ASoC: codecs: msm8916-wcd-analog: add MBHC support

MBHC (MultiButton Headset Control) support is available in pm8921 in two
blocks, one to detect mechanical headset insertion and removal and other
block to support headset type detection and 5 button detection and othe
features like impedance calculation.

This patch adds support to:
1> Support to NC and NO type of headset Jacks.
2> Mechanical insertion and detection of headset jack.
3> Detect a 3 pole Headphone and a 4 pole Headset.
4> Detect 5 buttons.

Tested it on DB410c with Audio Mezz board with 4 pole and 3 pole
headset/headphones.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Damien Riegel <damien.riegel@savoirfairelinux.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/qcom,msm8916-wcd-analog.txt

@@ -31,9 +31,22 @@ Required properties
  - vdd-cdc-io-supply: phandle to VDD_CDC_IO regulator DT node.
  - vdd-cdc-tx-rx-cx-supply: phandle to VDD_CDC_TX/RX/CX regulator DT node.
  - vdd-micbias-supply: phandle of VDD_MICBIAS supply's regulator DT node.
-
 Optional Properties:
+ - qcom,mbhc-vthreshold-low: Array of 5 threshold voltages in mV for 5 buttons
+			     detection on headset when the mbhc is powered up
+			     by internal current source, this is a low power.
+ - qcom,mbhc-vthreshold-high: Array of 5 thresold voltages in mV for 5 buttons
+			      detection on headset when mbhc is powered up
+			       from micbias.
 - qcom,micbias-lvl:  Voltage (mV) for Mic Bias
+- qcom,hphl-jack-type-normally-open: boolean, present if hphl pin on jack is a
+				     NO (Normally Open). If not specified, then
+				     its assumed that hphl pin on jack is NC
+				     (Normally Closed).
+- qcom,gnd-jack-type-normally-open: boolean, present if gnd pin on jack is
+				    NO (Normally Open). If not specified, then
+				    its assumed that gnd pin on jack is NC
+				    (Normally Closed).
 - qcom,micbias1-ext-cap: boolean, present if micbias1 has external capacitor
 			 connected.
 - qcom,micbias2-ext-cap: boolean, present if micbias2 has external capacitor
@@ -49,6 +62,8 @@ spmi_bus {
 		reg-names = "pmic-codec-core";
 		clocks = <&gcc GCC_CODEC_DIGCODEC_CLK>;
 		clock-names = "mclk";
+		qcom,mbhc-vthreshold-low = <75 150 237 450 500>;
+		qcom,mbhc-vthreshold-high = <75 150 237 450 500>;
 		interrupt-parent = <&spmi_bus>;
 		interrupts = <0x1 0xf0 0x0 IRQ_TYPE_NONE>,
 			     <0x1 0xf0 0x1 IRQ_TYPE_NONE>,

sound/soc/codecs/msm8916-wcd-analog.c

@@ -12,9 +12,16 @@
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/tlv.h>
+#include <sound/jack.h>
 
 #define CDC_D_REVISION1			(0xf000)
 #define CDC_D_PERPH_SUBTYPE		(0xf005)
+#define CDC_D_INT_EN_SET		(0x015)
+#define CDC_D_INT_EN_CLR		(0x016)
+#define MBHC_SWITCH_INT			BIT(7)
+#define MBHC_MIC_ELECTRICAL_INS_REM_DET	BIT(6)
+#define MBHC_BUTTON_PRESS_DET		BIT(5)
+#define MBHC_BUTTON_RELEASE_DET		BIT(4)
 #define CDC_D_CDC_RST_CTL		(0xf046)
 #define RST_CTL_DIG_SW_RST_N_MASK	BIT(7)
 #define RST_CTL_DIG_SW_RST_N_RESET	0
@@ -37,6 +44,8 @@
 #define DIG_CLK_CTL_RXD1_CLK_EN		BIT(0)
 #define DIG_CLK_CTL_RXD2_CLK_EN		BIT(1)
 #define DIG_CLK_CTL_RXD3_CLK_EN		BIT(2)
+#define DIG_CLK_CTL_D_MBHC_CLK_EN_MASK	BIT(3)
+#define DIG_CLK_CTL_D_MBHC_CLK_EN	BIT(3)
 #define DIG_CLK_CTL_TXD_CLK_EN		BIT(4)
 #define DIG_CLK_CTL_NCP_CLK_EN_MASK	BIT(6)
 #define DIG_CLK_CTL_NCP_CLK_EN		BIT(6)
@@ -132,8 +141,51 @@
 #define MICB_1_INT_TX3_INT_PULLUP_EN_TX1N_TO_GND	0
 
