xref: /openbmc/linux/drivers/hid/usbhid/hiddev.c (revision be709d48)
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/sched/signal.h>
31 #include <linux/module.h>
32 #include <linux/init.h>
33 #include <linux/input.h>
34 #include <linux/usb.h>
35 #include <linux/hid.h>
36 #include <linux/hiddev.h>
37 #include <linux/compat.h>
38 #include <linux/vmalloc.h>
39 #include <linux/nospec.h>
40 #include "usbhid.h"
41 
42 #ifdef CONFIG_USB_DYNAMIC_MINORS
43 #define HIDDEV_MINOR_BASE	0
44 #define HIDDEV_MINORS		256
45 #else
46 #define HIDDEV_MINOR_BASE	96
47 #define HIDDEV_MINORS		16
48 #endif
49 #define HIDDEV_BUFFER_SIZE	2048
50 
51 struct hiddev_list {
52 	struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
53 	int head;
54 	int tail;
55 	unsigned flags;
56 	struct fasync_struct *fasync;
57 	struct hiddev *hiddev;
58 	struct list_head node;
59 	struct mutex thread_lock;
60 };
61 
62 /*
63  * Find a report, given the report's type and ID.  The ID can be specified
64  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
65  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
66  * given type which follows old_id.
67  */
68 static struct hid_report *
69 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
70 {
71 	unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
72 	unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
73 	struct hid_report_enum *report_enum;
74 	struct hid_report *report;
75 	struct list_head *list;
76 
77 	if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
78 	    rinfo->report_type > HID_REPORT_TYPE_MAX)
79 		return NULL;
80 
81 	report_enum = hid->report_enum +
82 		(rinfo->report_type - HID_REPORT_TYPE_MIN);
83 
84 	switch (flags) {
85 	case 0: /* Nothing to do -- report_id is already set correctly */
86 		break;
87 
88 	case HID_REPORT_ID_FIRST:
89 		if (list_empty(&report_enum->report_list))
90 			return NULL;
91 
92 		list = report_enum->report_list.next;
93 		report = list_entry(list, struct hid_report, list);
94 		rinfo->report_id = report->id;
95 		break;
96 
97 	case HID_REPORT_ID_NEXT:
98 		report = report_enum->report_id_hash[rid];
99 		if (!report)
100 			return NULL;
101 
102 		list = report->list.next;
103 		if (list == &report_enum->report_list)
104 			return NULL;
105 
106 		report = list_entry(list, struct hid_report, list);
107 		rinfo->report_id = report->id;
108 		break;
109 
110 	default:
111 		return NULL;
112 	}
113 
114 	return report_enum->report_id_hash[rinfo->report_id];
115 }
116 
117 /*
118  * Perform an exhaustive search of the report table for a usage, given its
119  * type and usage id.
120  */
121 static struct hid_field *
122 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
123 {
124 	int i, j;
125 	struct hid_report *report;
126 	struct hid_report_enum *report_enum;
127 	struct hid_field *field;
128 
129 	if (uref->report_type < HID_REPORT_TYPE_MIN ||
130 	    uref->report_type > HID_REPORT_TYPE_MAX)
131 		return NULL;
132 
133 	report_enum = hid->report_enum +
134 		(uref->report_type - HID_REPORT_TYPE_MIN);
135 
136 	list_for_each_entry(report, &report_enum->report_list, list) {
137 		for (i = 0; i < report->maxfield; i++) {
138 			field = report->field[i];
139 			for (j = 0; j < field->maxusage; j++) {
140 				if (field->usage[j].hid == uref->usage_code) {
141 					uref->report_id = report->id;
142 					uref->field_index = i;
143 					uref->usage_index = j;
144 					return field;
145 				}
146 			}
147 		}
148 	}
149 
150 	return NULL;
151 }
152 
153 static void hiddev_send_event(struct hid_device *hid,
154 			      struct hiddev_usage_ref *uref)
155 {
156 	struct hiddev *hiddev = hid->hiddev;
157 	struct hiddev_list *list;
