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1 /* linux/include/linux/clockchips.h
3 * This file contains the structure definitions for clockchips.
5 * If you are not a clockchip, or the time of day code, you should
6 * not be including this file!
8 #ifndef _LINUX_CLOCKCHIPS_H
9 #define _LINUX_CLOCKCHIPS_H
11 #ifdef CONFIG_GENERIC_CLOCKEVENTS
13 # include <linux/clocksource.h>
14 # include <linux/cpumask.h>
15 # include <linux/ktime.h>
16 # include <linux/notifier.h>
18 struct clock_event_device
;
21 /* Clock event mode commands for legacy ->set_mode(): OBSOLETE */
22 enum clock_event_mode
{
23 CLOCK_EVT_MODE_UNUSED
,
24 CLOCK_EVT_MODE_SHUTDOWN
,
25 CLOCK_EVT_MODE_PERIODIC
,
26 CLOCK_EVT_MODE_ONESHOT
,
27 CLOCK_EVT_MODE_RESUME
,
31 * Possible states of a clock event device.
33 * DETACHED: Device is not used by clockevents core. Initial state or can be
34 * reached from SHUTDOWN.
35 * SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT.
36 * PERIODIC: Device is programmed to generate events periodically. Can be
37 * reached from DETACHED or SHUTDOWN.
38 * ONESHOT: Device is programmed to generate event only once. Can be reached
39 * from DETACHED or SHUTDOWN.
41 enum clock_event_state
{
42 CLOCK_EVT_STATE_DETACHED
,
43 CLOCK_EVT_STATE_SHUTDOWN
,
44 CLOCK_EVT_STATE_PERIODIC
,
45 CLOCK_EVT_STATE_ONESHOT
,
49 * Clock event features
51 # define CLOCK_EVT_FEAT_PERIODIC 0x000001
52 # define CLOCK_EVT_FEAT_ONESHOT 0x000002
53 # define CLOCK_EVT_FEAT_KTIME 0x000004
56 * x86(64) specific (mis)features:
58 * - Clockevent source stops in C3 State and needs broadcast support.
59 * - Local APIC timer is used as a dummy device.
61 # define CLOCK_EVT_FEAT_C3STOP 0x000008
62 # define CLOCK_EVT_FEAT_DUMMY 0x000010
65 * Core shall set the interrupt affinity dynamically in broadcast mode
67 # define CLOCK_EVT_FEAT_DYNIRQ 0x000020
68 # define CLOCK_EVT_FEAT_PERCPU 0x000040
71 * Clockevent device is based on a hrtimer for broadcast
73 # define CLOCK_EVT_FEAT_HRTIMER 0x000080
76 * struct clock_event_device - clock event device descriptor
77 * @event_handler: Assigned by the framework to be called by the low
78 * level handler of the event source
79 * @set_next_event: set next event function using a clocksource delta
80 * @set_next_ktime: set next event function using a direct ktime value
81 * @next_event: local storage for the next event in oneshot mode
82 * @max_delta_ns: maximum delta value in ns
83 * @min_delta_ns: minimum delta value in ns
84 * @mult: nanosecond to cycles multiplier
85 * @shift: nanoseconds to cycles divisor (power of two)
86 * @mode: operating mode, relevant only to ->set_mode(), OBSOLETE
87 * @state: current state of the device, assigned by the core code
89 * @retries: number of forced programming retries
90 * @set_mode: legacy set mode function, only for modes <= CLOCK_EVT_MODE_RESUME.
