drivers/input/joydev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Joystick device driver for the input driver suite.
   4  *
   5  * Copyright (c) 1999-2002 Vojtech Pavlik
   6  * Copyright (c) 1999 Colin Van Dyke
   7  */
   8
   9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11 #include <asm/io.h>
  12 #include <linux/delay.h>
  13 #include <linux/errno.h>
  14 #include <linux/joystick.h>
  15 #include <linux/input.h>
  16 #include <linux/kernel.h>
  17 #include <linux/major.h>
  18 #include <linux/sched.h>
  19 #include <linux/slab.h>
  20 #include <linux/mm.h>
  21 #include <linux/module.h>
  22 #include <linux/poll.h>
  23 #include <linux/init.h>
  24 #include <linux/device.h>
  25 #include <linux/cdev.h>
  26
  27 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  28 MODULE_DESCRIPTION("Joystick device interfaces");
  29 MODULE_LICENSE("GPL");
  30
  31 #define JOYDEV_MINOR_BASE       0
  32 #define JOYDEV_MINORS           16
  33 #define JOYDEV_BUFFER_SIZE      64
  34
  35 struct joydev {
  36         int open;
  37         struct input_handle handle;
  38         wait_queue_head_t wait;
  39         struct list_head client_list;
  40         spinlock_t client_lock; /* protects client_list */
  41         struct mutex mutex;
  42         struct device dev;
  43         struct cdev cdev;
  44         bool exist;
  45
  46         struct js_corr corr[ABS_CNT];
  47         struct JS_DATA_SAVE_TYPE glue;
  48         int nabs;
  49         int nkey;
  50         __u16 keymap[KEY_MAX - BTN_MISC + 1];
  51         __u16 keypam[KEY_MAX - BTN_MISC + 1];
  52         __u8 absmap[ABS_CNT];
  53         __u8 abspam[ABS_CNT];
  54         __s16 abs[ABS_CNT];
  55 };
  56
  57 struct joydev_client {
  58         struct js_event buffer[JOYDEV_BUFFER_SIZE];
  59         int head;
  60         int tail;
  61         int startup;
  62         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  63         struct fasync_struct *fasync;
  64         struct joydev *joydev;
  65         struct list_head node;
  66 };
  67
  68 static int joydev_correct(int value, struct js_corr *corr)
  69 {
  70         switch (corr->type) {
  71
  72         case JS_CORR_NONE:
  73                 break;
  74
  75         case JS_CORR_BROKEN:
  76                 value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
  77                         ((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
  78                         ((corr->coef[2] * (value - corr->coef[0])) >> 14);
  79                 break;
  80
  81         default:
  82                 return 0;
  83         }
  84
  85         return clamp(value, -32767, 32767);
  86 }
  87
  88 static void joydev_pass_event(struct joydev_client *client,
  89                               struct js_event *event)
  90 {
  91         struct joydev *joydev = client->joydev;
  92
  93         /*
  94          * IRQs already disabled, just acquire the lock
  95          */
  96         spin_lock(&client->buffer_lock);
  97
  98         client->buffer[client->head] = *event;
  99
 100         if (client->startup == joydev->nabs + joydev->nkey) {
 101                 client->head++;
 102                 client->head &= JOYDEV_BUFFER_SIZE - 1;
 103                 if (client->tail == client->head)
 104                         client->startup = 0;
 105         }
 106
 107         spin_unlock(&client->buffer_lock);
 108
 109         kill_fasync(&client->fasync, SIGIO, POLL_IN);
 110 }
 111
 112 static void joydev_event(struct input_handle *handle,
 113                          unsigned int type, unsigned int code, int value)
 114 {
 115         struct joydev *joydev = handle->private;
 116         struct joydev_client *client;
 117         struct js_event event;
 118
 119         switch (type) {
 120
 121         case EV_KEY:
 122                 if (code < BTN_MISC || value == 2)
 123                         return;
 124                 event.type = JS_EVENT_BUTTON;
 125                 event.number = joydev->keymap[code - BTN_MISC];
 126                 event.value = value;
 127                 break;
 128
 129         case EV_ABS:
 130                 event.type = JS_EVENT_AXIS;
 131                 event.number = joydev->absmap[code];
 132                 event.value = joydev_correct(value,
 133                                         &joydev->corr[event.number]);
 134                 if (event.value == joydev->abs[event.number])
 135                         return;
 136                 joydev->abs[event.number] = event.value;
 137                 break;
 138
 139         default:
 140                 return;
 141         }
 142
 143         event.time = jiffies_to_msecs(jiffies);
 144
 145         rcu_read_lock();
