On Monday 28 January 2013, Vinod Koul wrote:
On Fri, Jan 18, 2013 at 05:03:40PM +0530, Padmavathi Venna wrote:
This patch set adds support for generic dma device tree bindings for Samsung platforms and is dependent on the following patches from Vinod Koul next branch 1)of: Add generic device tree DMA helpers 2)dmaengine: add helper function to request a slave DMA channel
Changes look fairly decent. I need somone with better knowldge of DT to akc this before this is applied. Arnd...?
Thanks for the pointer, it seems everthing is coming together today ;-)
The binding looks good, aside from the wording on some of the properties in there that could be a little clearer.
The method of calling dma_request_channel() from the xlate() function is a little bit clumsy IMHO, but it does work and is the easiest way to retrofit generic DT support to this driver, given that it already provides a global filter function. It's also apparently what Jon had in mind, and what Matt is doing on AM33XX.
I'll probably propose something similar on dw_dma, since I was just (this hour, actually) looking at the same problem there. I believe you had something smarter in mind when we discussed it in San Diego, but I don't remember what the idea was. I would need something like
struct dma_chan *dma_channel_get(struct dma_device *);
and I assume that there is a reason for why I can't call this from the xlate() function but instead have to go through dma_request_channel(), but I don't completely understand that part of the puzzle.
Arnd