env/eeprom.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2000-2010
   4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   5  *
   6  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   7  * Andreas Heppel <aheppel@sysgo.de>
   8  */
   9
  10 #include <common.h>
  11 #include <command.h>
  12 #include <environment.h>
  13 #include <linux/stddef.h>
  14 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  15 #include <i2c.h>
  16 #endif
  17 #include <search.h>
  18 #include <errno.h>
  19 #include <linux/compiler.h>     /* for BUG_ON */
  20
  21 DECLARE_GLOBAL_DATA_PTR;
  22
  23 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
  24                            uchar *buffer, unsigned cnt)
  25 {
  26         int rcode;
  27 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  28         int old_bus = i2c_get_bus_num();
  29
  30         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  31                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  32 #endif
  33
  34         rcode = eeprom_read(dev_addr, offset, buffer, cnt);
  35
  36 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  37         i2c_set_bus_num(old_bus);
  38 #endif
  39
  40         return rcode;
  41 }
  42
  43 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
  44                             uchar *buffer, unsigned cnt)
  45 {
  46         int rcode;
  47 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  48         int old_bus = i2c_get_bus_num();
  49
  50         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  51                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  52 #endif
  53
  54         rcode = eeprom_write(dev_addr, offset, buffer, cnt);
  55
  56 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  57         i2c_set_bus_num(old_bus);
  58 #endif
  59
  60         return rcode;
  61 }
  62
  63 /** Call this function from overridden env_get_char_spec() if you need
  64  * this functionality.
  65  */
  66 int env_eeprom_get_char(int index)
  67 {
  68         uchar c;
  69         unsigned int off = CONFIG_ENV_OFFSET;
  70
  71 #ifdef CONFIG_ENV_OFFSET_REDUND
  72         if (gd->env_valid == ENV_REDUND)
  73                 off = CONFIG_ENV_OFFSET_REDUND;
  74 #endif
  75         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
  76                         off + index + offsetof(env_t, data), &c, 1);
  77
  78         return c;
  79 }
  80
  81 static int env_eeprom_load(void)
  82 {
  83         char buf_env[CONFIG_ENV_SIZE];
  84         unsigned int off = CONFIG_ENV_OFFSET;
  85
  86 #ifdef CONFIG_ENV_OFFSET_REDUND
  87         ulong len, crc[2], crc_tmp;
  88         unsigned int off_env[2];
  89         uchar rdbuf[64], flags[2];
  90         int i, crc_ok[2] = {0, 0};
  91
  92         eeprom_init(-1);        /* prepare for EEPROM read/write */
  93
  94         off_env[0] = CONFIG_ENV_OFFSET;
  95         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
  96
  97         for (i = 0; i < 2; i++) {
  98                 /* read CRC */
  99                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 100                                 off_env[i] + offsetof(env_t, crc),
 101                                 (uchar *)&crc[i], sizeof(ulong));
 102                 /* read FLAGS */
 103                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 104                                 off_env[i] + offsetof(env_t, flags),
 105                                 (uchar *)&flags[i], sizeof(uchar));
 106
 107                 crc_tmp = 0;
 108                 len = ENV_SIZE;
 109                 off = off_env[i] + offsetof(env_t, data);
 110                 while (len > 0) {
 111                         int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 112
 113                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 114                                         rdbuf, n);
 115
 116                         crc_tmp = crc32(crc_tmp, rdbuf, n);
 117                         len -= n;
 118                         off += n;
 119                 }
 120
 121                 if (crc_tmp == crc[i])
 122                         crc_ok[i] = 1;
 123         }
 124
 125         if (!crc_ok[0] && !crc_ok[1]) {
 126                 gd->env_addr    = 0;
 127                 gd->env_valid = ENV_INVALID;
 128         } else if (crc_ok[0] && !crc_ok[1]) {
 129                 gd->env_valid = ENV_VALID;
 130         } else if (!crc_ok[0] && crc_ok[1]) {
 131                 gd->env_valid = ENV_REDUND;
 132         } else {
 133                 /* both ok - check serial */
 134                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 135                         gd->env_valid = ENV_VALID;
 136                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 137                         gd->env_valid = ENV_REDUND;
 138                 else if (flags[0] == 0xFF && flags[1] == 0)
 139                         gd->env_valid = ENV_REDUND;
 140                 else if (flags[1] == 0xFF && flags[0] == 0)
 141                         gd->env_valid = ENV_VALID;
 142                 else /* flags are equal - almost impossible */
 143                         gd->env_valid = ENV_VALID;
 144         }
 145
 146 #else /* CONFIG_ENV_OFFSET_REDUND */
 147         ulong crc, len, new;
 148         uchar rdbuf[64];
 149
 150         eeprom_init(-1);        /* prepare for EEPROM read/write */
 151
 152         /* read old CRC */
 153         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 154                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 155                         (uchar *)&crc, sizeof(ulong));
 156
 157         new = 0;
 158         len = ENV_SIZE;
 159         off = offsetof(env_t, data);
 160         while (len > 0) {
 161                 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 162
 163                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 164                                 CONFIG_ENV_OFFSET + off, rdbuf, n);
 165                 new = crc32(new, rdbuf, n);
 166                 len -= n;
 167                 off += n;
 168         }
 169
 170         if (crc == new) {
 171                 gd->env_valid = ENV_VALID;
 172         } else {
 173                 gd->env_valid = ENV_INVALID;
 174         }
 175 #endif /* CONFIG_ENV_OFFSET_REDUND */
 176
 177         off = CONFIG_ENV_OFFSET;
 178 #ifdef CONFIG_ENV_OFFSET_REDUND
 179         if (gd->env_valid == ENV_REDUND)
 180                 off = CONFIG_ENV_OFFSET_REDUND;
 181 #endif
 182
 183         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 184                 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
 185
 186         return env_import(buf_env, 1);
 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         .load           = env_eeprom_load,
 234         .save           = env_save_ptr(env_eeprom_save),
 235 };