rampis: HLK-RM04 - Setup I2C as GPIO

The I2C function of the RT5350 SoC on the HLK-RM04 is used for GPIO1 and GPIO2.

Take note that the I2C_SD pin is GPIO1 on the RT5350 and is exposed on the HLK-RM04 as GPIO0
Likewise the I2C_SCLK pin is GPIO2 on the RT5350 and is exposed on the HLK-RM04 as GPIO1

 group   mode 1    mode 2   hlk-rm04 pin & export
  i2c    i2c_sd    gpio1   (pin 8, hlk-rm04:gpio0)
  i2c    i2c_sclk  gpio2   (pin 9, hlk-rm04:gpio1)

reference:
  http://www.hlktech.net/product_detail.php?ProId=39
  http://cdn.sparkfun.com/datasheets/Wireless/WiFi/RT5350.pdf

Signed-off-by: John Clark <[email protected]>

SVN-Revision: 48664

target/linux/ramips/dts/HLKRM04.dts

@@ -60,7 +60,7 @@
 	pinctrl {
 		state_default: pinctrl0 {
 			gpio {
-				ralink,group = "jtag";
+				ralink,group = "i2c", "jtag";
 				ralink,function = "gpio";
 			};
 		};
@@ -82,6 +82,25 @@
 		status = "okay";
 	};
 
+	gpio-export {
+		compatible = "gpio-export";
+		#size-cells = <0>;
+
+		/* I2C */
+		gpio1 {
+			/* I2C_I2C_SD */
+			gpio-export,name = "hlk-rm04:gpio0";
+			gpio-export,direction_may_change = <1>;
+			gpios = <&gpio0 1 0>;
+		};
+		gpio2 {
+			/* I2C_I2C_SCLK */
+			gpio-export,name = "hlk-rm04:gpio1";
+			gpio-export,direction_may_change = <1>;
+			gpios = <&gpio0 2 0>;
+		};
+	};
+
 	gpio-keys-polled {
 		compatible = "gpio-keys-polled";
 		#address-cells = <1>;