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