RE: [PATCH v4 1/2] dt-bindings: PCI: amd-mdb: Add CPM6 support

[Musham, Sai Krishna]

Public

Hi Rob,

> -----Original Message-----
> From: Rob Herring <robh@xxxxxxxxxx>
> Sent: Thursday, August 13, 2026 4:24 AM
> To: Musham, Sai Krishna <sai.krishna.musham@xxxxxxx>
> Cc: bhelgaas@xxxxxxxxxx; lpieralisi@xxxxxxxxxx; kw@xxxxxxxxx;
> mani@xxxxxxxxxx; krzk+dt@xxxxxxxxxx; conor+dt@xxxxxxxxxx;
> cassel@xxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; Simek, Michal <michal.simek@xxxxxxx>;
> Gogada, Bharat Kumar <bharat.kumar.gogada@xxxxxxx>; Havalige,
> Thippeswamy <thippeswamy.havalige@xxxxxxx>; Sanwal, Pranav
> <Pranav.sanwal@xxxxxxx>
> Subject: Re: [PATCH v4 1/2] dt-bindings: PCI: amd-mdb: Add CPM6 support
>
> On Sat, Aug 08, 2026 at 04:22:55PM +0530, Sai Krishna Musham wrote:
> > The AMD CPM6 PCIe controller is based on the Synopsys DesignWare PCIe
> IP.
> > Add "intr" to snps,dw-pcie.yaml vendor-specific reg-names for the
> > per-controller interrupt register region used by CPM6.
> >
> > Update amd,versal2-mdb-host.yaml with separate register definitions:
> > - MDB5: 4 regions (slcr, config, dbi, atu)
> > - CPM6: 5 regions (slcr, config, dbi, atu, intr)
> >
> > Signed-off-by: Sai Krishna Musham <sai.krishna.musham@xxxxxxx>
> > ---
> > Changes in v4:
> > - None
> >
> > Changes in v3:
> > - Update subject to match history.
> > - Move allOf to the end, after required block.
> > - Drop the CPM6 example.
> >
> > Changes in v2:
> > - Update the CPM6 device tree binding and example.
> >
> > v1 https://lore.kernel.org/all/20260402180006.486229-2-
> sai.krishna.musham@xxxxxxx/
> > v2 https://lore.kernel.org/all/20260728202044.1785986-2-
> sai.krishna.musham@xxxxxxx/
> > v3 https://lore.kernel.org/all/20260803144412.713639-2-
> sai.krishna.musham@xxxxxxx/
> > ---
> >  .../bindings/pci/amd,versal2-mdb-host.yaml    | 45 ++++++++++++++++---
> >  .../devicetree/bindings/pci/snps,dw-pcie.yaml |  2 +
> >  2 files changed, 42 insertions(+), 5 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/pci/amd,versal2-mdb-
> host.yaml b/Documentation/devicetree/bindings/pci/amd,versal2-mdb-
> host.yaml
> > index 406c15e1dee1..672589066854 100644
> > --- a/Documentation/devicetree/bindings/pci/amd,versal2-mdb-host.yaml
> > +++ b/Documentation/devicetree/bindings/pci/amd,versal2-mdb-host.yaml
> > @@ -9,27 +9,30 @@ title: AMD Versal2 MDB(Multimedia DMA Bridge) Host
> Controller
> >  maintainers:
> >    - Thippeswamy Havalige <thippeswamy.havalige@xxxxxxx>
> >
> > -allOf:
> > -  - $ref: /schemas/pci/pci-host-bridge.yaml#
> > -  - $ref: /schemas/pci/snps,dw-pcie.yaml#
> > -
> >  properties:
> >    compatible:
> > -    const: amd,versal2-mdb-host
> > +    enum:
> > +      - amd,versal2-mdb-host
> > +      - amd,versal2-cpm6-host
> > +      - amd,versal2-cpm6-host1
>
> What is host and host1 difference? Please explain somewhere.
>

Thanks for the review, I will provide the difference between host and
host1 in commit message in next patch.

> >
> >    reg:
> > +    minItems: 4
> >      items:
> >        - description: MDB System Level Control and Status Register (SLCR) Base
> >        - description: configuration region
> >        - description: data bus interface
> >        - description: address translation unit register
> > +      - description: CPM6 PCIe error and event interrupt registers
> >
> >    reg-names:
> > +    minItems: 4
> >      items:
> >        - const: slcr
> >        - const: config
> >        - const: dbi
> >        - const: atu
> > +      - const: intr
> >
> >    ranges:
> >      maxItems: 2
> > @@ -92,6 +95,38 @@ required:
> >    - "#interrupt-cells"
> >    - interrupt-controller
> >
> > +allOf:
> > +  - $ref: /schemas/pci/pci-host-bridge.yaml#
> > +  - $ref: /schemas/pci/snps,dw-pcie.yaml#
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            const: amd,versal2-mdb-host
> > +    then:
> > +      properties:
> > +        reg:
> > +          minItems: 4
>
> Drop. 4 is already the min.
>

Thanks, I will fix it.

> > +          maxItems: 4
> > +        reg-names:
> > +          minItems: 4
> > +          maxItems: 4
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            enum:
> > +              - amd,versal2-cpm6-host
> > +              - amd,versal2-cpm6-host1
> > +    then:
> > +      properties:
> > +        reg:
> > +          minItems: 5
> > +          maxItems: 5
>
> Drop. 5 is already the max.
>

Thanks, I will fix it.

> > +        reg-names:
> > +          minItems: 5
> > +          maxItems: 5
> > +
> >  unevaluatedProperties: false
> >
> >  examples:
> > diff --git a/Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml
> b/Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml
> > index b3216141881c..21f86609ddb6 100644
> > --- a/Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml
> > +++ b/Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml
> > @@ -117,6 +117,8 @@ properties:
> >                enum: [ ecam ]
> >              - description: AMD MDB PCIe SLCR region
> >                const: slcr
> > +            - description: AMD CPM6 PCIe error and event interrupt registers
> > +              const: intr
> >      allOf:
> >        - contains:
> >            enum: [ dbi, ctrl ]
> > --
> > 2.44.4
> >