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_CPU_DYING, 20 CLOCK_EVT_NOTIFY_CPU_DEAD, 21 }; 22 23 #ifdef CONFIG_GENERIC_CLOCKEVENTS 24 25 #include <linux/clocksource.h> 26 #include <linux/cpumask.h> 27 #include <linux/ktime.h> 28 #include <linux/notifier.h> 29 30 struct clock_event_device; 31 struct module; 32 33 /* Clock event mode commands for legacy ->set_mode(): OBSOLETE */ 34 enum clock_event_mode { 35 CLOCK_EVT_MODE_UNUSED = 0, 36 CLOCK_EVT_MODE_SHUTDOWN, 37 CLOCK_EVT_MODE_PERIODIC, 38 CLOCK_EVT_MODE_ONESHOT, 39 CLOCK_EVT_MODE_RESUME, 40 }; 41 42 /* 43 * Possible states of a clock event device. 44 * 45 * DETACHED: Device is not used by clockevents core. Initial state or can be 46 * reached from SHUTDOWN. 47 * SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT. 48 * PERIODIC: Device is programmed to generate events periodically. Can be 49 * reached from DETACHED or SHUTDOWN. 50 * ONESHOT: Device is programmed to generate event only once. Can be reached 51 * from DETACHED or SHUTDOWN. 52 */ 53 enum clock_event_state { 54 CLOCK_EVT_STATE_DETACHED = 0, 55 CLOCK_EVT_STATE_SHUTDOWN, 56 CLOCK_EVT_STATE_PERIODIC, 57 CLOCK_EVT_STATE_ONESHOT, 58 }; 59 60 /* 61 * Clock event features 62 */ 63 #define CLOCK_EVT_FEAT_PERIODIC 0x000001 64 #define CLOCK_EVT_FEAT_ONESHOT 0x000002 65 #define CLOCK_EVT_FEAT_KTIME 0x000004 66 /* 67 * x86(64) specific misfeatures: 68 * 69 * - Clockevent source stops in C3 State and needs broadcast support. 70 * - Local APIC timer is used as a dummy device. 71 */ 72 #define CLOCK_EVT_FEAT_C3STOP 0x000008 73 #define CLOCK_EVT_FEAT_DUMMY 0x000010 74 75 /* 76 * Core shall set the interrupt affinity dynamically in broadcast mode 77 */ 78 #define CLOCK_EVT_FEAT_DYNIRQ 0x000020 79 #define CLOCK_EVT_FEAT_PERCPU 0x000040 80 81 /* 82 * Clockevent device is based on a hrtimer for broadcast 83 */ 84 #define CLOCK_EVT_FEAT_HRTIMER 0x000080 85 86 /** 87 * struct clock_event_device - clock event device descriptor 88 * @event_handler: Assigned by the framework to be called by the low 89 * level handler of the event source 90 * @set_next_event: set next event function using a clocksource delta 91 * @set_next_ktime: set next event function using a direct ktime value 92 * @next_event: local storage for the next event in oneshot mode 93 * @max_delta_ns: maximum delta value in ns 94 * @min_delta_ns: minimum delta value in ns 95 * @mult: nanosecond to cycles multiplier 96 * @shift: nanoseconds to cycles divisor (power of two) 97 * @mode: operating mode, relevant only to ->set_mode(), OBSOLETE 98 * @state: current state of the device, assigned by the core code 99 * @features: features 100 * @retries: number of forced programming retries 101 * @set_mode: legacy set mode function, only for modes <= CLOCK_EVT_MODE_RESUME. 102 * @set_state_periodic: switch state to periodic, if !set_mode 103 * @set_state_oneshot: switch state to oneshot, if !set_mode 104 * @set_state_shutdown: switch state to shutdown, if !set_mode 105 * @tick_resume: resume clkevt device, if !set_mode 106 * @broadcast: function to broadcast events 107 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration 108 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration 109 * @name: ptr to clock event name 110 * @rating: variable to rate clock event devices 111 * @irq: IRQ number (only for non CPU local devices) 112 * @bound_on: Bound on CPU 113 * @cpumask: cpumask to indicate for which CPUs this device works 114 * @list: list head for the management code 115 * @owner: module reference 116 */ 117 struct clock_event_device { 118 void (*event_handler)(struct clock_event_device *); 119 int (*set_next_event)(unsigned long evt, 120 struct clock_event_device *); 121 int (*set_next_ktime)(ktime_t expires, 122 struct clock_event_device *); 123 ktime_t next_event; 124 u64 max_delta_ns; 125 u64 min_delta_ns; 126 u32 mult; 127 u32 shift; 128 enum clock_event_mode mode; 129 enum clock_event_state state; 130 unsigned int features; 131 unsigned long retries; 132 133 /* 134 * State transition callback(s): Only one of the two groups should be 135 * defined: 136 * - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME. 137 * - set_state_{shutdown|periodic|oneshot}(), tick_resume(). 