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 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 for legacy ->set_mode(): OBSOLETE */ 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 * Possible states of a clock event device. 46 * 47 * DETACHED: Device is not used by clockevents core. Initial state or can be 48 * reached from SHUTDOWN. 49 * SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT. 50 * PERIODIC: Device is programmed to generate events periodically. Can be 51 * reached from DETACHED or SHUTDOWN. 52 * ONESHOT: Device is programmed to generate event only once. Can be reached 53 * from DETACHED or SHUTDOWN. 54 */ 55 enum clock_event_state { 56 CLOCK_EVT_STATE_DETACHED = 0, 57 CLOCK_EVT_STATE_SHUTDOWN, 58 CLOCK_EVT_STATE_PERIODIC, 59 CLOCK_EVT_STATE_ONESHOT, 60 }; 61 62 /* 63 * Clock event features 64 */ 65 #define CLOCK_EVT_FEAT_PERIODIC 0x000001 66 #define CLOCK_EVT_FEAT_ONESHOT 0x000002 67 #define CLOCK_EVT_FEAT_KTIME 0x000004 68 /* 69 * x86(64) specific misfeatures: 70 * 71 * - Clockevent source stops in C3 State and needs broadcast support. 72 * - Local APIC timer is used as a dummy device. 73 */ 74 #define CLOCK_EVT_FEAT_C3STOP 0x000008 75 #define CLOCK_EVT_FEAT_DUMMY 0x000010 76 77 /* 78 * Core shall set the interrupt affinity dynamically in broadcast mode 79 */ 80 #define CLOCK_EVT_FEAT_DYNIRQ 0x000020 81 #define CLOCK_EVT_FEAT_PERCPU 0x000040 82 83 /* 84 * Clockevent device is based on a hrtimer for broadcast 85 */ 86 #define CLOCK_EVT_FEAT_HRTIMER 0x000080 87 88 /** 89 * struct clock_event_device - clock event device descriptor 90 * @event_handler: Assigned by the framework to be called by the low 91 * level handler of the event source 92 * @set_next_event: set next event function using a clocksource delta 93 * @set_next_ktime: set next event function using a direct ktime value 94 * @next_event: local storage for the next event in oneshot mode 95 * @max_delta_ns: maximum delta value in ns 96 * @min_delta_ns: minimum delta value in ns 97 * @mult: nanosecond to cycles multiplier 98 * @shift: nanoseconds to cycles divisor (power of two) 99 * @mode: operating mode, relevant only to ->set_mode(), OBSOLETE 100 * @state: current state of the device, assigned by the core code 101 * @features: features 102 * @retries: number of forced programming retries 103 * @set_mode: legacy set mode function, only for modes <= CLOCK_EVT_MODE_RESUME. 104 * @set_state_periodic: switch state to periodic, if !set_mode 105 * @set_state_oneshot: switch state to oneshot, if !set_mode 106 * @set_state_shutdown: switch state to shutdown, if !set_mode 107 * @tick_resume: resume clkevt device, if !set_mode 108 * @broadcast: function to broadcast events 109 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration 110 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration 111 * @name: ptr to clock event name 112 * @rating: variable to rate clock event devices 113 * @irq: IRQ number (only for non CPU local devices) 114 * @bound_on: Bound on CPU 115 * @cpumask: cpumask to indicate for which CPUs this device works 116 * @list: list head for the management code 117 * @owner: module reference 118 */ 119 struct clock_event_device { 120 void (*event_handler)(struct clock_event_device *); 121 int (*set_next_event)(unsigned long evt, 122 struct clock_event_device *); 123 int (*set_next_ktime)(ktime_t expires, 124 struct clock_event_device *); 125 ktime_t next_event; 126 u64 max_delta_ns; 127 u64 min_delta_ns; 128 u32 mult; 129 u32 shift; 130 enum clock_event_mode mode; 131 enum clock_event_state state; 132 unsigned int features; 133 unsigned long retries; 134 135 /* 136 * State transition callback(s): Only one of the two groups should be 137 * defined: 138 * - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME. 139 * - set_state_{shutdown|periodic|oneshot}(), tick_resume(). 140 */ 141 void (*set_mode)(enum clock_event_mode mode, 142 struct clock_event_device *); 143 int (*set_state_periodic)(struct clock_event_device *); 144 int (*set_state_oneshot)(struct clock_event_device *); 145 int (*set_state_shutdown)(struct clock_event_device *); 146 int (*tick_resume)(struct clock_event_device *); 147 148 void (*broadcast)(const struct cpumask *mask); 149 void (*suspend)(struct clock_event_device *); 150 void (*resume)(struct clock_event_device *); 151 unsigned long min_delta_ticks; 152 unsigned long max_delta_ticks; 153 154 const char *name; 155 int rating; 156 int irq; 157 int bound_on; 158 const struct cpumask *cpumask; 159 struct list_head list; 160 struct module *owner; 161 } ____cacheline_aligned; 162 163 /* 164 * Calculate a multiplication factor for scaled math, which is used to convert 165 * nanoseconds based values to clock ticks: 166 * 167 * clock_ticks = (nanoseconds * factor) >> shift. 168 * 169 * div_sc is the rearranged equation to calculate a factor from a given clock 170 * ticks / nanoseconds ratio: 171 * 172 * factor = (clock_ticks << shift) / nanoseconds 173 */ 174 static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec, 175 int shift) 176 { 177 uint64_t tmp = ((uint64_t)ticks) << shift; 178 179 do_div(tmp, nsec); 180 return (unsigned long) tmp; 181 } 182 183 /* Clock event layer functions */ 184 extern u64 clockevent_delta2ns(unsigned long latch, 185 struct clock_event_device *evt); 186 extern void clockevents_register_device(struct clock_event_device *dev); 187 extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu); 188 189 extern void clockevents_config(struct clock_event_device *dev, u32 freq); 190 extern void clockevents_config_and_register(struct clock_event_device *dev, 191 u32 freq, unsigned long min_delta, 192 unsigned long max_delta); 193 194 extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq); 195 196 static inline void 197 clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec) 198 { 199 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, 200 freq, minsec); 201 } 202 203 /* Should be core only, but is abused by arm bl_switcher */ 204 extern void clockevents_set_state(struct clock_event_device *dev, 205 enum clock_event_state state); 206 extern int clockevents_program_event(struct clock_event_device *dev, 207 ktime_t expires, bool force); 208 209 extern void clockevents_suspend(void); 210 extern void clockevents_resume(void); 211 212 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 213 #ifdef CONFIG_ARCH_HAS_TICK_BROADCAST 214 extern void tick_broadcast(const struct cpumask *mask); 215 #else 216 #define tick_broadcast NULL 217 #endif 218 extern int tick_receive_broadcast(void); 219 #endif 220 221 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) 222 extern void tick_setup_hrtimer_broadcast(void); 223 extern int tick_check_broadcast_expired(void); 224 #else 225 static inline int tick_check_broadcast_expired(void) { return 0; } 226 static inline void tick_setup_hrtimer_broadcast(void) {}; 227 #endif 228 229 extern int clockevents_notify(unsigned long reason, void *arg); 230 231 #else /* CONFIG_GENERIC_CLOCKEVENTS */ 232 233 static inline void clockevents_suspend(void) {} 234 static inline void clockevents_resume(void) {} 235 236 static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; } 237 static inline int tick_check_broadcast_expired(void) { return 0; } 238 static inline void tick_setup_hrtimer_broadcast(void) {}; 239 static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; } 240 241 #endif 242 243 #endif 244