ASoC: TWL4030: Make the enum filter generic for twl4030

Modify the enum filter to more generic that it will filter
out the enums with text "Invalid".
The enum filter also required for the capture path.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/twl4030.c

@@ -298,26 +298,24 @@ static const struct soc_enum twl4030_handsfreer_enum =
 static const struct snd_kcontrol_new twl4030_dapm_handsfreer_control =
 SOC_DAPM_ENUM("Route", twl4030_handsfreer_enum);
 
-static int outmixer_event(struct snd_soc_dapm_widget *w,
+/*
+ * This function filters out the non valid mux settings, named as "Invalid"
+ * in the enum texts.
+ * Just refuse to set an invalid mux mode.
+ */
+static int twl4030_enum_event(struct snd_soc_dapm_widget *w,
 	struct snd_kcontrol *kcontrol, int event)
 {
 	struct soc_enum *e = (struct soc_enum *)kcontrol->private_value;
 	int ret = 0;
 	int val;
 
-	switch (e->reg) {
-	case TWL4030_REG_PREDL_CTL:
-	case TWL4030_REG_PREDR_CTL:
-	case TWL4030_REG_EAR_CTL:
 	val = w->value >> e->shift_l;
-		if (val == 3) {
-			printk(KERN_WARNING
-			"Invalid MUX setting for register 0x%02x (%d)\n",
+	if (!strcmp("Invalid", e->texts[val])) {
+		printk(KERN_WARNING "Invalid MUX setting on 0x%02x (%d)\n",
 			e->reg, val);
 		ret = -1;
 	}
-		break;
-	}
 
 	return ret;
 }
@@ -810,14 +808,14 @@ static const struct snd_soc_dapm_widget twl4030_dapm_widgets[] = {
 	/* Output MUX controls */
 	/* Earpiece */
 	SND_SOC_DAPM_MUX_E("Earpiece Mux", SND_SOC_NOPM, 0, 0,
-		&twl4030_dapm_earpiece_control, outmixer_event,
+		&twl4030_dapm_earpiece_control, twl4030_enum_event,
 		SND_SOC_DAPM_PRE_REG),
 	/* PreDrivL/R */
 	SND_SOC_DAPM_MUX_E("PredriveL Mux", SND_SOC_NOPM, 0, 0,
-		&twl4030_dapm_predrivel_control, outmixer_event,
+		&twl4030_dapm_predrivel_control, twl4030_enum_event,
 		SND_SOC_DAPM_PRE_REG),
 	SND_SOC_DAPM_MUX_E("PredriveR Mux", SND_SOC_NOPM, 0, 0,
-		&twl4030_dapm_predriver_control, outmixer_event,
+		&twl4030_dapm_predriver_control, twl4030_enum_event,
 		SND_SOC_DAPM_PRE_REG),
 	/* HeadsetL/R */
 	SND_SOC_DAPM_MUX("HeadsetL Mux", SND_SOC_NOPM, 0, 0,