mc146818.c revision 1.22
1 /* $NetBSD: mc146818.c,v 1.22 2025/09/07 21:45:16 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 1.22 2025/09/07 21:45:16 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->todr_dev = sc->sc_dev; 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 = device_private(handle->todr_dev); 82 int s, timeout, cent, year; 83 84 s = splclock(); /* XXX really needed? */ 85 86 timeout = 1000000; /* XXX how long should we wait? */ 87 for (;;) { 88 if (((*sc->sc_mcread)(sc, MC_REGA) & MC_REGA_UIP) == 0) 89 break; 90 if (--timeout < 0) { 91 printf("%s: timeout\n", __func__); 92 return EBUSY; 93 } 94 } 95 96 #define FROMREG(x) ((sc->sc_flag & MC146818_BCD) ? bcdtobin(x) : (x)) 97 98 dt->dt_sec = FROMREG((*sc->sc_mcread)(sc, MC_SEC)); 99 dt->dt_min = FROMREG((*sc->sc_mcread)(sc, MC_MIN)); 100 dt->dt_hour = FROMREG((*sc->sc_mcread)(sc, MC_HOUR)); 101 dt->dt_wday = FROMREG((*sc->sc_mcread)(sc, MC_DOW)); 102 dt->dt_day = FROMREG((*sc->sc_mcread)(sc, MC_DOM)); 103 dt->dt_mon = FROMREG((*sc->sc_mcread)(sc, MC_MONTH)); 104 year = FROMREG((*sc->sc_mcread)(sc, MC_YEAR)); 105 if (sc->sc_getcent) { 106 cent = (*sc->sc_getcent)(sc); 107 year += cent * 100; 108 } 109 110 #undef FROMREG 111 112 year += sc->sc_year0; 113 if (year < POSIX_BASE_YEAR && 114 (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0) 115 year += 100; 116 dt->dt_year = year; 117 118 splx(s); 119 120 return 0; 121 } 122 123 /* 124 * todr_settime function: 125 * Set the time of day clock based on the value of the struct timeval arg. 126 * Return 0 on success, an error number othersize. 127 */ 128 int 129 mc146818_settime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt) 130 { 131 struct mc146818_softc *sc = device_private(handle->todr_dev); 132 int s, cent, year; 133 134 s = splclock(); /* XXX really needed? */ 135 136 /* 137 * Disable RTC updates during clock updates 138 */ 139 140 (*sc->sc_mcwrite)(sc, MC_REGB, 141 (*sc->sc_mcread)(sc, MC_REGB) | MC_REGB_SET); 142 143 #define TOREG(x) ((sc->sc_flag & MC146818_BCD) ? bintobcd(x) : (x)) 144 145 (*sc->sc_mcwrite)(sc, MC_SEC, TOREG(dt->dt_sec)); 146 (*sc->sc_mcwrite)(sc, MC_MIN, TOREG(dt->dt_min)); 147 (*sc->sc_mcwrite)(sc, MC_HOUR, TOREG(dt->dt_hour)); 148 (*sc->sc_mcwrite)(sc, MC_DOW, TOREG(dt->dt_wday)); 149 (*sc->sc_mcwrite)(sc, MC_DOM, TOREG(dt->dt_day)); 150 (*sc->sc_mcwrite)(sc, MC_MONTH, TOREG(dt->dt_mon)); 151 152 year = dt->dt_year - sc->sc_year0; 153 if (sc->sc_setcent) { 154 cent = year / 100; 155 (*sc->sc_setcent)(sc, cent); 156 year -= cent * 100; 157 } 158 if (year > 99 && 159 (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0) 160 year -= 100; 161 (*sc->sc_mcwrite)(sc, MC_YEAR, TOREG(year)); 162 163 #undef TOREG 164 165 /* 166 * Re-enable RTC updates 167 */ 168 169 (*sc->sc_mcwrite)(sc, MC_REGB, 170 (*sc->sc_mcread)(sc, MC_REGB) & ~MC_REGB_SET); 171 172 splx(s); 173 174 return 0; 175 } 176
Indexes created Wed Sep 24 15:09:51 GMT 2025