drivers/hid/uhid.c

   1 /*
   2  * User-space I/O driver support for HID subsystem
   3  * Copyright (c) 2012 David Herrmann
   4  */
   5
   6 /*
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the Free
   9  * Software Foundation; either version 2 of the License, or (at your option)
  10  * any later version.
  11  */
  12
  13 #include <linux/atomic.h>
  14 #include <linux/compat.h>
  15 #include <linux/device.h>
  16 #include <linux/fs.h>
  17 #include <linux/hid.h>
  18 #include <linux/input.h>
  19 #include <linux/miscdevice.h>
  20 #include <linux/module.h>
  21 #include <linux/mutex.h>
  22 #include <linux/poll.h>
  23 #include <linux/sched.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/uhid.h>
  26 #include <linux/wait.h>
  27
  28 #define UHID_NAME       "uhid"
  29 #define UHID_BUFSIZE    32
  30
  31 struct uhid_device {
  32         struct mutex devlock;
  33         bool running;
  34
  35         __u8 *rd_data;
  36         uint rd_size;
  37
  38         struct hid_device *hid;
  39         struct uhid_event input_buf;
  40
  41         wait_queue_head_t waitq;
  42         spinlock_t qlock;
  43         __u8 head;
  44         __u8 tail;
  45         struct uhid_event *outq[UHID_BUFSIZE];
  46
  47         struct mutex report_lock;
  48         wait_queue_head_t report_wait;
  49         atomic_t report_done;
  50         atomic_t report_id;
  51         struct uhid_event report_buf;
  52 };
  53
  54 static struct miscdevice uhid_misc;
  55
  56 static void uhid_queue(struct uhid_device *uhid, struct uhid_event *ev)
  57 {
  58         __u8 newhead;
  59
  60         newhead = (uhid->head + 1) % UHID_BUFSIZE;
  61
  62         if (newhead != uhid->tail) {
  63                 uhid->outq[uhid->head] = ev;
  64                 uhid->head = newhead;
  65                 wake_up_interruptible(&uhid->waitq);
  66         } else {
  67                 hid_warn(uhid->hid, "Output queue is full\n");
  68                 kfree(ev);
  69         }
  70 }
  71
  72 static int uhid_queue_event(struct uhid_device *uhid, __u32 event)
  73 {
  74         unsigned long flags;
  75         struct uhid_event *ev;
  76
  77         ev = kzalloc(sizeof(*ev), GFP_KERNEL);
  78         if (!ev)
  79                 return -ENOMEM;
  80
  81         ev->type = event;
  82
  83         spin_lock_irqsave(&uhid->qlock, flags);
  84         uhid_queue(uhid, ev);
  85         spin_unlock_irqrestore(&uhid->qlock, flags);
  86
  87         return 0;
  88 }
  89
  90 static int uhid_hid_start(struct hid_device *hid)
  91 {
  92         struct uhid_device *uhid = hid->driver_data;
  93
  94         return uhid_queue_event(uhid, UHID_START);
  95 }
  96
  97 static void uhid_hid_stop(struct hid_device *hid)
  98 {
  99         struct uhid_device *uhid = hid->driver_data;
 100
 101         hid->claimed = 0;
 102         uhid_queue_event(uhid, UHID_STOP);
 103 }
 104
 105 static int uhid_hid_open(struct hid_device *hid)
 106 {
 107         struct uhid_device *uhid = hid->driver_data;
 108
 109         return uhid_queue_event(uhid, UHID_OPEN);
 110 }
 111
 112 static void uhid_hid_close(struct hid_device *hid)
 113 {
 114         struct uhid_device *uhid = hid->driver_data;
 115
 116         uhid_queue_event(uhid, UHID_CLOSE);
 117 }
 118
 119 static int uhid_hid_parse(struct hid_device *hid)
 120 {
 121         struct uhid_device *uhid = hid->driver_data;
 122
 123         return hid_parse_report(hid, uhid->rd_data, uhid->rd_size);
 124 }
 125
 126 static int uhid_hid_get_raw(struct hid_device *hid, unsigned char rnum,
 127                             __u8 *buf, size_t count, unsigned char rtype)
 128 {
 129         struct uhid_device *uhid = hid->driver_data;
 130         __u8 report_type;
 131         struct uhid_event *ev;
 132         unsigned long flags;
 133         int ret;
 134         size_t uninitialized_var(len);
 135         struct uhid_feature_answer_req *req;
 136
 137         if (!uhid->running)
 138                 return -EIO;
 139
 140         switch (rtype) {
 141         case HID_FEATURE_REPORT:
