On Tue, Apr 27, 2010 at 10:20 AM, Liam Girdwood <lrg@xxxxxxxxxxxxxxx> wrote: >> Another problem is that ASoC won't let me probe the DMA channels >> independently. That is, I cannot tell ASoC that I have a playback DMA >> and a capture DMA. ASoC does not recognize two DMA devices for a >> single SSI. If you can fix that, then I can turn the DMA driver into >> an OF driver. >> > > Iirc, the SSI and DMA controllers on your SoC mean that each DMA device > can only do one direction (either Playback or Capture). So I'm thinking > we create two DAI link entries for your sound card (one for playback and > the other for capture) and they both use the same SSI device but each > would have it's own DMA device. > > This would result in two separate pcm devices being exported to > userspace i.e one for playback only and the other for capture only. I > think this is also a more accurate representation of your hardware too > (since we have different DMA devices for each pcm stream direction). Ok, I'm trying to do this now, and I'm running into problems. So here's the device list: One machine One SSI Two DMA channels One codec So I create two dai_links in the machine driver. Each dai_link has two DAIs in it. The DAIs are identical, except for the platform_drv field. The platform_drv in the first DAI points to the first DMA channel, and the platform_drv of the second DAI points to the second DMA channel. When I boot Linux, I get this: asoc: cs4270 <-> /soc@e0000000/ssi@16000 mapping ok sysfs: cannot create duplicate filename '/devices/platform/soc-audio/cs4270' so it looks like when asoc is processing the dai_link, it tries to create a sysfs device for the codec twice. How do I avoid this? -- Timur Tabi Linux kernel developer at Freescale _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
