[PATCH v2 4/6] dt-bindings: dma: arm,dma-350: Document the CIX Sky1 integration

[Jelly Jia <Jelly.Jia@cixtech.com>]

The CIX Sky1 DMA-350 integration is the same device with SoC glue around
it, so it is described by the arm,dma-350 node itself with an additional
"cix,sky1-dma350" compatible rather than by a separate wrapper node.

Extend the binding with the CIX compatible and the resources the
integration needs: a clock, a reset, an optional reserved memory region
used when the controller cannot reach all of system memory, and the
syscon that routes the channel interrupts to the AP interrupt
controller on Sky1. The cix,irq-router property is only valid together
with the CIX compatible.

Assisted-by: LLM checkpatch sparse dt_binding_check dtbs_check
Signed-off-by: Jelly Jia <Jelly.Jia@cixtech.com>
---
v1 -> v2:
- Folded the integration into arm,dma-350.yaml: the Sky1 DMA-350 is the
  same device, so it keeps the generic compatible plus a device
  specific "cix,sky1-dma350" compatible, and the integration resources
  are described on the controller node.
- Dropped the separate cix,sky1-dma350.yaml wrapper binding.
 .../devicetree/bindings/dma/arm,dma-350.yaml  | 33 ++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/dma/arm,dma-350.yaml b/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
index 429f682f15d8..3b991985c416 100644
--- a/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
+++ b/Documentation/devicetree/bindings/dma/arm,dma-350.yaml
@@ -11,10 +11,23 @@ maintainers:
 
 allOf:
   - $ref: dma-controller.yaml#
+  - if:
+      not:
+        properties:
+          compatible:
+            contains:
+              const: cix,sky1-dma350
+    then:
+      properties:
+        cix,irq-router: false
 
 properties:
   compatible:
-    const: arm,dma-350
+    oneOf:
+      - const: arm,dma-350
+      - items:
+          - const: cix,sky1-dma350
+          - const: arm,dma-350
 
   reg:
     items:
@@ -36,6 +49,24 @@ properties:
     const: 1
     description: The cell is the trigger input number
 
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  memory-region:
+    maxItems: 1
+    description:
+      Reserved memory region used for DMA allocations when the controller
+      cannot reach all of system memory.
+
+  cix,irq-router:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      Syscon phandle for the CIX Sky1 subsystem register block that routes
+      DMA-350 channel interrupts to the AP interrupt controller.
+
 required:
   - compatible
   - reg
-- 
2.54.0