 #define CDC_A_MICB_2_EN			(0xf144)
+#define CDC_A_MICB_2_EN_ENABLE		BIT(7)
+#define CDC_A_MICB_2_PULL_DOWN_EN_MASK	BIT(5)
+#define CDC_A_MICB_2_PULL_DOWN_EN	BIT(5)
 #define CDC_A_TX_1_2_ATEST_CTL_2	(0xf145)
 #define CDC_A_MASTER_BIAS_CTL		(0xf146)
+#define CDC_A_MBHC_DET_CTL_1		(0xf147)
+#define CDC_A_MBHC_DET_CTL_L_DET_EN			BIT(7)
+#define CDC_A_MBHC_DET_CTL_GND_DET_EN			BIT(6)
+#define CDC_A_MBHC_DET_CTL_MECH_DET_TYPE_INSERTION	BIT(5)
+#define CDC_A_MBHC_DET_CTL_MECH_DET_TYPE_REMOVAL	(0)
+#define CDC_A_MBHC_DET_CTL_MECH_DET_TYPE_MASK		BIT(5)
+#define CDC_A_MBHC_DET_CTL_MECH_DET_TYPE_SHIFT		(5)
+#define CDC_A_MBHC_DET_CTL_MIC_CLAMP_CTL_AUTO		BIT(4)
+#define CDC_A_MBHC_DET_CTL_MIC_CLAMP_CTL_MANUAL		BIT(3)
+#define CDC_A_MBHC_DET_CTL_MIC_CLAMP_CTL_MASK		GENMASK(4, 3)
+#define CDC_A_MBHC_DET_CTL_MBHC_BIAS_EN			BIT(2)
+#define CDC_A_MBHC_DET_CTL_2		(0xf150)
+#define CDC_A_MBHC_DET_CTL_HS_L_DET_PULL_UP_CTRL_I_3P0	(BIT(7) | BIT(6))
+#define CDC_A_MBHC_DET_CTL_HS_L_DET_COMPA_CTRL_V0P9_VDD	BIT(5)
+#define CDC_A_PLUG_TYPE_MASK				GENMASK(4, 3)
+#define CDC_A_HPHL_PLUG_TYPE_NO				BIT(4)
+#define CDC_A_GND_PLUG_TYPE_NO				BIT(3)
+#define CDC_A_MBHC_DET_CTL_HPHL_100K_TO_GND_EN_MASK	BIT(0)
+#define CDC_A_MBHC_DET_CTL_HPHL_100K_TO_GND_EN		BIT(0)
+#define CDC_A_MBHC_FSM_CTL		(0xf151)
+#define CDC_A_MBHC_FSM_CTL_MBHC_FSM_EN			BIT(7)
+#define CDC_A_MBHC_FSM_CTL_MBHC_FSM_EN_MASK		BIT(7)
+#define CDC_A_MBHC_FSM_CTL_BTN_ISRC_CTRL_I_100UA	(0x3 << 4)
+#define CDC_A_MBHC_FSM_CTL_BTN_ISRC_CTRL_MASK		GENMASK(6, 4)
+#define CDC_A_MBHC_DBNC_TIMER		(0xf152)
+#define CDC_A_MBHC_DBNC_TIMER_BTN_DBNC_T_16MS		BIT(3)
+#define CDC_A_MBHC_DBNC_TIMER_INSREM_DBNC_T_256_MS	(0x9 << 4)
+#define CDC_A_MBHC_BTN0_ZDET_CTL_0	(0xf153)
+#define CDC_A_MBHC_BTN1_ZDET_CTL_1	(0xf154)
+#define CDC_A_MBHC_BTN2_ZDET_CTL_2	(0xf155)
+#define CDC_A_MBHC_BTN3_CTL		(0xf156)
+#define CDC_A_MBHC_BTN4_CTL		(0xf157)
+#define CDC_A_MBHC_BTN_VREF_FINE_SHIFT	(2)
+#define CDC_A_MBHC_BTN_VREF_FINE_MASK	GENMASK(4, 2)
+#define CDC_A_MBHC_BTN_VREF_COARSE_MASK	GENMASK(7, 5)
+#define CDC_A_MBHC_BTN_VREF_COARSE_SHIFT (5)
+#define CDC_A_MBHC_BTN_VREF_MASK	(CDC_A_MBHC_BTN_VREF_COARSE_MASK | \
+					CDC_A_MBHC_BTN_VREF_FINE_MASK)
+#define CDC_A_MBHC_RESULT_1		(0xf158)
+#define CDC_A_MBHC_RESULT_1_BTN_RESULT_MASK	GENMASK(4, 0)
 #define CDC_A_TX_1_EN			(0xf160)
 #define CDC_A_TX_2_EN			(0xf161)
 #define CDC_A_TX_1_2_TEST_CTL_1		(0xf162)
@@ -217,16 +269,34 @@
 #define MSM8916_WCD_ANALOG_FORMATS (SNDRV_PCM_FMTBIT_S16_LE |\
 				    SNDRV_PCM_FMTBIT_S24_LE)
 
