[RFC] dmaengine: Moving TI SDMA driver to dmaengine - design plan

[Raju, Sundaram]

> -----Original Message-----
> From: Russell King - ARM Linux [mailto:linux at arm.linux.org.uk]
> Sent: Friday, July 08, 2011 3:34 PM
> To: Raju, Sundaram
> Cc: linux-arm-kernel at lists.infradead.org; linux-omap at vger.kernel.org; Dan;
> Shilimkar, Santosh; linux-kernel at vger.kernel.org
> Subject: Re: [RFC] dmaengine: Moving TI SDMA driver to dmaengine - design
> plan
> 
> On Fri, Jul 08, 2011 at 01:52:17PM +0530, Raju, Sundaram wrote:
> > I am planning to move TI SDMA driver in OMAP tree
> > into the dmaengine framework.
> >
> > The first immediate issue of concern I noticed is the
> > huge number of client drivers that use the existing SDMA driver.
> > More than 15 client drivers are using the current SDMA driver.
> >
> > Moving the SDMA driver along with all of these client drivers at a
> > single stretch seems a humungous task.
> > I noticed a model in the existing DMA drivers in dmaengine
> > framework that will over come this issue.
> 
> It _is_ sane to build a dmaengine driver on top of the existing SoC
> private API, then convert the drivers to DMA engine, and then cleanup
> the resulting DMA engine driver.

Yes, that is what I thought. Thanks.

> 
> What we must make sure though is that the DMA engine slave API (which
> isn't well documented) is correctly implemented before drivers are
> converted over to use the DMA engine support code, otherwise we may
> end up with lots of drivers that require re-fixing several times over.
>

Very true! Agreed!
I will send over the patches for review once I am done with testing.

Regards,
Sundaram