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 * @name: ptr to clock event name 60 * @features: features 61 * @max_delta_ns: maximum delta value in ns 62 * @min_delta_ns: minimum delta value in ns 63 * @mult: nanosecond to cycles multiplier 64 * @shift: nanoseconds to cycles divisor (power of two) 65 * @rating: variable to rate clock event devices 66 * @irq: IRQ number (only for non CPU local devices) 67 * @cpumask: cpumask to indicate for which CPUs this device works 68 * @set_next_event: set next event function 69 * @set_mode: set mode function 70 * @event_handler: Assigned by the framework to be called by the low 71 * level handler of the event source 72 * @broadcast: function to broadcast events 73 * @list: list head for the management code 74 * @mode: operating mode assigned by the management code 75 * @next_event: local storage for the next event in oneshot mode 76 */ 77 struct clock_event_device { 78 const char *name; 79 unsigned int features; 80 u64 max_delta_ns; 81 u64 min_delta_ns; 82 u32 mult; 83 u32 shift; 84 int rating; 85 int irq; 86 const struct cpumask *cpumask; 87 int (*set_next_event)(unsigned long evt, 88 struct clock_event_device *); 89 void (*set_mode)(enum clock_event_mode mode, 90 struct clock_event_device *); 91 void (*event_handler)(struct clock_event_device *); 92 void (*broadcast)(const struct cpumask *mask); 93 struct list_head list; 94 enum clock_event_mode mode; 95 ktime_t next_event; 96 }; 97 98 /* 99 * Calculate a multiplication factor for scaled math, which is used to convert 100 * nanoseconds based values to clock ticks: 101 * 102 * clock_ticks = (nanoseconds * factor) >> shift. 103 * 104 * div_sc is the rearranged equation to calculate a factor from a given clock 105 * ticks / nanoseconds ratio: 106 * 107 * factor = (clock_ticks << shift) / nanoseconds 108 */ 109 static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec, 110 int shift) 111 { 112 uint64_t tmp = ((uint64_t)ticks) << shift; 113 114 do_div(tmp, nsec); 115 return (unsigned long) tmp; 116 } 117 118 /* Clock event layer functions */ 119 extern u64 clockevent_delta2ns(unsigned long latch, 120 struct clock_event_device *evt); 121 extern void clockevents_register_device(struct clock_event_device *dev); 122 123 extern void clockevents_exchange_device(struct clock_event_device *old, 124 struct clock_event_device *new); 125 extern void clockevents_set_mode(struct clock_event_device *dev, 126 enum clock_event_mode mode); 127 extern int clockevents_register_notifier(struct notifier_block *nb); 128 extern int clockevents_program_event(struct clock_event_device *dev, 129 ktime_t expires, ktime_t now); 130 131 extern void clockevents_handle_noop(struct clock_event_device *dev); 132 133 static inline void 134 clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec) 135 { 136 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, 137 freq, minsec); 138 } 139 140 #ifdef CONFIG_GENERIC_CLOCKEVENTS 141 extern void clockevents_notify(unsigned long reason, void *arg); 142 #else 143 # define clockevents_notify(reason, arg) do { } while (0) 144 #endif 145 146 #else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */ 147 148 #define clockevents_notify(reason, arg) do { } while (0) 149 150 #endif 151 152 #endif 153