commit 9b479412a7e43888f52840e03b57eed710e46af6
author Nico Huber <nico.h@gmx.de> Sun Aug 27 11:55:56 2017 +0200
committer Nico Huber <nico.h@gmx.de> Tue Dec 12 14:26:37 2017 +0000
tree 327ed066e30f61d7a284bb787a29c34a8332bd47
parent b7470499e80e1910ff078a55ac46a097b7f0c903

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>

common/hw-gfx-gma-config_helpers.adb

diff --git a/common/hw-gfx-gma-config_helpers.adb b/common/hw-gfx-gma-config_helpers.adb
index 6eff5d2..f2b4ef6 100644
--- a/common/hw-gfx-gma-config_helpers.adb
+++ b/common/hw-gfx-gma-config_helpers.adb
@@ -181,9 +181,9 @@
    -- Validates that a given configuration should work with
    -- a given framebuffer.
    function Validate_Config
-     (Framebuffer : Framebuffer_Type;
-      Port_Cfg    : Port_Config;
-      Pipe        : Pipe_Index)
+     (FB       : Framebuffer_Type;
+      Port_Cfg : Port_Config;
+      Pipe     : Pipe_Index)
       return Boolean
    is
    begin
@@ -193,18 +193,21 @@
       -- Only 32bpp RGB (ignored for VGA plane)
       -- Stride must be big enough and a multiple of 64 bytes or the tile size
       -- (ignored for VGA plane)
-      -- Tiling is only supported on newer generations (with Plane_Control)
+      -- Tiling and rotation is only supported on newer generations (with
+      -- Plane_Control)
+      -- 90 degree rotations are only supported with Y-tiling
       return
-         ((Framebuffer.Width = Pos32 (Port_Cfg.Mode.H_Visible) and
-           Framebuffer.Height = Pos32 (Port_Cfg.Mode.V_Visible)) or
-          (Framebuffer.Width <= Config.Maximum_Scalable_Width (Pipe) and
-           Framebuffer.Width <= Pos32 (Port_Cfg.Mode.H_Visible) and
-           Framebuffer.Height <= Pos32 (Port_Cfg.Mode.V_Visible))) and
-         (Framebuffer.Offset /= VGA_PLANE_FRAMEBUFFER_OFFSET or Pipe = Primary)
-         and
-         (Framebuffer.Offset = VGA_PLANE_FRAMEBUFFER_OFFSET or
-          (Framebuffer.BPC = 8 and Valid_Stride (Framebuffer) and
-           (Config.Has_Plane_Control or Framebuffer.Tiling = Linear)));
+         ((Rotated_Width (FB) = Port_Cfg.Mode.H_Visible and
+           Rotated_Height (FB) = Port_Cfg.Mode.V_Visible) or
+          (Rotated_Width (FB) <= Config.Maximum_Scalable_Width (Pipe) and
+           Rotated_Width (FB) <= Port_Cfg.Mode.H_Visible and
+           Rotated_Height (FB) <= Port_Cfg.Mode.V_Visible)) and
+         (FB.Offset /= VGA_PLANE_FRAMEBUFFER_OFFSET or Pipe = Primary) and
+         (FB.Offset = VGA_PLANE_FRAMEBUFFER_OFFSET or
+          (FB.BPC = 8 and Valid_Stride (FB) and
+           (Config.Has_Plane_Control or
+            (FB.Tiling = Linear and FB.Rotation = No_Rotation)) and
+           (FB.Tiling = Y_Tiled or not Rotation_90 (FB))));
    end Validate_Config;
 
 end HW.GFX.GMA.Config_Helpers;