return change;
 }
 
+#define HDSPM_CONTROL_TRISTATE(xname, xindex) \
+{      .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
+       .name = xname, \
+       .private_value = xindex, \
+       .info = snd_hdspm_info_tristate, \
+       .get = snd_hdspm_get_tristate, \
+       .put = snd_hdspm_put_tristate \
+}
+
+static int hdspm_tristate(struct hdspm *hdspm, u32 regmask)
+{
+       u32 reg = hdspm->settings_register & (regmask * 3);
+       return reg / regmask;
+}
+
+static int hdspm_set_tristate(struct hdspm *hdspm, int mode, u32 regmask)
+{
+       hdspm->settings_register &= ~(regmask * 3);
+       hdspm->settings_register |= (regmask * mode);
+       hdspm_write(hdspm, HDSPM_WR_SETTINGS, hdspm->settings_register);
+
+       return 0;
+}
+
+static int snd_hdspm_info_tristate(struct snd_kcontrol *kcontrol,
+                                      struct snd_ctl_elem_info *uinfo)
+{
+       u32 regmask = kcontrol->private_value;
+
+       static char *texts_spdif[] = { "Optical", "Coaxial", "Internal" };
+       static char *texts_levels[] = { "Hi Gain", "+4 dBu", "-10 dBV" };
+
+       switch (regmask) {
+       case HDSPM_c0_Input0:
+               ENUMERATED_CTL_INFO(uinfo, texts_spdif);
+               break;
+       default:
+               ENUMERATED_CTL_INFO(uinfo, texts_levels);
+               break;
+       }
+       return 0;
+}
+
+static int snd_hdspm_get_tristate(struct snd_kcontrol *kcontrol,
+                                     struct snd_ctl_elem_value *ucontrol)
+{
+       struct hdspm *hdspm = snd_kcontrol_chip(kcontrol);
+       u32 regmask = kcontrol->private_value;
+
+       spin_lock_irq(&hdspm->lock);
+       ucontrol->value.enumerated.item[0] = hdspm_tristate(hdspm, regmask);
+       spin_unlock_irq(&hdspm->lock);
+       return 0;
+}
+
+static int snd_hdspm_put_tristate(struct snd_kcontrol *kcontrol,
+                                     struct snd_ctl_elem_value *ucontrol)
+{
+       struct hdspm *hdspm = snd_kcontrol_chip(kcontrol);
+       u32 regmask = kcontrol->private_value;
+       int change;
+       int val;
+
+       if (!snd_hdspm_use_is_exclusive(hdspm))
+               return -EBUSY;
+       val = ucontrol->value.integer.value[0];
+       if (val < 0)
+               val = 0;
+       if (val > 2)
+               val = 2;
+
+       spin_lock_irq(&hdspm->lock);
+       change = val != hdspm_tristate(hdspm, regmask);
+       hdspm_set_tristate(hdspm, val, regmask);
+       spin_unlock_irq(&hdspm->lock);
+       return change;
+}
+
 #define HDSPM_MADI_SPEEDMODE(xname, xindex) \
 {      .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
        .name = xname, \