ASoC: AMD: Use mixer control to switch between DMICs

Having mixer control to switch between DMICs prevents user to
initiate capture simultaneously on both the DMIcs.
Earlier 2 separate devices, one for each DMIC, gave an option of
using them simultaneously, which is not supported.
Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
Link: https://lore.kernel.org/r/20200530095519.24324-1-akshu.agrawal@amd.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/amd/acp3x-rt5682-max9836.c

@@ -188,25 +188,27 @@ static int acp3x_ec_dmic0_startup(struct snd_pcm_substream *substream)
 
 	machine->cap_i2s_instance = I2S_BT_INSTANCE;
 	snd_soc_dai_set_bclk_ratio(codec_dai, 64);
-	if (dmic_sel)
-		gpiod_set_value(dmic_sel, 0);
 
 	return rt5682_clk_enable(substream);
 }
 
-static int acp3x_ec_dmic1_startup(struct snd_pcm_substream *substream)
-{
-	struct snd_soc_pcm_runtime *rtd = substream->private_data;
-	struct snd_soc_card *card = rtd->card;
-	struct snd_soc_dai *codec_dai = asoc_rtd_to_codec(rtd, 0);
-	struct acp3x_platform_info *machine = snd_soc_card_get_drvdata(card);
+static int dmic_switch;
 
-	machine->cap_i2s_instance = I2S_BT_INSTANCE;
-	snd_soc_dai_set_bclk_ratio(codec_dai, 64);
-	if (dmic_sel)
-		gpiod_set_value(dmic_sel, 1);
+static int dmic_get(struct snd_kcontrol *kcontrol,
+			 struct snd_ctl_elem_value *ucontrol)
+{
+	ucontrol->value.integer.value[0] = dmic_switch;
+	return 0;
+}
 
-	return rt5682_clk_enable(substream);
+static int dmic_set(struct snd_kcontrol *kcontrol,
+			 struct snd_ctl_elem_value *ucontrol)
+{
+	if (dmic_sel) {
+		dmic_switch = ucontrol->value.integer.value[0];
+		gpiod_set_value(dmic_sel, dmic_switch);
+	}
+	return 0;
 }
 
 static void rt5682_shutdown(struct snd_pcm_substream *substream)
@@ -229,11 +231,6 @@ static const struct snd_soc_ops acp3x_ec_cap0_ops = {
 	.shutdown = rt5682_shutdown,
 };
 
-static const struct snd_soc_ops acp3x_ec_cap1_ops = {
-	.startup = acp3x_ec_dmic1_startup,
-	.shutdown = rt5682_shutdown,
-};
-
 SND_SOC_DAILINK_DEF(acp3x_i2s,
 	DAILINK_COMP_ARRAY(COMP_CPU("acp3x_i2s_playcap.0")));
 SND_SOC_DAILINK_DEF(acp3x_bt,
@@ -279,21 +276,26 @@ static struct snd_soc_dai_link acp3x_dai_5682_98357[] = {
 		.ops = &acp3x_ec_cap0_ops,
 		SND_SOC_DAILINK_REG(acp3x_bt, cros_ec, platform),
 	},
-	{
-		.name = "acp3x-ec-dmic1-capture",
-		.stream_name = "Capture DMIC1",
-		.dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF
-				| SND_SOC_DAIFMT_CBS_CFS,
-		.dpcm_capture = 1,
-		.ops = &acp3x_ec_cap1_ops,
-		SND_SOC_DAILINK_REG(acp3x_bt, cros_ec, platform),
-	},
 };
 
+static const char * const dmic_mux_text[] = {
+	"Front Mic",
+	"Rear Mic",
+};
+
+static SOC_ENUM_SINGLE_DECL(
+		acp3x_dmic_enum, SND_SOC_NOPM, 0, dmic_mux_text);
+
+static const struct snd_kcontrol_new acp3x_dmic_mux_control =
+	SOC_DAPM_ENUM_EXT("DMIC Select Mux", acp3x_dmic_enum,
+			  dmic_get, dmic_set);
+
 static const struct snd_soc_dapm_widget acp3x_widgets[] = {
 	SND_SOC_DAPM_HP("Headphone Jack", NULL),
 	SND_SOC_DAPM_SPK("Spk", NULL),
 	SND_SOC_DAPM_MIC("Headset Mic", NULL),
+	SND_SOC_DAPM_MUX("Dmic Mux", SND_SOC_NOPM, 0, 0,
+			 &acp3x_dmic_mux_control),
 };
 
 static const struct snd_soc_dapm_route acp3x_audio_route[] = {
@@ -301,6 +303,8 @@ static const struct snd_soc_dapm_route acp3x_audio_route[] = {
 	{"Headphone Jack", NULL, "HPOR"},
 	{"IN1P", NULL, "Headset Mic"},
 	{"Spk", NULL, "Speaker"},
+	{"Dmic Mux", "Front Mic", "DMIC"},
+	{"Dmic Mux", "Rear Mic", "DMIC"},
 };
 
 static const struct snd_kcontrol_new acp3x_mc_controls[] = {