[mirror_ubuntu-bionic-kernel.git] / include / linux / clocksource.h

/*  linux/include/linux/clocksource.h
 *
 *  This file contains the structure definitions for clocksources.
 *
 *  If you are not a clocksource, or timekeeping code, you should
 *  not be including this file!
 */
#ifndef _LINUX_CLOCKSOURCE_H
#define _LINUX_CLOCKSOURCE_H

#include <linux/types.h>
#include <linux/timex.h>
#include <linux/time.h>
#include <linux/list.h>
#include <linux/cache.h>
#include <linux/timer.h>
#include <linux/init.h>
#include <asm/div64.h>
#include <asm/io.h>

/* clocksource cycle base type */
typedef u64 cycle_t;
struct clocksource;
struct module;

#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
#include <asm/clocksource.h>
#endif

/**
 * struct cyclecounter - hardware abstraction for a free running counter
 *	Provides completely state-free accessors to the underlying hardware.
 *	Depending on which hardware it reads, the cycle counter may wrap
 *	around quickly. Locking rules (if necessary) have to be defined
 *	by the implementor and user of specific instances of this API.
 *
 * @read:		returns the current cycle value
 * @mask:		bitmask for two's complement
 *			subtraction of non 64 bit counters,
 *			see CLOCKSOURCE_MASK() helper macro
 * @mult:		cycle to nanosecond multiplier
 * @shift:		cycle to nanosecond divisor (power of two)
 */
struct cyclecounter {
	cycle_t (*read)(const struct cyclecounter *cc);
	cycle_t mask;
	u32 mult;
	u32 shift;
};

/**
 * struct timecounter - layer above a %struct cyclecounter which counts nanoseconds
 *	Contains the state needed by timecounter_read() to detect
 *	cycle counter wrap around. Initialize with
 *	timecounter_init(). Also used to convert cycle counts into the
 *	corresponding nanosecond counts with timecounter_cyc2time(). Users
 *	of this code are responsible for initializing the underlying
 *	cycle counter hardware, locking issues and reading the time
 *	more often than the cycle counter wraps around. The nanosecond
 *	counter will only wrap around after ~585 years.
 *
 * @cc:			the cycle counter used by this instance
 * @cycle_last:		most recent cycle counter value seen by
 *			timecounter_read()
 * @nsec:		continuously increasing count
 */
struct timecounter {
	const struct cyclecounter *cc;
	cycle_t cycle_last;
	u64 nsec;
};

/**
 * cyclecounter_cyc2ns - converts cycle counter cycles to nanoseconds
 * @cc:		Pointer to cycle counter.
 * @cycles:	Cycles
 *
 * XXX - This could use some mult_lxl_ll() asm optimization. Same code
 * as in cyc2ns, but with unsigned result.
 */
static inline u64 cyclecounter_cyc2ns(const struct cyclecounter *cc,
				      cycle_t cycles)
{
	u64 ret = (u64)cycles;
	ret = (ret * cc->mult) >> cc->shift;
	return ret;
}

/**
 * timecounter_init - initialize a time counter
 * @tc:			Pointer to time counter which is to be initialized/reset
 * @cc:			A cycle counter, ready to be used.
 * @start_tstamp:	Arbitrary initial time stamp.
 *
 * After this call the current cycle register (roughly) corresponds to
 * the initial time stamp. Every call to timecounter_read() increments
 * the time stamp counter by the number of elapsed nanoseconds.
 */
extern void timecounter_init(struct timecounter *tc,
			     const struct cyclecounter *cc,
			     u64 start_tstamp);

/**
 * timecounter_read - return nanoseconds elapsed since timecounter_init()
 *                    plus the initial time stamp
 * @tc:          Pointer to time counter.
 *
 * In other words, keeps track of time since the same epoch as
 * the function which generated the initial time stamp.
 */
extern u64 timecounter_read(struct timecounter *tc);

