Re: [PATCH 2/5] dt-bindings: iommu: verisilicon: Add binding for VSI IOMMU

[Benjamin Gaignard]

Le 16/06/2025 à 17:14, Conor Dooley a écrit :
> On Mon, Jun 16, 2025 at 04:55:50PM +0200, Benjamin Gaignard wrote:
> > Add a device tree binding for the Verisilicon (VSI) IOMMU. This IOMMU sits
> > in front of hardware encoder and decoder blocks on SoCs using Verisilicon IP,
> > such as the Rockchip RK3588.
> >
> > Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
> > ---
> >   .../bindings/iommu/verisilicon,iommu.yaml     | 71 +++++++++++++++++++
> >   1 file changed, 71 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/iommu/verisilicon,iommu.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/iommu/verisilicon,iommu.yaml b/Documentation/devicetree/bindings/iommu/verisilicon,iommu.yaml
> > new file mode 100644
> > index 000000000000..acef855fc61d
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iommu/verisilicon,iommu.yaml
> > @@ -0,0 +1,71 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/iommu/verisilicon,iommu.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Verisilicon IOMMU
> > +
> > +maintainers:
> > +  - Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
> > +
> > +description: |+
> > +  A Versilicon iommu translates io virtual addresses to physical addresses for
> > +  its associated video decoder.
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
> > +      - items:
> > +          - const: verisilicon,iommu
> You're missing a soc-specific compatible at the very least here, but is
> there really no versioning on the IP at all? I'd be surprised if
> verisilicon only produced exactly one version of an iommu IP.

I only aware this version of the iommu for the moment.
Does adding verisilicon,rk3588-iommu sound good for you ?

> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    items:
> > +      - description: Core clock
> > +      - description: Interface clock
> > +
> > +  clock-names:
> > +    items:
> > +      - const: aclk
> > +      - const: iface
> Why "aclk" rather than core, to match the description?

I will change that, the driver doesn't care of the clock name anyway

> > +
> > +  "#iommu-cells":
> > +    const: 0
> > +
> > +  power-domains:
> > +    maxItems: 1
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +  - clocks
> > +  - clock-names
> > +  - "#iommu-cells"
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/rockchip,rk3588-cru.h>
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +
> > +    bus {
> > +      #address-cells = <2>;
> > +      #size-cells = <2>;
> > +
> > +      vsi_mmu: iommu@fdca0000 {
> The "vsi_mmu" label can be dropped here, it has no users.

ok.

Thanks,
Benjamin

> Cheers,
> Conor.
>
> > +        compatible = "verisilicon,iommu";
> > +        reg = <0x0 0xfdca0000 0x0 0x600>;
> > +        interrupts = <GIC_SPI 109 IRQ_TYPE_LEVEL_HIGH 0>;
> > +        clocks = <&cru ACLK_AV1>, <&cru PCLK_AV1>;
> > +        clock-names = "aclk", "iface";
> > +        #iommu-cells = <0>;
> > +      };
> > +    };
> > --
> > 2.43.0