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