1* ARM Performance Monitor Units 2 3ARM cores often have a PMU for counting cpu and cache events like cache misses 4and hits. The interface to the PMU is part of the ARM ARM. The ARM PMU 5representation in the device tree should be done as under:- 6 7Required properties: 8 9- compatible : should be one of 10 "arm,armv8-pmuv3" 11 "arm,cortex-a17-pmu" 12 "arm,cortex-a15-pmu" 13 "arm,cortex-a12-pmu" 14 "arm,cortex-a9-pmu" 15 "arm,cortex-a8-pmu" 16 "arm,cortex-a7-pmu" 17 "arm,cortex-a5-pmu" 18 "arm,arm11mpcore-pmu" 19 "arm,arm1176-pmu" 20 "arm,arm1136-pmu" 21 "qcom,scorpion-pmu" 22 "qcom,scorpion-mp-pmu" 23 "qcom,krait-pmu" 24- interrupts : 1 combined interrupt or 1 per core. If the interrupt is a per-cpu 25 interrupt (PPI) then 1 interrupt should be specified. 26 27Optional properties: 28 29- interrupt-affinity : Valid only when using SPIs, specifies a list of phandles 30 to CPU nodes corresponding directly to the affinity of 31 the SPIs listed in the interrupts property. 32 33 This property should be present when there is more than 34 a single SPI. 35 36- qcom,no-pc-write : Indicates that this PMU doesn't support the 0xc and 0xd 37 events. 38 39Example: 40 41pmu { 42 compatible = "arm,cortex-a9-pmu"; 43 interrupts = <100 101>; 44}; 45