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

[Kumar Gala]

On Jun 30, 2008, at 10:35 AM, Scott Wood wrote:

> 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 <galak at kernel.crashing.org>
>>
>> [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 at 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.

I believe this comes into play when we have more than one DMA  
controller and sometimes there are special uses like on 8610.

- k