1 /* $NetBSD: cmos.c,v 1.14 2023/12/20 15:00:07 thorpej 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 1.14 2023/12/20 15:00:07 thorpej Exp $");
63
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/kernel.h>
67 #include <sys/ioctl.h>
68 #include <sys/proc.h>
69 #include <sys/device.h>
70 #include <sys/conf.h>
71 #include <sys/kauth.h>
72
73 #include <sys/bus.h>
74 #include <machine/intr.h>
75
76 #include <dev/isa/isareg.h>
77 #include <dev/isa/isavar.h>
78 #include <dev/ic/mc146818reg.h>
79 #include <i386/isa/nvram.h>
80
81 #include "ioconf.h"
82
83 #define CMOS_SUM 32
84 #define CMOS_BIOSSPEC 34 /* start of BIOS-specific configuration data */
85
86 #define NVRAM_SUM (MC_NVRAM_START + CMOS_SUM)
87 #define NVRAM_BIOSSPEC (MC_NVRAM_START + CMOS_BIOSSPEC)
88
89 #define CMOS_SIZE NVRAM_BIOSSPEC
90
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,
99 .d_close = nullclose,
100 .d_read = cmos_read,
101 .d_write = cmos_write,
102 .d_ioctl = noioctl,
103 .d_stop = nostop,
104 .d_tty = notty,
105 .d_poll = nopoll,
106 .d_mmap = nommap,
107 .d_kqfilter = nokqfilter,
108 .d_discard = nodiscard,
109 .d_flag = D_OTHER | D_MPSAFE
110 };
111
112 static kmutex_t cmos_lock;
113 static uint8_t cmos_buf[CMOS_SIZE];
114
115 void
cmosattach(int n)116 cmosattach(int n)
117 {
118
119 mutex_init(&cmos_lock, MUTEX_DEFAULT, IPL_NONE);
120 }
121
122 int
cmos_open(dev_t dev,int flags,int ifmt,struct lwp * l)123 cmos_open(dev_t dev, int flags, int ifmt, struct lwp *l)
124 {
125
126 return kauth_authorize_machdep(l->l_cred,
127 KAUTH_MACHDEP_NVRAM, NULL, NULL, NULL, NULL);
128 }
129
130 static void
cmos_fetch(void)131 cmos_fetch(void)
132 {
133 int i, s;
134 uint8_t *p;
135
136 p = cmos_buf;
137 s = splclock();
138 for (i = 0; i < CMOS_SIZE; i++)
139 *p++ = mc146818_read(NULL, i);
140 splx(s);
141 }
142
143 int
cmos_read(dev_t dev,struct uio * uio,int ioflag)144 cmos_read(dev_t dev, struct uio *uio, int ioflag)
145 {
146 int error;
147
148 if (uio->uio_offset + uio->uio_resid > CMOS_SIZE)
149 return EINVAL;
150
151 mutex_enter(&cmos_lock);
152 cmos_fetch();
153 error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio);
154 mutex_exit(&cmos_lock);
155
156 return error;
157 }
158
159 int
cmos_write(dev_t dev,struct uio * uio,int ioflag)160 cmos_write(dev_t dev, struct uio *uio, int ioflag)
161 {
162 int error = 0, i, s;
163
164 if (uio->uio_offset + uio->uio_resid > CMOS_SIZE)
165 return EINVAL;
166
167 mutex_enter(&cmos_lock);
168 cmos_fetch();
169 error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio);
170 if (error == 0) {
171 cmos_sum(cmos_buf, NVRAM_DISKETTE, NVRAM_SUM, NVRAM_SUM);
172 s = splclock();
173 for (i = NVRAM_DISKETTE; i < CMOS_SIZE; i++)
174 mc146818_write(NULL, i, cmos_buf[i]);
175 splx(s);
176 }
177 mutex_exit(&cmos_lock);
178
179 return error;
180 }
181
182 static void
cmos_sum(uint8_t * p,int from,int to,int offset)183 cmos_sum(uint8_t *p, int from, int to, int offset)
184 {
185 int i;
186 uint16_t sum;
187
188 #ifdef CMOS_DEBUG
189 printf("%s: from %d to %d and store %d\n", __func__, from, to, offset);
190 #endif
191
192 sum = 0;
193 for (i = from; i < to; i++)
194 sum += p[i];
195 p[offset] = sum >> 8;
196 p[offset + 1] = sum & 0xff;
197 }
198