xref: /linux/drivers/hid/usbhid/hiddev.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 <linux/vmalloc.h>
38 #include "usbhid.h"
39 
40 #ifdef CONFIG_USB_DYNAMIC_MINORS
41 #define HIDDEV_MINOR_BASE	0
42 #define HIDDEV_MINORS		256
43 #else
44 #define HIDDEV_MINOR_BASE	96
45 #define HIDDEV_MINORS		16
46 #endif
47 #define HIDDEV_BUFFER_SIZE	2048
48 
49 struct hiddev {
50 	int exist;
51 	int open;
52 	struct mutex existancelock;
53 	wait_queue_head_t wait;
54 	struct hid_device *hid;
55 	struct list_head list;
56 	spinlock_t list_lock;
57 };
58 
59 struct hiddev_list {
60 	struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
61 	int head;
62 	int tail;
63 	unsigned flags;
64 	struct fasync_struct *fasync;
65 	struct hiddev *hiddev;
66 	struct list_head node;
67 	struct mutex thread_lock;
68 };
69 
70 /*
71  * Find a report, given the report's type and ID.  The ID can be specified
72  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
73  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
74  * given type which follows old_id.
75  */
76 static struct hid_report *
77 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
78 {
79 	unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
80 	unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
81 	struct hid_report_enum *report_enum;
82 	struct hid_report *report;
83 	struct list_head *list;
84 
85 	if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
86 	    rinfo->report_type > HID_REPORT_TYPE_MAX)
87 		return NULL;
88 
89 	report_enum = hid->report_enum +
90 		(rinfo->report_type - HID_REPORT_TYPE_MIN);
91 
92 	switch (flags) {
93 	case 0: /* Nothing to do -- report_id is already set correctly */
94 		break;
95 
96 	case HID_REPORT_ID_FIRST:
97 		if (list_empty(&report_enum->report_list))
98 			return NULL;
99 
100 		list = report_enum->report_list.next;
101 		report = list_entry(list, struct hid_report, list);
102 		rinfo->report_id = report->id;
103 		break;
104 
105 	case HID_REPORT_ID_NEXT:
106 		report = report_enum->report_id_hash[rid];
107 		if (!report)
108 			return NULL;
109 
110 		list = report->list.next;
111 		if (list == &report_enum->report_list)
112 			return NULL;
113 
114 		report = list_entry(list, struct hid_report, list);
115 		rinfo->report_id = report->id;
116 		break;
117 
118 	default:
119 		return NULL;
120 	}
121 
122 	return report_enum->report_id_hash[rinfo->report_id];
123 }
124 
125 /*
126  * Perform an exhaustive search of the report table for a usage, given its
127  * type and usage id.
128  */
129 static struct hid_field *
130 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
131 {
132 	int i, j;
133 	struct hid_report *report;
134 	struct hid_report_enum *report_enum;
135 	struct hid_field *field;
136 
137 	if (uref->report_type < HID_REPORT_TYPE_MIN ||
138 	    uref->report_type > HID_REPORT_TYPE_MAX)
139 		return NULL;
140 
141 	report_enum = hid->report_enum +
142 		(uref->report_type - HID_REPORT_TYPE_MIN);
143 
144 	list_for_each_entry(report, &report_enum->report_list, list) {
145 		for (i = 0; i < report->maxfield; i++) {
146 			field = report->field[i];
147 			for (j = 0; j < field->maxusage; j++) {
148 				if (field->usage[j].hid == uref->usage_code) {
149 					uref->report_id = report->id;
150 					uref->field_index = i;
151 					uref->usage_index = j;
152 					return field;
153 				}
154 			}
155 		}
156 	}
157 
158 	return NULL;
159 }
160 
161 static void hiddev_send_event(struct hid_device *hid,