+static int btn_mask = SND_JACK_BTN_0 | SND_JACK_BTN_1 |
+	       SND_JACK_BTN_2 | SND_JACK_BTN_3 | SND_JACK_BTN_4;
+static int hs_jack_mask = SND_JACK_HEADPHONE | SND_JACK_HEADSET;
+
 static const char * const supply_names[] = {
 	"vdd-cdc-io",
 	"vdd-cdc-tx-rx-cx",
 };
 
+#define MBHC_MAX_BUTTONS	(5)
+
 struct pm8916_wcd_analog_priv {
 	u16 pmic_rev;
 	u16 codec_version;
+	bool	mbhc_btn_enabled;
+	/* special event to detect accessory type */
+	bool	mbhc_btn0_pressed;
+	bool	detect_accessory_type;
 	struct clk *mclk;
+	struct snd_soc_codec *codec;
 	struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
+	struct snd_soc_jack *jack;
+	bool hphl_jack_type_normally_open;
+	bool gnd_jack_type_normally_open;
+	/* Voltage threshold when internal current source of 100uA is used */
+	u32 vref_btn_cs[MBHC_MAX_BUTTONS];
+	/* Voltage threshold when microphone bias is ON */
+	u32 vref_btn_micb[MBHC_MAX_BUTTONS];
 	unsigned int micbias1_cap_mode;
 	unsigned int micbias2_cap_mode;
 	unsigned int micbias_mv;
@@ -373,6 +443,97 @@ static int pm8916_wcd_analog_enable_micbias_int1(struct
 						     wcd->micbias1_cap_mode);
 }
 
