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 */
51#ifndef _LINUX_TIMEX_H
52#define _LINUX_TIMEX_H
53
54#include <asm/param.h>
55
56/*
57 * The following defines establish the engineering parameters of the PLL
58 * model. The HZ variable establishes the timer interrupt frequency, 100 Hz
59 * for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the
60 * OSF/1 kernel. The SHIFT_HZ define expresses the same value as the
61 * nearest power of two in order to avoid hardware multiply operations.
62 */
63#if HZ >= 12 && HZ < 24
64# define SHIFT_HZ	4
65#elif HZ >= 24 && HZ < 48
66# define SHIFT_HZ	5
67#elif HZ >= 48 && HZ < 96
68# define SHIFT_HZ	6
69#elif HZ >= 96 && HZ < 192
70# define SHIFT_HZ	7
71#elif HZ >= 192 && HZ < 384
72# define SHIFT_HZ	8
73#elif HZ >= 384 && HZ < 768
74# define SHIFT_HZ	9
75#elif HZ >= 768 && HZ < 1536
76# define SHIFT_HZ	10
77#else
78# error You lose.
79#endif
80
81/*
82 * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen
83 * for a slightly underdamped convergence characteristic. SHIFT_KH
84 * establishes the damping of the FLL and is chosen by wisdom and black
85 * art.
86 *
87 * MAXTC establishes the maximum time constant of the PLL. With the
88 * SHIFT_KG and SHIFT_KF values given and a time constant range from
89 * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours,
90 * respectively.
91 */
92#define SHIFT_KG 6		/* phase factor (shift) */
93#define SHIFT_KF 16		/* PLL frequency factor (shift) */
94#define SHIFT_KH 2		/* FLL frequency factor (shift) */
95#define MAXTC 6			/* maximum time constant (shift) */
96
97/*
98 * The SHIFT_SCALE define establishes the decimal point of the time_phase
99 * variable which serves as an extension to the low-order bits of the
100 * system clock variable. The SHIFT_UPDATE define establishes the decimal
101 * point of the time_offset variable which represents the current offset
102 * with respect to standard time. The FINEUSEC define represents 1 usec in
103 * scaled units.
104 *
105 * SHIFT_USEC defines the scaling (shift) of the time_freq and
106 * time_tolerance variables, which represent the current frequency
107 * offset and maximum frequency tolerance.
108 *
109 * FINEUSEC is 1 us in SHIFT_UPDATE units of the time_phase variable.
110 */
111#define SHIFT_SCALE 22		/* phase scale (shift) */
112#define SHIFT_UPDATE (SHIFT_KG + MAXTC) /* time offset scale (shift) */
113#define SHIFT_USEC 16		/* frequency offset scale (shift) */
114#define FINEUSEC (1L << SHIFT_SCALE) /* 1 us in phase units */
115
116#define MAXPHASE 512000L        /* max phase error (us) */
117#define MAXFREQ (512L << SHIFT_USEC)  /* max frequency error (ppm) */
118#define MAXTIME (200L << PPS_AVG) /* max PPS error (jitter) (200 us) */
119#define MINSEC 16L              /* min interval between updates (s) */
120#define MAXSEC 1200L            /* max interval between updates (s) */
121#define	NTP_PHASE_LIMIT	(MAXPHASE << 5)	/* beyond max. dispersion */
122
123/*
124 * The following defines are used only if a pulse-per-second (PPS)
125 * signal is available and connected via a modem control lead, such as
126 * produced by the optional ppsclock feature incorporated in the Sun
127 * asynch driver. They establish the design parameters of the frequency-
128 * lock loop used to discipline the CPU clock oscillator to the PPS
129 * signal.
130 *
131 * PPS_AVG is the averaging factor for the frequency loop, as well as
132 * the time and frequency dispersion.
133 *
134 * PPS_SHIFT and PPS_SHIFTMAX specify the minimum and maximum
135 * calibration intervals, respectively, in seconds as a power of two.
136 *
137 * PPS_VALID is the maximum interval before the PPS signal is considered
138 * invalid and protocol updates used directly instead.
139 *
140 * MAXGLITCH is the maximum interval before a time offset of more than
141 * MAXTIME is believed.
