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-port_detect.adb b/common/g45/hw-gfx-gma-port_detect.adb
new file mode 100644
index 0000000..c865079
--- /dev/null
+++ b/common/g45/hw-gfx-gma-port_detect.adb
@@ -0,0 +1,124 @@
+--
+-- Copyright (C) 2016-2017 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.GFX.GMA.Config;
+with HW.GFX.GMA.Registers;
+with HW.GFX.GMA.Config_Helpers;
+
+package body HW.GFX.GMA.Port_Detect
+is
+
+   PORT_DETECTED                    : constant := 1 * 2 **  2;
+
+   PORTB_HOTPLUG_INT_EN             : constant := 1 * 2 ** 29;
+   PORTC_HOTPLUG_INT_EN             : constant := 1 * 2 ** 28;
+   PORTD_HOTPLUG_INT_EN             : constant := 1 * 2 ** 27;
+   SDVOB_HOTPLUG_INT_EN             : constant := 1 * 2 ** 26;
+   SDVOC_HOTPLUG_INT_EN             : constant := 1 * 2 ** 25;
+   CRT_HOTPLUG_INT_EN               : constant := 1 * 2 ** 9;
+   CRT_HOTPLUG_ACTIVATION_PERIOD_64 : constant := 1 * 2 ** 8;
+
+   type HDMI_Port_Value is array (GMCH_HDMI_Port) of Word32;
+   type DP_Port_Value is array (GMCH_DP_Port) of Word32;
+   HDMI_PORT_HOTPLUG_EN : constant HDMI_Port_Value :=
+     (DIGI_B => SDVOB_HOTPLUG_INT_EN,
+      DIGI_C => SDVOC_HOTPLUG_INT_EN);
+   DP_PORT_HOTPLUG_EN : constant DP_Port_Value :=
+     (DIGI_B => PORTB_HOTPLUG_INT_EN,
+      DIGI_C => PORTC_HOTPLUG_INT_EN,
+      DIGI_D => PORTD_HOTPLUG_INT_EN);
+
+   type HDMI_Regs is array (GMCH_HDMI_Port) of Registers.Registers_Index;
+   type DP_Regs is array (GMCH_DP_Port) of Registers.Registers_Index;
+   GMCH_HDMI : constant HDMI_Regs :=
+     (DIGI_B => Registers.GMCH_HDMIB,
+      DIGI_C => Registers.GMCH_HDMIC);
+   GMCH_DP : constant DP_Regs :=
+     (DIGI_B => Registers.GMCH_DP_B,
+      DIGI_C => Registers.GMCH_DP_C,
+      DIGI_D => Registers.GMCH_DP_D);
+
+   HOTPLUG_INT_STATUS : constant array (Active_Port_Type) of word32 :=
+     (DP1    => 3 * 2 ** 17,
+      DP2    => 3 * 2 ** 19,
+      DP3    => 3 * 2 ** 21,
+      HDMI1  => 1 * 2 **  2,
+      HDMI2  => 1 * 2 **  3,
+      Analog => 1 * 2 ** 11,
+      others => 0);
+
+   procedure Initialize
+   is
+      Detected : Boolean;
+      hotplug_mask_set : Word32 :=
+        CRT_HOTPLUG_INT_EN or CRT_HOTPLUG_ACTIVATION_PERIOD_64;
+
+      To_HDMI_Port : constant array (GMCH_HDMI_Port) of Port_Type :=
+        (DIGI_B => HDMI1,
+         DIGI_C => HDMI2);
+      To_DP_Port : constant array (GMCH_DP_Port) of Port_Type :=
+        (DIGI_B => DP1,
+         DIGI_C => DP2,
+         DIGI_D => DP3);
+
+   begin
+      for HDMI_Port in GMCH_HDMI_Port loop
+         Registers.Is_Set_Mask
+           (Register => GMCH_HDMI (HDMI_Port),
+            Mask     => PORT_DETECTED,
+            Result   => Detected);
+         Config.Valid_Port (To_HDMI_Port (HDMI_Port)) := Detected;
+         hotplug_mask_set := hotplug_mask_set or
+           (if Detected then HDMI_PORT_HOTPLUG_EN (HDMI_Port) else 0);
+      end loop;
+      for DP_Port in GMCH_DP_Port loop
+         Registers.Is_Set_Mask
+           (Register => GMCH_DP (DP_Port),
+            Mask     => PORT_DETECTED,
+            Result   => Detected);
+         Config.Valid_Port (To_DP_Port (DP_Port)) := Detected;
+         hotplug_mask_set := hotplug_mask_set or
+           (if Detected then DP_PORT_HOTPLUG_EN (DP_Port) else 0);
+      end loop;
+      Registers.Write
+        (Register => Registers.PORT_HOTPLUG_EN,
+         Value => hotplug_mask_set);
+   end Initialize;
+
+   procedure Hotplug_Detect (Port : in Active_Port_Type; Detected : out Boolean)
+   is
+      Ctl32 : Word32;
+   begin
+      Registers.Read (Register => Registers.PORT_HOTPLUG_STAT,
+                      Value    => Ctl32);
+      Detected := (Ctl32 and HOTPLUG_INT_STATUS (Port)) /= 0;
+
+      if Detected then
+         registers.Set_Mask
+           (Register => Registers.PORT_HOTPLUG_STAT,
+            Mask     => HOTPLUG_INT_STATUS (Port));
+      end if;
+   end Hotplug_Detect;
+
+   procedure Clear_Hotplug_Detect (Port : Active_Port_Type)
+   is
+      Ignored_HPD : Boolean;
+   begin
+      pragma Warnings (GNATprove, Off, "unused assignment to ""Ignored_HPD""",
+                       Reason => "We want to clear pending events only");
+      Port_Detect.Hotplug_Detect (Port, Ignored_HPD);
+      pragma Warnings (GNATprove, On, "unused assignment to ""Ignored_HPD""");
+   end Clear_Hotplug_Detect;
+
+end HW.GFX.GMA.Port_Detect;