 146         list_for_each_entry_rcu(client, &joydev->client_list, node)
 147                 joydev_pass_event(client, &event);
 148         rcu_read_unlock();
 149
 150         wake_up_interruptible(&joydev->wait);
 151 }
 152
 153 static int joydev_fasync(int fd, struct file *file, int on)
 154 {
 155         struct joydev_client *client = file->private_data;
 156
 157         return fasync_helper(fd, file, on, &client->fasync);
 158 }
 159
 160 static void joydev_free(struct device *dev)
 161 {
 162         struct joydev *joydev = container_of(dev, struct joydev, dev);
 163
 164         input_put_device(joydev->handle.dev);
 165         kfree(joydev);
 166 }
 167
 168 static void joydev_attach_client(struct joydev *joydev,
 169                                  struct joydev_client *client)
 170 {
 171         spin_lock(&joydev->client_lock);
 172         list_add_tail_rcu(&client->node, &joydev->client_list);
 173         spin_unlock(&joydev->client_lock);
 174 }
 175
 176 static void joydev_detach_client(struct joydev *joydev,
 177                                  struct joydev_client *client)
 178 {
 179         spin_lock(&joydev->client_lock);
 180         list_del_rcu(&client->node);
 181         spin_unlock(&joydev->client_lock);
 182         synchronize_rcu();
 183 }
 184
 185 static void joydev_refresh_state(struct joydev *joydev)
 186 {
 187         struct input_dev *dev = joydev->handle.dev;
 188         int i, val;
 189
 190         for (i = 0; i < joydev->nabs; i++) {
 191                 val = input_abs_get_val(dev, joydev->abspam[i]);
 192                 joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
 193         }
 194 }
 195
 196 static int joydev_open_device(struct joydev *joydev)
 197 {
 198         int retval;
 199
 200         retval = mutex_lock_interruptible(&joydev->mutex);
 201         if (retval)
 202                 return retval;
 203
 204         if (!joydev->exist)
 205                 retval = -ENODEV;
 206         else if (!joydev->open++) {
 207                 retval = input_open_device(&joydev->handle);
 208                 if (retval)
 209                         joydev->open--;
 210                 else
 211                         joydev_refresh_state(joydev);
 212         }
 213
 214         mutex_unlock(&joydev->mutex);
 215         return retval;
 216 }
 217
 218 static void joydev_close_device(struct joydev *joydev)
 219 {
 220         mutex_lock(&joydev->mutex);
 221
 222         if (joydev->exist && !--joydev->open)
 223                 input_close_device(&joydev->handle);
 224
 225         mutex_unlock(&joydev->mutex);
 226 }
 227
 228 /*
 229  * Wake up users waiting for IO so they can disconnect from
 230  * dead device.
 231  */
 232 static void joydev_hangup(struct joydev *joydev)
 233 {
 234         struct joydev_client *client;
 235
 236         spin_lock(&joydev->client_lock);
 237         list_for_each_entry(client, &joydev->client_list, node)
 238                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 239         spin_unlock(&joydev->client_lock);
 240
 241         wake_up_interruptible(&joydev->wait);
 242 }
 243
 244 static int joydev_release(struct inode *inode, struct file *file)
 245 {
 246         struct joydev_client *client = file->private_data;
 247         struct joydev *joydev = client->joydev;
 248
 249         joydev_detach_client(joydev, client);
 250         kfree(client);
 251
 252         joydev_close_device(joydev);
 253
 254         return 0;
 255 }
 256
 257 static int joydev_open(struct inode *inode, struct file *file)
 258 {
 259         struct joydev *joydev =
 260                         container_of(inode->i_cdev, struct joydev, cdev);
 261         struct joydev_client *client;
 262         int error;
 263
 264         client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
 265         if (!client)
 266                 return -ENOMEM;
 267
 268         spin_lock_init(&client->buffer_lock);
 269         client->joydev = joydev;
 270         joydev_attach_client(joydev, client);
 271
 272         error = joydev_open_device(joydev);
 273         if (error)
 274                 goto err_free_client;
 275
 276         file->private_data = client;
 277         stream_open(inode, file);
 278
 279         return 0;
 280
 281  err_free_client:
 282         joydev_detach_client(joydev, client);
 283         kfree(client);
 284         return error;
 285 }
 286
 287 static int joydev_generate_startup_event(struct joydev_client *client,
 288                                          struct input_dev *input,
 289                                          struct js_event *event)
 290 {
 291         struct joydev *joydev = client->joydev;
 292         int have_event;
 293
 294         spin_lock_irq(&client->buffer_lock);
