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 <env.h>
  13 #include <env_internal.h>
  14 #include <linux/stddef.h>
  15 #include <u-boot/crc.h>
  16 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  17 #include <i2c.h>
  18 #endif
  19 #include <search.h>
  20 #include <errno.h>
  21 #include <linux/compiler.h>     /* for BUG_ON */
  22
  23 DECLARE_GLOBAL_DATA_PTR;
  24
  25 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
  26                            uchar *buffer, unsigned cnt)
  27 {
  28         int rcode;
  29 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  30         int old_bus = i2c_get_bus_num();
  31
  32         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  33                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  34 #endif
  35
  36         rcode = eeprom_read(dev_addr, offset, buffer, cnt);
  37
  38 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  39         i2c_set_bus_num(old_bus);
  40 #endif
  41
  42         return rcode;
  43 }
  44
  45 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
  46                             uchar *buffer, unsigned cnt)
  47 {
  48         int rcode;
  49 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  50         int old_bus = i2c_get_bus_num();
  51
  52         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  53                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  54 #endif
  55
  56         rcode = eeprom_write(dev_addr, offset, buffer, cnt);
  57
  58 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  59         i2c_set_bus_num(old_bus);
  60 #endif
  61
  62         return rcode;
  63 }
  64
  65 /** Call this function from overridden env_get_char_spec() if you need
  66  * this functionality.
  67  */
  68 int env_eeprom_get_char(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 == ENV_REDUND)
  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 static int env_eeprom_load(void)
  84 {
  85         char buf_env[CONFIG_ENV_SIZE];
  86         unsigned int off = CONFIG_ENV_OFFSET;
  87
  88 #ifdef CONFIG_ENV_OFFSET_REDUND
  89         ulong len, crc[2], crc_tmp;
  90         unsigned int off_env[2];
  91         uchar rdbuf[64], flags[2];
  92         int i, crc_ok[2] = {0, 0};
  93
  94         eeprom_init(-1);        /* prepare for EEPROM read/write */
  95
  96         off_env[0] = CONFIG_ENV_OFFSET;
  97         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
  98
  99         for (i = 0; i < 2; i++) {
 100                 /* read CRC */
 101                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 102                                 off_env[i] + offsetof(env_t, crc),
 103                                 (uchar *)&crc[i], sizeof(ulong));
 104                 /* read FLAGS */
 105                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 106                                 off_env[i] + offsetof(env_t, flags),
 107                                 (uchar *)&flags[i], sizeof(uchar));
 108
 109                 crc_tmp = 0;
 110                 len = ENV_SIZE;
 111                 off = off_env[i] + offsetof(env_t, data);
 112                 while (len > 0) {
 113                         int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 114
 115                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 116                                         rdbuf, n);
 117
 118                         crc_tmp = crc32(crc_tmp, rdbuf, n);
 119                         len -= n;
 120                         off += n;
 121                 }
 122
 123                 if (crc_tmp == crc[i])
 124                         crc_ok[i] = 1;
 125         }
 126
 127         if (!crc_ok[0] && !crc_ok[1]) {
 128                 gd->env_addr    = 0;
 129                 gd->env_valid = ENV_INVALID;
 130         } else if (crc_ok[0] && !crc_ok[1]) {
 131                 gd->env_valid = ENV_VALID;
 132         } else if (!crc_ok[0] && crc_ok[1]) {
 133                 gd->env_valid = ENV_REDUND;
 134         } else {
 135                 /* both ok - check serial */
 136                 if (flags[0] == ENV_REDUND_ACTIVE &&
 137                     flags[1] == ENV_REDUND_OBSOLETE)
 138                         gd->env_valid = ENV_VALID;
 139                 else if (flags[0] == ENV_REDUND_OBSOLETE &&
 140                          flags[1] == ENV_REDUND_ACTIVE)
 141                         gd->env_valid = ENV_REDUND;
 142                 else if (flags[0] == 0xFF && flags[1] == 0)
 143                         gd->env_valid = ENV_REDUND;
 144                 else if (flags[1] == 0xFF && flags[0] == 0)
 145                         gd->env_valid = ENV_VALID;
 146                 else /* flags are equal - almost impossible */
 147                         gd->env_valid = ENV_VALID;
 148         }
 149
 150 #else /* CONFIG_ENV_OFFSET_REDUND */
 151         ulong crc, len, new;
 152         uchar rdbuf[64];
 153
 154         eeprom_init(-1);        /* prepare for EEPROM read/write */
 155
 156         /* read old CRC */
 157         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 158                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 159                         (uchar *)&crc, sizeof(ulong));
 160
 161         new = 0;
 162         len = ENV_SIZE;
 163         off = offsetof(env_t, data);
 164         while (len > 0) {
 165                 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 166
 167                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 168                                 CONFIG_ENV_OFFSET + off, rdbuf, n);
 169                 new = crc32(new, rdbuf, n);
 170                 len -= n;
 171                 off += n;
 172         }
 173
 174         if (crc == new) {
 175                 gd->env_valid = ENV_VALID;
 176         } else {
 177                 gd->env_valid = ENV_INVALID;
 178         }
 179 #endif /* CONFIG_ENV_OFFSET_REDUND */
 180
 181         off = CONFIG_ENV_OFFSET;
 182 #ifdef CONFIG_ENV_OFFSET_REDUND
 183         if (gd->env_valid == ENV_REDUND)
 184                 off = CONFIG_ENV_OFFSET_REDUND;
 185 #endif
 186
 187         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 188                 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
 189
 190         return env_import(buf_env, 1);
 191 }
 192
 193 static int env_eeprom_save(void)
 194 {
 195         env_t   env_new;
 196         int     rc;
 197         unsigned int off        = CONFIG_ENV_OFFSET;
 198 #ifdef CONFIG_ENV_OFFSET_REDUND
 199         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 200         char flag_obsolete      = ENV_REDUND_OBSOLETE;
 201 #endif
 202
 203         rc = env_export(&env_new);
 204         if (rc)
 205                 return rc;
 206
 207 #ifdef CONFIG_ENV_OFFSET_REDUND
 208         if (gd->env_valid == ENV_VALID) {
 209                 off     = CONFIG_ENV_OFFSET_REDUND;
 210                 off_red = CONFIG_ENV_OFFSET;
 211         }
 212
 213         env_new.flags = ENV_REDUND_ACTIVE;
 214 #endif
 215
 216         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 217                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 218
 219 #ifdef CONFIG_ENV_OFFSET_REDUND
 220         if (rc == 0) {
 221                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 222                                  off_red + offsetof(env_t, flags),
 223                                  (uchar *)&flag_obsolete, 1);
 224
 225                 if (gd->env_valid == ENV_VALID)
 226                         gd->env_valid = ENV_REDUND;
 227                 else
 228                         gd->env_valid = ENV_VALID;
 229         }
 230 #endif
 231         return rc;
 232 }
 233
 234 U_BOOT_ENV_LOCATION(eeprom) = {
 235         .location       = ENVL_EEPROM,
 236         ENV_NAME("EEPROM")
 237         .load           = env_eeprom_load,
 238         .save           = env_save_ptr(env_eeprom_save),
 239 };