/* $NetBSD: freebsd_timex.h,v 1.4 2007/12/04 18:40:08 dsl Exp $ */ /****************************************************************************** * * * Copyright (c) David L. Mills 1993, 1994 * * * * 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 * * 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 */ /* * This header file defines the Network Time Protocol (NTP) interfaces * for user and daemon application programs. These are implemented using * private syscalls and data structures and require specific kernel * support. * * NAME * ntp_gettime - NTP user application interface * * SYNOPSIS * #include <sys/timex.h> * * int syscall(SYS_ntp_gettime, tptr) * * int SYS_ntp_gettime defined in syscall.h header file * struct ntptimeval *tptr pointer to ntptimeval structure * * NAME * ntp_adjtime - NTP daemon application interface * * SYNOPSIS * #include <sys/timex.h> * * int syscall(SYS_ntp_adjtime, mode, tptr) * * int SYS_ntp_adjtime defined in syscall.h header file * struct timex *tptr pointer to timex structure * */ #ifndef _FREEBSD_TIMEX_H #define _FREEBSD_TIMEX_H 1 #ifndef MSDOS /* Microsoft specific */ #include <sys/syscall.h> #endif /* MSDOS */ /* * The following defines establish the engineering parameters of the * phase-lock loop (PLL) model used in the kernel implementation. These * parameters have been carefully chosen by analysis for good stability * and wide dynamic range. * * The hz variable is defined in the kernel build environment. It * establishes the timer interrupt frequency, 100 Hz for the SunOS * kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the OSF/1 * kernel. SHIFT_HZ expresses the same value as the nearest power of two * in order to avoid hardware multiply operations. * * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen * for a slightly underdamped convergence characteristic. * * 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_HZ 7 /* log2(hz) */ #define SHIFT_KG 6 /* phase factor (shift) */ #define SHIFT_KF 16 /* frequency factor (shift) */ #define MAXTC 6 /* maximum time constant (shift) */ /* * The following defines establish the scaling of the various variables * used by the PLL. They are chosen to allow the greatest precision * possible without overflow of a 32-bit word. * * SHIFT_SCALE defines the scaling (shift) of the time_phase variable, * which serves as a an extension to the low-order bits of the system * clock variable time.tv_usec. * * SHIFT_UPDATE defines the scaling (shift) of the time_offset variable, * which represents the current time 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. * * FINEUSEC is 1 us in SHIFT_UPDATE units of the time_phase variable. */ #define SHIFT_SCALE 23 /* phase scale (shift) */ #define SHIFT_UPDATE (SHIFT_KG + MAXTC) /* time offset scale (shift) */ #define SHIFT_USEC 16 /* frequency offset scale (shift) */ #define FINEUSEC (1L << SHIFT_SCALE) /* 1 us in phase units */ /* * The following defines establish the performance envelope of the PLL. * They insure it operates within predefined limits, in order to satisfy * correctness assertions. An excursion which exceeds these bounds is * clamped to the bound and operation proceeds accordingly. In practice, * this can occur only if something has failed or is operating out of * tolerance, but otherwise the PLL continues to operate in a stable * mode. * * MAXPHASE must be set greater than or equal to CLOCK.MAX (128 ms), as * defined in the NTP specification. CLOCK.MAX establishes the maximum * time offset allowed before the system time is reset, rather than * incrementally adjusted. Here, the maximum offset is clamped to * MAXPHASE only in order to prevent overflow errors due to defective * protocol implementations. * * MAXFREQ is the maximum frequency tolerance of the CPU clock * oscillator plus the maximum slew rate allowed by the protocol. It * should be set to at least the frequency tolerance of the oscillator * plus 100 ppm for vernier frequency adjustments. If the kernel * PPS discipline code is configured (PPS_SYNC), the oscillator time and * frequency are disciplined to an external source, presumably with * negligible time and frequency error relative to UTC, and MAXFREQ can * be reduced. * * MAXTIME is the maximum jitter tolerance of the PPS signal if the * kernel PPS discipline code is configured (PPS_SYNC). * * MINSEC and MAXSEC define the lower and upper bounds on the interval * between protocol updates. */ #define MAXPHASE 128000L /* max phase error (us) */ #ifdef PPS_SYNC #define MAXFREQ (100L << SHIFT_USEC) /* max freq error (100 ppm) */ #define MAXTIME (200L << PPS_AVG) /* max PPS error (jitter) (200 us) */ #else #define MAXFREQ (200L << SHIFT_USEC) /* max freq error (200 ppm) */ #endif /* PPS_SYNC */ #define MINSEC 16L /* min interval between updates (s) */ #define MAXSEC 1200L /* max interval between updates (s) */ #ifdef PPS_SYNC /* * The following defines are used only if a pulse-per-second (PPS) * signal is available and connected via a modem control lead, such as * produced by the optional ppsclock feature incorporated in the Sun * asynch driver. They establish the design parameters of the frequency- * lock loop used to discipline the CPU clock oscillator to the PPS * signal. * * PPS_AVG is the averaging factor for the frequency loop, as well as * the time and frequency dispersion. * * PPS_SHIFT and PPS_SHIFTMAX specify the minimum and maximum * calibration intervals, respectively, in seconds as a power of two. * * PPS_VALID is the maximum interval before the PPS signal is considered * invalid and protocol updates used directly instead. * * MAXGLITCH is the maximum interval before a time offset of more than * MAXTIME is believed. */ #define PPS_AVG 2 /* pps averaging constant (shift) */ #define PPS_SHIFT 2 /* min interval duration (s) (shift) */ #define PPS_SHIFTMAX 8 /* max interval duration (s) (shift) */ #define PPS_VALID 120 /* pps signal watchdog max (s) */ #define MAXGLITCH 30 /* pps signal glitch max (s) */ #endif /* PPS_SYNC */ /* * The following defines and structures define the user interface for * the ntp_gettime() and ntp_adjtime() system calls. * * 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_CLKB 0x4000 /* set clock B */ #define MOD_CLKA 0x8000 /* set 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_INS 0x0010 /* insert leap (rw) */ #define STA_DEL 0x0020 /* delete leap (rw) */ #define STA_UNSYNC 0x0040 /* clock unsynchronized (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 /* 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 /* clock not synchronized */ /* * NTP user interface (ntp_gettime()) - used to read kernel clock values * * Note: maximum error = NTP synch distance = dispersion + delay / 2; * estimated error = NTP dispersion. */ struct freebsd_ntptimeval { struct timeval time; /* current time (ro) */ long maxerror; /* maximum error (us) (ro) */ long esterror; /* estimated error (us) (ro) */ int time_state; /* what ntp_gettime returns */ }; /* * NTP daemon interface - (ntp_adjtime()) used to discipline CPU clock * oscillator */ struct freebsd_timex { unsigned int modes; /* clock mode bits (wo) */ long offset; /* time offset (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; /* pll time constant (rw) */ long precision; /* clock precision (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. */ 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) */ }; #ifdef __FreeBSD__ /* * sysctl identifiers underneath kern.ntp_pll */ #define NTP_PLL_GETTIME 1 /* used by ntp_gettime() */ #define NTP_PLL_MAXID 2 /* number of valid ids */ #define NTP_PLL_NAMES { \ { 0, 0 }, \ { "gettime", CTLTYPE_STRUCT }, \ } #ifndef _KERNEL #include <sys/cdefs.h> __BEGIN_DECLS extern int ntp_gettime(struct ntptimeval *); extern int ntp_adjtime(struct timex *); __END_DECLS #endif /* not _KERNEL */ #endif /* __FreeBSD__ */ #endif /* _FREEBSD_TIMEX_H */
