xref: /linux/drivers/hid/usbhid/hiddev.c (revision 12871a0bd67dd4db4418e1daafcd46e9d329ef10)
1 /*
2  *  Copyright (c) 2001 Paul Stewart
3  *  Copyright (c) 2001 Vojtech Pavlik
4  *
5  *  HID char devices, giving access to raw HID device events.
6  *
7  */
8 
9 /*
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23  *
24  * Should you need to contact me, the author, you can do so either by
25  * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
26  */
27 
28 #include <linux/poll.h>
29 #include <linux/slab.h>
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/input.h>
33 #include <linux/usb.h>
34 #include <linux/hid.h>
35 #include <linux/hiddev.h>
36 #include <linux/compat.h>
37 #include "usbhid.h"
38 
39 #ifdef CONFIG_USB_DYNAMIC_MINORS
40 #define HIDDEV_MINOR_BASE	0
41 #define HIDDEV_MINORS		256
42 #else
43 #define HIDDEV_MINOR_BASE	96
44 #define HIDDEV_MINORS		16
45 #endif
46 #define HIDDEV_BUFFER_SIZE	2048
47 
48 struct hiddev {
49 	int exist;
50 	int open;
51 	struct mutex existancelock;
52 	wait_queue_head_t wait;
53 	struct hid_device *hid;
54 	struct list_head list;
55 	spinlock_t list_lock;
56 };
57 
58 struct hiddev_list {
59 	struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
60 	int head;
61 	int tail;
62 	unsigned flags;
63 	struct fasync_struct *fasync;
64 	struct hiddev *hiddev;
65 	struct list_head node;
66 	struct mutex thread_lock;
67 };
68 
69 /*
70  * Find a report, given the report's type and ID.  The ID can be specified
71  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
72  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
73  * given type which follows old_id.
74  */
75 static struct hid_report *
76 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
77 {
78 	unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
79 	unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
80 	struct hid_report_enum *report_enum;
81 	struct hid_report *report;
82 	struct list_head *list;
83 
84 	if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
85 	    rinfo->report_type > HID_REPORT_TYPE_MAX)
86 		return NULL;
87 
88 	report_enum = hid->report_enum +
89 		(rinfo->report_type - HID_REPORT_TYPE_MIN);
90 
91 	switch (flags) {
92 	case 0: /* Nothing to do -- report_id is already set correctly */
93 		break;
94 
95 	case HID_REPORT_ID_FIRST:
96 		if (list_empty(&report_enum->report_list))
97 			return NULL;
98 
99 		list = report_enum->report_list.next;
100 		report = list_entry(list, struct hid_report, list);
101 		rinfo->report_id = report->id;
102 		break;
103 
104 	case HID_REPORT_ID_NEXT:
105 		report = report_enum->report_id_hash[rid];
106 		if (!report)
107 			return NULL;
108 
109 		list = report->list.next;
110 		if (list == &report_enum->report_list)
111 			return NULL;
112 
113 		report = list_entry(list, struct hid_report, list);
114 		rinfo->report_id = report->id;
115 		break;
116 
117 	default:
118 		return NULL;
119 	}
120 
121 	return report_enum->report_id_hash[rinfo->report_id];
122 }
123 
124 /*
125  * Perform an exhaustive search of the report table for a usage, given its
126  * type and usage id.
