staging:iio:ad7606: Let the common probe function return int

The common probe function for the ad7606 currently returns a struct iio_dev
pointer. The returned value is not used by the individual driver probe
functions other than for error checking.

Let the common probe function return a int instead to report the error
value directly (or 0 on success). This allows to simplify the code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/adc/ad7606.h

@@ -78,8 +78,7 @@ struct ad7606_bus_ops {
 	int (*read_block)(struct device *, int, void *);
 };
 
-struct iio_dev *ad7606_probe(struct device *dev, int irq,
-			      void __iomem *base_address,
+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 iio_dev *indio_dev, int irq);

drivers/staging/iio/adc/ad7606_core.c

@@ -443,8 +443,7 @@ static const struct iio_info ad7606_info_range = {
 	.attrs = &ad7606_attribute_group_range,
 };
 
-struct iio_dev *ad7606_probe(struct device *dev, int irq,
-			     void __iomem *base_address,
+int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 		 const char *name, unsigned int id,
 		 const struct ad7606_bus_ops *bops)
 {
@@ -455,7 +454,7 @@ struct iio_dev *ad7606_probe(struct device *dev, int irq,
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 	if (!indio_dev)
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 
 	st = iio_priv(indio_dev);
 
@@ -469,7 +468,7 @@ struct iio_dev *ad7606_probe(struct device *dev, int irq,
 	if (!IS_ERR(st->reg)) {
 		ret = regulator_enable(st->reg);
 		if (ret)
-			return ERR_PTR(ret);
+			return ret;
 	}
 
 	st->pdata = pdata;
@@ -519,7 +518,7 @@ struct iio_dev *ad7606_probe(struct device *dev, int irq,
 
 	dev_set_drvdata(dev, indio_dev);
 
-	return indio_dev;
+	return 0;
 error_unregister_ring:
 	ad7606_ring_cleanup(indio_dev);
 
@@ -532,7 +531,7 @@ struct iio_dev *ad7606_probe(struct device *dev, int irq,
 error_disable_reg:
 	if (!IS_ERR(st->reg))
 		regulator_disable(st->reg);
-	return ERR_PTR(ret);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(ad7606_probe);
 

drivers/staging/iio/adc/ad7606_par.c

@@ -51,7 +51,6 @@ static int ad7606_par_probe(struct platform_device *pdev)
 {
 	const struct platform_device_id *id = platform_get_device_id(pdev);
 	struct resource *res;
-	struct iio_dev *indio_dev;
 	void __iomem *addr;
 	resource_size_t remap_size;
 	int irq;
@@ -69,15 +68,10 @@ static int ad7606_par_probe(struct platform_device *pdev)
 
 	remap_size = resource_size(res);
 
-	indio_dev = ad7606_probe(&pdev->dev, irq, addr,
+	return ad7606_probe(&pdev->dev, irq, addr,
 			    id->name, id->driver_data,
 			    remap_size > 1 ? &ad7606_par16_bops :
 			    &ad7606_par8_bops);
-
-	if (IS_ERR(indio_dev))
-		return PTR_ERR(indio_dev);
-
-	return 0;
 }
 
 static int ad7606_par_remove(struct platform_device *pdev)

drivers/staging/iio/adc/ad7606_spi.c

@@ -43,16 +43,10 @@ static const struct ad7606_bus_ops ad7606_spi_bops = {
 static int ad7606_spi_probe(struct spi_device *spi)
 {
 	const struct spi_device_id *id = spi_get_device_id(spi);
-	struct iio_dev *indio_dev;
 
-	indio_dev = ad7606_probe(&spi->dev, spi->irq, NULL,
+	return ad7606_probe(&spi->dev, spi->irq, NULL,
 			    id->name, id->driver_data,
 			    &ad7606_spi_bops);
-
-	if (IS_ERR(indio_dev))
-		return PTR_ERR(indio_dev);
-
-	return 0;
 }
 
 static int ad7606_spi_remove(struct spi_device *spi)