USB HID: hiddev - fix race between hiddev_send_event() and hiddev_release()
[safe/jmp/linux-2.6] / 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 "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      64
47
48 struct hiddev {
49         int exist;
50         int open;
51         wait_queue_head_t wait;
52         struct hid_device *hid;
53         struct list_head list;
54         spinlock_t list_lock;
55 };
56
57 struct hiddev_list {
58         struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
59         int head;
60         int tail;
61         unsigned flags;
62         struct fasync_struct *fasync;
63         struct hiddev *hiddev;
64         struct list_head node;
65 };
66
67 static struct hiddev *hiddev_table[HIDDEV_MINORS];
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         int retval;
228         struct hiddev_list *list = file->private_data;
229
230         retval = fasync_helper(fd, file, on, &list->fasync);
231
232         return retval < 0 ? retval : 0;
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         hiddev_fasync(-1, file, 0);
245
246         spin_lock_irqsave(&list->hiddev->list_lock, flags);
247         list_del(&list->node);
248         spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
249
250         if (!--list->hiddev->open) {
251                 if (list->hiddev->exist)
252                         usbhid_close(list->hiddev->hid);
253                 else
254                         kfree(list->hiddev);
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         unsigned long flags;
269
270         int i = iminor(inode) - HIDDEV_MINOR_BASE;
271
272         if (i >= HIDDEV_MINORS || !hiddev_table[i])
273                 return -ENODEV;
274
275         if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
276                 return -ENOMEM;
277
278         list->hiddev = hiddev_table[i];
279
280         spin_lock_irqsave(&list->hiddev->list_lock, flags);
281         list_add_tail(&list->node, &hiddev_table[i]->list);
282         spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
283
284         file->private_data = list;
285
286         if (!list->hiddev->open++)
287                 if (list->hiddev->exist)
288                         usbhid_open(hiddev_table[i]->hid);
289
290         return 0;
291 }
292
293 /*
294  * "write" file op
295  */
296 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
297 {
298         return -EINVAL;
299 }
300
301 /*
302  * "read" file op
303  */
304 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
305 {
306         DECLARE_WAITQUEUE(wait, current);
307         struct hiddev_list *list = file->private_data;
308         int event_size;
309         int retval = 0;
310
311         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
312                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
313
314         if (count < event_size)
315                 return 0;
316
317         while (retval == 0) {
318                 if (list->head == list->tail) {
319                         add_wait_queue(&list->hiddev->wait, &wait);
320                         set_current_state(TASK_INTERRUPTIBLE);
321
322                         while (list->head == list->tail) {
323                                 if (file->f_flags & O_NONBLOCK) {
324                                         retval = -EAGAIN;
325                                         break;
326                                 }
327                                 if (signal_pending(current)) {
328                                         retval = -ERESTARTSYS;
329                                         break;
330                                 }
331                                 if (!list->hiddev->exist) {
332                                         retval = -EIO;
333                                         break;
334                                 }
335
336                                 schedule();
337                                 set_current_state(TASK_INTERRUPTIBLE);
338                         }
339
340                         set_current_state(TASK_RUNNING);
341                         remove_wait_queue(&list->hiddev->wait, &wait);
342                 }
343
344                 if (retval)
345                         return retval;
346
347
348                 while (list->head != list->tail &&
349                        retval + event_size <= count) {
350                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
351                                 if (list->buffer[list->tail].field_index !=
352                                     HID_FIELD_INDEX_NONE) {
353                                         struct hiddev_event event;
354                                         event.hid = list->buffer[list->tail].usage_code;
355                                         event.value = list->buffer[list->tail].value;
356                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event)))
357                                                 return -EFAULT;
358                                         retval += sizeof(struct hiddev_event);
359                                 }
360                         } else {
361                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
362                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
363                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref)))
364                                                 return -EFAULT;
365                                         retval += sizeof(struct hiddev_usage_ref);
366                                 }
367                         }
368                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
369                 }
370
371         }
372
373         return retval;
374 }
375
376 /*
377  * "poll" file op
378  * No kernel lock - fine
379  */
380 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
381 {
382         struct hiddev_list *list = file->private_data;
383
384         poll_wait(file, &list->hiddev->wait, wait);
385         if (list->head != list->tail)
386                 return POLLIN | POLLRDNORM;
387         if (!list->hiddev->exist)
388                 return POLLERR | POLLHUP;
389         return 0;
390 }
391
392 /*
393  * "ioctl" file op
394  */
395 static int hiddev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
396 {
397         struct hiddev_list *list = file->private_data;
398         struct hiddev *hiddev = list->hiddev;
399         struct hid_device *hid = hiddev->hid;
400         struct usb_device *dev = hid_to_usb_dev(hid);
401         struct hiddev_collection_info cinfo;
402         struct hiddev_report_info rinfo;
403         struct hiddev_field_info finfo;
