dt-bindings: dmaengine: Add Loongson Multi-Channel DMA controller

The Loongson-2K0300/Loongson-2K3000 have built-in multi-channel DMA
controllers, which are similar except for some of the register offsets
and number of channels.

Obviously, this is quite different from the APB DMA controller used in
the Loongson-2K0500/Loongson-2K1000, such as the latter being a
single-channel DMA controller.

To avoid cluttering a single dt-binding file, add a new yaml file.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://patch.msgid.link/135802de72b84f643d0b0624f3f79f13777147a1.1772853681.git.zhoubinbin@loongson.cn
Signed-off-by: Vinod Koul <vkoul@kernel.org>

2 files changed, 83 insertions, 1 deletions

diff --git a/Documentation/devicetree/bindings/dma/loongson,ls2k0300-dma.yaml b/Documentation/devicetree/bindings/dma/loongson,ls2k0300-dma.yaml
new file mode 100644
index 000000000000..c3151d806b55
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/loongson,ls2k0300-dma.yaml
@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dma/loongson,ls2k0300-dma.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Looongson-2 Multi-Channel DMA controller
+
+description:
+  The Loongson-2 Multi-Channel DMA controller is used for transferring data
+  between system memory and the peripherals on the APB bus.
+
+maintainers:
+  - Binbin Zhou <zhoubinbin@loongson.cn>
+
+allOf:
+  - $ref: dma-controller.yaml#
+
+properties:
+  compatible:
+    enum:
+      - loongson,ls2k0300-dma
+      - loongson,ls2k3000-dma
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    description:
+      Should contain all of the per-channel DMA interrupts in ascending order
+      with respect to the DMA channel index.
+    minItems: 4
+    maxItems: 8
+
+  clocks:
+    maxItems: 1
+
+  '#dma-cells':
+    const: 2
+    description: |
+      DMA request from clients consists of 2 cells:
+        1. Channel index
+        2. Transfer request factor number, If no transfer factor, use 0.
+           The number is SoC-specific, and this should be specified with
+           relation to the device to use the DMA controller.
+
+  dma-channels:
+    enum: [4, 8]
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - '#dma-cells'
+  - dma-channels
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/clock/loongson,ls2k-clk.h>
+
+    dma-controller@1612c000 {
+        compatible = "loongson,ls2k0300-dma";
+        reg = <0x1612c000 0xff>;
+        interrupt-parent = <&liointc0>;
+        interrupts = <23 IRQ_TYPE_LEVEL_HIGH>,
+                     <24 IRQ_TYPE_LEVEL_HIGH>,
+                     <25 IRQ_TYPE_LEVEL_HIGH>,
+                     <26 IRQ_TYPE_LEVEL_HIGH>,
+                     <27 IRQ_TYPE_LEVEL_HIGH>,
+                     <28 IRQ_TYPE_LEVEL_HIGH>,
+                     <29 IRQ_TYPE_LEVEL_HIGH>,
+                     <30 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&clk LS2K0300_CLK_APB_GATE>;
+        #dma-cells = <2>;
+        dma-channels = <8>;
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index f0cad0b6ad8f..3b60dce82e78 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14948,10 +14948,11 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
 F:	drivers/gpio/gpio-loongson-64bit.c
 
-LOONGSON-2 APB DMA DRIVER
+LOONGSON-2 DMA DRIVER
 M:	Binbin Zhou <zhoubinbin@loongson.cn>
 L:	dmaengine@vger.kernel.org
 S:	Maintained
+F:	Documentation/devicetree/bindings/dma/loongson,ls2k0300-dma.yaml
 F:	Documentation/devicetree/bindings/dma/loongson,ls2x-apbdma.yaml
 F:	drivers/dma/loongson/loongson2-apb-dma.c