 295
 296         have_event = client->startup < joydev->nabs + joydev->nkey;
 297
 298         if (have_event) {
 299
 300                 event->time = jiffies_to_msecs(jiffies);
 301                 if (client->startup < joydev->nkey) {
 302                         event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 303                         event->number = client->startup;
 304                         event->value = !!test_bit(joydev->keypam[event->number],
 305                                                   input->key);
 306                 } else {
 307                         event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
 308                         event->number = client->startup - joydev->nkey;
 309                         event->value = joydev->abs[event->number];
 310                 }
 311                 client->startup++;
 312         }
 313
 314         spin_unlock_irq(&client->buffer_lock);
 315
 316         return have_event;
 317 }
 318
 319 static int joydev_fetch_next_event(struct joydev_client *client,
 320                                    struct js_event *event)
 321 {
 322         int have_event;
 323
 324         spin_lock_irq(&client->buffer_lock);
 325
 326         have_event = client->head != client->tail;
 327         if (have_event) {
 328                 *event = client->buffer[client->tail++];
 329                 client->tail &= JOYDEV_BUFFER_SIZE - 1;
 330         }
 331
 332         spin_unlock_irq(&client->buffer_lock);
 333
 334         return have_event;
 335 }
 336
 337 /*
 338  * Old joystick interface
 339  */
 340 static ssize_t joydev_0x_read(struct joydev_client *client,
 341                               struct input_dev *input,
 342                               char __user *buf)
 343 {
 344         struct joydev *joydev = client->joydev;
 345         struct JS_DATA_TYPE data;
 346         int i;
 347
 348         spin_lock_irq(&input->event_lock);
 349
 350         /*
 351          * Get device state
 352          */
 353         for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 354                 data.buttons |=
 355                         test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 356         data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 357         data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
 358
 359         /*
 360          * Reset reader's event queue
 361          */
 362         spin_lock(&client->buffer_lock);
 363         client->startup = 0;
 364         client->tail = client->head;
 365         spin_unlock(&client->buffer_lock);
 366
 367         spin_unlock_irq(&input->event_lock);
 368
 369         if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 370                 return -EFAULT;
 371
 372         return sizeof(struct JS_DATA_TYPE);
 373 }
 374
 375 static inline int joydev_data_pending(struct joydev_client *client)
 376 {
 377         struct joydev *joydev = client->joydev;
 378
 379         return client->startup < joydev->nabs + joydev->nkey ||
 380                 client->head != client->tail;
 381 }
 382
 383 static ssize_t joydev_read(struct file *file, char __user *buf,
 384                            size_t count, loff_t *ppos)
 385 {
 386         struct joydev_client *client = file->private_data;
 387         struct joydev *joydev = client->joydev;
 388         struct input_dev *input = joydev->handle.dev;
 389         struct js_event event;
 390         int retval;
 391
 392         if (!joydev->exist)
 393                 return -ENODEV;
 394
 395         if (count < sizeof(struct js_event))
 396                 return -EINVAL;
 397
 398         if (count == sizeof(struct JS_DATA_TYPE))
 399                 return joydev_0x_read(client, input, buf);
 400
 401         if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
 402                 return -EAGAIN;
 403
 404         retval = wait_event_interruptible(joydev->wait,
 405                         !joydev->exist || joydev_data_pending(client));
 406         if (retval)
 407                 return retval;
 408
 409         if (!joydev->exist)
 410                 return -ENODEV;
 411
 412         while (retval + sizeof(struct js_event) <= count &&
 413                joydev_generate_startup_event(client, input, &event)) {
 414
 415                 if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 416                         return -EFAULT;
 417
 418                 retval += sizeof(struct js_event);
 419         }
 420
 421         while (retval + sizeof(struct js_event) <= count &&
 422                joydev_fetch_next_event(client, &event)) {
 423
 424                 if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 425                         return -EFAULT;