+static void pm8916_wcd_setup_mbhc(struct pm8916_wcd_analog_priv *wcd)
+{
+	struct snd_soc_codec *codec = wcd->codec;
+	u32 plug_type = 0;
+	u32 int_en_mask;
+
+	snd_soc_write(codec, CDC_A_MBHC_DET_CTL_1,
+		      CDC_A_MBHC_DET_CTL_L_DET_EN |
+		      CDC_A_MBHC_DET_CTL_MECH_DET_TYPE_INSERTION |
+		      CDC_A_MBHC_DET_CTL_MIC_CLAMP_CTL_AUTO |
+		      CDC_A_MBHC_DET_CTL_MBHC_BIAS_EN);
+
+	if (wcd->hphl_jack_type_normally_open)
+		plug_type |= CDC_A_HPHL_PLUG_TYPE_NO;
+
+	if (wcd->gnd_jack_type_normally_open)
+		plug_type |= CDC_A_GND_PLUG_TYPE_NO;
+
+	snd_soc_write(codec, CDC_A_MBHC_DET_CTL_2,
+		      CDC_A_MBHC_DET_CTL_HS_L_DET_PULL_UP_CTRL_I_3P0 |
+		      CDC_A_MBHC_DET_CTL_HS_L_DET_COMPA_CTRL_V0P9_VDD |
+		      plug_type |
+		      CDC_A_MBHC_DET_CTL_HPHL_100K_TO_GND_EN);
+
+
+	snd_soc_write(codec, CDC_A_MBHC_DBNC_TIMER,
+		      CDC_A_MBHC_DBNC_TIMER_INSREM_DBNC_T_256_MS |
+		      CDC_A_MBHC_DBNC_TIMER_BTN_DBNC_T_16MS);
+
+	/* enable MBHC clock */
+	snd_soc_update_bits(codec, CDC_D_CDC_DIG_CLK_CTL,
+			    DIG_CLK_CTL_D_MBHC_CLK_EN_MASK,
+			    DIG_CLK_CTL_D_MBHC_CLK_EN);
+
+	int_en_mask = MBHC_SWITCH_INT;
+	if (wcd->mbhc_btn_enabled)
+		int_en_mask |= MBHC_BUTTON_PRESS_DET | MBHC_BUTTON_RELEASE_DET;
+
+	snd_soc_update_bits(codec, CDC_D_INT_EN_CLR, int_en_mask, 0);
+	snd_soc_update_bits(codec, CDC_D_INT_EN_SET, int_en_mask, int_en_mask);
+	wcd->mbhc_btn0_pressed = false;
+	wcd->detect_accessory_type = true;
+}
+
+static int pm8916_mbhc_configure_bias(struct pm8916_wcd_analog_priv *priv,
+				      bool micbias2_enabled)
+{
+	struct snd_soc_codec *codec = priv->codec;
+	u32 coarse, fine, reg_val, reg_addr;
+	int *vrefs, i;
+
+	if (!micbias2_enabled) { /* use internal 100uA Current source */
+		/* Enable internal 2.2k Internal Rbias Resistor */
+		snd_soc_update_bits(codec, CDC_A_MICB_1_INT_RBIAS,
+				    MICB_1_INT_TX2_INT_RBIAS_EN_MASK,
+				    MICB_1_INT_TX2_INT_RBIAS_EN_ENABLE);
+		/* Remove pull down on MIC BIAS2 */
+		snd_soc_update_bits(codec, CDC_A_MICB_2_EN,
+				   CDC_A_MICB_2_PULL_DOWN_EN_MASK,
+				   0);
+		/* enable 100uA internal current source */
+		snd_soc_update_bits(codec, CDC_A_MBHC_FSM_CTL,
+				    CDC_A_MBHC_FSM_CTL_BTN_ISRC_CTRL_MASK,
+				    CDC_A_MBHC_FSM_CTL_BTN_ISRC_CTRL_I_100UA);
+	}
+	snd_soc_update_bits(codec, CDC_A_MBHC_FSM_CTL,
+			CDC_A_MBHC_FSM_CTL_MBHC_FSM_EN_MASK,
+			CDC_A_MBHC_FSM_CTL_MBHC_FSM_EN);
+
+	if (micbias2_enabled)
+		vrefs = &priv->vref_btn_micb[0];
+	else
+		vrefs = &priv->vref_btn_cs[0];
+
+	/* program vref ranges for all the buttons */
+	reg_addr = CDC_A_MBHC_BTN0_ZDET_CTL_0;
+	for (i = 0; i <  MBHC_MAX_BUTTONS; i++) {
+		/* split mv in to coarse parts of 100mv & fine parts of 12mv */
+		coarse = (vrefs[i] / 100);
+		fine = ((vrefs[i] % 100) / 12);
+		reg_val = (coarse << CDC_A_MBHC_BTN_VREF_COARSE_SHIFT) |
+			 (fine << CDC_A_MBHC_BTN_VREF_FINE_SHIFT);
+		snd_soc_update_bits(codec, reg_addr,
+			       CDC_A_MBHC_BTN_VREF_MASK,
+			       reg_val);
+		reg_addr++;
+	}
+
+	return 0;
+}
+
 static int pm8916_wcd_analog_enable_micbias_int2(struct
 						  snd_soc_dapm_widget
 						  *w, struct snd_kcontrol
@@ -381,6 +542,15 @@ static int pm8916_wcd_analog_enable_micbias_int2(struct
 	struct snd_soc_codec *codec = snd_soc_dapm_to_codec(w->dapm);
 	struct pm8916_wcd_analog_priv *wcd = snd_soc_codec_get_drvdata(codec);
 
+	switch (event) {
+	case SND_SOC_DAPM_POST_PMU:
+		pm8916_mbhc_configure_bias(wcd, true);
+		break;
+	case SND_SOC_DAPM_POST_PMD:
+		pm8916_mbhc_configure_bias(wcd, false);
+		break;
+	}
+
 	return pm8916_wcd_analog_enable_micbias_int(codec, event, w->reg,
 						     wcd->micbias2_cap_mode);
 }
@@ -548,9 +718,14 @@ static int pm8916_wcd_analog_probe(struct snd_soc_codec *codec)
 		snd_soc_write(codec, wcd_reg_defaults_2_0[reg].reg,
 			      wcd_reg_defaults_2_0[reg].def);
 
+	priv->codec = codec;
+
 	snd_soc_update_bits(codec, CDC_D_CDC_RST_CTL,
 			    RST_CTL_DIG_SW_RST_N_MASK,
 			    RST_CTL_DIG_SW_RST_N_REMOVE_RESET);
+
+	pm8916_wcd_setup_mbhc(priv);
+
 	return 0;
 }
 
@@ -749,11 +924,130 @@ static const struct snd_soc_dapm_widget pm8916_wcd_analog_dapm_widgets[] = {
 	SND_SOC_DAPM_SUPPLY("A_MCLK2", CDC_D_CDC_TOP_CLK_CTL, 3, 0, NULL, 0),
 };
 
+static int pm8916_wcd_analog_set_jack(struct snd_soc_codec *codec,
+				      struct snd_soc_jack *jack,
+				      void *data)
+{
+	struct pm8916_wcd_analog_priv *wcd = snd_soc_codec_get_drvdata(codec);
+
+	wcd->jack = jack;
+
+	return 0;
+}
+
 static struct regmap *pm8916_get_regmap(struct device *dev)
 {
 	return dev_get_regmap(dev->parent, NULL);
 }
 
