timex.h

Go to the documentation of this file.

 
/*-
 ***********************************************************************
 *                                     *
 * Copyright (c) David L. Mills 1993-2001                  *
 * Copyright (c) Poul-Henning Kamp 2000-2001                           *
 *                                     *
 * 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.                                   *
 *                                     *
 ***********************************************************************
 *
 * This header file defines the Network Time Protocol (NTP) interfaces
 * for user and daemon application programs.
 *
 * This file was originally created 17 Sep 93 by David L. Mills, Professor
 * of University of Delaware, building on work which had already been ongoing
 * for a decade and a half at that point in time.
 *
 * In 2000 the APIs got a upgrade from microseconds to nanoseconds,
 * a joint work between Poul-Henning Kamp and David L. Mills.
 *
 */
 
#ifndef _SYS_TIMEX_H_
#define _SYS_TIMEX_H_ 1
 
#define NTP_API     4       /* NTP API version */
 
#if defined(__FreeBSD__) || defined(__rtems__)
#include <sys/_timespec.h>
#endif /* __FreeBSD__ */
 
/*
 * The following defines establish the performance envelope of the
 * kernel discipline loop. Phase or frequency errors greater than
 * NAXPHASE or MAXFREQ are clamped to these maxima. For update intervals
 * less than MINSEC, the loop always operates in PLL mode; while, for
 * update intervals greater than MAXSEC, the loop always operates in FLL
 * mode. Between these two limits the operating mode is selected by the
 * STA_FLL bit in the status word.
 */
 
#define MAXPHASE    500000000L  /* max phase error (ns) */
#define MAXFREQ     500000L     /* max freq error (ns/s) */
#define MINSEC      256     /* min FLL update interval (s) */
#define MAXSEC      2048        /* max PLL update interval (s) */
#define NANOSECOND  1000000000L /* nanoseconds in one second */
#define SCALE_PPM   (65536 / 1000)  /* crude ns/s to scaled PPM */
#define MAXTC       10      /* max time constant */
 
/*
 * Control mode codes (timex.modes)
 */
#define MOD_OFFSET  0x0001      /* set time offset */
#define MOD_FREQUENCY   0x0002      /* set frequency offset */
#define MOD_MAXERROR    0x0004      /* set maximum time error */
#define MOD_ESTERROR    0x0008      /* set estimated time error */
#define MOD_STATUS  0x0010      /* set clock status bits */
#define MOD_TIMECONST   0x0020      /* set PLL time constant */
#define MOD_PPSMAX  0x0040      /* set PPS maximum averaging time */
#define MOD_TAI     0x0080      /* set TAI offset */
#define MOD_MICRO   0x1000      /* select microsecond resolution */
#define MOD_NANO    0x2000      /* select nanosecond resolution */
#define MOD_CLKB    0x4000      /* select clock B */
#define MOD_CLKA    0x8000      /* select clock A */
 
/*
 * 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      /* enable FLL 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_NANO    0x2000      /* resolution (0 = us, 1 = ns) (ro) */
#define STA_MODE    0x4000      /* mode (0 = PLL, 1 = FLL) (ro) */
#define STA_CLK     0x8000      /* clock source (0 = A, 1 = B) (ro) */
 
#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
    STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK)
 
/*
 * Clock states (ntptimeval.time_state)
 */
#define TIME_OK     0       /* no leap second warning */
#define TIME_INS    1       /* insert leap second warning */
#define TIME_DEL    2       /* delete leap second warning */
#define TIME_OOP    3       /* leap second in progress */
#define TIME_WAIT   4       /* leap second has occurred */
#define TIME_ERROR  5       /* error (see status word) */
 
/*
 * NTP user interface -- ntp_gettime(2) - used to read kernel clock values
 */
struct ntptimeval {
    struct timespec time;       /* current time (ns) (ro) */
    long maxerror;          /* maximum error (us) (ro) */
    long esterror;          /* estimated error (us) (ro) */
    long tai;           /* TAI offset */
    int time_state;         /* time status */
};
 
/*
 * NTP daemon interface -- ntp_adjtime(2) -- used to discipline CPU clock
 * oscillator and control/determine status.
 *
 * Note: The offset, precision and jitter members are in microseconds if
 * STA_NANO is zero and nanoseconds if not.
 */
struct timex {
    unsigned int modes;     /* clock mode bits (wo) */
    long    offset;         /* time offset (ns/us) (rw) */
    long    freq;           /* frequency offset (scaled PPM) (rw) */
    long    maxerror;       /* maximum error (us) (rw) */
    long    esterror;       /* estimated error (us) (rw) */
    int status;         /* clock status bits (rw) */
    long    constant;       /* poll interval (log2 s) (rw) */
    long    precision;      /* clock precision (ns/us) (ro) */
    long    tolerance;      /* clock frequency tolerance (scaled
                     * PPM) (ro) */
    /*
     * The following read-only structure members are implemented
     * only if the PPS signal discipline is configured in the
     * kernel. They are included in all configurations to insure
     * portability.
     */
    long    ppsfreq;        /* PPS frequency (scaled PPM) (ro) */
    long    jitter;         /* PPS jitter (ns/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) */
};
 
#if defined(__FreeBSD__) || defined(__rtems__)
 
#ifdef _KERNEL
void    ntp_update_second(int64_t *adjustment, time_t *newsec);
#else /* !_KERNEL */
#include <sys/cdefs.h>
 
__BEGIN_DECLS
int ntp_adjtime(struct timex *);
int ntp_gettime(struct ntptimeval *);
__END_DECLS
#endif /* _KERNEL */
 
#endif /* __FreeBSD__ */
 
#endif /* !_SYS_TIMEX_H_ */