dt-bindings: Add snapshot of QPNP AMOLED regulator bindings

QPNP AMOLED Triple power supply regulator devices

QPNP OLEDB module provides AVDD voltage rail output for bias and QPNP AB/IBB

module provides ELVDD/ELVSS voltage rail output to power up AMOLED panels.

For PM8150A, allowed voltage levels are as below:

AVDD - Programmable output from 4.925 V to 8.1 V.

ELVDD  - Programmable output from 4.6 V to 6.1 V.

ELVSS  - Programmable output from -0.8 V to -5.4 V.

This document describes the bindings for AMOLED regulator devices.

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Required Node Structure

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AMOLED regulator device must be described in two level of device nodes.

- compatible:

	Usage:      required

	Value type: <string>

	Definition: should be "qcom,qpnp-amoled-regulator"

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Second Level Nodes - OLEDB/AB/IBB specific

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Subnode common properties for OLEDB and AB/IBB regulator devices.

- reg:

	Usage:      required

	Value type: <prop-encoded-array>

	Definition: Register base for OLEDB, AB and IBB modules which are

		    represented as child nodes.

- reg-names:

	Usage:      required

	Value type: <string>

	Definition: The name of the register defined in the reg property.

- regulator-name:

	Usage:      required

	Value type: <string>

	Definition: A string used to describe the regulator.

- regulator-min-microvolt:

	Usage:      required

	Value type: <u32>

	Definition: Minimum voltage (in uV) supported by the regulator.

- regulator-max-microvolt:

	Usage:      required

	Value type: <u32>

	Definition: Maximum voltage (in uV) supported by the regulator.

- qcom,swire-control:

	Usage:	    optional

	Value type: <empty>

	Definition: A boolean property to specify that the regulator output is

		    controlled by SWIRE signal. When this is specified, output

		    voltage of the regulator is not controlled by SW.

- qcom,aod-pd-control:

	Usage:      optional

	Value type: <empty>

	Definition: A boolean property to specify that the pull down control

		    for AB/IBB needs to be configured during AOD mode.

Example:

pm8150a_amoled: oledb@e000 {

	compatible = "qcom,qpnp-amoled-regulator";

	oledb_vreg: oledb@e000 {

		reg = <0xe000>;

		reg-names = "oledb_base";

		regulator-name = "oledb_vreg";

		regulator-min-microvolt = <4925000>;

		regulator-max-microvolt = <8100000>;

		qcom,swire-control;

	};

	ab_vreg: ab@de00 {

		reg = <0xde00>;

		reg-names = "ab_base";

		regulator-name = "ab_vreg";

		regulator-min-microvolt = <4600000>;

		regulator-max-microvolt = <6100000>;

		qcom,swire-control;

		qcom,aod-pd-control;

	};

	ibb_vreg: ibb@dc00 {

		reg = <0xdc00>;

		reg-names = "ibb_base";

		regulator-name = "ibb_vreg";

		regulator-min-microvolt = <800000>;

		regulator-max-microvolt = <5400000>;

		qcom,swire-control;

		qcom,aod-pd-control;

	};

};