Re: [PATCH v5 04/15] dt-bindings: spi: dw: Add AMD Pensando Elba SoC SPI Controller bindings

[Serge Semin]

On Mon, Jun 20, 2022 at 09:46:25PM +0200, Krzysztof Kozlowski wrote:
> On 20/06/2022 21:30, Serge Semin wrote:
> > On Mon, Jun 13, 2022 at 12:56:47PM -0700, Brad Larson wrote:
> >> From: Brad Larson <blarson@xxxxxxx>
> >>
> >> The AMD Pensando Elba SoC has integrated the DW APB SPI Controller
> >>
> >> Signed-off-by: Brad Larson <blarson@xxxxxxx>
> >> ---
> >>  Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml | 2 ++
> >>  1 file changed, 2 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> >> index e25d44c218f2..2a55b947cffc 100644
> >> --- a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> >> +++ b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> >> @@ -73,6 +73,8 @@ properties:
> >>                - renesas,r9a06g032-spi # RZ/N1D
> >>                - renesas,r9a06g033-spi # RZ/N1S
> >>            - const: renesas,rzn1-spi   # RZ/N1
> > 
> >> +      - description: AMD Pensando Elba SoC SPI Controller
> >> +        const: amd,pensando-elba-spi
> > 
> > Not enough. The driver requires to have a phandle reference to the
> > Pensando System Controller. So the property like
> > "amd,pensando-elba-syscon" is also needed to be added to the DT schema
> > otherwise should the dt-schema tool correctly handle the
> > "unevaluatedProperties: false" setting (Rob says it isn't fully
> > supported at the moment), the dtbs_check procedure will fail on your
> > dts evaluation.
> 

> The property was here before, now removed, so I assume it was also
> removed from the driver and DTS. Isn't that the case?

Ah, the property has been indeed removed. The driver now searches for
the system controller by the next compatible string:
"amd,pensando-elba-syscon" using the
syscon_regmap_lookup_by_compatible() method. My mistake. Sorry for the
noise.

* Though personally I'd prefer to have a property with the phandle
reference in order to signify the connection between the system controller
and the SPI-controller. Otherwise the implicit DT bindings like having
the "amd,pensando-elba-syscon"-compatible syscon gets to be
hidden behind the DT scene. But seeing we have already got the Microsemi
platform with such semantic, I can't insist on fixing this.

-Sergey

> 
> Otherwise this is incomplete binding...
> 
> Best regards,
> Krzysztof