Re: [PATCH v8 1/4] dt-bindings: dmaengine: Add MediaTek Command-Queue DMA controller bindings

[Rob Herring]

On Wed, Dec 23, 2020 at 05:30:44PM +0800, EastL Lee wrote:
> Document the devicetree bindings for MediaTek Command-Queue DMA controller
> which could be found on MT6779 SoC or other similar Mediatek SoCs.
> 
> Signed-off-by: EastL Lee <EastL.Lee@xxxxxxxxxxxx>
> ---
>  .../devicetree/bindings/dma/mtk-cqdma.yaml         | 104 +++++++++++++++++++++

Use compatible string for filename:

mediatek,cqdma.yaml

>  1 file changed, 104 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/mtk-cqdma.yaml
> 
> diff --git a/Documentation/devicetree/bindings/dma/mtk-cqdma.yaml b/Documentation/devicetree/bindings/dma/mtk-cqdma.yaml
> new file mode 100644
> index 0000000..a76a263
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/mtk-cqdma.yaml
> @@ -0,0 +1,104 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/dma/mtk-cqdma.yaml#

Don't forget to update this.

> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MediaTek Command-Queue DMA controller Device Tree Binding
> +
> +maintainers:
> +  - EastL Lee <EastL.Lee@xxxxxxxxxxxx>
> +
> +description:
> +  MediaTek Command-Queue DMA controller (CQDMA) on Mediatek SoC
> +  is dedicated to memory-to-memory transfer through queue based
> +  descriptor management.
> +
> +allOf:
> +  - $ref: "dma-controller.yaml#"
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +          - mediatek,mt6765-cqdma
> +          - mediatek,mt6779-cqdma
> +      - const: mediatek,cqdma
> +
> +  reg:
> +    minItems: 1
> +    maxItems: 5
> +    description:
> +        A base address of MediaTek Command-Queue DMA controller,
> +        a channel will have a set of base address.
> +
> +  interrupts:
> +    minItems: 1
> +    maxItems: 5
> +    description:
> +        A interrupt number of MediaTek Command-Queue DMA controller,
> +        one interrupt number per dma-channels.
> +
> +  clocks:
> +    maxItems: 1
> +
> +  clock-names:
> +    const: cqdma
> +
> +  dma-channel-mask:
> +    description:
> +       For DMA capability, We will know the addressing capability of
> +       MediaTek Command-Queue DMA controller through dma-channel-mask.
> +      minimum: 1
> +      maximum: 63

Indentation is wrong here so this has no effect.

A mask of 63 is 6 channels...

> +
> +  dma-channels:
> +    description:
> +      Number of DMA channels supported by MediaTek Command-Queue DMA
> +      controller, support up to five.
> +      minimum: 1
> +      maximum: 5

Same here.

Do you really need both dma-channels and dma-channel-mask? You should be 
able to get one from the other.

> +
> +  dma-requests:
> +    description:
> +      Number of DMA request (virtual channel) supported by MediaTek
> +      Command-Queue DMA controller, support up to 32.
> +      minimum: 1
> +      maximum: 32

And here.

You are missing '#dma-cells' also.

> +
> +required:
> +  - "#dma-cells"
> +  - compatible
> +  - reg
> +  - interrupts
> +  - clocks
> +  - clock-names
> +  - dma-channel-mask
> +  - dma-channels
> +  - dma-requests
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/clock/mt6779-clk.h>
> +    cqdma: dma-controller@10212000 {
> +        compatible = "mediatek,mt6779-cqdma";

This should fail validation because it doesn't match the schema. You ran 
'make dt_binding_check', right?

> +        reg = <0x10212000 0x80>,
> +            <0x10212080 0x80>,
> +            <0x10212100 0x80>;
> +        interrupts = <GIC_SPI 139 IRQ_TYPE_LEVEL_LOW>,
> +            <GIC_SPI 140 IRQ_TYPE_LEVEL_LOW>,
> +            <GIC_SPI 141 IRQ_TYPE_LEVEL_LOW>;
> +        clocks = <&infracfg_ao CLK_INFRA_CQ_DMA>;
> +        clock-names = "cqdma";
> +        dma-channel-mask = <63>;

6 channels or...

> +        dma-channels = <3>;

3?

> +        dma-requests = <32>;
> +        #dma-cells = <1>;
> +    };
> +
> +...
> -- 
> 1.9.1
>