ALSA: cs5535audio: rename V_REFOUT control to MIC Bias

This drops the AD1888 V_REFOUT control, and replaces it with a MIC Bias
Enable control.  It also moves the MIC bias enabling into a separate
function.

Signed-off-by: Andres Salomon <dilinger@debian.org>
diff --git a/sound/pci/cs5535audio/cs5535audio_olpc.c b/sound/pci/cs5535audio/cs5535audio_olpc.c
index 7f26cfb..73811e0 100644
--- a/sound/pci/cs5535audio/cs5535audio_olpc.c
+++ b/sound/pci/cs5535audio/cs5535audio_olpc.c
@@ -31,6 +31,20 @@
 		geode_gpio_clear(OLPC_GPIO_MIC_AC, GPIO_OUTPUT_VAL);
 }
 
+/*
+ * OLPC XO-1's V_REFOUT is a mic bias enable.
+ */
+void olpc_mic_bias(struct snd_ac97 *ac97, int on)
+{
+	int err;
+
+	on = on ? 0 : 1;
+	err = snd_ac97_update_bits(ac97, AC97_AD_MISC,
+			1 << AC97_AD_VREFD_SHIFT, on << AC97_AD_VREFD_SHIFT);
+	if (err < 0)
+		snd_printk(KERN_ERR "setting MIC Bias - %d\n", err);
+}
+
 static int olpc_dc_info(struct snd_kcontrol *kctl,
 		struct snd_ctl_elem_info *uinfo)
 {
@@ -56,7 +70,36 @@
 	return 1;
 }
 
-static struct snd_kcontrol_new snd_cs5535audio_controls __devinitdata =
+static int olpc_mic_info(struct snd_kcontrol *kctl,
+		struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+	uinfo->count = 1;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 1;
+	return 0;
+}
+
+static int olpc_mic_get(struct snd_kcontrol *kctl, struct snd_ctl_elem_value *v)
+{
+	struct cs5535audio *cs5535au = snd_kcontrol_chip(kctl);
+	struct snd_ac97 *ac97 = cs5535au->ac97;
+	int i;
+
+	i = (snd_ac97_read(ac97, AC97_AD_MISC) >> AC97_AD_VREFD_SHIFT) & 0x1;
+	v->value.integer.value[0] = i ? 0 : 1;
+	return 0;
+}
+
+static int olpc_mic_put(struct snd_kcontrol *kctl, struct snd_ctl_elem_value *v)
+{
+	struct cs5535audio *cs5535au = snd_kcontrol_chip(kctl);
+
+	olpc_mic_bias(cs5535au->ac97, v->value.integer.value[0]);
+	return 1;
+}
+
+static struct snd_kcontrol_new olpc_cs5535audio_ctls[] __devinitdata = {
 {
 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 	.name = "DC Mode Enable",
@@ -64,6 +107,15 @@
 	.get = olpc_dc_get,
 	.put = olpc_dc_put,
 	.private_value = 0
+},
+{
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "MIC Bias Enable",
+	.info = olpc_mic_info,
+	.get = olpc_mic_get,
+	.put = olpc_mic_put,
+	.private_value = 0,
+},
 };
 
 void __devinit olpc_prequirks(struct snd_card *card,
@@ -80,6 +132,7 @@
 int __devinit olpc_quirks(struct snd_card *card, struct snd_ac97 *ac97)
 {
 	struct snd_ctl_elem_id elem;
+	int i, err;
 
 	if (!machine_is_olpc())
 		return 0;
@@ -90,8 +143,20 @@
 	strncpy(elem.name, "High Pass Filter Enable", sizeof(elem.name));
 	snd_ctl_remove_id(card, &elem);
 
-	/* add the override for OLPC's HPF */
-	return snd_ctl_add(card, snd_ctl_new1(&snd_cs5535audio_controls,
-						ac97->private_data));
+	/* drop the original V_REFOUT control */
+	memset(&elem, 0, sizeof(elem));
+	elem.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+	strncpy(elem.name, "V_REFOUT Enable", sizeof(elem.name));
+	snd_ctl_remove_id(card, &elem);
+
+	/* add the OLPC-specific controls */
+	for (i = 0; i < ARRAY_SIZE(olpc_cs5535audio_ctls); i++) {
+		err = snd_ctl_add(card, snd_ctl_new1(&olpc_cs5535audio_ctls[i],
+				ac97->private_data));
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
 }