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