[alsa-devel] [PATCH 03/17] ASoC: Add a generic dmaengine_pcm driver

Peter Ujfalusi peter.ujfalusi at ti.com
Wed Apr 17 15:06:38 CEST 2013

On 04/17/2013 12:48 PM, Lars-Peter Clausen wrote:
> This sounds like it needs more than just support for custom channel names.
> The generic driver currently expects that there is exactly one DMA channel
> for capture and one for playback (well and in case the DAI link is simplex
> only either one of them).
> What are these 8 channels exactly used for?

We have 7 FIFOs which can be configured either playback or capture. The last
channel is used for debug purposes only right now.
Basically we can dynamically configure the 8 DMA channel for playback/capture
and the mixing of incoming streams done inside of the AESS.
We have 7 DAIs and we have playback/capture on those (some only have playback
some only capture some duplex). Right now we have kind of static DMA bindings
for them, I'm working on a dynamic model right now.

So one IP (one driver) which can request 8 DMA and depending on the stream
(DAI in use) we pick one of them to be used.


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