http://dev.kewl.org/v4l-dvb/patches/

tda9887_experimental.diff ------------------------- A patch for FM experimenters. This allows overriding the default stereo mode parameters for reception.

For example, to default to mono, use: options tda9887 radio_override=1 regb=0x9e regc=0xb0 rege=0x20

Refer to http://dl.ivtvdriver.org/datasheets/tuners/TDA9887_3.pdf for more details.