dt-bindings: Add dt binding for MSM GFX LDO driver

Qualcomm Technologies, Inc. GFX LDO for Graphics

The GPU core on MSM 8953 can be powered by an internal (on-die)

MSM LDO or BHS based on its operating corner.

This document describes the bindings that apply for the GFX LDO regulator.

- compatible

	Usage:      required

	Value type: <string>

	Definition: should be "qcom,msm8953-gfx-ldo" for MSM8953 and

		    "qcom,sdm660-gfx-ldo" for SDM660

- reg

	Usage:      required

	Value type: <prop-encoded-array>

	Definition: Addresses and sizes for the memory of the GFX ldo

- reg-names

	Usage:      required

	Value type: <stringlist>

	Definition: Address names. "ldo_addr", "efuse_addr". Must be

		    specified in the same order as the corresponding addresses

		    are specified 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 corner value which should be 1 to represent the

		    lowest supported corner.

- regulator-max-microvolt

	Usage:      required

	Value type: <u32>

	Definition: Maximum corner value which should be equal to qcom,num-corners.

- qcom,num-corners

	Usage:      required

	Value type: <u32>

	Definition: Number of voltage corners present. Many other

		    properties are sized based upon this value.

- qcom,num-ldo-corners

	Usage:      required

	Value type: <u32>

	Definition: Number of voltage corners defined for the ldo. It is a

		    subset of qcom,num-corners (i.e. 1 to qcom,num-ldo-corners

		    are the corners for ldo operation)

- qcom,init-corner

	Usage:      required

	Value type: <u32>

	Definition: The initial-corner at which the GFX rail is powered on.

- qcom,ldo-enable-corner-map

	Usage:      required

	Value type: <prop-encoded-array>

	Definition: Integer values ( / 0) which indicate the GFX corners in which

		    ldo is to enabled. The length of this property

		    should be equal to qcom,num-corners.

- qcom,ldo-voltage-ceiling

	Usage:      required

	Value type: <prop-encoded-array>

	Definition: Array of ceiling voltages in microvolts for voltage corners

		    ordered from lowest voltage corner to highest voltage corner.

		    This property must be of length defined by qcom,num-ldo-corners.

- qcom,ldo-voltage-floor

	Usage:      required

	Value type: <prop-encoded-array>

	Definition: Array of floor voltages in microvolts for voltage corners

		    ordered from lowest voltage corner to highest voltage corner.

		    This property must be of length defined by qcom,num-ldo-corners.

- vdd-cx-supply

	Usage:      optional

	Value type: <phandle>

	Definition: Parent regulator supply to the ldo.

- qcom,vdd-cx-corner-map

	Usage:      required if vdd-cx-supply is specified.

	Value type: <prop-encoded-array>

	Definition: Array of integers which define the mapping of the VDD_CX corner

		    to the corresponding GFX voltage corner. The elements in

		    the array are ordered from lowest voltage corner to highest

		    voltage corner.  The length of this property must be equal to

		    the value defined by qcom,num-corners.

- mem-acc-supply

	Usage:      optional

	Value type: <phandle>

	Definition: Regulator to vote for the memory accelerator configuration.

		    Not Present: memory accelerator configuration not supported.

- qcom,mem-acc-corner-map:

	Usage:      optional

	Value type: <prop-encoded-aray>

	Definition: Array of integer which defines the mapping from mem-acc

		    corner value for each gfx corner. The elements in the array

		    are ordered from lowest voltage corner to highest voltage corner.

- qcom,ldo-init-voltage-adjustment

	Usage:      optional

	Value type: <prop-encoded-aray>

	Definition: Array of voltages in microvolts which indicate the static

		    adjustment to be applied to the open-loop voltages for the

		    LDO supported corners. The length of this property must be

		    equal to qcom,num-ldo-corners.

=======

Example

=======

	gfx_vreg_corner: ldo@0185f000 {

		compatible = "qcom,msm8953-gfx-ldo";

		reg = <0x0185f000 0x30>, <0xa0000 0x1000>;

		reg-names = "ldo_addr", "efuse_addr";

		regulator-name = "msm_gfx_ldo";

		regulator-min-microvolt = <1>;

		regulator-max-microvolt = <7>;

		qcom,ldo-voltage-ceiling = <500000 700000 900000>;

		qcom,ldo-voltage-floor = <400000 600000 800000>;

		qcom,num-corners = <7>;

		qcom,num-ldo-corners = <3>;

		qcom,ldo-enable-corner-map = <1 1 1 0 0 0 0>;

		qcom,init-corner = <5>;

		vdd-cx-supply = <&pm8953_s2_level>;

		qcom,vdd-cx-corner-map = <RPM_SMD_REGULATOR_LEVEL_LOW_SVS>,

					<RPM_SMD_REGULATOR_LEVEL_LOW_SVS>,

					<RPM_SMD_REGULATOR_LEVEL_LOW_SVS>,

					<RPM_SMD_REGULATOR_LEVEL_SVS>,

					<RPM_SMD_REGULATOR_LEVEL_NOM>,

					<RPM_SMD_REGULATOR_LEVEL_NOM_PLUS>,

					<RPM_SMD_REGULATOR_LEVEL_TURBO>;

		mem-acc-supply = <&gfx_mem_acc>;

		qcom,mem-acc-corner-map = <1 1 2 2 2 2 2>;

		qcom,ldo-init-voltage-adjustment = <10000 20000 30000>;

	};