ASoC: max98090: add digital mic mux to record path

The max98090 driver currently treats the digital mic enable as a supply
on the record path, causing the digital mic enable to always be turned on
when attempting to record.  This is incorrect, however, since the digital
mic enable is also a mux control where 0 selects the ADC output as input
to the record-path DSP and 1 selects the digital mic.  This patch adds
a virtual DMIC mux to the reocrd path so that we can switch between the
ADC and the digital mic for recording.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/max98090.c

@@ -857,6 +857,14 @@ static const struct soc_enum mic2_mux_enum =
 static const struct snd_kcontrol_new max98090_mic2_mux =
 	SOC_DAPM_ENUM("MIC2 Mux", mic2_mux_enum);
 
+static const char *dmic_mux_text[] = { "ADC", "DMIC" };
+
+static const struct soc_enum dmic_mux_enum =
+	SOC_ENUM_SINGLE_EXT(ARRAY_SIZE(dmic_mux_text), dmic_mux_text);
+
+static const struct snd_kcontrol_new max98090_dmic_mux =
+	SOC_DAPM_ENUM_VIRT("DMIC Mux", dmic_mux_enum);
+
 static const char *max98090_micpre_text[] = { "Off", "On" };
 
 static const struct soc_enum max98090_pa1en_enum =
@@ -1144,6 +1152,9 @@ static const struct snd_soc_dapm_widget max98090_dapm_widgets[] = {
 	SND_SOC_DAPM_MUX("MIC2 Mux", SND_SOC_NOPM,
 		0, 0, &max98090_mic2_mux),
 
+	SND_SOC_DAPM_VIRT_MUX("DMIC Mux", SND_SOC_NOPM,
+		0, 0, &max98090_dmic_mux),
+
 	SND_SOC_DAPM_PGA_E("MIC1 Input", M98090_REG_MIC1_INPUT_LEVEL,
 		M98090_MIC_PA1EN_SHIFT, 0, NULL, 0, max98090_micinput_event,
 		SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
@@ -1336,11 +1347,14 @@ static const struct snd_soc_dapm_route max98090_dapm_routes[] = {
 	{"ADCL", NULL, "SHDN"},
 	{"ADCR", NULL, "SHDN"},
 
-	{"LBENL Mux", "Normal", "ADCL"},
-	{"LBENL Mux", "Normal", "DMICL"},
+	{"DMIC Mux", "ADC", "ADCL"},
+	{"DMIC Mux", "ADC", "ADCR"},
+	{"DMIC Mux", "DMIC", "DMICL"},
+	{"DMIC Mux", "DMIC", "DMICR"},
+
+	{"LBENL Mux", "Normal", "DMIC Mux"},
 	{"LBENL Mux", "Loopback", "LTENL Mux"},
-	{"LBENR Mux", "Normal", "ADCR"},
-	{"LBENR Mux", "Normal", "DMICR"},
+	{"LBENR Mux", "Normal", "DMIC Mux"},
 	{"LBENR Mux", "Loopback", "LTENR Mux"},
 
 	{"AIFOUTL", NULL, "LBENL Mux"},