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 <linux/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 #ifdef CONFIG_COMPAT
 295
 296 struct input_event_compat {
 297         struct compat_timeval time;
 298         __u16 type;
 299         __u16 code;
 300         __s32 value;
 301 };
 302
 303 /* Note to the author of this code: did it ever occur to
 304    you why the ifdefs are needed? Think about it again. -AK */
 305 #ifdef CONFIG_X86_64
 306 #  define COMPAT_TEST is_compat_task()
 307 #elif defined(CONFIG_IA64)
 308 #  define COMPAT_TEST IS_IA32_PROCESS(task_pt_regs(current))
 309 #elif defined(CONFIG_S390)
 310 #  define COMPAT_TEST test_thread_flag(TIF_31BIT)
 311 #elif defined(CONFIG_MIPS)
 312 #  define COMPAT_TEST test_thread_flag(TIF_32BIT_ADDR)
 313 #else
 314 #  define COMPAT_TEST test_thread_flag(TIF_32BIT)
 315 #endif
 316
 317 static inline size_t evdev_event_size(void)
 318 {
 319         return COMPAT_TEST ?
 320                 sizeof(struct input_event_compat) : sizeof(struct input_event);
 321 }
 322
 323 static int evdev_event_from_user(const char __user *buffer,
 324                                  struct input_event *event)
 325 {
 326         if (COMPAT_TEST) {
 327                 struct input_event_compat compat_event;
 328
 329                 if (copy_from_user(&compat_event, buffer,
 330                                    sizeof(struct input_event_compat)))
 331                         return -EFAULT;
 332
 333                 event->time.tv_sec = compat_event.time.tv_sec;
 334                 event->time.tv_usec = compat_event.time.tv_usec;
 335                 event->type = compat_event.type;
 336                 event->code = compat_event.code;
 337                 event->value = compat_event.value;
 338
 339         } else {
 340                 if (copy_from_user(event, buffer, sizeof(struct input_event)))
 341                         return -EFAULT;
 342         }
 343
 344         return 0;
 345 }
 346
 347 static int evdev_event_to_user(char __user *buffer,
 348                                 const struct input_event *event)
 349 {
 350         if (COMPAT_TEST) {
 351                 struct input_event_compat compat_event;
 352
 353                 compat_event.time.tv_sec = event->time.tv_sec;
 354                 compat_event.time.tv_usec = event->time.tv_usec;
 355                 compat_event.type = event->type;
 356                 compat_event.code = event->code;
 357                 compat_event.value = event->value;
 358
 359                 if (copy_to_user(buffer, &compat_event,
 360                                  sizeof(struct input_event_compat)))
 361                         return -EFAULT;
 362
 363         } else {
 364                 if (copy_to_user(buffer, event, sizeof(struct input_event)))
 365                         return -EFAULT;
 366         }
 367
 368         return 0;
 369 }
 370
 371 #else
 372
 373 static inline size_t evdev_event_size(void)
 374 {
 375         return sizeof(struct input_event);
 376 }
 377
 378 static int evdev_event_from_user(const char __user *buffer,
 379                                  struct input_event *event)
 380 {
 381         if (copy_from_user(event, buffer, sizeof(struct input_event)))
 382                 return -EFAULT;
 383
 384         return 0;
 385 }
 386
 387 static int evdev_event_to_user(char __user *buffer,
 388                                 const struct input_event *event)
 389 {
 390         if (copy_to_user(buffer, event, sizeof(struct input_event)))
 391                 return -EFAULT;
 392
 393         return 0;
 394 }
 395
 396 #endif /* CONFIG_COMPAT */
 397
 398 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 399                            size_t count, loff_t *ppos)
 400 {
 401         struct evdev_client *client = file->private_data;
 402         struct evdev *evdev = client->evdev;
 403         struct input_event event;
 404         int retval;
 405
 406         retval = mutex_lock_interruptible(&evdev->mutex);
 407         if (retval)
 408                 return retval;
 409
 410         if (!evdev->exist) {
 411                 retval = -ENODEV;
 412                 goto out;
