Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
[linux-2.6.git] / drivers / hid / usbhid / hiddev.c
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/smp_lock.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 "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      64
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 static struct hiddev *hiddev_table[HIDDEV_MINORS];
71
72 /*
73  * Find a report, given the report's type and ID.  The ID can be specified
74  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
75  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
76  * given type which follows old_id.
77  */
78 static struct hid_report *
79 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
80 {
81         unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
82         unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
83         struct hid_report_enum *report_enum;
84         struct hid_report *report;
85         struct list_head *list;
86
87         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
88             rinfo->report_type > HID_REPORT_TYPE_MAX)
89                 return NULL;
90
91         report_enum = hid->report_enum +
92                 (rinfo->report_type - HID_REPORT_TYPE_MIN);
93
94         switch (flags) {
95         case 0: /* Nothing to do -- report_id is already set correctly */
96                 break;
97
98         case HID_REPORT_ID_FIRST:
99                 if (list_empty(&report_enum->report_list))
100                         return NULL;
101
102                 list = report_enum->report_list.next;
103                 report = list_entry(list, struct hid_report, list);
104                 rinfo->report_id = report->id;
105                 break;
106
107         case HID_REPORT_ID_NEXT:
108                 report = report_enum->report_id_hash[rid];
109                 if (!report)
110                         return NULL;
111
112                 list = report->list.next;
113                 if (list == &report_enum->report_list)
114                         return NULL;
115
116                 report = list_entry(list, struct hid_report, list);
117                 rinfo->report_id = report->id;
118                 break;
119
120         default:
121                 return NULL;
122         }
123
124         return report_enum->report_id_hash[rinfo->report_id];
125 }
126
127 /*
128  * Perform an exhaustive search of the report table for a usage, given its
129  * type and usage id.
130  */
131 static struct hid_field *
132 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
133 {
134         int i, j;
135         struct hid_report *report;
136         struct hid_report_enum *report_enum;
137         struct hid_field *field;
138
139         if (uref->report_type < HID_REPORT_TYPE_MIN ||
140             uref->report_type > HID_REPORT_TYPE_MAX)
141                 return NULL;
142
143         report_enum = hid->report_enum +
144                 (uref->report_type - HID_REPORT_TYPE_MIN);
145
146         list_for_each_entry(report, &report_enum->report_list, list) {
147                 for (i = 0; i < report->maxfield; i++) {
148                         field = report->field[i];
149                         for (j = 0; j < field->maxusage; j++) {
150                                 if (field->usage[j].hid == uref->usage_code) {
151                                         uref->report_id = report->id;
152                                         uref->field_index = i;
153                                         uref->usage_index = j;
154                                         return field;
155                                 }
156                         }
157                 }
158         }
159
160         return NULL;
161 }
162
163 static void hiddev_send_event(struct hid_device *hid,
164                               struct hiddev_usage_ref *uref)
165 {
166         struct hiddev *hiddev = hid->hiddev;
167         struct hiddev_list *list;
168         unsigned long flags;
169
170         spin_lock_irqsave(&hiddev->list_lock, flags);
171         list_for_each_entry(list, &hiddev->list, node) {
172                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
173                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
174                         list->buffer[list->head] = *uref;
175                         list->head = (list->head + 1) &
176                                 (HIDDEV_BUFFER_SIZE - 1);
177                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
178                 }
179         }
180         spin_unlock_irqrestore(&hiddev->list_lock, flags);
181
182         wake_up_interruptible(&hiddev->wait);
183 }
184
185 /*
186  * This is where hid.c calls into hiddev to pass an event that occurred over
187  * the interrupt pipe
188  */
189 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
190                       struct hid_usage *usage, __s32 value)
191 {
192         unsigned type = field->report_type;
193         struct hiddev_usage_ref uref;
194
195         uref.report_type =
196           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
