drivers/input/mousedev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Input driver to ExplorerPS/2 device driver module.
   4  *
   5  * Copyright (c) 1999-2002 Vojtech Pavlik
   6  * Copyright (c) 2004      Dmitry Torokhov
   7  */
   8
   9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11 #define MOUSEDEV_MINOR_BASE     32
  12 #define MOUSEDEV_MINORS         31
  13 #define MOUSEDEV_MIX            63
  14
  15 #include <linux/bitops.h>
  16 #include <linux/sched.h>
  17 #include <linux/slab.h>
  18 #include <linux/poll.h>
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/input.h>
  22 #include <linux/random.h>
  23 #include <linux/major.h>
  24 #include <linux/device.h>
  25 #include <linux/cdev.h>
  26 #include <linux/kernel.h>
  27
  28 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  29 MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
  30 MODULE_LICENSE("GPL");
  31
  32 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_X
  33 #define CONFIG_INPUT_MOUSEDEV_SCREEN_X  1024
  34 #endif
  35 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_Y
  36 #define CONFIG_INPUT_MOUSEDEV_SCREEN_Y  768
  37 #endif
  38
  39 static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
  40 module_param(xres, uint, 0644);
  41 MODULE_PARM_DESC(xres, "Horizontal screen resolution");
  42
  43 static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
  44 module_param(yres, uint, 0644);
  45 MODULE_PARM_DESC(yres, "Vertical screen resolution");
  46
  47 static unsigned tap_time = 200;
  48 module_param(tap_time, uint, 0644);
  49 MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");
  50
  51 struct mousedev_hw_data {
  52         int dx, dy, dz;
  53         int x, y;
  54         int abs_event;
  55         unsigned long buttons;
  56 };
  57
  58 struct mousedev {
  59         int open;
  60         struct input_handle handle;
  61         wait_queue_head_t wait;
  62         struct list_head client_list;
  63         spinlock_t client_lock; /* protects client_list */
  64         struct mutex mutex;
  65         struct device dev;
  66         struct cdev cdev;
  67         bool exist;
  68
  69         struct list_head mixdev_node;
  70         bool opened_by_mixdev;
  71
  72         struct mousedev_hw_data packet;
  73         unsigned int pkt_count;
  74         int old_x[4], old_y[4];
  75         int frac_dx, frac_dy;
  76         unsigned long touch;
  77
  78         int (*open_device)(struct mousedev *mousedev);
  79         void (*close_device)(struct mousedev *mousedev);
  80 };
  81
  82 enum mousedev_emul {
  83         MOUSEDEV_EMUL_PS2,
  84         MOUSEDEV_EMUL_IMPS,
  85         MOUSEDEV_EMUL_EXPS
  86 };
  87
  88 struct mousedev_motion {
  89         int dx, dy, dz;
  90         unsigned long buttons;
  91 };
  92
  93 #define PACKET_QUEUE_LEN        16
  94 struct mousedev_client {
  95         struct fasync_struct *fasync;
  96         struct mousedev *mousedev;
  97         struct list_head node;
  98
  99         struct mousedev_motion packets[PACKET_QUEUE_LEN];
 100         unsigned int head, tail;
 101         spinlock_t packet_lock;
 102         int pos_x, pos_y;
 103
 104         u8 ps2[6];
 105         unsigned char ready, buffer, bufsiz;
 106         unsigned char imexseq, impsseq;
 107         enum mousedev_emul mode;
 108         unsigned long last_buttons;
 109 };
 110
 111 #define MOUSEDEV_SEQ_LEN        6
 112
 113 static unsigned char mousedev_imps_seq[] = { 0xf3, 200, 0xf3, 100, 0xf3, 80 };
 114 static unsigned char mousedev_imex_seq[] = { 0xf3, 200, 0xf3, 200, 0xf3, 80 };
 115
 116 static struct mousedev *mousedev_mix;
 117 static LIST_HEAD(mousedev_mix_list);
 118
 119 #define fx(i)  (mousedev->old_x[(mousedev->pkt_count - (i)) & 03])
 120 #define fy(i)  (mousedev->old_y[(mousedev->pkt_count - (i)) & 03])
 121
 122 static void mousedev_touchpad_event(struct input_dev *dev,
 123                                     struct mousedev *mousedev,
 124                                     unsigned int code, int value)
 125 {
 126         int size, tmp;
 127         enum { FRACTION_DENOM = 128 };
 128
 129         switch (code) {
 130
 131         case ABS_X:
 132
 133                 fx(0) = value;
 134                 if (mousedev->touch && mousedev->pkt_count >= 2) {
 135                         size = input_abs_get_max(dev, ABS_X) -
 136                                         input_abs_get_min(dev, ABS_X);
 137                         if (size == 0)
 138                                 size = 256 * 2;
 139
 140                         tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size;
 141                         tmp += mousedev->frac_dx;
 142                         mousedev->packet.dx = tmp / FRACTION_DENOM;
 143                         mousedev->frac_dx =
 144                                 tmp - mousedev->packet.dx * FRACTION_DENOM;
 145                 }
 146                 break;
 147
 148         case ABS_Y:
 149                 fy(0) = value;
 150                 if (mousedev->touch && mousedev->pkt_count >= 2) {
 151                         /* use X size for ABS_Y to keep the same scale */
 152                         size = input_abs_get_max(dev, ABS_X) -
 153                                         input_abs_get_min(dev, ABS_X);
 154                         if (size == 0)
 155                                 size = 256 * 2;
 156
 157                         tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size;