 426
 427                 retval += sizeof(struct js_event);
 428         }
 429
 430         return retval;
 431 }
 432
 433 /* No kernel lock - fine */
 434 static __poll_t joydev_poll(struct file *file, poll_table *wait)
 435 {
 436         struct joydev_client *client = file->private_data;
 437         struct joydev *joydev = client->joydev;
 438
 439         poll_wait(file, &joydev->wait, wait);
 440         return (joydev_data_pending(client) ? (EPOLLIN | EPOLLRDNORM) : 0) |
 441                 (joydev->exist ?  0 : (EPOLLHUP | EPOLLERR));
 442 }
 443
 444 static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
 445                                      void __user *argp, size_t len)
 446 {
 447         __u8 *abspam;
 448         int i;
 449         int retval = 0;
 450
 451         len = min(len, sizeof(joydev->abspam));
 452
 453         /* Validate the map. */
 454         abspam = memdup_user(argp, len);
 455         if (IS_ERR(abspam))
 456                 return PTR_ERR(abspam);
 457
 458         for (i = 0; i < len && i < joydev->nabs; i++) {
 459                 if (abspam[i] > ABS_MAX) {
 460                         retval = -EINVAL;
 461                         goto out;
 462                 }
 463         }
 464
 465         memcpy(joydev->abspam, abspam, len);
 466
 467         for (i = 0; i < joydev->nabs; i++)
 468                 joydev->absmap[joydev->abspam[i]] = i;
 469
 470  out:
 471         kfree(abspam);
 472         return retval;
 473 }
 474
 475 static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
 476                                       void __user *argp, size_t len)
 477 {
 478         __u16 *keypam;
 479         int i;
 480         int retval = 0;
 481
 482         if (len % sizeof(*keypam))
 483                 return -EINVAL;
 484
 485         len = min(len, sizeof(joydev->keypam));
 486
 487         /* Validate the map. */
 488         keypam = memdup_user(argp, len);
 489         if (IS_ERR(keypam))
 490                 return PTR_ERR(keypam);
 491
 492         for (i = 0; i < (len / 2) && i < joydev->nkey; i++) {
 493                 if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
 494                         retval = -EINVAL;
 495                         goto out;
 496                 }
 497         }
 498
 499         memcpy(joydev->keypam, keypam, len);
 500
 501         for (i = 0; i < joydev->nkey; i++)
 502                 joydev->keymap[joydev->keypam[i] - BTN_MISC] = i;
 503
 504  out:
 505         kfree(keypam);
 506         return retval;
 507 }
 508
 509
 510 static int joydev_ioctl_common(struct joydev *joydev,
 511                                 unsigned int cmd, void __user *argp)
 512 {
 513         struct input_dev *dev = joydev->handle.dev;
 514         size_t len;
 515         int i;
 516         const char *name;
 517
 518         /* Process fixed-sized commands. */
 519         switch (cmd) {
 520
 521         case JS_SET_CAL:
 522                 return copy_from_user(&joydev->glue.JS_CORR, argp,
 523                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 524
 525         case JS_GET_CAL:
 526                 return copy_to_user(argp, &joydev->glue.JS_CORR,
 527                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 528
 529         case JS_SET_TIMEOUT:
 530                 return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 531
 532         case JS_GET_TIMEOUT:
 533                 return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 534
 535         case JSIOCGVERSION:
 536                 return put_user(JS_VERSION, (__u32 __user *) argp);
 537
 538         case JSIOCGAXES:
 539                 return put_user(joydev->nabs, (__u8 __user *) argp);
 540
 541         case JSIOCGBUTTONS:
 542                 return put_user(joydev->nkey, (__u8 __user *) argp);
 543
 544         case JSIOCSCORR:
 545                 if (copy_from_user(joydev->corr, argp,
 546                               sizeof(joydev->corr[0]) * joydev->nabs))
 547                         return -EFAULT;
 548
 549                 for (i = 0; i < joydev->nabs; i++) {
 550                         int val = input_abs_get_val(dev, joydev->abspam[i]);
 551                         joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
 552                 }
 553                 return 0;
 554
 555         case JSIOCGCORR:
 556                 return copy_to_user(argp, joydev->corr,
 557                         sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
 558
 559         }
 560
 561         /*
 562          * Process variable-sized commands (the axis and button map commands
 563          * are considered variable-sized to decouple them from the values of
 564          * ABS_MAX and KEY_MAX).
