61 lines
1.4 KiB
Plaintext
61 lines
1.4 KiB
Plaintext
Generic cpufreq driver
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It is a generic DT based cpufreq driver for frequency management. It supports
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both uniprocessor (UP) and symmetric multiprocessor (SMP) systems which share
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clock and voltage across all CPUs.
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Both required and optional properties listed below must be defined
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under node /cpus/cpu@0.
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Required properties:
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- None
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Optional properties:
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- operating-points: Refer to Documentation/devicetree/bindings/opp/opp.txt for
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details. OPPs *must* be supplied either via DT, i.e. this property, or
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populated at runtime.
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- clock-latency: Specify the possible maximum transition latency for clock,
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in unit of nanoseconds.
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- voltage-tolerance: Specify the CPU voltage tolerance in percentage.
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- #cooling-cells:
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Please refer to Documentation/devicetree/bindings/thermal/thermal.txt.
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Examples:
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cpus {
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#address-cells = <1>;
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#size-cells = <0>;
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cpu@0 {
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compatible = "arm,cortex-a9";
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reg = <0>;
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next-level-cache = <&L2>;
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operating-points = <
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/* kHz uV */
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792000 1100000
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396000 950000
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198000 850000
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>;
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clock-latency = <61036>; /* two CLK32 periods */
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#cooling-cells = <2>;
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};
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cpu@1 {
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compatible = "arm,cortex-a9";
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reg = <1>;
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next-level-cache = <&L2>;
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};
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cpu@2 {
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compatible = "arm,cortex-a9";
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reg = <2>;
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next-level-cache = <&L2>;
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};
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cpu@3 {
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compatible = "arm,cortex-a9";
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reg = <3>;
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next-level-cache = <&L2>;
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};
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};
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