dt-bindings: edma: devicetree documentation for PCIe eDMA

Qualcomm Technologies Inc PCIe eDMA controller

QCOM PCIe eDMA controller provides DMA capabilities for

peripheral connected and uses PCIe to transfer data.

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Node Structure

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Main node properties:

- compatible

  Usage: required

  Value type: <string>

  Definition: "qcom,pci-edma"

- #dma-cells

  Usage: required

  Value type: <u32>

  Definition: Number of parameters client will provide.  Must be set to 2.

	1st parameter: channel index, 0 for TX, 1 for RX

	2nd parameter: event processing priority, set to 0 for highest priority

- reg

  Usage: required

  Value type: Array (2-cell) of <u32>

  Definition: First cell is eDMA register base address. Second cell is size of

	eDMA register space.

- interrupts

  Usage: required

  Value type: Array of <u32>

  Definition: Array of tuples which describe interrupt lines for eDMA.

- interrupts-names

  Usage: required

  Value type: Array of <u32>

  Definition: Array of names which map to interrupt lines for eDMA.

- interrupt-parent

  Usage: required

  Value type: <phandle>

  Definition: phandle of the interrupt controller that services interrupts for

	this device

- qcom,n-tl-init

  Usage: optional

  Value type: <u32>

  Definition: Number of transfer and descriptor arrays to start with. If this

	entry is not presetn, default value is 2.

- qcom,n-tl-ele

  Usage: optional

  Value type: <u32>

  Definition: Number of elements for each transfer and descriptor array. If this

	entry is not present, default value is 1024.

- qcom,n-max-ev-ch

  Usage: optional

  Value type: <u32>

  Definition: Total number of virtual (client) eDMA channels available. If this

	entry is not present, default value is 32.

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Example

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pci_edma: qcom,pci-edma@40002000 {

	compatible = "qcom,pci-edma";

	#dma-cells = <2>;

	reg = <0x40002000 0x2000>;

	interrupts = <GIC_SPI 86 IRQ_TYPE_LEVEL_HIGH>;

	interrupt-names = "pci-edma-int";

	interrupt-parent = <&intc>;

	qcom,n-max-ev-ch = <32>;

	qcom,n-tl-init = <2>;

	qcom,n-tl-ele = <1024>;

	status = "ok";

};