ad1848_set_channel_gain
ad1848_set_channel_gain(sc, AD1848_DAC_CHANNEL, &vol_mid);
ad1848_set_channel_gain(sc, AD1848_MONITOR_CHANNEL, &vol_0);
ad1848_set_channel_gain(sc, AD1848_AUX1_CHANNEL, &vol_mid); /* CD volume */
ad1848_set_channel_gain(sc, AD1848_AUX2_CHANNEL, &vol_mid); /* CD volume */
ad1848_set_channel_gain(sc, AD1848_LINE_CHANNEL, &vol_mid);
ad1848_set_channel_gain(sc, AD1848_MONO_CHANNEL, &vol_0);
ad1848_set_channel_gain(sc, AD1848_AUX2_CHANNEL, &vol_0);
error = ad1848_set_channel_gain(ac, dev, &vol);
int ad1848_set_channel_gain(struct ad1848_softc *, int,
ad1848_set_channel_gain(ac, AD1848_DAC_CHANNEL, &vol_dac);
ad1848_set_channel_gain(ac, AD1848_AUX2_CHANNEL, &vol_opl3);