127  */
128 static struct hid_field *
129 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
130 {
131 	int i, j;
132 	struct hid_report *report;
133 	struct hid_report_enum *report_enum;
134 	struct hid_field *field;
135 
136 	if (uref->report_type < HID_REPORT_TYPE_MIN ||
137 	    uref->report_type > HID_REPORT_TYPE_MAX)
138 		return NULL;
139 
140 	report_enum = hid->report_enum +
141 		(uref->report_type - HID_REPORT_TYPE_MIN);
142 
143 	list_for_each_entry(report, &report_enum->report_list, list) {
144 		for (i = 0; i < report->maxfield; i++) {
145 			field = report->field[i];
146 			for (j = 0; j < field->maxusage; j++) {
147 				if (field->usage[j].hid == uref->usage_code) {
148 					uref->report_id = report->id;
149 					uref->field_index = i;
150 					uref->usage_index = j;
151 					return field;
152 				}
153 			}
154 		}
155 	}
156 
157 	return NULL;
158 }
159 
160 static void hiddev_send_event(struct hid_device *hid,
161 			      struct hiddev_usage_ref *uref)
162 {
163 	struct hiddev *hiddev = hid->hiddev;
164 	struct hiddev_list *list;
165 	unsigned long flags;
166 
167 	spin_lock_irqsave(&hiddev->list_lock, flags);
168 	list_for_each_entry(list, &hiddev->list, node) {
169 		if (uref->field_index != HID_FIELD_INDEX_NONE ||
170 		    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
171 			list->buffer[list->head] = *uref;
172 			list->head = (list->head + 1) &
173 				(HIDDEV_BUFFER_SIZE - 1);
174 			kill_fasync(&list->fasync, SIGIO, POLL_IN);
175 		}
176 	}
177 	spin_unlock_irqrestore(&hiddev->list_lock, flags);
178 
179 	wake_up_interruptible(&hiddev->wait);
180 }
181 
182 /*
183  * This is where hid.c calls into hiddev to pass an event that occurred over
184  * the interrupt pipe
185  */
186 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
187 		      struct hid_usage *usage, __s32 value)
188 {
189 	unsigned type = field->report_type;
190 	struct hiddev_usage_ref uref;
191 
192 	uref.report_type =
193 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
194 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
195 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
196 	uref.report_id = field->report->id;
197 	uref.field_index = field->index;
198 	uref.usage_index = (usage - field->usage);
199 	uref.usage_code = usage->hid;
200 	uref.value = value;
201 
202 	hiddev_send_event(hid, &uref);
203 }
204 EXPORT_SYMBOL_GPL(hiddev_hid_event);
205 
206 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
207 {
208 	unsigned type = report->type;
209 	struct hiddev_usage_ref uref;
210 
211 	memset(&uref, 0, sizeof(uref));
212 	uref.report_type =
213 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
214 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
215 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
216 	uref.report_id = report->id;
217 	uref.field_index = HID_FIELD_INDEX_NONE;
218 
219 	hiddev_send_event(hid, &uref);
220 }
221 
222 /*
223  * fasync file op
224  */
225 static int hiddev_fasync(int fd, struct file *file, int on)
226 {
227 	struct hiddev_list *list = file->private_data;
228 
229 	return fasync_helper(fd, file, on, &list->fasync);
230 }
231 
232 
233 /*
234  * release file op
235  */
236 static int hiddev_release(struct inode * inode, struct file * file)
237 {
238 	struct hiddev_list *list = file->private_data;
239 	unsigned long flags;
240 
241 	spin_lock_irqsave(&list->hiddev->list_lock, flags);
242 	list_del(&list->node);
243 	spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
244 
245 	mutex_lock(&list->hiddev->existancelock);
246 	if (!--list->hiddev->open) {
247 		if (list->hiddev->exist) {
248 			usbhid_close(list->hiddev->hid);
