1 /*- 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1982, 1990, 1993 4 * The Regents of the University of California. 5 * Copyright (c) 2011 The FreeBSD Foundation 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department. 11 * 12 * Portions of this software were developed by Julien Ridoux at the University 13 * of Melbourne under sponsorship from the FreeBSD Foundation. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 3. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * from: Utah $Hdr: clock.c 1.18 91/01/21$ 40 * from: @(#)clock.c 8.2 (Berkeley) 1/12/94 41 * from: NetBSD: clock_subr.c,v 1.6 2001/07/07 17:04:02 thorpej Exp 42 * and 43 * from: src/sys/i386/isa/clock.c,v 1.176 2001/09/04 44 */ 45 46 /* 47 * Helpers for time-of-day clocks. This is useful for architectures that need 48 * support multiple models of such clocks, and generally serves to make the 49 * code more machine-independent. 50 * If the clock in question can also be used as a time counter, the driver 51 * needs to initiate this. 52 * This code is not yet used by all architectures. 53 */ 54 55 #include <sys/cdefs.h> 56 __FBSDID("$FreeBSD$"); 57 58 #include "opt_ffclock.h" 59 60 #include <sys/param.h> 61 #include <sys/systm.h> 62 #include <sys/kernel.h> 63 #include <sys/bus.h> 64 #include <sys/clock.h> 65 #include <sys/lock.h> 66 #include <sys/mutex.h> 67 #include <sys/sysctl.h> 68 #ifdef FFCLOCK 69 #include <sys/timeffc.h> 70 #endif 71 #include <sys/timetc.h> 72 73 #include "clock_if.h" 74 75 static device_t clock_dev = NULL; 76 static long clock_res; 77 static struct timespec clock_adj; 78 struct mtx resettodr_lock; 79 MTX_SYSINIT(resettodr_init, &resettodr_lock, "tod2rl", MTX_DEF); 80 81 /* XXX: should be kern. now, it's no longer machdep. */ 82 static int disable_rtc_set; 83 SYSCTL_INT(_machdep, OID_AUTO, disable_rtc_set, CTLFLAG_RW, &disable_rtc_set, 84 0, "Disallow adjusting time-of-day clock"); 85 86 void 87 clock_register(device_t dev, long res) /* res has units of microseconds */ 88 { 89 90 if (clock_dev != NULL) { 91 if (clock_res <= res) { 92 if (bootverbose) 93 device_printf(dev, "not installed as " 94 "time-of-day clock: clock %s has higher " 95 "resolution\n", device_get_name(clock_dev)); 96 return; 97 } 98 if (bootverbose) 99 device_printf(clock_dev, "removed as " 100 "time-of-day clock: clock %s has higher " 101 "resolution\n", device_get_name(dev)); 102 } 103 clock_dev = dev; 104 clock_res = res; 105 clock_adj.tv_sec = res / 2 / 1000000; 106 clock_adj.tv_nsec = res / 2 % 1000000 * 1000; 107 if (bootverbose) 108 device_printf(dev, "registered as a time-of-day clock " 109 "(resolution %ldus, adjustment %jd.%09jds)\n", res, 110 (intmax_t)clock_adj.tv_sec, (intmax_t)clock_adj.tv_nsec); 111 } 112 113 /* 114 * inittodr and settodr derived from the i386 versions written 115 * by Christoph Robitschko <chmr@edvz.tu-graz.ac.at>, reintroduced and 116 * updated by Chris Stenton <chris@gnome.co.uk> 8/10/94 117 */ 118 119 /* 120 * Initialize the time of day register, based on the time base which is, e.g. 121 * from a filesystem. 122 */ 123 void 124 inittodr(time_t base) 125 { 126 struct timespec ts; 127 int error; 128 129 if (clock_dev == NULL) { 130 printf("warning: no time-of-day clock registered, system time " 131 "will not be set accurately\n"); 132 goto wrong_time; 133 } 134 /* XXX: We should poll all registered RTCs in case of failure */ 135 mtx_lock(&resettodr_lock); 136 error = CLOCK_GETTIME(clock_dev, &ts); 137 mtx_unlock(&resettodr_lock); 138 if (error != 0 && error != EINVAL) { 139 printf("warning: clock_gettime failed (%d), the system time " 140 "will not be set accurately\n", error); 141 goto wrong_time; 142 } 143 if (error == EINVAL || ts.tv_sec < 0) { 144 printf("Invalid time in real time clock.\n" 145 "Check and reset the date immediately!\n"); 146 goto wrong_time; 147 } 148 149 ts.tv_sec += utc_offset(); 150 timespecadd(&ts, &clock_adj); 151 tc_setclock(&ts); 152 #ifdef FFCLOCK 153 ffclock_reset_clock(&ts); 154 #endif 155 return; 156 157 wrong_time: 158 if (base > 0) { 159 ts.tv_sec = base; 160 ts.tv_nsec = 0; 161 tc_setclock(&ts); 162 } 163 } 164 165 /* 166 * Write system time back to RTC 167 */ 168 void 169 resettodr(void) 170 { 171 struct timespec ts; 172 int error; 173 174 if (disable_rtc_set || clock_dev == NULL) 175 return; 176 177 getnanotime(&ts); 178 timespecadd(&ts, &clock_adj); 179 ts.tv_sec -= utc_offset(); 180 /* XXX: We should really set all registered RTCs */ 181 mtx_lock(&resettodr_lock); 182 error = CLOCK_SETTIME(clock_dev, &ts); 183 mtx_unlock(&resettodr_lock); 184 if (error != 0) 185 printf("warning: clock_settime failed (%d), time-of-day clock " 186 "not adjusted to system time\n", error); 187 } 188