1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * HID raw devices, giving access to raw HID events. |
4 | * |
5 | * In comparison to hiddev, this device does not process the |
6 | * hid events at all (no parsing, no lookups). This lets applications |
7 | * to work on raw hid events as they want to, and avoids a need to |
8 | * use a transport-specific userspace libhid/libusb libraries. |
9 | * |
10 | * Copyright (c) 2007-2014 Jiri Kosina |
11 | */ |
12 | |
13 | |
14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
15 | |
16 | #include <linux/fs.h> |
17 | #include <linux/module.h> |
18 | #include <linux/errno.h> |
19 | #include <linux/kernel.h> |
20 | #include <linux/init.h> |
21 | #include <linux/cdev.h> |
22 | #include <linux/poll.h> |
23 | #include <linux/device.h> |
24 | #include <linux/major.h> |
25 | #include <linux/slab.h> |
26 | #include <linux/hid.h> |
27 | #include <linux/mutex.h> |
28 | #include <linux/sched/signal.h> |
29 | #include <linux/string.h> |
30 | |
31 | #include <linux/hidraw.h> |
32 | |
33 | static int hidraw_major; |
34 | static struct cdev hidraw_cdev; |
35 | static const struct class hidraw_class = { |
36 | .name = "hidraw" , |
37 | }; |
38 | static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES]; |
39 | static DECLARE_RWSEM(minors_rwsem); |
40 | |
41 | static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) |
42 | { |
43 | struct hidraw_list *list = file->private_data; |
44 | int ret = 0, len; |
45 | DECLARE_WAITQUEUE(wait, current); |
46 | |
47 | mutex_lock(&list->read_mutex); |
48 | |
49 | while (ret == 0) { |
50 | if (list->head == list->tail) { |
51 | add_wait_queue(wq_head: &list->hidraw->wait, wq_entry: &wait); |
52 | set_current_state(TASK_INTERRUPTIBLE); |
53 | |
54 | while (list->head == list->tail) { |
55 | if (signal_pending(current)) { |
56 | ret = -ERESTARTSYS; |
57 | break; |
58 | } |
59 | if (!list->hidraw->exist) { |
60 | ret = -EIO; |
61 | break; |
62 | } |
63 | if (file->f_flags & O_NONBLOCK) { |
64 | ret = -EAGAIN; |
65 | break; |
66 | } |
67 | |
68 | /* allow O_NONBLOCK to work well from other threads */ |
69 | mutex_unlock(lock: &list->read_mutex); |
70 | schedule(); |
71 | mutex_lock(&list->read_mutex); |
72 | set_current_state(TASK_INTERRUPTIBLE); |
73 | } |
74 | |
75 | set_current_state(TASK_RUNNING); |
76 | remove_wait_queue(wq_head: &list->hidraw->wait, wq_entry: &wait); |
77 | } |
78 | |
79 | if (ret) |
80 | goto out; |
81 | |
82 | len = list->buffer[list->tail].len > count ? |
83 | count : list->buffer[list->tail].len; |
84 | |
85 | if (list->buffer[list->tail].value) { |
86 | if (copy_to_user(to: buffer, from: list->buffer[list->tail].value, n: len)) { |
87 | ret = -EFAULT; |
88 | goto out; |
89 | } |
90 | ret = len; |
91 | } |
92 | |
93 | kfree(objp: list->buffer[list->tail].value); |
94 | list->buffer[list->tail].value = NULL; |
95 | list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1); |
96 | } |
97 | out: |
98 | mutex_unlock(lock: &list->read_mutex); |
99 | return ret; |
100 | } |
101 | |
102 | /* |
103 | * The first byte of the report buffer is expected to be a report number. |
104 | */ |
105 | static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type) |
106 | { |
107 | unsigned int minor = iminor(inode: file_inode(f: file)); |
