Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | #include <linux/time.h> |
| 57 | |
Roman Zippel | eea83d8 | 2008-05-01 04:34:33 -0700 | [diff] [blame] | 58 | #define NTP_API 4 /* NTP API version */ |
| 59 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | * syscall interface - used (mainly by NTP daemon) |
| 62 | * to discipline kernel clock oscillator |
| 63 | */ |
| 64 | struct timex { |
| 65 | unsigned int modes; /* mode selector */ |
| 66 | long offset; /* time offset (usec) */ |
| 67 | long freq; /* frequency offset (scaled ppm) */ |
| 68 | long maxerror; /* maximum error (usec) */ |
| 69 | long esterror; /* estimated error (usec) */ |
| 70 | int status; /* clock command/status */ |
| 71 | long constant; /* pll time constant */ |
| 72 | long precision; /* clock precision (usec) (read only) */ |
| 73 | long tolerance; /* clock frequency tolerance (ppm) |
| 74 | * (read only) |
| 75 | */ |
Richard Cochran | 094aa18 | 2011-02-01 13:52:20 +0000 | [diff] [blame] | 76 | struct timeval time; /* (read only, except for ADJ_SETOFFSET) */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | long tick; /* (modified) usecs between clock ticks */ |
| 78 | |
| 79 | long ppsfreq; /* pps frequency (scaled ppm) (ro) */ |
| 80 | long jitter; /* pps jitter (us) (ro) */ |
| 81 | int shift; /* interval duration (s) (shift) (ro) */ |
| 82 | long stabil; /* pps stability (scaled ppm) (ro) */ |
| 83 | long jitcnt; /* jitter limit exceeded (ro) */ |
| 84 | long calcnt; /* calibration intervals (ro) */ |
| 85 | long errcnt; /* calibration errors (ro) */ |
| 86 | long stbcnt; /* stability limit exceeded (ro) */ |
| 87 | |
Roman Zippel | 153b5d0 | 2008-05-01 04:34:37 -0700 | [diff] [blame] | 88 | int tai; /* TAI offset (ro) */ |
| 89 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | int :32; int :32; int :32; int :32; |
| 91 | int :32; int :32; int :32; int :32; |
Roman Zippel | 153b5d0 | 2008-05-01 04:34:37 -0700 | [diff] [blame] | 92 | int :32; int :32; int :32; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | }; |
| 94 | |
| 95 | /* |
| 96 | * Mode codes (timex.mode) |
| 97 | */ |
| 98 | #define ADJ_OFFSET 0x0001 /* time offset */ |
| 99 | #define ADJ_FREQUENCY 0x0002 /* frequency offset */ |
| 100 | #define ADJ_MAXERROR 0x0004 /* maximum time error */ |
| 101 | #define ADJ_ESTERROR 0x0008 /* estimated time error */ |
| 102 | #define ADJ_STATUS 0x0010 /* clock status */ |
| 103 | #define ADJ_TIMECONST 0x0020 /* pll time constant */ |
Roman Zippel | 153b5d0 | 2008-05-01 04:34:37 -0700 | [diff] [blame] | 104 | #define ADJ_TAI 0x0080 /* set TAI offset */ |
Richard Cochran | 094aa18 | 2011-02-01 13:52:20 +0000 | [diff] [blame] | 105 | #define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */ |
Roman Zippel | eea83d8 | 2008-05-01 04:34:33 -0700 | [diff] [blame] | 106 | #define ADJ_MICRO 0x1000 /* select microsecond resolution */ |
| 107 | #define ADJ_NANO 0x2000 /* select nanosecond resolution */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | #define ADJ_TICK 0x4000 /* tick value */ |
Roman Zippel | 916c7a8 | 2008-08-20 16:46:08 -0700 | [diff] [blame] | 109 | |
| 110 | #ifdef __KERNEL__ |
| 111 | #define ADJ_ADJTIME 0x8000 /* switch between adjtime/adjtimex modes */ |
| 112 | #define ADJ_OFFSET_SINGLESHOT 0x0001 /* old-fashioned adjtime */ |
| 113 | #define ADJ_OFFSET_READONLY 0x2000 /* read-only adjtime */ |
