Kernel-4.18.0-80.el8_fsl-imx-dma

• Freescale Direct Memory Access (DMA) Controller for i.MX

This document will only describe differences to the generic DMA Controller and
DMA request bindings as described in dma/dma.txt .

• DMA controller

Required properties:

• compatible : Should be “fsl,-dma”. chip can be imx1, imx21 or imx27
• reg : Should contain DMA registers location and length
• interrupts : First item should be DMA interrupt, second one is optional and
  should contain DMA Error interrupt
• #dma-cells : Has to be 1. imx-dma does not support anything else.

Optional properties:

• #dma-channels : Number of DMA channels supported. Should be 16.
• #dma-requests : Number of DMA requests supported.

Example:

dma: dma@10001000 {
    compatible = "fsl,imx27-dma";
    reg = <0x10001000 0x1000>;
    interrupts = <32 33>;
    #dma-cells = <1>;
    #dma-channels = <16>;
};

• DMA client

Clients have to specify the DMA requests with phandles in a list.

Required properties:

• dmas: List of one or more DMA request specifiers. One DMA request specifier
  consists of a phandle to the DMA controller followed by the integer
  specifying the request line.
• dma-names: List of string identifiers for the DMA requests. For the correct
  names, have a look at the specific client driver.

Example:

sdhci1: sdhci@10013000 {
    ...
    dmas = <&dma 7>;
    dma-names = "rx-tx";
    ...
};