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 * 2004-08-12 Christoph Lameter
51 * Reworked time interpolation logic
52 */
53 #ifndef _LINUX_TIMEX_H
54 #define _LINUX_TIMEX_H
55
56 #include <linux/time.h>
57
58 #define NTP_API 4 /* NTP API version */
59
60 /*
61 * syscall interface - used (mainly by NTP daemon)
62 * to discipline kernel clock oscillator
63 */
64 struct timex {
65 unsigned int modes; /* mode selector */
66 long offset; /* time offset (usec) */
67 long freq; /* frequency offset (scaled ppm) */
68 long maxerror; /* maximum error (usec) */
69 long esterror; /* estimated error (usec) */
70 int status; /* clock command/status */
71 long constant; /* pll time constant */
72 long precision; /* clock precision (usec) (read only) */
73 long tolerance; /* clock frequency tolerance (ppm)
74 * (read only)
75 */
76 struct timeval time; /* (read only) */
77 long tick; /* (modified) usecs between clock ticks */
78
79 long ppsfreq; /* pps frequency (scaled ppm) (ro) */
80 long jitter; /* pps jitter (us) (ro) */
81 int shift; /* interval duration (s) (shift) (ro) */
82 long stabil; /* pps stability (scaled ppm) (ro) */
83 long jitcnt; /* jitter limit exceeded (ro) */
84 long calcnt; /* calibration intervals (ro) */
85 long errcnt; /* calibration errors (ro) */
86 long stbcnt; /* stability limit exceeded (ro) */
87
88 int tai; /* TAI offset (ro) */
89
90 int :32; int :32; int :32; int :32;
91 int :32; int :32; int :32; int :32;
92 int :32; int :32; int :32;
93 };
94
95 /*
96 * Mode codes (timex.mode)
97 */
98 #define ADJ_OFFSET 0x0001 /* time offset */
99 #define ADJ_FREQUENCY 0x0002 /* frequency offset */
100 #define ADJ_MAXERROR 0x0004 /* maximum time error */
101 #define ADJ_ESTERROR 0x0008 /* estimated time error */
102 #define ADJ_STATUS 0x0010 /* clock status */
103 #define ADJ_TIMECONST 0x0020 /* pll time constant */
104 #define ADJ_TAI 0x0080 /* set TAI offset */
105 #define ADJ_MICRO 0x1000 /* select microsecond resolution */
106 #define ADJ_NANO 0x2000 /* select nanosecond resolution */
107 #define ADJ_TICK 0x4000 /* tick value */
108
109 #ifdef __KERNEL__
110 #define ADJ_ADJTIME 0x8000 /* switch between adjtime/adjtimex modes */
111 #define ADJ_OFFSET_SINGLESHOT 0x0001 /* old-fashioned adjtime */
112 #define ADJ_OFFSET_READONLY 0x2000 /* read-only adjtime */
113 #else
114 #define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */
115 #define ADJ_OFFSET_SS_READ 0xa001 /* read-only adjtime */
116 #endif
117
118 /* xntp 3.4 compatibility names */
119 #define MOD_OFFSET ADJ_OFFSET
120 #define MOD_FREQUENCY ADJ_FREQUENCY
121 #define MOD_MAXERROR ADJ_MAXERROR
122 #define MOD_ESTERROR ADJ_ESTERROR
123 #define MOD_STATUS ADJ_STATUS
124 #define MOD_TIMECONST ADJ_TIMECONST
125
126
127 /*
128 * Status codes (timex.status)
129 */
130 #define STA_PLL 0x0001 /* enable PLL updates (rw) */
131 #define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */
132 #define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */
133 #define STA_FLL 0x0008 /* select frequency-lock mode (rw) */
134
135 #define STA_INS 0x0010 /* insert leap (rw) */
136 #define STA_DEL 0x0020 /* delete leap (rw) */
137 #define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */
138 #define STA_FREQHOLD 0x0080 /* hold frequency (rw) */
139
140 #define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */
141 #define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */
142 #define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */
143 #define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */
144
145 #define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */
146 #define STA_NANO 0x2000 /* resolution (0 = us, 1 = ns) (ro) */
147 #define STA_MODE 0x4000 /* mode (0 = PLL, 1 = FLL) (ro) */
148 #define STA_CLK 0x8000 /* clock source (0 = A, 1 = B) (ro) */
149
150 /* read-only bits */
151 #define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
152 STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK)
153
154 /*
155 * Clock states (time_state)
156 */
157 #define TIME_OK 0 /* clock synchronized, no leap second */
158 #define TIME_INS 1 /* insert leap second */
159 #define TIME_DEL 2 /* delete leap second */
160 #define TIME_OOP 3 /* leap second in progress */
161 #define TIME_WAIT 4 /* leap second has occurred */
162 #define TIME_ERROR 5 /* clock not synchronized */
163 #define TIME_BAD TIME_ERROR /* bw compat */
164
165 #ifdef __KERNEL__
166 #include <linux/compiler.h>
167 #include <linux/types.h>
168 #include <linux/param.h>
169
170 #include <asm/timex.h>
171
172 /*
173 * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen
174 * for a slightly underdamped convergence characteristic. SHIFT_KH
175 * establishes the damping of the FLL and is chosen by wisdom and black
176 * art.
