[net-next-2.6.git] / drivers / hid / hid-roccat.c

/*
 * Roccat driver for Linux
 *
 * Copyright (c) 2010 Stefan Achatz <erazor_de@users.sourceforge.net>
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

/*
 * Module roccat is a char device used to report special events of roccat
 * hardware to userland. These events include requests for on-screen-display of
 * profile or dpi settings or requests for execution of macro sequences that are
 * not stored in device. The information in these events depends on hid device
 * implementation and contains data that is not available in a single hid event
 * or else hidraw could have been used.
 * It is inspired by hidraw, but uses only one circular buffer for all readers.
 */

#include <linux/cdev.h>
#include <linux/poll.h>
#include <linux/sched.h>

#include "hid-roccat.h"

#define ROCCAT_FIRST_MINOR 0
#define ROCCAT_MAX_DEVICES 8

/* should be a power of 2 for performance reason */
#define ROCCAT_CBUF_SIZE 16

struct roccat_report {
	uint8_t *value;
	int len;
};

struct roccat_device {
	unsigned int minor;
	int open;
	int exist;
	wait_queue_head_t wait;
	struct device *dev;
	struct hid_device *hid;
	struct list_head readers;
	/* protects modifications of readers list */
	struct mutex readers_lock;

	/*
	 * circular_buffer has one writer and multiple readers with their own
	 * read pointers
	 */
	struct roccat_report cbuf[ROCCAT_CBUF_SIZE];
	int cbuf_end;
	struct mutex cbuf_lock;
};

struct roccat_reader {
	struct list_head node;
	struct roccat_device *device;
	int cbuf_start;
};

static int roccat_major;
static struct class *roccat_class;
static struct cdev roccat_cdev;

static struct roccat_device *devices[ROCCAT_MAX_DEVICES];
/* protects modifications of devices array */
static DEFINE_MUTEX(devices_lock);

static ssize_t roccat_read(struct file *file, char __user *buffer,
		size_t count, loff_t *ppos)
{
	struct roccat_reader *reader = file->private_data;
	struct roccat_device *device = reader->device;
	struct roccat_report *report;
	ssize_t retval = 0, len;
	DECLARE_WAITQUEUE(wait, current);

	mutex_lock(&device->cbuf_lock);

	/* no data? */
	if (reader->cbuf_start == device->cbuf_end) {
		add_wait_queue(&device->wait, &wait);
		set_current_state(TASK_INTERRUPTIBLE);

		/* wait for data */
		while (reader->cbuf_start == device->cbuf_end) {
			if (file->f_flags & O_NONBLOCK) {
				retval = -EAGAIN;
				break;
			}
			if (signal_pending(current)) {
				retval = -ERESTARTSYS;
				break;
			}
			if (!device->exist) {
				retval = -EIO;
				break;
			}

			mutex_unlock(&device->cbuf_lock);
			schedule();
			mutex_lock(&device->cbuf_lock);
			set_current_state(TASK_INTERRUPTIBLE);
		}

		set_current_state(TASK_RUNNING);
		remove_wait_queue(&device->wait, &wait);
	}

	/* here we either have data or a reason to return if retval is set */
	if (retval)
		goto exit_unlock;

	report = &device->cbuf[reader->cbuf_start];
	/*
	 * If report is larger than requested amount of data, rest of report
	 * is lost!
	 */
	len = report->len > count ? count : report->len;

	if (copy_to_user(buffer, report->value, len)) {
		retval = -EFAULT;
		goto exit_unlock;
	}
	retval += len;
	reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE;

exit_unlock:
	mutex_unlock(&device->cbuf_lock);
	return retval;
}

static unsigned int roccat_poll(struct file *file, poll_table *wait)
{
	struct roccat_reader *reader = file->private_data;
	poll_wait(file, &reader->device->wait, wait);
	if (reader->cbuf_start != reader->device->cbuf_end)
		return POLLIN | POLLRDNORM;
	if (!reader->device->exist)
		return POLLERR | POLLHUP;
	return 0;
}

static int roccat_open(struct inode *inode, struct file *file)
{
	unsigned int minor = iminor(inode);
	struct roccat_reader *reader;
	struct roccat_device *device;
	int error = 0;

