Subject: Re: [PATCH v4 1/4] dt-bindings: net: phy: Add support for NXP TJA11xx

From: Andrew Lunn <[email-masked]>
Date: Fri, 13 Mar 2020 19:10:56 +0100

> > diff --git a/Documentation/devicetree/bindings/net/nxp,tja11xx.yaml b/Documentation/devicetree/bindings/net/nxp,tja11xx.yaml
> > new file mode 100644
> > index 000000000000..42be0255512b
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/net/nxp,tja11xx.yaml
> > @@ -0,0 +1,61 @@
> > +# SPDX-License-Identifier: GPL-2.0+
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/net/nxp,tja11xx.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: NXP TJA11xx PHY
> > +
> > +maintainers:
> > +  - Andrew Lunn <[email-masked]>
> > +  - Florian Fainelli <[email-masked]>
> > +  - Heiner Kallweit <[email-masked]>
> > +
> > +description:
> > +  Bindings for NXP TJA11xx automotive PHYs
> > +
> > +allOf:
> > +  - $ref: ethernet-phy.yaml#
> > +
> > +patternProperties:
> > +  "^ethernet-phy@[0-9a-f]+$":
> > +    type: object
> > +    description: |
> > +      Some packages have multiple PHYs. Secondary PHY should be defines as
> > +      subnode of the first (parent) PHY.
> 
> 
> There are QSGMII PHYs which have 4 PHYs embedded and AFAICT they are
> defined as 4 separate Ethernet PHY nodes and this would not be quite a
> big stretch to represent them that way compared to how they are.
> 
> I would recommend doing the same thing and not bend the MDIO framework
> to support the registration of "nested" Ethernet PHY nodes.

Hi Florian

The issue here is the missing PHY ID in the secondary PHY. Because of
that, the secondary does not probe in the normal way. We need the
primary to be involved to some degree. It needs to register it. What
i'm not so clear on is if it just needs to register it, or if these
sub nodes are actually needed, given the current code.

    Andrew