[PATCH v2 2/2] iio: accel: adxl380: Optimize reading of FIFO entries in interrupt handler

[Francesco Lavra]

In order to minimize the time required for transferring FIFO data from the
sensor to the host machine, perform the read from the FIFO in a single call
to regmap_bulk_read().
This allows reading acceleration data for all 3 axes at 16 kHz
sampling frequency using a 1MHz I2C bus frequency.

Signed-off-by: Francesco Lavra <flavra@xxxxxxxxxxxx>
---
 drivers/iio/accel/adxl380.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/accel/adxl380.c b/drivers/iio/accel/adxl380.c
index 650cdbffd4a7..e3e6b182eb3d 100644
--- a/drivers/iio/accel/adxl380.c
+++ b/drivers/iio/accel/adxl380.c
@@ -965,14 +965,12 @@ static irqreturn_t adxl380_irq_handler(int irq, void  *p)
 		return IRQ_HANDLED;
 
 	fifo_entries = rounddown(fifo_entries, st->fifo_set_size);
-	for (i = 0; i < fifo_entries; i += st->fifo_set_size) {
-		ret = regmap_noinc_read(st->regmap, ADXL380_FIFO_DATA,
-					&st->fifo_buf[i],
-					2 * st->fifo_set_size);
-		if (ret)
-			return IRQ_HANDLED;
+	ret = regmap_noinc_read(st->regmap, ADXL380_FIFO_DATA, &st->fifo_buf,
+				sizeof(*st->fifo_buf) * fifo_entries);
+	if (ret)
+		return IRQ_HANDLED;
+	for (i = 0; i < fifo_entries; i += st->fifo_set_size)
 		iio_push_to_buffers(indio_dev, &st->fifo_buf[i]);
-	}
 
 	return IRQ_HANDLED;
 }
-- 
2.39.5