158 	unsigned long flags;
159 
160 	spin_lock_irqsave(&hiddev->list_lock, flags);
161 	list_for_each_entry(list, &hiddev->list, node) {
162 		if (uref->field_index != HID_FIELD_INDEX_NONE ||
163 		    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
164 			list->buffer[list->head] = *uref;
165 			list->head = (list->head + 1) &
166 				(HIDDEV_BUFFER_SIZE - 1);
167 			kill_fasync(&list->fasync, SIGIO, POLL_IN);
168 		}
169 	}
170 	spin_unlock_irqrestore(&hiddev->list_lock, flags);
171 
172 	wake_up_interruptible(&hiddev->wait);
173 }
174 
175 /*
176  * This is where hid.c calls into hiddev to pass an event that occurred over
177  * the interrupt pipe
178  */
179 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
180 		      struct hid_usage *usage, __s32 value)
181 {
182 	unsigned type = field->report_type;
183 	struct hiddev_usage_ref uref;
184 
185 	uref.report_type =
186 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
187 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
188 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
189 	uref.report_id = field->report->id;
190 	uref.field_index = field->index;
191 	uref.usage_index = (usage - field->usage);
192 	uref.usage_code = usage->hid;
193 	uref.value = value;
194 
195 	hiddev_send_event(hid, &uref);
196 }
197 EXPORT_SYMBOL_GPL(hiddev_hid_event);
198 
199 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
200 {
201 	unsigned type = report->type;
202 	struct hiddev_usage_ref uref;
203 
204 	memset(&uref, 0, sizeof(uref));
205 	uref.report_type =
206 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
207 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
208 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
209 	uref.report_id = report->id;
210 	uref.field_index = HID_FIELD_INDEX_NONE;
211 
212 	hiddev_send_event(hid, &uref);
213 }
214 
215 /*
216  * fasync file op
217  */
218 static int hiddev_fasync(int fd, struct file *file, int on)
219 {
220 	struct hiddev_list *list = file->private_data;
221 
222 	return fasync_helper(fd, file, on, &list->fasync);
223 }
224 
225 
226 /*
227  * release file op
228  */
229 static int hiddev_release(struct inode * inode, struct file * file)
230 {
231 	struct hiddev_list *list = file->private_data;
232 	unsigned long flags;
233 
234 	spin_lock_irqsave(&list->hiddev->list_lock, flags);
235 	list_del(&list->node);
236 	spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
237 
238 	mutex_lock(&list->hiddev->existancelock);
239 	if (!--list->hiddev->open) {
240 		if (list->hiddev->exist) {
241 			hid_hw_close(list->hiddev->hid);
242 			hid_hw_power(list->hiddev->hid, PM_HINT_NORMAL);
243 		} else {
244 			mutex_unlock(&list->hiddev->existancelock);
245 			kfree(list->hiddev);
246 			vfree(list);
247 			return 0;
248 		}
249 	}
250 
251 	mutex_unlock(&list->hiddev->existancelock);
252 	vfree(list);
253 
254 	return 0;
255 }
256 
257 /*
258  * open file op
259  */
260 static int hiddev_open(struct inode *inode, struct file *file)
261 {
262 	struct hiddev_list *list;
263 	struct usb_interface *intf;
264 	struct hid_device *hid;
265 	struct hiddev *hiddev;
266 	int res;
267 
268 	intf = usbhid_find_interface(iminor(inode));
269 	if (!intf)
270 		return -ENODEV;
271 	hid = usb_get_intfdata(intf);
272 	hiddev = hid->hiddev;
273 
274 	if (!(list = vzalloc(sizeof(struct hiddev_list))))
275 		return -ENOMEM;
276 	mutex_init(&list->thread_lock);
277 	list->hiddev = hiddev;
278 	file->private_data = list;
279 
280 	/*
281 	 * no need for locking because the USB major number
282 	 * is shared which usbcore guards against disconnect
283 	 */
284 	if (list->hiddev->exist) {
285 		if (!list->hiddev->open++) {
