drivers/input/joydev.c

   1 /*
   2  * Joystick device driver for the input driver suite.
   3  *
   4  * Copyright (c) 1999-2002 Vojtech Pavlik
   5  * Copyright (c) 1999 Colin Van Dyke
   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 as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <asm/io.h>
  16 #include <linux/delay.h>
  17 #include <linux/errno.h>
  18 #include <linux/joystick.h>
  19 #include <linux/input.h>
  20 #include <linux/kernel.h>
  21 #include <linux/major.h>
  22 #include <linux/sched.h>
  23 #include <linux/slab.h>
  24 #include <linux/mm.h>
  25 #include <linux/module.h>
  26 #include <linux/poll.h>
  27 #include <linux/init.h>
  28 #include <linux/device.h>
  29 #include <linux/cdev.h>
  30
  31 MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");
  32 MODULE_DESCRIPTION("Joystick device interfaces");
  33 MODULE_SUPPORTED_DEVICE("input/js");
  34 MODULE_LICENSE("GPL");
  35
  36 #define JOYDEV_MINOR_BASE       0
  37 #define JOYDEV_MINORS           16
  38 #define JOYDEV_BUFFER_SIZE      64
  39
  40 struct joydev {
  41         int open;
  42         struct input_handle handle;
  43         wait_queue_head_t wait;
  44         struct list_head client_list;
  45         spinlock_t client_lock; /* protects client_list */
  46         struct mutex mutex;
  47         struct device dev;
  48         struct cdev cdev;
  49         bool exist;
  50
  51         struct js_corr corr[ABS_CNT];
  52         struct JS_DATA_SAVE_TYPE glue;
  53         int nabs;
  54         int nkey;
  55         __u16 keymap[KEY_MAX - BTN_MISC + 1];
  56         __u16 keypam[KEY_MAX - BTN_MISC + 1];
  57         __u8 absmap[ABS_CNT];
  58         __u8 abspam[ABS_CNT];
  59         __s16 abs[ABS_CNT];
  60 };
  61
  62 struct joydev_client {
  63         struct js_event buffer[JOYDEV_BUFFER_SIZE];
  64         int head;
  65         int tail;
  66         int startup;
  67         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  68         struct fasync_struct *fasync;
  69         struct joydev *joydev;
  70         struct list_head node;
  71 };
  72
  73 static int joydev_correct(int value, struct js_corr *corr)
  74 {
  75         switch (corr->type) {
  76
  77         case JS_CORR_NONE:
  78                 break;
  79
  80         case JS_CORR_BROKEN:
  81                 value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
  82                         ((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
  83                         ((corr->coef[2] * (value - corr->coef[0])) >> 14);
  84                 break;
  85
  86         default:
  87                 return 0;
  88         }
  89
  90         return clamp(value, -32767, 32767);
  91 }
  92
  93 static void joydev_pass_event(struct joydev_client *client,
  94                               struct js_event *event)
  95 {
  96         struct joydev *joydev = client->joydev;
  97
  98         /*
  99          * IRQs already disabled, just acquire the lock
 100          */
 101         spin_lock(&client->buffer_lock);
 102
 103         client->buffer[client->head] = *event;
 104
 105         if (client->startup == joydev->nabs + joydev->nkey) {
 106                 client->head++;
 107                 client->head &= JOYDEV_BUFFER_SIZE - 1;
 108                 if (client->tail == client->head)
 109                         client->startup = 0;
 110         }
 111
 112         spin_unlock(&client->buffer_lock);
 113
 114         kill_fasync(&client->fasync, SIGIO, POLL_IN);
 115 }
 116
 117 static void joydev_event(struct input_handle *handle,
 118                          unsigned int type, unsigned int code, int value)
 119 {
 120         struct joydev *joydev = handle->private;
 121         struct joydev_client *client;
