Is there a binding for IORESOURCE_DMA population?

[Shawn Guo]

On Sun, Jul 17, 2011 at 04:54:21AM +0800, Tabi Timur-B04825 wrote:
> Arnd Bergmann wrote:
> > But that would mean that the code interpreting that property has to
> > know about the specific dmaengine implementation, and needs to be
> > changed every time we add a new one.
> 
> And like I said, the SSI driver will already need to know the specifics of 
> the DMA controller.  The PowerPC device tree node for the SSI already 
> works this way:
> 
>              ssi at 15000 {
>                      compatible = "fsl,mpc8610-ssi";
>                      cell-index = <0>;
>                      reg = <0x15000 0x100>;
>                      interrupts = <75 2 0 0>;
>                      fsl,mode = "i2s-slave";
>                      codec-handle = <&wm8776>;
>                      fsl,playback-dma = <&dma00>;
>                      fsl,capture-dma = <&dma01>;
>                      fsl,fifo-depth = <15>;
>                      fsl,ssi-asynchronous;
>               };
> 
> On PowerPC, the SSI driver knows that "fsl,playback-dma" points to a 
> Freescale e500 DMA controller channel node.  The driver currently does not 
> work with any other DMA controller.  This is what needs to be fixed.
> 
> > Alternatively, you'd end up with the device drivers having to
> > read the properties themselves to get to the number and pass
> > that to the common dmaengine code.
> 
> The SSI won't be able to use any common DMA engine code, because DMA needs 
> to be set up in a very specific way for audio.
> 
i.mx sdma was implemented as a generic dmaengine driver, and i.mx ssi
driver is working with the generic dmaengine api.

-- 
Regards,
Shawn