eeprom.c 5.4 KB

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