Use devm_* functions in probe to remove some code and to make it easier
to add further calls to the probe function.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
---
 drivers/iio/adc/mcp320x.c | 30 ++++++++++--------------------
 1 file changed, 10 insertions(+), 20 deletions(-)

diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c
index b4c69acb33e3..28398f34628a 100644
--- a/drivers/iio/adc/mcp320x.c
+++ b/drivers/iio/adc/mcp320x.c
@@ -371,6 +371,11 @@ static const struct mcp320x_chip_info mcp320x_chip_infos[] = {
 	},
 };
 
+static void mcp320x_reg_disable(void *reg)
+{
+	regulator_disable(reg);
+}
+
 static int mcp320x_probe(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev;
@@ -445,27 +450,13 @@ static int mcp320x_probe(struct spi_device *spi)
 	if (ret < 0)
 		return ret;
 
-	mutex_init(&adc->lock);
-
-	ret = iio_device_register(indio_dev);
-	if (ret < 0)
-		goto reg_disable;
-
-	return 0;
-
-reg_disable:
-	regulator_disable(adc->reg);
-
-	return ret;
-}
+	ret = devm_add_action_or_reset(&spi->dev, mcp320x_reg_disable, adc->reg);
+	if (ret)
+		return ret;
 
-static void mcp320x_remove(struct spi_device *spi)
-{
-	struct iio_dev *indio_dev = spi_get_drvdata(spi);
-	struct mcp320x *adc = iio_priv(indio_dev);
+	mutex_init(&adc->lock);
 
-	iio_device_unregister(indio_dev);
-	regulator_disable(adc->reg);
+	return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
 static const struct of_device_id mcp320x_dt_ids[] = {
@@ -520,7 +511,6 @@ static struct spi_driver mcp320x_driver = {
 		.of_match_table = mcp320x_dt_ids,
 	},
 	.probe = mcp320x_probe,
-	.remove = mcp320x_remove,
 	.id_table = mcp320x_id,
 };
 module_spi_driver(mcp320x_driver);
-- 
2.34.1

On Wed, Aug 24, 2022 at 1:46 PM Vincent Whitchurch
<vincent.whitchurch@axis.com> wrote:
>
> Use devm_* functions in probe to remove some code and to make it easier
> to add further calls to the probe function.

...

> +       mutex_init(&adc->lock);

> +       return devm_iio_device_register(&spi->dev, indio_dev);

Do you still need to destroy the mutex? If so, you may not call devm_
variant of iio_device_register() or you have to wrap mutex_destroy()
accordingly.

-- 
With Best Regards,
Andy Shevchenko

On Thu, Aug 25, 2022 at 10:01:58PM +0200, Andy Shevchenko wrote:
> On Wed, Aug 24, 2022 at 1:46 PM Vincent Whitchurch
> <vincent.whitchurch@axis.com> wrote:
> >
> > Use devm_* functions in probe to remove some code and to make it easier
> > to add further calls to the probe function.
> 
> ...
> 
> > +       mutex_init(&adc->lock);
> 
> > +       return devm_iio_device_register(&spi->dev, indio_dev);
> 
> Do you still need to destroy the mutex? If so, you may not call devm_
> variant of iio_device_register() or you have to wrap mutex_destroy()
> accordingly.

mutex_destroy() is only used to ensure that mutex debugging catches
further use of the mutex.  Isn't it rather overkill to add specific
cleanup to do only that, especially in this case when it's anyway going
to get freed immediately afterwards?  The vast majority of IIO drivers
don't call mutex_destroy() (256 calls to mutex_init() in HEAD vs 12 to
mutex_destroy()).