[PATCH v2 2/2] ARM: dts: at_xdmac: add bindings documentation

[Ludovic Desroches]

On Fri, Jul 04, 2014 at 09:58:34AM +0100, Mark Rutland wrote:
> On Fri, Jul 04, 2014 at 08:36:10AM +0100, Ludovic Desroches wrote:
> > Add bindings documentation for the new Atmel DMA controller (XDMAC)
> > introduced with SAMA5D4.
> > 
> > Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
> > ---
> >  .../devicetree/bindings/dma/atmel-xdma.txt         |   39 ++++++++++++++++++++
> >  1 file changed, 39 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..1e09fda
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/dma/atmel-xdma.txt
> > @@ -0,0 +1,39 @@
> > +* Atmel Extensible Direct Memory Access Controller (XDMAC)
> > +
> > +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.
> 
> Could you please move the description of the two cells in the
> dma-specifier here? It makes it far easier to read the binding.

Of course, I'll do it for next version.

> 
> Cheers,
> Mark.
> 
> > +
> > +Example:
> > +
> > +dma1: dma-controller at f0004000 {
> > +	compatible = "atmel,sama5d4-dma";
> > +	reg = <0xf0004000 0x200>;
> > +	interrupts = <50 4 0>;
> > +	#dma-cells = <2>;
> > +};
> > +
> > +DMA clients connected to the Atmel XDMA controller must use the format
> > +described in the dma.txt file, using a three-cell specifier for each channel:
> > +a phandle plus two integer cells.
> > +The two 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 at f8024000 {
> > +	compatible = "atmel,at91sam9x5-i2c";
> > +	reg = <0xf8024000 0x4000>;
> > +	interrupts = <34 4 6>;
> > +	dmas = <&dma0 0x00000001 0x06000000>,
> > +	       <&dma0 0x00000001 0x07000000>;
> > +	dma-names = "tx", "rx";
> > +};
> > -- 
> > 1.7.9.5
> > 
> > --
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