[PATCH v2 5/7] iio: tsl2772: add support for regulator framework

[Brian Masney <masneyb@onstation.org>]

This patch adds support for the regulator framework to the tsl2772
driver. Driver was tested using a LG Nexus 5 (hammerhead) phone with
the two regulators and on a Raspberry Pi 2 without any regulators
controlling the power to the sensor.

Signed-off-by: Brian Masney <masneyb@onstation.org>
---
 .../devicetree/bindings/iio/light/tsl2772.txt |  4 +
 drivers/iio/light/tsl2772.c                   | 82 ++++++++++++++++++-
 2 files changed, 85 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/iio/light/tsl2772.txt b/Documentation/devicetree/bindings/iio/light/tsl2772.txt
index ab553d52b9fc..bfde8b2c8790 100644
--- a/Documentation/devicetree/bindings/iio/light/tsl2772.txt
+++ b/Documentation/devicetree/bindings/iio/light/tsl2772.txt
@@ -21,6 +21,8 @@ Optional properties:
                          TSL2772_DIODE_BOTH.
   - amstaos,prox_power - must be TSL2772_100_mA, TSL2772_50_mA, TSL2772_25_mA,
                          or TSL2772_13_mA.
+  - vdd-supply: phandle to the regulator that provides power to the sensor.
+  - vddio-supply: phandle to the regulator that provides power to the bus.
   - interrupt-parent: should be the phandle for the interrupt controller
   - interrupts: the sole interrupt generated by the device
 
@@ -35,5 +37,7 @@ tsl2772@39 {
 	compatible = "amstaos,tsl2772";
 	reg = <0x39>;
 	interrupts-extended = <&msmgpio 61 IRQ_TYPE_EDGE_FALLING>;
+	vdd-supply = <&pm8941_l17>;
+	vddio-supply = <&pm8941_lvs1>;
 	amstaos,prox_diode = <TSL2772_DIODE0>;
 };
diff --git a/drivers/iio/light/tsl2772.c b/drivers/iio/light/tsl2772.c
index 0be57f2ecb02..f6a27f8b3ca7 100644
--- a/drivers/iio/light/tsl2772.c
+++ b/drivers/iio/light/tsl2772.c
@@ -20,6 +20,7 @@
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/platform_data/tsl2772.h>
+#include <linux/regulator/consumer.h>
 
 /* Cal defs */
 #define PROX_STAT_CAL			0
@@ -146,6 +147,9 @@ struct tsl2772_chip {
 	struct mutex prox_mutex;
 	struct mutex als_mutex;
 	struct i2c_client *client;
+	struct regulator *vdd_supply;
+	struct regulator *vddio_supply;
+	bool regulators_enabled;
 	u16 prox_data;
 	struct tsl2772_als_info als_cur_info;
 	struct tsl2772_settings settings;
@@ -609,6 +613,46 @@ static int tsl2772_als_calibrate(struct iio_dev *indio_dev)
 	return ret;
 }
 
+static int tsl2772_enable_regulators(struct tsl2772_chip *chip)
+{
+	int ret;
+
+	ret = regulator_enable(chip->vddio_supply);
+	if (ret < 0) {
+		dev_err(&chip->client->dev, "Failed to enable regulator: %d\n",
+			ret);
+		return ret;
+	}
+
+	ret = regulator_enable(chip->vdd_supply);
+	if (ret < 0) {
+		regulator_disable(chip->vddio_supply);
+		dev_err(&chip->client->dev, "Failed to enable regulator: %d\n",
+			ret);
+		return ret;
+	}
+
+	chip->regulators_enabled = true;
+
+	return 0;
+}
+
+static void tsl2772_disable_regulators(struct tsl2772_chip *chip)
+{
+	if (!chip->regulators_enabled)
+		return;
+
+	regulator_disable(chip->vdd_supply);
+	regulator_disable(chip->vddio_supply);
+
+	chip->regulators_enabled = false;
+}
+
+static void tsl2772_disable_regulators_action(void *_data)
+{
+	tsl2772_disable_regulators(_data);
+}
+
 static int tsl2772_chip_on(struct iio_dev *indio_dev)
 {
 	struct tsl2772_chip *chip = iio_priv(indio_dev);
@@ -666,6 +710,10 @@ static int tsl2772_chip_on(struct iio_dev *indio_dev)
 	chip->als_gain_time_scale = als_time_us *
 		tsl2772_als_gain[chip->settings.als_gain];
 
+	ret = tsl2772_enable_regulators(chip);
+	if (ret < 0)
+		return ret;
+
 	/*
 	 * TSL2772 Specific power-on / adc enable sequence
 	 * Power on the device 1st.
@@ -724,10 +772,13 @@ static int tsl2772_chip_on(struct iio_dev *indio_dev)
 static int tsl2772_chip_off(struct iio_dev *indio_dev)
 {
 	struct tsl2772_chip *chip = iio_priv(indio_dev);
+	int ret;
 
 	/* turn device off */
 	chip->tsl2772_chip_status = TSL2772_CHIP_SUSPENDED;
-	return tsl2772_write_control_reg(chip, 0x00);
+	ret = tsl2772_write_control_reg(chip, 0x00);
+	tsl2772_disable_regulators(chip);
+	return ret;
 }
 
 /**
@@ -1666,6 +1717,35 @@ static int tsl2772_probe(struct i2c_client *clientp,
 	chip->client = clientp;
 	i2c_set_clientdata(clientp, indio_dev);
 
+	chip->vddio_supply = devm_regulator_get(&clientp->dev, "vddio");
+	if (IS_ERR(chip->vddio_supply)) {
+		if (PTR_ERR(chip->vddio_supply) != -EPROBE_DEFER)
+			dev_err(&clientp->dev,
+				"Failed to get vddio regulator %d\n",
+				(int)PTR_ERR(chip->vddio_supply));
+
+		return PTR_ERR(chip->vddio_supply);
+	}
+
+	chip->vdd_supply = devm_regulator_get(&clientp->dev, "vdd");
+	if (IS_ERR(chip->vdd_supply)) {
+		if (PTR_ERR(chip->vdd_supply) != -EPROBE_DEFER)
+			dev_err(&clientp->dev,
+				"Failed to get vdd regulator %d\n",
+				(int)PTR_ERR(chip->vdd_supply));
+
+		return PTR_ERR(chip->vdd_supply);
+	}
+
+	ret = devm_add_action(&clientp->dev, tsl2772_disable_regulators_action,
+			      chip);
+	if (ret < 0) {
+		tsl2772_disable_regulators_action(chip);
+		dev_err(&clientp->dev, "Failed to setup regulator cleanup action %d\n",
+			ret);
+		return ret;
+	}
+
 	ret = i2c_smbus_read_byte_data(chip->client,
 				       TSL2772_CMD_REG | TSL2772_CHIPID);
 	if (ret < 0)
-- 
2.17.1