iio: adc: berlin2-adc: convert probe to device-managed only

This driver requires only a devm_add_action_or_reset() hook for the
power-down of the device, and then devm_iio_device_register() can be used
directly.
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210926192642.4051329-1-aardelean@deviqon.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/berlin2-adc.c

@@ -280,6 +280,13 @@ static const struct iio_info berlin2_adc_info = {
 	.read_raw	= berlin2_adc_read_raw,
 };
 
+static void berlin2_adc_powerdown(void *regmap)
+{
+	regmap_update_bits(regmap, BERLIN2_SM_CTRL,
+			   BERLIN2_SM_CTRL_ADC_POWER, 0);
+
+}
+
 static int berlin2_adc_probe(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev;
@@ -293,7 +300,6 @@ static int berlin2_adc_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	priv = iio_priv(indio_dev);
-	platform_set_drvdata(pdev, indio_dev);
 
 	priv->regmap = syscon_node_to_regmap(parent_np);
 	of_node_put(parent_np);
@@ -333,29 +339,12 @@ static int berlin2_adc_probe(struct platform_device *pdev)
 			   BERLIN2_SM_CTRL_ADC_POWER,
 			   BERLIN2_SM_CTRL_ADC_POWER);
 
-	ret = iio_device_register(indio_dev);
-	if (ret) {
-		/* Power down the ADC */
-		regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
-				   BERLIN2_SM_CTRL_ADC_POWER, 0);
+	ret = devm_add_action_or_reset(&pdev->dev, berlin2_adc_powerdown,
+				       priv->regmap);
+	if (ret)
 		return ret;
-	}
-
-	return 0;
-}
-
-static int berlin2_adc_remove(struct platform_device *pdev)
-{
-	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
-	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-
-	/* Power down the ADC */
-	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
-			   BERLIN2_SM_CTRL_ADC_POWER, 0);
 
-	return 0;
+	return devm_iio_device_register(&pdev->dev, indio_dev);
 }
 
 static const struct of_device_id berlin2_adc_match[] = {
@@ -370,7 +359,6 @@ static struct platform_driver berlin2_adc_driver = {
 		.of_match_table	= berlin2_adc_match,
 	},
 	.probe	= berlin2_adc_probe,
-	.remove	= berlin2_adc_remove,
 };
 module_platform_driver(berlin2_adc_driver);