include/linux/clocksource.h

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.
40  * @read:		Returns a cycle value, passes clocksource as argument
46  * @maxadj:		Maximum adjustment value to mult (~11%)
49  * @archdata:		Optional arch-specific data
50  * @max_cycles:		Maximum safe cycle value which won't overflow on
55  * @rating:		Rating value for selection (higher is better)
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
70  * @id:			Defaults to CSID_GENERIC. The id value is captured
86  * @cs_last:		Last clocksource value for clocksource watchdog
87  * @wd_last:		Last watchdog value corresponding to @cs_last
151 #define CLOCKSOURCE_MASK(bits) GENMASK_ULL((bits) - 1, 0)
171  * clocksource_khz2mult - calculates mult from khz and shift
173  * @shift_constant:	Clocksource shift factor
176  * multiplier, given the clocksource shift value
184  * clocksource_hz2mult - calculates mult from hz and shift
186  * @shift_constant:	Clocksource shift factor
190  * clocksource shift value
198  * clocksource_cyc2ns - converts clocksource cycles to nanoseconds
208  * XXX - This could use some mult_lxl_ll() asm optimization
306 	 * latency's frequency and maximum value goes up with the number of  in clocksource_get_max_watchdog_retry()
316  * struct clocksource_base - hardware abstraction for clock on which a clocksource
318  * @id:			Defaults to CSID_GENERIC. The id value is used for conversion