48 lines
1.9 KiB
YAML
48 lines
1.9 KiB
YAML
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# SPDX-License-Identifier: GPL-2.0-only
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%YAML 1.2
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---
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$id: http://devicetree.org/schemas/powerpc/sleep.yaml#
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$schema: http://devicetree.org/meta-schemas/core.yaml#
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title: PowerPC sleep property
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maintainers:
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- Rob Herring <robh@kernel.org>
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description: |
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Devices on SOCs often have mechanisms for placing devices into low-power
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states that are decoupled from the devices' own register blocks. Sometimes,
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this information is more complicated than a cell-index property can
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reasonably describe. Thus, each device controlled in such a manner
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may contain a "sleep" property which describes these connections.
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The sleep property consists of one or more sleep resources, each of
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which consists of a phandle to a sleep controller, followed by a
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controller-specific sleep specifier of zero or more cells.
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The semantics of what type of low power modes are possible are defined
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by the sleep controller. Some examples of the types of low power modes
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that may be supported are:
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- Dynamic: The device may be disabled or enabled at any time.
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- System Suspend: The device may request to be disabled or remain
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awake during system suspend, but will not be disabled until then.
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- Permanent: The device is disabled permanently (until the next hard
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reset).
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Some devices may share a clock domain with each other, such that they should
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only be suspended when none of the devices are in use. Where reasonable,
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such nodes should be placed on a virtual bus, where the bus has the sleep
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property. If the clock domain is shared among devices that cannot be
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reasonably grouped in this manner, then create a virtual sleep controller
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(similar to an interrupt nexus, except that defining a standardized
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sleep-map should wait until its necessity is demonstrated).
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select: true
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properties:
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sleep:
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$ref: /schemas/types.yaml#/definitions/phandle-array
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additionalProperties: true
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