Re: [PATCH v2 1/4] dt-bindings: dma: snps,dw-axi-dmac: Add compatible string for Agilex5

Rob Herring
2025-12-09T21:21:55Z

On Mon, Dec 08, 2025 at 09:57:42AM +0800, Khairul Anuar Romli wrote:
> The address bus on Agilex5 is limited to 40 bits. When SMMU is enable this
> will cause address truncation and translation faults. Hence introducing
> "altr,agilex5-axi-dma" to enable platform specific configuration to
> configure the dma addressable bit mask.
>
> Add a fallback capability for the compatible property to allow driver to
> probe and initialize with a newly added compatible string without requiring
> additional entry in the driver.
>
> Add dma-ranges to the binding schema to allow specifying DMA address
> mapping between the controller and its parent bus.
>
> Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
> ---
> Changes in v2:
> - Add dma-ranges
> ---
> .../bindings/dma/snps,dw-axi-dmac.yaml | 23 +++++++++++++++----
> 1 file changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> index a393a33c8908..1a1800d9b544 100644
> --- a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> +++ b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> @@ -17,11 +17,15 @@ allOf:
>
> properties:
> compatible:
> - enum:
> - - snps,axi-dma-1.01a
> - - intel,kmb-axi-dma
> - - starfive,jh7110-axi-dma
> - - starfive,jh8100-axi-dma
> + oneOf:
> + - enum:
> + - snps,axi-dma-1.01a
> + - intel,kmb-axi-dma
> + - starfive,jh7110-axi-dma
> + - starfive,jh8100-axi-dma
> + - items:
> + - const: altr,agilex5-axi-dma
> + - const: snps,axi-dma-1.01a
>
> reg:
> minItems: 1
> @@ -104,6 +108,15 @@ properties:
> minimum: 1
> maximum: 256
>
> + dma-ranges:
> + description: |
> + Describe memory addresses translation between the DMA address and the
> + CPU address. Each memory region, is declared with 3-6 32-bit cells
> + parameters:
> + - param 1: device base address
> + - param 2: physical base address
> + - param 3: size of the memory region.

No need to generically describe dma-ranges. Just 'dma-ranges: true'
unless you define constaints on the number of entries or want to put
some description about why it is needed here.

> +
> required:
> - compatible
> - reg
> --
> 2.43.7
>