 413         }
 414
 415         while (retval < count) {
 416
 417                 if (evdev_event_from_user(buffer + retval, &event)) {
 418                         retval = -EFAULT;
 419                         goto out;
 420                 }
 421
 422                 input_inject_event(&evdev->handle,
 423                                    event.type, event.code, event.value);
 424                 retval += evdev_event_size();
 425         }
 426
 427  out:
 428         mutex_unlock(&evdev->mutex);
 429         return retval;
 430 }
 431
 432 static int evdev_fetch_next_event(struct evdev_client *client,
 433                                   struct input_event *event)
 434 {
 435         int have_event;
 436
 437         spin_lock_irq(&client->buffer_lock);
 438
 439         have_event = client->head != client->tail;
 440         if (have_event) {
 441                 *event = client->buffer[client->tail++];
 442                 client->tail &= EVDEV_BUFFER_SIZE - 1;
 443         }
 444
 445         spin_unlock_irq(&client->buffer_lock);
 446
 447         return have_event;
 448 }
 449
 450 static ssize_t evdev_read(struct file *file, char __user *buffer,
 451                           size_t count, loff_t *ppos)
 452 {
 453         struct evdev_client *client = file->private_data;
 454         struct evdev *evdev = client->evdev;
 455         struct input_event event;
 456         int retval;
 457
 458         if (count < evdev_event_size())
 459                 return -EINVAL;
 460
 461         if (client->head == client->tail && evdev->exist &&
 462             (file->f_flags & O_NONBLOCK))
 463                 return -EAGAIN;
 464
 465         retval = wait_event_interruptible(evdev->wait,
 466                 client->head != client->tail || !evdev->exist);
 467         if (retval)
 468                 return retval;
 469
 470         if (!evdev->exist)
 471                 return -ENODEV;
 472
 473         while (retval + evdev_event_size() <= count &&
 474                evdev_fetch_next_event(client, &event)) {
 475
 476                 if (evdev_event_to_user(buffer + retval, &event))
 477                         return -EFAULT;
 478
 479                 retval += evdev_event_size();
 480         }
 481
 482         return retval;
 483 }
 484
 485 /* No kernel lock - fine */
 486 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 487 {
 488         struct evdev_client *client = file->private_data;
 489         struct evdev *evdev = client->evdev;
 490
 491         poll_wait(file, &evdev->wait, wait);
 492         return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 493                 (evdev->exist ? 0 : (POLLHUP | POLLERR));
 494 }
 495
 496 #ifdef CONFIG_COMPAT
 497
 498 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 499 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 500
 501 #ifdef __BIG_ENDIAN
 502 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 503                         unsigned int maxlen, void __user *p, int compat)
 504 {
 505         int len, i;
 506
 507         if (compat) {
 508                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 509                 if (len > maxlen)
 510                         len = maxlen;
 511
 512                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 513                         if (copy_to_user((compat_long_t __user *) p + i,
 514                                          (compat_long_t *) bits +
 515                                                 i + 1 - ((i % 2) << 1),
 516                                          sizeof(compat_long_t)))
 517                                 return -EFAULT;
 518         } else {
 519                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 520                 if (len > maxlen)
 521                         len = maxlen;
 522
 523                 if (copy_to_user(p, bits, len))
 524                         return -EFAULT;
 525         }
 526
 527         return len;
 528 }
 529 #else
 530 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 531                         unsigned int maxlen, void __user *p, int compat)
 532 {
 533         int len = compat ?
