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 */
  12 enum 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
  32 struct clock_event_device;
  33 struct module;
  34
  35 /* Clock event mode commands */
  36 enum 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         /* Legacy ->set_mode() callback doesn't support below modes */
  44 };
  45
  46 /*
  47  * Clock event features
  48  */
  49 #define CLOCK_EVT_FEAT_PERIODIC         0x000001
  50 #define CLOCK_EVT_FEAT_ONESHOT          0x000002
  51 #define CLOCK_EVT_FEAT_KTIME            0x000004
  52 /*
  53  * x86(64) specific misfeatures:
  54  *
  55  * - Clockevent source stops in C3 State and needs broadcast support.
  56  * - Local APIC timer is used as a dummy device.
  57  */
  58 #define CLOCK_EVT_FEAT_C3STOP           0x000008
  59 #define CLOCK_EVT_FEAT_DUMMY            0x000010
  60
  61 /*
  62  * Core shall set the interrupt affinity dynamically in broadcast mode
  63  */
  64 #define CLOCK_EVT_FEAT_DYNIRQ           0x000020
  65 #define CLOCK_EVT_FEAT_PERCPU           0x000040
  66
  67 /*
  68  * Clockevent device is based on a hrtimer for broadcast
  69  */
  70 #define CLOCK_EVT_FEAT_HRTIMER          0x000080
  71
  72 /**
  73  * struct clock_event_device - clock event device descriptor
  74  * @event_handler:      Assigned by the framework to be called by the low
  75  *                      level handler of the event source
  76  * @set_next_event:     set next event function using a clocksource delta
  77  * @set_next_ktime:     set next event function using a direct ktime value
  78  * @next_event:         local storage for the next event in oneshot mode
  79  * @max_delta_ns:       maximum delta value in ns
  80  * @min_delta_ns:       minimum delta value in ns
  81  * @mult:               nanosecond to cycles multiplier
  82  * @shift:              nanoseconds to cycles divisor (power of two)
  83  * @mode:               operating mode assigned by the management code
  84  * @features:           features
  85  * @retries:            number of forced programming retries
  86  * @set_mode:           legacy set mode function, only for modes <= CLOCK_EVT_MODE_RESUME.
  87  * @set_mode_periodic:  switch mode to periodic, if !set_mode
  88  * @set_mode_oneshot:   switch mode to oneshot, if !set_mode
  89  * @set_mode_shutdown:  switch mode to shutdown, if !set_mode
  90  * @set_mode_resume:    resume clkevt device, if !set_mode
  91  * @broadcast:          function to broadcast events
  92  * @min_delta_ticks:    minimum delta value in ticks stored for reconfiguration
  93  * @max_delta_ticks:    maximum delta value in ticks stored for reconfiguration
  94  * @name:               ptr to clock event name
  95  * @rating:             variable to rate clock event devices
  96  * @irq:                IRQ number (only for non CPU local devices)
  97  * @bound_on:           Bound on CPU
  98  * @cpumask:            cpumask to indicate for which CPUs this device works
  99  * @list:               list head for the management code
 100  * @owner:              module reference
 101  */
 102 struct clock_event_device {
 103         void                    (*event_handler)(struct clock_event_device *);
 104         int                     (*set_next_event)(unsigned long evt,
 105                                                   struct clock_event_device *);
 106         int                     (*set_next_ktime)(ktime_t expires,
 107                                                   struct clock_event_device *);
 108         ktime_t                 next_event;
 109         u64                     max_delta_ns;
 110         u64                     min_delta_ns;
 111         u32                     mult;
 112         u32                     shift;
 113         enum clock_event_mode   mode;
 114         unsigned int            features;
 115         unsigned long           retries;
 116
 117         /*
 118          * Mode transition callback(s): Only one of the two groups should be
 119          * defined:
 120          * - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME.
 121          * - set_mode_{shutdown|periodic|oneshot|resume}().
