P1022 audio driver help!

Timur Tabi timur at tabi.org
Sat May 31 01:48:33 EST 2014

On 05/30/2014 01:03 AM, eshe168 wrote:
> @timur
> hi,
> Audio card (wm8776) cannot work in full duplex, CPU is FSL P1022.
> The PCB design about audio card reference FSL P1022 development board,
> and palying or recording is OK separately.
> My question is whether P1022 audio driver cannot support full duplex?

I was never able to get the P1022ds audio to work in full duplex.  After 
trying for a few weeks, I just gave up.

If you look inside fsl_ssi.c (the main driver) you'll see this comment I 

  * FIXME: The documentation says that SxCCR[WL] should not be
  * modified while the SSI is enabled.  The only time this can
  * happen is if we're trying to do simultaneous playback and
  * capture in asynchronous mode.  Unfortunately, I have been enable
  * to get that to work at all on the P1022DS.  Therefore, we don't
  * bother to disable/enable the SSI when setting SxCCR[WL], because
  * the SSI will stop anyway.  Maybe one day, this will get fixed.

(it should say "I have been unable" instead of "I have been enable")

Full duplex works fine on the MPC8610, which has the same audio 
controller as the P1022, so I know the controller is physically capable 
of it.  I just don't know why it doesn't work on the P1022DS.  I also 
don't know if it's a problem with the P1022DS board or with the P1022 
SOC itself.

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