1 files changed, 92 insertions, 0 deletions
diff --git a/drivers/platform/x86/uniwill/uniwill-wmi.c b/drivers/platform/x86/uniwill/uniwill-wmi.c
new file mode 100644
index 000000000000..31d9c39f14ab
--- /dev/null
+++ b/drivers/platform/x86/uniwill/uniwill-wmi.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Linux hotkey driver for Uniwill notebooks.
+ *
+ * Special thanks go to Pőcze Barnabás, Christoffer Sandberg and Werner Sembach
+ * for supporting the development of this driver either through prior work or
+ * by answering questions regarding the underlying WMI interface.
+ *
+ * Copyright (C) 2025 Armin Wolf <W_Armin@gmx.de>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/mod_devicetable.h>
+#include <linux/notifier.h>
+#include <linux/printk.h>
+#include <linux/types.h>
+#include <linux/wmi.h>
+
+#include "uniwill-wmi.h"
+
+#define DRIVER_NAME		"uniwill-wmi"
+#define UNIWILL_EVENT_GUID	"ABBC0F72-8EA1-11D1-00A0-C90629100000"
+
+static BLOCKING_NOTIFIER_HEAD(uniwill_wmi_chain_head);
+
+static void devm_uniwill_wmi_unregister_notifier(void *data)
+{
+	struct notifier_block *nb = data;
+
+	blocking_notifier_chain_unregister(&uniwill_wmi_chain_head, nb);
+}
+
+int devm_uniwill_wmi_register_notifier(struct device *dev, struct notifier_block *nb)
+{
+	int ret;
+
+	ret = blocking_notifier_chain_register(&uniwill_wmi_chain_head, nb);
+	if (ret < 0)
+		return ret;
+
+	return devm_add_action_or_reset(dev, devm_uniwill_wmi_unregister_notifier, nb);
+}
+
+static void uniwill_wmi_notify(struct wmi_device *wdev, union acpi_object *obj)
+{
+	u32 value;
+
+	if (obj->type != ACPI_TYPE_INTEGER)
+		return;
+
+	value = obj->integer.value;
+
+	dev_dbg(&wdev->dev, "Received WMI event %u\n", value);
+
+	blocking_notifier_call_chain(&uniwill_wmi_chain_head, value, NULL);
+}
+
+/*
+ * We cannot fully trust this GUID since Uniwill just copied the WMI GUID
+ * from the Windows driver example, and others probably did the same.
+ *
+ * Because of this we cannot use this WMI GUID for autoloading. Instead the
+ * associated driver will be registered manually after matching a DMI table.
+ */
+static const struct wmi_device_id uniwill_wmi_id_table[] = {
+	{ UNIWILL_EVENT_GUID, NULL },
+	{ }
+};
+
+static struct wmi_driver uniwill_wmi_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+	.id_table = uniwill_wmi_id_table,
+	.notify = uniwill_wmi_notify,
+	.no_singleton = true,
+};
+
+int __init uniwill_wmi_register_driver(void)
+{
+	return wmi_driver_register(&uniwill_wmi_driver);
+}
+
+void __exit uniwill_wmi_unregister_driver(void)
+{
+	wmi_driver_unregister(&uniwill_wmi_driver);
+}