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/miscdevice.h>
  26 #include <linux/module.h>
  27 #include <linux/poll.h>
  28 #include <linux/init.h>
  29 #include <linux/device.h>
  30 #include <linux/cdev.h>
  31
  32 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  33 MODULE_DESCRIPTION("Joystick device interfaces");
  34 MODULE_SUPPORTED_DEVICE("input/js");
  35 MODULE_LICENSE("GPL");
  36
  37 #define JOYDEV_MINOR_BASE       0
  38 #define JOYDEV_MINORS           16
  39 #define JOYDEV_BUFFER_SIZE      64
  40
  41 struct joydev {
  42         int open;
  43         struct input_handle handle;
  44         wait_queue_head_t wait;
  45         struct list_head client_list;
  46         spinlock_t client_lock; /* protects client_list */
  47         struct mutex mutex;
  48         struct device dev;
  49         struct cdev cdev;
  50         bool exist;
  51
  52         struct js_corr corr[ABS_CNT];
  53         struct JS_DATA_SAVE_TYPE glue;
  54         int nabs;
  55         int nkey;
  56         __u16 keymap[KEY_MAX - BTN_MISC + 1];
  57         __u16 keypam[KEY_MAX - BTN_MISC + 1];
  58         __u8 absmap[ABS_CNT];
  59         __u8 abspam[ABS_CNT];
  60         __s16 abs[ABS_CNT];
  61 };
  62
  63 struct joydev_client {
  64         struct js_event buffer[JOYDEV_BUFFER_SIZE];
  65         int head;
  66         int tail;
  67         int startup;
  68         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  69         struct fasync_struct *fasync;
  70         struct joydev *joydev;
  71         struct list_head node;
  72 };
  73
  74 static int joydev_correct(int value, struct js_corr *corr)
  75 {
  76         switch (corr->type) {
  77
  78         case JS_CORR_NONE:
  79                 break;
  80
  81         case JS_CORR_BROKEN:
  82                 value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
  83                         ((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
  84                         ((corr->coef[2] * (value - corr->coef[0])) >> 14);
  85                 break;
  86
  87         default:
  88                 return 0;
  89         }
  90
  91         return value < -32767 ? -32767 : (value > 32767 ? 32767 : value);
  92 }
  93
  94 static void joydev_pass_event(struct joydev_client *client,
  95                               struct js_event *event)
  96 {
  97         struct joydev *joydev = client->joydev;
  98
  99         /*
 100          * IRQs already disabled, just acquire the lock
 101          */
 102         spin_lock(&client->buffer_lock);
 103
 104         client->buffer[client->head] = *event;
 105
 106         if (client->startup == joydev->nabs + joydev->nkey) {
 107                 client->head++;
 108                 client->head &= JOYDEV_BUFFER_SIZE - 1;
 109                 if (client->tail == client->head)
 110                         client->startup = 0;
 111         }
 112
 113         spin_unlock(&client->buffer_lock);
 114
 115         kill_fasync(&client->fasync, SIGIO, POLL_IN);
 116 }
 117
 118 static void joydev_event(struct input_handle *handle,
 119                          unsigned int type, unsigned int code, int value)
 120 {
 121         struct joydev *joydev = handle->private;
 122         struct joydev_client *client;
 123         struct js_event event;
 124
 125         switch (type) {
 126
 127         case EV_KEY:
 128                 if (code < BTN_MISC || value == 2)
 129                         return;
 130                 event.type = JS_EVENT_BUTTON;
 131                 event.number = joydev->keymap[code - BTN_MISC];
 132                 event.value = value;
 133                 break;
 134
 135         case EV_ABS:
 136                 event.type = JS_EVENT_AXIS;
 137                 event.number = joydev->absmap[code];
 138                 event.value = joydev_correct(value,
 139                                         &joydev->corr[event.number]);
 140                 if (event.value == joydev->abs[event.number])
 141                         return;
 142                 joydev->abs[event.number] = event.value;
 143                 break;
 144
 145         default:
 146                 return;
 147         }
 148
 149         event.time = jiffies_to_msecs(jiffies);
 150
 151         rcu_read_lock();
 152         list_for_each_entry_rcu(client, &joydev->client_list, node)
 153                 joydev_pass_event(client, &event);
 154         rcu_read_unlock();
 155
 156         wake_up_interruptible(&joydev->wait);
 157 }
 158
 159 static int joydev_fasync(int fd, struct file *file, int on)
 160 {
 161         struct joydev_client *client = file->private_data;
 162
