xref: /openbmc/linux/drivers/hid/usbhid/hiddev.c (revision feac8c8b)
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 "usbhid.h"
40 
41 #ifdef CONFIG_USB_DYNAMIC_MINORS
42 #define HIDDEV_MINOR_BASE	0
43 #define HIDDEV_MINORS		256
44 #else
45 #define HIDDEV_MINOR_BASE	96
46 #define HIDDEV_MINORS		16
47 #endif
48 #define HIDDEV_BUFFER_SIZE	2048
49 
50 struct hiddev_list {
51 	struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
52 	int head;
53 	int tail;
54 	unsigned flags;
55 	struct fasync_struct *fasync;
56 	struct hiddev *hiddev;
57 	struct list_head node;
58 	struct mutex thread_lock;
59 };
60 
61 /*
62  * Find a report, given the report's type and ID.  The ID can be specified
63  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
64  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
65  * given type which follows old_id.
66  */
67 static struct hid_report *
68 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
69 {
70 	unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
71 	unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
72 	struct hid_report_enum *report_enum;
73 	struct hid_report *report;
74 	struct list_head *list;
75 
76 	if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
77 	    rinfo->report_type > HID_REPORT_TYPE_MAX)
78 		return NULL;
79 
80 	report_enum = hid->report_enum +
81 		(rinfo->report_type - HID_REPORT_TYPE_MIN);
82 
83 	switch (flags) {
84 	case 0: /* Nothing to do -- report_id is already set correctly */
85 		break;
86 
87 	case HID_REPORT_ID_FIRST:
88 		if (list_empty(&report_enum->report_list))
89 			return NULL;
90 
91 		list = report_enum->report_list.next;
92 		report = list_entry(list, struct hid_report, list);
93 		rinfo->report_id = report->id;
94 		break;
95 
96 	case HID_REPORT_ID_NEXT:
97 		report = report_enum->report_id_hash[rid];
98 		if (!report)
99 			return NULL;
100 
101 		list = report->list.next;
102 		if (list == &report_enum->report_list)
103 			return NULL;
104 
105 		report = list_entry(list, struct hid_report, list);
106 		rinfo->report_id = report->id;
107 		break;
108 
109 	default:
110 		return NULL;
111 	}
112 
113 	return report_enum->report_id_hash[rinfo->report_id];
114 }
115 
116 /*
117  * Perform an exhaustive search of the report table for a usage, given its
118  * type and usage id.
119  */
120 static struct hid_field *
121 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
122 {
123 	int i, j;
124 	struct hid_report *report;
125 	struct hid_report_enum *report_enum;
126 	struct hid_field *field;
127 
128 	if (uref->report_type < HID_REPORT_TYPE_MIN ||
129 	    uref->report_type > HID_REPORT_TYPE_MAX)
130 		return NULL;
131 
132 	report_enum = hid->report_enum +
133 		(uref->report_type - HID_REPORT_TYPE_MIN);
134 
135 	list_for_each_entry(report, &report_enum->report_list, list) {
136 		for (i = 0; i < report->maxfield; i++) {
137 			field = report->field[i];
138 			for (j = 0; j < field->maxusage; j++) {
139 				if (field->usage[j].hid == uref->usage_code) {
140 					uref->report_id = report->id;
141 					uref->field_index = i;
142 					uref->usage_index = j;
143 					return field;
144 				}
145 			}
146 		}
147 	}
148 
149 	return NULL;
150 }
151 
152 static void hiddev_send_event(struct hid_device *hid,
153 			      struct hiddev_usage_ref *uref)
154 {
155 	struct hiddev *hiddev = hid->hiddev;
156 	struct hiddev_list *list;
157 	unsigned long flags;
158 