+static irqreturn_t mbhc_btn_release_irq_handler(int irq, void *arg)
+{
+	struct pm8916_wcd_analog_priv *priv = arg;
+
+	if (priv->detect_accessory_type) {
+		struct snd_soc_codec *codec = priv->codec;
+		u32 val = snd_soc_read(codec, CDC_A_MBHC_RESULT_1);
+
+		/* check if its BTN0 thats released */
+		if ((val >= 0) && !(val & CDC_A_MBHC_RESULT_1_BTN_RESULT_MASK))
+			priv->mbhc_btn0_pressed = false;
+
+	} else {
+		snd_soc_jack_report(priv->jack, 0, btn_mask);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mbhc_btn_press_irq_handler(int irq, void *arg)
+{
+	struct pm8916_wcd_analog_priv *priv = arg;
+	struct snd_soc_codec *codec = priv->codec;
+	u32 btn_result;
+
+	btn_result = snd_soc_read(codec, CDC_A_MBHC_RESULT_1) &
+				  CDC_A_MBHC_RESULT_1_BTN_RESULT_MASK;
+
+	switch (btn_result) {
+	case 0xf:
+		snd_soc_jack_report(priv->jack, SND_JACK_BTN_4, btn_mask);
+		break;
+	case 0x7:
+		snd_soc_jack_report(priv->jack, SND_JACK_BTN_3, btn_mask);
+		break;
+	case 0x3:
+		snd_soc_jack_report(priv->jack, SND_JACK_BTN_2, btn_mask);
+		break;
+	case 0x1:
+		snd_soc_jack_report(priv->jack, SND_JACK_BTN_1, btn_mask);
+		break;
+	case 0x0:
+		/* handle BTN_0 specially for type detection */
+		if (priv->detect_accessory_type)
+			priv->mbhc_btn0_pressed = true;
+		else
+			snd_soc_jack_report(priv->jack,
+					    SND_JACK_BTN_0, btn_mask);
+		break;
+	default:
+		dev_err(codec->dev,
+			"Unexpected button press result (%x)", btn_result);
+		break;
+	}
+
+	return IRQ_HANDLED;
+}
+
+
+static irqreturn_t pm8916_mbhc_switch_irq_handler(int irq, void *arg)
+{
+	struct pm8916_wcd_analog_priv *priv = arg;
+	struct snd_soc_codec *codec = priv->codec;
+	bool ins = false;
+
+	if (snd_soc_read(codec, CDC_A_MBHC_DET_CTL_1) &
+				CDC_A_MBHC_DET_CTL_MECH_DET_TYPE_MASK)
+		ins = true;
+
+	/* Set the detection type appropriately */
+	snd_soc_update_bits(codec, CDC_A_MBHC_DET_CTL_1,
+			    CDC_A_MBHC_DET_CTL_MECH_DET_TYPE_MASK,
+			    (!ins << CDC_A_MBHC_DET_CTL_MECH_DET_TYPE_SHIFT));
+
+
+	if (ins) { /* hs insertion */
+		bool micbias_enabled = false;
+
+		if (snd_soc_read(codec, CDC_A_MICB_2_EN) &
+				CDC_A_MICB_2_EN_ENABLE)
+			micbias_enabled = true;
+
+		pm8916_mbhc_configure_bias(priv, micbias_enabled);
+
+		/*
+		 * if only a btn0 press event is receive just before
+		 * insert event then its a 3 pole headphone else if
+		 * both press and release event received then its
+		 * a headset.
+		 */
+		if (priv->mbhc_btn0_pressed)
+			snd_soc_jack_report(priv->jack,
+					    SND_JACK_HEADPHONE, hs_jack_mask);
+		else
+			snd_soc_jack_report(priv->jack,
+					    SND_JACK_HEADSET, hs_jack_mask);
+
+		priv->detect_accessory_type = false;
+
+	} else { /* removal */
+		snd_soc_jack_report(priv->jack, 0, hs_jack_mask);
+		priv->detect_accessory_type = true;
+		priv->mbhc_btn0_pressed = false;
+	}
+
+	return IRQ_HANDLED;
+}
+
 static struct snd_soc_dai_driver pm8916_wcd_analog_dai[] = {
 	[0] = {
 	       .name = "pm8916_wcd_analog_pdm_rx",
@@ -782,6 +1076,7 @@ static struct snd_soc_dai_driver pm8916_wcd_analog_dai[] = {
 static const struct snd_soc_codec_driver pm8916_wcd_analog = {
 	.probe = pm8916_wcd_analog_probe,
 	.remove = pm8916_wcd_analog_remove,
+	.set_jack = pm8916_wcd_analog_set_jack,
 	.get_regmap = pm8916_get_regmap,
 	.component_driver = {
 		.controls = pm8916_wcd_analog_snd_controls,
@@ -796,6 +1091,7 @@ static const struct snd_soc_codec_driver pm8916_wcd_analog = {
 static int pm8916_wcd_analog_parse_dt(struct device *dev,
 				       struct pm8916_wcd_analog_priv *priv)
 {
+	int rval;
 
 	if (of_property_read_bool(dev->of_node, "qcom,micbias1-ext-cap"))
 		priv->micbias1_cap_mode = MICB_1_EN_EXT_BYP_CAP;
@@ -810,6 +1106,39 @@ static int pm8916_wcd_analog_parse_dt(struct device *dev,
 	of_property_read_u32(dev->of_node, "qcom,micbias-lvl",
 			     &priv->micbias_mv);
 
