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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 * 26 Sep 94 David L. Mills
21 * Added defines for hybrid phase/frequency-lock loop.
22 *
23 * 19 Mar 94 David L. Mills
24 * Moved defines from kernel routines to header file and added new
25 * defines for PPS phase-lock loop.
26 *
27 * 20 Feb 94 David L. Mills
28 * Revised status codes and structures for external clock and PPS
29 * signal discipline.
30 *
31 * 28 Nov 93 David L. Mills
32 * Adjusted parameters to improve stability and increase poll
33 * interval.
34 *
35 * 17 Sep 93 David L. Mills
36 * Created file $NTP/include/sys/timex.h
37 * 07 Oct 93 Torsten Duwe
38 * Derived linux/timex.h
39 * 1995-08-13 Torsten Duwe
40 * kernel PLL updated to 1994-12-13 specs (rfc-1589)
41 */
42 #ifndef _LINUX_TIMEX_H
43 #define _LINUX_TIMEX_H
44
45 /*
46 * The following defines establish the engineering parameters of the PLL
47 * model. The HZ variable establishes the timer interrupt frequency, 100 Hz
48 * for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the
49 * OSF/1 kernel. The SHIFT_HZ define expresses the same value as the
50 * nearest power of two in order to avoid hardware multiply operations.
51 */
52 #ifdef __alpha__
53 # define SHIFT_HZ 10 /* log2(HZ) */
54 #else
55 # define SHIFT_HZ 7 /* log2(HZ) */
56 #endif
57
58 /*
59 * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen
60 * for a slightly underdamped convergence characteristic. SHIFT_KH
61 * establishes the damping of the FLL and is chosen by wisdom and black
62 * art.
63 *
64 * MAXTC establishes the maximum time constant of the PLL. With the
65 * SHIFT_KG and SHIFT_KF values given and a time constant range from
66 * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours,
67 * respectively.
68 */
69 #define SHIFT_KG 6 /* phase factor (shift) */
70 #define SHIFT_KF 16 /* PLL frequency factor (shift) */
71 #define SHIFT_KH 2 /* FLL frequency factor (shift) */
72 #define MAXTC 6 /* maximum time constant (shift) */
73
74 /*
75 * The SHIFT_SCALE define establishes the decimal point of the time_phase
76 * variable which serves as a an extension to the low-order bits of the
77 * system clock variable. The SHIFT_UPDATE define establishes the decimal
78 * point of the time_offset variable which represents the current offset
79 * with respect to standard time. The FINEUSEC define represents 1 usec in
80 * scaled units.
81 *
82 * SHIFT_USEC defines the scaling (shift) of the time_freq and
83 * time_tolerance variables, which represent the current frequency
84 * offset and maximum frequency tolerance.
85 *
86 * FINEUSEC is 1 us in SHIFT_UPDATE units of the time_phase variable.
87 */
88 #define SHIFT_SCALE 22 /* phase scale (shift) */
89 #define SHIFT_UPDATE (SHIFT_KG + MAXTC) /* time offset scale (shift) */
90 #define SHIFT_USEC 16 /* frequency offset scale (shift) */
91 #define FINEUSEC (1L << SHIFT_SCALE) /* 1 us in phase units */
92
93 #define MAXPHASE 512000L /* max phase error (us) */
94 #define MAXFREQ (512L << SHIFT_USEC) /* max frequency error (ppm) */
95 #define MAXTIME (200L << PPS_AVG) /* max PPS error (jitter) (200 us) */
96 #define MINSEC 16L /* min interval between updates (s) */
97 #define MAXSEC 1200L /* max interval between updates (s) */
98
99 /*
100 * The following defines are used only if a pulse-per-second (PPS)
101 * signal is available and connected via a modem control lead, such as
102 * produced by the optional ppsclock feature incorporated in the Sun
103 * asynch driver. They establish the design parameters of the frequency-
104 * lock loop used to discipline the CPU clock oscillator to the PPS
105 * signal.
106 *
107 * PPS_AVG is the averaging factor for the frequency loop, as well as
108 * the time and frequency dispersion.
109 *
110 * PPS_SHIFT and PPS_SHIFTMAX specify the minimum and maximum
111 * calibration intervals, respectively, in seconds as a power of two.
112 *
113 * PPS_VALID is the maximum interval before the PPS signal is considered
114 * invalid and protocol updates used directly instead.
115 *
116 * MAXGLITCH is the maximum interval before a time offset of more than
117 * MAXTIME is believed.
118 */
119 #define PPS_AVG 2 /* pps averaging constant (shift) */
120 #define PPS_SHIFT 2 /* min interval duration (s) (shift) */
121 #define PPS_SHIFTMAX 8 /* max interval duration (s) (shift) */
122 #define PPS_VALID 120 /* pps signal watchdog max (s) */
123 #define MAXGLITCH 30 /* pps signal glitch max (s) */
124
125 #ifndef __alpha__
126 /*
127 * This definitively is wrong for the Alpha and none of the
128 * kernel code seems to reference this anymore.
