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.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/st_accel_i2c.c

@@ -177,16 +177,7 @@ static int st_accel_i2c_probe(struct i2c_client *client)
 	if (ret)
 		return ret;
 
-	ret = st_accel_common_probe(indio_dev);
-	if (ret < 0)
-		goto st_accel_power_off;
-
-	return 0;
-
-st_accel_power_off:
-	st_sensors_power_disable(indio_dev);
-
-	return ret;
+	return st_accel_common_probe(indio_dev);
 }
 
 static int st_accel_i2c_remove(struct i2c_client *client)
@@ -195,8 +186,6 @@ static int st_accel_i2c_remove(struct i2c_client *client)
 
 	st_accel_common_remove(indio_dev);
 
-	st_sensors_power_disable(indio_dev);
-
 	return 0;
 }
 

drivers/iio/accel/st_accel_spi.c

@@ -127,16 +127,7 @@ static int st_accel_spi_probe(struct spi_device *spi)
 	if (err)
 		return err;
 
-	err = st_accel_common_probe(indio_dev);
-	if (err < 0)
-		goto st_accel_power_off;
-
-	return 0;
-
-st_accel_power_off:
-	st_sensors_power_disable(indio_dev);
-
-	return err;
+	return st_accel_common_probe(indio_dev);
 }
 
 static int st_accel_spi_remove(struct spi_device *spi)
@@ -145,8 +136,6 @@ static int st_accel_spi_remove(struct spi_device *spi)
 
 	st_accel_common_remove(indio_dev);
 
-	st_sensors_power_disable(indio_dev);
-
 	return 0;
 }
 

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)
 {

drivers/iio/gyro/st_gyro_i2c.c

@@ -90,16 +90,7 @@ static int st_gyro_i2c_probe(struct i2c_client *client,
 	if (err)
 		return err;
 
-	err = st_gyro_common_probe(indio_dev);
-	if (err < 0)
-		goto st_gyro_power_off;
-
-	return 0;
-
-st_gyro_power_off:
-	st_sensors_power_disable(indio_dev);
-
-	return err;
+	return st_gyro_common_probe(indio_dev);
 }
 
 static int st_gyro_i2c_remove(struct i2c_client *client)
@@ -108,8 +99,6 @@ static int st_gyro_i2c_remove(struct i2c_client *client)
 
 	st_gyro_common_remove(indio_dev);
 
-	st_sensors_power_disable(indio_dev);
-
 	return 0;
 }
 

drivers/iio/gyro/st_gyro_spi.c

@@ -94,16 +94,7 @@ static int st_gyro_spi_probe(struct spi_device *spi)
 	if (err)
 		return err;
 
-	err = st_gyro_common_probe(indio_dev);
-	if (err < 0)
-		goto st_gyro_power_off;
-
-	return 0;
-
-st_gyro_power_off:
-	st_sensors_power_disable(indio_dev);
-
-	return err;
+	return st_gyro_common_probe(indio_dev);
 }
 
 static int st_gyro_spi_remove(struct spi_device *spi)
@@ -112,8 +103,6 @@ static int st_gyro_spi_remove(struct spi_device *spi)
 
 	st_gyro_common_remove(indio_dev);
 
-	st_sensors_power_disable(indio_dev);
-
 	return 0;
 }
 

drivers/iio/magnetometer/st_magn_i2c.c

@@ -86,16 +86,7 @@ static int st_magn_i2c_probe(struct i2c_client *client,
 	if (err)
 		return err;
 
-	err = st_magn_common_probe(indio_dev);
-	if (err < 0)
-		goto st_magn_power_off;
-
-	return 0;
-
-st_magn_power_off:
-	st_sensors_power_disable(indio_dev);
-
-	return err;
+	return st_magn_common_probe(indio_dev);
 }
 
 static int st_magn_i2c_remove(struct i2c_client *client)
@@ -104,8 +95,6 @@ static int st_magn_i2c_remove(struct i2c_client *client)
 
 	st_magn_common_remove(indio_dev);
 
-	st_sensors_power_disable(indio_dev);
-
 	return 0;
 }
 

drivers/iio/magnetometer/st_magn_spi.c

@@ -80,16 +80,7 @@ static int st_magn_spi_probe(struct spi_device *spi)
 	if (err)
 		return err;
 
-	err = st_magn_common_probe(indio_dev);
-	if (err < 0)
-		goto st_magn_power_off;
-
-	return 0;
-
-st_magn_power_off:
-	st_sensors_power_disable(indio_dev);
-
-	return err;
+	return st_magn_common_probe(indio_dev);
 }
 
 static int st_magn_spi_remove(struct spi_device *spi)
@@ -98,8 +89,6 @@ static int st_magn_spi_remove(struct spi_device *spi)
 
 	st_magn_common_remove(indio_dev);
 
-	st_sensors_power_disable(indio_dev);
-
 	return 0;
 }
 

drivers/iio/pressure/st_pressure_i2c.c

@@ -103,16 +103,7 @@ static int st_press_i2c_probe(struct i2c_client *client,
 	if (ret)
 		return ret;
 
-	ret = st_press_common_probe(indio_dev);
-	if (ret < 0)
-		goto st_press_power_off;
-
-	return 0;
-
-st_press_power_off:
-	st_sensors_power_disable(indio_dev);
-
-	return ret;
+	return st_press_common_probe(indio_dev);
 }
 
 static int st_press_i2c_remove(struct i2c_client *client)
@@ -121,8 +112,6 @@ static int st_press_i2c_remove(struct i2c_client *client)
 
 	st_press_common_remove(indio_dev);
 
-	st_sensors_power_disable(indio_dev);
-
 	return 0;
 }
 

drivers/iio/pressure/st_pressure_spi.c

@@ -86,16 +86,7 @@ static int st_press_spi_probe(struct spi_device *spi)
 	if (err)
 		return err;
 
-	err = st_press_common_probe(indio_dev);
-	if (err < 0)
-		goto st_press_power_off;
-
-	return 0;
-
-st_press_power_off:
-	st_sensors_power_disable(indio_dev);
-
-	return err;
+	return st_press_common_probe(indio_dev);
 }
 
 static int st_press_spi_remove(struct spi_device *spi)
@@ -104,8 +95,6 @@ static int st_press_spi_remove(struct spi_device *spi)
 
 	st_press_common_remove(indio_dev);
 
-	st_sensors_power_disable(indio_dev);
-
 	return 0;
 }
 

include/linux/iio/common/st_sensors.h

@@ -293,8 +293,6 @@ int st_sensors_set_axis_enable(struct iio_dev *indio_dev, u8 axis_enable);
 
 int st_sensors_power_enable(struct iio_dev *indio_dev);
 
-void st_sensors_power_disable(struct iio_dev *indio_dev);
-
 int st_sensors_debugfs_reg_access(struct iio_dev *indio_dev,
 				  unsigned reg, unsigned writeval,
 				  unsigned *readval);