/**
 * timecounter_cyc2time - convert a cycle counter to same
 *                        time base as values returned by
 *                        timecounter_read()
 * @tc:		Pointer to time counter.
 * @cycle_tstamp:	a value returned by tc->cc->read()
 *
 * Cycle counts that are converted correctly as long as they
 * fall into the interval [-1/2 max cycle count, +1/2 max cycle count],
 * with "max cycle count" == cs->mask+1.
 *
 * This allows conversion of cycle counter values which were generated
 * in the past.
 */
extern u64 timecounter_cyc2time(struct timecounter *tc,
				cycle_t cycle_tstamp);

/**
 * struct clocksource - hardware abstraction for a free running counter
 *	Provides mostly state-free accessors to the underlying hardware.
 *	This is the structure used for system time.
 *
 * @name:		ptr to clocksource name
 * @list:		list head for registration
 * @rating:		rating value for selection (higher is better)
 *			To avoid rating inflation the following
 *			list should give you a guide as to how
 *			to assign your clocksource a rating
 *			1-99: Unfit for real use
 *				Only available for bootup and testing purposes.
 *			100-199: Base level usability.
 *				Functional for real use, but not desired.
 *			200-299: Good.
 *				A correct and usable clocksource.
 *			300-399: Desired.
 *				A reasonably fast and accurate clocksource.
 *			400-499: Perfect
 *				The ideal clocksource. A must-use where
 *				available.
 * @read:		returns a cycle value, passes clocksource as argument
 * @enable:		optional function to enable the clocksource
 * @disable:		optional function to disable the clocksource
 * @mask:		bitmask for two's complement
 *			subtraction of non 64 bit counters
 * @mult:		cycle to nanosecond multiplier
 * @shift:		cycle to nanosecond divisor (power of two)
 * @max_idle_ns:	max idle time permitted by the clocksource (nsecs)
 * @maxadj:		maximum adjustment value to mult (~11%)
 * @flags:		flags describing special properties
 * @archdata:		arch-specific data
 * @suspend:		suspend function for the clocksource, if necessary
 * @resume:		resume function for the clocksource, if necessary
 * @cycle_last:		most recent cycle counter value seen by ::read()
 * @owner:		module reference, must be set by clocksource in modules
 */
struct clocksource {
	/*
	 * Hotpath data, fits in a single cache line when the
	 * clocksource itself is cacheline aligned.
	 */
	cycle_t (*read)(struct clocksource *cs);
	cycle_t cycle_last;
	cycle_t mask;
	u32 mult;
	u32 shift;
	u64 max_idle_ns;
	u32 maxadj;
#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
	struct arch_clocksource_data archdata;
#endif

	const char *name;
	struct list_head list;
	int rating;
	int (*enable)(struct clocksource *cs);
	void (*disable)(struct clocksource *cs);
	unsigned long flags;
	void (*suspend)(struct clocksource *cs);
	void (*resume)(struct clocksource *cs);

	/* private: */
#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
	/* Watchdog related data, used by the framework */
	struct list_head wd_list;
	cycle_t cs_last;
	cycle_t wd_last;
#endif
	struct module *owner;
} ____cacheline_aligned;

/*
 * Clock source flags bits::
 */
#define CLOCK_SOURCE_IS_CONTINUOUS		0x01
#define CLOCK_SOURCE_MUST_VERIFY		0x02

#define CLOCK_SOURCE_WATCHDOG			0x10
#define CLOCK_SOURCE_VALID_FOR_HRES		0x20
#define CLOCK_SOURCE_UNSTABLE			0x40
#define CLOCK_SOURCE_SUSPEND_NONSTOP		0x80

/* simplify initialization of mask field */
#define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1)

/**
 * clocksource_khz2mult - calculates mult from khz and shift
 * @khz:		Clocksource frequency in KHz
 * @shift_constant:	Clocksource shift factor
 *
 * Helper functions that converts a khz counter frequency to a timsource
 * multiplier, given the clocksource shift value
 */
static inline u32 clocksource_khz2mult(u32 khz, u32 shift_constant)
{
	/*  khz = cyc/(Million ns)
	 *  mult/2^shift  = ns/cyc
	 *  mult = ns/cyc * 2^shift
	 *  mult = 1Million/khz * 2^shift
	 *  mult = 1000000 * 2^shift / khz
	 *  mult = (1000000<<shift) / khz
	 */
	u64 tmp = ((u64)1000000) << shift_constant;

