cmos.c revision 1.6
1/* $NetBSD: cmos.c,v 1.6 2008/06/28 15:09:49 ad 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 * 3. The name of David Young may not be used to endorse or promote 47 * products derived from this software without specific prior 48 * written permission. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 51 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 52 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 53 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE 54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 55 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 56 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 57 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 58 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 59 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 60 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 61 * SUCH DAMAGE. 62 */ 63 64#include <sys/cdefs.h> 65__KERNEL_RCSID(0, "$NetBSD: cmos.c,v 1.6 2008/06/28 15:09:49 ad Exp $"); 66 67#include <sys/param.h> 68#include <sys/systm.h> 69#include <sys/kernel.h> 70#include <sys/malloc.h> 71#include <sys/ioctl.h> 72#include <sys/proc.h> 73#include <sys/device.h> 74#include <sys/conf.h> 75#include <sys/kauth.h> 76 77#include <machine/bus.h> 78#include <machine/intr.h> 79 80#include <dev/isa/isareg.h> 81#include <dev/isa/isavar.h> 82#include <dev/ic/mc146818reg.h> 83#include <i386/isa/nvram.h> 84 85#define CMOS_SUM 32 86#define CMOS_BIOSSPEC 34 /* start of BIOS-specific configuration data */ 87 88#define NVRAM_SUM (MC_NVRAM_START + CMOS_SUM) 89#define NVRAM_BIOSSPEC (MC_NVRAM_START + CMOS_BIOSSPEC) 90 91#define CMOS_SIZE NVRAM_BIOSSPEC 92 93void cmosattach(int); 94dev_type_open(cmos_open); 95dev_type_read(cmos_read); 96dev_type_write(cmos_write); 97 98static void cmos_sum(uint8_t *, int, int, int); 99 100const struct cdevsw cmos_cdevsw = { 101 .d_open = cmos_open, .d_close = nullclose, .d_read = cmos_read, 102 .d_write = cmos_write, .d_ioctl = noioctl, 103 .d_stop = nostop, .d_tty = notty, .d_poll = nopoll, .d_mmap = nommap, 104 .d_kqfilter = nokqfilter, .d_flag = D_OTHER | D_MPSAFE 105}; 106 107static kmutex_t cmos_lock; 108static uint8_t cmos_buf[CMOS_SIZE]; 109 110void 111cmosattach(int n) 112{ 113 114 mutex_init(&cmos_lock, MUTEX_DEFAULT, IPL_NONE); 115} 116 117int 118cmos_open(dev_t dev, int flags, int ifmt, struct lwp *l) 119{ 120 121 return kauth_authorize_generic(kauth_cred_get(), 122 KAUTH_GENERIC_ISSUSER, NULL); 123} 124 125static void 126cmos_fetch(void) 127{ 128 int i, s; 129 uint8_t *p; 130 131 p = cmos_buf; 132 s = splclock(); 133 for (i = 0; i < CMOS_SIZE; i++) 134 *p++ = mc146818_read(NULL, i); 135 splx(s); 136} 137 138int 139cmos_read(dev_t dev, struct uio *uio, int ioflag) 140{ 141 int error; 142 143 if (uio->uio_offset + uio->uio_resid > CMOS_SIZE) 144 return EINVAL; 145 146 mutex_enter(&cmos_lock); 147 cmos_fetch(); 148 error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio); 149 mutex_exit(&cmos_lock); 150 151 return error; 152} 153 154int 155cmos_write(dev_t dev, struct uio *uio, int ioflag) 156{ 157 int error = 0, i, s; 158 159 if (uio->uio_offset + uio->uio_resid > CMOS_SIZE) 160 return EINVAL; 161 162 mutex_enter(&cmos_lock); 163 cmos_fetch(); 164 error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio); 165 if (error == 0) { 166 cmos_sum(cmos_buf, NVRAM_DISKETTE, NVRAM_SUM, NVRAM_SUM); 167 s = splclock(); 168 for (i = NVRAM_DISKETTE; i < CMOS_SIZE; i++) 169 mc146818_write(NULL, i, cmos_buf[i]); 170 splx(s); 171 } 172 mutex_exit(&cmos_lock); 173 174 return error; 175} 176 177static void 178cmos_sum(uint8_t *p, int from, int to, int offset) 179{ 180 int i; 181 uint16_t sum; 182 183#ifdef CMOS_DEBUG 184 printf("%s: from %d to %d and store %d\n", __func__, from, to, offset); 185#endif 186 187 sum = 0; 188 for (i = from; i < to; i++) 189 sum += p[i]; 190 p[offset] = sum >> 8; 191 p[offset + 1] = sum & 0xff; 192} 193