159 	spin_lock_irqsave(&hiddev->list_lock, flags);
160 	list_for_each_entry(list, &hiddev->list, node) {
161 		if (uref->field_index != HID_FIELD_INDEX_NONE ||
162 		    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
163 			list->buffer[list->head] = *uref;
164 			list->head = (list->head + 1) &
165 				(HIDDEV_BUFFER_SIZE - 1);
166 			kill_fasync(&list->fasync, SIGIO, POLL_IN);
167 		}
168 	}
169 	spin_unlock_irqrestore(&hiddev->list_lock, flags);
170 
171 	wake_up_interruptible(&hiddev->wait);
172 }
173 
174 /*
175  * This is where hid.c calls into hiddev to pass an event that occurred over
176  * the interrupt pipe
177  */
178 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
179 		      struct hid_usage *usage, __s32 value)
180 {
181 	unsigned type = field->report_type;
182 	struct hiddev_usage_ref uref;
183 
184 	uref.report_type =
185 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
186 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
187 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
188 	uref.report_id = field->report->id;
189 	uref.field_index = field->index;
190 	uref.usage_index = (usage - field->usage);
191 	uref.usage_code = usage->hid;
192 	uref.value = value;
193 
194 	hiddev_send_event(hid, &uref);
195 }
196 EXPORT_SYMBOL_GPL(hiddev_hid_event);
197 
198 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
199 {
200 	unsigned type = report->type;
201 	struct hiddev_usage_ref uref;
202 
203 	memset(&uref, 0, sizeof(uref));
204 	uref.report_type =
205 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
206 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
207 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
208 	uref.report_id = report->id;
209 	uref.field_index = HID_FIELD_INDEX_NONE;
210 
211 	hiddev_send_event(hid, &uref);
212 }
213 
214 /*
215  * fasync file op
216  */
217 static int hiddev_fasync(int fd, struct file *file, int on)
218 {
219 	struct hiddev_list *list = file->private_data;
220 
221 	return fasync_helper(fd, file, on, &list->fasync);
222 }
223 
224 
225 /*
226  * release file op
227  */
228 static int hiddev_release(struct inode * inode, struct file * file)
229 {
230 	struct hiddev_list *list = file->private_data;
231 	unsigned long flags;
232 
233 	spin_lock_irqsave(&list->hiddev->list_lock, flags);
234 	list_del(&list->node);
235 	spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
236 
237 	mutex_lock(&list->hiddev->existancelock);
238 	if (!--list->hiddev->open) {
239 		if (list->hiddev->exist) {
240 			hid_hw_close(list->hiddev->hid);
241 			hid_hw_power(list->hiddev->hid, PM_HINT_NORMAL);
242 		} else {
243 			mutex_unlock(&list->hiddev->existancelock);
244 			kfree(list->hiddev);
245 			vfree(list);
246 			return 0;
247 		}
248 	}
249 
250 	mutex_unlock(&list->hiddev->existancelock);
251 	vfree(list);
252 
253 	return 0;
254 }
255 
256 /*
257  * open file op
258  */
259 static int hiddev_open(struct inode *inode, struct file *file)
260 {
261 	struct hiddev_list *list;
262 	struct usb_interface *intf;
263 	struct hid_device *hid;
264 	struct hiddev *hiddev;
265 	int res;
266 
267 	intf = usbhid_find_interface(iminor(inode));
268 	if (!intf)
269 		return -ENODEV;
270 	hid = usb_get_intfdata(intf);
271 	hiddev = hid->hiddev;
272 
273 	if (!(list = vzalloc(sizeof(struct hiddev_list))))
274 		return -ENOMEM;
275 	mutex_init(&list->thread_lock);
276 	list->hiddev = hiddev;
277 	file->private_data = list;
278 
