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