iio: make use of devm_iio_kfifo_buffer_setup() helper

All drivers that already call devm_iio_kfifo_allocate() &
iio_device_attach_buffer() are simple to convert to
iio_device_attach_kfifo_buffer() in a single go.

This change does that; the unwind order is preserved.
What is important, is that the devm_iio_kfifo_buffer_setup() be called
after the indio_dev->modes is assigned, to make sure that
INDIO_BUFFER_SOFTWARE flag is set and not overridden by the assignment to
indio_dev->modes.

Also, the INDIO_BUFFER_SOFTWARE has been removed from the assignments of
'indio_dev->modes' because it is set by devm_iio_kfifo_buffer_setup().

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>x
Link: https://lore.kernel.org/r/20210215104043.91251-4-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

1 files changed, 6 insertions, 9 deletions

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
index f1103ecedd64..16730a780964 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
@@ -739,20 +739,17 @@ static const struct iio_buffer_setup_ops st_lsm6dsx_buffer_ops = {
 
 int st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw *hw)
 {
-	struct iio_buffer *buffer;
-	int i;
+	int i, ret;
 
 	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
 		if (!hw->iio_devs[i])
 			continue;
 
-		buffer = devm_iio_kfifo_allocate(hw->dev);
-		if (!buffer)
-			return -ENOMEM;
-
-		iio_device_attach_buffer(hw->iio_devs[i], buffer);
-		hw->iio_devs[i]->modes |= INDIO_BUFFER_SOFTWARE;
-		hw->iio_devs[i]->setup_ops = &st_lsm6dsx_buffer_ops;
+		ret = devm_iio_kfifo_buffer_setup(hw->dev, hw->iio_devs[i],
+						  INDIO_BUFFER_SOFTWARE,
+						  &st_lsm6dsx_buffer_ops);
+		if (ret)
+			return ret;
 	}
 
 	return 0;