mc146818.c revision 1.9
1 /* $NetBSD: mc146818.c,v 1.9 2006/09/06 06:26:54 simonb Exp $ */ 2 3 /* 4 * Copyright (c) 2003 Izumi Tsutsui. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /* 30 * mc146818 and compatible time of day chip subroutines 31 */ 32 33 #include <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: mc146818.c,v 1.9 2006/09/06 06:26:54 simonb Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/device.h> 39 #include <sys/errno.h> 40 41 #include <machine/bus.h> 42 43 #include <dev/clock_subr.h> 44 45 #include <dev/ic/mc146818reg.h> 46 #include <dev/ic/mc146818var.h> 47 48 int mc146818_gettime(todr_chip_handle_t, volatile struct timeval *); 49 int mc146818_settime(todr_chip_handle_t, volatile struct timeval *); 50 51 void 52 mc146818_attach(struct mc146818_softc *sc) 53 { 54 todr_chip_handle_t handle; 55 56 #ifdef DIAGNOSTIC 57 if (sc->sc_mcread == NULL || 58 sc->sc_mcwrite == NULL) 59 panic("mc146818_attach: invalid read/write functions"); 60 #endif 61 62 printf(": mc146818 compatible time-of-day clock\n"); 63 64 handle = &sc->sc_handle; 65 handle->cookie = sc; 66 handle->todr_gettime = mc146818_gettime; 67 handle->todr_settime = mc146818_settime; 68 handle->todr_setwen = NULL; 69 } 70 71 /* 72 * todr_gettime function: 73 * Get time of day and convert it to a struct timeval. 74 * Return 0 on success, an error number othersize. 75 */ 76 int 77 mc146818_gettime(todr_chip_handle_t handle, volatile struct timeval *tv) 78 { 79 struct mc146818_softc *sc; 80 struct clock_ymdhms dt; 81 int s, timeout, cent, year; 82 83 sc = handle->cookie; 84 85 s = splclock(); /* XXX really needed? */ 86 87 todr_wenable(handle, 1); 88 89 timeout = 1000000; /* XXX how long should we wait? */ 90 for (;;) { 91 if ((*sc->sc_mcread)(sc, MC_REGA) & MC_REGA_UIP) 92 break; 93 if (--timeout < 0) { 94 printf("mc146818_gettime: timeout\n"); 95 return EBUSY; 96 } 97 } 98 99 #define FROMREG(x) ((sc->sc_flag & MC146818_BCD) ? FROMBCD(x) : (x)) 100 101 dt.dt_sec = FROMREG((*sc->sc_mcread)(sc, MC_SEC)); 102 dt.dt_min = FROMREG((*sc->sc_mcread)(sc, MC_MIN)); 103 dt.dt_hour = FROMREG((*sc->sc_mcread)(sc, MC_HOUR)); 104 dt.dt_wday = FROMREG((*sc->sc_mcread)(sc, MC_DOW)); 105 dt.dt_day = FROMREG((*sc->sc_mcread)(sc, MC_DOM)); 106 dt.dt_mon = FROMREG((*sc->sc_mcread)(sc, MC_MONTH)); 107 year = FROMREG((*sc->sc_mcread)(sc, MC_YEAR)); 108 if (sc->sc_getcent) { 109 cent = (*sc->sc_getcent)(sc); 110 year += cent * 100; 111 } 112 113 #undef FROMREG 114 115 year += sc->sc_year0; 116 if (year < POSIX_BASE_YEAR && 117 (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0) 118 year += 100; 119 dt.dt_year = year; 120 121 todr_wenable(handle, 0); 122 123 splx(s); 124 125 /* simple sanity checks */ 126 if (dt.dt_mon > 12 || dt.dt_day > 31 || 127 dt.dt_hour >= 24 || dt.dt_min >= 60 || dt.dt_sec >= 60) 128 return EIO; 129 130 tv->tv_sec = clock_ymdhms_to_secs(&dt); 131 tv->tv_usec = 0; 132 return 0; 133 } 134 135 /* 136 * todr_settime function: 137 * Set the time of day clock based on the value of the struct timeval arg. 138 * Return 0 on success, an error number othersize. 139 */ 140 int 141 mc146818_settime(todr_chip_handle_t handle, volatile struct timeval *tv) 142 { 143 struct mc146818_softc *sc; 144 struct clock_ymdhms dt; 145 int s, timeout, cent, year; 146 147 sc = handle->cookie; 148 149 /* Note: we ignore `tv_usec' */ 150 clock_secs_to_ymdhms(tv->tv_sec, &dt); 151 152 s = splclock(); /* XXX really needed? */ 153 154 todr_wenable(handle, 1); 155 156 timeout = 1000000; /* XXX how long should we wait? */ 157 for (;;) { 158 if ((*sc->sc_mcread)(sc, MC_REGA) & MC_REGA_UIP) 159 break; 160 if (--timeout < 0) { 161 printf("mc146818_settime: timeout\n"); 162 return EBUSY; 163 } 164 } 165 166 #define TOREG(x) ((sc->sc_flag & MC146818_BCD) ? TOBCD(x) : (x)) 167 168 (*sc->sc_mcwrite)(sc, MC_SEC, TOREG(dt.dt_sec)); 169 (*sc->sc_mcwrite)(sc, MC_MIN, TOREG(dt.dt_min)); 170 (*sc->sc_mcwrite)(sc, MC_HOUR, TOREG(dt.dt_hour)); 171 (*sc->sc_mcwrite)(sc, MC_DOW, TOREG(dt.dt_wday)); 172 (*sc->sc_mcwrite)(sc, MC_DOM, TOREG(dt.dt_day)); 173 (*sc->sc_mcwrite)(sc, MC_MONTH, TOREG(dt.dt_mon)); 174 175 year = dt.dt_year - sc->sc_year0; 176 if (sc->sc_setcent) { 177 cent = year / 100; 178 (*sc->sc_setcent)(sc, cent); 179 year -= cent * 100; 180 } 181 if (year > 99 && 182 (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0) 183 year -= 100; 184 (*sc->sc_mcwrite)(sc, MC_YEAR, TOREG(year)); 185 186 #undef TOREG 187 188 todr_wenable(handle, 0); 189 190 splx(s); 191 192 return 0; 193 } 194
Indexes created Fri Sep 26 08:10:20 GMT 2025