drivers/input/mousedev.c

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