common/env_eeprom.c

   1 /*
   2  * (C) Copyright 2000-2002
   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
  35 #ifdef CONFIG_ENV_OFFSET_REDUND
  36 #define ACTIVE_FLAG   1
  37 #define OBSOLETE_FLAG 0
  38 #endif
  39
  40 DECLARE_GLOBAL_DATA_PTR;
  41
  42 env_t *env_ptr = NULL;
  43
  44 char * env_name_spec = "EEPROM";
  45 int env_eeprom_bus = -1;
  46
  47 static int eeprom_bus_read (unsigned dev_addr, unsigned offset, uchar *buffer,
  48                                 unsigned cnt)
  49 {
  50         int rcode;
  51 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  52         int old_bus = i2c_get_bus_num();
  53
  54         if (gd->flags & GD_FLG_RELOC) {
  55                 if (env_eeprom_bus == -1) {
  56                         I2C_MUX_DEVICE *dev = NULL;
  57                         dev = i2c_mux_ident_muxstring(
  58                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  59                         if (dev != NULL) {
  60                                 env_eeprom_bus = dev->busid;
  61                         } else
  62                                 printf ("error adding env eeprom bus.\n");
  63                 }
  64                 if (old_bus != env_eeprom_bus) {
  65                         i2c_set_bus_num(env_eeprom_bus);
  66                         old_bus = env_eeprom_bus;
  67                 }
  68         } else {
  69                 rcode = i2c_mux_ident_muxstring_f(
  70                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  71         }
  72 #endif
  73
  74         rcode = eeprom_read (dev_addr, offset, buffer, cnt);
  75 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  76         if (old_bus != env_eeprom_bus)
  77                 i2c_set_bus_num(old_bus);
  78 #endif
  79         return rcode;
  80 }
  81
  82 static int eeprom_bus_write (unsigned dev_addr, unsigned offset, uchar *buffer,
  83                                 unsigned cnt)
  84 {
  85         int rcode;
  86 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  87         int old_bus = i2c_get_bus_num();
  88
  89         rcode = i2c_mux_ident_muxstring_f((uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  90 #endif
  91         rcode = eeprom_write (dev_addr, offset, buffer, cnt);
  92 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  93         i2c_set_bus_num(old_bus);
  94 #endif
  95         return rcode;
  96 }
  97
  98 uchar env_get_char_spec (int index)
  99 {
 100         uchar c;
 101         unsigned int off;
 102         off = CONFIG_ENV_OFFSET;
 103 #ifdef CONFIG_ENV_OFFSET_REDUND
 104         if (gd->env_valid == 2)
 105                 off = CONFIG_ENV_OFFSET_REDUND;
 106 #endif
 107
 108         eeprom_bus_read (CONFIG_SYS_DEF_EEPROM_ADDR,
 109                      off + index + offsetof(env_t,data),
 110                      &c, 1);
 111
 112         return (c);
 113 }
 114
 115 void env_relocate_spec (void)
 116 {
 117         unsigned int off = CONFIG_ENV_OFFSET;
 118 #ifdef CONFIG_ENV_OFFSET_REDUND
 119         if (gd->env_valid == 2)
 120                 off = CONFIG_ENV_OFFSET_REDUND;
 121 #endif
 122         eeprom_bus_read (CONFIG_SYS_DEF_EEPROM_ADDR,
 123                      off,
 124                      (uchar*)env_ptr,
 125                      CONFIG_ENV_SIZE);
 126 }
 127
 128 int saveenv(void)
 129 {
 130         int rc;
 131         unsigned int off = CONFIG_ENV_OFFSET;
 132 #ifdef CONFIG_ENV_OFFSET_REDUND
 133         unsigned int off_red = CONFIG_ENV_OFFSET_REDUND;
 134         char flag_obsolete = OBSOLETE_FLAG;
 135         if (gd->env_valid == 1) {
 136                 off = CONFIG_ENV_OFFSET_REDUND;
 137                 off_red = CONFIG_ENV_OFFSET;
 138         }
 139
 140         env_ptr->flags = ACTIVE_FLAG;
 141 #endif
 142
 143         rc = eeprom_bus_write (CONFIG_SYS_DEF_EEPROM_ADDR,
 144                              off,
 145                              (uchar *)env_ptr,
 146                              CONFIG_ENV_SIZE);
 147
 148 #ifdef CONFIG_ENV_OFFSET_REDUND
 149         if (rc == 0) {
 150                 eeprom_bus_write (CONFIG_SYS_DEF_EEPROM_ADDR,
 151                                   off_red + offsetof(env_t,flags),
 152                                   (uchar *)&flag_obsolete,
 153                                   1);
 154                 if (gd->env_valid == 1)
 155                         gd->env_valid = 2;
 156                 else
 157                         gd->env_valid = 1;