 565          */
 566         switch (cmd & ~IOCSIZE_MASK) {
 567
 568         case (JSIOCSAXMAP & ~IOCSIZE_MASK):
 569                 return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
 570
 571         case (JSIOCGAXMAP & ~IOCSIZE_MASK):
 572                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
 573                 return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
 574
 575         case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
 576                 return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
 577
 578         case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
 579                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
 580                 return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
 581
 582         case JSIOCGNAME(0):
 583                 name = dev->name;
 584                 if (!name)
 585                         return 0;
 586
 587                 len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
 588                 return copy_to_user(argp, name, len) ? -EFAULT : len;
 589         }
 590
 591         return -EINVAL;
 592 }
 593
 594 #ifdef CONFIG_COMPAT
 595 static long joydev_compat_ioctl(struct file *file,
 596                                 unsigned int cmd, unsigned long arg)
 597 {
 598         struct joydev_client *client = file->private_data;
 599         struct joydev *joydev = client->joydev;
 600         void __user *argp = (void __user *)arg;
 601         s32 tmp32;
 602         struct JS_DATA_SAVE_TYPE_32 ds32;
 603         int retval;
 604
 605         retval = mutex_lock_interruptible(&joydev->mutex);
 606         if (retval)
 607                 return retval;
 608
 609         if (!joydev->exist) {
 610                 retval = -ENODEV;
 611                 goto out;
 612         }
 613
 614         switch (cmd) {
 615
 616         case JS_SET_TIMELIMIT:
 617                 retval = get_user(tmp32, (s32 __user *) arg);
 618                 if (retval == 0)
 619                         joydev->glue.JS_TIMELIMIT = tmp32;
 620                 break;
 621
 622         case JS_GET_TIMELIMIT:
 623                 tmp32 = joydev->glue.JS_TIMELIMIT;
 624                 retval = put_user(tmp32, (s32 __user *) arg);
 625                 break;
 626
 627         case JS_SET_ALL:
 628                 retval = copy_from_user(&ds32, argp,
 629                                         sizeof(ds32)) ? -EFAULT : 0;
 630                 if (retval == 0) {
 631                         joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
 632                         joydev->glue.BUSY          = ds32.BUSY;
 633                         joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
 634                         joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
 635                         joydev->glue.JS_SAVE       = ds32.JS_SAVE;
 636                         joydev->glue.JS_CORR       = ds32.JS_CORR;
 637                 }
 638                 break;
 639
 640         case JS_GET_ALL:
 641                 ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
 642                 ds32.BUSY          = joydev->glue.BUSY;
 643                 ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
 644                 ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
 645                 ds32.JS_SAVE       = joydev->glue.JS_SAVE;
 646                 ds32.JS_CORR       = joydev->glue.JS_CORR;
 647
 648                 retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
 649                 break;
 650
 651         default:
 652                 retval = joydev_ioctl_common(joydev, cmd, argp);
 653                 break;
 654         }
 655
 656  out:
 657         mutex_unlock(&joydev->mutex);
 658         return retval;
 659 }
 660 #endif /* CONFIG_COMPAT */
 661
 662 static long joydev_ioctl(struct file *file,
 663                          unsigned int cmd, unsigned long arg)
 664 {
 665         struct joydev_client *client = file->private_data;
 666         struct joydev *joydev = client->joydev;
 667         void __user *argp = (void __user *)arg;
 668         int retval;
 669
 670         retval = mutex_lock_interruptible(&joydev->mutex);
 671         if (retval)
 672                 return retval;
 673
 674         if (!joydev->exist) {
 675                 retval = -ENODEV;
 676                 goto out;
 677         }
 678
 679         switch (cmd) {
 680
 681         case JS_SET_TIMELIMIT:
 682                 retval = get_user(joydev->glue.JS_TIMELIMIT,
 683                                   (long __user *) arg);
 684                 break;
 685
 686         case JS_GET_TIMELIMIT:
 687                 retval = put_user(joydev->glue.JS_TIMELIMIT,
 688                                   (long __user *) arg);
 689                 break;
 690
 691         case JS_SET_ALL:
 692                 retval = copy_from_user(&joydev->glue, argp,
 693                                         sizeof(joydev->glue)) ? -EFAULT : 0;
 694                 break;
 695
 696         case JS_GET_ALL:
 697                 retval = copy_to_user(argp, &joydev->glue,
 698                                       sizeof(joydev->glue)) ? -EFAULT : 0;
 699                 break;
 700
 701         default:
 702                 retval = joydev_ioctl_common(joydev, cmd, argp);
 703                 break;
 704         }
 705  out:
 706         mutex_unlock(&joydev->mutex);
 707         return retval;
 708 }
 709
 710 static const struct file_operations joydev_fops = {
 711         .owner          = THIS_MODULE,
 712         .read           = joydev_read,
 713         .poll           = joydev_poll,
 714         .open           = joydev_open,
 715         .release        = joydev_release,
 716         .unlocked_ioctl = joydev_ioctl,
 717 #ifdef CONFIG_COMPAT
 718         .compat_ioctl   = joydev_compat_ioctl,
 719 #endif
 720         .fasync         = joydev_fasync,
 721         .llseek         = no_llseek,
 722 };
 723
 724 /*
 725  * Mark device non-existent. This disables writes, ioctls and
 726  * prevents new users from opening the device. Already posted
 727  * blocking reads will stay, however new ones will fail.
