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         31
  16 #define MOUSEDEV_MIX            63
  17
  18 #include <linux/bitops.h>
  19 #include <linux/sched.h>
  20 #include <linux/slab.h>
  21 #include <linux/poll.h>
  22 #include <linux/module.h>
  23 #include <linux/init.h>
  24 #include <linux/input.h>
  25 #include <linux/random.h>
  26 #include <linux/major.h>
  27 #include <linux/device.h>
  28 #include <linux/cdev.h>
  29 #include <linux/kernel.h>
  30
  31 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  32 MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
  33 MODULE_LICENSE("GPL");
  34
  35 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_X
  36 #define CONFIG_INPUT_MOUSEDEV_SCREEN_X  1024
  37 #endif
  38 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_Y
  39 #define CONFIG_INPUT_MOUSEDEV_SCREEN_Y  768
  40 #endif
  41
  42 static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
  43 module_param(xres, uint, 0644);
  44 MODULE_PARM_DESC(xres, "Horizontal screen resolution");
  45
  46 static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
  47 module_param(yres, uint, 0644);
  48 MODULE_PARM_DESC(yres, "Vertical screen resolution");
  49
  50 static unsigned tap_time = 200;
  51 module_param(tap_time, uint, 0644);
  52 MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");
  53
  54 struct mousedev_hw_data {
  55         int dx, dy, dz;
  56         int x, y;
  57         int abs_event;
  58         unsigned long buttons;
  59 };
  60
  61 struct mousedev {
  62         int open;
  63         struct input_handle handle;
  64         wait_queue_head_t wait;
  65         struct list_head client_list;
  66         spinlock_t client_lock; /* protects client_list */
  67         struct mutex mutex;
  68         struct device dev;
  69         struct cdev cdev;
  70         bool exist;
  71
  72         struct list_head mixdev_node;
  73         bool opened_by_mixdev;
  74
  75         struct mousedev_hw_data packet;
  76         unsigned int pkt_count;
  77         int old_x[4], old_y[4];
  78         int frac_dx, frac_dy;
  79         unsigned long touch;
  80
  81         int (*open_device)(struct mousedev *mousedev);
  82         void (*close_device)(struct mousedev *mousedev);
  83 };
  84
  85 enum mousedev_emul {
  86         MOUSEDEV_EMUL_PS2,
  87         MOUSEDEV_EMUL_IMPS,
  88         MOUSEDEV_EMUL_EXPS
  89 };
  90
  91 struct mousedev_motion {
  92         int dx, dy, dz;
  93         unsigned long buttons;
  94 };
  95
  96 #define PACKET_QUEUE_LEN        16
  97 struct mousedev_client {
  98         struct fasync_struct *fasync;
  99         struct mousedev *mousedev;
 100         struct list_head node;
 101
 102         struct mousedev_motion packets[PACKET_QUEUE_LEN];
 103         unsigned int head, tail;
 104         spinlock_t packet_lock;
 105         int pos_x, pos_y;
 106
 107         u8 ps2[6];
 108         unsigned char ready, buffer, bufsiz;
 109         unsigned char imexseq, impsseq;
 110         enum mousedev_emul mode;
 111         unsigned long last_buttons;
 112 };
 113
 114 #define MOUSEDEV_SEQ_LEN        6
 115
 116 static unsigned char mousedev_imps_seq[] = { 0xf3, 200, 0xf3, 100, 0xf3, 80 };
 117 static unsigned char mousedev_imex_seq[] = { 0xf3, 200, 0xf3, 200, 0xf3, 80 };
 118
 119 static struct mousedev *mousedev_mix;
 120 static LIST_HEAD(mousedev_mix_list);
 121
 122 #define fx(i)  (mousedev->old_x[(mousedev->pkt_count - (i)) & 03])
 123 #define fy(i)  (mousedev->old_y[(mousedev->pkt_count - (i)) & 03])
 124
 125 static void mousedev_touchpad_event(struct input_dev *dev,
 126                                     struct mousedev *mousedev,
 127                                     unsigned int code, int value)
 128 {
 129         int size, tmp;
 130         enum { FRACTION_DENOM = 128 };
 131
 132         switch (code) {
 133
 134         case ABS_X:
 135
 136                 fx(0) = value;
 137                 if (mousedev->touch && mousedev->pkt_count >= 2) {
 138                         size = input_abs_get_max(dev, ABS_X) -
 139                                         input_abs_get_min(dev, ABS_X);
 140                         if (size == 0)
 141                                 size = 256 * 2;
 142
 143                         tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size;
 144                         tmp += mousedev->frac_dx;
 145                         mousedev->packet.dx = tmp / FRACTION_DENOM;
 146                         mousedev->frac_dx =
 147                                 tmp - mousedev->packet.dx * FRACTION_DENOM;
 148                 }
