GUSMASK_MIC_IN
(sc->sc_mixcontrol & GUSMASK_MIC_IN) == 0) {
sc->sc_mixcontrol |= GUSMASK_MIC_IN;
(sc->sc_mixcontrol & GUSMASK_MIC_IN)) {
sc->sc_mixcontrol &= ~GUSMASK_MIC_IN;
sc->sc_mixcontrol |= GUSMASK_MIC_IN; /* 1 enables. */
sc->sc_mixcontrol & GUSMASK_MIC_IN ? 0 : 1;