xref: /openbmc/linux/drivers/hid/usbhid/hiddev.c (revision 63dc02bd)
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 			mutex_unlock(&list->hiddev->existancelock);
252 			kfree(list->hiddev);
253 			kfree(list);
254 			return 0;
255 		}
256 	}
257 
258 	mutex_unlock(&list->hiddev->existancelock);
259 	kfree(list);
260 
261 	return 0;
262 }
263 
264 /*
265  * open file op
266  */
267 static int hiddev_open(struct inode *inode, struct file *file)
268 {
269 	struct hiddev_list *list;
270 	struct usb_interface *intf;
271 	struct hid_device *hid;
272 	struct hiddev *hiddev;
273 	int res;
274 
275 	intf = usbhid_find_interface(iminor(inode));
276 	if (!intf)
277 		return -ENODEV;
278 	hid = usb_get_intfdata(intf);
279 	hiddev = hid->hiddev;
280 
281 	if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
282 		return -ENOMEM;
283 	mutex_init(&list->thread_lock);
284 	list->hiddev = hiddev;
285 	file->private_data = list;
286 
287 	/*
288 	 * no need for locking because the USB major number
289 	 * is shared which usbcore guards against disconnect
290 	 */
291 	if (list->hiddev->exist) {
292 		if (!list->hiddev->open++) {
293 			res = usbhid_open(hiddev->hid);
294 			if (res < 0) {
295 				res = -EIO;
296 				goto bail;
297 			}
298 		}
299 	} else {
300 		res = -ENODEV;
301 		goto bail;
302 	}
303 
304 	spin_lock_irq(&list->hiddev->list_lock);
305 	list_add_tail(&list->node, &hiddev->list);
306 	spin_unlock_irq(&list->hiddev->list_lock);
307 
308 	mutex_lock(&hiddev->existancelock);
309 	if (!list->hiddev->open++)
310 		if (list->hiddev->exist) {
311 			struct hid_device *hid = hiddev->hid;
312 			res = usbhid_get_power(hid);
313 			if (res < 0) {
314 				res = -EIO;
315 				goto bail_unlock;
316 			}
317 			usbhid_open(hid);
318 		}
319 	mutex_unlock(&hiddev->existancelock);
320 	return 0;
321 bail_unlock:
322 	mutex_unlock(&hiddev->existancelock);
323 bail:
324 	file->private_data = NULL;
325 	kfree(list);
326 	return res;
327 }
328 
329 /*
330  * "write" file op
331  */
332 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
333 {
334 	return -EINVAL;
335 }
336 
337 /*
338  * "read" file op
339  */
340 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
341 {
342 	DEFINE_WAIT(wait);
343 	struct hiddev_list *list = file->private_data;
344 	int event_size;
345 	int retval;
346 
347 	event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
348 		sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
349 
350 	if (count < event_size)
351 		return 0;
352 
353 	/* lock against other threads */
354 	retval = mutex_lock_interruptible(&list->thread_lock);
355 	if (retval)
356 		return -ERESTARTSYS;
357 
358 	while (retval == 0) {
359 		if (list->head == list->tail) {
360 			prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
361 
362 			while (list->head == list->tail) {
363 				if (file->f_flags & O_NONBLOCK) {
364 					retval = -EAGAIN;
365 					break;
366 				}
367 				if (signal_pending(current)) {
368 					retval = -ERESTARTSYS;
369 					break;
370 				}
371 				if (!list->hiddev->exist) {
372 					retval = -EIO;
373 					break;
374 				}
375 
376 				/* let O_NONBLOCK tasks run */
377 				mutex_unlock(&list->thread_lock);
378 				schedule();
379 				if (mutex_lock_interruptible(&list->thread_lock)) {
380 					finish_wait(&list->hiddev->wait, &wait);
381 					return -EINTR;
382 				}
383 				set_current_state(TASK_INTERRUPTIBLE);
384 			}
385 			finish_wait(&list->hiddev->wait, &wait);
386 
387 		}
388 
389 		if (retval) {
390 			mutex_unlock(&list->thread_lock);
391 			return retval;
392 		}
393 
394 
395 		while (list->head != list->tail &&
396 		       retval + event_size <= count) {
397 			if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