 149                 break;
 150
 151         case ABS_Y:
 152                 fy(0) = value;
 153                 if (mousedev->touch && mousedev->pkt_count >= 2) {
 154                         /* use X size for ABS_Y to keep the same scale */
 155                         size = input_abs_get_max(dev, ABS_X) -
 156                                         input_abs_get_min(dev, ABS_X);
 157                         if (size == 0)
 158                                 size = 256 * 2;
 159
 160                         tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size;
 161                         tmp += mousedev->frac_dy;
 162                         mousedev->packet.dy = tmp / FRACTION_DENOM;
 163                         mousedev->frac_dy = tmp -
 164                                 mousedev->packet.dy * FRACTION_DENOM;
 165                 }
 166                 break;
 167         }
 168 }
 169
 170 static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev,
 171                                 unsigned int code, int value)
 172 {
 173         int min, max, size;
 174
 175         switch (code) {
 176
 177         case ABS_X:
 178                 min = input_abs_get_min(dev, ABS_X);
 179                 max = input_abs_get_max(dev, ABS_X);
 180
 181                 size = max - min;
 182                 if (size == 0)
 183                         size = xres ? : 1;
 184
 185                 value = clamp(value, min, max);
 186
 187                 mousedev->packet.x = ((value - min) * xres) / size;
 188                 mousedev->packet.abs_event = 1;
 189                 break;
 190
 191         case ABS_Y:
 192                 min = input_abs_get_min(dev, ABS_Y);
 193                 max = input_abs_get_max(dev, ABS_Y);
 194
 195                 size = max - min;
 196                 if (size == 0)
 197                         size = yres ? : 1;
 198
 199                 value = clamp(value, min, max);
 200
 201                 mousedev->packet.y = yres - ((value - min) * yres) / size;
 202                 mousedev->packet.abs_event = 1;
 203                 break;
 204         }
 205 }
 206
 207 static void mousedev_rel_event(struct mousedev *mousedev,
 208                                 unsigned int code, int value)
 209 {
 210         switch (code) {
 211         case REL_X:
 212                 mousedev->packet.dx += value;
 213                 break;
 214
 215         case REL_Y:
 216                 mousedev->packet.dy -= value;
 217                 break;
 218
 219         case REL_WHEEL:
 220                 mousedev->packet.dz -= value;
 221                 break;
 222         }
 223 }
 224
 225 static void mousedev_key_event(struct mousedev *mousedev,
 226                                 unsigned int code, int value)
 227 {
 228         int index;
 229
 230         switch (code) {
 231
 232         case BTN_TOUCH:
 233         case BTN_0:
 234         case BTN_LEFT:          index = 0; break;
 235
 236         case BTN_STYLUS:
 237         case BTN_1:
 238         case BTN_RIGHT:         index = 1; break;
 239
 240         case BTN_2:
 241         case BTN_FORWARD:
 242         case BTN_STYLUS2:
 243         case BTN_MIDDLE:        index = 2; break;
 244
 245         case BTN_3:
 246         case BTN_BACK:
 247         case BTN_SIDE:          index = 3; break;
 248
 249         case BTN_4:
 250         case BTN_EXTRA:         index = 4; break;
 251
 252         default:                return;
 253         }
 254
 255         if (value) {
 256                 set_bit(index, &mousedev->packet.buttons);
 257                 set_bit(index, &mousedev_mix->packet.buttons);
 258         } else {
 259                 clear_bit(index, &mousedev->packet.buttons);
 260                 clear_bit(index, &mousedev_mix->packet.buttons);
 261         }
 262 }
 263
 264 static void mousedev_notify_readers(struct mousedev *mousedev,
 265                                     struct mousedev_hw_data *packet)
 266 {
 267         struct mousedev_client *client;
 268         struct mousedev_motion *p;
 269         unsigned int new_head;
 270         int wake_readers = 0;
 271
 272         rcu_read_lock();
 273         list_for_each_entry_rcu(client, &mousedev->client_list, node) {
 274
 275                 /* Just acquire the lock, interrupts already disabled */
 276                 spin_lock(&client->packet_lock);
 277
 278                 p = &client->packets[client->head];
 279                 if (client->ready && p->buttons != mousedev->packet.buttons) {
 280                         new_head = (client->head + 1) % PACKET_QUEUE_LEN;
