[PATCH 3/7] platform/x86: uniwill-laptop: Add AC auto boot support

[Armin Wolf]

Some devices support a "AC auto boot" feature where the system will
automatically boot when being connected to a power source.

Add support for this feature.

Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
---
 .../ABI/testing/sysfs-driver-uniwill-laptop   | 11 ++++
 .../admin-guide/laptops/uniwill-laptop.rst    |  7 +++
 drivers/platform/x86/uniwill/uniwill-acpi.c   | 51 +++++++++++++++++++
 3 files changed, 69 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-driver-uniwill-laptop b/Documentation/ABI/testing/sysfs-driver-uniwill-laptop
index 2397c65c969a..57272f906184 100644
--- a/Documentation/ABI/testing/sysfs-driver-uniwill-laptop
+++ b/Documentation/ABI/testing/sysfs-driver-uniwill-laptop
@@ -78,3 +78,14 @@ Description:
 
 		Reading this file returns the profile names with the currently active one in
 		brackets.
+
+What:		/sys/bus/platform/devices/INOU0000:XX/ac_auto_boot
+Date:		March 2026
+KernelVersion:	7.1
+Contact:	Armin Wolf <W_Armin@xxxxxx>
+Description:
+		Allows userspace applications to configure if the device should boot automatically
+		when being connected to a power source. Writing "1"/"0" into this file
+		enables/disables this functionality.
+
+		Reading this file returns the current status of the AC auto boot functionality.
diff --git a/Documentation/admin-guide/laptops/uniwill-laptop.rst b/Documentation/admin-guide/laptops/uniwill-laptop.rst
index 2b1e5da703a5..b6213fb1d3e0 100644
--- a/Documentation/admin-guide/laptops/uniwill-laptop.rst
+++ b/Documentation/admin-guide/laptops/uniwill-laptop.rst
@@ -98,6 +98,13 @@ allow it.
 
 See Documentation/ABI/testing/sysfs-driver-uniwill-laptop for details.
 
+AC Auto Boot
+------------
+
+The ``uniwill-laptop`` driver allows the user to configure if the system should automatically
+boot when being connected to a power source, see
+Documentation/ABI/testing/sysfs-driver-uniwill-laptop for details.
+
 References
 ==========
 
diff --git a/drivers/platform/x86/uniwill/uniwill-acpi.c b/drivers/platform/x86/uniwill/uniwill-acpi.c
index b3be2f2dbdd8..897c6163de53 100644
--- a/drivers/platform/x86/uniwill/uniwill-acpi.c
+++ b/drivers/platform/x86/uniwill/uniwill-acpi.c
@@ -112,6 +112,9 @@
 
 #define EC_ADDR_BAT_CYCLE_COUNT_2	0x04A7
 
+#define EC_ADDR_OEM_9			0x0726
+#define AC_AUTO_BOOT_ENABLE		BIT(3)
+
 #define EC_ADDR_PROJECT_ID		0x0740
 #define PROJECT_ID_NONE			0x00
 #define PROJECT_ID_GI			0x01
@@ -364,6 +367,7 @@
 #define UNIWILL_FEATURE_NVIDIA_CTGP_CONTROL	BIT(10)
 #define UNIWILL_FEATURE_USB_C_POWER_PRIORITY	BIT(11)
 #define UNIWILL_FEATURE_KEYBOARD_BACKLIGHT	BIT(12)
+#define UNIWILL_FEATURE_AC_AUTO_BOOT		BIT(13)
 
 enum usb_c_power_priority_options {
 	USB_C_POWER_PRIORITY_CHARGING = 0,
@@ -586,6 +590,7 @@ static const struct regmap_bus uniwill_ec_bus = {
 static bool uniwill_writeable_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
+	case EC_ADDR_OEM_9:
 	case EC_ADDR_AP_OEM:
 	case EC_ADDR_LIGHTBAR_AC_CTRL:
 	case EC_ADDR_LIGHTBAR_AC_RED:
@@ -625,6 +630,7 @@ static bool uniwill_readable_reg(struct device *dev, unsigned int reg)
 	case EC_ADDR_SECOND_FAN_RPM_1:
 	case EC_ADDR_SECOND_FAN_RPM_2:
 	case EC_ADDR_BAT_ALERT:
+	case EC_ADDR_OEM_9:
 	case EC_ADDR_PROJECT_ID:
 	case EC_ADDR_AP_OEM:
 	case EC_ADDR_LIGHTBAR_AC_CTRL:
@@ -1136,6 +1142,45 @@ static int usb_c_power_priority_init(struct uniwill_data *data)
 	return 0;
 }
 
+static ssize_t ac_auto_boot_store(struct device *dev, struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct uniwill_data *data = dev_get_drvdata(dev);
+	unsigned int regval;
+	bool enable;
+	int ret;
+
+	ret = kstrtobool(buf, &enable);
+	if (ret < 0)
+		return ret;
+
+	if (enable)
+		regval = AC_AUTO_BOOT_ENABLE;
+	else
+		regval = 0;
+
+	ret = regmap_update_bits(data->regmap, EC_ADDR_OEM_9, AC_AUTO_BOOT_ENABLE, regval);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static ssize_t ac_auto_boot_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct uniwill_data *data = dev_get_drvdata(dev);
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(data->regmap, EC_ADDR_OEM_9, &regval);
+	if (ret < 0)
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", !!(regval & AC_AUTO_BOOT_ENABLE));
+}
+
+static DEVICE_ATTR_RW(ac_auto_boot);
+
 static struct attribute *uniwill_attrs[] = {
 	/* Keyboard-related */
 	&dev_attr_fn_lock.attr,
@@ -1147,6 +1192,7 @@ static struct attribute *uniwill_attrs[] = {
 	/* Power-management-related */
 	&dev_attr_ctgp_offset.attr,
 	&dev_attr_usb_c_power_priority.attr,
+	&dev_attr_ac_auto_boot.attr,
 	NULL
 };
 
@@ -1186,6 +1232,11 @@ static umode_t uniwill_attr_is_visible(struct kobject *kobj, struct attribute *a
 			return attr->mode;
 	}
 
+	if (attr == &dev_attr_ac_auto_boot.attr) {
+		if (uniwill_device_supports(data, UNIWILL_FEATURE_AC_AUTO_BOOT))
+			return attr->mode;
+	}
+
 	return 0;
 }
 
-- 
2.39.5