398 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
399 					struct hiddev_event event;
400 
401 					event.hid = list->buffer[list->tail].usage_code;
402 					event.value = list->buffer[list->tail].value;
403 					if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
404 						mutex_unlock(&list->thread_lock);
405 						return -EFAULT;
406 					}
407 					retval += sizeof(struct hiddev_event);
408 				}
409 			} else {
410 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
411 				    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
412 
413 					if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
414 						mutex_unlock(&list->thread_lock);
415 						return -EFAULT;
416 					}
417 					retval += sizeof(struct hiddev_usage_ref);
418 				}
419 			}
420 			list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
421 		}
422 
423 	}
424 	mutex_unlock(&list->thread_lock);
425 
426 	return retval;
427 }
428 
429 /*
430  * "poll" file op
431  * No kernel lock - fine
432  */
433 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
434 {
435 	struct hiddev_list *list = file->private_data;
436 
437 	poll_wait(file, &list->hiddev->wait, wait);
438 	if (list->head != list->tail)
439 		return POLLIN | POLLRDNORM;
440 	if (!list->hiddev->exist)
441 		return POLLERR | POLLHUP;
442 	return 0;
443 }
444 
445 /*
446  * "ioctl" file op
447  */
448 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
449 {
450 	struct hid_device *hid = hiddev->hid;
451 	struct hiddev_report_info rinfo;
452 	struct hiddev_usage_ref_multi *uref_multi = NULL;
453 	struct hiddev_usage_ref *uref;
454 	struct hid_report *report;
455 	struct hid_field *field;
456 	int i;
457 
458 	uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
459 	if (!uref_multi)
460 		return -ENOMEM;
461 	uref = &uref_multi->uref;
462 	if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
463 		if (copy_from_user(uref_multi, user_arg,
464 				   sizeof(*uref_multi)))
465 			goto fault;
466 	} else {
467 		if (copy_from_user(uref, user_arg, sizeof(*uref)))
468 			goto fault;
469 	}
470 
471 	switch (cmd) {
472 	case HIDIOCGUCODE:
473 		rinfo.report_type = uref->report_type;
474 		rinfo.report_id = uref->report_id;
475 		if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
476 			goto inval;
477 
478 		if (uref->field_index >= report->maxfield)
479 			goto inval;
480 
481 		field = report->field[uref->field_index];
482 		if (uref->usage_index >= field->maxusage)
483 			goto inval;
484 
485 		uref->usage_code = field->usage[uref->usage_index].hid;
486 
487 		if (copy_to_user(user_arg, uref, sizeof(*uref)))
488 			goto fault;
489 
490 		goto goodreturn;
491 
492 	default:
493 		if (cmd != HIDIOCGUSAGE &&
494 		    cmd != HIDIOCGUSAGES &&
495 		    uref->report_type == HID_REPORT_TYPE_INPUT)
496 			goto inval;
497 
498 		if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
499 			field = hiddev_lookup_usage(hid, uref);
500 			if (field == NULL)
501 				goto inval;
502 		} else {
503 			rinfo.report_type = uref->report_type;
504 			rinfo.report_id = uref->report_id;
505 			if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
506 				goto inval;
507 
508 			if (uref->field_index >= report->maxfield)
509 				goto inval;
510 
511 			field = report->field[uref->field_index];
512 
513 			if (cmd == HIDIOCGCOLLECTIONINDEX) {
514 				if (uref->usage_index >= field->maxusage)
515 					goto inval;
516 			} else if (uref->usage_index >= field->report_count)
517 				goto inval;
518 
519 			else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
520 				 (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
521 				  uref->usage_index + uref_multi->num_values > field->report_count))
522 				goto inval;
