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 DECLARE_GLOBAL_DATA_PTR;
  36
  37 env_t *env_ptr = NULL;
  38
  39 char * env_name_spec = "EEPROM";
  40 int env_eeprom_bus = -1;
  41
  42 static int eeprom_bus_read (unsigned dev_addr, unsigned offset, uchar *buffer,
  43                                 unsigned cnt)
  44 {
  45         int rcode;
  46 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  47         int old_bus = i2c_get_bus_num();
  48
  49         if (gd->flags & GD_FLG_RELOC) {
  50                 if (env_eeprom_bus == -1) {
  51                         I2C_MUX_DEVICE *dev = NULL;
  52                         dev = i2c_mux_ident_muxstring(
  53                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  54                         if (dev != NULL) {
  55                                 env_eeprom_bus = dev->busid;
  56                         } else
  57                                 printf ("error adding env eeprom bus.\n");
  58                 }
  59                 if (old_bus != env_eeprom_bus) {
  60                         i2c_set_bus_num(env_eeprom_bus);
  61                         old_bus = env_eeprom_bus;
  62                 }
  63         } else {
  64                 rcode = i2c_mux_ident_muxstring_f(
  65                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  66         }
  67 #endif
  68
  69         rcode = eeprom_read (dev_addr, offset, buffer, cnt);
  70 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  71         if (old_bus != env_eeprom_bus)
  72                 i2c_set_bus_num(old_bus);
  73 #endif
  74         return rcode;
  75 }
  76
  77 static int eeprom_bus_write (unsigned dev_addr, unsigned offset, uchar *buffer,
  78                                 unsigned cnt)
  79 {
  80         int rcode;
  81 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  82         int old_bus = i2c_get_bus_num();
  83
  84         rcode = i2c_mux_ident_muxstring_f((uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  85 #endif
  86         rcode = eeprom_write (dev_addr, offset, buffer, cnt);
  87 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  88         i2c_set_bus_num(old_bus);
  89 #endif
  90         return rcode;
  91 }
  92
  93 uchar env_get_char_spec (int index)
  94 {
  95         uchar c;
  96         unsigned int off;
  97         off = CONFIG_ENV_OFFSET;
  98 #ifdef CONFIG_ENV_OFFSET_REDUND
  99         if (gd->env_valid == 2)
 100                 off = CONFIG_ENV_OFFSET_REDUND;
 101 #endif
 102
 103         eeprom_bus_read (CONFIG_SYS_DEF_EEPROM_ADDR,
 104                      off + index + offsetof(env_t,data),
 105                      &c, 1);
 106
 107         return (c);
 108 }
 109
 110 void env_relocate_spec (void)
 111 {
 112         unsigned int off = CONFIG_ENV_OFFSET;
 113 #ifdef CONFIG_ENV_OFFSET_REDUND
 114         if (gd->env_valid == 2)
 115                 off = CONFIG_ENV_OFFSET_REDUND;
 116 #endif
 117         eeprom_bus_read (CONFIG_SYS_DEF_EEPROM_ADDR,
 118                      off,
 119                      (uchar*)env_ptr,
 120                      CONFIG_ENV_SIZE);
 121 }
 122
 123 int saveenv(void)
 124 {
 125         int rc;
 126         unsigned int off = CONFIG_ENV_OFFSET;
 127 #ifdef CONFIG_ENV_OFFSET_REDUND
 128         unsigned int off_red = CONFIG_ENV_OFFSET_REDUND;
 129         char flag_obsolete = OBSOLETE_FLAG;
 130         if (gd->env_valid == 1) {
 131                 off = CONFIG_ENV_OFFSET_REDUND;
 132                 off_red = CONFIG_ENV_OFFSET;
 133         }
 134
 135         env_ptr->flags = ACTIVE_FLAG;
 136 #endif
 137
 138         rc = eeprom_bus_write (CONFIG_SYS_DEF_EEPROM_ADDR,
 139                              off,
 140                              (uchar *)env_ptr,
 141                              CONFIG_ENV_SIZE);
 142
 143 #ifdef CONFIG_ENV_OFFSET_REDUND
 144         if (rc == 0) {
 145                 eeprom_bus_write (CONFIG_SYS_DEF_EEPROM_ADDR,
 146                                   off_red + offsetof(env_t,flags),
 147                                   (uchar *)&flag_obsolete,
 148                                   1);
 149                 if (gd->env_valid == 1)
 150                         gd->env_valid = 2;
 151                 else
 152                         gd->env_valid = 1;
 153
 154         }
 155 #endif
 156
 157         return rc;
 158 }
 159
 160 /************************************************************************
 161  * Initialize Environment use
 162  *
 163  * We are still running from ROM, so data use is limited
 164  * Use a (moderately small) buffer on the stack
 165  */
 166
 167 #ifdef CONFIG_ENV_OFFSET_REDUND
 168 int env_init(void)
 169 {
 170         ulong len;
 171         ulong crc[2], crc_tmp;
 172         unsigned int off, off_env[2];
 173         uchar buf[64];
 174         int crc_ok[2] = {0,0};
 175         unsigned char flags[2];
 176         int i;
 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                 if (crc_tmp == crc[i])
 207                         crc_ok[i] = 1;
 208         }
 209
 210         if (!crc_ok[0] && !crc_ok[1]) {
 211                 gd->env_addr  = 0;
 212                 gd->env_valid = 0;
 213
 214                 return 0;
 215         } else if (crc_ok[0] && !crc_ok[1]) {
 216                 gd->env_valid = 1;
 217         }
 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         while (len > 0) {
 259                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 260
 261                 eeprom_bus_read (CONFIG_SYS_DEF_EEPROM_ADDR,
 262                                 CONFIG_ENV_OFFSET + off, buf, n);
 263                 new = crc32 (new, buf, n);
 264                 len -= n;
 265                 off += n;
 266         }
 267
 268         if (crc == new) {
 269                 gd->env_addr  = offsetof(env_t,data);
 270                 gd->env_valid = 1;
 271         } else {
 272                 gd->env_addr  = 0;
 273                 gd->env_valid = 0;
 274         }
 275
 276         return (0);
 277 }
 278 #endif