/* SPDX-License-Identifier: GPL-2.0 */

  /*  linux/include/linux/clockchips.h
   *
   *  This file contains the structure definitions for clockchips.
   *
   *  If you are not a clockchip, or the time of day code, you should
   *  not be including this file!
   */
  #ifndef _LINUX_CLOCKCHIPS_H
  #define _LINUX_CLOCKCHIPS_H

  #ifdef CONFIG_GENERIC_CLOCKEVENTS

  # include <linux/clocksource.h>
  # include <linux/cpumask.h>
  # include <linux/ktime.h>
  # include <linux/notifier.h>

  
  struct clock_event_device;

  struct module;

  /*
   * Possible states of a clock event device.
   *
   * DETACHED:	Device is not used by clockevents core. Initial state or can be
   *		reached from SHUTDOWN.
   * SHUTDOWN:	Device is powered-off. Can be reached from PERIODIC or ONESHOT.
   * PERIODIC:	Device is programmed to generate events periodically. Can be
   *		reached from DETACHED or SHUTDOWN.
   * ONESHOT:	Device is programmed to generate event only once. Can be reached
   *		from DETACHED or SHUTDOWN.

   * ONESHOT_STOPPED: Device was programmed in ONESHOT mode and is temporarily
   *		    stopped.

   */
  enum clock_event_state {

  	CLOCK_EVT_STATE_DETACHED,

  	CLOCK_EVT_STATE_SHUTDOWN,
  	CLOCK_EVT_STATE_PERIODIC,
  	CLOCK_EVT_STATE_ONESHOT,

  	CLOCK_EVT_STATE_ONESHOT_STOPPED,

  };

  /*
   * Clock event features
   */

  # define CLOCK_EVT_FEAT_PERIODIC	0x000001
  # define CLOCK_EVT_FEAT_ONESHOT		0x000002
  # define CLOCK_EVT_FEAT_KTIME		0x000004

  /*

   * x86(64) specific (mis)features:

   *
   * - Clockevent source stops in C3 State and needs broadcast support.
   * - Local APIC timer is used as a dummy device.
   */

  # define CLOCK_EVT_FEAT_C3STOP		0x000008
  # define CLOCK_EVT_FEAT_DUMMY		0x000010

  /*
   * Core shall set the interrupt affinity dynamically in broadcast mode
   */

  # define CLOCK_EVT_FEAT_DYNIRQ		0x000020
  # define CLOCK_EVT_FEAT_PERCPU		0x000040

  /*
   * Clockevent device is based on a hrtimer for broadcast
   */

  # define CLOCK_EVT_FEAT_HRTIMER		0x000080

  /**
   * struct clock_event_device - clock event device descriptor

   * @event_handler:	Assigned by the framework to be called by the low
   *			level handler of the event source

   * @set_next_event:	set next event function using a clocksource delta
   * @set_next_ktime:	set next event function using a direct ktime value

   * @next_event:		local storage for the next event in oneshot mode

   * @max_delta_ns:	maximum delta value in ns
   * @min_delta_ns:	minimum delta value in ns
   * @mult:		nanosecond to cycles multiplier
   * @shift:		nanoseconds to cycles divisor (power of two)

   * @state_use_accessors:current state of the device, assigned by the core code

   * @features:		features
   * @retries:		number of forced programming retries

   * @set_state_periodic:	switch state to periodic
   * @set_state_oneshot:	switch state to oneshot
   * @set_state_oneshot_stopped: switch state to oneshot_stopped
   * @set_state_shutdown:	switch state to shutdown
   * @tick_resume:	resume clkevt device

   * @broadcast:		function to broadcast events

   * @min_delta_ticks:	minimum delta value in ticks stored for reconfiguration
   * @max_delta_ticks:	maximum delta value in ticks stored for reconfiguration

   * @name:		ptr to clock event name

   * @rating:		variable to rate clock event devices

   * @irq:		IRQ number (only for non CPU local devices)

