Re: [PATCH v2 2/4] platform/x86/uniwill: Implement USB-C power priority setting

From: Werner Sembach

Date: Fri Feb 27 2026 - 13:48:28 EST



Am 27.02.26 um 10:31 schrieb Armin Wolf:
Am 26.02.26 um 21:50 schrieb Werner Sembach:

On some devices Uniwill offers the option to set the USB-C port to
prioritise charging or performance. This patch exposes this setting to the
userspace via sysfs for all TUXEDO devices supporting it.

Signed-off-by: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>
---
  drivers/platform/x86/uniwill/uniwill-acpi.c | 103 ++++++++++++++++++--
  1 file changed, 97 insertions(+), 6 deletions(-)

diff --git a/drivers/platform/x86/uniwill/uniwill-acpi.c b/drivers/platform/x86/uniwill/uniwill-acpi.c
index 7ab82cf16f388..a34b1eed74eb2 100644
--- a/drivers/platform/x86/uniwill/uniwill-acpi.c
+++ b/drivers/platform/x86/uniwill/uniwill-acpi.c
@@ -266,8 +266,8 @@
  #define BATTERY_CHARGE_FULL_OVER_24H    BIT(3)
  #define BATTERY_ERM_STATUS_REACHED    BIT(4)
  -#define EC_ADDR_CHARGE_PRIO        0x07CC
-#define CHARGING_PERFORMANCE        BIT(7)
+#define EC_ADDR_USB_C_POWER_PRIORITY    0x07CC
+#define USB_C_POWER_PRIORITY        BIT(7)
    /* Same bits as EC_ADDR_LIGHTBAR_AC_CTRL except LIGHTBAR_S3_OFF */
  #define EC_ADDR_LIGHTBAR_BAT_CTRL    0x07E2
@@ -324,6 +324,7 @@
  #define UNIWILL_FEATURE_PRIMARY_FAN        BIT(7)
  #define UNIWILL_FEATURE_SECONDARY_FAN        BIT(8)
  #define UNIWILL_FEATURE_NVIDIA_CTGP_CONTROL    BIT(9)
+#define UNIWILL_FEATURE_USB_C_POWER_PRIORITY    BIT(10)
    struct uniwill_data {
      struct device *dev;
@@ -343,6 +344,8 @@ struct uniwill_data {
      struct mutex input_lock;    /* Protects input sequence during notify */
      struct input_dev *input_device;
      struct notifier_block nb;
+    struct mutex usb_c_power_priority_lock; /* Protects dependent bit write and state safe */
+    unsigned int last_usb_c_power_priority;
  };
    struct uniwill_battery_entry {
@@ -527,6 +530,7 @@ static bool uniwill_writeable_reg(struct device *dev, unsigned int reg)
      case EC_ADDR_CTGP_DB_CTGP_OFFSET:
      case EC_ADDR_CTGP_DB_TPP_OFFSET:
      case EC_ADDR_CTGP_DB_DB_OFFSET:
+    case EC_ADDR_USB_C_POWER_PRIORITY:
          return true;
      default:
          return false;
@@ -565,6 +569,7 @@ static bool uniwill_readable_reg(struct device *dev, unsigned int reg)
      case EC_ADDR_CTGP_DB_CTGP_OFFSET:
      case EC_ADDR_CTGP_DB_TPP_OFFSET:
      case EC_ADDR_CTGP_DB_DB_OFFSET:
+    case EC_ADDR_USB_C_POWER_PRIORITY:
          return true;
      default:
          return false;
@@ -587,6 +592,7 @@ static bool uniwill_volatile_reg(struct device *dev, unsigned int reg)
      case EC_ADDR_TRIGGER:
      case EC_ADDR_SWITCH_STATUS:
      case EC_ADDR_CHARGE_CTRL:
+    case EC_ADDR_USB_C_POWER_PRIORITY:
          return true;
      default:
          return false;
@@ -883,6 +889,78 @@ static int uniwill_nvidia_ctgp_init(struct uniwill_data *data)
      return 0;
  }
  +enum usb_c_power_priority_options {
+    USB_C_POWER_PRIORITY_OPTIONS_CHARGING = 0,
+    USB_C_POWER_PRIORITY_OPTIONS_PERFORMANCE,
+};
+
+static const char * const USB_C_POWER_PRIORITY_OPTIONS_TEXT[] = {
+    [USB_C_POWER_PRIORITY_OPTIONS_CHARGING]        = "charging",
+    [USB_C_POWER_PRIORITY_OPTIONS_PERFORMANCE]    = "performance",
+};
+
+static const u8 USB_C_POWER_PRIORITY_OPTIONS_VALUE[] = {
+    [USB_C_POWER_PRIORITY_OPTIONS_CHARGING]        = 0,
+    [USB_C_POWER_PRIORITY_OPTIONS_PERFORMANCE]    = USB_C_POWER_PRIORITY,
+};
+
+static ssize_t usb_c_power_priority_store(struct device *dev,
+                      struct device_attribute *attr,
+                      const char *buf, size_t count)
+{
+    struct uniwill_data *data = dev_get_drvdata(dev);
+    unsigned int value;
+    int ret;
