iio: accel: adxl367: do not update FIFO watermark on scan mode update

Currently, the driver updates the FIFO watermark inside both
update_scan_mode() and hwfifo_set_watermark(). Inside the IIO core,
hwfifo_set_watermark() is called immediately after update_scan_mode(),
making the first call to set_fifo_samples() redundant.

Remove the first call to set_fifo_samples(), and merge the
set_fifo_samples() function into the set_fifo_watermark()
function. Also, since fifo_set_size is always set inside of
update_scan_mode(), and it cannot be set to 0, remove the
zero check from set_fifo_samples().
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220514182010.152784-1-cosmin.tanislav@analog.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/adxl367.c

@@ -447,21 +447,17 @@ static int adxl367_set_fifo_format(struct adxl367_state *st,
 					     fifo_format));
 }
 
-static int adxl367_set_fifo_samples(struct adxl367_state *st,
-				    unsigned int fifo_watermark,
-				    unsigned int fifo_set_size)
+static int adxl367_set_fifo_watermark(struct adxl367_state *st,
+				      unsigned int fifo_watermark)
 {
-	unsigned int fifo_samples = fifo_watermark * fifo_set_size;
+	unsigned int fifo_samples = fifo_watermark * st->fifo_set_size;
 	unsigned int fifo_samples_h, fifo_samples_l;
 	int ret;
 
 	if (fifo_samples > ADXL367_FIFO_MAX_WATERMARK)
 		fifo_samples = ADXL367_FIFO_MAX_WATERMARK;
 
-	if (fifo_set_size == 0)
-		return 0;
-
-	fifo_samples /= fifo_set_size;
+	fifo_samples /= st->fifo_set_size;
 
 	fifo_samples_h = FIELD_PREP(ADXL367_SAMPLES_H_MASK,
 				    FIELD_GET(ADXL367_SAMPLES_VAL_H_MASK,
@@ -475,30 +471,8 @@ static int adxl367_set_fifo_samples(struct adxl367_state *st,
 	if (ret)
 		return ret;
 
-	return regmap_update_bits(st->regmap, ADXL367_REG_FIFO_SAMPLES,
-				  ADXL367_SAMPLES_L_MASK, fifo_samples_l);
-}
-
-static int adxl367_set_fifo_set_size(struct adxl367_state *st,
-				     unsigned int fifo_set_size)
-{
-	int ret;
-
-	ret = adxl367_set_fifo_samples(st, st->fifo_watermark, fifo_set_size);
-	if (ret)
-		return ret;
-
-	st->fifo_set_size = fifo_set_size;
-
-	return 0;
-}
-
-static int adxl367_set_fifo_watermark(struct adxl367_state *st,
-				      unsigned int fifo_watermark)
-{
-	int ret;
-
-	ret = adxl367_set_fifo_samples(st, fifo_watermark, st->fifo_set_size);
+	ret = regmap_update_bits(st->regmap, ADXL367_REG_FIFO_SAMPLES,
+				 ADXL367_SAMPLES_L_MASK, fifo_samples_l);
 	if (ret)
 		return ret;
 
@@ -1276,14 +1250,11 @@ static int adxl367_update_scan_mode(struct iio_dev *indio_dev,
 {
 	struct adxl367_state *st  = iio_priv(indio_dev);
 	enum adxl367_fifo_format fifo_format;
-	unsigned int fifo_set_size;
 	int ret;
 
 	if (!adxl367_find_mask_fifo_format(active_scan_mask, &fifo_format))
 		return -EINVAL;
 
-	fifo_set_size = bitmap_weight(active_scan_mask, indio_dev->masklength);
-
 	mutex_lock(&st->lock);
 
 	ret = adxl367_set_measure_en(st, false);
@@ -1294,11 +1265,12 @@ static int adxl367_update_scan_mode(struct iio_dev *indio_dev,
 	if (ret)
 		goto out;
 
-	ret = adxl367_set_fifo_set_size(st, fifo_set_size);
+	ret = adxl367_set_measure_en(st, true);
 	if (ret)
 		goto out;
 
-	ret = adxl367_set_measure_en(st, true);
+	st->fifo_set_size = bitmap_weight(active_scan_mask,
+					  indio_dev->masklength);
 
 out:
 	mutex_unlock(&st->lock);