eXMeritus HWW-1U-1A: Add support for the AT24C128N I2C EEPROM

[u-boot] / include / configs / HWW1U1A.h

diff --git a/include/configs/HWW1U1A.h b/include/configs/HWW1U1A.h
index 168f70feb9b3b2c3ed99773722d468a98296fc20..01597b965b6ce16e2584b640eee76336050988d8 100644 (file)
--- a/include/configs/HWW1U1A.h
+++ b/include/configs/HWW1U1A.h
@@ -240,7 +240,29 @@
 /* Turn off RTC square-wave output to save battery */
 #define CONFIG_SYS_RTC_DS1337_NOOSC
 
-/* PCA9554 is at I2C1-0x3f (I know it says "PCA953X", it's a PCA9554) */
+/*
+ * AT24C128N EEPROM at I2C0-0x53.
+ *
+ * That Atmel EEPROM has 128kbit of memory (16kByte) divided into 256 pages
+ * of 64 bytes per page.  The chip uses 2-byte addresses and has a max write
+ * cycle time of 20ms according to the datasheet.
+ *
+ * NOTE: Our environment is stored on regular direct-attached FLASH, this
+ * chip is only used as a write-protected backup for certain key settings
+ * such as the serial# and macaddr values.  (EG: "env import")
+ */
+#define CONFIG_CMD_EEPROM
+#define CONFIG_ENV_EEPROM_IS_ON_I2C
+#define CONFIG_SYS_I2C_EEPROM_ADDR 0x53
+#define CONFIG_SYS_I2C_EEPROM_ADDR_LEN 2
+#define CONFIG_SYS_EEPROM_PAGE_WRITE_BITS 6 /* 1 << 6 == 64 byte pages */
+#define CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS 21
+
+/*
+ * PCA9554 is at I2C1-0x3f (I know it says "PCA953X", it's a PCA9554).  You
+ * must first select the I2C1 bus with "i2c dev 1" or the "pca953x" command
+ * will not be able to access the chip.
+ */
 #define CONFIG_PCA953X
 #define CONFIG_CMD_PCA953X
 #define CONFIG_CMD_PCA953X_INFO
@@ -449,6 +471,9 @@ const char *hww1u1a_get_ps1(void);
        "flinitramfs=0xe8800000\0"                                      \
        "fldevicetree=0xeff20000\0"                                     \
        "flbootm=bootm ${flkernel} ${flinitramfs} ${fldevicetree}\0"    \
-       "flboot=run preboot; run flbootm\0"
+       "flboot=run preboot; run flbootm\0"                             \
+       "restore_eeprom=i2c dev 0 && "                                  \
+                       "eeprom read $loadaddr 0x0000 0x2000 && "       \
+                       "env import -c $loadaddr 0x2000\0"
 
 #endif /* __CONFIG_H */