 158                         tmp += mousedev->frac_dy;
 159                         mousedev->packet.dy = tmp / FRACTION_DENOM;
 160                         mousedev->frac_dy = tmp -
 161                                 mousedev->packet.dy * FRACTION_DENOM;
 162                 }
 163                 break;
 164         }
 165 }
 166
 167 static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev,
 168                                 unsigned int code, int value)
 169 {
 170         int min, max, size;
 171
 172         switch (code) {
 173
 174         case ABS_X:
 175                 min = input_abs_get_min(dev, ABS_X);
 176                 max = input_abs_get_max(dev, ABS_X);
 177
 178                 size = max - min;
 179                 if (size == 0)
 180                         size = xres ? : 1;
 181
 182                 value = clamp(value, min, max);
 183
 184                 mousedev->packet.x = ((value - min) * xres) / size;
 185                 mousedev->packet.abs_event = 1;
 186                 break;
 187
 188         case ABS_Y:
 189                 min = input_abs_get_min(dev, ABS_Y);
 190                 max = input_abs_get_max(dev, ABS_Y);
 191
 192                 size = max - min;
 193                 if (size == 0)
 194                         size = yres ? : 1;
 195
 196                 value = clamp(value, min, max);
 197
 198                 mousedev->packet.y = yres - ((value - min) * yres) / size;
 199                 mousedev->packet.abs_event = 1;
 200                 break;
 201         }
 202 }
 203
 204 static void mousedev_rel_event(struct mousedev *mousedev,
 205                                 unsigned int code, int value)
 206 {
 207         switch (code) {
 208         case REL_X:
 209                 mousedev->packet.dx += value;
 210                 break;
 211
 212         case REL_Y:
 213                 mousedev->packet.dy -= value;
 214                 break;
 215
 216         case REL_WHEEL:
 217                 mousedev->packet.dz -= value;
 218                 break;
 219         }
 220 }
 221
 222 static void mousedev_key_event(struct mousedev *mousedev,
 223                                 unsigned int code, int value)
 224 {
 225         int index;
 226
 227         switch (code) {
 228
 229         case BTN_TOUCH:
 230         case BTN_0:
 231         case BTN_LEFT:          index = 0; break;
 232
 233         case BTN_STYLUS:
 234         case BTN_1:
 235         case BTN_RIGHT:         index = 1; break;
 236
 237         case BTN_2:
 238         case BTN_FORWARD:
 239         case BTN_STYLUS2:
 240         case BTN_MIDDLE:        index = 2; break;
 241
 242         case BTN_3:
 243         case BTN_BACK:
 244         case BTN_SIDE:          index = 3; break;
 245
 246         case BTN_4:
 247         case BTN_EXTRA:         index = 4; break;
 248
 249         default:                return;
 250         }
 251
 252         if (value) {
 253                 set_bit(index, &mousedev->packet.buttons);
 254                 set_bit(index, &mousedev_mix->packet.buttons);
 255         } else {
 256                 clear_bit(index, &mousedev->packet.buttons);
 257                 clear_bit(index, &mousedev_mix->packet.buttons);
 258         }
 259 }
 260
 261 static void mousedev_notify_readers(struct mousedev *mousedev,
 262                                     struct mousedev_hw_data *packet)
 263 {
 264         struct mousedev_client *client;
 265         struct mousedev_motion *p;
 266         unsigned int new_head;
 267         int wake_readers = 0;
 268
 269         rcu_read_lock();
 270         list_for_each_entry_rcu(client, &mousedev->client_list, node) {
 271
 272                 /* Just acquire the lock, interrupts already disabled */
 273                 spin_lock(&client->packet_lock);
 274
 275                 p = &client->packets[client->head];
 276                 if (client->ready && p->buttons != mousedev->packet.buttons) {
 277                         new_head = (client->head + 1) % PACKET_QUEUE_LEN;
 278                         if (new_head != client->tail) {
 279                                 p = &client->packets[client->head = new_head];
 280                                 memset(p, 0, sizeof(struct mousedev_motion));
 281                         }
 282                 }
 283
 284                 if (packet->abs_event) {
 285                         p->dx += packet->x - client->pos_x;
 286                         p->dy += packet->y - client->pos_y;
 287                         client->pos_x = packet->x;
 288                         client->pos_y = packet->y;
 289                 }
 290
 291                 client->pos_x += packet->dx;
 292                 client->pos_x = clamp_val(client->pos_x, 0, xres);
 293
 294                 client->pos_y += packet->dy;
 295                 client->pos_y = clamp_val(client->pos_y, 0, yres);
 296
 297                 p->dx += packet->dx;
 298                 p->dy += packet->dy;
 299                 p->dz += packet->dz;
 300                 p->buttons = mousedev->packet.buttons;
 301
 302                 if (p->dx || p->dy || p->dz ||
 303                     p->buttons != client->last_buttons)
 304                         client->ready = 1;
 305
 306                 spin_unlock(&client->packet_lock);
 307
 308                 if (client->ready) {
 309                         kill_fasync(&client->fasync, SIGIO, POLL_IN);
 310                         wake_readers = 1;
