kernel_samsung_msm8974/Documentation/devicetree/bindings/arm/msm/pmu.txt

* Qcom Performance Monitor Units
Qcom cores have several PMUs for counting CPU side, L2 and bus side events.

For the L1CC PMU:
In most cases the L1 cache controller PMU is a per cpu unit. The irq-is-percpu
flag becomes a requirement if this is the case.

Required Properties:

- compatible : Should be "qcom,krait-pmu"
- interrupts : 1 combined interrupt or 1 per core. See the devicetree/bindings/gic.txt for more details on this format.

Optional:

- qcom,irq-is-percpu: 	Define this if the IRQ of the PMU is a PPI. This will tell perf to use
			the per_cpu IRQ API for request and free.

Example:

 arm-pmu {
                compatible = "qcom,krait-pmu";
                qcom,irq-is-percpu;
                interrupts = <1 7 0xf00>;
        };

For the L2CC PMU:
If the L2 cache controller PMU is available, its DT bindings should be defined as
follows.

Required Properties:

- compatible: Should be "qcom,l2-pmu"
- interrupts : 1 combined interrupt.

Example:

  l2-pmu {
                compatible = "qcom,l2-pmu";
                interrupts = <0 1 0>;
        };