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 kfree(evdev); 128 } 129 130 /* 131 * Grabs an event device (along with underlying input device). 132 * This function is called with evdev->mutex taken. 133 */ 134 static int evdev_grab(struct evdev *evdev, struct evdev_client *client) 135 { 136 int error; 137 138 if (evdev->grab) 139 return -EBUSY; 140 141 error = input_grab_device(&evdev->handle); 142 if (error) 143 return error; 144 145 rcu_assign_pointer(evdev->grab, client); 146 synchronize_rcu(); 147 148 return 0; 149 } 150 151 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client) 152 { 153 if (evdev->grab != client) 154 return -EINVAL; 155 156 rcu_assign_pointer(evdev->grab, NULL); 157 synchronize_rcu(); 158 input_release_device(&evdev->handle); 159 160 return 0; 161 } 162 163 static void evdev_attach_client(struct evdev *evdev, 164 struct evdev_client *client) 165 { 166 spin_lock(&evdev->client_lock); 167 list_add_tail_rcu(&client->node, &evdev->client_list); 168 spin_unlock(&evdev->client_lock); 169 synchronize_rcu(); 170 } 171 172 static void evdev_detach_client(struct evdev *evdev, 173 struct evdev_client *client) 174 { 175 spin_lock(&evdev->client_lock); 176 list_del_rcu(&client->node); 177 spin_unlock(&evdev->client_lock); 178 synchronize_rcu(); 179 } 180 181 static int evdev_open_device(struct evdev *evdev) 182 { 183 int retval; 184 185 retval = mutex_lock_interruptible(&evdev->mutex); 186 if (retval) 187 return retval; 188 189 if (!evdev->exist) 190 retval = -ENODEV; 191 else if (!evdev->open++) { 192 retval = input_open_device(&evdev->handle); 193 if (retval) 194 evdev->open--; 195 } 196 197 mutex_unlock(&evdev->mutex); 198 return retval; 199 } 200 201 static void evdev_close_device(struct evdev *evdev) 202 { 203 mutex_lock(&evdev->mutex); 204 205 if (evdev->exist && !--evdev->open) 206 input_close_device(&evdev->handle); 207 208 mutex_unlock(&evdev->mutex); 209 } 210 211 /* 212 * Wake up users waiting for IO so they can disconnect from 213 * dead device. 214 */ 215 static void evdev_hangup(struct evdev *evdev) 216 { 217 struct evdev_client *client; 218 219 spin_lock(&evdev->client_lock); 220 list_for_each_entry(client, &evdev->client_list, node) 221 kill_fasync(&client->fasync, SIGIO, POLL_HUP); 222 spin_unlock(&evdev->client_lock); 223 224 wake_up_interruptible(&evdev->wait); 225 } 226 227 static int evdev_release(struct inode *inode, struct file *file) 228 { 229 struct evdev_client *client = file->private_data; 230 struct evdev *evdev = client->evdev; 231 232 mutex_lock(&evdev->mutex); 233 if (evdev->grab == client) 234 evdev_ungrab(evdev, client); 235 mutex_unlock(&evdev->mutex); 236 237 evdev_fasync(-1, file, 0); 238 evdev_detach_client(evdev, client); 239 kfree(client); 240 241 evdev_close_device(evdev); 242 put_device(&evdev->dev); 243 244 return 0; 245 } 246 247 static int evdev_open(struct inode *inode, struct file *file) 248 { 249 struct evdev *evdev; 250 struct evdev_client *client; 251 int i = iminor(inode) - EVDEV_MINOR_BASE; 252 int error; 253 254 if (i >= EVDEV_MINORS) 255 return -ENODEV; 256 257 error = mutex_lock_interruptible(&evdev_table_mutex); 258 if (error) 259 return error; 260 evdev = evdev_table[i]; 261 if (evdev) 262 get_device(&evdev->dev); 263 mutex_unlock(&evdev_table_mutex); 264 265 if (!evdev) 266 return -ENODEV; 267 268 client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL); 269 if (!client) { 270 error = -ENOMEM; 271 goto err_put_evdev; 272 } 273 274 spin_lock_init(&client->buffer_lock); 275 client->evdev = evdev; 276 evdev_attach_client(evdev, client); 277 278 error = evdev_open_device(evdev); 279 if (error) 280 goto err_free_client; 281 282 file->private_data = client; 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 #ifdef CONFIG_COMPAT 294 295 struct input_event_compat { 296 struct compat_timeval time; 297 __u16 type; 298 __u16 code; 299 __s32 value; 300 }; 301 302 /* Note to the author of this code: did it ever occur to 303 you why the ifdefs are needed? Think about it again. -AK */ 304 #ifdef CONFIG_X86_64 305 # define COMPAT_TEST is_compat_task() 306 #elif defined(CONFIG_IA64) 307 # define COMPAT_TEST IS_IA32_PROCESS(task_pt_regs(current)) 308 #elif defined(CONFIG_S390) 309 # define COMPAT_TEST test_thread_flag(TIF_31BIT) 310 #elif defined(CONFIG_MIPS) 311 # define COMPAT_TEST test_thread_flag(TIF_32BIT_ADDR) 312 #else 313 # define COMPAT_TEST test_thread_flag(TIF_32BIT) 314 #endif 315 316 static inline size_t evdev_event_size(void) 317 { 318 return COMPAT_TEST ? 319 sizeof(struct input_event_compat) : sizeof(struct input_event); 320 } 321 322 static int evdev_event_from_user(const char __user *buffer, 323 struct input_event *event) 324 { 325 if (COMPAT_TEST) { 326 struct input_event_compat compat_event; 327 328 if (copy_from_user(&compat_event, buffer, 329 sizeof(struct input_event_compat))) 330 return -EFAULT; 331 332 event->time.tv_sec = compat_event.time.tv_sec; 333 event->time.tv_usec = compat_event.time.tv_usec; 334 event->type = compat_event.type; 335 event->code = compat_event.code; 336 event->value = compat_event.value; 337 338 } else { 339 if (copy_from_user(event, buffer, sizeof(struct input_event))) 340 return -EFAULT; 341 } 342 343 return 0; 344 } 345 346 static int evdev_event_to_user(char __user *buffer, 347 const struct input_event *event) 348 { 349 if (COMPAT_TEST) { 350 struct input_event_compat compat_event; 351 352 compat_event.time.tv_sec = event->time.tv_sec; 353 compat_event.time.tv_usec = event->time.tv_usec; 354 compat_event.type = event->type; 355 compat_event.code = event->code; 356 compat_event.value = event->value; 357 358 if (copy_to_user(buffer, &compat_event, 359 sizeof(struct input_event_compat))) 360 return -EFAULT; 361 362 } else { 363 if (copy_to_user(buffer, event, sizeof(struct input_event))) 364 return -EFAULT; 365 } 366 367 return 0; 368 } 369 370 #else 371 372 static inline size_t evdev_event_size(void) 373 { 374 return sizeof(struct input_event); 375 } 376 377 static int evdev_event_from_user(const char __user *buffer, 378 struct input_event *event) 379 { 380 if (copy_from_user(event, buffer, sizeof(struct input_event))) 381 return -EFAULT; 382 383 return 0; 384 } 385 386 static int evdev_event_to_user(char __user *buffer, 387 const struct input_event *event) 388 { 389 if (copy_to_user(buffer, event, sizeof(struct input_event))) 390 return -EFAULT; 391 392 return 0; 393 } 394 395 #endif /* CONFIG_COMPAT */ 396 397 static ssize_t evdev_write(struct file *file, const char __user *buffer, 398 size_t count, loff_t *ppos) 399 { 400 struct evdev_client *client = file->private_data; 401 struct evdev *evdev = client->evdev; 402 struct input_event event; 403 int retval; 404 405 retval = mutex_lock_interruptible(&evdev->mutex); 406 if (retval) 407 return retval; 408 409 if (!evdev->exist) { 410 retval = -ENODEV; 411 goto out; 412 } 413 414 while (retval < count) { 415 416 if (evdev_event_from_user(buffer + retval, &event)) { 417 retval = -EFAULT; 418 goto out; 419 } 420 421 input_inject_event(&evdev->handle, 422 