LXR linux/include/linux/clockchips.h

   1/*  linux/include/linux/clockchips.h
   2 *
   3 *  This file contains the structure definitions for clockchips.
   4 *
   5 *  If you are not a clockchip, or the time of day code, you should
   6 *  not be including this file!
   7 */
   8#ifndef _LINUX_CLOCKCHIPS_H
   9#define _LINUX_CLOCKCHIPS_H
  10
  11/* Clock event notification values */
  12enum clock_event_nofitiers {
  13        CLOCK_EVT_NOTIFY_ADD,
  14        CLOCK_EVT_NOTIFY_BROADCAST_ON,
  15        CLOCK_EVT_NOTIFY_BROADCAST_OFF,
  16        CLOCK_EVT_NOTIFY_BROADCAST_FORCE,
  17        CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
  18        CLOCK_EVT_NOTIFY_BROADCAST_EXIT,
  19        CLOCK_EVT_NOTIFY_SUSPEND,
  20        CLOCK_EVT_NOTIFY_RESUME,
  21        CLOCK_EVT_NOTIFY_CPU_DYING,
  22        CLOCK_EVT_NOTIFY_CPU_DEAD,
  23};
  24
  25#ifdef CONFIG_GENERIC_CLOCKEVENTS_BUILD
  26
  27#include <linux/clocksource.h>
  28#include <linux/cpumask.h>
  29#include <linux/ktime.h>
  30#include <linux/notifier.h>
  31
  32struct clock_event_device;
  33struct module;
  34
  35/* Clock event mode commands */
  36enum clock_event_mode {
  37        CLOCK_EVT_MODE_UNUSED = 0,
  38        CLOCK_EVT_MODE_SHUTDOWN,
  39        CLOCK_EVT_MODE_PERIODIC,
  40        CLOCK_EVT_MODE_ONESHOT,
  41        CLOCK_EVT_MODE_RESUME,
  42};
  43
  44/*
  45 * Clock event features
  46 */
  47#define CLOCK_EVT_FEAT_PERIODIC         0x000001
  48#define CLOCK_EVT_FEAT_ONESHOT          0x000002
  49#define CLOCK_EVT_FEAT_KTIME            0x000004
  50/*
  51 * x86(64) specific misfeatures:
  52 *
  53 * - Clockevent source stops in C3 State and needs broadcast support.
  54 * - Local APIC timer is used as a dummy device.
  55 */
  56#define CLOCK_EVT_FEAT_C3STOP           0x000008
  57#define CLOCK_EVT_FEAT_DUMMY            0x000010
  58
  59/*
  60 * Core shall set the interrupt affinity dynamically in broadcast mode
  61 */
  62#define CLOCK_EVT_FEAT_DYNIRQ           0x000020
  63#define CLOCK_EVT_FEAT_PERCPU           0x000040
  64
  65/*
  66 * Clockevent device is based on a hrtimer for broadcast
  67 */
  68#define CLOCK_EVT_FEAT_HRTIMER          0x000080
  69
  70/**
  71 * struct clock_event_device - clock event device descriptor
  72 * @event_handler:      Assigned by the framework to be called by the low
  73 *                      level handler of the event source
  74 * @set_next_event:     set next event function using a clocksource delta
  75 * @set_next_ktime:     set next event function using a direct ktime value
  76 * @next_event:         local storage for the next event in oneshot mode
  77 * @max_delta_ns:       maximum delta value in ns
  78 * @min_delta_ns:       minimum delta value in ns
  79 * @mult:               nanosecond to cycles multiplier
  80 * @shift:              nanoseconds to cycles divisor (power of two)
  81 * @mode:               operating mode assigned by the management code
  82 * @features:           features
  83 * @retries:            number of forced programming retries
  84 * @set_mode:           set mode function
  85 * @broadcast:          function to broadcast events
  86 * @min_delta_ticks:    minimum delta value in ticks stored for reconfiguration
  87 * @max_delta_ticks:    maximum delta value in ticks stored for reconfiguration
  88 * @name:               ptr to clock event name
  89 * @rating:             variable to rate clock event devices
  90 * @irq:                IRQ number (only for non CPU local devices)
  91 * @bound_on:           Bound on CPU
  92 * @cpumask:            cpumask to indicate for which CPUs this device works
  93 * @list:               list head for the management code
  94 * @owner:              module reference
  95 */
  96struct clock_event_device {
  97        void                    (*event_handler)(struct clock_event_device *);
  98        int                     (*set_next_event)(unsigned long evt,
  99                                                  struct clock_event_device *);
 100        int                     (*set_next_ktime)(ktime_t expires,
 101                                                  struct clock_event_device *);
 102        ktime_t                 next_event;
 103        u64                     max_delta_ns;
 104        u64                     min_delta_ns;
 105        u32                     mult;
 106        u32                     shift;
