Re: [PATCH 2/4] dt-bindings: net: Add bindings for Qualcomm QCA807x

From: Robert Marko
Date: Thu Jan 07 2021 - 11:42:28 EST


On Sun, Jan 3, 2021 at 6:00 PM Andrew Lunn <andrew@xxxxxxx> wrote:
>
> > > > + qcom,tx-driver-strength:
> > > > + description: PSGMII/QSGMII TX driver strength control.
> > > > + $ref: /schemas/types.yaml#/definitions/uint32
> > > > + enum: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
> > >
> > > Please use the actual values here, and have the driver convert to the
> > > value poked into the register. So the property would be
> > > qcom,tx-driver-strength-mv and it would have the value 220 for
> > > example.
> >
> > The LED binding has properties for specifying the current already. And
> > it's max current which is the h/w property where as anything less is
> > just software configuration (IOW, doesn't belong in DT).
>
> Hi Rob
>
> My understanding of this is it is the drive strength of the SERDES
> line. Nothing to do with LEDs. The description needs improving.

Yes, this is used to set the PSGMII/QSMII SerDes TX driver strength.
It has nothing to do with LEDs.
I agree that the description is a bit confusing, I will try to make it
a bit clearer.
>
> Andrew