* 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,<chip>-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"; ... }; |