f5ffeca508
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 <shreeya.patel@collabora.com> Link: https://lore.kernel.org/r/20220812100424.529425-1-shreeya.patel@collabora.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.