* MSM Subsystem Power Manager (spm-v2)

S4 generation of MSMs have SPM hardware blocks to control the Application
Processor Sub-System power. These SPM blocks run individual state machine
to determine what the core (L2 or Krait/Scorpion) would do when the WFI
instruction is executed by the core. The SAW hardware block handles SPM and
AVS functionality for the cores.

The devicetree representation of the SPM block should be:

Required properties

- compatible: "qcom,spm-v2"
- reg: The physical address and the size of the SPM's memory mapped registers
- qcom,cpu: phandle for the CPU that the SPM block is attached to.  This field
	is required on only for SPMs that control the CPU. This field is not required
	for SPMs that control L2/CCI/L3
- qcom,saw2-ver-reg: The location of the version register
- qcom,name: The name with which a SPM device is identified by the power
	management code.

Optional properties:

- qcom,saw2-avs-ctl: The AVS control register
- qcom,saw2-avs-hysterisis: The AVS hysterisis register to delay the AVS
	controller requests
- qcom,vctl-timeout-us: The timeout value in us to wait for voltage to change
	after sending the voltage command to the PMIC
- qcom,saw2-avs-limit: The AVS limit register
- qcom,saw2-avs-dly: The AVS delay register is used to specify the delay values
	between AVS controller requests
- qcom,vctl-port: The PVC (PMIC Virtual Channel) port used for changing
	voltage
- qcom,vctl-port-ub: The PVC (PMIC Virtual Channel) port used for changing
	voltage
- qcom,phase-port: The PVC port used for changing the number of phases
- qcom,pfm-port: The PVC port used for enabling PWM/PFM modes
- qcom,cpu-vctl-list: List of cpu node phandles, whose voltage the spm device
	can control.

Example :
	qcom,spm@9A10000 {
		compatible = "qcom,spm-v2";
		#address-cells = <1>;
		#size-cells = <1>;
		reg = <0x9A10000 0x1000>;
		qcom,name = "system-cbf"; /* CBF SAW */
		qcom,saw2-ver-reg = <0xFD0>;
		qcom,cpu-vctl-list = <&CPU0 &CPU1 &CPU2 &CPU3>;
		qcom,vctl-timeout-us = <50>;
		qcom,vctl-port = <0x0>;
		qcom,phase-port = <0x1>;
		qcom,saw2-avs-ctl = <0x1100>;
		qcom,pfm-port = <0x2>;
};