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