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  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #include <common.h>
  12 #include <command.h>
  13 #include <environment.h>
  14 #include <linux/stddef.h>
  15 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  16 #include <i2c.h>
  17 #endif
  18 #include <search.h>
  19 #include <errno.h>
  20 #include <linux/compiler.h>     /* for BUG_ON */
  21
  22 DECLARE_GLOBAL_DATA_PTR;
  23
  24 env_t *env_ptr;
  25
  26 char *env_name_spec = "EEPROM";
  27
  28 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
  29                            uchar *buffer, unsigned cnt)
  30 {
  31         int rcode;
  32 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  33         int old_bus = i2c_get_bus_num();
  34
  35         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  36                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  37 #endif
  38
  39         rcode = eeprom_read(dev_addr, offset, buffer, cnt);
  40
  41 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  42         i2c_set_bus_num(old_bus);
  43 #endif
  44
  45         return rcode;
  46 }
  47
  48 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
  49                             uchar *buffer, unsigned cnt)
  50 {
  51         int rcode;
  52 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  53         int old_bus = i2c_get_bus_num();
  54
  55         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  56                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  57 #endif
  58
  59         rcode = eeprom_write(dev_addr, offset, buffer, cnt);
  60
  61 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  62         i2c_set_bus_num(old_bus);
  63 #endif
  64
  65         return rcode;
  66 }
  67
  68 uchar env_get_char_spec(int index)
  69 {
  70         uchar c;
  71         unsigned int off = CONFIG_ENV_OFFSET;
  72
  73 #ifdef CONFIG_ENV_OFFSET_REDUND
  74         if (gd->env_valid == 2)
  75                 off = CONFIG_ENV_OFFSET_REDUND;
  76 #endif
  77         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
  78                         off + index + offsetof(env_t, data), &c, 1);
  79
  80         return c;
  81 }
  82
  83 void env_relocate_spec(void)
  84 {
  85         char buf_env[CONFIG_ENV_SIZE];
  86         unsigned int off = CONFIG_ENV_OFFSET;
  87
  88 #ifdef CONFIG_ENV_OFFSET_REDUND
  89         ulong len, crc[2], crc_tmp;
  90         unsigned int off_env[2];
  91         uchar rdbuf[64], flags[2];
  92         int i, crc_ok[2] = {0, 0};
  93
  94         eeprom_init();  /* prepare for EEPROM read/write */
  95
  96         off_env[0] = CONFIG_ENV_OFFSET;
  97         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
  98
  99         for (i = 0; i < 2; i++) {
 100                 /* read CRC */
 101                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 102                                 off_env[i] + offsetof(env_t, crc),
 103                                 (uchar *)&crc[i], sizeof(ulong));
 104                 /* read FLAGS */
 105                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 106                                 off_env[i] + offsetof(env_t, flags),
 107                                 (uchar *)&flags[i], sizeof(uchar));
 108
 109                 crc_tmp = 0;
 110                 len = ENV_SIZE;
 111                 off = off_env[i] + offsetof(env_t, data);
 112                 while (len > 0) {
 113                         int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 114
 115                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 116                                         rdbuf, n);
 117
 118                         crc_tmp = crc32(crc_tmp, rdbuf, n);
 119                         len -= n;
 120                         off += n;
 121                 }
 122
 123                 if (crc_tmp == crc[i])
 124                         crc_ok[i] = 1;
 125         }
 126
 127         if (!crc_ok[0] && !crc_ok[1]) {
 128                 gd->env_addr    = 0;
 129                 gd->env_valid   = 0;
 130         } else if (crc_ok[0] && !crc_ok[1]) {
 131                 gd->env_valid = 1;
 132         } else if (!crc_ok[0] && crc_ok[1]) {
 133                 gd->env_valid = 2;
 134         } else {
 135                 /* both ok - check serial */
 136                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 137                         gd->env_valid = 1;
 138                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 139                         gd->env_valid = 2;
 140                 else if (flags[0] == 0xFF && flags[1] == 0)
 141                         gd->env_valid = 2;
 142                 else if (flags[1] == 0xFF && flags[0] == 0)
 143                         gd->env_valid = 1;
 144                 else /* flags are equal - almost impossible */
 145                         gd->env_valid = 1;
 146         }
 147
 148         if (gd->env_valid == 2)
 149                 gd->env_addr = off_env[1] + offsetof(env_t, data);
 150         else if (gd->env_valid == 1)
 151                 gd->env_addr = off_env[0] + offsetof(env_t, data);
 152
 153 #else /* CONFIG_ENV_OFFSET_REDUND */
 154         ulong crc, len, new;
 155         uchar rdbuf[64];
 156
 157         eeprom_init();  /* prepare for EEPROM read/write */
 158
 159         /* read old CRC */
 160         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 161                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 162                         (uchar *)&crc, sizeof(ulong));
 163
 164         new = 0;
 165         len = ENV_SIZE;
 166         off = offsetof(env_t, data);
 167         while (len > 0) {
 168                 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 169
 170                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 171                                 CONFIG_ENV_OFFSET + off, rdbuf, n);
 172                 new = crc32(new, rdbuf, n);
 173                 len -= n;
 174                 off += n;
 175         }
 176
 177         if (crc == new) {
 178                 gd->env_addr    = offsetof(env_t, data);
 179                 gd->env_valid   = 1;
 180         } else {
 181                 gd->env_addr    = 0;
 182                 gd->env_valid   = 0;
 183         }
 184 #endif /* CONFIG_ENV_OFFSET_REDUND */
 185
 186         off = CONFIG_ENV_OFFSET;
 187 #ifdef CONFIG_ENV_OFFSET_REDUND
 188         if (gd->env_valid == 2)
 189                 off = CONFIG_ENV_OFFSET_REDUND;
 190 #endif
 191
 192         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 193                 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
 194
 195         env_import(buf_env, 1);
 196 }
 197
 198 int saveenv(void)
 199 {
 200         env_t   env_new;
 201         int     rc;
 202         unsigned int off        = CONFIG_ENV_OFFSET;
 203 #ifdef CONFIG_ENV_OFFSET_REDUND
 204         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 205         char flag_obsolete      = OBSOLETE_FLAG;
 206 #endif
 207
 208         BUG_ON(env_ptr != NULL);
 209
 210         rc = env_export(&env_new);
 211         if (rc)
 212                 return rc;
 213
 214 #ifdef CONFIG_ENV_OFFSET_REDUND
 215         if (gd->env_valid == 1) {
 216                 off     = CONFIG_ENV_OFFSET_REDUND;
 217                 off_red = CONFIG_ENV_OFFSET;
 218         }
 219
 220         env_new.flags = ACTIVE_FLAG;
 221 #endif
 222
 223         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 224                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 225
 226 #ifdef CONFIG_ENV_OFFSET_REDUND
 227         if (rc == 0) {
 228                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 229                                  off_red + offsetof(env_t, flags),
 230                                  (uchar *)&flag_obsolete, 1);
 231
 232                 if (gd->env_valid == 1)
 233                         gd->env_valid = 2;
 234                 else
 235                         gd->env_valid = 1;
 236         }
 237 #endif
 238         return rc;
 239 }
 240
 241 /*
 242  * Initialize Environment use
 243  *
 244  * We are still running from ROM, so data use is limited.
 245  * Use a (moderately small) buffer on the stack
 246  */
 247 int env_init(void)
 248 {
 249         gd->env_addr = (ulong)&default_environment[0];
 250         gd->env_valid = 1;
 251         return 0;
 252 }