drivers/intel/gma: Export Read_EDID() to C

Change-Id: Icf802904c569e621ca3b3105b6107936776c5cee
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31458
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/drivers/intel/gma/Kconfig

@@ -54,6 +54,9 @@ config INTEL_GMA_SWSMISCI
 	  Select this option for Atom-based platforms which use the SWSMISCI
 	  register (0xe0) rather than the SWSCI register (0xe8).
 
+config INTEL_GMA_LIBGFXINIT_EDID
+	bool
+
 config GFX_GMA_ANALOG_I2C_HDMI_B
 	bool
 
@@ -71,7 +74,7 @@ config GFX_GMA
 		|| SOC_INTEL_BROADWELL || SOC_INTEL_SKYLAKE || SOC_INTEL_APOLLOLAKE \
 		|| SOC_INTEL_KABYLAKE || SOC_INTEL_COFFEELAKE \
 		|| SOC_INTEL_WHISKEYLAKE
-	depends on MAINBOARD_USE_LIBGFXINIT
+	depends on MAINBOARD_USE_LIBGFXINIT || INTEL_GMA_LIBGFXINIT_EDID
 	select RAMSTAGE_LIBHWBASE
 
 config GFX_GMA_INTERNAL_IS_EDP

src/drivers/intel/gma/Makefile.inc

@@ -50,7 +50,7 @@ CONFIG_GFX_GMA_DEFAULT_MMIO := 0 # dummy, will be overwritten at runtime
 
 subdirs-y += ../../../../3rdparty/libgfxinit
 
-ramstage-y += gma.ads
+ramstage-y += gma.ads gma.adb
 
 ramstage-$(CONFIG_MAINBOARD_USE_LIBGFXINIT) += gma-gfx_init.ads
 ifeq ($(CONFIG_LINEAR_FRAMEBUFFER),y)

src/drivers/intel/gma/gma.adb

@@ -0,0 +1,37 @@
+with HW.GFX.GMA;
+with HW.GFX.GMA.Display_Probing;
+
+use HW.GFX.GMA;
+
+package body GMA is
+
+   function read_edid
+     (raw_edid :    out HW.GFX.EDID.Raw_EDID_Data;
+      port     : in     Interfaces.C.int)
+      return Interfaces.C.int
+   is
+      use type Interfaces.C.int;
+      success : Boolean := true;
+   begin
+      if port not in Active_Port_Type'Pos (Active_Port_Type'First)
+                     .. Active_Port_Type'Pos (Active_Port_Type'Last)
+      then
+         raw_edid := (others => 0);
+         return -2;
+      else
+         if not HW.GFX.GMA.Is_Initialized then
+            HW.GFX.GMA.Initialize (Success => success);
+         end if;
+         if success then
+            HW.GFX.GMA.Display_Probing.Read_EDID
+              (raw_edid, Active_Port_Type'Val (port), success);
+         end if;
+         if success then
+            return 0;
+         else
+            return -1;
+         end if;
+      end if;
+   end read_edid;
+
+end GMA;

src/drivers/intel/gma/gma.ads

@@ -1,2 +1,14 @@
+with Interfaces.C;
+
+with HW.GFX.EDID;
+
 package GMA is
+
+   function read_edid
+     (raw_edid :    out HW.GFX.EDID.Raw_EDID_Data;
+      Port     : in     Interfaces.C.int)
+      return Interfaces.C.int
+   with
+      Export, Convention => C, External_Name => "gma_read_edid";
+
 end GMA;

src/drivers/intel/gma/libgfxinit.h

@@ -14,6 +14,19 @@
 #ifndef DRIVERS_INTEL_GMA_LIBGFXINIT_H
 #define DRIVERS_INTEL_GMA_LIBGFXINIT_H
 
+enum {
+	GMA_PORT_DISABLED,
+	GMA_PORT_INTERNAL,
+	GMA_PORT_DP1,
+	GMA_PORT_DP2,
+	GMA_PORT_DP3,
+	GMA_PORT_HDMI1,	/* or DVI */
+	GMA_PORT_HDMI2,	/* or DVI */
+	GMA_PORT_HDMI3,	/* or DVI */
+	GMA_PORT_ANALOG,
+};
+
 void gma_gfxinit(int *lightup_ok);
+int gma_read_edid(unsigned char edid[], int port);
 
 #endif