 122         struct js_event event;
 123
 124         switch (type) {
 125
 126         case EV_KEY:
 127                 if (code < BTN_MISC || value == 2)
 128                         return;
 129                 event.type = JS_EVENT_BUTTON;
 130                 event.number = joydev->keymap[code - BTN_MISC];
 131                 event.value = value;
 132                 break;
 133
 134         case EV_ABS:
 135                 event.type = JS_EVENT_AXIS;
 136                 event.number = joydev->absmap[code];
 137                 event.value = joydev_correct(value,
 138                                         &joydev->corr[event.number]);
 139                 if (event.value == joydev->abs[event.number])
 140                         return;
 141                 joydev->abs[event.number] = event.value;
 142                 break;
 143
 144         default:
 145                 return;
 146         }
 147
 148         event.time = jiffies_to_msecs(jiffies);
 149
 150         rcu_read_lock();
 151         list_for_each_entry_rcu(client, &joydev->client_list, node)
 152                 joydev_pass_event(client, &event);
 153         rcu_read_unlock();
 154
 155         wake_up_interruptible(&joydev->wait);
 156 }
 157
 158 static int joydev_fasync(int fd, struct file *file, int on)
 159 {
 160         struct joydev_client *client = file->private_data;
 161
 162         return fasync_helper(fd, file, on, &client->fasync);
 163 }
 164
 165 static void joydev_free(struct device *dev)
 166 {
 167         struct joydev *joydev = container_of(dev, struct joydev, dev);
 168
 169         input_put_device(joydev->handle.dev);
 170         kfree(joydev);
 171 }
 172
 173 static void joydev_attach_client(struct joydev *joydev,
 174                                  struct joydev_client *client)
 175 {
 176         spin_lock(&joydev->client_lock);
 177         list_add_tail_rcu(&client->node, &joydev->client_list);
 178         spin_unlock(&joydev->client_lock);
 179 }
 180
 181 static void joydev_detach_client(struct joydev *joydev,
 182                                  struct joydev_client *client)
 183 {
 184         spin_lock(&joydev->client_lock);
 185         list_del_rcu(&client->node);
 186         spin_unlock(&joydev->client_lock);
 187         synchronize_rcu();
 188 }
 189
 190 static void joydev_refresh_state(struct joydev *joydev)
 191 {
 192         struct input_dev *dev = joydev->handle.dev;
 193         int i, val;
 194
 195         for (i = 0; i < joydev->nabs; i++) {
 196                 val = input_abs_get_val(dev, joydev->abspam[i]);
 197                 joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
 198         }
 199 }
 200
 201 static int joydev_open_device(struct joydev *joydev)
 202 {
 203         int retval;
 204
 205         retval = mutex_lock_interruptible(&joydev->mutex);
 206         if (retval)
 207                 return retval;
 208
 209         if (!joydev->exist)
 210                 retval = -ENODEV;
 211         else if (!joydev->open++) {
 212                 retval = input_open_device(&joydev->handle);
 213                 if (retval)
 214                         joydev->open--;
 215                 else
 216                         joydev_refresh_state(joydev);
 217         }
 218
 219         mutex_unlock(&joydev->mutex);
 220         return retval;
 221 }
 222
 223 static void joydev_close_device(struct joydev *joydev)
 224 {
 225         mutex_lock(&joydev->mutex);
 226
 227         if (joydev->exist && !--joydev->open)
 228                 input_close_device(&joydev->handle);
 229
 230         mutex_unlock(&joydev->mutex);
 231 }
 232
 233 /*
 234  * Wake up users waiting for IO so they can disconnect from
 235  * dead device.
