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 */ 41 enum clock_event_state { 42 CLOCK_EVT_STATE_DETACHED, 43 CLOCK_EVT_STATE_SHUTDOWN, 44 CLOCK_EVT_STATE_PERIODIC, 45 CLOCK_EVT_STATE_ONESHOT, 46 }; 47 48 /* 49 * Clock event features 50 */ 51 # define CLOCK_EVT_FEAT_PERIODIC 0x000001 52 # define CLOCK_EVT_FEAT_ONESHOT 0x000002 53 # define CLOCK_EVT_FEAT_KTIME 0x000004 54 55 /* 56 * x86(64) specific (mis)features: 57 * 58 * - Clockevent source stops in C3 State and needs broadcast support. 59 * - Local APIC timer is used as a dummy device. 60 */ 61 # define CLOCK_EVT_FEAT_C3STOP 0x000008 62 # define CLOCK_EVT_FEAT_DUMMY 0x000010 63 64 /* 65 * Core shall set the interrupt affinity dynamically in broadcast mode 66 */ 67 # define CLOCK_EVT_FEAT_DYNIRQ 0x000020 68 # define CLOCK_EVT_FEAT_PERCPU 0x000040 69 70 /* 71 * Clockevent device is based on a hrtimer for broadcast 72 */ 73 # define CLOCK_EVT_FEAT_HRTIMER 0x000080 74 75 /** 76 * struct clock_event_device - clock event device descriptor 77 * @event_handler: Assigned by the framework to be called by the low 78 * level handler of the event source 79 * @set_next_event: set next event function using a clocksource delta 80 * @set_next_ktime: set next event function using a direct ktime value 81 * @next_event: local storage for the next event in oneshot mode 82 * @max_delta_ns: maximum delta value in ns 83 * @min_delta_ns: minimum delta value in ns 84 * @mult: nanosecond to cycles multiplier 85 * @shift: nanoseconds to cycles divisor (power of two) 86 * @mode: operating mode, relevant only to ->set_mode(), OBSOLETE 87 * @state: current state of the device, assigned by the core code 88 * @features: features 89 * @retries: number of forced programming retries 90 * @set_mode: legacy set mode function, only for modes <= CLOCK_EVT_MODE_RESUME. 91 * @set_state_periodic: switch state to periodic, if !set_mode 92 * @set_state_oneshot: switch state to oneshot, if !set_mode 93 * @set_state_shutdown: switch state to shutdown, if !set_mode 94 * @tick_resume: resume clkevt device, if !set_mode 95 * @broadcast: function to broadcast events 96 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration 97 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration 98 * @name: ptr to clock event name 99 * @rating: variable to rate clock event devices 100 * @irq: IRQ number (only for non CPU local devices) 101 * @bound_on: Bound on CPU 102 * @cpumask: cpumask to indicate for which CPUs this device works 103 * @list: list head for the management code 104 * @owner: module reference 105 */ 106 struct clock_event_device { 107 void (*event_handler)(struct clock_event_device *); 108 int (*set_next_event)(unsigned long evt, struct clock_event_device *); 109 int (*set_next_ktime)(ktime_t expires, struct clock_event_device *); 110 ktime_t next_event; 111 u64 max_delta_ns; 112 u64 min_delta_ns; 113 u32 mult; 114 u32 shift; 115 enum clock_event_mode mode; 116 enum clock_event_state state; 117 unsigned int features; 118 unsigned long retries; 119 120 /* 121 * State transition callback(s): Only one of the two groups should be 122 * defined: 123 * - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME. 124 * - set_state_{shutdown|periodic|oneshot}(), tick_resume(). 125 */ 126 void (*set_mode)(enum clock_event_mode mode, struct clock_event_device *); 127 int (*set_state_periodic)(struct clock_event_device *); 128 int (*set_state_oneshot)(struct clock_event_device *); 129 int (*set_state_shutdown)(struct clock_event_device *); 130 int (*tick_resume)(struct clock_event_device *); 131 132 void (*broadcast)(const struct cpumask *mask); 133 void (*suspend)(struct clock_event_device *); 134 void (*resume)(struct clock_event_device *); 135 unsigned long min_delta_ticks; 136 unsigned long max_delta_ticks; 137 138 const char *name; 139 int rating; 140 int irq; 141 int bound_on; 142 const struct cpumask *cpumask; 143 struct list_head list; 144 struct module *owner; 145 } ____cacheline_aligned; 146 147 /* 148 * Calculate a multiplication factor for scaled math, which is used to convert 149 * nanoseconds based values to clock ticks: 150 * 151 * clock_ticks = (nanoseconds * factor) >> shift. 152 * 153 * div_sc is the rearranged equation to calculate a factor from a given clock 154 * ticks / nanoseconds ratio: 155 * 156 * factor = (clock_ticks << shift) / nanoseconds 157 */ 158 static inline unsigned long 159 div_sc(unsigned long ticks, unsigned long nsec, int shift) 160 { 161 u64 tmp = ((u64)ticks) << shift; 162 163 do_div(tmp, nsec); 164 165 return (unsigned long) tmp; 166 } 167 168 /* Clock event layer functions */ 169 extern u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt); 170 extern void clockevents_register_device(struct clock_event_device *dev); 171 extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu); 172 173 extern void clockevents_config(struct clock_event_device *dev, u32 freq); 174 extern void clockevents_config_and_register(struct clock_event_device *dev, 175 u32 freq, unsigned long min_delta, 176 unsigned long max_delta); 177 178 extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq); 179 180 static inline void 181 clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec) 182 { 183 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, freq, minsec); 184 } 185 186 extern void clockevents_suspend(void); 187 extern void clockevents_resume(void); 188 189 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 190 # ifdef CONFIG_ARCH_HAS_TICK_BROADCAST 191 extern void tick_broadcast(const struct cpumask *mask); 192 # else 193 # define tick_broadcast NULL 194 # endif 195 extern int tick_receive_broadcast(void); 196 # endif 197 198 # if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) 199 extern void tick_setup_hrtimer_broadcast(void); 200 extern int tick_check_broadcast_expired(void); 201 # else 202 static inline int tick_check_broadcast_expired(void) { return 0; } 203 static inline void tick_setup_hrtimer_broadcast(void) { } 204 # endif 205 206 extern int clockevents_notify(unsigned long reason, void *arg); 207 208 #else /* !CONFIG_GENERIC_CLOCKEVENTS: */ 209 210 static inline void clockevents_suspend(void) { } 211 static inline void clockevents_resume(void) { } 212 static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; } 213 static inline int tick_check_broadcast_expired(void) { return 0; } 214 static inline void tick_setup_hrtimer_broadcast(void) { } 215 216 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ 217 218 #endif /* _LINUX_CLOCKCHIPS_H */ 219