404         struct hiddev_usage_ref_multi *uref_multi = NULL;
405         struct hiddev_usage_ref *uref;
406         struct hiddev_devinfo dinfo;
407         struct hid_report *report;
408         struct hid_field *field;
409         struct usbhid_device *usbhid = hid->driver_data;
410         void __user *user_arg = (void __user *)arg;
411         int i;
412
413         if (!hiddev->exist)
414                 return -EIO;
415
416         switch (cmd) {
417
418         case HIDIOCGVERSION:
419                 return put_user(HID_VERSION, (int __user *)arg);
420
421         case HIDIOCAPPLICATION:
422                 if (arg < 0 || arg >= hid->maxapplication)
423                         return -EINVAL;
424
425                 for (i = 0; i < hid->maxcollection; i++)
426                         if (hid->collection[i].type ==
427                             HID_COLLECTION_APPLICATION && arg-- == 0)
428                                 break;
429
430                 if (i == hid->maxcollection)
431                         return -EINVAL;
432
433                 return hid->collection[i].usage;
434
435         case HIDIOCGDEVINFO:
436                 dinfo.bustype = BUS_USB;
437                 dinfo.busnum = dev->bus->busnum;
438                 dinfo.devnum = dev->devnum;
439                 dinfo.ifnum = usbhid->ifnum;
440                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
441                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
442                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
443                 dinfo.num_applications = hid->maxapplication;
444                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
445                         return -EFAULT;
446
447                 return 0;
448
449         case HIDIOCGFLAG:
450                 if (put_user(list->flags, (int __user *)arg))
451                         return -EFAULT;
452
453                 return 0;
454
455         case HIDIOCSFLAG:
456                 {
457                         int newflags;
458                         if (get_user(newflags, (int __user *)arg))
459                                 return -EFAULT;
460
461                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
462                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
463                              (newflags & HIDDEV_FLAG_UREF) == 0))
464                                 return -EINVAL;
465
466                         list->flags = newflags;
467
468                         return 0;
469                 }
470
471         case HIDIOCGSTRING:
472                 {
473                         int idx, len;
474                         char *buf;
475
476                         if (get_user(idx, (int __user *)arg))
477                                 return -EFAULT;
478
479                         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
480                                 return -ENOMEM;
481
482                         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
483                                 kfree(buf);
484                                 return -EINVAL;
485                         }
486
487                         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
488                                 kfree(buf);
489                                 return -EFAULT;
490                         }
491
492                         kfree(buf);
493
494                         return len;
495                 }
496
497         case HIDIOCINITREPORT:
498                 usbhid_init_reports(hid);
499
500                 return 0;
501
502         case HIDIOCGREPORT:
503                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
504                         return -EFAULT;
505
506                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
507                         return -EINVAL;
508
509                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
510                         return -EINVAL;
511
512                 usbhid_submit_report(hid, report, USB_DIR_IN);
513                 usbhid_wait_io(hid);
514
515                 return 0;
516
517         case HIDIOCSREPORT:
518                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
519                         return -EFAULT;
520
521                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
522                         return -EINVAL;
523
524                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
525                         return -EINVAL;
526
527                 usbhid_submit_report(hid, report, USB_DIR_OUT);
528                 usbhid_wait_io(hid);
529
530                 return 0;
531
532         case HIDIOCGREPORTINFO:
533                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
534                         return -EFAULT;
535
536                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
537                         return -EINVAL;
538
539                 rinfo.num_fields = report->maxfield;
540
541                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
542                         return -EFAULT;
543
544                 return 0;
545
546         case HIDIOCGFIELDINFO:
547                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
548                         return -EFAULT;
549                 rinfo.report_type = finfo.report_type;
550                 rinfo.report_id = finfo.report_id;
551                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
552                         return -EINVAL;
553
554                 if (finfo.field_index >= report->maxfield)
555                         return -EINVAL;
556
557                 field = report->field[finfo.field_index];
558                 memset(&finfo, 0, sizeof(finfo));
559                 finfo.report_type = rinfo.report_type;
560                 finfo.report_id = rinfo.report_id;
561                 finfo.field_index = field->report_count - 1;
562                 finfo.maxusage = field->maxusage;
563                 finfo.flags = field->flags;
564                 finfo.physical = field->physical;
565                 finfo.logical = field->logical;
566                 finfo.application = field->application;
567                 finfo.logical_minimum = field->logical_minimum;
568                 finfo.logical_maximum = field->logical_maximum;
569                 finfo.physical_minimum = field->physical_minimum;
570                 finfo.physical_maximum = field->physical_maximum;
571                 finfo.unit_exponent = field->unit_exponent;
572                 finfo.unit = field->unit;
573
574                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
575                         return -EFAULT;
