iio:ad5791: 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/iio/dac/ad5791.c b/drivers/iio/dac/ad5791.c
index 3cee89b..d64acbd 100644
--- a/drivers/iio/dac/ad5791.c
+++ b/drivers/iio/dac/ad5791.c
@@ -270,9 +270,9 @@
*val >>= chan->scan_type.shift;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
- *val = 0;
- *val2 = (((u64)st->vref_mv) * 1000000ULL) >> chan->scan_type.realbits;
- return IIO_VAL_INT_PLUS_MICRO;
+ *val = st->vref_mv;
+ *val2 = (1 << chan->scan_type.realbits) - 1;
+ return IIO_VAL_FRACTIONAL;
case IIO_CHAN_INFO_OFFSET:
val64 = (((u64)st->vref_neg_mv) << chan->scan_type.realbits);
do_div(val64, st->vref_mv);