[deliverable/linux.git] / include / linux / timex.h

/*****************************************************************************
 *                                                                           *
 * Copyright (c) David L. Mills 1993                                         *
 *                                                                           *
 * Permission to use, copy, modify, and distribute this software and its     *
 * documentation for any purpose and without fee is hereby granted, provided *
 * that the above copyright notice appears in all copies and that both the   *
 * copyright notice and this permission notice appear in supporting          *
 * documentation, and that the name University of Delaware not be used in    *
 * advertising or publicity pertaining to distribution of the software       *
 * without specific, written prior permission.  The University of Delaware   *
 * makes no representations about the suitability this software for any      *
 * purpose.  It is provided "as is" without express or implied warranty.     *
 *                                                                           *
 *****************************************************************************/

/*
 * Modification history timex.h
 *
 * 29 Dec 97	Russell King
 *	Moved CLOCK_TICK_RATE, CLOCK_TICK_FACTOR and FINETUNE to asm/timex.h
 *	for ARM machines
 *
 *  9 Jan 97    Adrian Sun
 *      Shifted LATCH define to allow access to alpha machines.
 *
 * 26 Sep 94	David L. Mills
 *	Added defines for hybrid phase/frequency-lock loop.
 *
 * 19 Mar 94	David L. Mills
 *	Moved defines from kernel routines to header file and added new
 *	defines for PPS phase-lock loop.
 *
 * 20 Feb 94	David L. Mills
 *	Revised status codes and structures for external clock and PPS
 *	signal discipline.
 *
 * 28 Nov 93	David L. Mills
 *	Adjusted parameters to improve stability and increase poll
 *	interval.
 *
 * 17 Sep 93    David L. Mills
 *      Created file $NTP/include/sys/timex.h
 * 07 Oct 93    Torsten Duwe
 *      Derived linux/timex.h
 * 1995-08-13    Torsten Duwe
 *      kernel PLL updated to 1994-12-13 specs (rfc-1589)
 * 1997-08-30    Ulrich Windl
 *      Added new constant NTP_PHASE_LIMIT
 * 2004-08-12    Christoph Lameter
 *      Reworked time interpolation logic
 */
#ifndef _LINUX_TIMEX_H
#define _LINUX_TIMEX_H

#include <linux/compiler.h>
#include <linux/time.h>

#include <asm/param.h>

/*
 * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen
 * for a slightly underdamped convergence characteristic. SHIFT_KH
 * establishes the damping of the FLL and is chosen by wisdom and black
 * art.
 *
 * MAXTC establishes the maximum time constant of the PLL. With the
 * SHIFT_KG and SHIFT_KF values given and a time constant range from
 * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours,
 * respectively.
 */
#define SHIFT_PLL	4	/* PLL frequency factor (shift) */
#define SHIFT_FLL	2	/* FLL frequency factor (shift) */
#define MAXTC		10	/* maximum time constant (shift) */

/*
 * The SHIFT_UPDATE define establishes the decimal point of the
 * time_offset variable which represents the current offset with
 * respect to standard time.
 *
 * SHIFT_USEC defines the scaling (shift) of the time_freq and
 * time_tolerance variables, which represent the current frequency
 * offset and maximum frequency tolerance.
 */
#define SHIFT_UPDATE (SHIFT_HZ + 1) /* time offset scale (shift) */
#define SHIFT_USEC 16		/* frequency offset scale (shift) */
#define SHIFT_NSEC 12		/* kernel frequency offset scale */

#define MAXPHASE 512000L        /* max phase error (us) */
#define MAXFREQ (512L << SHIFT_USEC)  /* max frequency error (ppm) */
#define MAXFREQ_NSEC (512000L << SHIFT_NSEC) /* max frequency error (ppb) */
#define MINSEC 256		/* min interval between updates (s) */
#define MAXSEC 2048		/* max interval between updates (s) */
#define	NTP_PHASE_LIMIT	(MAXPHASE << 5)	/* beyond max. dispersion */