177 *
178 * MAXTC establishes the maximum time constant of the PLL. With the
179 * SHIFT_KG and SHIFT_KF values given and a time constant range from
180 * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours,
181 * respectively.
182 */
183 #define SHIFT_PLL 4 /* PLL frequency factor (shift) */
184 #define SHIFT_FLL 2 /* FLL frequency factor (shift) */
185 #define MAXTC 10 /* maximum time constant (shift) */
186
187 /*
188 * SHIFT_USEC defines the scaling (shift) of the time_freq and
189 * time_tolerance variables, which represent the current frequency
190 * offset and maximum frequency tolerance.
191 */
192 #define SHIFT_USEC 16 /* frequency offset scale (shift) */
193 #define PPM_SCALE (NSEC_PER_USEC << (NTP_SCALE_SHIFT - SHIFT_USEC))
194 #define PPM_SCALE_INV_SHIFT 19
195 #define PPM_SCALE_INV ((1ll << (PPM_SCALE_INV_SHIFT + NTP_SCALE_SHIFT)) / \
196 PPM_SCALE + 1)
197
198 #define MAXPHASE 500000000l /* max phase error (ns) */
199 #define MAXFREQ 500000 /* max frequency error (ns/s) */
200 #define MAXFREQ_SCALED ((s64)MAXFREQ << NTP_SCALE_SHIFT)
201 #define MINSEC 256 /* min interval between updates (s) */
202 #define MAXSEC 2048 /* max interval between updates (s) */
203 #define NTP_PHASE_LIMIT ((MAXPHASE / NSEC_PER_USEC) << 5) /* beyond max. dispersion */
204
205 /*
206 * kernel variables
207 * Note: maximum error = NTP synch distance = dispersion + delay / 2;
208 * estimated error = NTP dispersion.
209 */
210 extern unsigned long tick_usec; /* USER_HZ period (usec) */
211 extern unsigned long tick_nsec; /* ACTHZ period (nsec) */
212 extern int tickadj; /* amount of adjustment per tick */
213
214 /*
215 * phase-lock loop variables
216 */
217 extern int time_status; /* clock synchronization status bits */
218 extern long time_maxerror; /* maximum error */
219 extern long time_esterror; /* estimated error */
220
221 extern long time_adjust; /* The amount of adjtime left */
222
223 extern void ntp_init(void);
224 extern void ntp_clear(void);
225
226 /**
227 * ntp_synced - Returns 1 if the NTP status is not UNSYNC
228 *
229 */
ntp_synced(void)230 static inline int ntp_synced(void)
231 {
232 return !(time_status & STA_UNSYNC);
233 }
234
235 /* Required to safely shift negative values */
236 #define shift_right(x, s) ({ \
237 __typeof__(x) __x = (x); \
238 __typeof__(s) __s = (s); \
239 __x < 0 ? -(-__x >> __s) : __x >> __s; \
240 })
241
242 #define NTP_SCALE_SHIFT 32
243
244 #ifdef CONFIG_NO_HZ
245 #define NTP_INTERVAL_FREQ (2)
246 #else
247 #define NTP_INTERVAL_FREQ (HZ)
248 #endif
249 #define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ)
250
251 /* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */
252 extern u64 tick_length;
253
254 extern void second_overflow(void);
255 extern void update_ntp_one_tick(void);
256 extern int do_adjtimex(struct timex *);
257
258 /* Don't use! Compatibility define for existing users. */
259 #define tickadj (500/HZ ? : 1)
260
261 int read_current_timer(unsigned long *timer_val);
262
263 #endif /* KERNEL */
264
265 #endif /* LINUX_TIMEX_H */
266