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 #include <asm/io.h>
  14 #include <asm/system.h>
  15 #include <linux/delay.h>
  16 #include <linux/errno.h>
  17 #include <linux/joystick.h>
  18 #include <linux/input.h>
  19 #include <linux/kernel.h>
  20 #include <linux/major.h>
  21 #include <linux/slab.h>
  22 #include <linux/mm.h>
  23 #include <linux/miscdevice.h>
  24 #include <linux/module.h>
  25 #include <linux/poll.h>
  26 #include <linux/init.h>
  27 #include <linux/device.h>
  28
  29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  30 MODULE_DESCRIPTION("Joystick device interfaces");
  31 MODULE_SUPPORTED_DEVICE("input/js");
  32 MODULE_LICENSE("GPL");
  33
  34 #define JOYDEV_MINOR_BASE       0
  35 #define JOYDEV_MINORS           16
  36 #define JOYDEV_BUFFER_SIZE      64
  37
  38 struct joydev {
  39         int exist;
  40         int open;
  41         int minor;
  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
  49         struct js_corr corr[ABS_MAX + 1];
  50         struct JS_DATA_SAVE_TYPE glue;
  51         int nabs;
  52         int nkey;
  53         __u16 keymap[KEY_MAX - BTN_MISC + 1];
  54         __u16 keypam[KEY_MAX - BTN_MISC + 1];
  55         __u8 absmap[ABS_MAX + 1];
  56         __u8 abspam[ABS_MAX + 1];
  57         __s16 abs[ABS_MAX + 1];
  58 };
  59
  60 struct joydev_client {
  61         struct js_event buffer[JOYDEV_BUFFER_SIZE];
  62         int head;
  63         int tail;
  64         int startup;
  65         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  66         struct fasync_struct *fasync;
  67         struct joydev *joydev;
  68         struct list_head node;
  69 };
  70
  71 static struct joydev *joydev_table[JOYDEV_MINORS];
  72 static DEFINE_MUTEX(joydev_table_mutex);
  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         synchronize_rcu();
 181 }
 182
 183 static void joydev_detach_client(struct joydev *joydev,
 184                                  struct joydev_client *client)
 185 {
 186         spin_lock(&joydev->client_lock);
 187         list_del_rcu(&client->node);
 188         spin_unlock(&joydev->client_lock);
 189         synchronize_rcu();
 190 }
 191
 192 static int joydev_open_device(struct joydev *joydev)
 193 {
 194         int retval;
 195
 196         retval = mutex_lock_interruptible(&joydev->mutex);
 197         if (retval)
 198                 return retval;
 199
 200         if (!joydev->exist)
 201                 retval = -ENODEV;
 202         else if (!joydev->open++) {
 203                 retval = input_open_device(&joydev->handle);
 204                 if (retval)
 205                         joydev->open--;
 206         }
 207
 208         mutex_unlock(&joydev->mutex);
 209         return retval;
 210 }
 211
 212 static void joydev_close_device(struct joydev *joydev)
 213 {
 214         mutex_lock(&joydev->mutex);
 215
 216         if (joydev->exist && !--joydev->open)
 217                 input_close_device(&joydev->handle);
 218
 219         mutex_unlock(&joydev->mutex);
 220 }
 221
 222 /*
 223  * Wake up users waiting for IO so they can disconnect from
 224  * dead device.