162 			      struct hiddev_usage_ref *uref)
163 {
164 	struct hiddev *hiddev = hid->hiddev;
165 	struct hiddev_list *list;
166 	unsigned long flags;
167 
168 	spin_lock_irqsave(&hiddev->list_lock, flags);
169 	list_for_each_entry(list, &hiddev->list, node) {
170 		if (uref->field_index != HID_FIELD_INDEX_NONE ||
171 		    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
172 			list->buffer[list->head] = *uref;
173 			list->head = (list->head + 1) &
174 				(HIDDEV_BUFFER_SIZE - 1);
175 			kill_fasync(&list->fasync, SIGIO, POLL_IN);
176 		}
177 	}
178 	spin_unlock_irqrestore(&hiddev->list_lock, flags);
179 
180 	wake_up_interruptible(&hiddev->wait);
181 }
182 
183 /*
184  * This is where hid.c calls into hiddev to pass an event that occurred over
185  * the interrupt pipe
186  */
187 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
188 		      struct hid_usage *usage, __s32 value)
189 {
190 	unsigned type = field->report_type;
191 	struct hiddev_usage_ref uref;
192 
193 	uref.report_type =
194 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
195 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
196 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
197 	uref.report_id = field->report->id;
198 	uref.field_index = field->index;
199 	uref.usage_index = (usage - field->usage);
200 	uref.usage_code = usage->hid;
201 	uref.value = value;
202 
203 	hiddev_send_event(hid, &uref);
204 }
205 EXPORT_SYMBOL_GPL(hiddev_hid_event);
206 
207 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
208 {
209 	unsigned type = report->type;
210 	struct hiddev_usage_ref uref;
211 
212 	memset(&uref, 0, sizeof(uref));
213 	uref.report_type =
214 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
215 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
216 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
217 	uref.report_id = report->id;
218 	uref.field_index = HID_FIELD_INDEX_NONE;
219 
220 	hiddev_send_event(hid, &uref);
221 }
222 
223 /*
224  * fasync file op
225  */
226 static int hiddev_fasync(int fd, struct file *file, int on)
227 {
228 	struct hiddev_list *list = file->private_data;
229 
230 	return fasync_helper(fd, file, on, &list->fasync);
231 }
232 
233 
234 /*
235  * release file op
236  */
237 static int hiddev_release(struct inode * inode, struct file * file)
238 {
239 	struct hiddev_list *list = file->private_data;
240 	unsigned long flags;
241 
242 	spin_lock_irqsave(&list->hiddev->list_lock, flags);
243 	list_del(&list->node);
244 	spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
245 
246 	mutex_lock(&list->hiddev->existancelock);
247 	if (!--list->hiddev->open) {
248 		if (list->hiddev->exist) {
249 			usbhid_close(list->hiddev->hid);
250 			usbhid_put_power(list->hiddev->hid);
251 		} else {
252 			mutex_unlock(&list->hiddev->existancelock);
253 			kfree(list->hiddev);
254 			vfree(list);
255 			return 0;
256 		}
257 	}
258 
259 	mutex_unlock(&list->hiddev->existancelock);
260 	vfree(list);
261 
262 	return 0;
263 }
264 
265 /*
266  * open file op
267  */
268 static int hiddev_open(struct inode *inode, struct file *file)
269 {
270 	struct hiddev_list *list;
271 	struct usb_interface *intf;
272 	struct hid_device *hid;
273 	struct hiddev *hiddev;
274 	int res;
275 
276 	intf = usbhid_find_interface(iminor(inode));
277 	if (!intf)
278 		return -ENODEV;
279 	hid = usb_get_intfdata(intf);
280 	hiddev = hid->hiddev;
281 
282 	if (!(list = vzalloc(sizeof(struct hiddev_list))))
