Loading nouveau.ko would fail with unknown symbols, if the backlight
class device support is not provided in the kernel. Let's make the
backlight support dependant on the kernel configuration.
This is a bit ugly, the proper way would be to check for the config in
Makefile.kernel whether to build nouveau_backlight.o at all, and if not,
nouveau_drv.h should provide the stubs.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Several nvidia-based systems don't support backlight control via the
standard ACPI control mechanisms. Instead, it's necessary for the driver
to modify the backlight control registers directly. This patch adds
support for determining whether the registers appear to be in use, and
if so registers a kernel backlight device to control them. The backlight
can then be controlled via existing userspace tools.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Pekka Paalanen
Matthew Garrett