197           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
198            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
199         uref.report_id = field->report->id;
200         uref.field_index = field->index;
201         uref.usage_index = (usage - field->usage);
202         uref.usage_code = usage->hid;
203         uref.value = value;
204
205         hiddev_send_event(hid, &uref);
206 }
207 EXPORT_SYMBOL_GPL(hiddev_hid_event);
208
209 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
210 {
211         unsigned type = report->type;
212         struct hiddev_usage_ref uref;
213
214         memset(&uref, 0, sizeof(uref));
215         uref.report_type =
216           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
217           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
218            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
219         uref.report_id = report->id;
220         uref.field_index = HID_FIELD_INDEX_NONE;
221
222         hiddev_send_event(hid, &uref);
223 }
224
225 /*
226  * fasync file op
227  */
228 static int hiddev_fasync(int fd, struct file *file, int on)
229 {
230         struct hiddev_list *list = file->private_data;
231
232         return fasync_helper(fd, file, on, &list->fasync);
233 }
234
235
236 /*
237  * release file op
238  */
239 static int hiddev_release(struct inode * inode, struct file * file)
240 {
241         struct hiddev_list *list = file->private_data;
242         unsigned long flags;
243
244         spin_lock_irqsave(&list->hiddev->list_lock, flags);
245         list_del(&list->node);
246         spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
247
248         if (!--list->hiddev->open) {
249                 if (list->hiddev->exist) {
250                         usbhid_close(list->hiddev->hid);
251                         usbhid_put_power(list->hiddev->hid);
252                 } else {
253                         kfree(list->hiddev);
254                 }
255         }
256
257         kfree(list);
258
259         return 0;
260 }
261
262 /*
263  * open file op
264  */
265 static int hiddev_open(struct inode *inode, struct file *file)
266 {
267         struct hiddev_list *list;
268         int res;
269
270         int i = iminor(inode) - HIDDEV_MINOR_BASE;
271
272         if (i >= HIDDEV_MINORS || i < 0 || !hiddev_table[i])
273                 return -ENODEV;
274
275         if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
276                 return -ENOMEM;
277         mutex_init(&list->thread_lock);
278
279         list->hiddev = hiddev_table[i];
280
281
282         file->private_data = list;
283
284         /*
285          * no need for locking because the USB major number
286          * is shared which usbcore guards against disconnect
287          */
288         if (list->hiddev->exist) {
289                 if (!list->hiddev->open++) {
290                         res = usbhid_open(hiddev_table[i]->hid);
291                         if (res < 0) {
292                                 res = -EIO;
293                                 goto bail;
294                         }
295                 }
296         } else {
297                 res = -ENODEV;
298                 goto bail;
299         }
300
301         spin_lock_irq(&list->hiddev->list_lock);
302         list_add_tail(&list->node, &hiddev_table[i]->list);
303         spin_unlock_irq(&list->hiddev->list_lock);
304
305         if (!list->hiddev->open++)
306                 if (list->hiddev->exist) {
307                         struct hid_device *hid = hiddev_table[i]->hid;
308                         res = usbhid_get_power(hid);
309                         if (res < 0) {
310                                 res = -EIO;
311                                 goto bail;
312                         }
313                         usbhid_open(hid);
314                 }
315
316         return 0;
317 bail:
318         file->private_data = NULL;
319         kfree(list);
320         return res;
321 }
322
323 /*
324  * "write" file op
325  */
326 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
327 {
328         return -EINVAL;
329 }
330
331 /*
332  * "read" file op
333  */
334 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
335 {
336         DEFINE_WAIT(wait);
337         struct hiddev_list *list = file->private_data;
338         int event_size;
339         int retval;
340
341         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
342                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
343
344         if (count < event_size)
345                 return 0;
346
347         /* lock against other threads */
348         retval = mutex_lock_interruptible(&list->thread_lock);
349         if (retval)
350                 return -ERESTARTSYS;
351
352         while (retval == 0) {
353                 if (list->head == list->tail) {
354                         prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
355
356                         while (list->head == list->tail) {
357                                 if (file->f_flags & O_NONBLOCK) {
358                                         retval = -EAGAIN;