/*
 * syscall interface - used (mainly by NTP daemon)
 * to discipline kernel clock oscillator
 */
struct timex {
	unsigned int modes;	/* mode selector */
	long offset;		/* time offset (usec) */
	long freq;		/* frequency offset (scaled ppm) */
	long maxerror;		/* maximum error (usec) */
	long esterror;		/* estimated error (usec) */
	int status;		/* clock command/status */
	long constant;		/* pll time constant */
	long precision;		/* clock precision (usec) (read only) */
	long tolerance;		/* clock frequency tolerance (ppm)
				 * (read only)
				 */
	struct timeval time;	/* (read only) */
	long tick;		/* (modified) usecs between clock ticks */

	long ppsfreq;           /* pps frequency (scaled ppm) (ro) */
	long jitter;            /* pps jitter (us) (ro) */
	int shift;              /* interval duration (s) (shift) (ro) */
	long stabil;            /* pps stability (scaled ppm) (ro) */
	long jitcnt;            /* jitter limit exceeded (ro) */
	long calcnt;            /* calibration intervals (ro) */
	long errcnt;            /* calibration errors (ro) */
	long stbcnt;            /* stability limit exceeded (ro) */

	int  :32; int  :32; int  :32; int  :32;
	int  :32; int  :32; int  :32; int  :32;
	int  :32; int  :32; int  :32; int  :32;
};

/*
 * Mode codes (timex.mode)
 */
#define ADJ_OFFSET		0x0001	/* time offset */
#define ADJ_FREQUENCY		0x0002	/* frequency offset */
#define ADJ_MAXERROR		0x0004	/* maximum time error */
#define ADJ_ESTERROR		0x0008	/* estimated time error */
#define ADJ_STATUS		0x0010	/* clock status */
#define ADJ_TIMECONST		0x0020	/* pll time constant */
#define ADJ_TICK		0x4000	/* tick value */
#define ADJ_OFFSET_SINGLESHOT	0x8001	/* old-fashioned adjtime */
#define ADJ_OFFSET_SS_READ	0xa001  /* read-only adjtime */

/* xntp 3.4 compatibility names */
#define MOD_OFFSET	ADJ_OFFSET
#define MOD_FREQUENCY	ADJ_FREQUENCY
#define MOD_MAXERROR	ADJ_MAXERROR
#define MOD_ESTERROR	ADJ_ESTERROR
#define MOD_STATUS	ADJ_STATUS
#define MOD_TIMECONST	ADJ_TIMECONST
#define MOD_CLKB	ADJ_TICK
#define MOD_CLKA	ADJ_OFFSET_SINGLESHOT /* 0x8000 in original */


/*
 * Status codes (timex.status)
 */
#define STA_PLL		0x0001	/* enable PLL updates (rw) */
#define STA_PPSFREQ	0x0002	/* enable PPS freq discipline (rw) */
#define STA_PPSTIME	0x0004	/* enable PPS time discipline (rw) */
#define STA_FLL		0x0008	/* select frequency-lock mode (rw) */

#define STA_INS		0x0010	/* insert leap (rw) */
#define STA_DEL		0x0020	/* delete leap (rw) */
#define STA_UNSYNC	0x0040	/* clock unsynchronized (rw) */
#define STA_FREQHOLD	0x0080	/* hold frequency (rw) */

#define STA_PPSSIGNAL	0x0100	/* PPS signal present (ro) */
#define STA_PPSJITTER	0x0200	/* PPS signal jitter exceeded (ro) */
#define STA_PPSWANDER	0x0400	/* PPS signal wander exceeded (ro) */
#define STA_PPSERROR	0x0800	/* PPS signal calibration error (ro) */

#define STA_CLOCKERR	0x1000	/* clock hardware fault (ro) */

#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
    STA_PPSERROR | STA_CLOCKERR) /* read-only bits */

/*
 * Clock states (time_state)
 */
#define TIME_OK		0	/* clock synchronized, no leap second */
#define TIME_INS	1	/* insert leap second */
#define TIME_DEL	2	/* delete leap second */
#define TIME_OOP	3	/* leap second in progress */
#define TIME_WAIT	4	/* leap second has occurred */
#define TIME_ERROR	5	/* clock not synchronized */
#define TIME_BAD	TIME_ERROR /* bw compat */

#ifdef __KERNEL__
#include <asm/timex.h>

/*
 * kernel variables
 * Note: maximum error = NTP synch distance = dispersion + delay / 2;
 * estimated error = NTP dispersion.
 */
extern unsigned long tick_usec;		/* USER_HZ period (usec) */
extern unsigned long tick_nsec;		/* ACTHZ          period (nsec) */
extern int tickadj;			/* amount of adjustment per tick */