 163         return fasync_helper(fd, file, on, &client->fasync);
 164 }
 165
 166 static void joydev_free(struct device *dev)
 167 {
 168         struct joydev *joydev = container_of(dev, struct joydev, dev);
 169
 170         input_put_device(joydev->handle.dev);
 171         kfree(joydev);
 172 }
 173
 174 static void joydev_attach_client(struct joydev *joydev,
 175                                  struct joydev_client *client)
 176 {
 177         spin_lock(&joydev->client_lock);
 178         list_add_tail_rcu(&client->node, &joydev->client_list);
 179         spin_unlock(&joydev->client_lock);
 180 }
 181
 182 static void joydev_detach_client(struct joydev *joydev,
 183                                  struct joydev_client *client)
 184 {
 185         spin_lock(&joydev->client_lock);
 186         list_del_rcu(&client->node);
 187         spin_unlock(&joydev->client_lock);
 188         synchronize_rcu();
 189 }
 190
 191 static int joydev_open_device(struct joydev *joydev)
 192 {
 193         int retval;
 194
 195         retval = mutex_lock_interruptible(&joydev->mutex);
 196         if (retval)
 197                 return retval;
 198
 199         if (!joydev->exist)
 200                 retval = -ENODEV;
 201         else if (!joydev->open++) {
 202                 retval = input_open_device(&joydev->handle);
 203                 if (retval)
 204                         joydev->open--;
 205         }
 206
 207         mutex_unlock(&joydev->mutex);
 208         return retval;
 209 }
 210
 211 static void joydev_close_device(struct joydev *joydev)
 212 {
 213         mutex_lock(&joydev->mutex);
 214
 215         if (joydev->exist && !--joydev->open)
 216                 input_close_device(&joydev->handle);
 217
 218         mutex_unlock(&joydev->mutex);
 219 }
 220
 221 /*
 222  * Wake up users waiting for IO so they can disconnect from
 223  * dead device.
 224  */
 225 static void joydev_hangup(struct joydev *joydev)
 226 {
 227         struct joydev_client *client;
 228
 229         spin_lock(&joydev->client_lock);
 230         list_for_each_entry(client, &joydev->client_list, node)
 231                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 232         spin_unlock(&joydev->client_lock);
 233
 234         wake_up_interruptible(&joydev->wait);
 235 }
 236
 237 static int joydev_release(struct inode *inode, struct file *file)
 238 {
 239         struct joydev_client *client = file->private_data;
 240         struct joydev *joydev = client->joydev;
 241
 242         joydev_detach_client(joydev, client);
 243         kfree(client);
 244
 245         joydev_close_device(joydev);
 246         put_device(&joydev->dev);
 247
 248         return 0;
 249 }
 250
 251 static int joydev_open(struct inode *inode, struct file *file)
 252 {
 253         struct joydev *joydev =
 254                         container_of(inode->i_cdev, struct joydev, cdev);
 255         struct joydev_client *client;
 256         int error;
 257
 258         client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
 259         if (!client)
 260                 return -ENOMEM;
 261
 262         spin_lock_init(&client->buffer_lock);
 263         client->joydev = joydev;
 264         joydev_attach_client(joydev, client);
 265
 266         error = joydev_open_device(joydev);
 267         if (error)
 268                 goto err_free_client;
 269
 270         file->private_data = client;
 271         nonseekable_open(inode, file);
 272
 273         get_device(&joydev->dev);
 274         return 0;
 275
 276  err_free_client:
 277         joydev_detach_client(joydev, client);
 278         kfree(client);
 279         return error;
 280 }
 281
 282 static int joydev_generate_startup_event(struct joydev_client *client,
 283                                          struct input_dev *input,
 284                                          struct js_event *event)
 285 {
 286         struct joydev *joydev = client->joydev;
 287         int have_event;
 288
 289         spin_lock_irq(&client->buffer_lock);
 290
 291         have_event = client->startup < joydev->nabs + joydev->nkey;
 292
 293         if (have_event) {
 294
 295                 event->time = jiffies_to_msecs(jiffies);
 296                 if (client->startup < joydev->nkey) {
 297                         event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 298                         event->number = client->startup;
 299                         event->value = !!test_bit(joydev->keypam[event->number],
 300                                                   input->key);
 301                 } else {
 302                         event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