| 114 | #else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | #define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */ |
Roman Zippel | 916c7a8 | 2008-08-20 16:46:08 -0700 | [diff] [blame] | 116 | #define ADJ_OFFSET_SS_READ 0xa001 /* read-only adjtime */ |
| 117 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | |
john stultz | c95b450 | 2009-08-27 17:04:42 -0700 | [diff] [blame] | 119 | /* NTP userland likes the MOD_ prefix better */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | #define MOD_OFFSET ADJ_OFFSET |
| 121 | #define MOD_FREQUENCY ADJ_FREQUENCY |
| 122 | #define MOD_MAXERROR ADJ_MAXERROR |
| 123 | #define MOD_ESTERROR ADJ_ESTERROR |
| 124 | #define MOD_STATUS ADJ_STATUS |
| 125 | #define MOD_TIMECONST ADJ_TIMECONST |
john stultz | c95b450 | 2009-08-27 17:04:42 -0700 | [diff] [blame] | 126 | #define MOD_TAI ADJ_TAI |
| 127 | #define MOD_MICRO ADJ_MICRO |
| 128 | #define MOD_NANO ADJ_NANO |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | |
| 130 | |
| 131 | /* |
| 132 | * Status codes (timex.status) |
| 133 | */ |
| 134 | #define STA_PLL 0x0001 /* enable PLL updates (rw) */ |
| 135 | #define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */ |
| 136 | #define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */ |
| 137 | #define STA_FLL 0x0008 /* select frequency-lock mode (rw) */ |
| 138 | |
| 139 | #define STA_INS 0x0010 /* insert leap (rw) */ |
| 140 | #define STA_DEL 0x0020 /* delete leap (rw) */ |
| 141 | #define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */ |
| 142 | #define STA_FREQHOLD 0x0080 /* hold frequency (rw) */ |
| 143 | |
| 144 | #define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */ |
| 145 | #define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */ |
| 146 | #define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */ |
| 147 | #define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */ |
| 148 | |
| 149 | #define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */ |
Roman Zippel | eea83d8 | 2008-05-01 04:34:33 -0700 | [diff] [blame] | 150 | #define STA_NANO 0x2000 /* resolution (0 = us, 1 = ns) (ro) */ |
| 151 | #define STA_MODE 0x4000 /* mode (0 = PLL, 1 = FLL) (ro) */ |
| 152 | #define STA_CLK 0x8000 /* clock source (0 = A, 1 = B) (ro) */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | |
Roman Zippel | eea83d8 | 2008-05-01 04:34:33 -0700 | [diff] [blame] | 154 | /* read-only bits */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | #define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \ |
Roman Zippel | eea83d8 | 2008-05-01 04:34:33 -0700 | [diff] [blame] | 156 | STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | |
| 158 | /* |
| 159 | * Clock states (time_state) |
| 160 | */ |
| 161 | #define TIME_OK 0 /* clock synchronized, no leap second */ |
| 162 | #define TIME_INS 1 /* insert leap second */ |
| 163 | #define TIME_DEL 2 /* delete leap second */ |
| 164 | #define TIME_OOP 3 /* leap second in progress */ |
| 165 | #define TIME_WAIT 4 /* leap second has occurred */ |
| 166 | #define TIME_ERROR 5 /* clock not synchronized */ |
| 167 | #define TIME_BAD TIME_ERROR /* bw compat */ |
| 168 | |
| 169 | #ifdef __KERNEL__ |
Mike Frysinger | c29541b | 2008-12-01 14:18:11 -0800 | [diff] [blame] | 170 | #include <linux/compiler.h> |
| 171 | #include <linux/types.h> |
| 172 | #include <linux/param.h> |
| 173 | |
