DMA Requester Device Tree Configuration

In the DTSI file, the DMA controller requester needs to include the general configuration information of the used DMA module, see the following code block for an example.

tdm: tdm@10090000 {
......
dmas = <&dma 20 1>, <&dma 21 1>; 
dma-names = "rx", "tx";
......
};

The following list provides explanations for the parameters.

• dmas: The field contains 3 parameters:
  • &dma: The referenced DMA node.
  • 20/21: The DMA channel ID.
  • 1: The burst transaction length, "1" indicates to transfer 4 words at a time.

  For example, in the code <&dma 20 1>, 20 indicates channel number; 1 indicates burst length is 4.

• dma-names: The names of the DMA channels, including "rx" for the receiver channel and "tx" for the transceiver channel. The names can also be found in the DMA driver.