ARM: dts: at91: add envelope detector mux to the Axentia TSE-850

The envelope detector can analyze 6 different signals, selectable with a
mux controlled by three gpio pins.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

arch/arm/boot/dts/at91-tse850-3.dts

@@ -86,16 +86,43 @@ dac: dpot-dac {
 		#io-channel-cells = <1>;
 	};
 
-	envelope-detector {
+	env_det: envelope-detector {
 		compatible = "axentia,tse850-envelope-detector";
 		io-channels = <&dac 0>;
 		io-channel-names = "dac";
+		#io-channel-cells = <1>;
 
 		interrupt-parent = <&pioA>;
 		interrupts = <3 IRQ_TYPE_EDGE_RISING>;
 		interrupt-names = "comp";
 	};
 
+	mux: mux-controller {
+		compatible = "gpio-mux";
+		#mux-control-cells = <0>;
+
+		mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
+			    <&pioA 1 GPIO_ACTIVE_HIGH>,
+			    <&pioA 2 GPIO_ACTIVE_HIGH>;
+		idle-state = <0>;
+	};
+
+	envelope-detector-mux {
+		compatible = "io-channel-mux";
+		io-channels = <&env_det 0>;
+		io-channel-names = "parent";
+
+		mux-controls = <&mux>;
+
+		channels = "", "",
+			 "sync-1",
+			 "in",
+			 "out",
+			 "sync-2",
+			 "sys-reg",
+			 "ana-reg";
+	};
+
 	leds {
 		compatible = "gpio-leds";