[PATCH v2 1/8] dt-bindings: dma: marvell,mmp-dma: Add SpacemiT K1 PDMA support

[Guodong Xu]

Add "spacemit,k1-pdma" compatible string to support SpacemiT K1 PDMA
controller. This variant requires:
- clocks: Clock controller for the DMA
- resets: Reset controller for the DMA

Also add explicit #dma-cells property definition with proper constraints:
- 2 cells for marvell,pdma-1.0 and spacemit,k1-pdma
    - (request number + unused)
- 1 cell for other variants
    - (request number only)

This fixes "make dtbs_check W=3" warnings about unevaluated properties.

Signed-off-by: Guodong Xu <guodong at riscstar.com>
---
v2:
- Used more specific compatible string "spacemit,k1-pdma"
- Enhanced DT bindings with conditional constraints:
  - clocks/resets properties only required for SpacemiT K1
  - #dma-cells set to 2 for marvell,pdma-1.0 and spacemit,k1-pdma
  - #dma-cells set to 1 for other variants, ie.
      marvell,adma-1.0 and  marvell,pxa910-squ
---
 .../devicetree/bindings/dma/marvell,mmp-dma.yaml   | 49 ++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/Documentation/devicetree/bindings/dma/marvell,mmp-dma.yaml b/Documentation/devicetree/bindings/dma/marvell,mmp-dma.yaml
index d447d5207be0436bc7fb648dffe31f8b780b491d..7b5f7ccfc9dbb69bfef250146cba5434548f3702 100644
--- a/Documentation/devicetree/bindings/dma/marvell,mmp-dma.yaml
+++ b/Documentation/devicetree/bindings/dma/marvell,mmp-dma.yaml
@@ -18,6 +18,7 @@ properties:
       - marvell,pdma-1.0
       - marvell,adma-1.0
       - marvell,pxa910-squ
+      - spacemit,k1-pdma
 
   reg:
     maxItems: 1
@@ -32,6 +33,19 @@ properties:
       A phandle to the SRAM pool
     $ref: /schemas/types.yaml#/definitions/phandle
 
+  clocks:
+    description: Clock for the controller
+    maxItems: 1
+
+  resets:
+    description: Reset controller for the DMA controller
+    maxItems: 1
+
+  '#dma-cells':
+    description:
+      DMA specifier, consisting of a phandle to DMA controller plus the
+      following integer cells
+
   '#dma-channels':
     deprecated: true
 
@@ -52,12 +66,47 @@ allOf:
           contains:
             enum:
               - marvell,pdma-1.0
+              - spacemit,k1-pdma
     then:
       properties:
         asram: false
     else:
       required:
         - asram
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: spacemit,k1-pdma
+    then:
+      required:
+        - clocks
+        - resets
+    else:
+      properties:
+        clocks: false
+        resets: false
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - marvell,pdma-1.0
+              - spacemit,k1-pdma
+    then:
+      properties:
+        '#dma-cells':
+          const: 2
+          description:
+            The first cell contains the DMA request number for the peripheral
+            device. The second cell is currently unused but must be present for
+            backward compatibility.
+    else:
+      properties:
+        '#dma-cells':
+          const: 1
+          description:
+            The cell contains the DMA request number for the peripheral device.
 
 unevaluatedProperties: false
 

-- 
2.43.0