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