1/*
2 * Copyright (c) David L. Mills 1993, 1994
3 *
4 * Permission to use, copy, modify, and distribute this software and its
5 * documentation for any purpose and without fee is hereby granted, provided
6 * that the above copyright notice appears in all copies and that both the
7 * copyright notice and this permission notice appear in supporting
8 * documentation, and that the name University of Delaware not be used in
9 * advertising or publicity pertaining to distribution of the software
10 * without specific, written prior permission.	The University of Delaware
11 * makes no representations about the suitability this software for any
12 * purpose.  It is provided "as is" without express or implied warranty.
13 */
14
15/*
16 * Copyright 2014 Garrett D'Amore <garrett@damore.org>
17 *
18 * Copyright 1996-1997, 2002 Sun Microsystems, Inc.  All rights reserved.
19 * Use is subject to license terms.
20 */
21
22#ifndef	_SYS_TIMEX_H
23#define	_SYS_TIMEX_H
24
25#ifdef	__cplusplus
26extern "C" {
27#endif
28
29#include <sys/types.h>
30#include <sys/time.h>
31#include <sys/syscall.h>
32#include <sys/inttypes.h>
33
34/*
35 * The following defines establish the engineering parameters of the
36 * phase-lock loop (PLL) model used in the kernel implementation. These
37 * parameters have been carefully chosen by analysis for good stability
38 * and wide dynamic range.
39 *
40 * The hz variable is defined in the kernel build environment. It
41 * establishes the timer interrupt frequency.
42 *
43 * SCALE_KG and SCALE_KF establish the damping of the PLL and are chosen
44 * for a slightly underdamped convergence characteristic. SCALE_KH
45 * establishes the damping of the FLL and is chosen by wisdom and black
46 * art.
47 *
48 * MAXTC establishes the maximum time constant of the PLL. With the
49 * SCALE_KG and SCALE_KF values given and a time constant range from
50 * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours,
51 * respectively.
52 */
53#define	SCALE_KG	(1<<6)	/* phase factor (multiplier) */
54#define	SCALE_KF	(1<<16)	/* PLL frequency factor (multiplier) */
55#define	SCALE_KH	(1<<2)	/* FLL frequency factor (multiplier) */
56#define	MAXTC		(1<<6)	/* maximum time constant */
57
58
59/*
60 * The following defines establish the scaling of the various variables
61 * used by the PLL. They are chosen to allow the greatest precision
62 * possible without overflow of a 32-bit word.
63 *
64 * SCALE_PHASE defines the scaling (multiplier) of the time_phase variable,
65 * which serves as a an extension to the low-order bits of the system
66 * clock variable time.tv_usec.
67 *
68 * SCALE_UPDATE defines the scaling (multiplier) of the time_offset variable,
69 * which represents the current time offset with respect to standard
70 * time.
71 *
72 * SCALE_USEC defines the scaling (multiplier) of the time_freq and
73 * time_tolerance variables, which represent the current frequency
74 * offset and maximum frequency tolerance.
75 *
76 * FINEUSEC is 1 us in SCALE_UPDATE units of the time_phase variable.
77 */
78#define	SCALE_PHASE	(1<<22)	/* phase scale */
79#define	SCALE_USEC	(1<<16)
80#define	SCALE_UPDATE	(SCALE_KG * MAXTC) /*  */
81#define	FINEUSEC	(1<<22)	/* 1 us in phase units */
82
83/*
84 * The following defines establish the performance envelope of the PLL.
85 * They insure it operates within predefined limits, in order to satisfy
86 * correctness assertions. An excursion which exceeds these bounds is
87 * clamped to the bound and operation proceeds accordingly. In practice,
88 * this can occur only if something has failed or is operating out of
89 * tolerance, but otherwise the PLL continues to operate in a stable
90 * mode.
91 *
92 * MAXPHASE must be set greater than or equal to CLOCK.MAX (128 ms), as
93 * defined in the NTP specification. CLOCK.MAX establishes the maximum
94 * time offset allowed before the system time is reset, rather than
95 * incrementally adjusted. Here, the maximum offset is clamped to
96 * MAXPHASE only in order to prevent overflow errors due to defective
97 * protocol implementations.