 158
 159         }
 160 #endif
 161
 162         return rc;
 163 }
 164
 165 /************************************************************************
 166  * Initialize Environment use
 167  *
 168  * We are still running from ROM, so data use is limited
 169  * Use a (moderately small) buffer on the stack
 170  */
 171
 172 #ifdef CONFIG_ENV_OFFSET_REDUND
 173 int env_init(void)
 174 {
 175         ulong len;
 176         ulong crc[2], crc_tmp;
 177         unsigned int off, off_env[2];
 178         uchar buf[64];
 179         int crc_ok[2] = {0,0};
 180         unsigned char flags[2];
 181         int i;
 182
 183         eeprom_init (); /* prepare for EEPROM read/write */
 184
 185         off_env[0] = CONFIG_ENV_OFFSET;
 186         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
 187
 188         for (i = 0; i < 2; i++) {
 189                 /* read CRC */
 190                 eeprom_bus_read (CONFIG_SYS_DEF_EEPROM_ADDR,
 191                         off_env[i] + offsetof(env_t,crc),
 192                         (uchar *)&crc[i], sizeof(ulong));
 193                 /* read FLAGS */
 194                 eeprom_bus_read (CONFIG_SYS_DEF_EEPROM_ADDR,
 195                         off_env[i] + offsetof(env_t,flags),
 196                         (uchar *)&flags[i], sizeof(uchar));
 197
 198                 crc_tmp= 0;
 199                 len = ENV_SIZE;
 200                 off = off_env[i] + offsetof(env_t,data);
 201                 while (len > 0) {
 202                         int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 203
 204                         eeprom_bus_read (CONFIG_SYS_DEF_EEPROM_ADDR, off,
 205                                 buf, n);
 206
 207                         crc_tmp = crc32 (crc_tmp, buf, n);
 208                         len -= n;
 209                         off += n;
 210                 }
 211                 if (crc_tmp == crc[i])
 212                         crc_ok[i] = 1;
 213         }
 214
 215         if (!crc_ok[0] && !crc_ok[1]) {
 216                 gd->env_addr  = 0;
 217                 gd->env_valid = 0;
 218
 219                 return 0;
 220         } else if (crc_ok[0] && !crc_ok[1]) {
 221                 gd->env_valid = 1;
 222         }
 223         else if (!crc_ok[0] && crc_ok[1]) {
 224                 gd->env_valid = 2;
 225         } else {
 226                 /* both ok - check serial */
 227                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 228                         gd->env_valid = 1;
 229                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 230                         gd->env_valid = 2;
 231                 else if (flags[0] == 0xFF && flags[1] == 0)
 232                         gd->env_valid = 2;
 233                 else if(flags[1] == 0xFF && flags[0] == 0)
 234                         gd->env_valid = 1;
 235                 else /* flags are equal - almost impossible */
 236                         gd->env_valid = 1;
 237         }
 238
 239         if (gd->env_valid == 2)
 240                 gd->env_addr = off_env[1] + offsetof(env_t,data);
 241         else if (gd->env_valid == 1)
 242                 gd->env_addr = off_env[0] + offsetof(env_t,data);
 243
 244         return (0);
 245 }
 246 #else
 247 int env_init(void)
 248 {
 249         ulong crc, len, new;
 250         unsigned off;
 251         uchar buf[64];
 252
 253         eeprom_init (); /* prepare for EEPROM read/write */
 254
 255         /* read old CRC */
 256         eeprom_bus_read (CONFIG_SYS_DEF_EEPROM_ADDR,
 257                      CONFIG_ENV_OFFSET+offsetof(env_t,crc),
 258                      (uchar *)&crc, sizeof(ulong));
 259
 260         new = 0;
 261         len = ENV_SIZE;
 262         off = offsetof(env_t,data);
 263         while (len > 0) {
 264                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 265
 266                 eeprom_bus_read (CONFIG_SYS_DEF_EEPROM_ADDR,
 267                                 CONFIG_ENV_OFFSET + off, buf, n);
 268                 new = crc32 (new, buf, n);
 269                 len -= n;
 270                 off += n;
 271         }
 272
 273         if (crc == new) {
 274                 gd->env_addr  = offsetof(env_t,data);
 275                 gd->env_valid = 1;
 276         } else {
 277                 gd->env_addr  = 0;
 278                 gd->env_valid = 0;
 279         }
 280
 281         return (0);
 282 }
 283 #endif