1 /*- 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1982, 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: Utah $Hdr: clock.c 1.18 91/01/21$ 35 * from: @(#)clock.c 8.2 (Berkeley) 1/12/94 36 * from: NetBSD: clock_subr.c,v 1.6 2001/07/07 17:04:02 thorpej Exp 37 * and 38 * from: src/sys/i386/isa/clock.c,v 1.176 2001/09/04 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/bus.h> 48 #include <sys/clock.h> 49 #include <sys/sysctl.h> 50 #include <sys/timetc.h> 51 52 static int adjkerntz; /* local offset from GMT in seconds */ 53 static int wall_cmos_clock; /* wall CMOS clock assumed if != 0 */ 54 int disable_rtc_set; /* disable resettodr() if != 0 */ 55 56 int tz_minuteswest; 57 int tz_dsttime; 58 59 /* 60 * These have traditionally been in machdep, but should probably be moved to 61 * kern. 62 */ 63 SYSCTL_INT(_machdep, OID_AUTO, disable_rtc_set, 64 CTLFLAG_RW, &disable_rtc_set, 0, ""); 65 66 SYSCTL_INT(_machdep, OID_AUTO, wall_cmos_clock, 67 CTLFLAG_RW, &wall_cmos_clock, 0, ""); 68 69 static int 70 sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS) 71 { 72 int error; 73 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, 74 req); 75 if (!error && req->newptr) 76 resettodr(); 77 return (error); 78 } 79 80 SYSCTL_PROC(_machdep, OID_AUTO, adjkerntz, CTLTYPE_INT|CTLFLAG_RW, 81 &adjkerntz, 0, sysctl_machdep_adjkerntz, "I", ""); 82 83 /*--------------------------------------------------------------------* 84 * Generic routines to convert between a POSIX date 85 * (seconds since 1/1/1970) and yr/mo/day/hr/min/sec 86 * Derived from NetBSD arch/hp300/hp300/clock.c 87 */ 88 89 90 #define FEBRUARY 2 91 #define days_in_year(y) (leapyear(y) ? 366 : 365) 92 #define days_in_month(y, m) \ 93 (month_days[(m) - 1] + (m == FEBRUARY ? leapyear(y) : 0)) 94 /* Day of week. Days are counted from 1/1/1970, which was a Thursday */ 95 #define day_of_week(days) (((days) + 4) % 7) 96 97 static const int month_days[12] = { 98 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 99 }; 100 101 102 /* 103 * This inline avoids some unnecessary modulo operations 104 * as compared with the usual macro: 105 * ( ((year % 4) == 0 && 106 * (year % 100) != 0) || 107 * ((year % 400) == 0) ) 108 * It is otherwise equivalent. 109 */ 110 static __inline int 111 leapyear(int year) 112 { 113 int rv = 0; 114 115 if ((year & 3) == 0) { 116 rv = 1; 117 if ((year % 100) == 0) { 118 rv = 0; 119 if ((year % 400) == 0) 120 rv = 1; 121 } 122 } 123 return (rv); 124 } 125 126 int 127 clock_ct_to_ts(struct clocktime *ct, struct timespec *ts) 128 { 129 time_t secs; 130 int i, year, days; 131 132 year = ct->year; 133 134 /* Sanity checks. */ 135 if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 || 136 ct->day > days_in_month(year, ct->mon) || 137 ct->hour > 23 || ct->min > 59 || ct->sec > 59 || 138 ct->year > 2037) /* time_t overflow */ 139 return (EINVAL); 140 141 /* 142 * Compute days since start of time 143 * First from years, then from months. 144 */ 145 days = 0; 146 for (i = POSIX_BASE_YEAR; i < year; i++) 147 days += days_in_year(i); 148 149 /* Months */ 150 for (i = 1; i < ct->mon; i++) 151 days += days_in_month(year, i); 152 days += (ct->day - 1); 153 154 /* XXX Dow sanity check. Dow is not used, so should we check it? */ 155 if (ct->dow != -1 && ct->dow != day_of_week(days)) 156 return (EINVAL); 157 158 /* Add hours, minutes, seconds. */ 159 secs = ((days * 24 + ct->hour) * 60 + ct->min) * 60 + ct->sec; 160 161 ts->tv_sec = secs; 162 ts->tv_nsec = ct->nsec; 163 return (0); 164 } 165 166 void 167 clock_ts_to_ct(struct timespec *ts, struct clocktime *ct) 168 { 169 int i, year, days; 170 time_t rsec; /* remainder seconds */ 171 time_t secs; 172 173 secs = ts->tv_sec; 174 days = secs / SECDAY; 175 rsec = secs % SECDAY; 176 177 ct->dow = day_of_week(days); 178 179 /* Subtract out whole years, counting them in i. */ 180 for (year = POSIX_BASE_YEAR; days >= days_in_year(year); year++) 181 days -= days_in_year(year); 182 ct->year = year; 183 184 /* Subtract out whole months, counting them in i. */ 185 for (i = 1; days >= days_in_month(year, i); i++) 186 days -= days_in_month(year, i); 187 ct->mon = i; 188 189 /* Days are what is left over (+1) from all that. */ 190 ct->day = days + 1; 191 192 /* Hours, minutes, seconds are easy */ 193 ct->hour = rsec / 3600; 194 rsec = rsec % 3600; 195 ct->min = rsec / 60; 196 rsec = rsec % 60; 197 ct->sec = rsec; 198 ct->nsec = ts->tv_nsec; 199 } 200 201 int 202 utc_offset(void) 203 { 204 205 return (tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0)); 206 } 207