108 | struct hid_device *dev; |
109 | __u8 *buf; |
110 | int ret = 0; |
111 | |
112 | lockdep_assert_held(&minors_rwsem); |
113 | |
114 | if (!hidraw_table[minor] || !hidraw_table[minor]->exist) { |
115 | ret = -ENODEV; |
116 | goto out; |
117 | } |
118 | |
119 | dev = hidraw_table[minor]->hid; |
120 | |
121 | if (count > HID_MAX_BUFFER_SIZE) { |
122 | hid_warn(dev, "pid %d passed too large report\n" , |
123 | task_pid_nr(current)); |
124 | ret = -EINVAL; |
125 | goto out; |
126 | } |
127 | |
128 | if (count < 2) { |
129 | hid_warn(dev, "pid %d passed too short report\n" , |
130 | task_pid_nr(current)); |
131 | ret = -EINVAL; |
132 | goto out; |
133 | } |
134 | |
135 | buf = memdup_user(buffer, count); |
136 | if (IS_ERR(ptr: buf)) { |
137 | ret = PTR_ERR(ptr: buf); |
138 | goto out; |
139 | } |
140 | |
141 | if ((report_type == HID_OUTPUT_REPORT) && |
142 | !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) { |
143 | ret = hid_hw_output_report(hdev: dev, buf, len: count); |
144 | /* |
145 | * compatibility with old implementation of USB-HID and I2C-HID: |
146 | * if the device does not support receiving output reports, |
147 | * on an interrupt endpoint, fallback to SET_REPORT HID command. |
148 | */ |
149 | if (ret != -ENOSYS) |
150 | goto out_free; |
151 | } |
152 | |
153 | ret = hid_hw_raw_request(hdev: dev, reportnum: buf[0], buf, len: count, rtype: report_type, |
154 | reqtype: HID_REQ_SET_REPORT); |
155 | |
156 | out_free: |
157 | kfree(objp: buf); |
158 | out: |
159 | return ret; |
160 | } |
161 | |
162 | static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) |
163 | { |
164 | ssize_t ret; |
165 | down_read(sem: &minors_rwsem); |
166 | ret = hidraw_send_report(file, buffer, count, report_type: HID_OUTPUT_REPORT); |
167 | up_read(sem: &minors_rwsem); |
168 | return ret; |
169 | } |
170 | |
171 | |
172 | /* |
173 | * This function performs a Get_Report transfer over the control endpoint |
174 | * per section 7.2.1 of the HID specification, version 1.1. The first byte |
175 | * of buffer is the report number to request, or 0x0 if the device does not |
176 | * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT |
177 | * or HID_INPUT_REPORT. |
178 | */ |
179 | static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type) |
180 | { |
181 | unsigned int minor = iminor(inode: file_inode(f: file)); |
182 | struct hid_device *dev; |
183 | __u8 *buf; |
184 | int ret = 0, len; |
185 | unsigned char report_number; |
186 | |
187 | lockdep_assert_held(&minors_rwsem); |
188 | |
189 | if (!hidraw_table[minor] || !hidraw_table[minor]->exist) { |
190 | ret = -ENODEV; |
191 | goto out; |
192 | } |
193 | |
194 | dev = hidraw_table[minor]->hid; |
195 | |
196 | if (!dev->ll_driver->raw_request) { |
197 | ret = -ENODEV; |
198 | goto out; |
199 | } |
200 | |
201 | if (count > HID_MAX_BUFFER_SIZE) { |
202 | hid_warn(dev, "pid %d passed too large report\n" , |
203 | task_pid_nr(current)); |
204 | ret = -EINVAL; |
205 | goto out; |
206 | } |
207 | |
208 | if (count < 2) { |
209 | hid_warn(dev, "pid %d passed too short report\n" , |
210 | task_pid_nr(current)); |
211 | ret = -EINVAL; |
212 | goto out; |
213 | } |
214 | |
215 | buf = kmalloc(size: count, GFP_KERNEL); |
216 | if (!buf) { |
217 | ret = -ENOMEM; |
218 | goto out; |
219 | } |
220 | |
221 | /* |