 142                 report_type = UHID_FEATURE_REPORT;
 143                 break;
 144         case HID_OUTPUT_REPORT:
 145                 report_type = UHID_OUTPUT_REPORT;
 146                 break;
 147         case HID_INPUT_REPORT:
 148                 report_type = UHID_INPUT_REPORT;
 149                 break;
 150         default:
 151                 return -EINVAL;
 152         }
 153
 154         ret = mutex_lock_interruptible(&uhid->report_lock);
 155         if (ret)
 156                 return ret;
 157
 158         ev = kzalloc(sizeof(*ev), GFP_KERNEL);
 159         if (!ev) {
 160                 ret = -ENOMEM;
 161                 goto unlock;
 162         }
 163
 164         spin_lock_irqsave(&uhid->qlock, flags);
 165         ev->type = UHID_FEATURE;
 166         ev->u.feature.id = atomic_inc_return(&uhid->report_id);
 167         ev->u.feature.rnum = rnum;
 168         ev->u.feature.rtype = report_type;
 169
 170         atomic_set(&uhid->report_done, 0);
 171         uhid_queue(uhid, ev);
 172         spin_unlock_irqrestore(&uhid->qlock, flags);
 173
 174         ret = wait_event_interruptible_timeout(uhid->report_wait,
 175                                 atomic_read(&uhid->report_done), 5 * HZ);
 176
 177         /*
 178          * Make sure "uhid->running" is cleared on shutdown before
 179          * "uhid->report_done" is set.
 180          */
 181         smp_rmb();
 182         if (!ret || !uhid->running) {
 183                 ret = -EIO;
 184         } else if (ret < 0) {
 185                 ret = -ERESTARTSYS;
 186         } else {
 187                 spin_lock_irqsave(&uhid->qlock, flags);
 188                 req = &uhid->report_buf.u.feature_answer;
 189
 190                 if (req->err) {
 191                         ret = -EIO;
 192                 } else {
 193                         ret = 0;
 194                         len = min(count,
 195                                 min_t(size_t, req->size, UHID_DATA_MAX));
 196                         memcpy(buf, req->data, len);
 197                 }
 198
 199                 spin_unlock_irqrestore(&uhid->qlock, flags);
 200         }
 201
 202         atomic_set(&uhid->report_done, 1);
 203
 204 unlock:
 205         mutex_unlock(&uhid->report_lock);
 206         return ret ? ret : len;
 207 }
 208
 209 static int uhid_hid_output_raw(struct hid_device *hid, __u8 *buf, size_t count,
 210                                unsigned char report_type)
 211 {
 212         struct uhid_device *uhid = hid->driver_data;
 213         __u8 rtype;
 214         unsigned long flags;
 215         struct uhid_event *ev;
 216
 217         switch (report_type) {
 218         case HID_FEATURE_REPORT:
 219                 rtype = UHID_FEATURE_REPORT;
 220                 break;
 221         case HID_OUTPUT_REPORT:
 222                 rtype = UHID_OUTPUT_REPORT;
 223                 break;
 224         default:
 225                 return -EINVAL;
 226         }
 227
 228         if (count < 1 || count > UHID_DATA_MAX)
 229                 return -EINVAL;
 230
 231         ev = kzalloc(sizeof(*ev), GFP_KERNEL);
 232         if (!ev)
 233                 return -ENOMEM;
 234
 235         ev->type = UHID_OUTPUT;
 236         ev->u.output.size = count;
 237         ev->u.output.rtype = rtype;
 238         memcpy(ev->u.output.data, buf, count);
 239
 240         spin_lock_irqsave(&uhid->qlock, flags);
 241         uhid_queue(uhid, ev);
 242         spin_unlock_irqrestore(&uhid->qlock, flags);
 243
 244         return count;
 245 }
 246
 247 static int uhid_hid_output_report(struct hid_device *hid, __u8 *buf,
 248                                   size_t count)
 249 {
 250         return uhid_hid_output_raw(hid, buf, count, HID_OUTPUT_REPORT);
 251 }
 252
 253 static int uhid_raw_request(struct hid_device *hid, unsigned char reportnum,
 254                             __u8 *buf, size_t len, unsigned char rtype,
 255                             int reqtype)
 256 {
 257         switch (reqtype) {
 258         case HID_REQ_GET_REPORT:
 259                 return uhid_hid_get_raw(hid, reportnum, buf, len, rtype);
