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Date:   Fri, 17 Jul 2020 00:32:36 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     Matthew Hagan <mnhagan88@gmail.com>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>, linux@armlinux.org.uk,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        John Crispin <john@phrozen.org>,
        Jonathan McDowell <noodles@earth.li>,
        Rob Herring <robh+dt@kernel.org>, devicetree@vger.kernel.org
Subject: Re: [PATCH 2/2] dt-bindings: net: dsa: qca8k: Add PORT0_PAD_CTRL
 properties
Message-ID: <20200716223236.GA1314837@lunn.ch>
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On Thu, Jul 16, 2020 at 03:09:25PM -0700, Jakub Kicinski wrote:
> On Mon, 13 Jul 2020 21:50:26 +0100 Matthew Hagan wrote:
> > Add names and decriptions of additional PORT0_PAD_CTRL properties.
> > 
> > Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
> > ---
> >  Documentation/devicetree/bindings/net/dsa/qca8k.txt | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/net/dsa/qca8k.txt b/Documentation/devicetree/bindings/net/dsa/qca8k.txt
> > index ccbc6d89325d..3d34c4f2e891 100644
> > --- a/Documentation/devicetree/bindings/net/dsa/qca8k.txt
> > +++ b/Documentation/devicetree/bindings/net/dsa/qca8k.txt
> > @@ -13,6 +13,14 @@ Optional properties:
> >  
> >  - reset-gpios: GPIO to be used to reset the whole device
> >  
> > +Optional MAC configuration properties:
> > +
> > +- qca,exchange-mac0-mac6:	If present, internally swaps MAC0 and MAC6.
> 
> Perhaps we can say a little more here?
> 
> > +- qca,sgmii-rxclk-falling-edge:	If present, sets receive clock phase to
> > +				falling edge.
> > +- qca,sgmii-txclk-falling-edge:	If present, sets transmit clock phase to
> > +				falling edge.
> 
> These are not something that other vendors may implement and therefore
> something we may want to make generic? Andrew?

I've never seen any other vendor implement this. Which to me makes me
think this is a vendor extension, to Ciscos vendor extension of
1000BaseX.

Matthew, do you have a real use cases of these? I don't see a DT patch
making use of them. And if you do, what is the PHY on the other end
which also allows you to invert the clocks?

       Andrew