dt-bindings: dma: Add Amlogic A9 SoC DMA

Add documentation describing the Amlogic A9 SoC DMA. And add
the properties specific values defines into a new include file.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
Link: https://patch.msgid.link/20260903-amlogic-dma-v12-1-f769bc344056@amlogic.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/dma/amlogic,a9-dma.yaml

@@ -0,0 +1,68 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dma/amlogic,a9-dma.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Amlogic general DMA controller
+
+description:
+  This is a general-purpose peripheral DMA controller. It currently supports
+  major peripherals including I2C, I3C, PIO, and CAN-BUS. Transmit and receive
+  for the same peripheral use two separate channels, controlled by different
+  register sets. I2C and I3C transfer data in 1-byte units, while PIO and
+  CAN-BUS transfer data in 4-byte units. From the controller’s perspective,
+  there is no significant difference.
+
+maintainers:
+  - Xianwei Zhao <xianwei.zhao@amlogic.com>
+
+properties:
+  compatible:
+    const: amlogic,a9-dma
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: sys
+
+  '#dma-cells':
+    const: 2
+    description:
+      The first cell is the DMA channel type(AMLOGIC_A9_DMA_TX or AMLOGIC_A9_DMA_RX).
+      The second cell is the DMA channel index.
+
+  dma-channels:
+    maximum: 64
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - '#dma-cells'
+  - dma-channels
+
+allOf:
+  - $ref: dma-controller.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    dma-controller@fe400000 {
+        compatible = "amlogic,a9-dma";
+        reg = <0xfe400000 0x4000>;
+        interrupts = <GIC_SPI 35 IRQ_TYPE_EDGE_RISING>;
+        clocks = <&clkc 45>;
+        #dma-cells = <2>;
+        dma-channels = <28>;
+    };

include/dt-bindings/dma/amlogic,a9-dma.h

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
+
+#ifndef __DT_BINDINGS_DMA_AMLOGIC_DMA_H__
+#define __DT_BINDINGS_DMA_AMLOGIC_DMA_H__
+
+#define AMLOGIC_A9_DMA_TX		0
+#define AMLOGIC_A9_DMA_RX		1
+#endif /* __DT_BINDINGS_DMA_AMLOGIC_DMA_H__ */