aspeed: Add I2C Driver

Add Device Model based I2C driver for ast2500/ast2400 SoCs.
The driver is very limited, it only supports master mode and
synchronous byte-by-byte reads/writes, no DMA or Pool Buffers.

Signed-off-by: Maxim Sloyko <maxims@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Heiko Schocher <hs@denx.de>
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index 4e9afc1..c58bc1e 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -114,6 +114,15 @@
 	  enable status register. This config option can be enabled in such
 	  cases.
 
+config SYS_I2C_ASPEED
+	bool "Aspeed I2C Controller"
+	depends on DM_I2C && ARCH_ASPEED
+	help
+	  Say yes here to select Aspeed I2C Host Controller. The driver
+	  supports AST2500 and AST2400 controllers, but is very limited.
+	  Only single master mode is supported and only byte-by-byte
+	  synchronous reads and writes are supported, no Pool Buffers or DMA.
+
 config SYS_I2C_INTEL
 	bool "Intel I2C/SMBUS driver"
 	depends on DM_I2C