 236  */
 237 static void joydev_hangup(struct joydev *joydev)
 238 {
 239         struct joydev_client *client;
 240
 241         spin_lock(&joydev->client_lock);
 242         list_for_each_entry(client, &joydev->client_list, node)
 243                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 244         spin_unlock(&joydev->client_lock);
 245
 246         wake_up_interruptible(&joydev->wait);
 247 }
 248
 249 static int joydev_release(struct inode *inode, struct file *file)
 250 {
 251         struct joydev_client *client = file->private_data;
 252         struct joydev *joydev = client->joydev;
 253
 254         joydev_detach_client(joydev, client);
 255         kfree(client);
 256
 257         joydev_close_device(joydev);
 258
 259         return 0;
 260 }
 261
 262 static int joydev_open(struct inode *inode, struct file *file)
 263 {
 264         struct joydev *joydev =
 265                         container_of(inode->i_cdev, struct joydev, cdev);
 266         struct joydev_client *client;
 267         int error;
 268
 269         client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
 270         if (!client)
 271                 return -ENOMEM;
 272
 273         spin_lock_init(&client->buffer_lock);
 274         client->joydev = joydev;
 275         joydev_attach_client(joydev, client);
 276
 277         error = joydev_open_device(joydev);
 278         if (error)
 279                 goto err_free_client;
 280
 281         file->private_data = client;
 282         nonseekable_open(inode, file);
 283
 284         return 0;
 285
 286  err_free_client:
 287         joydev_detach_client(joydev, client);
 288         kfree(client);
 289         return error;
 290 }
 291
 292 static int joydev_generate_startup_event(struct joydev_client *client,
 293                                          struct input_dev *input,
 294                                          struct js_event *event)
 295 {
 296         struct joydev *joydev = client->joydev;
 297         int have_event;
 298
 299         spin_lock_irq(&client->buffer_lock);
 300
 301         have_event = client->startup < joydev->nabs + joydev->nkey;
 302
 303         if (have_event) {
 304
 305                 event->time = jiffies_to_msecs(jiffies);
 306                 if (client->startup < joydev->nkey) {
 307                         event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 308                         event->number = client->startup;
 309                         event->value = !!test_bit(joydev->keypam[event->number],
 310                                                   input->key);
 311                 } else {
 312                         event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
 313                         event->number = client->startup - joydev->nkey;
 314                         event->value = joydev->abs[event->number];
 315                 }
 316                 client->startup++;
 317         }
 318
 319         spin_unlock_irq(&client->buffer_lock);
 320
 321         return have_event;
 322 }
 323
 324 static int joydev_fetch_next_event(struct joydev_client *client,
 325                                    struct js_event *event)
 326 {
 327         int have_event;
 328
 329         spin_lock_irq(&client->buffer_lock);
 330
 331         have_event = client->head != client->tail;
 332         if (have_event) {
 333                 *event = client->buffer[client->tail++];
 334                 client->tail &= JOYDEV_BUFFER_SIZE - 1;
 335         }
 336
 337         spin_unlock_irq(&client->buffer_lock);
 338
 339         return have_event;
 340 }
 341
 342 /*
 343  * Old joystick interface
 344  */
 345 static ssize_t joydev_0x_read(struct joydev_client *client,
 346                               struct input_dev *input,
 347                               char __user *buf)
 348 {
 349         struct joydev *joydev = client->joydev;
 350         struct JS_DATA_TYPE data;
 351         int i;
 352
 353         spin_lock_irq(&input->event_lock);
 354
 355         /*
 356          * Get device state
 357          */
 358         for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 359                 data.buttons |=
 360                         test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 361         data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 362         data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
 363
 364         /*
 365          * Reset reader's event queue
 366          */
 367         spin_lock(&client->buffer_lock);
 368         client->startup = 0;
 369         client->tail = client->head;
 370         spin_unlock(&client->buffer_lock);
 371
 372         spin_unlock_irq(&input->event_lock);
 373
 374         if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 375                 return -EFAULT;
 376
 377         return sizeof(struct JS_DATA_TYPE);
 378 }
 379
 380 static inline int joydev_data_pending(struct joydev_client *client)
 381 {
 382         struct joydev *joydev = client->joydev;
 383
 384         return client->startup < joydev->nabs + joydev->nkey ||
 385                 client->head != client->tail;
 386 }
 387
 388 static ssize_t joydev_read(struct file *file, char __user *buf,
 389                            size_t count, loff_t *ppos)
 390 {
 391         struct joydev_client *client = file->private_data;
 392         struct joydev *joydev = client->joydev;
 393         struct input_dev *input = joydev->handle.dev;
 394         struct js_event event;
 395         int retval;
 396
 397         if (!joydev->exist)
 398                 return -ENODEV;
 399
 400         if (count < sizeof(struct js_event))
 401                 return -EINVAL;
 402
