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 int env_eeprom_bus = -1;
  28
  29 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
  30                            uchar *buffer, unsigned cnt)
  31 {
  32         int rcode;
  33 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  34         int old_bus = i2c_get_bus_num();
  35
  36         if (gd->flags & GD_FLG_RELOC) {
  37                 if (env_eeprom_bus == -1) {
  38                         I2C_MUX_DEVICE *dev = NULL;
  39                         dev = i2c_mux_ident_muxstring(
  40                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  41                         if (dev != NULL)
  42                                 env_eeprom_bus = dev->busid;
  43                         else
  44                                 printf("error adding env eeprom bus.\n");
  45                 }
  46                 if (old_bus != env_eeprom_bus) {
  47                         i2c_set_bus_num(env_eeprom_bus);
  48                         old_bus = env_eeprom_bus;
  49                 }
  50         } else {
  51                 rcode = i2c_mux_ident_muxstring_f(
  52                                 (uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  53         }
  54 #endif
  55
  56         rcode = eeprom_read(dev_addr, offset, buffer, cnt);
  57
  58 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  59         if (old_bus != env_eeprom_bus)
  60                 i2c_set_bus_num(old_bus);
  61 #endif
  62         return rcode;
  63 }
  64
  65 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
  66                             uchar *buffer, unsigned cnt)
  67 {
  68         int rcode;
  69 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  70         int old_bus = i2c_get_bus_num();
  71
  72         rcode = i2c_mux_ident_muxstring_f((uchar *)CONFIG_I2C_ENV_EEPROM_BUS);
  73 #endif
  74         rcode = eeprom_write(dev_addr, offset, buffer, cnt);
  75 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  76         i2c_set_bus_num(old_bus);
  77 #endif
  78         return rcode;
  79 }
  80
  81 uchar env_get_char_spec(int index)
  82 {
  83         uchar c;
  84         unsigned int off = CONFIG_ENV_OFFSET;
  85
  86 #ifdef CONFIG_ENV_OFFSET_REDUND
  87         if (gd->env_valid == 2)
  88                 off = CONFIG_ENV_OFFSET_REDUND;
  89 #endif
  90         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
  91                         off + index + offsetof(env_t, data), &c, 1);
  92
  93         return c;
  94 }
  95
  96 void env_relocate_spec(void)
  97 {
  98         char buf[CONFIG_ENV_SIZE];
  99         unsigned int off = CONFIG_ENV_OFFSET;
 100
 101 #ifdef CONFIG_ENV_OFFSET_REDUND
 102         if (gd->env_valid == 2)
 103                 off = CONFIG_ENV_OFFSET_REDUND;
 104 #endif
 105         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 106                         off, (uchar *)buf, CONFIG_ENV_SIZE);
 107
 108         env_import(buf, 1);
 109 }
 110
 111 int saveenv(void)
 112 {
 113         env_t   env_new;
 114         ssize_t len;
 115         char    *res;
 116         int     rc;
 117         unsigned int off        = CONFIG_ENV_OFFSET;
 118 #ifdef CONFIG_ENV_OFFSET_REDUND
 119         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 120         char flag_obsolete      = OBSOLETE_FLAG;
 121 #endif
 122
 123         BUG_ON(env_ptr != NULL);
 124
 125         res = (char *)&env_new.data;
 126         len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
 127         if (len < 0) {
 128                 error("Cannot export environment: errno = %d\n", errno);
 129                 return 1;
 130         }
 131         env_new.crc = crc32(0, env_new.data, ENV_SIZE);
 132
 133 #ifdef CONFIG_ENV_OFFSET_REDUND
 134         if (gd->env_valid == 1) {
 135                 off     = CONFIG_ENV_OFFSET_REDUND;
 136                 off_red = CONFIG_ENV_OFFSET;
 137         }
 138
 139         env_new.flags = ACTIVE_FLAG;
 140 #endif
 141
 142         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 143                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 144
 145 #ifdef CONFIG_ENV_OFFSET_REDUND
 146         if (rc == 0) {
 147                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 148                                  off_red + offsetof(env_t, flags),
 149                                  (uchar *)&flag_obsolete, 1);
 150
 151                 if (gd->env_valid == 1)
 152                         gd->env_valid = 2;
 153                 else
 154                         gd->env_valid = 1;
 155         }
 156 #endif
 157         return rc;
 158 }
 159
 160 /*
 161  * Initialize Environment use
 162  *
 163  * We are still running from ROM, so data use is limited.
