common/env_eeprom.c

   1 /*
   2  * (C) Copyright 2000-2010
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   6  * Andreas Heppel <aheppel@sysgo.de>
   7  *
   8  * See file CREDITS for list of people who contributed to this
   9  * project.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License as
  13  * published by the Free Software Foundation; either version 2 of
  14  * the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  24  * MA 02111-1307 USA
  25  */
  26
  27 #include <common.h>
  28 #include <command.h>
  29 #include <environment.h>
  30 #include <linux/stddef.h>
  31 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  32 #include <i2c.h>
  33 #endif
  34 #include <search.h>
  35 #include <errno.h>
  36 #include <linux/compiler.h>     /* for BUG_ON */
  37
  38 DECLARE_GLOBAL_DATA_PTR;
  39
  40 env_t *env_ptr = NULL;
  41
  42 char *env_name_spec = "EEPROM";
  43 int env_eeprom_bus = -1;
  44
  45 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
  46         uchar *buffer, unsigned cnt)
  47 {
  48         int rcode;
  49 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  50         int old_bus = i2c_get_bus_num();
  51
  52         if (gd->flags & GD_FLG_RELOC) {
  53                 if (env_eeprom_bus == -1) {
  54                         I2C_MUX_DEVICE *dev = NULL;
  55                         dev = i2c_mux_ident_muxstring(
  56                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  57                         if (dev != NULL)
  58                                 env_eeprom_bus = dev->busid;
  59                         else
  60                                 printf ("error adding env eeprom bus.\n");
  61                 }
  62                 if (old_bus != env_eeprom_bus) {
  63                         i2c_set_bus_num(env_eeprom_bus);
  64                         old_bus = env_eeprom_bus;
  65                 }
  66         } else {
  67                 rcode = i2c_mux_ident_muxstring_f(
  68                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  69         }
  70 #endif
  71
  72         rcode = eeprom_read (dev_addr, offset, buffer, cnt);
  73
  74 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  75         if (old_bus != env_eeprom_bus)
  76                 i2c_set_bus_num(old_bus);
  77 #endif
  78         return rcode;
  79 }
  80
  81 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
  82         uchar *buffer, unsigned cnt)
  83 {
  84         int rcode;
  85 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  86         int old_bus = i2c_get_bus_num();
  87
  88         rcode = i2c_mux_ident_muxstring_f((uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  89 #endif
  90         rcode = eeprom_write(dev_addr, offset, buffer, cnt);
  91 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  92         i2c_set_bus_num(old_bus);
  93 #endif
  94         return rcode;
  95 }
  96
  97 uchar env_get_char_spec (int index)
  98 {
  99         uchar c;
 100         unsigned int off;
 101         off = CONFIG_ENV_OFFSET;
 102
 103 #ifdef CONFIG_ENV_OFFSET_REDUND
 104         if (gd->env_valid == 2)
 105                 off = CONFIG_ENV_OFFSET_REDUND;
 106 #endif
 107         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 108                      off + index + offsetof(env_t,data),
 109                      &c, 1);
 110
 111         return (c);
 112 }
 113
 114 void env_relocate_spec (void)
 115 {
 116         char buf[CONFIG_ENV_SIZE];
 117         unsigned int off = CONFIG_ENV_OFFSET;
 118
 119 #ifdef CONFIG_ENV_OFFSET_REDUND
 120         if (gd->env_valid == 2)
 121                 off = CONFIG_ENV_OFFSET_REDUND;
 122 #endif
 123         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 124                      off,
 125                      (uchar *)buf,
 126                      CONFIG_ENV_SIZE);
 127
 128         env_import(buf, 1);
 129 }
 130
 131 int saveenv(void)
 132 {
 133         env_t   env_new;
 134         ssize_t len;
 135         char    *res;
 136         int rc;
 137         unsigned int off = CONFIG_ENV_OFFSET;
 138 #ifdef CONFIG_ENV_OFFSET_REDUND
 139         unsigned int off_red = CONFIG_ENV_OFFSET_REDUND;
 140         char flag_obsolete = OBSOLETE_FLAG;
 141 #endif
 142
 143         BUG_ON(env_ptr != NULL);
 144
 145         res = (char *)&env_new.data;
 146         len = hexport_r(&env_htab, '\0', &res, ENV_SIZE, 0, NULL);
 147         if (len < 0) {
 148                 error("Cannot export environment: errno = %d\n", errno);
 149                 return 1;
 150         }
 151         env_new.crc = crc32(0, env_new.data, ENV_SIZE);
 152
 153 #ifdef CONFIG_ENV_OFFSET_REDUND
 154         if (gd->env_valid == 1) {
 155                 off = CONFIG_ENV_OFFSET_REDUND;
 156                 off_red = CONFIG_ENV_OFFSET;
 157         }
 158
 159         env_new.flags = ACTIVE_FLAG;
 160 #endif
 161
 162         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 163                              off,
 164                              (uchar *)&env_new,
 165                              CONFIG_ENV_SIZE);
 166
 167 #ifdef CONFIG_ENV_OFFSET_REDUND
 168         if (rc == 0) {
 169                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 170                                   off_red + offsetof(env_t,flags),
 171                                   (uchar *)&flag_obsolete,
 172                                   1);
 173                 if (gd->env_valid == 1)
 174                         gd->env_valid = 2;
 175                 else
 176                         gd->env_valid = 1;
 177
 178         }
 179 #endif
 180
 181         return rc;
 182 }
 183
 184 /*
 185  * Initialize Environment use
 186  *
 187  * We are still running from ROM, so data use is limited.
