Add bindings documentation for the new Atmel DMA controller (XDMAC) introduced with SAMA5D4. Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx> --- .../devicetree/bindings/dma/atmel-xdma.txt | 48 ++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/atmel-xdma.txt diff --git a/Documentation/devicetree/bindings/dma/atmel-xdma.txt b/Documentation/devicetree/bindings/dma/atmel-xdma.txt new file mode 100644 index 0000000..647f099 --- /dev/null +++ b/Documentation/devicetree/bindings/dma/atmel-xdma.txt @@ -0,0 +1,48 @@ +* Atmel Extensible Direct Memory Access Controller (XDMAC) + +* XDMA Controller +Required properties: +- compatible: Should be "atmel,<chip>-dma". +- reg: Should contain DMA registers location and length. +- interrupts: Should contain DMA interrupt. +- #dma-cells: Must be <2>, used to represent the number of integer cells in +the dmas property of client devices. + - The 1st cell specifies the memory interface (16 most significant bits) and + the peripheral interface (16 less significant bits) to use. + - The 2nd cell specifies the channel configuration register: + - bit 30-24: PERID, peripheral identifier. + +Example: + +dma1: dma-controller@f0004000 { + compatible = "atmel,sama5d4-dma"; + reg = <0xf0004000 0x200>; + interrupts = <50 4 0>; + #dma-cells = <2>; +}; + + +* DMA clients +DMA clients connected to the Atmel XDMA controller must use the format +described in the dma.txt file, using a two-cell specifier for each channel. +The three cells in order are: +1. A phandle pointing to the DMA controller. +2. The memory interface (16 most significant bits), the peripheral interface +(16 less significant bits). +3. Channel configuration register. Configurable fields are: + - bit 30-24: PERID, peripheral identifier. + +Example: + +i2c2: i2c@f8024000 { + compatible = "atmel,at91sam9x5-i2c"; + reg = <0xf8024000 0x4000>; + interrupts = <34 4 6>; + dmas = <&dma1 + (AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1)) + AT91_XDMAC_DT_PERID(6)>, + <&dma1 + (AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1)) + AT91_XDMAC_DT_PERID(7)>; + dma-names = "tx", "rx"; +}; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html