[alsa-devel] Wolfson 5102 on Beaglebone Black using ALSA

[Peter Ujfalusi]

On 05/15/16 01:16, Clark Dunson wrote:
> Hey everybody!
> 
> We have been working on integrating the Wolfson 5102 codec with the
> Beaglebone Black.  We’ve made pretty decent progress, got the arizona code
> in kernel 4.4 registering the wm5102 as ALSA sound card (both player and
> recorder), have McAsp0 as 24.576 MHz clock source, and have 12 IRQs showing
> up in /proc/interrupts.
> 
> We have been working with sound{compatible = "simple-audio-card”}, but now
> have hit our first real question.  sysclk is hard coded to ‘0’ under
> simple-audio-card, and we had to hack the kernel and change that to ‘1’ to
> achieve ALSA sound card registration.  We’d all like for this work to
> proceed without having to hack the kernel, and wondered if one of you might
> recommend another approach or selection for device tree sound{compatible}
> that might work out better?

For simple card you would need:
http://mailman.alsa-project.org/pipermail/alsa-devel/2016-February/104316.html
to be able to select the McASP clocks.

It is not going to apply on linux-next becasue of:
http://mailman.alsa-project.org/pipermail/alsa-devel/2016-May/107783.html

but it is not should not be a big issue to resolve (one patch to move the
clkid to binding header).

The davinci-mcasp driver will remain broken in this sense for a foreseen
future as we need to convert the daVinci architecture to CCF first to be able
to progress with the clock selection.

-- 
Péter