 311                 }
 312         }
 313         rcu_read_unlock();
 314
 315         if (wake_readers)
 316                 wake_up_interruptible(&mousedev->wait);
 317 }
 318
 319 static void mousedev_touchpad_touch(struct mousedev *mousedev, int value)
 320 {
 321         if (!value) {
 322                 if (mousedev->touch &&
 323                     time_before(jiffies,
 324                                 mousedev->touch + msecs_to_jiffies(tap_time))) {
 325                         /*
 326                          * Toggle left button to emulate tap.
 327                          * We rely on the fact that mousedev_mix always has 0
 328                          * motion packet so we won't mess current position.
 329                          */
 330                         set_bit(0, &mousedev->packet.buttons);
 331                         set_bit(0, &mousedev_mix->packet.buttons);
 332                         mousedev_notify_readers(mousedev, &mousedev_mix->packet);
 333                         mousedev_notify_readers(mousedev_mix,
 334                                                 &mousedev_mix->packet);
 335                         clear_bit(0, &mousedev->packet.buttons);
 336                         clear_bit(0, &mousedev_mix->packet.buttons);
 337                 }
 338                 mousedev->touch = mousedev->pkt_count = 0;
 339                 mousedev->frac_dx = 0;
 340                 mousedev->frac_dy = 0;
 341
 342         } else if (!mousedev->touch)
 343                 mousedev->touch = jiffies;
 344 }
 345
 346 static void mousedev_event(struct input_handle *handle,
 347                            unsigned int type, unsigned int code, int value)
 348 {
 349         struct mousedev *mousedev = handle->private;
 350
 351         switch (type) {
 352
 353         case EV_ABS:
 354                 /* Ignore joysticks */
 355                 if (test_bit(BTN_TRIGGER, handle->dev->keybit))
 356                         return;
 357
 358                 if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
 359                         mousedev_touchpad_event(handle->dev,
 360                                                 mousedev, code, value);
 361                 else
 362                         mousedev_abs_event(handle->dev, mousedev, code, value);
 363
 364                 break;
 365
 366         case EV_REL:
 367                 mousedev_rel_event(mousedev, code, value);
 368                 break;
 369
 370         case EV_KEY:
 371                 if (value != 2) {
 372                         if (code == BTN_TOUCH &&
 373                             test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
 374                                 mousedev_touchpad_touch(mousedev, value);
 375                         else
 376                                 mousedev_key_event(mousedev, code, value);
 377                 }
 378                 break;
 379
 380         case EV_SYN:
 381                 if (code == SYN_REPORT) {
 382                         if (mousedev->touch) {
 383                                 mousedev->pkt_count++;
 384                                 /*
 385                                  * Input system eats duplicate events,
 386                                  * but we need all of them to do correct
 387                                  * averaging so apply present one forward
 388                                  */
 389                                 fx(0) = fx(1);
 390                                 fy(0) = fy(1);
 391                         }
 392
 393                         mousedev_notify_readers(mousedev, &mousedev->packet);
 394                         mousedev_notify_readers(mousedev_mix, &mousedev->packet);
 395
 396                         mousedev->packet.dx = mousedev->packet.dy =
 397                                 mousedev->packet.dz = 0;
 398                         mousedev->packet.abs_event = 0;
 399                 }
 400                 break;
 401         }
 402 }
 403
 404 static int mousedev_fasync(int fd, struct file *file, int on)
 405 {
 406         struct mousedev_client *client = file->private_data;
 407
 408         return fasync_helper(fd, file, on, &client->fasync);
 409 }
 410
 411 static void mousedev_free(struct device *dev)
 412 {
 413         struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
 414
 415         input_put_device(mousedev->handle.dev);
 416         kfree(mousedev);
 417 }
 418
 419 static int mousedev_open_device(struct mousedev *mousedev)
 420 {
 421         int retval;
 422
 423         retval = mutex_lock_interruptible(&mousedev->mutex);
 424         if (retval)
 425                 return retval;
 426
 427         if (!mousedev->exist)
 428                 retval = -ENODEV;
 429         else if (!mousedev->open++) {
 430                 retval = input_open_device(&mousedev->handle);
 431                 if (retval)
 432                         mousedev->open--;
 433         }
 434
 435         mutex_unlock(&mousedev->mutex);
 436         return retval;
 437 }
 438
 439 static void mousedev_close_device(struct mousedev *mousedev)
 440 {
 441         mutex_lock(&mousedev->mutex);
 442
 443         if (mousedev->exist && !--mousedev->open)
 444                 input_close_device(&mousedev->handle);
 445
 446         mutex_unlock(&mousedev->mutex);
 447 }
 448
 449 /*
 450  * Open all available devices so they can all be multiplexed in one.
 451  * stream. Note that this function is called with mousedev_mix->mutex
 452  * held.
 453  */
 454 static int mixdev_open_devices(struct mousedev *mixdev)
 455 {
 456         int error;
 457
 458         error = mutex_lock_interruptible(&mixdev->mutex);
 459         if (error)
 460                 return error;
 461
 462         if (!mixdev->open++) {
 463                 struct mousedev *mousedev;
 464
 465                 list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
 466                         if (!mousedev->opened_by_mixdev) {
 467                                 if (mousedev_open_device(mousedev))
 468                                         continue;
 469
 470                                 mousedev->opened_by_mixdev = true;
 471                         }
 472                 }
 473         }
 474
 475         mutex_unlock(&mixdev->mutex);
 476         return 0;
 477 }
 478
 479 /*
 480  * Close all devices that were opened as part of multiplexed
 481  * device. Note that this function is called with mousedev_mix->mutex
 482  * held.
 483  */
 484 static void mixdev_close_devices(struct mousedev *mixdev)
 485 {
 486         mutex_lock(&mixdev->mutex);
 487
 488         if (!--mixdev->open) {
 489                 struct mousedev *mousedev;
 490
 491                 list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
 492                         if (mousedev->opened_by_mixdev) {
 493                                 mousedev->opened_by_mixdev = false;
 494                                 mousedev_close_device(mousedev);
 495                         }
 496                 }
 497         }
 498
 499         mutex_unlock(&mixdev->mutex);
 500 }
 501
 502
 503 static void mousedev_attach_client(struct mousedev *mousedev,
 504                                    struct mousedev_client *client)
 505 {
 506         spin_lock(&mousedev->client_lock);
 507         list_add_tail_rcu(&client->node, &mousedev->client_list);
 508         spin_unlock(&mousedev->client_lock);
 509 }
 510
 511 static void mousedev_detach_client(struct mousedev *mousedev,
 512                                    struct mousedev_client *client)
 513 {
 514         spin_lock(&mousedev->client_lock);
 515         list_del_rcu(&client->node);
 516         spin_unlock(&mousedev->client_lock);
 517         synchronize_rcu();
 518 }
 519
 520 static int mousedev_release(struct inode *inode, struct file *file)
 521 {
 522         struct mousedev_client *client = file->private_data;
 523         struct mousedev *mousedev = client->mousedev;
 524
 525         mousedev_detach_client(mousedev, client);
 526         kfree(client);
 527
 528         mousedev->close_device(mousedev);
 529
 530         return 0;
 531 }
 532
 533 static int mousedev_open(struct inode *inode, struct file *file)
 534 {
 535         struct mousedev_client *client;
 536         struct mousedev *mousedev;
 537         int error;
 538
 539 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
 540         if (imajor(inode) == MISC_MAJOR)
 541                 mousedev = mousedev_mix;
 542         else
 543 #endif
 544                 mousedev = container_of(inode->i_cdev, struct mousedev, cdev);
 545
 546         client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
 547         if (!client)
 548                 return -ENOMEM;
 549
 550         spin_lock_init(&client->packet_lock);
 551         client->pos_x = xres / 2;
 552         client->pos_y = yres / 2;
 553         client->mousedev = mousedev;
 554         mousedev_attach_client(mousedev, client);
 555
 556         error = mousedev->open_device(mousedev);
 557         if (error)
 558                 goto err_free_client;
 559
 560         file->private_data = client;
 561         stream_open(inode, file);
 562
 563         return 0;
 564
 565  err_free_client:
 566         mousedev_detach_client(mousedev, client);
 567         kfree(client);
 568         return error;
 569 }
 570
 571 static void mousedev_packet(struct mousedev_client *client, u8 *ps2_data)
 572 {
 573         struct mousedev_motion *p = &client->packets[client->tail];
 574         s8 dx, dy, dz;
 575
 576         dx = clamp_val(p->dx, -127, 127);
 577         p->dx -= dx;
 578
 579         dy = clamp_val(p->dy, -127, 127);
 580         p->dy -= dy;
 581
 582         ps2_data[0] = BIT(3);
 583         ps2_data[0] |= ((dx & BIT(7)) >> 3) | ((dy & BIT(7)) >> 2);
 584         ps2_data[0] |= p->buttons & 0x07;
 585         ps2_data[1] = dx;
 586         ps2_data[2] = dy;
 587
 588         switch (client->mode) {
 589         case MOUSEDEV_EMUL_EXPS:
 590                 dz = clamp_val(p->dz, -7, 7);
 591                 p->dz -= dz;
 592
 593                 ps2_data[3] = (dz & 0x0f) | ((p->buttons & 0x18) << 1);
 594                 client->bufsiz = 4;
 595                 break;
 596