576
577                 return 0;
578
579         case HIDIOCGUCODE:
580                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
581                 if (!uref_multi)
582                         return -ENOMEM;
583                 uref = &uref_multi->uref;
584                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
585                         goto fault;
586
587                 rinfo.report_type = uref->report_type;
588                 rinfo.report_id = uref->report_id;
589                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
590                         goto inval;
591
592                 if (uref->field_index >= report->maxfield)
593                         goto inval;
594
595                 field = report->field[uref->field_index];
596                 if (uref->usage_index >= field->maxusage)
597                         goto inval;
598
599                 uref->usage_code = field->usage[uref->usage_index].hid;
600
601                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
602                         goto fault;
603
604                 kfree(uref_multi);
605                 return 0;
606
607         case HIDIOCGUSAGE:
608         case HIDIOCSUSAGE:
609         case HIDIOCGUSAGES:
610         case HIDIOCSUSAGES:
611         case HIDIOCGCOLLECTIONINDEX:
612                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
613                 if (!uref_multi)
614                         return -ENOMEM;
615                 uref = &uref_multi->uref;
616                 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
617                         if (copy_from_user(uref_multi, user_arg,
618                                            sizeof(*uref_multi)))
619                                 goto fault;
620                 } else {
621                         if (copy_from_user(uref, user_arg, sizeof(*uref)))
622                                 goto fault;
623                 }
624
625                 if (cmd != HIDIOCGUSAGE &&
626                     cmd != HIDIOCGUSAGES &&
627                     uref->report_type == HID_REPORT_TYPE_INPUT)
628                         goto inval;
629
630                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
631                         field = hiddev_lookup_usage(hid, uref);
632                         if (field == NULL)
633                                 goto inval;
634                 } else {
635                         rinfo.report_type = uref->report_type;
636                         rinfo.report_id = uref->report_id;
637                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
638                                 goto inval;
639
640                         if (uref->field_index >= report->maxfield)
641                                 goto inval;
642
643                         field = report->field[uref->field_index];
644
645                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
646                                 if (uref->usage_index >= field->maxusage)
647                                         goto inval;
648                         } else if (uref->usage_index >= field->report_count)
649                                 goto inval;
650
651                         else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
652                                  (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
653                                   uref->usage_index + uref_multi->num_values > field->report_count))
654                                 goto inval;
655                         }
656
657                 switch (cmd) {
658                         case HIDIOCGUSAGE:
659                                 uref->value = field->value[uref->usage_index];
660                                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
661                                         goto fault;
662                                 goto goodreturn;
663
664                         case HIDIOCSUSAGE:
665                                 field->value[uref->usage_index] = uref->value;
666                                 goto goodreturn;
667
668                         case HIDIOCGCOLLECTIONINDEX:
669                                 kfree(uref_multi);
670                                 return field->usage[uref->usage_index].collection_index;
671                         case HIDIOCGUSAGES:
672                                 for (i = 0; i < uref_multi->num_values; i++)
673                                         uref_multi->values[i] =
674                                             field->value[uref->usage_index + i];
675                                 if (copy_to_user(user_arg, uref_multi,
676                                                  sizeof(*uref_multi)))
677                                         goto fault;
678                                 goto goodreturn;
679                         case HIDIOCSUSAGES:
680                                 for (i = 0; i < uref_multi->num_values; i++)
681                                         field->value[uref->usage_index + i] =
682                                             uref_multi->values[i];
683                                 goto goodreturn;
684                 }
685
686 goodreturn:
687                 kfree(uref_multi);
688                 return 0;
689 fault:
690                 kfree(uref_multi);
691                 return -EFAULT;
692 inval:
693                 kfree(uref_multi);
694                 return -EINVAL;
695
696         case HIDIOCGCOLLECTIONINFO:
697                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
698                         return -EFAULT;
699
700                 if (cinfo.index >= hid->maxcollection)
701                         return -EINVAL;
702
703                 cinfo.type = hid->collection[cinfo.index].type;
704                 cinfo.usage = hid->collection[cinfo.index].usage;
705                 cinfo.level = hid->collection[cinfo.index].level;
706
707                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
708                         return -EFAULT;
709                 return 0;
710
711         default:
712
713                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
714                         return -EINVAL;
715
716                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
717                         int len;
718                         if (!hid->name)
719                                 return 0;
720                         len = strlen(hid->name) + 1;
721                         if (len > _IOC_SIZE(cmd))
722                                  len = _IOC_SIZE(cmd);
723                         return copy_to_user(user_arg, hid->name, len) ?
