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 <linux/stddef.h>
  16 #include <u-boot/crc.h>
  17 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  18 #include <i2c.h>
  19 #endif
  20 #include <search.h>
  21 #include <errno.h>
  22 #include <linux/compiler.h>     /* for BUG_ON */
  23
  24 DECLARE_GLOBAL_DATA_PTR;
  25
  26 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
  27                            uchar *buffer, unsigned cnt)
  28 {
  29         int rcode;
  30 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  31         int old_bus = i2c_get_bus_num();
  32
  33         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  34                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  35 #endif
  36
  37         rcode = eeprom_read(dev_addr, offset, buffer, cnt);
  38
  39 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  40         i2c_set_bus_num(old_bus);
  41 #endif
  42
  43         return rcode;
  44 }
  45
  46 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
  47                             uchar *buffer, unsigned cnt)
  48 {
  49         int rcode;
  50 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  51         int old_bus = i2c_get_bus_num();
  52
  53         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  54                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  55 #endif
  56
  57         rcode = eeprom_write(dev_addr, offset, buffer, cnt);
  58
  59 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  60         i2c_set_bus_num(old_bus);
  61 #endif
  62
  63         return rcode;
  64 }
  65
  66 /** Call this function from overridden env_get_char_spec() if you need
  67  * this functionality.
  68  */
  69 int env_eeprom_get_char(int index)
  70 {
  71         uchar c;
  72         unsigned int off = CONFIG_ENV_OFFSET;
  73
  74 #ifdef CONFIG_ENV_OFFSET_REDUND
  75         if (gd->env_valid == ENV_REDUND)
  76                 off = CONFIG_ENV_OFFSET_REDUND;
  77 #endif
  78         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
  79                         off + index + offsetof(env_t, data), &c, 1);
  80
  81         return c;
  82 }
  83
  84 static int env_eeprom_load(void)
  85 {
  86         char buf_env[CONFIG_ENV_SIZE];
  87         unsigned int off = CONFIG_ENV_OFFSET;
  88
  89 #ifdef CONFIG_ENV_OFFSET_REDUND
  90         ulong len, crc[2], crc_tmp;
  91         unsigned int off_env[2];
  92         uchar rdbuf[64], flags[2];
  93         int i, crc_ok[2] = {0, 0};
  94
  95         eeprom_init(-1);        /* prepare for EEPROM read/write */
  96
  97         off_env[0] = CONFIG_ENV_OFFSET;
  98         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
  99
 100         for (i = 0; i < 2; i++) {
 101                 /* read CRC */
 102                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 103                                 off_env[i] + offsetof(env_t, crc),
 104                                 (uchar *)&crc[i], sizeof(ulong));
 105                 /* read FLAGS */
 106                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 107                                 off_env[i] + offsetof(env_t, flags),
 108                                 (uchar *)&flags[i], sizeof(uchar));
 109
 110                 crc_tmp = 0;
 111                 len = ENV_SIZE;
 112                 off = off_env[i] + offsetof(env_t, data);
 113                 while (len > 0) {
 114                         int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 115
 116                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 117                                         rdbuf, n);
 118
 119                         crc_tmp = crc32(crc_tmp, rdbuf, n);
 120                         len -= n;
 121                         off += n;
 122                 }
 123
 124                 if (crc_tmp == crc[i])
 125                         crc_ok[i] = 1;
 126         }
 127
 128         if (!crc_ok[0] && !crc_ok[1]) {
 129                 gd->env_addr    = 0;
 130                 gd->env_valid = ENV_INVALID;
 131         } else if (crc_ok[0] && !crc_ok[1]) {
 132                 gd->env_valid = ENV_VALID;
 133         } else if (!crc_ok[0] && crc_ok[1]) {
 134                 gd->env_valid = ENV_REDUND;
 135         } else {
 136                 /* both ok - check serial */
 137                 if (flags[0] == ENV_REDUND_ACTIVE &&
 138                     flags[1] == ENV_REDUND_OBSOLETE)
 139                         gd->env_valid = ENV_VALID;
 140                 else if (flags[0] == ENV_REDUND_OBSOLETE &&
 141                          flags[1] == ENV_REDUND_ACTIVE)
 142                         gd->env_valid = ENV_REDUND;
 143                 else if (flags[0] == 0xFF && flags[1] == 0)
 144                         gd->env_valid = ENV_REDUND;
 145                 else if (flags[1] == 0xFF && flags[0] == 0)
 146                         gd->env_valid = ENV_VALID;
 147                 else /* flags are equal - almost impossible */
 148                         gd->env_valid = ENV_VALID;
 149         }
 150
 151 #else /* CONFIG_ENV_OFFSET_REDUND */
 152         ulong crc, len, new;
 153         uchar rdbuf[64];
 154
 155         eeprom_init(-1);        /* prepare for EEPROM read/write */
 156
 157         /* read old CRC */
 158         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 159                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 160                         (uchar *)&crc, sizeof(ulong));
 161
 162         new = 0;
 163         len = ENV_SIZE;
 164         off = offsetof(env_t, data);
 165         while (len > 0) {
 166                 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 167
 168                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 169                                 CONFIG_ENV_OFFSET + off, rdbuf, n);
 170                 new = crc32(new, rdbuf, n);
 171                 len -= n;
 172                 off += n;
 173         }
 174
 175         if (crc == new) {
 176                 gd->env_valid = ENV_VALID;
 177         } else {
 178                 gd->env_valid = ENV_INVALID;
 179         }
 180 #endif /* CONFIG_ENV_OFFSET_REDUND */
 181
 182         off = CONFIG_ENV_OFFSET;
 183 #ifdef CONFIG_ENV_OFFSET_REDUND
 184         if (gd->env_valid == ENV_REDUND)
 185                 off = CONFIG_ENV_OFFSET_REDUND;
 186 #endif
 187
 188         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 189                 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
 190
 191         return env_import(buf_env, 1);
 192 }
 193
 194 static int env_eeprom_save(void)
 195 {
 196         env_t   env_new;
 197         int     rc;
 198         unsigned int off        = CONFIG_ENV_OFFSET;
 199 #ifdef CONFIG_ENV_OFFSET_REDUND
 200         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 201         char flag_obsolete      = ENV_REDUND_OBSOLETE;
 202 #endif
 203
 204         rc = env_export(&env_new);
 205         if (rc)
 206                 return rc;
 207
 208 #ifdef CONFIG_ENV_OFFSET_REDUND
 209         if (gd->env_valid == ENV_VALID) {
 210                 off     = CONFIG_ENV_OFFSET_REDUND;
 211                 off_red = CONFIG_ENV_OFFSET;
 212         }
 213
 214         env_new.flags = ENV_REDUND_ACTIVE;
 215 #endif
 216
 217         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 218                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 219
 220 #ifdef CONFIG_ENV_OFFSET_REDUND
 221         if (rc == 0) {
 222                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 223                                  off_red + offsetof(env_t, flags),
 224                                  (uchar *)&flag_obsolete, 1);
 225
 226                 if (gd->env_valid == ENV_VALID)
 227                         gd->env_valid = ENV_REDUND;
 228                 else
 229                         gd->env_valid = ENV_VALID;
 230         }
 231 #endif
 232         return rc;
 233 }
 234
 235 U_BOOT_ENV_LOCATION(eeprom) = {
 236         .location       = ENVL_EEPROM,
 237         ENV_NAME("EEPROM")
 238         .load           = env_eeprom_load,
 239         .save           = env_save_ptr(env_eeprom_save),
 240 };