regulator: arizona-micsupp: Enable SYSCLK for charge pump

If we are in non-bypass mode then the SYSCLK is required for full charge
pump operation, otherwise we will fall back to bypass mode. Use the DAPM
context exposed by the ASoC driver to manage this.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/regulator/Kconfig

@@ -91,6 +91,7 @@ config REGULATOR_AAT2870
 config REGULATOR_ARIZONA
 	tristate "Wolfson Arizona class devices"
 	depends on MFD_ARIZONA
+	depends on SND_SOC
 	help
 	  Support for the regulators found on Wolfson Arizona class
 	  devices.

drivers/regulator/arizona-micsupp.c

@@ -21,6 +21,8 @@
 #include <linux/regulator/machine.h>
 #include <linux/gpio.h>
 #include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <sound/soc.h>
 
 #include <linux/mfd/arizona/core.h>
 #include <linux/mfd/arizona/pdata.h>
@@ -34,6 +36,8 @@ struct arizona_micsupp {
 
 	struct regulator_consumer_supply supply;
 	struct regulator_init_data init_data;
+
+	struct work_struct check_cp_work;
 };
 
 static int arizona_micsupp_list_voltage(struct regulator_dev *rdev,
@@ -72,9 +76,73 @@ static int arizona_micsupp_map_voltage(struct regulator_dev *rdev,
 	return selector;
 }
 
+static void arizona_micsupp_check_cp(struct work_struct *work)
+{
+	struct arizona_micsupp *micsupp =
+		container_of(work, struct arizona_micsupp, check_cp_work);
+	struct snd_soc_dapm_context *dapm = micsupp->arizona->dapm;
+	struct arizona *arizona = micsupp->arizona;
+	struct regmap *regmap = arizona->regmap;
+	unsigned int reg;
+	int ret;
+
+	ret = regmap_read(regmap, ARIZONA_MIC_CHARGE_PUMP_1, &reg);
+	if (ret != 0) {
+		dev_err(arizona->dev, "Failed to read CP state: %d\n", ret);
+		return;
+	}
+
+	if (dapm) {
+		if ((reg & (ARIZONA_CPMIC_ENA | ARIZONA_CPMIC_BYPASS)) ==
+		    ARIZONA_CPMIC_ENA)
+			snd_soc_dapm_force_enable_pin(dapm, "MICSUPP");
+		else
+			snd_soc_dapm_disable_pin(dapm, "MICSUPP");
+
+		snd_soc_dapm_sync(dapm);
+	}
+}
+
+static int arizona_micsupp_enable(struct regulator_dev *rdev)
+{
+	struct arizona_micsupp *micsupp = rdev_get_drvdata(rdev);
+	int ret;
+
+	ret = regulator_enable_regmap(rdev);
+
+	if (ret == 0)
+		schedule_work(&micsupp->check_cp_work);
+
+	return ret;
+}
+
+static int arizona_micsupp_disable(struct regulator_dev *rdev)
+{
+	struct arizona_micsupp *micsupp = rdev_get_drvdata(rdev);
+	int ret;
+
+	ret = regulator_disable_regmap(rdev);
+	if (ret == 0)
+		schedule_work(&micsupp->check_cp_work);
+
+	return ret;
+}
+
+static int arizona_micsupp_set_bypass(struct regulator_dev *rdev, bool ena)
+{
+	struct arizona_micsupp *micsupp = rdev_get_drvdata(rdev);
+	int ret;
+
+	ret = regulator_set_bypass_regmap(rdev, ena);
+	if (ret == 0)
+		schedule_work(&micsupp->check_cp_work);
+
+	return ret;
+}
+
 static struct regulator_ops arizona_micsupp_ops = {
-	.enable = regulator_enable_regmap,
-	.disable = regulator_disable_regmap,
+	.enable = arizona_micsupp_enable,
+	.disable = arizona_micsupp_disable,
 	.is_enabled = regulator_is_enabled_regmap,
 
 	.list_voltage = arizona_micsupp_list_voltage,
@@ -84,7 +152,7 @@ static struct regulator_ops arizona_micsupp_ops = {
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 
 	.get_bypass = regulator_get_bypass_regmap,
-	.set_bypass = regulator_set_bypass_regmap,
+	.set_bypass = arizona_micsupp_set_bypass,
 };
 
 static const struct regulator_desc arizona_micsupp = {
@@ -131,6 +199,7 @@ static int arizona_micsupp_probe(struct platform_device *pdev)
 	}
 
 	micsupp->arizona = arizona;
+	INIT_WORK(&micsupp->check_cp_work, arizona_micsupp_check_cp);
 
 	/*
 	 * Since the chip usually supplies itself we provide some