iio: st_sensors: remove st_sensors_power_disable() function

This change converts the st_sensors_power_enable() function to use
devm_add_action_or_reset() handlers to register regulator_disable hooks for
when the drivers get unloaded.

The parent device of the IIO device object is used. This is based on the
assumption that all other devm_ calls in the ST sensors use this reference.

This makes the st_sensors_power_disable() un-needed.
Removing this also changes unload order a bit, as all ST drivers would call
st_sensors_power_disable() first and iio_device_unregister() after that.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210823112204.243255-4-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

1 files changed, 15 insertions, 19 deletions

diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c
index 0bbb090b108c..a5a140de9a23 100644
--- a/drivers/iio/common/st_sensors/st_sensors_core.c
+++ b/drivers/iio/common/st_sensors/st_sensors_core.c
@@ -215,13 +215,19 @@ int st_sensors_set_axis_enable(struct iio_dev *indio_dev, u8 axis_enable)
 }
 EXPORT_SYMBOL(st_sensors_set_axis_enable);
 
+static void st_reg_disable(void *reg)
+{
+	regulator_disable(reg);
+}
+
 int st_sensors_power_enable(struct iio_dev *indio_dev)
 {
 	struct st_sensor_data *pdata = iio_priv(indio_dev);
+	struct device *parent = indio_dev->dev.parent;
 	int err;
 
 	/* Regulators not mandatory, but if requested we should enable them. */
-	pdata->vdd = devm_regulator_get(indio_dev->dev.parent, "vdd");
+	pdata->vdd = devm_regulator_get(parent, "vdd");
 	if (IS_ERR(pdata->vdd)) {
 		dev_err(&indio_dev->dev, "unable to get Vdd supply\n");
 		return PTR_ERR(pdata->vdd);
@@ -233,36 +239,26 @@ int st_sensors_power_enable(struct iio_dev *indio_dev)
 		return err;
 	}
 
-	pdata->vdd_io = devm_regulator_get(indio_dev->dev.parent, "vddio");
+	err = devm_add_action_or_reset(parent, st_reg_disable, pdata->vdd);
+	if (err)
+		return err;
+
+	pdata->vdd_io = devm_regulator_get(parent, "vddio");
 	if (IS_ERR(pdata->vdd_io)) {
 		dev_err(&indio_dev->dev, "unable to get Vdd_IO supply\n");
-		err = PTR_ERR(pdata->vdd_io);
-		goto st_sensors_disable_vdd;
+		return PTR_ERR(pdata->vdd_io);
 	}
 	err = regulator_enable(pdata->vdd_io);
 	if (err != 0) {
 		dev_warn(&indio_dev->dev,
 			 "Failed to enable specified Vdd_IO supply\n");
-		goto st_sensors_disable_vdd;
+		return err;
 	}
 
-	return 0;
-
-st_sensors_disable_vdd:
-	regulator_disable(pdata->vdd);
-	return err;
+	return devm_add_action_or_reset(parent, st_reg_disable, pdata->vdd_io);
 }
 EXPORT_SYMBOL(st_sensors_power_enable);
 
-void st_sensors_power_disable(struct iio_dev *indio_dev)
-{
-	struct st_sensor_data *pdata = iio_priv(indio_dev);
-
-	regulator_disable(pdata->vdd);
-	regulator_disable(pdata->vdd_io);
-}
-EXPORT_SYMBOL(st_sensors_power_disable);
-
 static int st_sensors_set_drdy_int_pin(struct iio_dev *indio_dev,
 					struct st_sensors_platform_data *pdata)
 {