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

Dr. H. Nikolaus Schaller hns at goldelico.com
Sat Nov 16 14:24:16 CET 2013

Am 16.11.2013 um 14:13 schrieb Benjamin Deering:

> While trying to figure out the issue with headset detection in 3.11 and 3.12 kernels I noticed that I am not getting reasonable values from the micsense adc.
> cat /sys/devices/platform/twl4030_madc_hwmon/in7_input
> On a 3.7 kernel I get ~20 unplugged and ~820 with my headphones plugged in.  I am getting ~830 always with 3.12.  The number changes (828, 833, 830) so it is doing a read.  I tried increasing the timeout in twl4030_madc_wait_conversion_ready:
> timeout = 1 + jiffies + msecs_to_jiffies(timeout_ms);
> but it made no difference, I think timeouts would have shown up in the logs.
> I looked at the schematics to see what the other ADC channels were connected to.  It looks like (non-existant) light sensor on in6_input?  in8_input jumps from ~2000 to ~5000 is usb is connected.  I don't know what expected values would be on the other channels to test.


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).

the ADCIN7 is MICSENSE but can work only if the microphone is really powered (VHSMICOUT).

> Is there some supply voltage that isn't being provided to micsense, or some misconfiguration in the twl4030-madc?  I will keep looking, but maybe someone will know right away.

So you may need to enable the hsmic in amixer.


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