 260         case HID_REQ_SET_REPORT:
 261                 /* TODO: implement proper SET_REPORT functionality */
 262                 return -ENOSYS;
 263         default:
 264                 return -EIO;
 265         }
 266 }
 267
 268 static struct hid_ll_driver uhid_hid_driver = {
 269         .start = uhid_hid_start,
 270         .stop = uhid_hid_stop,
 271         .open = uhid_hid_open,
 272         .close = uhid_hid_close,
 273         .parse = uhid_hid_parse,
 274         .output_report = uhid_hid_output_report,
 275         .raw_request = uhid_raw_request,
 276 };
 277
 278 #ifdef CONFIG_COMPAT
 279
 280 /* Apparently we haven't stepped on these rakes enough times yet. */
 281 struct uhid_create_req_compat {
 282         __u8 name[128];
 283         __u8 phys[64];
 284         __u8 uniq[64];
 285
 286         compat_uptr_t rd_data;
 287         __u16 rd_size;
 288
 289         __u16 bus;
 290         __u32 vendor;
 291         __u32 product;
 292         __u32 version;
 293         __u32 country;
 294 } __attribute__((__packed__));
 295
 296 static int uhid_event_from_user(const char __user *buffer, size_t len,
 297                                 struct uhid_event *event)
 298 {
 299         if (is_compat_task()) {
 300                 u32 type;
 301
 302                 if (get_user(type, buffer))
 303                         return -EFAULT;
 304
 305                 if (type == UHID_CREATE) {
 306                         /*
 307                          * This is our messed up request with compat pointer.
 308                          * It is largish (more than 256 bytes) so we better
 309                          * allocate it from the heap.
 310                          */
 311                         struct uhid_create_req_compat *compat;
 312
 313                         compat = kzalloc(sizeof(*compat), GFP_KERNEL);
 314                         if (!compat)
 315                                 return -ENOMEM;
 316
 317                         buffer += sizeof(type);
 318                         len -= sizeof(type);
 319                         if (copy_from_user(compat, buffer,
 320                                            min(len, sizeof(*compat)))) {
 321                                 kfree(compat);
 322                                 return -EFAULT;
 323                         }
 324
 325                         /* Shuffle the data over to proper structure */
 326                         event->type = type;
 327
 328                         memcpy(event->u.create.name, compat->name,
 329                                 sizeof(compat->name));
 330                         memcpy(event->u.create.phys, compat->phys,
 331                                 sizeof(compat->phys));
 332                         memcpy(event->u.create.uniq, compat->uniq,
 333                                 sizeof(compat->uniq));
 334
 335                         event->u.create.rd_data = compat_ptr(compat->rd_data);
 336                         event->u.create.rd_size = compat->rd_size;
 337
 338                         event->u.create.bus = compat->bus;
 339                         event->u.create.vendor = compat->vendor;
 340                         event->u.create.product = compat->product;
 341                         event->u.create.version = compat->version;
 342                         event->u.create.country = compat->country;
 343
 344                         kfree(compat);
 345                         return 0;
 346                 }
 347                 /* All others can be copied directly */
 348         }
 349
 350         if (copy_from_user(event, buffer, min(len, sizeof(*event))))
 351                 return -EFAULT;
 352
 353         return 0;
 354 }
 355 #else
 356 static int uhid_event_from_user(const char __user *buffer, size_t len,
 357                                 struct uhid_event *event)
 358 {
 359         if (copy_from_user(event, buffer, min(len, sizeof(*event))))
 360                 return -EFAULT;
 361
 362         return 0;
 363 }
 364 #endif
 365
