SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/input.h>
  20 #include <linux/major.h>
  21 #include <linux/device.h>
  22 #include "input-compat.h"
  23
  24 struct evdev {
  25         int exist;
  26         int open;
  27         int minor;
  28         char name[16];
  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         kill_fasync(&client->fasync, SIGIO, POLL_IN);
  63 }
  64
  65 /*
  66  * Pass incoming event to all connected clients.
  67  */
  68 static void evdev_event(struct input_handle *handle,
  69                         unsigned int type, unsigned int code, int value)
  70 {
  71         struct evdev *evdev = handle->private;
  72         struct evdev_client *client;
  73         struct input_event event;
  74
  75         do_gettimeofday(&event.time);
  76         event.type = type;
  77         event.code = code;
  78         event.value = value;
  79
  80         rcu_read_lock();
  81
  82         client = rcu_dereference(evdev->grab);
  83         if (client)
  84                 evdev_pass_event(client, &event);
  85         else
  86                 list_for_each_entry_rcu(client, &evdev->client_list, node)
  87                         evdev_pass_event(client, &event);
  88
  89         rcu_read_unlock();
  90
  91         wake_up_interruptible(&evdev->wait);
  92 }
  93
  94 static int evdev_fasync(int fd, struct file *file, int on)
  95 {
  96         struct evdev_client *client = file->private_data;
  97         int retval;
  98
  99         retval = fasync_helper(fd, file, on, &client->fasync);
 100
 101         return retval < 0 ? retval : 0;
 102 }
 103
 104 static int evdev_flush(struct file *file, fl_owner_t id)
 105 {
 106         struct evdev_client *client = file->private_data;
 107         struct evdev *evdev = client->evdev;
 108         int retval;
 109
 110         retval = mutex_lock_interruptible(&evdev->mutex);
 111         if (retval)
 112                 return retval;
 113
 114         if (!evdev->exist)
 115                 retval = -ENODEV;
 116         else
 117                 retval = input_flush_device(&evdev->handle, file);
 118
 119         mutex_unlock(&evdev->mutex);
 120         return retval;
 121 }
 122
 123 static void evdev_free(struct device *dev)
 124 {
 125         struct evdev *evdev = container_of(dev, struct evdev, dev);
 126
 127         input_put_device(evdev->handle.dev);
 128         kfree(evdev);
 129 }
 130
 131 /*
 132  * Grabs an event device (along with underlying input device).
 133  * This function is called with evdev->mutex taken.
 134  */
 135 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 136 {
 137         int error;
 138
 139         if (evdev->grab)
 140                 return -EBUSY;
 141
 142         error = input_grab_device(&evdev->handle);
 143         if (error)
 144                 return error;
 145
 146         rcu_assign_pointer(evdev->grab, client);
 147         synchronize_rcu();
 148
 149         return 0;
 150 }
 151
 152 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 153 {
 154         if (evdev->grab != client)
 155                 return  -EINVAL;
 156
 157         rcu_assign_pointer(evdev->grab, NULL);
 158         synchronize_rcu();
 159         input_release_device(&evdev->handle);
 160
 161         return 0;
 162 }
 163
 164 static void evdev_attach_client(struct evdev *evdev,
 165                                 struct evdev_client *client)
 166 {
 167         spin_lock(&evdev->client_lock);
 168         list_add_tail_rcu(&client->node, &evdev->client_list);
 169         spin_unlock(&evdev->client_lock);
 170         synchronize_rcu();
 171 }
 172
 173 static void evdev_detach_client(struct evdev *evdev,
 174                                 struct evdev_client *client)
 175 {
 176         spin_lock(&evdev->client_lock);
 177         list_del_rcu(&client->node);
 178         spin_unlock(&evdev->client_lock);
 179         synchronize_rcu();
 180 }
 181
 182 static int evdev_open_device(struct evdev *evdev)
 183 {
 184         int retval;
 185
 186         retval = mutex_lock_interruptible(&evdev->mutex);
 187         if (retval)
 188                 return retval;
 189
 190         if (!evdev->exist)
 191                 retval = -ENODEV;
 192         else if (!evdev->open++) {
 193                 retval = input_open_device(&evdev->handle);
 194                 if (retval)
 195                         evdev->open--;
 196         }
 197
 198         mutex_unlock(&evdev->mutex);
 199         return retval;
 200 }
 201
 202 static void evdev_close_device(struct evdev *evdev)
 203 {
 204         mutex_lock(&evdev->mutex);
 205
 206         if (evdev->exist && !--evdev->open)
 207                 input_close_device(&evdev->handle);
 208
 209         mutex_unlock(&evdev->mutex);
 210 }
 211
 212 /*
 213  * Wake up users waiting for IO so they can disconnect from
 214  * dead device.
