return 0;
 }
 
+static int spdif_loopback_get(struct snd_kcontrol *ctl,
+                             struct snd_ctl_elem_value *value)
+{
+       struct oxygen *chip = ctl->private_data;
+
+       value->value.integer.value[0] =
+               !!(oxygen_read32(chip, OXYGEN_SPDIF_CONTROL)
+                  & OXYGEN_SPDIF_LOOPBACK);
+       return 0;
+}
+
+static int spdif_loopback_put(struct snd_kcontrol *ctl,
+                             struct snd_ctl_elem_value *value)
+{
+       struct oxygen *chip = ctl->private_data;
+       u32 oldreg, newreg;
+       int changed;
+
+       spin_lock_irq(&chip->reg_lock);
+       oldreg = oxygen_read32(chip, OXYGEN_SPDIF_CONTROL);
+       if (value->value.integer.value[0])
+               newreg = oldreg | OXYGEN_SPDIF_LOOPBACK;
+       else
+               newreg = oldreg & ~OXYGEN_SPDIF_LOOPBACK;
+       changed = newreg != oldreg;
+       if (changed)
+               oxygen_write32(chip, OXYGEN_SPDIF_CONTROL, newreg);
+       spin_unlock_irq(&chip->reg_lock);
+       return changed;
+}
+
 static int ac97_switch_get(struct snd_kcontrol *ctl,
                           struct snd_ctl_elem_value *value)
 {
                .info = spdif_info,
                .get = spdif_input_default_get,
        },
+       {
+               .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+               .name = SNDRV_CTL_NAME_IEC958("Loopback ", NONE, SWITCH),
+               .info = snd_ctl_boolean_mono_info,
+               .get = spdif_loopback_get,
+               .put = spdif_loopback_put,
+       },
 };
 
 static const struct snd_kcontrol_new ac97_controls[] = {