event.type, event.code, event.value); 423 retval += evdev_event_size(); 424 } 425 426 out: 427 mutex_unlock(&evdev->mutex); 428 return retval; 429 } 430 431 static int evdev_fetch_next_event(struct evdev_client *client, 432 struct input_event *event) 433 { 434 int have_event; 435 436 spin_lock_irq(&client->buffer_lock); 437 438 have_event = client->head != client->tail; 439 if (have_event) { 440 *event = client->buffer[client->tail++]; 441 client->tail &= EVDEV_BUFFER_SIZE - 1; 442 } 443 444 spin_unlock_irq(&client->buffer_lock); 445 446 return have_event; 447 } 448 449 static ssize_t evdev_read(struct file *file, char __user *buffer, 450 size_t count, loff_t *ppos) 451 { 452 struct evdev_client *client = file->private_data; 453 struct evdev *evdev = client->evdev; 454 struct input_event event; 455 int retval; 456 457 if (count < evdev_event_size()) 458 return -EINVAL; 459 460 if (client->head == client->tail && evdev->exist && 461 (file->f_flags & O_NONBLOCK)) 462 return -EAGAIN; 463 464 retval = wait_event_interruptible(evdev->wait, 465 client->head != client->tail || !evdev->exist); 466 if (retval) 467 return retval; 468 469 if (!evdev->exist) 470 return -ENODEV; 471 472 while (retval + evdev_event_size() <= count && 473 evdev_fetch_next_event(client, &event)) { 474 475 if (evdev_event_to_user(buffer + retval, &event)) 476 return -EFAULT; 477 478 retval += evdev_event_size(); 479 } 480 481 return retval; 482 } 483 484 /* No kernel lock - fine */ 485 static unsigned int evdev_poll(struct file *file, poll_table *wait) 486 { 487 struct evdev_client *client = file->private_data; 488 struct evdev *evdev = client->evdev; 489 490 poll_wait(file, &evdev->wait, wait); 491 return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) | 492 (evdev->exist ? 0 : (POLLHUP | POLLERR)); 493 } 494 495 #ifdef CONFIG_COMPAT 496 497 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8) 498 #define NBITS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1) 499 500 #ifdef __BIG_ENDIAN 501 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 502 unsigned int maxlen, void __user *p, int compat) 503 { 504 int len, i; 505 506 if (compat) { 507 len = NBITS_COMPAT(maxbit) * sizeof(compat_long_t); 508 if (len > maxlen) 509 len = maxlen; 510 511 for (i = 0; i < len / sizeof(compat_long_t); i++) 512 if (copy_to_user((compat_long_t __user *) p + i, 513 (compat_long_t *) bits + 514 i + 1 - ((i % 2) << 1), 515 sizeof(compat_long_t))) 516 return -EFAULT; 517 } else { 518 len = NBITS(maxbit) * sizeof(long); 519 if (len > maxlen) 520 len = maxlen; 521 522 if (copy_to_user(p, bits, len)) 523 return -EFAULT; 524 } 525 526 return len; 527 } 528 #else 529 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 530 unsigned int maxlen, void __user *p, int compat) 531 { 532 int len = compat ? 533 NBITS_COMPAT(maxbit) * sizeof(compat_long_t) : 534 NBITS(maxbit) * sizeof(long); 535 536 if (len > maxlen) 537 len = maxlen; 538 539 return copy_to_user(p, bits, len) ? -EFAULT : len; 540 } 541 #endif /* __BIG_ENDIAN */ 542 543 #else 544 545 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 546 unsigned int maxlen, void __user *p, int compat) 547 { 548 int len = NBITS(maxbit) * sizeof(long); 549 550 if (len > maxlen) 551 len = maxlen; 552 553 return copy_to_user(p, bits, len) ? -EFAULT : len; 554 } 555 556 #endif /* CONFIG_COMPAT */ 557 558 static int str_to_user(const char *str, unsigned int maxlen, void __user *p) 559 { 560 int len; 561 562 if (!str) 563 return -ENOENT; 564 565 len = strlen(str) + 1; 566 if (len > maxlen) 