root/include/linux/clockchips.h

INCLUDED FROM

DEFINITIONS

1. div_sc
2. clockevents_calc_mult_shift
3. tick_check_broadcast_expired
4. tick_setup_hrtimer_broadcast
5. clockevents_notify
6. clockevents_suspend
7. clockevents_resume
8. clockevents_notify
9. tick_check_broadcast_expired
10. tick_setup_hrtimer_broadcast

/*  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

/*
 * 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)
 * @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)
 * @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_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;
        int                     bound_on;
        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 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

#ifdef CONFIG_GENERIC_CLOCKEVENTS
extern int clockevents_notify(unsigned long reason, void *arg);
#else
static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
#endif

#else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */

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

static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
static inline int tick_check_broadcast_expired(void) { return 0; }
static inline void tick_setup_hrtimer_broadcast(void) {};

#endif

#endif