* Used for tracing information. No usable types. */
        ALARM_REALTIME_FREEZER,
        ALARM_BOOTTIME_FREEZER,
};

#define ALARMTIMER_STATE_INACTIVE       0x00
#define ALARMTIMER_STATE_ENQUEUED       0x01

/**
 * struct alarm - Alarm timer structure
 * @node:       timerqueue node for adding to the event list this value
 *              also includes the expiration time.
 * @timer:      hrtimer used to schedule events while running
 * @function:   Function pointer to be executed when the timer fires.
 * @type:       Alarm type (BOOTTIME/REALTIME).
 * @state:      Flag that represents if the alarm is set to fire or not.
 * @data:       Internal data value.
 */
struct alarm {
        struct timerqueue_node  node;
        struct hrtimer          timer;
        void                    (*function)(struct alarm *, ktime_t now);
        enum alarmtimer_type    type;
        int                     state;
        void                    *data;
};

void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
                void (*function)(struct alarm *, ktime_t));
void alarm_start(struct alarm *alarm, ktime_t start);
void alarm_start_relative(struct alarm *alarm, ktime_t start);
void alarm_restart(struct alarm *alarm);
int alarm_try_to_cancel(struct alarm *alarm);
int alarm_cancel(struct alarm *alarm);

u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
u64 alarm_forward_now(struct alarm *alarm, ktime_t interval);
ktime_t alarm_expires_remaining(const struct alarm *alarm);

#ifdef CONFIG_RTC_CLASS
/* Provide way to access the rtc device being used by alarmtimers */
struct rtc_device *alarmtimer_get_rtcdev(void);
#else
static inline struct rtc_device *alarmtimer_get_rtcdev(void) { return NULL; }
#endif

#endif