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1da177e4 LT |
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 | ||
1da177e4 LT |
56 | #include <linux/compiler.h> |
57 | #include <linux/time.h> | |
58 | ||
59 | #include <asm/param.h> | |
1da177e4 | 60 | |
eea83d89 RZ |
61 | #define NTP_API 4 /* NTP API version */ |
62 | ||
1da177e4 LT |
63 | /* |
64 | * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen | |
65 | * for a slightly underdamped convergence characteristic. SHIFT_KH | |
66 | * establishes the damping of the FLL and is chosen by wisdom and black | |
67 | * art. | |
68 | * | |
69 | * MAXTC establishes the maximum time constant of the PLL. With the | |
70 | * SHIFT_KG and SHIFT_KF values given and a time constant range from | |
71 | * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours, | |
72 | * respectively. | |
73 | */ | |
f1992393 RZ |
74 | #define SHIFT_PLL 4 /* PLL frequency factor (shift) */ |
75 | #define SHIFT_FLL 2 /* FLL frequency factor (shift) */ | |
76 | #define MAXTC 10 /* maximum time constant (shift) */ | |
1da177e4 LT |
77 | |
78 | /* | |
1da177e4 LT |
79 | * SHIFT_USEC defines the scaling (shift) of the time_freq and |
80 | * time_tolerance variables, which represent the current frequency | |
81 | * offset and maximum frequency tolerance. | |
1da177e4 | 82 | */ |
1da177e4 | 83 | #define SHIFT_USEC 16 /* frequency offset scale (shift) */ |
074b3b87 RZ |
84 | #define PPM_SCALE (NSEC_PER_USEC << (TICK_LENGTH_SHIFT - SHIFT_USEC)) |
85 | #define PPM_SCALE_INV_SHIFT 20 | |
86 | #define PPM_SCALE_INV ((1ll << (PPM_SCALE_INV_SHIFT + TICK_LENGTH_SHIFT)) / \ | |
87 | PPM_SCALE + 1) | |
1da177e4 | 88 | |
9f14f669 | 89 | #define MAXPHASE 500000000l /* max phase error (ns) */ |
074b3b87 RZ |
90 | #define MAXFREQ 500000 /* max frequency error (ns/s) */ |
91 | #define MAXFREQ_SCALED ((s64)MAXFREQ << TICK_LENGTH_SHIFT) | |
f1992393 RZ |
92 | #define MINSEC 256 /* min interval between updates (s) */ |
93 | #define MAXSEC 2048 /* max interval between updates (s) */ | |
9f14f669 | 94 | #define NTP_PHASE_LIMIT ((MAXPHASE / NSEC_PER_USEC) << 5) /* beyond max. dispersion */ |
1da177e4 | 95 | |
1da177e4 LT |
96 | /* |
97 | * syscall interface - used (mainly by NTP daemon) | |
98 | * to discipline kernel clock oscillator | |
99 | */ | |
100 | struct timex { | |
101 | unsigned int modes; /* mode selector */ | |
102 | long offset; /* time offset (usec) */ | |
103 | long freq; /* frequency offset (scaled ppm) */ | |
104 | long maxerror; /* maximum error (usec) */ | |
105 | long esterror; /* estimated error (usec) */ | |
106 | int status; /* clock command/status */ | |
107 | long constant; /* pll time constant */ | |
108 | long precision; /* clock precision (usec) (read only) */ | |
109 | long tolerance; /* clock frequency tolerance (ppm) | |
110 | * (read only) | |
111 | */ | |
112 | struct timeval time; /* (read only) */ | |
113 | long tick; /* (modified) usecs between clock ticks */ | |
114 | ||
115 | long ppsfreq; /* pps frequency (scaled ppm) (ro) */ | |
116 | long jitter; /* pps jitter (us) (ro) */ | |
117 | int shift; /* interval duration (s) (shift) (ro) */ | |
118 | long stabil; /* pps stability (scaled ppm) (ro) */ | |
119 | long jitcnt; /* jitter limit exceeded (ro) */ | |
120 | long calcnt; /* calibration intervals (ro) */ | |
121 | long errcnt; /* calibration errors (ro) */ | |
122 | long stbcnt; /* stability limit exceeded (ro) */ | |
123 | ||
124 | int :32; int :32; int :32; int :32; | |
125 | int :32; int :32; int :32; int :32; | |
126 | int :32; int :32; int :32; int :32; | |
127 | }; | |
128 | ||
129 | /* | |
130 | * Mode codes (timex.mode) | |
131 | */ | |
132 | #define ADJ_OFFSET 0x0001 /* time offset */ | |
133 | #define ADJ_FREQUENCY 0x0002 /* frequency offset */ | |
134 | #define ADJ_MAXERROR 0x0004 /* maximum time error */ | |
135 | #define ADJ_ESTERROR 0x0008 /* estimated time error */ | |
136 | #define ADJ_STATUS 0x0010 /* clock status */ | |
137 | #define ADJ_TIMECONST 0x0020 /* pll time constant */ | |
eea83d89 RZ |
138 | #define ADJ_MICRO 0x1000 /* select microsecond resolution */ |
139 | #define ADJ_NANO 0x2000 /* select nanosecond resolution */ | |
1da177e4 LT |
140 | #define ADJ_TICK 0x4000 /* tick value */ |
141 | #define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */ | |
52bfb360 | 142 | #define ADJ_OFFSET_SS_READ 0xa001 /* read-only adjtime */ |
1da177e4 LT |
143 | |
144 | /* xntp 3.4 compatibility names */ | |
145 | #define MOD_OFFSET ADJ_OFFSET | |
146 | #define MOD_FREQUENCY ADJ_FREQUENCY | |
