gma: Add G45 support

The following ports are implemented: HDMI/DVI, VGA, LVDS and DP.

Tested with gfx_test and coreboot on a Thinkpad X200 (GM45).

Change-Id: Ifc05a1516329a61772af84558e5bfceb4d4ca277
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/21295
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: Nico Huber <nico.h@gmx.de>
diff --git a/common/g45/hw-gfx-gma-power_and_clocks.adb b/common/g45/hw-gfx-gma-power_and_clocks.adb
new file mode 100644
index 0000000..d6ee9f9
--- /dev/null
+++ b/common/g45/hw-gfx-gma-power_and_clocks.adb
@@ -0,0 +1,50 @@
+--
+-- Copyright (C) 2016 secunet Security Networks AG
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; either version 2 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+
+with HW.Time;
+with HW.GFX.GMA.Config;
+with HW.GFX.GMA.Registers;
+
+package body HW.GFX.GMA.Power_And_Clocks is
+
+   FSB_FREQ_SEL_MASK : constant := 7 * 2 ** 0;
+   CLKCFG_FSB_400    : constant Frequency_Type := 100_000_000;
+   CLKCFG_FSB_533    : constant Frequency_Type := 133_333_333;
+   CLKCFG_FSB_667    : constant Frequency_Type := 166_666_666;
+   CLKCFG_FSB_800    : constant Frequency_Type := 200_000_000;
+   CLKCFG_FSB_1067   : constant Frequency_Type := 266_666_666;
+   CLKCFG_FSB_1333   : constant Frequency_Type := 333_333_333;
+
+   -- The Raw Freq is 1/4 of the FSB freq
+   procedure Initialize
+   is
+      CLK_CFG : Word32;
+      type Freq_Sel is new Natural range 0 .. 7;
+   begin
+      Registers.Read
+        (Register => Registers.GMCH_CLKCFG,
+         Value => CLK_CFG);
+      case Freq_Sel (CLK_CFG and FSB_FREQ_SEL_MASK) is
+         when 0      => Config.Raw_Clock := CLKCFG_FSB_1067;
+         when 1      => Config.Raw_Clock := CLKCFG_FSB_533;
+         when 2      => Config.Raw_Clock := CLKCFG_FSB_800;
+         when 3      => Config.Raw_Clock := CLKCFG_FSB_667;
+         when 4      => Config.Raw_Clock := CLKCFG_FSB_1333;
+         when 5      => Config.Raw_Clock := CLKCFG_FSB_400;
+         when 6      => Config.Raw_Clock := CLKCFG_FSB_1067;
+         when 7      => Config.Raw_Clock := CLKCFG_FSB_1333;
+      end case;
+   end Initialize;
+
+end HW.GFX.GMA.Power_And_Clocks;