Documentation: devicetree: dma: Binding documentation for TI DMA crossbar

Texas Instruments DMA Crossbar (DMA request router)

Required properties:

- compatible:	"ti,dra7-dma-crossbar" for DRA7xx DMA crossbar

- reg:		Memory map for accessing module

- #dma-cells:	Should be set to <1>.

		Clients should use the crossbar request number (input)

- dma-requests:	Number of DMA requests the crossbar can receive

- dma-masters:	phandle pointing to the DMA controller

The DMA controller node need to have the following poroperties:

- dma-requests:	Number of DMA requests the controller can handle

Optional properties:

- ti,dma-safe-map: Safe routing value for unused request lines

Example:

/* DMA controller */

sdma: dma-controller@4a056000 {

	compatible = "ti,omap4430-sdma";

	reg = <0x4a056000 0x1000>;

	interrupts =	<GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>,

			<GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>,

			<GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>,

			<GIC_SPI 10 IRQ_TYPE_LEVEL_HIGH>;

	#dma-cells = <1>;

	dma-channels = <32>;

	dma-requests = <127>;

};

/* DMA crossbar */

sdma_xbar: dma-router@4a002b78 {

	compatible = "ti,dra7-dma-crossbar";

	reg = <0x4a002b78 0xfc>;

	#dma-cells = <1>;

	dma-requests = <205>;

	ti,dma-safe-map = <0>;

	dma-masters = <&sdma>;

};

/* DMA client */

uart1: serial@4806a000 {

	compatible = "ti,omap4-uart";

	reg = <0x4806a000 0x100>;

	interrupts-extended = <&gic GIC_SPI 67 IRQ_TYPE_LEVEL_HIGH>;

	ti,hwmods = "uart1";

	clock-frequency = <48000000>;

	status = "disabled";

	dmas = <&sdma_xbar 49>, <&sdma_xbar 50>;

	dma-names = "tx", "rx";

};