projects / u-boot.git / blame
| Commit | Line | Data |
|---|---|---|
| 53633a89 TR |
1 | * Freescale Direct Memory Access (DMA) Controller for i.MX |
| 2 | ||
| 3 | This document will only describe differences to the generic DMA Controller and | |
| 4 | DMA request bindings as described in dma/dma.txt . | |
| 5 | ||
| 6 | * DMA controller | |
| 7 | ||
| 8 | Required properties: | |
| 9 | - compatible : Should be "fsl,<chip>-dma". chip can be imx1, imx21 or imx27 | |
| 10 | - reg : Should contain DMA registers location and length | |
| 11 | - interrupts : First item should be DMA interrupt, second one is optional and | |
| 12 | should contain DMA Error interrupt | |
| 13 | - #dma-cells : Has to be 1. imx-dma does not support anything else. | |
| 14 | ||
| 15 | Optional properties: | |
| 16 | - dma-channels : Number of DMA channels supported. Should be 16. | |
| 17 | - #dma-channels : deprecated | |
| 18 | - dma-requests : Number of DMA requests supported. | |
| 19 | - #dma-requests : deprecated | |
| 20 | ||
| 21 | Example: | |
| 22 | ||
| 23 | dma: dma@10001000 { | |
| 24 | compatible = "fsl,imx27-dma"; | |
| 25 | reg = <0x10001000 0x1000>; | |
| 26 | interrupts = <32 33>; | |
| 27 | #dma-cells = <1>; | |
| 28 | dma-channels = <16>; | |
| 29 | }; | |
| 30 | ||
| 31 | ||
| 32 | * DMA client | |
| 33 | ||
| 34 | Clients have to specify the DMA requests with phandles in a list. | |
| 35 | ||
| 36 | Required properties: | |
| 37 | - dmas: List of one or more DMA request specifiers. One DMA request specifier | |
| 38 | consists of a phandle to the DMA controller followed by the integer | |
| 39 | specifying the request line. | |
| 40 | - dma-names: List of string identifiers for the DMA requests. For the correct | |
| 41 | names, have a look at the specific client driver. | |
| 42 | ||
| 43 | Example: | |
| 44 | ||
| 45 | sdhci1: sdhci@10013000 { | |
| 46 | ... | |
| 47 | dmas = <&dma 7>; | |
| 48 | dma-names = "rx-tx"; | |
| 49 | ... | |
| 50 | }; |