359                                         break;
360                                 }
361                                 if (signal_pending(current)) {
362                                         retval = -ERESTARTSYS;
363                                         break;
364                                 }
365                                 if (!list->hiddev->exist) {
366                                         retval = -EIO;
367                                         break;
368                                 }
369
370                                 /* let O_NONBLOCK tasks run */
371                                 mutex_unlock(&list->thread_lock);
372                                 schedule();
373                                 if (mutex_lock_interruptible(&list->thread_lock))
374                                         return -EINTR;
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 unsigned int 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 POLLIN | POLLRDNORM;
432         if (!list->hiddev->exist)
433                 return POLLERR | POLLHUP;
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         lock_kernel();
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
474                 field = report->field[uref->field_index];
475                 if (uref->usage_index >= field->maxusage)
476                         goto inval;
477
478                 uref->usage_code = field->usage[uref->usage_index].hid;
479
480                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
481                         goto fault;
482
483                 goto goodreturn;
484
485         default:
486                 if (cmd != HIDIOCGUSAGE &&
487                     cmd != HIDIOCGUSAGES &&
488                     uref->report_type == HID_REPORT_TYPE_INPUT)
489                         goto inval;
490
491                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
492                         field = hiddev_lookup_usage(hid, uref);
493                         if (field == NULL)
494                                 goto inval;
495                 } else {
496                         rinfo.report_type = uref->report_type;
497                         rinfo.report_id = uref->report_id;
498                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
499                                 goto inval;
500
501                         if (uref->field_index >= report->maxfield)
502                                 goto inval;
503
504                         field = report->field[uref->field_index];
505
506                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
507                                 if (uref->usage_index >= field->maxusage)
508                                         goto inval;
509                         } else if (uref->usage_index >= field->report_count)
510                                 goto inval;
511
512                         else 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
518                 switch (cmd) {
519                 case HIDIOCGUSAGE:
520                         uref->value = field->value[uref->usage_index];
521                         if (copy_to_user(user_arg, uref, sizeof(*uref)))
522                                 goto fault;
523                         goto goodreturn;
524
525                 case HIDIOCSUSAGE:
526                         field->value[uref->usage_index] = uref->value;
527                         goto goodreturn;
528
529                 case HIDIOCGCOLLECTIONINDEX:
530                         i = field->usage[uref->usage_index].collection_index;
531                         unlock_kernel();
532                         kfree(uref_multi);
533                         return i;
534                 case HIDIOCGUSAGES:
535                         for (i = 0; i < uref_multi->num_values; i++)
536                                 uref_multi->values[i] =
537                                     field->value[uref->usage_index + i];
538                         if (copy_to_user(user_arg, uref_multi,
539                                          sizeof(*uref_multi)))
540                                 goto fault;
541                         goto goodreturn;
542                 case HIDIOCSUSAGES:
543                         for (i = 0; i < uref_multi->num_values; i++)
544                                 field->value[uref->usage_index + i] =
545                                     uref_multi->values[i];
546                         goto goodreturn;
547                 }
548
549 goodreturn:
550                 unlock_kernel();
551                 kfree(uref_multi);
552                 return 0;
553 fault:
554                 unlock_kernel();
555                 kfree(uref_multi);
556                 return -EFAULT;
557 inval:
558                 unlock_kernel();
559                 kfree(uref_multi);
560                 return -EINVAL;
561         }
562 }
563
564 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
565 {
566         struct hid_device *hid = hiddev->hid;
567         struct usb_device *dev = hid_to_usb_dev(hid);
568         int idx, len;
