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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /Documentation/devicetree/bindings/cpufreq/cpufreq-dt.txt
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+Generic cpufreq driver
+
+It is a generic DT based cpufreq driver for frequency management. It supports
+both uniprocessor (UP) and symmetric multiprocessor (SMP) systems which share
+clock and voltage across all CPUs.
+
+Both required and optional properties listed below must be defined
+under node /cpus/cpu@0.
+
+Required properties:
+- None
+
+Optional properties:
+- operating-points: Refer to Documentation/devicetree/bindings/power/opp.txt for
+ details. OPPs *must* be supplied either via DT, i.e. this property, or
+ populated at runtime.
+- clock-latency: Specify the possible maximum transition latency for clock,
+ in unit of nanoseconds.
+- voltage-tolerance: Specify the CPU voltage tolerance in percentage.
+- #cooling-cells:
+- cooling-min-level:
+- cooling-max-level:
+ Please refer to Documentation/devicetree/bindings/thermal/thermal.txt.
+
+Examples:
+
+cpus {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ cpu@0 {
+ compatible = "arm,cortex-a9";
+ reg = <0>;
+ next-level-cache = <&L2>;
+ operating-points = <
+ /* kHz uV */
+ 792000 1100000
+ 396000 950000
+ 198000 850000
+ >;
+ clock-latency = <61036>; /* two CLK32 periods */
+ #cooling-cells = <2>;
+ cooling-min-level = <0>;
+ cooling-max-level = <2>;
+ };
+
+ cpu@1 {
+ compatible = "arm,cortex-a9";
+ reg = <1>;
+ next-level-cache = <&L2>;
+ };
+
+ cpu@2 {
+ compatible = "arm,cortex-a9";
+ reg = <2>;
+ next-level-cache = <&L2>;
+ };
+
+ cpu@3 {
+ compatible = "arm,cortex-a9";
+ reg = <3>;
+ next-level-cache = <&L2>;
+ };
+};