142 */
143#define PPS_AVG 2		/* pps averaging constant (shift) */
144#define PPS_SHIFT 2		/* min interval duration (s) (shift) */
145#define PPS_SHIFTMAX 8		/* max interval duration (s) (shift) */
146#define PPS_VALID 120		/* pps signal watchdog max (s) */
147#define MAXGLITCH 30		/* pps signal glitch max (s) */
148
149/*
150 * Pick up the architecture specific timex specifications
151 */
152#include <asm/timex.h>
153
154/* LATCH is used in the interval timer and ftape setup. */
155#define LATCH  ((CLOCK_TICK_RATE + HZ/2) / HZ)	/* For divider */
156
157/*
158 * syscall interface - used (mainly by NTP daemon)
159 * to discipline kernel clock oscillator
160 */
161struct timex {
162	unsigned int modes;	/* mode selector */
163	long offset;		/* time offset (usec) */
164	long freq;		/* frequency offset (scaled ppm) */
165	long maxerror;		/* maximum error (usec) */
166	long esterror;		/* estimated error (usec) */
167	int status;		/* clock command/status */
168	long constant;		/* pll time constant */
169	long precision;		/* clock precision (usec) (read only) */
170	long tolerance;		/* clock frequency tolerance (ppm)
171				 * (read only)
172				 */
173	struct timeval time;	/* (read only) */
174	long tick;		/* (modified) usecs between clock ticks */
175
176	long ppsfreq;           /* pps frequency (scaled ppm) (ro) */
177	long jitter;            /* pps jitter (us) (ro) */
178	int shift;              /* interval duration (s) (shift) (ro) */
179	long stabil;            /* pps stability (scaled ppm) (ro) */
180	long jitcnt;            /* jitter limit exceeded (ro) */
181	long calcnt;            /* calibration intervals (ro) */
182	long errcnt;            /* calibration errors (ro) */
183	long stbcnt;            /* stability limit exceeded (ro) */
184
185	int  :32; int  :32; int  :32; int  :32;
186	int  :32; int  :32; int  :32; int  :32;
187	int  :32; int  :32; int  :32; int  :32;
188};
189
190/*
191 * Mode codes (timex.mode)
192 */
193#define ADJ_OFFSET		0x0001	/* time offset */
194#define ADJ_FREQUENCY		0x0002	/* frequency offset */
195#define ADJ_MAXERROR		0x0004	/* maximum time error */
196#define ADJ_ESTERROR		0x0008	/* estimated time error */
197#define ADJ_STATUS		0x0010	/* clock status */
198#define ADJ_TIMECONST		0x0020	/* pll time constant */
199#define ADJ_TICK		0x4000	/* tick value */
200#define ADJ_OFFSET_SINGLESHOT	0x8001	/* old-fashioned adjtime */
201
202/* xntp 3.4 compatibility names */
203#define MOD_OFFSET	ADJ_OFFSET
204#define MOD_FREQUENCY	ADJ_FREQUENCY
205#define MOD_MAXERROR	ADJ_MAXERROR
206#define MOD_ESTERROR	ADJ_ESTERROR
207#define MOD_STATUS	ADJ_STATUS
208#define MOD_TIMECONST	ADJ_TIMECONST
209#define MOD_CLKB	ADJ_TICK
210#define MOD_CLKA	ADJ_OFFSET_SINGLESHOT /* 0x8000 in original */
211
212
213/*
214 * Status codes (timex.status)
215 */
216#define STA_PLL		0x0001	/* enable PLL updates (rw) */
217#define STA_PPSFREQ	0x0002	/* enable PPS freq discipline (rw) */
218#define STA_PPSTIME	0x0004	/* enable PPS time discipline (rw) */
219#define STA_FLL		0x0008	/* select frequency-lock mode (rw) */
220
221#define STA_INS		0x0010	/* insert leap (rw) */
222#define STA_DEL		0x0020	/* delete leap (rw) */
223#define STA_UNSYNC	0x0040	/* clock unsynchronized (rw) */
224#define STA_FREQHOLD	0x0080	/* hold frequency (rw) */
225
226#define STA_PPSSIGNAL	0x0100	/* PPS signal present (ro) */
227#define STA_PPSJITTER	0x0200	/* PPS signal jitter exceeded (ro) */
228#define STA_PPSWANDER	0x0400	/* PPS signal wander exceeded (ro) */
229#define STA_PPSERROR	0x0800	/* PPS signal calibration error (ro) */
230
231#define STA_CLOCKERR	0x1000	/* clock hardware fault (ro) */
232
233#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
234    STA_PPSERROR | STA_CLOCKERR) /* read-only bits */
235
236/*
237 * Clock states (time_state)
238 */
239#define TIME_OK		0	/* clock synchronized, no leap second */
240#define TIME_INS	1	/* insert leap second */
241#define TIME_DEL	2	/* delete leap second */
242#define TIME_OOP	3	/* leap second in progress */
243#define TIME_WAIT	4	/* leap second has occurred */
244#define TIME_ERROR	5	/* clock not synchronized */
245#define TIME_BAD	TIME_ERROR /* bw compat */
246
247#ifdef __KERNEL__
248/*
249 * kernel variables
250 * Note: maximum error = NTP synch distance = dispersion + delay / 2;
251 * estimated error = NTP dispersion.
252 */
253extern long tick;                      /* timer interrupt period */
254extern int tickadj;			/* amount of adjustment per tick */
255
256/*
257 * phase-lock loop variables
258 */
259extern int time_state;		/* clock status */
260extern int time_status;		/* clock synchronization status bits */
261extern long time_offset;	/* time adjustment (us) */
262extern long time_constant;	/* pll time constant */
263extern long time_tolerance;	/* frequency tolerance (ppm) */
264extern long time_precision;	/* clock precision (us) */
265extern long time_maxerror;	/* maximum error */
266extern long time_esterror;	/* estimated error */
267
268extern long time_phase;		/* phase offset (scaled us) */
269extern long time_freq;		/* frequency offset (scaled ppm) */
270extern long time_adj;		/* tick adjust (scaled 1 / HZ) */
271extern long time_reftime;	/* time at last adjustment (s) */
272
273extern long time_adjust;	/* The amount of adjtime left */
274
275/* interface variables pps->timer interrupt */
276extern long pps_offset;		/* pps time offset (us) */
277extern long pps_jitter;		/* time dispersion (jitter) (us) */
278extern long pps_freq;		/* frequency offset (scaled ppm) */
279extern long pps_stabil;		/* frequency dispersion (scaled ppm) */
280extern long pps_valid;		/* pps signal watchdog counter */
281
282/* interface variables pps->adjtimex */
283extern int pps_shift;		/* interval duration (s) (shift) */
284extern long pps_jitcnt;		/* jitter limit exceeded */
285extern long pps_calcnt;		/* calibration intervals */
286extern long pps_errcnt;		/* calibration errors */
287extern long pps_stbcnt;		/* stability limit exceeded */
288
289#endif /* KERNEL */
290
291#endif /* LINUX_TIMEX_H */
292