[PATCH 3/5] iio:gyro: do not allocate/de-allocate buffer here but link setup_ops to st_sensors_buffer

[Denis Ciocca <denis.ciocca@xxxxxx>]

Setup buffer_setup_ops pre/post enable/disable to use
st_sensor_buffers functions for memory allocation/de-allocation.

Signed-off-by: Denis Ciocca <denis.ciocca@xxxxxx>
---
 drivers/iio/gyro/st_gyro_buffer.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/iio/gyro/st_gyro_buffer.c b/drivers/iio/gyro/st_gyro_buffer.c
index c6ddfecc1fc3..48811457a943 100644
--- a/drivers/iio/gyro/st_gyro_buffer.c
+++ b/drivers/iio/gyro/st_gyro_buffer.c
@@ -31,17 +31,11 @@ int st_gyro_trig_set_state(struct iio_trigger *trig, bool state)
 
 static int st_gyro_buffer_postenable(struct iio_dev *indio_dev)
 {
-	struct st_sensor_data *gdata = iio_priv(indio_dev);
 	int err;
 
-	gdata->buffer_data = kmalloc(indio_dev->scan_bytes,
-				     GFP_DMA | GFP_KERNEL);
-	if (!gdata->buffer_data)
-		return -ENOMEM;
-
 	err = iio_triggered_buffer_postenable(indio_dev);
 	if (err < 0)
-		goto st_gyro_free_buffer;
+		return err;
 
 	err = st_sensors_set_axis_enable(indio_dev,
 					 (u8)indio_dev->active_scan_mask[0]);
@@ -58,15 +52,12 @@ static int st_gyro_buffer_postenable(struct iio_dev *indio_dev)
 	st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
 st_gyro_buffer_predisable:
 	iio_triggered_buffer_predisable(indio_dev);
-st_gyro_free_buffer:
-	kfree(gdata->buffer_data);
 	return err;
 }
 
 static int st_gyro_buffer_predisable(struct iio_dev *indio_dev)
 {
 	int err, err2;
-	struct st_sensor_data *gdata = iio_priv(indio_dev);
 
 	err = st_sensors_set_enable(indio_dev, false);
 	if (err < 0)
@@ -79,13 +70,14 @@ static int st_gyro_buffer_predisable(struct iio_dev *indio_dev)
 	if (!err)
 		err = err2;
 
-	kfree(gdata->buffer_data);
 	return err;
 }
 
 static const struct iio_buffer_setup_ops st_gyro_buffer_setup_ops = {
+	.preenable = &st_sensors_buffer_preenable,
 	.postenable = &st_gyro_buffer_postenable,
 	.predisable = &st_gyro_buffer_predisable,
+	.postdisable = &st_sensors_buffer_postdisable,
 };
 
 int st_gyro_allocate_ring(struct iio_dev *indio_dev)
-- 
2.22.0