eeprom.c revision 1.32 1 1.32 riastrad /* $NetBSD: eeprom.c,v 1.32 2018/09/03 16:29:28 riastradh Exp $ */
2 1.2 cgd
3 1.12 gwr /*-
4 1.12 gwr * Copyright (c) 1996 The NetBSD Foundation, Inc.
5 1.1 gwr * All rights reserved.
6 1.1 gwr *
7 1.12 gwr * This code is derived from software contributed to The NetBSD Foundation
8 1.12 gwr * by Gordon W. Ross.
9 1.12 gwr *
10 1.1 gwr * Redistribution and use in source and binary forms, with or without
11 1.1 gwr * modification, are permitted provided that the following conditions
12 1.1 gwr * are met:
13 1.1 gwr * 1. Redistributions of source code must retain the above copyright
14 1.1 gwr * notice, this list of conditions and the following disclaimer.
15 1.1 gwr * 2. Redistributions in binary form must reproduce the above copyright
16 1.1 gwr * notice, this list of conditions and the following disclaimer in the
17 1.1 gwr * documentation and/or other materials provided with the distribution.
18 1.1 gwr *
19 1.12 gwr * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 1.12 gwr * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 1.12 gwr * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 1.14 gwr * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 1.14 gwr * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 1.12 gwr * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 1.12 gwr * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 1.12 gwr * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 1.12 gwr * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 1.12 gwr * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 1.12 gwr * POSSIBILITY OF SUCH DAMAGE.
30 1.1 gwr */
31 1.1 gwr
32 1.1 gwr /*
33 1.1 gwr * Access functions for the EEPROM (Electrically Eraseable PROM)
34 1.1 gwr * The main reason for the existence of this module is to
35 1.1 gwr * handle the painful task of updating the EEPROM contents.
36 1.1 gwr * After a write, it must not be touched for 10 milliseconds.
37 1.1 gwr * (See the Sun-3 Architecture Manual sec. 5.9)
38 1.1 gwr */
39 1.25 lukem
40 1.25 lukem #include <sys/cdefs.h>
41 1.32 riastrad __KERNEL_RCSID(0, "$NetBSD: eeprom.c,v 1.32 2018/09/03 16:29:28 riastradh Exp $");
42 1.1 gwr
43 1.1 gwr #include <sys/param.h>
44 1.4 gwr #include <sys/systm.h>
45 1.4 gwr #include <sys/device.h>
46 1.1 gwr #include <sys/conf.h>
47 1.1 gwr #include <sys/buf.h>
48 1.1 gwr #include <sys/malloc.h>
49 1.13 gwr #include <sys/proc.h>
50 1.20 thorpej #include <sys/kernel.h>
51 1.1 gwr
52 1.4 gwr #include <machine/autoconf.h>
53 1.18 gwr #include <machine/idprom.h>
54 1.1 gwr #include <machine/eeprom.h>
55 1.1 gwr
56 1.18 gwr #ifndef EEPROM_SIZE
57 1.18 gwr #define EEPROM_SIZE 0x800
58 1.15 gwr #endif
59 1.1 gwr
60 1.18 gwr struct eeprom *eeprom_copy; /* soft copy. */
61 1.18 gwr
62 1.15 gwr static int ee_update(int off, int cnt);
63 1.1 gwr
64 1.31 tsutsui static uint8_t *eeprom_va; /* mapping to actual device */
65 1.18 gwr static int ee_size; /* size of usable part. */
