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

From: Oleksij Rempel
Date: Tue Apr 02 2024 - 11:48:44 EST


On Tue, Apr 02, 2024 at 08:26:37AM -0500, Rob Herring wrote:
> > + 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?

I'm not against describing it consequent with regulator till the wire
end, but right now I have no idea how it should be described by using
regulator bindings. There are maximum 2 rails going in to PSE PI on one
side and 4 rails with at least 5 combinations supported by standard on
other side. Instead of inventing anything new, I suggested to describe
supported output combinations by using IEEE 802.3 standard.

Regards,
Oleksij
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