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
  34 /* Clock event mode commands */
  35 enum clock_event_mode {
  36         CLOCK_EVT_MODE_UNUSED = 0,
  37         CLOCK_EVT_MODE_SHUTDOWN,
  38         CLOCK_EVT_MODE_PERIODIC,
  39         CLOCK_EVT_MODE_ONESHOT,
  40         CLOCK_EVT_MODE_RESUME,
  41 };
  42
  43 /*
  44  * Clock event features
  45  */
  46 #define CLOCK_EVT_FEAT_PERIODIC         0x000001
  47 #define CLOCK_EVT_FEAT_ONESHOT          0x000002
  48 #define CLOCK_EVT_FEAT_KTIME            0x000004
  49 /*
  50  * x86(64) specific misfeatures:
  51  *
  52  * - Clockevent source stops in C3 State and needs broadcast support.
  53  * - Local APIC timer is used as a dummy device.
  54  */
  55 #define CLOCK_EVT_FEAT_C3STOP           0x000008
  56 #define CLOCK_EVT_FEAT_DUMMY            0x000010
  57
  58 /*
  59  * Core shall set the interrupt affinity dynamically in broadcast mode
  60  */
  61 #define CLOCK_EVT_FEAT_DYNIRQ           0x000020
  62
  63 /**
  64  * struct clock_event_device - clock event device descriptor
  65  * @event_handler:      Assigned by the framework to be called by the low
  66  *                      level handler of the event source
  67  * @set_next_event:     set next event function using a clocksource delta
  68  * @set_next_ktime:     set next event function using a direct ktime value
  69  * @next_event:         local storage for the next event in oneshot mode
  70  * @max_delta_ns:       maximum delta value in ns
  71  * @min_delta_ns:       minimum delta value in ns
  72  * @mult:               nanosecond to cycles multiplier
  73  * @shift:              nanoseconds to cycles divisor (power of two)
  74  * @mode:               operating mode assigned by the management code
  75  * @features:           features
  76  * @retries:            number of forced programming retries
  77  * @set_mode:           set mode function
  78  * @broadcast:          function to broadcast events
  79  * @min_delta_ticks:    minimum delta value in ticks stored for reconfiguration
  80  * @max_delta_ticks:    maximum delta value in ticks stored for reconfiguration
  81  * @name:               ptr to clock event name
  82  * @rating:             variable to rate clock event devices
  83  * @irq:                IRQ number (only for non CPU local devices)
  84  * @cpumask:            cpumask to indicate for which CPUs this device works
  85  * @list:               list head for the management code
  86  */
  87 struct clock_event_device {
  88         void                    (*event_handler)(struct clock_event_device *);
  89         int                     (*set_next_event)(unsigned long evt,
  90                                                   struct clock_event_device *);
  91         int                     (*set_next_ktime)(ktime_t expires,
  92                                                   struct clock_event_device *);
  93         ktime_t                 next_event;
  94         u64                     max_delta_ns;
  95         u64                     min_delta_ns;
  96         u32                     mult;
  97         u32                     shift;
  98         enum clock_event_mode   mode;
  99         unsigned int            features;
 100         unsigned long           retries;
 101
 102         void                    (*broadcast)(const struct cpumask *mask);
 103         void                    (*set_mode)(enum clock_event_mode mode,
 104                                             struct clock_event_device *);
 105         void                    (*suspend)(struct clock_event_device *);
 106         void                    (*resume)(struct clock_event_device *);
 107         unsigned long           min_delta_ticks;
 108         unsigned long           max_delta_ticks;
 109
 110         const char              *name;
 111         int                     rating;
 112         int                     irq;
 113         const struct cpumask    *cpumask;
 114         struct list_head        list;
 115 } ____cacheline_aligned;
 116
 117 /*
 118  * Calculate a multiplication factor for scaled math, which is used to convert
 119  * nanoseconds based values to clock ticks:
 120  *
 121  * clock_ticks = (nanoseconds * factor) >> shift.
 122  *
 123  * div_sc is the rearranged equation to calculate a factor from a given clock
 124  * ticks / nanoseconds ratio:
 125  *
 126  * factor = (clock_ticks << shift) / nanoseconds
 127  */
 128 static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec,
 129                                    int shift)
 130 {
 131         uint64_t tmp = ((uint64_t)ticks) << shift;
 132
 133         do_div(tmp, nsec);
 134         return (unsigned long) tmp;
 135 }
 136
 137 /* Clock event layer functions */
 138 extern u64 clockevent_delta2ns(unsigned long latch,
 139                                struct clock_event_device *evt);
 140 extern void clockevents_register_device(struct clock_event_device *dev);
 141
 142 extern void clockevents_config(struct clock_event_device *dev, u32 freq);
 143 extern void clockevents_config_and_register(struct clock_event_device *dev,
 144                                             u32 freq, unsigned long min_delta,
 145                                             unsigned long max_delta);
 146
 147 extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);
 148
 149 extern void clockevents_exchange_device(struct clock_event_device *old,
 150                                         struct clock_event_device *new);
 151 extern void clockevents_set_mode(struct clock_event_device *dev,
 152                                  enum clock_event_mode mode);
 153 extern int clockevents_register_notifier(struct notifier_block *nb);
 154 extern int clockevents_program_event(struct clock_event_device *dev,
 155                                      ktime_t expires, bool force);
 156
 157 extern void clockevents_handle_noop(struct clock_event_device *dev);
 158
 159 static inline void
 160 clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
 161 {
 162         return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC,
 163                                       freq, minsec);
 164 }
 165
 166 extern void clockevents_suspend(void);
 167 extern void clockevents_resume(void);
 168
 169 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 170 #ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
 171 extern void tick_broadcast(const struct cpumask *mask);
 172 #else
 173 #define tick_broadcast  NULL
 174 #endif
 175 extern int tick_receive_broadcast(void);
 176 #endif
 177
 178 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
 179 extern int tick_check_broadcast_expired(void);
 180 #else
 181 static inline int tick_check_broadcast_expired(void) { return 0; }
 182 #endif
 183
 184 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 185 extern void clockevents_notify(unsigned long reason, void *arg);
 186 #else
 187 static inline void clockevents_notify(unsigned long reason, void *arg) {}
 188 #endif
 189
 190 #else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */
 191
 192 static inline void clockevents_suspend(void) {}
 193 static inline void clockevents_resume(void) {}
 194
 195 static inline void clockevents_notify(unsigned long reason, void *arg) {}
 196 static inline int tick_check_broadcast_expired(void) { return 0; }
 197
 198 #endif
 199
 200 #endif