249 			usbhid_put_power(list->hiddev->hid);
250 		} else {
251 			kfree(list->hiddev);
252 		}
253 	}
254 
255 	kfree(list);
256 	mutex_unlock(&list->hiddev->existancelock);
257 
258 	return 0;
259 }
260 
261 /*
262  * open file op
263  */
264 static int hiddev_open(struct inode *inode, struct file *file)
265 {
266 	struct hiddev_list *list;
267 	struct usb_interface *intf;
268 	struct hid_device *hid;
269 	struct hiddev *hiddev;
270 	int res;
271 
272 	intf = usbhid_find_interface(iminor(inode));
273 	if (!intf)
274 		return -ENODEV;
275 	hid = usb_get_intfdata(intf);
276 	hiddev = hid->hiddev;
277 
278 	if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
279 		return -ENOMEM;
280 	mutex_init(&list->thread_lock);
281 	list->hiddev = hiddev;
282 	file->private_data = list;
283 
284 	/*
285 	 * no need for locking because the USB major number
286 	 * is shared which usbcore guards against disconnect
287 	 */
288 	if (list->hiddev->exist) {
289 		if (!list->hiddev->open++) {
290 			res = usbhid_open(hiddev->hid);
291 			if (res < 0) {
292 				res = -EIO;
293 				goto bail;
294 			}
295 		}
296 	} else {
297 		res = -ENODEV;
298 		goto bail;
299 	}
300 
301 	spin_lock_irq(&list->hiddev->list_lock);
302 	list_add_tail(&list->node, &hiddev->list);
303 	spin_unlock_irq(&list->hiddev->list_lock);
304 
305 	mutex_lock(&hiddev->existancelock);
306 	if (!list->hiddev->open++)
307 		if (list->hiddev->exist) {
308 			struct hid_device *hid = hiddev->hid;
309 			res = usbhid_get_power(hid);
310 			if (res < 0) {
311 				res = -EIO;
312 				goto bail_unlock;
313 			}
314 			usbhid_open(hid);
315 		}
316 	mutex_unlock(&hiddev->existancelock);
317 	return 0;
318 bail_unlock:
319 	mutex_unlock(&hiddev->existancelock);
320 bail:
321 	file->private_data = NULL;
322 	kfree(list);
323 	return res;
324 }
325 
326 /*
327  * "write" file op
328  */
329 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
330 {
331 	return -EINVAL;
332 }
333 
334 /*
335  * "read" file op
336  */
337 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
338 {
339 	DEFINE_WAIT(wait);
340 	struct hiddev_list *list = file->private_data;
341 	int event_size;
342 	int retval;
343 
344 	event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
345 		sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
346 
347 	if (count < event_size)
348 		return 0;
349 
350 	/* lock against other threads */
351 	retval = mutex_lock_interruptible(&list->thread_lock);
352 	if (retval)
353 		return -ERESTARTSYS;
354 
355 	while (retval == 0) {
356 		if (list->head == list->tail) {
357 			prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
358 
359 			while (list->head == list->tail) {
360 				if (file->f_flags & O_NONBLOCK) {
361 					retval = -EAGAIN;
362 					break;
363 				}
364 				if (signal_pending(current)) {
365 					retval = -ERESTARTSYS;
366 					break;
367 				}
368 				if (!list->hiddev->exist) {
369 					retval = -EIO;
370 					break;
371 				}
372 
373 				/* let O_NONBLOCK tasks run */
374 				mutex_unlock(&list->thread_lock);
375 				schedule();
376 				if (mutex_lock_interruptible(&list->thread_lock)) {
377 					finish_wait(&list->hiddev->wait, &wait);
378 					return -EINTR;
379 				}
380 				set_current_state(TASK_INTERRUPTIBLE);
381 			}
382 			finish_wait(&list->hiddev->wait, &wait);
383 
384 		}
385 
386 		if (retval) {
387 			mutex_unlock(&list->thread_lock);
388 			return retval;
389 		}
390 
391 
392 		while (list->head != list->tail &&
393 		       retval + event_size <= count) {
394 			if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
395 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
396 					struct hiddev_event event;
