1 /* $NetBSD: cmos.c,v 1.13 2021/09/21 14:36:34 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 1.13 2021/09/21 14:36:34 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
92 dev_type_open(cmos_open);
93 dev_type_read(cmos_read);
94 dev_type_write(cmos_write);
95
96 static void cmos_sum(uint8_t *, int, int, int);
97
98 const 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
113 static kmutex_t cmos_lock;
114 static uint8_t cmos_buf[CMOS_SIZE];
115
116 void
cmosattach(int n)117 cmosattach(int n)
118 {
119
120 mutex_init(&cmos_lock, MUTEX_DEFAULT, IPL_NONE);
121 }
122
123 int
cmos_open(dev_t dev,int flags,int ifmt,struct lwp * l)124 cmos_open(dev_t dev, int flags, int ifmt, struct lwp *l)
125 {
126
127 return kauth_authorize_machdep(l->l_cred,
128 KAUTH_MACHDEP_NVRAM, NULL, NULL, NULL, NULL);
129 }
130
131 static void
cmos_fetch(void)132 cmos_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
144 int
cmos_read(dev_t dev,struct uio * uio,int ioflag)145 cmos_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
160 int
cmos_write(dev_t dev,struct uio * uio,int ioflag)161 cmos_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
183 static void
cmos_sum(uint8_t * p,int from,int to,int offset)184 cmos_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