iio: adc: adc128s052: Simplify adc128_probe()

Turn 'adc128_probe()' into a full resource managed function to simplify the
code.

This way, the .remove function can be removed.
Doing so, the only 'spi_get_drvdata()' call is removed and the
corresponding 'spi_set_drvdata()' can be removed as well.

Suggested-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/4fa7fcc59c40e27af0569138d656c698a53dbd44.1630002770.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ti-adc128s052.c

@@ -132,6 +132,11 @@ static const struct iio_info adc128_info = {
 	.read_raw = adc128_read_raw,
 };
 
+static void adc128_disable_regulator(void *reg)
+{
+	regulator_disable(reg);
+}
+
 static int adc128_probe(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev;
@@ -151,8 +156,6 @@ static int adc128_probe(struct spi_device *spi)
 	adc = iio_priv(indio_dev);
 	adc->spi = spi;
 
-	spi_set_drvdata(spi, indio_dev);
-
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &adc128_info;
@@ -167,29 +170,14 @@ static int adc128_probe(struct spi_device *spi)
 	ret = regulator_enable(adc->reg);
 	if (ret < 0)
 		return ret;
-
-	mutex_init(&adc->lock);
-
-	ret = iio_device_register(indio_dev);
+	ret = devm_add_action_or_reset(&spi->dev, adc128_disable_regulator,
+				       adc->reg);
 	if (ret)
-		goto err_disable_regulator;
-
-	return 0;
-
-err_disable_regulator:
-	regulator_disable(adc->reg);
-	return ret;
-}
-
-static int adc128_remove(struct spi_device *spi)
-{
-	struct iio_dev *indio_dev = spi_get_drvdata(spi);
-	struct adc128 *adc = iio_priv(indio_dev);
+		return ret;
 
-	iio_device_unregister(indio_dev);
-	regulator_disable(adc->reg);
+	mutex_init(&adc->lock);
 
-	return 0;
+	return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
 static const struct of_device_id adc128_of_match[] = {
@@ -231,7 +219,6 @@ static struct spi_driver adc128_driver = {
 		.acpi_match_table = ACPI_PTR(adc128_acpi_match),
 	},
 	.probe = adc128_probe,
-	.remove = adc128_remove,
 	.id_table = adc128_id,
 };
 module_spi_driver(adc128_driver);