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 #ifdef CONFIG_GENERIC_CLOCKEVENTS 12 13 # include <linux/clocksource.h> 14 # include <linux/cpumask.h> 15 # include <linux/ktime.h> 16 # include <linux/notifier.h> 17 18 struct clock_event_device; 19 struct module; 20 21 /* Clock event mode commands for legacy ->set_mode(): OBSOLETE */ 22 enum clock_event_mode { 23 CLOCK_EVT_MODE_UNUSED, 24 CLOCK_EVT_MODE_SHUTDOWN, 25 CLOCK_EVT_MODE_PERIODIC, 26 CLOCK_EVT_MODE_ONESHOT, 27 CLOCK_EVT_MODE_RESUME, 28 }; 29 30 /* 31 * Possible states of a clock event device. 32 * 33 * DETACHED: Device is not used by clockevents core. Initial state or can be 34 * reached from SHUTDOWN. 35 * SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT. 36 * PERIODIC: Device is programmed to generate events periodically. Can be 37 * reached from DETACHED or SHUTDOWN. 38 * ONESHOT: Device is programmed to generate event only once. Can be reached 39 * from DETACHED or SHUTDOWN. 40 * ONESHOT_STOPPED: Device was programmed in ONESHOT mode and is temporarily 41 * stopped. 42 */ 43 enum clock_event_state { 44 CLOCK_EVT_STATE_DETACHED, 45 CLOCK_EVT_STATE_SHUTDOWN, 46 CLOCK_EVT_STATE_PERIODIC, 47 CLOCK_EVT_STATE_ONESHOT, 48 CLOCK_EVT_STATE_ONESHOT_STOPPED, 49 }; 50 51 /* 52 * Clock event features 53 */ 54 # define CLOCK_EVT_FEAT_PERIODIC 0x000001 55 # define CLOCK_EVT_FEAT_ONESHOT 0x000002 56 # define CLOCK_EVT_FEAT_KTIME 0x000004 57 58 /* 59 * x86(64) specific (mis)features: 60 * 61 * - Clockevent source stops in C3 State and needs broadcast support. 62 * - Local APIC timer is used as a dummy device. 63 */ 64 # define CLOCK_EVT_FEAT_C3STOP 0x000008 65 # define CLOCK_EVT_FEAT_DUMMY 0x000010 66 67 /* 68 * Core shall set the interrupt affinity dynamically in broadcast mode 69 */ 70 # define CLOCK_EVT_FEAT_DYNIRQ 0x000020 71 # define CLOCK_EVT_FEAT_PERCPU 0x000040 72 73 /* 74 * Clockevent device is based on a hrtimer for broadcast 75 */ 76 # define CLOCK_EVT_FEAT_HRTIMER 0x000080 77 78 /** 79 * struct clock_event_device - clock event device descriptor 80 * @event_handler: Assigned by the framework to be called by the low 81 * level handler of the event source 82 * @set_next_event: set next event function using a clocksource delta 83 * @set_next_ktime: set next event function using a direct ktime value 84 * @next_event: local storage for the next event in oneshot mode 85 * @max_delta_ns: maximum delta value in ns 86 * @min_delta_ns: minimum delta value in ns 87 * @mult: nanosecond to cycles multiplier 88 * @shift: nanoseconds to cycles divisor (power of two) 89 * @mode: operating mode, relevant only to ->set_mode(), OBSOLETE 90 * @state_use_accessors:current state of the device, assigned by the core code 91 * @features: features 92 * @retries: number of forced programming retries 93 * @set_mode: legacy set mode function, only for modes <= CLOCK_EVT_MODE_RESUME. 94 * @set_state_periodic: switch state to periodic, if !set_mode 95 * @set_state_oneshot: switch state to oneshot, if !set_mode 96 * @set_state_oneshot_stopped: switch state to oneshot_stopped, if !set_mode 97 * @set_state_shutdown: switch state to shutdown, if !set_mode 98 * @tick_resume: resume clkevt device, if !set_mode 99 * @broadcast: function to broadcast events 100 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration 101 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration 102 * @name: ptr to clock event name 103 * @rating: variable to rate clock event devices 104 * @irq: IRQ number (only for non CPU local devices) 105 * @bound_on: Bound on CPU 106 * @cpumask: cpumask to indicate for which CPUs this device works 107 * @list: list head for the management code 108 * @owner: module reference 109 */ 110 struct clock_event_device { 111 void (*event_handler)(struct clock_event_device *); 112 int (*set_next_event)(unsigned long evt, struct clock_event_device *); 113 int (*set_next_ktime)(ktime_t expires, struct clock_event_device *); 114 ktime_t next_event; 115 u64 max_delta_ns; 116 u64 min_delta_ns; 117 u32 mult; 118 u32 shift; 119 enum clock_event_mode mode; 120 enum clock_event_state state_use_accessors; 121 unsigned int features; 122 unsigned long retries; 123 124 /* 125 * State transition callback(s): Only one of the two groups should be 126 * defined: 127 * - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME. 128 * - set_state_{shutdown|periodic|oneshot|oneshot_stopped}(), tick_resume(). 