 303                         event->number = client->startup - joydev->nkey;
 304                         event->value = joydev->abs[event->number];
 305                 }
 306                 client->startup++;
 307         }
 308
 309         spin_unlock_irq(&client->buffer_lock);
 310
 311         return have_event;
 312 }
 313
 314 static int joydev_fetch_next_event(struct joydev_client *client,
 315                                    struct js_event *event)
 316 {
 317         int have_event;
 318
 319         spin_lock_irq(&client->buffer_lock);
 320
 321         have_event = client->head != client->tail;
 322         if (have_event) {
 323                 *event = client->buffer[client->tail++];
 324                 client->tail &= JOYDEV_BUFFER_SIZE - 1;
 325         }
 326
 327         spin_unlock_irq(&client->buffer_lock);
 328
 329         return have_event;
 330 }
 331
 332 /*
 333  * Old joystick interface
 334  */
 335 static ssize_t joydev_0x_read(struct joydev_client *client,
 336                               struct input_dev *input,
 337                               char __user *buf)
 338 {
 339         struct joydev *joydev = client->joydev;
 340         struct JS_DATA_TYPE data;
 341         int i;
 342
 343         spin_lock_irq(&input->event_lock);
 344
 345         /*
 346          * Get device state
 347          */
 348         for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 349                 data.buttons |=
 350                         test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 351         data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 352         data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
 353
 354         /*
 355          * Reset reader's event queue
 356          */
 357         spin_lock(&client->buffer_lock);
 358         client->startup = 0;
 359         client->tail = client->head;
 360         spin_unlock(&client->buffer_lock);
 361
 362         spin_unlock_irq(&input->event_lock);
 363
 364         if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 365                 return -EFAULT;
 366
 367         return sizeof(struct JS_DATA_TYPE);
 368 }
 369
 370 static inline int joydev_data_pending(struct joydev_client *client)
 371 {
 372         struct joydev *joydev = client->joydev;
 373
 374         return client->startup < joydev->nabs + joydev->nkey ||
 375                 client->head != client->tail;
 376 }
 377
 378 static ssize_t joydev_read(struct file *file, char __user *buf,
 379                            size_t count, loff_t *ppos)
 380 {
 381         struct joydev_client *client = file->private_data;
 382         struct joydev *joydev = client->joydev;
 383         struct input_dev *input = joydev->handle.dev;
 384         struct js_event event;
 385         int retval;
 386
 387         if (!joydev->exist)
 388                 return -ENODEV;
 389
 390         if (count < sizeof(struct js_event))
 391                 return -EINVAL;
 392
 393         if (count == sizeof(struct JS_DATA_TYPE))
 394                 return joydev_0x_read(client, input, buf);
 395
 396         if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
 397                 return -EAGAIN;
 398
 399         retval = wait_event_interruptible(joydev->wait,
 400                         !joydev->exist || joydev_data_pending(client));
 401         if (retval)
 402                 return retval;
 403
 404         if (!joydev->exist)
 405                 return -ENODEV;
 406
 407         while (retval + sizeof(struct js_event) <= count &&
 408                joydev_generate_startup_event(client, input, &event)) {
 409
 410                 if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 411                         return -EFAULT;
 412
 413                 retval += sizeof(struct js_event);
 414         }
 415
 416         while (retval + sizeof(struct js_event) <= count &&
 417                joydev_fetch_next_event(client, &event)) {
 418
 419                 if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 420                         return -EFAULT;
 421
 422                 retval += sizeof(struct js_event);
 423         }
 424
 425         return retval;
 426 }
 427
 428 /* No kernel lock - fine */
 429 static unsigned int joydev_poll(struct file *file, poll_table *wait)
 430 {
 431         struct joydev_client *client = file->private_data;
 432         struct joydev *joydev = client->joydev;
 433
 434         poll_wait(file, &joydev->wait, wait);
 435         return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
 436                 (joydev->exist ?  0 : (POLLHUP | POLLERR));
