2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1988 University of Utah.
5 * Copyright (c) 1982, 1990, 1993
6 * The Regents of the University of California. All rights reserved.
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * from: Utah $Hdr: clock.c 1.18 91/01/21$
37 * from: @(#)clock.c 8.2 (Berkeley) 1/12/94
38 * from: NetBSD: clock_subr.c,v 1.6 2001/07/07 17:04:02 thorpej Exp
40 * from: src/sys/i386/isa/clock.c,v 1.176 2001/09/04
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
50 #include <sys/clock.h>
51 #include <sys/limits.h>
52 #include <sys/sysctl.h>
53 #include <sys/timetc.h>
59 * The adjkerntz and wall_cmos_clock sysctls are in the "machdep" sysctl
60 * namespace because they were misplaced there originally.
64 sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS)
67 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
68 if (!error && req->newptr)
72 SYSCTL_PROC(_machdep, OID_AUTO, adjkerntz, CTLTYPE_INT | CTLFLAG_RW |
73 CTLFLAG_MPSAFE, &adjkerntz, 0, sysctl_machdep_adjkerntz, "I",
74 "Local offset from UTC in seconds");
77 SYSCTL_INT(_debug, OID_AUTO, clocktime, CTLFLAG_RWTUN,
78 &ct_debug, 0, "Enable printing of clocktime debugging");
80 static int wall_cmos_clock;
81 SYSCTL_INT(_machdep, OID_AUTO, wall_cmos_clock, CTLFLAG_RW,
82 &wall_cmos_clock, 0, "Enables application of machdep.adjkerntz");
84 /*--------------------------------------------------------------------*
85 * Generic routines to convert between a POSIX date
86 * (seconds since 1/1/1970) and yr/mo/day/hr/min/sec
87 * Derived from NetBSD arch/hp300/hp300/clock.c
92 #define days_in_year(y) (leapyear(y) ? 366 : 365)
93 #define days_in_month(y, m) \
94 (month_days[(m) - 1] + (m == FEBRUARY ? leapyear(y) : 0))
95 /* Day of week. Days are counted from 1/1/1970, which was a Thursday */
96 #define day_of_week(days) (((days) + 4) % 7)
98 static const int month_days[12] = {
99 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
103 * Optimization: using a precomputed count of days between POSIX_BASE_YEAR and
104 * some recent year avoids lots of unnecessary loop iterations in conversion.
105 * recent_base_days is the number of days before the start of recent_base_year.
107 static const int recent_base_year = 2017;
108 static const int recent_base_days = 17167;
111 * This inline avoids some unnecessary modulo operations
112 * as compared with the usual macro:
113 * ( ((year % 4) == 0 &&
114 * (year % 100) != 0) ||
115 * ((year % 400) == 0) )
116 * It is otherwise equivalent.
123 if ((year & 3) == 0) {
125 if ((year % 100) == 0) {
127 if ((year % 400) == 0)
135 print_ct(struct clocktime *ct)
137 printf("[%04d-%02d-%02d %02d:%02d:%02d]",
138 ct->year, ct->mon, ct->day,
139 ct->hour, ct->min, ct->sec);
143 clock_ct_to_ts(struct clocktime *ct, struct timespec *ts)
154 * Many realtime clocks store the year as 2-digit BCD; pivot on 70 to
155 * determine century. Some clocks have a "century bit" and drivers do
156 * year += 100, so interpret values between 70-199 as relative to 1900.
165 if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 ||
166 ct->day > days_in_month(year, ct->mon) ||
167 ct->hour > 23 || ct->min > 59 || ct->sec > 59 || year < 1970 ||
168 (sizeof(time_t) == 4 && year > 2037)) { /* time_t overflow */
170 printf(" = EINVAL\n");
175 * Compute days since start of time
176 * First from years, then from months.
178 if (year >= recent_base_year) {
179 i = recent_base_year;
180 days = recent_base_days;
185 for (; i < year; i++)
186 days += days_in_year(i);
189 for (i = 1; i < ct->mon; i++)
190 days += days_in_month(year, i);
191 days += (ct->day - 1);
193 ts->tv_sec = (((time_t)days * 24 + ct->hour) * 60 + ct->min) * 60 +
195 ts->tv_nsec = ct->nsec;
198 printf(" = %jd.%09ld\n", (intmax_t)ts->tv_sec, ts->tv_nsec);
203 clock_ts_to_ct(struct timespec *ts, struct clocktime *ct)
205 time_t i, year, days;
206 time_t rsec; /* remainder seconds */
210 days = secs / SECDAY;
211 rsec = secs % SECDAY;
213 ct->dow = day_of_week(days);
215 /* Subtract out whole years. */
216 if (days >= recent_base_days) {
217 year = recent_base_year;
218 days -= recent_base_days;
220 year = POSIX_BASE_YEAR;
222 for (; days >= days_in_year(year); year++)
223 days -= days_in_year(year);
226 /* Subtract out whole months, counting them in i. */
227 for (i = 1; days >= days_in_month(year, i); i++)
228 days -= days_in_month(year, i);
231 /* Days are what is left over (+1) from all that. */
234 /* Hours, minutes, seconds are easy */
235 ct->hour = rsec / 3600;
240 ct->nsec = ts->tv_nsec;
242 printf("ts_to_ct(%jd.%09ld) = ",
243 (intmax_t)ts->tv_sec, ts->tv_nsec);
248 KASSERT(ct->year >= 0 && ct->year < 10000,
249 ("year %d isn't a 4 digit year", ct->year));
250 KASSERT(ct->mon >= 1 && ct->mon <= 12,
251 ("month %d not in 1-12", ct->mon));
252 KASSERT(ct->day >= 1 && ct->day <= 31,
253 ("day %d not in 1-31", ct->day));
254 KASSERT(ct->hour >= 0 && ct->hour <= 23,
255 ("hour %d not in 0-23", ct->hour));
256 KASSERT(ct->min >= 0 && ct->min <= 59,
257 ("minute %d not in 0-59", ct->min));
258 /* Not sure if this interface needs to handle leapseconds or not. */
259 KASSERT(ct->sec >= 0 && ct->sec <= 60,
260 ("seconds %d not in 0-60", ct->sec));
267 return (tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0));