/*
 * phase-lock loop variables
 */
extern int time_status;		/* clock synchronization status bits */
extern long time_maxerror;	/* maximum error */
extern long time_esterror;	/* estimated error */

extern long time_freq;		/* frequency offset (scaled ppm) */

extern long time_adjust;	/* The amount of adjtime left */

extern void ntp_clear(void);

/**
 * ntp_synced - Returns 1 if the NTP status is not UNSYNC
 *
 */
static inline int ntp_synced(void)
{
	return !(time_status & STA_UNSYNC);
}

/* Required to safely shift negative values */
#define shift_right(x, s) ({	\
	__typeof__(x) __x = (x);	\
	__typeof__(s) __s = (s);	\
	__x < 0 ? -(-__x >> __s) : __x >> __s;	\
})

#define TICK_LENGTH_SHIFT	32

#ifdef CONFIG_NO_HZ
#define NTP_INTERVAL_FREQ  (2)
#else
#define NTP_INTERVAL_FREQ  (HZ)
#endif
#define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ)

/* Returns how long ticks are at present, in ns / 2^(SHIFT_SCALE-10). */
extern u64 current_tick_length(void);

extern void second_overflow(void);
extern void update_ntp_one_tick(void);
extern int do_adjtimex(struct timex *);

/* Don't use! Compatibility define for existing users. */
#define tickadj	(500/HZ ? : 1)