567 len = maxlen; 568 569 return copy_to_user(p, str, len) ? -EFAULT : len; 570 } 571 572 static long evdev_do_ioctl(struct file *file, unsigned int cmd, 573 void __user *p, int compat_mode) 574 { 575 struct evdev_client *client = file->private_data; 576 struct evdev *evdev = client->evdev; 577 struct input_dev *dev = evdev->handle.dev; 578 struct input_absinfo abs; 579 struct ff_effect effect; 580 int __user *ip = (int __user *)p; 581 int i, t, u, v; 582 int error; 583 584 switch (cmd) { 585 586 case EVIOCGVERSION: 587 return put_user(EV_VERSION, ip); 588 589 case EVIOCGID: 590 if (copy_to_user(p, &dev->id, sizeof(struct input_id))) 591 return -EFAULT; 592 return 0; 593 594 case EVIOCGREP: 595 if (!test_bit(EV_REP, dev->evbit)) 596 return -ENOSYS; 597 if (put_user(dev->rep[REP_DELAY], ip)) 598 return -EFAULT; 599 if (put_user(dev->rep[REP_PERIOD], ip + 1)) 600 return -EFAULT; 601 return 0; 602 603 case EVIOCSREP: 604 if (!test_bit(EV_REP, dev->evbit)) 605 return -ENOSYS; 606 if (get_user(u, ip)) 607 return -EFAULT; 608 if (get_user(v, ip + 1)) 609 return -EFAULT; 610 611 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u); 612 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v); 613 614 return 0; 615 616 case EVIOCGKEYCODE: 617 if (get_user(t, ip)) 618 return -EFAULT; 619 620 error = dev->getkeycode(dev, t, &v); 621 if (error) 622 return error; 623 624 if (put_user(v, ip + 1)) 625 return -EFAULT; 626 627 return 0; 628 629 case EVIOCSKEYCODE: 630 if (get_user(t, ip) || get_user(v, ip + 1)) 631 return -EFAULT; 632 633 return dev->setkeycode(dev, t, v); 634 635 case EVIOCSFF: 636 if (copy_from_user(&effect, p, sizeof(effect))) 637 return -EFAULT; 638 639 error = input_ff_upload(dev, &effect, file); 640 641 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) 642 return -EFAULT; 643 644 return error; 645 646 case EVIOCRMFF: 647 return input_ff_erase(dev, (int)(unsigned long) p, file); 648 649 case EVIOCGEFFECTS: 650 i = test_bit(EV_FF, dev->evbit) ? 651 dev->ff->max_effects : 0; 652 if (put_user(i, ip)) 653 return -EFAULT; 654 return 0; 655 656 case EVIOCGRAB: 657 if (p) 658 return evdev_grab(evdev, client); 659 else 660 return evdev_ungrab(evdev, client); 661 662 default: 663 664 if (_IOC_TYPE(cmd) != 'E') 665 return -EINVAL; 666 667 if (_IOC_DIR(cmd) == _IOC_READ) { 668 669 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) { 670 671 unsigned long *bits; 672 int len; 673 674 switch (_IOC_NR(cmd) & EV_MAX) { 675 676 case 0: bits = dev->evbit; len = EV_MAX; break; 677 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break; 678 case EV_REL: bits = dev->relbit; len = REL_MAX; break; 679 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break; 680 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break; 681 case EV_LED: bits = dev->ledbit; len = LED_MAX; break; 682 case EV_SND: bits = dev->sndbit; len = SND_MAX; break; 683 case EV_FF: bits = dev->ffbit; len = FF_MAX; break; 684 case EV_SW: bits = dev->swbit; len = SW_MAX; break; 685 default: return -EINVAL; 686 } 687 return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode); 688 } 689 690 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0))) 691 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd), 692 p, compat_mode); 693 694 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0))) 695 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd), 696 p, compat_mode); 697 698 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0))) 699 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd), 