 728  */
 729 static void joydev_mark_dead(struct joydev *joydev)
 730 {
 731         mutex_lock(&joydev->mutex);
 732         joydev->exist = false;
 733         mutex_unlock(&joydev->mutex);
 734 }
 735
 736 static void joydev_cleanup(struct joydev *joydev)
 737 {
 738         struct input_handle *handle = &joydev->handle;
 739
 740         joydev_mark_dead(joydev);
 741         joydev_hangup(joydev);
 742
 743         /* joydev is marked dead so no one else accesses joydev->open */
 744         if (joydev->open)
 745                 input_close_device(handle);
 746 }
 747
 748 /*
 749  * These codes are copied from from hid-ids.h, unfortunately there is no common
 750  * usb_ids/bt_ids.h header.
 751  */
 752 #define USB_VENDOR_ID_SONY                      0x054c
 753 #define USB_DEVICE_ID_SONY_PS3_CONTROLLER               0x0268
 754 #define USB_DEVICE_ID_SONY_PS4_CONTROLLER               0x05c4
 755 #define USB_DEVICE_ID_SONY_PS4_CONTROLLER_2             0x09cc
 756 #define USB_DEVICE_ID_SONY_PS4_CONTROLLER_DONGLE        0x0ba0
 757
 758 #define USB_VENDOR_ID_THQ                       0x20d6
 759 #define USB_DEVICE_ID_THQ_PS3_UDRAW                     0xcb17
 760
 761 #define ACCEL_DEV(vnd, prd)                                             \
 762         {                                                               \
 763                 .flags = INPUT_DEVICE_ID_MATCH_VENDOR |                 \
 764                                 INPUT_DEVICE_ID_MATCH_PRODUCT |         \
 765                                 INPUT_DEVICE_ID_MATCH_PROPBIT,          \
 766                 .vendor = (vnd),                                        \
 767                 .product = (prd),                                       \
 768                 .propbit = { BIT_MASK(INPUT_PROP_ACCELEROMETER) },      \
 769         }
 770
 771 static const struct input_device_id joydev_blacklist[] = {
 772         /* Avoid touchpads and touchscreens */
 773         {
 774                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 775                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 776                 .evbit = { BIT_MASK(EV_KEY) },
 777                 .keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
 778         },
 779         /* Avoid tablets, digitisers and similar devices */
 780         {
 781                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 782                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 783                 .evbit = { BIT_MASK(EV_KEY) },
 784                 .keybit = { [BIT_WORD(BTN_DIGI)] = BIT_MASK(BTN_DIGI) },
 785         },
 786         /* Disable accelerometers on composite devices */
 787         ACCEL_DEV(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS3_CONTROLLER),
 788         ACCEL_DEV(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER),
 789         ACCEL_DEV(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER_2),
 790         ACCEL_DEV(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER_DONGLE),
 791         ACCEL_DEV(USB_VENDOR_ID_THQ, USB_DEVICE_ID_THQ_PS3_UDRAW),
 792         { /* sentinel */ }
 793 };
 794
 795 static bool joydev_dev_is_blacklisted(struct input_dev *dev)
 796 {
 797         const struct input_device_id *id;
 798
 799         for (id = joydev_blacklist; id->flags; id++) {
 800                 if (input_match_device_id(dev, id)) {
 801                         dev_dbg(&dev->dev,
 802                                 "joydev: blacklisting '%s'\n", dev->name);
 803                         return true;
 804                 }
 805         }
 806
 807         return false;
 808 }
 809
 810 static bool joydev_dev_is_absolute_mouse(struct input_dev *dev)
 811 {
 812         DECLARE_BITMAP(jd_scratch, KEY_CNT);
 813         bool ev_match = false;
 814
 815         BUILD_BUG_ON(ABS_CNT > KEY_CNT || EV_CNT > KEY_CNT);
 816
 817         /*
 818          * Virtualization (VMware, etc) and remote management (HP
 819          * ILO2) solutions use absolute coordinates for their virtual
 820          * pointing devices so that there is one-to-one relationship
 821          * between pointer position on the host screen and virtual
 822          * guest screen, and so their mice use ABS_X, ABS_Y and 3
 823          * primary button events. This clashes with what joydev
 824          * considers to be joysticks (a device with at minimum ABS_X
 825          * axis).