66 1.18 gwr
67 1.18 gwr static int ee_busy, ee_want; /* serialization */
68 1.1 gwr
69 1.31 tsutsui static int eeprom_match(device_t, cfdata_t, void *);
70 1.31 tsutsui static void eeprom_attach(device_t, device_t, void *);
71 1.4 gwr
72 1.31 tsutsui CFATTACH_DECL_NEW(eeprom, 0,
73 1.24 thorpej eeprom_match, eeprom_attach, NULL, NULL);
74 1.4 gwr
75 1.26 chs static int
76 1.31 tsutsui eeprom_match(device_t parent, cfdata_t cf, void *args)
77 1.4 gwr {
78 1.4 gwr struct confargs *ca = args;
79 1.4 gwr
80 1.19 chs /* This driver only supports one instance. */
81 1.19 chs if (eeprom_va != NULL)
82 1.31 tsutsui return 0;
83 1.8 gwr
84 1.16 gwr if (bus_peek(ca->ca_bustype, ca->ca_paddr, 1) == -1)
85 1.31 tsutsui return 0;
86 1.8 gwr
87 1.31 tsutsui return 1;
88 1.4 gwr }
89 1.4 gwr
90 1.26 chs static void
91 1.31 tsutsui eeprom_attach(device_t parent, device_t self, void *args)
92 1.4 gwr {
93 1.16 gwr struct confargs *ca = args;
94 1.31 tsutsui uint8_t *src, *dst, *lim;
95 1.4 gwr
96 1.31 tsutsui aprint_normal("\n");
97 1.18 gwr #ifdef DIAGNOSTIC
98 1.18 gwr if (sizeof(struct eeprom) != EEPROM_SIZE)
99 1.18 gwr panic("eeprom struct wrong");
100 1.18 gwr #endif
101 1.16 gwr
102 1.18 gwr ee_size = EEPROM_SIZE;
103 1.18 gwr eeprom_va = bus_mapin(ca->ca_bustype, ca->ca_paddr, ee_size);
104 1.31 tsutsui if (eeprom_va == NULL)
105 1.31 tsutsui panic("%s: can't map va", __func__);
106 1.15 gwr
107 1.15 gwr /* Keep a "soft" copy of the EEPROM to make access simpler. */
108 1.18 gwr eeprom_copy = malloc(ee_size, M_DEVBUF, M_NOWAIT);
109 1.31 tsutsui if (eeprom_copy == NULL)
110 1.31 tsutsui panic("%s: malloc eeprom_copy", __func__);
111 1.18 gwr
112 1.18 gwr /*
113 1.18 gwr * On the 3/80, do not touch the last 40 bytes!
114 1.18 gwr * Writes there are ignored, reads show zero.
115 1.18 gwr * Reduce ee_size and clear the last part of the
116 1.18 gwr * soft copy. Note: ee_update obeys ee_size.
117 1.18 gwr */
118 1.27 thorpej if (cpu_machine_id == ID_SUN3X_80)
119 1.18 gwr ee_size -= 40;
120 1.15 gwr
121 1.15 gwr /* Do only byte access in the EEPROM. */
122 1.15 gwr src = eeprom_va;
123 1.31 tsutsui dst = (uint8_t *)eeprom_copy;
124 1.18 gwr lim = dst + ee_size;
125 1.18 gwr
126 1.31 tsutsui do {
127 1.31 tsutsui *dst++ = *src++;
128 1.31 tsutsui } while (dst < lim);
129 1.18 gwr
130 1.18 gwr if (ee_size < EEPROM_SIZE) {
131 1.18 gwr /* Clear out the last part. */
132 1.21 tsutsui memset(dst, 0, (EEPROM_SIZE - ee_size));
133 1.18 gwr }
134 1.4 gwr }
135 1.4 gwr
136 1.1 gwr
137 1.13 gwr /* Take the lock. */
138 1.13 gwr static int
139 1.26 chs ee_take(void)
140 1.1 gwr {
141 1.1 gwr int error = 0;
142 1.26 chs
143 1.1 gwr while (ee_busy) {
144 1.1 gwr ee_want = 1;
145 1.1 gwr error = tsleep(&ee_busy, PZERO | PCATCH, "eeprom", 0);
146 1.1 gwr ee_want = 0;
147 1.1 gwr if (error) /* interrupted */
148 1.15 gwr return error;
149 1.1 gwr }
150 1.1 gwr ee_busy = 1;
151 1.1 gwr return error;
152 1.1 gwr }
153 1.1 gwr
154 1.13 gwr /* Give the lock. */
