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 <eeprom.h>
  13 #include <env.h>
  14 #include <env_internal.h>
  15 #include <asm/global_data.h>
  16 #include <linux/stddef.h>
  17 #include <u-boot/crc.h>
  18 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  19 #include <i2c.h>
  20 #endif
  21 #include <search.h>
  22 #include <errno.h>
  23 #include <linux/compiler.h>     /* for BUG_ON */
  24
  25 DECLARE_GLOBAL_DATA_PTR;
  26
  27 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
  28                            uchar *buffer, unsigned cnt)
  29 {
  30         int rcode;
  31 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  32         int old_bus = i2c_get_bus_num();
  33
  34         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  35                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  36 #endif
  37
  38         rcode = eeprom_read(dev_addr, offset, buffer, cnt);
  39
  40 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  41         i2c_set_bus_num(old_bus);
  42 #endif
  43
  44         return rcode;
  45 }
  46
  47 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
  48                             uchar *buffer, unsigned cnt)
  49 {
  50         int rcode;
  51 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  52         int old_bus = i2c_get_bus_num();
  53
  54         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  55                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  56 #endif
  57
  58         rcode = eeprom_write(dev_addr, offset, buffer, cnt);
  59
  60 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  61         i2c_set_bus_num(old_bus);
  62 #endif
  63
  64         return rcode;
  65 }
  66
  67 static int env_eeprom_load(void)
  68 {
  69         char buf_env[CONFIG_ENV_SIZE];
  70         unsigned int off = CONFIG_ENV_OFFSET;
  71
  72 #ifdef CONFIG_ENV_OFFSET_REDUND
  73         ulong len, crc[2], crc_tmp;
  74         unsigned int off_env[2];
  75         uchar rdbuf[64], flags[2];
  76         int i, crc_ok[2] = {0, 0};
  77
  78         eeprom_init(-1);        /* prepare for EEPROM read/write */
  79
  80         off_env[0] = CONFIG_ENV_OFFSET;
  81         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
  82
  83         for (i = 0; i < 2; i++) {
  84                 /* read CRC */
  85                 eeprom_bus_read(CONFIG_SYS_I2C_EEPROM_ADDR,
  86                                 off_env[i] + offsetof(env_t, crc),
  87                                 (uchar *)&crc[i], sizeof(ulong));
  88                 /* read FLAGS */
  89                 eeprom_bus_read(CONFIG_SYS_I2C_EEPROM_ADDR,
  90                                 off_env[i] + offsetof(env_t, flags),
  91                                 (uchar *)&flags[i], sizeof(uchar));
  92
  93                 crc_tmp = 0;
  94                 len = ENV_SIZE;
  95                 off = off_env[i] + offsetof(env_t, data);
  96                 while (len > 0) {
  97                         int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
  98
  99                         eeprom_bus_read(CONFIG_SYS_I2C_EEPROM_ADDR, off,
 100                                         rdbuf, n);
 101
 102                         crc_tmp = crc32(crc_tmp, rdbuf, n);
 103                         len -= n;
 104                         off += n;
 105                 }
 106
 107                 if (crc_tmp == crc[i])
 108                         crc_ok[i] = 1;
 109         }
 110
 111         if (!crc_ok[0] && !crc_ok[1]) {
 112                 gd->env_addr    = 0;
 113                 gd->env_valid = ENV_INVALID;
 114         } else if (crc_ok[0] && !crc_ok[1]) {
 115                 gd->env_valid = ENV_VALID;
 116         } else if (!crc_ok[0] && crc_ok[1]) {
 117                 gd->env_valid = ENV_REDUND;
 118         } else {
 119                 /* both ok - check serial */