 366 static int uhid_dev_create(struct uhid_device *uhid,
 367                            const struct uhid_event *ev)
 368 {
 369         struct hid_device *hid;
 370         int ret;
 371
 372         if (uhid->running)
 373                 return -EALREADY;
 374
 375         uhid->rd_size = ev->u.create.rd_size;
 376         if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE)
 377                 return -EINVAL;
 378
 379         uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL);
 380         if (!uhid->rd_data)
 381                 return -ENOMEM;
 382
 383         if (copy_from_user(uhid->rd_data, ev->u.create.rd_data,
 384                            uhid->rd_size)) {
 385                 ret = -EFAULT;
 386                 goto err_free;
 387         }
 388
 389         hid = hid_allocate_device();
 390         if (IS_ERR(hid)) {
 391                 ret = PTR_ERR(hid);
 392                 goto err_free;
 393         }
 394
 395         strncpy(hid->name, ev->u.create.name, 127);
 396         hid->name[127] = 0;
 397         strncpy(hid->phys, ev->u.create.phys, 63);
 398         hid->phys[63] = 0;
 399         strncpy(hid->uniq, ev->u.create.uniq, 63);
 400         hid->uniq[63] = 0;
 401
 402         hid->ll_driver = &uhid_hid_driver;
 403         hid->bus = ev->u.create.bus;
 404         hid->vendor = ev->u.create.vendor;
 405         hid->product = ev->u.create.product;
 406         hid->version = ev->u.create.version;
 407         hid->country = ev->u.create.country;
 408         hid->driver_data = uhid;
 409         hid->dev.parent = uhid_misc.this_device;
 410
 411         uhid->hid = hid;
 412         uhid->running = true;
 413
 414         ret = hid_add_device(hid);
 415         if (ret) {
 416                 hid_err(hid, "Cannot register HID device\n");
 417                 goto err_hid;
 418         }
 419
 420         return 0;
 421
 422 err_hid:
 423         hid_destroy_device(hid);
 424         uhid->hid = NULL;
 425         uhid->running = false;
 426 err_free:
 427         kfree(uhid->rd_data);
 428         return ret;
 429 }
 430
 431 static int uhid_dev_create2(struct uhid_device *uhid,
 432                             const struct uhid_event *ev)
 433 {
 434         struct hid_device *hid;
 435         int ret;
 436
 437         if (uhid->running)
 438                 return -EALREADY;
 439
 440         uhid->rd_size = ev->u.create2.rd_size;
 441         if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE)
 442                 return -EINVAL;
 443
 444         uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL);
 445         if (!uhid->rd_data)
 446                 return -ENOMEM;
 447
 448         memcpy(uhid->rd_data, ev->u.create2.rd_data, uhid->rd_size);
 449
 450         hid = hid_allocate_device();
 451         if (IS_ERR(hid)) {
 452                 ret = PTR_ERR(hid);
 453                 goto err_free;
 454         }
 455
 456         strncpy(hid->name, ev->u.create2.name, 127);
 457         hid->name[127] = 0;
 458         strncpy(hid->phys, ev->u.create2.phys, 63);
 459         hid->phys[63] = 0;
 460         strncpy(hid->uniq, ev->u.create2.uniq, 63);
 461         hid->uniq[63] = 0;
 462
 463         hid->ll_driver = &uhid_hid_driver;
 464         hid->bus = ev->u.create2.bus;
 465         hid->vendor = ev->u.create2.vendor;
 466         hid->product = ev->u.create2.product;
 467         hid->version = ev->u.create2.version;
 468         hid->country = ev->u.create2.country;
 469         hid->driver_data = uhid;
 470         hid->dev.parent = uhid_misc.this_device;
 471
 472         uhid->hid = hid;
 473         uhid->running = true;
 474
 475         ret = hid_add_device(hid);
 476         if (ret) {
 477                 hid_err(hid, "Cannot register HID device\n");
 478                 goto err_hid;
 479         }
 480
 481         return 0;
 482
 483 err_hid:
 484         hid_destroy_device(hid);
 485         uhid->hid = NULL;
 486         uhid->running = false;
 487 err_free:
 488         kfree(uhid->rd_data);
 489         return ret;
 490 }
 491
