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 /* 42 * Helpers for time-of-day clocks. This is useful for architectures that need 43 * support multiple models of such clocks, and generally serves to make the 44 * code more machine-independent. 45 * If the clock in question can also be used as a time counter, the driver 46 * needs to initiate this. 47 * This code is not yet used by all architectures. 48 */ 49 50 #include <sys/cdefs.h> 51 __FBSDID("$FreeBSD$"); 52 53 #include <sys/param.h> 54 #include <sys/systm.h> 55 #include <sys/kernel.h> 56 #include <sys/bus.h> 57 #include <sys/clock.h> 58 #include <sys/sysctl.h> 59 #include <sys/timetc.h> 60 61 #include "clock_if.h" 62 63 static device_t clock_dev = NULL; 64 static long clock_res; 65 66 /* XXX: should be kern. now, it's no longer machdep. */ 67 static int disable_rtc_set; 68 SYSCTL_INT(_machdep, OID_AUTO, disable_rtc_set, 69 CTLFLAG_RW, &disable_rtc_set, 0, ""); 70 71 void 72 clock_register(device_t dev, long res) /* res has units of microseconds */ 73 { 74 75 if (clock_dev != NULL) { 76 if (clock_res > res) { 77 if (bootverbose) { 78 device_printf(dev, "not installed as " 79 "time-of-day clock: clock %s has higher " 80 "resolution\n", device_get_name(clock_dev)); 81 } 82 return; 83 } else { 84 if (bootverbose) { 85 device_printf(clock_dev, "removed as " 86 "time-of-day clock: clock %s has higher " 87 "resolution\n", device_get_name(dev)); 88 } 89 } 90 } 91 clock_dev = dev; 92 clock_res = res; 93 if (bootverbose) { 94 device_printf(dev, "registered as a time-of-day clock " 95 "(resolution %ldus)\n", res); 96 } 97 } 98 99 /* 100 * inittodr and settodr derived from the i386 versions written 101 * by Christoph Robitschko <chmr@edvz.tu-graz.ac.at>, reintroduced and 102 * updated by Chris Stenton <chris@gnome.co.uk> 8/10/94 103 */ 104 105 /* 106 * Initialize the time of day register, based on the time base which is, e.g. 107 * from a filesystem. 108 */ 109 void 110 inittodr(time_t base) 111 { 112 struct timespec diff, ref, ts; 113 int error; 114 115 if (base) { 116 ref.tv_sec = base; 117 ref.tv_nsec = 0; 118 tc_setclock(&ref); 119 } 120 121 if (clock_dev == NULL) { 122 printf("warning: no time-of-day clock registered, system time " 123 "will not be set accurately\n"); 124 return; 125 } 126 /* XXX: We should poll all registered RTCs in case of failure */ 127 error = CLOCK_GETTIME(clock_dev, &ts); 128 if (error != 0 && error != EINVAL) { 129 printf("warning: clock_gettime failed (%d), the system time " 130 "will not be set accurately\n", error); 131 return; 132 } 133 if (error == EINVAL || ts.tv_sec < 0) { 134 printf("Invalid time in real time clock.\n"); 135 printf("Check and reset the date immediately!\n"); 136 } 137 138 ts.tv_sec += utc_offset(); 139 140 if (timespeccmp(&ref, &ts, >)) { 141 diff = ref; 142 timespecsub(&ref, &ts); 143 } else { 144 diff = ts; 145 timespecsub(&diff, &ref); 146 } 147 if (ts.tv_sec >= 2) { 148 /* badly off, adjust it */ 149 tc_setclock(&ts); 150 } 151 } 152 153 /* 154 * Write system time back to RTC 155 */ 156 void 157 resettodr() 158 { 159 struct timespec ts; 160 int error; 161 162 if (disable_rtc_set || clock_dev == NULL) 163 return; 164 165 getnanotime(&ts); 166 ts.tv_sec -= utc_offset(); 167 /* XXX: We should really set all registered RTCs */ 168 if ((error = CLOCK_SETTIME(clock_dev, &ts)) != 0) { 169 printf("warning: clock_settime failed (%d), time-of-day clock " 170 "not adjusted to system time\n", error); 171 return; 172 } 173 } 174