Re: [PATCH net-next v1 2/7] dt-bindings: net: phy: add PoDL PSE property

[Oleksij Rempel <o.rempel@pengutronix.de>]

On Mon, Aug 22, 2022 at 09:34:47PM +0200, Andrew Lunn wrote:
> On Mon, Aug 22, 2022 at 01:45:34PM -0500, Rob Herring wrote:
> > On Fri, Aug 19, 2022 at 02:01:04PM +0200, Oleksij Rempel wrote:
> > > Add property to reference node representing a PoDL Power Sourcing Equipment.
> > > 
> > > Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> > > ---
> > >  Documentation/devicetree/bindings/net/ethernet-phy.yaml | 6 ++++++
> > >  1 file changed, 6 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
> > > index ed1415a4381f2..49c74e177c788 100644
> > > --- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml
> > > +++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
> > > @@ -144,6 +144,12 @@ properties:
> > >        Mark the corresponding energy efficient ethernet mode as
> > >        broken and request the ethernet to stop advertising it.
> > >  
> > > +  ieee802.3-podl-pse:
> > > +    $ref: /schemas/types.yaml#/definitions/phandle
> > > +    description:
> > > +      Specifies a reference to a node representing a Power over Data Lines
> > > +      Power Sourcing Equipment.
> > 
> > Ah, here is the consumer.
> > 
> > Why do you anything more than just a -supply property here for the 
> > PoE/PoDL supply? The only reason I see is you happen to want a separate 
> > driver for this and a separate node happens to be a convenient way to 
> > instantiate drivers in Linux. Convince me otherwise.
> 
> The regulator binding provides a lot of very useful properties, which
> look to do a good job describing the regulator part of a PoE/PeDL
> supplier side. What however is missing is the communication part, the
> power provider and the power consumer communicate with each other, via
> a serial protocol. They negotiate the supply of power, a sleep mode
> where power is reduced, but not removed, etc.
> 
> So a Power Sourcing Equipment driver is very likely to have a
> regulator embedded in it, but its more than a regulator.

@Rob, is it enough to convince?

Regards,
Oleksij
-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |