xref: /openbmc/linux/Documentation/ABI/testing/sysfs-driver-typec-displayport (revision 001b0c78)

What:		/sys/bus/typec/devices/.../displayport/configuration
Date:		July 2018
Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
Description:
		Shows the current DisplayPort configuration for the connector.
		Valid values are USB, source and sink. Source means DisplayPort
		source, and sink means DisplayPort sink.

		All supported configurations are listed as space separated list
		with the active one wrapped in square brackets.

		Source example:

			USB [source] sink

		The configuration can be changed by writing to the file

		Note. USB configuration does not equal to Exit Mode. It is
		separate configuration defined in VESA DisplayPort Alt Mode on
		USB Type-C Standard. Functionally it equals to the situation
		where the mode has been exited (to exit the mode, see
		Documentation/ABI/testing/sysfs-bus-typec, and use file
		/sys/bus/typec/devices/.../active).

What:		/sys/bus/typec/devices/.../displayport/pin_assignment
Date:		July 2018
Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
Description:
		VESA DisplayPort Alt Mode on USB Type-C Standard defines six
		different pin assignments for USB Type-C connector that are
		labeled A, B, C, D, E, and F. The supported pin assignments are
		listed as space separated list with the active one wrapped in
		square brackets.

		Example:

			C [D]

		Pin assignment can be changed by writing to the file. It is
		possible to set pin assignment before configuration has been
		set, but the assignment will not be active before the
		connector is actually configured.

		Note. As of VESA DisplayPort Alt Mode on USB Type-C Standard
		version 1.0b, pin assignments A, B, and F are deprecated. Only
		pin assignment D can now carry simultaneously one channel of
		USB SuperSpeed protocol. From user perspective pin assignments C
		and E are equal, where all channels on the connector are used
		for carrying DisplayPort protocol (allowing higher resolutions).

What:		/sys/bus/typec/devices/.../displayport/hpd
Date:		Dec 2022
Contact:	Badhri Jagan Sridharan <badhri@google.com>
Description:
		VESA DisplayPort Alt Mode on USB Type-C Standard defines how
		HotPlugDetect(HPD) shall be supported on the USB-C connector when
		operating in DisplayPort Alt Mode. This is a read only node which
		reflects the current state of HPD.

		Valid values:
			- 1: when HPD’s logical state is high (HPD_High) as defined
			     by VESA DisplayPort Alt Mode on USB Type-C Standard.
			- 0 when HPD’s logical state is low (HPD_Low) as defined by
			     VESA DisplayPort Alt Mode on USB Type-C Standard.