linux/drivers/input/evbug.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (c) 1999-2001 Vojtech Pavlik
 */

/*
 *  Input driver event debug module - dumps all events into syslog
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/device.h>

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Input driver event debug module");
MODULE_LICENSE("GPL");

static void evbug_event(struct input_handle *handle, unsigned int type, unsigned int code, int value)
{
	printk(KERN_DEBUG pr_fmt("Event. Dev: %s, Type: %d, Code: %d, Value: %d\n"),
	       dev_name(&handle->dev->dev), type, code, value);
}

static int evbug_connect(struct input_handler *handler, struct input_dev *dev,
			 const struct input_device_id *id)
{
	struct input_handle *handle;
	int error;

	handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
	if (!handle)
		return -ENOMEM;

	handle->dev = dev;
	handle->handler = handler;
	handle->name = "evbug";

	error = input_register_handle(handle);
	if (error)
		goto err_free_handle;

	error = input_open_device(handle);
	if (error)
		goto err_unregister_handle;

	printk(KERN_DEBUG pr_fmt("Connected device: %s (%s at %s)\n"),
	       dev_name(&dev->dev),
	       dev->name ?: "unknown",
	       dev->phys ?: "unknown");

	return 0;

 err_unregister_handle:
	input_unregister_handle(handle);
 err_free_handle:
	kfree(handle);
	return error;
}

static void evbug_disconnect(struct input_handle *handle)
{
	printk(KERN_DEBUG pr_fmt("Disconnected device: %s\n"),
	       dev_name(&handle->dev->dev));

	input_close_device(handle);
	input_unregister_handle(handle);
	kfree(handle);
}

static const struct input_device_id evbug_ids[] = {
	{ .driver_info = 1 },	/* Matches all devices */
	{ },			/* Terminating zero entry */
};

MODULE_DEVICE_TABLE(input, evbug_ids);

static struct input_handler evbug_handler = {
	.event =	evbug_event,
	.connect =	evbug_connect,
	.disconnect =	evbug_disconnect,
	.name =		"evbug",
	.id_table =	evbug_ids,
};

static int __init evbug_init(void)
{
	return input_register_handler(&evbug_handler);
}

static void __exit evbug_exit(void)
{
	input_unregister_handler(&evbug_handler);
}

module_init(evbug_init);
module_exit(evbug_exit);