147 | #define MOD_MAXERROR ADJ_MAXERROR | |
148 | #define MOD_ESTERROR ADJ_ESTERROR | |
149 | #define MOD_STATUS ADJ_STATUS | |
150 | #define MOD_TIMECONST ADJ_TIMECONST | |
1da177e4 LT |
151 | |
152 | ||
153 | /* | |
154 | * Status codes (timex.status) | |
155 | */ | |
156 | #define STA_PLL 0x0001 /* enable PLL updates (rw) */ | |
157 | #define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */ | |
158 | #define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */ | |
159 | #define STA_FLL 0x0008 /* select frequency-lock mode (rw) */ | |
160 | ||
161 | #define STA_INS 0x0010 /* insert leap (rw) */ | |
162 | #define STA_DEL 0x0020 /* delete leap (rw) */ | |
163 | #define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */ | |
164 | #define STA_FREQHOLD 0x0080 /* hold frequency (rw) */ | |
165 | ||
166 | #define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */ | |
167 | #define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */ | |
168 | #define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */ | |
169 | #define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */ | |
170 | ||
171 | #define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */ | |
eea83d89 RZ |
172 | #define STA_NANO 0x2000 /* resolution (0 = us, 1 = ns) (ro) */ |
173 | #define STA_MODE 0x4000 /* mode (0 = PLL, 1 = FLL) (ro) */ | |
174 | #define STA_CLK 0x8000 /* clock source (0 = A, 1 = B) (ro) */ | |
1da177e4 | 175 | |
eea83d89 | 176 | /* read-only bits */ |
1da177e4 | 177 | #define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \ |
eea83d89 | 178 | STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK) |
1da177e4 LT |
179 | |
180 | /* | |
181 | * Clock states (time_state) | |
182 | */ | |
183 | #define TIME_OK 0 /* clock synchronized, no leap second */ | |
184 | #define TIME_INS 1 /* insert leap second */ | |
185 | #define TIME_DEL 2 /* delete leap second */ | |
186 | #define TIME_OOP 3 /* leap second in progress */ | |
187 | #define TIME_WAIT 4 /* leap second has occurred */ | |
188 | #define TIME_ERROR 5 /* clock not synchronized */ | |
189 | #define TIME_BAD TIME_ERROR /* bw compat */ | |
190 | ||
191 | #ifdef __KERNEL__ | |
ee6baf88 DW |
192 | #include <asm/timex.h> |
193 | ||
1da177e4 LT |
194 | /* |
195 | * kernel variables | |
196 | * Note: maximum error = NTP synch distance = dispersion + delay / 2; | |
197 | * estimated error = NTP dispersion. | |
198 | */ | |
199 | extern unsigned long tick_usec; /* USER_HZ period (usec) */ | |
200 | extern unsigned long tick_nsec; /* ACTHZ period (nsec) */ | |
201 | extern int tickadj; /* amount of adjustment per tick */ | |
202 | ||
203 | /* | |
204 | * phase-lock loop variables | |
205 | */ | |
1da177e4 | 206 | extern int time_status; /* clock synchronization status bits */ |
1da177e4 LT |
207 | extern long time_maxerror; /* maximum error */ |
208 | extern long time_esterror; /* estimated error */ | |
1da177e4 LT |
209 | |
210 | extern long time_adjust; /* The amount of adjtime left */ | |
1da177e4 | 211 | |
b0ee7556 | 212 | extern void ntp_clear(void); |
b149ee22 JS |
213 | |
214 | /** | |
215 | * ntp_synced - Returns 1 if the NTP status is not UNSYNC | |
216 | * | |
217 | */ | |
218 | static inline int ntp_synced(void) | |
219 | { | |
220 | return !(time_status & STA_UNSYNC); | |
221 | } | |
222 | ||
1bb34a41 JS |
223 | /* Required to safely shift negative values */ |
224 | #define shift_right(x, s) ({ \ | |
225 | __typeof__(x) __x = (x); \ | |
226 | __typeof__(s) __s = (s); \ | |
227 | __x < 0 ? -(-__x >> __s) : __x >> __s; \ | |
228 | }) | |
229 | ||
19923c19 RZ |
230 | #define TICK_LENGTH_SHIFT 32 |
231 | ||
f4304ab2 JS |
232 | #ifdef CONFIG_NO_HZ |
233 | #define NTP_INTERVAL_FREQ (2) | |
234 | #else | |
235 | #define NTP_INTERVAL_FREQ (HZ) | |
236 | #endif | |
10a398d0 | 237 | #define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ) |
f4304ab2 | 238 | |
726c14bf | 239 | /* Returns how long ticks are at present, in ns / 2^(SHIFT_SCALE-10). */ |
19923c19 | 240 | extern u64 current_tick_length(void); |
726c14bf | 241 | |
4c7ee8de JS |
242 | extern void second_overflow(void); |
243 | extern void update_ntp_one_tick(void); | |
3158e941 SR |
244 | extern int do_adjtimex(struct timex *); |
245 | ||
7236e978 RZ |
246 | /* Don't use! Compatibility define for existing users. */ |
247 | #define tickadj (500/HZ ? : 1) | |
248 | ||
941e492b AM |
249 | int read_current_timer(unsigned long *timer_val); |
250 | ||
1da177e4 LT |
251 | #endif /* KERNEL */ |
252 | ||
253 | #endif /* LINUX_TIMEX_H */ |