[PATCH 1/2] dt-bindings: dmaengine: Add UniPhier external DMA controller bindings

[Kunihiko Hayashi]

Add external DMA controller bindings implemented in Socionext UniPhier
SoCs.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
---
 .../devicetree/bindings/dma/uniphier-xdmac.txt     | 86 ++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/uniphier-xdmac.txt

diff --git a/Documentation/devicetree/bindings/dma/uniphier-xdmac.txt b/Documentation/devicetree/bindings/dma/uniphier-xdmac.txt
new file mode 100644
index 00000000..4e3927f
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/uniphier-xdmac.txt
@@ -0,0 +1,86 @@
+Socionext UniPhier external DMA controller bindings
+
+This describes the devicetree bindings for an external DMA engine to perform
+memory-to-memory or peripheral-to-memory data transfer, implemented in
+Socionext UniPhier SoCs.
+
+* DMA controller
+
+Required properties:
+- compatible: Should be "socionext,uniphier-xdmac".
+- reg: Specifies offset and length of the register set for the device.
+- interrupts: An interrupt specifier associated with the DMA controller.
+- #dma-cells: Must be <2>. The first cell represents the channel index.
+	The second cell represents the factor for transfer request.
+	This is mentioned in DMA client section.
+- dma-channels : Number of DMA channels supported. Should be 16.
+
+Example:
+	xdmac: dma-controller@5fc10000 {
+		compatible = "socionext,uniphier-xdmac";
+		reg = <0x5fc10000 0x1000>, <0x5fc20000 0x800>;
+		interrupts = <0 188 4>;
+		#dma-cells = <2>;
+		dma-channels = <16>;
+	};
+
+* DMA client
+
+Required properties:
+- dmas: A list of DMA channel requests.
+- dma-names: Names of the requested channels corresponding to dmas.
+
+DMA clients must use the format described in the dma.txt file, using a two cell
+specifier for each channel.
+
+Each DMA request consists of 3 cells:
+ 1. A phandle pointing to the DMA controller
+ 2. Channel index
+ 3. 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. The list of the factor number
+	can be found below.
+
+	0x0	none
+	0x8	UART ch0 Rx
+	0x9	UART ch0 Tx
+	0xa	UART ch1 Rx
+	0xb	UART ch1 Tx
+	0xc	UART ch2 Rx
+	0xd	UART ch2 Tx
+	0xe	UART ch3 Rx
+	0xf	UART ch3 Tx
+	0x14	SCSSI ch1 Rx
+	0x15	SCSSI ch1 Tx
+	0x16	SCSSI ch0 Rx
+	0x17	SCSSI ch0 Tx
+	0x18	SCSSI ch2 Rx
+	0x19	SCSSI ch2 Tx
+	0x1a	SCSSI ch3 Rx
+	0x1b	SCSSI ch3 Tx
+	0x21	I2C ch0 Rx
+	0x22	I2C ch0 Tx
+	0x23	I2C ch1 Rx
+	0x24	I2C ch1 Tx
+	0x25	I2C ch2 Rx
+	0x26	I2C ch2 Tx
+	0x27	I2C ch3 Rx
+	0x28	I2C ch3 Tx
+	0x29	I2C ch4 Rx
+	0x2a	I2C ch4 Tx
+	0x2b	I2C ch5 Rx
+	0x2c	I2C ch5 Tx
+	0x2d	I2C ch6 Rx
+	0x2e	I2C ch6 Tx
+
+Example:
+	spi3: spi@54006300 {
+		compatible = "socionext,uniphier-scssi";
+		reg = <0x54006300 0x100>;
+		interrupts = <0 39 4>;
+		clocks = <&peri_clk 14>;
+		resets = <&peri_rst 14>;
+
+		dmas = <&xdmac 0 0x1a>, <&xdmac 1 0x1b>;
+		dma-names = "rx", "tx";
+	};
-- 
2.7.4