279 	/*
280 	 * no need for locking because the USB major number
281 	 * is shared which usbcore guards against disconnect
282 	 */
283 	if (list->hiddev->exist) {
284 		if (!list->hiddev->open++) {
285 			res = hid_hw_open(hiddev->hid);
286 			if (res < 0)
287 				goto bail;
288 		}
289 	} else {
290 		res = -ENODEV;
291 		goto bail;
292 	}
293 
294 	spin_lock_irq(&list->hiddev->list_lock);
295 	list_add_tail(&list->node, &hiddev->list);
296 	spin_unlock_irq(&list->hiddev->list_lock);
297 
298 	mutex_lock(&hiddev->existancelock);
299 	if (!list->hiddev->open++)
300 		if (list->hiddev->exist) {
301 			struct hid_device *hid = hiddev->hid;
302 			res = hid_hw_power(hid, PM_HINT_FULLON);
303 			if (res < 0)
304 				goto bail_unlock;
305 			res = hid_hw_open(hid);
306 			if (res < 0)
307 				goto bail_normal_power;
308 		}
309 	mutex_unlock(&hiddev->existancelock);
310 	return 0;
311 bail_normal_power:
312 	hid_hw_power(hid, PM_HINT_NORMAL);
313 bail_unlock:
314 	mutex_unlock(&hiddev->existancelock);
315 bail:
316 	file->private_data = NULL;
317 	vfree(list);
318 	return res;
319 }
320 
321 /*
322  * "write" file op
323  */
324 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
325 {
326 	return -EINVAL;
327 }
328 
329 /*
330  * "read" file op
331  */
332 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
333 {
334 	DEFINE_WAIT(wait);
335 	struct hiddev_list *list = file->private_data;
336 	int event_size;
337 	int retval;
338 
339 	event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
340 		sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
341 
342 	if (count < event_size)
343 		return 0;
344 
345 	/* lock against other threads */
346 	retval = mutex_lock_interruptible(&list->thread_lock);
347 	if (retval)
348 		return -ERESTARTSYS;
349 
350 	while (retval == 0) {
351 		if (list->head == list->tail) {
352 			prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
353 
354 			while (list->head == list->tail) {
355 				if (signal_pending(current)) {
356 					retval = -ERESTARTSYS;
357 					break;
358 				}
359 				if (!list->hiddev->exist) {
360 					retval = -EIO;
361 					break;
362 				}
363 				if (file->f_flags & O_NONBLOCK) {
364 					retval = -EAGAIN;
365 					break;
366 				}
367 
368 				/* let O_NONBLOCK tasks run */
369 				mutex_unlock(&list->thread_lock);
370 				schedule();
371 				if (mutex_lock_interruptible(&list->thread_lock)) {
372 					finish_wait(&list->hiddev->wait, &wait);
373 					return -EINTR;
374 				}
375 				set_current_state(TASK_INTERRUPTIBLE);
376 			}
377 			finish_wait(&list->hiddev->wait, &wait);
378 
379 		}
380 
381 		if (retval) {
382 			mutex_unlock(&list->thread_lock);
383 			return retval;
384 		}
385 
386 
387 		while (list->head != list->tail &&
388 		       retval + event_size <= count) {
389 			if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
390 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
391 					struct hiddev_event event;
392 
393 					event.hid = list->buffer[list->tail].usage_code;
394 					event.value = list->buffer[list->tail].value;
395 					if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
396 						mutex_unlock(&list->thread_lock);
397 						return -EFAULT;
398 					}
399 					retval += sizeof(struct hiddev_event);
400 				}
401 			} else {
402 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
403 				    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
404 
