Re: [PATCH 2/3] spi: dt-bindings: cdns,xspi: add ACMD and internal DMA properties

[Conor Dooley]

On Thu, Oct 29, 2026 at 04:03:17PM +0000, Nuno Sá wrote:
> The Cadence xSPI controller supports an auto command (ACMD) mode where
> high level sequences (read, program, erase) are handled by the
> controller and data can be moved by its internal DMA. Whether ACMD can
> be used, and whether the internal DMA bus requester interface is wired,
> depends on how the IP is integrated (e.g. external SRAM, interconnect
> wiring) and cannot be discovered from the controller.
> 
> Add the cdns,has-acmd and cdns,has-internal-dma boolean properties to
> describe that. The internal DMA is only used by ACMD, so properly
> reflect that.

Why would these properties be needed? What the controller support surely
can be determined from the specific compatible for the SoC integration?

> 
> Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
> ---
>  Documentation/devicetree/bindings/spi/cdns,xspi.yaml | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/spi/cdns,xspi.yaml b/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
> index 38a5795589de..9708ede79730 100644
> --- a/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
> +++ b/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
> @@ -40,11 +40,29 @@ properties:
>    interrupts:
>      maxItems: 1
>  
> +  cdns,has-acmd:
> +    type: boolean
> +    description:
> +      The controller supports the auto command (ACMD) mode. The IP may need
> +      external hardware (like SRAM) at SoC integration to fully leverage
> +      ACMD.
> +
> +  cdns,has-internal-dma:
> +    type: boolean
> +    description:
> +      The controller internal DMA bus requester interface is wired at SoC
> +      integration, so the controller can move ACMD data to and from memory
> +      on its own.
> +
>  required:
>    - compatible
>    - reg
>    - interrupts
>  
> +dependencies:
> +  cdns,has-internal-dma:
> +    - cdns,has-acmd
> +
>  allOf:
>    - $ref: spi-controller.yaml#
>    - if:
> 
> -- 
> 2.56.0
>

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