397 
398 					event.hid = list->buffer[list->tail].usage_code;
399 					event.value = list->buffer[list->tail].value;
400 					if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
401 						mutex_unlock(&list->thread_lock);
402 						return -EFAULT;
403 					}
404 					retval += sizeof(struct hiddev_event);
405 				}
406 			} else {
407 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
408 				    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
409 
410 					if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
411 						mutex_unlock(&list->thread_lock);
412 						return -EFAULT;
413 					}
414 					retval += sizeof(struct hiddev_usage_ref);
415 				}
416 			}
417 			list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
418 		}
419 
420 	}
421 	mutex_unlock(&list->thread_lock);
422 
423 	return retval;
424 }
425 
426 /*
427  * "poll" file op
428  * No kernel lock - fine
429  */
430 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
431 {
432 	struct hiddev_list *list = file->private_data;
433 
434 	poll_wait(file, &list->hiddev->wait, wait);
435 	if (list->head != list->tail)
436 		return POLLIN | POLLRDNORM;
437 	if (!list->hiddev->exist)
438 		return POLLERR | POLLHUP;
439 	return 0;
440 }
441 
442 /*
443  * "ioctl" file op
444  */
445 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
446 {
447 	struct hid_device *hid = hiddev->hid;
448 	struct hiddev_report_info rinfo;
449 	struct hiddev_usage_ref_multi *uref_multi = NULL;
450 	struct hiddev_usage_ref *uref;
451 	struct hid_report *report;
452 	struct hid_field *field;
453 	int i;
454 
455 	uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
456 	if (!uref_multi)
457 		return -ENOMEM;
458 	uref = &uref_multi->uref;
459 	if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
460 		if (copy_from_user(uref_multi, user_arg,
461 				   sizeof(*uref_multi)))
462 			goto fault;
463 	} else {
464 		if (copy_from_user(uref, user_arg, sizeof(*uref)))
465 			goto fault;
466 	}
467 
468 	switch (cmd) {
469 	case HIDIOCGUCODE:
470 		rinfo.report_type = uref->report_type;
471 		rinfo.report_id = uref->report_id;
472 		if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
473 			goto inval;
474 
475 		if (uref->field_index >= report->maxfield)
476 			goto inval;
477 
478 		field = report->field[uref->field_index];
479 		if (uref->usage_index >= field->maxusage)
480 			goto inval;
481 
482 		uref->usage_code = field->usage[uref->usage_index].hid;
483 
484 		if (copy_to_user(user_arg, uref, sizeof(*uref)))
485 			goto fault;
486 
487 		goto goodreturn;
488 
489 	default:
490 		if (cmd != HIDIOCGUSAGE &&
491 		    cmd != HIDIOCGUSAGES &&
492 		    uref->report_type == HID_REPORT_TYPE_INPUT)
493 			goto inval;
494 
495 		if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
496 			field = hiddev_lookup_usage(hid, uref);
497 			if (field == NULL)
498 				goto inval;
499 		} else {
500 			rinfo.report_type = uref->report_type;
501 			rinfo.report_id = uref->report_id;
502 			if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
503 				goto inval;
504 
505 			if (uref->field_index >= report->maxfield)
506 				goto inval;
507 
508 			field = report->field[uref->field_index];
509 
510 			if (cmd == HIDIOCGCOLLECTIONINDEX) {
511 				if (uref->usage_index >= field->maxusage)
512 					goto inval;
513 			} else if (uref->usage_index >= field->report_count)
514 				goto inval;
515 
516 			else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
517 				 (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
518 				  uref->usage_index + uref_multi->num_values > field->report_count))
519 				goto inval;
520 		}
521 
