From f5ffeca5086fef68765f3c1dbc9a12183833adf0 Mon Sep 17 00:00:00 2001 From: Shreeya Patel Date: Fri, 12 Aug 2022 15:34:24 +0530 Subject: [PATCH] iio: light: ltrf216a: Add raw attribute Add IIO_CHAN_INFO_RAW to the mask to be able to read raw values from the light sensor. The userspace code for brightness control in steam deck uses the in_illuminance_input value through sysfs and multiplies it with a constant stored in BIOS at factory calibration time. The downstream driver for LTRF216A that we have been using has incorrect formula for LUX calculation which we corrected in the upstreamed driver. Now to be able to use the upstreamed driver, we need to add some magic in userspace so that the brightness control works like before even with the updated LUX formula. Hence, we need the raw data to calculate a constant that can be added in userspace code. Downstream driver LUX formula :- (greendata*8*LTRF216A_WIN_FAC) / (data->als_gain_fac*data->int_time_fac*10) Upstreamed driver LUX formula :- (greendata*45*LTRF216A_WIN_FAC) / (data->als_gain_fac*data->int_time_fac) greendata is the ALS_DATA which we would like to get through sysfs using the raw attribute. Signed-off-by: Shreeya Patel Link: https://lore.kernel.org/r/20220812100424.529425-1-shreeya.patel@collabora.com Signed-off-by: Jonathan Cameron --- drivers/iio/light/ltrf216a.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/iio/light/ltrf216a.c b/drivers/iio/light/ltrf216a.c index e6e24e70d2b9a..4b8ef36b69125 100644 --- a/drivers/iio/light/ltrf216a.c +++ b/drivers/iio/light/ltrf216a.c @@ -93,6 +93,7 @@ static const struct iio_chan_spec ltrf216a_channels[] = { { .type = IIO_LIGHT, .info_mask_separate = + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_PROCESSED) | BIT(IIO_CHAN_INFO_INT_TIME), .info_mask_separate_available = @@ -259,6 +260,18 @@ static int ltrf216a_read_raw(struct iio_dev *indio_dev, int ret; switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = ltrf216a_set_power_state(data, true); + if (ret) + return ret; + mutex_lock(&data->lock); + ret = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0); + mutex_unlock(&data->lock); + ltrf216a_set_power_state(data, false); + if (ret < 0) + return ret; + *val = ret; + return IIO_VAL_INT; case IIO_CHAN_INFO_PROCESSED: mutex_lock(&data->lock); ret = ltrf216a_get_lux(data); -- 2.30.2