iio:accel: preenable/postenable/predisable fixup for ST accel buffer

This patch is trying to cleanup for good the buffers operation functions.
There is no need of using preenable, all can be done into
postenable.
Let's also rename the goto label using operation to perform and not
where it fails.

Note, not stable material. This is cleaning up the logic flow rather
than fixing a bug.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/st_accel_buffer.c

@@ -29,56 +29,52 @@ int st_accel_trig_set_state(struct iio_trigger *trig, bool state)
 	return st_sensors_set_dataready_irq(indio_dev, state);
 }
 
-static int st_accel_buffer_preenable(struct iio_dev *indio_dev)
-{
-	return st_sensors_set_enable(indio_dev, true);
-}
-
 static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
 {
-	int err;
 	struct st_sensor_data *adata = iio_priv(indio_dev);
+	int err;
 
 	adata->buffer_data = kmalloc(indio_dev->scan_bytes,
 				     GFP_DMA | GFP_KERNEL);
-	if (adata->buffer_data == NULL) {
-		err = -ENOMEM;
-		goto allocate_memory_error;
-	}
+	if (!adata->buffer_data)
+		return -ENOMEM;
 
 	err = iio_triggered_buffer_postenable(indio_dev);
 	if (err < 0)
-		goto st_accel_buffer_postenable_error;
+		goto st_accel_free_buffer;
 
 	err = st_sensors_set_axis_enable(indio_dev,
-					(u8)indio_dev->active_scan_mask[0]);
+					 (u8)indio_dev->active_scan_mask[0]);
 	if (err < 0)
-		goto st_sensors_set_axis_enable_error;
+		goto st_accel_buffer_predisable;
 
-	return err;
+	err = st_sensors_set_enable(indio_dev, true);
+	if (err < 0)
+		goto st_accel_buffer_enable_all_axis;
 
-st_sensors_set_axis_enable_error:
+	return 0;
+
+st_accel_buffer_enable_all_axis:
+	st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
+st_accel_buffer_predisable:
 	iio_triggered_buffer_predisable(indio_dev);
-st_accel_buffer_postenable_error:
+st_accel_free_buffer:
 	kfree(adata->buffer_data);
-allocate_memory_error:
 	return err;
 }
 
 static int st_accel_buffer_predisable(struct iio_dev *indio_dev)
 {
-	int err, err2;
 	struct st_sensor_data *adata = iio_priv(indio_dev);
-
-	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
-	if (err < 0)
-		goto st_accel_buffer_predisable_error;
+	int err, err2;
 
 	err = st_sensors_set_enable(indio_dev, false);
 	if (err < 0)
-		goto st_accel_buffer_predisable_error;
+		goto st_accel_buffer_predisable;
 
-st_accel_buffer_predisable_error:
+	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
+
+st_accel_buffer_predisable:
 	err2 = iio_triggered_buffer_predisable(indio_dev);
 	if (!err)
 		err = err2;
@@ -88,7 +84,6 @@ st_accel_buffer_predisable_error:
 }
 
 static const struct iio_buffer_setup_ops st_accel_buffer_setup_ops = {
-	.preenable = &st_accel_buffer_preenable,
 	.postenable = &st_accel_buffer_postenable,
 	.predisable = &st_accel_buffer_predisable,
 };