 826          *
 827          * Here we are trying to separate absolute mice from
 828          * joysticks. A device is, for joystick detection purposes,
 829          * considered to be an absolute mouse if the following is
 830          * true:
 831          *
 832          * 1) Event types are exactly
 833          *      EV_ABS, EV_KEY and EV_SYN
 834          *    or
 835          *      EV_ABS, EV_KEY, EV_SYN and EV_MSC
 836          *    or
 837          *      EV_ABS, EV_KEY, EV_SYN, EV_MSC and EV_REL.
 838          * 2) Absolute events are exactly ABS_X and ABS_Y.
 839          * 3) Keys are exactly BTN_LEFT, BTN_RIGHT and BTN_MIDDLE.
 840          * 4) Device is not on "Amiga" bus.
 841          */
 842
 843         bitmap_zero(jd_scratch, EV_CNT);
 844         /* VMware VMMouse, HP ILO2 */
 845         __set_bit(EV_ABS, jd_scratch);
 846         __set_bit(EV_KEY, jd_scratch);
 847         __set_bit(EV_SYN, jd_scratch);
 848         if (bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
 849                 ev_match = true;
 850
 851         /* HP ILO2, AMI BMC firmware */
 852         __set_bit(EV_MSC, jd_scratch);
 853         if (bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
 854                 ev_match = true;
 855
 856         /* VMware Virtual USB Mouse, QEMU USB Tablet, ATEN BMC firmware */
 857         __set_bit(EV_REL, jd_scratch);
 858         if (bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
 859                 ev_match = true;
 860
 861         if (!ev_match)
 862                 return false;
 863
 864         bitmap_zero(jd_scratch, ABS_CNT);
 865         __set_bit(ABS_X, jd_scratch);
 866         __set_bit(ABS_Y, jd_scratch);
 867         if (!bitmap_equal(dev->absbit, jd_scratch, ABS_CNT))
 868                 return false;
 869
 870         bitmap_zero(jd_scratch, KEY_CNT);
 871         __set_bit(BTN_LEFT, jd_scratch);
 872         __set_bit(BTN_RIGHT, jd_scratch);
 873         __set_bit(BTN_MIDDLE, jd_scratch);
 874
 875         if (!bitmap_equal(dev->keybit, jd_scratch, KEY_CNT))
 876                 return false;
 877
 878         /*
 879          * Amiga joystick (amijoy) historically uses left/middle/right
 880          * button events.
 881          */
 882         if (dev->id.bustype == BUS_AMIGA)
 883                 return false;
 884
 885         return true;
 886 }
 887
 888 static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
 889 {
 890         /* Disable blacklisted devices */
 891         if (joydev_dev_is_blacklisted(dev))
 892                 return false;
 893
 894         /* Avoid absolute mice */
 895         if (joydev_dev_is_absolute_mouse(dev))
 896                 return false;
 897
 898         return true;
 899 }
 900
 901 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 902                           const struct input_device_id *id)
 903 {
 904         struct joydev *joydev;
 905         int i, j, t, minor, dev_no;
 906         int error;
 907
 908         minor = input_get_new_minor(JOYDEV_MINOR_BASE, JOYDEV_MINORS, true);
 909         if (minor < 0) {
 910                 error = minor;
 911                 pr_err("failed to reserve new minor: %d\n", error);
 912                 return error;
 913         }
 914
 915         joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
 916         if (!joydev) {
 917                 error = -ENOMEM;
 918                 goto err_free_minor;
 919         }
 920
 921         INIT_LIST_HEAD(&joydev->client_list);
 922         spin_lock_init(&joydev->client_lock);
 923         mutex_init(&joydev->mutex);
 924         init_waitqueue_head(&joydev->wait);
 925         joydev->exist = true;
 926
 927         dev_no = minor;
 928         /* Normalize device number if it falls into legacy range */
 929         if (dev_no < JOYDEV_MINOR_BASE + JOYDEV_MINORS)
 930                 dev_no -= JOYDEV_MINOR_BASE;
 931         dev_set_name(&joydev->dev, "js%d", dev_no);
 932
 933         joydev->handle.dev = input_get_device(dev);
 934         joydev->handle.name = dev_name(&joydev->dev);
 935         joydev->handle.handler = handler;
 936         joydev->handle.private = joydev;
 937
 938         for_each_set_bit(i, dev->absbit, ABS_CNT) {
 939                 joydev->absmap[i] = joydev->nabs;
 940                 joydev->abspam[joydev->nabs] = i;
 941                 joydev->nabs++;
 942         }
 943
 944         for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 945                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 946                         joydev->keymap[i] = joydev->nkey;
 947                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 948                         joydev->nkey++;
 949                 }
 950
 951         for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 952                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 953                         joydev->keymap[i] = joydev->nkey;
 954                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 955                         joydev->nkey++;
 956                 }
 957
 958         for (i = 0; i < joydev->nabs; i++) {
