On Fri, 27 Nov 2020 11:40:37 +0200
Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote:
> 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.
>
> Cc: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
Series applied to the togreg branch of iio.git and pushed out as testing
for the autobuilders to work their magic.
Thanks,
Jonathan
> ---
> drivers/iio/adc/ad7298.c | 46 +++++++++++++---------------------------
> 1 file changed, 15 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/iio/adc/ad7298.c b/drivers/iio/adc/ad7298.c
> index fa1047f74a1f..ecdb01bd5b2f 100644
> --- 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);
