[PATCH v2 1/3] iio: light: as73211: use IIO_VAL_FRACTIONAL for intensity scales

From: Javier Carrasco
Date: Wed Jan 03 2024 - 07:09:30 EST


The scale values associated to the light channels are calculated as a
division that can be better expressed as an IIO_VAL_FRACTIONAL type
instead of the current IIO_VAL_INT.

Note that the constant values used for the calculation were scaled up to
work with integers, turning the nW/cm^2 units from the datasheet into
nW/m^2, which would not be necessary with the IIO_VAL_FRACTIONAL type.
But to avoid issues from current users of the driver, the units must be
kept.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx>
---
drivers/iio/light/as73211.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/iio/light/as73211.c b/drivers/iio/light/as73211.c
index ec97a3a46839..b4c6f389a292 100644
--- a/drivers/iio/light/as73211.c
+++ b/drivers/iio/light/as73211.c
@@ -356,25 +356,24 @@ static int as73211_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec cons
return IIO_VAL_INT_PLUS_MICRO;

case IIO_INTENSITY: {
- unsigned int scale;

switch (chan->channel2) {
case IIO_MOD_X:
- scale = AS73211_SCALE_X;
+ *val = AS73211_SCALE_X;
break;
case IIO_MOD_Y:
- scale = AS73211_SCALE_Y;
+ *val = AS73211_SCALE_Y;
break;
case IIO_MOD_Z:
- scale = AS73211_SCALE_Z;
+ *val = AS73211_SCALE_Z;
break;
default:
return -EINVAL;
}
- scale /= as73211_gain(data);
- scale /= as73211_integration_time_1024cyc(data);
- *val = scale;
- return IIO_VAL_INT;
+ *val2 = as73211_integration_time_1024cyc(data) *
+ as73211_gain(data);
+
+ return IIO_VAL_FRACTIONAL;

default:
return -EINVAL;

--
2.39.2