	tmp += khz/2; /* round for do_div */
	do_div(tmp, khz);

	return (u32)tmp;
}

/**
 * clocksource_hz2mult - calculates mult from hz and shift
 * @hz:			Clocksource frequency in Hz
 * @shift_constant:	Clocksource shift factor
 *
 * Helper functions that converts a hz counter
 * frequency to a timsource multiplier, given the
 * clocksource shift value
 */
static inline u32 clocksource_hz2mult(u32 hz, u32 shift_constant)
{
	/*  hz = cyc/(Billion ns)
	 *  mult/2^shift  = ns/cyc
	 *  mult = ns/cyc * 2^shift
	 *  mult = 1Billion/hz * 2^shift
	 *  mult = 1000000000 * 2^shift / hz
	 *  mult = (1000000000<<shift) / hz
	 */
	u64 tmp = ((u64)1000000000) << shift_constant;

	tmp += hz/2; /* round for do_div */
	do_div(tmp, hz);

	return (u32)tmp;
}

/**
 * clocksource_cyc2ns - converts clocksource cycles to nanoseconds
 * @cycles:	cycles
 * @mult:	cycle to nanosecond multiplier
 * @shift:	cycle to nanosecond divisor (power of two)
 *
 * Converts cycles to nanoseconds, using the given mult and shift.
 *
 * XXX - This could use some mult_lxl_ll() asm optimization
 */
static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
{
	return ((u64) cycles * mult) >> shift;
}


extern int clocksource_register(struct clocksource*);
extern void clocksource_unregister(struct clocksource*);
extern void clocksource_touch_watchdog(void);
extern struct clocksource* clocksource_get_next(void);
extern void clocksource_change_rating(struct clocksource *cs, int rating);
extern void clocksource_suspend(void);
extern void clocksource_resume(void);
extern struct clocksource * __init __weak clocksource_default_clock(void);
extern void clocksource_mark_unstable(struct clocksource *cs);

extern void
clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec);

/*
 * Don't call __clocksource_register_scale directly, use
 * clocksource_register_hz/khz
 */
extern int
__clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq);
extern void
__clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq);

static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)
{
	return __clocksource_register_scale(cs, 1, hz);
}

static inline int clocksource_register_khz(struct clocksource *cs, u32 khz)
{
	return __clocksource_register_scale(cs, 1000, khz);
}

static inline void __clocksource_updatefreq_hz(struct clocksource *cs, u32 hz)
{
	__clocksource_updatefreq_scale(cs, 1, hz);
}

static inline void __clocksource_updatefreq_khz(struct clocksource *cs, u32 khz)
{
	__clocksource_updatefreq_scale(cs, 1000, khz);
}


extern int timekeeping_notify(struct clocksource *clock);

extern cycle_t clocksource_mmio_readl_up(struct clocksource *);
extern cycle_t clocksource_mmio_readl_down(struct clocksource *);
extern cycle_t clocksource_mmio_readw_up(struct clocksource *);
extern cycle_t clocksource_mmio_readw_down(struct clocksource *);

extern int clocksource_mmio_init(void __iomem *, const char *,
	unsigned long, int, unsigned, cycle_t (*)(struct clocksource *));

extern int clocksource_i8253_init(void);

struct device_node;
typedef void(*clocksource_of_init_fn)(struct device_node *);
#ifdef CONFIG_CLKSRC_OF
extern void clocksource_of_init(void);

#define CLOCKSOURCE_OF_DECLARE(name, compat, fn)			\
	static const struct of_device_id __clksrc_of_table_##name	\
		__used __section(__clksrc_of_table)			\
		 = { .compatible = compat,				\
		     .data = (fn == (clocksource_of_init_fn)NULL) ? fn : fn }
#else
static inline void clocksource_of_init(void) {}
#define CLOCKSOURCE_OF_DECLARE(name, compat, fn)			\
	static const struct of_device_id __clksrc_of_table_##name	\
		__attribute__((unused))					\
		 = { .compatible = compat,				\
		     .data = (fn == (clocksource_of_init_fn)NULL) ? fn : fn }
#endif

