Hi Laurent, Vinod > > pattern 1) > > 1st DMA > > [mem] -> [SSI] -> speaker > > > > pattern 2) > > 1st DMA 2nd DMA > > [mem] -> [SRC] -> [SSI] -> speaker > > > > pattern 3) > > 1st DMA 2nd DMA > > [mem] -> [SRC] -> [DVC] -> [SSI] -> speaker > > > > SRC : 9 channel > > DVC : 3 channel > > SSI : 9 channel > > > > Data path is board/platform specific at this point. > > (it is nice if we can select these pattern flexibility in the future) > > Unfortunately, this channel size is depends on SoC, > > and above is "playback" pattern only, we need to have "capture" pattern too. > > (similar path, but different direction and different ID). > > Now, it is controlled under sound driver, because sound knows all > > information and, board/platform specific data path. > > > > I thought that it is possible if sound driver uses 2 generic sound DMA > > layer, but is it wrong ? > > It's not wrong, but I wonder if it's the best solution. > > Supporting the R-Car DMAC with a generic DMA engine driver is I think the best > solution, as the DMAC is a general-purpose DMA engine, not specific to sound. > There's no issue there. > > The second DMA controller is specific to the sound subsystem. I thus wonder if > the additional complexity of supporting it through the DMA engine API (both in > terms of code complexity on the DMA driver side and the sound driver side and > in terms of DT bindings complexity) is worth it, or if it would be simpler and > cleaner to support it with a driver specific to R-Car sound. You're more > knowledgeable than I am on the subject, so I'll trust your judgment. Yes, I agree to your opinion. R-Car DMAC should keep "general-purpose" DMA engine. It is easy to control if 1st/2nd DMA was separated from sound driver point of view. I guess sound HW which needs 2 DMAC is very rare case(?). I want "keep it simple" Vinod, this means, we want to have 2 different DMA (= 1st/2nd) for sound. 1st DMA is general DMAC, 2nd DMA is sound specific DMAC. What is you opinion ? Best regards --- Kuninori Morimoto -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
