As an appendix to the instructions posted by Aldrin in comment #11, if you want to install the module in a more permanent way, replace the last step (sudo insmod ...) by this:
$ uname -r > include/config/kernel.release
$ sudo make M=drivers/video/backlight modules_install
As an appendix to the instructions posted by Aldrin in comment #11, if you want to install the module in a more permanent way, replace the last step (sudo insmod ...) by this: config/ kernel. release video/backlight modules_install
$ uname -r > include/
$ sudo make M=drivers/