diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/timex.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/timex.h')
-rw-r--r-- | include/linux/timex.h | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/include/linux/timex.h b/include/linux/timex.h new file mode 100644 index 000000000000..74fdd07d3792 --- /dev/null +++ b/include/linux/timex.h | |||
@@ -0,0 +1,320 @@ | |||
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/config.h> | ||
57 | #include <linux/compiler.h> | ||
58 | #include <linux/time.h> | ||
59 | |||
60 | #include <asm/param.h> | ||
61 | #include <asm/timex.h> | ||
62 | |||
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 | */ | ||
74 | #define SHIFT_KG 6 /* phase factor (shift) */ | ||
75 | #define SHIFT_KF 16 /* PLL frequency factor (shift) */ | ||
76 | #define SHIFT_KH 2 /* FLL frequency factor (shift) */ | ||
77 | #define MAXTC 6 /* maximum time constant (shift) */ | ||
78 | |||
79 | /* | ||
80 | * The SHIFT_SCALE define establishes the decimal point of the time_phase | ||
81 | * variable which serves as an extension to the low-order bits of the | ||
82 | * system clock variable. The SHIFT_UPDATE define establishes the decimal | ||
83 | * point of the time_offset variable which represents the current offset | ||
84 | * with respect to standard time. The FINENSEC define represents 1 nsec in | ||
85 | * scaled units. | ||
86 | * | ||
87 | * SHIFT_USEC defines the scaling (shift) of the time_freq and | ||
88 | * time_tolerance variables, which represent the current frequency | ||
89 | * offset and maximum frequency tolerance. | ||
90 | * | ||
91 | * FINENSEC is 1 ns in SHIFT_UPDATE units of the time_phase variable. | ||
92 | */ | ||
93 | #define SHIFT_SCALE 22 /* phase scale (shift) */ | ||
94 | #define SHIFT_UPDATE (SHIFT_KG + MAXTC) /* time offset scale (shift) */ | ||
95 | #define SHIFT_USEC 16 /* frequency offset scale (shift) */ | ||
96 | #define FINENSEC (1L << (SHIFT_SCALE - 10)) /* ~1 ns in phase units */ | ||
97 | |||
98 | #define MAXPHASE 512000L /* max phase error (us) */ | ||
99 | #define MAXFREQ (512L << SHIFT_USEC) /* max frequency error (ppm) */ | ||
100 | #define MAXTIME (200L << PPS_AVG) /* max PPS error (jitter) (200 us) */ | ||
101 | #define MINSEC 16L /* min interval between updates (s) */ | ||
102 | #define MAXSEC 1200L /* max interval between updates (s) */ | ||
103 | #define NTP_PHASE_LIMIT (MAXPHASE << 5) /* beyond max. dispersion */ | ||
104 | |||
105 | /* | ||
106 | * The following defines are used only if a pulse-per-second (PPS) | ||
107 | * signal is available and connected via a modem control lead, such as | ||
108 | * produced by the optional ppsclock feature incorporated in the Sun | ||
109 | * asynch driver. They establish the design parameters of the frequency- | ||
110 | * lock loop used to discipline the CPU clock oscillator to the PPS | ||
111 | * signal. | ||
112 | * | ||
113 | * PPS_AVG is the averaging factor for the frequency loop, as well as | ||
114 | * the time and frequency dispersion. | ||
115 | * | ||
116 | * PPS_SHIFT and PPS_SHIFTMAX specify the minimum and maximum | ||
117 | * calibration intervals, respectively, in seconds as a power of two. | ||
118 | * | ||
119 | * PPS_VALID is the maximum interval before the PPS signal is considered | ||
120 | * invalid and protocol updates used directly instead. | ||
121 | * | ||
122 | * MAXGLITCH is the maximum interval before a time offset of more than | ||
123 | * MAXTIME is believed. | ||
124 | */ | ||
125 | #define PPS_AVG 2 /* pps averaging constant (shift) */ | ||
126 | #define PPS_SHIFT 2 /* min interval duration (s) (shift) */ | ||
127 | #define PPS_SHIFTMAX 8 /* max interval duration (s) (shift) */ | ||
128 | #define PPS_VALID 120 /* pps signal watchdog max (s) */ | ||
129 | #define MAXGLITCH 30 /* pps signal glitch max (s) */ | ||
130 | |||
131 | /* | ||
132 | * syscall interface - used (mainly by NTP daemon) | ||
133 | * to discipline kernel clock oscillator | ||
134 | */ | ||
135 | struct timex { | ||
136 | unsigned int modes; /* mode selector */ | ||
137 | long offset; /* time offset (usec) */ | ||
138 | long freq; /* frequency offset (scaled ppm) */ | ||
139 | long maxerror; /* maximum error (usec) */ | ||
140 | long esterror; /* estimated error (usec) */ | ||
141 | int status; /* clock command/status */ | ||
