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

[Jean-Michel Hautbois]

2014-10-09 17:19 GMT+02:00 Fabio Estevam <festevam at gmail.com>:
> On Thu, Oct 9, 2014 at 12:14 PM, Jean-Michel Hautbois
> <jean-michel.hautbois at vodalys.com> wrote:
>
>> 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 ?
>
> We do defer probing already:
>
>     sgtl5000->mclk = devm_clk_get(&client->dev, NULL);
>     if (IS_ERR(sgtl5000->mclk)) {
>         ret = PTR_ERR(sgtl5000->mclk);
>         dev_err(&client->dev, "Failed to get mclock: %d\n", ret);
>         /* Defer the probe to see if the clk will be provided later */
>         if (ret == -ENOENT)
>             return -EPROBE_DEFER;
>         return ret;
>     }

Yes, sorry about that, missed it.

>>
>> 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.
>
> That would be great, thanks.

Do I need to keep actual defaults if the resistor or voltage are not
specified in DT ?
Or should I set it to off (which is probably more logical) ?
And one or two patches (one resistor and one voltage patch, or both in
the same) ?

JM