Simplify the code by using devm_regulator_get_enable_read_voltage().

Also simplify == NULL check while we are touching that line.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/iio/dac/ad5446.c | 57 ++++++++++++++----------------------------------
 1 file changed, 16 insertions(+), 41 deletions(-)

diff --git a/drivers/iio/dac/ad5446.c b/drivers/iio/dac/ad5446.c
index 708629efc157..574de97c1c08 100644
--- a/drivers/iio/dac/ad5446.c
+++ b/drivers/iio/dac/ad5446.c
@@ -32,7 +32,6 @@
  * struct ad5446_state - driver instance specific data
  * @dev:		this device
  * @chip_info:		chip model specific constants, available modes etc
- * @reg:		supply regulator
  * @vref_mv:		actual reference voltage used
  * @cached_val:		store/retrieve values during power down
  * @pwr_down_mode:	power down mode (1k, 100k or tristate)
@@ -43,7 +42,6 @@
 struct ad5446_state {
 	struct device		*dev;
 	const struct ad5446_chip_info	*chip_info;
-	struct regulator		*reg;
 	unsigned short			vref_mv;
 	unsigned			cached_val;
 	unsigned			pwr_down_mode;
@@ -226,32 +224,16 @@ static int ad5446_probe(struct device *dev, const char *name,
 {
 	struct ad5446_state *st;
 	struct iio_dev *indio_dev;
-	struct regulator *reg;
-	int ret, voltage_uv = 0;
-
-	reg = devm_regulator_get(dev, "vcc");
-	if (!IS_ERR(reg)) {
-		ret = regulator_enable(reg);
-		if (ret)
-			return ret;
-
-		ret = regulator_get_voltage(reg);
-		if (ret < 0)
-			goto error_disable_reg;
-
-		voltage_uv = ret;
-	}
+	int ret;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
-	if (indio_dev == NULL) {
-		ret = -ENOMEM;
-		goto error_disable_reg;
-	}
+	if (!indio_dev)
+		return -ENOMEM;
+
 	st = iio_priv(indio_dev);
 	st->chip_info = chip_info;
 
 	dev_set_drvdata(dev, indio_dev);
-	st->reg = reg;
 	st->dev = dev;
 
 	indio_dev->name = name;
@@ -264,33 +246,26 @@ static int ad5446_probe(struct device *dev, const char *name,
 
 	st->pwr_down_mode = MODE_PWRDWN_1k;
 
-	if (st->chip_info->int_vref_mv)
-		st->vref_mv = st->chip_info->int_vref_mv;
-	else if (voltage_uv)
-		st->vref_mv = voltage_uv / 1000;
-	else
-		dev_warn(dev, "reference voltage unspecified\n");
-
-	ret = iio_device_register(indio_dev);
-	if (ret)
-		goto error_disable_reg;
-
-	return 0;
+	ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
+	if (ret < 0 && ret != -ENODEV)
+		return ret;
+	if (ret == -ENODEV) {
+		if (chip_info->int_vref_mv)
+			st->vref_mv = chip_info->int_vref_mv;
+		else
+			dev_warn(dev, "reference voltage unspecified\n");
+	} else {
+		st->vref_mv = ret / 1000;
+	}
 
-error_disable_reg:
-	if (!IS_ERR(reg))
-		regulator_disable(reg);
-	return ret;
+	return iio_device_register(indio_dev);
 }
 
 static void ad5446_remove(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
-	struct ad5446_state *st = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
-	if (!IS_ERR(st->reg))
-		regulator_disable(st->reg);
 }
 
 #if IS_ENABLED(CONFIG_SPI_MASTER)

-- 
2.43.0