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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 * 17 Sep 93 David L. Mills
21 * Created file $NTP/include/sys/timex.h
22 * 07 Oct 93 Torsten Duwe
23 * Derived linux/timex.h
24 * 1995-08-13 Torsten Duwe
25 * kernel PLL updated to 1994-12-13 specs (rfc-1489)
26 */
27 #ifndef _LINUX_TIMEX_H
28 #define _LINUX_TIMEX_H
29
30 /*
31 * The following defines establish the engineering parameters of the PLL
32 * model. The HZ variable establishes the timer interrupt frequency, 100 Hz
33 * for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the
34 * OSF/1 kernel. The SHIFT_HZ define expresses the same value as the
35 * nearest power of two in order to avoid hardware multiply operations.
36 */
37 #ifdef __alpha__
38 # define SHIFT_HZ 10 /* log2(HZ) */
39 #else
40 # define SHIFT_HZ 7 /* log2(HZ) */
41 #endif
42
43 /*
44 * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen
45 * for a slightly underdamped convergence characteristic. SHIFT_KH
46 * establishes the damping of the FLL and is chosen by wisdom and black
47 * art.
48 *
49 * MAXTC establishes the maximum time constant of the PLL. With the
50 * SHIFT_KG and SHIFT_KF values given and a time constant range from
51 * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours,
52 * respectively.
53 */
54 #define SHIFT_KG 6 /* phase factor (shift) */
55 #define SHIFT_KF 16 /* PLL frequency factor (shift) */
56 #define SHIFT_KH 2 /* FLL frequency factor (shift) */
57 #define MAXTC 6 /* maximum time constant (shift) */
58
59 /*
60 * The SHIFT_SCALE define establishes the decimal point of the time_phase
61 * variable which serves as a an extension to the low-order bits of the
62 * system clock variable. The SHIFT_UPDATE define establishes the decimal
63 * point of the time_offset variable which represents the current offset
64 * with respect to standard time. The FINEUSEC define represents 1 usec in
65 * scaled units.
66 *
67 * SHIFT_USEC defines the scaling (shift) of the time_freq and
68 * time_tolerance variables, which represent the current frequency
69 * offset and maximum frequency tolerance.
70 */
71 #define SHIFT_SCALE 22 /* shift for phase scale factor */
72 #define SHIFT_UPDATE (SHIFT_KG + MAXTC) /* shift for offset scale factor */
73 #define SHIFT_USEC 16 /* frequency offset scale (shift) */
74 #define FINEUSEC (1L << SHIFT_SCALE) /* 1 us in phase units */
75
76 #define MAXPHASE 512000L /* max phase error (us) */
77 #define MAXFREQ (512000L << SHIFT_USEC) /* max frequency error (ppm) */
78 #define MAXTIME (200L << PPS_AVG) /* max PPS error (jitter) (200 us) */
79 #define MINSEC 16L /* min interval between updates (s) */
80 #define MAXSEC 1200L /* max interval between updates (s) */
81
82 /*
83 * The following defines are used only if a pulse-per-second (PPS)
84 * signal is available and connected via a modem control lead, such as
85 * produced by the optional ppsclock feature incorporated in the Sun
86 * asynch driver. They establish the design parameters of the frequency-
87 * lock loop used to discipline the CPU clock oscillator to the PPS
88 * signal.
89 *
90 * PPS_AVG is the averaging factor for the frequency loop, as well as
91 * the time and frequency dispersion.
92 *
93 * PPS_SHIFT and PPS_SHIFTMAX specify the minimum and maximum
94 * calibration intervals, respectively, in seconds as a power of two.
95 *
96 * PPS_VALID is the maximum interval before the PPS signal is considered
97 * invalid and protocol updates used directly instead.
98 *
99 * MAXGLITCH is the maximum interval before a time offset of more than
100 * MAXTIME is believed.