 959                 j = joydev->abspam[i];
 960                 if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
 961                         joydev->corr[i].type = JS_CORR_NONE;
 962                         continue;
 963                 }
 964                 joydev->corr[i].type = JS_CORR_BROKEN;
 965                 joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
 966
 967                 t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
 968                 joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
 969                 joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
 970
 971                 t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
 972                         - 2 * input_abs_get_flat(dev, j);
 973                 if (t) {
 974                         joydev->corr[i].coef[2] = (1 << 29) / t;
 975                         joydev->corr[i].coef[3] = (1 << 29) / t;
 976                 }
 977         }
 978
 979         joydev->dev.devt = MKDEV(INPUT_MAJOR, minor);
 980         joydev->dev.class = &input_class;
 981         joydev->dev.parent = &dev->dev;
 982         joydev->dev.release = joydev_free;
 983         device_initialize(&joydev->dev);
 984
 985         error = input_register_handle(&joydev->handle);
 986         if (error)
 987                 goto err_free_joydev;
 988
 989         cdev_init(&joydev->cdev, &joydev_fops);
 990
 991         error = cdev_device_add(&joydev->cdev, &joydev->dev);
 992         if (error)
 993                 goto err_cleanup_joydev;
 994
 995         return 0;
 996
 997  err_cleanup_joydev:
 998         joydev_cleanup(joydev);
 999         input_unregister_handle(&joydev->handle);
1000  err_free_joydev:
1001         put_device(&joydev->dev);
1002  err_free_minor:
1003         input_free_minor(minor);
1004         return error;
1005 }
1006
1007 static void joydev_disconnect(struct input_handle *handle)
1008 {
1009         struct joydev *joydev = handle->private;
1010
1011         cdev_device_del(&joydev->cdev, &joydev->dev);
1012         joydev_cleanup(joydev);
1013         input_free_minor(MINOR(joydev->dev.devt));
1014         input_unregister_handle(handle);
1015         put_device(&joydev->dev);
1016 }
1017
1018 static const struct input_device_id joydev_ids[] = {
1019         {
1020                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1021                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
1022                 .evbit = { BIT_MASK(EV_ABS) },
1023                 .absbit = { BIT_MASK(ABS_X) },
1024         },
1025         {
1026                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1027                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
1028                 .evbit = { BIT_MASK(EV_ABS) },
1029                 .absbit = { BIT_MASK(ABS_Z) },
1030         },
1031         {
1032                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1033                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
1034                 .evbit = { BIT_MASK(EV_ABS) },
1035                 .absbit = { BIT_MASK(ABS_WHEEL) },
1036         },
1037         {
1038                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1039                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
1040                 .evbit = { BIT_MASK(EV_ABS) },
1041                 .absbit = { BIT_MASK(ABS_THROTTLE) },
1042         },
1043         {
1044                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1045                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
1046                 .evbit = { BIT_MASK(EV_KEY) },
1047                 .keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
1048         },
1049         {
1050                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1051                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
1052                 .evbit = { BIT_MASK(EV_KEY) },
1053                 .keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
1054         },
1055         {
1056                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1057                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
1058                 .evbit = { BIT_MASK(EV_KEY) },
1059                 .keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
1060         },
1061         { }     /* Terminating entry */
1062 };
1063
1064 MODULE_DEVICE_TABLE(input, joydev_ids);
1065
1066 static struct input_handler joydev_handler = {
1067         .event          = joydev_event,
1068         .match          = joydev_match,
1069         .connect        = joydev_connect,
1070         .disconnect     = joydev_disconnect,
1071         .legacy_minors  = true,
1072         .minor          = JOYDEV_MINOR_BASE,
1073         .name           = "joydev",
1074         .id_table       = joydev_ids,
1075 };
1076
1077 static int __init joydev_init(void)
1078 {
1079         return input_register_handler(&joydev_handler);
1080 }
1081
1082 static void __exit joydev_exit(void)
1083 {
1084         input_unregister_handler(&joydev_handler);
1085 }
1086
1087 module_init(joydev_init);
1088 module_exit(joydev_exit);