RE: [PATCH net] dt-bindings: net: tja11xx: fix the broken binding

[Wei Fang]

> > +properties:
> > +  compatible:
> > +    enum:
> > +      - ethernet-phy-id0180.dc40
> > +      - ethernet-phy-id0180.dd00
> > +      - ethernet-phy-id0180.dc80
> > +      - ethernet-phy-id001b.b010
> > +      - ethernet-phy-id001b.b031
> 
> This shows the issues with using a compatible. The driver has:
> 
> #define PHY_ID_TJA_1120                 0x001BB031
> 
>                 PHY_ID_MATCH_MODEL(PHY_ID_TJA_1120),
> 
> which means the lowest nibble is ignored. The driver will quite happy also probe
> for hardware using 001b.b030, 001b.b032, 001b.b033, ... 001b.b03f
> 
> Given you are inside NXP, do any of these exist? Was 001b.b030 too broken it
> never left the QA lab? Are there any hardware issues which might result in a
> new silicon stepping?

Yes, some of the revisions do exist, but the driver should be compatible with
these different revisions.

For 001b.b030, I don't think it is broken, based on the latest data sheet of
TJA1120 (Rev 0.6 26 January 2023), the PHY ID is 001b.b030. I don't know
why it is defined as 001b.b031 in the driver, it may be a typo.
> 
> Does ethernet-phy-id0180.dc41 exist? etc.
I think other TJA PHYs should also have different revisions.

Because the driver ignores the lowest nibble of the PHY ID, I think it is fine to
define the lowest nibble of the PHY ID in these compatible strings as 0, and
there is no need to list all revisions. And I don't know which revisions exist,
because I haven't found or have no permission to download some PHY data
sheets. I think what I can do is to modify "ethernet-phy-id001b.b031" to
"ethernet-phy-id001b.b030".