 597         case MOUSEDEV_EMUL_IMPS:
 598                 dz = clamp_val(p->dz, -127, 127);
 599                 p->dz -= dz;
 600
 601                 ps2_data[0] |= ((p->buttons & 0x10) >> 3) |
 602                                ((p->buttons & 0x08) >> 1);
 603                 ps2_data[3] = dz;
 604
 605                 client->bufsiz = 4;
 606                 break;
 607
 608         case MOUSEDEV_EMUL_PS2:
 609         default:
 610                 p->dz = 0;
 611
 612                 ps2_data[0] |= ((p->buttons & 0x10) >> 3) |
 613                                ((p->buttons & 0x08) >> 1);
 614
 615                 client->bufsiz = 3;
 616                 break;
 617         }
 618
 619         if (!p->dx && !p->dy && !p->dz) {
 620                 if (client->tail == client->head) {
 621                         client->ready = 0;
 622                         client->last_buttons = p->buttons;
 623                 } else
 624                         client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
 625         }
 626 }
 627
 628 static void mousedev_generate_response(struct mousedev_client *client,
 629                                         int command)
 630 {
 631         client->ps2[0] = 0xfa; /* ACK */
 632
 633         switch (command) {
 634
 635         case 0xeb: /* Poll */
 636                 mousedev_packet(client, &client->ps2[1]);
 637                 client->bufsiz++; /* account for leading ACK */
 638                 break;
 639
 640         case 0xf2: /* Get ID */
 641                 switch (client->mode) {
 642                 case MOUSEDEV_EMUL_PS2:
 643                         client->ps2[1] = 0;
 644                         break;
 645                 case MOUSEDEV_EMUL_IMPS:
 646                         client->ps2[1] = 3;
 647                         break;
 648                 case MOUSEDEV_EMUL_EXPS:
 649                         client->ps2[1] = 4;
 650                         break;
 651                 }
 652                 client->bufsiz = 2;
 653                 break;
 654
 655         case 0xe9: /* Get info */
 656                 client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
 657                 client->bufsiz = 4;
 658                 break;
 659
 660         case 0xff: /* Reset */
 661                 client->impsseq = client->imexseq = 0;
 662                 client->mode = MOUSEDEV_EMUL_PS2;
 663                 client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
 664                 client->bufsiz = 3;
 665                 break;
 666
 667         default:
 668                 client->bufsiz = 1;
 669                 break;
 670         }
 671         client->buffer = client->bufsiz;
 672 }
 673
 674 static ssize_t mousedev_write(struct file *file, const char __user *buffer,
 675                                 size_t count, loff_t *ppos)
 676 {
 677         struct mousedev_client *client = file->private_data;
 678         unsigned char c;
 679         unsigned int i;
 680
 681         for (i = 0; i < count; i++) {
 682
 683                 if (get_user(c, buffer + i))
 684                         return -EFAULT;
 685
 686                 spin_lock_irq(&client->packet_lock);
 687
 688                 if (c == mousedev_imex_seq[client->imexseq]) {
 689                         if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
 690                                 client->imexseq = 0;
 691                                 client->mode = MOUSEDEV_EMUL_EXPS;
 692                         }
 693                 } else
 694                         client->imexseq = 0;
 695
 696                 if (c == mousedev_imps_seq[client->impsseq]) {
 697                         if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
 698                                 client->impsseq = 0;
 699                                 client->mode = MOUSEDEV_EMUL_IMPS;
 700                         }
 701                 } else
 702                         client->impsseq = 0;
 703
 704                 mousedev_generate_response(client, c);
 705
 706                 spin_unlock_irq(&client->packet_lock);
 707                 cond_resched();
 708         }
 709
 710         kill_fasync(&client->fasync, SIGIO, POLL_IN);
 711         wake_up_interruptible(&client->mousedev->wait);
 712
 713         return count;
 714 }
 715
 716 static ssize_t mousedev_read(struct file *file, char __user *buffer,
 717                              size_t count, loff_t *ppos)
 718 {
 719         struct mousedev_client *client = file->private_data;
 720         struct mousedev *mousedev = client->mousedev;
 721         u8 data[sizeof(client->ps2)];
 722         int retval = 0;
 723
 724         if (!client->ready && !client->buffer && mousedev->exist &&
 725             (file->f_flags & O_NONBLOCK))
 726                 return -EAGAIN;
 727