142 | long constant; /* pll time constant */ | ||
143 | long precision; /* clock precision (usec) (read only) */ | ||
144 | long tolerance; /* clock frequency tolerance (ppm) | ||
145 | * (read only) | ||
146 | */ | ||
147 | struct timeval time; /* (read only) */ | ||
148 | long tick; /* (modified) usecs between clock ticks */ | ||
149 | |||
150 | long ppsfreq; /* pps frequency (scaled ppm) (ro) */ | ||
151 | long jitter; /* pps jitter (us) (ro) */ | ||
152 | int shift; /* interval duration (s) (shift) (ro) */ | ||
153 | long stabil; /* pps stability (scaled ppm) (ro) */ | ||
154 | long jitcnt; /* jitter limit exceeded (ro) */ | ||
155 | long calcnt; /* calibration intervals (ro) */ | ||
156 | long errcnt; /* calibration errors (ro) */ | ||
157 | long stbcnt; /* stability limit exceeded (ro) */ | ||
158 | |||
159 | int :32; int :32; int :32; int :32; | ||
160 | int :32; int :32; int :32; int :32; | ||
161 | int :32; int :32; int :32; int :32; | ||
162 | }; | ||
163 | |||
164 | /* | ||
165 | * Mode codes (timex.mode) | ||
166 | */ | ||
167 | #define ADJ_OFFSET 0x0001 /* time offset */ | ||
168 | #define ADJ_FREQUENCY 0x0002 /* frequency offset */ | ||
169 | #define ADJ_MAXERROR 0x0004 /* maximum time error */ | ||
170 | #define ADJ_ESTERROR 0x0008 /* estimated time error */ | ||
171 | #define ADJ_STATUS 0x0010 /* clock status */ | ||
172 | #define ADJ_TIMECONST 0x0020 /* pll time constant */ | ||
173 | #define ADJ_TICK 0x4000 /* tick value */ | ||
174 | #define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */ | ||
175 | |||
176 | /* xntp 3.4 compatibility names */ | ||
177 | #define MOD_OFFSET ADJ_OFFSET | ||
178 | #define MOD_FREQUENCY ADJ_FREQUENCY | ||
179 | #define MOD_MAXERROR ADJ_MAXERROR | ||
180 | #define MOD_ESTERROR ADJ_ESTERROR | ||
181 | #define MOD_STATUS ADJ_STATUS | ||
182 | #define MOD_TIMECONST ADJ_TIMECONST | ||
183 | #define MOD_CLKB ADJ_TICK | ||
184 | #define MOD_CLKA ADJ_OFFSET_SINGLESHOT /* 0x8000 in original */ | ||
185 | |||
186 | |||
187 | /* | ||
188 | * Status codes (timex.status) | ||
189 | */ | ||
190 | #define STA_PLL 0x0001 /* enable PLL updates (rw) */ | ||
191 | #define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */ | ||
192 | #define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */ | ||
193 | #define STA_FLL 0x0008 /* select frequency-lock mode (rw) */ | ||
194 | |||
195 | #define STA_INS 0x0010 /* insert leap (rw) */ | ||
196 | #define STA_DEL 0x0020 /* delete leap (rw) */ | ||
197 | #define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */ | ||
198 | #define STA_FREQHOLD 0x0080 /* hold frequency (rw) */ | ||
199 | |||
200 | #define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */ | ||
201 | #define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */ | ||
202 | #define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */ | ||
203 | #define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */ | ||
204 | |||
205 | #define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */ | ||
206 | |||
207 | #define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \ | ||
208 | STA_PPSERROR | STA_CLOCKERR) /* read-only bits */ | ||
209 | |||
210 | /* | ||
211 | * Clock states (time_state) | ||
212 | */ | ||
213 | #define TIME_OK 0 /* clock synchronized, no leap second */ | ||
214 | #define TIME_INS 1 /* insert leap second */ | ||
215 | #define TIME_DEL 2 /* delete leap second */ | ||
216 | #define TIME_OOP 3 /* leap second in progress */ | ||
217 | #define TIME_WAIT 4 /* leap second has occurred */ | ||
218 | #define TIME_ERROR 5 /* clock not synchronized */ | ||
219 | #define TIME_BAD TIME_ERROR /* bw compat */ | ||
220 | |||
221 | #ifdef __KERNEL__ | ||
222 | /* | ||
223 | * kernel variables | ||
224 | * Note: maximum error = NTP synch distance = dispersion + delay / 2; | ||
225 | * estimated error = NTP dispersion. | ||
226 | */ | ||
227 | extern unsigned long tick_usec; /* USER_HZ period (usec) */ | ||
228 | extern unsigned long tick_nsec; /* ACTHZ period (nsec) */ | ||
229 | extern int tickadj; /* amount of adjustment per tick */ | ||
230 | |||
231 | /* | ||
232 | * phase-lock loop variables | ||
233 | */ | ||
234 | extern int time_state; /* clock status */ | ||
235 | extern int time_status; /* clock synchronization status bits */ | ||
236 | extern long time_offset; /* time adjustment (us) */ | ||