522 		switch (cmd) {
523 		case HIDIOCGUSAGE:
524 			uref->value = field->value[uref->usage_index];
525 			if (copy_to_user(user_arg, uref, sizeof(*uref)))
526 				goto fault;
527 			goto goodreturn;
528 
529 		case HIDIOCSUSAGE:
530 			field->value[uref->usage_index] = uref->value;
531 			goto goodreturn;
532 
533 		case HIDIOCGCOLLECTIONINDEX:
534 			i = field->usage[uref->usage_index].collection_index;
535 			kfree(uref_multi);
536 			return i;
537 		case HIDIOCGUSAGES:
538 			for (i = 0; i < uref_multi->num_values; i++)
539 				uref_multi->values[i] =
540 				    field->value[uref->usage_index + i];
541 			if (copy_to_user(user_arg, uref_multi,
542 					 sizeof(*uref_multi)))
543 				goto fault;
544 			goto goodreturn;
545 		case HIDIOCSUSAGES:
546 			for (i = 0; i < uref_multi->num_values; i++)
547 				field->value[uref->usage_index + i] =
548 				    uref_multi->values[i];
549 			goto goodreturn;
550 		}
551 
552 goodreturn:
553 		kfree(uref_multi);
554 		return 0;
555 fault:
556 		kfree(uref_multi);
557 		return -EFAULT;
558 inval:
559 		kfree(uref_multi);
560 		return -EINVAL;
561 	}
562 }
563 
564 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
565 {
566 	struct hid_device *hid = hiddev->hid;
567 	struct usb_device *dev = hid_to_usb_dev(hid);
568 	int idx, len;
569 	char *buf;
570 
571 	if (get_user(idx, (int __user *)user_arg))
572 		return -EFAULT;
573 
574 	if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
575 		return -ENOMEM;
576 
577 	if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
578 		kfree(buf);
579 		return -EINVAL;
580 	}
581 
582 	if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
583 		kfree(buf);
584 		return -EFAULT;
585 	}
586 
587 	kfree(buf);
588 
589 	return len;
590 }
591 
592 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
593 {
594 	struct hiddev_list *list = file->private_data;
595 	struct hiddev *hiddev = list->hiddev;
596 	struct hid_device *hid;
597 	struct hiddev_collection_info cinfo;
598 	struct hiddev_report_info rinfo;
599 	struct hiddev_field_info finfo;
600 	struct hiddev_devinfo dinfo;
601 	struct hid_report *report;
602 	struct hid_field *field;
603 	void __user *user_arg = (void __user *)arg;
604 	int i, r = -EINVAL;
605 
606 	/* Called without BKL by compat methods so no BKL taken */
607 
608 	mutex_lock(&hiddev->existancelock);
609 	if (!hiddev->exist) {
610 		r = -ENODEV;
611 		goto ret_unlock;
612 	}
613 
614 	hid = hiddev->hid;
615 
616 	switch (cmd) {
617 
618 	case HIDIOCGVERSION:
619 		r = put_user(HID_VERSION, (int __user *)arg) ?
620 			-EFAULT : 0;
621 		break;
622 
623 	case HIDIOCAPPLICATION:
624 		if (arg < 0 || arg >= hid->maxapplication)
625 			break;
626 
627 		for (i = 0; i < hid->maxcollection; i++)
628 			if (hid->collection[i].type ==
629 			    HID_COLLECTION_APPLICATION && arg-- == 0)
630 				break;
631 
632 		if (i < hid->maxcollection)
633 			r = hid->collection[i].usage;
634 		break;
635 
636 	case HIDIOCGDEVINFO:
637 		{
638 			struct usb_device *dev = hid_to_usb_dev(hid);
639 			struct usbhid_device *usbhid = hid->driver_data;
640 
641 			dinfo.bustype = BUS_USB;
642 			dinfo.busnum = dev->bus->busnum;
643 			dinfo.devnum = dev->devnum;
644 			dinfo.ifnum = usbhid->ifnum;
645 			dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
646 			dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
647 			dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
648 			dinfo.num_applications = hid->maxapplication;
649 
650 			r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
651 				-EFAULT : 0;
652 			break;
653 		}
654 
655 	case HIDIOCGFLAG:
656 		r = put_user(list->flags, (int __user *)arg) ?