 403         if (count == sizeof(struct JS_DATA_TYPE))
 404                 return joydev_0x_read(client, input, buf);
 405
 406         if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
 407                 return -EAGAIN;
 408
 409         retval = wait_event_interruptible(joydev->wait,
 410                         !joydev->exist || joydev_data_pending(client));
 411         if (retval)
 412                 return retval;
 413
 414         if (!joydev->exist)
 415                 return -ENODEV;
 416
 417         while (retval + sizeof(struct js_event) <= count &&
 418                joydev_generate_startup_event(client, input, &event)) {
 419
 420                 if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 421                         return -EFAULT;
 422
 423                 retval += sizeof(struct js_event);
 424         }
 425
 426         while (retval + sizeof(struct js_event) <= count &&
 427                joydev_fetch_next_event(client, &event)) {
 428
 429                 if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 430                         return -EFAULT;
 431
 432                 retval += sizeof(struct js_event);
 433         }
 434
 435         return retval;
 436 }
 437
 438 /* No kernel lock - fine */
 439 static unsigned int joydev_poll(struct file *file, poll_table *wait)
 440 {
 441         struct joydev_client *client = file->private_data;
 442         struct joydev *joydev = client->joydev;
 443
 444         poll_wait(file, &joydev->wait, wait);
 445         return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
 446                 (joydev->exist ?  0 : (POLLHUP | POLLERR));
 447 }
 448
 449 static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
 450                                      void __user *argp, size_t len)
 451 {
 452         __u8 *abspam;
 453         int i;
 454         int retval = 0;
 455
 456         len = min(len, sizeof(joydev->abspam));
 457
 458         /* Validate the map. */
 459         abspam = memdup_user(argp, len);
 460         if (IS_ERR(abspam))
 461                 return PTR_ERR(abspam);
 462
 463         for (i = 0; i < joydev->nabs; i++) {
 464                 if (abspam[i] > ABS_MAX) {
 465                         retval = -EINVAL;
 466                         goto out;
 467                 }
 468         }
 469
 470         memcpy(joydev->abspam, abspam, len);
 471
 472         for (i = 0; i < joydev->nabs; i++)
 473                 joydev->absmap[joydev->abspam[i]] = i;
 474
 475  out:
 476         kfree(abspam);
 477         return retval;
 478 }
 479
 480 static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
 481                                       void __user *argp, size_t len)
 482 {
 483         __u16 *keypam;
 484         int i;
 485         int retval = 0;
 486
 487         len = min(len, sizeof(joydev->keypam));
 488
 489         /* Validate the map. */
 490         keypam = memdup_user(argp, len);
 491         if (IS_ERR(keypam))
 492                 return PTR_ERR(keypam);
 493
 494         for (i = 0; i < joydev->nkey; i++) {
 495                 if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
 496                         retval = -EINVAL;
 497                         goto out;
 498                 }
 499         }
 500
 501         memcpy(joydev->keypam, keypam, len);
 502
 503         for (i = 0; i < joydev->nkey; i++)
 504                 joydev->keymap[keypam[i] - BTN_MISC] = i;
 505
 506  out:
 507         kfree(keypam);
 508         return retval;
 509 }
 510
 511
 512 static int joydev_ioctl_common(struct joydev *joydev,
 513                                 unsigned int cmd, void __user *argp)
 514 {
 515         struct input_dev *dev = joydev->handle.dev;
 516         size_t len;
 517         int i;
 518         const char *name;
 519
 520         /* Process fixed-sized commands. */
 521         switch (cmd) {
 522
 523         case JS_SET_CAL:
 524                 return copy_from_user(&joydev->glue.JS_CORR, argp,
 525                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 526
 527         case JS_GET_CAL:
 528                 return copy_to_user(argp, &joydev->glue.JS_CORR,
 529                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 530
 531         case JS_SET_TIMEOUT:
 532                 return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 533
 534         case JS_GET_TIMEOUT:
 535                 return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 536
 537         case JSIOCGVERSION:
 538                 return put_user(JS_VERSION, (__u32 __user *) argp);
 539
 540         case JSIOCGAXES:
 541                 return put_user(joydev->nabs, (__u8 __user *) argp);
 542
 543         case JSIOCGBUTTONS:
 544                 return put_user(joydev->nkey, (__u8 __user *) argp);
 545
 546         case JSIOCSCORR:
 547                 if (copy_from_user(joydev->corr, argp,
 548                               sizeof(joydev->corr[0]) * joydev->nabs))
 549                         return -EFAULT;
 550
 551                 for (i = 0; i < joydev->nabs; i++) {
 552                         int val = input_abs_get_val(dev, joydev->abspam[i]);
 553                         joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
 554                 }
 555                 return 0;
 556
 557         case JSIOCGCORR:
 558                 return copy_to_user(argp, joydev->corr,
 559                         sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
 560
 561         }
 562
 563         /*
 564          * Process variable-sized commands (the axis and button map commands
 565          * are considered variable-sized to decouple them from the values of
 566          * ABS_MAX and KEY_MAX).
 567          */
 568         switch (cmd & ~IOCSIZE_MASK) {
 569
 570         case (JSIOCSAXMAP & ~IOCSIZE_MASK):
 571                 return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
 572
 573         case (JSIOCGAXMAP & ~IOCSIZE_MASK):
 574                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
 575                 return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
 576
 577         case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
 578                 return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
 579
 580         case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
 581                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
 582                 return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
 583
 584         case JSIOCGNAME(0):
 585                 name = dev->name;
 586                 if (!name)
 587                         return 0;
 588
 589                 len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
 590                 return copy_to_user(argp, name, len) ? -EFAULT : len;
 591         }
 592
 593         return -EINVAL;
 594 }
 595
 596 #ifdef CONFIG_COMPAT
 597 static long joydev_compat_ioctl(struct file *file,
 598                                 unsigned int cmd, unsigned long arg)
 599 {
 600         struct joydev_client *client = file->private_data;
 601         struct joydev *joydev = client->joydev;
 602         void __user *argp = (void __user *)arg;
 603         s32 tmp32;
 604         struct JS_DATA_SAVE_TYPE_32 ds32;
 605         int retval;
 606
 607         retval = mutex_lock_interruptible(&joydev->mutex);
 608         if (retval)
 609                 return retval;
 610
 611         if (!joydev->exist) {
 612                 retval = -ENODEV;
 613                 goto out;
 614         }
 615
 616         switch (cmd) {
 617
 618         case JS_SET_TIMELIMIT:
 619                 retval = get_user(tmp32, (s32 __user *) arg);
 620                 if (retval == 0)
 621                         joydev->glue.JS_TIMELIMIT = tmp32;
 622                 break;
 623
 624         case JS_GET_TIMELIMIT:
 625                 tmp32 = joydev->glue.JS_TIMELIMIT;
 626                 retval = put_user(tmp32, (s32 __user *) arg);
 627                 break;
 628
 629         case JS_SET_ALL:
 630                 retval = copy_from_user(&ds32, argp,
 631                                         sizeof(ds32)) ? -EFAULT : 0;
 632                 if (retval == 0) {
 633                         joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
 634                         joydev->glue.BUSY          = ds32.BUSY;
 635                         joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
 636                         joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
 637                         joydev->glue.JS_SAVE       = ds32.JS_SAVE;
 638                         joydev->glue.JS_CORR       = ds32.JS_CORR;
 639                 }
 640                 break;
 641
 642         case JS_GET_ALL:
 643                 ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
 644                 ds32.BUSY          = joydev->glue.BUSY;
 645                 ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
 646                 ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
 647                 ds32.JS_SAVE       = joydev->glue.JS_SAVE;
 648                 ds32.JS_CORR       = joydev->glue.JS_CORR;
 649
 650                 retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
 651                 break;
 652
 653         default:
 654                 retval = joydev_ioctl_common(joydev, cmd, argp);
 655                 break;
 656         }
 657
 658  out:
 659         mutex_unlock(&joydev->mutex);
 660         return retval;
 661 }
 662 #endif /* CONFIG_COMPAT */
 663
 664 static long joydev_ioctl(struct file *file,
 665                          unsigned int cmd, unsigned long arg)
 666 {