#endif /* KERNEL */

#endif /* LINUX_TIMEX_H */
Commit	Line	Data
1da177e4 LT	1	/*****************************************************************************
	2	* *
	3	* Copyright (c) David L. Mills 1993 *
	4	* *
	5	* Permission to use, copy, modify, and distribute this software and its *
	6	* documentation for any purpose and without fee is hereby granted, provided *
	7	* that the above copyright notice appears in all copies and that both the *
	8	* copyright notice and this permission notice appear in supporting *
	9	* documentation, and that the name University of Delaware not be used in *
	10	* advertising or publicity pertaining to distribution of the software *
	11	* without specific, written prior permission. The University of Delaware *
	12	* makes no representations about the suitability this software for any *
	13	* purpose. It is provided "as is" without express or implied warranty. *
	14	* *
	15	*****************************************************************************/
	16
	17	/*
	18	* Modification history timex.h
	19	*
	20	* 29 Dec 97 Russell King
	21	* Moved CLOCK_TICK_RATE, CLOCK_TICK_FACTOR and FINETUNE to asm/timex.h
	22	* for ARM machines
	23	*
	24	* 9 Jan 97 Adrian Sun
	25	* Shifted LATCH define to allow access to alpha machines.
	26	*
	27	* 26 Sep 94 David L. Mills
	28	* Added defines for hybrid phase/frequency-lock loop.
	29	*
	30	* 19 Mar 94 David L. Mills
	31	* Moved defines from kernel routines to header file and added new
	32	* defines for PPS phase-lock loop.
	33	*
	34	* 20 Feb 94 David L. Mills
	35	* Revised status codes and structures for external clock and PPS
	36	* signal discipline.
	37	*
	38	* 28 Nov 93 David L. Mills
	39	* Adjusted parameters to improve stability and increase poll
	40	* interval.
	41	*
	42	* 17 Sep 93 David L. Mills
	43	* Created file $NTP/include/sys/timex.h
	44	* 07 Oct 93 Torsten Duwe
	45	* Derived linux/timex.h
	46	* 1995-08-13 Torsten Duwe
	47	* kernel PLL updated to 1994-12-13 specs (rfc-1589)
	48	* 1997-08-30 Ulrich Windl
	49	* Added new constant NTP_PHASE_LIMIT
	50	* 2004-08-12 Christoph Lameter
	51	* Reworked time interpolation logic
	52	*/
	53	#ifndef _LINUX_TIMEX_H
	54	#define _LINUX_TIMEX_H
	55
1da177e4 LT	56	#include <linux/compiler.h>
	57	#include <linux/time.h>
	58
	59	#include <asm/param.h>
1da177e4 LT	60
	61	/*
	62	* SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen
	63	* for a slightly underdamped convergence characteristic. SHIFT_KH
	64	* establishes the damping of the FLL and is chosen by wisdom and black
	65	* art.
	66	*
	67	* MAXTC establishes the maximum time constant of the PLL. With the
	68	* SHIFT_KG and SHIFT_KF values given and a time constant range from
	69	* zero to MAXTC, the PLL will converge in 15 minutes to 16 hours,
	70	* respectively.
	71	*/
f1992393 RZ	72	#define SHIFT_PLL 4 /* PLL frequency factor (shift) */
	73	#define SHIFT_FLL 2 /* FLL frequency factor (shift) */
	74	#define MAXTC 10 /* maximum time constant (shift) */
1da177e4 LT	75
1da177e4 LT	76	/*
0883d899 RZ	77	* The SHIFT_UPDATE define establishes the decimal point of the
	78	* time_offset variable which represents the current offset with
	79	* respect to standard time.
1da177e4 LT	80	*
	81	* SHIFT_USEC defines the scaling (shift) of the time_freq and
	82	* time_tolerance variables, which represent the current frequency
	83	* offset and maximum frequency tolerance.
1da177e4	84	*/
3d3675cc	85	#define SHIFT_UPDATE (SHIFT_HZ + 1) /* time offset scale (shift) */
1da177e4	86	#define SHIFT_USEC 16 /* frequency offset scale (shift) */
04b617e7	87	#define SHIFT_NSEC 12 /* kernel frequency offset scale */
1da177e4 LT	88
	89	#define MAXPHASE 512000L /* max phase error (us) */
	90	#define MAXFREQ (512L << SHIFT_USEC) /* max frequency error (ppm) */
04b617e7	91	#define MAXFREQ_NSEC (512000L << SHIFT_NSEC) /* max frequency error (ppb) */
f1992393 RZ	92	#define MINSEC 256 /* min interval between updates (s) */
f1992393 RZ	93	#define MAXSEC 2048 /* max interval between updates (s) */
1da177e4 LT	94	#define NTP_PHASE_LIMIT (MAXPHASE << 5) /* beyond max. dispersion */
1da177e4 LT	95
1da177e4 LT	96	/*
	97	* syscall interface - used (mainly by NTP daemon)
	98	* to discipline kernel clock oscillator
	99	*/
	100	struct timex {
	101	unsigned int modes; /* mode selector */
	102	long offset; /* time offset (usec) */
	103	long freq; /* frequency offset (scaled ppm) */
	104	long maxerror; /* maximum error (usec) */
	105	long esterror; /* estimated error (usec) */
	106	int status; /* clock command/status */
	107	long constant; /* pll time constant */
	108	long precision; /* clock precision (usec) (read only) */
	109	long tolerance; /* clock frequency tolerance (ppm)
	110	* (read only)
	111	*/
	112	struct timeval time; /* (read only) */
	113	long tick; /* (modified) usecs between clock ticks */
	114
	115	long ppsfreq; /* pps frequency (scaled ppm) (ro) */
	116	long jitter; /* pps jitter (us) (ro) */