 728         retval = wait_event_interruptible(mousedev->wait,
 729                         !mousedev->exist || client->ready || client->buffer);
 730         if (retval)
 731                 return retval;
 732
 733         if (!mousedev->exist)
 734                 return -ENODEV;
 735
 736         spin_lock_irq(&client->packet_lock);
 737
 738         if (!client->buffer && client->ready) {
 739                 mousedev_packet(client, client->ps2);
 740                 client->buffer = client->bufsiz;
 741         }
 742
 743         if (count > client->buffer)
 744                 count = client->buffer;
 745
 746         memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
 747         client->buffer -= count;
 748
 749         spin_unlock_irq(&client->packet_lock);
 750
 751         if (copy_to_user(buffer, data, count))
 752                 return -EFAULT;
 753
 754         return count;
 755 }
 756
 757 /* No kernel lock - fine */
 758 static __poll_t mousedev_poll(struct file *file, poll_table *wait)
 759 {
 760         struct mousedev_client *client = file->private_data;
 761         struct mousedev *mousedev = client->mousedev;
 762         __poll_t mask;
 763
 764         poll_wait(file, &mousedev->wait, wait);
 765
 766         mask = mousedev->exist ? EPOLLOUT | EPOLLWRNORM : EPOLLHUP | EPOLLERR;
 767         if (client->ready || client->buffer)
 768                 mask |= EPOLLIN | EPOLLRDNORM;
 769
 770         return mask;
 771 }
 772
 773 static const struct file_operations mousedev_fops = {
 774         .owner          = THIS_MODULE,
 775         .read           = mousedev_read,
 776         .write          = mousedev_write,
 777         .poll           = mousedev_poll,
 778         .open           = mousedev_open,
 779         .release        = mousedev_release,
 780         .fasync         = mousedev_fasync,
 781         .llseek         = noop_llseek,
 782 };
 783
 784 /*
 785  * Mark device non-existent. This disables writes, ioctls and
 786  * prevents new users from opening the device. Already posted
 787  * blocking reads will stay, however new ones will fail.
 788  */
 789 static void mousedev_mark_dead(struct mousedev *mousedev)
 790 {
 791         mutex_lock(&mousedev->mutex);
 792         mousedev->exist = false;
 793         mutex_unlock(&mousedev->mutex);
 794 }
 795
 796 /*
 797  * Wake up users waiting for IO so they can disconnect from
 798  * dead device.
 799  */
 800 static void mousedev_hangup(struct mousedev *mousedev)
 801 {
 802         struct mousedev_client *client;
 803
 804         spin_lock(&mousedev->client_lock);
 805         list_for_each_entry(client, &mousedev->client_list, node)
 806                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 807         spin_unlock(&mousedev->client_lock);
 808
 809         wake_up_interruptible(&mousedev->wait);
 810 }
 811
 812 static void mousedev_cleanup(struct mousedev *mousedev)
 813 {
 814         struct input_handle *handle = &mousedev->handle;
 815
 816         mousedev_mark_dead(mousedev);
 817         mousedev_hangup(mousedev);
 818
 819         /* mousedev is marked dead so no one else accesses mousedev->open */
 820         if (mousedev->open)
 821                 input_close_device(handle);
 822 }
 823
 824 static int mousedev_reserve_minor(bool mixdev)
 825 {
 826         int minor;
 827
 828         if (mixdev) {
 829                 minor = input_get_new_minor(MOUSEDEV_MIX, 1, false);
 830                 if (minor < 0)
 831                         pr_err("failed to reserve mixdev minor: %d\n", minor);
 832         } else {
 833                 minor = input_get_new_minor(MOUSEDEV_MINOR_BASE,
 834                                             MOUSEDEV_MINORS, true);
 835                 if (minor < 0)
 836                         pr_err("failed to reserve new minor: %d\n", minor);
 837         }
 838
 839         return minor;
 840 }
 841
 842 static struct mousedev *mousedev_create(struct input_dev *dev,
 843                                         struct input_handler *handler,
 844                                         bool mixdev)
 845 {
 846         struct mousedev *mousedev;
 847         int minor;
 848         int error;
 849
 850         minor = mousedev_reserve_minor(mixdev);
 851         if (minor < 0) {
 852                 error = minor;
 853                 goto err_out;
 854         }
 855
 856         mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
 857         if (!mousedev) {
 858                 error = -ENOMEM;
 859                 goto err_free_minor;
 860         }
 861
 862         INIT_LIST_HEAD(&mousedev->client_list);
 863         INIT_LIST_HEAD(&mousedev->mixdev_node);
 864         spin_lock_init(&mousedev->client_lock);
 865         mutex_init(&mousedev->mutex);
 866         lockdep_set_subclass(&mousedev->mutex,
