Re: Is there a binding for IORESOURCE_DMA population?

[Tabi Timur-B04825 <B04825-KZfg59tc24xl57MIdRCFDg@public.gmane.org>]

Shawn Guo wrote:
> It's not about virtual or physical channel.  I'm asking suggestion on
> how we bind the channel number for each dma client device in device
> tree and how they will get the number from device tree when they get
> probed.

I guess I'm still confused.  Why do we need to bind the channel number? 
It's just a resource that can be owned by the driver without needing a 
device tree.

There is no value in doing this:

         dma00: dma-channel@0 {
                 compatible = "fsl,sdma-channel";
                 reg = <0>;
         };

This tells us literally nothing.

On PowerPC, we assign DMA channels to the SSI node because that mapping is 
hard-wired in the chip, and it was an easy way to assign some channels to 
the async driver and other channels to the audio driver.  Do you have the 
same problem?

-- 
Timur Tabi
Linux kernel developer at Freescale