 667         struct joydev_client *client = file->private_data;
 668         struct joydev *joydev = client->joydev;
 669         void __user *argp = (void __user *)arg;
 670         int retval;
 671
 672         retval = mutex_lock_interruptible(&joydev->mutex);
 673         if (retval)
 674                 return retval;
 675
 676         if (!joydev->exist) {
 677                 retval = -ENODEV;
 678                 goto out;
 679         }
 680
 681         switch (cmd) {
 682
 683         case JS_SET_TIMELIMIT:
 684                 retval = get_user(joydev->glue.JS_TIMELIMIT,
 685                                   (long __user *) arg);
 686                 break;
 687
 688         case JS_GET_TIMELIMIT:
 689                 retval = put_user(joydev->glue.JS_TIMELIMIT,
 690                                   (long __user *) arg);
 691                 break;
 692
 693         case JS_SET_ALL:
 694                 retval = copy_from_user(&joydev->glue, argp,
 695                                         sizeof(joydev->glue)) ? -EFAULT : 0;
 696                 break;
 697
 698         case JS_GET_ALL:
 699                 retval = copy_to_user(argp, &joydev->glue,
 700                                       sizeof(joydev->glue)) ? -EFAULT : 0;
 701                 break;
 702
 703         default:
 704                 retval = joydev_ioctl_common(joydev, cmd, argp);
 705                 break;
 706         }
 707  out:
 708         mutex_unlock(&joydev->mutex);
 709         return retval;
 710 }
 711
 712 static const struct file_operations joydev_fops = {
 713         .owner          = THIS_MODULE,
 714         .read           = joydev_read,
 715         .poll           = joydev_poll,
 716         .open           = joydev_open,
 717         .release        = joydev_release,
 718         .unlocked_ioctl = joydev_ioctl,
 719 #ifdef CONFIG_COMPAT
 720         .compat_ioctl   = joydev_compat_ioctl,
 721 #endif
 722         .fasync         = joydev_fasync,
 723         .llseek         = no_llseek,
 724 };
 725
 726 /*
 727  * Mark device non-existent. This disables writes, ioctls and
 728  * prevents new users from opening the device. Already posted
 729  * blocking reads will stay, however new ones will fail.
 730  */
 731 static void joydev_mark_dead(struct joydev *joydev)
 732 {
 733         mutex_lock(&joydev->mutex);
 734         joydev->exist = false;
 735         mutex_unlock(&joydev->mutex);
 736 }
 737
 738 static void joydev_cleanup(struct joydev *joydev)
 739 {
 740         struct input_handle *handle = &joydev->handle;
 741
 742         joydev_mark_dead(joydev);
 743         joydev_hangup(joydev);
 744
 745         cdev_del(&joydev->cdev);
 746
 747         /* joydev is marked dead so no one else accesses joydev->open */
 748         if (joydev->open)
 749                 input_close_device(handle);
 750 }
 751
 752 static bool joydev_dev_is_absolute_mouse(struct input_dev *dev)
 753 {
 754         DECLARE_BITMAP(jd_scratch, KEY_CNT);
 755
 756         BUILD_BUG_ON(ABS_CNT > KEY_CNT || EV_CNT > KEY_CNT);
 757
 758         /*
 759          * Virtualization (VMware, etc) and remote management (HP
 760          * ILO2) solutions use absolute coordinates for their virtual
 761          * pointing devices so that there is one-to-one relationship
 762          * between pointer position on the host screen and virtual
 763          * guest screen, and so their mice use ABS_X, ABS_Y and 3
 764          * primary button events. This clashes with what joydev
 765          * considers to be joysticks (a device with at minimum ABS_X
 766          * axis).
 767          *
 768          * Here we are trying to separate absolute mice from
 769          * joysticks. A device is, for joystick detection purposes,
 770          * considered to be an absolute mouse if the following is
 771          * true:
 772          *
 773          * 1) Event types are exactly EV_ABS, EV_KEY and EV_SYN.
 774          * 2) Absolute events are exactly ABS_X and ABS_Y.
