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 defined(CONFIG_SYS_I2C)
  53         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  54                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  55 #else
  56         if (gd->flags & GD_FLG_RELOC) {
  57                 if (env_eeprom_bus == -1) {
  58                         I2C_MUX_DEVICE *dev = NULL;
  59                         dev = i2c_mux_ident_muxstring(
  60                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  61                         if (dev != NULL)
  62                                 env_eeprom_bus = dev->busid;
  63                         else
  64                                 printf("error adding env eeprom bus.\n");
  65                 }
  66                 if (old_bus != env_eeprom_bus) {
  67                         i2c_set_bus_num(env_eeprom_bus);
  68                         old_bus = env_eeprom_bus;
  69                 }
  70         } else {
  71                 rcode = i2c_mux_ident_muxstring_f(
  72                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  73         }
  74 #endif
  75 #endif
  76
  77         rcode = eeprom_read(dev_addr, offset, buffer, cnt);
  78
  79 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  80 #if defined(CONFIG_SYS_I2C)
  81         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  82 #else
  83         if (old_bus != env_eeprom_bus)
  84 #endif
  85                 i2c_set_bus_num(old_bus);
  86 #endif
  87         return rcode;
  88 }
  89
  90 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
  91                             uchar *buffer, unsigned cnt)
  92 {
  93         int rcode;
  94 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  95         int old_bus = i2c_get_bus_num();
  96
  97 #if defined(CONFIG_SYS_I2C)
  98         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  99                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
 100 #else
 101         rcode = i2c_mux_ident_muxstring_f((uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
 102 #endif
 103 #endif
 104         rcode = eeprom_write(dev_addr, offset, buffer, cnt);
 105 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
 106         i2c_set_bus_num(old_bus);
 107 #endif
 108         return rcode;
 109 }
 110
 111 uchar env_get_char_spec(int index)
 112 {
 113         uchar c;
 114         unsigned int off = CONFIG_ENV_OFFSET;
 115
 116 #ifdef CONFIG_ENV_OFFSET_REDUND
 117         if (gd->env_valid == 2)
 118                 off = CONFIG_ENV_OFFSET_REDUND;
 119 #endif
 120         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 121                         off + index + offsetof(env_t, data), &c, 1);
 122
 123         return c;
 124 }
 125
 126 void env_relocate_spec(void)
 127 {
 128         char buf[CONFIG_ENV_SIZE];
 129         unsigned int off = CONFIG_ENV_OFFSET;
 130
 131 #ifdef CONFIG_ENV_OFFSET_REDUND
 132         if (gd->env_valid == 2)
 133                 off = CONFIG_ENV_OFFSET_REDUND;
 134 #endif
 135         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 136                         off, (uchar *)buf, CONFIG_ENV_SIZE);
 137
 138         env_import(buf, 1);
 139 }
 140
 141 int saveenv(void)
 142 {
 143         env_t   env_new;
 144         ssize_t len;
 145         char    *res;
 146         int     rc;
 147         unsigned int off        = CONFIG_ENV_OFFSET;
 148 #ifdef CONFIG_ENV_OFFSET_REDUND
 149         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 150         char flag_obsolete      = OBSOLETE_FLAG;
 151 #endif
 152
 153         BUG_ON(env_ptr != NULL);
 154
 155         res = (char *)&env_new.data;
 156         len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
 157         if (len < 0) {
 158                 error("Cannot export environment: errno = %d\n", errno);
 159                 return 1;
 160         }
 161         env_new.crc = crc32(0, env_new.data, ENV_SIZE);
 162
 163 #ifdef CONFIG_ENV_OFFSET_REDUND
 164         if (gd->env_valid == 1) {
 165                 off     = CONFIG_ENV_OFFSET_REDUND;
 166                 off_red = CONFIG_ENV_OFFSET;
 167         }
 168
 169         env_new.flags = ACTIVE_FLAG;
 170 #endif
 171
 172         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 173                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 174
 175 #ifdef CONFIG_ENV_OFFSET_REDUND
 176         if (rc == 0) {
 177                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 178                                  off_red + offsetof(env_t, flags),
 179                                  (uchar *)&flag_obsolete, 1);
 180
 181                 if (gd->env_valid == 1)
 182                         gd->env_valid = 2;
 183                 else
 184                         gd->env_valid = 1;
 185         }
 186 #endif
 187         return rc;
 188 }
 189
 190 /*
 191  * Initialize Environment use
 192  *
 193  * We are still running from ROM, so data use is limited.
 194  * Use a (moderately small) buffer on the stack
 195  */
 196 #ifdef CONFIG_ENV_OFFSET_REDUND
 197 int env_init(void)
 198 {
 199         ulong len, crc[2], crc_tmp;
 200         unsigned int off, off_env[2];
 201         uchar buf[64], flags[2];
 202         int i, crc_ok[2] = {0, 0};
 203
 204         eeprom_init();  /* prepare for EEPROM read/write */
 205
 206         off_env[0] = CONFIG_ENV_OFFSET;
 207         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
 208
 209         for (i = 0; i < 2; i++) {
 210                 /* read CRC */
 211                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 212                                 off_env[i] + offsetof(env_t, crc),
 213                                 (uchar *)&crc[i], sizeof(ulong));
 214                 /* read FLAGS */
 215                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 216                                 off_env[i] + offsetof(env_t, flags),
 217                                 (uchar *)&flags[i], sizeof(uchar));
 218
 219                 crc_tmp = 0;
 220                 len = ENV_SIZE;
 221                 off = off_env[i] + offsetof(env_t, data);
 222                 while (len > 0) {
 223                         int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 224
 225                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 226                                         buf, n);
 227
 228                         crc_tmp = crc32(crc_tmp, buf, n);
 229                         len -= n;
 230                         off += n;
 231                 }
 232
 233                 if (crc_tmp == crc[i])
 234                         crc_ok[i] = 1;
 235         }
 236
 237         if (!crc_ok[0] && !crc_ok[1]) {
 238                 gd->env_addr    = 0;
 239                 gd->env_valid   = 0;
 240
 241                 return 0;
 242         } else if (crc_ok[0] && !crc_ok[1]) {
 243                 gd->env_valid = 1;
 244         } else if (!crc_ok[0] && crc_ok[1]) {
 245                 gd->env_valid = 2;
 246         } else {
 247                 /* both ok - check serial */
 248                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 249                         gd->env_valid = 1;
 250                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 251                         gd->env_valid = 2;
 252                 else if (flags[0] == 0xFF && flags[1] == 0)
 253                         gd->env_valid = 2;
 254                 else if (flags[1] == 0xFF && flags[0] == 0)
 255                         gd->env_valid = 1;
 256                 else /* flags are equal - almost impossible */
 257                         gd->env_valid = 1;
 258         }
 259
 260         if (gd->env_valid == 2)
 261                 gd->env_addr = off_env[1] + offsetof(env_t, data);
 262         else if (gd->env_valid == 1)
 263                 gd->env_addr = off_env[0] + offsetof(env_t, data);
 264
 265         return 0;
 266 }
 267 #else
 268 int env_init(void)
 269 {
 270         ulong crc, len, new;
 271         unsigned off;
 272         uchar buf[64];
 273
 274         eeprom_init();  /* prepare for EEPROM read/write */
 275
 276         /* read old CRC */
 277         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 278                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 279                         (uchar *)&crc, sizeof(ulong));
 280
 281         new = 0;
 282         len = ENV_SIZE;
 283         off = offsetof(env_t, data);
 284
 285         while (len > 0) {
 286                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 287
 288                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 289                                 CONFIG_ENV_OFFSET + off, buf, n);
 290                 new = crc32(new, buf, n);
 291                 len -= n;
 292                 off += n;
 293         }
 294
 295         if (crc == new) {
 296                 gd->env_addr    = offsetof(env_t, data);
 297                 gd->env_valid   = 1;
 298         } else {
 299                 gd->env_addr    = 0;
 300                 gd->env_valid   = 0;
 301         }
 302
 303         return 0;
 304 }
 305 #endif