HelenOS sources

hda_get_amp_gain_mute  282 uspace/drv/audio/hdaudio/codec.c 	rc = hda_get_amp_gain_mute(codec, aw, 0x8000, &gmleft);
hda_get_amp_gain_mute  286 uspace/drv/audio/hdaudio/codec.c 	rc = hda_get_amp_gain_mute(codec, aw, 0xa000, &gmright);
hda_get_amp_gain_mute  318 uspace/drv/audio/hdaudio/codec.c 		rc = hda_get_amp_gain_mute(codec, aw, 0x0000 + i, &gmleft);
hda_get_amp_gain_mute  322 uspace/drv/audio/hdaudio/codec.c 		rc = hda_get_amp_gain_mute(codec, aw, 0x2000 + i, &gmright);
HelenOS homepage, sources at GitHub