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 56#include <linux/compiler.h> 57#include <linux/time.h> 58 59#include <asm/param.h> 60 61#define NTP_API 4 /* NTP API version */ 62 63/* 64 * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen 65 * for a slightly underdamped convergence characteristic. SHIFT_KH 66 * establishes the damping of the FLL and is chosen by wisdom and black 67 * art. 68 * 69 * MAXTC establishes the maximum time constant of the PLL. With the 70 * SHIFT_KG and SHIFT_KF values given and a time constant range from 71 * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours, 72 * respectively. 73 */ 74#define SHIFT_PLL 4 /* PLL frequency factor (shift) */ 75#define SHIFT_FLL 2 /* FLL frequency factor (shift) */ 76#define MAXTC 10 /* maximum time constant (shift) */ 77 78/* 79 * SHIFT_USEC defines the scaling (shift) of the time_freq and 80 * time_tolerance variables, which represent the current frequency 81 * offset and maximum frequency tolerance. 82 */ 83#define SHIFT_USEC 16 /* frequency offset scale (shift) */ 84#define PPM_SCALE (NSEC_PER_USEC << (NTP_SCALE_SHIFT - SHIFT_USEC)) 85#define PPM_SCALE_INV_SHIFT 19 86#define PPM_SCALE_INV ((1ll << (PPM_SCALE_INV_SHIFT + NTP_SCALE_SHIFT)) / \ 87 PPM_SCALE + 1) 88 89#define MAXPHASE 500000000l /* max phase error (ns) */ 90#define MAXFREQ 500000 /* max frequency error (ns/s) */ 91#define MAXFREQ_SCALED ((s64)MAXFREQ << NTP_SCALE_SHIFT) 92#define MINSEC 256 /* min interval between updates (s) */ 93#define MAXSEC 2048 /* max interval between updates (s) */ 94#define NTP_PHASE_LIMIT ((MAXPHASE / NSEC_PER_USEC) << 5) /* beyond max. dispersion */ 95 96/* 97 * syscall interface - used (mainly by NTP daemon) 98 * to discipline kernel clock oscillator 99 */ 100struct timex { 101 unsigned int modes; /* mode selector */ 102 long offset; /* time offset (usec) */ 103 long freq; /* frequency offset (scaled ppm) */ 104 long maxerror; /* maximum error (usec) */ 105 long esterror; /* estimated error (usec) */ 106 int status; /* clock command/status */ 107 long constant; /* pll time constant */ 108 long precision; /* clock precision (usec) (read only) */ 109 long tolerance; /* clock frequency tolerance (ppm) 110 * (read only) 111 */ 112 struct timeval time; /* (read only) */ 113 long tick; /* (modified) usecs between clock ticks */ 114 115 long ppsfreq; /* pps frequency (scaled ppm) (ro) */ 116 long jitter; /* pps jitter (us) (ro) */ 117 int shift; /* interval duration (s) (shift) (ro) */ 118 long stabil; /* pps stability (scaled ppm) (ro) */ 119 long jitcnt; /* jitter limit exceeded (ro) */ 120 long calcnt; /* calibration intervals (ro) */ 121 long errcnt; /* calibration errors (ro) */ 122 long stbcnt; /* stability limit exceeded (ro) */ 123 124 int tai; /* TAI offset (ro) */ 125 126 int :32; int :32; int :32; int :32; 127 int :32; int :32; int :32; int :32; 128 int :32; int :32; int :32; 129}; 130 131/* 132 * Mode codes (timex.mode) 133 */ 134#define ADJ_OFFSET 0x0001 /* time offset */ 135#define ADJ_FREQUENCY 0x0002 /* frequency offset */ 136#define ADJ_MAXERROR 0x0004 /* maximum time error */ 137#define ADJ_ESTERROR 0x0008 /* estimated time error */ 138#define ADJ_STATUS 0x0010 /* clock status */ 139#define ADJ_TIMECONST 0x0020 /* pll time constant */ 140#define ADJ_TAI 0x0080 /* set TAI offset */ 141#define ADJ_MICRO 0x1000 /* select microsecond resolution */ 142#define ADJ_NANO 0x2000 /* select nanosecond resolution */ 143#define ADJ_TICK 0x4000 /* tick value */ 144 145#ifdef __KERNEL__ 146#define ADJ_ADJTIME 0x8000 /* switch between adjtime/adjtimex modes */ 147#define ADJ_OFFSET_SINGLESHOT 0x0001 /* old-fashioned adjtime */ 148#define ADJ_OFFSET_READONLY 0x2000 /* read-only adjtime */ 149#else 