Qualcomm Resource Power Manager (RPM)

This driver is used to interface with the Resource Power Manager (RPM) found in
various Qualcomm platforms. The RPM allows each component in the system to vote
for state of the system resources, such as clocks, regulators and bus
frequencies.

- compatible:
	Usage: required
	Value type: <string>
	Definition: must be one of:
		    "qcom,rpm-apq8064"
		    "qcom,rpm-msm8660"
		    "qcom,rpm-msm8960"

- reg:
	Usage: required
	Value type: <prop-encoded-array>
	Definition: base address and size of the RPM's message ram

- interrupts:
	Usage: required
	Value type: <prop-encoded-array>
	Definition: three entries specifying the RPM's:
		    1. acknowledgement interrupt
		    2. error interrupt
		    3. wakeup interrupt

- interrupt-names:
	Usage: required
	Value type: <string-array>
	Definition: must be the three strings "ack", "err" and "wakeup", in order

- #address-cells:
	Usage: required
	Value type: <u32>
	Definition: must be 1

- #size-cells:
	Usage: required
	Value type: <u32>
	Definition: must be 0

- qcom,ipc:
	Usage: required
	Value type: <prop-encoded-array>

	Definition: three entries specifying the outgoing ipc bit used for
		    signaling the RPM:
		    - phandle to a syscon node representing the apcs registers
		    - u32 representing offset to the register within the syscon
		    - u32 representing the ipc bit within the register


= SUBDEVICES

The RPM exposes resources to its subnodes. The below bindings specify the set
of valid subnodes that can operate on these resources.

== Switch-mode Power Supply regulator

- compatible:
	Usage: required
	Value type: <string>
	Definition: must be one of:
		    "qcom,rpm-pm8058-smps"
		    "qcom,rpm-pm8901-ftsmps"
		    "qcom,rpm-pm8921-smps"
		    "qcom,rpm-pm8921-ftsmps"

- reg:
	Usage: required
	Value type: <u32>
	Definition: resource as defined in <dt-bindings/mfd/qcom-rpm.h>
		    must be one of:
		    QCOM_RPM_PM8058_SMPS0 - QCOM_RPM_PM8058_SMPS4,
		    QCOM_RPM_PM8821_SMPS1 - QCOM_RPM_PM8821_SMPS2,
		    QCOM_RPM_PM8901_SMPS0 - QCOM_RPM_PM8901_SMPS4,
		    QCOM_RPM_PM8921_SMPS1 - QCOM_RPM_PM8921_SMPS8

- bias-pull-down:
	Usage: optional
	Value type: <empty>
	Definition: enable pull down of the regulator when inactive

- qcom,switch-mode-frequency:
	Usage: required
	Value type: <u32>
	Definition: Frequency (Hz) of the switch-mode power supply;
		    must be one of:
		    19200000, 9600000, 6400000, 4800000, 3840000, 3200000,
		    2740000, 2400000, 2130000, 1920000, 1750000, 1600000,
		    1480000, 1370000, 1280000, 1200000

- qcom,force-mode:
	Usage: optional (default if no other qcom,force-mode is specified)
	Value type: <u32>
	Defintion: indicates that the regulator should be forced to a
		   particular mode, valid values are:
		   QCOM_RPM_FORCE_MODE_NONE - do not force any mode
		   QCOM_RPM_FORCE_MODE_LPM - force into low power mode
		   QCOM_RPM_FORCE_MODE_HPM - force into high power mode
		   QCOM_RPM_FORCE_MODE_AUTO - allow regulator to automatically
					      select its own mode based on
					      realtime current draw, only for:
					      qcom,rpm-pm8921-smps,
					      qcom,rpm-pm8921-ftsmps

- qcom,power-mode-hysteretic:
	Usage: optional
	Value type: <empty>
	Definition: select that the power supply should operate in hysteretic
		    mode, instead of the default pwm mode

Standard regulator bindings are used inside switch mode power supply subnodes.
Check Documentation/devicetree/bindings/regulator/regulator.txt for more
details.

