Move the complexity of calculating the fixed point scale to the core.
Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
---
drivers/iio/adc/ad7791.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/iio/adc/ad7791.c b/drivers/iio/adc/ad7791.c
index c202035..c19f8fd 100644
--- a/drivers/iio/adc/ad7791.c
+++ b/drivers/iio/adc/ad7791.c
@@ -202,7 +202,6 @@ static int ad7791_read_raw(struct iio_dev *indio_dev,
{
struct ad7791_state *st = iio_priv(indio_dev);
bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR);
- unsigned long long scale_pv;
switch (info) {
case IIO_CHAN_INFO_RAW:
@@ -220,23 +219,26 @@ static int ad7791_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_SCALE:
/* The monitor channel uses an internal reference. */
if (chan->address == AD7791_CH_AVDD_MONITOR) {
- scale_pv = 5850000000000ULL;
+ /*
+ * The signal is attenuated by a factor of 5 and
+ * compared against a 1.17V internal reference.
+ */
+ *val = 1170 * 5;
} else {
int voltage_uv;
voltage_uv = regulator_get_voltage(st->reg);
if (voltage_uv < 0)
return voltage_uv;
- scale_pv = (unsigned long long)voltage_uv * 1000000;
+
+ *val = voltage_uv / 1000;
}
if (unipolar)
- scale_pv >>= chan->scan_type.realbits;
+ *val2 = chan->scan_type.realbits;
else
- scale_pv >>= chan->scan_type.realbits - 1;
- *val2 = do_div(scale_pv, 1000000000);
- *val = scale_pv;
+ *val2 = chan->scan_type.realbits - 1;
- return IIO_VAL_INT_PLUS_NANO;
+ return IIO_VAL_FRACTIONAL_LOG2;
}
return -EINVAL;
--
1.8.0
--
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