i.MX6ULL: USB Mic Input to SAI2 I2S Output

[ph99004]

I am trying to build an audio bridge where someone can attach a USB Microphone to the i.MX6ULL and have the audio be converted to I2S and output SAI2.

SAI2_MCLK will be supplied so the i.MX6ULL will act as a slave. Clock could vary from fs*256 where fs could be 48 kHz or 44.1 kHz.

I have no real Codec so I am expecting to use the DUMMY codec for this project.

I don't want the user to do anything other than plug in the microphone and it work.

I am thinking I will need to write a small .C file which directs the necessary ALSA/SoC modules/sound drivers.

Have you guys done anything like this and would you recommend a course of action?  Do you have any code you might share?

Thank you.

Phil

[igorpadykov]

Hi Phil

one can look at simple-audio-card patch:

https://patchwork.kernel.org/project/linux-arm-kernel/patch/1462233386-23185-1-git-send-email-festev...

and ALSA sound driver description in Chapter 7 Audio  i.MX Linux Reference Manual​

Best regards
igor

[ph99004]

Igor,

Thank you for your quick reply.  Most appreciated.

Can you give me an overview what is needed to be done, in general, new-user kind of language? This way, I can start researching each step and ask questions when needed.

Phil