RE: [PATCH 3/3] dt-bindings: rcar-gen3-phy-usb2: Add r7s9210 support

[Chris Brandt <Chris.Brandt@renesas.com>]

Hi Geert,

On Wednesday, November 14, 2018, Geert Uytterhoeven wrote:
> >  Required properties:
> > -- compatible: "renesas,usb2-phy-r8a774a1" if the device is a part of an
> R8A774A1
> > +- compatible: "renesas,usb2-phy-r7s9210" if the device is a part of an
> R7S9210
> > +             SoC.
> > +             "renesas,usb2-phy-r8a774a1" if the device is a part of an
> R8A774A1
> >               SoC.
> >               "renesas,usb2-phy-r8a7795" if the device is a part of an
> R8A7795
> >               SoC.
> > @@ -16,8 +18,8 @@ Required properties:
> >               R8A77990 SoC.
> >               "renesas,usb2-phy-r8a77995" if the device is a part of an
> >               R8A77995 SoC.
> > -             "renesas,rcar-gen3-usb2-phy" for a generic R-Car Gen3 or
> RZ/G2
> > -             compatible device.
> > +             "renesas,rcar-gen3-usb2-phy" for a generic R-Car Gen3,
> RZ/G2 or
> > +             RZ/A2 compatible device.
> 
> Is it a good idea to declare RZ/A2 compatible to R-Car Gen3?
> Usually we don't do that for Renesas IP cores used in different
> families[*].
> Of course, I know you do have a good relationship with the actual RZ/A2
> hardware designers ;-)
> 
> In light of Shimoda-san's comment w.r.t. R-Car H3 USB port1 in the driver
> code, perhaps "renesas,rcar-gen3-usb2-phy" should not be used?

Well, I think the IP block seems the same....however...
I did point out that the COMMCTRL register defaults to a different 
value. No idea why that is. Honestly, I did not go and check all the other 
registers bits. So I guess I wonder what "compatible" really means:

"Compatible: Different, but close enough that it will work" ???

Chris