 281                         if (new_head != client->tail) {
 282                                 p = &client->packets[client->head = new_head];
 283                                 memset(p, 0, sizeof(struct mousedev_motion));
 284                         }
 285                 }
 286
 287                 if (packet->abs_event) {
 288                         p->dx += packet->x - client->pos_x;
 289                         p->dy += packet->y - client->pos_y;
 290                         client->pos_x = packet->x;
 291                         client->pos_y = packet->y;
 292                 }
 293
 294                 client->pos_x += packet->dx;
 295                 client->pos_x = clamp_val(client->pos_x, 0, xres);
 296
 297                 client->pos_y += packet->dy;
 298                 client->pos_y = clamp_val(client->pos_y, 0, yres);
 299
 300                 p->dx += packet->dx;
 301                 p->dy += packet->dy;
 302                 p->dz += packet->dz;
 303                 p->buttons = mousedev->packet.buttons;
 304
 305                 if (p->dx || p->dy || p->dz ||
 306                     p->buttons != client->last_buttons)
 307                         client->ready = 1;
 308
 309                 spin_unlock(&client->packet_lock);
 310
 311                 if (client->ready) {
 312                         kill_fasync(&client->fasync, SIGIO, POLL_IN);
 313                         wake_readers = 1;
 314                 }
 315         }
 316         rcu_read_unlock();
 317
 318         if (wake_readers)
 319                 wake_up_interruptible(&mousedev->wait);
 320 }
 321
 322 static void mousedev_touchpad_touch(struct mousedev *mousedev, int value)
 323 {
 324         if (!value) {
 325                 if (mousedev->touch &&
 326                     time_before(jiffies,
 327                                 mousedev->touch + msecs_to_jiffies(tap_time))) {
 328                         /*
 329                          * Toggle left button to emulate tap.
 330                          * We rely on the fact that mousedev_mix always has 0
 331                          * motion packet so we won't mess current position.
 332                          */
 333                         set_bit(0, &mousedev->packet.buttons);
 334                         set_bit(0, &mousedev_mix->packet.buttons);
 335                         mousedev_notify_readers(mousedev, &mousedev_mix->packet);
 336                         mousedev_notify_readers(mousedev_mix,
 337                                                 &mousedev_mix->packet);
 338                         clear_bit(0, &mousedev->packet.buttons);
 339                         clear_bit(0, &mousedev_mix->packet.buttons);
 340                 }
 341                 mousedev->touch = mousedev->pkt_count = 0;
 342                 mousedev->frac_dx = 0;
 343                 mousedev->frac_dy = 0;
 344
 345         } else if (!mousedev->touch)
 346                 mousedev->touch = jiffies;
 347 }
 348
 349 static void mousedev_event(struct input_handle *handle,
 350                            unsigned int type, unsigned int code, int value)
 351 {
 352         struct mousedev *mousedev = handle->private;
 353
 354         switch (type) {
 355
 356         case EV_ABS:
 357                 /* Ignore joysticks */
 358                 if (test_bit(BTN_TRIGGER, handle->dev->keybit))
 359                         return;
 360
 361                 if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
 362                         mousedev_touchpad_event(handle->dev,
 363                                                 mousedev, code, value);
 364                 else
 365                         mousedev_abs_event(handle->dev, mousedev, code, value);
 366
 367                 break;
 368
 369         case EV_REL:
 370                 mousedev_rel_event(mousedev, code, value);
 371                 break;
 372
 373         case EV_KEY:
 374                 if (value != 2) {
 375                         if (code == BTN_TOUCH &&
 376                             test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
 377                                 mousedev_touchpad_touch(mousedev, value);
 378                         else
 379                                 mousedev_key_event(mousedev, code, value);
 380                 }
 381                 break;
 382
 383         case EV_SYN:
 384                 if (code == SYN_REPORT) {
 385                         if (mousedev->touch) {
 386                                 mousedev->pkt_count++;
 387                                 /*
 388                                  * Input system eats duplicate events,