286 			res = hid_hw_open(hiddev->hid);
287 			if (res < 0)
288 				goto bail;
289 		}
290 	} else {
291 		res = -ENODEV;
292 		goto bail;
293 	}
294 
295 	spin_lock_irq(&list->hiddev->list_lock);
296 	list_add_tail(&list->node, &hiddev->list);
297 	spin_unlock_irq(&list->hiddev->list_lock);
298 
299 	mutex_lock(&hiddev->existancelock);
300 	if (!list->hiddev->open++)
301 		if (list->hiddev->exist) {
302 			struct hid_device *hid = hiddev->hid;
303 			res = hid_hw_power(hid, PM_HINT_FULLON);
304 			if (res < 0)
305 				goto bail_unlock;
306 			res = hid_hw_open(hid);
307 			if (res < 0)
308 				goto bail_normal_power;
309 		}
310 	mutex_unlock(&hiddev->existancelock);
311 	return 0;
312 bail_normal_power:
313 	hid_hw_power(hid, PM_HINT_NORMAL);
314 bail_unlock:
315 	mutex_unlock(&hiddev->existancelock);
316 bail:
317 	file->private_data = NULL;
318 	vfree(list);
319 	return res;
320 }
321 
322 /*
323  * "write" file op
324  */
325 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
326 {
327 	return -EINVAL;
328 }
329 
330 /*
331  * "read" file op
332  */
333 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
334 {
335 	DEFINE_WAIT(wait);
336 	struct hiddev_list *list = file->private_data;
337 	int event_size;
338 	int retval;
339 
340 	event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
341 		sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
342 
343 	if (count < event_size)
344 		return 0;
345 
346 	/* lock against other threads */
347 	retval = mutex_lock_interruptible(&list->thread_lock);
348 	if (retval)
349 		return -ERESTARTSYS;
350 
351 	while (retval == 0) {
352 		if (list->head == list->tail) {
353 			prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
354 
355 			while (list->head == list->tail) {
356 				if (signal_pending(current)) {
357 					retval = -ERESTARTSYS;
358 					break;
359 				}
360 				if (!list->hiddev->exist) {
361 					retval = -EIO;
362 					break;
363 				}
364 				if (file->f_flags & O_NONBLOCK) {
365 					retval = -EAGAIN;
366 					break;
367 				}
368 
369 				/* let O_NONBLOCK tasks run */
370 				mutex_unlock(&list->thread_lock);
371 				schedule();
372 				if (mutex_lock_interruptible(&list->thread_lock)) {
373 					finish_wait(&list->hiddev->wait, &wait);
374 					return -EINTR;
375 				}
376 				set_current_state(TASK_INTERRUPTIBLE);
377 			}
378 			finish_wait(&list->hiddev->wait, &wait);
379 
380 		}
381 
382 		if (retval) {
383 			mutex_unlock(&list->thread_lock);
384 			return retval;
385 		}
386 
387 
388 		while (list->head != list->tail &&
389 		       retval + event_size <= count) {
390 			if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
391 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
392 					struct hiddev_event event;
393 
394 					event.hid = list->buffer[list->tail].usage_code;
395 					event.value = list->buffer[list->tail].value;
396 					if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
397 						mutex_unlock(&list->thread_lock);
398 						return -EFAULT;
399 					}
400 					retval += sizeof(struct hiddev_event);
401 				}
402 			} else {
403 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
404 				    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
405 
406 					if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
407 						mutex_unlock(&list->thread_lock);
408 						return -EFAULT;
409 					}
410 					retval += sizeof(struct hiddev_usage_ref);
411 				}
412 			}
413 			list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
414 		}
415 
416 	}
417 	mutex_unlock(&list->thread_lock);
418 
419 	return retval;
420 }
421 
422 /*
423  * "poll" file op
424  * No kernel lock - fine
425  */
