Re: [PATCH v2 06/10] arm64: allwinner: a64: Add devicetree binding for DMA controller

[Brüns, Stefan]

On Montag, 18. September 2017 10:11:34 CEST Maxime Ripard wrote:
> On Sun, Sep 17, 2017 at 05:19:52AM +0200, Stefan Brüns wrote:
> > The A64 is register compatible with the H3, but has a different number
> > of dma channels and request ports.
> > 
> > Attach additional properties to the node to allow future reuse of the
> > compatible for controllers with different number of channels/requests.
> > 
> > If dma-requests is not specified, the register layout defined maximum
> > of 32 is used.
> > 
> > Signed-off-by: Stefan Brüns <stefan.bruens@xxxxxxxxxxxxxx>
> > ---
> > 
> >  .../devicetree/bindings/dma/sun6i-dma.txt          | 26
> >  ++++++++++++++++++++++ 1 file changed, 26 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/dma/sun6i-dma.txt
> > b/Documentation/devicetree/bindings/dma/sun6i-dma.txt index
> > 98fbe1a5c6dd..6ebc79f95202 100644
> > --- a/Documentation/devicetree/bindings/dma/sun6i-dma.txt
> > +++ b/Documentation/devicetree/bindings/dma/sun6i-dma.txt
> > 
> > @@ -27,6 +27,32 @@ Example:
> >  		#dma-cells = <1>;
> >  	
> >  	};
> > 
> > +-------------------------------------------------------------------------
> > ----- +For A64 DMA controller:
> > +
> > +Required properties:
> > +- compatible:	"allwinner,sun50i-a64-dma"
> > +- dma-channels: Number of DMA channels supported by the controller.
> > +		Refer to Documentation/devicetree/bindings/dma/dma.txt
> > +- all properties above, i.e. reg, interrupts, clocks, resets and
> > #dma-cells +
> > +Optional properties:
> > +- dma-requests: Number of DMA request signals supported by the
> > controller.
> > +		Refer to Documentation/devicetree/bindings/dma/dma.txt
> 
> You're error'ing out if dma-requests, so it isn't optional. I guess we
> should just make it mandatory.

No, it defaults to DMA_CHAN_MAX_DRQ = 31, see patch 07/10.

Kind regards,

Stefan