compulab: eeprom: add support for defining eeprom i2c bus

Create CONFIG_SYS_I2C_EEPROM_BUS #define to tell the EEPROM
module what I2C bus the EEPROM is located at. Make cl_eeprom_read()
switch to that bus when reading EEPROM.

Cc: Igor Grinberg <grinberg@compulab.co.il>
Cc: Dmitry Lifshitz <lifshitz@compulab.co.il>
Cc: Tom Rini <trini@ti.com>
Cc: Marek Vasut <marex@denx.de>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
Acked-by: Dmitry Lifshitz <lifshitz@compulab.co.il>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>

board/compulab/common/eeprom.c

@@ -31,8 +31,19 @@ static int cl_eeprom_layout; /* Implicitly LAYOUT_INVALID */
 
 static int cl_eeprom_read(uint offset, uchar *buf, int len)
 {
-	return i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, offset,
+	int res;
+	unsigned int current_i2c_bus = i2c_get_bus_num();
+
+	res = i2c_set_bus_num(CONFIG_SYS_I2C_EEPROM_BUS);
+	if (res < 0)
+		return res;
+
+	res = i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, offset,
 			CONFIG_SYS_I2C_EEPROM_ADDR_LEN, buf, len);
+
+	i2c_set_bus_num(current_i2c_bus);
+
+	return res;
 }
 
 static int cl_eeprom_setup_layout(void)

include/configs/cm_t335.h

@@ -107,6 +107,7 @@
 /* I2C Configuration */
 #define CONFIG_SYS_I2C_EEPROM_ADDR	0x50	/* Main EEPROM */
 #define CONFIG_SYS_I2C_EEPROM_ADDR_LEN	1
+#define CONFIG_SYS_I2C_EEPROM_BUS	0
 
 /* SPL */
 #define CONFIG_SPL_LDSCRIPT		"$(CPUDIR)/am33xx/u-boot-spl.lds"

include/configs/cm_t35.h

@@ -135,6 +135,7 @@
 #define CONFIG_SYS_I2C_OMAP34XX
 #define CONFIG_SYS_I2C_EEPROM_ADDR	0x50
 #define CONFIG_SYS_I2C_EEPROM_ADDR_LEN	1
+#define CONFIG_SYS_I2C_EEPROM_BUS	0
 #define CONFIG_I2C_MULTI_BUS
 
 /*

include/configs/cm_t54.h

@@ -30,6 +30,7 @@
 #define CONFIG_SYS_I2C_OMAP34XX
 #define CONFIG_SYS_I2C_EEPROM_ADDR	0x50
 #define CONFIG_SYS_I2C_EEPROM_ADDR_LEN	1
+#define CONFIG_SYS_I2C_EEPROM_BUS	0
 
 /* Enable SD/MMC CD and WP GPIOs */
 #define OMAP_HSMMC_USE_GPIO