283 		return -ENOMEM;
284 	mutex_init(&list->thread_lock);
285 	list->hiddev = hiddev;
286 	file->private_data = list;
287 
288 	/*
289 	 * no need for locking because the USB major number
290 	 * is shared which usbcore guards against disconnect
291 	 */
292 	if (list->hiddev->exist) {
293 		if (!list->hiddev->open++) {
294 			res = usbhid_open(hiddev->hid);
295 			if (res < 0) {
296 				res = -EIO;
297 				goto bail;
298 			}
299 		}
300 	} else {
301 		res = -ENODEV;
302 		goto bail;
303 	}
304 
305 	spin_lock_irq(&list->hiddev->list_lock);
306 	list_add_tail(&list->node, &hiddev->list);
307 	spin_unlock_irq(&list->hiddev->list_lock);
308 
309 	mutex_lock(&hiddev->existancelock);
310 	if (!list->hiddev->open++)
311 		if (list->hiddev->exist) {
312 			struct hid_device *hid = hiddev->hid;
313 			res = usbhid_get_power(hid);
314 			if (res < 0) {
315 				res = -EIO;
316 				goto bail_unlock;
317 			}
318 			usbhid_open(hid);
319 		}
320 	mutex_unlock(&hiddev->existancelock);
321 	return 0;
322 bail_unlock:
323 	mutex_unlock(&hiddev->existancelock);
324 bail:
325 	file->private_data = NULL;
326 	vfree(list);
327 	return res;
328 }
329 
330 /*
331  * "write" file op
332  */
333 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
334 {
335 	return -EINVAL;
336 }
337 
338 /*
339  * "read" file op
340  */
341 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
342 {
343 	DEFINE_WAIT(wait);
344 	struct hiddev_list *list = file->private_data;
345 	int event_size;
346 	int retval;
347 
348 	event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
349 		sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
350 
351 	if (count < event_size)
352 		return 0;
353 
354 	/* lock against other threads */
355 	retval = mutex_lock_interruptible(&list->thread_lock);
356 	if (retval)
357 		return -ERESTARTSYS;
358 
359 	while (retval == 0) {
360 		if (list->head == list->tail) {
361 			prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
362 
363 			while (list->head == list->tail) {
364 				if (signal_pending(current)) {
365 					retval = -ERESTARTSYS;
366 					break;
367 				}
368 				if (!list->hiddev->exist) {
369 					retval = -EIO;
370 					break;
371 				}
372 				if (file->f_flags & O_NONBLOCK) {
373 					retval = -EAGAIN;
374 					break;
375 				}
376 
377 				/* let O_NONBLOCK tasks run */
378 				mutex_unlock(&list->thread_lock);
379 				schedule();
380 				if (mutex_lock_interruptible(&list->thread_lock)) {
381 					finish_wait(&list->hiddev->wait, &wait);
382 					return -EINTR;
383 				}
384 				set_current_state(TASK_INTERRUPTIBLE);
385 			}
386 			finish_wait(&list->hiddev->wait, &wait);
387 
388 		}
389 
390 		if (retval) {
391 			mutex_unlock(&list->thread_lock);
392 			return retval;
393 		}
394 
395 
396 		while (list->head != list->tail &&
397 		       retval + event_size <= count) {
398 			if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
399 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
400 					struct hiddev_event event;
401 
402 					event.hid = list->buffer[list->tail].usage_code;
403 					event.value = list->buffer[list->tail].value;
404 					if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
405 						mutex_unlock(&list->thread_lock);
406 						return -EFAULT;
407 					}
408 					retval += sizeof(struct hiddev_event);
409 				}
410 			} else {
411 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