222 | * Read the first byte from the user. This is the report number, |
223 | * which is passed to hid_hw_raw_request(). |
224 | */ |
225 | if (copy_from_user(to: &report_number, from: buffer, n: 1)) { |
226 | ret = -EFAULT; |
227 | goto out_free; |
228 | } |
229 | |
230 | ret = hid_hw_raw_request(hdev: dev, reportnum: report_number, buf, len: count, rtype: report_type, |
231 | reqtype: HID_REQ_GET_REPORT); |
232 | |
233 | if (ret < 0) |
234 | goto out_free; |
235 | |
236 | len = (ret < count) ? ret : count; |
237 | |
238 | if (copy_to_user(to: buffer, from: buf, n: len)) { |
239 | ret = -EFAULT; |
240 | goto out_free; |
241 | } |
242 | |
243 | ret = len; |
244 | |
245 | out_free: |
246 | kfree(objp: buf); |
247 | out: |
248 | return ret; |
249 | } |
250 | |
251 | static __poll_t hidraw_poll(struct file *file, poll_table *wait) |
252 | { |
253 | struct hidraw_list *list = file->private_data; |
254 | __poll_t mask = EPOLLOUT | EPOLLWRNORM; /* hidraw is always writable */ |
255 | |
256 | poll_wait(filp: file, wait_address: &list->hidraw->wait, p: wait); |
257 | if (list->head != list->tail) |
258 | mask |= EPOLLIN | EPOLLRDNORM; |
259 | if (!list->hidraw->exist) |
260 | mask |= EPOLLERR | EPOLLHUP; |
261 | return mask; |
262 | } |
263 | |
264 | static int hidraw_open(struct inode *inode, struct file *file) |
265 | { |
266 | unsigned int minor = iminor(inode); |
267 | struct hidraw *dev; |
268 | struct hidraw_list *list; |
269 | unsigned long flags; |
270 | int err = 0; |
271 | |
272 | if (!(list = kzalloc(size: sizeof(struct hidraw_list), GFP_KERNEL))) { |
273 | err = -ENOMEM; |
274 | goto out; |
275 | } |
276 | |
277 | /* |
278 | * Technically not writing to the hidraw_table but a write lock is |
279 | * required to protect the device refcount. This is symmetrical to |
280 | * hidraw_release(). |
281 | */ |
282 | down_write(sem: &minors_rwsem); |
283 | if (!hidraw_table[minor] || !hidraw_table[minor]->exist) { |
284 | err = -ENODEV; |
285 | goto out_unlock; |
286 | } |
287 | |
288 | dev = hidraw_table[minor]; |
289 | if (!dev->open++) { |
290 | err = hid_hw_power(hdev: dev->hid, PM_HINT_FULLON); |
291 | if (err < 0) { |
292 | dev->open--; |
293 | goto out_unlock; |
294 | } |
295 | |
296 | err = hid_hw_open(hdev: dev->hid); |
297 | if (err < 0) { |
298 | hid_hw_power(hdev: dev->hid, PM_HINT_NORMAL); |
299 | dev->open--; |
300 | goto out_unlock; |
301 | } |
302 | } |
303 | |
304 | list->hidraw = hidraw_table[minor]; |
305 | mutex_init(&list->read_mutex); |
306 | spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags); |
307 | list_add_tail(new: &list->node, head: &hidraw_table[minor]->list); |
308 | spin_unlock_irqrestore(lock: &hidraw_table[minor]->list_lock, flags); |
309 | file->private_data = list; |
310 | out_unlock: |
311 | up_write(sem: &minors_rwsem); |
312 | out: |
313 | if (err < 0) |
314 | kfree(objp: list); |
315 | return err; |
316 | |
317 | } |
318 | |
319 | static int hidraw_fasync(int fd, struct file *file, int on) |
320 | { |
321 | struct hidraw_list *list = file->private_data; |
322 | |
323 | return fasync_helper(fd, file, on, &list->fasync); |
324 | } |
325 | |
326 | static void drop_ref(struct hidraw *hidraw, int exists_bit) |
327 | { |
328 | if (exists_bit) { |
329 | hidraw->exist = 0; |
330 | if (hidraw->open) { |
