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