 120                 if (flags[0] == ENV_REDUND_ACTIVE &&
 121                     flags[1] == ENV_REDUND_OBSOLETE)
 122                         gd->env_valid = ENV_VALID;
 123                 else if (flags[0] == ENV_REDUND_OBSOLETE &&
 124                          flags[1] == ENV_REDUND_ACTIVE)
 125                         gd->env_valid = ENV_REDUND;
 126                 else if (flags[0] == 0xFF && flags[1] == 0)
 127                         gd->env_valid = ENV_REDUND;
 128                 else if (flags[1] == 0xFF && flags[0] == 0)
 129                         gd->env_valid = ENV_VALID;
 130                 else /* flags are equal - almost impossible */
 131                         gd->env_valid = ENV_VALID;
 132         }
 133
 134 #else /* CONFIG_ENV_OFFSET_REDUND */
 135         ulong crc, len, new;
 136         uchar rdbuf[64];
 137
 138         eeprom_init(-1);        /* prepare for EEPROM read/write */
 139
 140         /* read old CRC */
 141         eeprom_bus_read(CONFIG_SYS_I2C_EEPROM_ADDR,
 142                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 143                         (uchar *)&crc, sizeof(ulong));
 144
 145         new = 0;
 146         len = ENV_SIZE;
 147         off = offsetof(env_t, data);
 148         while (len > 0) {
 149                 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 150
 151                 eeprom_bus_read(CONFIG_SYS_I2C_EEPROM_ADDR,
 152                                 CONFIG_ENV_OFFSET + off, rdbuf, n);
 153                 new = crc32(new, rdbuf, n);
 154                 len -= n;
 155                 off += n;
 156         }
 157
 158         if (crc == new) {
 159                 gd->env_valid = ENV_VALID;
 160         } else {
 161                 gd->env_valid = ENV_INVALID;
 162         }
 163 #endif /* CONFIG_ENV_OFFSET_REDUND */
 164
 165         off = CONFIG_ENV_OFFSET;
 166 #ifdef CONFIG_ENV_OFFSET_REDUND
 167         if (gd->env_valid == ENV_REDUND)
 168                 off = CONFIG_ENV_OFFSET_REDUND;
 169 #endif
 170
 171         eeprom_bus_read(CONFIG_SYS_I2C_EEPROM_ADDR,
 172                 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
 173
 174         return env_import(buf_env, 1, H_EXTERNAL);
 175 }
 176
 177 static int env_eeprom_save(void)
 178 {
 179         env_t   env_new;
 180         int     rc;
 181         unsigned int off        = CONFIG_ENV_OFFSET;
 182 #ifdef CONFIG_ENV_OFFSET_REDUND
 183         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 184         char flag_obsolete      = ENV_REDUND_OBSOLETE;
 185 #endif
 186
 187         rc = env_export(&env_new);
 188         if (rc)
 189                 return rc;
 190
 191 #ifdef CONFIG_ENV_OFFSET_REDUND
 192         if (gd->env_valid == ENV_VALID) {
 193                 off     = CONFIG_ENV_OFFSET_REDUND;
 194                 off_red = CONFIG_ENV_OFFSET;
 195         }
 196
 197         env_new.flags = ENV_REDUND_ACTIVE;
 198 #endif
 199
 200         rc = eeprom_bus_write(CONFIG_SYS_I2C_EEPROM_ADDR,
 201                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 202
 203 #ifdef CONFIG_ENV_OFFSET_REDUND
 204         if (rc == 0) {
 205                 eeprom_bus_write(CONFIG_SYS_I2C_EEPROM_ADDR,
 206                                  off_red + offsetof(env_t, flags),
 207                                  (uchar *)&flag_obsolete, 1);
 208
 209                 if (gd->env_valid == ENV_VALID)
 210                         gd->env_valid = ENV_REDUND;
 211                 else
 212                         gd->env_valid = ENV_VALID;
 213         }
 214 #endif
 215         return rc;
 216 }
 217
 218 U_BOOT_ENV_LOCATION(eeprom) = {
 219         .location       = ENVL_EEPROM,
 220         ENV_NAME("EEPROM")
 221         .load           = env_eeprom_load,
 222         .save           = env_save_ptr(env_eeprom_save),
 223 };