staging: iio: adc: ad7606: Use devm functions in probe

Switch to devm version of request_irq, iio_triggered_buffer_setup,
iio_device_register. To avoid potential ordering issues in probe,
devm_add_action_or_reset() is used for the regulator_disable(). This
simplifies the code and decreases the chance of bugs.
Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/staging/iio/adc/ad7606.c

@@ -418,6 +418,13 @@ static const struct iio_info ad7606_info_range = {
 	.attrs = &ad7606_attribute_group_range,
 };
 
+static void ad7606_regulator_disable(void *data)
+{
+	struct ad7606_state *st = data;
+
+	regulator_disable(st->reg);
+}
+
 int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 		 const char *name, unsigned int id,
 		 const struct ad7606_bus_ops *bops)
@@ -431,6 +438,7 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 		return -ENOMEM;
 
 	st = iio_priv(indio_dev);
+	dev_set_drvdata(dev, indio_dev);
 
 	st->dev = dev;
 	mutex_init(&st->lock);
@@ -451,11 +459,15 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 		return ret;
 	}
 
+	ret = devm_add_action_or_reset(dev, ad7606_regulator_disable, st);
+	if (ret)
+		return ret;
+
 	st->chip_info = &ad7606_chip_info_tbl[id];
 
 	ret = ad7606_request_gpios(st);
 	if (ret)
-		goto error_disable_reg;
+		return ret;
 
 	indio_dev->dev.parent = dev;
 	if (st->gpio_os) {
@@ -480,50 +492,21 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 	if (ret)
 		dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
 
-	ret = request_irq(irq, ad7606_interrupt, IRQF_TRIGGER_FALLING, name,
-			  indio_dev);
-	if (ret)
-		goto error_disable_reg;
-
-	ret = iio_triggered_buffer_setup(indio_dev, &ad7606_trigger_handler,
-					 NULL, NULL);
+	ret = devm_request_irq(dev, irq, ad7606_interrupt, IRQF_TRIGGER_FALLING,
+			       name, indio_dev);
 	if (ret)
-		goto error_free_irq;
+		return ret;
 
-	ret = iio_device_register(indio_dev);
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+					      &ad7606_trigger_handler,
+					      NULL, NULL);
 	if (ret)
-		goto error_unregister_ring;
-
-	dev_set_drvdata(dev, indio_dev);
-
-	return 0;
-error_unregister_ring:
-	iio_triggered_buffer_cleanup(indio_dev);
-
-error_free_irq:
-	free_irq(irq, indio_dev);
+		return ret;
 
-error_disable_reg:
-	regulator_disable(st->reg);
-	return ret;
+	return devm_iio_device_register(dev, indio_dev);
 }
 EXPORT_SYMBOL_GPL(ad7606_probe);
 
-int ad7606_remove(struct device *dev, int irq)
-{
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
-	struct ad7606_state *st = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-	iio_triggered_buffer_cleanup(indio_dev);
-
-	free_irq(irq, indio_dev);
-	regulator_disable(st->reg);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(ad7606_remove);
-
 #ifdef CONFIG_PM_SLEEP
 
 static int ad7606_suspend(struct device *dev)

drivers/staging/iio/adc/ad7606.h

@@ -85,7 +85,6 @@ struct ad7606_bus_ops {
 int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 		 const char *name, unsigned int id,
 		 const struct ad7606_bus_ops *bops);
-int ad7606_remove(struct device *dev, int irq);
 
 enum ad7606_supported_device_ids {
 	ID_AD7605_4,

drivers/staging/iio/adc/ad7606_par.c

@@ -72,11 +72,6 @@ static int ad7606_par_probe(struct platform_device *pdev)
 			    &ad7606_par8_bops);
 }
 
-static int ad7606_par_remove(struct platform_device *pdev)
-{
-	return ad7606_remove(&pdev->dev, platform_get_irq(pdev, 0));
-}
-
 static const struct platform_device_id ad7606_driver_ids[] = {
 	{
 		.name		= "ad7605-4",
@@ -98,7 +93,6 @@ MODULE_DEVICE_TABLE(platform, ad7606_driver_ids);
 
 static struct platform_driver ad7606_driver = {
 	.probe = ad7606_par_probe,
-	.remove	= ad7606_par_remove,
 	.id_table = ad7606_driver_ids,
 	.driver = {
 		.name	 = "ad7606",

drivers/staging/iio/adc/ad7606_spi.c

@@ -49,11 +49,6 @@ static int ad7606_spi_probe(struct spi_device *spi)
 			    &ad7606_spi_bops);
 }
 
-static int ad7606_spi_remove(struct spi_device *spi)
-{
-	return ad7606_remove(&spi->dev, spi->irq);
-}
-
 static const struct spi_device_id ad7606_id[] = {
 	{"ad7605-4", ID_AD7605_4},
 	{"ad7606-8", ID_AD7606_8},
@@ -69,7 +64,6 @@ static struct spi_driver ad7606_driver = {
 		.pm = AD7606_PM_OPS,
 	},
 	.probe = ad7606_spi_probe,
-	.remove = ad7606_spi_remove,
 	.id_table = ad7606_id,
 };
 module_spi_driver(ad7606_driver);