sys/dev/ic/mc146818.c

   1 /*      $NetBSD: mc146818.c,v 1.17 2008/12/11 00:17:21 kenh 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 1.17 2008/12/11 00:17:21 kenh 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 int mc146818_gettime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
  47 int mc146818_settime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
  48
  49 void
  50 mc146818_attach(struct mc146818_softc *sc)
  51 {
  52         todr_chip_handle_t handle;
  53
  54 #ifdef DIAGNOSTIC
  55         if (sc->sc_mcread == NULL ||
  56             sc->sc_mcwrite == NULL)
  57                 panic("%s: invalid read/write functions", __func__);
  58 #endif
  59
  60         aprint_normal(": mc146818 compatible time-of-day clock");
  61
  62         handle = &sc->sc_handle;
  63         handle->cookie = sc;
  64         handle->todr_gettime = NULL;
  65         handle->todr_settime = NULL;
  66         handle->todr_gettime_ymdhms = mc146818_gettime_ymdhms;
  67         handle->todr_settime_ymdhms = mc146818_settime_ymdhms;
  68         handle->todr_setwen  = NULL;
  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         todr_wenable(handle, 1);
  89
  90         timeout = 1000000;      /* XXX how long should we wait? */
  91         for (;;) {
  92                 if (((*sc->sc_mcread)(sc, MC_REGA) & MC_REGA_UIP) == 0)
  93                         break;
  94                 if (--timeout < 0) {
  95                         printf("%s: timeout\n", __func__);
  96                         return EBUSY;
  97                 }
  98         }
  99
 100 #define FROMREG(x)      ((sc->sc_flag & MC146818_BCD) ? FROMBCD(x) : (x))
 101
 102         dt->dt_sec  = FROMREG((*sc->sc_mcread)(sc, MC_SEC));
 103         dt->dt_min  = FROMREG((*sc->sc_mcread)(sc, MC_MIN));
 104         dt->dt_hour = FROMREG((*sc->sc_mcread)(sc, MC_HOUR));
 105         dt->dt_wday = FROMREG((*sc->sc_mcread)(sc, MC_DOW));
 106         dt->dt_day  = FROMREG((*sc->sc_mcread)(sc, MC_DOM));
 107         dt->dt_mon  = FROMREG((*sc->sc_mcread)(sc, MC_MONTH));
 108         year       = FROMREG((*sc->sc_mcread)(sc, MC_YEAR));
 109         if (sc->sc_getcent) {
 110                 cent = (*sc->sc_getcent)(sc);
 111                 year += cent * 100;
 112         }
 113
 114 #undef FROMREG
 115
 116         year += sc->sc_year0;
 117         if (year < POSIX_BASE_YEAR &&
 118             (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0)
 119                 year += 100;
 120         dt->dt_year = year;
 121
 122         todr_wenable(handle, 0);
 123
 124         splx(s);
 125
 126         return 0;
 127 }
 128
 129 /*
 130  * todr_settime function:
 131  *  Set the time of day clock based on the value of the struct timeval arg.
 132  *  Return 0 on success, an error number othersize.
 133  */
 134 int
 135 mc146818_settime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt)
 136 {
 137         struct mc146818_softc *sc;
 138         int s, cent, year;
 139
 140         sc = handle->cookie;
 141
 142         s = splclock();         /* XXX really needed? */
 143
 144         todr_wenable(handle, 1);
 145
 146         /*
 147          * Disable RTC updates during clock updates
 148          */
 149
 150         (*sc->sc_mcwrite)(sc, MC_REGB,
 151             (*sc->sc_mcread)(sc, MC_REGB) | MC_REGB_SET);
 152
 153 #define TOREG(x)        ((sc->sc_flag & MC146818_BCD) ? TOBCD(x) : (x))
 154
 155         (*sc->sc_mcwrite)(sc, MC_SEC, TOREG(dt->dt_sec));
 156         (*sc->sc_mcwrite)(sc, MC_MIN, TOREG(dt->dt_min));
 157         (*sc->sc_mcwrite)(sc, MC_HOUR, TOREG(dt->dt_hour));
 158         (*sc->sc_mcwrite)(sc, MC_DOW, TOREG(dt->dt_wday));
 159         (*sc->sc_mcwrite)(sc, MC_DOM, TOREG(dt->dt_day));
 160         (*sc->sc_mcwrite)(sc, MC_MONTH, TOREG(dt->dt_mon));
 161
 162         year = dt->dt_year - sc->sc_year0;
 163         if (sc->sc_setcent) {
 164                 cent = year / 100;
 165                 (*sc->sc_setcent)(sc, cent);
 166                 year -= cent * 100;
 167         }
 168         if (year > 99 &&
 169             (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0)
 170                 year -= 100;
 171         (*sc->sc_mcwrite)(sc, MC_YEAR, TOREG(year));
 172
 173 #undef TOREG
 174
 175         /*
 176          * Re-enable RTC updates
 177          */
 178
 179         (*sc->sc_mcwrite)(sc, MC_REGB,
 180             (*sc->sc_mcread)(sc, MC_REGB) & ~MC_REGB_SET);
 181
 182         todr_wenable(handle, 0);
 183
 184         splx(s);
 185
 186         return 0;
 187 }