700 p, compat_mode); 701 702 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0))) 703 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd), 704 p, compat_mode); 705 706 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) 707 return str_to_user(dev->name, _IOC_SIZE(cmd), p); 708 709 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) 710 return str_to_user(dev->phys, _IOC_SIZE(cmd), p); 711 712 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) 713 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p); 714 715 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) { 716 717 t = _IOC_NR(cmd) & ABS_MAX; 718 719 abs.value = dev->abs[t]; 720 abs.minimum = dev->absmin[t]; 721 abs.maximum = dev->absmax[t]; 722 abs.fuzz = dev->absfuzz[t]; 723 abs.flat = dev->absflat[t]; 724 725 if (copy_to_user(p, &abs, sizeof(struct input_absinfo))) 726 return -EFAULT; 727 728 return 0; 729 } 730 731 } 732 733 if (_IOC_DIR(cmd) == _IOC_WRITE) { 734 735 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) { 736 737 t = _IOC_NR(cmd) & ABS_MAX; 738 739 if (copy_from_user(&abs, p, 740 sizeof(struct input_absinfo))) 741 return -EFAULT; 742 743 /* 744 * Take event lock to ensure that we are not 745 * changing device parameters in the middle 746 * of event. 747 */ 748 spin_lock_irq(&dev->event_lock); 749 750 dev->abs[t] = abs.value; 751 dev->absmin[t] = abs.minimum; 752 dev->absmax[t] = abs.maximum; 753 dev->absfuzz[t] = abs.fuzz; 754 dev->absflat[t] = abs.flat; 755 756 spin_unlock_irq(&dev->event_lock); 757 758 return 0; 759 } 760 } 761 } 762 return -EINVAL; 763 } 764 765 static long evdev_ioctl_handler(struct file *file, unsigned int cmd, 766 void __user *p, int compat_mode) 767 { 768 struct evdev_client *client = file->private_data; 769 struct evdev *evdev = client->evdev; 770 int retval; 771 772 retval = mutex_lock_interruptible(&evdev->mutex); 773 if (retval) 774 return retval; 775 776 if (!evdev->exist) { 777 retval = -ENODEV; 778 goto out; 779 } 780 781 retval = evdev_do_ioctl(file, cmd, p, compat_mode); 782 783 out: 784 mutex_unlock(&evdev->mutex); 785 return retval; 786 } 787 788 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 789 { 790 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0); 791 } 792 793 #ifdef CONFIG_COMPAT 794 static long evdev_ioctl_compat(struct file *file, 795 unsigned int cmd, unsigned long arg) 796 { 797 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1); 798 } 799 #endif 800 801 static const struct file_operations evdev_fops = { 802 .owner = THIS_MODULE, 803 .read = evdev_read, 804 .write = evdev_write, 805 .poll = evdev_poll, 806 .open = evdev_open, 807 .release = evdev_release, 808 .unlocked_ioctl = evdev_ioctl, 809 #ifdef CONFIG_COMPAT 810 .compat_ioctl = evdev_ioctl_compat, 811 #endif 812 .fasync = evdev_fasync, 813 .flush = evdev_flush 814 }; 815 816 static int evdev_install_chrdev(struct evdev *evdev) 817 { 818 /* 819 * No need to do any locking here as calls to connect and 820 * disconnect are serialized by the input core 821 */ 822 evdev_table[evdev->minor] = evdev; 823 return 0; 824 } 825 826 static void evdev_remove_chrdev(struct evdev *evdev) 827 { 828 /* 829 * Lock evdev table to prevent race with evdev_open() 830 */ 831 mutex_lock(&evdev_table_mutex); 832 evdev_table[evdev->minor] = NULL; 833 mutex_unlock(&evdev_table_mutex); 834 } 835 836 /* 837 * Mark device non-existent. This disables writes, ioctls and 838 * prevents new users from opening the device. Already posted 839 * blocking reads will stay, however new