	reader = kzalloc(sizeof(struct roccat_reader), GFP_KERNEL);
	if (!reader)
		return -ENOMEM;

	mutex_lock(&devices_lock);

	device = devices[minor];

	mutex_lock(&device->readers_lock);

	if (!device) {
		printk(KERN_EMERG "roccat device with minor %d doesn't exist\n",
				minor);
		error = -ENODEV;
		goto exit_err;
	}

	if (!device->open++) {
		/* power on device on adding first reader */
		if (device->hid->ll_driver->power) {
			error = device->hid->ll_driver->power(device->hid,
					PM_HINT_FULLON);
			if (error < 0) {
				--device->open;
				goto exit_err;
			}
		}
		error = device->hid->ll_driver->open(device->hid);
		if (error < 0) {
			if (device->hid->ll_driver->power)
				device->hid->ll_driver->power(device->hid,
						PM_HINT_NORMAL);
			--device->open;
			goto exit_err;
		}
	}

	reader->device = device;
	/* new reader doesn't get old events */
	reader->cbuf_start = device->cbuf_end;

	list_add_tail(&reader->node, &device->readers);
	file->private_data = reader;

exit_unlock:
	mutex_unlock(&device->readers_lock);
	mutex_unlock(&devices_lock);
	return error;
exit_err:
	kfree(reader);
	goto exit_unlock;
}

static int roccat_release(struct inode *inode, struct file *file)
{
	unsigned int minor = iminor(inode);
	struct roccat_reader *reader = file->private_data;
	struct roccat_device *device;

	mutex_lock(&devices_lock);

	device = devices[minor];
	if (!device) {
		mutex_unlock(&devices_lock);
		printk(KERN_EMERG "roccat device with minor %d doesn't exist\n",
				minor);
		return -ENODEV;
	}

	mutex_lock(&device->readers_lock);
	list_del(&reader->node);
	mutex_unlock(&device->readers_lock);
	kfree(reader);

	if (!--device->open) {
		/* removing last reader */
		if (device->exist) {
			if (device->hid->ll_driver->power)
				device->hid->ll_driver->power(device->hid,
						PM_HINT_NORMAL);
			device->hid->ll_driver->close(device->hid);
		} else {
			kfree(device);
		}
	}

	mutex_unlock(&devices_lock);

	return 0;
}

/*
 * roccat_report_event() - output data to readers
 * @minor: minor device number returned by roccat_connect()
 * @data: pointer to data
 * @len: size of data
 *
 * Return value is zero on success, a negative error code on failure.
 *
 * This is called from interrupt handler.
 */
int roccat_report_event(int minor, u8 const *data, int len)
{
	struct roccat_device *device;
	struct roccat_reader *reader;
	struct roccat_report *report;
	uint8_t *new_value;

	new_value = kmemdup(data, len, GFP_ATOMIC);
	if (!new_value)
		return -ENOMEM;

	device = devices[minor];

	report = &device->cbuf[device->cbuf_end];

	/* passing NULL is safe */
	kfree(report->value);

	report->value = new_value;
	report->len = len;
	device->cbuf_end = (device->cbuf_end + 1) % ROCCAT_CBUF_SIZE;

	list_for_each_entry(reader, &device->readers, node) {
		/*
		 * As we already inserted one element, the buffer can't be
		 * empty. If start and end are equal, buffer is full and we
		 * increase start, so that slow reader misses one event, but
		 * gets the newer ones in the right order.
		 */
		if (reader->cbuf_start == device->cbuf_end)
			reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE;
	}

	wake_up_interruptible(&device->wait);
	return 0;
}
EXPORT_SYMBOL_GPL(roccat_report_event);

/*
 * roccat_connect() - create a char device for special event output
 * @hid: the hid device the char device should be connected to.
 *
 * Return value is minor device number in Range [0, ROCCAT_MAX_DEVICES] on
 * success, a negative error code on failure.
 */
int roccat_connect(struct hid_device *hid)
{
	unsigned int minor;
	struct roccat_device *device;
	int temp;

	device = kzalloc(sizeof(struct roccat_device), GFP_KERNEL);
	if (!device)
		return -ENOMEM;

	mutex_lock(&devices_lock);

	for (minor = 0; minor < ROCCAT_MAX_DEVICES; ++minor) {
		if (devices[minor])
			continue;
		break;
	}

