Re: [PATCH v2 2/4] dmaengine: add driver for Samsung s3c24xx SoCs

[Tomasz Figa <t.figa@samsung.com>]

On Monday 19 of August 2013 10:18:12 Vinod Koul wrote:
> On Wed, Aug 14, 2013 at 02:00:25PM +0200, Heiko Stübner wrote:
> > This adds a new driver to support the s3c24xx dma using the dmaengine
> > and makes the old one in mach-s3c24xx obsolete in the long run.
> > 
> > Conceptually the s3c24xx-dma feels like a distant relative of the pl08x
> > with numerous virtual channels being mapped to a lot less physical
> > ones.
> > The driver therefore borrows a lot from the amba-pl08x driver in this
> > regard. Functionality-wise the driver gains a memcpy ability in
> > addition
> > to the slave_sg one.
> 
> If that is the case why cant we have this driver supported from pl08x
> driver? If the delta is only mapping then can that be seprated or both
> mapping hanlded? Maybe you and Linus have already though about that?

Well, the similarity here is only conceptual. Both controllers are 
completely different in terms of their programming interfaces, not even 
mentioning that s3c24xx-dma doesn't support LLIs and this must be handled 
in software.

Best regards,
Tomasz