523 		}
524 
525 		switch (cmd) {
526 		case HIDIOCGUSAGE:
527 			uref->value = field->value[uref->usage_index];
528 			if (copy_to_user(user_arg, uref, sizeof(*uref)))
529 				goto fault;
530 			goto goodreturn;
531 
532 		case HIDIOCSUSAGE:
533 			field->value[uref->usage_index] = uref->value;
534 			goto goodreturn;
535 
536 		case HIDIOCGCOLLECTIONINDEX:
537 			i = field->usage[uref->usage_index].collection_index;
538 			kfree(uref_multi);
539 			return i;
540 		case HIDIOCGUSAGES:
541 			for (i = 0; i < uref_multi->num_values; i++)
542 				uref_multi->values[i] =
543 				    field->value[uref->usage_index + i];
544 			if (copy_to_user(user_arg, uref_multi,
545 					 sizeof(*uref_multi)))
546 				goto fault;
547 			goto goodreturn;
548 		case HIDIOCSUSAGES:
549 			for (i = 0; i < uref_multi->num_values; i++)
550 				field->value[uref->usage_index + i] =
551 				    uref_multi->values[i];
552 			goto goodreturn;
553 		}
554 
555 goodreturn:
556 		kfree(uref_multi);
557 		return 0;
558 fault:
559 		kfree(uref_multi);
560 		return -EFAULT;
561 inval:
562 		kfree(uref_multi);
563 		return -EINVAL;
564 	}
565 }
566 
567 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
568 {
569 	struct hid_device *hid = hiddev->hid;
570 	struct usb_device *dev = hid_to_usb_dev(hid);
571 	int idx, len;
572 	char *buf;
573 
574 	if (get_user(idx, (int __user *)user_arg))
575 		return -EFAULT;
576 
577 	if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
578 		return -ENOMEM;
579 
580 	if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
581 		kfree(buf);
582 		return -EINVAL;
583 	}
584 
585 	if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
586 		kfree(buf);
587 		return -EFAULT;
588 	}
589 
590 	kfree(buf);
591 
592 	return len;
593 }
594 
595 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
596 {
597 	struct hiddev_list *list = file->private_data;
598 	struct hiddev *hiddev = list->hiddev;
599 	struct hid_device *hid;
600 	struct hiddev_collection_info cinfo;
601 	struct hiddev_report_info rinfo;
602 	struct hiddev_field_info finfo;
603 	struct hiddev_devinfo dinfo;
604 	struct hid_report *report;
605 	struct hid_field *field;
606 	void __user *user_arg = (void __user *)arg;
607 	int i, r = -EINVAL;
608 
609 	/* Called without BKL by compat methods so no BKL taken */
610 
611 	mutex_lock(&hiddev->existancelock);
612 	if (!hiddev->exist) {
613 		r = -ENODEV;
614 		goto ret_unlock;
615 	}
616 
617 	hid = hiddev->hid;
618 
619 	switch (cmd) {
620 
621 	case HIDIOCGVERSION:
622 		r = put_user(HID_VERSION, (int __user *)arg) ?
623 			-EFAULT : 0;
624 		break;
625 
626 	case HIDIOCAPPLICATION:
627 		if (arg < 0 || arg >= hid->maxapplication)
628 			break;
629 
630 		for (i = 0; i < hid->maxcollection; i++)
631 			if (hid->collection[i].type ==
632 			    HID_COLLECTION_APPLICATION && arg-- == 0)
633 				break;
634 
635 		if (i < hid->maxcollection)
636 			r = hid->collection[i].usage;
637 		break;
638 
639 	case HIDIOCGDEVINFO:
640 		{
641 			struct usb_device *dev = hid_to_usb_dev(hid);
642 			struct usbhid_device *usbhid = hid->driver_data;
643 
644 			memset(&dinfo, 0, sizeof(dinfo));
645 
646 			dinfo.bustype = BUS_USB;
647 			dinfo.busnum = dev->bus->busnum;
648 			dinfo.devnum = dev->devnum;
649 			dinfo.ifnum = usbhid->ifnum;
650 			dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
651 			dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
652 			dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
653 			dinfo.num_applications = hid->maxapplication;
654 
655 			r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
656 				-EFAULT : 0;
657 			break;
658 		}
659 
660 	case HIDIOCGFLAG:
661 		r = put_user(list->flags, (int __user *)arg) ?