91 * @set_state_periodic: switch state to periodic, if !set_mode
92 * @set_state_oneshot: switch state to oneshot, if !set_mode
93 * @set_state_shutdown: switch state to shutdown, if !set_mode
94 * @tick_resume: resume clkevt device, if !set_mode
95 * @broadcast: function to broadcast events
96 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration
97 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration
98 * @name: ptr to clock event name
99 * @rating: variable to rate clock event devices
100 * @irq: IRQ number (only for non CPU local devices)
101 * @bound_on: Bound on CPU
102 * @cpumask: cpumask to indicate for which CPUs this device works
103 * @list: list head for the management code
104 * @owner: module reference
106 struct clock_event_device
{
107 void (*event_handler
)(struct clock_event_device
*);
108 int (*set_next_event
)(unsigned long evt
, struct clock_event_device
*);
109 int (*set_next_ktime
)(ktime_t expires
, struct clock_event_device
*);
115 enum clock_event_mode mode
;
116 enum clock_event_state state
;
117 unsigned int features
;
118 unsigned long retries
;
121 * State transition callback(s): Only one of the two groups should be
123 * - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME.
124 * - set_state_{shutdown|periodic|oneshot}(), tick_resume().
126 void (*set_mode
)(enum clock_event_mode mode
, struct clock_event_device
*);
127 int (*set_state_periodic
)(struct clock_event_device
*);
128 int (*set_state_oneshot
)(struct clock_event_device
*);
129 int (*set_state_shutdown
)(struct clock_event_device
*);
130 int (*tick_resume
)(struct clock_event_device
*);
132 void (*broadcast
)(const struct cpumask
*mask
);
133 void (*suspend
)(struct clock_event_device
*);
134 void (*resume
)(struct clock_event_device
*);
135 unsigned long min_delta_ticks
;
136 unsigned long max_delta_ticks
;
142 const struct cpumask
*cpumask
;
143 struct list_head list
;
144 struct module
*owner
;
145 } ____cacheline_aligned
;
148 * Calculate a multiplication factor for scaled math, which is used to convert
149 * nanoseconds based values to clock ticks:
151 * clock_ticks = (nanoseconds * factor) >> shift.
153 * div_sc is the rearranged equation to calculate a factor from a given clock
154 * ticks / nanoseconds ratio:
156 * factor = (clock_ticks << shift) / nanoseconds
158 static inline unsigned long
159 div_sc(unsigned long ticks
, unsigned long nsec
, int shift
)
161 u64 tmp
= ((u64
)ticks
) << shift
;
165 return (unsigned long) tmp
;
168 /* Clock event layer functions */
169 extern u64
clockevent_delta2ns(unsigned long latch
, struct clock_event_device
*evt
);
170 extern void clockevents_register_device(struct clock_event_device
*dev
);
171 extern int clockevents_unbind_device(struct clock_event_device
*ced
, int cpu
);
173 extern void clockevents_config(struct clock_event_device
*dev
, u32 freq
);
174 extern void clockevents_config_and_register(struct clock_event_device
*dev
,
175 u32 freq
, unsigned long min_delta
,
176 unsigned long max_delta
);
178 extern int clockevents_update_freq(struct clock_event_device
*ce
, u32 freq
);
181 clockevents_calc_mult_shift(struct clock_event_device
*ce
, u32 freq
, u32 minsec
)
183 return clocks_calc_mult_shift(&ce
->mult
, &ce
->shift
, NSEC_PER_SEC
, freq
, minsec
);
186 extern void clockevents_suspend(void);
187 extern void clockevents_resume(void);
189 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
190 # ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
191 extern void tick_broadcast(const struct cpumask
*mask
);
193 # define tick_broadcast NULL
195 extern int tick_receive_broadcast(void);
198 # if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
199 extern void tick_setup_hrtimer_broadcast(void);
200 extern int tick_check_broadcast_expired(void);
202 static inline int tick_check_broadcast_expired(void) { return 0; }
203 static inline void tick_setup_hrtimer_broadcast(void) { }
206 extern int clockevents_notify(unsigned long reason
, void *arg
);
208 #else /* !CONFIG_GENERIC_CLOCKEVENTS: */
210 static inline void clockevents_suspend(void) { }
211 static inline void clockevents_resume(void) { }
212 static inline int clockevents_notify(unsigned long reason
, void *arg
) { return 0; }
213 static inline int tick_check_broadcast_expired(void) { return 0; }
214 static inline void tick_setup_hrtimer_broadcast(void) { }
216 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
218 #endif /* _LINUX_CLOCKCHIPS_H */