From: Guodong Xu <guodong@riscstar.com>

Add k3 compatible string.

Signed-off-by: Guodong Xu <guodong@riscstar.com>
Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
---
 Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml b/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml
index ec06235baf5c..62ce6d81526b 100644
--- a/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml
+++ b/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml
@@ -14,7 +14,9 @@ allOf:
 
 properties:
   compatible:
-    const: spacemit,k1-pdma
+    enum:
+      - spacemit,k1-pdma
+      - spacemit,k3-pdma
 
   reg:
     maxItems: 1

-- 
2.53.0

On Thu, Mar 26, 2026 at 04:17:17PM +0800, Troy Mitchell wrote:
> From: Guodong Xu <guodong@riscstar.com>
> 
> Add k3 compatible string.

That's obvious. What you need to explain is why it is not compatible with
the existing k1.
pw-bot: changes-requested
Cheers,
Conor.

> 
> Signed-off-by: Guodong Xu <guodong@riscstar.com>
> Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
> ---
>  Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml b/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml
> index ec06235baf5c..62ce6d81526b 100644
> --- a/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml
> +++ b/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml
> @@ -14,7 +14,9 @@ allOf:
>  
>  properties:
>    compatible:
> -    const: spacemit,k1-pdma
> +    enum:
> +      - spacemit,k1-pdma
> +      - spacemit,k3-pdma
>  
>    reg:
>      maxItems: 1
> 
> -- 
> 2.53.0
> 

Hi Conor,

On Fri Mar 27, 2026 at 2:34 AM CST, Conor Dooley wrote:
> On Thu, Mar 26, 2026 at 04:17:17PM +0800, Troy Mitchell wrote:
>> From: Guodong Xu <guodong@riscstar.com>
>> 
>> Add k3 compatible string.
>
> That's obvious. What you need to explain is why it is not compatible with
> the existing k1.
>
Thanks for the review.

The SpacemiT K3 PDMA requires a new compatible string because it is not fully
backward compatible with the K1 implementation due to two main hardware differences:
- Variable extended DRCMR base: The DRCMR (DMA Request/Command Register) base
  address for extended DMA request numbers (>= 64) is different in the K3 hardware
  implementation.
- Memory addressing capabilities: Unlike the K1 SoC, where some DMA masters had
  memory addressing limitations (restricted to the 0-4GB space) and required a
  dedicated dma-bus, the K3 DMA masters have full memory addressing capabilities.

I will update the commit message in the v3 series.

                                              -Troy