diff options
| -rw-r--r-- | drivers/iio/light/ltr390.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/iio/light/ltr390.c b/drivers/iio/light/ltr390.c index 16e06f2ab878..7e58b50f3660 100644 --- a/drivers/iio/light/ltr390.c +++ b/drivers/iio/light/ltr390.c @@ -46,6 +46,8 @@ #define LTR390_UVS_MODE BIT(3) #define LTR390_SENSOR_ENABLE BIT(1) +#define LTR390_FRACTIONAL_PRECISION 100 + /* * At 20-bit resolution (integration time: 400ms) and 18x gain, 2300 counts of * the sensor are equal to 1 UV Index [Datasheet Page#8]. @@ -125,6 +127,14 @@ static int ltr390_set_mode(struct ltr390_data *data, enum ltr390_mode mode) return 0; } +static int ltr390_counts_per_uvi(struct ltr390_data *data) +{ + const int orig_gain = 18; + const int orig_int_time = 400; + + return DIV_ROUND_CLOSEST(23 * data->gain * data->int_time_us, 10 * orig_gain * orig_int_time); +} + static int ltr390_read_raw(struct iio_dev *iio_device, struct iio_chan_spec const *chan, int *val, int *val2, long mask) @@ -164,8 +174,8 @@ static int ltr390_read_raw(struct iio_dev *iio_device, case IIO_CHAN_INFO_SCALE: switch (chan->type) { case IIO_UVINDEX: - *val = LTR390_WINDOW_FACTOR; - *val2 = LTR390_COUNTS_PER_UVI; + *val = LTR390_WINDOW_FACTOR * LTR390_FRACTIONAL_PRECISION; + *val2 = ltr390_counts_per_uvi(data); return IIO_VAL_FRACTIONAL; case IIO_LIGHT: |