+
+    ret = sysfs_match_string(USB_C_POWER_PRIORITY_OPTIONS_TEXT, buf);
+    if (ret < 0)
+        return ret;
+
+    value = USB_C_POWER_PRIORITY_OPTIONS_VALUE[ret];
+
+    guard(mutex)(&data->usb_c_power_priority_lock);
+
+    ret = regmap_update_bits(data->regmap, EC_ADDR_USB_C_POWER_PRIORITY,
+                 USB_C_POWER_PRIORITY, value);
+    if (ret < 0)
+        return ret;
+
+    data->last_usb_c_power_priority = value;
+
+    return count;
+}
+
+static ssize_t usb_c_power_priority_show(struct device *dev,
+                     struct device_attribute *attr,
+                     char *buf)
+{
+    struct uniwill_data *data = dev_get_drvdata(dev);
+    unsigned int value;
+    ssize_t count = 0;
+    int ret;
+
+    ret = regmap_read(data->regmap, EC_ADDR_USB_C_POWER_PRIORITY, &value);
+    if (ret < 0)
+        return ret;
+
+    value &= USB_C_POWER_PRIORITY;
+
+    for (int i = 0; i < ARRAY_SIZE(USB_C_POWER_PRIORITY_OPTIONS_VALUE); ++i) {
+        if (USB_C_POWER_PRIORITY_OPTIONS_VALUE[i] == value)
+            count += sysfs_emit_at(buf, count, "[%s] ",
+ USB_C_POWER_PRIORITY_OPTIONS_TEXT[i]);
+        else
+            count += sysfs_emit_at(buf, count, "%s ",
+ USB_C_POWER_PRIORITY_OPTIONS_TEXT[i]);
+    }
+    if (count)
+        buf[count - 1] = '\n';
+
+    return count;
+}
+
+static DEVICE_ATTR_RW(usb_c_power_priority);
+
  static struct attribute *uniwill_attrs[] = {
      /* Keyboard-related */
      &dev_attr_fn_lock.attr,
@@ -893,6 +971,7 @@ static struct attribute *uniwill_attrs[] = {
      &dev_attr_breathing_in_suspend.attr,
      /* Power-management-related */
      &dev_attr_ctgp_offset.attr,
+    &dev_attr_usb_c_power_priority.attr,
      NULL
  };
  @@ -927,6 +1006,11 @@ static umode_t uniwill_attr_is_visible(struct kobject *kobj, struct attribute *a
              return attr->mode;
      }
  +    if (attr == &dev_attr_usb_c_power_priority.attr) {
+        if (uniwill_device_supports(data, UNIWILL_FEATURE_USB_C_POWER_PRIORITY))
+            return attr->mode;
+    }
+
      return 0;
  }
  @@ -1417,11 +1501,13 @@ static int uniwill_notifier_call(struct notifier_block *nb, unsigned long action
            return NOTIFY_OK;
      case UNIWILL_OSD_DC_ADAPTER_CHANGED:
-        /* noop for the time being, will change once charging priority
-         * gets implemented.
-         */
+        if (!uniwill_device_supports(data, UNIWILL_FEATURE_USB_C_POWER_PRIORITY))
+            return NOTIFY_DONE;
  -        return NOTIFY_OK;
+        return notifier_from_errno(regmap_update_bits(data->regmap,
+                                  EC_ADDR_OEM_4,
+                                  USB_C_POWER_PRIORITY,
+ data->last_usb_c_power_priority));

You need to lock the associated mutex here before accessing last_usb_c_power_priority. Since this
is not possible inside a switch statement when using guard(), i suggest that you move this code
(feature check + register access) into a small helper function.

      case UNIWILL_OSD_FN_LOCK:
          if (!uniwill_device_supports(data, UNIWILL_FEATURE_FN_LOCK))
              return NOTIFY_DONE;
@@ -1515,10 +1601,15 @@ static int uniwill_probe(struct platform_device *pdev)
          return PTR_ERR(regmap);
        data->regmap = regmap;
+
      ret = devm_mutex_init(&pdev->dev, &data->super_key_lock);
      if (ret < 0)
          return ret;
  +    ret = devm_mutex_init(&pdev->dev, &data->usb_c_power_priority_lock);
+    if (ret < 0)
+        return ret;

last_usb_c_power_priority still needs to be initialized with the value of USB_C_POWER_PRIORITY here.
I suggest that you move all of this (feature check + mutex + init) into a small helper function.
ack

Thanks,
Armin Wolf

+
      ret = uniwill_ec_init(data);
      if (ret < 0)
          return ret;