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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*****************************************************************************
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 Torvalds1da177e2005-04-16 15:20:36 -070056#include <linux/compiler.h>
57#include <linux/time.h>
58
59#include <asm/param.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
Roman Zippeleea83d82008-05-01 04:34:33 -070061#define NTP_API 4 /* NTP API version */
62
Linus Torvalds1da177e2005-04-16 15:20:36 -070063/*
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 */
Roman Zippelf1992392006-09-30 23:28:28 -070074#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) */
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78/*
Roman Zippel0883d892006-09-30 23:28:29 -070079 * The SHIFT_UPDATE define establishes the decimal point of the
80 * time_offset variable which represents the current offset with
81 * respect to standard time.
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 *
83 * SHIFT_USEC defines the scaling (shift) of the time_freq and
84 * time_tolerance variables, which represent the current frequency
85 * offset and maximum frequency tolerance.
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 */
Roman Zippel3d3675c2006-09-30 23:28:25 -070087#define SHIFT_UPDATE (SHIFT_HZ + 1) /* time offset scale (shift) */
Linus Torvalds1da177e2005-04-16 15:20:36 -070088#define SHIFT_USEC 16 /* frequency offset scale (shift) */
Roman Zippel04b617e2006-09-30 23:28:27 -070089#define SHIFT_NSEC 12 /* kernel frequency offset scale */
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
91#define MAXPHASE 512000L /* max phase error (us) */
92#define MAXFREQ (512L << SHIFT_USEC) /* max frequency error (ppm) */
Roman Zippel04b617e2006-09-30 23:28:27 -070093#define MAXFREQ_NSEC (512000L << SHIFT_NSEC) /* max frequency error (ppb) */
Roman Zippelf1992392006-09-30 23:28:28 -070094#define MINSEC 256 /* min interval between updates (s) */
95#define MAXSEC 2048 /* max interval between updates (s) */
Linus Torvalds1da177e2005-04-16 15:20:36 -070096#define NTP_PHASE_LIMIT (MAXPHASE << 5) /* beyond max. dispersion */
97
98/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 * syscall interface - used (mainly by NTP daemon)
100 * to discipline kernel clock oscillator
101 */
102struct timex {
103 unsigned int modes; /* mode selector */
104 long offset; /* time offset (usec) */
105 long freq; /* frequency offset (scaled ppm) */
106 long maxerror; /* maximum error (usec) */
107 long esterror; /* estimated error (usec) */
108 int status; /* clock command/status */
109 long constant; /* pll time constant */
110 long precision; /* clock precision (usec) (read only) */
111 long tolerance; /* clock frequency tolerance (ppm)
112 * (read only)
113 */
114 struct timeval time; /* (read only) */
115 long tick; /* (modified) usecs between clock ticks */
116
117 long ppsfreq; /* pps frequency (scaled ppm) (ro) */
118 long jitter; /* pps jitter (us) (ro) */
119 int shift; /* interval duration (s) (shift) (ro) */
120 long stabil; /* pps stability (scaled ppm) (ro) */
121 long jitcnt; /* jitter limit exceeded (ro) */
122 long calcnt; /* calibration intervals (ro) */
123 long errcnt; /* calibration errors (ro) */
124 long stbcnt; /* stability limit exceeded (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; 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 */
Roman Zippeleea83d82008-05-01 04:34:33 -0700140#define ADJ_MICRO 0x1000 /* select microsecond resolution */
141#define ADJ_NANO 0x2000 /* select nanosecond resolution */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142#define ADJ_TICK 0x4000 /* tick value */
143#define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */
John Stultz52bfb362007-11-26 20:42:19 +0100144#define ADJ_OFFSET_SS_READ 0xa001 /* read-only adjtime */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
146/* xntp 3.4 compatibility names */
147#define MOD_OFFSET ADJ_OFFSET
148#define MOD_FREQUENCY ADJ_FREQUENCY
149#define MOD_MAXERROR ADJ_MAXERROR
150#define MOD_ESTERROR ADJ_ESTERROR
151#define MOD_STATUS ADJ_STATUS
152#define MOD_TIMECONST ADJ_TIMECONST
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
154
155/*
156 * Status codes (timex.status)
157 */
158#define STA_PLL 0x0001 /* enable PLL updates (rw) */
159#define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */
