phy: apple: Add DP TX phy driver

This driver is found on Apple's Mac mini (M2, 2023) and controls one
output of the main display controller. It is connected to a MCDP 29XX
(public known part is MCDP 2900) DP 1.4 to HDMI 2.0a protocol converter.

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

Author: jannau

drivers/phy/apple/Kconfig

@@ -9,3 +9,14 @@ config PHY_APPLE_ATC
 	  Enable this to add support for the Apple Type-C PHY, switch
 	  and mux found in Apple SoCs such as the M1.
 	  This driver currently provides support for USB2 and USB3.
+
+config PHY_APPLE_DPTX
+	tristate "Apple DPTX PHY"
+	depends on ARCH_APPLE || COMPILE_TEST
+	default ARCH_APPLE
+	select GENERIC_PHY
+	help
+	  Enable this to add support for the Apple DPTX PHY found on Apple SoCs
+	  such as the M2.
+	  This driver provides support for DisplayPort and is used on the
+	  Mac mini (M2, 2023).

drivers/phy/apple/Makefile

@@ -4,3 +4,6 @@ CFLAGS_trace.o			:= -I$(src)
 obj-$(CONFIG_PHY_APPLE_ATC)		+= phy-apple-atc.o
 phy-apple-atc-y			:= atc.o
 phy-apple-atc-$(CONFIG_TRACING)	+= trace.o
+
+obj-$(CONFIG_PHY_APPLE_DPTX)	+= phy-apple-dptx.o
+phy-apple-dptx-y		+= dptx.o