Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik...
[linux-2.6] / drivers / usb / input / 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 };
55
56 struct hiddev_list {
57         struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
58         int head;
59         int tail;
60         unsigned flags;
61         struct fasync_struct *fasync;
62         struct hiddev *hiddev;
63         struct list_head node;
64 };
65
66 static struct hiddev *hiddev_table[HIDDEV_MINORS];
67
68 /*
69  * Find a report, given the report's type and ID.  The ID can be specified
70  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
71  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
72  * given type which follows old_id.
73  */
74 static struct hid_report *
75 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
76 {
77         unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
78         unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
79         struct hid_report_enum *report_enum;
80         struct hid_report *report;
81         struct list_head *list;
82
83         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
84             rinfo->report_type > HID_REPORT_TYPE_MAX)
85                 return NULL;
86
87         report_enum = hid->report_enum +
88                 (rinfo->report_type - HID_REPORT_TYPE_MIN);
89
90         switch (flags) {
91         case 0: /* Nothing to do -- report_id is already set correctly */
92                 break;
93
94         case HID_REPORT_ID_FIRST:
95                 if (list_empty(&report_enum->report_list))
96                         return NULL;
97
98                 list = report_enum->report_list.next;
99                 report = list_entry(list, struct hid_report, list);
100                 rinfo->report_id = report->id;
101                 break;
102
103         case HID_REPORT_ID_NEXT:
104                 report = report_enum->report_id_hash[rid];
105                 if (!report)
106                         return NULL;
107
108                 list = report->list.next;
109                 if (list == &report_enum->report_list)
110                         return NULL;
111
112                 report = list_entry(list, struct hid_report, list);
113                 rinfo->report_id = report->id;
114                 break;
115
116         default:
117                 return NULL;
118         }
119
120         return report_enum->report_id_hash[rinfo->report_id];
121 }
122
123 /*
124  * Perform an exhaustive search of the report table for a usage, given its
125  * type and usage id.
126  */
127 static struct hid_field *
128 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
129 {
130         int i, j;
131         struct hid_report *report;
132         struct hid_report_enum *report_enum;
133         struct hid_field *field;
134
135         if (uref->report_type < HID_REPORT_TYPE_MIN ||
136             uref->report_type > HID_REPORT_TYPE_MAX)
137                 return NULL;
138
139         report_enum = hid->report_enum +
140                 (uref->report_type - HID_REPORT_TYPE_MIN);
141
142         list_for_each_entry(report, &report_enum->report_list, list) {
143                 for (i = 0; i < report->maxfield; i++) {
144                         field = report->field[i];
145                         for (j = 0; j < field->maxusage; j++) {
146                                 if (field->usage[j].hid == uref->usage_code) {
147                                         uref->report_id = report->id;
148                                         uref->field_index = i;
149                                         uref->usage_index = j;
150                                         return field;
151                                 }
152                         }
153                 }
154         }
155
156         return NULL;
157 }
158
159 static void hiddev_send_event(struct hid_device *hid,
160                               struct hiddev_usage_ref *uref)
161 {
162         struct hiddev *hiddev = hid->hiddev;
163         struct hiddev_list *list;
164
165         list_for_each_entry(list, &hiddev->list, node) {
166                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
167                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
168                         list->buffer[list->head] = *uref;
169                         list->head = (list->head + 1) &
170                                 (HIDDEV_BUFFER_SIZE - 1);
171                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
172                 }
173         }
174
175         wake_up_interruptible(&hiddev->wait);
176 }
177
178 /*
179  * This is where hid.c calls into hiddev to pass an event that occurred over
180  * the interrupt pipe
181  */
182 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
183                       struct hid_usage *usage, __s32 value)
184 {
185         unsigned type = field->report_type;
186         struct hiddev_usage_ref uref;
187
188         uref.report_type =
189           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
190           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
191            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
192         uref.report_id = field->report->id;
193         uref.field_index = field->index;
194         uref.usage_index = (usage - field->usage);
195         uref.usage_code = usage->hid;
196         uref.value = value;
197
198         hiddev_send_event(hid, &uref);
199 }
200 EXPORT_SYMBOL_GPL(hiddev_hid_event);
201
202 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
203 {
204         unsigned type = report->type;
205         struct hiddev_usage_ref uref;
206
207         memset(&uref, 0, sizeof(uref));
208         uref.report_type =
209           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
210           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
211            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
212         uref.report_id = report->id;
213         uref.field_index = HID_FIELD_INDEX_NONE;
214
215         hiddev_send_event(hid, &uref);
216 }
217
218 /*
219  * fasync file op
220  */
221 static int hiddev_fasync(int fd, struct file *file, int on)
222 {
223         int retval;
224         struct hiddev_list *list = file->private_data;
225
226         retval = fasync_helper(fd, file, on, &list->fasync);
227
228         return retval < 0 ? retval : 0;