129 */ 130 void (*set_mode)(enum clock_event_mode mode, struct clock_event_device *); 131 int (*set_state_periodic)(struct clock_event_device *); 132 int (*set_state_oneshot)(struct clock_event_device *); 133 int (*set_state_oneshot_stopped)(struct clock_event_device *); 134 int (*set_state_shutdown)(struct clock_event_device *); 135 int (*tick_resume)(struct clock_event_device *); 136 137 void (*broadcast)(const struct cpumask *mask); 138 void (*suspend)(struct clock_event_device *); 139 void (*resume)(struct clock_event_device *); 140 unsigned long min_delta_ticks; 141 unsigned long max_delta_ticks; 142 143 const char *name; 144 int rating; 145 int irq; 146 int bound_on; 147 const struct cpumask *cpumask; 148 struct list_head list; 149 struct module *owner; 150 } ____cacheline_aligned; 151 152 /* Helpers to verify state of a clockevent device */ 153 static inline bool clockevent_state_detached(struct clock_event_device *dev) 154 { 155 return dev->state_use_accessors == CLOCK_EVT_STATE_DETACHED; 156 } 157 158 static inline bool clockevent_state_shutdown(struct clock_event_device *dev) 159 { 160 return dev->state_use_accessors == CLOCK_EVT_STATE_SHUTDOWN; 161 } 162 163 static inline bool clockevent_state_periodic(struct clock_event_device *dev) 164 { 165 return dev->state_use_accessors == CLOCK_EVT_STATE_PERIODIC; 166 } 167 168 static inline bool clockevent_state_oneshot(struct clock_event_device *dev) 169 { 170 return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT; 171 } 172 173 static inline bool clockevent_state_oneshot_stopped(struct clock_event_device *dev) 174 { 175 return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT_STOPPED; 176 } 177 178 /* 179 * Calculate a multiplication factor for scaled math, which is used to convert 180 * nanoseconds based values to clock ticks: 181 * 182 * clock_ticks = (nanoseconds * factor) >> shift. 183 * 184 * div_sc is the rearranged equation to calculate a factor from a given clock 185 * ticks / nanoseconds ratio: 186 * 187 * factor = (clock_ticks << shift) / nanoseconds 188 */ 189 static inline unsigned long 190 div_sc(unsigned long ticks, unsigned long nsec, int shift) 191 { 192 u64 tmp = ((u64)ticks) << shift; 193 194 do_div(tmp, nsec); 195 196 return (unsigned long) tmp; 197 } 198 199 /* Clock event layer functions */ 200 extern u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt); 201 extern void clockevents_register_device(struct clock_event_device *dev); 202 extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu); 203 204 extern void clockevents_config(struct clock_event_device *dev, u32 freq); 205 extern void clockevents_config_and_register(struct clock_event_device *dev, 206 u32 freq, unsigned long min_delta, 207 unsigned long max_delta); 208 209 extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq); 210 211 static inline void 212 clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec) 213 { 214 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, freq, minsec); 215 } 216 217 extern void clockevents_suspend(void); 218 extern void clockevents_resume(void); 219 220 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 221 # ifdef CONFIG_ARCH_HAS_TICK_BROADCAST 222 extern void tick_broadcast(const struct cpumask *mask); 223 # else 224 # define tick_broadcast NULL 225 # endif 226 extern int tick_receive_broadcast(void); 227 # endif 228 229 # if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) 230 extern void tick_setup_hrtimer_broadcast(void); 231 extern int tick_check_broadcast_expired(void); 232 # else 233 static inline int tick_check_broadcast_expired(void) { return 0; } 234 static inline void tick_setup_hrtimer_broadcast(void) { } 235 # endif 236 237 extern int clockevents_notify(unsigned long reason, void *arg); 238 239 #else /* !CONFIG_GENERIC_CLOCKEVENTS: */ 240 241 static inline void clockevents_suspend(void) { } 242 static inline void clockevents_resume(void) { } 243 static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; } 244 static inline int tick_check_broadcast_expired(void) { return 0; } 245 static inline void tick_setup_hrtimer_broadcast(void) { } 246 247 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ 248 249 #endif /* _LINUX_CLOCKCHIPS_H */ 250