331 | hid_hw_close(hdev: hidraw->hid); |
332 | wake_up_interruptible(&hidraw->wait); |
333 | } |
334 | device_destroy(cls: &hidraw_class, |
335 | MKDEV(hidraw_major, hidraw->minor)); |
336 | } else { |
337 | --hidraw->open; |
338 | } |
339 | if (!hidraw->open) { |
340 | if (!hidraw->exist) { |
341 | hidraw_table[hidraw->minor] = NULL; |
342 | kfree(objp: hidraw); |
343 | } else { |
344 | /* close device for last reader */ |
345 | hid_hw_close(hdev: hidraw->hid); |
346 | hid_hw_power(hdev: hidraw->hid, PM_HINT_NORMAL); |
347 | } |
348 | } |
349 | } |
350 | |
351 | static int hidraw_release(struct inode * inode, struct file * file) |
352 | { |
353 | unsigned int minor = iminor(inode); |
354 | struct hidraw_list *list = file->private_data; |
355 | unsigned long flags; |
356 | |
357 | down_write(sem: &minors_rwsem); |
358 | |
359 | spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags); |
360 | while (list->tail != list->head) { |
361 | kfree(objp: list->buffer[list->tail].value); |
362 | list->buffer[list->tail].value = NULL; |
363 | list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1); |
364 | } |
365 | list_del(entry: &list->node); |
366 | spin_unlock_irqrestore(lock: &hidraw_table[minor]->list_lock, flags); |
367 | kfree(objp: list); |
368 | |
369 | drop_ref(hidraw: hidraw_table[minor], exists_bit: 0); |
370 | |
371 | up_write(sem: &minors_rwsem); |
372 | return 0; |
373 | } |
374 | |
375 | static long hidraw_ioctl(struct file *file, unsigned int cmd, |
376 | unsigned long arg) |
377 | { |
378 | struct inode *inode = file_inode(f: file); |
379 | unsigned int minor = iminor(inode); |
380 | long ret = 0; |
381 | struct hidraw *dev; |
382 | void __user *user_arg = (void __user*) arg; |
383 | |
384 | down_read(sem: &minors_rwsem); |
385 | dev = hidraw_table[minor]; |
386 | if (!dev || !dev->exist) { |
387 | ret = -ENODEV; |
388 | goto out; |
389 | } |
390 | |
391 | switch (cmd) { |
392 | case HIDIOCGRDESCSIZE: |
393 | if (put_user(dev->hid->rsize, (int __user *)arg)) |
394 | ret = -EFAULT; |
395 | break; |
396 | |
397 | case HIDIOCGRDESC: |
398 | { |
399 | __u32 len; |
400 | |
401 | if (get_user(len, (int __user *)arg)) |
402 | ret = -EFAULT; |
403 | else if (len > HID_MAX_DESCRIPTOR_SIZE - 1) |
404 | ret = -EINVAL; |
405 | else if (copy_to_user(to: user_arg + offsetof( |
406 | struct hidraw_report_descriptor, |
407 | value[0]), |
408 | from: dev->hid->rdesc, |
409 | min(dev->hid->rsize, len))) |
410 | ret = -EFAULT; |
411 | break; |
412 | } |
413 | case HIDIOCGRAWINFO: |
414 | { |
415 | struct hidraw_devinfo dinfo; |
416 | |
417 | dinfo.bustype = dev->hid->bus; |
418 | dinfo.vendor = dev->hid->vendor; |
419 | dinfo.product = dev->hid->product; |
420 | if (copy_to_user(to: user_arg, from: &dinfo, n: sizeof(dinfo))) |
421 | ret = -EFAULT; |
422 | break; |
423 | } |
424 | default: |
425 | { |
426 | struct hid_device *hid = dev->hid; |
427 | if (_IOC_TYPE(cmd) != 'H') { |
428 | ret = -EINVAL; |
429 | break; |
430 | } |
431 | |
432 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) { |
433 | int len = _IOC_SIZE(cmd); |
434 | ret = hidraw_send_report(file, buffer: user_arg, count: len, report_type: HID_FEATURE_REPORT); |
435 | break; |
436 | } |
437 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) { |
438 | int len = _IOC_SIZE(cmd); |