155 1.13 gwr static void
156 1.26 chs ee_give(void)
157 1.1 gwr {
158 1.1 gwr ee_busy = 0;
159 1.1 gwr if (ee_want) {
160 1.1 gwr ee_want = 0;
161 1.1 gwr wakeup(&ee_busy);
162 1.1 gwr }
163 1.1 gwr }
164 1.1 gwr
165 1.13 gwr /*
166 1.15 gwr * This is called by mem.c to handle /dev/eeprom
167 1.13 gwr */
168 1.13 gwr int
169 1.13 gwr eeprom_uio(struct uio *uio)
170 1.1 gwr {
171 1.15 gwr int cnt, error;
172 1.1 gwr int off; /* NOT off_t */
173 1.31 tsutsui uint8_t *va;
174 1.15 gwr
175 1.18 gwr if (eeprom_copy == NULL)
176 1.31 tsutsui return ENXIO;
177 1.1 gwr
178 1.1 gwr off = uio->uio_offset;
179 1.18 gwr if ((off < 0) || (off > EEPROM_SIZE))
180 1.31 tsutsui return EFAULT;
181 1.1 gwr
182 1.32 riastrad cnt = uimin(uio->uio_resid, (EEPROM_SIZE - off));
183 1.15 gwr if (cnt == 0)
184 1.31 tsutsui return 0; /* EOF */
185 1.15 gwr
186 1.31 tsutsui va = ((uint8_t *)eeprom_copy) + off;
187 1.15 gwr error = uiomove(va, (int)cnt, uio);
188 1.15 gwr
189 1.15 gwr /* If we wrote the rambuf, update the H/W. */
190 1.31 tsutsui if (error == 0 && (uio->uio_rw != UIO_READ)) {
191 1.15 gwr error = ee_take();
192 1.31 tsutsui if (error == 0)
193 1.15 gwr error = ee_update(off, cnt);
194 1.15 gwr ee_give();
195 1.1 gwr }
196 1.1 gwr
197 1.31 tsutsui return error;
198 1.1 gwr }
199 1.1 gwr
200 1.1 gwr /*
201 1.15 gwr * Update the EEPROM from the soft copy.
202 1.15 gwr * Other than the attach function, this is
203 1.15 gwr * the ONLY place we touch the EEPROM H/W.
204 1.1 gwr */
205 1.13 gwr static int
206 1.15 gwr ee_update(int off, int cnt)
207 1.1 gwr {
208 1.31 tsutsui volatile uint8_t *ep;
209 1.31 tsutsui uint8_t *bp;
210 1.15 gwr int errcnt;
211 1.1 gwr
212 1.1 gwr if (eeprom_va == NULL)
213 1.1 gwr return (ENXIO);
214 1.1 gwr
215 1.18 gwr /*
216 1.18 gwr * This check is NOT redundant with the one in
217 1.18 gwr * eeprom_uio above if we are on a 3/80 where
218 1.18 gwr * ee_size < EEPROM_SIZE
219 1.18 gwr */
220 1.18 gwr if (cnt > (ee_size - off))
221 1.18 gwr cnt = (ee_size - off);
222 1.18 gwr
223 1.31 tsutsui bp = ((uint8_t *)eeprom_copy) + off;
224 1.1 gwr ep = eeprom_va + off;
225 1.15 gwr errcnt = 0;
226 1.1 gwr
227 1.1 gwr while (cnt > 0) {
228 1.1 gwr /*
229 1.1 gwr * DO NOT WRITE IT UNLESS WE HAVE TO because the
230 1.1 gwr * EEPROM has a limited number of write cycles.
231 1.1 gwr * After some number of writes it just fails!
232 1.1 gwr */
233 1.1 gwr if (*ep != *bp) {
234 1.31 tsutsui *ep = *bp;
235 1.1 gwr /*
236 1.1 gwr * We have written the EEPROM, so now we must
237 1.1 gwr * sleep for at least 10 milliseconds while
238 1.1 gwr * holding the lock to prevent all access to
239 1.1 gwr * the EEPROM while it recovers.
240 1.1 gwr */
241 1.31 tsutsui (void)tsleep(eeprom_va, PZERO - 1, "eeprom", hz / 50);
242 1.1 gwr }
243 1.1 gwr /* Make sure the write worked. */
244 1.1 gwr if (*ep != *bp)
245 1.15 gwr errcnt++;
246 1.1 gwr ep++;
247 1.1 gwr bp++;
248 1.1 gwr cnt--;
249 1.1 gwr }
250 1.31 tsutsui return errcnt ? EIO : 0;
251 1.1 gwr }
252