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
;
22 * Possible states of a clock event device.
24 * DETACHED: Device is not used by clockevents core. Initial state or can be
25 * reached from SHUTDOWN.
26 * SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT.
27 * PERIODIC: Device is programmed to generate events periodically. Can be
28 * reached from DETACHED or SHUTDOWN.
29 * ONESHOT: Device is programmed to generate event only once. Can be reached
30 * from DETACHED or SHUTDOWN.
31 * ONESHOT_STOPPED: Device was programmed in ONESHOT mode and is temporarily
34 enum clock_event_state
{
35 CLOCK_EVT_STATE_DETACHED
,
36 CLOCK_EVT_STATE_SHUTDOWN
,
37 CLOCK_EVT_STATE_PERIODIC
,
38 CLOCK_EVT_STATE_ONESHOT
,
39 CLOCK_EVT_STATE_ONESHOT_STOPPED
,
43 * Clock event features
45 # define CLOCK_EVT_FEAT_PERIODIC 0x000001
46 # define CLOCK_EVT_FEAT_ONESHOT 0x000002
47 # define CLOCK_EVT_FEAT_KTIME 0x000004
50 * x86(64) specific (mis)features:
52 * - Clockevent source stops in C3 State and needs broadcast support.
53 * - Local APIC timer is used as a dummy device.
55 # define CLOCK_EVT_FEAT_C3STOP 0x000008
56 # define CLOCK_EVT_FEAT_DUMMY 0x000010
59 * Core shall set the interrupt affinity dynamically in broadcast mode
61 # define CLOCK_EVT_FEAT_DYNIRQ 0x000020
62 # define CLOCK_EVT_FEAT_PERCPU 0x000040
65 * Clockevent device is based on a hrtimer for broadcast
67 # define CLOCK_EVT_FEAT_HRTIMER 0x000080
70 * struct clock_event_device - clock event device descriptor
71 * @event_handler: Assigned by the framework to be called by the low
72 * level handler of the event source
73 * @set_next_event: set next event function using a clocksource delta
74 * @set_next_ktime: set next event function using a direct ktime value
75 * @next_event: local storage for the next event in oneshot mode
76 * @max_delta_ns: maximum delta value in ns
77 * @min_delta_ns: minimum delta value in ns
78 * @mult: nanosecond to cycles multiplier
79 * @shift: nanoseconds to cycles divisor (power of two)
80 * @state_use_accessors:current state of the device, assigned by the core code
82 * @retries: number of forced programming retries
83 * @set_state_periodic: switch state to periodic
84 * @set_state_oneshot: switch state to oneshot
85 * @set_state_oneshot_stopped: switch state to oneshot_stopped
86 * @set_state_shutdown: switch state to shutdown
87 * @tick_resume: resume clkevt device
88 * @broadcast: function to broadcast events
89 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration
90 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration
91 * @name: ptr to clock event name
92 * @rating: variable to rate clock event devices
93 * @irq: IRQ number (only for non CPU local devices)
94 * @bound_on: Bound on CPU
95 * @cpumask: cpumask to indicate for which CPUs this device works
96 * @list: list head for the management code
97 * @owner: module reference
99 struct clock_event_device
{
100 void (*event_handler
)(struct clock_event_device
*);
101 int (*set_next_event
)(unsigned long evt
, struct clock_event_device
*);
102 int (*set_next_ktime
)(ktime_t expires
, struct clock_event_device
*);
108 enum clock_event_state state_use_accessors
;
109 unsigned int features
;
110 unsigned long retries
;
112 int (*set_state_periodic
)(struct clock_event_device
*);
113 int (*set_state_oneshot
)(struct clock_event_device
*);
114 int (*set_state_oneshot_stopped
)(struct clock_event_device
*);
115 int (*set_state_shutdown
)(struct clock_event_device
*);
116 int (*tick_resume
)(struct clock_event_device
*);
118 void (*broadcast
)(const struct cpumask
*mask
);
119 void (*suspend
)(struct clock_event_device
*);
120 void (*resume
)(struct clock_event_device
*);
121 unsigned long min_delta_ticks
;
122 unsigned long max_delta_ticks
;
128 const struct cpumask
*cpumask
;
129 struct list_head list
;
130 struct module
*owner
;
131 } ____cacheline_aligned
;
133 /* Helpers to verify state of a clockevent device */
134 static inline bool clockevent_state_detached(struct clock_event_device
*dev
)
136 return dev
->state_use_accessors
== CLOCK_EVT_STATE_DETACHED
;
139 static inline bool clockevent_state_shutdown(struct clock_event_device
*dev
)
141 return dev
->state_use_accessors
== CLOCK_EVT_STATE_SHUTDOWN
;
144 static inline bool clockevent_state_periodic(struct clock_event_device
*dev
)
146 return dev
->state_use_accessors
== CLOCK_EVT_STATE_PERIODIC
;
149 static inline bool clockevent_state_oneshot(struct clock_event_device
*dev
)
151 return dev
->state_use_accessors
== CLOCK_EVT_STATE_ONESHOT
;
154 static inline bool clockevent_state_oneshot_stopped(struct clock_event_device
*dev
)
156 return dev
->state_use_accessors
== CLOCK_EVT_STATE_ONESHOT_STOPPED
;
160 * Calculate a multiplication factor for scaled math, which is used to convert
161 * nanoseconds based values to clock ticks:
163 * clock_ticks = (nanoseconds * factor) >> shift.
165 * div_sc is the rearranged equation to calculate a factor from a given clock
166 * ticks / nanoseconds ratio:
168 * factor = (clock_ticks << shift) / nanoseconds
170 static inline unsigned long
171 div_sc(unsigned long ticks
, unsigned long nsec
, int shift
)
173 u64 tmp
= ((u64
)ticks
) << shift
;
177 return (unsigned long) tmp
;
180 /* Clock event layer functions */
181 extern u64
clockevent_delta2ns(unsigned long latch
, struct clock_event_device
*evt
);
182 extern void clockevents_register_device(struct clock_event_device
*dev
);
183 extern int clockevents_unbind_device(struct clock_event_device
*ced
, int cpu
);
185 extern void clockevents_config(struct clock_event_device
*dev
, u32 freq
);
186 extern void clockevents_config_and_register(struct clock_event_device
*dev
,
187 u32 freq
, unsigned long min_delta
,
188 unsigned long max_delta
);
190 extern int clockevents_update_freq(struct clock_event_device
*ce
, u32 freq
);
193 clockevents_calc_mult_shift(struct clock_event_device
*ce
, u32 freq
, u32 maxsec
)
195 return clocks_calc_mult_shift(&ce
->mult
, &ce
->shift
, NSEC_PER_SEC
, freq
, maxsec
);
198 extern void clockevents_suspend(void);
199 extern void clockevents_resume(void);
201 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
202 # ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
203 extern void tick_broadcast(const struct cpumask
*mask
);
205 # define tick_broadcast NULL
207 extern int tick_receive_broadcast(void);
210 # if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
211 extern void tick_setup_hrtimer_broadcast(void);
212 extern int tick_check_broadcast_expired(void);
214 static inline int tick_check_broadcast_expired(void) { return 0; }
215 static inline void tick_setup_hrtimer_broadcast(void) { }
218 #else /* !CONFIG_GENERIC_CLOCKEVENTS: */
220 static inline void clockevents_suspend(void) { }
221 static inline void clockevents_resume(void) { }
222 static inline int tick_check_broadcast_expired(void) { return 0; }
223 static inline void tick_setup_hrtimer_broadcast(void) { }
225 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
227 #endif /* _LINUX_CLOCKCHIPS_H */