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Diffstat (limited to 'Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt b/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt new file mode 100644 index 000000000..0715695e9 --- /dev/null +++ b/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt @@ -0,0 +1,65 @@ +Generic ARM big LITTLE cpufreq driver's DT glue +----------------------------------------------- + +This is DT specific glue layer for generic cpufreq driver for big LITTLE +systems. + +Both required and optional properties listed below must be defined +under node /cpus/cpu@x. Where x is the first cpu inside a cluster. + +FIXME: Cpus should boot in the order specified in DT and all cpus for a cluster +must be present contiguously. Generic DT driver will check only node 'x' for +cpu:x. + +Required properties: +- operating-points: Refer to Documentation/devicetree/bindings/power/opp.txt + for details + +Optional properties: +- clock-latency: Specify the possible maximum transition latency for clock, + in unit of nanoseconds. + +Examples: + +cpus { + #address-cells = <1>; + #size-cells = <0>; + + cpu@0 { + compatible = "arm,cortex-a15"; + reg = <0>; + next-level-cache = <&L2>; + operating-points = < + /* kHz uV */ + 792000 1100000 + 396000 950000 + 198000 850000 + >; + clock-latency = <61036>; /* two CLK32 periods */ + }; + + cpu@1 { + compatible = "arm,cortex-a15"; + reg = <1>; + next-level-cache = <&L2>; + }; + + cpu@100 { + compatible = "arm,cortex-a7"; + reg = <100>; + next-level-cache = <&L2>; + operating-points = < + /* kHz uV */ + 792000 950000 + 396000 750000 + 198000 450000 + >; + clock-latency = <61036>; /* two CLK32 periods */ + }; + + cpu@101 { + compatible = "arm,cortex-a7"; + reg = <101>; + next-level-cache = <&L2>; + }; +}; |