 775          * 3) Keys are exactly BTN_LEFT, BTN_RIGHT and BTN_MIDDLE.
 776          * 4) Device is not on "Amiga" bus.
 777          */
 778
 779         bitmap_zero(jd_scratch, EV_CNT);
 780         __set_bit(EV_ABS, jd_scratch);
 781         __set_bit(EV_KEY, jd_scratch);
 782         __set_bit(EV_SYN, jd_scratch);
 783         if (!bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
 784                 return false;
 785
 786         bitmap_zero(jd_scratch, ABS_CNT);
 787         __set_bit(ABS_X, jd_scratch);
 788         __set_bit(ABS_Y, jd_scratch);
 789         if (!bitmap_equal(dev->absbit, jd_scratch, ABS_CNT))
 790                 return false;
 791
 792         bitmap_zero(jd_scratch, KEY_CNT);
 793         __set_bit(BTN_LEFT, jd_scratch);
 794         __set_bit(BTN_RIGHT, jd_scratch);
 795         __set_bit(BTN_MIDDLE, jd_scratch);
 796
 797         if (!bitmap_equal(dev->keybit, jd_scratch, KEY_CNT))
 798                 return false;
 799
 800         /*
 801          * Amiga joystick (amijoy) historically uses left/middle/right
 802          * button events.
 803          */
 804         if (dev->id.bustype == BUS_AMIGA)
 805                 return false;
 806
 807         return true;
 808 }
 809
 810 static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
 811 {
 812         /* Avoid touchpads and touchscreens */
 813         if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_TOUCH, dev->keybit))
 814                 return false;
 815
 816         /* Avoid tablets, digitisers and similar devices */
 817         if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
 818                 return false;
 819
 820         /* Avoid absolute mice */
 821         if (joydev_dev_is_absolute_mouse(dev))
 822                 return false;
 823
 824         return true;
 825 }
 826
 827 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 828                           const struct input_device_id *id)
 829 {
 830         struct joydev *joydev;
 831         int i, j, t, minor, dev_no;
 832         int error;
 833
 834         minor = input_get_new_minor(JOYDEV_MINOR_BASE, JOYDEV_MINORS, true);
 835         if (minor < 0) {
 836                 error = minor;
 837                 pr_err("failed to reserve new minor: %d\n", error);
 838                 return error;
 839         }
 840
 841         joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
 842         if (!joydev) {
 843                 error = -ENOMEM;
 844                 goto err_free_minor;
 845         }
 846
 847         INIT_LIST_HEAD(&joydev->client_list);
 848         spin_lock_init(&joydev->client_lock);
 849         mutex_init(&joydev->mutex);
 850         init_waitqueue_head(&joydev->wait);
 851         joydev->exist = true;
 852
 853         dev_no = minor;
 854         /* Normalize device number if it falls into legacy range */
 855         if (dev_no < JOYDEV_MINOR_BASE + JOYDEV_MINORS)
 856                 dev_no -= JOYDEV_MINOR_BASE;
 857         dev_set_name(&joydev->dev, "js%d", dev_no);
 858
 859         joydev->handle.dev = input_get_device(dev);
 860         joydev->handle.name = dev_name(&joydev->dev);
 861         joydev->handle.handler = handler;
 862         joydev->handle.private = joydev;
 863
 864         for_each_set_bit(i, dev->absbit, ABS_CNT) {
 865                 joydev->absmap[i] = joydev->nabs;
 866                 joydev->abspam[joydev->nabs] = i;
 867                 joydev->nabs++;
 868         }
 869
 870         for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 871                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 872                         joydev->keymap[i] = joydev->nkey;
 873                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 874                         joydev->nkey++;
 875                 }
 876
 877         for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 878                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 879                         joydev->keymap[i] = joydev->nkey;
 880                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 881                         joydev->nkey++;
 882                 }
 883
 884         for (i = 0; i < joydev->nabs; i++) {
 885                 j = joydev->abspam[i];
 886                 if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
 887                         joydev->corr[i].type = JS_CORR_NONE;
 888                         continue;
 889                 }
 890                 joydev->corr[i].type = JS_CORR_BROKEN;
 891                 joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
 892
 893                 t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
 894                 joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
