2 /*  linux/include/linux/clocksource.h
6  *  If you are not a clocksource, or timekeeping code, you should
24 struct clocksource;
29 #include <asm/clocksource.h>
32 #include <vdso/clocksource.h>
35  * struct clocksource - hardware abstraction for a free running counter
39  * @read:		Returns a cycle value, passes clocksource as argument
44  * @max_idle_ns:	Maximum idle time permitted by the clocksource (nsecs)
51  * @name:		Pointer to clocksource name
56  *			to assign your clocksource a rating
62  *				A correct and usable clocksource.
64  *				A reasonably fast and accurate clocksource.
66  *				The ideal clocksource. A must-use where
70  *			validate the clocksource from which the snapshot was
73  * @enable:		Optional function to enable the clocksource
74  * @disable:		Optional function to disable the clocksource
75  * @suspend:		Optional suspend function for the clocksource
76  * @resume:		Optional resume function for the clocksource
77  * @mark_unstable:	Optional function to inform the clocksource driver that
78  *			the watchdog marked the clocksource unstable
82  * @cs_last:		Last clocksource value for clocksource watchdog
84  * @owner:		Module reference, must be set by clocksource in modules
90  * The pointer to the clocksource itself is handed to the read
92  * clocksource into your own struct. Depending on the amount of
96 struct clocksource {  struct
97 	u64			(*read)(struct clocksource *cs);  argument
115 	int			(*enable)(struct clocksource *cs);  argument
116 	void			(*disable)(struct clocksource *cs);  argument
117 	void			(*suspend)(struct clocksource *cs);  argument
118 	void			(*resume)(struct clocksource *cs);  argument
119 	void			(*mark_unstable)(struct clocksource *cs);  argument
120 	void			(*tick_stable)(struct clocksource *cs);  argument
166  * @khz:		Clocksource frequency in KHz
167  * @shift_constant:	Clocksource shift factor
170  * multiplier, given the clocksource shift value
179  * @hz:			Clocksource frequency in Hz
180  * @shift_constant:	Clocksource shift factor
184  * clocksource shift value
192  * clocksource_cyc2ns - converts clocksource cycles to nanoseconds
197  * Converts clocksource cycles to nanoseconds, using the given @mult and @shift.
199  * with absolute clocksource cycles (as those will easily overflow),
200  * but is only intended to be used with relative (delta) clocksource cycles.
210 extern int clocksource_unregister(struct clocksource*);
212 extern void clocksource_change_rating(struct clocksource *cs, int rating);
215 extern struct clocksource * __init clocksource_default_clock(void);
216 extern void clocksource_mark_unstable(struct clocksource *cs);
218 clocksource_start_suspend_timing(struct clocksource *cs, u64 start_cycles);
219 extern u64 clocksource_stop_suspend_timing(struct clocksource *cs, u64 now);
231 __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq);
233 __clocksource_update_freq_scale(struct clocksource *cs, u32 scale, u32 freq);
236  * Don't call this unless you are a default clocksource
239 static inline int __clocksource_register(struct clocksource *cs)  in __clocksource_register()
244 static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)  in clocksource_register_hz()
249 static inline int clocksource_register_khz(struct clocksource *cs, u32 khz)  in clocksource_register_khz()
254 static inline void __clocksource_update_freq_hz(struct clocksource *cs, u32 hz)  in __clocksource_update_freq_hz()
259 static inline void __clocksource_update_freq_khz(struct clocksource *cs, u32 khz)  in __clocksource_update_freq_khz()
265 extern void clocksource_arch_init(struct clocksource *cs);
267 static inline void clocksource_arch_init(struct clocksource *cs) { }  in clocksource_arch_init()
270 extern int timekeeping_notify(struct clocksource *clock);
272 extern u64 clocksource_mmio_readl_up(struct clocksource *);
273 extern u64 clocksource_mmio_readl_down(struct clocksource *);
274 extern u64 clocksource_mmio_readw_up(struct clocksource *);
275 extern u64 clocksource_mmio_readw_down(struct clocksource *);
278 	unsigned long, int, unsigned, u64 (*)(struct clocksource *));
295 void clocksource_verify_percpu(struct clocksource *cs);