229 }
230
231
232 /*
233  * release file op
234  */
235 static int hiddev_release(struct inode * inode, struct file * file)
236 {
237         struct hiddev_list *list = file->private_data;
238
239         hiddev_fasync(-1, file, 0);
240         list_del(&list->node);
241
242         if (!--list->hiddev->open) {
243                 if (list->hiddev->exist)
244                         usbhid_close(list->hiddev->hid);
245                 else
246                         kfree(list->hiddev);
247         }
248
249         kfree(list);
250
251         return 0;
252 }
253
254 /*
255  * open file op
256  */
257 static int hiddev_open(struct inode *inode, struct file *file)
258 {
259         struct hiddev_list *list;
260
261         int i = iminor(inode) - HIDDEV_MINOR_BASE;
262
263         if (i >= HIDDEV_MINORS || !hiddev_table[i])
264                 return -ENODEV;
265
266         if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
267                 return -ENOMEM;
268
269         list->hiddev = hiddev_table[i];
270         list_add_tail(&list->node, &hiddev_table[i]->list);
271         file->private_data = list;
272
273         if (!list->hiddev->open++)
274                 if (list->hiddev->exist)
275                         usbhid_open(hiddev_table[i]->hid);
276
277         return 0;
278 }
279
280 /*
281  * "write" file op
282  */
283 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
284 {
285         return -EINVAL;
286 }
287
288 /*
289  * "read" file op
290  */
291 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
292 {
293         DECLARE_WAITQUEUE(wait, current);
294         struct hiddev_list *list = file->private_data;
295         int event_size;
296         int retval = 0;
297
298         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
299                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
300
301         if (count < event_size)
302                 return 0;
303
304         while (retval == 0) {
305                 if (list->head == list->tail) {
306                         add_wait_queue(&list->hiddev->wait, &wait);
307                         set_current_state(TASK_INTERRUPTIBLE);
308
309                         while (list->head == list->tail) {
310                                 if (file->f_flags & O_NONBLOCK) {
311                                         retval = -EAGAIN;
312                                         break;
313                                 }
314                                 if (signal_pending(current)) {
315                                         retval = -ERESTARTSYS;
316                                         break;
317                                 }
318                                 if (!list->hiddev->exist) {
319                                         retval = -EIO;
320                                         break;
321                                 }
322
323                                 schedule();
324                                 set_current_state(TASK_INTERRUPTIBLE);
325                         }
326
327                         set_current_state(TASK_RUNNING);
328                         remove_wait_queue(&list->hiddev->wait, &wait);
329                 }
330
331                 if (retval)
332                         return retval;
333
334
335                 while (list->head != list->tail &&
336                        retval + event_size <= count) {
337                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
338                                 if (list->buffer[list->tail].field_index !=
339                                     HID_FIELD_INDEX_NONE) {
340                                         struct hiddev_event event;
341                                         event.hid = list->buffer[list->tail].usage_code;
342                                         event.value = list->buffer[list->tail].value;
343                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event)))
344                                                 return -EFAULT;
345                                         retval += sizeof(struct hiddev_event);
346                                 }
347                         } else {
348                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
349                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
350                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref)))
351                                                 return -EFAULT;
352                                         retval += sizeof(struct hiddev_usage_ref);
353                                 }
354                         }
355                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
356                 }
357
358         }
359
360         return retval;
361 }
362
363 /*
364  * "poll" file op
365  * No kernel lock - fine
366  */
367 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
368 {
369         struct hiddev_list *list = file->private_data;
370
371         poll_wait(file, &list->hiddev->wait, wait);
372         if (list->head != list->tail)
373                 return POLLIN | POLLRDNORM;
374         if (!list->hiddev->exist)
375                 return POLLERR | POLLHUP;
376         return 0;
377 }
378
379 /*
380  * "ioctl" file op
381  */
382 static int hiddev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
383 {
384         struct hiddev_list *list = file->private_data;
385         struct hiddev *hiddev = list->hiddev;
386         struct hid_device *hid = hiddev->hid;
387         struct usb_device *dev = hid_to_usb_dev(hid);
388         struct hiddev_collection_info cinfo;
389         struct hiddev_report_info rinfo;
390         struct hiddev_field_info finfo;
391         struct hiddev_usage_ref_multi *uref_multi = NULL;
392         struct hiddev_usage_ref *uref;
393         struct hiddev_devinfo dinfo;
394         struct hid_report *report;
395         struct hid_field *field;
396         struct usbhid_device *usbhid = hid->driver_data;
397         void __user *user_arg = (void __user *)arg;
398         int i;
399
400         if (!hiddev->exist)
401                 return -EIO;
402
403         switch (cmd) {
404
405         case HIDIOCGVERSION:
406                 return put_user(HID_VERSION, (int __user *)arg);
407
408         case HIDIOCAPPLICATION:
409                 if (arg < 0 || arg >= hid->maxapplication)
