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cmos.c revision 1.9
      1 /*	$NetBSD: cmos.c,v 1.9 2011/07/01 18:11:24 dyoung 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 1.9 2011/07/01 18:11:24 dyoung 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 #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 }
    190