From 3addcb9343dbf1d9c8465210a887180edc326270 Mon Sep 17 00:00:00 2001 From: Timur Tabi Date: Mon, 2 Aug 2010 13:03:23 -0500 Subject: [PATCH] fsl: verify writes to the MAC address EEPROM Update the code which writes to the on-board EEPROM so that it can detect if the write failed because the EEPROM is write-protected. Most of the 8xxx-class Freescale reference boards use an AT24C02 EEPROM to store MAC addresses and similar information. With this patch, if the EEPROM is protected, the "mac save" command will display an error message indicating that the write has not succeeded. Signed-off-by: Timur Tabi Signed-off-by: Kumar Gala --- board/freescale/common/sys_eeprom.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/board/freescale/common/sys_eeprom.c b/board/freescale/common/sys_eeprom.c index 3929ad0aac..43f61f9541 100644 --- a/board/freescale/common/sys_eeprom.c +++ b/board/freescale/common/sys_eeprom.c @@ -204,7 +204,7 @@ static void update_crc(void) */ static int prog_eeprom(void) { - int ret = 0; /* shut up gcc */ + int ret = 0; int i; void *p; #ifdef CONFIG_SYS_EEPROM_BUS_NUM @@ -225,6 +225,11 @@ static int prog_eeprom(void) i2c_set_bus_num(CONFIG_SYS_EEPROM_BUS_NUM); #endif + /* + * The AT24C02 datasheet says that data can only be written in page + * mode, which means 8 bytes at a time, and it takes up to 5ms to + * complete a given write. + */ for (i = 0, p = &e; i < sizeof(e); i += 8, p += 8) { ret = i2c_write(CONFIG_SYS_I2C_EEPROM_ADDR, i, CONFIG_SYS_I2C_EEPROM_ADDR_LEN, p, min((sizeof(e) - i), 8)); @@ -233,12 +238,23 @@ static int prog_eeprom(void) udelay(5000); /* 5ms write cycle timing */ } + if (!ret) { + /* Verify the write by reading back the EEPROM and comparing */ + struct eeprom e2; + + ret = i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, 0, + CONFIG_SYS_I2C_EEPROM_ADDR_LEN, (void *)&e2, sizeof(e2)); + if (!ret && memcmp(&e, &e2, sizeof(e))) + ret = -1; + } + #ifdef CONFIG_SYS_EEPROM_BUS_NUM i2c_set_bus_num(bus); #endif if (ret) { printf("Programming failed.\n"); + has_been_read = 0; return -1; } -- 2.25.1