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 201