drivers/input/evdev.c

   1 /*
   2  * Event char devices, giving access to raw input device events.
   3  *
   4  * Copyright (c) 1999-2002 Vojtech Pavlik
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published by
   8  * the Free Software Foundation.
   9  */
  10
  11 #define EVDEV_MINOR_BASE        64
  12 #define EVDEV_MINORS            32
  13 #define EVDEV_BUFFER_SIZE       64
  14
  15 #include <linux/poll.h>
  16 #include <linux/sched.h>
  17 #include <linux/slab.h>
  18 #include <linux/module.h>
  19 #include <linux/init.h>
  20 #include <linux/input.h>
  21 #include <linux/major.h>
  22 #include <linux/device.h>
  23 #include "input-compat.h"
  24
  25 struct evdev {
  26         int exist;
  27         int open;
  28         int minor;
  29         struct input_handle handle;
  30         wait_queue_head_t wait;
  31         struct evdev_client *grab;
  32         struct list_head client_list;
  33         spinlock_t client_lock; /* protects client_list */
  34         struct mutex mutex;
  35         struct device dev;
  36 };
  37
  38 struct evdev_client {
  39         struct input_event buffer[EVDEV_BUFFER_SIZE];
  40         int head;
  41         int tail;
  42         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  43         struct fasync_struct *fasync;
  44         struct evdev *evdev;
  45         struct list_head node;
  46 };
  47
  48 static struct evdev *evdev_table[EVDEV_MINORS];
  49 static DEFINE_MUTEX(evdev_table_mutex);
  50
  51 static void evdev_pass_event(struct evdev_client *client,
  52                              struct input_event *event)
  53 {
  54         /*
  55          * Interrupts are disabled, just acquire the lock
  56          */
  57         spin_lock(&client->buffer_lock);
  58         client->buffer[client->head++] = *event;
  59         client->head &= EVDEV_BUFFER_SIZE - 1;
  60         spin_unlock(&client->buffer_lock);
  61
  62         if (event->type == EV_SYN)
  63                 kill_fasync(&client->fasync, SIGIO, POLL_IN);
  64 }
  65
  66 /*
  67  * Pass incoming event to all connected clients.
  68  */
  69 static void evdev_event(struct input_handle *handle,
  70                         unsigned int type, unsigned int code, int value)
  71 {
  72         struct evdev *evdev = handle->private;
  73         struct evdev_client *client;
  74         struct input_event event;
  75
  76         do_gettimeofday(&event.time);
  77         event.type = type;
  78         event.code = code;
  79         event.value = value;
  80
  81         rcu_read_lock();
  82
  83         client = rcu_dereference(evdev->grab);
  84         if (client)
  85                 evdev_pass_event(client, &event);
  86         else
  87                 list_for_each_entry_rcu(client, &evdev->client_list, node)
  88                         evdev_pass_event(client, &event);
  89
  90         rcu_read_unlock();
  91
  92         wake_up_interruptible(&evdev->wait);
  93 }
  94
  95 static int evdev_fasync(int fd, struct file *file, int on)
  96 {
  97         struct evdev_client *client = file->private_data;
  98
  99         return fasync_helper(fd, file, on, &client->fasync);
 100 }
 101
 102 static int evdev_flush(struct file *file, fl_owner_t id)
 103 {
 104         struct evdev_client *client = file->private_data;
 105         struct evdev *evdev = client->evdev;
 106         int retval;
 107
 108         retval = mutex_lock_interruptible(&evdev->mutex);
 109         if (retval)
 110                 return retval;
 111
 112         if (!evdev->exist)
 113                 retval = -ENODEV;
 114         else
 115                 retval = input_flush_device(&evdev->handle, file);
 116
 117         mutex_unlock(&evdev->mutex);
 118         return retval;
 119 }
 120
 121 static void evdev_free(struct device *dev)
 122 {
 123         struct evdev *evdev = container_of(dev, struct evdev, dev);
 124
 125         input_put_device(evdev->handle.dev);
 126         kfree(evdev);
 127 }
 128
 129 /*
 130  * Grabs an event device (along with underlying input device).
 131  * This function is called with evdev->mutex taken.
 132  */
 133 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 134 {
 135         int error;
 136
 137         if (evdev->grab)
 138                 return -EBUSY;
 139
 140         error = input_grab_device(&evdev->handle);
 141         if (error)
 142                 return error;
 143
 144         rcu_assign_pointer(evdev->grab, client);
 145         synchronize_rcu();
 146
 147         return 0;
 148 }
 149
 150 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 151 {
 152         if (evdev->grab != client)
 153                 return  -EINVAL;
 154
 155         rcu_assign_pointer(evdev->grab, NULL);
 156         synchronize_rcu();
 157         input_release_device(&evdev->handle);
 158
 159         return 0;
 160 }
 161
 162 static void evdev_attach_client(struct evdev *evdev,
 163                                 struct evdev_client *client)
 164 {
 165         spin_lock(&evdev->client_lock);
 166         list_add_tail_rcu(&client->node, &evdev->client_list);
 167         spin_unlock(&evdev->client_lock);
 168         synchronize_rcu();
 169 }
 170
 171 static void evdev_detach_client(struct evdev *evdev,
 172                                 struct evdev_client *client)
 173 {
 174         spin_lock(&evdev->client_lock);
 175         list_del_rcu(&client->node);
 176         spin_unlock(&evdev->client_lock);
 177         synchronize_rcu();
 178 }
 179
 180 static int evdev_open_device(struct evdev *evdev)
 181 {
 182         int retval;
 183
 184         retval = mutex_lock_interruptible(&evdev->mutex);
 185         if (retval)
 186                 return retval;
 187
 188         if (!evdev->exist)
 189                 retval = -ENODEV;
 190         else if (!evdev->open++) {
 191                 retval = input_open_device(&evdev->handle);
 192                 if (retval)
 193                         evdev->open--;
 194         }
 195
 196         mutex_unlock(&evdev->mutex);
 197         return retval;
 198 }
 199
 200 static void evdev_close_device(struct evdev *evdev)
 201 {
 202         mutex_lock(&evdev->mutex);
 203
 204         if (evdev->exist && !--evdev->open)
 205                 input_close_device(&evdev->handle);
 206
 207         mutex_unlock(&evdev->mutex);
 208 }
 209
 210 /*
 211  * Wake up users waiting for IO so they can disconnect from
 212  * dead device.
 213  */
 214 static void evdev_hangup(struct evdev *evdev)
 215 {
 216         struct evdev_client *client;
 217
 218         spin_lock(&evdev->client_lock);
 219         list_for_each_entry(client, &evdev->client_list, node)
 220                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 221         spin_unlock(&evdev->client_lock);
 222
 223         wake_up_interruptible(&evdev->wait);
 224 }
 225
 226 static int evdev_release(struct inode *inode, struct file *file)
 227 {
 228         struct evdev_client *client = file->private_data;
 229         struct evdev *evdev = client->evdev;
 230
 231         mutex_lock(&evdev->mutex);
 232         if (evdev->grab == client)
 233                 evdev_ungrab(evdev, client);
 234         mutex_unlock(&evdev->mutex);
 235
 236         evdev_detach_client(evdev, client);
 237         kfree(client);
 238
 239         evdev_close_device(evdev);
 240         put_device(&evdev->dev);
 241
 242         return 0;
 243 }
 244
 245 static int evdev_open(struct inode *inode, struct file *file)
 246 {
 247         struct evdev *evdev;
 248         struct evdev_client *client;
 249         int i = iminor(inode) - EVDEV_MINOR_BASE;
 250         int error;
 251
 252         if (i >= EVDEV_MINORS)
 253                 return -ENODEV;
 254
 255         error = mutex_lock_interruptible(&evdev_table_mutex);
 256         if (error)
 257                 return error;
 258         evdev = evdev_table[i];
 259         if (evdev)
 260                 get_device(&evdev->dev);
 261         mutex_unlock(&evdev_table_mutex);
 262
 263         if (!evdev)
 264                 return -ENODEV;
 265
 266         client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
 267         if (!client) {
 268                 error = -ENOMEM;
 269                 goto err_put_evdev;
 270         }
 271
 272         spin_lock_init(&client->buffer_lock);
 273         client->evdev = evdev;
 274         evdev_attach_client(evdev, client);
 275
 276         error = evdev_open_device(evdev);
 277         if (error)
 278                 goto err_free_client;
 279
 280         file->private_data = client;
 281         nonseekable_open(inode, file);
 282
 283         return 0;
 284
 285  err_free_client:
 286         evdev_detach_client(evdev, client);
 287         kfree(client);
 288  err_put_evdev:
 289         put_device(&evdev->dev);
 290         return error;
 291 }
 292
 293 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 294                            size_t count, loff_t *ppos)
 295 {
 296         struct evdev_client *client = file->private_data;
 297         struct evdev *evdev = client->evdev;
 298         struct input_event event;
 299         int retval;
 300
 301         retval = mutex_lock_interruptible(&evdev->mutex);
 302         if (retval)
 303                 return retval;
 304
 305         if (!evdev->exist) {
 306                 retval = -ENODEV;
 307                 goto out;
 308         }
 309
 310         while (retval < count) {
 311
 312                 if (input_event_from_user(buffer + retval, &event)) {
 313                         retval = -EFAULT;
 314                         goto out;
 315                 }
 316
 317                 input_inject_event(&evdev->handle,
 318                                    event.type, event.code, event.value);
 319                 retval += input_event_size();
 320         }
 321
 322  out:
 323         mutex_unlock(&evdev->mutex);
 324         return retval;
 325 }
 326
 327 static int evdev_fetch_next_event(struct evdev_client *client,
 328                                   struct input_event *event)
 329 {
 330         int have_event;
 331
 332         spin_lock_irq(&client->buffer_lock);
 333
 334         have_event = client->head != client->tail;
 335         if (have_event) {
 336                 *event = client->buffer[client->tail++];
 337                 client->tail &= EVDEV_BUFFER_SIZE - 1;
 338         }
 339
 340         spin_unlock_irq(&client->buffer_lock);
 341
 342         return have_event;
 343 }
 344
 345 static ssize_t evdev_read(struct file *file, char __user *buffer,
 346                           size_t count, loff_t *ppos)
 347 {
 348         struct evdev_client *client = file->private_data;
 349         struct evdev *evdev = client->evdev;
 350         struct input_event event;
 351         int retval;
 352
 353         if (count < input_event_size())
 354                 return -EINVAL;
 355
 356         if (client->head == client->tail && evdev->exist &&
 357             (file->f_flags & O_NONBLOCK))
 358                 return -EAGAIN;
 359
 360         retval = wait_event_interruptible(evdev->wait,
 361                 client->head != client->tail || !evdev->exist);
 362         if (retval)
 363                 return retval;
 364
 365         if (!evdev->exist)
 366                 return -ENODEV;
 367
 368         while (retval + input_event_size() <= count &&
 369                evdev_fetch_next_event(client, &event)) {
 370
 371                 if (input_event_to_user(buffer + retval, &event))
 372                         return -EFAULT;
 373
 374                 retval += input_event_size();
 375         }
 376
 377         return retval;
 378 }
 379
 380 /* No kernel lock - fine */
 381 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 382 {
 383         struct evdev_client *client = file->private_data;
 384         struct evdev *evdev = client->evdev;
 385
 386         poll_wait(file, &evdev->wait, wait);
 387         return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 388                 (evdev->exist ? 0 : (POLLHUP | POLLERR));
 389 }
 390
 391 #ifdef CONFIG_COMPAT
 392
 393 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 394 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 395
 396 #ifdef __BIG_ENDIAN
 397 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 398                         unsigned int maxlen, void __user *p, int compat)
 399 {
 400         int len, i;
 401
 402         if (compat) {
 403                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 404                 if (len > maxlen)
 405                         len = maxlen;
 406
 407                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 408                         if (copy_to_user((compat_long_t __user *) p + i,
 409                                          (compat_long_t *) bits +
 410                                                 i + 1 - ((i % 2) << 1),
 411                                          sizeof(compat_long_t)))
 412                                 return -EFAULT;
 413         } else {
 414                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 415                 if (len > maxlen)
 416                         len = maxlen;
 417
 418                 if (copy_to_user(p, bits, len))
 419                         return -EFAULT;
 420         }
 421
 422         return len;
 423 }
 424 #else
 425 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 426                         unsigned int maxlen, void __user *p, int compat)
 427 {
 428         int len = compat ?
 429                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 430                         BITS_TO_LONGS(maxbit) * sizeof(long);
 431
 432         if (len > maxlen)
 433                 len = maxlen;
 434
 435         return copy_to_user(p, bits, len) ? -EFAULT : len;
 436 }
 437 #endif /* __BIG_ENDIAN */
 438
 439 #else
 440
 441 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 442                         unsigned int maxlen, void __user *p, int compat)
 443 {
 444         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 445
 446         if (len > maxlen)
 447                 len = maxlen;
 448
 449         return copy_to_user(p, bits, len) ? -EFAULT : len;
 450 }
 451
 452 #endif /* CONFIG_COMPAT */
 453
 454 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 455 {
 456         int len;
 457
 458         if (!str)
 459                 return -ENOENT;
 460
 461         len = strlen(str) + 1;
 462         if (len > maxlen)
 463                 len = maxlen;
 464
 465         return copy_to_user(p, str, len) ? -EFAULT : len;
 466 }
 467
 468 #define OLD_KEY_MAX     0x1ff
 469 static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
 470 {
 471         static unsigned long keymax_warn_time;
 472         unsigned long *bits;
 473         int len;
 474
 475         switch (_IOC_NR(cmd) & EV_MAX) {
 476
 477         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 478         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 479         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 480         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 481         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 482         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 483         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 484         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 485         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 486         default: return -EINVAL;
 487         }
 488
 489         /*
 490          * Work around bugs in userspace programs that like to do
 491          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
 492          * should be in bytes, not in bits.
 493          */
 494         if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
 495                 len = OLD_KEY_MAX;
 496                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
 497                         printk(KERN_WARNING
 498                                 "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
 499                                 "limiting output to %zu bytes. See "
 500                                 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
 501                                 OLD_KEY_MAX,
 502                                 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
 503         }
 504
 505         return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
 506 }
 507 #undef OLD_KEY_MAX
 508
 509 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 510                            void __user *p, int compat_mode)
 511 {
 512         struct evdev_client *client = file->private_data;
 513         struct evdev *evdev = client->evdev;
 514         struct input_dev *dev = evdev->handle.dev;
 515         struct input_absinfo abs;
 516         struct ff_effect effect;
 517         int __user *ip = (int __user *)p;
 518         unsigned int i, t, u, v;
 519         int error;
 520
 521         switch (cmd) {
 522
 523         case EVIOCGVERSION:
 524                 return put_user(EV_VERSION, ip);
 525
 526         case EVIOCGID:
 527                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
 528                         return -EFAULT;
 529                 return 0;
 530
 531         case EVIOCGREP:
 532                 if (!test_bit(EV_REP, dev->evbit))
 533                         return -ENOSYS;
 534                 if (put_user(dev->rep[REP_DELAY], ip))
 535                         return -EFAULT;
 536                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
 537                         return -EFAULT;
 538                 return 0;
 539
 540         case EVIOCSREP:
 541                 if (!test_bit(EV_REP, dev->evbit))
 542                         return -ENOSYS;
 543                 if (get_user(u, ip))
 544                         return -EFAULT;
 545                 if (get_user(v, ip + 1))
 546                         return -EFAULT;
 547
 548                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
 549                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
 550
 551                 return 0;
 552
 553         case EVIOCGKEYCODE:
 554                 if (get_user(t, ip))
 555                         return -EFAULT;
 556
 557                 error = input_get_keycode(dev, t, &v);
 558                 if (error)
 559                         return error;
 560
 561                 if (put_user(v, ip + 1))
 562                         return -EFAULT;
 563
 564                 return 0;
 565
 566         case EVIOCSKEYCODE:
 567                 if (get_user(t, ip) || get_user(v, ip + 1))
 568                         return -EFAULT;
 569
 570                 return input_set_keycode(dev, t, v);
 571
 572         case EVIOCRMFF:
 573                 return input_ff_erase(dev, (int)(unsigned long) p, file);
 574
 575         case EVIOCGEFFECTS:
 576                 i = test_bit(EV_FF, dev->evbit) ?
 577                                 dev->ff->max_effects : 0;
 578                 if (put_user(i, ip))
 579                         return -EFAULT;
 580                 return 0;
 581
 582         case EVIOCGRAB:
 583                 if (p)
 584                         return evdev_grab(evdev, client);
 585                 else
 586                         return evdev_ungrab(evdev, client);
 587
 588         default:
 589
 590                 if (_IOC_TYPE(cmd) != 'E')
 591                         return -EINVAL;
 592
 593                 if (_IOC_DIR(cmd) == _IOC_READ) {
 594
 595                         if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
 596                                 return handle_eviocgbit(dev, cmd, p, compat_mode);
 597
 598                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
 599                                 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
 600                                                     p, compat_mode);
 601
 602                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
 603                                 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
 604                                                     p, compat_mode);
 605
 606                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
 607                                 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
 608                                                     p, compat_mode);
 609
 610                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
 611                                 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
 612                                                     p, compat_mode);
 613
 614                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
 615                                 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
 616
 617                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
 618                                 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
 619
 620                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
 621                                 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
 622
 623                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 624
 625                                 t = _IOC_NR(cmd) & ABS_MAX;
 626
 627                                 abs.value = dev->abs[t];
 628                                 abs.minimum = dev->absmin[t];
 629                                 abs.maximum = dev->absmax[t];
 630                                 abs.fuzz = dev->absfuzz[t];
 631                                 abs.flat = dev->absflat[t];
 632                                 abs.resolution = dev->absres[t];
 633
 634                                 if (copy_to_user(p, &abs, min_t(size_t,
 635                                                                 _IOC_SIZE(cmd),
 636                                                                 sizeof(struct input_absinfo))))
 637                                         return -EFAULT;
 638
 639                                 return 0;
 640                         }
 641
 642                 }
 643
 644                 if (_IOC_DIR(cmd) == _IOC_WRITE) {
 645
 646                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {
 647
 648                                 if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
 649                                         return -EFAULT;
 650
 651                                 error = input_ff_upload(dev, &effect, file);
 652
 653                                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
 654                                         return -EFAULT;
 655
 656                                 return error;
 657                         }
 658
 659                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
 660
 661                                 t = _IOC_NR(cmd) & ABS_MAX;
 662
 663                                 if (copy_from_user(&abs, p, min_t(size_t,
 664                                                                   _IOC_SIZE(cmd),
 665                                                                   sizeof(struct input_absinfo))))
 666                                         return -EFAULT;
 667
 668                                 /*
 669                                  * Take event lock to ensure that we are not
 670                                  * changing device parameters in the middle
 671                                  * of event.
 672                                  */
 673                                 spin_lock_irq(&dev->event_lock);
 674
 675                                 dev->abs[t] = abs.value;
 676                                 dev->absmin[t] = abs.minimum;
 677                                 dev->absmax[t] = abs.maximum;
 678                                 dev->absfuzz[t] = abs.fuzz;
 679                                 dev->absflat[t] = abs.flat;
 680                                 dev->absres[t] = _IOC_SIZE(cmd) < sizeof(struct input_absinfo) ?
 681                                                         0 : abs.resolution;
 682
 683                                 spin_unlock_irq(&dev->event_lock);
 684
 685                                 return 0;
 686                         }
 687                 }
 688         }
 689         return -EINVAL;
 690 }
 691
 692 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
 693                                 void __user *p, int compat_mode)
 694 {
 695         struct evdev_client *client = file->private_data;
 696         struct evdev *evdev = client->evdev;
 697         int retval;
 698
 699         retval = mutex_lock_interruptible(&evdev->mutex);
 700         if (retval)
 701                 return retval;
 702
 703         if (!evdev->exist) {
 704                 retval = -ENODEV;
 705                 goto out;
 706         }
 707
 708         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
 709
 710  out:
 711         mutex_unlock(&evdev->mutex);
 712         return retval;
 713 }
 714
 715 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 716 {
 717         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
 718 }
 719
 720 #ifdef CONFIG_COMPAT
 721 static long evdev_ioctl_compat(struct file *file,
 722                                 unsigned int cmd, unsigned long arg)
 723 {
 724         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
 725 }
 726 #endif
 727
 728 static const struct file_operations evdev_fops = {
 729         .owner          = THIS_MODULE,
 730         .read           = evdev_read,
 731         .write          = evdev_write,
 732         .poll           = evdev_poll,
 733         .open           = evdev_open,
 734         .release        = evdev_release,
 735         .unlocked_ioctl = evdev_ioctl,
 736 #ifdef CONFIG_COMPAT
 737         .compat_ioctl   = evdev_ioctl_compat,
 738 #endif
 739         .fasync         = evdev_fasync,
 740         .flush          = evdev_flush
 741 };
 742
 743 static int evdev_install_chrdev(struct evdev *evdev)
 744 {
 745         /*
 746          * No need to do any locking here as calls to connect and
 747          * disconnect are serialized by the input core
 748          */
 749         evdev_table[evdev->minor] = evdev;
 750         return 0;
 751 }
 752
 753 static void evdev_remove_chrdev(struct evdev *evdev)
 754 {
 755         /*
 756          * Lock evdev table to prevent race with evdev_open()
 757          */
 758         mutex_lock(&evdev_table_mutex);
 759         evdev_table[evdev->minor] = NULL;
 760         mutex_unlock(&evdev_table_mutex);
 761 }
 762
 763 /*
 764  * Mark device non-existent. This disables writes, ioctls and
 765  * prevents new users from opening the device. Already posted
 766  * blocking reads will stay, however new ones will fail.
 767  */
 768 static void evdev_mark_dead(struct evdev *evdev)
 769 {
 770         mutex_lock(&evdev->mutex);
 771         evdev->exist = 0;
 772         mutex_unlock(&evdev->mutex);
 773 }
 774
 775 static void evdev_cleanup(struct evdev *evdev)
 776 {
 777         struct input_handle *handle = &evdev->handle;
 778
 779         evdev_mark_dead(evdev);
 780         evdev_hangup(evdev);
 781         evdev_remove_chrdev(evdev);
 782
 783         /* evdev is marked dead so no one else accesses evdev->open */
 784         if (evdev->open) {
 785                 input_flush_device(handle, NULL);
 786                 input_close_device(handle);
 787         }
 788 }
 789
 790 /*
 791  * Create new evdev device. Note that input core serializes calls
 792  * to connect and disconnect so we don't need to lock evdev_table here.
 793  */
 794 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 795                          const struct input_device_id *id)
 796 {
 797         struct evdev *evdev;
 798         int minor;
 799         int error;
 800
 801         for (minor = 0; minor < EVDEV_MINORS; minor++)
 802                 if (!evdev_table[minor])
 803                         break;
 804
 805         if (minor == EVDEV_MINORS) {
 806                 printk(KERN_ERR "evdev: no more free evdev devices\n");
 807                 return -ENFILE;
 808         }
 809
 810         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
 811         if (!evdev)
 812                 return -ENOMEM;
 813
 814         INIT_LIST_HEAD(&evdev->client_list);
 815         spin_lock_init(&evdev->client_lock);
 816         mutex_init(&evdev->mutex);
 817         init_waitqueue_head(&evdev->wait);
 818
 819         dev_set_name(&evdev->dev, "event%d", minor);
 820         evdev->exist = 1;
 821         evdev->minor = minor;
 822
 823         evdev->handle.dev = input_get_device(dev);
 824         evdev->handle.name = dev_name(&evdev->dev);
 825         evdev->handle.handler = handler;
 826         evdev->handle.private = evdev;
 827
 828         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
 829         evdev->dev.class = &input_class;
 830         evdev->dev.parent = &dev->dev;
 831         evdev->dev.release = evdev_free;
 832         device_initialize(&evdev->dev);
 833
 834         error = input_register_handle(&evdev->handle);
 835         if (error)
 836                 goto err_free_evdev;
 837
 838         error = evdev_install_chrdev(evdev);
 839         if (error)
 840                 goto err_unregister_handle;
 841
 842         error = device_add(&evdev->dev);
 843         if (error)
 844                 goto err_cleanup_evdev;
 845
 846         return 0;
 847
 848  err_cleanup_evdev:
 849         evdev_cleanup(evdev);
 850  err_unregister_handle:
 851         input_unregister_handle(&evdev->handle);
 852  err_free_evdev:
 853         put_device(&evdev->dev);
 854         return error;
 855 }
 856
 857 static void evdev_disconnect(struct input_handle *handle)
 858 {
 859         struct evdev *evdev = handle->private;
 860
 861         device_del(&evdev->dev);
 862         evdev_cleanup(evdev);
 863         input_unregister_handle(handle);
 864         put_device(&evdev->dev);
 865 }
 866
 867 static const struct input_device_id evdev_ids[] = {
 868         { .driver_info = 1 },   /* Matches all devices */
 869         { },                    /* Terminating zero entry */
 870 };
 871
 872 MODULE_DEVICE_TABLE(input, evdev_ids);
 873
 874 static struct input_handler evdev_handler = {
 875         .event          = evdev_event,
 876         .connect        = evdev_connect,
 877         .disconnect     = evdev_disconnect,
 878         .fops           = &evdev_fops,
 879         .minor          = EVDEV_MINOR_BASE,
 880         .name           = "evdev",
 881         .id_table       = evdev_ids,
 882 };
 883
 884 static int __init evdev_init(void)
 885 {
 886         return input_register_handler(&evdev_handler);
 887 }
 888
 889 static void __exit evdev_exit(void)
 890 {
 891         input_unregister_handler(&evdev_handler);
 892 }
 893
 894 module_init(evdev_init);
 895 module_exit(evdev_exit);
 896
 897 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 898 MODULE_DESCRIPTION("Input driver event char devices");
 899 MODULE_LICENSE("GPL");