150#define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */ 151#define ADJ_OFFSET_SS_READ 0xa001 /* read-only adjtime */ 152#endif 153 154/* xntp 3.4 compatibility names */ 155#define MOD_OFFSET ADJ_OFFSET 156#define MOD_FREQUENCY ADJ_FREQUENCY 157#define MOD_MAXERROR ADJ_MAXERROR 158#define MOD_ESTERROR ADJ_ESTERROR 159#define MOD_STATUS ADJ_STATUS 160#define MOD_TIMECONST ADJ_TIMECONST 161 162 163/* 164 * Status codes (timex.status) 165 */ 166#define STA_PLL 0x0001 /* enable PLL updates (rw) */ 167#define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */ 168#define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */ 169#define STA_FLL 0x0008 /* select frequency-lock mode (rw) */ 170 171#define STA_INS 0x0010 /* insert leap (rw) */ 172#define STA_DEL 0x0020 /* delete leap (rw) */ 173#define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */ 174#define STA_FREQHOLD 0x0080 /* hold frequency (rw) */ 175 176#define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */ 177#define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */ 178#define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */ 179#define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */ 180 181#define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */ 182#define STA_NANO 0x2000 /* resolution (0 = us, 1 = ns) (ro) */ 183#define STA_MODE 0x4000 /* mode (0 = PLL, 1 = FLL) (ro) */ 184#define STA_CLK 0x8000 /* clock source (0 = A, 1 = B) (ro) */ 185 186/* read-only bits */ 187#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \ 188 STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK) 189 190/* 191 * Clock states (time_state) 192 */ 193#define TIME_OK 0 /* clock synchronized, no leap second */ 194#define TIME_INS 1 /* insert leap second */ 195#define TIME_DEL 2 /* delete leap second */ 196#define TIME_OOP 3 /* leap second in progress */ 197#define TIME_WAIT 4 /* leap second has occurred */ 198#define TIME_ERROR 5 /* clock not synchronized */ 199#define TIME_BAD TIME_ERROR /* bw compat */ 200 201#ifdef __KERNEL__ 202#include <asm/timex.h> 203 204/* 205 * kernel variables 206 * Note: maximum error = NTP synch distance = dispersion + delay / 2; 207 * estimated error = NTP dispersion. 208 */ 209extern unsigned long tick_usec; /* USER_HZ period (usec) */ 210extern unsigned long tick_nsec; /* ACTHZ period (nsec) */ 211extern int tickadj; /* amount of adjustment per tick */ 212 213/* 214 * phase-lock loop variables 215 */ 216extern int time_status; /* clock synchronization status bits */ 217extern long time_maxerror; /* maximum error */ 218extern long time_esterror; /* estimated error */ 219 220extern long time_adjust; /* The amount of adjtime left */ 221 222extern void ntp_init(void); 223extern void ntp_clear(void); 224 225/** 226 * ntp_synced - Returns 1 if the NTP status is not UNSYNC 227 * 228 */ 229static inline int ntp_synced(void) 230{ 231 return !(time_status & STA_UNSYNC); 232} 233 234/* Required to safely shift negative values */ 235#define shift_right(x, s) ({ \ 236 __typeof__(x) __x = (x); \ 237 __typeof__(s) __s = (s); \ 238 __x < 0 ? -(-__x >> __s) : __x >> __s; \ 239}) 240 241#define NTP_SCALE_SHIFT 32 242 243#ifdef CONFIG_NO_HZ 244#define NTP_INTERVAL_FREQ (2) 245#else 246#define NTP_INTERVAL_FREQ (HZ) 247#endif 248#define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ) 249 250/* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */ 251extern u64 tick_length; 252 253extern void second_overflow(void); 254extern void update_ntp_one_tick(void); 255extern int do_adjtimex(struct timex *); 256 257/* Don't use! Compatibility define for existing users. */ 258#define tickadj (500/HZ ? : 1) 259 260int read_current_timer(unsigned long *timer_val); 261 262#endif /* KERNEL */ 263 264#endif /* LINUX_TIMEX_H */ 265