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

[Fabio Estevam]

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;
    }

>
> 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.