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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#define CLOCK_EVT_FEAT_PERCPU 0x000040
64
65/*
66 * Clockevent device is based on a hrtimer for broadcast
67 */
68#define CLOCK_EVT_FEAT_HRTIMER 0x000080
69
70/**
71 * struct clock_event_device - clock event device descriptor
72 * @event_handler: Assigned by the framework to be called by the low
73 * level handler of the event source
74 * @set_next_event: set next event function using a clocksource delta
75 * @set_next_ktime: set next event function using a direct ktime value
76 * @next_event: local storage for the next event in oneshot mode
77 * @max_delta_ns: maximum delta value in ns
78 * @min_delta_ns: minimum delta value in ns
79 * @mult: nanosecond to cycles multiplier
80 * @shift: nanoseconds to cycles divisor (power of two)
81 * @mode: operating mode assigned by the management code
82 * @features: features
83 * @retries: number of forced programming retries
84 * @set_mode: set mode function
85 * @broadcast: function to broadcast events
86 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration
87 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration
88 * @name: ptr to clock event name
89 * @rating: variable to rate clock event devices
90 * @irq: IRQ number (only for non CPU local devices)
91 * @bound_on: Bound on CPU
92 * @cpumask: cpumask to indicate for which CPUs this device works
93 * @list: list head for the management code
94 * @owner: module reference
95 */
96struct clock_event_device {
97 void (*event_handler)(struct clock_event_device *);
98 int (*set_next_event)(unsigned long evt,
99 struct clock_event_device *);
100 int (*set_next_ktime)(ktime_t expires,
101 struct clock_event_device *);
102 ktime_t next_event;
103 u64 max_delta_ns;
104 u64 min_delta_ns;
105 u32 mult;
106 u32 shift;
107 enum clock_event_mode mode;
108 unsigned int features;
109 unsigned long retries;
110
111 void (*broadcast)(const struct cpumask *mask);
112 void (*set_mode)(enum clock_event_mode mode,
113 struct clock_event_device *);
114 void (*suspend)(struct clock_event_device *);
115 void (*resume)(struct clock_event_device *);
116 unsigned long min_delta_ticks;
117 unsigned long max_delta_ticks;
118
119 const char *name;
120 int rating;
121 int irq;
122 int bound_on;
123 const struct cpumask *cpumask;
124 struct list_head list;
125 struct module *owner;
126} ____cacheline_aligned;
127
128/*
129 * Calculate a multiplication factor for scaled math, which is used to convert
130 * nanoseconds based values to clock ticks:
131 *
132 * clock_ticks = (nanoseconds * factor) >> shift.
133 *
134 * div_sc is the rearranged equation to calculate a factor from a given clock
135 * ticks / nanoseconds ratio:
136 *
137 * factor = (clock_ticks << shift) / nanoseconds
138 */
139static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec,
140 int shift)
141{
142 uint64_t tmp = ((uint64_t)ticks) << shift;
143
144 do_div(tmp, nsec);
145 return (unsigned long) tmp;
146}
147
148/* Clock event layer functions */
149extern u64 clockevent_delta2ns(unsigned long latch,
150 struct clock_event_device *evt);
151extern void clockevents_register_device(struct clock_event_device *dev);
152extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu);
153
154extern void clockevents_config(struct clock_event_device *dev, u32 freq);
155extern void clockevents_config_and_register(struct clock_event_device *dev,
156 u32 freq, unsigned long min_delta,
157 unsigned long max_delta);
158
159extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);
160
161extern void clockevents_exchange_device(struct clock_event_device *old,
162 struct clock_event_device *new);
163extern void clockevents_set_mode(struct clock_event_device *dev,
164 enum clock_event_mode mode);
165extern int clockevents_program_event(struct clock_event_device *dev,
166 ktime_t expires, bool force);
167
168extern void clockevents_handle_noop(struct clock_event_device *dev);
169
170static inline void
171clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
172{
173 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC,
174 freq, minsec);
175}
176
177extern void clockevents_suspend(void);
178extern void clockevents_resume(void);
179
180#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
181#ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
182extern void tick_broadcast(const struct cpumask *mask);
183#else
184#define tick_broadcast NULL
185#endif
186extern int tick_receive_broadcast(void);
187#endif
188
189#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
190extern void tick_setup_hrtimer_broadcast(void);
191extern int tick_check_broadcast_expired(void);
192#else
193static inline int tick_check_broadcast_expired(void) { return 0; }
194static inline void tick_setup_hrtimer_broadcast(void) {};
195#endif
196
197#ifdef CONFIG_GENERIC_CLOCKEVENTS
198extern int clockevents_notify(unsigned long reason, void *arg);
199#else
200static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
201#endif
202
203#else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */
204
205static inline void clockevents_suspend(void) {}
206static inline void clockevents_resume(void) {}
207
208static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
209static inline int tick_check_broadcast_expired(void) { return 0; }
210static inline void tick_setup_hrtimer_broadcast(void) {};
211
212#endif
213
214#endif