 389                                  * but we need all of them to do correct
 390                                  * averaging so apply present one forward
 391                                  */
 392                                 fx(0) = fx(1);
 393                                 fy(0) = fy(1);
 394                         }
 395
 396                         mousedev_notify_readers(mousedev, &mousedev->packet);
 397                         mousedev_notify_readers(mousedev_mix, &mousedev->packet);
 398
 399                         mousedev->packet.dx = mousedev->packet.dy =
 400                                 mousedev->packet.dz = 0;
 401                         mousedev->packet.abs_event = 0;
 402                 }
 403                 break;
 404         }
 405 }
 406
 407 static int mousedev_fasync(int fd, struct file *file, int on)
 408 {
 409         struct mousedev_client *client = file->private_data;
 410
 411         return fasync_helper(fd, file, on, &client->fasync);
 412 }
 413
 414 static void mousedev_free(struct device *dev)
 415 {
 416         struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
 417
 418         input_put_device(mousedev->handle.dev);
 419         kfree(mousedev);
 420 }
 421
 422 static int mousedev_open_device(struct mousedev *mousedev)
 423 {
 424         int retval;
 425
 426         retval = mutex_lock_interruptible(&mousedev->mutex);
 427         if (retval)
 428                 return retval;
 429
 430         if (!mousedev->exist)
 431                 retval = -ENODEV;
 432         else if (!mousedev->open++) {
 433                 retval = input_open_device(&mousedev->handle);
 434                 if (retval)
 435                         mousedev->open--;
 436         }
 437
 438         mutex_unlock(&mousedev->mutex);
 439         return retval;
 440 }
 441
 442 static void mousedev_close_device(struct mousedev *mousedev)
 443 {
 444         mutex_lock(&mousedev->mutex);
 445
 446         if (mousedev->exist && !--mousedev->open)
 447                 input_close_device(&mousedev->handle);
 448
 449         mutex_unlock(&mousedev->mutex);
 450 }
 451
 452 /*
 453  * Open all available devices so they can all be multiplexed in one.
 454  * stream. Note that this function is called with mousedev_mix->mutex
 455  * held.
 456  */
 457 static int mixdev_open_devices(struct mousedev *mixdev)
 458 {
 459         int error;
 460
 461         error = mutex_lock_interruptible(&mixdev->mutex);
 462         if (error)
 463                 return error;
 464
 465         if (!mixdev->open++) {
 466                 struct mousedev *mousedev;
 467
 468                 list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
 469                         if (!mousedev->opened_by_mixdev) {
 470                                 if (mousedev_open_device(mousedev))
 471                                         continue;
 472
 473                                 mousedev->opened_by_mixdev = true;
 474                         }
 475                 }
 476         }
 477
 478         mutex_unlock(&mixdev->mutex);
 479         return 0;
 480 }
 481
 482 /*
 483  * Close all devices that were opened as part of multiplexed
 484  * device. Note that this function is called with mousedev_mix->mutex
 485  * held.
 486  */
 487 static void mixdev_close_devices(struct mousedev *mixdev)
 488 {
 489         mutex_lock(&mixdev->mutex);
 490
 491         if (!--mixdev->open) {
 492                 struct mousedev *mousedev;
 493
 494                 list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
 495                         if (mousedev->opened_by_mixdev) {
 496                                 mousedev->opened_by_mixdev = false;
 497                                 mousedev_close_device(mousedev);
 498                         }
 499                 }
 500         }
 501
 502         mutex_unlock(&mixdev->mutex);
 503 }
 504
 505
 506 static void mousedev_attach_client(struct mousedev *mousedev,
 507                                    struct mousedev_client *client)
 508 {
 509         spin_lock(&mousedev->client_lock);
 510         list_add_tail_rcu(&client->node, &mousedev->client_list);
 511         spin_unlock(&mousedev->client_lock);
 512 }
 513
 514 static void mousedev_detach_client(struct mousedev *mousedev,
 515                                    struct mousedev_client *client)
 516 {
 517         spin_lock(&mousedev->client_lock);
 518         list_del_rcu(&client->node);
 519         spin_unlock(&mousedev->client_lock);
 520         synchronize_rcu();
 521 }
 522