405 					if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
406 						mutex_unlock(&list->thread_lock);
407 						return -EFAULT;
408 					}
409 					retval += sizeof(struct hiddev_usage_ref);
410 				}
411 			}
412 			list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
413 		}
414 
415 	}
416 	mutex_unlock(&list->thread_lock);
417 
418 	return retval;
419 }
420 
421 /*
422  * "poll" file op
423  * No kernel lock - fine
424  */
425 static __poll_t hiddev_poll(struct file *file, poll_table *wait)
426 {
427 	struct hiddev_list *list = file->private_data;
428 
429 	poll_wait(file, &list->hiddev->wait, wait);
430 	if (list->head != list->tail)
431 		return EPOLLIN | EPOLLRDNORM;
432 	if (!list->hiddev->exist)
433 		return EPOLLERR | EPOLLHUP;
434 	return 0;
435 }
436 
437 /*
438  * "ioctl" file op
439  */
440 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
441 {
442 	struct hid_device *hid = hiddev->hid;
443 	struct hiddev_report_info rinfo;
444 	struct hiddev_usage_ref_multi *uref_multi = NULL;
445 	struct hiddev_usage_ref *uref;
446 	struct hid_report *report;
447 	struct hid_field *field;
448 	int i;
449 
450 	uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
451 	if (!uref_multi)
452 		return -ENOMEM;
453 	uref = &uref_multi->uref;
454 	if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
455 		if (copy_from_user(uref_multi, user_arg,
456 				   sizeof(*uref_multi)))
457 			goto fault;
458 	} else {
459 		if (copy_from_user(uref, user_arg, sizeof(*uref)))
460 			goto fault;
461 	}
462 
463 	switch (cmd) {
464 	case HIDIOCGUCODE:
465 		rinfo.report_type = uref->report_type;
466 		rinfo.report_id = uref->report_id;
467 		if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
468 			goto inval;
469 
470 		if (uref->field_index >= report->maxfield)
471 			goto inval;
472 
473 		field = report->field[uref->field_index];
474 		if (uref->usage_index >= field->maxusage)
475 			goto inval;
476 
477 		uref->usage_code = field->usage[uref->usage_index].hid;
478 
479 		if (copy_to_user(user_arg, uref, sizeof(*uref)))
480 			goto fault;
481 
482 		goto goodreturn;
483 
484 	default:
485 		if (cmd != HIDIOCGUSAGE &&
486 		    cmd != HIDIOCGUSAGES &&
487 		    uref->report_type == HID_REPORT_TYPE_INPUT)
488 			goto inval;
489 
490 		if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
491 			field = hiddev_lookup_usage(hid, uref);
492 			if (field == NULL)
493 				goto inval;
494 		} else {
495 			rinfo.report_type = uref->report_type;
496 			rinfo.report_id = uref->report_id;
497 			if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
498 				goto inval;
499 
500 			if (uref->field_index >= report->maxfield)
501 				goto inval;
502 
503 			field = report->field[uref->field_index];
504 
505 			if (cmd == HIDIOCGCOLLECTIONINDEX) {
506 				if (uref->usage_index >= field->maxusage)
507 					goto inval;
508 			} else if (uref->usage_index >= field->report_count)
509 				goto inval;
510 		}
511 
512 		if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
513 		    (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
514 		     uref->usage_index + uref_multi->num_values > field->report_count))
515 			goto inval;
516 
517 		switch (cmd) {
518 		case HIDIOCGUSAGE:
519 			uref->value = field->value[uref->usage_index];
520 			if (copy_to_user(user_arg, uref, sizeof(*uref)))
521 				goto fault;
522 			goto goodreturn;
523 
524 		case HIDIOCSUSAGE:
525 			field->value[uref->usage_index] = uref->value;
