staging:iio:ad7780: Report scale as fractional value

Move the complexity of calculating the fixed point scale to the core.

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

diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c
index 4f2522a..273add3 100644 (file)
--- a/drivers/staging/iio/adc/ad7780.c
+++ b/drivers/staging/iio/adc/ad7780.c
@@ -90,17 +90,14 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
                           long m)
 {
        struct ad7780_state *st = iio_priv(indio_dev);
-       unsigned long scale_uv;
 
        switch (m) {
        case IIO_CHAN_INFO_RAW:
                return ad_sigma_delta_single_conversion(indio_dev, chan, val);
        case IIO_CHAN_INFO_SCALE:
-               scale_uv = (st->int_vref_mv * 100000 * st->gain)
-                       >> (chan->scan_type.realbits - 1);
-               *val =  scale_uv / 100000;
-               *val2 = (scale_uv % 100000) * 10;
-               return IIO_VAL_INT_PLUS_MICRO;
+               *val = st->int_vref_mv * st->gain;
+               *val2 = chan->scan_type.realbits - 1;
+               return IIO_VAL_FRACTIONAL_LOG2;
        case IIO_CHAN_INFO_OFFSET:
                *val -= (1 << (chan->scan_type.realbits - 1));
                return IIO_VAL_INT;