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 static char env_buf[CONFIG_ENV_SIZE];
  42
  43 char *env_name_spec = "EEPROM";
  44 int env_eeprom_bus = -1;
  45
  46 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
  47                            uchar *buffer, unsigned cnt)
  48 {
  49         int rcode;
  50 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  51         int old_bus = i2c_get_bus_num();
  52
  53         if (gd->flags & GD_FLG_RELOC) {
  54                 if (env_eeprom_bus == -1) {
  55                         I2C_MUX_DEVICE *dev = NULL;
  56                         dev = i2c_mux_ident_muxstring(
  57                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  58                         if (dev != NULL)
  59                                 env_eeprom_bus = dev->busid;
  60                         else
  61                                 printf("error adding env eeprom bus.\n");
  62                 }
  63                 if (old_bus != env_eeprom_bus) {
  64                         i2c_set_bus_num(env_eeprom_bus);
  65                         old_bus = env_eeprom_bus;
  66                 }
  67         } else {
  68                 rcode = i2c_mux_ident_muxstring_f(
  69                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  70         }
  71 #endif
  72
  73         rcode = eeprom_read(dev_addr, offset, buffer, cnt);
  74
  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,
  83                             uchar *buffer, 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 = CONFIG_ENV_OFFSET;
 102
 103 #ifdef CONFIG_ENV_OFFSET_REDUND
 104         if (gd->env_valid == 2)
 105                 off = CONFIG_ENV_OFFSET_REDUND;
 106 #endif
 107         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 108                         off + index + offsetof(env_t, data), &c, 1);
 109
 110         return c;
 111 }
 112
 113 void env_relocate_spec(void)
 114 {
 115         char *buf = env_buf;
 116         unsigned int off = CONFIG_ENV_OFFSET;
 117
 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, (uchar *)buf, CONFIG_ENV_SIZE);
 124
 125         env_import(buf, 1);
 126 }
 127
 128 int saveenv(void)
 129 {
 130         env_t   *env_new = (env_t *)env_buf;
 131         ssize_t len;
 132         char    *res;
 133         int     rc;
 134         unsigned int off        = CONFIG_ENV_OFFSET;
 135 #ifdef CONFIG_ENV_OFFSET_REDUND
 136         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 137         char flag_obsolete      = OBSOLETE_FLAG;
 138 #endif
 139
 140         BUG_ON(env_ptr != NULL);
 141
 142         res = (char *)env_new->data;
 143         len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
 144         if (len < 0) {
 145                 error("Cannot export environment: errno = %d\n", errno);
 146                 return 1;
 147         }
 148         env_new->crc = crc32(0, env_new->data, ENV_SIZE);
 149
 150 #ifdef CONFIG_ENV_OFFSET_REDUND
 151         if (gd->env_valid == 1) {
 152                 off     = CONFIG_ENV_OFFSET_REDUND;
 153                 off_red = CONFIG_ENV_OFFSET;
 154         }
 155
 156         env_new->flags = ACTIVE_FLAG;
 157 #endif
 158
 159         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 160                               off, (uchar *)env_new, CONFIG_ENV_SIZE);
 161
 162 #ifdef CONFIG_ENV_OFFSET_REDUND
 163         if (rc == 0) {
 164                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 165                                  off_red + offsetof(env_t, flags),
 166                                  (uchar *)&flag_obsolete, 1);
 167
 168                 if (gd->env_valid == 1)
 169                         gd->env_valid = 2;
 170                 else
 171                         gd->env_valid = 1;
 172         }
 173 #endif
 174         return rc;
 175 }
 176
 177 /*
 178  * Initialize Environment use
 179  *
 180  * We are still running from ROM, so data use is limited.
 181  * Use a (moderately small) buffer on the stack
 182  */
 183 #ifdef CONFIG_ENV_OFFSET_REDUND
 184 int env_init(void)
 185 {
 186         ulong len, crc[2], crc_tmp;
 187         unsigned int off, off_env[2];
 188         uchar buf[64], flags[2];
 189         int i, crc_ok[2] = {0, 0};
 190
 191         eeprom_init();  /* prepare for EEPROM read/write */
 192
 193         off_env[0] = CONFIG_ENV_OFFSET;
 194         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
 195
 196         for (i = 0; i < 2; i++) {
 197                 /* read CRC */
 198                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 199                                 off_env[i] + offsetof(env_t, crc),
 200                                 (uchar *)&crc[i], sizeof(ulong));
 201                 /* read FLAGS */
 202                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 203                                 off_env[i] + offsetof(env_t, flags),
 204                                 (uchar *)&flags[i], sizeof(uchar));
 205
 206                 crc_tmp = 0;
 207                 len = ENV_SIZE;
 208                 off = off_env[i] + offsetof(env_t, data);
 209                 while (len > 0) {
 210                         int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 211
 212                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 213                                         buf, n);
 214
 215                         crc_tmp = crc32(crc_tmp, buf, n);
 216                         len -= n;
 217                         off += n;
 218                 }
 219
 220                 if (crc_tmp == crc[i])
 221                         crc_ok[i] = 1;
 222         }
 223
 224         if (!crc_ok[0] && !crc_ok[1]) {
 225                 gd->env_addr    = 0;
 226                 gd->env_valid   = 0;
 227
 228                 return 0;
 229         } else if (crc_ok[0] && !crc_ok[1]) {
 230                 gd->env_valid = 1;
 231         } else if (!crc_ok[0] && crc_ok[1]) {
 232                 gd->env_valid = 2;
 233         } else {
 234                 /* both ok - check serial */
 235                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 236                         gd->env_valid = 1;
 237                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 238                         gd->env_valid = 2;
 239                 else if (flags[0] == 0xFF && flags[1] == 0)
 240                         gd->env_valid = 2;
 241                 else if (flags[1] == 0xFF && flags[0] == 0)
 242                         gd->env_valid = 1;
 243                 else /* flags are equal - almost impossible */
 244                         gd->env_valid = 1;
 245         }
 246
 247         if (gd->env_valid == 2)
 248                 gd->env_addr = off_env[1] + offsetof(env_t, data);
 249         else if (gd->env_valid == 1)
 250                 gd->env_addr = off_env[0] + offsetof(env_t, data);
 251
 252         return 0;
 253 }
 254 #else
 255 int env_init(void)
 256 {
 257         ulong crc, len, new;
 258         unsigned off;
 259         uchar buf[64];
 260
 261         eeprom_init();  /* prepare for EEPROM read/write */
 262
 263         /* read old CRC */
 264         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 265                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 266                         (uchar *)&crc, sizeof(ulong));
 267
 268         new = 0;
 269         len = ENV_SIZE;
 270         off = offsetof(env_t, data);
 271
 272         while (len > 0) {
 273                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 274
 275                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 276                                 CONFIG_ENV_OFFSET + off, buf, n);
 277                 new = crc32(new, buf, n);
 278                 len -= n;
 279                 off += n;
 280         }
 281
 282         if (crc == new) {
 283                 gd->env_addr    = offsetof(env_t, data);
 284                 gd->env_valid   = 1;
 285         } else {
 286                 gd->env_addr    = 0;
 287                 gd->env_valid   = 0;
 288         }
 289
 290         return 0;
 291 }
 292 #endif