1Generic cpufreq driver 2 3It is a generic DT based cpufreq driver for frequency management. It supports 4both uniprocessor (UP) and symmetric multiprocessor (SMP) systems which share 5clock and voltage across all CPUs. 6 7Both required and optional properties listed below must be defined 8under node /cpus/cpu@0. 9 10Required properties: 11- None 12 13Optional properties: 14- operating-points: Refer to Documentation/devicetree/bindings/opp/opp.txt for 15 details. OPPs *must* be supplied either via DT, i.e. this property, or 16 populated at runtime. 17- clock-latency: Specify the possible maximum transition latency for clock, 18 in unit of nanoseconds. 19- voltage-tolerance: Specify the CPU voltage tolerance in percentage. 20- #cooling-cells: 21 Please refer to Documentation/devicetree/bindings/thermal/thermal.txt. 22 23Examples: 24 25cpus { 26 #address-cells = <1>; 27 #size-cells = <0>; 28 29 cpu@0 { 30 compatible = "arm,cortex-a9"; 31 reg = <0>; 32 next-level-cache = <&L2>; 33 operating-points = < 34 /* kHz uV */ 35 792000 1100000 36 396000 950000 37 198000 850000 38 >; 39 clock-latency = <61036>; /* two CLK32 periods */ 40 #cooling-cells = <2>; 41 }; 42 43 cpu@1 { 44 compatible = "arm,cortex-a9"; 45 reg = <1>; 46 next-level-cache = <&L2>; 47 }; 48 49 cpu@2 { 50 compatible = "arm,cortex-a9"; 51 reg = <2>; 52 next-level-cache = <&L2>; 53 }; 54 55 cpu@3 { 56 compatible = "arm,cortex-a9"; 57 reg = <3>; 58 next-level-cache = <&L2>; 59 }; 60}; 61