* Low Power Management Levels

The application processor in MSM can do a variety of C-States for low power
management. These C-States are invoked by the CPUIdle framework when the core
becomes idle. But based on the time available until the next scheduled wakeup,
the system can do a combination of low power modes of different resources -
L2, XO, Vdd Dig and Vdd Mem. The combination is captured in the device tree as
lpm-level. The units for voltage are dependent on the PMIC used on the target
and are in uV.

The required nodes for lpm-levels are:

- compatible: "qcom,lpm-levels"
- reg: The numeric level id
- qcom,mode: The sleep mode of the processor, values for the property are:
		"wfi" - Wait for Interrupt
		"ramp_down_and_wfi" - Ramp down and wait for interrupt
		"standalone_pc" - Standalone power collapse
		"pc" - Power Collapse
		"retention" - Retention
		"pc_suspend" - Suspended Power Collapse
		"pc_no_xo_shutdown" - Power Collapse with no XO shutdown
- qcom,xo: The state of XO clock. Values are "xo_on" and "xo_off"
- qcom,l2: The state of L2 cache. Values are:
		"l2_cache_pc" - L2 cache in power collapse
		"l2_cache_retenetion" - L2 cache in retention
		"l2_cache_gdhs" - L2 cache in GDHS
		"l2_cache_active" - L2 cache in active mode
- qcom,vdd-mem-upper-bound: The upper bound value of mem voltage in uV
- qcom,vdd-mem-lower-bound: The lower bound value of mem voltage in uV
- qcom,vdd-dig-upper-bound: The upper bound value of dig voltage in uV
                            or an RBCPR (Rapid Bridge Core Power Reduction)
                            corner voltage.
- qcom,vdd-dig-lower-bound: The lower bound value of dig voltage in uV
                            or an RBCPR (Rapid Bridge Core Power Reduction)
                            corner voltage.
- qcom,latency-us: The latency in handling the interrupt if this level was
	chosen, in uSec
- qcom,ss-power: The steady state power expelled when the processor is in this
	level in mWatts
- qcom,energy-overhead: The energy used up in entering and exiting this level
	in mWatts.uSec
- qcom,time-overhead: The time spent in entering and exiting this level in uS

Optional properties
- qcom,irqs-detectable: The field indicates whether the IRQs are detectable by
			the GIC controller when entering a low power mode.
- qcom,gpio-detectable: The field indicates whether the GPIOs can be detected
			by the GPIO interrupt controller during a given low
			power mode.
- qcom,use-qtimer: Indicates whether the target uses the synchronized QTimer.

Example:

qcom,lpm-levels {
	qcom,use-qtimer;
	qcom,lpm-level@0 {
		reg = <0>;
		qcom,mode = "wfi";
		qcom,xo = "xo_on";
		qcom,l2 = "l2_cache_active";
		qcom,vdd-mem-upper-bound = <1150000>; /* MAX */
		qcom,vdd-mem-lower-bound = <1050000>; /* ACTIVE */
		qcom,vdd-dig-upper-bound = <5>; /* MAX */
		qcom,vdd-dig-lower-bound = <3>;  /* ACTIVE */
		qcom,irqs-detectable;
		qcom,gpio-detectable;
		qcom,latency-us = <100>;
		qcom,ss-power = <650>;
		qcom,energy-overhead = <801>;
		qcom,time-overhead = <200>;
	};
};