439 | ret = hidraw_get_report(file, buffer: user_arg, count: len, report_type: HID_FEATURE_REPORT); |
440 | break; |
441 | } |
442 | |
443 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSINPUT(0))) { |
444 | int len = _IOC_SIZE(cmd); |
445 | ret = hidraw_send_report(file, buffer: user_arg, count: len, report_type: HID_INPUT_REPORT); |
446 | break; |
447 | } |
448 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGINPUT(0))) { |
449 | int len = _IOC_SIZE(cmd); |
450 | ret = hidraw_get_report(file, buffer: user_arg, count: len, report_type: HID_INPUT_REPORT); |
451 | break; |
452 | } |
453 | |
454 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSOUTPUT(0))) { |
455 | int len = _IOC_SIZE(cmd); |
456 | ret = hidraw_send_report(file, buffer: user_arg, count: len, report_type: HID_OUTPUT_REPORT); |
457 | break; |
458 | } |
459 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGOUTPUT(0))) { |
460 | int len = _IOC_SIZE(cmd); |
461 | ret = hidraw_get_report(file, buffer: user_arg, count: len, report_type: HID_OUTPUT_REPORT); |
462 | break; |
463 | } |
464 | |
465 | /* Begin Read-only ioctls. */ |
466 | if (_IOC_DIR(cmd) != _IOC_READ) { |
467 | ret = -EINVAL; |
468 | break; |
469 | } |
470 | |
471 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) { |
472 | int len = strlen(hid->name) + 1; |
473 | if (len > _IOC_SIZE(cmd)) |
474 | len = _IOC_SIZE(cmd); |
475 | ret = copy_to_user(to: user_arg, from: hid->name, n: len) ? |
476 | -EFAULT : len; |
477 | break; |
478 | } |
479 | |
480 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) { |
481 | int len = strlen(hid->phys) + 1; |
482 | if (len > _IOC_SIZE(cmd)) |
483 | len = _IOC_SIZE(cmd); |
484 | ret = copy_to_user(to: user_arg, from: hid->phys, n: len) ? |
485 | -EFAULT : len; |
486 | break; |
487 | } |
488 | |
489 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWUNIQ(0))) { |
490 | int len = strlen(hid->uniq) + 1; |
491 | if (len > _IOC_SIZE(cmd)) |
492 | len = _IOC_SIZE(cmd); |
493 | ret = copy_to_user(to: user_arg, from: hid->uniq, n: len) ? |
494 | -EFAULT : len; |
495 | break; |
496 | } |
497 | } |
498 | |
499 | ret = -ENOTTY; |
500 | } |
501 | out: |
502 | up_read(sem: &minors_rwsem); |
503 | return ret; |
504 | } |
505 | |
506 | static const struct file_operations hidraw_ops = { |
507 | .owner = THIS_MODULE, |
508 | .read = hidraw_read, |
509 | .write = hidraw_write, |
510 | .poll = hidraw_poll, |
511 | .open = hidraw_open, |
512 | .release = hidraw_release, |
513 | .unlocked_ioctl = hidraw_ioctl, |
514 | .fasync = hidraw_fasync, |
515 | .compat_ioctl = compat_ptr_ioctl, |
516 | .llseek = noop_llseek, |
517 | }; |
518 | |
519 | int hidraw_report_event(struct hid_device *hid, u8 *data, int len) |
520 | { |
521 | struct hidraw *dev = hid->hidraw; |
522 | struct hidraw_list *list; |
523 | int ret = 0; |
524 | unsigned long flags; |
525 | |
526 | spin_lock_irqsave(&dev->list_lock, flags); |
527 | list_for_each_entry(list, &dev->list, node) { |
528 | int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1); |
529 | |
530 | if (new_head == list->tail) |
531 | continue; |
532 | |
533 | if (!(list->buffer[list->head].value = kmemdup(p: data, size: len, GFP_ATOMIC))) { |
534 | ret = -ENOMEM; |
535 | break; |
536 | } |
537 | list->buffer[list->head].len = len; |
