cmos.c revision 1.12
1/* $NetBSD: cmos.c,v 1.12 2015/08/20 14:40:16 christos 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 1.12 2015/08/20 14:40:16 christos 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 <sys/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#include "ioconf.h" 83 84#define CMOS_SUM 32 85#define CMOS_BIOSSPEC 34 /* start of BIOS-specific configuration data */ 86 87#define NVRAM_SUM (MC_NVRAM_START + CMOS_SUM) 88#define NVRAM_BIOSSPEC (MC_NVRAM_START + CMOS_BIOSSPEC) 89 90#define CMOS_SIZE NVRAM_BIOSSPEC 91 92dev_type_open(cmos_open); 93dev_type_read(cmos_read); 94dev_type_write(cmos_write); 95 96static void cmos_sum(uint8_t *, int, int, int); 97 98const struct cdevsw cmos_cdevsw = { 99 .d_open = cmos_open, 100 .d_close = nullclose, 101 .d_read = cmos_read, 102 .d_write = cmos_write, 103 .d_ioctl = noioctl, 104 .d_stop = nostop, 105 .d_tty = notty, 106 .d_poll = nopoll, 107 .d_mmap = nommap, 108 .d_kqfilter = nokqfilter, 109 .d_discard = nodiscard, 110 .d_flag = D_OTHER | D_MPSAFE 111}; 112 113static kmutex_t cmos_lock; 114static uint8_t cmos_buf[CMOS_SIZE]; 115 116void 117cmosattach(int n) 118{ 119 120 mutex_init(&cmos_lock, MUTEX_DEFAULT, IPL_NONE); 121} 122 123int 124cmos_open(dev_t dev, int flags, int ifmt, struct lwp *l) 125{ 126 127 return kauth_authorize_machdep(kauth_cred_get(), 128 KAUTH_MACHDEP_NVRAM, NULL, NULL, NULL, NULL); 129} 130 131static void 132cmos_fetch(void) 133{ 134 int i, s; 135 uint8_t *p; 136 137 p = cmos_buf; 138 s = splclock(); 139 for (i = 0; i < CMOS_SIZE; i++) 140 *p++ = mc146818_read(NULL, i); 141 splx(s); 142} 143 144int 145cmos_read(dev_t dev, struct uio *uio, int ioflag) 146{ 147 int error; 148 149 if (uio->uio_offset + uio->uio_resid > CMOS_SIZE) 150 return EINVAL; 151 152 mutex_enter(&cmos_lock); 153 cmos_fetch(); 154 error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio); 155 mutex_exit(&cmos_lock); 156 157 return error; 158} 159 160int 161cmos_write(dev_t dev, struct uio *uio, int ioflag) 162{ 163 int error = 0, i, s; 164 165 if (uio->uio_offset + uio->uio_resid > CMOS_SIZE) 166 return EINVAL; 167 168 mutex_enter(&cmos_lock); 169 cmos_fetch(); 170 error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio); 171 if (error == 0) { 172 cmos_sum(cmos_buf, NVRAM_DISKETTE, NVRAM_SUM, NVRAM_SUM); 173 s = splclock(); 174 for (i = NVRAM_DISKETTE; i < CMOS_SIZE; i++) 175 mc146818_write(NULL, i, cmos_buf[i]); 176 splx(s); 177 } 178 mutex_exit(&cmos_lock); 179 180 return error; 181} 182 183static void 184cmos_sum(uint8_t *p, int from, int to, int offset) 185{ 186 int i; 187 uint16_t sum; 188 189#ifdef CMOS_DEBUG 190 printf("%s: from %d to %d and store %d\n", __func__, from, to, offset); 191#endif 192 193 sum = 0; 194 for (i = from; i < to; i++) 195 sum += p[i]; 196 p[offset] = sum >> 8; 197 p[offset + 1] = sum & 0xff; 198} 199