ones will fail. 840 */ 841 static void evdev_mark_dead(struct evdev *evdev) 842 { 843 mutex_lock(&evdev->mutex); 844 evdev->exist = 0; 845 mutex_unlock(&evdev->mutex); 846 } 847 848 static void evdev_cleanup(struct evdev *evdev) 849 { 850 struct input_handle *handle = &evdev->handle; 851 852 evdev_mark_dead(evdev); 853 evdev_hangup(evdev); 854 evdev_remove_chrdev(evdev); 855 856 /* evdev is marked dead so no one else accesses evdev->open */ 857 if (evdev->open) { 858 input_flush_device(handle, NULL); 859 input_close_device(handle); 860 } 861 } 862 863 /* 864 * Create new evdev device. Note that input core serializes calls 865 * to connect and disconnect so we don't need to lock evdev_table here. 866 */ 867 static int evdev_connect(struct input_handler *handler, struct input_dev *dev, 868 const struct input_device_id *id) 869 { 870 struct evdev *evdev; 871 int minor; 872 int error; 873 874 for (minor = 0; minor < EVDEV_MINORS; minor++) 875 if (!evdev_table[minor]) 876 break; 877 878 if (minor == EVDEV_MINORS) { 879 printk(KERN_ERR "evdev: no more free evdev devices\n"); 880 return -ENFILE; 881 } 882 883 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL); 884 if (!evdev) 885 return -ENOMEM; 886 887 INIT_LIST_HEAD(&evdev->client_list); 888 spin_lock_init(&evdev->client_lock); 889 mutex_init(&evdev->mutex); 890 init_waitqueue_head(&evdev->wait); 891 892 snprintf(evdev->name, sizeof(evdev->name), "event%d", minor); 893 evdev->exist = 1; 894 evdev->minor = minor; 895 896 evdev->handle.dev = dev; 897 evdev->handle.name = evdev->name; 898 evdev->handle.handler = handler; 899 evdev->handle.private = evdev; 900 901 strlcpy(evdev->dev.bus_id, evdev->name, sizeof(evdev->dev.bus_id)); 902 evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor); 903 evdev->dev.class = &input_class; 904 evdev->dev.parent = &dev->dev; 905 evdev->dev.release = evdev_free; 906 device_initialize(&evdev->dev); 907 908 error = input_register_handle(&evdev->handle); 909 if (error) 910 goto err_free_evdev; 911 912 error = evdev_install_chrdev(evdev); 913 if (error) 914 goto err_unregister_handle; 915 916 error = device_add(&evdev->dev); 917 if (error) 918 goto err_cleanup_evdev; 919 920 return 0; 921 922 err_cleanup_evdev: 923 evdev_cleanup(evdev); 924 err_unregister_handle: 925 input_unregister_handle(&evdev->handle); 926 err_free_evdev: 927 put_device(&evdev->dev); 928 return error; 929 } 930 931 static void evdev_disconnect(struct input_handle *handle) 932 { 933 struct evdev *evdev = handle->private; 934 935 device_del(&evdev->dev); 936 evdev_cleanup(evdev); 937 input_unregister_handle(handle); 938 put_device(&evdev->dev); 939 } 940 941 static const struct input_device_id evdev_ids[] = { 942 { .driver_info = 1 }, /* Matches all devices */ 943 { }, /* Terminating zero entry */ 944 }; 945 946 MODULE_DEVICE_TABLE(input, evdev_ids); 947 948 static struct input_handler evdev_handler = { 949 .event = evdev_event, 950 .connect = evdev_connect, 951 .disconnect = evdev_disconnect, 952 .fops = &evdev_fops, 953 .minor = EVDEV_MINOR_BASE, 954 .name = "evdev", 955 .id_table = evdev_ids, 956 }; 957 958 static int __init evdev_init(void) 959 { 960 return input_register_handler(&evdev_handler); 961 } 962 963 static void __exit evdev_exit(void) 964 { 965 input_unregister_handler(&evdev_handler); 966 } 967 968 module_init(evdev_init); 969 module_exit(evdev_exit); 970 971 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>"); 972 MODULE_DESCRIPTION("Input driver event char devices"); 973 MODULE_LICENSE("GPL"); 974