1 /* $NetBSD: nvram.c,v 1.23 2023/01/06 10:28:28 tsutsui Exp $ */
2
3 /*
4 * Copyright (c) 1995 Leo Weppelman.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 /*
29 * Nvram driver
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: nvram.c,v 1.23 2023/01/06 10:28:28 tsutsui Exp $");
34
35 #include <sys/param.h>
36 #include <sys/conf.h>
37 #include <sys/kernel.h>
38 #include <sys/proc.h>
39 #include <sys/systm.h>
40 #include <sys/device.h>
41 #include <sys/buf.h>
42 #include <sys/uio.h>
43
44 #include <machine/iomap.h>
45 #include <machine/cpu.h>
46
47 #include <atari/dev/clockreg.h>
48 #include <atari/dev/nvramvar.h>
49
50 #include "ioconf.h"
51
52 #include "nvr.h"
53
54 #ifdef NVRAM_DEBUG
55 #define DPRINTF(a) printf a
56 #else
57 #define DPRINTF(a)
58 #endif
59
60 #define MC_NVRAM_CSUM (MC_NVRAM_START + MC_NVRAM_SIZE - 2)
61
62 #if NNVR > 0
63 static void nvram_set_csum(u_char csum);
64 static int nvram_csum_valid(u_char csum);
65 static u_char nvram_csum(void);
66
67 /*
68 * Auto config stuff....
69 */
70 static void nvr_attach(device_t, device_t, void *);
71 static int nvr_match(device_t, cfdata_t, void *);
72
73 CFATTACH_DECL_NEW(nvr, sizeof(struct nvr_softc),
74 nvr_match, nvr_attach, NULL, NULL);
75
76 /*ARGSUSED*/
77 static int
nvr_match(device_t parent,cfdata_t cf,void * aux)78 nvr_match(device_t parent, cfdata_t cf, void *aux)
79 {
80
81 if (!strcmp((char *)aux, "nvr"))
82 return 1;
83 return 0;
84 }
85
86 /*ARGSUSED*/
87 static void
nvr_attach(device_t parent,device_t self,void * aux)88 nvr_attach(device_t parent, device_t self, void *aux)
89 {
90 struct nvr_softc *sc;
91 int nreg;
92
93 /*
94 * Check the validity of the NVram contents
95 */
96 /* XXX: Milan's firmware seems to use different check method */
97 if ((machineid & ATARI_MILAN) == 0) {
98 if (!nvram_csum_valid(nvram_csum())) {
99 aprint_error(": Invalid checksum - re-initialized");
100 for (nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM;
101 nreg++)
102 mc146818_write(RTC, nreg, 0);
103 nvram_set_csum(nvram_csum());
104 }
105 }
106 sc = device_private(self);
107 sc->sc_dev = self;
108 sc->sc_flags = NVR_CONFIGURED;
109 aprint_normal("\n");
110 }
111 /*
112 * End of auto config stuff....
113 */
114 #endif /* NNVR > 0 */
115
116 /*
117 * Kernel internal interface
118 */
119 int
nvr_get_byte(int byteno)120 nvr_get_byte(int byteno)
121 {
122 #if NNVR > 0
123 struct nvr_softc *sc;
124
125 sc = device_lookup_private(&nvr_cd, 0);
126 if ((sc->sc_flags & NVR_CONFIGURED) == 0)
127 return NVR_INVALID;
128 return mc146818_read(RTC, byteno + MC_NVRAM_START) & 0xff;
129 #else
130 return NVR_INVALID;
131 #endif /* NNVR > 0 */
132 }
133
134 #if NNVR > 0
135
136 int
nvram_uio(struct uio * uio)137 nvram_uio(struct uio *uio)
138 {
139 int i;
140 off_t offset;
141 int nleft;
142 uint8_t buf[MC_NVRAM_CSUM - MC_NVRAM_START + 1];
143 uint8_t *p;
144 struct nvr_softc *sc;
145
146 sc = device_lookup_private(&nvr_cd,0);
147 if ((sc->sc_flags & NVR_CONFIGURED) == 0)
148 return ENXIO;
149
150 DPRINTF(("Request to transfer %d bytes offset: %d, %s nvram\n",
151 (long)uio->uio_resid, (long)uio->uio_offset,
152 (uio->uio_rw == UIO_READ) ? "from" : "to"));
153
154 offset = uio->uio_offset + MC_NVRAM_START;
155 nleft = uio->uio_resid;
156 if (offset + nleft >= MC_NVRAM_CSUM) {
157 if (offset == MC_NVRAM_CSUM)
158 return 0;
159 nleft = MC_NVRAM_CSUM - offset;
160 if (nleft <= 0)
161 return EINVAL;
162 }
163 DPRINTF(("Translated: offset = %d, bytes: %d\n", (long)offset, nleft));
164
165 if (uio->uio_rw == UIO_READ) {
166 for (i = 0, p = buf; i < nleft; i++, p++)
167 *p = mc146818_read(RTC, offset + i);
168 }
169 if ((i = uiomove(buf, nleft, uio)) != 0)
170 return i;
171 if (uio->uio_rw == UIO_WRITE) {
172 for (i = 0, p = buf; i < nleft; i++, p++)
173 mc146818_write(RTC, offset + i, *p);
174 nvram_set_csum(nvram_csum());
175 }
176 return 0;
177 }
178
179 static u_char
nvram_csum(void)180 nvram_csum(void)
181 {
182 uint8_t csum;
183 int nreg;
184
185 for (csum = 0, nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; nreg++)
186 csum += mc146818_read(RTC, nreg);
187 return csum;
188 }
189
190 static int
nvram_csum_valid(u_char csum)191 nvram_csum_valid(u_char csum)
192 {
193
194 if (((~csum & 0xff) != mc146818_read(RTC, MC_NVRAM_CSUM))
195 || (csum != mc146818_read(RTC, MC_NVRAM_CSUM + 1)))
196 return 0;
197 return 1;
198 }
199
200 static void
nvram_set_csum(u_char csum)201 nvram_set_csum(u_char csum)
202 {
203
204 mc146818_write(RTC, MC_NVRAM_CSUM, ~csum);
205 mc146818_write(RTC, MC_NVRAM_CSUM + 1, csum);
206 }
207 #endif /* NNVR > 0 */
208