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"); 975