	117	int shift; /* interval duration (s) (shift) (ro) */
	118	long stabil; /* pps stability (scaled ppm) (ro) */
	119	long jitcnt; /* jitter limit exceeded (ro) */
	120	long calcnt; /* calibration intervals (ro) */
	121	long errcnt; /* calibration errors (ro) */
	122	long stbcnt; /* stability limit exceeded (ro) */
	123
	124	int :32; int :32; int :32; int :32;
	125	int :32; int :32; int :32; int :32;
	126	int :32; int :32; int :32; int :32;
	127	};
	128
	129	/*
	130	* Mode codes (timex.mode)
	131	*/
	132	#define ADJ_OFFSET 0x0001 /* time offset */
	133	#define ADJ_FREQUENCY 0x0002 /* frequency offset */
	134	#define ADJ_MAXERROR 0x0004 /* maximum time error */
	135	#define ADJ_ESTERROR 0x0008 /* estimated time error */
	136	#define ADJ_STATUS 0x0010 /* clock status */
	137	#define ADJ_TIMECONST 0x0020 /* pll time constant */
	138	#define ADJ_TICK 0x4000 /* tick value */
	139	#define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */
52bfb360	140	#define ADJ_OFFSET_SS_READ 0xa001 /* read-only adjtime */
1da177e4 LT	141
	142	/* xntp 3.4 compatibility names */
	143	#define MOD_OFFSET ADJ_OFFSET
	144	#define MOD_FREQUENCY ADJ_FREQUENCY
	145	#define MOD_MAXERROR ADJ_MAXERROR
	146	#define MOD_ESTERROR ADJ_ESTERROR
	147	#define MOD_STATUS ADJ_STATUS
	148	#define MOD_TIMECONST ADJ_TIMECONST
	149	#define MOD_CLKB ADJ_TICK
	150	#define MOD_CLKA ADJ_OFFSET_SINGLESHOT /* 0x8000 in original */
	151
	152
	153	/*
	154	* Status codes (timex.status)
	155	*/
	156	#define STA_PLL 0x0001 /* enable PLL updates (rw) */
	157	#define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */
	158	#define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */
	159	#define STA_FLL 0x0008 /* select frequency-lock mode (rw) */
	160
	161	#define STA_INS 0x0010 /* insert leap (rw) */
	162	#define STA_DEL 0x0020 /* delete leap (rw) */
	163	#define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */
	164	#define STA_FREQHOLD 0x0080 /* hold frequency (rw) */
	165
	166	#define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */
	167	#define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */
	168	#define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */
	169	#define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */
	170
	171	#define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */
	172
	173	#define STA_RONLY (STA_PPSSIGNAL \| STA_PPSJITTER \| STA_PPSWANDER \| \
	174	STA_PPSERROR \| STA_CLOCKERR) /* read-only bits */
	175
	176	/*
	177	* Clock states (time_state)
	178	*/
	179	#define TIME_OK 0 /* clock synchronized, no leap second */
	180	#define TIME_INS 1 /* insert leap second */
	181	#define TIME_DEL 2 /* delete leap second */
	182	#define TIME_OOP 3 /* leap second in progress */
	183	#define TIME_WAIT 4 /* leap second has occurred */
	184	#define TIME_ERROR 5 /* clock not synchronized */
	185	#define TIME_BAD TIME_ERROR /* bw compat */
	186
	187	#ifdef __KERNEL__
ee6baf88 DW	188	#include <asm/timex.h>
ee6baf88 DW	189
1da177e4 LT	190	/*
	191	* kernel variables
	192	* Note: maximum error = NTP synch distance = dispersion + delay / 2;
	193	* estimated error = NTP dispersion.
	194	*/
	195	extern unsigned long tick_usec; /* USER_HZ period (usec) */
	196	extern unsigned long tick_nsec; /* ACTHZ period (nsec) */
	197	extern int tickadj; /* amount of adjustment per tick */
	198
	199	/*
	200	* phase-lock loop variables
	201	*/
1da177e4	202	extern int time_status; /* clock synchronization status bits */
1da177e4 LT	203	extern long time_maxerror; /* maximum error */
	204	extern long time_esterror; /* estimated error */
	205
	206	extern long time_freq; /* frequency offset (scaled ppm) */
1da177e4 LT	207
1da177e4 LT	208	extern long time_adjust; /* The amount of adjtime left */
1da177e4	209
b0ee7556	210	extern void ntp_clear(void);
b149ee22	211
	212	/**
	213	* ntp_synced - Returns 1 if the NTP status is not UNSYNC
	214	*
	215	*/
	216	static inline int ntp_synced(void)
	217	{
	218	return !(time_status & STA_UNSYNC);
	219	}
	220
1bb34a41	221	/* Required to safely shift negative values */
	222	#define shift_right(x, s) ({ \
	223	__typeof__(x) __x = (x); \
	224	__typeof__(s) __s = (s); \
	225	__x < 0 ? -(-__x >> __s) : __x >> __s; \
	226	})
	227
19923c19 RZ	228	#define TICK_LENGTH_SHIFT 32
19923c19 RZ	229
f4304ab2	230	#ifdef CONFIG_NO_HZ
	231	#define NTP_INTERVAL_FREQ (2)
	232	#else
	233	#define NTP_INTERVAL_FREQ (HZ)
	234	#endif
	235	#define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ)
	236
726c14bf	237	/* Returns how long ticks are at present, in ns / 2^(SHIFT_SCALE-10). */
19923c19	238	extern u64 current_tick_length(void);
726c14bf	239
4c7ee8de	240	extern void second_overflow(void);
4c7ee8de	241	extern void update_ntp_one_tick(void);
3158e941 SR	242	extern int do_adjtimex(struct timex *);
3158e941 SR	243
7236e978 RZ	244	/* Don't use! Compatibility define for existing users. */
	245	#define tickadj (500/HZ ? : 1)
	246
1da177e4 LT	247	#endif /* KERNEL */
	248
	249	#endif /* LINUX_TIMEX_H */