662 			-EFAULT : 0;
663 		break;
664 
665 	case HIDIOCSFLAG:
666 		{
667 			int newflags;
668 
669 			if (get_user(newflags, (int __user *)arg)) {
670 				r = -EFAULT;
671 				break;
672 			}
673 
674 			if ((newflags & ~HIDDEV_FLAGS) != 0 ||
675 			    ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
676 			     (newflags & HIDDEV_FLAG_UREF) == 0))
677 				break;
678 
679 			list->flags = newflags;
680 
681 			r = 0;
682 			break;
683 		}
684 
685 	case HIDIOCGSTRING:
686 		r = hiddev_ioctl_string(hiddev, cmd, user_arg);
687 		break;
688 
689 	case HIDIOCINITREPORT:
690 		usbhid_init_reports(hid);
691 		r = 0;
692 		break;
693 
694 	case HIDIOCGREPORT:
695 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
696 			r = -EFAULT;
697 			break;
698 		}
699 
700 		if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
701 			break;
702 
703 		report = hiddev_lookup_report(hid, &rinfo);
704 		if (report == NULL)
705 			break;
706 
707 		usbhid_submit_report(hid, report, USB_DIR_IN);
708 		usbhid_wait_io(hid);
709 
710 		r = 0;
711 		break;
712 
713 	case HIDIOCSREPORT:
714 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
715 			r = -EFAULT;
716 			break;
717 		}
718 
719 		if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
720 			break;
721 
722 		report = hiddev_lookup_report(hid, &rinfo);
723 		if (report == NULL)
724 			break;
725 
726 		usbhid_submit_report(hid, report, USB_DIR_OUT);
727 		usbhid_wait_io(hid);
728 
729 		r = 0;
730 		break;
731 
732 	case HIDIOCGREPORTINFO:
733 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
734 			r = -EFAULT;
735 			break;
736 		}
737 
738 		report = hiddev_lookup_report(hid, &rinfo);
739 		if (report == NULL)
740 			break;
741 
742 		rinfo.num_fields = report->maxfield;
743 
744 		r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
745 			-EFAULT : 0;
746 		break;
747 
748 	case HIDIOCGFIELDINFO:
749 		if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
750 			r = -EFAULT;
751 			break;
752 		}
753 
754 		rinfo.report_type = finfo.report_type;
755 		rinfo.report_id = finfo.report_id;
756 
757 		report = hiddev_lookup_report(hid, &rinfo);
758 		if (report == NULL)
759 			break;
760 
761 		if (finfo.field_index >= report->maxfield)
762 			break;
763 
764 		field = report->field[finfo.field_index];
765 		memset(&finfo, 0, sizeof(finfo));
766 		finfo.report_type = rinfo.report_type;
767 		finfo.report_id = rinfo.report_id;
768 		finfo.field_index = field->report_count - 1;
769 		finfo.maxusage = field->maxusage;
770 		finfo.flags = field->flags;
771 		finfo.physical = field->physical;
772 		finfo.logical = field->logical;
773 		finfo.application = field->application;
774 		finfo.logical_minimum = field->logical_minimum;
775 		finfo.logical_maximum = field->logical_maximum;
776 		finfo.physical_minimum = field->physical_minimum;
777 		finfo.physical_maximum = field->physical_maximum;
778 		finfo.unit_exponent = field->unit_exponent;
779 		finfo.unit = field->unit;
780 
781 		r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
782 			-EFAULT : 0;
783 		break;
784 
785 	case HIDIOCGUCODE:
786 		/* fall through */
787 	case HIDIOCGUSAGE:
788 	case HIDIOCSUSAGE:
789 	case HIDIOCGUSAGES:
790 	case HIDIOCSUSAGES:
791 	case HIDIOCGCOLLECTIONINDEX:
792 		r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
793 		break;
794 
795 	case HIDIOCGCOLLECTIONINFO:
796 		if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
797 			r = -EFAULT;
798 			break;
799 		}
800 
801 		if (cinfo.index >= hid->maxcollection)
802 			break;
803 
804 		cinfo.type = hid->collection[cinfo.index].type;
805 		cinfo.usage = hid->collection[cinfo.index].usage;
806 		cinfo.level = hid->collection[cinfo.index].level;
807 
808 		r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
809 			-EFAULT : 0;
810 		break;
811 
812 	default:
813 		if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
814 			break;
815 
816 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
817 			int len = strlen(hid->name) + 1;
818 			if (len > _IOC_SIZE(cmd))
819 				 len = _IOC_SIZE(cmd);
820 			r = copy_to_user(user_arg, hid->name, len) ?
