extcon: arizona: Use regulated mode for microphone supply when detecting

When starting microphone detection some headsets should be exposed to
the fully regulated microphone bias in order to ensure that they behave
in an optimal fashion.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/extcon/Kconfig

@@ -47,7 +47,7 @@ config EXTCON_MAX8997
 
 config EXTCON_ARIZONA
 	tristate "Wolfson Arizona EXTCON support"
-	depends on MFD_ARIZONA && INPUT
+	depends on MFD_ARIZONA && INPUT && SND_SOC
 	help
 	  Say Y here to enable support for external accessory detection
 	  with Wolfson Arizona devices. These are audio CODECs with

drivers/extcon/extcon-arizona.c

@@ -27,6 +27,8 @@
 #include <linux/regulator/consumer.h>
 #include <linux/extcon.h>
 
+#include <sound/soc.h>
+
 #include <linux/mfd/arizona/core.h>
 #include <linux/mfd/arizona/pdata.h>
 #include <linux/mfd/arizona/registers.h>
@@ -113,6 +115,52 @@ static void arizona_extcon_set_mode(struct arizona_extcon_info *info, int mode)
 	dev_dbg(arizona->dev, "Set jack polarity to %d\n", mode);
 }
 
+static const char *arizona_extcon_get_micbias(struct arizona_extcon_info *info)
+{
+	switch (info->micd_modes[0].bias >> ARIZONA_MICD_BIAS_SRC_SHIFT) {
+	case 1:
+		return "MICBIAS1";
+	case 2:
+		return "MICBIAS2";
+	case 3:
+		return "MICBIAS3";
+	default:
+		return "MICVDD";
+	}
+}
+
+static void arizona_extcon_pulse_micbias(struct arizona_extcon_info *info)
+{
+	struct arizona *arizona = info->arizona;
+	const char *widget = arizona_extcon_get_micbias(info);
+	struct snd_soc_dapm_context *dapm = arizona->dapm;
+	int ret;
+
+	mutex_lock(&dapm->card->dapm_mutex);
+
+	ret = snd_soc_dapm_force_enable_pin(dapm, widget);
+	if (ret != 0)
+		dev_warn(arizona->dev, "Failed to enable %s: %d\n",
+			 widget, ret);
+
+	mutex_unlock(&dapm->card->dapm_mutex);
+
+	snd_soc_dapm_sync(dapm);
+
+	if (!arizona->pdata.micd_force_micbias) {
+		mutex_lock(&dapm->card->dapm_mutex);
+
+		ret = snd_soc_dapm_disable_pin(arizona->dapm, widget);
+		if (ret != 0)
+			dev_warn(arizona->dev, "Failed to disable %s: %d\n",
+				 widget, ret);
+
+		mutex_unlock(&dapm->card->dapm_mutex);
+
+		snd_soc_dapm_sync(dapm);
+	}
+}
+
 static void arizona_start_mic(struct arizona_extcon_info *info)
 {
 	struct arizona *arizona = info->arizona;
@@ -122,6 +170,15 @@ static void arizona_start_mic(struct arizona_extcon_info *info)
 	/* Microphone detection can't use idle mode */
 	pm_runtime_get(info->dev);
 
+	if (info->detecting) {
+		ret = regulator_allow_bypass(info->micvdd, false);
+		if (ret != 0) {
+			dev_err(arizona->dev,
+				"Failed to regulate MICVDD: %d\n",
+				ret);
+		}
+	}
+
 	ret = regulator_enable(info->micvdd);
 	if (ret != 0) {
 		dev_err(arizona->dev, "Failed to enable MICVDD: %d\n",
@@ -138,6 +195,8 @@ static void arizona_start_mic(struct arizona_extcon_info *info)
 			   ARIZONA_ACCESSORY_DETECT_MODE_1,
 			   ARIZONA_ACCDET_MODE_MASK, ARIZONA_ACCDET_MODE_MIC);
 
