Banana Pi BPI-M5 DMA

BPI-M5/BPI-M2 Pro/BPI-M2S/BPI-CM4/BPI-CM5
1

I would like to use the DMA function of BPI-M5, but I couldn’t find any information about the DMA controller in the manual. I would like to ask:

  1. Where can I find information about the DMA controller?
  2. Which driver file under driver/dma/ corresponds to the DMA controller driver for BPI-M5?