arm64: dts: apple: t8112: Add dp-altmode dts hacks

Enable DP alt mode for the front left USB-C port of Macbook Air 13 (M2,
13/15-inch) and Macbook Pro (M2, 13-inch).
Can't easily enabled on on the M2 Mac Mini since dcpext is used for the
HDMI port and dcp bringup is troublesome.

Signed-off-by: Janne Grunau <j@jannau.net>

Author: jannau

arch/arm64/boot/dts/apple/t8112-j413.dts

@@ -9,6 +9,8 @@
 
 /dts-v1/;
 
+#define ENABLE_DCPEXT_TYPEC
+
 #include "t8112.dtsi"
 #include "t8112-jxxx.dtsi"
 #include <dt-bindings/leds/common.h>

arch/arm64/boot/dts/apple/t8112-j415.dts

@@ -9,6 +9,8 @@
 
 /dts-v1/;
 
+#define ENABLE_DCPEXT_TYPEC
+
 #include "t8112.dtsi"
 #include "t8112-jxxx.dtsi"
 #include <dt-bindings/leds/common.h>

arch/arm64/boot/dts/apple/t8112-j493.dts

@@ -9,6 +9,8 @@
 
 /dts-v1/;
 
+#define ENABLE_DCPEXT_TYPEC
+
 #include "t8112.dtsi"
 #include "t8112-jxxx.dtsi"
 #include <dt-bindings/leds/common.h>

arch/arm64/boot/dts/apple/t8112-jxxx.dtsi

@@ -96,6 +96,11 @@
 			power-role = "dual";
 			data-role = "dual";
 
+#ifdef ENABLE_DCPEXT_TYPEC
+			/* hacks */
+			displayport = <&dcpext>;
+#endif
+
 			ports {
 				#address-cells = <1>;
 				#size-cells = <0>;
@@ -116,6 +121,47 @@
 	};
 };
 
+#ifdef ENABLE_DCPEXT_TYPEC
+/ {
+	aliases {
+		dcpext = &dcpext;
+	};
+};
+
+&display {
+	iommus = <&disp0_dart 0>, <&dispext0_dart 0>;
+};
+
+&dispext0_dart {
+	status = "okay";
+};
+
+&dcpext_dart {
+	status = "okay";
+};
+
+&dcpext_mbox {
+	status = "okay";
+};
+
+&dcpext {
+	status = "okay";
+	apple,connector-type = "DP";
+
+	/* hacks */
+	apple,dptx-phy = <1>;
+	phys = <&atcphy1 PHY_TYPE_DP>;
+	phy-names = "dp-phy";
+	mux-controls = <&atcphy1_xbar 0>;
+	mux-control-names = "dp-xbar";
+	mux-index = <2>;
+};
+
+&dpaudio1 {
+	status = "okay";
+};
+#endif
+
 /* USB controllers */
 &dwc3_0 {
 	ports {