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 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
  25                            uchar *buffer, unsigned cnt)
  26 {
  27         int rcode;
  28 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  29         int old_bus = i2c_get_bus_num();
  30
  31         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  32                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  33 #endif
  34
  35         rcode = eeprom_read(dev_addr, offset, buffer, cnt);
  36
  37 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  38         i2c_set_bus_num(old_bus);
  39 #endif
  40
  41         return rcode;
  42 }
  43
  44 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
  45                             uchar *buffer, unsigned cnt)
  46 {
  47         int rcode;
  48 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  49         int old_bus = i2c_get_bus_num();
  50
  51         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  52                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  53 #endif
  54
  55         rcode = eeprom_write(dev_addr, offset, buffer, cnt);
  56
  57 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  58         i2c_set_bus_num(old_bus);
  59 #endif
  60
  61         return rcode;
  62 }
  63
  64 static int env_eeprom_get_char(int index)
  65 {
  66         uchar c;
  67         unsigned int off = CONFIG_ENV_OFFSET;
  68
  69 #ifdef CONFIG_ENV_OFFSET_REDUND
  70         if (gd->env_valid == ENV_REDUND)
  71                 off = CONFIG_ENV_OFFSET_REDUND;
  72 #endif
  73         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
  74                         off + index + offsetof(env_t, data), &c, 1);
  75
  76         return c;
  77 }
  78
  79 static int env_eeprom_load(void)
  80 {
  81         char buf_env[CONFIG_ENV_SIZE];
  82         unsigned int off = CONFIG_ENV_OFFSET;
  83
  84 #ifdef CONFIG_ENV_OFFSET_REDUND
  85         ulong len, crc[2], crc_tmp;
  86         unsigned int off_env[2];
  87         uchar rdbuf[64], flags[2];
  88         int i, crc_ok[2] = {0, 0};
  89
  90         eeprom_init(-1);        /* prepare for EEPROM read/write */
  91
  92         off_env[0] = CONFIG_ENV_OFFSET;
  93         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
  94
  95         for (i = 0; i < 2; i++) {
  96                 /* read CRC */
  97                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
  98                                 off_env[i] + offsetof(env_t, crc),
  99                                 (uchar *)&crc[i], sizeof(ulong));
 100                 /* read FLAGS */
 101                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 102                                 off_env[i] + offsetof(env_t, flags),
 103                                 (uchar *)&flags[i], sizeof(uchar));
 104
 105                 crc_tmp = 0;
 106                 len = ENV_SIZE;
 107                 off = off_env[i] + offsetof(env_t, data);
 108                 while (len > 0) {
 109                         int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 110
 111                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 112                                         rdbuf, n);
 113
 114                         crc_tmp = crc32(crc_tmp, rdbuf, n);
 115                         len -= n;
 116                         off += n;
 117                 }
 118
 119                 if (crc_tmp == crc[i])
 120                         crc_ok[i] = 1;
 121         }
 122
 123         if (!crc_ok[0] && !crc_ok[1]) {
 124                 gd->env_addr    = 0;
 125                 gd->env_valid = ENV_INVALID;
 126         } else if (crc_ok[0] && !crc_ok[1]) {
 127                 gd->env_valid = ENV_VALID;
 128         } else if (!crc_ok[0] && crc_ok[1]) {
 129                 gd->env_valid = ENV_REDUND;
 130         } else {
 131                 /* both ok - check serial */
 132                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 133                         gd->env_valid = ENV_VALID;
 134                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 135                         gd->env_valid = ENV_REDUND;
 136                 else if (flags[0] == 0xFF && flags[1] == 0)
 137                         gd->env_valid = ENV_REDUND;
 138                 else if (flags[1] == 0xFF && flags[0] == 0)
 139                         gd->env_valid = ENV_VALID;
 140                 else /* flags are equal - almost impossible */
 141                         gd->env_valid = ENV_VALID;
 142         }
 143
 144 #else /* CONFIG_ENV_OFFSET_REDUND */
 145         ulong crc, len, new;
 146         uchar rdbuf[64];
 147
 148         eeprom_init(-1);        /* prepare for EEPROM read/write */
 149
 150         /* read old CRC */
 151         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 152                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 153                         (uchar *)&crc, sizeof(ulong));
 154
 155         new = 0;
 156         len = ENV_SIZE;
 157         off = offsetof(env_t, data);
 158         while (len > 0) {
 159                 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 160
 161                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 162                                 CONFIG_ENV_OFFSET + off, rdbuf, n);
 163                 new = crc32(new, rdbuf, n);
 164                 len -= n;
 165                 off += n;
 166         }
 167
 168         if (crc == new) {
 169                 gd->env_valid = ENV_VALID;
 170         } else {
 171                 gd->env_valid = ENV_INVALID;
 172         }
 173 #endif /* CONFIG_ENV_OFFSET_REDUND */
 174
 175         off = CONFIG_ENV_OFFSET;
 176 #ifdef CONFIG_ENV_OFFSET_REDUND
 177         if (gd->env_valid == ENV_REDUND)
 178                 off = CONFIG_ENV_OFFSET_REDUND;
 179 #endif
 180
 181         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 182                 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
 183
 184         env_import(buf_env, 1);
 185
 186         return 0;
 187 }
 188
 189 static int env_eeprom_save(void)
 190 {
 191         env_t   env_new;
 192         int     rc;
 193         unsigned int off        = CONFIG_ENV_OFFSET;
 194 #ifdef CONFIG_ENV_OFFSET_REDUND
 195         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 196         char flag_obsolete      = OBSOLETE_FLAG;
 197 #endif
 198
 199         rc = env_export(&env_new);
 200         if (rc)
 201                 return rc;
 202
 203 #ifdef CONFIG_ENV_OFFSET_REDUND
 204         if (gd->env_valid == ENV_VALID) {
 205                 off     = CONFIG_ENV_OFFSET_REDUND;
 206                 off_red = CONFIG_ENV_OFFSET;
 207         }
 208
 209         env_new.flags = ACTIVE_FLAG;
 210 #endif
 211
 212         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 213                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 214
 215 #ifdef CONFIG_ENV_OFFSET_REDUND
 216         if (rc == 0) {
 217                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 218                                  off_red + offsetof(env_t, flags),
 219                                  (uchar *)&flag_obsolete, 1);
 220
 221                 if (gd->env_valid == ENV_VALID)
 222                         gd->env_valid = ENV_REDUND;
 223                 else
 224                         gd->env_valid = ENV_VALID;
 225         }
 226 #endif
 227         return rc;
 228 }
 229
 230 U_BOOT_ENV_LOCATION(eeprom) = {
 231         .location       = ENVL_EEPROM,
 232         ENV_NAME("EEPROM")
 233         .get_char       = env_eeprom_get_char,
 234         .load           = env_eeprom_load,
 235         .save           = env_save_ptr(env_eeprom_save),
 236 };