526 			goto goodreturn;
527 
528 		case HIDIOCGCOLLECTIONINDEX:
529 			i = field->usage[uref->usage_index].collection_index;
530 			kfree(uref_multi);
531 			return i;
532 		case HIDIOCGUSAGES:
533 			for (i = 0; i < uref_multi->num_values; i++)
534 				uref_multi->values[i] =
535 				    field->value[uref->usage_index + i];
536 			if (copy_to_user(user_arg, uref_multi,
537 					 sizeof(*uref_multi)))
538 				goto fault;
539 			goto goodreturn;
540 		case HIDIOCSUSAGES:
541 			for (i = 0; i < uref_multi->num_values; i++)
542 				field->value[uref->usage_index + i] =
543 				    uref_multi->values[i];
544 			goto goodreturn;
545 		}
546 
547 goodreturn:
548 		kfree(uref_multi);
549 		return 0;
550 fault:
551 		kfree(uref_multi);
552 		return -EFAULT;
553 inval:
554 		kfree(uref_multi);
555 		return -EINVAL;
556 	}
557 }
558 
559 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
560 {
561 	struct hid_device *hid = hiddev->hid;
562 	struct usb_device *dev = hid_to_usb_dev(hid);
563 	int idx, len;
564 	char *buf;
565 
566 	if (get_user(idx, (int __user *)user_arg))
567 		return -EFAULT;
568 
569 	if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
570 		return -ENOMEM;
571 
572 	if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
573 		kfree(buf);
574 		return -EINVAL;
575 	}
576 
577 	if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
578 		kfree(buf);
579 		return -EFAULT;
580 	}
581 
582 	kfree(buf);
583 
584 	return len;
585 }
586 
587 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
588 {
589 	struct hiddev_list *list = file->private_data;
590 	struct hiddev *hiddev = list->hiddev;
591 	struct hid_device *hid;
592 	struct hiddev_collection_info cinfo;
593 	struct hiddev_report_info rinfo;
594 	struct hiddev_field_info finfo;
595 	struct hiddev_devinfo dinfo;
596 	struct hid_report *report;
597 	struct hid_field *field;
598 	void __user *user_arg = (void __user *)arg;
599 	int i, r = -EINVAL;
600 
601 	/* Called without BKL by compat methods so no BKL taken */
602 
603 	mutex_lock(&hiddev->existancelock);
604 	if (!hiddev->exist) {
605 		r = -ENODEV;
606 		goto ret_unlock;
607 	}
608 
609 	hid = hiddev->hid;
610 
611 	switch (cmd) {
612 
613 	case HIDIOCGVERSION:
614 		r = put_user(HID_VERSION, (int __user *)arg) ?
615 			-EFAULT : 0;
616 		break;
617 
618 	case HIDIOCAPPLICATION:
619 		if (arg >= hid->maxapplication)
620 			break;
621 
622 		for (i = 0; i < hid->maxcollection; i++)
623 			if (hid->collection[i].type ==
624 			    HID_COLLECTION_APPLICATION && arg-- == 0)
625 				break;
626 
627 		if (i < hid->maxcollection)
628 			r = hid->collection[i].usage;
629 		break;
630 
631 	case HIDIOCGDEVINFO:
632 		{
633 			struct usb_device *dev = hid_to_usb_dev(hid);
634 			struct usbhid_device *usbhid = hid->driver_data;
635 
636 			memset(&dinfo, 0, sizeof(dinfo));
637 
638 			dinfo.bustype = BUS_USB;
639 			dinfo.busnum = dev->bus->busnum;
640 			dinfo.devnum = dev->devnum;
641 			dinfo.ifnum = usbhid->ifnum;
642 			dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
643 			dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
644 			dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
645 			dinfo.num_applications = hid->maxapplication;
646 
647 			r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
648 				-EFAULT : 0;
649 			break;
650 		}
651 
652 	case HIDIOCGFLAG:
653 		r = put_user(list->flags, (int __user *)arg) ?
