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 */ 51 #ifndef _LINUX_TIMEX_H 52 #define _LINUX_TIMEX_H 53 54 #include <asm/param.h> 55 56 /* 57 * The following defines establish the engineering parameters of the PLL 58 * model. The HZ variable establishes the timer interrupt frequency, 100 Hz 59 * for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the 60 * OSF/1 kernel. The SHIFT_HZ define expresses the same value as the 61 * nearest power of two in order to avoid hardware multiply operations. 62 */ 63 #if HZ >= 12 && HZ < 24 64 # define SHIFT_HZ 4 65 #elif HZ >= 24 && HZ < 48 66 # define SHIFT_HZ 5 67 #elif HZ >= 48 && HZ < 96 68 # define SHIFT_HZ 6 69 #elif HZ >= 96 && HZ < 192 70 # define SHIFT_HZ 7 71 #elif HZ >= 192 && HZ < 384 72 # define SHIFT_HZ 8 73 #elif HZ >= 384 && HZ < 768 74 # define SHIFT_HZ 9 75 #elif HZ >= 768 && HZ < 1536 76 # define SHIFT_HZ 10 77 #else 78 # error You lose. 79 #endif 80 81 /* 82 * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen 83 * for a slightly underdamped convergence characteristic. SHIFT_KH 84 * establishes the damping of the FLL and is chosen by wisdom and black 85 * art. 86 * 87 * MAXTC establishes the maximum time constant of the PLL. With the 88 * SHIFT_KG and SHIFT_KF values given and a time constant range from 89 * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours, 90 * respectively. 91 */ 92 #define SHIFT_KG 6 /* phase factor (shift) */ 93 #define SHIFT_KF 16 /* PLL frequency factor (shift) */ 94 #define SHIFT_KH 2 /* FLL frequency factor (shift) */ 95 #define MAXTC 6 /* maximum time constant (shift) */ 96 97 /* 98 * The SHIFT_SCALE define establishes the decimal point of the time_phase 99 * variable which serves as an extension to the low-order bits of the 100 * system clock variable. The SHIFT_UPDATE define establishes the decimal 101 * point of the time_offset variable which represents the current offset 102 * with respect to standard time. The FINEUSEC define represents 1 usec in 103 * scaled units. 104 * 105 * SHIFT_USEC defines the scaling (shift) of the time_freq and 106 * time_tolerance variables, which represent the current frequency 107 * offset and maximum frequency tolerance. 108 * 109 * FINEUSEC is 1 us in SHIFT_UPDATE units of the time_phase variable. 110 */ 111 #define SHIFT_SCALE 22 /* phase scale (shift) */ 112 #define SHIFT_UPDATE (SHIFT_KG + MAXTC) /* time offset scale (shift) */ 113 #define SHIFT_USEC 16 /* frequency offset scale (shift) */ 114 #define FINEUSEC (1L << SHIFT_SCALE) /* 1 us in phase units */ 115 116 #define MAXPHASE 512000L /* max phase error (us) */ 117 #define MAXFREQ (512L << SHIFT_USEC) /* max frequency error (ppm) */ 118 #define MAXTIME (200L << PPS_AVG) /* max PPS error (jitter) (200 us) */ 119 #define MINSEC 16L /* min interval between updates (s) */ 120 #define MAXSEC 1200L /* max interval between updates (s) */ 121 #define NTP_PHASE_LIMIT (MAXPHASE << 5) /* beyond max. dispersion */ 122 123 /* 124 * The following defines are used only if a pulse-per-second (PPS) 125 * signal is available and connected via a modem control lead, such as 126 * produced by the optional ppsclock feature incorporated in the Sun 127 * asynch driver. They establish the design parameters of the frequency- 128 * lock loop used to discipline the CPU clock oscillator to the PPS 129 * signal. 130 * 131 * PPS_AVG is the averaging factor for the frequency loop, as well as 132 * the time and frequency dispersion. 133 * 134 * PPS_SHIFT and PPS_SHIFTMAX specify the minimum and maximum 135 * calibration intervals, respectively, in seconds as a power of two. 136 * 137 * PPS_VALID is the maximum interval before the PPS signal is considered 138 * invalid and protocol updates used directly instead. 139 * 140 * MAXGLITCH is the maximum interval before a time offset of more than 141 * MAXTIME is believed. 142 */ 143 #define PPS_AVG 2 /* pps averaging constant (shift) */ 144 #define PPS_SHIFT 2 /* min interval duration (s) (shift) */ 145 #define PPS_SHIFTMAX 8 /* max interval duration (s) (shift) */ 146 #define PPS_VALID 120 /* pps signal watchdog max (s) */ 147 #define MAXGLITCH 30 /* pps signal glitch max (s) */ 148 149 /* 150 * Pick up the architecture specific timex specifications 151 */ 152 #include <asm/timex.h> 153 154 /* LATCH is used in the interval timer and ftape setup. */ 155 #define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */ 156 157 /* 158 * syscall interface - used (mainly by NTP daemon) 159 * to discipline kernel clock oscillator 160 */ 161 struct timex { 162 unsigned int modes; /* mode selector */ 163 long offset; /* time offset (usec) */ 164 long freq; /* frequency offset (scaled ppm) */ 165 long maxerror; /* maximum error (usec) */ 166 long esterror; /* estimated error (usec) */ 167 int status; /* clock command/status */ 168 long constant; /* pll time constant */ 169 long precision; /* clock precision (usec) (read only) */ 170 long tolerance; /* clock frequency tolerance (ppm) 171 * (read only) 172 */ 173 struct timeval time; /* (read only) */ 174 long tick; /* (modified) usecs between clock ticks */ 175 176 long ppsfreq; /* pps frequency (scaled ppm) (ro) */ 177 long jitter; /* pps jitter (us) (ro) */ 178 int shift; /* interval duration (s) (shift) (ro) */ 179 long stabil; /* pps stability (scaled ppm) (ro) */ 180 long jitcnt; /* jitter limit exceeded (ro) */ 181 long calcnt; /* calibration intervals (ro) */ 182 long errcnt; /* calibration errors (ro) */ 183 long stbcnt; /* stability limit exceeded (ro) */ 184 185 int :32; int :32; int :32; int :32; 186 int :32; int :32; int :32; int :32; 187 int :32; int :32; int :32; int :32; 188 }; 189 190 /* 191 * Mode codes (timex.mode) 192 */ 193 #define ADJ_OFFSET 0x0001 /* time offset */ 194 #define ADJ_FREQUENCY 0x0002 /* frequency offset */ 195 #define ADJ_MAXERROR 0x0004 /* maximum time error */ 196 #define ADJ_ESTERROR 0x0008 /* estimated time error */ 197 #define ADJ_STATUS 0x0010 /* clock status */ 198 #define ADJ_TIMECONST 0x0020 /* pll time constant */ 199 #define ADJ_TICK 0x4000 /* tick value */ 200 #define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */ 201 202 /* xntp 3.4 compatibility names */ 203 #define MOD_OFFSET ADJ_OFFSET 204 #define MOD_FREQUENCY ADJ_FREQUENCY 205 #define MOD_MAXERROR ADJ_MAXERROR 206 #define MOD_ESTERROR ADJ_ESTERROR 207 #define MOD_STATUS ADJ_STATUS 208 #define MOD_TIMECONST ADJ_TIMECONST 209 #define MOD_CLKB ADJ_TICK 210 #define MOD_CLKA ADJ_OFFSET_SINGLESHOT /* 0x8000 in original */ 211 212 213 /* 214 * Status codes (timex.status) 215 */ 216 #define STA_PLL 0x0001 /* enable PLL updates (rw) */ 217 #define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */ 218 #define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */ 219 #define STA_FLL 0x0008 /* select frequency-lock mode (rw) */ 220 221 #define STA_INS 0x0010 /* insert leap (rw) */ 222 #define STA_DEL 0x0020 /* delete leap (rw) */ 223 #define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */ 224 #define STA_FREQHOLD 0x0080 /* hold frequency (rw) */ 225 226 #define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */ 227 #define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */ 228 #define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */ 229 #define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */ 230 231 #define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */ 232 233 #define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \ 234 STA_PPSERROR | STA_CLOCKERR) /* read-only bits */ 235 236 /* 237 * Clock states (time_state) 238 */ 239 #define TIME_OK 0 /* clock synchronized, no leap second */ 240 #define TIME_INS 1 /* insert leap second */ 241 #define TIME_DEL 2 /* delete leap second */ 242 #define TIME_OOP 3 /* leap second in progress */ 243 #define TIME_WAIT 4 /* leap second has occurred */ 244 #define TIME_ERROR 5 /* clock not synchronized */ 245 #define TIME_BAD TIME_ERROR /* bw compat */ 246 247 #ifdef __KERNEL__ 248 /* 249 * kernel variables 250 * Note: maximum error = NTP synch distance = dispersion + delay / 2; 251 * estimated error = NTP dispersion. 252 */ 253 extern long tick; /* timer interrupt period */ 254 extern int tickadj; /* amount of adjustment per tick */ 255 256 /* 257 * phase-lock loop variables 258 */ 259 extern int time_state; /* clock status */ 260 extern int time_status; /* clock synchronization status bits */ 261 extern long time_offset; /* time adjustment (us) */ 262 extern long time_constant; /* pll time constant */ 263 extern long time_tolerance; /* frequency tolerance (ppm) */ 264 extern long time_precision; /* clock precision (us) */ 265 extern long time_maxerror; /* maximum error */ 266 extern long time_esterror; /* estimated error */ 267 268 extern long time_phase; /* phase offset (scaled us) */ 269 extern long time_freq; /* frequency offset (scaled ppm) */ 270 extern long time_adj; /* tick adjust (scaled 1 / HZ) */ 271 extern long time_reftime; /* time at last adjustment (s) */ 272 273 extern long time_adjust; /* The amount of adjtime left */ 274 275 /* interface variables pps->timer interrupt */ 276 extern long pps_offset; /* pps time offset (us) */ 277 extern long pps_jitter; /* time dispersion (jitter) (us) */ 278 extern long pps_freq; /* frequency offset (scaled ppm) */ 279 extern long pps_stabil; /* frequency dispersion (scaled ppm) */ 280 extern long pps_valid; /* pps signal watchdog counter */ 281 282 /* interface variables pps->adjtimex */ 283 extern int pps_shift; /* interval duration (s) (shift) */ 284 extern long pps_jitcnt; /* jitter limit exceeded */ 285 extern long pps_calcnt; /* calibration intervals */ 286 extern long pps_errcnt; /* calibration errors */ 287 extern long pps_stbcnt; /* stability limit exceeded */ 288 289 #endif /* KERNEL */ 290 291 #endif /* LINUX_TIMEX_H */ 292