--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Lenovo WMI Events driver. Lenovo WMI interfaces provide various
+ * hardware triggered events that many drivers need to have propagated.
+ * This driver provides a uniform entrypoint for these events so that
+ * any driver that needs to respond to these events can subscribe to a
+ * notifier chain.
+ *
+ * Copyright (C) 2025 Derek J. Clark <derekjohn.clark@gmail.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/types.h>
+#include <linux/wmi.h>
+
+#include "wmi-events.h"
+#include "wmi-gamezone.h"
+
+#define THERMAL_MODE_EVENT_GUID "D320289E-8FEA-41E0-86F9-911D83151B5F"
+
+#define LWMI_EVENT_DEVICE(guid, type) \
+ .guid_string = (guid), .context = &(enum lwmi_events_type) \
+ { \
+ type \
+ }
+
+static BLOCKING_NOTIFIER_HEAD(events_chain_head);
+
+struct lwmi_events_priv {
+ struct wmi_device *wdev;
+ enum lwmi_events_type type;
+};
+
+/**
+ * lwmi_events_register_notifier() - Add a notifier to the notifier chain.
+ * @nb: The notifier_block struct to register
+ *
+ * Call blocking_notifier_chain_register to register the notifier block to the
+ * lenovo-wmi-events driver blocking notifier chain.
+ *
+ * Return: 0 on success, %-EEXIST on error.
+ */
+int lwmi_events_register_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&events_chain_head, nb);
+}
+EXPORT_SYMBOL_NS_GPL(lwmi_events_register_notifier, "LENOVO_WMI_EVENTS");
+
+/**
+ * lwmi_events_unregister_notifier() - Remove a notifier from the notifier
+ * chain.
+ * @nb: The notifier_block struct to unregister
+ *
+ * Call blocking_notifier_chain_unregister to unregister the notifier block
+ * from the lenovo-wmi-events driver blocking notifier chain.
+ *
+ * Return: 0 on success, %-ENOENT on error.
+ */
+int lwmi_events_unregister_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&events_chain_head, nb);
+}
+EXPORT_SYMBOL_NS_GPL(lwmi_events_unregister_notifier, "LENOVO_WMI_EVENTS");
+
+/**
+ * devm_lwmi_events_unregister_notifier() - Remove a notifier from the notifier
+ * chain.
+ * @data: Void pointer to the notifier_block struct to unregister.
+ *
+ * Call lwmi_events_unregister_notifier to unregister the notifier block from
+ * the lenovo-wmi-events driver blocking notifier chain.
+ *
+ * Return: 0 on success, %-ENOENT on error.
+ */
+static void devm_lwmi_events_unregister_notifier(void *data)
+{
+ struct notifier_block *nb = data;
+
+ lwmi_events_unregister_notifier(nb);
+}
+
+/**
+ * devm_lwmi_events_register_notifier() - Add a notifier to the notifier chain.
+ * @dev: The parent device of the notifier_block struct.
+ * @nb: The notifier_block struct to register
+ *
+ * Call lwmi_events_register_notifier to register the notifier block to the
+ * lenovo-wmi-events driver blocking notifier chain. Then add, as a device
+ * managed action, unregister_notifier to automatically unregister the
+ * notifier block upon its parent device removal.
+ *
+ * Return: 0 on success, or an error code.
+ */
+int devm_lwmi_events_register_notifier(struct device *dev,
+ struct notifier_block *nb)
+{
+ int ret;
+
+ ret = lwmi_events_register_notifier(nb);
+ if (ret < 0)
+ return ret;
+
+ return devm_add_action_or_reset(dev, devm_lwmi_events_unregister_notifier, nb);
+}
+EXPORT_SYMBOL_NS_GPL(devm_lwmi_events_register_notifier, "LENOVO_WMI_EVENTS");
+
+/**
+ * lwmi_events_notify() - Call functions for the notifier call chain.
+ * @wdev: The parent WMI device of the driver.
+ * @obj: ACPI object passed by the registered WMI Event.
+ *
+ * Validate WMI event data and notify all registered drivers of the event and
+ * its output.
+ *
+ * Return: 0 on success, or an error code.
+ */
+static void lwmi_events_notify(struct wmi_device *wdev, union acpi_object *obj)
+{
+ struct lwmi_events_priv *priv = dev_get_drvdata(&wdev->dev);
+ int sel_prof;
+ int ret;
+
+ switch (priv->type) {
+ case LWMI_EVENT_THERMAL_MODE:
+ if (obj->type != ACPI_TYPE_INTEGER)
+ return;
+
+ sel_prof = obj->integer.value;
+
+ switch (sel_prof) {
+ case LWMI_GZ_THERMAL_MODE_QUIET:
+ case LWMI_GZ_THERMAL_MODE_BALANCED:
+ case LWMI_GZ_THERMAL_MODE_PERFORMANCE:
+ case LWMI_GZ_THERMAL_MODE_EXTREME:
+ case LWMI_GZ_THERMAL_MODE_CUSTOM:
+ ret = blocking_notifier_call_chain(&events_chain_head,
+ LWMI_EVENT_THERMAL_MODE,
+ &sel_prof);
+ if (ret == NOTIFY_BAD)
+ dev_err(&wdev->dev,
+ "Failed to send notification to call chain for WMI Events\n");
+ return;
+ default:
+ dev_err(&wdev->dev, "Got invalid thermal mode: %x",
+ sel_prof);
+ return;
+ }
+ break;
+ default:
+ return;
+ }
+}
+
+static int lwmi_events_probe(struct wmi_device *wdev, const void *context)
+{
+ struct lwmi_events_priv *priv;
+
+ if (!context)
+ return -EINVAL;
+
+ priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->wdev = wdev;
+ priv->type = *(enum lwmi_events_type *)context;
+ dev_set_drvdata(&wdev->dev, priv);
+
+ return 0;
+}
+
+static const struct wmi_device_id lwmi_events_id_table[] = {
+ { LWMI_EVENT_DEVICE(THERMAL_MODE_EVENT_GUID, LWMI_EVENT_THERMAL_MODE) },
+ {}
+};
+
+static struct wmi_driver lwmi_events_driver = {
+ .driver = {
+ .name = "lenovo_wmi_events",
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ },
+ .id_table = lwmi_events_id_table,
+ .probe = lwmi_events_probe,
+ .notify = lwmi_events_notify,
+ .no_singleton = true,
+};
+
+module_wmi_driver(lwmi_events_driver);
+
+MODULE_DEVICE_TABLE(wmi, lwmi_events_id_table);
+MODULE_AUTHOR("Derek J. Clark <derekjohn.clark@gmail.com>");
+MODULE_DESCRIPTION("Lenovo WMI Events Driver");
+MODULE_LICENSE("GPL");
projects / thirdparty / linux.git / commitdiff
