1 /* $NetBSD: mc146818.c,v 1.21 2024/03/06 02:31:44 thorpej 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 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 /* 28 * mc146818 and compatible time of day chip subroutines 29 */ 30 31 #include <sys/cdefs.h> 32 __KERNEL_RCSID(0, "$NetBSD: mc146818.c,v 1.21 2024/03/06 02:31:44 thorpej Exp $"); 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/device.h> 37 #include <sys/errno.h> 38 39 #include <sys/bus.h> 40 41 #include <dev/clock_subr.h> 42 43 #include <dev/ic/mc146818reg.h> 44 #include <dev/ic/mc146818var.h> 45 46 void 47 mc146818_attach(struct mc146818_softc *sc) 48 { 49 todr_chip_handle_t handle; 50 51 #ifdef DIAGNOSTIC 52 if (sc->sc_mcread == NULL || 53 sc->sc_mcwrite == NULL) 54 panic("%s: invalid read/write functions", __func__); 55 #endif 56 57 aprint_normal(": mc146818 compatible time-of-day clock"); 58 59 handle = &sc->sc_handle; 60 handle->cookie = sc; 61 KASSERT(handle->todr_gettime == NULL); 62 KASSERT(handle->todr_settime == NULL); 63 if (handle->todr_gettime_ymdhms == NULL) { 64 handle->todr_gettime_ymdhms = mc146818_gettime_ymdhms; 65 } 66 if (handle->todr_settime_ymdhms == NULL) { 67 handle->todr_settime_ymdhms = mc146818_settime_ymdhms; 68 } 69 70 todr_attach(handle); 71 } 72 73 /* 74 * todr_gettime function: 75 * Get time of day and convert it to a struct timeval. 76 * Return 0 on success, an error number othersize. 77 */ 78 int 79 mc146818_gettime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt) 80 { 81 struct mc146818_softc *sc; 82 int s, timeout, cent, year; 83 84 sc = handle->cookie; 85 86 s = splclock(); /* XXX really needed? */ 87 88 timeout = 1000000; /* XXX how long should we wait? */ 89 for (;;) { 90 if (((*sc->sc_mcread)(sc, MC_REGA) & MC_REGA_UIP) == 0) 91 break; 92 if (--timeout < 0) { 93 printf("%s: timeout\n", __func__); 94 return EBUSY; 95 } 96 } 97 98 #define FROMREG(x) ((sc->sc_flag & MC146818_BCD) ? bcdtobin(x) : (x)) 99 100 dt->dt_sec = FROMREG((*sc->sc_mcread)(sc, MC_SEC)); 101 dt->dt_min = FROMREG((*sc->sc_mcread)(sc, MC_MIN)); 102 dt->dt_hour = FROMREG((*sc->sc_mcread)(sc, MC_HOUR)); 103 dt->dt_wday = FROMREG((*sc->sc_mcread)(sc, MC_DOW)); 104 dt->dt_day = FROMREG((*sc->sc_mcread)(sc, MC_DOM)); 105 dt->dt_mon = FROMREG((*sc->sc_mcread)(sc, MC_MONTH)); 106 year = FROMREG((*sc->sc_mcread)(sc, MC_YEAR)); 107 if (sc->sc_getcent) { 108 cent = (*sc->sc_getcent)(sc); 109 year += cent * 100; 110 } 111 112 #undef FROMREG 113 114 year += sc->sc_year0; 115 if (year < POSIX_BASE_YEAR && 116 (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0) 117 year += 100; 118 dt->dt_year = year; 119 120 splx(s); 121 122 return 0; 123 } 124 125 /* 126 * todr_settime function: 127 * Set the time of day clock based on the value of the struct timeval arg. 128 * Return 0 on success, an error number othersize. 129 */ 130 int 131 mc146818_settime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt) 132 { 133 struct mc146818_softc *sc; 134 int s, cent, year; 135 136 sc = handle->cookie; 137 138 s = splclock(); /* XXX really needed? */ 139 140 /* 141 * Disable RTC updates during clock updates 142 */ 143 144 (*sc->sc_mcwrite)(sc, MC_REGB, 145 (*sc->sc_mcread)(sc, MC_REGB) | MC_REGB_SET); 146 147 #define TOREG(x) ((sc->sc_flag & MC146818_BCD) ? bintobcd(x) : (x)) 148 149 (*sc->sc_mcwrite)(sc, MC_SEC, TOREG(dt->dt_sec)); 150 (*sc->sc_mcwrite)(sc, MC_MIN, TOREG(dt->dt_min)); 151 (*sc->sc_mcwrite)(sc, MC_HOUR, TOREG(dt->dt_hour)); 152 (*sc->sc_mcwrite)(sc, MC_DOW, TOREG(dt->dt_wday)); 153 (*sc->sc_mcwrite)(sc, MC_DOM, TOREG(dt->dt_day)); 154 (*sc->sc_mcwrite)(sc, MC_MONTH, TOREG(dt->dt_mon)); 155 156 year = dt->dt_year - sc->sc_year0; 157 if (sc->sc_setcent) { 158 cent = year / 100; 159 (*sc->sc_setcent)(sc, cent); 160 year -= cent * 100; 161 } 162 if (year > 99 && 163 (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0) 164 year -= 100; 165 (*sc->sc_mcwrite)(sc, MC_YEAR, TOREG(year)); 166 167 #undef TOREG 168 169 /* 170 * Re-enable RTC updates 171 */ 172 173 (*sc->sc_mcwrite)(sc, MC_REGB, 174 (*sc->sc_mcread)(sc, MC_REGB) & ~MC_REGB_SET); 175 176 splx(s); 177 178 return 0; 179 } 180