iio: accel: adxl380: Optimize reading of FIFO entries in interrupt handler

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_noinc_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@baylibre.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/accel/adxl380.c b/drivers/iio/accel/adxl380.c
index a77c2323d1aa48744f854cd537b4bf72ed2ccbad..8870d22e8cdddba9a45b979d0b07986ead8a447d 100644 (file)
--- a/drivers/iio/accel/adxl380.c
+++ b/drivers/iio/accel/adxl380.c
@@ -967,14 +967,12 @@ 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;
 }