 215  */
 216 static void evdev_hangup(struct evdev *evdev)
 217 {
 218         struct evdev_client *client;
 219
 220         spin_lock(&evdev->client_lock);
 221         list_for_each_entry(client, &evdev->client_list, node)
 222                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 223         spin_unlock(&evdev->client_lock);
 224
 225         wake_up_interruptible(&evdev->wait);
 226 }
 227
 228 static int evdev_release(struct inode *inode, struct file *file)
 229 {
 230         struct evdev_client *client = file->private_data;
 231         struct evdev *evdev = client->evdev;
 232
 233         mutex_lock(&evdev->mutex);
 234         if (evdev->grab == client)
 235                 evdev_ungrab(evdev, client);
 236         mutex_unlock(&evdev->mutex);
 237
 238         evdev_fasync(-1, file, 0);
 239         evdev_detach_client(evdev, client);
 240         kfree(client);
 241
 242         evdev_close_device(evdev);
 243         put_device(&evdev->dev);
 244
 245         return 0;
 246 }
 247
 248 static int evdev_open(struct inode *inode, struct file *file)
 249 {
 250         struct evdev *evdev;
 251         struct evdev_client *client;
 252         int i = iminor(inode) - EVDEV_MINOR_BASE;
 253         int error;
 254
 255         if (i >= EVDEV_MINORS)
 256                 return -ENODEV;
 257
 258         error = mutex_lock_interruptible(&evdev_table_mutex);
 259         if (error)
 260                 return error;
 261         evdev = evdev_table[i];
 262         if (evdev)
 263                 get_device(&evdev->dev);
 264         mutex_unlock(&evdev_table_mutex);
 265
 266         if (!evdev)
 267                 return -ENODEV;
 268
 269         client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
 270         if (!client) {
 271                 error = -ENOMEM;
 272                 goto err_put_evdev;
 273         }
 274
 275         spin_lock_init(&client->buffer_lock);
 276         client->evdev = evdev;
 277         evdev_attach_client(evdev, client);
 278
 279         error = evdev_open_device(evdev);
 280         if (error)
 281                 goto err_free_client;
 282
 283         file->private_data = client;
 284         return 0;
 285
 286  err_free_client:
 287         evdev_detach_client(evdev, client);
 288         kfree(client);
 289  err_put_evdev:
 290         put_device(&evdev->dev);
 291         return error;
 292 }
 293
 294 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 295                            size_t count, loff_t *ppos)
 296 {
 297         struct evdev_client *client = file->private_data;
 298         struct evdev *evdev = client->evdev;
 299         struct input_event event;
 300         int retval;
 301
 302         retval = mutex_lock_interruptible(&evdev->mutex);
 303         if (retval)
 304                 return retval;
 305
 306         if (!evdev->exist) {
 307                 retval = -ENODEV;
 308                 goto out;
 309         }
 310
 311         while (retval < count) {
 312
 313                 if (input_event_from_user(buffer + retval, &event)) {
 314                         retval = -EFAULT;
 315                         goto out;
 316                 }
 317
 318                 input_inject_event(&evdev->handle,
 319                                    event.type, event.code, event.value);
 320                 retval += input_event_size();
 321         }
 322
 323  out:
 324         mutex_unlock(&evdev->mutex);
 325         return retval;
 326 }
 327
 328 static int evdev_fetch_next_event(struct evdev_client *client,
 329                                   struct input_event *event)
 330 {
 331         int have_event;
 332
 333         spin_lock_irq(&client->buffer_lock);
 334
 335         have_event = client->head != client->tail;
 336         if (have_event) {
 337                 *event = client->buffer[client->tail++];
 338                 client->tail &= EVDEV_BUFFER_SIZE - 1;
 339         }
 340
 341         spin_unlock_irq(&client->buffer_lock);
 342
 343         return have_event;
 344 }
 345
 346 static ssize_t evdev_read(struct file *file, char __user *buffer,
 347                           size_t count, loff_t *ppos)
 348 {
 349         struct evdev_client *client = file->private_data;
 350         struct evdev *evdev = client->evdev;
 351         struct input_event event;
 352         int retval;
 353
 354         if (count < input_event_size())
 355                 return -EINVAL;
 356
 357         if (client->head == client->tail && evdev->exist &&
 358             (file->f_flags & O_NONBLOCK))
 359                 return -EAGAIN;
 360
 361         retval = wait_event_interruptible(evdev->wait,