#endif /* _LINUX_CLOCKSOURCE_H */
Commit	Line	Data
734efb46 JS	1	/* linux/include/linux/clocksource.h
	2	*
	3	* This file contains the structure definitions for clocksources.
	4	*
	5	* If you are not a clocksource, or timekeeping code, you should
	6	* not be including this file!
	7	*/
	8	#ifndef _LINUX_CLOCKSOURCE_H
	9	#define _LINUX_CLOCKSOURCE_H
	10
	11	#include <linux/types.h>
	12	#include <linux/timex.h>
	13	#include <linux/time.h>
	14	#include <linux/list.h>
329c8d84	15	#include <linux/cache.h>
5d8b34fd	16	#include <linux/timer.h>
f1b82746	17	#include <linux/init.h>
734efb46 JS	18	#include <asm/div64.h>
	19	#include <asm/io.h>
	20
	21	/* clocksource cycle base type */
	22	typedef u64 cycle_t;
5d8b34fd	23	struct clocksource;
09ac369c	24	struct module;
734efb46	25
ae7bd11b	26	#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
433bd805	27	#include <asm/clocksource.h>
ae7bd11b	28	#endif
433bd805	29
a038a353 PO	30	/**
	31	* struct cyclecounter - hardware abstraction for a free running counter
	32	* Provides completely state-free accessors to the underlying hardware.
	33	* Depending on which hardware it reads, the cycle counter may wrap
	34	* around quickly. Locking rules (if necessary) have to be defined
	35	* by the implementor and user of specific instances of this API.
	36	*
	37	* @read: returns the current cycle value
	38	* @mask: bitmask for two's complement
	39	* subtraction of non 64 bit counters,
	40	* see CLOCKSOURCE_MASK() helper macro
	41	* @mult: cycle to nanosecond multiplier
	42	* @shift: cycle to nanosecond divisor (power of two)
	43	*/
	44	struct cyclecounter {
	45	cycle_t (read)(const struct cyclecounter cc);
	46	cycle_t mask;
	47	u32 mult;
	48	u32 shift;
	49	};
	50
	51	/**
	52	* struct timecounter - layer above a %struct cyclecounter which counts nanoseconds
	53	* Contains the state needed by timecounter_read() to detect
	54	* cycle counter wrap around. Initialize with
	55	* timecounter_init(). Also used to convert cycle counts into the
	56	* corresponding nanosecond counts with timecounter_cyc2time(). Users
	57	* of this code are responsible for initializing the underlying
	58	* cycle counter hardware, locking issues and reading the time
	59	* more often than the cycle counter wraps around. The nanosecond
	60	* counter will only wrap around after ~585 years.
	61	*
	62	* @cc: the cycle counter used by this instance
	63	* @cycle_last: most recent cycle counter value seen by
	64	* timecounter_read()
	65	* @nsec: continuously increasing count
	66	*/
	67	struct timecounter {
	68	const struct cyclecounter *cc;
	69	cycle_t cycle_last;
	70	u64 nsec;
	71	};
	72
	73	/**
	74	* cyclecounter_cyc2ns - converts cycle counter cycles to nanoseconds
b1b73d09	75	* @cc: Pointer to cycle counter.
a038a353 PO	76	* @cycles: Cycles
	77	*
	78	* XXX - This could use some mult_lxl_ll() asm optimization. Same code
	79	* as in cyc2ns, but with unsigned result.
	80	*/
	81	static inline u64 cyclecounter_cyc2ns(const struct cyclecounter *cc,
	82	cycle_t cycles)
	83	{
	84	u64 ret = (u64)cycles;
	85	ret = (ret * cc->mult) >> cc->shift;
	86	return ret;
	87	}
	88
	89	/**
	90	* timecounter_init - initialize a time counter
	91	* @tc: Pointer to time counter which is to be initialized/reset
	92	* @cc: A cycle counter, ready to be used.
	93	* @start_tstamp: Arbitrary initial time stamp.
	94	*
	95	* After this call the current cycle register (roughly) corresponds to