98 *
99 * MAXFREQ is the maximum frequency tolerance of the CPU clock
100 * oscillator plus the maximum slew rate allowed by the protocol. It
101 * should be set to at least the frequency tolerance of the oscillator
102 * plus 100 ppm for vernier frequency adjustments. The oscillator time and
103 * frequency are disciplined to an external source, presumably with
104 * negligible time and frequency error relative to UTC, and MAXFREQ can
105 * be reduced.
106 *
107 * MAXTIME is the maximum jitter tolerance of the PPS signal.
108 *
109 * MINSEC and MAXSEC define the lower and upper bounds on the interval
110 * between protocol updates.
111 */
112#define	MAXPHASE 512000		/* max phase error (us) */
113#define	MAXFREQ (512 * SCALE_USEC) /* max freq error (100 ppm) */
114#define	MAXTIME (200 << PPS_AVG) /* max PPS error (jitter) (200 us) */
115#define	MINSEC 16		/* min interval between updates (s) */
116#define	MAXSEC 1200		/* max interval between updates (s) */
117
118/*
119 * The following defines are used only if a pulse-per-second (PPS)
120 * signal is available and connected via a modem control lead, such as
121 * produced by the optional ppsclock feature incorporated in the Sun
122 * asynch driver. They establish the design parameters of the frequency-
123 * lock loop used to discipline the CPU clock oscillator to the PPS
124 * signal.
125 *
126 * PPS_AVG is the averaging factor for the frequency loop, as well as
127 * the time and frequency dispersion.
128 *
129 * PPS_SHIFT and PPS_SHIFTMAX specify the minimum and maximum
130 * calibration intervals, respectively, in seconds as a power of two.
131 *
132 * PPS_VALID is the maximum interval before the PPS signal is considered
133 * invalid and protocol updates used directly instead.
134 *
135 * MAXGLITCH is the maximum interval before a time offset of more than
136 * MAXTIME is believed.
137 */
138#define	PPS_AVG 2		/* pps averaging constant (shift) */
139#define	PPS_SHIFT 2		/* min interval duration (s) (shift) */
140#define	PPS_SHIFTMAX 8		/* max interval duration (s) (shift) */
141#define	PPS_VALID 120		/* pps signal watchdog max (s) */
142#define	MAXGLITCH 30		/* pps signal glitch max (s) */
143
144/*
145 * The following defines and structures define the user interface for
146 * the ntp_gettime() and ntp_adjtime() system calls.
147 *
148 * Control mode codes (timex.modes)
149 */
150#define	MOD_OFFSET	0x0001	/* set time offset */
151#define	MOD_FREQUENCY	0x0002	/* set frequency offset */
152#define	MOD_MAXERROR	0x0004	/* set maximum time error */
153#define	MOD_ESTERROR	0x0008	/* set estimated time error */
154#define	MOD_STATUS	0x0010	/* set clock status bits */
155#define	MOD_TIMECONST	0x0020	/* set pll time constant */
156#define	MOD_CLKB	0x4000	/* set clock B */
157#define	MOD_CLKA	0x8000	/* set clock A */
158
159/*
160 * Status codes (timex.status)
161 */
162#define	STA_PLL		0x0001	/* enable PLL updates (rw) */
163#define	STA_PPSFREQ	0x0002	/* enable PPS freq discipline (rw) */
164#define	STA_PPSTIME	0x0004	/* enable PPS time discipline (rw) */
165#define	STA_FLL		0x0008	/* select frequency-lock mode (rw) */
166
167#define	STA_INS		0x0010	/* insert leap (rw) */
168#define	STA_DEL		0x0020	/* delete leap (rw) */
169#define	STA_UNSYNC	0x0040	/* clock unsynchronized (rw) */
170#define	STA_FREQHOLD	0x0080	/* hold frequency (rw) */
171
172#define	STA_PPSSIGNAL	0x0100	/* PPS signal present (ro) */
173#define	STA_PPSJITTER	0x0200	/* PPS signal jitter exceeded (ro) */
174#define	STA_PPSWANDER	0x0400	/* PPS signal wander exceeded (ro) */
175#define	STA_PPSERROR	0x0800	/* PPS signal calibration error (ro) */
176
177#define	STA_CLOCKERR	0x1000	/* clock hardware fault (ro) */
178
179#define	STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
180    STA_PPSERROR | STA_CLOCKERR) /* read-only bits */
181
182/*
183 * Clock states (time_state)
184 */
185#define	TIME_OK		0	/* no leap second warning */
186#define	TIME_INS	1	/* insert leap second warning */
187#define	TIME_DEL	2	/* delete leap second warning */
188#define	TIME_OOP	3	/* leap second in progress */
189#define	TIME_WAIT	4	/* leap second has occured */
190#define	TIME_ERROR	5	/* clock not synchronized */
191
192/*
193 * NTP user interface (ntp_gettime()) - used to read kernel clock values
194 *
195 * Note: maximum error = NTP synch distance = dispersion + delay / 2;
196 * estimated error = NTP dispersion.
