FreeBSD/Linux Kernel Cross Reference
sys/sys/timex.h
1 /***********************************************************************
2 * *
3 * Copyright (c) David L. Mills 1993-1998 *
4 * *
5 * Permission to use, copy, modify, and distribute this software and *
6 * its documentation for any purpose and without fee is hereby *
7 * granted, provided that the above copyright notice appears in all *
8 * copies and that both the copyright notice and this permission *
9 * notice appear in supporting documentation, and that the name *
10 * University of Delaware not be used in advertising or publicity *
11 * pertaining to distribution of the software without specific, *
12 * written prior permission. The University of Delaware makes no *
13 * representations about the suitability this software for any *
14 * purpose. It is provided "as is" without express or implied *
15 * warranty. *
16 * *
17 **********************************************************************/
18
19 /*
20 * $FreeBSD$
21 *
22 * Modification history timex.h
23 *
24 * 17 Nov 98 David L. Mills
25 * Revised for nanosecond kernel and user interface.
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
44 */
45 /*
46 * This header file defines the Network Time Protocol (NTP) interfaces
47 * for user and daemon application programs. These are implemented using
48 * defined syscalls and data structures and require specific kernel
49 * support.
50 *
51 * The original precision time kernels developed from 1993 have an
52 * ultimate resolution of one microsecond; however, the most recent
53 * kernels have an ultimate resolution of one nanosecond. In these
54 * kernels, a ntp_adjtime() syscalls can be used to determine which
55 * resolution is in use and to select either one at any time. The
56 * resolution selected affects the scaling of certain fields in the
57 * ntp_gettime() and ntp_adjtime() syscalls, as described below.
58 *
59 * NAME
60 * ntp_gettime - NTP user application interface
61 *
62 * SYNOPSIS
63 * #include <sys/timex.h>
64 *
65 * int ntp_gettime(struct ntptimeval *ntv);
66 *
67 * DESCRIPTION
68 * The time returned by ntp_gettime() is in a timespec structure,
69 * but may be in either microsecond (seconds and microseconds) or
70 * nanosecond (seconds and nanoseconds) format. The particular
71 * format in use is determined by the STA_NANO bit of the status
72 * word returned by the ntp_adjtime() syscall.
73 *
74 * NAME
75 * ntp_adjtime - NTP daemon application interface
76 *
77 * SYNOPSIS
78 * #include <sys/timex.h>
79 * #include <sys/syscall.h>
80 *
81 * int syscall(SYS_ntp_adjtime, tptr);
82 * int SYS_ntp_adjtime;
83 * struct timex *tptr;
84 *
85 * DESCRIPTION
86 * Certain fields of the timex structure are interpreted in either
87 * microseconds or nanoseconds according to the state of the
88 * STA_NANO bit in the status word. See the description below for
89 * further information.
90 */
91 #ifndef _SYS_TIMEX_H_
92 #define _SYS_TIMEX_H_ 1
93 #define NTP_API 3 /* NTP API version */
94
95 #ifndef MSDOS /* Microsoft specific */
96 #include <sys/syscall.h>
97 #endif /* MSDOS */
98
99 /*
100 * The following defines establish the performance envelope of the
101 * kernel discipline loop. Phase or frequency errors greater than
102 * NAXPHASE or MAXFREQ are clamped to these maxima. For update intervals
103 * less than MINSEC, the loop always operates in PLL mode; while, for
104 * update intervals greater than MAXSEC, the loop always operates in FLL
105 * mode. Between these two limits the operating mode is selected by the
106 * STA_FLL bit in the status word.
107 */
108 #define MAXPHASE 500000000L /* max phase error (ns) */
109 #define MAXFREQ 500000L /* max freq error (ns/s) */
110 #define MINSEC 256 /* min FLL update interval (s) */
111 #define MAXSEC 2048 /* max PLL update interval (s) */
112 #define NANOSECOND 1000000000L /* nanoseconds in one second */
113 #define SCALE_PPM (65536 / 1000) /* crude ns/s to scaled PPM */
114 #define MAXTC 10 /* max time constant */
115
116 /*
117 * The following defines and structures define the user interface for
118 * the ntp_gettime() and ntp_adjtime() syscalls.
