devicetree: Add bindings documentation for Analog Devices AXI-DMAC

Add the devicetree descriptor for the Analog Devices AXI-DMAC DMA
controller. This is a soft peripheral used in FPGAs and the bindings
describe how it is connected to the system (clock, interrupt, memory map)
as well as the configuration options that were used when the peripheral was
instantiated.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/dma/adi,axi-dmac.txt b/Documentation/devicetree/bindings/dma/adi,axi-dmac.txt
new file mode 100644
index 000000000000..47cb1d14b690
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/adi,axi-dmac.txt
@@ -0,0 +1,61 @@
+Analog Device AXI-DMAC DMA controller
+
+Required properties:
+ - compatible: Must be "adi,axi-dmac-1.00.a".
+ - reg: Specification for the controllers memory mapped register map.
+ - interrupts: Specification for the controllers interrupt.
+ - clocks: Phandle and specifier to the controllers AXI interface clock
+ - #dma-cells: Must be 1.
+
+Required sub-nodes:
+ - adi,channels: This sub-node must contain a sub-node for each DMA channel. For
+   the channel sub-nodes the following bindings apply. They must match the
+   configuration options of the peripheral as it was instantiated.
+
+Required properties for adi,channels sub-node:
+ - #size-cells: Must be 0
+ - #address-cells: Must be 1
+
+Required channel sub-node properties:
+ - reg: Which channel this node refers to.
+ - adi,length-width: Width of the DMA transfer length register.
+ - adi,source-bus-width,
+   adi,destination-bus-width: Width of the source or destination bus in bits.
+ - adi,source-bus-type,
+   adi,destination-bus-type: Type of the source or destination bus. Must be one
+   of the following:
+	0 (AXI_DMAC_TYPE_AXI_MM): Memory mapped AXI interface
+	1 (AXI_DMAC_TYPE_AXI_STREAM): Streaming AXI interface
+	2 (AXI_DMAC_TYPE_AXI_FIFO): FIFO interface
+
+Optional channel properties:
+ - adi,cyclic: Must be set if the channel supports hardware cyclic DMA
+   transfers.
+ - adi,2d: Must be set if the channel supports hardware 2D DMA transfers.
+
+DMA clients connected to the AXI-DMAC DMA controller must use the format
+described in the dma.txt file using a one-cell specifier. The value of the
+specifier refers to the DMA channel index.
+
+Example:
+
+dma: dma@7c420000 {
+	compatible = "adi,axi-dmac-1.00.a";
+	reg = <0x7c420000 0x10000>;
+	interrupts = <0 57 0>;
+	clocks = <&clkc 16>;
+	#dma-cells = <1>;
+
+	adi,channels {
+		#size-cells = <0>;
+		#address-cells = <1>;
+
+		dma-channel@0 {
+			reg = <0>;
+			adi,source-bus-width = <32>;
+			adi,source-bus-type = <ADI_AXI_DMAC_TYPE_MM_AXI>;
+			adi,destination-bus-width = <64>;
+			adi,destination-bus-type = <ADI_AXI_DMAC_TYPE_FIFO>;
+		};
+	};
+};