dmaengine: dma350: Support slave_sg, cyclic and DMA-250

[PATCH 13/14] dt-bindings: dma: dma350: Support ARM DMA-250

Posted by Jisheng Zhang 1 month, 1 week ago

Compared with ARM DMA-350, DMA-250 is a simplified version, they share
many common parts, but they do have difference. The difference will be
handled in next driver patch, while let's add DMA-250 compatible string
to dt-binding now.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
 Documentation/devicetree/bindings/dma/arm,dma-350.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/dma/arm,dma-350.yaml b/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
index 94752516e51a..d49736b7de5e 100644
--- a/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
+++ b/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
@@ -15,6 +15,7 @@ allOf:
 properties:
   compatible:
     const: arm,dma-350
+    const: arm,dma-250
 
   reg:
     items:
-- 
2.50.0

Re: [PATCH 13/14] dt-bindings: dma: dma350: Support ARM DMA-250

Posted by Krzysztof Kozlowski 1 month, 1 week ago

On 23/08/2025 17:40, Jisheng Zhang wrote:
> Compared with ARM DMA-350, DMA-250 is a simplified version, they share
> many common parts, but they do have difference. The difference will be
> handled in next driver patch, while let's add DMA-250 compatible string
> to dt-binding now.
> 
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
> ---
>  Documentation/devicetree/bindings/dma/arm,dma-350.yaml | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/Documentation/devicetree/bindings/dma/arm,dma-350.yaml b/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
> index 94752516e51a..d49736b7de5e 100644
> --- a/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
> +++ b/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
> @@ -15,6 +15,7 @@ allOf:
>  properties:
>    compatible:
>      const: arm,dma-350
> +    const: arm,dma-250

This obviously cannot work and was NEVER tested. Please test your code
before you send it to mailing lists.

Best regards,
Krzysztof

Re: [PATCH 13/14] dt-bindings: dma: dma350: Support ARM DMA-250

Posted by Robin Murphy 1 month ago

On 2025-08-23 5:11 pm, Krzysztof Kozlowski wrote:
> On 23/08/2025 17:40, Jisheng Zhang wrote:
>> Compared with ARM DMA-350, DMA-250 is a simplified version, they share
>> many common parts, but they do have difference. The difference will be
>> handled in next driver patch, while let's add DMA-250 compatible string
>> to dt-binding now.
>>
>> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
>> ---
>>   Documentation/devicetree/bindings/dma/arm,dma-350.yaml | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/Documentation/devicetree/bindings/dma/arm,dma-350.yaml b/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
>> index 94752516e51a..d49736b7de5e 100644
>> --- a/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
>> +++ b/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
>> @@ -15,6 +15,7 @@ allOf:
>>   properties:
>>     compatible:
>>       const: arm,dma-350
>> +    const: arm,dma-250
> 
> This obviously cannot work and was NEVER tested. Please test your code
> before you send it to mailing lists.

Also, DMA-250 should be 100% "compatible" with DMA-350 in the DT sense, 
since it shares the same register layout and general functionality, and 
the detailed features and even exact model are discoverable from ID 
registers (hence why the current driver explicitly checks for 
PRODUCTID_DMA350 as that's the only one it knows it definitely understands).

Thanks,
Robin.