David Woodhouse | ee6baf8 | 2006-09-12 20:36:03 -0700 | [diff] [blame] | 174 | #include <asm/timex.h> |
| 175 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | /* |
john stultz | 22cfbbf | 2009-05-06 11:43:57 +0200 | [diff] [blame] | 177 | * SHIFT_PLL is used as a dampening factor to define how much we |
| 178 | * adjust the frequency correction for a given offset in PLL mode. |
| 179 | * It also used in dampening the offset correction, to define how |
| 180 | * much of the current value in time_offset we correct for each |
| 181 | * second. Changing this value changes the stiffness of the ntp |
| 182 | * adjustment code. A lower value makes it more flexible, reducing |
| 183 | * NTP convergence time. A higher value makes it stiffer, increasing |
| 184 | * convergence time, but making the clock more stable. |
Mike Frysinger | c29541b | 2008-12-01 14:18:11 -0800 | [diff] [blame] | 185 | * |
john stultz | e13cf6e | 2009-05-11 18:13:13 -0700 | [diff] [blame] | 186 | * In David Mills' nanokernel reference implementation SHIFT_PLL is 4. |
john stultz | 22cfbbf | 2009-05-06 11:43:57 +0200 | [diff] [blame] | 187 | * However this seems to increase convergence time much too long. |
| 188 | * |
| 189 | * https://lists.ntp.org/pipermail/hackers/2008-January/003487.html |
| 190 | * |
| 191 | * In the above mailing list discussion, it seems the value of 4 |
| 192 | * was appropriate for other Unix systems with HZ=100, and that |
| 193 | * SHIFT_PLL should be decreased as HZ increases. However, Linux's |
| 194 | * clock steering implementation is HZ independent. |
| 195 | * |
| 196 | * Through experimentation, a SHIFT_PLL value of 2 was found to allow |
| 197 | * for fast convergence (very similar to the NTPv3 code used prior to |
| 198 | * v2.6.19), with good clock stability. |
| 199 | * |
| 200 | * |
| 201 | * SHIFT_FLL is used as a dampening factor to define how much we |
| 202 | * adjust the frequency correction for a given offset in FLL mode. |
john stultz | e13cf6e | 2009-05-11 18:13:13 -0700 | [diff] [blame] | 203 | * In David Mills' nanokernel reference implementation SHIFT_FLL is 2. |
john stultz | 22cfbbf | 2009-05-06 11:43:57 +0200 | [diff] [blame] | 204 | * |
| 205 | * MAXTC establishes the maximum time constant of the PLL. |
Mike Frysinger | c29541b | 2008-12-01 14:18:11 -0800 | [diff] [blame] | 206 | */ |
john stultz | 22cfbbf | 2009-05-06 11:43:57 +0200 | [diff] [blame] | 207 | #define SHIFT_PLL 2 /* PLL frequency factor (shift) */ |
Mike Frysinger | c29541b | 2008-12-01 14:18:11 -0800 | [diff] [blame] | 208 | #define SHIFT_FLL 2 /* FLL frequency factor (shift) */ |
| 209 | #define MAXTC 10 /* maximum time constant (shift) */ |
| 210 | |
| 211 | /* |
| 212 | * SHIFT_USEC defines the scaling (shift) of the time_freq and |
| 213 | * time_tolerance variables, which represent the current frequency |
| 214 | * offset and maximum frequency tolerance. |
| 215 | */ |
| 216 | #define SHIFT_USEC 16 /* frequency offset scale (shift) */ |
Ingo Molnar | 2b9d149 | 2009-02-22 15:48:43 +0100 | [diff] [blame] | 217 | #define PPM_SCALE ((s64)NSEC_PER_USEC << (NTP_SCALE_SHIFT - SHIFT_USEC)) |
Mike Frysinger | c29541b | 2008-12-01 14:18:11 -0800 | [diff] [blame] | 218 | #define PPM_SCALE_INV_SHIFT 19 |
john stultz | 22cfbbf | 2009-05-06 11:43:57 +0200 | [diff] [blame] | 219 | #define PPM_SCALE_INV ((1LL << (PPM_SCALE_INV_SHIFT + NTP_SCALE_SHIFT)) / \ |
