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_DYING,
40 CLOCK_EVT_NOTIFY_CPU_DEAD,
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 * struct clock_event_device - clock event device descriptor
60 * @event_handler: Assigned by the framework to be called by the low
61 * level handler of the event source
62 * @set_next_event: set next event function using a clocksource delta
63 * @set_next_ktime: set next event function using a direct ktime value
64 * @next_event: local storage for the next event in oneshot mode
65 * @max_delta_ns: maximum delta value in ns
66 * @min_delta_ns: minimum delta value in ns
67 * @mult: nanosecond to cycles multiplier
68 * @shift: nanoseconds to cycles divisor (power of two)
69 * @mode: operating mode assigned by the management code
70 * @features: features
71 * @retries: number of forced programming retries
72 * @set_mode: set mode function
73 * @broadcast: function to broadcast events
74 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration
75 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration
76 * @name: ptr to clock event name
77 * @rating: variable to rate clock event devices
78 * @irq: IRQ number (only for non CPU local devices)
79 * @cpumask: cpumask to indicate for which CPUs this device works
80 * @list: list head for the management code
81 */
82 struct clock_event_device {
83 void (*event_handler)(struct clock_event_device *);
84 int (*set_next_event)(unsigned long evt,
85 struct clock_event_device *);
86 int (*set_next_ktime)(ktime_t expires,
87 struct clock_event_device *);
88 ktime_t next_event;
89 u64 max_delta_ns;
90 u64 min_delta_ns;
91 u32 mult;
92 u32 shift;
93 enum clock_event_mode mode;
94 unsigned int features;
95 unsigned long retries;
96
97 void (*broadcast)(const struct cpumask *mask);
98 void (*set_mode)(enum clock_event_mode mode,
99 struct clock_event_device *);
100 unsigned long min_delta_ticks;
101 unsigned long max_delta_ticks;
102
103 const char *name;
104 int rating;
105 int irq;
106 const struct cpumask *cpumask;
107 struct list_head list;
108 } ____cacheline_aligned;
109
110 /*
111 * Calculate a multiplication factor for scaled math, which is used to convert
112 * nanoseconds based values to clock ticks:
113 *
114 * clock_ticks = (nanoseconds * factor) >> shift.
115 *
116 * div_sc is the rearranged equation to calculate a factor from a given clock
117 * ticks / nanoseconds ratio:
118 *
119 * factor = (clock_ticks << shift) / nanoseconds
120 */
div_sc(unsigned long ticks,unsigned long nsec,int shift)121 static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec,
122 int shift)
123 {
124 uint64_t tmp = ((uint64_t)ticks) << shift;
125
126 do_div(tmp, nsec);
127 return (unsigned long) tmp;
128 }
129
130 /* Clock event layer functions */
131 extern u64 clockevent_delta2ns(unsigned long latch,
132 struct clock_event_device *evt);
133 extern void clockevents_register_device(struct clock_event_device *dev);
134
135 extern void clockevents_config_and_register(struct clock_event_device *dev,
136 u32 freq, unsigned long min_delta,
137 unsigned long max_delta);
138
139 extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);
140
141 extern void clockevents_exchange_device(struct clock_event_device *old,
142 struct clock_event_device *new);
143 extern void clockevents_set_mode(struct clock_event_device *dev,
144 enum clock_event_mode mode);
145 extern int clockevents_register_notifier(struct notifier_block *nb);
146 extern int clockevents_program_event(struct clock_event_device *dev,
147 ktime_t expires, bool force);
148
149 extern void clockevents_handle_noop(struct clock_event_device *dev);
150
151 static inline void
clockevents_calc_mult_shift(struct clock_event_device * ce,u32 freq,u32 minsec)152 clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
153 {
154 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC,
155 freq, minsec);
156 }
157
158 #ifdef CONFIG_GENERIC_CLOCKEVENTS
159 extern void clockevents_notify(unsigned long reason, void *arg);
160 #else
161 # define clockevents_notify(reason, arg) do { } while (0)
162 #endif
163
164 #else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */
165
166 #define clockevents_notify(reason, arg) do { } while (0)
167
168 #endif
169
170 #endif
171