xref: /kernel/linux/linux-5.10/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-dpaux-padctl.txt

Device tree binding for NVIDIA Tegra DPAUX pad controller
========================================================

The Tegra Display Port Auxiliary (DPAUX) pad controller manages two pins
which can be assigned to either the DPAUX channel or to an I2C
controller.

This document defines the device-specific binding for the DPAUX pad
controller. Refer to pinctrl-bindings.txt in this directory for generic
information about pin controller device tree bindings. Please refer to
the binding document ../display/tegra/nvidia,tegra20-host1x.txt for more
details on the DPAUX binding.

Pin muxing:
-----------

Child nodes contain the pinmux configurations following the conventions
from the pinctrl-bindings.txt document.

Since only three configurations are possible, only three child nodes are
needed to describe the pin mux'ing options for the DPAUX pads.
Furthermore, given that the pad functions are only applicable to a
single set of pads, the child nodes only need to describe the pad group
the functions are being applied to rather than the individual pads.

Required properties:
- groups: Must be "dpaux-io"
- function: Must be either "aux", "i2c" or "off".

Example:
--------

	dpaux@545c0000 {
		...

		state_dpaux_aux: pinmux-aux {
			groups = "dpaux-io";
			function = "aux";
		};

		state_dpaux_i2c: pinmux-i2c {
			groups = "dpaux-io";
			function = "i2c";
		};

		state_dpaux_off: pinmux-off {
			groups = "dpaux-io";
			function = "off";
		};
	};

	...

	i2c@7000d100 {
		...
		pinctrl-0 = <&state_dpaux_i2c>;
		pinctrl-1 = <&state_dpaux_off>;
		pinctrl-names = "default", "idle";
	};