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 (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 = CONFIG_ENV_OFFSET;
 101
 102 #ifdef CONFIG_ENV_OFFSET_REDUND
 103         if (gd->env_valid == 2)
 104                 off = CONFIG_ENV_OFFSET_REDUND;
 105 #endif
 106         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 107                         off + index + offsetof(env_t, data), &c, 1);
 108
 109         return c;
 110 }
 111
 112 void env_relocate_spec(void)
 113 {
 114         char buf[CONFIG_ENV_SIZE];
 115         unsigned int off = CONFIG_ENV_OFFSET;
 116
 117 #ifdef CONFIG_ENV_OFFSET_REDUND
 118         if (gd->env_valid == 2)
 119                 off = CONFIG_ENV_OFFSET_REDUND;
 120 #endif
 121         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 122                         off, (uchar *)buf, CONFIG_ENV_SIZE);
 123
 124         env_import(buf, 1);
 125 }
 126
 127 int saveenv(void)
 128 {
 129         env_t   env_new;
 130         ssize_t len;
 131         char    *res;
 132         int     rc;
 133         unsigned int off        = CONFIG_ENV_OFFSET;
 134 #ifdef CONFIG_ENV_OFFSET_REDUND
 135         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 136         char flag_obsolete      = OBSOLETE_FLAG;
 137 #endif
 138
 139         BUG_ON(env_ptr != NULL);
 140
 141         res = (char *)&env_new.data;
 142         len = hexport_r(&env_htab, '\0', &res, ENV_SIZE, 0, NULL);
 143         if (len < 0) {
 144                 error("Cannot export environment: errno = %d\n", errno);
 145                 return 1;
 146         }
 147         env_new.crc = crc32(0, env_new.data, ENV_SIZE);
 148
 149 #ifdef CONFIG_ENV_OFFSET_REDUND
 150         if (gd->env_valid == 1) {
 151                 off     = CONFIG_ENV_OFFSET_REDUND;
 152                 off_red = CONFIG_ENV_OFFSET;
 153         }
 154
 155         env_new.flags = ACTIVE_FLAG;
 156 #endif
 157
 158         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 159                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 160
 161 #ifdef CONFIG_ENV_OFFSET_REDUND
 162         if (rc == 0) {
 163                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 164                                  off_red + offsetof(env_t, flags),
 165                                  (uchar *)&flag_obsolete, 1);
 166
 167                 if (gd->env_valid == 1)
 168                         gd->env_valid = 2;
 169                 else
 170                         gd->env_valid = 1;
 171         }
 172 #endif
 173         return rc;
 174 }
 175
 176 /*
 177  * Initialize Environment use
 178  *
 179  * We are still running from ROM, so data use is limited.
 180  * Use a (moderately small) buffer on the stack
 181  */
 182 #ifdef CONFIG_ENV_OFFSET_REDUND
 183 int env_init(void)
 184 {
 185         ulong len, crc[2], crc_tmp;
 186         unsigned int off, off_env[2];
 187         uchar buf[64], flags[2];
 188         int i, crc_ok[2] = {0, 0};
 189
 190         eeprom_init();  /* prepare for EEPROM read/write */
 191
 192         off_env[0] = CONFIG_ENV_OFFSET;
 193         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
 194
 195         for (i = 0; i < 2; i++) {
 196                 /* read CRC */
 197                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 198                                 off_env[i] + offsetof(env_t, crc),
 199                                 (uchar *)&crc[i], sizeof(ulong));
 200                 /* read FLAGS */
 201                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 202                                 off_env[i] + offsetof(env_t, flags),
 203                                 (uchar *)&flags[i], sizeof(uchar));
 204
 205                 crc_tmp = 0;
 206                 len = ENV_SIZE;
 207                 off = off_env[i] + offsetof(env_t, data);
 208                 while (len > 0) {
 209                         int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 210
 211                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 212                                         buf, n);
 213
 214                         crc_tmp = crc32(crc_tmp, buf, n);
 215                         len -= n;
 216                         off += n;
 217                 }
 218
 219                 if (crc_tmp == crc[i])
 220                         crc_ok[i] = 1;
 221         }
 222
 223         if (!crc_ok[0] && !crc_ok[1]) {
 224                 gd->env_addr    = 0;
 225                 gd->env_valid   = 0;
 226
 227                 return 0;
 228         } else if (crc_ok[0] && !crc_ok[1]) {
 229                 gd->env_valid = 1;
 230         } else if (!crc_ok[0] && crc_ok[1]) {
 231                 gd->env_valid = 2;
 232         } else {
 233                 /* both ok - check serial */
 234                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 235                         gd->env_valid = 1;
 236                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 237                         gd->env_valid = 2;
 238                 else if (flags[0] == 0xFF && flags[1] == 0)
 239                         gd->env_valid = 2;
 240                 else if (flags[1] == 0xFF && flags[0] == 0)
 241                         gd->env_valid = 1;
 242                 else /* flags are equal - almost impossible */
 243                         gd->env_valid = 1;
 244         }
 245
 246         if (gd->env_valid == 2)
 247                 gd->env_addr = off_env[1] + offsetof(env_t, data);
 248         else if (gd->env_valid == 1)
 249                 gd->env_addr = off_env[0] + offsetof(env_t, data);
 250
 251         return 0;
 252 }
 253 #else
 254 int env_init(void)
 255 {
 256         ulong crc, len, new;
 257         unsigned off;
 258         uchar buf[64];
 259
 260         eeprom_init();  /* prepare for EEPROM read/write */
 261
 262         /* read old CRC */
 263         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 264                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 265                         (uchar *)&crc, sizeof(ulong));
 266
 267         new = 0;
 268         len = ENV_SIZE;
 269         off = offsetof(env_t, data);
 270
 271         while (len > 0) {
 272                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 273
 274                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 275                                 CONFIG_ENV_OFFSET + off, buf, n);
 276                 new = crc32(new, buf, n);
 277                 len -= n;
 278                 off += n;
 279         }
 280
 281         if (crc == new) {
 282                 gd->env_addr    = offsetof(env_t, data);
 283                 gd->env_valid   = 1;
 284         } else {
 285                 gd->env_addr    = 0;
 286                 gd->env_valid   = 0;
 287         }
 288
 289         return 0;
 290 }
 291 #endif