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_BUILD 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 20 /* Clock event mode commands */ 21 enum clock_event_mode { 22 CLOCK_EVT_MODE_UNUSED = 0, 23 CLOCK_EVT_MODE_SHUTDOWN, 24 CLOCK_EVT_MODE_PERIODIC, 25 CLOCK_EVT_MODE_ONESHOT, 26 CLOCK_EVT_MODE_RESUME, 27 }; 28 29 /* Clock event notification values */ 30 enum clock_event_nofitiers { 31 CLOCK_EVT_NOTIFY_ADD, 32 CLOCK_EVT_NOTIFY_BROADCAST_ON, 33 CLOCK_EVT_NOTIFY_BROADCAST_OFF, 34 CLOCK_EVT_NOTIFY_BROADCAST_FORCE, 35 CLOCK_EVT_NOTIFY_BROADCAST_ENTER, 36 CLOCK_EVT_NOTIFY_BROADCAST_EXIT, 37 CLOCK_EVT_NOTIFY_SUSPEND, 38 CLOCK_EVT_NOTIFY_RESUME, 39 CLOCK_EVT_NOTIFY_CPU_DYING, 40 CLOCK_EVT_NOTIFY_CPU_DEAD, 41 }; 42 43 /* 44 * Clock event features 45 */ 46 #define CLOCK_EVT_FEAT_PERIODIC 0x000001 47 #define CLOCK_EVT_FEAT_ONESHOT 0x000002 48 /* 49 * x86(64) specific misfeatures: 50 * 51 * - Clockevent source stops in C3 State and needs broadcast support. 52 * - Local APIC timer is used as a dummy device. 53 */ 54 #define CLOCK_EVT_FEAT_C3STOP 0x000004 55 #define CLOCK_EVT_FEAT_DUMMY 0x000008 56 57 /** 58 * struct clock_event_device - clock event device descriptor 59 * @event_handler: Assigned by the framework to be called by the low 60 * level handler of the event source 61 * @set_next_event: set next event function 62 * @next_event: local storage for the next event in oneshot mode 63 * @max_delta_ns: maximum delta value in ns 64 * @min_delta_ns: minimum delta value in ns 65 * @mult: nanosecond to cycles multiplier 66 * @shift: nanoseconds to cycles divisor (power of two) 67 * @mode: operating mode assigned by the management code 68 * @features: features 69 * @retries: number of forced programming retries 70 * @set_mode: set mode function 71 * @broadcast: function to broadcast events 72 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration 73 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration 74 * @name: ptr to clock event name 75 * @rating: variable to rate clock event devices 76 * @irq: IRQ number (only for non CPU local devices) 77 * @cpumask: cpumask to indicate for which CPUs this device works 78 * @list: list head for the management code 79 */ 80 struct clock_event_device { 81 void (*event_handler)(struct clock_event_device *); 82 int (*set_next_event)(unsigned long evt, 83 struct clock_event_device *); 84 ktime_t next_event; 85 u64 max_delta_ns; 86 u64 min_delta_ns; 87 u32 mult; 88 u32 shift; 89 enum clock_event_mode mode; 90 unsigned int features; 91 unsigned long retries; 92 93 void (*broadcast)(const struct cpumask *mask); 94 void (*set_mode)(enum clock_event_mode mode, 95 struct clock_event_device *); 96 unsigned long min_delta_ticks; 97 unsigned long max_delta_ticks; 98 99 const char *name; 100 int rating; 101 int irq; 102 const struct cpumask *cpumask; 103 struct list_head list; 104 } ____cacheline_aligned; 105 106 /* 107 * Calculate a multiplication factor for scaled math, which is used to convert 108 * nanoseconds based values to clock ticks: 109 * 110 * clock_ticks = (nanoseconds * factor) >> shift. 111 * 112 * div_sc is the rearranged equation to calculate a factor from a given clock 113 * ticks / nanoseconds ratio: 114 * 115 * factor = (clock_ticks << shift) / nanoseconds 116 */ 117 static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec, 118 int shift) 119 { 120 uint64_t tmp = ((uint64_t)ticks) << shift; 121 122 do_div(tmp, nsec); 123 return (unsigned long) tmp; 124 } 125 126 /* Clock event layer functions */ 127 extern u64 clockevent_delta2ns(unsigned long latch, 128 struct clock_event_device *evt); 129 extern void clockevents_register_device(struct clock_event_device *dev); 130 131 extern void clockevents_config_and_register(struct clock_event_device *dev, 132 u32 freq, unsigned long min_delta, 133 unsigned long max_delta); 134 135 extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq); 136 137 extern void clockevents_exchange_device(struct clock_event_device *old, 138 struct clock_event_device *new); 139 extern void clockevents_set_mode(struct clock_event_device *dev, 140 enum clock_event_mode mode); 141 extern int clockevents_register_notifier(struct notifier_block *nb); 142 extern int clockevents_program_event(struct clock_event_device *dev, 143 ktime_t expires, ktime_t now); 144 145 extern void clockevents_handle_noop(struct clock_event_device *dev); 146 147 static inline void 148 clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec) 149 { 150 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, 151 freq, minsec); 152 } 153 154 #ifdef CONFIG_GENERIC_CLOCKEVENTS 155 extern void clockevents_notify(unsigned long reason, void *arg); 156 #else 157 # define clockevents_notify(reason, arg) do { } while (0) 158 #endif 159 160 #else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */ 161 162 #define clockevents_notify(reason, arg) do { } while (0) 163 164 #endif 165 166 #endif 167