412 				    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
413 
414 					if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
415 						mutex_unlock(&list->thread_lock);
416 						return -EFAULT;
417 					}
418 					retval += sizeof(struct hiddev_usage_ref);
419 				}
420 			}
421 			list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
422 		}
423 
424 	}
425 	mutex_unlock(&list->thread_lock);
426 
427 	return retval;
428 }
429 
430 /*
431  * "poll" file op
432  * No kernel lock - fine
433  */
434 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
435 {
436 	struct hiddev_list *list = file->private_data;
437 
438 	poll_wait(file, &list->hiddev->wait, wait);
439 	if (list->head != list->tail)
440 		return POLLIN | POLLRDNORM;
441 	if (!list->hiddev->exist)
442 		return POLLERR | POLLHUP;
443 	return 0;
444 }
445 
446 /*
447  * "ioctl" file op
448  */
449 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
450 {
451 	struct hid_device *hid = hiddev->hid;
452 	struct hiddev_report_info rinfo;
453 	struct hiddev_usage_ref_multi *uref_multi = NULL;
454 	struct hiddev_usage_ref *uref;
455 	struct hid_report *report;
456 	struct hid_field *field;
457 	int i;
458 
459 	uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
460 	if (!uref_multi)
461 		return -ENOMEM;
462 	uref = &uref_multi->uref;
463 	if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
464 		if (copy_from_user(uref_multi, user_arg,
465 				   sizeof(*uref_multi)))
466 			goto fault;
467 	} else {
468 		if (copy_from_user(uref, user_arg, sizeof(*uref)))
469 			goto fault;
470 	}
471 
472 	switch (cmd) {
473 	case HIDIOCGUCODE:
474 		rinfo.report_type = uref->report_type;
475 		rinfo.report_id = uref->report_id;
476 		if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
477 			goto inval;
478 
479 		if (uref->field_index >= report->maxfield)
480 			goto inval;
481 
482 		field = report->field[uref->field_index];
483 		if (uref->usage_index >= field->maxusage)
484 			goto inval;
485 
486 		uref->usage_code = field->usage[uref->usage_index].hid;
487 
488 		if (copy_to_user(user_arg, uref, sizeof(*uref)))
489 			goto fault;
490 
491 		goto goodreturn;
492 
493 	default:
494 		if (cmd != HIDIOCGUSAGE &&
495 		    cmd != HIDIOCGUSAGES &&
496 		    uref->report_type == HID_REPORT_TYPE_INPUT)
497 			goto inval;
498 
499 		if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
500 			field = hiddev_lookup_usage(hid, uref);
501 			if (field == NULL)
502 				goto inval;
503 		} else {
504 			rinfo.report_type = uref->report_type;
505 			rinfo.report_id = uref->report_id;
506 			if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
507 				goto inval;
508 
509 			if (uref->field_index >= report->maxfield)
510 				goto inval;
511 
512 			field = report->field[uref->field_index];
513 
514 			if (cmd == HIDIOCGCOLLECTIONINDEX) {
515 				if (uref->usage_index >= field->maxusage)
516 					goto inval;
517 			} else if (uref->usage_index >= field->report_count)
518 				goto inval;
519 
520 			else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
521 				 (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
522 				  uref->usage_index + uref_multi->num_values > field->report_count))
523 				goto inval;
524 		}
525 
526 		switch (cmd) {
527 		case HIDIOCGUSAGE:
528 			uref->value = field->value[uref->usage_index];
529 			if (copy_to_user(user_arg, uref, sizeof(*uref)))
530 				goto fault;
531 			goto goodreturn;
532 
533 		case HIDIOCSUSAGE:
534 			field->value[uref->usage_index] = uref->value;
535 			goto goodreturn;
536 
537 		case HIDIOCGCOLLECTIONINDEX:
538 			i = field->usage[uref->usage_index].collection_index;
539 			kfree(uref_multi);
540 			return i;
541 		case HIDIOCGUSAGES:
542 			for (i = 0; i < uref_multi->num_values; i++)
543 				uref_multi->values[i] =
544 				    field->value[uref->usage_index + i];
545 			if (copy_to_user(user_arg, uref_multi,
546 					 sizeof(*uref_multi)))
547 				goto fault;
548 			goto goodreturn;
549 		case HIDIOCSUSAGES:
550 			for (i = 0; i < uref_multi->num_values; i++)
551 				field->value[uref->usage_index + i] =
552 				    uref_multi->values[i];
553 			goto goodreturn;
554 		}
555 
556 goodreturn:
557 		kfree(uref_multi);
558 		return 0;
559 fault:
560 		kfree(uref_multi);
561 		return -EFAULT;
562 inval:
563 		kfree(uref_multi);
564 		return -EINVAL;
565 	}
566 }
567 
568 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
569 {
570 	struct hid_device *hid = hiddev->hid;
571 	struct usb_device *dev = hid_to_usb_dev(hid);
572 	int idx, len;
573 	char *buf;
574 
575 	if (get_user(idx, (int __user *)user_arg))
576 		return -EFAULT;
577 
578 	if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
579 		return -ENOMEM;
580 
581 	if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
582 		kfree(buf);
583 		return -EINVAL;
584 	}
585 
586 	if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
587 		kfree(buf);
588 		return -EFAULT;
589 	}
590 
591 	kfree(buf);
592 
593 	return len;
594 }
595 
596 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
597 {
598 	struct hiddev_list *list = file->private_data;
599 	struct hiddev *hiddev = list->hiddev;
600 	struct hid_device *hid;
601 	struct hiddev_collection_info cinfo;
602 	struct hiddev_report_info rinfo;
603 	struct hiddev_field_info finfo;
604 	struct hiddev_devinfo dinfo;
605 	struct hid_report *report;
606 	struct hid_field *field;
607 	void __user *user_arg = (void __user *)arg;
608 	int i, r = -EINVAL;
609 
610 	/* Called without BKL by compat methods so no BKL taken */
611 
612 	mutex_lock(&hiddev->existancelock);
613 	if (!hiddev->exist) {
614 		r = -ENODEV;
615 		goto ret_unlock;
616 	}
617 
618 	hid = hiddev->hid;
619 
620 	switch (cmd) {
621 
622 	case HIDIOCGVERSION:
623 		r = put_user(HID_VERSION, (int __user *)arg) ?
624 			-EFAULT : 0;
625 		break;
626 
627 	case HIDIOCAPPLICATION:
628 		if (arg >= hid->maxapplication)
629 			break;
630 
631 		for (i = 0; i < hid->maxcollection; i++)
632 			if (hid->collection[i].type ==
633 			    HID_COLLECTION_APPLICATION && arg-- == 0)
634 				break;
635 
636 		if (i < hid->maxcollection)
637 			r = hid->collection[i].usage;
638 		break;
639 
640 	case HIDIOCGDEVINFO:
641 		{
642 			struct usb_device *dev = hid_to_usb_dev(hid);
643 			struct usbhid_device *usbhid = hid->driver_data;
644 
645 			memset(&dinfo, 0, sizeof(dinfo));
646 
647 			dinfo.bustype = BUS_USB;
648 			dinfo.busnum = dev->bus->busnum;
649 			dinfo.devnum = dev->devnum;
650 			dinfo.ifnum = usbhid->ifnum;
651 			dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
652 			dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
653 			dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
654 			dinfo.num_applications = hid->maxapplication;
655 
656 			r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
657 				-EFAULT : 0;
658 			break;
659 		}
660 
661 	case HIDIOCGFLAG:
662 		r = put_user(list->flags, (int __user *)arg) ?