	96	* the initial time stamp. Every call to timecounter_read() increments
	97	* the time stamp counter by the number of elapsed nanoseconds.
	98	*/
	99	extern void timecounter_init(struct timecounter *tc,
	100	const struct cyclecounter *cc,
	101	u64 start_tstamp);
	102
	103	/**
	104	* timecounter_read - return nanoseconds elapsed since timecounter_init()
	105	* plus the initial time stamp
	106	* @tc: Pointer to time counter.
	107	*
	108	* In other words, keeps track of time since the same epoch as
	109	* the function which generated the initial time stamp.
	110	*/
	111	extern u64 timecounter_read(struct timecounter *tc);
	112
	113	/**
	114	* timecounter_cyc2time - convert a cycle counter to same
	115	* time base as values returned by
	116	* timecounter_read()
	117	* @tc: Pointer to time counter.
b1b73d09	118	* @cycle_tstamp: a value returned by tc->cc->read()
a038a353 PO	119	*
	120	* Cycle counts that are converted correctly as long as they
	121	* fall into the interval [-1/2 max cycle count, +1/2 max cycle count],
	122	* with "max cycle count" == cs->mask+1.
	123	*
	124	* This allows conversion of cycle counter values which were generated
	125	* in the past.
	126	*/
	127	extern u64 timecounter_cyc2time(struct timecounter *tc,
	128	cycle_t cycle_tstamp);
	129
734efb46 JS	130	/**
	131	* struct clocksource - hardware abstraction for a free running counter
	132	* Provides mostly state-free accessors to the underlying hardware.
a038a353	133	* This is the structure used for system time.
734efb46 JS	134	*
	135	* @name: ptr to clocksource name
	136	* @list: list head for registration
	137	* @rating: rating value for selection (higher is better)
	138	* To avoid rating inflation the following
	139	* list should give you a guide as to how
	140	* to assign your clocksource a rating
	141	* 1-99: Unfit for real use
	142	* Only available for bootup and testing purposes.
	143	* 100-199: Base level usability.
	144	* Functional for real use, but not desired.
	145	* 200-299: Good.
	146	* A correct and usable clocksource.
	147	* 300-399: Desired.
	148	* A reasonably fast and accurate clocksource.
	149	* 400-499: Perfect
	150	* The ideal clocksource. A must-use where
	151	* available.
8e19608e	152	* @read: returns a cycle value, passes clocksource as argument
4614e6ad MD	153	* @enable: optional function to enable the clocksource
4614e6ad MD	154	* @disable: optional function to disable the clocksource
734efb46 JS	155	* @mask: bitmask for two's complement
734efb46 JS	156	* subtraction of non 64 bit counters
0a544198	157	* @mult: cycle to nanosecond multiplier
734efb46	158	* @shift: cycle to nanosecond divisor (power of two)
98962465	159	* @max_idle_ns: max idle time permitted by the clocksource (nsecs)
b1b73d09	160	* @maxadj: maximum adjustment value to mult (~11%)
73b08d2a	161	* @flags: flags describing special properties
433bd805	162	* @archdata: arch-specific data
c54a42b1	163	* @suspend: suspend function for the clocksource, if necessary
b52f52a0	164	* @resume: resume function for the clocksource, if necessary
b1b73d09	165	* @cycle_last: most recent cycle counter value seen by ::read()
09ac369c	166	* @owner: module reference, must be set by clocksource in modules
734efb46 JS	167	*/
734efb46 JS	168	struct clocksource {
329c8d84	169	/*
369db4c9 TG	170	* Hotpath data, fits in a single cache line when the
369db4c9 TG	171	* clocksource itself is cacheline aligned.
329c8d84	172	*/
