Re: [RFC PATCH 1/2] dt-bindings: iommu: add bindings for sprd iommu

[Rob Herring <robh@kernel.org>]

On Wed, Dec 23, 2020 at 07:16:32PM +0800, Chunyan Zhang wrote:
> From: Chunyan Zhang <chunyan.zhang@unisoc.com>
> 
> This patch only adds bindings to support display iommu, support for others
> would be added once finished tests with those devices, such as Image
> codec(jpeg) processor, a few signal processors, including VSP(video),
> GSP(graphic), ISP(image), and camera CPP, etc.
> 
> Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
> ---
>  .../devicetree/bindings/iommu/sprd,iommu.yaml | 44 +++++++++++++++++++
>  1 file changed, 44 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iommu/sprd,iommu.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iommu/sprd,iommu.yaml b/Documentation/devicetree/bindings/iommu/sprd,iommu.yaml
> new file mode 100644
> index 000000000000..4d9a578a7cc9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iommu/sprd,iommu.yaml
> @@ -0,0 +1,44 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright 2020 Unisoc Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iommu/sprd,iommu.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Unisoc IOMMU and Multi-media MMU
> +
> +maintainers:
> +  - Chunyan Zhang <zhang.lyra@gmail.com>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - sprd,iommu-disp

Needs to be Soc specific. Is this block specific to display subsys or 
that just happens to be where the instance is?

> +
> +  reg:
> +    maxItems: 1
> +
> +  "#iommu-cells":
> +    const: 0
> +    description:
> +      Unisoc IOMMUs are all single-master IOMMU devices, therefore no
> +      additional information needs to associate with its master device.
> +      Please refer to the generic bindings document for more details,
> +      Documentation/devicetree/bindings/iommu/iommu.txt
> +
> +required:
> +  - compatible
> +  - reg
> +  - "#iommu-cells"
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    iommu_disp: iommu@63000000 {
> +      compatible = "sprd,iommu-disp";
> +      reg = <0x63000000 0x880>;
> +      #iommu-cells = <0>;
> +    };
> +
> +...
> -- 
> 2.25.1
>