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 /** Call this function from overridden env_get_char_spec() if you need
  68  * this functionality.
  69  */
  70 int env_eeprom_get_char(int index)
  71 {
  72         uchar c;
  73         unsigned int off = CONFIG_ENV_OFFSET;
  74
  75 #ifdef CONFIG_ENV_OFFSET_REDUND
  76         if (gd->env_valid == ENV_REDUND)
  77                 off = CONFIG_ENV_OFFSET_REDUND;
  78 #endif
  79         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
  80                         off + index + offsetof(env_t, data), &c, 1);
  81
  82         return c;
  83 }
  84
  85 static int env_eeprom_load(void)
  86 {
  87         char buf_env[CONFIG_ENV_SIZE];
  88         unsigned int off = CONFIG_ENV_OFFSET;
  89
  90 #ifdef CONFIG_ENV_OFFSET_REDUND
  91         ulong len, crc[2], crc_tmp;
  92         unsigned int off_env[2];
  93         uchar rdbuf[64], flags[2];
  94         int i, crc_ok[2] = {0, 0};
  95
  96         eeprom_init(-1);        /* prepare for EEPROM read/write */
  97
  98         off_env[0] = CONFIG_ENV_OFFSET;
  99         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
 100
 101         for (i = 0; i < 2; i++) {
 102                 /* read CRC */
 103                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 104                                 off_env[i] + offsetof(env_t, crc),
 105                                 (uchar *)&crc[i], sizeof(ulong));
 106                 /* read FLAGS */
 107                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 108                                 off_env[i] + offsetof(env_t, flags),
 109                                 (uchar *)&flags[i], sizeof(uchar));
 110
 111                 crc_tmp = 0;
 112                 len = ENV_SIZE;
 113                 off = off_env[i] + offsetof(env_t, data);
 114                 while (len > 0) {
 115                         int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 116
 117                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 118                                         rdbuf, n);
 119
 120                         crc_tmp = crc32(crc_tmp, rdbuf, n);
 121                         len -= n;
 122                         off += n;
 123                 }
 124
 125                 if (crc_tmp == crc[i])
 126                         crc_ok[i] = 1;
 127         }
 128
 129         if (!crc_ok[0] && !crc_ok[1]) {
 130                 gd->env_addr    = 0;
 131                 gd->env_valid = ENV_INVALID;
 132         } else if (crc_ok[0] && !crc_ok[1]) {
 133                 gd->env_valid = ENV_VALID;
 134         } else if (!crc_ok[0] && crc_ok[1]) {
 135                 gd->env_valid = ENV_REDUND;
 136         } else {
 137                 /* both ok - check serial */
 138                 if (flags[0] == ENV_REDUND_ACTIVE &&
 139                     flags[1] == ENV_REDUND_OBSOLETE)
 140                         gd->env_valid = ENV_VALID;
 141                 else if (flags[0] == ENV_REDUND_OBSOLETE &&
 142                          flags[1] == ENV_REDUND_ACTIVE)
 143                         gd->env_valid = ENV_REDUND;
 144                 else if (flags[0] == 0xFF && flags[1] == 0)
 145                         gd->env_valid = ENV_REDUND;
 146                 else if (flags[1] == 0xFF && flags[0] == 0)
 147                         gd->env_valid = ENV_VALID;
 148                 else /* flags are equal - almost impossible */
 149                         gd->env_valid = ENV_VALID;
 150         }
 151
 152 #else /* CONFIG_ENV_OFFSET_REDUND */
 153         ulong crc, len, new;
 154         uchar rdbuf[64];
 155
 156         eeprom_init(-1);        /* prepare for EEPROM read/write */
 157
 158         /* read old CRC */
 159         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 160                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 161                         (uchar *)&crc, sizeof(ulong));
 162
 163         new = 0;
 164         len = ENV_SIZE;
 165         off = offsetof(env_t, data);
 166         while (len > 0) {
 167                 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 168
 169                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 170                                 CONFIG_ENV_OFFSET + off, rdbuf, n);
 171                 new = crc32(new, rdbuf, n);
 172                 len -= n;
 173                 off += n;
 174         }
 175
 176         if (crc == new) {
 177                 gd->env_valid = ENV_VALID;
 178         } else {
 179                 gd->env_valid = ENV_INVALID;
 180         }
 181 #endif /* CONFIG_ENV_OFFSET_REDUND */
 182
 183         off = CONFIG_ENV_OFFSET;
 184 #ifdef CONFIG_ENV_OFFSET_REDUND
 185         if (gd->env_valid == ENV_REDUND)
 186                 off = CONFIG_ENV_OFFSET_REDUND;
 187 #endif
 188
 189         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 190                 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
 191
 192         return env_import(buf_env, 1, H_EXTERNAL);
 193 }
 194
 195 static int env_eeprom_save(void)
 196 {
 197         env_t   env_new;
 198         int     rc;
 199         unsigned int off        = CONFIG_ENV_OFFSET;
 200 #ifdef CONFIG_ENV_OFFSET_REDUND
 201         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 202         char flag_obsolete      = ENV_REDUND_OBSOLETE;
 203 #endif
 204
 205         rc = env_export(&env_new);
 206         if (rc)
 207                 return rc;
 208
 209 #ifdef CONFIG_ENV_OFFSET_REDUND
 210         if (gd->env_valid == ENV_VALID) {
 211                 off     = CONFIG_ENV_OFFSET_REDUND;
 212                 off_red = CONFIG_ENV_OFFSET;
 213         }
 214
 215         env_new.flags = ENV_REDUND_ACTIVE;
 216 #endif
 217
 218         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 219                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 220
 221 #ifdef CONFIG_ENV_OFFSET_REDUND
 222         if (rc == 0) {
 223                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 224                                  off_red + offsetof(env_t, flags),
 225                                  (uchar *)&flag_obsolete, 1);
 226
 227                 if (gd->env_valid == ENV_VALID)
 228                         gd->env_valid = ENV_REDUND;
 229                 else
 230                         gd->env_valid = ENV_VALID;
 231         }
 232 #endif
 233         return rc;
 234 }
 235
 236 U_BOOT_ENV_LOCATION(eeprom) = {
 237         .location       = ENVL_EEPROM,
 238         ENV_NAME("EEPROM")
 239         .load           = env_eeprom_load,
 240         .save           = env_save_ptr(env_eeprom_save),
 241 };