663 			-EFAULT : 0;
664 		break;
665 
666 	case HIDIOCSFLAG:
667 		{
668 			int newflags;
669 
670 			if (get_user(newflags, (int __user *)arg)) {
671 				r = -EFAULT;
672 				break;
673 			}
674 
675 			if ((newflags & ~HIDDEV_FLAGS) != 0 ||
676 			    ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
677 			     (newflags & HIDDEV_FLAG_UREF) == 0))
678 				break;
679 
680 			list->flags = newflags;
681 
682 			r = 0;
683 			break;
684 		}
685 
686 	case HIDIOCGSTRING:
687 		r = hiddev_ioctl_string(hiddev, cmd, user_arg);
688 		break;
689 
690 	case HIDIOCINITREPORT:
691 		usbhid_init_reports(hid);
692 		r = 0;
693 		break;
694 
695 	case HIDIOCGREPORT:
696 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
697 			r = -EFAULT;
698 			break;
699 		}
700 
701 		if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
702 			break;
703 
704 		report = hiddev_lookup_report(hid, &rinfo);
705 		if (report == NULL)
706 			break;
707 
708 		usbhid_submit_report(hid, report, USB_DIR_IN);
709 		usbhid_wait_io(hid);
710 
711 		r = 0;
712 		break;
713 
714 	case HIDIOCSREPORT:
715 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
716 			r = -EFAULT;
717 			break;
718 		}
719 
720 		if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
721 			break;
722 
723 		report = hiddev_lookup_report(hid, &rinfo);
724 		if (report == NULL)
725 			break;
726 
727 		usbhid_submit_report(hid, report, USB_DIR_OUT);
728 		usbhid_wait_io(hid);
729 
730 		r = 0;
731 		break;
732 
733 	case HIDIOCGREPORTINFO:
734 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
735 			r = -EFAULT;
736 			break;
737 		}
738 
739 		report = hiddev_lookup_report(hid, &rinfo);
740 		if (report == NULL)
741 			break;
742 
743 		rinfo.num_fields = report->maxfield;
744 
745 		r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
746 			-EFAULT : 0;
747 		break;
748 
749 	case HIDIOCGFIELDINFO:
750 		if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
751 			r = -EFAULT;
752 			break;
753 		}
754 
755 		rinfo.report_type = finfo.report_type;
756 		rinfo.report_id = finfo.report_id;
757 
758 		report = hiddev_lookup_report(hid, &rinfo);
759 		if (report == NULL)
760 			break;
761 
762 		if (finfo.field_index >= report->maxfield)
763 			break;
764 
765 		field = report->field[finfo.field_index];
766 		memset(&finfo, 0, sizeof(finfo));
767 		finfo.report_type = rinfo.report_type;
768 		finfo.report_id = rinfo.report_id;
769 		finfo.field_index = field->report_count - 1;
770 		finfo.maxusage = field->maxusage;
771 		finfo.flags = field->flags;
772 		finfo.physical = field->physical;
773 		finfo.logical = field->logical;
774 		finfo.application = field->application;
775 		finfo.logical_minimum = field->logical_minimum;
776 		finfo.logical_maximum = field->logical_maximum;
777 		finfo.physical_minimum = field->physical_minimum;
778 		finfo.physical_maximum = field->physical_maximum;
779 		finfo.unit_exponent = field->unit_exponent;
780 		finfo.unit = field->unit;
781 
782 		r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
783 			-EFAULT : 0;
784 		break;
785 
786 	case HIDIOCGUCODE:
787 		/* fall through */
788 	case HIDIOCGUSAGE:
789 	case HIDIOCSUSAGE:
790 	case HIDIOCGUSAGES:
791 	case HIDIOCSUSAGES:
792 	case HIDIOCGCOLLECTIONINDEX:
793 		r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
794 		break;
795 
796 	case HIDIOCGCOLLECTIONINFO:
797 		if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
798 			r = -EFAULT;
799 			break;
800 		}
801 
802 		if (cinfo.index >= hid->maxcollection)
803 			break;
804 
805 		cinfo.type = hid->collection[cinfo.index].type;
806 		cinfo.usage = hid->collection[cinfo.index].usage;
807 		cinfo.level = hid->collection[cinfo.index].level;
808 
809 		r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
810 			-EFAULT : 0;
811 		break;
812 
813 	default:
814 		if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
815 			break;
816 
817 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
818 			int len = strlen(hid->name) + 1;
819 			if (len > _IOC_SIZE(cmd))
820 				 len = _IOC_SIZE(cmd);
821 			r = copy_to_user(user_arg, hid->name, len) ?