119 *
120 * Control mode codes (timex.modes)
121 */
122 #define MOD_OFFSET 0x0001 /* set time offset */
123 #define MOD_FREQUENCY 0x0002 /* set frequency offset */
124 #define MOD_MAXERROR 0x0004 /* set maximum time error */
125 #define MOD_ESTERROR 0x0008 /* set estimated time error */
126 #define MOD_STATUS 0x0010 /* set clock status bits */
127 #define MOD_TIMECONST 0x0020 /* set PLL time constant */
128 #define MOD_PPSMAX 0x0040 /* set PPS maximum averaging time */
129 #define MOD_MICRO 0x1000 /* select microsecond resolution */
130 #define MOD_NANO 0x2000 /* select nanosecond resolution */
131 #define MOD_CLKB 0x4000 /* select clock B */
132 #define MOD_CLKA 0x8000 /* select clock A */
133
134 /*
135 * Status codes (timex.status)
136 */
137 #define STA_PLL 0x0001 /* enable PLL updates (rw) */
138 #define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */
139 #define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */
140 #define STA_FLL 0x0008 /* enable FLL mode (rw) */
141 #define STA_INS 0x0010 /* insert leap (rw) */
142 #define STA_DEL 0x0020 /* delete leap (rw) */
143 #define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */
144 #define STA_FREQHOLD 0x0080 /* hold frequency (rw) */
145 #define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */
146 #define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */
147 #define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */
148 #define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */
149 #define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */
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) */
153
154 #define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
155 STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK)
156
157 /*
158 * Clock states (time_state)
159 */
160 #define TIME_OK 0 /* no leap second warning */
161 #define TIME_INS 1 /* insert leap second warning */
162 #define TIME_DEL 2 /* delete leap second warning */
163 #define TIME_OOP 3 /* leap second in progress */
164 #define TIME_WAIT 4 /* leap second has occured */
165 #define TIME_ERROR 5 /* error (see status word) */
166
167 /*
168 * NTP user interface (ntp_gettime()) - used to read kernel clock values
169 *
170 * Note: The time member is in microseconds if STA_NANO is zero and
171 * nanoseconds if not.
172 */
173 struct ntptimeval {
174 struct timespec time; /* current time (ns) (ro) */
175 long maxerror; /* maximum error (us) (ro) */
176 long esterror; /* estimated error (us) (ro) */
177 int time_state; /* time status */
178 };
179
180 /*
181 * NTP daemon interface (ntp_adjtime()) - used to discipline CPU clock
182 * oscillator and determine status.
183 *
184 * Note: The offset, precision and jitter members are in microseconds if
185 * STA_NANO is zero and nanoseconds if not.
186 */
187 struct timex {
188 unsigned int modes; /* clock mode bits (wo) */
189 long offset; /* time offset (ns/us) (rw) */
190 long freq; /* frequency offset (scaled PPM) (rw) */
191 long maxerror; /* maximum error (us) (rw) */
192 long esterror; /* estimated error (us) (rw) */
193 int status; /* clock status bits (rw) */
194 long constant; /* poll interval (log2 s) (rw) */
195 long precision; /* clock precision (ns/us) (ro) */
196 long tolerance; /* clock frequency tolerance (scaled
197 * PPM) (ro) */
198 /*
199 * The following read-only structure members are implemented
200 * only if the PPS signal discipline is configured in the
201 * kernel. They are included in all configurations to insure
202 * portability.
203 */
204 long ppsfreq; /* PPS frequency (scaled PPM) (ro) */
205 long jitter; /* PPS jitter (ns/us) (ro) */
206 int shift; /* interval duration (s) (shift) (ro) */
207 long stabil; /* PPS stability (scaled PPM) (ro) */
208 long jitcnt; /* jitter limit exceeded (ro) */
209 long calcnt; /* calibration intervals (ro) */
210 long errcnt; /* calibration errors (ro) */
211 long stbcnt; /* stability limit exceeded (ro) */
212 };
213
214 #ifdef __FreeBSD__
215
216 #ifdef KERNEL
217 struct timecounter;
218 void ntp_update_second __P((struct timecounter *tc));
219 #else /* !KERNEL */
220 #include <sys/cdefs.h>
221
222 __BEGIN_DECLS
223 int ntp_adjtime __P((struct timex *));
224 int ntp_gettime __P((struct ntptimeval *));
225 __END_DECLS
226 #endif /* KERNEL */
227
228 #endif /* __FreeBSD__ */
229
230 #endif /* !_SYS_TIMEX_H_ */
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