	if (minor < ROCCAT_MAX_DEVICES) {
		devices[minor] = device;
	} else {
		mutex_unlock(&devices_lock);
		kfree(device);
		return -EINVAL;
	}

	device->dev = device_create(roccat_class, &hid->dev,
			MKDEV(roccat_major, minor), NULL,
			"%s%s%d", "roccat", hid->driver->name, minor);

	if (IS_ERR(device->dev)) {
		devices[minor] = NULL;
		mutex_unlock(&devices_lock);
		temp = PTR_ERR(device->dev);
		kfree(device);
		return temp;
	}

	mutex_unlock(&devices_lock);

	init_waitqueue_head(&device->wait);
	INIT_LIST_HEAD(&device->readers);
	mutex_init(&device->readers_lock);
	mutex_init(&device->cbuf_lock);
	device->minor = minor;
	device->hid = hid;
	device->exist = 1;
	device->cbuf_end = 0;

	return minor;
}
EXPORT_SYMBOL_GPL(roccat_connect);

/* roccat_disconnect() - remove char device from hid device
 * @minor: the minor device number returned by roccat_connect()
 */
void roccat_disconnect(int minor)
{
	struct roccat_device *device;

	mutex_lock(&devices_lock);
	device = devices[minor];
	devices[minor] = NULL;
	mutex_unlock(&devices_lock);

	device->exist = 0; /* TODO exist maybe not needed */

	device_destroy(roccat_class, MKDEV(roccat_major, minor));

	if (device->open) {
		device->hid->ll_driver->close(device->hid);
		wake_up_interruptible(&device->wait);
	} else {
		kfree(device);
	}
}
EXPORT_SYMBOL_GPL(roccat_disconnect);

static const struct file_operations roccat_ops = {
	.owner = THIS_MODULE,
	.read = roccat_read,
	.poll = roccat_poll,
	.open = roccat_open,
	.release = roccat_release,
	.llseek = noop_llseek,
};

static int __init roccat_init(void)
{
	int retval;
	dev_t dev_id;

	retval = alloc_chrdev_region(&dev_id, ROCCAT_FIRST_MINOR,
			ROCCAT_MAX_DEVICES, "roccat");

	roccat_major = MAJOR(dev_id);

	if (retval < 0) {
		printk(KERN_WARNING "roccat: can't get major number\n");
		return retval;
	}

	roccat_class = class_create(THIS_MODULE, "roccat");
	if (IS_ERR(roccat_class)) {
		retval = PTR_ERR(roccat_class);
		unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES);
		return retval;
	}

	cdev_init(&roccat_cdev, &roccat_ops);
	cdev_add(&roccat_cdev, dev_id, ROCCAT_MAX_DEVICES);

	return 0;
}

static void __exit roccat_exit(void)
{
	dev_t dev_id = MKDEV(roccat_major, 0);

	cdev_del(&roccat_cdev);
	class_destroy(roccat_class);
	unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES);
}

module_init(roccat_init);
module_exit(roccat_exit);

