make -C /lib/modules/$(uname -r)/build M=$(pwd) modules | pastebinit/home/atools/source/ideapad-laptop.c: In function ‘ideapad_acpi_add’:
/home/atools/source/ideapad-laptop.c:955:2: error: implicit declaration of function ‘acpi_video_get_backlight_type’ [-Werror=implicit-function-declaration]
  if (acpi_video_get_backlight_type() == acpi_backlight_vendor) {
  ^
/home/atools/source/ideapad-laptop.c:955:41: error: ‘acpi_backlight_vendor’ undeclared (first use in this function)
  if (acpi_video_get_backlight_type() == acpi_backlight_vendor) {
                                         ^
/home/atools/source/ideapad-laptop.c:955:41: note: each undeclared identifier is reported only once for each function it appears in
cc1: some warnings being treated as errors
make[1]: *** [/home/atools/source/ideapad-laptop.o] Error 1
make: *** [_module_/home/atools/source] Error 2