gma: Add Intel i945 (Gen3) graphics init support
Add i945G (desktop) and i945GM (mobile) generation support, modeled
after the existing G45 generation code with hardware-specific
adaptations based on the Linux i915 DRM driver and coreboot.
Key hardware differences from G45 (Gen4):
- GTT on separate PCI BAR3 (not within BAR0)
- Simple 32-bit GTT PTEs (addr[31:12] | valid[0])
- No DSPSURF register (uses DSPADDR/DSPLINOFF instead)
- Gen3 fence registers: 32-bit at split 0x2000/0x3000 addresses
- Different PLL limits (VCO 1400-2800 MHz, 96 MHz refclk)
- SDVO multiplier in DPLL register bits[7:4]
- LVDS restricted to Pipe B (pre-i965 requirement)
- CDClk: fixed 400 MHz (desktop) or GCFGC-based (mobile)
- No HDMI/DP, only VGA, LVDS, and SDVO outputs
- PCI IDs: 0x2772 (I945G), 0x27a2/0x27ae (I945GM)
TESTED with thinkpad x60: LVDS & VGA works with a linear framebuffer.
Change-Id: Ib67b3d0ee5e06df427869dce4db926ba57a80fd8
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.sourcearcade.org/c/libgfxinit/+/476
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: Nico Huber <nico.h@gmx.de>
diff --git a/common/i945/hw-gfx-gma-connectors.adb b/common/i945/hw-gfx-gma-connectors.adb
new file mode 100644
index 0000000..e774227
--- /dev/null
+++ b/common/i945/hw-gfx-gma-connectors.adb
@@ -0,0 +1,104 @@
+--
+-- Copyright (C) 2026 Arthur Heymans <arthur@aheymans.xyz>
+--
+-- 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.Panel;
+with HW.GFX.GMA.GMCH.VGA;
+with HW.GFX.GMA.GMCH.LVDS;
+
+with HW.Debug;
+with GNAT.Source_Info;
+
+package body HW.GFX.GMA.Connectors
+is
+
+ procedure Post_Reset_Off is null;
+ procedure Initialize is null;
+
+ ----------------------------------------------------------------------------
+
+ procedure Pre_On
+ (Pipe : in Pipe_Index;
+ Port_Cfg : in Port_Config;
+ PLL_Hint : in Word32;
+ Success : out Boolean)
+ is
+ begin
+ pragma Debug (Debug.Put_Line (GNAT.Source_Info.Enclosing_Entity));
+ Success := True;
+ end Pre_On;
+
+ procedure Post_On
+ (Pipe : in Pipe_Index;
+ Port_Cfg : in Port_Config;
+ PLL_Hint : in Word32;
+ Success : out Boolean)
+ is
+ begin
+ pragma Debug (Debug.Put_Line (GNAT.Source_Info.Enclosing_Entity));
+ Success := True;
+ if Port_Cfg.Port = LVDS then
+ GMCH.LVDS.On (Port_Cfg, Pipe);
+ elsif Port_Cfg.Port = VGA then
+ GMCH.VGA.On (Pipe, Port_Cfg.Mode);
+ end if;
+
+ Panel.On (Port_Cfg.Panel, Wait => False);
+ Panel.Backlight_On (Port_Cfg.Panel);
+ end Post_On;
+
+ ----------------------------------------------------------------------------
+
+ procedure Pre_Off (Port_Cfg : Port_Config)
+ is
+ begin
+ pragma Debug (Debug.Put_Line (GNAT.Source_Info.Enclosing_Entity));
+
+ Panel.Backlight_Off (Port_Cfg.Panel);
+ Panel.Off (Port_Cfg.Panel);
+ end Pre_Off;
+
+ procedure Post_Off (Port_Cfg : Port_Config)
+ is
+ begin
+ pragma Debug (Debug.Put_Line (GNAT.Source_Info.Enclosing_Entity));
+ if Port_Cfg.Port = LVDS then
+ GMCH.LVDS.Off;
+ elsif Port_Cfg.Port = VGA then
+ GMCH.VGA.Off;
+ end if;
+ end Post_Off;
+
+ ----------------------------------------------------------------------------
+
+ procedure Pre_All_Off
+ is
+ begin
+ pragma Debug (Debug.Put_Line (GNAT.Source_Info.Enclosing_Entity));
+
+ for P in Valid_Panels loop
+ Panel.Backlight_Off (P);
+ Panel.Off (P);
+ end loop;
+ end Pre_All_Off;
+
+ procedure Post_All_Off
+ is
+ begin
+ pragma Debug (Debug.Put_Line (GNAT.Source_Info.Enclosing_Entity));
+ GMCH.LVDS.Off;
+ GMCH.VGA.Off;
+ end Post_All_Off;
+
+end HW.GFX.GMA.Connectors;