822 				-EFAULT : len;
823 			break;
824 		}
825 
826 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
827 			int len = strlen(hid->phys) + 1;
828 			if (len > _IOC_SIZE(cmd))
829 				len = _IOC_SIZE(cmd);
830 			r = copy_to_user(user_arg, hid->phys, len) ?
831 				-EFAULT : len;
832 			break;
833 		}
834 	}
835 
836 ret_unlock:
837 	mutex_unlock(&hiddev->existancelock);
838 	return r;
839 }
840 
841 #ifdef CONFIG_COMPAT
842 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
843 {
844 	return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
845 }
846 #endif
847 
848 static const struct file_operations hiddev_fops = {
849 	.owner =	THIS_MODULE,
850 	.read =		hiddev_read,
851 	.write =	hiddev_write,
852 	.poll =		hiddev_poll,
853 	.open =		hiddev_open,
854 	.release =	hiddev_release,
855 	.unlocked_ioctl =	hiddev_ioctl,
856 	.fasync =	hiddev_fasync,
857 #ifdef CONFIG_COMPAT
858 	.compat_ioctl	= hiddev_compat_ioctl,
859 #endif
860 	.llseek		= noop_llseek,
861 };
862 
863 static char *hiddev_devnode(struct device *dev, umode_t *mode)
864 {
865 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
866 }
867 
868 static struct usb_class_driver hiddev_class = {
869 	.name =		"hiddev%d",
870 	.devnode =	hiddev_devnode,
871 	.fops =		&hiddev_fops,
872 	.minor_base =	HIDDEV_MINOR_BASE,
873 };
874 
875 /*
876  * This is where hid.c calls us to connect a hid device to the hiddev driver
877  */
878 int hiddev_connect(struct hid_device *hid, unsigned int force)
879 {
880 	struct hiddev *hiddev;
881 	struct usbhid_device *usbhid = hid->driver_data;
882 	int retval;
883 
884 	if (!force) {
885 		unsigned int i;
886 		for (i = 0; i < hid->maxcollection; i++)
887 			if (hid->collection[i].type ==
888 			    HID_COLLECTION_APPLICATION &&
889 			    !IS_INPUT_APPLICATION(hid->collection[i].usage))
890 				break;
891 
892 		if (i == hid->maxcollection)
893 			return -1;
894 	}
895 
896 	if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
897 		return -1;
898 
899 	init_waitqueue_head(&hiddev->wait);
900 	INIT_LIST_HEAD(&hiddev->list);
901 	spin_lock_init(&hiddev->list_lock);
902 	mutex_init(&hiddev->existancelock);
903 	hid->hiddev = hiddev;
904 	hiddev->hid = hid;
905 	hiddev->exist = 1;
906 	retval = usb_register_dev(usbhid->intf, &hiddev_class);
907 	if (retval) {
908 		hid_err(hid, "Not able to get a minor for this device\n");
909 		hid->hiddev = NULL;
910 		kfree(hiddev);
911 		return -1;
912 	}
913 	return 0;
914 }
915 
916 /*
917  * This is where hid.c calls us to disconnect a hiddev device from the
918  * corresponding hid device (usually because the usb device has disconnected)
919  */
920 static struct usb_class_driver hiddev_class;
921 void hiddev_disconnect(struct hid_device *hid)
922 {
923 	struct hiddev *hiddev = hid->hiddev;
924 	struct usbhid_device *usbhid = hid->driver_data;
925 
926 	usb_deregister_dev(usbhid->intf, &hiddev_class);
927 
928 	mutex_lock(&hiddev->existancelock);
929 	hiddev->exist = 0;
930 
931 	if (hiddev->open) {
932 		mutex_unlock(&hiddev->existancelock);
933 		usbhid_close(hiddev->hid);
934 		wake_up_interruptible(&hiddev->wait);
935 	} else {
936 		mutex_unlock(&hiddev->existancelock);
937 		kfree(hiddev);
938 	}
939 }
940