drivers/platform/x86/redmi-wmi.c

Source file repositories/reference/linux-study-clean/drivers/platform/x86/redmi-wmi.c

File Facts

System
Linux kernel
Corpus path
drivers/platform/x86/redmi-wmi.c
Extension
.c
Size
3852 bytes
Lines
155
Domain
Driver Families
Bucket
drivers/platform
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct redmi_wmi {
	struct input_dev *input_dev;
	/* Protects the key event sequence */
	struct mutex key_lock;
};

static int redmi_wmi_probe(struct wmi_device *wdev, const void *context)
{
	struct redmi_wmi *data;
	int err;

	/* Init dev */
	data = devm_kzalloc(&wdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	dev_set_drvdata(&wdev->dev, data);

	err = devm_mutex_init(&wdev->dev, &data->key_lock);
	if (err)
		return err;

	data->input_dev = devm_input_allocate_device(&wdev->dev);
	if (!data->input_dev)
		return -ENOMEM;

	data->input_dev->name = "Redmibook WMI keys";
	data->input_dev->phys = "wmi/input0";

	err = sparse_keymap_setup(data->input_dev, redmi_wmi_keymap, NULL);
	if (err)
		return err;

	return input_register_device(data->input_dev);
}

static void redmi_wmi_notify(struct wmi_device *wdev, union acpi_object *obj)
{
	struct key_entry *entry;
	struct redmi_wmi *data = dev_get_drvdata(&wdev->dev);
	bool autorelease = true;
	u32 payload;
	int value = 1;

	if (obj->type != ACPI_TYPE_BUFFER) {
		dev_err(&wdev->dev, "Bad response type %u\n", obj->type);
		return;
	}

	if (obj->buffer.length < 32) {
		dev_err(&wdev->dev, "Invalid buffer length %u\n", obj->buffer.length);
		return;
	}

	payload = get_unaligned_le32(obj->buffer.pointer);
	entry = sparse_keymap_entry_from_scancode(data->input_dev, payload);

	if (!entry) {
		dev_dbg(&wdev->dev, "Unknown WMI event with payload %u", payload);
		return;
	}

	/* AI key quirk */
	if (entry->keycode == KEY_ASSISTANT) {
		value = !(payload & AI_KEY_VALUE_MASK);
		autorelease = false;
	}

	guard(mutex)(&data->key_lock);
	sparse_keymap_report_entry(data->input_dev, entry, value, autorelease);
}

static const struct wmi_device_id redmi_wmi_id_table[] = {
	{ WMI_REDMIBOOK_KEYBOARD_EVENT_GUID, NULL },
	{ }
};

static struct wmi_driver redmi_wmi_driver = {
	.driver = {
		.name = "redmi-wmi",
		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
	},
	.id_table = redmi_wmi_id_table,
	.min_event_size = 32,
	.probe = redmi_wmi_probe,
	.notify = redmi_wmi_notify,
	.no_singleton = true,
};
module_wmi_driver(redmi_wmi_driver);

Annotation

Implementation Notes