== Low-dropout regulator

- compatible:
	Usage: required
	Value type: <string>
	Definition: must be one of:
		    "qcom,rpm-pm8058-pldo"
		    "qcom,rpm-pm8058-nldo"
		    "qcom,rpm-pm8901-pldo"
		    "qcom,rpm-pm8901-nldo"
		    "qcom,rpm-pm8921-pldo"
		    "qcom,rpm-pm8921-nldo"
		    "qcom,rpm-pm8921-nldo1200"

- reg:
	Usage: required
	Value type: <u32>
	Definition: resource as defined in <dt-bindings/mfd/qcom-rpm.h>
		    must be one of:
		    QCOM_RPM_PM8058_LDO0 - QCOM_RPM_PM8058_LDO25,
		    QCOM_RPM_PM8821_LDO1,
		    QCOM_RPM_PM8901_LDO0 - QCOM_RPM_PM8901_LDO6,
		    QCOM_RPM_PM8921_LDO1 - QCOM_RPM_PM8921_LDO29

- bias-pull-down:
	Usage: optional
	Value type: <empty>
	Definition: enable pull down of the regulator when inactive

- qcom,force-mode:
	Usage: optional
	Value type: <u32>
	Defintion: indicates that the regulator should not be forced to any
		   particular mode, valid values are:
		   QCOM_RPM_FORCE_MODE_NONE - do not force any mode
		   QCOM_RPM_FORCE_MODE_LPM - force into low power mode
		   QCOM_RPM_FORCE_MODE_HPM - force into high power mode
		   QCOM_RPM_FORCE_MODE_BYPASS - set regulator to use bypass
						mode, i.e.  to act as a switch
						and not regulate, only for:
						qcom,rpm-pm8921-pldo,
						qcom,rpm-pm8921-nldo,
						qcom,rpm-pm8921-nldo1200

Standard regulator bindings are used inside switch low-dropout regulator
subnodes.  Check Documentation/devicetree/bindings/regulator/regulator.txt for
more details.

== Negative Charge Pump

- compatible:
	Usage: required
	Value type: <string>
	Definition: must be one of:
		    "qcom,rpm-pm8058-ncp"
		    "qcom,rpm-pm8921-ncp"

- reg:
	Usage: required
	Value type: <u32>
	Definition: resource as defined in <dt-bindings/mfd/qcom-rpm.h>
		    must be one of:
		    QCOM_RPM_PM8058_NCP,
		    QCOM_RPM_PM8921_NCP

- qcom,switch-mode-frequency:
	Usage: required
	Value type: <u32>
	Definition: Frequency (Hz) of the swith mode power supply;
		    must be one of:
		    19200000, 9600000, 6400000, 4800000, 3840000, 3200000,
		    2740000, 2400000, 2130000, 1920000, 1750000, 1600000,
		    1480000, 1370000, 1280000, 1200000

Standard regulator bindings are used inside negative charge pump regulator
subnodes.  Check Documentation/devicetree/bindings/regulator/regulator.txt for
more details.

== Switch

- compatible:
	Usage: required
	Value type: <string>
	Definition: must be one of:
		    "qcom,rpm-pm8058-switch"
		    "qcom,rpm-pm8901-switch"
		    "qcom,rpm-pm8921-switch"

- reg:
	Usage: required
	Value type: <u32>
	Definition: resource as defined in <dt-bindings/mfd/qcom/qcom-rpm.h>
		    must be one of:
		    QCOM_RPM_PM8058_LVS0 - QCOM_RPM_PM8058_LVS1,
		    QCOM_RPM_PM8901_LVS0 - QCOM_RPM_PM8901_LVS3,
		    QCOM_RPM_PM8901_MVS,
		    QCOM_RPM_PM8921_LVS1 - QCOM_RPM_PM8921_LVS7,
		    QCOM_RPM_PM8921_MVS

= EXAMPLE

	#include <dt-bindings/mfd/qcom-rpm.h>

	rpm@108000 {
		compatible = "qcom,rpm-msm8960";
		reg = <0x108000 0x1000>;
		qcom,ipc = <&apcs 0x8 2>;

		interrupts = <0 19 0>, <0 21 0>, <0 22 0>;
		interrupt-names = "ack", "err", "wakeup";

		#address-cells = <1>;
		#size-cells = <0>;

		pm8921_smps1: pm8921-smps1 {
			compatible = "qcom,rpm-pm8921-smps";
			reg = <QCOM_RPM_PM8921_SMPS1>;

			regulator-min-microvolt = <1225000>;
			regulator-max-microvolt = <1225000>;
			regulator-always-on;

			bias-pull-down;

			qcom,switch-mode-frequency = <3200000>;
		};
	};

