Linux kernel mirror (for testing)
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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
18struct clock_event_device;
19
20/* Clock event mode commands */
21enum 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 */
30enum 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 */
76struct 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 */
108static 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 */
118extern unsigned long clockevent_delta2ns(unsigned long latch,
119 struct clock_event_device *evt);
120extern void clockevents_register_device(struct clock_event_device *dev);
121
122extern void clockevents_exchange_device(struct clock_event_device *old,
123 struct clock_event_device *new);
124extern void clockevents_set_mode(struct clock_event_device *dev,
125 enum clock_event_mode mode);
126extern int clockevents_register_notifier(struct notifier_block *nb);
127extern int clockevents_program_event(struct clock_event_device *dev,
128 ktime_t expires, ktime_t now);
129
130#ifdef CONFIG_GENERIC_CLOCKEVENTS
131extern 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