 534                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 535                         BITS_TO_LONGS(maxbit) * sizeof(long);
 536
 537         if (len > maxlen)
 538                 len = maxlen;
 539
 540         return copy_to_user(p, bits, len) ? -EFAULT : len;
 541 }
 542 #endif /* __BIG_ENDIAN */
 543
 544 #else
 545
 546 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 547                         unsigned int maxlen, void __user *p, int compat)
 548 {
 549         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 550
 551         if (len > maxlen)
 552                 len = maxlen;
 553
 554         return copy_to_user(p, bits, len) ? -EFAULT : len;
 555 }
 556
 557 #endif /* CONFIG_COMPAT */
 558
 559 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 560 {
 561         int len;
 562
 563         if (!str)
 564                 return -ENOENT;
 565
 566         len = strlen(str) + 1;
 567         if (len > maxlen)
 568                 len = maxlen;
 569
 570         return copy_to_user(p, str, len) ? -EFAULT : len;
 571 }
 572
 573 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 574                            void __user *p, int compat_mode)
 575 {
 576         struct evdev_client *client = file->private_data;
 577         struct evdev *evdev = client->evdev;
 578         struct input_dev *dev = evdev->handle.dev;
 579         struct input_absinfo abs;
 580         struct ff_effect effect;
 581         int __user *ip = (int __user *)p;
 582         int i, t, u, v;
 583         int error;
 584
 585         switch (cmd) {
 586
 587         case EVIOCGVERSION:
 588                 return put_user(EV_VERSION, ip);
 589
 590         case EVIOCGID:
 591                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
 592                         return -EFAULT;
 593                 return 0;
 594
 595         case EVIOCGREP:
 596                 if (!test_bit(EV_REP, dev->evbit))
 597                         return -ENOSYS;
 598                 if (put_user(dev->rep[REP_DELAY], ip))
 599                         return -EFAULT;
 600                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
 601                         return -EFAULT;
 602                 return 0;
 603
 604         case EVIOCSREP:
 605                 if (!test_bit(EV_REP, dev->evbit))
 606                         return -ENOSYS;
 607                 if (get_user(u, ip))
 608                         return -EFAULT;
 609                 if (get_user(v, ip + 1))
 610                         return -EFAULT;
 611
 612                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
 613                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
 614
 615                 return 0;
 616
 617         case EVIOCGKEYCODE:
 618                 if (get_user(t, ip))
 619                         return -EFAULT;
 620
 621                 error = input_get_keycode(dev, t, &v);
 622                 if (error)
 623                         return error;
 624
 625                 if (put_user(v, ip + 1))
 626                         return -EFAULT;
 627
 628                 return 0;
 629
 630         case EVIOCSKEYCODE:
 631                 if (get_user(t, ip) || get_user(v, ip + 1))
 632                         return -EFAULT;
 633
 634                 return input_set_keycode(dev, t, v);
 635
 636         case EVIOCSFF:
 637                 if (copy_from_user(&effect, p, sizeof(effect)))
 638                         return -EFAULT;
 639
 640                 error = input_ff_upload(dev, &effect, file);
 641
 642                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
 643                         return -EFAULT;
 644
 645                 return error;
 646
 647         case EVIOCRMFF:
 648                 return input_ff_erase(dev, (int)(unsigned long) p, file);
 649
 650         case EVIOCGEFFECTS:
 651                 i = test_bit(EV_FF, dev->evbit) ?
 652                                 dev->ff->max_effects : 0;
 653                 if (put_user(i, ip))
 654                         return -EFAULT;
 655                 return 0;
 656
 657         case EVIOCGRAB:
 658                 if (p)
 659                         return evdev_grab(evdev, client);
 660                 else
 661                         return evdev_ungrab(evdev, client);
 662
 663         default:
 664
 665                 if (_IOC_TYPE(cmd) != 'E')
 666                         return -EINVAL;
 667
 668                 if (_IOC_DIR(cmd) == _IOC_READ) {
 669
 670                         if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) {
 671
 672                                 unsigned long *bits;
 673                                 int len;
 674
 675                                 switch (_IOC_NR(cmd) & EV_MAX) {
 676
 677                                 case      0: bits = dev->evbit;  len = EV_MAX;  break;
 678                                 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 679                                 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 680                                 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 681                                 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 682                                 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 683                                 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 684                                 case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 685                                 case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 686                                 default: return -EINVAL;
 687                                 }
 688                                 return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
 689                         }
 690
 691                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
 692                                 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
 693                                                     p, compat_mode);
 694
 695                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
 696                                 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
 697                                                     p, compat_mode);
 698
 699                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
 700                                 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
 701                                                     p, compat_mode);
 702
 703                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
 704                                 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
 705                                                     p, compat_mode);
 706
 707                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
 708                                 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
 709
 710                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
 711                                 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
 712
 713                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
 714                                 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
 715
 716                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 717
 718                                 t = _IOC_NR(cmd) & ABS_MAX;
 719
 720                                 abs.value = dev->abs[t];
 721                                 abs.minimum = dev->absmin[t];
 722                                 abs.maximum = dev->absmax[t];
 723                                 abs.fuzz = dev->absfuzz[t];
 724                                 abs.flat = dev->absflat[t];
 725
 726                                 if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
 727                                         return -EFAULT;
 728
 729                                 return 0;
 730                         }
 731
 732                 }
 733
 734                 if (_IOC_DIR(cmd) == _IOC_WRITE) {
 735
 736                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
 737
 738                                 t = _IOC_NR(cmd) & ABS_MAX;
 739
 740                                 if (copy_from_user(&abs, p,
 741                                                 sizeof(struct input_absinfo)))
 742                                         return -EFAULT;
 743
 744                                 /*
 745                                  * Take event lock to ensure that we are not
 746                                  * changing device parameters in the middle
 747                                  * of event.
