1 /* SPDX-License-Identifier: GPL-2.0 */
36  * struct clocksource - hardware abstraction for a free running counter
37  *	Provides mostly state-free accessors to the underlying hardware.
49  * @archdata:		Optional arch-specific data
59  *			1-99: Unfit for real use
61  *			100-199: Base level usability.
63  *			200-299: Good.
65  *			300-399: Desired.
67  *			400-499: Perfect
68  *				The ideal clocksource. A must-use where
101 	u64			(*read)(struct clocksource *cs);
121 	int			(*enable)(struct clocksource *cs);
122 	void			(*disable)(struct clocksource *cs);
123 	void			(*suspend)(struct clocksource *cs);
124 	void			(*resume)(struct clocksource *cs);
125 	void			(*mark_unstable)(struct clocksource *cs);
126 	void			(*tick_stable)(struct clocksource *cs);
151 #define CLOCKSOURCE_MASK(bits) GENMASK_ULL((bits) - 1, 0)
156 	 *  mult/2^shift  = ns/cyc  in clocksource_freq2mult()
157 	 *  mult = ns/cyc * 2^shift  in clocksource_freq2mult()
158 	 *  mult = from/freq * 2^shift  in clocksource_freq2mult()
159 	 *  mult = from * 2^shift / freq  in clocksource_freq2mult()
164 	tmp += freq/2; /* round for do_div */  in clocksource_freq2mult()
171  * clocksource_khz2mult - calculates mult from khz and shift
184  * clocksource_hz2mult - calculates mult from hz and shift
198  * clocksource_cyc2ns - converts clocksource cycles to nanoseconds
208  * XXX - This could use some mult_lxl_ll() asm optimization
218 extern void clocksource_change_rating(struct clocksource *cs, int rating);
222 extern void clocksource_mark_unstable(struct clocksource *cs);
224 clocksource_start_suspend_timing(struct clocksource *cs, u64 start_cycles);
225 extern u64 clocksource_stop_suspend_timing(struct clocksource *cs, u64 now);
237 __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq);
239 __clocksource_update_freq_scale(struct clocksource *cs, u32 scale, u32 freq);
245 static inline int __clocksource_register(struct clocksource *cs)  in __clocksource_register()  argument
247 	return __clocksource_register_scale(cs, 1, 0);  in __clocksource_register()
250 static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)  in clocksource_register_hz()  argument
252 	return __clocksource_register_scale(cs, 1, hz);  in clocksource_register_hz()
255 static inline int clocksource_register_khz(struct clocksource *cs, u32 khz)  in clocksource_register_khz()  argument
257 	return __clocksource_register_scale(cs, 1000, khz);  in clocksource_register_khz()
260 static inline void __clocksource_update_freq_hz(struct clocksource *cs, u32 hz)  in __clocksource_update_freq_hz()  argument
262 	__clocksource_update_freq_scale(cs, 1, hz);  in __clocksource_update_freq_hz()
265 static inline void __clocksource_update_freq_khz(struct clocksource *cs, u32 khz)  in __clocksource_update_freq_khz()  argument
267 	__clocksource_update_freq_scale(cs, 1000, khz);  in __clocksource_update_freq_khz()
271 extern void clocksource_arch_init(struct clocksource *cs);
273 static inline void clocksource_arch_init(struct clocksource *cs) { }  in clocksource_arch_init()  argument
310 	return (ilog2(num_online_cpus()) / 2) + 1;  in clocksource_get_max_watchdog_retry()
313 void clocksource_verify_percpu(struct clocksource *cs);
316  * struct clocksource_base - hardware abstraction for clock on which a clocksource