[PATCH v2 1/3] dt-bindings: dma: fsl,edma: add per-channel child node support

[Peng Fan (OSS)]

From: Peng Fan <peng.fan at nxp.com>

Add support for optional per-channel child nodes (dma-channel@<addr>)
to the fsl,edma binding. Each child node can carry its own reg,
interrupts, iommus, and power-domains properties, describing a real
per-channel MMIO region.

Enables per-channel IOMMU stream ID assignment via the standard
iommus property on each child.

The interrupts property is removed from the required list since
channels with child nodes carry their own interrupts. Existing DTS
without child nodes remains valid.

Assisted-by: LLM
Signed-off-by: Peng Fan <peng.fan at nxp.com>
---
 .../devicetree/bindings/dma/fsl,edma.yaml          | 70 +++++++++++++++++++++-
 1 file changed, 69 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/dma/fsl,edma.yaml b/Documentation/devicetree/bindings/dma/fsl,edma.yaml
index f609038e35ae..19a103baccaf 100644
--- a/Documentation/devicetree/bindings/dma/fsl,edma.yaml
+++ b/Documentation/devicetree/bindings/dma/fsl,edma.yaml
@@ -104,11 +104,40 @@ properties:
       Bit semantics: 0 means channel available, 1 means channel unavailable
     default: 0
 
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 1
+
+  ranges: true
+
+patternProperties:
+  "^dma-channel@[0-9a-f]+$":
+    type: object
+    additionalProperties: false
+
+    properties:
+      reg:
+        maxItems: 1
+        description: Per-channel register region within the eDMA block.
+
+      interrupts:
+        maxItems: 1
+
+      iommus:
+        maxItems: 1
+
+      power-domains:
+        maxItems: 1
+
+    required:
+      - reg
+
 required:
   - "#dma-cells"
   - compatible
   - reg
-  - interrupts
   - dma-channels
 
 allOf:
@@ -351,3 +380,42 @@ examples:
                       <&pd IMX_SC_R_DMA_3_CH6>,
                       <&pd IMX_SC_R_DMA_3_CH7>;
     };
+
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    dma-controller at 42000000 {
+      compatible = "fsl,imx95-edma5";
+      reg = <0x42000000 0x210000>;
+      #dma-cells = <3>;
+      #address-cells = <1>;
+      #size-cells = <1>;
+      ranges;
+      dma-channels = <64>;
+      clocks = <&clk 0>;
+      clock-names = "dma";
+
+      dma-channel at 42020000 {
+        reg = <0x42020000 0x8000>;
+        interrupts = <GIC_SPI 129 IRQ_TYPE_LEVEL_HIGH>;
+        iommus = <&smmu 0x30>;
+      };
+
+      dma-channel at 42028000 {
+        reg = <0x42028000 0x8000>;
+        interrupts = <GIC_SPI 129 IRQ_TYPE_LEVEL_HIGH>;
+        iommus = <&smmu 0x30>;
+      };
+
+      dma-channel at 42030000 {
+        reg = <0x42030000 0x8000>;
+        interrupts = <GIC_SPI 130 IRQ_TYPE_LEVEL_HIGH>;
+        iommus = <&smmu 0x31>;
+      };
+
+      dma-channel at 42038000 {
+        reg = <0x42038000 0x8000>;
+        interrupts = <GIC_SPI 130 IRQ_TYPE_LEVEL_HIGH>;
+        iommus = <&smmu 0x31>;
+      };
+    };

-- 
2.51.0