160#define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */
161#define STA_FLL 0x0008 /* select frequency-lock mode (rw) */
162
163#define STA_INS 0x0010 /* insert leap (rw) */
164#define STA_DEL 0x0020 /* delete leap (rw) */
165#define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */
166#define STA_FREQHOLD 0x0080 /* hold frequency (rw) */
167
168#define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */
169#define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */
170#define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */
171#define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */
172
173#define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */
Roman Zippeleea83d82008-05-01 04:34:33 -0700174#define STA_NANO 0x2000 /* resolution (0 = us, 1 = ns) (ro) */
175#define STA_MODE 0x4000 /* mode (0 = PLL, 1 = FLL) (ro) */
176#define STA_CLK 0x8000 /* clock source (0 = A, 1 = B) (ro) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
Roman Zippeleea83d82008-05-01 04:34:33 -0700178/* read-only bits */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
Roman Zippeleea83d82008-05-01 04:34:33 -0700180 STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182/*
183 * Clock states (time_state)
184 */
185#define TIME_OK 0 /* clock synchronized, no leap second */
186#define TIME_INS 1 /* insert leap second */
187#define TIME_DEL 2 /* delete leap second */
188#define TIME_OOP 3 /* leap second in progress */
189#define TIME_WAIT 4 /* leap second has occurred */
190#define TIME_ERROR 5 /* clock not synchronized */
191#define TIME_BAD TIME_ERROR /* bw compat */
192
193#ifdef __KERNEL__
David Woodhouseee6baf82006-09-12 20:36:03 -0700194#include <asm/timex.h>
195
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196/*
197 * kernel variables
198 * Note: maximum error = NTP synch distance = dispersion + delay / 2;
199 * estimated error = NTP dispersion.
200 */
201extern unsigned long tick_usec; /* USER_HZ period (usec) */
202extern unsigned long tick_nsec; /* ACTHZ period (nsec) */
203extern int tickadj; /* amount of adjustment per tick */
204
205/*
206 * phase-lock loop variables
207 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208extern int time_status; /* clock synchronization status bits */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209extern long time_maxerror; /* maximum error */
210extern long time_esterror; /* estimated error */
211
212extern long time_freq; /* frequency offset (scaled ppm) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
214extern long time_adjust; /* The amount of adjtime left */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
Roman Zippelb0ee7552006-09-30 23:28:22 -0700216extern void ntp_clear(void);
john stultzb149ee22005-09-06 15:17:46 -0700217
218/**
219 * ntp_synced - Returns 1 if the NTP status is not UNSYNC
220 *
221 */
222static inline int ntp_synced(void)
223{
224 return !(time_status & STA_UNSYNC);
225}
226
john stultz1bb34a42005-10-30 15:01:42 -0800227/* Required to safely shift negative values */
228#define shift_right(x, s) ({ \
229 __typeof__(x) __x = (x); \
230 __typeof__(s) __s = (s); \
231 __x < 0 ? -(-__x >> __s) : __x >> __s; \
232})
233
Roman Zippel19923c12006-06-26 00:25:18 -0700234#define TICK_LENGTH_SHIFT 32
235
john stultzf4304ab2007-02-16 01:27:26 -0800236#ifdef CONFIG_NO_HZ
237#define NTP_INTERVAL_FREQ (2)
238#else
239#define NTP_INTERVAL_FREQ (HZ)
240#endif
Roman Zippel10a398d2008-03-04 15:14:26 -0800241#define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ)
john stultzf4304ab2007-02-16 01:27:26 -0800242
Paul Mackerras726c14b2006-02-17 10:30:23 +1100243/* Returns how long ticks are at present, in ns / 2^(SHIFT_SCALE-10). */
Roman Zippel19923c12006-06-26 00:25:18 -0700244extern u64 current_tick_length(void);
Paul Mackerras726c14b2006-02-17 10:30:23 +1100245
john stultz4c7ee8d2006-09-30 23:28:22 -0700246extern void second_overflow(void);
247extern void update_ntp_one_tick(void);
Stephen Rothwell3158e942006-03-26 01:37:29 -0800248extern int do_adjtimex(struct timex *);
249
Roman Zippel7236e972006-10-06 00:43:54 -0700250/* Don't use! Compatibility define for existing users. */
251#define tickadj (500/HZ ? : 1)
252
Andrew Morton941e4922008-02-06 01:36:42 -0800253int read_current_timer(unsigned long *timer_val);
254
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255#endif /* KERNEL */
256
257#endif /* LINUX_TIMEX_H */