Re: [PATCH 2/2] dt-bindings: dma: hisi: Add bindings for Hisi Ascend sdma

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 11/08/2023 05:48, Guo Mengqi wrote:
> Add device-tree binding documentation for the Hisi Ascend sdma
> controller.
> 
> Signed-off-by: Guo Mengqi <guomengqi3@huawei.com>
> ---
>  .../bindings/dma/hisi,ascend-sdma.yaml        | 82 +++++++++++++++++++
>  1 file changed, 82 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/hisi,ascend-sdma.yaml
> 
> diff --git a/Documentation/devicetree/bindings/dma/hisi,ascend-sdma.yaml b/Documentation/devicetree/bindings/dma/hisi,ascend-sdma.yaml
> new file mode 100644
> index 000000000000..beb2b3597f4d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/hisi,ascend-sdma.yaml
> @@ -0,0 +1,82 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/dma/hisi,ascend-sdma.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: HISI Ascend System DMA (SDMA) controller
> +
> +description: |
> +  The Ascend SDMA controller is used for transferring data

What is Ascend? SoC? Family? Model?

> +  in system memory. It utilizes IOMMU SVA feature and accepts
> +  virtual address from user process.
> +
> +maintainers:
> +  - Guo Mengqi <guomengqi3@huawei.com>
> +
> +allOf:
> +  - $ref: dma-controller.yaml#
> +
> +properties:
> +  compatible:
> +    const: hisilicon,sdma

Way too generic compatible. It must be *model specific*.

> +
> +  reg:
> +    maxItems: 1
> +
> +  '#dma-cells':
> +    const: 1
> +    description:
> +      Clients specify a single cell with channel number.
> +
> +  ascend_sdma_channel_map:

Missing vendor prefix, no underscores in property names, missing type/$ref.


I doubt this was ever tested.

> +    description: |
> +      bitmap, each bit stands for a channel that is allowed to
> +      use by this system. Maximum 32 bits.
> +    maximum: 0xffffffff
> +
> +  ascend_sdma_channel_iomem_size:
> +    description: |
> +      depends on different platforms to be released. There are

Ah, so compatible is not specific enough? No, please make compatibles
specific and drop this property.

> +      currently two possible values. A default value is used if
> +      the property is not set.
> +      - enum:
> +        - 0x400
> +        - 0x1000
> +
> +  iommus:
> +    maxItems: 1
> +
> +  pasid-num-bits:
> +    description: |
> +      sdma utilizes iommu sva feature to transfer user space data.
> +      It act as a basic dma controller if not bound to user space.
> +    const: 0x10
> +
> +  dma-coherent: true
> +
> +  dma-can-stall: true
> +
> +required:
> +  - compatible
> +  - reg
> +  - ascend_sdma_channel_map
> +  - '#dma-cells'
> +  - iommus
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    sdma: dma-controller@880E0000 {

Use lowercase hex and drop unused label.

> +      compatible = "hisilicon,sdma";
> +        reg = <0x880e0000 0x10000>;

Broken indentation.




Best regards,
Krzysztof