197 */
198struct ntptimeval {
199	struct timeval time;	/* current time (ro) */
200	int32_t maxerror;	/* maximum error (us) (ro) */
201	int32_t esterror;	/* estimated error (us) (ro) */
202};
203
204#if defined(_SYSCALL32)
205
206/* Kernel's view of _ILP32 application's ntptimeval struct */
207
208struct ntptimeval32 {
209	struct timeval32 time;
210	int32_t	maxerror;
211	int32_t esterror;
212};
213
214#endif	/* _SYSCALL32 */
215
216/*
217 * NTP daemon interface - (ntp_adjtime()) used to discipline CPU clock
218 * oscillator
219 */
220struct timex {
221	uint32_t modes;		/* clock mode bits (wo) */
222	int32_t offset;		/* time offset (us) (rw) */
223	int32_t freq;		/* frequency offset (scaled ppm) (rw) */
224	int32_t maxerror;	/* maximum error (us) (rw) */
225	int32_t esterror;	/* estimated error (us) (rw) */
226	int32_t status;		/* clock status bits (rw) */
227	int32_t constant;	/* pll time constant (rw) */
228	int32_t precision;	/* clock precision (us) (ro) */
229	int32_t tolerance;	/* clock freq tolerance (scaled ppm) (ro) */
230	int32_t ppsfreq;	/* pps frequency (scaled ppm) (ro) */
231	int32_t jitter;		/* pps jitter (us) (ro) */
232	int32_t shift;		/* interval duration (s) (shift) (ro) */
233	int32_t stabil;		/* pps stability (scaled ppm) (ro) */
234	int32_t jitcnt;		/* jitter limit exceeded (ro) */
235	int32_t calcnt;		/* calibration intervals (ro) */
236	int32_t errcnt;		/* calibration errors (ro) */
237	int32_t stbcnt;		/* stability limit exceeded (ro) */
238};
239
240/*
241 * NTP syscalls
242 */
243int ntp_gettime(struct ntptimeval *);
244int ntp_adjtime(struct timex *);
245
246#ifdef _KERNEL
247
248extern int32_t time_state;	/* clock state */
249extern int32_t time_status;	/* clock status bits */
250extern int32_t time_offset;	/* time adjustment (us) */
251extern int32_t time_freq;	/* frequency offset (scaled ppm) */
252extern int32_t time_maxerror;	/* maximum error (us) */
253extern int32_t time_esterror;	/* estimated error (us) */
254extern int32_t time_constant;	/* pll time constant */
255extern int32_t time_precision;	/* clock precision (us) */
256extern int32_t time_tolerance;	/* frequency tolerance (scaled ppm) */
257extern int32_t pps_shift;	/* interval duration (s) (shift) */
258extern int32_t pps_freq;	/* pps frequency offset (scaled ppm) */
259extern int32_t pps_jitter;	/* pps jitter (us) */
260extern int32_t pps_stabil;	/* pps stability (scaled ppm) */
261extern int32_t pps_jitcnt;	/* jitter limit exceeded */
262extern int32_t pps_calcnt;	/* calibration intervals */
263extern int32_t pps_errcnt;	/* calibration errors */
264extern int32_t pps_stbcnt;	/* stability limit exceeded */
265
266extern void clock_update(int);
267extern void ddi_hardpps(struct timeval *, int);
268
269#endif /* _KERNEL */
270
271
272#ifdef	__cplusplus
273}
274#endif
275
276#endif	/* _SYS_TIMEX_H */
277