426 static __poll_t hiddev_poll(struct file *file, poll_table *wait)
427 {
428 	struct hiddev_list *list = file->private_data;
429 
430 	poll_wait(file, &list->hiddev->wait, wait);
431 	if (list->head != list->tail)
432 		return EPOLLIN | EPOLLRDNORM;
433 	if (!list->hiddev->exist)
434 		return EPOLLERR | EPOLLHUP;
435 	return 0;
436 }
437 
438 /*
439  * "ioctl" file op
440  */
441 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
442 {
443 	struct hid_device *hid = hiddev->hid;
444 	struct hiddev_report_info rinfo;
445 	struct hiddev_usage_ref_multi *uref_multi = NULL;
446 	struct hiddev_usage_ref *uref;
447 	struct hid_report *report;
448 	struct hid_field *field;
449 	int i;
450 
451 	uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
452 	if (!uref_multi)
453 		return -ENOMEM;
454 	uref = &uref_multi->uref;
455 	if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
456 		if (copy_from_user(uref_multi, user_arg,
457 				   sizeof(*uref_multi)))
458 			goto fault;
459 	} else {
460 		if (copy_from_user(uref, user_arg, sizeof(*uref)))
461 			goto fault;
462 	}
463 
464 	switch (cmd) {
465 	case HIDIOCGUCODE:
466 		rinfo.report_type = uref->report_type;
467 		rinfo.report_id = uref->report_id;
468 		if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
469 			goto inval;
470 
471 		if (uref->field_index >= report->maxfield)
472 			goto inval;
473 		uref->field_index = array_index_nospec(uref->field_index,
474 						       report->maxfield);
475 
476 		field = report->field[uref->field_index];
477 		if (uref->usage_index >= field->maxusage)
478 			goto inval;
479 		uref->usage_index = array_index_nospec(uref->usage_index,
480 						       field->maxusage);
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 			uref->field_index = array_index_nospec(uref->field_index,
508 							       report->maxfield);
509 
510 			field = report->field[uref->field_index];
511 
512 			if (cmd == HIDIOCGCOLLECTIONINDEX) {
513 				if (uref->usage_index >= field->maxusage)
514 					goto inval;
515 				uref->usage_index =
516 					array_index_nospec(uref->usage_index,
517 							   field->maxusage);
518 			} else if (uref->usage_index >= field->report_count)
519 				goto inval;
520 		}
521 
522 		if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
523 			if (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
524 			    uref->usage_index + uref_multi->num_values >
525 			    field->report_count)
526 				goto inval;
527 
528 			uref->usage_index =
529 				array_index_nospec(uref->usage_index,
530 						   field->report_count -
531 						   uref_multi->num_values);
532 		}
533 
534 		switch (cmd) {
535 		case HIDIOCGUSAGE:
536 			uref->value = field->value[uref->usage_index];
537 			if (copy_to_user(user_arg, uref, sizeof(*uref)))
538 				goto fault;
539 			goto goodreturn;
540 
541 		case HIDIOCSUSAGE:
542 			field->value[uref->usage_index] = uref->value;
543 			goto goodreturn;
544 
545 		case HIDIOCGCOLLECTIONINDEX:
546 			i = field->usage[uref->usage_index].collection_index;
547 			kfree(uref_multi);
548 			return i;
549 		case HIDIOCGUSAGES:
550 			for (i = 0; i < uref_multi->num_values; i++)
551 				uref_multi->values[i] =
552 				    field->value[uref->usage_index + i];
553 			if (copy_to_user(user_arg, uref_multi,
554 					 sizeof(*uref_multi)))
555 				goto fault;
556 			goto goodreturn;
557 		case HIDIOCSUSAGES:
558 			for (i = 0; i < uref_multi->num_values; i++)
559 				field->value[uref->usage_index + i] =
560 				    uref_multi->values[i];
561 			goto goodreturn;
562 		}
563 
564 goodreturn:
565 		kfree(uref_multi);
566 		return 0;
567 fault:
568 		kfree(uref_multi);
569 		return -EFAULT;
570 inval:
571 		kfree(uref_multi);
572 		return -EINVAL;
573 	}
574 }
575 
576 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
577 {
578 	struct hid_device *hid = hiddev->hid;
579 	struct usb_device *dev = hid_to_usb_dev(hid);
580 	int idx, len;
581 	char *buf;
582 
583 	if (get_user(idx, (int __user *)user_arg))
584 		return -EFAULT;
585 
586 	if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
587 		return -ENOMEM;
588 
589 	if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
590 		kfree(buf);
591 		return -EINVAL;
592 	}
593 
594 	if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
595 		kfree(buf);
596 		return -EFAULT;
597 	}
598 
599 	kfree(buf);
600 
601 	return len;
602 }
603 
604 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
605 {
606 	struct hiddev_list *list = file->private_data;
607 	struct hiddev *hiddev = list->hiddev;
608 	struct hid_device *hid;
609 	struct hiddev_collection_info cinfo;
610 	struct hiddev_report_info rinfo;
611 	struct hiddev_field_info finfo;
612 	struct hiddev_devinfo dinfo;
613 	struct hid_report *report;
614 	struct hid_field *field;
615 	void __user *user_arg = (void __user *)arg;
616 	int i, r = -EINVAL;
617 
618 	/* Called without BKL by compat methods so no BKL taken */
619 
620 	mutex_lock(&hiddev->existancelock);
621 	if (!hiddev->exist) {
622 		r = -ENODEV;
623 		goto ret_unlock;
624 	}
625 
626 	hid = hiddev->hid;
627 
628 	switch (cmd) {
629 
630 	case HIDIOCGVERSION:
631 		r = put_user(HID_VERSION, (int __user *)arg) ?
632 			-EFAULT : 0;
633 		break;
634 
635 	case HIDIOCAPPLICATION:
636 		if (arg >= hid->maxapplication)
637 			break;
638 
639 		for (i = 0; i < hid->maxcollection; i++)
640 			if (hid->collection[i].type ==
641 			    HID_COLLECTION_APPLICATION && arg-- == 0)
642 				break;
643 
644 		if (i < hid->maxcollection)
645 			r = hid->collection[i].usage;
646 		break;
647 
648 	case HIDIOCGDEVINFO:
649 		{
650 			struct usb_device *dev = hid_to_usb_dev(hid);
651 			struct usbhid_device *usbhid = hid->driver_data;
652 
653 			memset(&dinfo, 0, sizeof(dinfo));
654 
655 			dinfo.bustype = BUS_USB;
656 			dinfo.busnum = dev->bus->busnum;
657 			dinfo.devnum = dev->devnum;
658 			dinfo.ifnum = usbhid->ifnum;
659 			dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
660 			dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
661 			dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
662 			dinfo.num_applications = hid->maxapplication;
663 
664 			r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
665 				-EFAULT : 0;
666 			break;
667 		}
668 
669 	case HIDIOCGFLAG:
670 		r = put_user(list->flags, (int __user *)arg) ?
671 			-EFAULT : 0;
672 		break;
673 
674 	case HIDIOCSFLAG:
675 		{
676 			int newflags;
677 
678 			if (get_user(newflags, (int __user *)arg)) {
679 				r = -EFAULT;
680 				break;
681 			}
682 
683 			if ((newflags & ~HIDDEV_FLAGS) != 0 ||
684 			    ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
685 			     (newflags & HIDDEV_FLAG_UREF) == 0))
686 				break;
687 
688 			list->flags = newflags;
689 
690 			r = 0;
691 			break;
692 		}
693 
694 	case HIDIOCGSTRING:
695 		r = hiddev_ioctl_string(hiddev, cmd, user_arg);
696 		break;
697 
698 	case HIDIOCINITREPORT:
699 		usbhid_init_reports(hid);
700 		hiddev->initialized = true;
701 		r = 0;
702 		break;
703 
704 	case HIDIOCGREPORT:
705 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
706 			r = -EFAULT;
707 			break;
708 		}
709 
710 		if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
711 			break;
712 
713 		report = hiddev_lookup_report(hid, &rinfo);
714 		if (report == NULL)
715 			break;
716 
717 		hid_hw_request(hid, report, HID_REQ_GET_REPORT);
