Subject: Re: [PATCH v2] powerpc: Add dma nodes to 83xx, 85xx and 86xx boards

From: Scott Wood <[email-masked]>
Date: Mon, 30 Jun 2008 10:35:13 -0500

On Mon, Jun 30, 2008 at 02:15:25PM +1000, David Gibson wrote:
> On Fri, Jun 27, 2008 at 04:10:17PM -0500, Kumar Gala wrote:
> > Added DMA nodes for the elo/elo-plus DMA engines.
> > 
> > Renamed the interrupt controller alias in mpc832x_rdb.dts to ipic so that
> > its the same as all the other boards.
> > 
> > Signed-off-by: Kumar Gala <[email-masked]>
> 
> [snip]
> > diff --git a/arch/powerpc/boot/dts/asp834x-redboot.dts b/arch/powerpc/boot/dts/asp834x-redboot.dts
> > index 972cf78..8b1bb0e 100644
> > --- a/arch/powerpc/boot/dts/asp834x-redboot.dts
> > +++ b/arch/powerpc/boot/dts/asp834x-redboot.dts
> > @@ -118,6 +118,41 @@
> >  			mode = "cpu";
> >  		};
> > 
> > +		dma@82a8 {
> > +			#address-cells = <1>;
> > +			#size-cells = <1>;
> > +			compatible = "fsl,mpc8347-dma", "fsl,elo-dma";
> > +			reg = <0x82a8 4>;
> > +			ranges = <0 0x8100 0x1a8>;
> > +			interrupt-parent = <&ipic>;
> > +			interrupts = <71 8>;
> > +			cell-index = <0>;
> 
> What's the cell-index in these nodes used to index?  Given the
> confusion there's been about the proper use of this property, a
> comment indicating which shared registers this is used to index is
> probably a good idea.

There's supposed to be a cell-index in the *channels* to index into the
shared summary register (the "reg" of the dma node itself).  I don't see any
purpose for a cell-index in the main dma node, though.

-Scott