tree 327ed066e30f61d7a284bb787a29c34a8332bd47
parent b7470499e80e1910ff078a55ac46a097b7f0c903
author Nico Huber <nico.h@gmx.de> 1503827756 +0200
committer Nico Huber <nico.h@gmx.de> 1513088797 +0000

gma: Add support for rotated framebuffers

As for the tiling, we enable support for rotated framebuffers on
platforms with Plane_Control. On every path where a rotated frame-
buffer may be expected, we have to exchange width and height in
case of 90 degree rotations. Beside the rotation setting itself,
the hardware needs to know the vertical stride instead of the hori-
zontal and a delicate page mapping in case of 90 degree rotations.
For that we divide the GTT space into two, the lower half contains
the linear mappings, the upper half mappings for a rotated scanout.

Change-Id: I1c901b7abc0fe7764bee87f6fda58ba9fa3f340d
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/22711
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: Stefan Reinauer <stefan.reinauer@coreboot.org>