iio: adc: ad7298: convert probe to device-managed functions

This change converts the probe of this driver to use device-managed
register functions, and a devm_add_action_or_reset() for the regulator
disable.

With this, the exit & error paths can be removed.
Another side-effect is that this should avoid some static-analyzer's check
with respect to a potential null dereference of the regulator. The null
dereference isn't likely to happen (under normal operation), so there isn't
a requirement to have this fixed/backported in other releases.

As a note: this is removing spi_set_drvdata() since there is no other
spi_get_drvdata() (or dev_get_drvdata()) call that need it.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20201127094038.91714-1-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ad7298.c b/drivers/iio/adc/ad7298.c
index fa1047f..ecdb01b 100644 (file)
--- a/drivers/iio/adc/ad7298.c
+++ b/drivers/iio/adc/ad7298.c
@@ -279,6 +279,13 @@ static const struct iio_info ad7298_info = {
        .update_scan_mode = ad7298_update_scan_mode,
 };
 
+static void ad7298_reg_disable(void *data)
+{
+       struct regulator *reg = data;
+
+       regulator_disable(reg);
+}
+
 static int ad7298_probe(struct spi_device *spi)
 {
        struct ad7298_state *st;
@@ -306,9 +313,12 @@ static int ad7298_probe(struct spi_device *spi)
                ret = regulator_enable(st->reg);
                if (ret)
                        return ret;
-       }
 
-       spi_set_drvdata(spi, indio_dev);
+               ret = devm_add_action_or_reset(&spi->dev, ad7298_reg_disable,
+                                              st->reg);
+               if (ret)
+                       return ret;
+       }
 
        st->spi = spi;
 
@@ -334,37 +344,12 @@ static int ad7298_probe(struct spi_device *spi)
        spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
        spi_message_add_tail(&st->scan_single_xfer[2], &st->scan_single_msg);
 
-       ret = iio_triggered_buffer_setup(indio_dev, NULL,
+       ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,
                        &ad7298_trigger_handler, NULL);
        if (ret)
-               goto error_disable_reg;
-
-       ret = iio_device_register(indio_dev);
-       if (ret)
-               goto error_cleanup_ring;
-
-       return 0;
-
-error_cleanup_ring:
-       iio_triggered_buffer_cleanup(indio_dev);
-error_disable_reg:
-       if (st->ext_ref)
-               regulator_disable(st->reg);
-
-       return ret;
-}
-
-static int ad7298_remove(struct spi_device *spi)
-{
-       struct iio_dev *indio_dev = spi_get_drvdata(spi);
-       struct ad7298_state *st = iio_priv(indio_dev);
-
-       iio_device_unregister(indio_dev);
-       iio_triggered_buffer_cleanup(indio_dev);
-       if (st->ext_ref)
-               regulator_disable(st->reg);
+               return ret;
 
-       return 0;
+       return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
 static const struct spi_device_id ad7298_id[] = {
@@ -378,7 +363,6 @@ static struct spi_driver ad7298_driver = {
                .name   = "ad7298",
        },
        .probe          = ad7298_probe,
-       .remove         = ad7298_remove,
        .id_table       = ad7298_id,
 };
 module_spi_driver(ad7298_driver);