1 /* $NetBSD: freebsd_timex.h,v 1.3 2001/09/16 16:34:35 wiz Exp $ */ 2 3 /****************************************************************************** 4 * * 5 * Copyright (c) David L. Mills 1993, 1994 * 6 * * 7 * Permission to use, copy, modify, and distribute this software and its * 8 * documentation for any purpose and without fee is hereby granted, provided * 9 * that the above copyright notice appears in all copies and that both the * 10 * copyright notice and this permission notice appear in supporting * 11 * documentation, and that the name University of Delaware not be used in * 12 * advertising or publicity pertaining to distribution of the software * 13 * without specific, written prior permission. The University of Delaware * 14 * makes no representations about the suitability this software for any * 15 * purpose. It is provided "as is" without express or implied warranty. * 16 * * 17 ******************************************************************************/ 18 19 /* 20 * Modification history timex.h 21 * 22 * 19 Mar 94 David L. Mills 23 * Moved defines from kernel routines to header file and added new 24 * defines for PPS phase-lock loop. 25 * 26 * 20 Feb 94 David L. Mills 27 * Revised status codes and structures for external clock and PPS 28 * signal discipline. 29 * 30 * 28 Nov 93 David L. Mills 31 * Adjusted parameters to improve stability and increase poll 32 * interval. 33 * 34 * 17 Sep 93 David L. Mills 35 * Created file 36 */ 37 /* 38 * This header file defines the Network Time Protocol (NTP) interfaces 39 * for user and daemon application programs. These are implemented using 40 * private syscalls and data structures and require specific kernel 41 * support. 42 * 43 * NAME 44 * ntp_gettime - NTP user application interface 45 * 46 * SYNOPSIS 47 * #include <sys/timex.h> 48 * 49 * int syscall(SYS_ntp_gettime, tptr) 50 * 51 * int SYS_ntp_gettime defined in syscall.h header file 52 * struct ntptimeval *tptr pointer to ntptimeval structure 53 * 54 * NAME 55 * ntp_adjtime - NTP daemon application interface 56 * 57 * SYNOPSIS 58 * #include <sys/timex.h> 59 * 60 * int syscall(SYS_ntp_adjtime, mode, tptr) 61 * 62 * int SYS_ntp_adjtime defined in syscall.h header file 63 * struct timex *tptr pointer to timex structure 64 * 65 */ 66 #ifndef _FREEBSD_TIMEX_H 67 #define _FREEBSD_TIMEX_H 1 68 69 #ifndef MSDOS /* Microsoft specific */ 70 #include <sys/syscall.h> 71 #endif /* MSDOS */ 72 73 /* 74 * The following defines establish the engineering parameters of the 75 * phase-lock loop (PLL) model used in the kernel implementation. These 76 * parameters have been carefully chosen by analysis for good stability 77 * and wide dynamic range. 78 * 79 * The hz variable is defined in the kernel build environment. It 80 * establishes the timer interrupt frequency, 100 Hz for the SunOS 81 * kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the OSF/1 82 * kernel. SHIFT_HZ expresses the same value as the nearest power of two 83 * in order to avoid hardware multiply operations. 84 * 85 * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen 86 * for a slightly underdamped convergence characteristic. 87 * 88 * MAXTC establishes the maximum time constant of the PLL. With the 89 * SHIFT_KG and SHIFT_KF values given and a time constant range from 90 * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours, 91 * respectively. 92 */ 93 #define SHIFT_HZ 7 /* log2(hz) */ 94 #define SHIFT_KG 6 /* phase factor (shift) */ 95 #define SHIFT_KF 16 /* frequency factor (shift) */ 96 #define MAXTC 6 /* maximum time constant (shift) */ 97 98 /* 99 * The following defines establish the scaling of the various variables 100 * used by the PLL. They are chosen to allow the greatest precision 101 * possible without overflow of a 32-bit word. 102 * 103 * SHIFT_SCALE defines the scaling (shift) of the time_phase variable, 104 * which serves as a an extension to the low-order bits of the system 105 * clock variable time.tv_usec. 106 * 107 * SHIFT_UPDATE defines the scaling (shift) of the time_offset variable, 108 * which represents the current time offset with respect to standard 109 * time. 110 * 111 * SHIFT_USEC defines the scaling (shift) of the time_freq and 112 * time_tolerance variables, which represent the current frequency 113 * offset and maximum frequency tolerance. 