410                         return -EINVAL;
411
412                 for (i = 0; i < hid->maxcollection; i++)
413                         if (hid->collection[i].type ==
414                             HID_COLLECTION_APPLICATION && arg-- == 0)
415                                 break;
416
417                 if (i == hid->maxcollection)
418                         return -EINVAL;
419
420                 return hid->collection[i].usage;
421
422         case HIDIOCGDEVINFO:
423                 dinfo.bustype = BUS_USB;
424                 dinfo.busnum = dev->bus->busnum;
425                 dinfo.devnum = dev->devnum;
426                 dinfo.ifnum = usbhid->ifnum;
427                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
428                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
429                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
430                 dinfo.num_applications = hid->maxapplication;
431                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
432                         return -EFAULT;
433
434                 return 0;
435
436         case HIDIOCGFLAG:
437                 if (put_user(list->flags, (int __user *)arg))
438                         return -EFAULT;
439
440                 return 0;
441
442         case HIDIOCSFLAG:
443                 {
444                         int newflags;
445                         if (get_user(newflags, (int __user *)arg))
446                                 return -EFAULT;
447
448                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
449                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
450                              (newflags & HIDDEV_FLAG_UREF) == 0))
451                                 return -EINVAL;
452
453                         list->flags = newflags;
454
455                         return 0;
456                 }
457
458         case HIDIOCGSTRING:
459                 {
460                         int idx, len;
461                         char *buf;
462
463                         if (get_user(idx, (int __user *)arg))
464                                 return -EFAULT;
465
466                         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
467                                 return -ENOMEM;
468
469                         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
470                                 kfree(buf);
471                                 return -EINVAL;
472                         }
473
474                         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
475                                 kfree(buf);
476                                 return -EFAULT;
477                         }
478
479                         kfree(buf);
480
481                         return len;
482                 }
483
484         case HIDIOCINITREPORT:
485                 usbhid_init_reports(hid);
486
487                 return 0;
488
489         case HIDIOCGREPORT:
490                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
491                         return -EFAULT;
492
493                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
494                         return -EINVAL;
495
496                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
497                         return -EINVAL;
498
499                 usbhid_submit_report(hid, report, USB_DIR_IN);
500                 usbhid_wait_io(hid);
501
502                 return 0;
503
504         case HIDIOCSREPORT:
505                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
506                         return -EFAULT;
507
508                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
509                         return -EINVAL;
510
511                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
512                         return -EINVAL;
513
514                 usbhid_submit_report(hid, report, USB_DIR_OUT);
515                 usbhid_wait_io(hid);
516
517                 return 0;
518
519         case HIDIOCGREPORTINFO:
520                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
521                         return -EFAULT;
522
523                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
524                         return -EINVAL;
525
526                 rinfo.num_fields = report->maxfield;
527
528                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
529                         return -EFAULT;
530
531                 return 0;
532
533         case HIDIOCGFIELDINFO:
534                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
535                         return -EFAULT;
536                 rinfo.report_type = finfo.report_type;
537                 rinfo.report_id = finfo.report_id;
538                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
539                         return -EINVAL;
540
541                 if (finfo.field_index >= report->maxfield)
542                         return -EINVAL;
543
544                 field = report->field[finfo.field_index];
545                 memset(&finfo, 0, sizeof(finfo));
546                 finfo.report_type = rinfo.report_type;
547                 finfo.report_id = rinfo.report_id;
548                 finfo.field_index = field->report_count - 1;
549                 finfo.maxusage = field->maxusage;
550                 finfo.flags = field->flags;
551                 finfo.physical = field->physical;
552                 finfo.logical = field->logical;
553                 finfo.application = field->application;
554                 finfo.logical_minimum = field->logical_minimum;
555                 finfo.logical_maximum = field->logical_maximum;
556                 finfo.physical_minimum = field->physical_minimum;
557                 finfo.physical_maximum = field->physical_maximum;
558                 finfo.unit_exponent = field->unit_exponent;
559                 finfo.unit = field->unit;
560
561                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
562                         return -EFAULT;
563
564                 return 0;
565
566         case HIDIOCGUCODE:
567                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
568                 if (!uref_multi)
569                         return -ENOMEM;
570                 uref = &uref_multi->uref;
571                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