 107        enum clock_event_mode   mode;
 108        unsigned int            features;
 109        unsigned long           retries;
 110
 111        void                    (*broadcast)(const struct cpumask *mask);
 112        void                    (*set_mode)(enum clock_event_mode mode,
 113                                            struct clock_event_device *);
 114        void                    (*suspend)(struct clock_event_device *);
 115        void                    (*resume)(struct clock_event_device *);
 116        unsigned long           min_delta_ticks;
 117        unsigned long           max_delta_ticks;
 118
 119        const char              *name;
 120        int                     rating;
 121        int                     irq;
 122        int                     bound_on;
 123        const struct cpumask    *cpumask;
 124        struct list_head        list;
 125        struct module           *owner;
 126} ____cacheline_aligned;
 127
 128/*
 129 * Calculate a multiplication factor for scaled math, which is used to convert
 130 * nanoseconds based values to clock ticks:
 131 *
 132 * clock_ticks = (nanoseconds * factor) >> shift.
 133 *
 134 * div_sc is the rearranged equation to calculate a factor from a given clock
 135 * ticks / nanoseconds ratio:
 136 *
 137 * factor = (clock_ticks << shift) / nanoseconds
 138 */
 139static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec,
 140                                   int shift)
 141{
 142        uint64_t tmp = ((uint64_t)ticks) << shift;
 143
 144        do_div(tmp, nsec);
 145        return (unsigned long) tmp;
 146}
 147
 148/* Clock event layer functions */
 149extern u64 clockevent_delta2ns(unsigned long latch,
 150                               struct clock_event_device *evt);
 151extern void clockevents_register_device(struct clock_event_device *dev);
 152extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu);
 153
 154extern void clockevents_config(struct clock_event_device *dev, u32 freq);
 155extern void clockevents_config_and_register(struct clock_event_device *dev,
 156                                            u32 freq, unsigned long min_delta,
 157                                            unsigned long max_delta);
 158
 159extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);
 160
 161extern void clockevents_exchange_device(struct clock_event_device *old,
 162                                        struct clock_event_device *new);
 163extern void clockevents_set_mode(struct clock_event_device *dev,
 164                                 enum clock_event_mode mode);
 165extern int clockevents_program_event(struct clock_event_device *dev,
 166                                     ktime_t expires, bool force);
 167
 168extern void clockevents_handle_noop(struct clock_event_device *dev);
 169
 170static inline void
 171clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
 172{
 173        return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC,
 174                                      freq, minsec);
 175}
 176
 177extern void clockevents_suspend(void);
 178extern void clockevents_resume(void);
 179
 180#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 181#ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
 182extern void tick_broadcast(const struct cpumask *mask);
 183#else
 184#define tick_broadcast  NULL
 185#endif
 186extern int tick_receive_broadcast(void);
 187#endif
 188
 189#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
 190extern void tick_setup_hrtimer_broadcast(void);
 191extern int tick_check_broadcast_expired(void);
 192#else
 193static inline int tick_check_broadcast_expired(void) { return 0; }
 194static inline void tick_setup_hrtimer_broadcast(void) {};
 195#endif
 196
 197#ifdef CONFIG_GENERIC_CLOCKEVENTS
 198extern int clockevents_notify(unsigned long reason, void *arg);
 199#else
 200static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
 201#endif
 202
 203#else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */
 204
 205static inline void clockevents_suspend(void) {}
 206static inline void clockevents_resume(void) {}
 207
 208static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
 209static inline int tick_check_broadcast_expired(void) { return 0; }
 210static inline void tick_setup_hrtimer_broadcast(void) {};
 211
 212#endif
 213
 214#endif
 215