2 files changed, 60 insertions, 0 deletions
diff --git a/src/mainboard/google/dedede/variants/bugzzy/Makefile.inc b/src/mainboard/google/dedede/variants/bugzzy/Makefile.inc
index fd60a18b69..74121943dd 100644
--- a/src/mainboard/google/dedede/variants/bugzzy/Makefile.inc
+++ b/src/mainboard/google/dedede/variants/bugzzy/Makefile.inc
@@ -1,5 +1,6 @@
 ## SPDX-License-Identifier: GPL-2.0-or-later
 
 ramstage-y += gpio.c
+ramstage-y += ramstage.c
 
 smm-y += variant.c
diff --git a/src/mainboard/google/dedede/variants/bugzzy/ramstage.c b/src/mainboard/google/dedede/variants/bugzzy/ramstage.c
new file mode 100644
index 0000000000..7844b6e360
--- /dev/null
+++ b/src/mainboard/google/dedede/variants/bugzzy/ramstage.c
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <bootstate.h>
+#include <arch/mmio.h>
+#include <delay.h>
+#include <bootmode.h>
+#include <device/device.h>
+#include <device/pci.h>
+#include <soc/pci_devs.h>
+#include <drivers/intel/gma/i915_reg.h>
+
+static void panel_power_on(uintptr_t igd_bar)
+{
+	setbits32((void *)(igd_bar + PCH_PP_CONTROL), PANEL_POWER_ON);
+}
+
+static void panel_reset_assert(uintptr_t igd_bar)
+{
+	clrsetbits32((void *)(igd_bar + PCH_GPIOB),
+		GPIO_CLOCK_VAL_OUT,
+		GPIO_CLOCK_DIR_MASK | GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_VAL_MASK);
+}
+
+static void panel_reset_deassert(uintptr_t igd_bar)
+{
+	const uint32_t data32 = GPIO_CLOCK_VAL_OUT |
+		GPIO_CLOCK_DIR_MASK | GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_VAL_MASK;
+	setbits32((void *)(igd_bar + PCH_GPIOB), data32);
+}
+
+/*
+ * Bugzzy uses panel-built-in touch screen, it needs to set panel power and
+ * reset signal to high for touch screen to work.
+ * On user mode, coreboot doesn't initialize graphics since there is no screen
+ * display before OS. We would add this WA to initialize required signals on
+ * user mode.
+ */
+static void wa_init_display_signal(void *unused)
+{
+	struct device *igd_dev = pcidev_path_on_root(SA_DEVFN_IGD);
+	uintptr_t igd_bar;
+
+	if (display_init_required() || !igd_dev)
+		return;
+
+	igd_bar = find_resource(igd_dev, PCI_BASE_ADDRESS_0)->base;
+	if (!igd_bar)
+		return;
+
+	panel_power_on(igd_bar);
+	mdelay(20);
+	panel_reset_deassert(igd_bar);
+	mdelay(2);
+	panel_reset_assert(igd_bar);
+	mdelay(2);
+	panel_reset_deassert(igd_bar);
+}
+
+BOOT_STATE_INIT_ENTRY(BS_POST_DEVICE, BS_ON_ENTRY, wa_init_display_signal, NULL);