Re: [PATCH v2 3/8] dt-bindings: power: Add apple,pmgr-pwrstate binding

From: Rob Herring
Date: Tue Oct 26 2021 - 14:27:56 EST


On Mon, Oct 25, 2021 at 11:47:13PM +0900, Hector Martin wrote:
> This syscon child node represents a single SoC device controlled by the
> PMGR block. This layout allows us to declare all device power state
> controls (power/clock gating and reset) in the device tree, including
> dependencies, instead of hardcoding it into the driver. The register
> layout is uniform.
>
> Each pmgr-pwrstate node provides genpd and reset features, to be
> consumed by downstream device nodes.
>
> Future SoCs are expected to use backwards compatible registers, and the
> "apple,pmgr-pwrstate" represents any such interfaces (possibly with
> additional features gated by the more specific compatible), allowing
> them to be bound without driver updates. If a backwards incompatible
> change is introduced in future SoCs, it will require a new compatible,
> such as "apple,pmgr-pwrstate-v2".
>
> Reviewed-by: Mark Kettenis <kettenis@xxxxxxxxxxx>
> Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
> ---
> .../bindings/power/apple,pmgr-pwrstate.yaml | 69 +++++++++++++++++++
> 1 file changed, 69 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml
>
> diff --git a/Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml b/Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml
> new file mode 100644
> index 000000000000..010f8b641304
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml
> @@ -0,0 +1,69 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/power/apple,pmgr-pwrstate.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Apple SoC PMGR Power States
> +
> +maintainers:
> + - Hector Martin <marcan@xxxxxxxxx>
> +
> +allOf:
> + - $ref: "power-domain.yaml#"
> +
> +description: |
> + Apple SoCs include a PMGR block responsible for power management,
> + which can control various clocks, resets, power states, and
> + performance features. This binding describes the device power
> + state registers, which control power states and resets.
> +
> + Each instance of a power controller within the PMGR syscon node
> + represents a generic power domain provider, as documented in
> + Documentation/devicetree/bindings/power/power-domain.yaml.
> + The provider controls a single SoC block. The power hierarchy is
> + represented via power-domains relationships between these nodes.
> +
> + See Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml
> + for the top-level PMGR node documentation.
> +
> +properties:
> + compatible:
> + items:
> + - enum:
> + - apple,t8103-pmgr-pwrstate
> + - const: apple,pmgr-pwrstate
> +
> + reg:
> + maxItems: 1
> +
> + "#power-domain-cells":
> + const: 0
> +
> + "#reset-cells":
> + const: 0
> +
> + power-domains:
> + description:
> + Reference to parent power domains. A domain may have multiple parents,
> + and all will be powered up when it is powered.
> + minItems: 1
> +
> + label:
> + description: |
> + Specifies the name of the SoC domain being controlled. This is used to
> + name the power/reset domains.
> +
> + apple,always-on:
> + description: |

Can drop '|' on these too. Otherwise,

Reviewed-by: Rob Herring <robh@xxxxxxxxxx>

> + Forces this power domain to always be powered up.
> + type: boolean
> +
> +required:
> + - compatible
> + - reg
> + - "#power-domain-cells"
> + - "#reset-cells"
> + - label
> +
> +additionalProperties: false
> --
> 2.33.0
>
>