569         char *buf;
570
571         if (get_user(idx, (int __user *)user_arg))
572                 return -EFAULT;
573
574         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
575                 return -ENOMEM;
576
577         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
578                 kfree(buf);
579                 return -EINVAL;
580         }
581
582         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
583                 kfree(buf);
584                 return -EFAULT;
585         }
586
587         kfree(buf);
588
589         return len;
590 }
591
592 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
593 {
594         struct hiddev_list *list = file->private_data;
595         struct hiddev *hiddev = list->hiddev;
596         struct hid_device *hid = hiddev->hid;
597         struct usb_device *dev = hid_to_usb_dev(hid);
598         struct hiddev_collection_info cinfo;
599         struct hiddev_report_info rinfo;
600         struct hiddev_field_info finfo;
601         struct hiddev_devinfo dinfo;
602         struct hid_report *report;
603         struct hid_field *field;
604         struct usbhid_device *usbhid = hid->driver_data;
605         void __user *user_arg = (void __user *)arg;
606         int i, r;
607         
608         /* Called without BKL by compat methods so no BKL taken */
609
610         /* FIXME: Who or what stop this racing with a disconnect ?? */
611         if (!hiddev->exist)
612                 return -EIO;
613
614         switch (cmd) {
615
616         case HIDIOCGVERSION:
617                 return put_user(HID_VERSION, (int __user *)arg);
618
619         case HIDIOCAPPLICATION:
620                 if (arg < 0 || arg >= hid->maxapplication)
621                         return -EINVAL;
622
623                 for (i = 0; i < hid->maxcollection; i++)
624                         if (hid->collection[i].type ==
625                             HID_COLLECTION_APPLICATION && arg-- == 0)
626                                 break;
627
628                 if (i == hid->maxcollection)
629                         return -EINVAL;
630
631                 return hid->collection[i].usage;
632
633         case HIDIOCGDEVINFO:
634                 dinfo.bustype = BUS_USB;
635                 dinfo.busnum = dev->bus->busnum;
636                 dinfo.devnum = dev->devnum;
637                 dinfo.ifnum = usbhid->ifnum;
638                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
639                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
640                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
641                 dinfo.num_applications = hid->maxapplication;
642                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
643                         return -EFAULT;
644
645                 return 0;
646
647         case HIDIOCGFLAG:
648                 if (put_user(list->flags, (int __user *)arg))
649                         return -EFAULT;
650
651                 return 0;
652
653         case HIDIOCSFLAG:
654                 {
655                         int newflags;
656                         if (get_user(newflags, (int __user *)arg))
657                                 return -EFAULT;
658
659                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
660                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
661                              (newflags & HIDDEV_FLAG_UREF) == 0))
662                                 return -EINVAL;
663
664                         list->flags = newflags;
665
666                         return 0;
667                 }
668
669         case HIDIOCGSTRING:
670                 mutex_lock(&hiddev->existancelock);
671                 if (hiddev->exist)
672                         r = hiddev_ioctl_string(hiddev, cmd, user_arg);
673                 else
674                         r = -ENODEV;
675                 mutex_unlock(&hiddev->existancelock);
676                 return r;
677
678         case HIDIOCINITREPORT:
679                 mutex_lock(&hiddev->existancelock);
680                 if (!hiddev->exist) {
681                         mutex_unlock(&hiddev->existancelock);
682                         return -ENODEV;
683                 }
684                 usbhid_init_reports(hid);
685                 mutex_unlock(&hiddev->existancelock);
686
687                 return 0;
688
689         case HIDIOCGREPORT:
690                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
691                         return -EFAULT;
692
693                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
694                         return -EINVAL;
695
696                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
697                         return -EINVAL;
698
699                 mutex_lock(&hiddev->existancelock);
700                 if (hiddev->exist) {
701                         usbhid_submit_report(hid, report, USB_DIR_IN);
702                         usbhid_wait_io(hid);
703                 }
704                 mutex_unlock(&hiddev->existancelock);
705
706                 return 0;
707