 362                 client->head != client->tail || !evdev->exist);
 363         if (retval)
 364                 return retval;
 365
 366         if (!evdev->exist)
 367                 return -ENODEV;
 368
 369         while (retval + input_event_size() <= count &&
 370                evdev_fetch_next_event(client, &event)) {
 371
 372                 if (input_event_to_user(buffer + retval, &event))
 373                         return -EFAULT;
 374
 375                 retval += input_event_size();
 376         }
 377
 378         return retval;
 379 }
 380
 381 /* No kernel lock - fine */
 382 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 383 {
 384         struct evdev_client *client = file->private_data;
 385         struct evdev *evdev = client->evdev;
 386
 387         poll_wait(file, &evdev->wait, wait);
 388         return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 389                 (evdev->exist ? 0 : (POLLHUP | POLLERR));
 390 }
 391
 392 #ifdef CONFIG_COMPAT
 393
 394 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 395 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 396
 397 #ifdef __BIG_ENDIAN
 398 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 399                         unsigned int maxlen, void __user *p, int compat)
 400 {
 401         int len, i;
 402
 403         if (compat) {
 404                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 405                 if (len > maxlen)
 406                         len = maxlen;
 407
 408                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 409                         if (copy_to_user((compat_long_t __user *) p + i,
 410                                          (compat_long_t *) bits +
 411                                                 i + 1 - ((i % 2) << 1),
 412                                          sizeof(compat_long_t)))
 413                                 return -EFAULT;
 414         } else {
 415                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 416                 if (len > maxlen)
 417                         len = maxlen;
 418
 419                 if (copy_to_user(p, bits, len))
 420                         return -EFAULT;
 421         }
 422
 423         return len;
 424 }
 425 #else
 426 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 427                         unsigned int maxlen, void __user *p, int compat)
 428 {
 429         int len = compat ?
 430                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 431                         BITS_TO_LONGS(maxbit) * sizeof(long);
 432
 433         if (len > maxlen)
 434                 len = maxlen;
 435
 436         return copy_to_user(p, bits, len) ? -EFAULT : len;
 437 }
 438 #endif /* __BIG_ENDIAN */
 439
 440 #else
 441
 442 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 443                         unsigned int maxlen, void __user *p, int compat)
 444 {
 445         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 446
 447         if (len > maxlen)
 448                 len = maxlen;
 449
 450         return copy_to_user(p, bits, len) ? -EFAULT : len;
 451 }
 452
 453 #endif /* CONFIG_COMPAT */
 454
 455 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 456 {
 457         int len;
 458
 459         if (!str)
 460                 return -ENOENT;
 461
 462         len = strlen(str) + 1;
 463         if (len > maxlen)
 464                 len = maxlen;
 465
 466         return copy_to_user(p, str, len) ? -EFAULT : len;
 467 }
 468
 469 #define OLD_KEY_MAX     0x1ff
 470 static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
 471 {
 472         static unsigned long keymax_warn_time;
 473         unsigned long *bits;
 474         int len;
 475
 476         switch (_IOC_NR(cmd) & EV_MAX) {
 477
 478         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 479         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 480         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 481         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 482         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 483         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 484         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 485         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 486         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 487         default: return -EINVAL;
 488         }
 489
 490         /*
 491          * Work around bugs in userspace programs that like to do
 492          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
 493          * should be in bytes, not in bits.
 494          */
 495         if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
 496                 len = OLD_KEY_MAX;
 497                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
 498                         printk(KERN_WARNING
 499                                 "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
 500                                 "limiting output to %zu bytes. See "
 501                                 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
 502                                 OLD_KEY_MAX,
 503                                 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
 504         }
 505
 506         return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
 507 }
 508 #undef OLD_KEY_MAX
 509
 510 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 511                            void __user *p, int compat_mode)
 512 {
 513         struct evdev_client *client = file->private_data;
 514         struct evdev *evdev = client->evdev;
 515         struct input_dev *dev = evdev->handle.dev;
 516         struct input_absinfo abs;
 517         struct ff_effect effect;
 518         int __user *ip = (int __user *)p;
 519         int i, t, u, v;
 520         int error;
 521
 522         switch (cmd) {
 523
 524         case EVIOCGVERSION:
 525                 return put_user(EV_VERSION, ip);
 526
 527         case EVIOCGID:
 528                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
 529                         return -EFAULT;
 530                 return 0;
 531
 532         case EVIOCGREP:
 533                 if (!test_bit(EV_REP, dev->evbit))
 534                         return -ENOSYS;
 535                 if (put_user(dev->rep[REP_DELAY], ip))
 536                         return -EFAULT;
 537                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
 538                         return -EFAULT;
 539                 return 0;
 540
 541         case EVIOCSREP:
 542                 if (!test_bit(EV_REP, dev->evbit))
 543                         return -ENOSYS;
 544                 if (get_user(u, ip))
 545                         return -EFAULT;
 546                 if (get_user(v, ip + 1))
 547                         return -EFAULT;
 548
 549                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
 550                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
 551
 552                 return 0;
 553
 554         case EVIOCGKEYCODE:
 555                 if (get_user(t, ip))
 556                         return -EFAULT;
 557
 558                 error = input_get_keycode(dev, t, &v);
 559                 if (error)
 560                         return error;
 561
 562                 if (put_user(v, ip + 1))
 563                         return -EFAULT;
 564
 565                 return 0;
 566
 567         case EVIOCSKEYCODE:
 568                 if (get_user(t, ip) || get_user(v, ip + 1))
 569                         return -EFAULT;
 570
 571                 return input_set_keycode(dev, t, v);
 572
 573         case EVIOCRMFF:
 574                 return input_ff_erase(dev, (int)(unsigned long) p, file);
 575
 576         case EVIOCGEFFECTS:
 577                 i = test_bit(EV_FF, dev->evbit) ?
 578                                 dev->ff->max_effects : 0;
 579                 if (put_user(i, ip))
 580                         return -EFAULT;
 581                 return 0;
 582
 583         case EVIOCGRAB:
 584                 if (p)
 585                         return evdev_grab(evdev, client);
 586                 else
 587                         return evdev_ungrab(evdev, client);
 588
 589         default:
 590
 591                 if (_IOC_TYPE(cmd) != 'E')
 592                         return -EINVAL;
 593
 594                 if (_IOC_DIR(cmd) == _IOC_READ) {
 595
 596                         if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
 597                                 return handle_eviocgbit(dev, cmd, p, compat_mode);
 598
 599                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
 600                                 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
 601                                                     p, compat_mode);
 602
 603                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
 604                                 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
 605                                                     p, compat_mode);
 606
 607                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
 608                                 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
 609                                                     p, compat_mode);
 610
 611                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
 612                                 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
 613                                                     p, compat_mode);
 614
 615                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
 616                                 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
 617
 618                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
 619                                 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
 620
 621                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
 622                                 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
 623
 624                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 625
 626                                 t = _IOC_NR(cmd) & ABS_MAX;
 627
 628                                 abs.value = dev->abs[t];
 629                                 abs.minimum = dev->absmin[t];
 630                                 abs.maximum = dev->absmax[t];
 631                                 abs.fuzz = dev->absfuzz[t];
 632                                 abs.flat = dev->absflat[t];
 633
 634                                 if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
 635                                         return -EFAULT;
 636
 637                                 return 0;
 638                         }
 639
 640                 }
 641
 642                 if (_IOC_DIR(cmd) == _IOC_WRITE) {
 643
 644                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {
 645
 646                                 if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
 647                                         return -EFAULT;
 648
 649                                 error = input_ff_upload(dev, &effect, file);
 650
 651                                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
 652                                         return -EFAULT;
 653
 654                                 return error;
 655                         }
 656
 657                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
 658
 659                                 t = _IOC_NR(cmd) & ABS_MAX;
 660
 661                                 if (copy_from_user(&abs, p,
 662                                                 sizeof(struct input_absinfo)))
 663                                         return -EFAULT;
 664
 665                                 /*
 666                                  * Take event lock to ensure that we are not
 667                                  * changing device parameters in the middle
 668                                  * of event.