654 			-EFAULT : 0;
655 		break;
656 
657 	case HIDIOCSFLAG:
658 		{
659 			int newflags;
660 
661 			if (get_user(newflags, (int __user *)arg)) {
662 				r = -EFAULT;
663 				break;
664 			}
665 
666 			if ((newflags & ~HIDDEV_FLAGS) != 0 ||
667 			    ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
668 			     (newflags & HIDDEV_FLAG_UREF) == 0))
669 				break;
670 
671 			list->flags = newflags;
672 
673 			r = 0;
674 			break;
675 		}
676 
677 	case HIDIOCGSTRING:
678 		r = hiddev_ioctl_string(hiddev, cmd, user_arg);
679 		break;
680 
681 	case HIDIOCINITREPORT:
682 		usbhid_init_reports(hid);
683 		hiddev->initialized = true;
684 		r = 0;
685 		break;
686 
687 	case HIDIOCGREPORT:
688 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
689 			r = -EFAULT;
690 			break;
691 		}
692 
693 		if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
694 			break;
695 
696 		report = hiddev_lookup_report(hid, &rinfo);
697 		if (report == NULL)
698 			break;
699 
700 		hid_hw_request(hid, report, HID_REQ_GET_REPORT);
701 		hid_hw_wait(hid);
702 
703 		r = 0;
704 		break;
705 
706 	case HIDIOCSREPORT:
707 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
708 			r = -EFAULT;
709 			break;
710 		}
711 
712 		if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
713 			break;
714 
715 		report = hiddev_lookup_report(hid, &rinfo);
716 		if (report == NULL)
717 			break;
718 
719 		hid_hw_request(hid, report, HID_REQ_SET_REPORT);
720 		hid_hw_wait(hid);
721 
722 		r = 0;
723 		break;
724 
725 	case HIDIOCGREPORTINFO:
726 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
727 			r = -EFAULT;
728 			break;
729 		}
730 
731 		report = hiddev_lookup_report(hid, &rinfo);
732 		if (report == NULL)
733 			break;
734 
735 		rinfo.num_fields = report->maxfield;
736 
737 		r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
738 			-EFAULT : 0;
739 		break;
740 
741 	case HIDIOCGFIELDINFO:
742 		if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
743 			r = -EFAULT;
744 			break;
745 		}
746 
747 		rinfo.report_type = finfo.report_type;
748 		rinfo.report_id = finfo.report_id;
749 
750 		report = hiddev_lookup_report(hid, &rinfo);
751 		if (report == NULL)
752 			break;
753 
754 		if (finfo.field_index >= report->maxfield)
755 			break;
756 
757 		field = report->field[finfo.field_index];
758 		memset(&finfo, 0, sizeof(finfo));
759 		finfo.report_type = rinfo.report_type;
760 		finfo.report_id = rinfo.report_id;
761 		finfo.field_index = field->report_count - 1;
762 		finfo.maxusage = field->maxusage;
763 		finfo.flags = field->flags;
764 		finfo.physical = field->physical;
765 		finfo.logical = field->logical;
766 		finfo.application = field->application;
767 		finfo.logical_minimum = field->logical_minimum;
768 		finfo.logical_maximum = field->logical_maximum;
769 		finfo.physical_minimum = field->physical_minimum;
770 		finfo.physical_maximum = field->physical_maximum;
771 		finfo.unit_exponent = field->unit_exponent;
772 		finfo.unit = field->unit;
773 
774 		r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
775 			-EFAULT : 0;
776 		break;
777 
778 	case HIDIOCGUCODE:
779 		/* fall through */
780 	case HIDIOCGUSAGE:
781 	case HIDIOCSUSAGE:
782 	case HIDIOCGUSAGES:
783 	case HIDIOCSUSAGES:
784 	case HIDIOCGCOLLECTIONINDEX:
785 		if (!hiddev->initialized) {
786 			usbhid_init_reports(hid);
787 			hiddev->initialized = true;
788 		}
789 		r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
790 		break;
791 
792 	case HIDIOCGCOLLECTIONINFO:
793 		if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
794 			r = -EFAULT;
795 			break;
796 		}
797 
798 		if (cinfo.index >= hid->maxcollection)
799 			break;
800 
801 		cinfo.type = hid->collection[cinfo.index].type;
802 		cinfo.usage = hid->collection[cinfo.index].usage;
803 		cinfo.level = hid->collection[cinfo.index].level;
804 
805 		r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
806 			-EFAULT : 0;
807 		break;
808 
809 	default:
810 		if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
811 			break;
812 
813 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
814 			int len = strlen(hid->name) + 1;
815 			if (len > _IOC_SIZE(cmd))
816 				 len = _IOC_SIZE(cmd);
817 			r = copy_to_user(user_arg, hid->name, len) ?
818 				-EFAULT : len;
819 			break;
820 		}
821 
822 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
823 			int len = strlen(hid->phys) + 1;
824 			if (len > _IOC_SIZE(cmd))
825 				len = _IOC_SIZE(cmd);
826 			r = copy_to_user(user_arg, hid->phys, len) ?