 523 static int mousedev_release(struct inode *inode, struct file *file)
 524 {
 525         struct mousedev_client *client = file->private_data;
 526         struct mousedev *mousedev = client->mousedev;
 527
 528         mousedev_detach_client(mousedev, client);
 529         kfree(client);
 530
 531         mousedev->close_device(mousedev);
 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
 542 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
 543         if (imajor(inode) == MISC_MAJOR)
 544                 mousedev = mousedev_mix;
 545         else
 546 #endif
 547                 mousedev = container_of(inode->i_cdev, struct mousedev, cdev);
 548
 549         client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
 550         if (!client)
 551                 return -ENOMEM;
 552
 553         spin_lock_init(&client->packet_lock);
 554         client->pos_x = xres / 2;
 555         client->pos_y = yres / 2;
 556         client->mousedev = mousedev;
 557         mousedev_attach_client(mousedev, client);
 558
 559         error = mousedev->open_device(mousedev);
 560         if (error)
 561                 goto err_free_client;
 562
 563         file->private_data = client;
 564         nonseekable_open(inode, file);
 565
 566         return 0;
 567
 568  err_free_client:
 569         mousedev_detach_client(mousedev, client);
 570         kfree(client);
 571         return error;
 572 }
 573
 574 static void mousedev_packet(struct mousedev_client *client, u8 *ps2_data)
 575 {
 576         struct mousedev_motion *p = &client->packets[client->tail];
 577         s8 dx, dy, dz;
 578
 579         dx = clamp_val(p->dx, -127, 127);
 580         p->dx -= dx;
 581
 582         dy = clamp_val(p->dy, -127, 127);
 583         p->dy -= dy;
 584
 585         ps2_data[0] = BIT(3);
 586         ps2_data[0] |= ((dx & BIT(7)) >> 3) | ((dy & BIT(7)) >> 2);
 587         ps2_data[0] |= p->buttons & 0x07;
 588         ps2_data[1] = dx;
 589         ps2_data[2] = dy;
 590
 591         switch (client->mode) {
 592         case MOUSEDEV_EMUL_EXPS:
 593                 dz = clamp_val(p->dz, -7, 7);
 594                 p->dz -= dz;
 595
 596                 ps2_data[3] = (dz & 0x0f) | ((p->buttons & 0x18) << 1);
 597                 client->bufsiz = 4;
 598                 break;
 599
 600         case MOUSEDEV_EMUL_IMPS:
 601                 dz = clamp_val(p->dz, -127, 127);
 602                 p->dz -= dz;
 603
 604                 ps2_data[0] |= ((p->buttons & 0x10) >> 3) |
 605                                ((p->buttons & 0x08) >> 1);
 606                 ps2_data[3] = dz;
 607
 608                 client->bufsiz = 4;
 609                 break;
 610
 611         case MOUSEDEV_EMUL_PS2:
 612         default:
 613                 p->dz = 0;
 614
 615                 ps2_data[0] |= ((p->buttons & 0x10) >> 3) |
 616                                ((p->buttons & 0x08) >> 1);
 617
 618                 client->bufsiz = 3;
 619                 break;
 620         }
 621
 622         if (!p->dx && !p->dy && !p->dz) {
 623                 if (client->tail == client->head) {
 624                         client->ready = 0;
 625                         client->last_buttons = p->buttons;
 626                 } else
 627                         client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
 628         }
 629 }
 630
 631 static void mousedev_generate_response(struct mousedev_client *client,
 632                                         int command)
 633 {
 634         client->ps2[0] = 0xfa; /* ACK */
 635
 636         switch (command) {
 637
 638         case 0xeb: /* Poll */
 639                 mousedev_packet(client, &client->ps2[1]);
 640                 client->bufsiz++; /* account for leading ACK */
 641                 break;
 642
 643         case 0xf2: /* Get ID */
 644                 switch (client->mode) {
 645                 case MOUSEDEV_EMUL_PS2:
 646                         client->ps2[1] = 0;
 647                         break;
 648                 case MOUSEDEV_EMUL_IMPS:
 649                         client->ps2[1] = 3;
 650                         break;
 651                 case MOUSEDEV_EMUL_EXPS:
 652                         client->ps2[1] = 4;
 653                         break;
 654                 }
 655                 client->bufsiz = 2;
 656                 break;
 657
 658         case 0xe9: /* Get info */
 659                 client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
 660                 client->bufsiz = 4;
 661                 break;
 662
 663         case 0xff: /* Reset */
 664                 client->impsseq = client->imexseq = 0;
