Merge "extcon: gpio: Add documentation for extcon gpio support"

GPIO Extcon device

This is a virtual device used to generate GPIO states from the GPIO ID pin

connected to a GPIO pin.

Required properties:

- compatible: Should be "extcon-gpio"

- extcon-id: The unique id of specific external connector.

	     Valid range is 0 (EXTCON_NONE) to 63 (EXTCON_NUM).

	     Refer include/linux/extcon.h for details.

- gpio: Specify GPIO (see gpio binding)

- debounce-ms: Debounce time for GPIO IRQ in ms

- irq-flags: interrupt flags (edge/level). Refer to "include/dt-bindings/interrupt-controller/irq.h"

- pinctrl-names, pinctrl-0, pinctrl-1,.. pinctrl-n: Refer to "Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt"

  for these optional properties

Example:

	extcon_storage_cd {

		compatible = "extcon-gpio";

		extcon-id = <62>; /* EXTCON_MECHANICAL */

		gpio = <&tlmm 126 GPIO_ACTIVE_LOW>;

		debounce-ms = <200>;

		irq-flags = <IRQ_TYPE_EDGE_BOTH>;

	}

	&ufshc_card {

		extcon = <&extcon_storage_cd>;

	};

	&sd_card {

		extcon = <&extcon_storage_cd>;

	};