 188  * Use a (moderately small) buffer on the stack
 189  */
 190
 191 #ifdef CONFIG_ENV_OFFSET_REDUND
 192 int env_init(void)
 193 {
 194         ulong len;
 195         ulong crc[2], crc_tmp;
 196         unsigned int off, off_env[2];
 197         uchar buf[64];
 198         int crc_ok[2] = {0,0};
 199         unsigned char flags[2];
 200         int i;
 201
 202         eeprom_init();  /* prepare for EEPROM read/write */
 203
 204         off_env[0] = CONFIG_ENV_OFFSET;
 205         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
 206
 207         for (i = 0; i < 2; i++) {
 208                 /* read CRC */
 209                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 210                         off_env[i] + offsetof(env_t,crc),
 211                         (uchar *)&crc[i], sizeof(ulong));
 212                 /* read FLAGS */
 213                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 214                         off_env[i] + offsetof(env_t,flags),
 215                         (uchar *)&flags[i], sizeof(uchar));
 216
 217                 crc_tmp = 0;
 218                 len = ENV_SIZE;
 219                 off = off_env[i] + offsetof(env_t,data);
 220                 while (len > 0) {
 221                         int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 222
 223                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 224                                 buf, n);
 225
 226                         crc_tmp = crc32(crc_tmp, buf, n);
 227                         len -= n;
 228                         off += n;
 229                 }
 230                 if (crc_tmp == crc[i])
 231                         crc_ok[i] = 1;
 232         }
 233
 234         if (!crc_ok[0] && !crc_ok[1]) {
 235                 gd->env_addr  = 0;
 236                 gd->env_valid = 0;
 237
 238                 return 0;
 239         } else if (crc_ok[0] && !crc_ok[1]) {
 240                 gd->env_valid = 1;
 241         }
 242         else if (!crc_ok[0] && crc_ok[1]) {
 243                 gd->env_valid = 2;
 244         } else {
 245                 /* both ok - check serial */
 246                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 247                         gd->env_valid = 1;
 248                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 249                         gd->env_valid = 2;
 250                 else if (flags[0] == 0xFF && flags[1] == 0)
 251                         gd->env_valid = 2;
 252                 else if(flags[1] == 0xFF && flags[0] == 0)
 253                         gd->env_valid = 1;
 254                 else /* flags are equal - almost impossible */
 255                         gd->env_valid = 1;
 256         }
 257
 258         if (gd->env_valid == 2)
 259                 gd->env_addr = off_env[1] + offsetof(env_t,data);
 260         else if (gd->env_valid == 1)
 261                 gd->env_addr = off_env[0] + offsetof(env_t,data);
 262
 263         return (0);
 264 }
 265 #else
 266 int env_init(void)
 267 {
 268         ulong crc, len, new;
 269         unsigned off;
 270         uchar buf[64];
 271
 272         eeprom_init();  /* prepare for EEPROM read/write */
 273
 274         /* read old CRC */
 275         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 276                      CONFIG_ENV_OFFSET+offsetof(env_t,crc),
 277                      (uchar *)&crc, sizeof(ulong));
 278
 279         new = 0;
 280         len = ENV_SIZE;
 281         off = offsetof(env_t,data);
 282
 283         while (len > 0) {
 284                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 285
 286                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 287                                 CONFIG_ENV_OFFSET + off, buf, n);
 288                 new = crc32(new, buf, n);
 289                 len -= n;
 290                 off += n;
 291         }
 292
 293         if (crc == new) {
 294                 gd->env_addr  = offsetof(env_t,data);
 295                 gd->env_valid = 1;
 296         } else {
 297                 gd->env_addr  = 0;
 298                 gd->env_valid = 0;
 299         }
 300
 301         return (0);
 302 }
 303 #endif