 437 }
 438
 439 static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
 440                                      void __user *argp, size_t len)
 441 {
 442         __u8 *abspam;
 443         int i;
 444         int retval = 0;
 445
 446         len = min(len, sizeof(joydev->abspam));
 447
 448         /* Validate the map. */
 449         abspam = kmalloc(len, GFP_KERNEL);
 450         if (!abspam)
 451                 return -ENOMEM;
 452
 453         if (copy_from_user(abspam, argp, len)) {
 454                 retval = -EFAULT;
 455                 goto out;
 456         }
 457
 458         for (i = 0; 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         len = min(len, sizeof(joydev->keypam));
 483
 484         /* Validate the map. */
 485         keypam = kmalloc(len, GFP_KERNEL);
 486         if (!keypam)
 487                 return -ENOMEM;
 488
 489         if (copy_from_user(keypam, argp, len)) {
 490                 retval = -EFAULT;
 491                 goto out;
 492         }
 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
 753 static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
 754 {
 755         /* Avoid touchpads and touchscreens */
 756         if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_TOUCH, dev->keybit))
 757                 return false;
 758
 759         /* Avoid tablets, digitisers and similar devices */
 760         if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
 761                 return false;
 762
 763         return true;
 764 }
 765
 766 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 767                           const struct input_device_id *id)
 768 {
 769         struct joydev *joydev;
 770         int i, j, t, minor, dev_no;
 771         int error;
 772
 773         minor = input_get_new_minor(JOYDEV_MINOR_BASE, JOYDEV_MINORS, true);
 774         if (minor < 0) {
 775                 error = minor;
 776                 pr_err("failed to reserve new minor: %d\n", error);
 777                 return error;
 778         }
 779
 780         joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
 781         if (!joydev) {
 782                 error = -ENOMEM;
 783                 goto err_free_minor;
 784         }
 785
 786         INIT_LIST_HEAD(&joydev->client_list);
 787         spin_lock_init(&joydev->client_lock);
 788         mutex_init(&joydev->mutex);
 789         init_waitqueue_head(&joydev->wait);
 790         joydev->exist = true;
 791
 792         dev_no = minor;
 793         /* Normalize device number if it falls into legacy range */
 794         if (dev_no < JOYDEV_MINOR_BASE + JOYDEV_MINORS)
 795                 dev_no -= JOYDEV_MINOR_BASE;
 796         dev_set_name(&joydev->dev, "js%d", dev_no);
 797
 798         joydev->handle.dev = input_get_device(dev);
 799         joydev->handle.name = dev_name(&joydev->dev);
 800         joydev->handle.handler = handler;
 801         joydev->handle.private = joydev;
 802
 803         for (i = 0; i < ABS_CNT; i++)
 804                 if (test_bit(i, dev->absbit)) {
 805                         joydev->absmap[i] = joydev->nabs;
 806                         joydev->abspam[joydev->nabs] = i;
 807                         joydev->nabs++;
 808                 }
 809
 810         for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 811                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 812                         joydev->keymap[i] = joydev->nkey;
 813                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 814                         joydev->nkey++;
 815                 }
 816
 817         for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 818                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 819                         joydev->keymap[i] = joydev->nkey;
 820                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 821                         joydev->nkey++;
 822                 }
 823
 824         for (i = 0; i < joydev->nabs; i++) {
 825                 j = joydev->abspam[i];
 826                 if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
 827                         joydev->corr[i].type = JS_CORR_NONE;
 828                         joydev->abs[i] = input_abs_get_val(dev, j);
 829                         continue;
 830                 }
 831                 joydev->corr[i].type = JS_CORR_BROKEN;
 832                 joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
 833
 834                 t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
 835                 joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