138 */ 139 void (*set_mode)(enum clock_event_mode mode, 140 struct clock_event_device *); 141 int (*set_state_periodic)(struct clock_event_device *); 142 int (*set_state_oneshot)(struct clock_event_device *); 143 int (*set_state_shutdown)(struct clock_event_device *); 144 int (*tick_resume)(struct clock_event_device *); 145 146 void (*broadcast)(const struct cpumask *mask); 147 void (*suspend)(struct clock_event_device *); 148 void (*resume)(struct clock_event_device *); 149 unsigned long min_delta_ticks; 150 unsigned long max_delta_ticks; 151 152 const char *name; 153 int rating; 154 int irq; 155 int bound_on; 156 const struct cpumask *cpumask; 157 struct list_head list; 158 struct module *owner; 159 } ____cacheline_aligned; 160 161 /* 162 * Calculate a multiplication factor for scaled math, which is used to convert 163 * nanoseconds based values to clock ticks: 164 * 165 * clock_ticks = (nanoseconds * factor) >> shift. 166 * 167 * div_sc is the rearranged equation to calculate a factor from a given clock 168 * ticks / nanoseconds ratio: 169 * 170 * factor = (clock_ticks << shift) / nanoseconds 171 */ 172 static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec, 173 int shift) 174 { 175 uint64_t tmp = ((uint64_t)ticks) << shift; 176 177 do_div(tmp, nsec); 178 return (unsigned long) tmp; 179 } 180 181 /* Clock event layer functions */ 182 extern u64 clockevent_delta2ns(unsigned long latch, 183 struct clock_event_device *evt); 184 extern void clockevents_register_device(struct clock_event_device *dev); 185 extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu); 186 187 extern void clockevents_config(struct clock_event_device *dev, u32 freq); 188 extern void clockevents_config_and_register(struct clock_event_device *dev, 189 u32 freq, unsigned long min_delta, 190 unsigned long max_delta); 191 192 extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq); 193 194 static inline void 195 clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec) 196 { 197 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, 198 freq, minsec); 199 } 200 201 /* Should be core only, but is abused by arm bl_switcher */ 202 extern void clockevents_set_state(struct clock_event_device *dev, 203 enum clock_event_state state); 204 extern int clockevents_program_event(struct clock_event_device *dev, 205 ktime_t expires, bool force); 206 207 extern void clockevents_suspend(void); 208 extern void clockevents_resume(void); 209 210 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 211 #ifdef CONFIG_ARCH_HAS_TICK_BROADCAST 212 extern void tick_broadcast(const struct cpumask *mask); 213 #else 214 #define tick_broadcast NULL 215 #endif 216 extern int tick_receive_broadcast(void); 217 #endif 218 219 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) 220 extern void tick_setup_hrtimer_broadcast(void); 221 extern int tick_check_broadcast_expired(void); 222 #else 223 static inline int tick_check_broadcast_expired(void) { return 0; } 224 static inline void tick_setup_hrtimer_broadcast(void) {}; 225 #endif 226 227 extern int clockevents_notify(unsigned long reason, void *arg); 228 229 #else /* CONFIG_GENERIC_CLOCKEVENTS */ 230 231 static inline void clockevents_suspend(void) {} 232 static inline void clockevents_resume(void) {} 233 234 static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; } 235 static inline int tick_check_broadcast_expired(void) { return 0; } 236 static inline void tick_setup_hrtimer_broadcast(void) {}; 237 static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; } 238 239 #endif 240 241 #endif 242