[PATCH 4/7] platform/x86: uniwill-laptop: Add support for USB powershare
From: Armin Wolf
Date: Sat May 30 2026 - 13:11:00 EST
Some devices support a "USB powershare" feature where the system will
continue to provide power via the USB ports when hibernating or
powered off.
Add support for this feaure.
Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
---
.../ABI/testing/sysfs-driver-uniwill-laptop | 16 ++-
.../admin-guide/laptops/uniwill-laptop.rst | 7 ++
drivers/platform/x86/uniwill/uniwill-acpi.c | 100 ++++++++++++++++++
3 files changed, 122 insertions(+), 1 deletion(-)
diff --git a/Documentation/ABI/testing/sysfs-driver-uniwill-laptop b/Documentation/ABI/testing/sysfs-driver-uniwill-laptop
index 57272f906184..943f92c6b561 100644
--- a/Documentation/ABI/testing/sysfs-driver-uniwill-laptop
+++ b/Documentation/ABI/testing/sysfs-driver-uniwill-laptop
@@ -86,6 +86,20 @@ 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.
+ enables/disables this functionality. Enabling both AC auto boot and USB powershare
+ at the same time is not supported.
Reading this file returns the current status of the AC auto boot functionality.
+
+What: /sys/bus/platform/devices/INOU0000:XX/usb_powershare_high
+Date: March 2026
+KernelVersion: 7.1
+Contact: Armin Wolf <W_Armin@xxxxxx>
+Description:
+ Allows userspace applications to configure if the device should continue to provide
+ power via the USB ports when hibernating or powered off. Might also increase the
+ power budget available to USB ports on some devices. Writing "1"/"0" into this
+ file enables/disables this functionality. Enabling both USB powershare and AC auto
+ boot at the same time is not supported.
+
+ Reading this file returns the current status of the USB powershare functionality.
diff --git a/Documentation/admin-guide/laptops/uniwill-laptop.rst b/Documentation/admin-guide/laptops/uniwill-laptop.rst
index b6213fb1d3e0..be50b45b82ef 100644
--- a/Documentation/admin-guide/laptops/uniwill-laptop.rst
+++ b/Documentation/admin-guide/laptops/uniwill-laptop.rst
@@ -105,6 +105,13 @@ The ``uniwill-laptop`` driver allows the user to configure if the system should
boot when being connected to a power source, see
Documentation/ABI/testing/sysfs-driver-uniwill-laptop for details.
+USB Powershare
+--------------
+
+The ``uniwill-laptop`` driver allows the user to configure if the system should continue to
+provide power via the USB ports when hibernating or powered off, 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 897c6163de53..00140c0a67a0 100644
--- a/drivers/platform/x86/uniwill/uniwill-acpi.c
+++ b/drivers/platform/x86/uniwill/uniwill-acpi.c
@@ -368,6 +368,7 @@
#define UNIWILL_FEATURE_USB_C_POWER_PRIORITY BIT(11)
#define UNIWILL_FEATURE_KEYBOARD_BACKLIGHT BIT(12)
#define UNIWILL_FEATURE_AC_AUTO_BOOT BIT(13)
+#define UNIWILL_FEATURE_USB_POWERSHARE BIT(14)
enum usb_c_power_priority_options {
USB_C_POWER_PRIORITY_CHARGING = 0,
@@ -393,6 +394,7 @@ struct uniwill_data {
bool last_fn_lock_state;
bool last_super_key_enable_state;
bool last_touchpad_toggle_enable_state;
+ bool last_usb_powershare_high_state;
struct mutex super_key_lock; /* Protects the toggling of the super key lock state */
struct list_head batteries;
struct mutex led_lock; /* Protects writes to the lightbar registers */
@@ -1181,6 +1183,70 @@ static ssize_t ac_auto_boot_show(struct device *dev, struct device_attribute *at
static DEVICE_ATTR_RW(ac_auto_boot);
+static int uniwill_write_usb_powershare_high(struct uniwill_data *data, bool status)
+{
+ unsigned int value;
+
+ if (status)
+ value = TRIGGER_USB_CHARGING;
+ else
+ value = 0;
+
+ /*
+ * Normaly this RMW-sequence could also trigger the super key toggle,
+ * but the EC seems to take care that those bits are always read as 0.
