eeprom.c revision 1.26
1 /* $NetBSD: eeprom.c,v 1.26 2005/01/22 15:36:09 chs Exp $ */ 2 3 /*- 4 * Copyright (c) 1996 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Gordon W. Ross. 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 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Access functions for the EEPROM (Electrically Eraseable PROM) 41 * The main reason for the existence of this module is to 42 * handle the painful task of updating the EEPROM contents. 43 * After a write, it must not be touched for 10 milliseconds. 44 * (See the Sun-3 Architecture Manual sec. 5.9) 45 */ 46 47 #include <sys/cdefs.h> 48 __KERNEL_RCSID(0, "$NetBSD: eeprom.c,v 1.26 2005/01/22 15:36:09 chs Exp $"); 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/device.h> 53 #include <sys/conf.h> 54 #include <sys/buf.h> 55 #include <sys/malloc.h> 56 #include <sys/proc.h> 57 #include <sys/kernel.h> 58 59 #include <machine/autoconf.h> 60 #include <machine/idprom.h> 61 #include <machine/eeprom.h> 62 63 #ifndef EEPROM_SIZE 64 #define EEPROM_SIZE 0x800 65 #endif 66 67 struct eeprom *eeprom_copy; /* soft copy. */ 68 69 static int ee_update(int off, int cnt); 70 71 static char *eeprom_va; /* mapping to actual device */ 72 static int ee_size; /* size of usable part. */ 73 74 static int ee_busy, ee_want; /* serialization */ 75 76 static int eeprom_match(struct device *, struct cfdata *, void *); 77 static void eeprom_attach(struct device *, struct device *, void *); 78 79 CFATTACH_DECL(eeprom, sizeof(struct device), 80 eeprom_match, eeprom_attach, NULL, NULL); 81 82 static int 83 eeprom_match(struct device *parent, struct cfdata *cf, void *args) 84 { 85 struct confargs *ca = args; 86 87 /* This driver only supports one instance. */ 88 if (eeprom_va != NULL) 89 return (0); 90 91 if (bus_peek(ca->ca_bustype, ca->ca_paddr, 1) == -1) 92 return (0); 93 94 return (1); 95 } 96 97 static void 98 eeprom_attach(struct device *parent, struct device *self, void *args) 99 { 100 struct confargs *ca = args; 101 char *src, *dst, *lim; 102 103 printf("\n"); 104 #ifdef DIAGNOSTIC 105 if (sizeof(struct eeprom) != EEPROM_SIZE) 106 panic("eeprom struct wrong"); 107 #endif 108 109 ee_size = EEPROM_SIZE; 110 eeprom_va = bus_mapin(ca->ca_bustype, ca->ca_paddr, ee_size); 111 if (!eeprom_va) 112 panic("eeprom_attach"); 113 114 /* Keep a "soft" copy of the EEPROM to make access simpler. */ 115 eeprom_copy = malloc(ee_size, M_DEVBUF, M_NOWAIT); 116 if (eeprom_copy == 0) 117 panic("eeprom_attach: malloc eeprom_copy"); 118 119 /* 120 * On the 3/80, do not touch the last 40 bytes! 121 * Writes there are ignored, reads show zero. 122 * Reduce ee_size and clear the last part of the 123 * soft copy. Note: ee_update obeys ee_size. 124 */ 125 if (cpu_machine_id == SUN3X_MACH_80) 126 ee_size -= 40; 127 128 /* Do only byte access in the EEPROM. */ 129 src = eeprom_va; 130 dst = (char*) eeprom_copy; 131 lim = dst + ee_size; 132 133 do *dst++ = *src++; 134 while (dst < lim); 135 136 if (ee_size < EEPROM_SIZE) { 137 /* Clear out the last part. */ 138 memset(dst, 0, (EEPROM_SIZE - ee_size)); 139 } 140 } 141 142 143 /* Take the lock. */ 144 static int 145 ee_take(void) 146 { 147 int error = 0; 148 149 while (ee_busy) { 150 ee_want = 1; 151 error = tsleep(&ee_busy, PZERO | PCATCH, "eeprom", 0); 152 ee_want = 0; 153 if (error) /* interrupted */ 154 return error; 155 } 156 ee_busy = 1; 157 return error; 158 } 159 160 /* Give the lock. */ 161 static void 162 ee_give(void) 163 { 164 ee_busy = 0; 165 if (ee_want) { 166 ee_want = 0; 167 wakeup(&ee_busy); 168 } 169 } 170 171 /* 172 * This is called by mem.c to handle /dev/eeprom 173 */ 174 int 175 eeprom_uio(struct uio *uio) 176 { 177 int cnt, error; 178 int off; /* NOT off_t */ 179 caddr_t va; 180 181 if (eeprom_copy == NULL) 182 return (ENXIO); 183 184 off = uio->uio_offset; 185 if ((off < 0) || (off > EEPROM_SIZE)) 186 return (EFAULT); 187 188 cnt = min(uio->uio_resid, (EEPROM_SIZE - off)); 189 if (cnt == 0) 190 return (0); /* EOF */ 191 192 va = ((char*)eeprom_copy) + off; 193 error = uiomove(va, (int)cnt, uio); 194 195 /* If we wrote the rambuf, update the H/W. */ 196 if (!error && (uio->uio_rw != UIO_READ)) { 197 error = ee_take(); 198 if (!error) 199 error = ee_update(off, cnt); 200 ee_give(); 201 } 202 203 return (error); 204 } 205 206 /* 207 * Update the EEPROM from the soft copy. 208 * Other than the attach function, this is 209 * the ONLY place we touch the EEPROM H/W. 210 */ 211 static int 212 ee_update(int off, int cnt) 213 { 214 volatile char *ep; 215 char *bp; 216 int errcnt; 217 218 if (eeprom_va == NULL) 219 return (ENXIO); 220 221 /* 222 * This check is NOT redundant with the one in 223 * eeprom_uio above if we are on a 3/80 where 224 * ee_size < EEPROM_SIZE 225 */ 226 if (cnt > (ee_size - off)) 227 cnt = (ee_size - off); 228 229 bp = ((char*)eeprom_copy) + off; 230 ep = eeprom_va + off; 231 errcnt = 0; 232 233 while (cnt > 0) { 234 /* 235 * DO NOT WRITE IT UNLESS WE HAVE TO because the 236 * EEPROM has a limited number of write cycles. 237 * After some number of writes it just fails! 238 */ 239 if (*ep != *bp) { 240 *ep = *bp; 241 /* 242 * We have written the EEPROM, so now we must 243 * sleep for at least 10 milliseconds while 244 * holding the lock to prevent all access to 245 * the EEPROM while it recovers. 246 */ 247 (void)tsleep(eeprom_va, PZERO-1, "eeprom", hz/50); 248 } 249 /* Make sure the write worked. */ 250 if (*ep != *bp) 251 errcnt++; 252 ep++; 253 bp++; 254 cnt--; 255 } 256 return (errcnt ? EIO : 0); 257 } 258
Indexes created Mon Sep 22 13:09:51 GMT 2025