+	arizona_extcon_pulse_micbias(info);
+
 	regmap_update_bits_check(arizona->regmap, ARIZONA_MIC_DETECT_1,
 				 ARIZONA_MICD_ENA, ARIZONA_MICD_ENA,
 				 &change);
@@ -150,18 +209,39 @@ static void arizona_start_mic(struct arizona_extcon_info *info)
 static void arizona_stop_mic(struct arizona_extcon_info *info)
 {
 	struct arizona *arizona = info->arizona;
+	const char *widget = arizona_extcon_get_micbias(info);
+	struct snd_soc_dapm_context *dapm = arizona->dapm;
 	bool change;
+	int ret;
 
 	regmap_update_bits_check(arizona->regmap, ARIZONA_MIC_DETECT_1,
 				 ARIZONA_MICD_ENA, 0,
 				 &change);
 
+	mutex_lock(&dapm->card->dapm_mutex);
+
+	ret = snd_soc_dapm_disable_pin(dapm, widget);
+	if (ret != 0)
+		dev_warn(arizona->dev,
+			 "Failed to disable %s: %d\n",
+			 widget, ret);
+
+	mutex_unlock(&dapm->card->dapm_mutex);
+
+	snd_soc_dapm_sync(dapm);
+
 	if (info->micd_reva) {
 		regmap_write(arizona->regmap, 0x80, 0x3);
 		regmap_write(arizona->regmap, 0x294, 2);
 		regmap_write(arizona->regmap, 0x80, 0x0);
 	}
 
+	ret = regulator_allow_bypass(info->micvdd, true);
+	if (ret != 0) {
+		dev_err(arizona->dev, "Failed to bypass MICVDD: %d\n",
+			ret);
+	}
+
 	if (change) {
 		regulator_disable(info->micvdd);
 		pm_runtime_mark_last_busy(info->dev);
@@ -564,6 +644,8 @@ static void arizona_start_hpdet_acc_id(struct arizona_extcon_info *info)
 
 	info->hpdet_active = true;
 
+	arizona_extcon_pulse_micbias(info);
+
 	ret = regmap_update_bits(arizona->regmap, 0x225, 0x4000, 0x4000);
 	if (ret != 0)
 		dev_warn(arizona->dev, "Failed to do magic: %d\n", ret);
@@ -649,6 +731,13 @@ static irqreturn_t arizona_micdet(int irq, void *data)
 			dev_err(arizona->dev, "Headset report failed: %d\n",
 				ret);
 
+		/* Don't need to regulate for button detection */
+		ret = regulator_allow_bypass(info->micvdd, false);
+		if (ret != 0) {
+			dev_err(arizona->dev, "Failed to bypass MICVDD: %d\n",
+				ret);
+		}
+
 		info->mic = true;
 		info->detecting = false;
 		goto handled;
@@ -716,6 +805,7 @@ static irqreturn_t arizona_micdet(int irq, void *data)
 			input_report_key(info->input,
 					 arizona_lvl_to_key[i].report, 0);
 		input_sync(info->input);
+		arizona_extcon_pulse_micbias(info);
 	}
 
 handled:
@@ -817,6 +907,9 @@ static int arizona_extcon_probe(struct platform_device *pdev)
 	int jack_irq_fall, jack_irq_rise;
 	int ret, mode, i;
 
+	if (!arizona->dapm || !arizona->dapm->card)
+		return -EPROBE_DEFER;
+
 	pdata = dev_get_platdata(arizona->dev);
 
 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);

include/linux/mfd/arizona/pdata.h

@@ -117,6 +117,9 @@ struct arizona_pdata {
 	/** Mic detect debounce level */
 	int micd_dbtime;
 
+	/** Force MICBIAS on for mic detect */
+	bool micd_force_micbias;
+
 	/** Headset polarity configurations */
 	struct arizona_micd_config *micd_configs;
 	int num_micd_configs;