572                         goto fault;
573
574                 rinfo.report_type = uref->report_type;
575                 rinfo.report_id = uref->report_id;
576                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
577                         goto inval;
578
579                 if (uref->field_index >= report->maxfield)
580                         goto inval;
581
582                 field = report->field[uref->field_index];
583                 if (uref->usage_index >= field->maxusage)
584                         goto inval;
585
586                 uref->usage_code = field->usage[uref->usage_index].hid;
587
588                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
589                         goto fault;
590
591                 kfree(uref_multi);
592                 return 0;
593
594         case HIDIOCGUSAGE:
595         case HIDIOCSUSAGE:
596         case HIDIOCGUSAGES:
597         case HIDIOCSUSAGES:
598         case HIDIOCGCOLLECTIONINDEX:
599                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
600                 if (!uref_multi)
601                         return -ENOMEM;
602                 uref = &uref_multi->uref;
603                 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
604                         if (copy_from_user(uref_multi, user_arg,
605                                            sizeof(*uref_multi)))
606                                 goto fault;
607                 } else {
608                         if (copy_from_user(uref, user_arg, sizeof(*uref)))
609                                 goto fault;
610                 }
611
612                 if (cmd != HIDIOCGUSAGE &&
613                     cmd != HIDIOCGUSAGES &&
614                     uref->report_type == HID_REPORT_TYPE_INPUT)
615                         goto inval;
616
617                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
618                         field = hiddev_lookup_usage(hid, uref);
619                         if (field == NULL)
620                                 goto inval;
621                 } else {
622                         rinfo.report_type = uref->report_type;
623                         rinfo.report_id = uref->report_id;
624                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
625                                 goto inval;
626
627                         if (uref->field_index >= report->maxfield)
628                                 goto inval;
629
630                         field = report->field[uref->field_index];
631
632                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
633                                 if (uref->usage_index >= field->maxusage)
634                                         goto inval;
635                         } else if (uref->usage_index >= field->report_count)
636                                 goto inval;
637
638                         else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
639                                  (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
640                                   uref->usage_index + uref_multi->num_values > field->report_count))
641                                 goto inval;
642                         }
643
644                 switch (cmd) {
645                         case HIDIOCGUSAGE:
646                                 uref->value = field->value[uref->usage_index];
647                                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
648                                         goto fault;
649                                 goto goodreturn;
650
651                         case HIDIOCSUSAGE:
652                                 field->value[uref->usage_index] = uref->value;
653                                 goto goodreturn;
654
655                         case HIDIOCGCOLLECTIONINDEX:
656                                 kfree(uref_multi);
657                                 return field->usage[uref->usage_index].collection_index;
658                         case HIDIOCGUSAGES:
659                                 for (i = 0; i < uref_multi->num_values; i++)
660                                         uref_multi->values[i] =
661                                             field->value[uref->usage_index + i];
662                                 if (copy_to_user(user_arg, uref_multi,
663                                                  sizeof(*uref_multi)))
664                                         goto fault;
665                                 goto goodreturn;
666                         case HIDIOCSUSAGES:
667                                 for (i = 0; i < uref_multi->num_values; i++)
668                                         field->value[uref->usage_index + i] =
669                                             uref_multi->values[i];
670                                 goto goodreturn;
671                 }
672
673 goodreturn:
674                 kfree(uref_multi);
675                 return 0;
676 fault:
677                 kfree(uref_multi);
678                 return -EFAULT;
679 inval:
680                 kfree(uref_multi);
681                 return -EINVAL;
682
683         case HIDIOCGCOLLECTIONINFO:
684                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
685                         return -EFAULT;
686
687                 if (cinfo.index >= hid->maxcollection)
688                         return -EINVAL;
689
690                 cinfo.type = hid->collection[cinfo.index].type;
691                 cinfo.usage = hid->collection[cinfo.index].usage;
692                 cinfo.level = hid->collection[cinfo.index].level;
693
694                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
695                         return -EFAULT;
696                 return 0;
697
698         default:
699
700                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
701                         return -EINVAL;
702
703                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
704                         int len;
705                         if (!hid->name)
706                                 return 0;
707                         len = strlen(hid->name) + 1;
708                         if (len > _IOC_SIZE(cmd))
709                                  len = _IOC_SIZE(cmd);
710                         return copy_to_user(user_arg, hid->name, len) ?
