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