 669                                  */
 670                                 spin_lock_irq(&dev->event_lock);
 671
 672                                 dev->abs[t] = abs.value;
 673                                 dev->absmin[t] = abs.minimum;
 674                                 dev->absmax[t] = abs.maximum;
 675                                 dev->absfuzz[t] = abs.fuzz;
 676                                 dev->absflat[t] = abs.flat;
 677
 678                                 spin_unlock_irq(&dev->event_lock);
 679
 680                                 return 0;
 681                         }
 682                 }
 683         }
 684         return -EINVAL;
 685 }
 686
 687 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
 688                                 void __user *p, int compat_mode)
 689 {
 690         struct evdev_client *client = file->private_data;
 691         struct evdev *evdev = client->evdev;
 692         int retval;
 693
 694         retval = mutex_lock_interruptible(&evdev->mutex);
 695         if (retval)
 696                 return retval;
 697
 698         if (!evdev->exist) {
 699                 retval = -ENODEV;
 700                 goto out;
 701         }
 702
 703         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
 704
 705  out:
 706         mutex_unlock(&evdev->mutex);
 707         return retval;
 708 }
 709
 710 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 711 {
 712         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
 713 }
 714
 715 #ifdef CONFIG_COMPAT
 716 static long evdev_ioctl_compat(struct file *file,
 717                                 unsigned int cmd, unsigned long arg)
 718 {
 719         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
 720 }
 721 #endif
 722
 723 static const struct file_operations evdev_fops = {
 724         .owner          = THIS_MODULE,
 725         .read           = evdev_read,
 726         .write          = evdev_write,
 727         .poll           = evdev_poll,
 728         .open           = evdev_open,
 729         .release        = evdev_release,
 730         .unlocked_ioctl = evdev_ioctl,
 731 #ifdef CONFIG_COMPAT
 732         .compat_ioctl   = evdev_ioctl_compat,
 733 #endif
 734         .fasync         = evdev_fasync,
 735         .flush          = evdev_flush
 736 };
 737
 738 static int evdev_install_chrdev(struct evdev *evdev)
 739 {
 740         /*
 741          * No need to do any locking here as calls to connect and
 742          * disconnect are serialized by the input core
 743          */
 744         evdev_table[evdev->minor] = evdev;
 745         return 0;
 746 }
 747
 748 static void evdev_remove_chrdev(struct evdev *evdev)
 749 {
 750         /*
 751          * Lock evdev table to prevent race with evdev_open()
 752          */
 753         mutex_lock(&evdev_table_mutex);
 754         evdev_table[evdev->minor] = NULL;
 755         mutex_unlock(&evdev_table_mutex);
 756 }
 757
 758 /*
 759  * Mark device non-existent. This disables writes, ioctls and
 760  * prevents new users from opening the device. Already posted
 761  * blocking reads will stay, however new ones will fail.