711                                 -EFAULT : len;
712                 }
713
714                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
715                         int len;
716                         if (!hid->phys)
717                                 return 0;
718                         len = strlen(hid->phys) + 1;
719                         if (len > _IOC_SIZE(cmd))
720                                 len = _IOC_SIZE(cmd);
721                         return copy_to_user(user_arg, hid->phys, len) ?
722                                 -EFAULT : len;
723                 }
724         }
725         return -EINVAL;
726 }
727
728 static const struct file_operations hiddev_fops = {
729         .owner =        THIS_MODULE,
730         .read =         hiddev_read,
731         .write =        hiddev_write,
732         .poll =         hiddev_poll,
733         .open =         hiddev_open,
734         .release =      hiddev_release,
735         .ioctl =        hiddev_ioctl,
736         .fasync =       hiddev_fasync,
737 };
738
739 static struct usb_class_driver hiddev_class = {
740         .name =         "hiddev%d",
741         .fops =         &hiddev_fops,
742         .minor_base =   HIDDEV_MINOR_BASE,
743 };
744
745 /*
746  * This is where hid.c calls us to connect a hid device to the hiddev driver
747  */
748 int hiddev_connect(struct hid_device *hid)
749 {
750         struct hiddev *hiddev;
751         struct usbhid_device *usbhid = hid->driver_data;
752         int i;
753         int retval;
754
755         for (i = 0; i < hid->maxcollection; i++)
756                 if (hid->collection[i].type ==
757                     HID_COLLECTION_APPLICATION &&
758                     !IS_INPUT_APPLICATION(hid->collection[i].usage))
759                         break;
760
761         if (i == hid->maxcollection && (hid->quirks & HID_QUIRK_HIDDEV) == 0)
762                 return -1;
763
764         if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
765                 return -1;
766
767         retval = usb_register_dev(usbhid->intf, &hiddev_class);
768         if (retval) {
769                 err("Not able to get a minor for this device.");
770                 kfree(hiddev);
771                 return -1;
772         }
773
774         init_waitqueue_head(&hiddev->wait);
775         INIT_LIST_HEAD(&hiddev->list);
776         hiddev->hid = hid;
777         hiddev->exist = 1;
778
779         hid->minor = usbhid->intf->minor;
780         hid->hiddev = hiddev;
781
782         hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
783
784         return 0;
785 }
786
787 /*
788  * This is where hid.c calls us to disconnect a hiddev device from the
789  * corresponding hid device (usually because the usb device has disconnected)
790  */
791 static struct usb_class_driver hiddev_class;
792 void hiddev_disconnect(struct hid_device *hid)
793 {
794         struct hiddev *hiddev = hid->hiddev;
795         struct usbhid_device *usbhid = hid->driver_data;
796
797         hiddev->exist = 0;
798
799         hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
800         usb_deregister_dev(usbhid->intf, &hiddev_class);
801
802         if (hiddev->open) {
803                 usbhid_close(hiddev->hid);
804                 wake_up_interruptible(&hiddev->wait);
805         } else {
806                 kfree(hiddev);
807         }
808 }
809
810 /* Currently this driver is a USB driver.  It's not a conventional one in
811  * the sense that it doesn't probe at the USB level.  Instead it waits to
812  * be connected by HID through the hiddev_connect / hiddev_disconnect
813  * routines.  The reason to register as a USB device is to gain part of the
814  * minor number space from the USB major.
815  *
816  * In theory, should the HID code be generalized to more than one physical
817  * medium (say, IEEE 1384), this driver will probably need to register its
818  * own major number, and in doing so, no longer need to register with USB.
819  * At that point the probe routine and hiddev_driver struct below will no
820  * longer be useful.
821  */
822
823
824 /* We never attach in this manner, and rely on HID to connect us.  This
825  * is why there is no disconnect routine defined in the usb_driver either.
826  */
827 static int hiddev_usbd_probe(struct usb_interface *intf,
828                              const struct usb_device_id *hiddev_info)
829 {
830         return -ENODEV;
831 }
832
833
834 static /* const */ struct usb_driver hiddev_driver = {
835         .name =         "hiddev",
836         .probe =        hiddev_usbd_probe,
837 };
838
839 int __init hiddev_init(void)
840 {
841         return usb_register(&hiddev_driver);
842 }
843
844 void hiddev_exit(void)
845 {
846         usb_deregister(&hiddev_driver);
847 }