718 		hid_hw_wait(hid);
719 
720 		r = 0;
721 		break;
722 
723 	case HIDIOCSREPORT:
724 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
725 			r = -EFAULT;
726 			break;
727 		}
728 
729 		if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
730 			break;
731 
732 		report = hiddev_lookup_report(hid, &rinfo);
733 		if (report == NULL)
734 			break;
735 
736 		hid_hw_request(hid, report, HID_REQ_SET_REPORT);
737 		hid_hw_wait(hid);
738 
739 		r = 0;
740 		break;
741 
742 	case HIDIOCGREPORTINFO:
743 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
744 			r = -EFAULT;
745 			break;
746 		}
747 
748 		report = hiddev_lookup_report(hid, &rinfo);
749 		if (report == NULL)
750 			break;
751 
752 		rinfo.num_fields = report->maxfield;
753 
754 		r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
755 			-EFAULT : 0;
756 		break;
757 
758 	case HIDIOCGFIELDINFO:
759 		if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
760 			r = -EFAULT;
761 			break;
762 		}
763 
764 		rinfo.report_type = finfo.report_type;
765 		rinfo.report_id = finfo.report_id;
766 
767 		report = hiddev_lookup_report(hid, &rinfo);
768 		if (report == NULL)
769 			break;
770 
771 		if (finfo.field_index >= report->maxfield)
772 			break;
773 		finfo.field_index = array_index_nospec(finfo.field_index,
774 						       report->maxfield);
775 
776 		field = report->field[finfo.field_index];
777 		memset(&finfo, 0, sizeof(finfo));
778 		finfo.report_type = rinfo.report_type;
779 		finfo.report_id = rinfo.report_id;
780 		finfo.field_index = field->report_count - 1;
781 		finfo.maxusage = field->maxusage;
782 		finfo.flags = field->flags;
783 		finfo.physical = field->physical;
784 		finfo.logical = field->logical;
785 		finfo.application = field->application;
786 		finfo.logical_minimum = field->logical_minimum;
787 		finfo.logical_maximum = field->logical_maximum;
788 		finfo.physical_minimum = field->physical_minimum;
789 		finfo.physical_maximum = field->physical_maximum;
790 		finfo.unit_exponent = field->unit_exponent;
791 		finfo.unit = field->unit;
792 
793 		r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
794 			-EFAULT : 0;
795 		break;
796 
797 	case HIDIOCGUCODE:
798 		/* fall through */
799 	case HIDIOCGUSAGE:
800 	case HIDIOCSUSAGE:
801 	case HIDIOCGUSAGES:
802 	case HIDIOCSUSAGES:
803 	case HIDIOCGCOLLECTIONINDEX:
804 		if (!hiddev->initialized) {
805 			usbhid_init_reports(hid);
806 			hiddev->initialized = true;
807 		}
808 		r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
809 		break;
810 
811 	case HIDIOCGCOLLECTIONINFO:
812 		if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
813 			r = -EFAULT;
814 			break;
815 		}
816 
817 		if (cinfo.index >= hid->maxcollection)
818 			break;
819 		cinfo.index = array_index_nospec(cinfo.index,
820 						 hid->maxcollection);
821 
822 		cinfo.type = hid->collection[cinfo.index].type;
823 		cinfo.usage = hid->collection[cinfo.index].usage;
824 		cinfo.level = hid->collection[cinfo.index].level;
825 
826 		r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
827 			-EFAULT : 0;
828 		break;
829 
830 	default:
831 		if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
832 			break;
833 
834 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
835 			int len = strlen(hid->name) + 1;
836 			if (len > _IOC_SIZE(cmd))
837 				 len = _IOC_SIZE(cmd);
838 			r = copy_to_user(user_arg, hid->name, len) ?
839 				-EFAULT : len;
840 			break;
841 		}
842 
843 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
844 			int len = strlen(hid->phys) + 1;
845 			if (len > _IOC_SIZE(cmd))
846 				len = _IOC_SIZE(cmd);
847 			r = copy_to_user(user_arg, hid->phys, len) ?
