[Gta04-owner] headset detection/twl4030 madc issue?

Benjamin Deering ben_deering at swissmail.org
Sun Nov 17 02:23:21 CET 2013

On 11/16/2013 08:24 AM, Dr. H. Nikolaus Schaller wrote:
> https://www.kernel.org/doc/Documentation/hwmon/twl4030-madc-hwmon
> ADCIN3 - ADCIN6 on the TPS65950 are shared with an optional car-kit interface that was probably in standardization when the chip was developed but is not used anywhere. Therefore we have not connected the pins.
> I.e. they should read 0 (or small values).
They do, so the issue is with the HSMIC voltage.
> So you may need to enable the hsmic in amixer.
This didn't make a difference
> the ADCIN7 is MICSENSE but can work only if the microphone is really powered (VHSMICOUT).
Is there an easy way to switch this?

I saw a change in twl4030.c that seemed to require changes in drivers 
that use it: 
I made a similar change in gta04-audio.c without understanding why, but 
it didn't have any effect.

diff --git a/sound/soc/omap/gta04-audio.c b/sound/soc/omap/gta04-audio.c
index bc72a30..86df6a3 100644
--- a/sound/soc/omap/gta04-audio.c
+++ b/sound/soc/omap/gta04-audio.c
@@ -127,8 +127,8 @@ static const struct snd_soc_dapm_route audio_map[] = {
         {"AUXR", NULL, "Line In"},

         /* Headset Mic: HSMIC with bias */
-       {"HSMIC", NULL, "Headset Mic Bias"},
-       {"Headset Mic Bias", NULL, "Headphone Mic"},
+       {"HSMIC", NULL, "Headset Mic"},
+       {"Headset Mic", NULL, "Headset Mic Bias"},

         {"MAINMIC", NULL, "Mic Bias 1"},
         {"Mic Bias 1", NULL, "Internal Mic"},

 From my playing around, it seems like the bias is working (values read 
high, except when I turned the bias off, then values read low).  My 
understanding from looking at the schematic is that the HS MIC bias 
pulls up on the ADC and HSMIC pulls down.  It seems like the amixer 
control isn't turning on the mic?


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