[PATCH v4 1/3] dt-bindings: dma: fsl-edma: add dma-channel-mask property description

[Frank Li]

On Wed, Feb 11, 2026 at 05:28:24PM +0800, Joy Zou wrote:
> Add documentation for the dma-channel-mask property in the fsl-edma
> binding. This property uses an inverted bit definition: bit value 0
> indicates the channel is available, while bit value 1 indicates
> unavailable.
>
> That was already used widely for i.MX8, i.MX9. Correcting the definition
> will break backward compatibility. This reversal only impacts the eDMA
> dts node and driver, and doesn't impact DMA consumer. Therefore,
> keep the inverted definition.
>
> Also add a note at the top of the binding to highlight this inverted
> definition to prevent confusion.
>
> Signed-off-by: Joy Zou <joy.zou at nxp.com>
> ---
Reviewed-by: Frank Li <Frank.Li at nxp.com>
>  Documentation/devicetree/bindings/dma/fsl,edma.yaml | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/dma/fsl,edma.yaml b/Documentation/devicetree/bindings/dma/fsl,edma.yaml
> index fa4248e2f1b9cecd00f1535744bfe6d9ecdba613..f609038e35ae1836b89c5b4d8a095b15a882fb87 100644
> --- a/Documentation/devicetree/bindings/dma/fsl,edma.yaml
> +++ b/Documentation/devicetree/bindings/dma/fsl,edma.yaml
> @@ -12,6 +12,9 @@ description: |
>    DMAMUX0 and DMAMUX1, specific DMA request source can only be multiplexed
>    by any channel of certain group, DMAMUX0 or DMAMUX1, but not both.
>
> +  This binding has an inverted dma-channel-mask definition compared to
> +  the common DMA binding for historical reasons.
> +
>  maintainers:
>    - Peng Fan <peng.fan at nxp.com>
>
> @@ -95,6 +98,12 @@ properties:
>        eDMA are implemented in big endian mode, otherwise in little mode.
>      type: boolean
>
> +  dma-channel-mask:
> +    description: |
> +      Bitmask of available DMA channels (inverted definition).
> +      Bit semantics: 0 means channel available, 1 means channel unavailable
> +    default: 0
> +
>  required:
>    - "#dma-cells"
>    - compatible
>
> --
> 2.37.1
>