657 			-EFAULT : 0;
658 		break;
659 
660 	case HIDIOCSFLAG:
661 		{
662 			int newflags;
663 
664 			if (get_user(newflags, (int __user *)arg)) {
665 				r = -EFAULT;
666 				break;
667 			}
668 
669 			if ((newflags & ~HIDDEV_FLAGS) != 0 ||
670 			    ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
671 			     (newflags & HIDDEV_FLAG_UREF) == 0))
672 				break;
673 
674 			list->flags = newflags;
675 
676 			r = 0;
677 			break;
678 		}
679 
680 	case HIDIOCGSTRING:
681 		r = hiddev_ioctl_string(hiddev, cmd, user_arg);
682 		break;
683 
684 	case HIDIOCINITREPORT:
685 		usbhid_init_reports(hid);
686 		r = 0;
687 		break;
688 
689 	case HIDIOCGREPORT:
690 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
691 			r = -EFAULT;
692 			break;
693 		}
694 
695 		if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
696 			break;
697 
698 		report = hiddev_lookup_report(hid, &rinfo);
699 		if (report == NULL)
700 			break;
701 
702 		usbhid_submit_report(hid, report, USB_DIR_IN);
703 		usbhid_wait_io(hid);
704 
705 		r = 0;
706 		break;
707 
708 	case HIDIOCSREPORT:
709 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
710 			r = -EFAULT;
711 			break;
712 		}
713 
714 		if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
715 			break;
716 
717 		report = hiddev_lookup_report(hid, &rinfo);
718 		if (report == NULL)
719 			break;
720 
721 		usbhid_submit_report(hid, report, USB_DIR_OUT);
722 		usbhid_wait_io(hid);
723 
724 		r = 0;
725 		break;
726 
727 	case HIDIOCGREPORTINFO:
728 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
729 			r = -EFAULT;
730 			break;
731 		}
732 
733 		report = hiddev_lookup_report(hid, &rinfo);
734 		if (report == NULL)
735 			break;
736 
737 		rinfo.num_fields = report->maxfield;
738 
739 		r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
740 			-EFAULT : 0;
741 		break;
742 
743 	case HIDIOCGFIELDINFO:
744 		if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
745 			r = -EFAULT;
746 			break;
747 		}
748 
749 		rinfo.report_type = finfo.report_type;
750 		rinfo.report_id = finfo.report_id;
751 
752 		report = hiddev_lookup_report(hid, &rinfo);
753 		if (report == NULL)
754 			break;
755 
756 		if (finfo.field_index >= report->maxfield)
757 			break;
758 
759 		field = report->field[finfo.field_index];
760 		memset(&finfo, 0, sizeof(finfo));
761 		finfo.report_type = rinfo.report_type;
762 		finfo.report_id = rinfo.report_id;
763 		finfo.field_index = field->report_count - 1;
764 		finfo.maxusage = field->maxusage;
765 		finfo.flags = field->flags;
766 		finfo.physical = field->physical;
767 		finfo.logical = field->logical;
768 		finfo.application = field->application;
769 		finfo.logical_minimum = field->logical_minimum;
770 		finfo.logical_maximum = field->logical_maximum;
771 		finfo.physical_minimum = field->physical_minimum;
772 		finfo.physical_maximum = field->physical_maximum;
773 		finfo.unit_exponent = field->unit_exponent;
774 		finfo.unit = field->unit;
775 
776 		r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
777 			-EFAULT : 0;
778 		break;
779 
780 	case HIDIOCGUCODE:
781 		/* fall through */
782 	case HIDIOCGUSAGE:
783 	case HIDIOCSUSAGE:
784 	case HIDIOCGUSAGES:
785 	case HIDIOCSUSAGES:
786 	case HIDIOCGCOLLECTIONINDEX:
787 		r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
788 		break;
789 
790 	case HIDIOCGCOLLECTIONINFO:
791 		if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
792 			r = -EFAULT;
793 			break;
794 		}
795 
796 		if (cinfo.index >= hid->maxcollection)
797 			break;
798 
799 		cinfo.type = hid->collection[cinfo.index].type;
800 		cinfo.usage = hid->collection[cinfo.index].usage;
801 		cinfo.level = hid->collection[cinfo.index].level;
802 
803 		r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
804 			-EFAULT : 0;
805 		break;
806 
807 	default:
808 		if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
809 			break;
810 
811 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
812 			int len = strlen(hid->name) + 1;
813 			if (len > _IOC_SIZE(cmd))
814 				 len = _IOC_SIZE(cmd);
815 			r = copy_to_user(user_arg, hid->name, len) ?
