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[CONFIG_ENV_SIZE];
  86         unsigned int off = CONFIG_ENV_OFFSET;
  87
  88 #ifdef CONFIG_ENV_OFFSET_REDUND
  89         if (gd->env_valid == 2)
  90                 off = CONFIG_ENV_OFFSET_REDUND;
  91 #endif
  92         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
  93                         off, (uchar *)buf, CONFIG_ENV_SIZE);
  94
  95         env_import(buf, 1);
  96 }
  97
  98 int saveenv(void)
  99 {
 100         env_t   env_new;
 101         int     rc;
 102         unsigned int off        = CONFIG_ENV_OFFSET;
 103 #ifdef CONFIG_ENV_OFFSET_REDUND
 104         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 105         char flag_obsolete      = OBSOLETE_FLAG;
 106 #endif
 107
 108         BUG_ON(env_ptr != NULL);
 109
 110         rc = env_export(&env_new);
 111         if (rc)
 112                 return rc;
 113
 114 #ifdef CONFIG_ENV_OFFSET_REDUND
 115         if (gd->env_valid == 1) {
 116                 off     = CONFIG_ENV_OFFSET_REDUND;
 117                 off_red = CONFIG_ENV_OFFSET;
 118         }
 119
 120         env_new.flags = ACTIVE_FLAG;
 121 #endif
 122
 123         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 124                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 125
 126 #ifdef CONFIG_ENV_OFFSET_REDUND
 127         if (rc == 0) {
 128                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 129                                  off_red + offsetof(env_t, flags),
 130                                  (uchar *)&flag_obsolete, 1);
 131
 132                 if (gd->env_valid == 1)
 133                         gd->env_valid = 2;
 134                 else
 135                         gd->env_valid = 1;
 136         }
 137 #endif
 138         return rc;
 139 }
 140
 141 /*
 142  * Initialize Environment use
 143  *
 144  * We are still running from ROM, so data use is limited.
 145  * Use a (moderately small) buffer on the stack
 146  */
 147 #ifdef CONFIG_ENV_OFFSET_REDUND
 148 int env_init(void)
 149 {
 150         ulong len, crc[2], crc_tmp;
 151         unsigned int off, off_env[2];
 152         uchar buf[64], flags[2];
 153         int i, crc_ok[2] = {0, 0};
 154
 155         eeprom_init();  /* prepare for EEPROM read/write */
 156
 157         off_env[0] = CONFIG_ENV_OFFSET;
 158         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
 159
 160         for (i = 0; i < 2; i++) {
 161                 /* read CRC */
 162                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 163                                 off_env[i] + offsetof(env_t, crc),
 164                                 (uchar *)&crc[i], sizeof(ulong));
 165                 /* read FLAGS */
 166                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 167                                 off_env[i] + offsetof(env_t, flags),
 168                                 (uchar *)&flags[i], sizeof(uchar));
 169
 170                 crc_tmp = 0;
 171                 len = ENV_SIZE;
 172                 off = off_env[i] + offsetof(env_t, data);
 173                 while (len > 0) {
 174                         int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 175
 176                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 177                                         buf, n);
 178
 179                         crc_tmp = crc32(crc_tmp, buf, n);
 180                         len -= n;
 181                         off += n;
 182                 }
 183
 184                 if (crc_tmp == crc[i])
 185                         crc_ok[i] = 1;
 186         }
 187
 188         if (!crc_ok[0] && !crc_ok[1]) {
 189                 gd->env_addr    = 0;
 190                 gd->env_valid   = 0;
 191
 192                 return 0;
 193         } else if (crc_ok[0] && !crc_ok[1]) {
 194                 gd->env_valid = 1;
 195         } else if (!crc_ok[0] && crc_ok[1]) {
 196                 gd->env_valid = 2;
 197         } else {
 198                 /* both ok - check serial */
 199                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 200                         gd->env_valid = 1;
 201                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 202                         gd->env_valid = 2;
 203                 else if (flags[0] == 0xFF && flags[1] == 0)
 204                         gd->env_valid = 2;
 205                 else if (flags[1] == 0xFF && flags[0] == 0)
 206                         gd->env_valid = 1;
 207                 else /* flags are equal - almost impossible */
 208                         gd->env_valid = 1;
 209         }
 210
 211         if (gd->env_valid == 2)
 212                 gd->env_addr = off_env[1] + offsetof(env_t, data);
 213         else if (gd->env_valid == 1)
 214                 gd->env_addr = off_env[0] + offsetof(env_t, data);
 215
 216         return 0;
 217 }
 218 #else
 219 int env_init(void)
 220 {
 221         ulong crc, len, new;
 222         unsigned off;
 223         uchar buf[64];
 224
 225         eeprom_init();  /* prepare for EEPROM read/write */
 226
 227         /* read old CRC */
 228         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 229                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 230                         (uchar *)&crc, sizeof(ulong));
 231
 232         new = 0;
 233         len = ENV_SIZE;
 234         off = offsetof(env_t, data);
 235
 236         while (len > 0) {
 237                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 238
 239                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 240                                 CONFIG_ENV_OFFSET + off, buf, n);
 241                 new = crc32(new, buf, n);
 242                 len -= n;
 243                 off += n;
 244         }
 245
 246         if (crc == new) {
 247                 gd->env_addr    = offsetof(env_t, data);
 248                 gd->env_valid   = 1;
 249         } else {
 250                 gd->env_addr    = 0;
 251                 gd->env_valid   = 0;
 252         }
 253
 254         return 0;
 255 }
 256 #endif