827 				-EFAULT : len;
828 			break;
829 		}
830 	}
831 
832 ret_unlock:
833 	mutex_unlock(&hiddev->existancelock);
834 	return r;
835 }
836 
837 #ifdef CONFIG_COMPAT
838 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
839 {
840 	return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
841 }
842 #endif
843 
844 static const struct file_operations hiddev_fops = {
845 	.owner =	THIS_MODULE,
846 	.read =		hiddev_read,
847 	.write =	hiddev_write,
848 	.poll =		hiddev_poll,
849 	.open =		hiddev_open,
850 	.release =	hiddev_release,
851 	.unlocked_ioctl =	hiddev_ioctl,
852 	.fasync =	hiddev_fasync,
853 #ifdef CONFIG_COMPAT
854 	.compat_ioctl	= hiddev_compat_ioctl,
855 #endif
856 	.llseek		= noop_llseek,
857 };
858 
859 static char *hiddev_devnode(struct device *dev, umode_t *mode)
860 {
861 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
862 }
863 
864 static struct usb_class_driver hiddev_class = {
865 	.name =		"hiddev%d",
866 	.devnode =	hiddev_devnode,
867 	.fops =		&hiddev_fops,
868 	.minor_base =	HIDDEV_MINOR_BASE,
869 };
870 
871 /*
872  * This is where hid.c calls us to connect a hid device to the hiddev driver
873  */
874 int hiddev_connect(struct hid_device *hid, unsigned int force)
875 {
876 	struct hiddev *hiddev;
877 	struct usbhid_device *usbhid = hid->driver_data;
878 	int retval;
879 
880 	if (!force) {
881 		unsigned int i;
882 		for (i = 0; i < hid->maxcollection; i++)
883 			if (hid->collection[i].type ==
884 			    HID_COLLECTION_APPLICATION &&
885 			    !IS_INPUT_APPLICATION(hid->collection[i].usage))
886 				break;
887 
888 		if (i == hid->maxcollection)
889 			return -1;
890 	}
891 
892 	if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
893 		return -1;
894 
895 	init_waitqueue_head(&hiddev->wait);
896 	INIT_LIST_HEAD(&hiddev->list);
897 	spin_lock_init(&hiddev->list_lock);
898 	mutex_init(&hiddev->existancelock);
899 	hid->hiddev = hiddev;
900 	hiddev->hid = hid;
901 	hiddev->exist = 1;
902 	retval = usb_register_dev(usbhid->intf, &hiddev_class);
903 	if (retval) {
904 		hid_err(hid, "Not able to get a minor for this device\n");
905 		hid->hiddev = NULL;
906 		kfree(hiddev);
907 		return -1;
908 	}
909 
910 	/*
911 	 * If HID_QUIRK_NO_INIT_REPORTS is set, make sure we don't initialize
912 	 * the reports.
913 	 */
914 	hiddev->initialized = hid->quirks & HID_QUIRK_NO_INIT_REPORTS;
915 
916 	hiddev->minor = usbhid->intf->minor;
917 
918 	return 0;
919 }
920 
921 /*
922  * This is where hid.c calls us to disconnect a hiddev device from the
923  * corresponding hid device (usually because the usb device has disconnected)
924  */
925 static struct usb_class_driver hiddev_class;
926 void hiddev_disconnect(struct hid_device *hid)
927 {
928 	struct hiddev *hiddev = hid->hiddev;
929 	struct usbhid_device *usbhid = hid->driver_data;
930 
931 	usb_deregister_dev(usbhid->intf, &hiddev_class);
932 
933 	mutex_lock(&hiddev->existancelock);
934 	hiddev->exist = 0;
935 
936 	if (hiddev->open) {
937 		mutex_unlock(&hiddev->existancelock);
938 		hid_hw_close(hiddev->hid);
939 		wake_up_interruptible(&hiddev->wait);
940 	} else {
941 		mutex_unlock(&hiddev->existancelock);
942 		kfree(hiddev);
943 	}
944 }
945