848 				-EFAULT : len;
849 			break;
850 		}
851 	}
852 
853 ret_unlock:
854 	mutex_unlock(&hiddev->existancelock);
855 	return r;
856 }
857 
858 #ifdef CONFIG_COMPAT
859 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
860 {
861 	return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
862 }
863 #endif
864 
865 static const struct file_operations hiddev_fops = {
866 	.owner =	THIS_MODULE,
867 	.read =		hiddev_read,
868 	.write =	hiddev_write,
869 	.poll =		hiddev_poll,
870 	.open =		hiddev_open,
871 	.release =	hiddev_release,
872 	.unlocked_ioctl =	hiddev_ioctl,
873 	.fasync =	hiddev_fasync,
874 #ifdef CONFIG_COMPAT
875 	.compat_ioctl	= hiddev_compat_ioctl,
876 #endif
877 	.llseek		= noop_llseek,
878 };
879 
880 static char *hiddev_devnode(struct device *dev, umode_t *mode)
881 {
882 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
883 }
884 
885 static struct usb_class_driver hiddev_class = {
886 	.name =		"hiddev%d",
887 	.devnode =	hiddev_devnode,
888 	.fops =		&hiddev_fops,
889 	.minor_base =	HIDDEV_MINOR_BASE,
890 };
891 
892 /*
893  * This is where hid.c calls us to connect a hid device to the hiddev driver
894  */
895 int hiddev_connect(struct hid_device *hid, unsigned int force)
896 {
897 	struct hiddev *hiddev;
898 	struct usbhid_device *usbhid = hid->driver_data;
899 	int retval;
900 
901 	if (!force) {
902 		unsigned int i;
903 		for (i = 0; i < hid->maxcollection; i++)
904 			if (hid->collection[i].type ==
905 			    HID_COLLECTION_APPLICATION &&
906 			    !IS_INPUT_APPLICATION(hid->collection[i].usage))
907 				break;
908 
909 		if (i == hid->maxcollection)
910 			return -1;
911 	}
912 
913 	if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
914 		return -1;
915 
916 	init_waitqueue_head(&hiddev->wait);
917 	INIT_LIST_HEAD(&hiddev->list);
918 	spin_lock_init(&hiddev->list_lock);
919 	mutex_init(&hiddev->existancelock);
920 	hid->hiddev = hiddev;
921 	hiddev->hid = hid;
922 	hiddev->exist = 1;
923 	retval = usb_register_dev(usbhid->intf, &hiddev_class);
924 	if (retval) {
925 		hid_err(hid, "Not able to get a minor for this device\n");
926 		hid->hiddev = NULL;
927 		kfree(hiddev);
928 		return -1;
929 	}
930 
931 	/*
932 	 * If HID_QUIRK_NO_INIT_REPORTS is set, make sure we don't initialize
933 	 * the reports.
934 	 */
935 	hiddev->initialized = hid->quirks & HID_QUIRK_NO_INIT_REPORTS;
936 
937 	hiddev->minor = usbhid->intf->minor;
938 
939 	return 0;
940 }
941 
942 /*
943  * This is where hid.c calls us to disconnect a hiddev device from the
944  * corresponding hid device (usually because the usb device has disconnected)
945  */
946 static struct usb_class_driver hiddev_class;
947 void hiddev_disconnect(struct hid_device *hid)
948 {
949 	struct hiddev *hiddev = hid->hiddev;
950 	struct usbhid_device *usbhid = hid->driver_data;
951 
952 	usb_deregister_dev(usbhid->intf, &hiddev_class);
953 
954 	mutex_lock(&hiddev->existancelock);
955 	hiddev->exist = 0;
956 
957 	if (hiddev->open) {
958 		mutex_unlock(&hiddev->existancelock);
959 		hid_hw_close(hiddev->hid);
960 		wake_up_interruptible(&hiddev->wait);
961 	} else {
962 		mutex_unlock(&hiddev->existancelock);
963 		kfree(hiddev);
964 	}
965 }
966