On Thu, 2015-10-08 at 08:51 -0700, Caleb Crome wrote:
Hi All, I'm in a constant struggle to bring up many channel audio on each separate SoC.
I can easily put a microcontroller in place that will collect and distrubute all the TDM channels to the codecs, and connect the hardware via an SPI interface to the SoC.
So, instead of:
CODECS <---TDM---> SoC
It would be
CODECS <---TDM---> uC <---SPI---> SoC
So, my questions are:
- I suspect the SPI interface could be used more universally than each
individual I2S/TDM interface (like FSL SSI vs. Ti McBSP vs. Ti McASP, etc). and the SPI port would provide a very common API regardless of SoC. Is that true?
Some SPI ports could probably be used for audio, but this depends on the SPI port HW capabilities. e.g. the SSP port on minnowboard can be configured for TDM, I2S and SPI (afaik). I don't think any advantage could be gained from running in SPI mode unless your HW permits some special features ?
- Is it feasible to integrate an SPI transport into the SoC/alsa
layer? What are the difficulties involved with that?
Yes, that's doable providing the SPI port is capable of supporting audio formats and has good DMA connectivity. A DAI driver would need to be written for your SPI port to allow it to send audio data within ASoC.
Liam
Cheers, -Caleb