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 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 }; 27 28 /* Clock event notification values */ 29 enum clock_event_nofitiers { 30 CLOCK_EVT_NOTIFY_ADD, 31 CLOCK_EVT_NOTIFY_BROADCAST_ON, 32 CLOCK_EVT_NOTIFY_BROADCAST_OFF, 33 CLOCK_EVT_NOTIFY_BROADCAST_ENTER, 34 CLOCK_EVT_NOTIFY_BROADCAST_EXIT, 35 CLOCK_EVT_NOTIFY_SUSPEND, 36 CLOCK_EVT_NOTIFY_RESUME, 37 CLOCK_EVT_NOTIFY_CPU_DEAD, 38 }; 39 40 /* 41 * Clock event features 42 */ 43 #define CLOCK_EVT_FEAT_PERIODIC 0x000001 44 #define CLOCK_EVT_FEAT_ONESHOT 0x000002 45 /* 46 * x86(64) specific misfeatures: 47 * 48 * - Clockevent source stops in C3 State and needs broadcast support. 49 * - Local APIC timer is used as a dummy device. 50 */ 51 #define CLOCK_EVT_FEAT_C3STOP 0x000004 52 #define CLOCK_EVT_FEAT_DUMMY 0x000008 53 54 /** 55 * struct clock_event_device - clock event device descriptor 56 * @name: ptr to clock event name 57 * @hints: usage hints 58 * @max_delta_ns: maximum delta value in ns 59 * @min_delta_ns: minimum delta value in ns 60 * @mult: nanosecond to cycles multiplier 61 * @shift: nanoseconds to cycles divisor (power of two) 62 * @rating: variable to rate clock event devices 63 * @irq: irq number (only for non cpu local devices) 64 * @cpumask: cpumask to indicate for which cpus this device works 65 * @set_next_event: set next event 66 * @set_mode: set mode function 67 * @evthandler: Assigned by the framework to be called by the low 68 * level handler of the event source 69 * @broadcast: function to broadcast events 70 * @list: list head for the management code 71 * @mode: operating mode assigned by the management code 72 * @next_event: local storage for the next event in oneshot mode 73 */ 74 struct clock_event_device { 75 const char *name; 76 unsigned int features; 77 unsigned long max_delta_ns; 78 unsigned long min_delta_ns; 79 unsigned long mult; 80 int shift; 81 int rating; 82 int irq; 83 cpumask_t cpumask; 84 int (*set_next_event)(unsigned long evt, 85 struct clock_event_device *); 86 void (*set_mode)(enum clock_event_mode mode, 87 struct clock_event_device *); 88 void (*event_handler)(struct clock_event_device *); 89 void (*broadcast)(cpumask_t mask); 90 struct list_head list; 91 enum clock_event_mode mode; 92 ktime_t next_event; 93 }; 94 95 /* 96 * Calculate a multiplication factor for scaled math, which is used to convert 97 * nanoseconds based values to clock ticks: 98 * 99 * clock_ticks = (nanoseconds * factor) >> shift. 100 * 101 * div_sc is the rearranged equation to calculate a factor from a given clock 102 * ticks / nanoseconds ratio: 103 * 104 * factor = (clock_ticks << shift) / nanoseconds 105 */ 106 static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec, 107 int shift) 108 { 109 uint64_t tmp = ((uint64_t)ticks) << shift; 110 111 do_div(tmp, nsec); 112 return (unsigned long) tmp; 113 } 114 115 /* Clock event layer functions */ 116 extern unsigned long clockevent_delta2ns(unsigned long latch, 117 struct clock_event_device *evt); 118 extern void clockevents_register_device(struct clock_event_device *dev); 119 120 extern void clockevents_exchange_device(struct clock_event_device *old, 121 struct clock_event_device *new); 122 extern 123 struct clock_event_device *clockevents_request_device(unsigned int features, 124 cpumask_t cpumask); 125 extern void clockevents_release_device(struct clock_event_device *dev); 126 extern void clockevents_set_mode(struct clock_event_device *dev, 127 enum clock_event_mode mode); 128 extern int clockevents_register_notifier(struct notifier_block *nb); 129 extern void clockevents_unregister_notifier(struct notifier_block *nb); 130 extern int clockevents_program_event(struct clock_event_device *dev, 131 ktime_t expires, ktime_t now); 132 133 extern void clockevents_notify(unsigned long reason, void *arg); 134 135 #else 136 137 static inline void clockevents_resume_events(void) { } 138 #define clockevents_notify(reason, arg) do { } while (0) 139 140 #endif 141 142 #endif 143