   * @bound_on:		Bound on CPU

   * @cpumask:		cpumask to indicate for which CPUs this device works

   * @list:		list head for the management code

   * @owner:		module reference

   */
  struct clock_event_device {

  	void			(*event_handler)(struct clock_event_device *);

  	int			(*set_next_event)(unsigned long evt, struct clock_event_device *);
  	int			(*set_next_ktime)(ktime_t expires, struct clock_event_device *);

  	ktime_t			next_event;

  	u64			max_delta_ns;
  	u64			min_delta_ns;

  	u32			mult;
  	u32			shift;

  	enum clock_event_state	state_use_accessors;

  	unsigned int		features;
  	unsigned long		retries;

  	int			(*set_state_periodic)(struct clock_event_device *);
  	int			(*set_state_oneshot)(struct clock_event_device *);

  	int			(*set_state_oneshot_stopped)(struct clock_event_device *);

  	int			(*set_state_shutdown)(struct clock_event_device *);

  	int			(*tick_resume)(struct clock_event_device *);

  
  	void			(*broadcast)(const struct cpumask *mask);

  	void			(*suspend)(struct clock_event_device *);
  	void			(*resume)(struct clock_event_device *);

  	unsigned long		min_delta_ticks;
  	unsigned long		max_delta_ticks;

  	const char		*name;

  	int			rating;
  	int			irq;

  	int			bound_on;

  	const struct cpumask	*cpumask;

  	struct list_head	list;

  	struct module		*owner;

  } ____cacheline_aligned;

  /* Helpers to verify state of a clockevent device */
  static inline bool clockevent_state_detached(struct clock_event_device *dev)
  {

  	return dev->state_use_accessors == CLOCK_EVT_STATE_DETACHED;

  }
  
  static inline bool clockevent_state_shutdown(struct clock_event_device *dev)
  {

  	return dev->state_use_accessors == CLOCK_EVT_STATE_SHUTDOWN;

  }
  
  static inline bool clockevent_state_periodic(struct clock_event_device *dev)
  {

  	return dev->state_use_accessors == CLOCK_EVT_STATE_PERIODIC;

  }
  
  static inline bool clockevent_state_oneshot(struct clock_event_device *dev)
  {

  	return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT;

  }
  
  static inline bool clockevent_state_oneshot_stopped(struct clock_event_device *dev)
  {

  	return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT_STOPPED;

  }

  /*
   * Calculate a multiplication factor for scaled math, which is used to convert
   * nanoseconds based values to clock ticks:
   *
   * clock_ticks = (nanoseconds * factor) >> shift.
   *
   * div_sc is the rearranged equation to calculate a factor from a given clock
   * ticks / nanoseconds ratio:
   *
   * factor = (clock_ticks << shift) / nanoseconds
   */

  static inline unsigned long
  div_sc(unsigned long ticks, unsigned long nsec, int shift)

  {

  	u64 tmp = ((u64)ticks) << shift;

  
  	do_div(tmp, nsec);

  	return (unsigned long) tmp;
  }
  
  /* Clock event layer functions */

  extern u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt);

  extern void clockevents_register_device(struct clock_event_device *dev);

  extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu);

  extern void clockevents_config_and_register(struct clock_event_device *dev,
  					    u32 freq, unsigned long min_delta,
  					    unsigned long max_delta);

  extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);

  static inline void

  clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 maxsec)

  {

  	return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, freq, maxsec);

  }

  extern void clockevents_suspend(void);
  extern void clockevents_resume(void);

  # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  #  ifdef CONFIG_ARCH_HAS_TICK_BROADCAST

  extern void tick_broadcast(const struct cpumask *mask);

  #  else
  #   define tick_broadcast	NULL
  #  endif

  extern int tick_receive_broadcast(void);

  # endif

  # if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)

  extern void tick_setup_hrtimer_broadcast(void);

  extern int tick_check_broadcast_expired(void);

  # else

  static inline int tick_check_broadcast_expired(void) { return 0; }

  static inline void tick_setup_hrtimer_broadcast(void) { }
  # endif

  #else /* !CONFIG_GENERIC_CLOCKEVENTS: */

  static inline void clockevents_suspend(void) { }
  static inline void clockevents_resume(void) { }

  static inline int tick_check_broadcast_expired(void) { return 0; }

  static inline void tick_setup_hrtimer_broadcast(void) { }

  #endif /* !CONFIG_GENERIC_CLOCKEVENTS */

  #endif /* _LINUX_CLOCKCHIPS_H */