 836                 joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
 837
 838                 t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
 839                         - 2 * input_abs_get_flat(dev, j);
 840                 if (t) {
 841                         joydev->corr[i].coef[2] = (1 << 29) / t;
 842                         joydev->corr[i].coef[3] = (1 << 29) / t;
 843
 844                         joydev->abs[i] =
 845                                 joydev_correct(input_abs_get_val(dev, j),
 846                                                joydev->corr + i);
 847                 }
 848         }
 849
 850         joydev->dev.devt = MKDEV(INPUT_MAJOR, minor);
 851         joydev->dev.class = &input_class;
 852         joydev->dev.parent = &dev->dev;
 853         joydev->dev.release = joydev_free;
 854         device_initialize(&joydev->dev);
 855
 856         error = input_register_handle(&joydev->handle);
 857         if (error)
 858                 goto err_free_joydev;
 859
 860         cdev_init(&joydev->cdev, &joydev_fops);
 861         error = cdev_add(&joydev->cdev, joydev->dev.devt, 1);
 862         if (error)
 863                 goto err_unregister_handle;
 864
 865         error = device_add(&joydev->dev);
 866         if (error)
 867                 goto err_cleanup_joydev;
 868
 869         return 0;
 870
 871  err_cleanup_joydev:
 872         joydev_cleanup(joydev);
 873  err_unregister_handle:
 874         input_unregister_handle(&joydev->handle);
 875  err_free_joydev:
 876         put_device(&joydev->dev);
 877  err_free_minor:
 878         input_free_minor(minor);
 879         return error;
 880 }
 881
 882 static void joydev_disconnect(struct input_handle *handle)
 883 {
 884         struct joydev *joydev = handle->private;
 885
 886         device_del(&joydev->dev);
 887         joydev_cleanup(joydev);
 888         input_free_minor(MINOR(joydev->dev.devt));
 889         input_unregister_handle(handle);
 890         put_device(&joydev->dev);
 891 }
 892
 893 static const struct input_device_id joydev_ids[] = {
 894         {
 895                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 896                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 897                 .evbit = { BIT_MASK(EV_ABS) },
 898                 .absbit = { BIT_MASK(ABS_X) },
 899         },
 900         {
 901                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 902                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 903                 .evbit = { BIT_MASK(EV_ABS) },
 904                 .absbit = { BIT_MASK(ABS_WHEEL) },
 905         },
 906         {
 907                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 908                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 909                 .evbit = { BIT_MASK(EV_ABS) },
 910                 .absbit = { BIT_MASK(ABS_THROTTLE) },
 911         },
 912         {
 913                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 914                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 915                 .evbit = { BIT_MASK(EV_KEY) },
 916                 .keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
 917         },
 918         {
 919                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 920                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 921                 .evbit = { BIT_MASK(EV_KEY) },
 922                 .keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
 923         },
 924         {
 925                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 926                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 927                 .evbit = { BIT_MASK(EV_KEY) },
 928                 .keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
 929         },
 930         { }     /* Terminating entry */
 931 };
 932
 933 MODULE_DEVICE_TABLE(input, joydev_ids);
 934
 935 static struct input_handler joydev_handler = {
 936         .event          = joydev_event,
 937         .match          = joydev_match,
 938         .connect        = joydev_connect,
 939         .disconnect     = joydev_disconnect,
 940         .legacy_minors  = true,
 941         .minor          = JOYDEV_MINOR_BASE,
 942         .name           = "joydev",
 943         .id_table       = joydev_ids,
 944 };
 945
 946 static int __init joydev_init(void)
 947 {
 948         return input_register_handler(&joydev_handler);
 949 }
 950
 951 static void __exit joydev_exit(void)
 952 {
 953         input_unregister_handler(&joydev_handler);
 954 }
 955
 956 module_init(joydev_init);
 957 module_exit(joydev_exit);