 748                                  */
 749                                 spin_lock_irq(&dev->event_lock);
 750
 751                                 dev->abs[t] = abs.value;
 752                                 dev->absmin[t] = abs.minimum;
 753                                 dev->absmax[t] = abs.maximum;
 754                                 dev->absfuzz[t] = abs.fuzz;
 755                                 dev->absflat[t] = abs.flat;
 756
 757                                 spin_unlock_irq(&dev->event_lock);
 758
 759                                 return 0;
 760                         }
 761                 }
 762         }
 763         return -EINVAL;
 764 }
 765
 766 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
 767                                 void __user *p, int compat_mode)
 768 {
 769         struct evdev_client *client = file->private_data;
 770         struct evdev *evdev = client->evdev;
 771         int retval;
 772
 773         retval = mutex_lock_interruptible(&evdev->mutex);
 774         if (retval)
 775                 return retval;
 776
 777         if (!evdev->exist) {
 778                 retval = -ENODEV;
 779                 goto out;
 780         }
 781
 782         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
 783
 784  out:
 785         mutex_unlock(&evdev->mutex);
 786         return retval;
 787 }
 788
 789 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 790 {
 791         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
 792 }
 793
 794 #ifdef CONFIG_COMPAT
 795 static long evdev_ioctl_compat(struct file *file,
 796                                 unsigned int cmd, unsigned long arg)
 797 {
 798         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
 799 }
 800 #endif
 801
 802 static const struct file_operations evdev_fops = {
 803         .owner          = THIS_MODULE,
 804         .read           = evdev_read,
 805         .write          = evdev_write,
 806         .poll           = evdev_poll,
 807         .open           = evdev_open,
 808         .release        = evdev_release,
 809         .unlocked_ioctl = evdev_ioctl,
 810 #ifdef CONFIG_COMPAT
 811         .compat_ioctl   = evdev_ioctl_compat,
 812 #endif
 813         .fasync         = evdev_fasync,
 814         .flush          = evdev_flush
 815 };
 816
 817 static int evdev_install_chrdev(struct evdev *evdev)
 818 {
 819         /*
 820          * No need to do any locking here as calls to connect and
 821          * disconnect are serialized by the input core
 822          */
 823         evdev_table[evdev->minor] = evdev;
 824         return 0;
 825 }
 826
 827 static void evdev_remove_chrdev(struct evdev *evdev)
 828 {
 829         /*
 830          * Lock evdev table to prevent race with evdev_open()
 831          */
 832         mutex_lock(&evdev_table_mutex);
 833         evdev_table[evdev->minor] = NULL;
 834         mutex_unlock(&evdev_table_mutex);
 835 }
 836
 837 /*
 838  * Mark device non-existent. This disables writes, ioctls and
 839  * prevents new users from opening the device. Already posted
 840  * blocking reads will stay, however new ones will fail.
