[alsa-devel] No sound captured with SGTL5000 on i.MX6 in I²S master mode

[Jean-Michel Hautbois]

2014-10-09 17:06 GMT+02:00 Fabio Estevam <festevam at gmail.com>:
> On Thu, Oct 9, 2014 at 11:26 AM, Jean-Michel Hautbois
> <jean-michel.hautbois at vodalys.com> wrote:
>> 2014-10-09 16:18 GMT+02:00 Fabio Estevam <festevam at gmail.com>:
>>> On Thu, Oct 9, 2014 at 11:02 AM, Jean-Michel Hautbois
>>> <jean-michel.hautbois at vodalys.com> wrote:
>>>
>>>> Here is an extract of the DT :
>>>> / {
>>>>     sound {
>>>>         compatible = "fsl,imx6q-vbx3-sgtl5000",
>>>>                  "fsl,imx-audio-sgtl5000";
>>>
>>> I am confused here: you say you use the simple-card, but your DTS
>>> still shows imx-audio-sgtl5000.
>>
>> I mentioned fsl-asoc-card, not simple card ?
>
> Yes, right, but for using fsl-asoc-card you should reference
> 'audio-cpu' instead of 'ssi-controller'.
>
> That's what Documentation/devicetree/bindings/sound/fsl-asoc-card.txt mentions.

Ouch, nice catch :).

Here is what I understand, in my cas, sgtl5000 has its clock routed
through a FPGA.
If the FPGA has not yet be probed, then, the module fails in loading :
[    4.985762] sgtl5000: probe of 1-000a failed with error -5

This is why after removing it and probing it again manually, it works.

This module should be able to defer probing too, is it going to be
done by someone or do I try to send some patch for this ?

BTW, I don't have sound on the microphone input, and I think there is
no way to select micbias voltage level neither from the source code
nor the DT ?
It could be interetsing to have something like sgtl5000-micbias-vg
which would give control on the voltage bias parameter ?
And maybe also something for bias resistor too ?

I can try to patch something.
Thanks,
JM