538 | list->head = new_head; |
539 | kill_fasync(&list->fasync, SIGIO, POLL_IN); |
540 | } |
541 | spin_unlock_irqrestore(lock: &dev->list_lock, flags); |
542 | |
543 | wake_up_interruptible(&dev->wait); |
544 | return ret; |
545 | } |
546 | EXPORT_SYMBOL_GPL(hidraw_report_event); |
547 | |
548 | int hidraw_connect(struct hid_device *hid) |
549 | { |
550 | int minor, result; |
551 | struct hidraw *dev; |
552 | |
553 | /* we accept any HID device, all applications */ |
554 | |
555 | dev = kzalloc(size: sizeof(struct hidraw), GFP_KERNEL); |
556 | if (!dev) |
557 | return -ENOMEM; |
558 | |
559 | result = -EINVAL; |
560 | |
561 | down_write(sem: &minors_rwsem); |
562 | |
563 | for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) { |
564 | if (hidraw_table[minor]) |
565 | continue; |
566 | hidraw_table[minor] = dev; |
567 | result = 0; |
568 | break; |
569 | } |
570 | |
571 | if (result) { |
572 | up_write(sem: &minors_rwsem); |
573 | kfree(objp: dev); |
574 | goto out; |
575 | } |
576 | |
577 | dev->dev = device_create(cls: &hidraw_class, parent: &hid->dev, MKDEV(hidraw_major, minor), |
578 | NULL, fmt: "%s%d" , "hidraw" , minor); |
579 | |
580 | if (IS_ERR(ptr: dev->dev)) { |
581 | hidraw_table[minor] = NULL; |
582 | up_write(sem: &minors_rwsem); |
583 | result = PTR_ERR(ptr: dev->dev); |
584 | kfree(objp: dev); |
585 | goto out; |
586 | } |
587 | |
588 | init_waitqueue_head(&dev->wait); |
589 | spin_lock_init(&dev->list_lock); |
590 | INIT_LIST_HEAD(list: &dev->list); |
591 | |
592 | dev->hid = hid; |
593 | dev->minor = minor; |
594 | |
595 | dev->exist = 1; |
596 | hid->hidraw = dev; |
597 | |
598 | up_write(sem: &minors_rwsem); |
599 | out: |
600 | return result; |
601 | |
602 | } |
603 | EXPORT_SYMBOL_GPL(hidraw_connect); |
604 | |
605 | void hidraw_disconnect(struct hid_device *hid) |
606 | { |
607 | struct hidraw *hidraw = hid->hidraw; |
608 | |
609 | down_write(sem: &minors_rwsem); |
610 | |
611 | drop_ref(hidraw, exists_bit: 1); |
612 | |
613 | up_write(sem: &minors_rwsem); |
614 | } |
615 | EXPORT_SYMBOL_GPL(hidraw_disconnect); |
616 | |
617 | int __init hidraw_init(void) |
618 | { |
619 | int result; |
620 | dev_t dev_id; |
621 | |
622 | result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR, |
623 | HIDRAW_MAX_DEVICES, "hidraw" ); |
624 | if (result < 0) { |
625 | pr_warn("can't get major number\n" ); |
626 | goto out; |
627 | } |
628 | |
629 | hidraw_major = MAJOR(dev_id); |
630 | |
631 | result = class_register(class: &hidraw_class); |
632 | if (result) |
633 | goto error_cdev; |
634 | |
635 | cdev_init(&hidraw_cdev, &hidraw_ops); |
636 | result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES); |
637 | if (result < 0) |
638 | goto error_class; |
639 | |
640 | pr_info("raw HID events driver (C) Jiri Kosina\n" ); |
641 | out: |
642 | return result; |
643 | |
644 | error_class: |
645 | class_unregister(class: &hidraw_class); |
646 | error_cdev: |
647 | unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES); |
648 | goto out; |
649 | } |
650 | |
651 | void hidraw_exit(void) |
652 | { |
653 | dev_t dev_id = MKDEV(hidraw_major, 0); |
654 | |
655 | cdev_del(&hidraw_cdev); |
656 | class_unregister(class: &hidraw_class); |
657 | unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES); |
658 | |
659 | } |
660 | |