ASoC: mediatek: mt8186-rt5682: Modify machine driver for two DMICs case

Having two DMICs, a front DMIC and a Rear DMIC,
but only host audio input AUX port0 is used for these two Dmics.
A "dmic-gpios" property is used for a mixer control to switch
the dmic signal source between the Front and Rear Dmic.

Refer to this one as an example,
commit 3cfbf07c6d
("ASoC: qcom: sc7180: Modify machine driver for 2mic")

Signed-off-by: Ajye Huang <ajye_huang@compal.corp-partner.google.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20221102125936.2176748-3-ajye_huang@compal.corp-partner.google.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/mediatek/mt8186/mt8186-mt6366-rt1019-rt5682s.c

@@ -7,6 +7,8 @@
 // Author: Jiaxin Yu <jiaxin.yu@mediatek.com>
 //
 
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/input.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
@@ -39,6 +41,8 @@
 
 struct mt8186_mt6366_rt1019_rt5682s_priv {
 	struct snd_soc_jack headset_jack, hdmi_jack;
+	struct gpio_desc *dmic_sel;
+	int dmic_switch;
 };
 
 /* Headset jack detection DAPM pins */
@@ -68,6 +72,94 @@ static struct snd_soc_codec_conf mt8186_mt6366_rt1019_rt5682s_codec_conf[] = {
 	},
 };
 
+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 mtk_soc_card_data *soc_card_data =
+		snd_soc_card_get_drvdata(dapm->card);
+	struct mt8186_mt6366_rt1019_rt5682s_priv *priv = soc_card_data->mach_priv;
+
+	ucontrol->value.integer.value[0] = priv->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 mtk_soc_card_data *soc_card_data =
+		snd_soc_card_get_drvdata(dapm->card);
+	struct mt8186_mt6366_rt1019_rt5682s_priv *priv = soc_card_data->mach_priv;
+
+	priv->dmic_switch = ucontrol->value.integer.value[0];
+	if (priv->dmic_sel) {
+		gpiod_set_value(priv->dmic_sel, priv->dmic_switch);
+		dev_info(dapm->card->dev, "dmic_set_value %d\n",
+			 priv->dmic_switch);
+	}
+	return 0;
+}
+
+static const char * const dmic_mux_text[] = {
+	"Front Mic",
+	"Rear Mic",
+};
+
+static SOC_ENUM_SINGLE_DECL(mt8186_dmic_enum,
+			    SND_SOC_NOPM, 0, dmic_mux_text);
+
+static const struct snd_kcontrol_new mt8186_dmic_mux_control =
+	SOC_DAPM_ENUM_EXT("DMIC Select Mux", mt8186_dmic_enum,
+			  dmic_get, dmic_set);
+
+static const struct snd_soc_dapm_widget dmic_widgets[] = {
+	SND_SOC_DAPM_MIC("DMIC", NULL),
+	SND_SOC_DAPM_MUX("Dmic Mux", SND_SOC_NOPM, 0, 0, &mt8186_dmic_mux_control),
+};
+
+static const struct snd_soc_dapm_route dmic_map[] = {
+	/* digital mics */
+	{"Dmic Mux", "Front Mic", "DMIC"},
+	{"Dmic Mux", "Rear Mic", "DMIC"},
+};
+
+static int primary_codec_init(struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_soc_card *card = rtd->card;
+	struct mtk_soc_card_data *soc_card_data = snd_soc_card_get_drvdata(card);
+	struct mt8186_mt6366_rt1019_rt5682s_priv *priv = soc_card_data->mach_priv;
+	int ret;
+
+	ret = mt8186_mt6366_init(rtd);
+
+	if (ret) {
+		dev_err(card->dev, "mt8186_mt6366_init failed: %d\n", ret);
+		return ret;
+	}
+
+	if (!priv->dmic_sel) {
+		dev_info(card->dev, "dmic_sel is null\n");
+		return ret;
+	}
+
+	ret = snd_soc_dapm_new_controls(&card->dapm, dmic_widgets,
+					ARRAY_SIZE(dmic_widgets));
+	if (ret) {
+		dev_err(card->dev, "DMic widget addition failed: %d\n", ret);
+		/* Don't need to add routes if widget addition failed */
+		return ret;
+	}
+
+	ret = snd_soc_dapm_add_routes(&card->dapm, dmic_map,
+				      ARRAY_SIZE(dmic_map));
+
+	if (ret)
+		dev_err(card->dev, "DMic map addition failed: %d\n", ret);
+
+	return ret;
+}
+
 static int mt8186_rt5682s_init(struct snd_soc_pcm_runtime *rtd)
 {
 	struct snd_soc_component *cmpnt_afe =
@@ -775,7 +867,7 @@ static struct snd_soc_dai_link mt8186_mt6366_rt1019_rt5682s_dai_links[] = {
 		.dpcm_playback = 1,
 		.dpcm_capture = 1,
 		.ignore_suspend = 1,
-		.init = mt8186_mt6366_init,
+		.init = primary_codec_init,
 		SND_SOC_DAILINK_REG(adda),
 	},
 	{
@@ -1015,6 +1107,14 @@ static int mt8186_mt6366_rt1019_rt5682s_dev_probe(struct platform_device *pdev)
 
 	soc_card_data->mach_priv = mach_priv;
 
+	mach_priv->dmic_sel = devm_gpiod_get_optional(&pdev->dev,
+						      "dmic", GPIOD_OUT_LOW);
+	if (IS_ERR(mach_priv->dmic_sel)) {
+		dev_err(&pdev->dev, "DMIC gpio failed err=%ld\n",
+			PTR_ERR(mach_priv->dmic_sel));
+		return PTR_ERR(mach_priv->dmic_sel);
+	}
+
 	adsp_node = of_parse_phandle(pdev->dev.of_node, "mediatek,adsp", 0);
 	if (adsp_node) {
 		struct mtk_sof_priv *sof_priv;