 122          */
 123         void                    (*set_mode)(enum clock_event_mode mode,
 124                                             struct clock_event_device *);
 125         int                     (*set_mode_periodic)(struct clock_event_device *);
 126         int                     (*set_mode_oneshot)(struct clock_event_device *);
 127         int                     (*set_mode_shutdown)(struct clock_event_device *);
 128         int                     (*set_mode_resume)(struct clock_event_device *);
 129
 130         void                    (*broadcast)(const struct cpumask *mask);
 131         void                    (*suspend)(struct clock_event_device *);
 132         void                    (*resume)(struct clock_event_device *);
 133         unsigned long           min_delta_ticks;
 134         unsigned long           max_delta_ticks;
 135
 136         const char              *name;
 137         int                     rating;
 138         int                     irq;
 139         int                     bound_on;
 140         const struct cpumask    *cpumask;
 141         struct list_head        list;
 142         struct module           *owner;
 143 } ____cacheline_aligned;
 144
 145 /*
 146  * Calculate a multiplication factor for scaled math, which is used to convert
 147  * nanoseconds based values to clock ticks:
 148  *
 149  * clock_ticks = (nanoseconds * factor) >> shift.
 150  *
 151  * div_sc is the rearranged equation to calculate a factor from a given clock
 152  * ticks / nanoseconds ratio:
 153  *
 154  * factor = (clock_ticks << shift) / nanoseconds
 155  */
 156 static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec,
 157                                    int shift)
 158 {
 159         uint64_t tmp = ((uint64_t)ticks) << shift;
 160
 161         do_div(tmp, nsec);
 162         return (unsigned long) tmp;
 163 }
 164
 165 /* Clock event layer functions */
 166 extern u64 clockevent_delta2ns(unsigned long latch,
 167                                struct clock_event_device *evt);
 168 extern void clockevents_register_device(struct clock_event_device *dev);
 169 extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu);
 170
 171 extern void clockevents_config(struct clock_event_device *dev, u32 freq);
 172 extern void clockevents_config_and_register(struct clock_event_device *dev,
 173                                             u32 freq, unsigned long min_delta,
 174                                             unsigned long max_delta);
 175
 176 extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);
 177
 178 extern void clockevents_exchange_device(struct clock_event_device *old,
 179                                         struct clock_event_device *new);
 180 extern void clockevents_set_mode(struct clock_event_device *dev,
 181                                  enum clock_event_mode mode);
 182 extern int clockevents_program_event(struct clock_event_device *dev,
 183                                      ktime_t expires, bool force);
 184
 185 extern void clockevents_handle_noop(struct clock_event_device *dev);
 186
 187 static inline void
 188 clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
 189 {
 190         return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC,
 191                                       freq, minsec);
 192 }
 193
 194 extern void clockevents_suspend(void);
 195 extern void clockevents_resume(void);
 196
 197 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 198 #ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
 199 extern void tick_broadcast(const struct cpumask *mask);
 200 #else
 201 #define tick_broadcast  NULL
 202 #endif
 203 extern int tick_receive_broadcast(void);
 204 #endif
 205
 206 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
 207 extern void tick_setup_hrtimer_broadcast(void);
 208 extern int tick_check_broadcast_expired(void);
 209 #else
 210 static inline int tick_check_broadcast_expired(void) { return 0; }
 211 static inline void tick_setup_hrtimer_broadcast(void) {};
 212 #endif
 213
 214 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 215 extern int clockevents_notify(unsigned long reason, void *arg);
 216 #else
 217 static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
 218 #endif
 219
 220 #else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */
 221
 222 static inline void clockevents_suspend(void) {}
 223 static inline void clockevents_resume(void) {}
 224
 225 static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
 226 static inline int tick_check_broadcast_expired(void) { return 0; }
 227 static inline void tick_setup_hrtimer_broadcast(void) {};
 228
 229 #endif
 230
 231 #endif