 665                 client->mode = MOUSEDEV_EMUL_PS2;
 666                 client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
 667                 client->bufsiz = 3;
 668                 break;
 669
 670         default:
 671                 client->bufsiz = 1;
 672                 break;
 673         }
 674         client->buffer = client->bufsiz;
 675 }
 676
 677 static ssize_t mousedev_write(struct file *file, const char __user *buffer,
 678                                 size_t count, loff_t *ppos)
 679 {
 680         struct mousedev_client *client = file->private_data;
 681         unsigned char c;
 682         unsigned int i;
 683
 684         for (i = 0; i < count; i++) {
 685
 686                 if (get_user(c, buffer + i))
 687                         return -EFAULT;
 688
 689                 spin_lock_irq(&client->packet_lock);
 690
 691                 if (c == mousedev_imex_seq[client->imexseq]) {
 692                         if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
 693                                 client->imexseq = 0;
 694                                 client->mode = MOUSEDEV_EMUL_EXPS;
 695                         }
 696                 } else
 697                         client->imexseq = 0;
 698
 699                 if (c == mousedev_imps_seq[client->impsseq]) {
 700                         if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
 701                                 client->impsseq = 0;
 702                                 client->mode = MOUSEDEV_EMUL_IMPS;
 703                         }
 704                 } else
 705                         client->impsseq = 0;
 706
 707                 mousedev_generate_response(client, c);
 708
 709                 spin_unlock_irq(&client->packet_lock);
 710                 cond_resched();
 711         }
 712
 713         kill_fasync(&client->fasync, SIGIO, POLL_IN);
 714         wake_up_interruptible(&client->mousedev->wait);
 715
 716         return count;
 717 }
 718
 719 static ssize_t mousedev_read(struct file *file, char __user *buffer,
 720                              size_t count, loff_t *ppos)
 721 {
 722         struct mousedev_client *client = file->private_data;
 723         struct mousedev *mousedev = client->mousedev;
 724         u8 data[sizeof(client->ps2)];
 725         int retval = 0;
 726
 727         if (!client->ready && !client->buffer && mousedev->exist &&
 728             (file->f_flags & O_NONBLOCK))
 729                 return -EAGAIN;
 730
 731         retval = wait_event_interruptible(mousedev->wait,
 732                         !mousedev->exist || client->ready || client->buffer);
 733         if (retval)
 734                 return retval;
 735
 736         if (!mousedev->exist)
 737                 return -ENODEV;
 738
 739         spin_lock_irq(&client->packet_lock);
 740
 741         if (!client->buffer && client->ready) {
 742                 mousedev_packet(client, client->ps2);
 743                 client->buffer = client->bufsiz;
 744         }
 745
 746         if (count > client->buffer)
 747                 count = client->buffer;
 748
 749         memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
 750         client->buffer -= count;
 751
 752         spin_unlock_irq(&client->packet_lock);
 753
 754         if (copy_to_user(buffer, data, count))
 755                 return -EFAULT;
 756
 757         return count;
 758 }
 759
 760 /* No kernel lock - fine */
 761 static __poll_t mousedev_poll(struct file *file, poll_table *wait)
 762 {
 763         struct mousedev_client *client = file->private_data;
 764         struct mousedev *mousedev = client->mousedev;
 765         __poll_t mask;
 766
 767         poll_wait(file, &mousedev->wait, wait);
 768
 769         mask = mousedev->exist ? EPOLLOUT | EPOLLWRNORM : EPOLLHUP | EPOLLERR;
 770         if (client->ready || client->buffer)
 771                 mask |= EPOLLIN | EPOLLRDNORM;
 772
 773         return mask;
 774 }
 775
 776 static const struct file_operations mousedev_fops = {
 777         .owner          = THIS_MODULE,
 778         .read           = mousedev_read,
 779         .write          = mousedev_write,
 780         .poll           = mousedev_poll,
 781         .open           = mousedev_open,
 782         .release        = mousedev_release,
 783         .fasync         = mousedev_fasync,
 784         .llseek         = noop_llseek,
 785 };
 786
 787 /*
 788  * Mark device non-existent. This disables writes, ioctls and
 789  * prevents new users from opening the device. Already posted
 790  * blocking reads will stay, however new ones will fail.
