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>

3 files changed, 18 insertions, 24 deletions

diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c
index 3441b0d61c5d..383cc3250342 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c
@@ -709,7 +709,6 @@ struct iio_dev *inv_icm42600_accel_init(struct inv_icm42600_state *st)
 	const char *name;
 	struct inv_icm42600_timestamp *ts;
 	struct iio_dev *indio_dev;
-	struct iio_buffer *buffer;
 	int ret;
 
 	name = devm_kasprintf(dev, GFP_KERNEL, "%s-accel", st->name);
@@ -720,23 +719,22 @@ struct iio_dev *inv_icm42600_accel_init(struct inv_icm42600_state *st)
 	if (!indio_dev)
 		return ERR_PTR(-ENOMEM);
 
-	buffer = devm_iio_kfifo_allocate(dev);
-	if (!buffer)
-		return ERR_PTR(-ENOMEM);
-
 	ts = iio_priv(indio_dev);
 	inv_icm42600_timestamp_init(ts, inv_icm42600_odr_to_period(st->conf.accel.odr));
 
 	iio_device_set_drvdata(indio_dev, st);
 	indio_dev->name = name;
 	indio_dev->info = &inv_icm42600_accel_info;
-	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
+	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = inv_icm42600_accel_channels;
 	indio_dev->num_channels = ARRAY_SIZE(inv_icm42600_accel_channels);
 	indio_dev->available_scan_masks = inv_icm42600_accel_scan_masks;
-	indio_dev->setup_ops = &inv_icm42600_buffer_ops;
 
-	iio_device_attach_buffer(indio_dev, buffer);
+	ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
+					  INDIO_BUFFER_SOFTWARE,
+					  &inv_icm42600_buffer_ops);
+	if (ret)
+		return ERR_PTR(ret);
 
 	ret = devm_iio_device_register(dev, indio_dev);
 	if (ret)
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c
index aee7b9ff4bf4..cec1dd0e0464 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c
@@ -720,7 +720,6 @@ struct iio_dev *inv_icm42600_gyro_init(struct inv_icm42600_state *st)
 	const char *name;
 	struct inv_icm42600_timestamp *ts;
 	struct iio_dev *indio_dev;
-	struct iio_buffer *buffer;
 	int ret;
 
 	name = devm_kasprintf(dev, GFP_KERNEL, "%s-gyro", st->name);
@@ -731,23 +730,23 @@ struct iio_dev *inv_icm42600_gyro_init(struct inv_icm42600_state *st)
 	if (!indio_dev)
 		return ERR_PTR(-ENOMEM);
 
-	buffer = devm_iio_kfifo_allocate(dev);
-	if (!buffer)
-		return ERR_PTR(-ENOMEM);
-
 	ts = iio_priv(indio_dev);
 	inv_icm42600_timestamp_init(ts, inv_icm42600_odr_to_period(st->conf.gyro.odr));
 
 	iio_device_set_drvdata(indio_dev, st);
 	indio_dev->name = name;
 	indio_dev->info = &inv_icm42600_gyro_info;
-	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
+	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = inv_icm42600_gyro_channels;
 	indio_dev->num_channels = ARRAY_SIZE(inv_icm42600_gyro_channels);
 	indio_dev->available_scan_masks = inv_icm42600_gyro_scan_masks;
 	indio_dev->setup_ops = &inv_icm42600_buffer_ops;
 
-	iio_device_attach_buffer(indio_dev, buffer);
+	ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
+					  INDIO_BUFFER_SOFTWARE,
+					  &inv_icm42600_buffer_ops);
+	if (ret)
+		return ERR_PTR(ret);
 
 	ret = devm_iio_device_register(dev, indio_dev);
 	if (ret)
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;