821 				-EFAULT : len;
822 			break;
823 		}
824 
825 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
826 			int len = strlen(hid->phys) + 1;
827 			if (len > _IOC_SIZE(cmd))
828 				len = _IOC_SIZE(cmd);
829 			r = copy_to_user(user_arg, hid->phys, len) ?
830 				-EFAULT : len;
831 			break;
832 		}
833 	}
834 
835 ret_unlock:
836 	mutex_unlock(&hiddev->existancelock);
837 	return r;
838 }
839 
840 #ifdef CONFIG_COMPAT
841 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
842 {
843 	return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
844 }
845 #endif
846 
847 static const struct file_operations hiddev_fops = {
848 	.owner =	THIS_MODULE,
849 	.read =		hiddev_read,
850 	.write =	hiddev_write,
851 	.poll =		hiddev_poll,
852 	.open =		hiddev_open,
853 	.release =	hiddev_release,
854 	.unlocked_ioctl =	hiddev_ioctl,
855 	.fasync =	hiddev_fasync,
856 #ifdef CONFIG_COMPAT
857 	.compat_ioctl	= hiddev_compat_ioctl,
858 #endif
859 	.llseek		= noop_llseek,
860 };
861 
862 static char *hiddev_devnode(struct device *dev, umode_t *mode)
863 {
864 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
865 }
866 
867 static struct usb_class_driver hiddev_class = {
868 	.name =		"hiddev%d",
869 	.devnode =	hiddev_devnode,
870 	.fops =		&hiddev_fops,
871 	.minor_base =	HIDDEV_MINOR_BASE,
872 };
873 
874 /*
875  * This is where hid.c calls us to connect a hid device to the hiddev driver
876  */
877 int hiddev_connect(struct hid_device *hid, unsigned int force)
878 {
879 	struct hiddev *hiddev;
880 	struct usbhid_device *usbhid = hid->driver_data;
881 	int retval;
882 
883 	if (!force) {
884 		unsigned int i;
885 		for (i = 0; i < hid->maxcollection; i++)
886 			if (hid->collection[i].type ==
887 			    HID_COLLECTION_APPLICATION &&
888 			    !IS_INPUT_APPLICATION(hid->collection[i].usage))
889 				break;
890 
891 		if (i == hid->maxcollection)
892 			return -1;
893 	}
894 
895 	if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
896 		return -1;
897 
898 	init_waitqueue_head(&hiddev->wait);
899 	INIT_LIST_HEAD(&hiddev->list);
900 	spin_lock_init(&hiddev->list_lock);
901 	mutex_init(&hiddev->existancelock);
902 	hid->hiddev = hiddev;
903 	hiddev->hid = hid;
904 	hiddev->exist = 1;
905 	retval = usb_register_dev(usbhid->intf, &hiddev_class);
906 	if (retval) {
907 		hid_err(hid, "Not able to get a minor for this device\n");
908 		hid->hiddev = NULL;
909 		kfree(hiddev);
910 		return -1;
911 	}
912 	return 0;
913 }
914 
915 /*
916  * This is where hid.c calls us to disconnect a hiddev device from the
917  * corresponding hid device (usually because the usb device has disconnected)
918  */
919 static struct usb_class_driver hiddev_class;
920 void hiddev_disconnect(struct hid_device *hid)
921 {
922 	struct hiddev *hiddev = hid->hiddev;
923 	struct usbhid_device *usbhid = hid->driver_data;
924 
925 	usb_deregister_dev(usbhid->intf, &hiddev_class);
926 
927 	mutex_lock(&hiddev->existancelock);
928 	hiddev->exist = 0;
929 
930 	if (hiddev->open) {
931 		mutex_unlock(&hiddev->existancelock);
932 		usbhid_close(hiddev->hid);
933 		wake_up_interruptible(&hiddev->wait);
934 	} else {
935 		mutex_unlock(&hiddev->existancelock);
936 		kfree(hiddev);
937 	}
938 }
939