8e19608e	173	cycle_t (read)(struct clocksource cs);
369db4c9	174	cycle_t cycle_last;
734efb46 JS	175	cycle_t mask;
	176	u32 mult;
	177	u32 shift;
98962465	178	u64 max_idle_ns;
d65670a7	179	u32 maxadj;
ae7bd11b	180	#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
433bd805	181	struct arch_clocksource_data archdata;
0aa366f3	182	#endif
433bd805	183
369db4c9 TG	184	const char *name;
	185	struct list_head list;
	186	int rating;
369db4c9 TG	187	int (enable)(struct clocksource cs);
	188	void (disable)(struct clocksource cs);
	189	unsigned long flags;
	190	void (suspend)(struct clocksource cs);
	191	void (resume)(struct clocksource cs);
5d8b34fd	192
b1b73d09	193	/* private: */
5d8b34fd TG	194	#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
	195	/* Watchdog related data, used by the framework */
	196	struct list_head wd_list;
b5199515	197	cycle_t cs_last;
5d8b34fd TG	198	cycle_t wd_last;
5d8b34fd TG	199	#endif
09ac369c	200	struct module *owner;
369db4c9	201	} ____cacheline_aligned;
734efb46	202
73b08d2a TG	203	/*
	204	* Clock source flags bits::
	205	*/
5d8b34fd TG	206	#define CLOCK_SOURCE_IS_CONTINUOUS 0x01
	207	#define CLOCK_SOURCE_MUST_VERIFY 0x02
	208
	209	#define CLOCK_SOURCE_WATCHDOG 0x10
	210	#define CLOCK_SOURCE_VALID_FOR_HRES 0x20
c55c87c8	211	#define CLOCK_SOURCE_UNSTABLE 0x40
5caf4636	212	#define CLOCK_SOURCE_SUSPEND_NONSTOP 0x80
73b08d2a	213
7f9f303a	214	/* simplify initialization of mask field */
1d76c262	215	#define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1)
734efb46 JS	216
	217	/**
	218	* clocksource_khz2mult - calculates mult from khz and shift
	219	* @khz: Clocksource frequency in KHz
	220	* @shift_constant: Clocksource shift factor
	221	*
	222	* Helper functions that converts a khz counter frequency to a timsource
	223	* multiplier, given the clocksource shift value
	224	*/
	225	static inline u32 clocksource_khz2mult(u32 khz, u32 shift_constant)
	226	{
	227	/* khz = cyc/(Million ns)
	228	* mult/2^shift = ns/cyc
	229	* mult = ns/cyc * 2^shift
	230	* mult = 1Million/khz * 2^shift
	231	* mult = 1000000 * 2^shift / khz
	232	* mult = (1000000<<shift) / khz
	233	*/
	234	u64 tmp = ((u64)1000000) << shift_constant;
	235
	236	tmp += khz/2; /* round for do_div */
	237	do_div(tmp, khz);
	238
	239	return (u32)tmp;
	240	}
	241
	242	/**
	243	* clocksource_hz2mult - calculates mult from hz and shift
	244	* @hz: Clocksource frequency in Hz
	245	* @shift_constant: Clocksource shift factor
	246	*
	247	* Helper functions that converts a hz counter
	248	* frequency to a timsource multiplier, given the
	249	* clocksource shift value
	250	*/
	251	static inline u32 clocksource_hz2mult(u32 hz, u32 shift_constant)
	252	{
	253	/* hz = cyc/(Billion ns)
	254	* mult/2^shift = ns/cyc
	255	* mult = ns/cyc * 2^shift
	256	* mult = 1Billion/hz * 2^shift
	257	* mult = 1000000000 * 2^shift / hz
	258	* mult = (1000000000<<shift) / hz
	259	*/
	260	u64 tmp = ((u64)1000000000) << shift_constant;
	261
	262	tmp += hz/2; /* round for do_div */
	263	do_div(tmp, hz);
	264
	265	return (u32)tmp;
	266	}
	267
734efb46	268	/**
155ec602	269	* clocksource_cyc2ns - converts clocksource cycles to nanoseconds
b1b73d09 KK	270	* @cycles: cycles
	271	* @mult: cycle to nanosecond multiplier
	272	* @shift: cycle to nanosecond divisor (power of two)
734efb46	273	*
155ec602	274	* Converts cycles to nanoseconds, using the given mult and shift.
734efb46 JS	275	*
