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Date:   Tue, 23 Aug 2022 16:44:37 +0200
From:   Oleksij Rempel <o.rempel@pengutronix.de>
To:     Andrew Lunn <andrew@lunn.ch>
Cc:     Rob Herring <robh@kernel.org>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Russell King <linux@armlinux.org.uk>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Jonathan Corbet <corbet@lwn.net>, kernel@pengutronix.de,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-doc@vger.kernel.org,
        David Jander <david@protonic.nl>
Subject: Re: [PATCH net-next v1 2/7] dt-bindings: net: phy: add PoDL PSE
 property
Message-ID: <20220823144437.GN10138@pengutronix.de>
References: <20220819120109.3857571-1-o.rempel@pengutronix.de>
 <20220819120109.3857571-3-o.rempel@pengutronix.de>
 <20220822184534.GB113650-robh@kernel.org>
 <YwPaV2Frj+b++8hZ@lunn.ch>
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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
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