 762  */
 763 static void evdev_mark_dead(struct evdev *evdev)
 764 {
 765         mutex_lock(&evdev->mutex);
 766         evdev->exist = 0;
 767         mutex_unlock(&evdev->mutex);
 768 }
 769
 770 static void evdev_cleanup(struct evdev *evdev)
 771 {
 772         struct input_handle *handle = &evdev->handle;
 773
 774         evdev_mark_dead(evdev);
 775         evdev_hangup(evdev);
 776         evdev_remove_chrdev(evdev);
 777
 778         /* evdev is marked dead so no one else accesses evdev->open */
 779         if (evdev->open) {
 780                 input_flush_device(handle, NULL);
 781                 input_close_device(handle);
 782         }
 783 }
 784
 785 /*
 786  * Create new evdev device. Note that input core serializes calls
 787  * to connect and disconnect so we don't need to lock evdev_table here.
 788  */
 789 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 790                          const struct input_device_id *id)
 791 {
 792         struct evdev *evdev;
 793         int minor;
 794         int error;
 795
 796         for (minor = 0; minor < EVDEV_MINORS; minor++)
 797                 if (!evdev_table[minor])
 798                         break;
 799
 800         if (minor == EVDEV_MINORS) {
 801                 printk(KERN_ERR "evdev: no more free evdev devices\n");
 802                 return -ENFILE;
 803         }
 804
 805         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
 806         if (!evdev)
 807                 return -ENOMEM;
 808
 809         INIT_LIST_HEAD(&evdev->client_list);
 810         spin_lock_init(&evdev->client_lock);
 811         mutex_init(&evdev->mutex);
 812         init_waitqueue_head(&evdev->wait);
 813
 814         snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);
 815         evdev->exist = 1;
 816         evdev->minor = minor;
 817
 818         evdev->handle.dev = input_get_device(dev);
 819         evdev->handle.name = evdev->name;
 820         evdev->handle.handler = handler;
 821         evdev->handle.private = evdev;
 822
 823         dev_set_name(&evdev->dev, evdev->name);
 824         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
 825         evdev->dev.class = &input_class;
 826         evdev->dev.parent = &dev->dev;
 827         evdev->dev.release = evdev_free;
 828         device_initialize(&evdev->dev);
 829
 830         error = input_register_handle(&evdev->handle);
 831         if (error)
 832                 goto err_free_evdev;
 833
 834         error = evdev_install_chrdev(evdev);
 835         if (error)
 836                 goto err_unregister_handle;
 837
 838         error = device_add(&evdev->dev);
 839         if (error)
 840                 goto err_cleanup_evdev;
 841
 842         return 0;
 843
 844  err_cleanup_evdev:
 845         evdev_cleanup(evdev);
 846  err_unregister_handle:
 847         input_unregister_handle(&evdev->handle);
 848  err_free_evdev:
 849         put_device(&evdev->dev);
 850         return error;
 851 }
 852
 853 static void evdev_disconnect(struct input_handle *handle)
 854 {
 855         struct evdev *evdev = handle->private;
 856
 857         device_del(&evdev->dev);
 858         evdev_cleanup(evdev);
 859         input_unregister_handle(handle);
 860         put_device(&evdev->dev);
 861 }
 862
 863 static const struct input_device_id evdev_ids[] = {
 864         { .driver_info = 1 },   /* Matches all devices */
 865         { },                    /* Terminating zero entry */
 866 };
 867
 868 MODULE_DEVICE_TABLE(input, evdev_ids);
 869
 870 static struct input_handler evdev_handler = {
 871         .event          = evdev_event,
 872         .connect        = evdev_connect,
 873         .disconnect     = evdev_disconnect,
 874         .fops           = &evdev_fops,
 875         .minor          = EVDEV_MINOR_BASE,
 876         .name           = "evdev",
 877         .id_table       = evdev_ids,
 878 };
 879
 880 static int __init evdev_init(void)
 881 {
 882         return input_register_handler(&evdev_handler);
 883 }
 884
 885 static void __exit evdev_exit(void)
 886 {
 887         input_unregister_handler(&evdev_handler);
 888 }
 889
 890 module_init(evdev_init);
 891 module_exit(evdev_exit);
 892
 893 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 894 MODULE_DESCRIPTION("Input driver event char devices");
 895 MODULE_LICENSE("GPL");