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;
  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 (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  53                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  54 #endif
  55
  56         rcode = eeprom_read(dev_addr, offset, buffer, cnt);
  57
  58 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  59         if (old_bus != env_eeprom_bus)
  60                 i2c_set_bus_num(old_bus);
  61 #endif
  62
  63         return rcode;
  64 }
  65
  66 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
  67                             uchar *buffer, unsigned cnt)
  68 {
  69         int rcode;
  70 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  71         int old_bus = i2c_get_bus_num();
  72
  73         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  74                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  75 #endif
  76
  77         rcode = eeprom_write(dev_addr, offset, buffer, cnt);
  78
  79 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  80         i2c_set_bus_num(old_bus);
  81 #endif
  82         return rcode;
  83 }
  84
  85 uchar env_get_char_spec(int index)
  86 {
  87         uchar c;
  88         unsigned int off = CONFIG_ENV_OFFSET;
  89
  90 #ifdef CONFIG_ENV_OFFSET_REDUND
  91         if (gd->env_valid == 2)
  92                 off = CONFIG_ENV_OFFSET_REDUND;
  93 #endif
  94         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
  95                         off + index + offsetof(env_t, data), &c, 1);
  96
  97         return c;
  98 }
  99
 100 void env_relocate_spec(void)
 101 {
 102         char buf[CONFIG_ENV_SIZE];
 103         unsigned int off = CONFIG_ENV_OFFSET;
 104
 105 #ifdef CONFIG_ENV_OFFSET_REDUND
 106         if (gd->env_valid == 2)
 107                 off = CONFIG_ENV_OFFSET_REDUND;
 108 #endif
 109         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 110                         off, (uchar *)buf, CONFIG_ENV_SIZE);
 111
 112         env_import(buf, 1);
 113 }
 114
 115 int saveenv(void)
 116 {
 117         env_t   env_new;
 118         ssize_t len;
 119         char    *res;
 120         int     rc;
 121         unsigned int off        = CONFIG_ENV_OFFSET;
 122 #ifdef CONFIG_ENV_OFFSET_REDUND
 123         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 124         char flag_obsolete      = OBSOLETE_FLAG;
 125 #endif
 126
 127         BUG_ON(env_ptr != NULL);
 128
 129         res = (char *)&env_new.data;
 130         len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
 131         if (len < 0) {
 132                 error("Cannot export environment: errno = %d\n", errno);
 133                 return 1;
 134         }
 135         env_new.crc = crc32(0, env_new.data, ENV_SIZE);
 136
 137 #ifdef CONFIG_ENV_OFFSET_REDUND
 138         if (gd->env_valid == 1) {
 139                 off     = CONFIG_ENV_OFFSET_REDUND;
 140                 off_red = CONFIG_ENV_OFFSET;
 141         }
 142
 143         env_new.flags = ACTIVE_FLAG;
 144 #endif
 145
 146         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 147                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 148
 149 #ifdef CONFIG_ENV_OFFSET_REDUND
 150         if (rc == 0) {
 151                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 152                                  off_red + offsetof(env_t, flags),
 153                                  (uchar *)&flag_obsolete, 1);
 154
 155                 if (gd->env_valid == 1)
 156                         gd->env_valid = 2;
 157                 else
 158                         gd->env_valid = 1;
 159         }
 160 #endif
 161         return rc;
 162 }
 163
 164 /*
 165  * Initialize Environment use
 166  *
 167  * We are still running from ROM, so data use is limited.
 168  * Use a (moderately small) buffer on the stack
 169  */
 170 #ifdef CONFIG_ENV_OFFSET_REDUND
 171 int env_init(void)
 172 {
 173         ulong len, crc[2], crc_tmp;
 174         unsigned int off, off_env[2];
 175         uchar buf[64], flags[2];
 176         int i, crc_ok[2] = {0, 0};
 177
 178         eeprom_init();  /* prepare for EEPROM read/write */
 179
 180         off_env[0] = CONFIG_ENV_OFFSET;
 181         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
 182
 183         for (i = 0; i < 2; i++) {
 184                 /* read CRC */
 185                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 186                                 off_env[i] + offsetof(env_t, crc),
 187                                 (uchar *)&crc[i], sizeof(ulong));
 188                 /* read FLAGS */
 189                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 190                                 off_env[i] + offsetof(env_t, flags),
 191                                 (uchar *)&flags[i], sizeof(uchar));
 192
 193                 crc_tmp = 0;
 194                 len = ENV_SIZE;
 195                 off = off_env[i] + offsetof(env_t, data);
 196                 while (len > 0) {
 197                         int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 198
 199                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 200                                         buf, n);
 201
 202                         crc_tmp = crc32(crc_tmp, buf, n);
 203                         len -= n;
 204                         off += n;
 205                 }
 206
 207                 if (crc_tmp == crc[i])
 208                         crc_ok[i] = 1;
 209         }
 210
 211         if (!crc_ok[0] && !crc_ok[1]) {
 212                 gd->env_addr    = 0;
 213                 gd->env_valid   = 0;
 214
 215                 return 0;
 216         } else if (crc_ok[0] && !crc_ok[1]) {
 217                 gd->env_valid = 1;
 218         } else if (!crc_ok[0] && crc_ok[1]) {
 219                 gd->env_valid = 2;
 220         } else {
 221                 /* both ok - check serial */
 222                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 223                         gd->env_valid = 1;
 224                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 225                         gd->env_valid = 2;
 226                 else if (flags[0] == 0xFF && flags[1] == 0)
 227                         gd->env_valid = 2;
 228                 else if (flags[1] == 0xFF && flags[0] == 0)
 229                         gd->env_valid = 1;
 230                 else /* flags are equal - almost impossible */
 231                         gd->env_valid = 1;
 232         }
 233
 234         if (gd->env_valid == 2)
 235                 gd->env_addr = off_env[1] + offsetof(env_t, data);
 236         else if (gd->env_valid == 1)
 237                 gd->env_addr = off_env[0] + offsetof(env_t, data);
 238
 239         return 0;
 240 }
 241 #else
 242 int env_init(void)
 243 {
 244         ulong crc, len, new;
 245         unsigned off;
 246         uchar buf[64];
 247
 248         eeprom_init();  /* prepare for EEPROM read/write */
 249
 250         /* read old CRC */
 251         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 252                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 253                         (uchar *)&crc, sizeof(ulong));
 254
 255         new = 0;
 256         len = ENV_SIZE;
 257         off = offsetof(env_t, data);
 258
 259         while (len > 0) {
 260                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 261
 262                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 263                                 CONFIG_ENV_OFFSET + off, buf, n);
 264                 new = crc32(new, buf, n);
 265                 len -= n;
 266                 off += n;
 267         }
 268
 269         if (crc == new) {
 270                 gd->env_addr    = offsetof(env_t, data);
 271                 gd->env_valid   = 1;
 272         } else {
 273                 gd->env_addr    = 0;
 274                 gd->env_valid   = 0;
 275         }
 276
 277         return 0;
 278 }
 279 #endif