[PATCH] iio: potentiometer: max5481: convert probe to device-managed

From: Alexandru Ardelean
Date: Thu Jun 24 2021 - 04:07:01 EST


The change converts the probe function to use the
devm_iio_device_register() function.

Before calling that, we need to register an action to store the wiper back
to non-volatile memory when the device is de-registered.

We don't need to do this if the probe fails, because the only place where
the probe can fail now is devm_iio_device_register() and that shouldn't
create an IIO device (for userspace to poke at) if it fails.

Signed-off-by: Alexandru Ardelean <aardelean@xxxxxxxxxxx>
---
drivers/iio/potentiometer/max5481.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/potentiometer/max5481.c b/drivers/iio/potentiometer/max5481.c
index 6e22b538091f..098d144a8fdd 100644
--- a/drivers/iio/potentiometer/max5481.c
+++ b/drivers/iio/potentiometer/max5481.c
@@ -125,6 +125,11 @@ static const struct of_device_id max5481_match[] = {
};
MODULE_DEVICE_TABLE(of, max5481_match);

+static void max5481_wiper_save(void *data)
+{
+ max5481_write_cmd(data, MAX5481_COPY_AB_TO_NV, 0);
+}
+
static int max5481_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
@@ -136,7 +141,6 @@ static int max5481_probe(struct spi_device *spi)
if (!indio_dev)
return -ENOMEM;

- spi_set_drvdata(spi, indio_dev);
data = iio_priv(indio_dev);

data->spi = spi;
@@ -158,18 +162,11 @@ static int max5481_probe(struct spi_device *spi)
if (ret < 0)
return ret;

- return iio_device_register(indio_dev);
-}
-
-static int max5481_remove(struct spi_device *spi)
-{
- struct iio_dev *indio_dev = spi_get_drvdata(spi);
- struct max5481_data *data = iio_priv(indio_dev);
-
- iio_device_unregister(indio_dev);
+ ret = devm_add_action(&spi->dev, max5481_wiper_save, data);
+ if (ret < 0)
+ return ret;

- /* save wiper reg to NV reg */
- return max5481_write_cmd(data, MAX5481_COPY_AB_TO_NV, 0);
+ return devm_iio_device_register(&spi->dev, indio_dev);
}

static const struct spi_device_id max5481_id_table[] = {
@@ -187,7 +184,6 @@ static struct spi_driver max5481_driver = {
.of_match_table = max5481_match,
},
.probe = max5481_probe,
- .remove = max5481_remove,
.id_table = max5481_id_table,
};

--
2.31.1