708         case HIDIOCSREPORT:
709                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
710                         return -EFAULT;
711
712                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
713                         return -EINVAL;
714
715                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
716                         return -EINVAL;
717
718                 mutex_lock(&hiddev->existancelock);
719                 if (hiddev->exist) {
720                         usbhid_submit_report(hid, report, USB_DIR_OUT);
721                         usbhid_wait_io(hid);
722                 }
723                 mutex_unlock(&hiddev->existancelock);
724
725                 return 0;
726
727         case HIDIOCGREPORTINFO:
728                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
729                         return -EFAULT;
730
731                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
732                         return -EINVAL;
733
734                 rinfo.num_fields = report->maxfield;
735
736                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
737                         return -EFAULT;
738
739                 return 0;
740
741         case HIDIOCGFIELDINFO:
742                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
743                         return -EFAULT;
744                 rinfo.report_type = finfo.report_type;
745                 rinfo.report_id = finfo.report_id;
746                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
747                         return -EINVAL;
748
749                 if (finfo.field_index >= report->maxfield)
750                         return -EINVAL;
751
752                 field = report->field[finfo.field_index];
753                 memset(&finfo, 0, sizeof(finfo));
754                 finfo.report_type = rinfo.report_type;
755                 finfo.report_id = rinfo.report_id;
756                 finfo.field_index = field->report_count - 1;
757                 finfo.maxusage = field->maxusage;
758                 finfo.flags = field->flags;
759                 finfo.physical = field->physical;
760                 finfo.logical = field->logical;
761                 finfo.application = field->application;
762                 finfo.logical_minimum = field->logical_minimum;
763                 finfo.logical_maximum = field->logical_maximum;
764                 finfo.physical_minimum = field->physical_minimum;
765                 finfo.physical_maximum = field->physical_maximum;
766                 finfo.unit_exponent = field->unit_exponent;
767                 finfo.unit = field->unit;
768
769                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
770                         return -EFAULT;
771
772                 return 0;
773
774         case HIDIOCGUCODE:
775                 /* fall through */
776         case HIDIOCGUSAGE:
777         case HIDIOCSUSAGE:
778         case HIDIOCGUSAGES:
779         case HIDIOCSUSAGES:
780         case HIDIOCGCOLLECTIONINDEX:
781                 mutex_lock(&hiddev->existancelock);
782                 if (hiddev->exist)
783                         r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
784                 else
785                         r = -ENODEV;
786                 mutex_unlock(&hiddev->existancelock);
787                 return r;
788
789         case HIDIOCGCOLLECTIONINFO:
790                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
791                         return -EFAULT;
792
793                 if (cinfo.index >= hid->maxcollection)
794                         return -EINVAL;
795
796                 cinfo.type = hid->collection[cinfo.index].type;
797                 cinfo.usage = hid->collection[cinfo.index].usage;
798                 cinfo.level = hid->collection[cinfo.index].level;
799
800                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
801                         return -EFAULT;
802                 return 0;
803
804         default:
805
806                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
807                         return -EINVAL;
808
809                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
810                         int len;
811                         if (!hid->name)
812                                 return 0;
813                         len = strlen(hid->name) + 1;
814                         if (len > _IOC_SIZE(cmd))
815                                  len = _IOC_SIZE(cmd);
816                         return copy_to_user(user_arg, hid->name, len) ?
817                                 -EFAULT : len;
818                 }
819
820                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
821                         int len;
822                         if (!hid->phys)
823                                 return 0;
824                         len = strlen(hid->phys) + 1;
825                         if (len > _IOC_SIZE(cmd))
826                                 len = _IOC_SIZE(cmd);
827                         return copy_to_user(user_arg, hid->phys, len) ?
