Move the complexity of calculating the fixed point scale to the core.
Also fix a off by one error in the comment describing the transfer function.
Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
---
drivers/iio/dac/ad5764.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/iio/dac/ad5764.c b/drivers/iio/dac/ad5764.c
index df7e028..a8ff5b2 100644
--- a/drivers/iio/dac/ad5764.c
+++ b/drivers/iio/dac/ad5764.c
@@ -217,7 +217,6 @@ static int ad5764_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val, int *val2, long info)
{
struct ad5764_state *st = iio_priv(indio_dev);
- unsigned long scale_uv;
unsigned int reg;
int vref;
int ret;
@@ -245,15 +244,14 @@ static int ad5764_read_raw(struct iio_dev *indio_dev,
*val = sign_extend32(*val, 5);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
- /* vout = 4 * vref + ((dac_code / 65535) - 0.5) */
+ /* vout = 4 * vref + ((dac_code / 65536) - 0.5) */
vref = ad5764_get_channel_vref(st, chan->channel);
if (vref < 0)
return vref;
- scale_uv = (vref * 4 * 100) >> chan->scan_type.realbits;
- *val = scale_uv / 100000;
- *val2 = (scale_uv % 100000) * 10;
- return IIO_VAL_INT_PLUS_MICRO;
+ *val = vref * 4 / 1000;
+ *val2 = chan->scan_type.realbits;
+ return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
*val = -(1 << chan->scan_type.realbits) / 2;
return IIO_VAL_INT;
--
1.8.0
--
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