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/hw-gfx-gma-config_helpers.adb b/common/hw-gfx-gma-config_helpers.adb
index 868d514..3b55968 100644
--- a/common/hw-gfx-gma-config_helpers.adb
+++ b/common/hw-gfx-gma-config_helpers.adb
@@ -29,15 +29,22 @@
begin
return
(case Config.Gen is
+ when I945 => -- LVDS, VGA, SDVO B/C on GMCH
+ (case Port is
+ when LVDS => LVDS,
+ when HDMI1 | DP1 => DIGI_B, -- SDVO B
+ when HDMI2 | DP2 => DIGI_C, -- SDVO C
+ when Analog => VGA,
+ when others => DIGI_A), -- n/a, actually
when G45 => -- everything on GMCH
- (case Port is
- when LVDS => LVDS,
- when eDP => DIGI_A, -- n/a, actually
- when HDMI1 | DP1 => DIGI_B,
- when HDMI2 | DP2 => DIGI_C,
- when HDMI3 | DP3 => DIGI_D,
- when Analog => VGA,
- when others => DIGI_A), -- n/a, actually
+ (case Port is
+ when LVDS => LVDS,
+ when eDP => DIGI_A, -- n/a, actually
+ when HDMI1 | DP1 => DIGI_B,
+ when HDMI2 | DP2 => DIGI_C,
+ when HDMI3 | DP3 => DIGI_D,
+ when Analog => VGA,
+ when others => DIGI_A), -- n/a, actually
when Ironlake => -- everything but eDP through FDI/PCH
(if Port = eDP then
DIGI_A