ARM: mvebu: add audio support to Armada 370 DB

This commit adds the necessary Device Tree informations to enable
audio support on the Armada 370 DB platform. In details it:

 * Instantiates the CS42L51 audio codec on the I2C0 bus, and
   configures this bus with the appropriate pin-muxing configuration.

 * Enables the I2S audio controller, and configures it with the
   appropriate pin-muxing configuration.

 * Through hog pins, ensures that the other pins possibly used for I2S
   are muxed with another function than I2S.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arch/arm/boot/dts/armada-370-db.dts

@@ -64,6 +64,22 @@ ethernet@74000 {
 				phy-mode = "rgmii-id";
 			};
 
+			i2c@11000 {
+				pinctrl-0 = <&i2c0_pins>;
+				pinctrl-names = "default";
+				status = "okay";
+				audio_codec: audio-codec@4a {
+					compatible = "cirrus,cs42l51";
+					reg = <0x4a>;
+				};
+			};
+
+			audio-controller@30000 {
+				pinctrl-0 = <&i2s_pins2>;
+				pinctrl-names = "default";
+				status = "okay";
+			};
+
 			mvsdio@d4000 {
 				pinctrl-0 = <&sdio_pins1>;
 				pinctrl-names = "default";
@@ -80,6 +96,30 @@ mvsdio@d4000 {
 				broken-cd;
 			};
 
+			pinctrl {
+				/*
+				 * These pins might be muxed as I2S by
+				 * the bootloader, but it conflicts
+				 * with the real I2S pins that are
+				 * muxed using i2s_pins. We must mux
+				 * those pins to a function other than
+				 * I2S.
+				 */
+				pinctrl-0 = <&hog_pins1 &hog_pins2>;
+				pinctrl-names = "default";
+
+				hog_pins1: hog-pins1 {
+					marvell,pins = "mpp6",  "mpp8", "mpp10",
+						       "mpp12", "mpp13";
+					marvell,function = "gpio";
+				};
+
+				hog_pins2: hog-pins2 {
+					marvell,pins = "mpp5", "mpp7", "mpp9";
+					marvell,function = "gpo";
+				};
+			};
+
 			usb@50000 {
 				status = "okay";
 			};
@@ -112,10 +152,18 @@ pcie@1,0 {
 				/* Port 0, Lane 0 */
 				status = "okay";
 			};
+
 			pcie@2,0 {
 				/* Port 1, Lane 0 */
 				status = "okay";
 			};
 		};
 	};
+
+	sound {
+	      compatible = "marvell,a370db-audio";
+	      marvell,audio-controller = <&audio_controller>;
+	      marvell,audio-codec = <&audio_codec>;
+	      status = "okay";
+	};
 };