iio: accel: adxl372: Fix/remove limitation for FIFO samples

Currently, the driver sets the FIFO_SAMPLES register with the number of
sample sets (maximum of 170 for 3 axis data, 256 for 2-axis and 512 for
single axis). However, the FIFO_SAMPLES register should store the number
of samples, regardless of how the FIFO format is configured.
Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Fixes: f4f55ce3 ("iio:adxl372: Add FIFO and interrupts support")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/adxl372.c

@@ -474,12 +474,17 @@ static int adxl372_configure_fifo(struct adxl372_state *st)
 	if (ret < 0)
 		return ret;
 
-	fifo_samples = st->watermark & 0xFF;
+	/*
+	 * watermark stores the number of sets; we need to write the FIFO
+	 * registers with the number of samples
+	 */
+	fifo_samples = (st->watermark * st->fifo_set_size);
 	fifo_ctl = ADXL372_FIFO_CTL_FORMAT_MODE(st->fifo_format) |
 		   ADXL372_FIFO_CTL_MODE_MODE(st->fifo_mode) |
-		   ADXL372_FIFO_CTL_SAMPLES_MODE(st->watermark);
+		   ADXL372_FIFO_CTL_SAMPLES_MODE(fifo_samples);
 
-	ret = regmap_write(st->regmap, ADXL372_FIFO_SAMPLES, fifo_samples);
+	ret = regmap_write(st->regmap,
+			   ADXL372_FIFO_SAMPLES, fifo_samples & 0xFF);
 	if (ret < 0)
 		return ret;