 164  * Use a (moderately small) buffer on the stack
 165  */
 166 #ifdef CONFIG_ENV_OFFSET_REDUND
 167 int env_init(void)
 168 {
 169         ulong len, crc[2], crc_tmp;
 170         unsigned int off, off_env[2];
 171         uchar buf[64], flags[2];
 172         int i, crc_ok[2] = {0, 0};
 173
 174         eeprom_init();  /* prepare for EEPROM read/write */
 175
 176         off_env[0] = CONFIG_ENV_OFFSET;
 177         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
 178
 179         for (i = 0; i < 2; i++) {
 180                 /* read CRC */
 181                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 182                                 off_env[i] + offsetof(env_t, crc),
 183                                 (uchar *)&crc[i], sizeof(ulong));
 184                 /* read FLAGS */
 185                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 186                                 off_env[i] + offsetof(env_t, flags),
 187                                 (uchar *)&flags[i], sizeof(uchar));
 188
 189                 crc_tmp = 0;
 190                 len = ENV_SIZE;
 191                 off = off_env[i] + offsetof(env_t, data);
 192                 while (len > 0) {
 193                         int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 194
 195                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 196                                         buf, n);
 197
 198                         crc_tmp = crc32(crc_tmp, buf, n);
 199                         len -= n;
 200                         off += n;
 201                 }
 202
 203                 if (crc_tmp == crc[i])
 204                         crc_ok[i] = 1;
 205         }
 206
 207         if (!crc_ok[0] && !crc_ok[1]) {
 208                 gd->env_addr    = 0;
 209                 gd->env_valid   = 0;
 210
 211                 return 0;
 212         } else if (crc_ok[0] && !crc_ok[1]) {
 213                 gd->env_valid = 1;
 214         } else if (!crc_ok[0] && crc_ok[1]) {
 215                 gd->env_valid = 2;
 216         } else {
 217                 /* both ok - check serial */
 218                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 219                         gd->env_valid = 1;
 220                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 221                         gd->env_valid = 2;
 222                 else if (flags[0] == 0xFF && flags[1] == 0)
 223                         gd->env_valid = 2;
 224                 else if (flags[1] == 0xFF && flags[0] == 0)
 225                         gd->env_valid = 1;
 226                 else /* flags are equal - almost impossible */
 227                         gd->env_valid = 1;
 228         }
 229
 230         if (gd->env_valid == 2)
 231                 gd->env_addr = off_env[1] + offsetof(env_t, data);
 232         else if (gd->env_valid == 1)
 233                 gd->env_addr = off_env[0] + offsetof(env_t, data);
 234
 235         return 0;
 236 }
 237 #else
 238 int env_init(void)
 239 {
 240         ulong crc, len, new;
 241         unsigned off;
 242         uchar buf[64];
 243
 244         eeprom_init();  /* prepare for EEPROM read/write */
 245
 246         /* read old CRC */
 247         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 248                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 249                         (uchar *)&crc, sizeof(ulong));
 250
 251         new = 0;
 252         len = ENV_SIZE;
 253         off = offsetof(env_t, data);
 254
 255         while (len > 0) {
 256                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 257
 258                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 259                                 CONFIG_ENV_OFFSET + off, buf, n);
 260                 new = crc32(new, buf, n);
 261                 len -= n;
 262                 off += n;
 263         }
 264
 265         if (crc == new) {
 266                 gd->env_addr    = offsetof(env_t, data);
 267                 gd->env_valid   = 1;
 268         } else {
 269                 gd->env_addr    = 0;
 270                 gd->env_valid   = 0;
 271         }
 272
 273         return 0;
 274 }
 275 #endif