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

[Benjamin Gaignard]

Le 16/06/2025 à 17:58, Conor Dooley a écrit :
> On Mon, Jun 16, 2025 at 05:50:50PM +0200, Benjamin Gaignard wrote:
>> Le 16/06/2025 à 17:42, Conor Dooley a écrit :
>>> On Mon, Jun 16, 2025 at 05:30:44PM +0200, Benjamin Gaignard wrote:
>>>> 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 at collabora.com>
>>>>>> ---
>>>>>>     .../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 at collabora.com>
>>>>>> +
>>>>>> +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.
>>> "for the moment", yeah. Is there any information that could be used to
>>> version this available?
>> The hardware block isn't documented in the TRM so I don't know if there is a version
>> field or something like that.
>>
>>>> Does adding verisilicon,rk3588-iommu sound good for you ?
>>> It'd be "rockchip,rk3588-iommu", but sure.
>> "rockchip,rk3588-iommu" is already use for other MMUs in rk3588.
> "rockchip,rk3588-video-iommu" then? Instances of an IP in an SoC get a
> specific compatible with the SoC vendor's prefix, so having verisilicon
> there isn't suitable unless they made the SoC.

Other hardware video codecs have a different IOMMU so I will suggest
"rockchip,rk3588-av1-iommu" which is specific to this video hardware block.