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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/* Clock event notification values */
12enum clock_event_nofitiers {
13 CLOCK_EVT_NOTIFY_ADD,
14 CLOCK_EVT_NOTIFY_BROADCAST_ON,
15 CLOCK_EVT_NOTIFY_BROADCAST_OFF,
16 CLOCK_EVT_NOTIFY_BROADCAST_FORCE,
17 CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
18 CLOCK_EVT_NOTIFY_BROADCAST_EXIT,
19 CLOCK_EVT_NOTIFY_SUSPEND,
20 CLOCK_EVT_NOTIFY_RESUME,
21 CLOCK_EVT_NOTIFY_CPU_DYING,
22 CLOCK_EVT_NOTIFY_CPU_DEAD,
23};
24
25#ifdef CONFIG_GENERIC_CLOCKEVENTS_BUILD
26
27#include <linux/clocksource.h>
28#include <linux/cpumask.h>
29#include <linux/ktime.h>
30#include <linux/notifier.h>
31
32struct clock_event_device;
33struct module;
34
35/* Clock event mode commands */
36enum clock_event_mode {
37 CLOCK_EVT_MODE_UNUSED = 0,
38 CLOCK_EVT_MODE_SHUTDOWN,
39 CLOCK_EVT_MODE_PERIODIC,
40 CLOCK_EVT_MODE_ONESHOT,
41 CLOCK_EVT_MODE_RESUME,
42};
43
44/*
45 * Clock event features
46 */
47#define CLOCK_EVT_FEAT_PERIODIC 0x000001
48#define CLOCK_EVT_FEAT_ONESHOT 0x000002
49#define CLOCK_EVT_FEAT_KTIME 0x000004
50/*
51 * x86(64) specific misfeatures:
52 *
53 * - Clockevent source stops in C3 State and needs broadcast support.
54 * - Local APIC timer is used as a dummy device.
55 */
56#define CLOCK_EVT_FEAT_C3STOP 0x000008
57#define CLOCK_EVT_FEAT_DUMMY 0x000010
58
59/*
60 * Core shall set the interrupt affinity dynamically in broadcast mode
61 */
62#define CLOCK_EVT_FEAT_DYNIRQ 0x000020
63
64/**
65 * struct clock_event_device - clock event device descriptor
66 * @event_handler: Assigned by the framework to be called by the low
67 * level handler of the event source
68 * @set_next_event: set next event function using a clocksource delta
69 * @set_next_ktime: set next event function using a direct ktime value
70 * @next_event: local storage for the next event in oneshot mode
71 * @max_delta_ns: maximum delta value in ns
72 * @min_delta_ns: minimum delta value in ns
73 * @mult: nanosecond to cycles multiplier
74 * @shift: nanoseconds to cycles divisor (power of two)
75 * @mode: operating mode assigned by the management code
76 * @features: features
77 * @retries: number of forced programming retries
78 * @set_mode: set mode function
79 * @broadcast: function to broadcast events
80 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration
81 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration
82 * @name: ptr to clock event name
83 * @rating: variable to rate clock event devices
84 * @irq: IRQ number (only for non CPU local devices)
85 * @cpumask: cpumask to indicate for which CPUs this device works
86 * @list: list head for the management code
87 * @owner: module reference
88 */
89struct clock_event_device {
90 void (*event_handler)(struct clock_event_device *);
91 int (*set_next_event)(unsigned long evt,
92 struct clock_event_device *);
93 int (*set_next_ktime)(ktime_t expires,
94 struct clock_event_device *);
95 ktime_t next_event;
96 u64 max_delta_ns;
97 u64 min_delta_ns;
98 u32 mult;
99 u32 shift;
100 enum clock_event_mode mode;
101 unsigned int features;
102 unsigned long retries;
103
104 void (*broadcast)(const struct cpumask *mask);
105 void (*set_mode)(enum clock_event_mode mode,
106 struct clock_event_device *);
107 void (*suspend)(struct clock_event_device *);
108 void (*resume)(struct clock_event_device *);
109 unsigned long min_delta_ticks;
110 unsigned long max_delta_ticks;
111
112 const char *name;
113 int rating;
114 int irq;
115 const struct cpumask *cpumask;
116 struct list_head list;
117 struct module *owner;
118} ____cacheline_aligned;
119
120/*
121 * Calculate a multiplication factor for scaled math, which is used to convert
122 * nanoseconds based values to clock ticks:
123 *
124 * clock_ticks = (nanoseconds * factor) >> shift.
125 *
126 * div_sc is the rearranged equation to calculate a factor from a given clock
127 * ticks / nanoseconds ratio:
128 *
129 * factor = (clock_ticks << shift) / nanoseconds
130 */
131static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec,
132 int shift)
133{
134 uint64_t tmp = ((uint64_t)ticks) << shift;
135
136 do_div(tmp, nsec);
137 return (unsigned long) tmp;
138}
139
140/* Clock event layer functions */
141extern u64 clockevent_delta2ns(unsigned long latch,
142 struct clock_event_device *evt);
143extern void clockevents_register_device(struct clock_event_device *dev);
144extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu);
145
146extern void clockevents_config(struct clock_event_device *dev, u32 freq);
147extern void clockevents_config_and_register(struct clock_event_device *dev,
148 u32 freq, unsigned long min_delta,
149 unsigned long max_delta);
150
151extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);
152
153extern void clockevents_exchange_device(struct clock_event_device *old,
154 struct clock_event_device *new);
155extern void clockevents_set_mode(struct clock_event_device *dev,
156 enum clock_event_mode mode);
157extern int clockevents_program_event(struct clock_event_device *dev,
158 ktime_t expires, bool force);
159
160extern void clockevents_handle_noop(struct clock_event_device *dev);
161
162static inline void
163clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
164{
165 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC,
166 freq, minsec);
167}
168
169extern void clockevents_suspend(void);
170extern void clockevents_resume(void);
171
172#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
173#ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
174extern void tick_broadcast(const struct cpumask *mask);
175#else
176#define tick_broadcast NULL
177#endif
178extern int tick_receive_broadcast(void);
179#endif
180
181#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
182extern int tick_check_broadcast_expired(void);
183#else
184static inline int tick_check_broadcast_expired(void) { return 0; }
185#endif
186
187#ifdef CONFIG_GENERIC_CLOCKEVENTS
188extern void clockevents_notify(unsigned long reason, void *arg);
189#else
190static inline void clockevents_notify(unsigned long reason, void *arg) {}
191#endif
192
193#else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */
194
195static inline void clockevents_suspend(void) {}
196static inline void clockevents_resume(void) {}
197
198static inline void clockevents_notify(unsigned long reason, void *arg) {}
199static inline int tick_check_broadcast_expired(void) { return 0; }
200
201#endif
202
203#endif