101 */
102 #define PPS_AVG 2 /* pps averaging constant (shift) */
103 #define PPS_SHIFT 2 /* min interval duration (s) (shift) */
104 #define PPS_SHIFTMAX 8 /* max interval duration (s) (shift) */
105 #define PPS_VALID 120 /* pps signal watchdog max (s) */
106 #define MAXGLITCH 30 /* pps signal glitch max (s) */
107
108 #define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
109 #define CLOCK_TICK_FACTOR 20 /* Factor of both 1000000 and CLOCK_TICK_RATE */
110 #define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */
111
112 #define FINETUNE ((((((long)LATCH * HZ - CLOCK_TICK_RATE) << SHIFT_HZ) * \
113 (1000000/CLOCK_TICK_FACTOR) / (CLOCK_TICK_RATE/CLOCK_TICK_FACTOR)) \
114 << (SHIFT_SCALE-SHIFT_HZ)) / HZ)
115
116 /*
117 * syscall interface - used (mainly by NTP daemon)
118 * to discipline kernel clock oscillator
119 */
120 struct timex {
121 unsigned int modes; /* mode selector */
122 long offset; /* time offset (usec) */
123 long freq; /* frequency offset (scaled ppm) */
124 long maxerror; /* maximum error (usec) */
125 long esterror; /* estimated error (usec) */
126 int status; /* clock command/status */
127 long constant; /* pll time constant */
128 long precision; /* clock precision (usec) (read only) */
129 long tolerance; /* clock frequency tolerance (ppm)
130 * (read only)
131 */
132 struct timeval time; /* (read only) */
133 long tick; /* (modified) usecs between clock ticks */
134
135 long ppsfreq; /* pps frequency (scaled ppm) (ro) */
136 long jitter; /* pps jitter (us) (ro) */
137 int shift; /* interval duration (s) (shift) (ro) */
138 long stabil; /* pps stability (scaled ppm) (ro) */
139 long jitcnt; /* jitter limit exceeded (ro) */
140 long calcnt; /* calibration intervals (ro) */
141 long errcnt; /* calibration errors (ro) */
142 long stbcnt; /* stability limit exceeded (ro) */
143
144 int :32; int :32; int :32; int :32;
145 int :32; int :32; int :32; int :32;
146 int :32; int :32; int :32; int :32;
147 };
148
149 /*
150 * Mode codes (timex.mode)
151 */
152 #define ADJ_OFFSET 0x0001 /* time offset */
153 #define ADJ_FREQUENCY 0x0002 /* frequency offset */
154 #define ADJ_MAXERROR 0x0004 /* maximum time error */
155 #define ADJ_ESTERROR 0x0008 /* estimated time error */
156 #define ADJ_STATUS 0x0010 /* clock status */
157 #define ADJ_TIMECONST 0x0020 /* pll time constant */
158 #define ADJ_TICK 0x4000 /* tick value */
159 #define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */
160
161 /* xntp 3.4 compatibility names */
162 #define MOD_OFFSET ADJ_OFFSET
163 #define MOD_FREQUENCY ADJ_FREQUENCY
164 #define MOD_MAXERROR ADJ_MAXERROR
165 #define MOD_ESTERROR ADJ_ESTERROR
166 #define MOD_STATUS ADJ_STATUS
167 #define MOD_TIMECONST ADJ_TIMECONST
168
169 /*
170 * Status codes (timex.status)
171 */
172 #define STA_PLL 0x0001 /* enable PLL updates (rw) */
173 #define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */
174 #define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */
175 #define STA_FLL 0x0008 /* select frequency-lock mode (rw) */
176
177 #define STA_INS 0x0010 /* insert leap (rw) */
178 #define STA_DEL 0x0020 /* delete leap (rw) */
179 #define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */
180 #define STA_FREQHOLD 0x0080 /* hold frequency (rw) */
181
182 #define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */
183 #define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */
184 #define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */
185 #define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */
186
187 #define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */
188
189 #define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
190 STA_PPSERROR | STA_CLOCKERR) /* read-only bits */
191
192 /*
193 * Clock states (time_state)
194 */
195 #define TIME_OK 0 /* clock synchronized */
196 #define TIME_INS 1 /* insert leap second */
197 #define TIME_DEL 2 /* delete leap second */
198 #define TIME_OOP 3 /* leap second in progress */
199 #define TIME_WAIT 4 /* leap second has occured */
200 #define TIME_ERROR 5 /* clock not synchronized */
201 #define TIME_BAD TIME_ERROR /* bw compat */
202
203 #ifdef __KERNEL__
204 /*
205 * kernel variables
206 */
207 extern long tick; /* timer interrupt period */
208 extern int tickadj; /* amount of adjustment per tick */
209
210 /*
211 * phase-lock loop variables
212 */
213 extern int time_state; /* clock status */
214 extern int time_status; /* clock synchronization status bits */
215 extern long time_offset; /* time adjustment (us) */
216 extern long time_constant; /* pll time constant */
217 extern long time_tolerance; /* frequency tolerance (ppm) */
218 extern long time_precision; /* clock precision (us) */
219 extern long time_maxerror; /* maximum error */
220 extern long time_esterror; /* estimated error */
221
222 extern long time_phase; /* phase offset (scaled us) */
223 extern long time_freq; /* frequency offset (scaled ppm) */
224 extern long time_adj; /* tick adjust (scaled 1 / HZ) */
225 extern long time_reftime; /* time at last adjustment (s) */
226
227 extern long time_adjust; /* The amount of adjtime left */
228
229 /* interface variables pps->timer interrupt */
230 extern long pps_offset; /* pps time offset (us) */
231 extern long pps_jitter; /* time dispersion (jitter) (us) */
232 extern long pps_freq; /* frequency offset (scaled ppm) */
233 extern long pps_stabil; /* frequency dispersion (scaled ppm) */
234 extern long pps_valid; /* pps signal watchdog counter */
235
236 /* interface variables pps->adjtimex */
237 extern int pps_shift; /* interval duration (s) (shift) */
238 extern long pps_jitcnt; /* jitter limit exceeded */
239 extern long pps_calcnt; /* calibration intervals */
240 extern long pps_errcnt; /* calibration errors */
241 extern long pps_stbcnt; /* stability limit exceeded */
242
243 #endif /* KERNEL */
244
245 #endif /* LINUX_TIMEX_H */
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*/