+ */
+ return regmap_update_bits(data->regmap, EC_ADDR_TRIGGER, TRIGGER_USB_CHARGING, value);
+}
+
+static ssize_t usb_powershare_high_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct uniwill_data *data = dev_get_drvdata(dev);
+ bool enable;
+ int ret;
+
+ ret = kstrtobool(buf, &enable);
+ if (ret < 0)
+ return ret;
+
+ ret = uniwill_write_usb_powershare_high(data, enable);
+ if (ret < 0)
+ return ret;
+
+ return count;
+}
+
+static int uniwill_read_usb_powershare_high(struct uniwill_data *data, bool *status)
+{
+ unsigned int value;
+ int ret;
+
+ ret = regmap_read(data->regmap, EC_ADDR_TRIGGER, &value);
+ if (ret < 0)
+ return ret;
+
+ *status = !!(value & TRIGGER_USB_CHARGING);
+
+ return 0;
+}
+
+static ssize_t usb_powershare_high_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct uniwill_data *data = dev_get_drvdata(dev);
+ bool status;
+ int ret;
+
+ ret = uniwill_read_usb_powershare_high(data, &status);
+ if (ret < 0)
+ return ret;
+
+ return sysfs_emit(buf, "%d\n", status);
+}
+
+static DEVICE_ATTR_RW(usb_powershare_high);
+
static struct attribute *uniwill_attrs[] = {
/* Keyboard-related */
&dev_attr_fn_lock.attr,
@@ -1193,6 +1259,7 @@ static struct attribute *uniwill_attrs[] = {
&dev_attr_ctgp_offset.attr,
&dev_attr_usb_c_power_priority.attr,
&dev_attr_ac_auto_boot.attr,
+ &dev_attr_usb_powershare_high.attr,
NULL
};
@@ -1237,6 +1304,11 @@ static umode_t uniwill_attr_is_visible(struct kobject *kobj, struct attribute *a
return attr->mode;
}
+ if (attr == &dev_attr_usb_powershare_high.attr) {
+ if (uniwill_device_supports(data, UNIWILL_FEATURE_USB_POWERSHARE))
+ return attr->mode;
+ }
+
return 0;
}
@@ -2382,6 +2454,18 @@ static int uniwill_suspend_kbd_led(struct uniwill_data *data)
return regmap_write(data->regmap, EC_ADDR_KBD_STATUS, regval);
}
+static int uniwill_suspend_usb_powershare(struct uniwill_data *data)
+{
+ if (!uniwill_device_supports(data, UNIWILL_FEATURE_USB_POWERSHARE))
+ return 0;
+
+ /*
+ * EC_ADDR_TRIGGER is marked as volatile, so we have to restore it
+ * ourselves.
+ */
+ return uniwill_read_usb_powershare_high(data, &data->last_usb_powershare_high_state);
+}
+
static int uniwill_suspend_nvidia_ctgp(struct uniwill_data *data)
{
if (!uniwill_device_supports(data, UNIWILL_FEATURE_NVIDIA_CTGP_CONTROL))
@@ -2416,6 +2500,10 @@ static int uniwill_suspend(struct device *dev)
if (ret < 0)
return ret;
+ ret = uniwill_suspend_usb_powershare(data);
+ if (ret < 0)
+ return ret;
+
ret = uniwill_suspend_nvidia_ctgp(data);
if (ret < 0)
return ret;
@@ -2479,6 +2567,14 @@ static int uniwill_resume_kbd_led(struct uniwill_data *data)
return regmap_write_bits(data->regmap, EC_ADDR_TRIGGER, RGB_APPLY_COLOR, RGB_APPLY_COLOR);
}
+static int uniwill_resume_usb_powershare(struct uniwill_data *data)
+{
+ if (!uniwill_device_supports(data, UNIWILL_FEATURE_USB_POWERSHARE))
+ return 0;
+
+ return uniwill_write_usb_powershare_high(data, data->last_usb_powershare_high_state);
+}
+
static int uniwill_resume_nvidia_ctgp(struct uniwill_data *data)
{
if (!uniwill_device_supports(data, UNIWILL_FEATURE_NVIDIA_CTGP_CONTROL))
@@ -2527,6 +2623,10 @@ static int uniwill_resume(struct device *dev)
if (ret < 0)
return ret;
+ ret = uniwill_resume_usb_powershare(data);
+ if (ret < 0)
+ return ret;
+
ret = uniwill_resume_nvidia_ctgp(data);
if (ret < 0)
return ret;
--
2.39.5