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
  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  */
  96 struct 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  */
 139 static 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 */
 149 extern u64 clockevent_delta2ns(unsigned long latch,
 150                                struct clock_event_device *evt);
 151 extern void clockevents_register_device(struct clock_event_device *dev);
 152 extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu);
 153
 154 extern void clockevents_config(struct clock_event_device *dev, u32 freq);
 155 extern void clockevents_config_and_register(struct clock_event_device *dev,
 156                                             u32 freq, unsigned long min_delta,
 157                                             unsigned long max_delta);
 158
 159 extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);
 160
 161 extern void clockevents_exchange_device(struct clock_event_device *old,
 162                                         struct clock_event_device *new);
 163 extern void clockevents_set_mode(struct clock_event_device *dev,
 164                                  enum clock_event_mode mode);
 165 extern int clockevents_program_event(struct clock_event_device *dev,
 166                                      ktime_t expires, bool force);
 167
 168 extern void clockevents_handle_noop(struct clock_event_device *dev);
 169
 170 static inline void
 171 clockevents_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
 177 extern void clockevents_suspend(void);
 178 extern void clockevents_resume(void);
 179
 180 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 181 #ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
 182 extern void tick_broadcast(const struct cpumask *mask);
 183 #else
 184 #define tick_broadcast  NULL
 185 #endif
 186 extern int tick_receive_broadcast(void);
 187 #endif
 188
 189 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
 190 extern void tick_setup_hrtimer_broadcast(void);
 191 extern int tick_check_broadcast_expired(void);
 192 #else
 193 static inline int tick_check_broadcast_expired(void) { return 0; }
 194 static inline void tick_setup_hrtimer_broadcast(void) {};
 195 #endif
 196
 197 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 198 extern int clockevents_notify(unsigned long reason, void *arg);
 199 #else
 200 static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
 201 #endif
 202
 203 #else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */
 204
 205 static inline void clockevents_suspend(void) {}
 206 static inline void clockevents_resume(void) {}
 207
 208 static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
 209 static inline int tick_check_broadcast_expired(void) { return 0; }
 210 static inline void tick_setup_hrtimer_broadcast(void) {};
 211
 212 #endif
 213
 214 #endif