ASoC: qcom: sc7180: Modify machine driver for 2mic

In addition, having mixer control to switch between DMICs by
using "dmic-gpios" property.

Refer to this one as an example,
commit b7a742cf ("ASoC: AMD: Use mixer control to switch between DMICs")
Signed-off-by: Ajye Huang <ajye_huang@compal.corp-partner.google.com>
Reviewed-by: Tzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20201106061433.1483129-3-ajye_huang@compal.corp-partner.google.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/qcom/sc7180.c

@@ -5,6 +5,8 @@
 // sc7180.c -- ALSA SoC Machine driver for SC7180
 
 #include <dt-bindings/sound/sc7180-lpass.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
@@ -28,6 +30,8 @@ struct sc7180_snd_data {
 	u32 pri_mi2s_clk_count;
 	struct snd_soc_jack hs_jack;
 	struct snd_soc_jack hdmi_jack;
+	struct gpio_desc *dmic_sel;
+	int dmic_switch;
 };
 
 static void sc7180_jack_free(struct snd_jack *jack)
@@ -169,6 +173,27 @@ static int sc7180_snd_startup(struct snd_pcm_substream *substream)
 	return 0;
 }
 
+static int dmic_get(struct snd_kcontrol *kcontrol,
+		    struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol);
+	struct sc7180_snd_data *data = snd_soc_card_get_drvdata(dapm->card);
+
+	ucontrol->value.integer.value[0] = data->dmic_switch;
+	return 0;
+}
+
+static int dmic_set(struct snd_kcontrol *kcontrol,
+		    struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol);
+	struct sc7180_snd_data *data = snd_soc_card_get_drvdata(dapm->card);
+
+	data->dmic_switch = ucontrol->value.integer.value[0];
+	gpiod_set_value(data->dmic_sel, data->dmic_switch);
+	return 0;
+}
+
 static void sc7180_snd_shutdown(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
@@ -206,6 +231,30 @@ static const struct snd_soc_dapm_widget sc7180_snd_widgets[] = {
 	SND_SOC_DAPM_MIC("Headset Mic", NULL),
 };
 
+static const char * const dmic_mux_text[] = {
+	"Front Mic",
+	"Rear Mic",
+};
+
+static SOC_ENUM_SINGLE_DECL(sc7180_dmic_enum,
+			    SND_SOC_NOPM, 0, dmic_mux_text);
+
+static const struct snd_kcontrol_new sc7180_dmic_mux_control =
+	SOC_DAPM_ENUM_EXT("DMIC Select Mux", sc7180_dmic_enum,
+			  dmic_get, dmic_set);
+
+static const struct snd_soc_dapm_widget sc7180_snd_dual_mic_widgets[] = {
+	SND_SOC_DAPM_HP("Headphone Jack", NULL),
+	SND_SOC_DAPM_MIC("Headset Mic", NULL),
+	SND_SOC_DAPM_MIC("DMIC", NULL),
+	SND_SOC_DAPM_MUX("Dmic Mux", SND_SOC_NOPM, 0, 0, &sc7180_dmic_mux_control),
+};
+
+static const struct snd_soc_dapm_route sc7180_snd_dual_mic_audio_route[] = {
+	{"Dmic Mux", "Front Mic", "DMIC"},
+	{"Dmic Mux", "Rear Mic", "DMIC"},
+};
+
 static void sc7180_add_ops(struct snd_soc_card *card)
 {
 	struct snd_soc_dai_link *link;
@@ -238,6 +287,18 @@ static int sc7180_snd_platform_probe(struct platform_device *pdev)
 	card->dapm_widgets = sc7180_snd_widgets;
 	card->num_dapm_widgets = ARRAY_SIZE(sc7180_snd_widgets);
 
+	if (of_property_read_bool(dev->of_node, "dmic-gpios")) {
+		card->dapm_widgets = sc7180_snd_dual_mic_widgets,
+		card->num_dapm_widgets = ARRAY_SIZE(sc7180_snd_dual_mic_widgets),
+		card->dapm_routes = sc7180_snd_dual_mic_audio_route,
+		card->num_dapm_routes = ARRAY_SIZE(sc7180_snd_dual_mic_audio_route),
+		data->dmic_sel = devm_gpiod_get(&pdev->dev, "dmic", GPIOD_OUT_LOW);
+		if (IS_ERR(data->dmic_sel)) {
+			dev_err(&pdev->dev, "DMIC gpio failed err=%ld\n", PTR_ERR(data->dmic_sel));
+			return PTR_ERR(data->dmic_sel);
+		}
+	}
+
 	ret = qcom_snd_parse_of(card);
 	if (ret)
 		return ret;