70 lines
2.1 KiB
Plaintext
70 lines
2.1 KiB
Plaintext
MediaTek Idle States for cpuidle driver
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ARM provides idle-state node to define the cpuidle states, as defined in [1].
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cpuidle-mediatek is the cpuidle driver for MediaTek SoCs and uses these idle
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states. Idle states have different enter/exit latency and residency values.
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A cpu can power down and warmboot if there is a sufficient time between the
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time it enters idle and the next known wake up. MediaTek idle-state is used
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to indicate a core entering a power down state without consulting any other
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cpu or the system resources. A core distinguishes itself in that the cpu
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acknowledges and permits the SoC to enter deeper sleep modes. The MediaTek
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Soc support suspend to idle state. This idle state will work efficiency when
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platform will enter suspend. Supend to idle will have the same conservation
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with system suspend in MediaTek SoC solution.
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The idle-state for MediaTek SoCs are distinguished by the compatible property
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of the idle-states device node.
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The devicetree representation of the idle state should be -
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Required properties:
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- compatible: Must be one of -
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"mediatek,idle-state",
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Other required and optional properties are specified in [1].
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Example:
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idle-states {
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entry-method = "arm,psci";
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cpuoff: cpuoff {
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compatible = "mediatek,idle-state";
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arm,psci-suspend-param = <0x00010001>;
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local-timer-stop;
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entry-latency-us = <50>;
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exit-latency-us = <100>;
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min-residency-us = <1400>;
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};
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clusteroff: clusteroff {
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compatible = "mediatek,idle-state";
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arm,psci-suspend-param = <0x01010001>;
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local-timer-stop;
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entry-latency-us = <50>;
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exit-latency-us = <100>;
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min-residency-us = <1400>;
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};
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mcusys: mcusys {
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compatible = "mediatek,idle-state";
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arm,psci-suspend-param = <0x01010002>;
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local-timer-stop;
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entry-latency-us = <150>;
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exit-latency-us = <200>;
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min-residency-us = <2000>;
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};
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s2idle: s2idle {
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compatible = "mediatek,idle-state";
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arm,psci-suspend-param = <0x01010100>;
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local-timer-stop;
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entry-latency-us = <0xffffffff>;
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exit-latency-us = <0xffffffff>;
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min-residency-us = <0xffffffff>;
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};
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};
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[1]. Documentation/devicetree/bindings/arm/idle-states.txt
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