816 				-EFAULT : len;
817 			break;
818 		}
819 
820 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
821 			int len = strlen(hid->phys) + 1;
822 			if (len > _IOC_SIZE(cmd))
823 				len = _IOC_SIZE(cmd);
824 			r = copy_to_user(user_arg, hid->phys, len) ?
825 				-EFAULT : len;
826 			break;
827 		}
828 	}
829 
830 ret_unlock:
831 	mutex_unlock(&hiddev->existancelock);
832 	return r;
833 }
834 
835 #ifdef CONFIG_COMPAT
836 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
837 {
838 	return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
839 }
840 #endif
841 
842 static const struct file_operations hiddev_fops = {
843 	.owner =	THIS_MODULE,
844 	.read =		hiddev_read,
845 	.write =	hiddev_write,
846 	.poll =		hiddev_poll,
847 	.open =		hiddev_open,
848 	.release =	hiddev_release,
849 	.unlocked_ioctl =	hiddev_ioctl,
850 	.fasync =	hiddev_fasync,
851 #ifdef CONFIG_COMPAT
852 	.compat_ioctl	= hiddev_compat_ioctl,
853 #endif
854 	.llseek		= noop_llseek,
855 };
856 
857 static char *hiddev_devnode(struct device *dev, mode_t *mode)
858 {
859 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
860 }
861 
862 static struct usb_class_driver hiddev_class = {
863 	.name =		"hiddev%d",
864 	.devnode =	hiddev_devnode,
865 	.fops =		&hiddev_fops,
866 	.minor_base =	HIDDEV_MINOR_BASE,
867 };
868 
869 /*
870  * This is where hid.c calls us to connect a hid device to the hiddev driver
871  */
872 int hiddev_connect(struct hid_device *hid, unsigned int force)
873 {
874 	struct hiddev *hiddev;
875 	struct usbhid_device *usbhid = hid->driver_data;
876 	int retval;
877 
878 	if (!force) {
879 		unsigned int i;
880 		for (i = 0; i < hid->maxcollection; i++)
881 			if (hid->collection[i].type ==
882 			    HID_COLLECTION_APPLICATION &&
883 			    !IS_INPUT_APPLICATION(hid->collection[i].usage))
884 				break;
885 
886 		if (i == hid->maxcollection)
887 			return -1;
888 	}
889 
890 	if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
891 		return -1;
892 
893 	init_waitqueue_head(&hiddev->wait);
894 	INIT_LIST_HEAD(&hiddev->list);
895 	spin_lock_init(&hiddev->list_lock);
896 	mutex_init(&hiddev->existancelock);
897 	hid->hiddev = hiddev;
898 	hiddev->hid = hid;
899 	hiddev->exist = 1;
900 	retval = usb_register_dev(usbhid->intf, &hiddev_class);
901 	if (retval) {
902 		hid_err(hid, "Not able to get a minor for this device\n");
903 		hid->hiddev = NULL;
904 		kfree(hiddev);
905 		return -1;
906 	}
907 	return 0;
908 }
909 
910 /*
911  * This is where hid.c calls us to disconnect a hiddev device from the
912  * corresponding hid device (usually because the usb device has disconnected)
913  */
914 static struct usb_class_driver hiddev_class;
915 void hiddev_disconnect(struct hid_device *hid)
916 {
917 	struct hiddev *hiddev = hid->hiddev;
918 	struct usbhid_device *usbhid = hid->driver_data;
919 
920 	mutex_lock(&hiddev->existancelock);
921 	hiddev->exist = 0;
922 
923 	usb_deregister_dev(usbhid->intf, &hiddev_class);
924 
925 	if (hiddev->open) {
926 		usbhid_close(hiddev->hid);
927 		wake_up_interruptible(&hiddev->wait);
928 	} else {
929 		kfree(hiddev);
930 	}
931 	mutex_unlock(&hiddev->existancelock);
932 }
933