 895                 joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
 896
 897                 t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
 898                         - 2 * input_abs_get_flat(dev, j);
 899                 if (t) {
 900                         joydev->corr[i].coef[2] = (1 << 29) / t;
 901                         joydev->corr[i].coef[3] = (1 << 29) / t;
 902                 }
 903         }
 904
 905         joydev->dev.devt = MKDEV(INPUT_MAJOR, minor);
 906         joydev->dev.class = &input_class;
 907         joydev->dev.parent = &dev->dev;
 908         joydev->dev.release = joydev_free;
 909         device_initialize(&joydev->dev);
 910
 911         error = input_register_handle(&joydev->handle);
 912         if (error)
 913                 goto err_free_joydev;
 914
 915         cdev_init(&joydev->cdev, &joydev_fops);
 916         joydev->cdev.kobj.parent = &joydev->dev.kobj;
 917         error = cdev_add(&joydev->cdev, joydev->dev.devt, 1);
 918         if (error)
 919                 goto err_unregister_handle;
 920
 921         error = device_add(&joydev->dev);
 922         if (error)
 923                 goto err_cleanup_joydev;
 924
 925         return 0;
 926
 927  err_cleanup_joydev:
 928         joydev_cleanup(joydev);
 929  err_unregister_handle:
 930         input_unregister_handle(&joydev->handle);
 931  err_free_joydev:
 932         put_device(&joydev->dev);
 933  err_free_minor:
 934         input_free_minor(minor);
 935         return error;
 936 }
 937
 938 static void joydev_disconnect(struct input_handle *handle)
 939 {
 940         struct joydev *joydev = handle->private;
 941
 942         device_del(&joydev->dev);
 943         joydev_cleanup(joydev);
 944         input_free_minor(MINOR(joydev->dev.devt));
 945         input_unregister_handle(handle);
 946         put_device(&joydev->dev);
 947 }
 948
 949 static const struct input_device_id joydev_ids[] = {
 950         {
 951                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 952                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 953                 .evbit = { BIT_MASK(EV_ABS) },
 954                 .absbit = { BIT_MASK(ABS_X) },
 955         },
 956         {
 957                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 958                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 959                 .evbit = { BIT_MASK(EV_ABS) },
 960                 .absbit = { BIT_MASK(ABS_Z) },
 961         },
 962         {
 963                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 964                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 965                 .evbit = { BIT_MASK(EV_ABS) },
 966                 .absbit = { BIT_MASK(ABS_WHEEL) },
 967         },
 968         {
 969                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 970                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 971                 .evbit = { BIT_MASK(EV_ABS) },
 972                 .absbit = { BIT_MASK(ABS_THROTTLE) },
 973         },
 974         {
 975                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 976                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 977                 .evbit = { BIT_MASK(EV_KEY) },
 978                 .keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
 979         },
 980         {
 981                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 982                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 983                 .evbit = { BIT_MASK(EV_KEY) },
 984                 .keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
 985         },
 986         {
 987                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 988                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 989                 .evbit = { BIT_MASK(EV_KEY) },
 990                 .keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
 991         },
 992         { }     /* Terminating entry */
 993 };
 994
 995 MODULE_DEVICE_TABLE(input, joydev_ids);
 996
 997 static struct input_handler joydev_handler = {
 998         .event          = joydev_event,
 999         .match          = joydev_match,
1000         .connect        = joydev_connect,
1001         .disconnect     = joydev_disconnect,
1002         .legacy_minors  = true,
1003         .minor          = JOYDEV_MINOR_BASE,
1004         .name           = "joydev",
1005         .id_table       = joydev_ids,
1006 };
1007
1008 static int __init joydev_init(void)
1009 {
1010         return input_register_handler(&joydev_handler);
1011 }
1012
1013 static void __exit joydev_exit(void)
1014 {
1015         input_unregister_handler(&joydev_handler);
1016 }
1017
1018 module_init(joydev_init);
1019 module_exit(joydev_exit);