mb/starlabs/starbook: Add CFR option to use native panel resolution

For boards for which set the 'Fixed Mode at boot' flag in the VBT, add
a CFR option to boot using the native panel resolution, rather than
a fixed/scaled video mode. This option selects between two VBT files:
one with the 'fixed mode' flag enabled, and one with it disabled.

This feature is mainly a workaround to a GNOME-related bug which
causes the creation of a 2nd display at the boot resolution. This
2nd display being a lower/different resolution than the native
panel resolution causes severe flickering/artifacting rendering
the display unusable unless this 2nd phantom display is disabled
on every boot

Change-Id: Ia75727f393744caf9062763e6118c1e2601512fa
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/87493
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sean Rhodes <sean@starlabs.systems>
Reviewed-by: Alicja Michalska <ahplka19@gmail.com>

src/mainboard/starlabs/starbook/Kconfig

@@ -264,4 +264,9 @@ config BOARD_SUPPORTS_HOTPLUG
 	default y if BOARD_STARLABS_STARBOOK_ADL
 	default n
 
+config BOARD_USES_FIXED_MODE_VBT
+	bool
+	default y if BOARD_STARLABS_STARBOOK_ADL_N || BOARD_STARLABS_STARBOOK_MTL
+	default n
+
 endif

src/mainboard/starlabs/starbook/cfr.c

@@ -57,6 +57,9 @@ static struct sm_obj_form devices = {
 	.ui_name = "Devices",
 	.obj_list = (const struct sm_object *[]) {
 		&card_reader,
+		#if CONFIG(BOARD_USES_FIXED_MODE_VBT)
+		&display_native_res,
+		#endif
 		#if CONFIG(BOARD_HAS_FPR)
 		&fingerprint_reader,
 		#endif

src/mainboard/starlabs/starbook/cfr.h

@@ -209,4 +209,12 @@ static const struct sm_object bluetooth_rtd3 = SM_DECLARE_BOOL({
 	.default_value	= true,
 });
 
+static const struct sm_object display_native_res = SM_DECLARE_BOOL({
+	.opt_name	= "display_native_res",
+	.ui_name	= "Display: Use Native Resolution",
+	.ui_helptext	= "Enabled: use the native panel resolution at boot.\n"
+			  "Disabled: use a fixed/scaled video mode at boot.",
+	.default_value	= false,
+});
+
 #endif /* _STARBOOK_CFR_H_ */

src/mainboard/starlabs/starbook/mainboard.c

@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <device/device.h>
+#include <drivers/intel/gma/opregion.h>
 #include <soc/ramstage.h>
 #include <option.h>
 #include <variants.h>
@@ -25,3 +26,11 @@ static void init_mainboard(void *chip_info)
 struct chip_operations mainboard_ops = {
 	.init = init_mainboard,
 };
+
+const char *mainboard_vbt_filename(void)
+{
+	if (CONFIG(BOARD_USES_FIXED_MODE_VBT) && get_uint_option("display_native_res", 0) == 1)
+		return "vbt_native_res.bin";
+
+	return "vbt.bin";
+}

src/mainboard/starlabs/starbook/variants/adl_n/Makefile.mk

@@ -8,3 +8,5 @@ ramstage-y += devtree.c
 ramstage-y += gpio.c
 ramstage-y += hda_verb.c
 ramstage-y += ramstage.c
+
+$(call add_vbt_to_cbfs, vbt_native_res.bin, data_native_res.vbt)

src/mainboard/starlabs/starbook/variants/mtl/Makefile.mk

@@ -7,3 +7,5 @@ romstage-y += romstage.c
 ramstage-y += devtree.c
 ramstage-y += gpio.c
 ramstage-y += hda_verb.c
+
+$(call add_vbt_to_cbfs, vbt_native_res.bin, data_native_res.vbt)