Logs from Linux' i915 suggest that not even the FSP/GOP takes proper
care of this. The sequence is mostly the same as on older platforms,
with a slightly different configuration of the backlight PWM.
We light the panel up with 50% PWM duty cycle. This often results in
an already rather high perceived brightness, but shouldn't be too
blinding.
Change-Id: I762a77c8df023a4c14af502af5edfeeb961da1ae
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/30246
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>