Re: [PATCH V2 3/6] dt-bindings: spi: Add compatible for Mediatek IPM IP with quad mode

[Leilk Liu <leilk.liu@mediatek.com>]

On Fri, 2022-02-25 at 13:01 -0600, Rob Herring wrote:
> On Mon, Feb 21, 2022 at 12:07:14PM +0800, Leilk Liu wrote:
> > This patch adds dt-binding documentation for Mediatek SPI IPM IP
> > with
> > quad mode.
> > 
> > Signed-off-by: Leilk Liu <leilk.liu@mediatek.com>
> > ---
> >  Documentation/devicetree/bindings/spi/mediatek,spi-mt65xx.yaml | 1
> > +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/spi/mediatek,spi-
> > mt65xx.yaml b/Documentation/devicetree/bindings/spi/mediatek,spi-
> > mt65xx.yaml
> > index 0a2fc0404cb3..241c0f5880d3 100644
> > --- a/Documentation/devicetree/bindings/spi/mediatek,spi-
> > mt65xx.yaml
> > +++ b/Documentation/devicetree/bindings/spi/mediatek,spi-
> > mt65xx.yaml
> > @@ -42,6 +42,7 @@ properties:
> >                - mediatek,mt8173-spi
> >                - mediatek,mt8183-spi
> >                - mediatek,ipm-spi-single
> > +              - mediatek,ipm-spi-quad
> 
> Can't you use the existing width properties to distinguish? Or is
> the 
> programming not a superset?
> 
"mediatek,ipm-spi-quad" include the feature of "mediatek,ipm-spi-
single".

> Is 'ipm' an SoC? If not, these need to be SoC specific.
> 
IPM is an version of SPI ip, we use this IP with ICs now.
So I define a compatible strings "mediatek,ipm-spi-xxx", then I can
reuse this strings with many ICs.
Currently, we plan to upstream MT7986 IC, this IC has two spi
controller ports, one support single mode only, the other support
single & quad mode both.
for example:
spi0 {
  ...
  compatible = "mediatek,ipm-spi-single";
  ...
}

spi1 {
  ...
  compatible = "mediatek,ipm-spi-quad";
  ...
}


> Rob