	276	* XXX - This could use some mult_lxl_ll() asm optimization
	277	*/
155ec602	278	static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
734efb46	279	{
155ec602	280	return ((u64) cycles * mult) >> shift;
5eb6d205 JS	281	}
	282
	283
92c7e002	284	extern int clocksource_register(struct clocksource*);
4713e22c	285	extern void clocksource_unregister(struct clocksource*);
7c3078b6	286	extern void clocksource_touch_watchdog(void);
92c7e002 TG	287	extern struct clocksource* clocksource_get_next(void);
92c7e002 TG	288	extern void clocksource_change_rating(struct clocksource *cs, int rating);
c54a42b1	289	extern void clocksource_suspend(void);
b52f52a0	290	extern void clocksource_resume(void);
f1b82746	291	extern struct clocksource * __init __weak clocksource_default_clock(void);
7285dd7f	292	extern void clocksource_mark_unstable(struct clocksource *cs);
734efb46	293
7d2f944a TG	294	extern void
	295	clocks_calc_mult_shift(u32 mult, u32 shift, u32 from, u32 to, u32 minsec);
	296
d7e81c26 JS	297	/*
	298	* Don't call __clocksource_register_scale directly, use
	299	* clocksource_register_hz/khz
	300	*/
	301	extern int
	302	__clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq);
852db46d JS	303	extern void
852db46d JS	304	__clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq);
d7e81c26 JS	305
	306	static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)
	307	{
	308	return __clocksource_register_scale(cs, 1, hz);
	309	}
	310
	311	static inline int clocksource_register_khz(struct clocksource *cs, u32 khz)
	312	{
	313	return __clocksource_register_scale(cs, 1000, khz);
	314	}
	315
852db46d JS	316	static inline void __clocksource_updatefreq_hz(struct clocksource *cs, u32 hz)
	317	{
	318	__clocksource_updatefreq_scale(cs, 1, hz);
	319	}
	320
	321	static inline void __clocksource_updatefreq_khz(struct clocksource *cs, u32 khz)
	322	{
	323	__clocksource_updatefreq_scale(cs, 1000, khz);
	324	}
d7e81c26	325
acc9a9dc	326
ba919d1c	327	extern int timekeeping_notify(struct clocksource *clock);
75c5158f	328
442c8176 RK	329	extern cycle_t clocksource_mmio_readl_up(struct clocksource *);
	330	extern cycle_t clocksource_mmio_readl_down(struct clocksource *);
	331	extern cycle_t clocksource_mmio_readw_up(struct clocksource *);
	332	extern cycle_t clocksource_mmio_readw_down(struct clocksource *);
	333
	334	extern int clocksource_mmio_init(void __iomem , const char ,
	335	unsigned long, int, unsigned, cycle_t ()(struct clocksource ));
	336
8c414ff3 RK	337	extern int clocksource_i8253_init(void);
8c414ff3 RK	338
3d5a9658 AB	339	struct device_node;
3d5a9658 AB	340	typedef void(clocksource_of_init_fn)(struct device_node );
ae278a93 SW	341	#ifdef CONFIG_CLKSRC_OF
	342	extern void clocksource_of_init(void);
	343
	344	#define CLOCKSOURCE_OF_DECLARE(name, compat, fn) \
	345	static const struct of_device_id __clksrc_of_table_##name \
	346	__used __section(__clksrc_of_table) \
3d5a9658 AB	347	= { .compatible = compat, \
3d5a9658 AB	348	.data = (fn == (clocksource_of_init_fn)NULL) ? fn : fn }
e1d7ef1c	349	#else
e0c25362	350	static inline void clocksource_of_init(void) {}
3d5a9658 AB	351	#define CLOCKSOURCE_OF_DECLARE(name, compat, fn) \
	352	static const struct of_device_id __clksrc_of_table_##name \
	353	__attribute__((unused)) \
	354	= { .compatible = compat, \
	355	.data = (fn == (clocksource_of_init_fn)NULL) ? fn : fn }
ae278a93 SW	356	#endif
ae278a93 SW	357
734efb46	358	#endif /* _LINUX_CLOCKSOURCE_H */