114 * 115 * FINEUSEC is 1 us in SHIFT_UPDATE units of the time_phase variable. 116 */ 117 #define SHIFT_SCALE 23 /* phase scale (shift) */ 118 #define SHIFT_UPDATE (SHIFT_KG + MAXTC) /* time offset scale (shift) */ 119 #define SHIFT_USEC 16 /* frequency offset scale (shift) */ 120 #define FINEUSEC (1L << SHIFT_SCALE) /* 1 us in phase units */ 121 122 /* 123 * The following defines establish the performance envelope of the PLL. 124 * They insure it operates within predefined limits, in order to satisfy 125 * correctness assertions. An excursion which exceeds these bounds is 126 * clamped to the bound and operation proceeds accordingly. In practice, 127 * this can occur only if something has failed or is operating out of 128 * tolerance, but otherwise the PLL continues to operate in a stable 129 * mode. 130 * 131 * MAXPHASE must be set greater than or equal to CLOCK.MAX (128 ms), as 132 * defined in the NTP specification. CLOCK.MAX establishes the maximum 133 * time offset allowed before the system time is reset, rather than 134 * incrementally adjusted. Here, the maximum offset is clamped to 135 * MAXPHASE only in order to prevent overflow errors due to defective 136 * protocol implementations. 137 * 138 * MAXFREQ is the maximum frequency tolerance of the CPU clock 139 * oscillator plus the maximum slew rate allowed by the protocol. It 140 * should be set to at least the frequency tolerance of the oscillator 141 * plus 100 ppm for vernier frequency adjustments. If the kernel 142 * PPS discipline code is configured (PPS_SYNC), the oscillator time and 143 * frequency are disciplined to an external source, presumably with 144 * negligible time and frequency error relative to UTC, and MAXFREQ can 145 * be reduced. 146 * 147 * MAXTIME is the maximum jitter tolerance of the PPS signal if the 148 * kernel PPS discipline code is configured (PPS_SYNC). 149 * 150 * MINSEC and MAXSEC define the lower and upper bounds on the interval 151 * between protocol updates. 152 */ 153 #define MAXPHASE 128000L /* max phase error (us) */ 154 #ifdef PPS_SYNC 155 #define MAXFREQ (100L << SHIFT_USEC) /* max freq error (100 ppm) */ 156 #define MAXTIME (200L << PPS_AVG) /* max PPS error (jitter) (200 us) */ 157 #else 158 #define MAXFREQ (200L << SHIFT_USEC) /* max freq error (200 ppm) */ 159 #endif /* PPS_SYNC */ 160 #define MINSEC 16L /* min interval between updates (s) */ 161 #define MAXSEC 1200L /* max interval between updates (s) */ 162 163 #ifdef PPS_SYNC 164 /* 165 * The following defines are used only if a pulse-per-second (PPS) 166 * signal is available and connected via a modem control lead, such as 167 * produced by the optional ppsclock feature incorporated in the Sun 168 * asynch driver. They establish the design parameters of the frequency- 169 * lock loop used to discipline the CPU clock oscillator to the PPS 170 * signal. 171 * 172 * PPS_AVG is the averaging factor for the frequency loop, as well as 173 * the time and frequency dispersion. 174 * 175 * PPS_SHIFT and PPS_SHIFTMAX specify the minimum and maximum 176 * calibration intervals, respectively, in seconds as a power of two. 177 * 178 * PPS_VALID is the maximum interval before the PPS signal is considered 179 * invalid and protocol updates used directly instead. 180 * 181 * MAXGLITCH is the maximum interval before a time offset of more than 182 * MAXTIME is believed. 183 */ 184 #define PPS_AVG 2 /* pps averaging constant (shift) */ 185 #define PPS_SHIFT 2 /* min interval duration (s) (shift) */ 186 #define PPS_SHIFTMAX 8 /* max interval duration (s) (shift) */ 187 #define PPS_VALID 120 /* pps signal watchdog max (s) */ 188 #define MAXGLITCH 30 /* pps signal glitch max (s) */ 189 #endif /* PPS_SYNC */ 190 191 /* 192 * The following defines and structures define the user interface for 193 * the ntp_gettime() and ntp_adjtime() system calls. 