sys/arch/i386/isa/cmos.c

   1 /*      $NetBSD: cmos.c,v 1.7 2009/04/15 20:44:26 elad Exp $    */
   2
   3 /*
   4  * Copyright (C) 2003 JONE System Co., Inc.
   5  * All right reserved.
   6  *
   7  * Copyright (C) 1999, 2000, 2001, 2002 JEPRO Co., Ltd.
   8  * All right reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  */
  33 /*
  34  * Copyright (c) 2007 David Young.  All right reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or
  37  * without modification, are permitted provided that the following
  38  * conditions are met:
  39  *
  40  * 1. Redistributions of source code must retain the above copyright
  41  *    notice, this list of conditions and the following disclaimer.
  42  * 2. Redistributions in binary form must reproduce the above
  43  *    copyright notice, this list of conditions and the following
  44  *    disclaimer in the documentation and/or other materials provided
  45  *    with the distribution.
  46  *
  47  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
  48  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  49  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  50  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
  51  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  52  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  53  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  54  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  55  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  56  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  57  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  */
  60
  61 #include <sys/cdefs.h>
  62 __KERNEL_RCSID(0, "$NetBSD: cmos.c,v 1.7 2009/04/15 20:44:26 elad Exp $");
  63
  64 #include <sys/param.h>
  65 #include <sys/systm.h>
  66 #include <sys/kernel.h>
  67 #include <sys/malloc.h>
  68 #include <sys/ioctl.h>
  69 #include <sys/proc.h>
  70 #include <sys/device.h>
  71 #include <sys/conf.h>
  72 #include <sys/kauth.h>
  73
  74 #include <machine/bus.h>
  75 #include <machine/intr.h>
  76
  77 #include <dev/isa/isareg.h>
  78 #include <dev/isa/isavar.h>
  79 #include <dev/ic/mc146818reg.h>
  80 #include <i386/isa/nvram.h>
  81
  82 #define CMOS_SUM        32
  83 #define CMOS_BIOSSPEC   34      /* start of BIOS-specific configuration data */
  84
  85 #define NVRAM_SUM       (MC_NVRAM_START + CMOS_SUM)
  86 #define NVRAM_BIOSSPEC  (MC_NVRAM_START + CMOS_BIOSSPEC)
  87
  88 #define CMOS_SIZE       NVRAM_BIOSSPEC
  89
  90 void cmosattach(int);
  91 dev_type_open(cmos_open);
  92 dev_type_read(cmos_read);
  93 dev_type_write(cmos_write);
  94
  95 static void cmos_sum(uint8_t *, int, int, int);
  96
  97 const struct cdevsw cmos_cdevsw = {
  98         .d_open = cmos_open, .d_close = nullclose, .d_read = cmos_read,
  99         .d_write = cmos_write, .d_ioctl = noioctl,
 100         .d_stop = nostop, .d_tty = notty, .d_poll = nopoll, .d_mmap = nommap,
 101         .d_kqfilter = nokqfilter, .d_flag = D_OTHER | D_MPSAFE
 102 };
 103
 104 static kmutex_t cmos_lock;
 105 static uint8_t cmos_buf[CMOS_SIZE];
 106
 107 void
 108 cmosattach(int n)
 109 {
 110
 111         mutex_init(&cmos_lock, MUTEX_DEFAULT, IPL_NONE);
 112 }
 113
 114 int
 115 cmos_open(dev_t dev, int flags, int ifmt, struct lwp *l)
 116 {
 117
 118         return kauth_authorize_machdep(kauth_cred_get(),
 119             KAUTH_MACHDEP_NVRAM, NULL, NULL, NULL, NULL);
 120 }
 121
 122 static void
 123 cmos_fetch(void)
 124 {
 125         int i, s;
 126         uint8_t *p;
 127
 128         p = cmos_buf;
 129         s = splclock();
 130         for (i = 0; i < CMOS_SIZE; i++)
 131                 *p++ = mc146818_read(NULL, i);
 132         splx(s);
 133 }
 134
 135 int
 136 cmos_read(dev_t dev, struct uio *uio, int ioflag)
 137 {
 138         int error;
 139
 140         if (uio->uio_offset + uio->uio_resid > CMOS_SIZE)
 141                 return EINVAL;
 142
 143         mutex_enter(&cmos_lock);
 144         cmos_fetch();
 145         error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio);
 146         mutex_exit(&cmos_lock);
 147
 148         return error;
 149 }
 150
 151 int
 152 cmos_write(dev_t dev, struct uio *uio, int ioflag)
 153 {
 154         int error = 0, i, s;
 155
 156         if (uio->uio_offset + uio->uio_resid > CMOS_SIZE)
 157                 return EINVAL;
 158
 159         mutex_enter(&cmos_lock);
 160         cmos_fetch();
 161         error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio);
 162         if (error == 0) {
 163                 cmos_sum(cmos_buf, NVRAM_DISKETTE, NVRAM_SUM, NVRAM_SUM);
 164                 s = splclock();
 165                 for (i = NVRAM_DISKETTE; i < CMOS_SIZE; i++)
 166                         mc146818_write(NULL, i, cmos_buf[i]);
 167                 splx(s);
 168         }
 169         mutex_exit(&cmos_lock);
 170
 171         return error;
 172 }
 173
 174 static void
 175 cmos_sum(uint8_t *p, int from, int to, int offset)
 176 {
 177         int i;
 178         uint16_t sum;
 179
 180 #ifdef CMOS_DEBUG
 181         printf("%s: from %d to %d and store %d\n", __func__, from, to, offset);
 182 #endif
 183
 184         sum = 0;
 185         for (i = from; i < to; i++)
 186                 sum += p[i];
 187         p[offset] = sum >> 8;
 188         p[offset + 1] = sum & 0xff;
 189 }