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