[PATCH 03/11] iio: dac: ad5686: use devm_regulator_get_enable_read_voltage()

[David Lechner <dlechner@xxxxxxxxxxxx>]

Simplify the code by using devm_regulator_get_enable_read_voltage().

There is a small change in behavior. Before, all errors from
devm_regulator_get_optional() were ignored and assumed to mean that
the external reference supply was absent. Now, only -ENODEV is checked
and other errors will cause a failure to probe. So now, this will
catch errors, like using the wrong data type for the devicetree
property.

Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
---
 drivers/iio/dac/ad5686.c | 53 ++++++++++++++----------------------------------
 drivers/iio/dac/ad5686.h |  2 --
 2 files changed, 15 insertions(+), 40 deletions(-)

diff --git a/drivers/iio/dac/ad5686.c b/drivers/iio/dac/ad5686.c
index 57cc0f0eedc6..a8a38879fc40 100644
--- a/drivers/iio/dac/ad5686.c
+++ b/drivers/iio/dac/ad5686.c
@@ -455,8 +455,9 @@ int ad5686_probe(struct device *dev,
 	struct ad5686_state *st;
 	struct iio_dev *indio_dev;
 	unsigned int val, ref_bit_msk;
+	bool has_external_vref;
 	u8 cmd;
-	int ret, i, voltage_uv = 0;
+	int ret, i;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 	if (indio_dev == NULL)
@@ -469,25 +470,14 @@ int ad5686_probe(struct device *dev,
 	st->write = write;
 	st->read = read;
 
-	st->reg = devm_regulator_get_optional(dev, "vcc");
-	if (!IS_ERR(st->reg)) {
-		ret = regulator_enable(st->reg);
-		if (ret)
-			return ret;
-
-		ret = regulator_get_voltage(st->reg);
-		if (ret < 0)
-			goto error_disable_reg;
-
-		voltage_uv = ret;
-	}
-
 	st->chip_info = &ad5686_chip_info_tbl[chip_type];
 
-	if (voltage_uv)
-		st->vref_mv = voltage_uv / 1000;
-	else
-		st->vref_mv = st->chip_info->int_vref_mv;
+	ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
+	if (ret < 0 && ret != -ENODEV)
+		return ret;
+
+	has_external_vref = ret != -ENODEV;
+	st->vref_mv = has_external_vref ? ret / 1000 : st->chip_info->int_vref_mv;
 
 	/* Set all the power down mode for all channels to 1K pulldown */
 	for (i = 0; i < st->chip_info->num_channels; i++)
@@ -505,12 +495,12 @@ int ad5686_probe(struct device *dev,
 	case AD5310_REGMAP:
 		cmd = AD5686_CMD_CONTROL_REG;
 		ref_bit_msk = AD5310_REF_BIT_MSK;
-		st->use_internal_vref = !voltage_uv;
+		st->use_internal_vref = !has_external_vref;
 		break;
 	case AD5683_REGMAP:
 		cmd = AD5686_CMD_CONTROL_REG;
 		ref_bit_msk = AD5683_REF_BIT_MSK;
-		st->use_internal_vref = !voltage_uv;
+		st->use_internal_vref = !has_external_vref;
 		break;
 	case AD5686_REGMAP:
 		cmd = AD5686_CMD_INTERNAL_REFER_SETUP;
@@ -519,40 +509,27 @@ int ad5686_probe(struct device *dev,
 	case AD5693_REGMAP:
 		cmd = AD5686_CMD_CONTROL_REG;
 		ref_bit_msk = AD5693_REF_BIT_MSK;
-		st->use_internal_vref = !voltage_uv;
+		st->use_internal_vref = !has_external_vref;
 		break;
 	default:
-		ret = -EINVAL;
-		goto error_disable_reg;
+		return -EINVAL;
 	}
 
-	val = (voltage_uv | ref_bit_msk);
+	val = (has_external_vref | ref_bit_msk);
 
 	ret = st->write(st, cmd, 0, !!val);
 	if (ret)
-		goto error_disable_reg;
-
-	ret = iio_device_register(indio_dev);
-	if (ret)
-		goto error_disable_reg;
-
-	return 0;
+		return ret;
 
-error_disable_reg:
-	if (!IS_ERR(st->reg))
-		regulator_disable(st->reg);
-	return ret;
+	return iio_device_register(indio_dev);
 }
 EXPORT_SYMBOL_NS_GPL(ad5686_probe, IIO_AD5686);
 
 void ad5686_remove(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
-	struct ad5686_state *st = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
-	if (!IS_ERR(st->reg))
-		regulator_disable(st->reg);
 }
 EXPORT_SYMBOL_NS_GPL(ad5686_remove, IIO_AD5686);
 
diff --git a/drivers/iio/dac/ad5686.h b/drivers/iio/dac/ad5686.h
index 5b150f344fda..62eb309711af 100644
--- a/drivers/iio/dac/ad5686.h
+++ b/drivers/iio/dac/ad5686.h
@@ -118,7 +118,6 @@ struct ad5686_chip_info {
  * struct ad5686_state - driver instance specific data
  * @spi:		spi_device
  * @chip_info:		chip model specific constants, available modes etc
- * @reg:		supply regulator
  * @vref_mv:		actual reference voltage used
  * @pwr_down_mask:	power down mask
  * @pwr_down_mode:	current power down mode
@@ -130,7 +129,6 @@ struct ad5686_chip_info {
 struct ad5686_state {
 	struct device			*dev;
 	const struct ad5686_chip_info	*chip_info;
-	struct regulator		*reg;
 	unsigned short			vref_mv;
 	unsigned int			pwr_down_mask;
 	unsigned int			pwr_down_mode;

-- 
2.43.0