 841  */
 842 static void evdev_mark_dead(struct evdev *evdev)
 843 {
 844         mutex_lock(&evdev->mutex);
 845         evdev->exist = 0;
 846         mutex_unlock(&evdev->mutex);
 847 }
 848
 849 static void evdev_cleanup(struct evdev *evdev)
 850 {
 851         struct input_handle *handle = &evdev->handle;
 852
 853         evdev_mark_dead(evdev);
 854         evdev_hangup(evdev);
 855         evdev_remove_chrdev(evdev);
 856
 857         /* evdev is marked dead so no one else accesses evdev->open */
 858         if (evdev->open) {
 859                 input_flush_device(handle, NULL);
 860                 input_close_device(handle);
 861         }
 862 }
 863
 864 /*
 865  * Create new evdev device. Note that input core serializes calls
 866  * to connect and disconnect so we don't need to lock evdev_table here.
 867  */
 868 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 869                          const struct input_device_id *id)
 870 {
 871         struct evdev *evdev;
 872         int minor;
 873         int error;
 874
 875         for (minor = 0; minor < EVDEV_MINORS; minor++)
 876                 if (!evdev_table[minor])
 877                         break;
 878
 879         if (minor == EVDEV_MINORS) {
 880                 printk(KERN_ERR "evdev: no more free evdev devices\n");
 881                 return -ENFILE;
 882         }
 883
 884         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
 885         if (!evdev)
 886                 return -ENOMEM;
 887
 888         INIT_LIST_HEAD(&evdev->client_list);
 889         spin_lock_init(&evdev->client_lock);
 890         mutex_init(&evdev->mutex);
 891         init_waitqueue_head(&evdev->wait);
 892
 893         snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);
 894         evdev->exist = 1;
 895         evdev->minor = minor;
 896
 897         evdev->handle.dev = input_get_device(dev);
 898         evdev->handle.name = evdev->name;
 899         evdev->handle.handler = handler;
 900         evdev->handle.private = evdev;
 901
 902         strlcpy(evdev->dev.bus_id, evdev->name, sizeof(evdev->dev.bus_id));
 903         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
 904         evdev->dev.class = &input_class;
 905         evdev->dev.parent = &dev->dev;
 906         evdev->dev.release = evdev_free;
 907         device_initialize(&evdev->dev);
 908
 909         error = input_register_handle(&evdev->handle);
 910         if (error)
 911                 goto err_free_evdev;
 912
 913         error = evdev_install_chrdev(evdev);
 914         if (error)
 915                 goto err_unregister_handle;
 916
 917         error = device_add(&evdev->dev);
 918         if (error)
 919                 goto err_cleanup_evdev;
 920
 921         return 0;
 922
 923  err_cleanup_evdev:
 924         evdev_cleanup(evdev);
 925  err_unregister_handle:
 926         input_unregister_handle(&evdev->handle);
 927  err_free_evdev:
 928         put_device(&evdev->dev);
 929         return error;
 930 }
 931
 932 static void evdev_disconnect(struct input_handle *handle)
 933 {
 934         struct evdev *evdev = handle->private;
 935
 936         device_del(&evdev->dev);
 937         evdev_cleanup(evdev);
 938         input_unregister_handle(handle);
 939         put_device(&evdev->dev);
 940 }
 941
 942 static const struct input_device_id evdev_ids[] = {
 943         { .driver_info = 1 },   /* Matches all devices */
 944         { },                    /* Terminating zero entry */
 945 };
 946
 947 MODULE_DEVICE_TABLE(input, evdev_ids);
 948
 949 static struct input_handler evdev_handler = {
 950         .event          = evdev_event,
 951         .connect        = evdev_connect,
 952         .disconnect     = evdev_disconnect,
 953         .fops           = &evdev_fops,
 954         .minor          = EVDEV_MINOR_BASE,
 955         .name           = "evdev",
 956         .id_table       = evdev_ids,
 957 };
 958
 959 static int __init evdev_init(void)
 960 {
 961         return input_register_handler(&evdev_handler);
 962 }
 963
 964 static void __exit evdev_exit(void)
 965 {
 966         input_unregister_handler(&evdev_handler);
 967 }
 968
 969 module_init(evdev_init);
 970 module_exit(evdev_exit);
 971
 972 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 973 MODULE_DESCRIPTION("Input driver event char devices");
 974 MODULE_LICENSE("GPL");