 492 static int uhid_dev_destroy(struct uhid_device *uhid)
 493 {
 494         if (!uhid->running)
 495                 return -EINVAL;
 496
 497         /* clear "running" before setting "report_done" */
 498         uhid->running = false;
 499         smp_wmb();
 500         atomic_set(&uhid->report_done, 1);
 501         wake_up_interruptible(&uhid->report_wait);
 502
 503         hid_destroy_device(uhid->hid);
 504         kfree(uhid->rd_data);
 505
 506         return 0;
 507 }
 508
 509 static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev)
 510 {
 511         if (!uhid->running)
 512                 return -EINVAL;
 513
 514         hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data,
 515                          min_t(size_t, ev->u.input.size, UHID_DATA_MAX), 0);
 516
 517         return 0;
 518 }
 519
 520 static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev)
 521 {
 522         if (!uhid->running)
 523                 return -EINVAL;
 524
 525         hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data,
 526                          min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0);
 527
 528         return 0;
 529 }
 530
 531 static int uhid_dev_feature_answer(struct uhid_device *uhid,
 532                                    struct uhid_event *ev)
 533 {
 534         unsigned long flags;
 535
 536         if (!uhid->running)
 537                 return -EINVAL;
 538
 539         spin_lock_irqsave(&uhid->qlock, flags);
 540
 541         /* id for old report; drop it silently */
 542         if (atomic_read(&uhid->report_id) != ev->u.feature_answer.id)
 543                 goto unlock;
 544         if (atomic_read(&uhid->report_done))
 545                 goto unlock;
 546
 547         memcpy(&uhid->report_buf, ev, sizeof(*ev));
 548         atomic_set(&uhid->report_done, 1);
 549         wake_up_interruptible(&uhid->report_wait);
 550
 551 unlock:
 552         spin_unlock_irqrestore(&uhid->qlock, flags);
 553         return 0;
 554 }
 555
 556 static int uhid_char_open(struct inode *inode, struct file *file)
 557 {
 558         struct uhid_device *uhid;
 559
 560         uhid = kzalloc(sizeof(*uhid), GFP_KERNEL);
 561         if (!uhid)
 562                 return -ENOMEM;
 563
 564         mutex_init(&uhid->devlock);
 565         mutex_init(&uhid->report_lock);
 566         spin_lock_init(&uhid->qlock);
 567         init_waitqueue_head(&uhid->waitq);
 568         init_waitqueue_head(&uhid->report_wait);
 569         uhid->running = false;
 570         atomic_set(&uhid->report_done, 1);
 571
 572         file->private_data = uhid;
 573         nonseekable_open(inode, file);
 574
 575         return 0;
 576 }
 577
 578 static int uhid_char_release(struct inode *inode, struct file *file)
 579 {
 580         struct uhid_device *uhid = file->private_data;
 581         unsigned int i;
 582
 583         uhid_dev_destroy(uhid);
 584
 585         for (i = 0; i < UHID_BUFSIZE; ++i)
 586                 kfree(uhid->outq[i]);
 587
 588         kfree(uhid);
 589
 590         return 0;
 591 }
 592
 593 static ssize_t uhid_char_read(struct file *file, char __user *buffer,
 594                                 size_t count, loff_t *ppos)
 595 {
 596         struct uhid_device *uhid = file->private_data;
 597         int ret;
 598         unsigned long flags;
 599         size_t len;
 600
 601         /* they need at least the "type" member of uhid_event */
 602         if (count < sizeof(__u32))
 603                 return -EINVAL;
 604
 605 try_again:
 606         if (file->f_flags & O_NONBLOCK) {
 607                 if (uhid->head == uhid->tail)
 608                         return -EAGAIN;
 609         } else {
 610                 ret = wait_event_interruptible(uhid->waitq,
 611                                                 uhid->head != uhid->tail);
 612                 if (ret)
 613                         return ret;
 614         }
 615
 616         ret = mutex_lock_interruptible(&uhid->devlock);
 617         if (ret)
 618                 return ret;
 619
 620         if (uhid->head == uhid->tail) {
