Re: [PATCH v3 3/3] PCI: imx6: Add support for i.MX8MQ

[Andrey Smirnov]

On Tue, Dec 18, 2018 at 1:10 PM Rob Herring <robh@xxxxxxxxxx> wrote:
>
> On Tue, Dec 18, 2018 at 12:09 PM Leonard Crestez
> <leonard.crestez@xxxxxxx> wrote:
> >
> > On 12/18/2018 5:15 PM, Rob Herring wrote:
> > > On Mon, Dec 17, 2018 at 08:07:02PM -0800, Andrey Smirnov wrote:
> > >> Add code needed to support i.MX8MQ variant.
> > >>
> > >> Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
> > >> Reviewed-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> >
> > >> --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > >> +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > >>
> > >> +Additional required properties for imx8mq-pcie:
> > >> +- fsl,controller-id: Logical ID of a given PCIE controller. PCIE1 is 0, PCIE2 is 1;
> > >> +
> > >
> > > Remove this.
> > >
> > > If GPR register offset is what you need, then put that into DT.
> > > Typically, we'd have a property with iomuxc phandle and offset.
> >
> > This series initially added explicit offsets but I suggested a single
> > "controller-id" because:
> >   * There are multiple bit and byte offsets
> >   * Other imx8 SOCs also have 2x pcie with other bit/byte offsets
> >
> > Hiding this behind a compatible string and single "controller-id" seem
> > preferable to elaborating register maps in dt bindings. It also makes
> > upgrades simpler: if features are added which use other bits there is no
> > need to describe them in DT and deal with compatibility headaches.
>
> You already have an id for the controllers: the address. Use that if
> you don't want to put the register offsets in DT.
>

Lucas, are you on board with this?

Thanks,
Andrey Smirnov