linux/Documentation/devicetree/bindings/dma/atmel-dma.txt
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   1* Atmel Direct Memory Access Controller (DMA)
   2
   3Required properties:
   4- compatible: Should be "atmel,<chip>-dma".
   5- reg: Should contain DMA registers location and length.
   6- interrupts: Should contain DMA interrupt.
   7- #dma-cells: Must be <2>, used to represent the number of integer cells in
   8the dmas property of client devices.
   9
  10Example:
  11
  12dma0: dma@ffffec00 {
  13        compatible = "atmel,at91sam9g45-dma";
  14        reg = <0xffffec00 0x200>;
  15        interrupts = <21>;
  16        #dma-cells = <2>;
  17};
  18
  19DMA clients connected to the Atmel DMA controller must use the format
  20described in the dma.txt file, using a three-cell specifier for each channel:
  21a phandle plus two interger cells.
  22The three cells in order are:
  23
  241. A phandle pointing to the DMA controller.
  252. The memory interface (16 most significant bits), the peripheral interface
  26(16 less significant bits).
  273. Parameters for the at91 DMA configuration register which are device
  28dependant:
  29  - bit 7-0: peripheral identifier for the hardware handshaking interface. The
  30  identifier can be different for tx and rx.
  31  - bit 11-8: FIFO configuration. 0 for half FIFO, 1 for ALAP, 1 for ASAP.
  32
  33Example:
  34
  35i2c0@i2c@f8010000 {
  36        compatible = "atmel,at91sam9x5-i2c";
  37        reg = <0xf8010000 0x100>;
  38        interrupts = <9 4 6>;
  39        dmas = <&dma0 1 7>,
  40               <&dma0 1 8>;
  41        dma-names = "tx", "rx";
  42};
  43