extcon: add Realtek DHC RTD SoC Type-C driver

This patch adds the extcon driver for Realtek DHC (digital home center)
RTD SoCs type-c module. This can be used to detect whether the port is
configured as a downstream or upstream facing port. And notify the status
of extcon to listeners.

Link: https://lore.kernel.org/lkml/20230904051253.23208-2-stanley_chang@realtek.com/
Signed-off-by: Stanley Chang <stanley_chang@realtek.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

drivers/extcon/Kconfig

@@ -191,4 +191,15 @@ config EXTCON_USBC_TUSB320
 	  Say Y here to enable support for USB Type C cable detection extcon
 	  support using a TUSB320.
 
+config EXTCON_RTK_TYPE_C
+	tristate "Realtek RTD SoC extcon Type-C Driver"
+	depends on ARCH_REALTEK || COMPILE_TEST
+	depends on TYPEC
+	select USB_COMMON
+	help
+	  Say Y here to enable extcon support for USB Type C cable detection
+	  when using the Realtek RTD SoC USB Type-C port.
+	  The DHC (Digital Home Hub) RTD series SoC contains a type c module.
+	  This driver will detect the status of the type-c port.
+
 endif

drivers/extcon/Makefile

@@ -25,3 +25,4 @@ obj-$(CONFIG_EXTCON_SM5502)	+= extcon-sm5502.o
 obj-$(CONFIG_EXTCON_USB_GPIO)	+= extcon-usb-gpio.o
 obj-$(CONFIG_EXTCON_USBC_CROS_EC) += extcon-usbc-cros-ec.o
 obj-$(CONFIG_EXTCON_USBC_TUSB320) += extcon-usbc-tusb320.o
+obj-$(CONFIG_EXTCON_RTK_TYPE_C) += extcon-rtk-type-c.o