129 */
130 #define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
131 #define CLOCK_TICK_FACTOR 20 /* Factor of both 1000000 and CLOCK_TICK_RATE */
132 #define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */
133
134 #define FINETUNE ((((((long)LATCH * HZ - CLOCK_TICK_RATE) << SHIFT_HZ) * \
135 (1000000/CLOCK_TICK_FACTOR) / (CLOCK_TICK_RATE/CLOCK_TICK_FACTOR)) \
136 << (SHIFT_SCALE-SHIFT_HZ)) / HZ)
137 #endif /* !__alpha__ */
138
139 /*
140 * syscall interface - used (mainly by NTP daemon)
141 * to discipline kernel clock oscillator
142 */
143 struct timex {
144 unsigned int modes; /* mode selector */
145 long offset; /* time offset (usec) */
146 long freq; /* frequency offset (scaled ppm) */
147 long maxerror; /* maximum error (usec) */
148 long esterror; /* estimated error (usec) */
149 int status; /* clock command/status */
150 long constant; /* pll time constant */
151 long precision; /* clock precision (usec) (read only) */
152 long tolerance; /* clock frequency tolerance (ppm)
153 * (read only)
154 */
155 struct timeval time; /* (read only) */
156 long tick; /* (modified) usecs between clock ticks */
157
158 long ppsfreq; /* pps frequency (scaled ppm) (ro) */
159 long jitter; /* pps jitter (us) (ro) */
160 int shift; /* interval duration (s) (shift) (ro) */
161 long stabil; /* pps stability (scaled ppm) (ro) */
162 long jitcnt; /* jitter limit exceeded (ro) */
163 long calcnt; /* calibration intervals (ro) */
164 long errcnt; /* calibration errors (ro) */
165 long stbcnt; /* stability limit exceeded (ro) */
166
167 int :32; int :32; int :32; int :32;
168 int :32; int :32; int :32; int :32;
169 int :32; int :32; int :32; int :32;
170 };
171
172 /*
173 * Mode codes (timex.mode)
174 */
175 #define ADJ_OFFSET 0x0001 /* time offset */
176 #define ADJ_FREQUENCY 0x0002 /* frequency offset */
177 #define ADJ_MAXERROR 0x0004 /* maximum time error */
178 #define ADJ_ESTERROR 0x0008 /* estimated time error */
179 #define ADJ_STATUS 0x0010 /* clock status */
180 #define ADJ_TIMECONST 0x0020 /* pll time constant */
181 #define ADJ_TICK 0x4000 /* tick value */
182 #define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */
183
184 /* xntp 3.4 compatibility names */
185 #define MOD_OFFSET ADJ_OFFSET
186 #define MOD_FREQUENCY ADJ_FREQUENCY
187 #define MOD_MAXERROR ADJ_MAXERROR
188 #define MOD_ESTERROR ADJ_ESTERROR
189 #define MOD_STATUS ADJ_STATUS
190 #define MOD_TIMECONST ADJ_TIMECONST
191 #define MOD_CLKB ADJ_TICK
192 #define MOD_CLKA ADJ_OFFSET_SINGLESHOT /* 0x8000 in original */
193
194
195 /*
196 * Status codes (timex.status)
197 */
198 #define STA_PLL 0x0001 /* enable PLL updates (rw) */
199 #define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */
200 #define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */
201 #define STA_FLL 0x0008 /* select frequency-lock mode (rw) */
202
203 #define STA_INS 0x0010 /* insert leap (rw) */
204 #define STA_DEL 0x0020 /* delete leap (rw) */
205 #define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */
206 #define STA_FREQHOLD 0x0080 /* hold frequency (rw) */
207
208 #define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */
209 #define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */
210 #define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */
211 #define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */
212
213 #define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */
214
215 #define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
216 STA_PPSERROR | STA_CLOCKERR) /* read-only bits */
217
218 /*
219 * Clock states (time_state)
220 */
221 #define TIME_OK 0 /* clock synchronized, no leap second */
222 #define TIME_INS 1 /* insert leap second */
223 #define TIME_DEL 2 /* delete leap second */
224 #define TIME_OOP 3 /* leap second in progress */
225 #define TIME_WAIT 4 /* leap second has occurred */
226 #define TIME_ERROR 5 /* clock not synchronized */
227 #define TIME_BAD TIME_ERROR /* bw compat */
228
229 #ifdef __KERNEL__
230 /*
231 * kernel variables
232 * Note: maximum error = NTP synch distance = dispersion + delay / 2;
233 * estimated error = NTP dispersion.
234 */
235 extern long tick; /* timer interrupt period */
236 extern int tickadj; /* amount of adjustment per tick */
237
238 /*
239 * phase-lock loop variables
240 */
241 extern int time_state; /* clock status */
242 extern int time_status; /* clock synchronization status bits */
243 extern long time_offset; /* time adjustment (us) */
244 extern long time_constant; /* pll time constant */
245 extern long time_tolerance; /* frequency tolerance (ppm) */
246 extern long time_precision; /* clock precision (us) */
247 extern long time_maxerror; /* maximum error */
248 extern long time_esterror; /* estimated error */
249
250 extern long time_phase; /* phase offset (scaled us) */
251 extern long time_freq; /* frequency offset (scaled ppm) */
252 extern long time_adj; /* tick adjust (scaled 1 / HZ) */
253 extern long time_reftime; /* time at last adjustment (s) */
254
255 extern long time_adjust; /* The amount of adjtime left */
256
257 /* interface variables pps->timer interrupt */
258 extern long pps_offset; /* pps time offset (us) */
259 extern long pps_jitter; /* time dispersion (jitter) (us) */
260 extern long pps_freq; /* frequency offset (scaled ppm) */
261 extern long pps_stabil; /* frequency dispersion (scaled ppm) */
262 extern long pps_valid; /* pps signal watchdog counter */
263
264 /* interface variables pps->adjtimex */
265 extern int pps_shift; /* interval duration (s) (shift) */
266 extern long pps_jitcnt; /* jitter limit exceeded */
267 extern long pps_calcnt; /* calibration intervals */
268 extern long pps_errcnt; /* calibration errors */
269 extern long pps_stbcnt; /* stability limit exceeded */
270
271 #endif /* KERNEL */
272
273 #endif /* LINUX_TIMEX_H */
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