828                                 -EFAULT : len;
829                 }
830         }
831         return -EINVAL;
832 }
833
834 #ifdef CONFIG_COMPAT
835 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
836 {
837         return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
838 }
839 #endif
840
841 static const struct file_operations hiddev_fops = {
842         .owner =        THIS_MODULE,
843         .read =         hiddev_read,
844         .write =        hiddev_write,
845         .poll =         hiddev_poll,
846         .open =         hiddev_open,
847         .release =      hiddev_release,
848         .unlocked_ioctl =       hiddev_ioctl,
849         .fasync =       hiddev_fasync,
850 #ifdef CONFIG_COMPAT
851         .compat_ioctl   = hiddev_compat_ioctl,
852 #endif
853 };
854
855 static char *hiddev_nodename(struct device *dev)
856 {
857         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
858 }
859
860 static struct usb_class_driver hiddev_class = {
861         .name =         "hiddev%d",
862         .nodename =     hiddev_nodename,
863         .fops =         &hiddev_fops,
864         .minor_base =   HIDDEV_MINOR_BASE,
865 };
866
867 /*
868  * This is where hid.c calls us to connect a hid device to the hiddev driver
869  */
870 int hiddev_connect(struct hid_device *hid, unsigned int force)
871 {
872         struct hiddev *hiddev;
873         struct usbhid_device *usbhid = hid->driver_data;
874         int retval;
875
876         if (!force) {
877                 unsigned int i;
878                 for (i = 0; i < hid->maxcollection; i++)
879                         if (hid->collection[i].type ==
880                             HID_COLLECTION_APPLICATION &&
881                             !IS_INPUT_APPLICATION(hid->collection[i].usage))
882                                 break;
883
884                 if (i == hid->maxcollection)
885                         return -1;
886         }
887
888         if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
889                 return -1;
890
891         init_waitqueue_head(&hiddev->wait);
892         INIT_LIST_HEAD(&hiddev->list);
893         spin_lock_init(&hiddev->list_lock);
894         mutex_init(&hiddev->existancelock);
895         hid->hiddev = hiddev;
896         hiddev->hid = hid;
897         hiddev->exist = 1;
898
899         /* when lock_kernel() usage is fixed in usb_open(),
900          * we could also fix it here */
901         lock_kernel();
902         retval = usb_register_dev(usbhid->intf, &hiddev_class);
903         if (retval) {
904                 err_hid("Not able to get a minor for this device.");
905                 hid->hiddev = NULL;
906                 unlock_kernel();
907                 kfree(hiddev);
908                 return -1;
909         } else {
910                 hid->minor = usbhid->intf->minor;
911                 hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
912         }
913         unlock_kernel();
914
915         return 0;
916 }
917
918 /*
919  * This is where hid.c calls us to disconnect a hiddev device from the
920  * corresponding hid device (usually because the usb device has disconnected)
921  */
922 static struct usb_class_driver hiddev_class;
923 void hiddev_disconnect(struct hid_device *hid)
924 {
925         struct hiddev *hiddev = hid->hiddev;
926         struct usbhid_device *usbhid = hid->driver_data;
927
928         mutex_lock(&hiddev->existancelock);
929         hiddev->exist = 0;
930         mutex_unlock(&hiddev->existancelock);
931
932         hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
933         usb_deregister_dev(usbhid->intf, &hiddev_class);
934
935         if (hiddev->open) {
936                 usbhid_close(hiddev->hid);
937                 wake_up_interruptible(&hiddev->wait);
938         } else {
939                 kfree(hiddev);
940         }
941 }
942
943 /* Currently this driver is a USB driver.  It's not a conventional one in
944  * the sense that it doesn't probe at the USB level.  Instead it waits to
945  * be connected by HID through the hiddev_connect / hiddev_disconnect
946  * routines.  The reason to register as a USB device is to gain part of the
947  * minor number space from the USB major.
948  *
949  * In theory, should the HID code be generalized to more than one physical
950  * medium (say, IEEE 1384), this driver will probably need to register its
951  * own major number, and in doing so, no longer need to register with USB.
952  * At that point the probe routine and hiddev_driver struct below will no
953  * longer be useful.
954  */
955
956
957 /* We never attach in this manner, and rely on HID to connect us.  This
958  * is why there is no disconnect routine defined in the usb_driver either.
959  */
960 static int hiddev_usbd_probe(struct usb_interface *intf,
961                              const struct usb_device_id *hiddev_info)
962 {
963         return -ENODEV;
964 }
965
966 static /* const */ struct usb_driver hiddev_driver = {
967         .name =         "hiddev",
968         .probe =        hiddev_usbd_probe,
969 };
970
971 int __init hiddev_init(void)
972 {
973         return usb_register(&hiddev_driver);
974 }
975
976 void hiddev_exit(void)
977 {
978         usb_deregister(&hiddev_driver);
979 }