On 22/09/2014 15:22, Ludovic Desroches : > Add bindings documentation for the new Atmel DMA controller (XDMAC) > introduced with SAMA5D4. > > Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx> Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx> > --- > .../devicetree/bindings/dma/atmel-xdma.txt | 50 ++++++++++++++++++++++ > 1 file changed, 50 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..ae587ad > --- /dev/null > +++ b/Documentation/devicetree/bindings/dma/atmel-xdma.txt > @@ -0,0 +1,50 @@ > +* Atmel Extensible Direct Memory Access Controller (XDMAC) > + > +* XDMA Controller > +Required properties: > +- compatible: Should be "atmel,<chip>-dma". > + <chip> compatible description: > + - sama5d4: first SoC adding the XDMAC > +- 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"; > +}; > -- Nicolas Ferre -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html