194 * 195 * Control mode codes (timex.modes) 196 */ 197 #define MOD_OFFSET 0x0001 /* set time offset */ 198 #define MOD_FREQUENCY 0x0002 /* set frequency offset */ 199 #define MOD_MAXERROR 0x0004 /* set maximum time error */ 200 #define MOD_ESTERROR 0x0008 /* set estimated time error */ 201 #define MOD_STATUS 0x0010 /* set clock status bits */ 202 #define MOD_TIMECONST 0x0020 /* set pll time constant */ 203 #define MOD_CLKB 0x4000 /* set clock B */ 204 #define MOD_CLKA 0x8000 /* set clock A */ 205 206 /* 207 * Status codes (timex.status) 208 */ 209 #define STA_PLL 0x0001 /* enable PLL updates (rw) */ 210 #define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */ 211 #define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */ 212 213 #define STA_INS 0x0010 /* insert leap (rw) */ 214 #define STA_DEL 0x0020 /* delete leap (rw) */ 215 #define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */ 216 217 #define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */ 218 #define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */ 219 #define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */ 220 #define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */ 221 222 #define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */ 223 224 #define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \ 225 STA_PPSERROR | STA_CLOCKERR) /* read-only bits */ 226 227 /* 228 * Clock states (time_state) 229 */ 230 #define TIME_OK 0 /* no leap second warning */ 231 #define TIME_INS 1 /* insert leap second warning */ 232 #define TIME_DEL 2 /* delete leap second warning */ 233 #define TIME_OOP 3 /* leap second in progress */ 234 #define TIME_WAIT 4 /* leap second has occurred */ 235 #define TIME_ERROR 5 /* clock not synchronized */ 236 237 /* 238 * NTP user interface (ntp_gettime()) - used to read kernel clock values 239 * 240 * Note: maximum error = NTP synch distance = dispersion + delay / 2; 241 * estimated error = NTP dispersion. 242 */ 243 struct freebsd_ntptimeval { 244 struct timeval time; /* current time (ro) */ 245 long maxerror; /* maximum error (us) (ro) */ 246 long esterror; /* estimated error (us) (ro) */ 247 int time_state; /* what ntp_gettime returns */ 248 }; 249 250 /* 251 * NTP daemon interface - (ntp_adjtime()) used to discipline CPU clock 252 * oscillator 253 */ 254 struct freebsd_timex { 255 unsigned int modes; /* clock mode bits (wo) */ 256 long offset; /* time offset (us) (rw) */ 257 long freq; /* frequency offset (scaled ppm) (rw) */ 258 long maxerror; /* maximum error (us) (rw) */ 259 long esterror; /* estimated error (us) (rw) */ 260 int status; /* clock status bits (rw) */ 261 long constant; /* pll time constant (rw) */ 262 long precision; /* clock precision (us) (ro) */ 263 long tolerance; /* clock frequency tolerance (scaled 264 * ppm) (ro) */ 265 /* 266 * The following read-only structure members are implemented 267 * only if the PPS signal discipline is configured in the 268 * kernel. 269 */ 270 long ppsfreq; /* pps frequency (scaled ppm) (ro) */ 271 long jitter; /* pps jitter (us) (ro) */ 272 int shift; /* interval duration (s) (shift) (ro) */ 273 long stabil; /* pps stability (scaled ppm) (ro) */ 274 long jitcnt; /* jitter limit exceeded (ro) */ 275 long calcnt; /* calibration intervals (ro) */ 276 long errcnt; /* calibration errors (ro) */ 277 long stbcnt; /* stability limit exceeded (ro) */ 278 279 }; 280 #ifdef __FreeBSD__ 281 282 /* 283 * sysctl identifiers underneath kern.ntp_pll 284 */ 285 #define NTP_PLL_GETTIME 1 /* used by ntp_gettime() */ 286 #define NTP_PLL_MAXID 2 /* number of valid ids */ 287 288 #define NTP_PLL_NAMES { \ 289 { 0, 0 }, \ 290 { "gettime", CTLTYPE_STRUCT }, \ 291 } 292 293 #ifndef _KERNEL 294 #include <sys/cdefs.h> 295 296 __BEGIN_DECLS 297 extern int ntp_gettime __P((struct ntptimeval *)); 298 extern int ntp_adjtime __P((struct timex *)); 299 __END_DECLS 300 301 #endif /* not _KERNEL */ 302 303 #endif /* __FreeBSD__ */ 304 #endif /* _FREEBSD_TIMEX_H */ 305