MODULE_AUTHOR("Stefan Achatz");
MODULE_DESCRIPTION("USB Roccat char device");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
206f5f2f SA	1	/*
	2	* Roccat driver for Linux
	3	*
	4	* Copyright (c) 2010 Stefan Achatz <erazor_de@users.sourceforge.net>
	5	*/
	6
	7	/*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License as published by the Free
	10	* Software Foundation; either version 2 of the License, or (at your option)
	11	* any later version.
	12	*/
	13
	14	/*
	15	* Module roccat is a char device used to report special events of roccat
	16	* hardware to userland. These events include requests for on-screen-display of
	17	* profile or dpi settings or requests for execution of macro sequences that are
	18	* not stored in device. The information in these events depends on hid device
	19	* implementation and contains data that is not available in a single hid event
	20	* or else hidraw could have been used.
	21	* It is inspired by hidraw, but uses only one circular buffer for all readers.
	22	*/
	23
	24	#include <linux/cdev.h>
	25	#include <linux/poll.h>
	26	#include <linux/sched.h>
	27
	28	#include "hid-roccat.h"
	29
	30	#define ROCCAT_FIRST_MINOR 0
	31	#define ROCCAT_MAX_DEVICES 8
	32
	33	/* should be a power of 2 for performance reason */
	34	#define ROCCAT_CBUF_SIZE 16
	35
	36	struct roccat_report {
	37	uint8_t *value;
	38	int len;
	39	};
	40
	41	struct roccat_device {
	42	unsigned int minor;
	43	int open;
	44	int exist;
	45	wait_queue_head_t wait;
	46	struct device *dev;
	47	struct hid_device *hid;
	48	struct list_head readers;
	49	/* protects modifications of readers list */
	50	struct mutex readers_lock;
	51
	52	/*
	53	* circular_buffer has one writer and multiple readers with their own
	54	* read pointers
	55	*/
	56	struct roccat_report cbuf[ROCCAT_CBUF_SIZE];
	57	int cbuf_end;
	58	struct mutex cbuf_lock;
	59	};
	60
	61	struct roccat_reader {
	62	struct list_head node;
	63	struct roccat_device *device;
	64	int cbuf_start;
65	};
66
67	static int roccat_major;
68	static struct class *roccat_class;
69	static struct cdev roccat_cdev;
70
71	static struct roccat_device *devices[ROCCAT_MAX_DEVICES];
72	/* protects modifications of devices array */
73	static DEFINE_MUTEX(devices_lock);
74
75	static ssize_t roccat_read(struct file file, char __user buffer,
76	size_t count, loff_t *ppos)
77	{
78	struct roccat_reader *reader = file->private_data;
79	struct roccat_device *device = reader->device;
80	struct roccat_report *report;
81	ssize_t retval = 0, len;
82	DECLARE_WAITQUEUE(wait, current);
83
84	mutex_lock(&device->cbuf_lock);
85
86	/* no data? */
87	if (reader->cbuf_start == device->cbuf_end) {
88	add_wait_queue(&device->wait, &wait);
89	set_current_state(TASK_INTERRUPTIBLE);
90
91	/* wait for data */
92	while (reader->cbuf_start == device->cbuf_end) {
93	if (file->f_flags & O_NONBLOCK) {
94	retval = -EAGAIN;
95	break;
96	}
97	if (signal_pending(current)) {
98	retval = -ERESTARTSYS;
99	break;
100	}
101	if (!device->exist) {
102	retval = -EIO;
103	break;
104	}
105
106	mutex_unlock(&device->cbuf_lock);
107	schedule();
108	mutex_lock(&device->cbuf_lock);
109	set_current_state(TASK_INTERRUPTIBLE);
110	}
111
112	set_current_state(TASK_RUNNING);
113	remove_wait_queue(&device->wait, &wait);
114	}
115
116	/* here we either have data or a reason to return if retval is set */
117	if (retval)
118	goto exit_unlock;
119
120	report = &device->cbuf[reader->cbuf_start];
121	/*
122	* If report is larger than requested amount of data, rest of report
123	* is lost!
124	*/
125	len = report->len > count ? count : report->len;
126
127	if (copy_to_user(buffer, report->value, len)) {
128	retval = -EFAULT;
129	goto exit_unlock;
130	}
131	retval += len;
132	reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE;
133
134	exit_unlock:
135	mutex_unlock(&device->cbuf_lock);
136	return retval;
137	}
138
139	static unsigned int roccat_poll(struct file file, poll_table wait)