 867                              mixdev ? SINGLE_DEPTH_NESTING : 0);
 868         init_waitqueue_head(&mousedev->wait);
 869
 870         if (mixdev) {
 871                 dev_set_name(&mousedev->dev, "mice");
 872
 873                 mousedev->open_device = mixdev_open_devices;
 874                 mousedev->close_device = mixdev_close_devices;
 875         } else {
 876                 int dev_no = minor;
 877                 /* Normalize device number if it falls into legacy range */
 878                 if (dev_no < MOUSEDEV_MINOR_BASE + MOUSEDEV_MINORS)
 879                         dev_no -= MOUSEDEV_MINOR_BASE;
 880                 dev_set_name(&mousedev->dev, "mouse%d", dev_no);
 881
 882                 mousedev->open_device = mousedev_open_device;
 883                 mousedev->close_device = mousedev_close_device;
 884         }
 885
 886         mousedev->exist = true;
 887         mousedev->handle.dev = input_get_device(dev);
 888         mousedev->handle.name = dev_name(&mousedev->dev);
 889         mousedev->handle.handler = handler;
 890         mousedev->handle.private = mousedev;
 891
 892         mousedev->dev.class = &input_class;
 893         if (dev)
 894                 mousedev->dev.parent = &dev->dev;
 895         mousedev->dev.devt = MKDEV(INPUT_MAJOR, minor);
 896         mousedev->dev.release = mousedev_free;
 897         device_initialize(&mousedev->dev);
 898
 899         if (!mixdev) {
 900                 error = input_register_handle(&mousedev->handle);
 901                 if (error)
 902                         goto err_free_mousedev;
 903         }
 904
 905         cdev_init(&mousedev->cdev, &mousedev_fops);
 906
 907         error = cdev_device_add(&mousedev->cdev, &mousedev->dev);
 908         if (error)
 909                 goto err_cleanup_mousedev;
 910
 911         return mousedev;
 912
 913  err_cleanup_mousedev:
 914         mousedev_cleanup(mousedev);
 915         if (!mixdev)
 916                 input_unregister_handle(&mousedev->handle);
 917  err_free_mousedev:
 918         put_device(&mousedev->dev);
 919  err_free_minor:
 920         input_free_minor(minor);
 921  err_out:
 922         return ERR_PTR(error);
 923 }
 924
 925 static void mousedev_destroy(struct mousedev *mousedev)
 926 {
 927         cdev_device_del(&mousedev->cdev, &mousedev->dev);
 928         mousedev_cleanup(mousedev);
 929         input_free_minor(MINOR(mousedev->dev.devt));
 930         if (mousedev != mousedev_mix)
 931                 input_unregister_handle(&mousedev->handle);
 932         put_device(&mousedev->dev);
 933 }
 934
 935 static int mixdev_add_device(struct mousedev *mousedev)
 936 {
 937         int retval;
 938
 939         retval = mutex_lock_interruptible(&mousedev_mix->mutex);
 940         if (retval)
 941                 return retval;
 942
 943         if (mousedev_mix->open) {
 944                 retval = mousedev_open_device(mousedev);
 945                 if (retval)
 946                         goto out;
 947
 948                 mousedev->opened_by_mixdev = true;
 949         }
 950
 951         get_device(&mousedev->dev);
 952         list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
 953
 954  out:
 955         mutex_unlock(&mousedev_mix->mutex);
 956         return retval;
 957 }
 958
 959 static void mixdev_remove_device(struct mousedev *mousedev)
 960 {
 961         mutex_lock(&mousedev_mix->mutex);
 962
 963         if (mousedev->opened_by_mixdev) {
 964                 mousedev->opened_by_mixdev = false;
 965                 mousedev_close_device(mousedev);
 966         }
 967
 968         list_del_init(&mousedev->mixdev_node);
 969         mutex_unlock(&mousedev_mix->mutex);
 970
 971         put_device(&mousedev->dev);
 972 }
 973
 974 static int mousedev_connect(struct input_handler *handler,
 975                             struct input_dev *dev,
 976                             const struct input_device_id *id)
 977 {
 978         struct mousedev *mousedev;
 979         int error;
 980
 981         mousedev = mousedev_create(dev, handler, false);
 982         if (IS_ERR(mousedev))
 983                 return PTR_ERR(mousedev);
 984
 985         error = mixdev_add_device(mousedev);
 986         if (error) {
 987                 mousedev_destroy(mousedev);
 988                 return error;
 989         }
 990
 991         return 0;
 992 }
 993
 994 static void mousedev_disconnect(struct input_handle *handle)
 995 {
 996         struct mousedev *mousedev = handle->private;
 997
 998         mixdev_remove_device(mousedev);
 999         mousedev_destroy(mousedev);
1000 }
1001
1002 static const struct input_device_id mousedev_ids[] = {
1003         {
1004                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1005                                 INPUT_DEVICE_ID_MATCH_KEYBIT |
1006                                 INPUT_DEVICE_ID_MATCH_RELBIT,