237 | extern long time_constant; /* pll time constant */ | ||
238 | extern long time_tolerance; /* frequency tolerance (ppm) */ | ||
239 | extern long time_precision; /* clock precision (us) */ | ||
240 | extern long time_maxerror; /* maximum error */ | ||
241 | extern long time_esterror; /* estimated error */ | ||
242 | |||
243 | extern long time_freq; /* frequency offset (scaled ppm) */ | ||
244 | extern long time_reftime; /* time at last adjustment (s) */ | ||
245 | |||
246 | extern long time_adjust; /* The amount of adjtime left */ | ||
247 | extern long time_next_adjust; /* Value for time_adjust at next tick */ | ||
248 | |||
249 | /* interface variables pps->timer interrupt */ | ||
250 | extern long pps_offset; /* pps time offset (us) */ | ||
251 | extern long pps_jitter; /* time dispersion (jitter) (us) */ | ||
252 | extern long pps_freq; /* frequency offset (scaled ppm) */ | ||
253 | extern long pps_stabil; /* frequency dispersion (scaled ppm) */ | ||
254 | extern long pps_valid; /* pps signal watchdog counter */ | ||
255 | |||
256 | /* interface variables pps->adjtimex */ | ||
257 | extern int pps_shift; /* interval duration (s) (shift) */ | ||
258 | extern long pps_jitcnt; /* jitter limit exceeded */ | ||
259 | extern long pps_calcnt; /* calibration intervals */ | ||
260 | extern long pps_errcnt; /* calibration errors */ | ||
261 | extern long pps_stbcnt; /* stability limit exceeded */ | ||
262 | |||
263 | #ifdef CONFIG_TIME_INTERPOLATION | ||
264 | |||
265 | #define TIME_SOURCE_CPU 0 | ||
266 | #define TIME_SOURCE_MMIO64 1 | ||
267 | #define TIME_SOURCE_MMIO32 2 | ||
268 | #define TIME_SOURCE_FUNCTION 3 | ||
269 | |||
270 | /* For proper operations time_interpolator clocks must run slightly slower | ||
271 | * than the standard clock since the interpolator may only correct by having | ||
272 | * time jump forward during a tick. A slower clock is usually a side effect | ||
273 | * of the integer divide of the nanoseconds in a second by the frequency. | ||
274 | * The accuracy of the division can be increased by specifying a shift. | ||
275 | * However, this may cause the clock not to be slow enough. | ||
276 | * The interpolator will self-tune the clock by slowing down if no | ||
277 | * resets occur or speeding up if the time jumps per analysis cycle | ||
278 | * become too high. | ||
279 | * | ||
280 | * Setting jitter compensates for a fluctuating timesource by comparing | ||
281 | * to the last value read from the timesource to insure that an earlier value | ||
282 | * is not returned by a later call. The price to pay | ||
283 | * for the compensation is that the timer routines are not as scalable anymore. | ||
284 | */ | ||
285 | |||
286 | struct time_interpolator { | ||
287 | u16 source; /* time source flags */ | ||
288 | u8 shift; /* increases accuracy of multiply by shifting. */ | ||
289 | /* Note that bits may be lost if shift is set too high */ | ||
290 | u8 jitter; /* if set compensate for fluctuations */ | ||
291 | u32 nsec_per_cyc; /* set by register_time_interpolator() */ | ||
292 | void *addr; /* address of counter or function */ | ||
293 | u64 mask; /* mask the valid bits of the counter */ | ||
294 | unsigned long offset; /* nsec offset at last update of interpolator */ | ||
295 | u64 last_counter; /* counter value in units of the counter at last update */ | ||
296 | u64 last_cycle; /* Last timer value if TIME_SOURCE_JITTER is set */ | ||
297 | u64 frequency; /* frequency in counts/second */ | ||
298 | long drift; /* drift in parts-per-million (or -1) */ | ||
299 | unsigned long skips; /* skips forward */ | ||
300 | unsigned long ns_skipped; /* nanoseconds skipped */ | ||
301 | struct time_interpolator *next; | ||
302 | }; | ||
303 | |||
304 | extern void register_time_interpolator(struct time_interpolator *); | ||
305 | extern void unregister_time_interpolator(struct time_interpolator *); | ||
306 | extern void time_interpolator_reset(void); | ||
307 | extern unsigned long time_interpolator_get_offset(void); | ||
308 | |||
309 | #else /* !CONFIG_TIME_INTERPOLATION */ | ||
310 | |||
311 | static inline void | ||
312 | time_interpolator_reset(void) | ||
313 | { | ||
314 | } | ||
315 | |||
316 | #endif /* !CONFIG_TIME_INTERPOLATION */ | ||
317 | |||
318 | #endif /* KERNEL */ | ||
319 | |||
320 | #endif /* LINUX_TIMEX_H */ | ||