140	{
141	struct roccat_reader *reader = file->private_data;
142	poll_wait(file, &reader->device->wait, wait);
143	if (reader->cbuf_start != reader->device->cbuf_end)
144	return POLLIN \| POLLRDNORM;
145	if (!reader->device->exist)
146	return POLLERR \| POLLHUP;
147	return 0;
148	}
149
150	static int roccat_open(struct inode inode, struct file file)
151	{
152	unsigned int minor = iminor(inode);
153	struct roccat_reader *reader;
154	struct roccat_device *device;
155	int error = 0;
156
157	reader = kzalloc(sizeof(struct roccat_reader), GFP_KERNEL);
158	if (!reader)
159	return -ENOMEM;
160
161	mutex_lock(&devices_lock);
162
163	device = devices[minor];
164
165	mutex_lock(&device->readers_lock);
166
167	if (!device) {
168	printk(KERN_EMERG "roccat device with minor %d doesn't exist\n",
169	minor);
170	error = -ENODEV;
dfe5c7b7	171	goto exit_err;
206f5f2f SA	172	}
	173
	174	if (!device->open++) {
	175	/* power on device on adding first reader */
	176	if (device->hid->ll_driver->power) {
	177	error = device->hid->ll_driver->power(device->hid,
	178	PM_HINT_FULLON);
	179	if (error < 0) {
	180	--device->open;
dfe5c7b7	181	goto exit_err;
206f5f2f SA	182	}
	183	}
	184	error = device->hid->ll_driver->open(device->hid);
	185	if (error < 0) {
	186	if (device->hid->ll_driver->power)
	187	device->hid->ll_driver->power(device->hid,
	188	PM_HINT_NORMAL);
	189	--device->open;
dfe5c7b7	190	goto exit_err;
206f5f2f SA	191	}
	192	}
	193
	194	reader->device = device;
	195	/* new reader doesn't get old events */
	196	reader->cbuf_start = device->cbuf_end;
	197
	198	list_add_tail(&reader->node, &device->readers);
	199	file->private_data = reader;
	200
	201	exit_unlock:
	202	mutex_unlock(&device->readers_lock);
	203	mutex_unlock(&devices_lock);
	204	return error;
dfe5c7b7 JL	205	exit_err:
	206	kfree(reader);
	207	goto exit_unlock;
206f5f2f SA	208	}
	209
	210	static int roccat_release(struct inode inode, struct file file)
	211	{
	212	unsigned int minor = iminor(inode);
	213	struct roccat_reader *reader = file->private_data;
	214	struct roccat_device *device;
	215
	216	mutex_lock(&devices_lock);
	217
	218	device = devices[minor];
	219	if (!device) {
	220	mutex_unlock(&devices_lock);
	221	printk(KERN_EMERG "roccat device with minor %d doesn't exist\n",
	222	minor);
	223	return -ENODEV;
	224	}
	225
	226	mutex_lock(&device->readers_lock);
	227	list_del(&reader->node);
	228	mutex_unlock(&device->readers_lock);
	229	kfree(reader);
	230
	231	if (!--device->open) {
	232	/* removing last reader */
	233	if (device->exist) {
	234	if (device->hid->ll_driver->power)
	235	device->hid->ll_driver->power(device->hid,
	236	PM_HINT_NORMAL);
	237	device->hid->ll_driver->close(device->hid);
	238	} else {
	239	kfree(device);
	240	}
	241	}
	242
	243	mutex_unlock(&devices_lock);
	244
	245	return 0;
	246	}
	247
	248	/*
	249	* roccat_report_event() - output data to readers
	250	* @minor: minor device number returned by roccat_connect()
	251	* @data: pointer to data
	252	* @len: size of data
	253	*
	254	* Return value is zero on success, a negative error code on failure.
	255	*
	256	* This is called from interrupt handler.
	257	*/
	258	int roccat_report_event(int minor, u8 const *data, int len)
	259	{
	260	struct roccat_device *device;
	261	struct roccat_reader *reader;
	262	struct roccat_report *report;
	263	uint8_t *new_value;
	264
	265	new_value = kmemdup(data, len, GFP_ATOMIC);
	266	if (!new_value)
	267	return -ENOMEM;
	268
	269	device = devices[minor];
	270
	271	report = &device->cbuf[device->cbuf_end];
272
273	/* passing NULL is safe */
274	kfree(report->value);
275
276	report->value = new_value;
277	report->len = len;
278	device->cbuf_end = (device->cbuf_end + 1) % ROCCAT_CBUF_SIZE;
279
280	list_for_each_entry(reader, &device->readers, node) {
281	/*
282	* As we already inserted one element, the buffer can't be
283	* empty. If start and end are equal, buffer is full and we
284	* increase start, so that slow reader misses one event, but
285	* gets the newer ones in the right order.
286	*/
287	if (reader->cbuf_start == device->cbuf_end)
288	reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE;
289	}
290
291	wake_up_interruptible(&device->wait);
292	return 0;
293	}
294	EXPORT_SYMBOL_GPL(roccat_report_event);
295
296	/*
297	* roccat_connect() - create a char device for special event output
298	* @hid: the hid device the char device should be connected to.
299	*
300	* Return value is minor device number in Range [0, ROCCAT_MAX_DEVICES] on
301	* success, a negative error code on failure.
302	*/
303	int roccat_connect(struct hid_device *hid)
304	{
305	unsigned int minor;
306	struct roccat_device *device;
307	int temp;
308
309	device = kzalloc(sizeof(struct roccat_device), GFP_KERNEL);
310	if (!device)
311	return -ENOMEM;
312
313	mutex_lock(&devices_lock);
314
315	for (minor = 0; minor < ROCCAT_MAX_DEVICES; ++minor) {
316	if (devices[minor])
317	continue;
318	break;
319	}
320
321	if (minor < ROCCAT_MAX_DEVICES) {
322	devices[minor] = device;
323	} else {
324	mutex_unlock(&devices_lock);
325	kfree(device);
326	return -EINVAL;
327	}
328
329	device->dev = device_create(roccat_class, &hid->dev,
330	MKDEV(roccat_major, minor), NULL,
331	"%s%s%d", "roccat", hid->driver->name, minor);
332
333	if (IS_ERR(device->dev)) {
334	devices[minor] = NULL;
335	mutex_unlock(&devices_lock);
336	temp = PTR_ERR(device->dev);
337	kfree(device);
338	return temp;
339	}
340
341	mutex_unlock(&devices_lock);
342
343	init_waitqueue_head(&device->wait);
344	INIT_LIST_HEAD(&device->readers);
345	mutex_init(&device->readers_lock);
346	mutex_init(&device->cbuf_lock);
347	device->minor = minor;
348	device->hid = hid;
349	device->exist = 1;
350	device->cbuf_end = 0;
351
352	return minor;
353	}
354	EXPORT_SYMBOL_GPL(roccat_connect);
355
356	/* roccat_disconnect() - remove char device from hid device
357	* @minor: the minor device number returned by roccat_connect()
358	*/
359	void roccat_disconnect(int minor)
360	{
361	struct roccat_device *device;
362
363	mutex_lock(&devices_lock);
364	device = devices[minor];
365	devices[minor] = NULL;
366	mutex_unlock(&devices_lock);
367
368	device->exist = 0; /* TODO exist maybe not needed */
369
370	device_destroy(roccat_class, MKDEV(roccat_major, minor));
371
372	if (device->open) {
373	device->hid->ll_driver->close(device->hid);
374	wake_up_interruptible(&device->wait);
375	} else {
376	kfree(device);
377	}
378	}
379	EXPORT_SYMBOL_GPL(roccat_disconnect);
380
381	static const struct file_operations roccat_ops = {
382	.owner = THIS_MODULE,
383	.read = roccat_read,
384	.poll = roccat_poll,
385	.open = roccat_open,
386	.release = roccat_release,
6038f373	387	.llseek = noop_llseek,
206f5f2f SA	388	};
	389
	390	static int __init roccat_init(void)
	391	{
	392	int retval;
	393	dev_t dev_id;
	394
	395	retval = alloc_chrdev_region(&dev_id, ROCCAT_FIRST_MINOR,
	396	ROCCAT_MAX_DEVICES, "roccat");
	397
	398	roccat_major = MAJOR(dev_id);
	399
	400	if (retval < 0) {
	401	printk(KERN_WARNING "roccat: can't get major number\n");
	402	return retval;
	403	}
	404
	405	roccat_class = class_create(THIS_MODULE, "roccat");
	406	if (IS_ERR(roccat_class)) {
	407	retval = PTR_ERR(roccat_class);
	408	unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES);
	409	return retval;
	410	}
	411
	412	cdev_init(&roccat_cdev, &roccat_ops);
	413	cdev_add(&roccat_cdev, dev_id, ROCCAT_MAX_DEVICES);
	414
	415	return 0;
	416	}
	417
	418	static void __exit roccat_exit(void)
	419	{
	420	dev_t dev_id = MKDEV(roccat_major, 0);
	421
	422	cdev_del(&roccat_cdev);
	423	class_destroy(roccat_class);
	424	unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES);
	425	}
	426
	427	module_init(roccat_init);
	428	module_exit(roccat_exit);
	429
	430	MODULE_AUTHOR("Stefan Achatz");
	431	MODULE_DESCRIPTION("USB Roccat char device");
	432	MODULE_LICENSE("GPL v2");