1007                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1008                 .keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1009                 .relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
1010         },      /* A mouse like device, at least one button,
1011                    two relative axes */
1012         {
1013                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1014                                 INPUT_DEVICE_ID_MATCH_RELBIT,
1015                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1016                 .relbit = { BIT_MASK(REL_WHEEL) },
1017         },      /* A separate scrollwheel */
1018         {
1019                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1020                                 INPUT_DEVICE_ID_MATCH_KEYBIT |
1021                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
1022                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1023                 .keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1024                 .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1025         },      /* A tablet like device, at least touch detection,
1026                    two absolute axes */
1027         {
1028                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1029                                 INPUT_DEVICE_ID_MATCH_KEYBIT |
1030                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
1031                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1032                 .keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
1033                                 BIT_MASK(BTN_TOOL_FINGER) },
1034                 .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1035                                 BIT_MASK(ABS_PRESSURE) |
1036                                 BIT_MASK(ABS_TOOL_WIDTH) },
1037         },      /* A touchpad */
1038         {
1039                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1040                         INPUT_DEVICE_ID_MATCH_KEYBIT |
1041                         INPUT_DEVICE_ID_MATCH_ABSBIT,
1042                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1043                 .keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1044                 .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1045         },      /* Mouse-like device with absolute X and Y but ordinary
1046                    clicks, like hp ILO2 High Performance mouse */
1047
1048         { },    /* Terminating entry */
1049 };
1050
1051 MODULE_DEVICE_TABLE(input, mousedev_ids);
1052
1053 static struct input_handler mousedev_handler = {
1054         .event          = mousedev_event,
1055         .connect        = mousedev_connect,
1056         .disconnect     = mousedev_disconnect,
1057         .legacy_minors  = true,
1058         .minor          = MOUSEDEV_MINOR_BASE,
1059         .name           = "mousedev",
1060         .id_table       = mousedev_ids,
1061 };
1062
1063 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1064 #include <linux/miscdevice.h>
1065
1066 static struct miscdevice psaux_mouse = {
1067         .minor  = PSMOUSE_MINOR,
1068         .name   = "psaux",
1069         .fops   = &mousedev_fops,
1070 };
1071
1072 static bool psaux_registered;
1073
1074 static void __init mousedev_psaux_register(void)
1075 {
1076         int error;
1077
1078         error = misc_register(&psaux_mouse);
1079         if (error)
1080                 pr_warn("could not register psaux device, error: %d\n",
1081                            error);
1082         else
1083                 psaux_registered = true;
1084 }
1085
1086 static void __exit mousedev_psaux_unregister(void)
1087 {
1088         if (psaux_registered)
1089                 misc_deregister(&psaux_mouse);
1090 }
1091 #else
1092 static inline void mousedev_psaux_register(void) { }
1093 static inline void mousedev_psaux_unregister(void) { }
1094 #endif
1095
1096 static int __init mousedev_init(void)
1097 {
1098         int error;
1099
1100         mousedev_mix = mousedev_create(NULL, &mousedev_handler, true);
1101         if (IS_ERR(mousedev_mix))
1102                 return PTR_ERR(mousedev_mix);
1103
1104         error = input_register_handler(&mousedev_handler);
1105         if (error) {
1106                 mousedev_destroy(mousedev_mix);
1107                 return error;
1108         }
1109
1110         mousedev_psaux_register();
1111
1112         pr_info("PS/2 mouse device common for all mice\n");
1113
1114         return 0;
1115 }
1116
1117 static void __exit mousedev_exit(void)
1118 {
1119         mousedev_psaux_unregister();
1120         input_unregister_handler(&mousedev_handler);
1121         mousedev_destroy(mousedev_mix);
1122 }
1123
1124 module_init(mousedev_init);
1125 module_exit(mousedev_exit);