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: two entries specifying the RPM's message ram and ipc register

- reg-names:
	Usage: required
	Value type: <string-array>
	Definition: must contain the following, in order:
		    "msg_ram"
		    "ipc"

- 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


= 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/soc/qcom,rpm.h>

- 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-none:
	Usage: optional (default if no other qcom,force-mode is specified)
	Value type: <empty>
	Defintion: indicates that the regulator should not be forced to any
	           particular mode

- qcom,force-mode-lpm:
	Usage: optional
	Value type: <empty>
	Definition: indicates that the regulator should be forced to operate in
	            low-power-mode

- qcom,force-mode-auto:
	Usage: optional (only available for 8960/8064)
	Value type: <empty>
	Definition: indicates that the regulator should be automatically pick
	            operating mode

- qcom,force-mode-hpm:
	Usage: optional (only available for 8960/8064)
	Value type: <empty>
	Definition: indicates that the regulator should be forced to operate in
	            high-power-mode

- qcom,force-mode-bypass: (only for 8960/8064)
	Usage: optional (only available for 8960/8064)
	Value type: <empty>
	Definition: indicates that the regulator should be forced to operate in
	            bypass mode

- qcom,power-mode-hysteretic:
	Usage: optional
	Value type: <empty>
	Definition: indicates that the power supply should operate in hysteretic
		    mode (defaults to qcom,power-mode-pwm if not specified)

- qcom,power-mode-pwm:
	Usage: optional
	Value type: <empty>
	Definition: indicates that the power supply should operate in 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/soc/qcom,rpm.h>

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

- qcom,force-mode-none:
	Usage: optional (default if no other qcom,force-mode is specified)
	Value type: <empty>
	Defintion: indicates that the regulator should not be forced to any
	           particular mode

- qcom,force-mode-lpm:
	Usage: optional
	Value type: <empty>
	Definition: indicates that the regulator should be forced to operate in
	            low-power-mode

- qcom,force-mode-auto:
	Usage: optional (only available for 8960/8064)
	Value type: <empty>
	Definition: indicates that the regulator should be automatically pick
	            operating mode

- qcom,force-mode-hpm:
	Usage: optional (only available for 8960/8064)
	Value type: <empty>
	Definition: indicates that the regulator should be forced to operate in
	            high-power-mode

- qcom,force-mode-bypass: (only for 8960/8064)
	Usage: optional (only available for 8960/8064)
	Value type: <empty>
	Definition: indicates that the regulator should be forced to operate in
	            bypass mode

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/soc/qcom,rpm.h>

- 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/soc/qcom/qcom,rpm.h>


= EXAMPLE

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

	rpm@108000 {
		compatible = "qcom,rpm-msm8960";
		reg = <0x108000 0x1000 0x2011008 0x4>;

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

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

		pm8921_s1: pm8921-s1 {
			compatible = "qcom,rpm-pm8921-smps";
			reg = <QCOM_RPM_PM8921_S1>;

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

			bias-pull-down;

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