+	if (of_property_read_bool(dev->of_node,
+				  "qcom,hphl-jack-type-normally-open"))
+		priv->hphl_jack_type_normally_open = true;
+	else
+		priv->hphl_jack_type_normally_open = false;
+
+	if (of_property_read_bool(dev->of_node,
+				  "qcom,gnd-jack-type-normally-open"))
+		priv->gnd_jack_type_normally_open = true;
+	else
+		priv->gnd_jack_type_normally_open = false;
+
+	priv->mbhc_btn_enabled = true;
+	rval = of_property_read_u32_array(dev->of_node,
+					  "qcom,mbhc-vthreshold-low",
+					  &priv->vref_btn_cs[0],
+					  MBHC_MAX_BUTTONS);
+	if (rval < 0) {
+		priv->mbhc_btn_enabled = false;
+	} else {
+		rval = of_property_read_u32_array(dev->of_node,
+						  "qcom,mbhc-vthreshold-high",
+						  &priv->vref_btn_micb[0],
+						  MBHC_MAX_BUTTONS);
+		if (rval < 0)
+			priv->mbhc_btn_enabled = false;
+	}
+
+	if (!priv->mbhc_btn_enabled)
+		dev_err(dev,
+			"DT property missing, MBHC btn detection disabled\n");
+
+
 	return 0;
 }
 
@@ -817,7 +1146,7 @@ static int pm8916_wcd_analog_spmi_probe(struct platform_device *pdev)
 {
 	struct pm8916_wcd_analog_priv *priv;
 	struct device *dev = &pdev->dev;
-	int ret, i;
+	int ret, i, irq;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -849,6 +1178,48 @@ static int pm8916_wcd_analog_spmi_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	irq = platform_get_irq_byname(pdev, "mbhc_switch_int");
+	if (irq < 0) {
+		dev_err(dev, "failed to get mbhc switch irq\n");
+		return irq;
+	}
+
+	ret = devm_request_irq(dev, irq, pm8916_mbhc_switch_irq_handler,
+			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
+			       IRQF_ONESHOT,
+			       "mbhc switch irq", priv);
+	if (ret)
+		dev_err(dev, "cannot request mbhc switch irq\n");
+
+	if (priv->mbhc_btn_enabled) {
+		irq = platform_get_irq_byname(pdev, "mbhc_but_press_det");
+		if (irq < 0) {
+			dev_err(dev, "failed to get button press irq\n");
+			return irq;
+		}
+
+		ret = devm_request_irq(dev, irq, mbhc_btn_press_irq_handler,
+				       IRQF_TRIGGER_RISING |
+				       IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+				       "mbhc btn press irq", priv);
+		if (ret)
+			dev_err(dev, "cannot request mbhc button press irq\n");
+
+		irq = platform_get_irq_byname(pdev, "mbhc_but_rel_det");
+		if (irq < 0) {
+			dev_err(dev, "failed to get button release irq\n");
+			return irq;
+		}
+
+		ret = devm_request_irq(dev, irq, mbhc_btn_release_irq_handler,
+				       IRQF_TRIGGER_RISING |
+				       IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+				       "mbhc btn release irq", priv);
+		if (ret)
+			dev_err(dev, "cannot request mbhc button release irq\n");
+
+	}
+
 	dev_set_drvdata(dev, priv);
 
 	return snd_soc_register_codec(dev, &pm8916_wcd_analog,