From 6be83443e5abf6ed07b0beda1fdaef077b986c72 Mon Sep 17 00:00:00 2001
From: Matt DeVillier <matt.devillier@gmail.com>
Date: Wed, 15 Oct 2025 10:57:00 -0500
Subject: [PATCH] mb/google/auron/var/lulu: Add CFR option to enable/disable
 touchscreen

Some LULU boards are equipped with a touchscreen, others are not. Since
Broadwell doesn't support the use of the i2c generic driver and runtime
detection, add a CFR menu option to allow selective disabling of the
touchscreen ACPI device by users whose boards do not have one.
This prevents a malfunctioning touchscreen device from appearing in
Device Manager under Windows.

TEST=build/boot lulu, boot Win11, verify no malfunctoning touchscreen
device shown in Device Manager when disabled in CFR option menu.

Change-Id: I423ef1cf085bc488b4740092b992a245e3fd7e7e
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/90166
Reviewed-by: Sean Rhodes <sean@starlabs.systems>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
---
 src/mainboard/google/auron/cfr.c       | 24 ++++++++++++++++++++++++
 src/mainboard/google/auron/mainboard.c | 15 +++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/src/mainboard/google/auron/cfr.c b/src/mainboard/google/auron/cfr.c
index e1d352665b..90106a5586 100644
--- a/src/mainboard/google/auron/cfr.c
+++ b/src/mainboard/google/auron/cfr.c
@@ -5,6 +5,20 @@
 #include <ec/google/chromeec/cfr.h>
 #include <soc/cfr.h>
 
+static const struct sm_object touchscreen = SM_DECLARE_ENUM({
+	.opt_name	= "touchscreen",
+	.ui_name	= "Touchscreen",
+	.ui_helptext	= "Enable or disable the integrated touchscreen device",
+	.default_value	= 1,
+	.values		= (const struct sm_enum_value[]) {
+		{ "Disabled",		0		},
+		{ "Enabled",		1		},
+		SM_ENUM_VALUE_END			},
+#if !CONFIG(BOARD_GOOGLE_LULU)
+	.flags		= CFR_OPTFLAG_SUPPRESS,
+#endif
+});
+
 static struct sm_obj_form system = {
 	.ui_name = "System",
 	.obj_list = (const struct sm_object *[]) {
@@ -21,8 +35,18 @@ static struct sm_obj_form ec = {
 		NULL
 	},
 };
+
+static struct sm_obj_form devices = {
+	.ui_name = "Devices",
+	.obj_list = (const struct sm_object *[]) {
+		&touchscreen,
+		NULL
+	},
+};
+
 static struct sm_obj_form *sm_root[] = {
 	&system,
+	&devices,
 	&ec,
 	NULL
 };
diff --git a/src/mainboard/google/auron/mainboard.c b/src/mainboard/google/auron/mainboard.c
index ed2e7b889c..14c8f67642 100644
--- a/src/mainboard/google/auron/mainboard.c
+++ b/src/mainboard/google/auron/mainboard.c
@@ -1,7 +1,9 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
+#include <acpi/acpigen.h>
 #include <device/device.h>
 #include <drivers/intel/gma/int15.h>
+#include <option.h>
 #include "ec.h"
 #include "variant.h"
 
@@ -15,6 +17,18 @@ static void mainboard_init(struct device *dev)
 	lan_init();
 }
 
+static void mainboard_fill_ssdt(const struct device *dev)
+{
+	if (CONFIG(BOARD_GOOGLE_LULU)) {
+		/* Get touchscreen enable option from CFR */
+		unsigned int touchscreen_enabled = get_uint_option("touchscreen", 1);
+
+		acpigen_write_scope("\\_SB.PCI0.I2C1");
+		acpigen_write_store_int_to_namestr(touchscreen_enabled ? 1 : 0, "S2EN");
+		acpigen_pop_len(); /* Scope */
+	}
+}
+
 static int mainboard_smbios_data(struct device *dev, int *handle,
 				 unsigned long *current)
 {
@@ -25,6 +39,7 @@ static void mainboard_enable(struct device *dev)
 {
 	dev->ops->init = mainboard_init;
 	dev->ops->get_smbios_data = mainboard_smbios_data;
+	dev->ops->acpi_fill_ssdt = mainboard_fill_ssdt;
 	install_intel_vga_int15_handler(GMA_INT15_ACTIVE_LFP_EDP, GMA_INT15_PANEL_FIT_CENTERING, GMA_INT15_BOOT_DISPLAY_DEFAULT, 0);
 }