 791  */
 792 static void mousedev_mark_dead(struct mousedev *mousedev)
 793 {
 794         mutex_lock(&mousedev->mutex);
 795         mousedev->exist = false;
 796         mutex_unlock(&mousedev->mutex);
 797 }
 798
 799 /*
 800  * Wake up users waiting for IO so they can disconnect from
 801  * dead device.
 802  */
 803 static void mousedev_hangup(struct mousedev *mousedev)
 804 {
 805         struct mousedev_client *client;
 806
 807         spin_lock(&mousedev->client_lock);
 808         list_for_each_entry(client, &mousedev->client_list, node)
 809                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 810         spin_unlock(&mousedev->client_lock);
 811
 812         wake_up_interruptible(&mousedev->wait);
 813 }
 814
 815 static void mousedev_cleanup(struct mousedev *mousedev)
 816 {
 817         struct input_handle *handle = &mousedev->handle;
 818
 819         mousedev_mark_dead(mousedev);
 820         mousedev_hangup(mousedev);
 821
 822         /* mousedev is marked dead so no one else accesses mousedev->open */
 823         if (mousedev->open)
 824                 input_close_device(handle);
 825 }
 826
 827 static int mousedev_reserve_minor(bool mixdev)
 828 {
 829         int minor;
 830
 831         if (mixdev) {
 832                 minor = input_get_new_minor(MOUSEDEV_MIX, 1, false);
 833                 if (minor < 0)
 834                         pr_err("failed to reserve mixdev minor: %d\n", minor);
 835         } else {
 836                 minor = input_get_new_minor(MOUSEDEV_MINOR_BASE,
 837                                             MOUSEDEV_MINORS, true);
 838                 if (minor < 0)
 839                         pr_err("failed to reserve new minor: %d\n", minor);
 840         }
 841
 842         return minor;
 843 }
 844
 845 static struct mousedev *mousedev_create(struct input_dev *dev,
 846                                         struct input_handler *handler,
 847                                         bool mixdev)
 848 {
 849         struct mousedev *mousedev;
 850         int minor;
 851         int error;
 852
 853         minor = mousedev_reserve_minor(mixdev);
 854         if (minor < 0) {
 855                 error = minor;
 856                 goto err_out;
 857         }
 858
 859         mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
 860         if (!mousedev) {
 861                 error = -ENOMEM;
 862                 goto err_free_minor;
 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                              mixdev ? SINGLE_DEPTH_NESTING : 0);
 871         init_waitqueue_head(&mousedev->wait);
 872
 873         if (mixdev) {
 874                 dev_set_name(&mousedev->dev, "mice");
 875
 876                 mousedev->open_device = mixdev_open_devices;
 877                 mousedev->close_device = mixdev_close_devices;
 878         } else {
 879                 int dev_no = minor;
 880                 /* Normalize device number if it falls into legacy range */
 881                 if (dev_no < MOUSEDEV_MINOR_BASE + MOUSEDEV_MINORS)
 882                         dev_no -= MOUSEDEV_MINOR_BASE;
 883                 dev_set_name(&mousedev->dev, "mouse%d", dev_no);
 884
 885                 mousedev->open_device = mousedev_open_device;
 886                 mousedev->close_device = mousedev_close_device;
 887         }
 888
 889         mousedev->exist = true;
 890         mousedev->handle.dev = input_get_device(dev);
 891         mousedev->handle.name = dev_name(&mousedev->dev);
 892         mousedev->handle.handler = handler;
 893         mousedev->handle.private = mousedev;
 894
 895         mousedev->dev.class = &input_class;
 896         if (dev)
 897                 mousedev->dev.parent = &dev->dev;
 898         mousedev->dev.devt = MKDEV(INPUT_MAJOR, minor);
 899         mousedev->dev.release = mousedev_free;
 900         device_initialize(&mousedev->dev);
 901
 902         if (!mixdev) {
 903                 error = input_register_handle(&mousedev->handle);
 904                 if (error)
 905                         goto err_free_mousedev;
 906         }
 907
 908         cdev_init(&mousedev->cdev, &mousedev_fops);
 909
 910         error = cdev_device_add(&mousedev->cdev, &mousedev->dev);
 911         if (error)
 912                 goto err_cleanup_mousedev;
 913