Mike Frysinger | c29541b | 2008-12-01 14:18:11 -0800 | [diff] [blame] | 220 | PPM_SCALE + 1) |
| 221 | |
john stultz | 22cfbbf | 2009-05-06 11:43:57 +0200 | [diff] [blame] | 222 | #define MAXPHASE 500000000L /* max phase error (ns) */ |
Mike Frysinger | c29541b | 2008-12-01 14:18:11 -0800 | [diff] [blame] | 223 | #define MAXFREQ 500000 /* max frequency error (ns/s) */ |
| 224 | #define MAXFREQ_SCALED ((s64)MAXFREQ << NTP_SCALE_SHIFT) |
| 225 | #define MINSEC 256 /* min interval between updates (s) */ |
| 226 | #define MAXSEC 2048 /* max interval between updates (s) */ |
| 227 | #define NTP_PHASE_LIMIT ((MAXPHASE / NSEC_PER_USEC) << 5) /* beyond max. dispersion */ |
| 228 | |
| 229 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | * kernel variables |
| 231 | * Note: maximum error = NTP synch distance = dispersion + delay / 2; |
| 232 | * estimated error = NTP dispersion. |
| 233 | */ |
| 234 | extern unsigned long tick_usec; /* USER_HZ period (usec) */ |
| 235 | extern unsigned long tick_nsec; /* ACTHZ period (nsec) */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | |
Roman Zippel | 7dffa3c | 2008-05-01 04:34:41 -0700 | [diff] [blame] | 237 | extern void ntp_init(void); |
Roman Zippel | b0ee755 | 2006-09-30 23:28:22 -0700 | [diff] [blame] | 238 | extern void ntp_clear(void); |
john stultz | b149ee2 | 2005-09-06 15:17:46 -0700 | [diff] [blame] | 239 | |
john stultz | 1bb34a4 | 2005-10-30 15:01:42 -0800 | [diff] [blame] | 240 | /* Required to safely shift negative values */ |
| 241 | #define shift_right(x, s) ({ \ |
| 242 | __typeof__(x) __x = (x); \ |
| 243 | __typeof__(s) __s = (s); \ |
| 244 | __x < 0 ? -(-__x >> __s) : __x >> __s; \ |
| 245 | }) |
| 246 | |
Roman Zippel | 7fc5c78 | 2008-05-01 04:34:38 -0700 | [diff] [blame] | 247 | #define NTP_SCALE_SHIFT 32 |
Roman Zippel | 19923c1 | 2006-06-26 00:25:18 -0700 | [diff] [blame] | 248 | |
john stultz | f4304ab | 2007-02-16 01:27:26 -0800 | [diff] [blame] | 249 | #define NTP_INTERVAL_FREQ (HZ) |
Roman Zippel | 10a398d | 2008-03-04 15:14:26 -0800 | [diff] [blame] | 250 | #define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ) |
john stultz | f4304ab | 2007-02-16 01:27:26 -0800 | [diff] [blame] | 251 | |
Roman Zippel | 8383c42 | 2008-05-01 04:34:39 -0700 | [diff] [blame] | 252 | /* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */ |
John Stultz | ea7cf49 | 2011-11-14 13:18:07 -0800 | [diff] [blame] | 253 | extern u64 ntp_tick_length(void); |
Paul Mackerras | 726c14b | 2006-02-17 10:30:23 +1100 | [diff] [blame] | 254 | |
john stultz | 4c7ee8d | 2006-09-30 23:28:22 -0700 | [diff] [blame] | 255 | extern void second_overflow(void); |
Stephen Rothwell | 3158e94 | 2006-03-26 01:37:29 -0800 | [diff] [blame] | 256 | extern int do_adjtimex(struct timex *); |
Alexander Gordeev | 025b40a | 2011-01-12 17:00:56 -0800 | [diff] [blame] | 257 | extern void hardpps(const struct timespec *, const struct timespec *); |
Stephen Rothwell | 3158e94 | 2006-03-26 01:37:29 -0800 | [diff] [blame] | 258 | |
Andrew Morton | 941e492 | 2008-02-06 01:36:42 -0800 | [diff] [blame] | 259 | int read_current_timer(unsigned long *timer_val); |
| 260 | |
Arnd Bergmann | 08604bd | 2009-06-16 15:31:12 -0700 | [diff] [blame] | 261 | /* The clock frequency of the i8253/i8254 PIT */ |
| 262 | #define PIT_TICK_RATE 1193182ul |
| 263 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | #endif /* KERNEL */ |
| 265 | |
| 266 | #endif /* LINUX_TIMEX_H */ |