How to enable the "handsfree" speaker for sound

On a board that is almost identical in configuration to the Beagle
Board I have the "handsfree" speaker leads available and want to use
the built-in amp to drive small speakers. This requires some magic
registers set inside the TWL4030 (or equivalent). Before I try to
figure it out from the alsamixer sources, maybe someone can tell me
that all I need is a simple command or a line in alsa configuration
file.

Anyone?