 914         return mousedev;
 915
 916  err_cleanup_mousedev:
 917         mousedev_cleanup(mousedev);
 918         if (!mixdev)
 919                 input_unregister_handle(&mousedev->handle);
 920  err_free_mousedev:
 921         put_device(&mousedev->dev);
 922  err_free_minor:
 923         input_free_minor(minor);
 924  err_out:
 925         return ERR_PTR(error);
 926 }
 927
 928 static void mousedev_destroy(struct mousedev *mousedev)
 929 {
 930         cdev_device_del(&mousedev->cdev, &mousedev->dev);
 931         mousedev_cleanup(mousedev);
 932         input_free_minor(MINOR(mousedev->dev.devt));
 933         if (mousedev != mousedev_mix)
 934                 input_unregister_handle(&mousedev->handle);
 935         put_device(&mousedev->dev);
 936 }
 937
 938 static int mixdev_add_device(struct mousedev *mousedev)
 939 {
 940         int retval;
 941
 942         retval = mutex_lock_interruptible(&mousedev_mix->mutex);
 943         if (retval)
 944                 return retval;
 945
 946         if (mousedev_mix->open) {
 947                 retval = mousedev_open_device(mousedev);
 948                 if (retval)
 949                         goto out;
 950
 951                 mousedev->opened_by_mixdev = true;
 952         }
 953
 954         get_device(&mousedev->dev);
 955         list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
 956
 957  out:
 958         mutex_unlock(&mousedev_mix->mutex);
 959         return retval;
 960 }
 961
 962 static void mixdev_remove_device(struct mousedev *mousedev)
 963 {
 964         mutex_lock(&mousedev_mix->mutex);
 965
 966         if (mousedev->opened_by_mixdev) {
 967                 mousedev->opened_by_mixdev = false;
 968                 mousedev_close_device(mousedev);
 969         }
 970
 971         list_del_init(&mousedev->mixdev_node);
 972         mutex_unlock(&mousedev_mix->mutex);
 973
 974         put_device(&mousedev->dev);
 975 }
 976
 977 static int mousedev_connect(struct input_handler *handler,
 978                             struct input_dev *dev,
 979                             const struct input_device_id *id)
 980 {
 981         struct mousedev *mousedev;
 982         int error;
 983
 984         mousedev = mousedev_create(dev, handler, false);
 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         .legacy_minors  = true,
1061         .minor          = MOUSEDEV_MINOR_BASE,
1062         .name           = "mousedev",
1063         .id_table       = mousedev_ids,
1064 };
1065
1066 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1067 #include <linux/miscdevice.h>
1068
1069 static struct miscdevice psaux_mouse = {
1070         .minor  = PSMOUSE_MINOR,
1071         .name   = "psaux",
1072         .fops   = &mousedev_fops,
1073 };
1074
1075 static bool psaux_registered;
1076
1077 static void __init mousedev_psaux_register(void)
1078 {
1079         int error;
1080
1081         error = misc_register(&psaux_mouse);
1082         if (error)
1083                 pr_warn("could not register psaux device, error: %d\n",
1084                            error);
1085         else
1086                 psaux_registered = true;
1087 }
1088
1089 static void __exit mousedev_psaux_unregister(void)
1090 {
1091         if (psaux_registered)
1092                 misc_deregister(&psaux_mouse);
1093 }
1094 #else
1095 static inline void mousedev_psaux_register(void) { }
1096 static inline void mousedev_psaux_unregister(void) { }
1097 #endif
1098
1099 static int __init mousedev_init(void)
1100 {
1101         int error;
1102
1103         mousedev_mix = mousedev_create(NULL, &mousedev_handler, true);
1104         if (IS_ERR(mousedev_mix))
1105                 return PTR_ERR(mousedev_mix);
1106
1107         error = input_register_handler(&mousedev_handler);
1108         if (error) {
1109                 mousedev_destroy(mousedev_mix);
1110                 return error;
1111         }
1112
1113         mousedev_psaux_register();
1114
1115         pr_info("PS/2 mouse device common for all mice\n");
1116
1117         return 0;
1118 }
1119
1120 static void __exit mousedev_exit(void)
1121 {
1122         mousedev_psaux_unregister();
1123         input_unregister_handler(&mousedev_handler);
1124         mousedev_destroy(mousedev_mix);
1125 }
1126
1127 module_init(mousedev_init);
1128 module_exit(mousedev_exit);