 621                 mutex_unlock(&uhid->devlock);
 622                 goto try_again;
 623         } else {
 624                 len = min(count, sizeof(**uhid->outq));
 625                 if (copy_to_user(buffer, uhid->outq[uhid->tail], len)) {
 626                         ret = -EFAULT;
 627                 } else {
 628                         kfree(uhid->outq[uhid->tail]);
 629                         uhid->outq[uhid->tail] = NULL;
 630
 631                         spin_lock_irqsave(&uhid->qlock, flags);
 632                         uhid->tail = (uhid->tail + 1) % UHID_BUFSIZE;
 633                         spin_unlock_irqrestore(&uhid->qlock, flags);
 634                 }
 635         }
 636
 637         mutex_unlock(&uhid->devlock);
 638         return ret ? ret : len;
 639 }
 640
 641 static ssize_t uhid_char_write(struct file *file, const char __user *buffer,
 642                                 size_t count, loff_t *ppos)
 643 {
 644         struct uhid_device *uhid = file->private_data;
 645         int ret;
 646         size_t len;
 647
 648         /* we need at least the "type" member of uhid_event */
 649         if (count < sizeof(__u32))
 650                 return -EINVAL;
 651
 652         ret = mutex_lock_interruptible(&uhid->devlock);
 653         if (ret)
 654                 return ret;
 655
 656         memset(&uhid->input_buf, 0, sizeof(uhid->input_buf));
 657         len = min(count, sizeof(uhid->input_buf));
 658
 659         ret = uhid_event_from_user(buffer, len, &uhid->input_buf);
 660         if (ret)
 661                 goto unlock;
 662
 663         switch (uhid->input_buf.type) {
 664         case UHID_CREATE:
 665                 ret = uhid_dev_create(uhid, &uhid->input_buf);
 666                 break;
 667         case UHID_CREATE2:
 668                 ret = uhid_dev_create2(uhid, &uhid->input_buf);
 669                 break;
 670         case UHID_DESTROY:
 671                 ret = uhid_dev_destroy(uhid);
 672                 break;
 673         case UHID_INPUT:
 674                 ret = uhid_dev_input(uhid, &uhid->input_buf);
 675                 break;
 676         case UHID_INPUT2:
 677                 ret = uhid_dev_input2(uhid, &uhid->input_buf);
 678                 break;
 679         case UHID_FEATURE_ANSWER:
 680                 ret = uhid_dev_feature_answer(uhid, &uhid->input_buf);
 681                 break;
 682         default:
 683                 ret = -EOPNOTSUPP;
 684         }
 685
 686 unlock:
 687         mutex_unlock(&uhid->devlock);
 688
 689         /* return "count" not "len" to not confuse the caller */
 690         return ret ? ret : count;
 691 }
 692
 693 static unsigned int uhid_char_poll(struct file *file, poll_table *wait)
 694 {
 695         struct uhid_device *uhid = file->private_data;
 696
 697         poll_wait(file, &uhid->waitq, wait);
 698
 699         if (uhid->head != uhid->tail)
 700                 return POLLIN | POLLRDNORM;
 701
 702         return 0;
 703 }
 704
 705 static const struct file_operations uhid_fops = {
 706         .owner          = THIS_MODULE,
 707         .open           = uhid_char_open,
 708         .release        = uhid_char_release,
 709         .read           = uhid_char_read,
 710         .write          = uhid_char_write,
 711         .poll           = uhid_char_poll,
 712         .llseek         = no_llseek,
 713 };
 714
 715 static struct miscdevice uhid_misc = {
 716         .fops           = &uhid_fops,
 717         .minor          = UHID_MINOR,
 718         .name           = UHID_NAME,
 719 };
 720
 721 static int __init uhid_init(void)
 722 {
 723         return misc_register(&uhid_misc);
 724 }
 725
 726 static void __exit uhid_exit(void)
 727 {
 728         misc_deregister(&uhid_misc);
 729 }
 730
 731 module_init(uhid_init);
 732 module_exit(uhid_exit);
 733 MODULE_LICENSE("GPL");
 734 MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>");
 735 MODULE_DESCRIPTION("User-space I/O driver support for HID subsystem");
 736 MODULE_ALIAS_MISCDEV(UHID_MINOR);
 737 MODULE_ALIAS("devname:" UHID_NAME);