724                                 -EFAULT : len;
725                 }
726
727                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
728                         int len;
729                         if (!hid->phys)
730                                 return 0;
731                         len = strlen(hid->phys) + 1;
732                         if (len > _IOC_SIZE(cmd))
733                                 len = _IOC_SIZE(cmd);
734                         return copy_to_user(user_arg, hid->phys, len) ?
735                                 -EFAULT : len;
736                 }
737         }
738         return -EINVAL;
739 }
740
741 static const struct file_operations hiddev_fops = {
742         .owner =        THIS_MODULE,
743         .read =         hiddev_read,
744         .write =        hiddev_write,
745         .poll =         hiddev_poll,
746         .open =         hiddev_open,
747         .release =      hiddev_release,
748         .ioctl =        hiddev_ioctl,
749         .fasync =       hiddev_fasync,
750 };
751
752 static struct usb_class_driver hiddev_class = {
753         .name =         "hiddev%d",
754         .fops =         &hiddev_fops,
755         .minor_base =   HIDDEV_MINOR_BASE,
756 };
757
758 /*
759  * This is where hid.c calls us to connect a hid device to the hiddev driver
760  */
761 int hiddev_connect(struct hid_device *hid)
762 {
763         struct hiddev *hiddev;
764         struct usbhid_device *usbhid = hid->driver_data;
765         int i;
766         int retval;
767
768         for (i = 0; i < hid->maxcollection; i++)
769                 if (hid->collection[i].type ==
770                     HID_COLLECTION_APPLICATION &&
771                     !IS_INPUT_APPLICATION(hid->collection[i].usage))
772                         break;
773
774         if (i == hid->maxcollection && (hid->quirks & HID_QUIRK_HIDDEV) == 0)
775                 return -1;
776
777         if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
778                 return -1;
779
780         retval = usb_register_dev(usbhid->intf, &hiddev_class);
781         if (retval) {
782                 err("Not able to get a minor for this device.");
783                 kfree(hiddev);
784                 return -1;
785         }
786
787         init_waitqueue_head(&hiddev->wait);
788         INIT_LIST_HEAD(&hiddev->list);
789         spin_lock_init(&hiddev->list_lock);
790         hiddev->hid = hid;
791         hiddev->exist = 1;
792
793         hid->minor = usbhid->intf->minor;
794         hid->hiddev = hiddev;
795
796         hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
797
798         return 0;
799 }
800
801 /*
802  * This is where hid.c calls us to disconnect a hiddev device from the
803  * corresponding hid device (usually because the usb device has disconnected)
804  */
805 static struct usb_class_driver hiddev_class;
806 void hiddev_disconnect(struct hid_device *hid)
807 {
808         struct hiddev *hiddev = hid->hiddev;
809         struct usbhid_device *usbhid = hid->driver_data;
810
811         hiddev->exist = 0;
812
813         hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
814         usb_deregister_dev(usbhid->intf, &hiddev_class);
815
816         if (hiddev->open) {
817                 usbhid_close(hiddev->hid);
818                 wake_up_interruptible(&hiddev->wait);
819         } else {
820                 kfree(hiddev);
821         }
822 }
823
824 /* Currently this driver is a USB driver.  It's not a conventional one in
825  * the sense that it doesn't probe at the USB level.  Instead it waits to
826  * be connected by HID through the hiddev_connect / hiddev_disconnect
827  * routines.  The reason to register as a USB device is to gain part of the
828  * minor number space from the USB major.
829  *
830  * In theory, should the HID code be generalized to more than one physical
831  * medium (say, IEEE 1384), this driver will probably need to register its
832  * own major number, and in doing so, no longer need to register with USB.
833  * At that point the probe routine and hiddev_driver struct below will no
834  * longer be useful.
835  */
836
837
838 /* We never attach in this manner, and rely on HID to connect us.  This
839  * is why there is no disconnect routine defined in the usb_driver either.
840  */
841 static int hiddev_usbd_probe(struct usb_interface *intf,
842                              const struct usb_device_id *hiddev_info)
843 {
844         return -ENODEV;
845 }
846
847
848 static /* const */ struct usb_driver hiddev_driver = {
849         .name =         "hiddev",
850         .probe =        hiddev_usbd_probe,
851 };
852
853 int __init hiddev_init(void)
854 {
855         return usb_register(&hiddev_driver);
856 }
857
858 void hiddev_exit(void)
859 {
860         usb_deregister(&hiddev_driver);
861 }