NFC: nfcmrvl: add i2c driver

This driver adds the support of I2C-based Marvell NFC controller.

Signed-off-by: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Documentation/devicetree/bindings/net/nfc/nfcmrvl.txt

@@ -1,7 +1,9 @@
 * Marvell International Ltd. NCI NFC Controller
 
 Required properties:
-- compatible: Should be "mrvl,nfc-uart".
+- compatible: Should be:
+  - "mrvl,nfc-uart" for UART devices
+  - "mrvl,nfc-i2c" for I2C devices
 
 Optional SoC specific properties:
 - pinctrl-names: Contains only one value - "default".
@@ -13,6 +15,12 @@ Optional UART-based chip specific properties:
 - flow-control: Specifies that the chip is using RTS/CTS.
 - break-control: Specifies that the chip needs specific break management.
 
+Optional I2C-based chip specific properties:
+- i2c-int-falling: Specifies that the chip read event shall be trigged on
+  		   falling edge.
+- i2c-int-rising: Specifies that the chip read event shall be trigged on
+  		  rising edge.
+
 Example (for ARM-based BeagleBoard Black with 88W8887 on UART5):
 
 &uart5 {
@@ -27,3 +35,27 @@ Example (for ARM-based BeagleBoard Black with 88W8887 on UART5):
 		flow-control;
         }
 };
+
+
+Example (for ARM-based BeagleBoard Black with 88W8887 on I2C1):
+
+&i2c1 {
+	status = "okay";
+	clock-frequency = <400000>;
+
+	nfcmrvli2c0: i2c@1 {
+		compatible = "mrvl,nfc-i2c";
+
+		reg = <0x8>;
+
+		/* I2C INT configuration */
+		interrupt-parent = <&gpio3>;
+		interrupts = <21 0>;
+
+		/* I2C INT trigger configuration */
+		i2c-int-rising;
+
+		/* Reset IO */
+		reset-n-io = <&gpio3 19 0>;
+	};
+};