/* 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,

  };

  enum alarmtimer_restart {
  	ALARMTIMER_NORESTART,
  	ALARMTIMER_RESTART,
  };

  
  #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;

  	enum alarmtimer_restart	(*function)(struct alarm *, ktime_t now);

  	enum alarmtimer_type	type;

  	int			state;

  	void			*data;
  };
  
  void alarm_init(struct alarm *alarm, enum alarmtimer_type type,

  		enum alarmtimer_restart (*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