From: Abhash Jha Date: Wed, 14 Aug 2024 11:31:34 +0000 (+0530) Subject: iio: light: ltr390: Calculate 'counts_per_uvi' dynamically X-Git-Tag: v6.12-rc1~39^2~37^2~8 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4bd7e5ce519a9f1de1a58fb10438e45aa9cc85ca;p=thirdparty%2Fkernel%2Flinux.git iio: light: ltr390: Calculate 'counts_per_uvi' dynamically counts_per_uvi depends on the current value of gain and resolution. Hence, we cannot use the hardcoded value 96. The `counts_per_uvi` function gives the count based on the current gain and resolution (integration time). Signed-off-by: Abhash Jha Link: https://patch.msgid.link/20240814113135.14575-3-abhashkumarjha123@gmail.com Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/light/ltr390.c b/drivers/iio/light/ltr390.c index 16e06f2ab8783..7e58b50f36603 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: