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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Roccat driver for Linux
4 *
5 * Copyright (c) 2010 Stefan Achatz <erazor_de@users.sourceforge.net>
6 */
7
8/*
9 */
10
11/*
12 * Module roccat is a char device used to report special events of roccat
13 * hardware to userland. These events include requests for on-screen-display of
14 * profile or dpi settings or requests for execution of macro sequences that are
15 * not stored in device. The information in these events depends on hid device
16 * implementation and contains data that is not available in a single hid event
17 * or else hidraw could have been used.
18 * It is inspired by hidraw, but uses only one circular buffer for all readers.
19 */
20
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23#include <linux/cdev.h>
24#include <linux/poll.h>
25#include <linux/sched/signal.h>
26#include <linux/hid-roccat.h>
27#include <linux/module.h>
28
29#define ROCCAT_FIRST_MINOR 0
30#define ROCCAT_MAX_DEVICES 8
31
32/* should be a power of 2 for performance reason */
33#define ROCCAT_CBUF_SIZE 16
34
35struct roccat_report {
36 uint8_t *value;
37};
38
39struct roccat_device {
40 unsigned int minor;
41 int report_size;
42 int open;
43 int exist;
44 wait_queue_head_t wait;
45 struct device *dev;
46 struct hid_device *hid;
47 struct list_head readers;
48 /* protects modifications of readers list */
49 struct mutex readers_lock;
50
51 /*
52 * circular_buffer has one writer and multiple readers with their own
53 * read pointers
54 */
55 struct roccat_report cbuf[ROCCAT_CBUF_SIZE];
56 int cbuf_end;
57 struct mutex cbuf_lock;
58};
59
60struct roccat_reader {
61 struct list_head node;
62 struct roccat_device *device;
63 int cbuf_start;
64};
65
66static int roccat_major;
67static struct cdev roccat_cdev;
68
69static struct roccat_device *devices[ROCCAT_MAX_DEVICES];
70/* protects modifications of devices array */
71static DEFINE_MUTEX(devices_lock);
72
73static ssize_t roccat_read(struct file *file, char __user *buffer,
74 size_t count, loff_t *ppos)
75{
76 struct roccat_reader *reader = file->private_data;
77 struct roccat_device *device = reader->device;
78 struct roccat_report *report;
79 ssize_t retval = 0, len;
80 DECLARE_WAITQUEUE(wait, current);
81
82 mutex_lock(&device->cbuf_lock);
83
84 /* no data? */
85 if (reader->cbuf_start == device->cbuf_end) {
86 add_wait_queue(&device->wait, &wait);
87 set_current_state(TASK_INTERRUPTIBLE);
88
89 /* wait for data */
90 while (reader->cbuf_start == device->cbuf_end) {
91 if (file->f_flags & O_NONBLOCK) {
92 retval = -EAGAIN;
93 break;
94 }
95 if (signal_pending(current)) {
96 retval = -ERESTARTSYS;
97 break;
98 }
99 if (!device->exist) {
100 retval = -EIO;
101 break;
102 }
103
104 mutex_unlock(&device->cbuf_lock);
105 schedule();
106 mutex_lock(&device->cbuf_lock);
107 set_current_state(TASK_INTERRUPTIBLE);
108 }
109
110 set_current_state(TASK_RUNNING);
111 remove_wait_queue(&device->wait, &wait);
112 }
113
114 /* here we either have data or a reason to return if retval is set */
115 if (retval)
116 goto exit_unlock;
117
118 report = &device->cbuf[reader->cbuf_start];
119 /*
120 * If report is larger than requested amount of data, rest of report
121 * is lost!
122 */
123 len = device->report_size > count ? count : device->report_size;
124
125 if (copy_to_user(buffer, report->value, len)) {
126 retval = -EFAULT;
127 goto exit_unlock;
128 }
129 retval += len;
130 reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE;
131
132exit_unlock:
133 mutex_unlock(&device->cbuf_lock);
134 return retval;
135}
136
137static __poll_t roccat_poll(struct file *file, poll_table *wait)
138{
139 struct roccat_reader *reader = file->private_data;
140 poll_wait(file, &reader->device->wait, wait);
141 if (reader->cbuf_start != reader->device->cbuf_end)
142 return EPOLLIN | EPOLLRDNORM;
143 if (!reader->device->exist)
144 return EPOLLERR | EPOLLHUP;
145 return 0;
146}
147
148static int roccat_open(struct inode *inode, struct file *file)
149{
150 unsigned int minor = iminor(inode);
151 struct roccat_reader *reader;
152 struct roccat_device *device;
153 int error = 0;
154
155 reader = kzalloc(sizeof(struct roccat_reader), GFP_KERNEL);
156 if (!reader)
157 return -ENOMEM;
158
159 mutex_lock(&devices_lock);
160
161 device = devices[minor];
162
163 if (!device) {
164 pr_emerg("roccat device with minor %d doesn't exist\n", minor);
165 error = -ENODEV;
166 goto exit_err_devices;
167 }
168
169 mutex_lock(&device->readers_lock);
170
171 if (!device->open++) {
172 /* power on device on adding first reader */
173 error = hid_hw_power(device->hid, PM_HINT_FULLON);
174 if (error < 0) {
175 --device->open;
176 goto exit_err_readers;
177 }
178
179 error = hid_hw_open(device->hid);
180 if (error < 0) {
181 hid_hw_power(device->hid, PM_HINT_NORMAL);
182 --device->open;
183 goto exit_err_readers;
184 }
185 }
186
187 reader->device = device;
188 /* new reader doesn't get old events */
189 reader->cbuf_start = device->cbuf_end;
190
191 list_add_tail(&reader->node, &device->readers);
192 file->private_data = reader;
193
194exit_err_readers:
195 mutex_unlock(&device->readers_lock);
196exit_err_devices:
197 mutex_unlock(&devices_lock);
198 if (error)
199 kfree(reader);
200 return error;
201}
202
203static int roccat_release(struct inode *inode, struct file *file)
204{
205 unsigned int minor = iminor(inode);
206 struct roccat_reader *reader = file->private_data;
207 struct roccat_device *device;
208
209 mutex_lock(&devices_lock);
210
211 device = devices[minor];
212 if (!device) {
213 mutex_unlock(&devices_lock);
214 pr_emerg("roccat device with minor %d doesn't exist\n", minor);
215 return -ENODEV;
216 }
217
218 mutex_lock(&device->readers_lock);
219 list_del(&reader->node);
220 mutex_unlock(&device->readers_lock);
221 kfree(reader);
222
223 if (!--device->open) {
224 /* removing last reader */
225 if (device->exist) {
226 hid_hw_power(device->hid, PM_HINT_NORMAL);
227 hid_hw_close(device->hid);
228 } else {
229 kfree(device);
230 }
231 }
232
233 mutex_unlock(&devices_lock);
234
235 return 0;
236}
237
238/*
239 * roccat_report_event() - output data to readers
240 * @minor: minor device number returned by roccat_connect()
241 * @data: pointer to data
242 *
243 * Return value is zero on success, a negative error code on failure.
244 *
245 * This is called from interrupt handler.
246 */
247int roccat_report_event(int minor, u8 const *data)
248{
249 struct roccat_device *device;
250 struct roccat_reader *reader;
251 struct roccat_report *report;
252 uint8_t *new_value;
253
254 device = devices[minor];
255
256 new_value = kmemdup(data, device->report_size, GFP_ATOMIC);
257 if (!new_value)
258 return -ENOMEM;
259
260 report = &device->cbuf[device->cbuf_end];
261
262 /* passing NULL is safe */
263 kfree(report->value);
264
265 report->value = new_value;
266 device->cbuf_end = (device->cbuf_end + 1) % ROCCAT_CBUF_SIZE;
267
268 list_for_each_entry(reader, &device->readers, node) {
269 /*
270 * As we already inserted one element, the buffer can't be
271 * empty. If start and end are equal, buffer is full and we
272 * increase start, so that slow reader misses one event, but
273 * gets the newer ones in the right order.
274 */
275 if (reader->cbuf_start == device->cbuf_end)
276 reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE;
277 }
278
279 wake_up_interruptible(&device->wait);
280 return 0;
281}
282EXPORT_SYMBOL_GPL(roccat_report_event);
283
284/*
285 * roccat_connect() - create a char device for special event output
286 * @class: the class thats used to create the device. Meant to hold device
287 * specific sysfs attributes.
288 * @hid: the hid device the char device should be connected to.
289 * @report_size: size of reports
290 *
291 * Return value is minor device number in Range [0, ROCCAT_MAX_DEVICES] on
292 * success, a negative error code on failure.
293 */
294int roccat_connect(struct class *klass, struct hid_device *hid, int report_size)
295{
296 unsigned int minor;
297 struct roccat_device *device;
298 int temp;
299
300 device = kzalloc(sizeof(struct roccat_device), GFP_KERNEL);
301 if (!device)
302 return -ENOMEM;
303
304 mutex_lock(&devices_lock);
305
306 for (minor = 0; minor < ROCCAT_MAX_DEVICES; ++minor) {
307 if (devices[minor])
308 continue;
309 break;
310 }
311
312 if (minor < ROCCAT_MAX_DEVICES) {
313 devices[minor] = device;
314 } else {
315 mutex_unlock(&devices_lock);
316 kfree(device);
317 return -EINVAL;
318 }
319
320 device->dev = device_create(klass, &hid->dev,
321 MKDEV(roccat_major, minor), NULL,
322 "%s%s%d", "roccat", hid->driver->name, minor);
323
324 if (IS_ERR(device->dev)) {
325 devices[minor] = NULL;
326 mutex_unlock(&devices_lock);
327 temp = PTR_ERR(device->dev);
328 kfree(device);
329 return temp;
330 }
331
332 mutex_unlock(&devices_lock);
333
334 init_waitqueue_head(&device->wait);
335 INIT_LIST_HEAD(&device->readers);
336 mutex_init(&device->readers_lock);
337 mutex_init(&device->cbuf_lock);
338 device->minor = minor;
339 device->hid = hid;
340 device->exist = 1;
341 device->cbuf_end = 0;
342 device->report_size = report_size;
343
344 return minor;
345}
346EXPORT_SYMBOL_GPL(roccat_connect);
347
348/* roccat_disconnect() - remove char device from hid device
349 * @minor: the minor device number returned by roccat_connect()
350 */
351void roccat_disconnect(int minor)
352{
353 struct roccat_device *device;
354
355 mutex_lock(&devices_lock);
356 device = devices[minor];
357 mutex_unlock(&devices_lock);
358
359 device->exist = 0; /* TODO exist maybe not needed */
360
361 device_destroy(device->dev->class, MKDEV(roccat_major, minor));
362
363 mutex_lock(&devices_lock);
364 devices[minor] = NULL;
365 mutex_unlock(&devices_lock);
366
367 if (device->open) {
368 hid_hw_close(device->hid);
369 wake_up_interruptible(&device->wait);
370 } else {
371 kfree(device);
372 }
373}
374EXPORT_SYMBOL_GPL(roccat_disconnect);
375
376static long roccat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
377{
378 struct inode *inode = file_inode(file);
379 struct roccat_device *device;
380 unsigned int minor = iminor(inode);
381 long retval = 0;
382
383 mutex_lock(&devices_lock);
384
385 device = devices[minor];
386 if (!device) {
387 retval = -ENODEV;
388 goto out;
389 }
390
391 switch (cmd) {
392 case ROCCATIOCGREPSIZE:
393 if (put_user(device->report_size, (int __user *)arg))
394 retval = -EFAULT;
395 break;
396 default:
397 retval = -ENOTTY;
398 }
399out:
400 mutex_unlock(&devices_lock);
401 return retval;
402}
403
404static const struct file_operations roccat_ops = {
405 .owner = THIS_MODULE,
406 .read = roccat_read,
407 .poll = roccat_poll,
408 .open = roccat_open,
409 .release = roccat_release,
410 .llseek = noop_llseek,
411 .unlocked_ioctl = roccat_ioctl,
412};
413
414static int __init roccat_init(void)
415{
416 int retval;
417 dev_t dev_id;
418
419 retval = alloc_chrdev_region(&dev_id, ROCCAT_FIRST_MINOR,
420 ROCCAT_MAX_DEVICES, "roccat");
421 if (retval < 0) {
422 pr_warn("can't get major number\n");
423 goto error;
424 }
425
426 roccat_major = MAJOR(dev_id);
427
428 cdev_init(&roccat_cdev, &roccat_ops);
429 retval = cdev_add(&roccat_cdev, dev_id, ROCCAT_MAX_DEVICES);
430
431 if (retval < 0) {
432 pr_warn("cannot add cdev\n");
433 goto cleanup_alloc_chrdev_region;
434 }
435 return 0;
436
437
438 cleanup_alloc_chrdev_region:
439 unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES);
440 error:
441 return retval;
442}
443
444static void __exit roccat_exit(void)
445{
446 dev_t dev_id = MKDEV(roccat_major, 0);
447
448 cdev_del(&roccat_cdev);
449 unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES);
450}
451
452module_init(roccat_init);
453module_exit(roccat_exit);
454
455MODULE_AUTHOR("Stefan Achatz");
456MODULE_DESCRIPTION("USB Roccat char device");
457MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Roccat driver for Linux
4 *
5 * Copyright (c) 2010 Stefan Achatz <erazor_de@users.sourceforge.net>
6 */
7
8/*
9 */
10
11/*
12 * Module roccat is a char device used to report special events of roccat
13 * hardware to userland. These events include requests for on-screen-display of
14 * profile or dpi settings or requests for execution of macro sequences that are
15 * not stored in device. The information in these events depends on hid device
16 * implementation and contains data that is not available in a single hid event
17 * or else hidraw could have been used.
18 * It is inspired by hidraw, but uses only one circular buffer for all readers.
19 */
20
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23#include <linux/cdev.h>
24#include <linux/poll.h>
25#include <linux/sched/signal.h>
26#include <linux/hid-roccat.h>
27#include <linux/module.h>
28
29#define ROCCAT_FIRST_MINOR 0
30#define ROCCAT_MAX_DEVICES 8
31
32/* should be a power of 2 for performance reason */
33#define ROCCAT_CBUF_SIZE 16
34
35struct roccat_report {
36 uint8_t *value;
37};
38
39struct roccat_device {
40 unsigned int minor;
41 int report_size;
42 int open;
43 int exist;
44 wait_queue_head_t wait;
45 struct device *dev;
46 struct hid_device *hid;
47 struct list_head readers;
48 /* protects modifications of readers list */
49 struct mutex readers_lock;
50
51 /*
52 * circular_buffer has one writer and multiple readers with their own
53 * read pointers
54 */
55 struct roccat_report cbuf[ROCCAT_CBUF_SIZE];
56 int cbuf_end;
57 struct mutex cbuf_lock;
58};
59
60struct roccat_reader {
61 struct list_head node;
62 struct roccat_device *device;
63 int cbuf_start;
64};
65
66static int roccat_major;
67static struct cdev roccat_cdev;
68
69static struct roccat_device *devices[ROCCAT_MAX_DEVICES];
70/* protects modifications of devices array */
71static DEFINE_MUTEX(devices_lock);
72
73static ssize_t roccat_read(struct file *file, char __user *buffer,
74 size_t count, loff_t *ppos)
75{
76 struct roccat_reader *reader = file->private_data;
77 struct roccat_device *device = reader->device;
78 struct roccat_report *report;
79 ssize_t retval = 0, len;
80 DECLARE_WAITQUEUE(wait, current);
81
82 mutex_lock(&device->cbuf_lock);
83
84 /* no data? */
85 if (reader->cbuf_start == device->cbuf_end) {
86 add_wait_queue(&device->wait, &wait);
87 set_current_state(TASK_INTERRUPTIBLE);
88
89 /* wait for data */
90 while (reader->cbuf_start == device->cbuf_end) {
91 if (file->f_flags & O_NONBLOCK) {
92 retval = -EAGAIN;
93 break;
94 }
95 if (signal_pending(current)) {
96 retval = -ERESTARTSYS;
97 break;
98 }
99 if (!device->exist) {
100 retval = -EIO;
101 break;
102 }
103
104 mutex_unlock(&device->cbuf_lock);
105 schedule();
106 mutex_lock(&device->cbuf_lock);
107 set_current_state(TASK_INTERRUPTIBLE);
108 }
109
110 set_current_state(TASK_RUNNING);
111 remove_wait_queue(&device->wait, &wait);
112 }
113
114 /* here we either have data or a reason to return if retval is set */
115 if (retval)
116 goto exit_unlock;
117
118 report = &device->cbuf[reader->cbuf_start];
119 /*
120 * If report is larger than requested amount of data, rest of report
121 * is lost!
122 */
123 len = device->report_size > count ? count : device->report_size;
124
125 if (copy_to_user(buffer, report->value, len)) {
126 retval = -EFAULT;
127 goto exit_unlock;
128 }
129 retval += len;
130 reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE;
131
132exit_unlock:
133 mutex_unlock(&device->cbuf_lock);
134 return retval;
135}
136
137static __poll_t roccat_poll(struct file *file, poll_table *wait)
138{
139 struct roccat_reader *reader = file->private_data;
140 poll_wait(file, &reader->device->wait, wait);
141 if (reader->cbuf_start != reader->device->cbuf_end)
142 return EPOLLIN | EPOLLRDNORM;
143 if (!reader->device->exist)
144 return EPOLLERR | EPOLLHUP;
145 return 0;
146}
147
148static int roccat_open(struct inode *inode, struct file *file)
149{
150 unsigned int minor = iminor(inode);
151 struct roccat_reader *reader;
152 struct roccat_device *device;
153 int error = 0;
154
155 reader = kzalloc(sizeof(struct roccat_reader), GFP_KERNEL);
156 if (!reader)
157 return -ENOMEM;
158
159 mutex_lock(&devices_lock);
160
161 device = devices[minor];
162
163 if (!device) {
164 pr_emerg("roccat device with minor %d doesn't exist\n", minor);
165 error = -ENODEV;
166 goto exit_err_devices;
167 }
168
169 mutex_lock(&device->readers_lock);
170
171 if (!device->open++) {
172 /* power on device on adding first reader */
173 error = hid_hw_power(device->hid, PM_HINT_FULLON);
174 if (error < 0) {
175 --device->open;
176 goto exit_err_readers;
177 }
178
179 error = hid_hw_open(device->hid);
180 if (error < 0) {
181 hid_hw_power(device->hid, PM_HINT_NORMAL);
182 --device->open;
183 goto exit_err_readers;
184 }
185 }
186
187 reader->device = device;
188 /* new reader doesn't get old events */
189 reader->cbuf_start = device->cbuf_end;
190
191 list_add_tail(&reader->node, &device->readers);
192 file->private_data = reader;
193
194exit_err_readers:
195 mutex_unlock(&device->readers_lock);
196exit_err_devices:
197 mutex_unlock(&devices_lock);
198 if (error)
199 kfree(reader);
200 return error;
201}
202
203static int roccat_release(struct inode *inode, struct file *file)
204{
205 unsigned int minor = iminor(inode);
206 struct roccat_reader *reader = file->private_data;
207 struct roccat_device *device;
208
209 mutex_lock(&devices_lock);
210
211 device = devices[minor];
212 if (!device) {
213 mutex_unlock(&devices_lock);
214 pr_emerg("roccat device with minor %d doesn't exist\n", minor);
215 return -ENODEV;
216 }
217
218 mutex_lock(&device->readers_lock);
219 list_del(&reader->node);
220 mutex_unlock(&device->readers_lock);
221 kfree(reader);
222
223 if (!--device->open) {
224 /* removing last reader */
225 if (device->exist) {
226 hid_hw_power(device->hid, PM_HINT_NORMAL);
227 hid_hw_close(device->hid);
228 } else {
229 kfree(device);
230 }
231 }
232
233 mutex_unlock(&devices_lock);
234
235 return 0;
236}
237
238/*
239 * roccat_report_event() - output data to readers
240 * @minor: minor device number returned by roccat_connect()
241 * @data: pointer to data
242 *
243 * Return value is zero on success, a negative error code on failure.
244 *
245 * This is called from interrupt handler.
246 */
247int roccat_report_event(int minor, u8 const *data)
248{
249 struct roccat_device *device;
250 struct roccat_reader *reader;
251 struct roccat_report *report;
252 uint8_t *new_value;
253
254 device = devices[minor];
255
256 new_value = kmemdup(data, device->report_size, GFP_ATOMIC);
257 if (!new_value)
258 return -ENOMEM;
259
260 report = &device->cbuf[device->cbuf_end];
261
262 /* passing NULL is safe */
263 kfree(report->value);
264
265 report->value = new_value;
266 device->cbuf_end = (device->cbuf_end + 1) % ROCCAT_CBUF_SIZE;
267
268 list_for_each_entry(reader, &device->readers, node) {
269 /*
270 * As we already inserted one element, the buffer can't be
271 * empty. If start and end are equal, buffer is full and we
272 * increase start, so that slow reader misses one event, but
273 * gets the newer ones in the right order.
274 */
275 if (reader->cbuf_start == device->cbuf_end)
276 reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE;
277 }
278
279 wake_up_interruptible(&device->wait);
280 return 0;
281}
282EXPORT_SYMBOL_GPL(roccat_report_event);
283
284/*
285 * roccat_connect() - create a char device for special event output
286 * @class: the class thats used to create the device. Meant to hold device
287 * specific sysfs attributes.
288 * @hid: the hid device the char device should be connected to.
289 * @report_size: size of reports
290 *
291 * Return value is minor device number in Range [0, ROCCAT_MAX_DEVICES] on
292 * success, a negative error code on failure.
293 */
294int roccat_connect(struct class *klass, struct hid_device *hid, int report_size)
295{
296 unsigned int minor;
297 struct roccat_device *device;
298 int temp;
299
300 device = kzalloc(sizeof(struct roccat_device), GFP_KERNEL);
301 if (!device)
302 return -ENOMEM;
303
304 mutex_lock(&devices_lock);
305
306 for (minor = 0; minor < ROCCAT_MAX_DEVICES; ++minor) {
307 if (devices[minor])
308 continue;
309 break;
310 }
311
312 if (minor < ROCCAT_MAX_DEVICES) {
313 devices[minor] = device;
314 } else {
315 mutex_unlock(&devices_lock);
316 kfree(device);
317 return -EINVAL;
318 }
319
320 device->dev = device_create(klass, &hid->dev,
321 MKDEV(roccat_major, minor), NULL,
322 "%s%s%d", "roccat", hid->driver->name, minor);
323
324 if (IS_ERR(device->dev)) {
325 devices[minor] = NULL;
326 mutex_unlock(&devices_lock);
327 temp = PTR_ERR(device->dev);
328 kfree(device);
329 return temp;
330 }
331
332 mutex_unlock(&devices_lock);
333
334 init_waitqueue_head(&device->wait);
335 INIT_LIST_HEAD(&device->readers);
336 mutex_init(&device->readers_lock);
337 mutex_init(&device->cbuf_lock);
338 device->minor = minor;
339 device->hid = hid;
340 device->exist = 1;
341 device->cbuf_end = 0;
342 device->report_size = report_size;
343
344 return minor;
345}
346EXPORT_SYMBOL_GPL(roccat_connect);
347
348/* roccat_disconnect() - remove char device from hid device
349 * @minor: the minor device number returned by roccat_connect()
350 */
351void roccat_disconnect(int minor)
352{
353 struct roccat_device *device;
354
355 mutex_lock(&devices_lock);
356 device = devices[minor];
357 mutex_unlock(&devices_lock);
358
359 device->exist = 0; /* TODO exist maybe not needed */
360
361 device_destroy(device->dev->class, MKDEV(roccat_major, minor));
362
363 mutex_lock(&devices_lock);
364 devices[minor] = NULL;
365 mutex_unlock(&devices_lock);
366
367 if (device->open) {
368 hid_hw_close(device->hid);
369 wake_up_interruptible(&device->wait);
370 } else {
371 kfree(device);
372 }
373}
374EXPORT_SYMBOL_GPL(roccat_disconnect);
375
376static long roccat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
377{
378 struct inode *inode = file_inode(file);
379 struct roccat_device *device;
380 unsigned int minor = iminor(inode);
381 long retval = 0;
382
383 mutex_lock(&devices_lock);
384
385 device = devices[minor];
386 if (!device) {
387 retval = -ENODEV;
388 goto out;
389 }
390
391 switch (cmd) {
392 case ROCCATIOCGREPSIZE:
393 if (put_user(device->report_size, (int __user *)arg))
394 retval = -EFAULT;
395 break;
396 default:
397 retval = -ENOTTY;
398 }
399out:
400 mutex_unlock(&devices_lock);
401 return retval;
402}
403
404static const struct file_operations roccat_ops = {
405 .owner = THIS_MODULE,
406 .read = roccat_read,
407 .poll = roccat_poll,
408 .open = roccat_open,
409 .release = roccat_release,
410 .llseek = noop_llseek,
411 .unlocked_ioctl = roccat_ioctl,
412};
413
414static int __init roccat_init(void)
415{
416 int retval;
417 dev_t dev_id;
418
419 retval = alloc_chrdev_region(&dev_id, ROCCAT_FIRST_MINOR,
420 ROCCAT_MAX_DEVICES, "roccat");
421 if (retval < 0) {
422 pr_warn("can't get major number\n");
423 goto error;
424 }
425
426 roccat_major = MAJOR(dev_id);
427
428 cdev_init(&roccat_cdev, &roccat_ops);
429 retval = cdev_add(&roccat_cdev, dev_id, ROCCAT_MAX_DEVICES);
430
431 if (retval < 0) {
432 pr_warn("cannot add cdev\n");
433 goto cleanup_alloc_chrdev_region;
434 }
435 return 0;
436
437
438 cleanup_alloc_chrdev_region:
439 unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES);
440 error:
441 return retval;
442}
443
444static void __exit roccat_exit(void)
445{
446 dev_t dev_id = MKDEV(roccat_major, 0);
447
448 cdev_del(&roccat_cdev);
449 unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES);
450}
451
452module_init(roccat_init);
453module_exit(roccat_exit);
454
455MODULE_AUTHOR("Stefan Achatz");
456MODULE_DESCRIPTION("USB Roccat char device");
457MODULE_LICENSE("GPL v2");