staging:iio:ad7291: Use IIO_VAL_FRACTIONAL_LOG2

This is a bit more straight forward and also allows better precession when using
the an in-kernel consumer.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/staging/iio/adc/ad7291.c b/drivers/staging/iio/adc/ad7291.c
index d088c66..a3a3a2f 100644 (file)
--- a/drivers/staging/iio/adc/ad7291.c
+++ b/drivers/staging/iio/adc/ad7291.c
@@ -456,7 +456,6 @@ static int ad7291_read_raw(struct iio_dev *indio_dev,
 {
        int ret;
        struct ad7291_chip_info *chip = iio_priv(indio_dev);
-       unsigned int scale_uv;
        u16 regval;
        s16 signval;
 
@@ -513,10 +512,9 @@ static int ad7291_read_raw(struct iio_dev *indio_dev,
        case IIO_CHAN_INFO_SCALE:
                switch (chan->type) {
                case IIO_VOLTAGE:
-                       scale_uv = (chip->int_vref_mv * 1000) >> AD7291_BITS;
-                       *val =  scale_uv / 1000;
-                       *val2 = (scale_uv % 1000) * 1000;
-                       return IIO_VAL_INT_PLUS_MICRO;
+                       *val = chip->int_vref_mv;
+                       *val2 = AD7291_BITS;
+                       return IIO_VAL_FRACTIONAL_LOG2;
                case IIO_TEMP:
                        /*
                         * One LSB of the ADC corresponds to 0.25 deg C.