i2c: atmel: add i2c driver

Add i2c driver.

Signed-off-by: Songjun Wu <songjun.wu@atmel.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Acked-by: Heiko Schocher <hs@denx.de>
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index b3e8405..8575a23 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -58,6 +58,16 @@
 	  bindings are supported.
 	  Binding info: doc/device-tree-bindings/i2c/i2c-gpio.txt
 
+config SYS_I2C_AT91
+	bool "Atmel I2C driver"
+	depends on DM_I2C && ARCH_AT91
+	help
+	  Add support for the Atmel I2C driver. A serious problem is that there
+	  is no documented way to issue repeated START conditions for more than
+	  two messages, as needed to support combined I2C messages. Use the
+	  i2c-gpio driver unless your system can cope with this limitation.
+	  Binding info: doc/device-tree-bindings/i2c/i2c-at91.txt
+
 config SYS_I2C_FSL
        bool "Freescale I2C bus driver"
        depends on DM_I2C