Re: [PATCH net-next v6 11/17] dt-bindings: net: pse-pd: Add another way of describing several PSE PIs

From: Rob Herring
Date: Tue Apr 02 2024 - 09:26:50 EST


On Tue, Mar 26, 2024 at 03:04:48PM +0100, Kory Maincent wrote:
> From: Kory Maincent (Dent Project) <kory.maincent@xxxxxxxxxxx>
>
> PSE PI setup may encompass multiple PSE controllers or auxiliary circuits
> that collectively manage power delivery to one Ethernet port.
> Such configurations might support a range of PoE standards and require
> the capability to dynamically configure power delivery based on the
> operational mode (e.g., PoE2 versus PoE4) or specific requirements of
> connected devices. In these instances, a dedicated PSE PI node becomes
> essential for accurately documenting the system architecture. This node
> would serve to detail the interactions between different PSE controllers,
> the support for various PoE modes, and any additional logic required to
> coordinate power delivery across the network infrastructure.
>
> The old usage of "#pse-cells" is unsuficient as it carries only the PSE PI
> index information.
>
> Signed-off-by: Kory Maincent <kory.maincent@xxxxxxxxxxx>
> ---
>
> Changes in v3:
> - New patch
>
> Changes in v4:
> - Remove $def
> - Fix pairset-names item list
> - Upgrade few properties description
> - Update the commit message
>
> Changes in v5:
> - Fix yamllint error.
> - Replace underscore by dash in properties names.
> - Add polarity-supported property.
>
> Changes in v6:
> - Reorder the pairset pinout table documentation to shrink the lines size.
> - Remove pairset and polarity as required fields.
> - Add vpwr-supply regulator supply.
> ---
> .../bindings/net/pse-pd/pse-controller.yaml | 102 ++++++++++++++++++++-
> 1 file changed, 99 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/net/pse-pd/pse-controller.yaml b/Documentation/devicetree/bindings/net/pse-pd/pse-controller.yaml
> index 2d382faca0e6..03f7f215c162 100644
> --- a/Documentation/devicetree/bindings/net/pse-pd/pse-controller.yaml
> +++ b/Documentation/devicetree/bindings/net/pse-pd/pse-controller.yaml
> @@ -13,6 +13,7 @@ description: Binding for the Power Sourcing Equipment (PSE) as defined in the
>
> maintainers:
> - Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
> + - Kory Maincent <kory.maincent@xxxxxxxxxxx>
>
> properties:
> $nodename:
> @@ -22,11 +23,106 @@ properties:
> description:
> Used to uniquely identify a PSE instance within an IC. Will be
> 0 on PSE nodes with only a single output and at least 1 on nodes
> - controlling several outputs.
> + controlling several outputs which are not described in the pse-pis
> + subnode. This property is deprecated, please use pse-pis instead.
> enum: [0, 1]
>
> -required:
> - - "#pse-cells"
> + pse-pis:
> + type: object
> + description:
> + Overview of the PSE PIs provided by the controller.
> +
> + properties:
> + "#address-cells":
> + const: 1
> +
> + "#size-cells":
> + const: 0
> +
> + required:
> + - "#address-cells"
> + - "#size-cells"
> +
> + patternProperties:
> + "^pse-pi@[0-9a-f]+$":
> + type: object
> + description:
> + PSE PI for power delivery via pairsets, compliant with IEEE
> + 802.3-2022, Section 145.2.4. Each pairset comprises a positive and
> + a negative VPSE pair, adhering to the pinout configurations
> + detailed in the standard.
> + See Documentation/networking/pse-pd/pse-pi.rst for details.
> +
> + properties:
> + reg:
> + description:
> + Address describing the PSE PI index.
> + maxItems: 1
> +
> + "#pse-cells":
> + const: 0
> +
> + pairset-names:
> + $ref: /schemas/types.yaml#/definitions/string-array
> + description:
> + Names of the pairsets as per IEEE 802.3-2022, Section 145.2.4.
> + Valid values are "alternative-a" and "alternative-b". Each name

Don't state constraints in prose which are defined as schema
constraints.

> + should correspond to a phandle in the 'pairset' property
> + pointing to the power supply for that pairset.
> + minItems: 1
> + maxItems: 2
> + items:
> + enum:
> + - alternative-a
> + - alternative-b
> +
> + pairsets:
> + $ref: /schemas/types.yaml#/definitions/phandle-array
> + description:
> + List of phandles, each pointing to the power supply for the
> + corresponding pairset named in 'pairset-names'. This property
> + aligns with IEEE 802.3-2022, Section 33.2.3 and 145.2.4.
> + PSE Pinout Alternatives (as per IEEE 802.3-2022 Table 145\u20133)
> + |-----------|---------------|---------------|---------------|---------------|
> + | Conductor | Alternative A | Alternative A | Alternative B | Alternative B |
> + | | (MDI-X) | (MDI) | (X) | (S) |
> + |-----------|---------------|---------------|---------------|---------------|
> + | 1 | Negative VPSE | Positive VPSE | \u2014 | \u2014 |
> + | 2 | Negative VPSE | Positive VPSE | \u2014 | \u2014 |
> + | 3 | Positive VPSE | Negative VPSE | \u2014 | \u2014 |
> + | 4 | \u2014 | \u2014 | Negative VPSE | Positive VPSE |
> + | 5 | \u2014 | \u2014 | Negative VPSE | Positive VPSE |
> + | 6 | Positive VPSE | Negative VPSE | \u2014 | \u2014 |
> + | 7 | \u2014 | \u2014 | Positive VPSE | Negative VPSE |
> + | 8 | \u2014 | \u2014 | Positive VPSE | Negative VPSE |
> + minItems: 1
> + maxItems: 2

"pairsets" does not follow the normal design pattern of foos, foo-names,
and #foo-cells. You could add #foo-cells I suppose, but what would cells
convey? I don't think it's a good fit for what you need.

The other oddity is the number of entries and the names are fixed. That
is usually defined per consumer.

As each entry is just a power rail, why can't the regulator binding be
used here?

> +
> + polarity-supported:
> + $ref: /schemas/types.yaml#/definitions/string-array
> + description:
> + Polarity configuration supported by the PSE PI pairsets.
> + minItems: 1
> + maxItems: 4
> + items:
> + enum:
> + - MDI-X
> + - MDI
> + - X
> + - S
> +
> + vpwr-supply:
> + description: Regulator power supply for the PSE PI.

I don't see this being used anywhere.

> +
> + required:
> + - reg
> + - "#pse-cells"
> +
> +oneOf:
> + - required:
> + - "#pse-cells"
> + - required:
> + - pse-pis
>
> additionalProperties: true
>
>
> --
> 2.25.1
>