[PATCH 3/3] [POWERPC] Add docs for Freescale DMA & DMA channel device tree nodes

[Kumar Gala]

On Nov 21, 2007, at 11:35 AM, Scott Wood wrote:

> On Wed, Nov 21, 2007 at 09:33:05AM -0600, Kumar Gala wrote:
>> On Nov 21, 2007, at 8:59 AM, Timur Tabi wrote:
>>>> +  Example:
>>>> +	dma at 21000 {
>>>
>>> Shouldn't this be dma at 21300?
>>
>> its an example that has not basis is reality :)
>
> But it should at least be internally consistent with this:
>
>>>> +		reg = <21300 4>;

ahh, i see.. yes I'll fix that.

> [snip]
>>> The DMA controller and the DMA channels need a "device-id", so that
>>> they can be identified by number.  Some peripherals, like the SSI,
>>> can only use the controller and channel number.  This is what I have
>>> in my 8610 DTS:
>>
>> Why not use reg for this?  I don't see any reason to add another
>> "unique id" when there is already one.
>
> A cell-index property would be useful here for indexing into the  
> summary
> status register.

Divide by 0x80.

>>>               dma at 21300 {
>>>                       #address-cells = <1>;
>>>                       #size-cells = <1>;
>>>                       compatible = "fsl,mpc8610-dma", "fsl,mpc8540-
>>> dma";
>>>       -->             device-id = <0>;
>
> I don't see any justification for having such a property in the  
> parent node,
> though.

huh?
- k