[Gta04-owner] Detecting headset plug: twl4030-madc IRQ issue

PaulK paulk at paulk.fr
Sat Apr 28 19:15:37 CEST 2012

I am now working on adding sound to Replicant. Dealing with the controls
seems very clear to me now, thanks to the docs on:

Currently, I am trying to get the twl4030-madc to report headset
plug/unplug. If I read correctly the docs, ADC7 is MICSENSE. 
Now the driver reports data through channels, so I guess what I'm
looking for is chan 7. 

A threaded IRQ is requested at probe and, if I got it correctly, is
supposed to call the twl4030_madc_threaded_irq_handler function when the
value of one ADC changes. Except that I didn't see that function getting
called when the headset is plugged or unplugged. I even tried removing
the battery (as it should report battery-related infos), it it didn't
get called either. 

Now there are a few confusing elements: there is a
twl4030_madc_enable_irq function that could lead me to think that it is
somehow disabled by default and the ADCs chip must somehow be told to
make use of the IRQ line. 

I have never dealt with IRQ interrupts before so I may be missing
something obvious here. Though, I would appreciate help discovering what
is actually going on and why this handler function never gets called.

Paul Kocialkowski, Replicant developer

Replicant is a fully free Android distribution

Website:        http://www.replicant.us
Wiki/Tracker:   http://redmine.replicant.us

More information about the Gta04-owner mailing list