From: Guodong Xu <guodong@riscstar.com>

Add the "spacemit,k3-pdma" compatible string for the SpacemiT K3 SoC.

While the K3 PDMA IP reuses most of the design found on the earlier K1 SoC,
a new compatible string is required due to the following hardware differences:

- Variable extended DRCMR base: The DRCMR (DMA Request/Command Register) base
  address for extended DMA request numbers (>= 64) differs from the K1
  implementation, requiring different driver ops.
- Memory addressing capabilities: Unlike the K1 SoC, which had memory addressing
  limitations (e.g., restricted to the 0-4GB space) and required a dedicated
  dma-bus with dma-ranges to restrict memory allocations, the K3 DMA masters
  possess full memory addressing capabilities.

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 Tue, Mar 31, 2026 at 04:27:04PM +0800, Troy Mitchell wrote:
> From: Guodong Xu <guodong@riscstar.com>
> 
> Add the "spacemit,k3-pdma" compatible string for the SpacemiT K3 SoC.
> 
> While the K3 PDMA IP reuses most of the design found on the earlier K1 SoC,
> a new compatible string is required due to the following hardware differences:

Please wrap commit message according to Linux coding style / submission
process (neither too early nor over the limit):
https://elixir.bootlin.com/linux/v6.4-rc1/source/Documentation/process/submitting-patches.rst#L597

> 
> - Variable extended DRCMR base: The DRCMR (DMA Request/Command Register) base
>   address for extended DMA request numbers (>= 64) differs from the K1
>   implementation, requiring different driver ops.

Please do not mention drivers.

> - Memory addressing capabilities: Unlike the K1 SoC, which had memory addressing
>   limitations (e.g., restricted to the 0-4GB space) and required a dedicated
>   dma-bus with dma-ranges to restrict memory allocations, the K3 DMA masters
>   possess full memory addressing capabilities.

Programming interface is still compatible, regardless of memory
addressing limitations, so that is rather incorrect reason.

Best regards,
Krzysztof

On Wed Apr 1, 2026 at 2:42 PM CST, Krzysztof Kozlowski wrote:
> On Tue, Mar 31, 2026 at 04:27:04PM +0800, Troy Mitchell wrote:
>> From: Guodong Xu <guodong@riscstar.com>
>> - Memory addressing capabilities: Unlike the K1 SoC, which had memory addressing
>>   limitations (e.g., restricted to the 0-4GB space) and required a dedicated
>>   dma-bus with dma-ranges to restrict memory allocations, the K3 DMA masters
>>   possess full memory addressing capabilities.
>
> Programming interface is still compatible, regardless of memory
> addressing limitations, so that is rather incorrect reason.
I'll remove this item. Thanks.

                            - Troy
>
> Best regards,
> Krzysztof