/*  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
  
  /* Clock event notification values */
  enum clock_event_nofitiers {
  	CLOCK_EVT_NOTIFY_ADD,
  	CLOCK_EVT_NOTIFY_BROADCAST_ON,
  	CLOCK_EVT_NOTIFY_BROADCAST_OFF,
  	CLOCK_EVT_NOTIFY_BROADCAST_FORCE,
  	CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
  	CLOCK_EVT_NOTIFY_BROADCAST_EXIT,
  	CLOCK_EVT_NOTIFY_SUSPEND,
  	CLOCK_EVT_NOTIFY_RESUME,
  	CLOCK_EVT_NOTIFY_CPU_DYING,
  	CLOCK_EVT_NOTIFY_CPU_DEAD,
  };
  
  #ifdef CONFIG_GENERIC_CLOCKEVENTS_BUILD
  
  #include <linux/clocksource.h>
  #include <linux/cpumask.h>
  #include <linux/ktime.h>
  #include <linux/notifier.h>
  
  struct clock_event_device;
  struct module;
  
  /* Clock event mode commands */
  enum clock_event_mode {
  	CLOCK_EVT_MODE_UNUSED = 0,
  	CLOCK_EVT_MODE_SHUTDOWN,
  	CLOCK_EVT_MODE_PERIODIC,
  	CLOCK_EVT_MODE_ONESHOT,
  	CLOCK_EVT_MODE_RESUME,
  };
  
  /*
   * Clock event features
   */
  #define CLOCK_EVT_FEAT_PERIODIC		0x000001
  #define CLOCK_EVT_FEAT_ONESHOT		0x000002
  #define CLOCK_EVT_FEAT_KTIME		0x000004
  /*
   * x86(64) specific misfeatures:
   *
   * - 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
  
  /**
   * 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)
   * @mode:		operating mode assigned by the management code
   * @features:		features
   * @retries:		number of forced programming retries
   * @set_mode:		set mode function
   * @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)
   * @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_mode	mode;
  	unsigned int		features;
  	unsigned long		retries;
  
  	void			(*broadcast)(const struct cpumask *mask);
  	void			(*set_mode)(enum clock_event_mode mode,
  					    struct clock_event_device *);
  	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;
  	const struct cpumask	*cpumask;
  	struct list_head	list;
  	struct module		*owner;
  } ____cacheline_aligned;
  
  /*
   * 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)
  {
  	uint64_t tmp = ((uint64_t)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(struct clock_event_device *dev, u32 freq);
  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);
  
  extern void clockevents_exchange_device(struct clock_event_device *old,
  					struct clock_event_device *new);
  extern void clockevents_set_mode(struct clock_event_device *dev,
  				 enum clock_event_mode mode);
  extern int clockevents_program_event(struct clock_event_device *dev,
  				     ktime_t expires, bool force);
  
  extern void clockevents_handle_noop(struct clock_event_device *dev);
  
  static inline void
  clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
  {
  	return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC,
  				      freq, minsec);
  }
  
  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 int tick_check_broadcast_expired(void);
  #else
  static inline int tick_check_broadcast_expired(void) { return 0; }
  #endif
  
  #ifdef CONFIG_GENERIC_CLOCKEVENTS
  extern void clockevents_notify(unsigned long reason, void *arg);
  #else
  static inline void clockevents_notify(unsigned long reason, void *arg) {}
  #endif
  
  #else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */
  
  static inline void clockevents_suspend(void) {}
  static inline void clockevents_resume(void) {}
  
  static inline void clockevents_notify(unsigned long reason, void *arg) {}
  static inline int tick_check_broadcast_expired(void) { return 0; }
  
  #endif
  
  #endif