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