 225  */
 226 static void joydev_hangup(struct joydev *joydev)
 227 {
 228         struct joydev_client *client;
 229
 230         spin_lock(&joydev->client_lock);
 231         list_for_each_entry(client, &joydev->client_list, node)
 232                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 233         spin_unlock(&joydev->client_lock);
 234
 235         wake_up_interruptible(&joydev->wait);
 236 }
 237
 238 static int joydev_release(struct inode *inode, struct file *file)
 239 {
 240         struct joydev_client *client = file->private_data;
 241         struct joydev *joydev = client->joydev;
 242
 243         joydev_detach_client(joydev, client);
 244         kfree(client);
 245
 246         joydev_close_device(joydev);
 247         put_device(&joydev->dev);
 248
 249         return 0;
 250 }
 251
 252 static int joydev_open(struct inode *inode, struct file *file)
 253 {
 254         struct joydev_client *client;
 255         struct joydev *joydev;
 256         int i = iminor(inode) - JOYDEV_MINOR_BASE;
 257         int error;
 258
 259         if (i >= JOYDEV_MINORS)
 260                 return -ENODEV;
 261
 262         error = mutex_lock_interruptible(&joydev_table_mutex);
 263         if (error)
 264                 return error;
 265         joydev = joydev_table[i];
 266         if (joydev)
 267                 get_device(&joydev->dev);
 268         mutex_unlock(&joydev_table_mutex);
 269
 270         if (!joydev)
 271                 return -ENODEV;
 272
 273         client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
 274         if (!client) {
 275                 error = -ENOMEM;
 276                 goto err_put_joydev;
 277         }
 278
 279         spin_lock_init(&client->buffer_lock);
 280         client->joydev = joydev;
 281         joydev_attach_client(joydev, client);
 282
 283         error = joydev_open_device(joydev);
 284         if (error)
 285                 goto err_free_client;
 286
 287         file->private_data = client;
 288         return 0;
 289
 290  err_free_client:
 291         joydev_detach_client(joydev, client);
 292         kfree(client);
 293  err_put_joydev:
 294         put_device(&joydev->dev);
 295         return error;
 296 }
 297
 298 static int joydev_generate_startup_event(struct joydev_client *client,
 299                                          struct input_dev *input,
 300                                          struct js_event *event)
 301 {
 302         struct joydev *joydev = client->joydev;
 303         int have_event;
 304
 305         spin_lock_irq(&client->buffer_lock);
 306
 307         have_event = client->startup < joydev->nabs + joydev->nkey;
 308
 309         if (have_event) {
 310
 311                 event->time = jiffies_to_msecs(jiffies);
 312                 if (client->startup < joydev->nkey) {
 313                         event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 314                         event->number = client->startup;
 315                         event->value = !!test_bit(joydev->keypam[event->number],
 316                                                   input->key);
 317                 } else {
 318                         event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
 319                         event->number = client->startup - joydev->nkey;
 320                         event->value = joydev->abs[event->number];
 321                 }
 322                 client->startup++;
 323         }
 324
 325         spin_unlock_irq(&client->buffer_lock);
 326
 327         return have_event;
 328 }
 329
 330 static int joydev_fetch_next_event(struct joydev_client *client,
 331                                    struct js_event *event)
 332 {
 333         int have_event;
 334
 335         spin_lock_irq(&client->buffer_lock);
 336
 337         have_event = client->head != client->tail;
 338         if (have_event) {
 339                 *event = client->buffer[client->tail++];
 340                 client->tail &= JOYDEV_BUFFER_SIZE - 1;
 341         }
 342
 343         spin_unlock_irq(&client->buffer_lock);
 344
 345         return have_event;
 346 }
 347
 348 /*
 349  * Old joystick interface
 350  */
 351 static ssize_t joydev_0x_read(struct joydev_client *client,
 352                               struct input_dev *input,
 353                               char __user *buf)
 354 {
 355         struct joydev *joydev = client->joydev;
 356         struct JS_DATA_TYPE data;
 357         int i;
 358
 359         spin_lock_irq(&input->event_lock);
 360
 361         /*
 362          * Get device state
 363          */
 364         for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 365                 data.buttons |=
 366                         test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 367         data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 368         data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
 369
 370         /*
 371          * Reset reader's event queue
 372          */
 373         spin_lock(&client->buffer_lock);
 374         client->startup = 0;
 375         client->tail = client->head;
 376         spin_unlock(&client->buffer_lock);
 377
 378         spin_unlock_irq(&input->event_lock);
 379
 380         if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 381                 return -EFAULT;
 382
 383         return sizeof(struct JS_DATA_TYPE);
 384 }
 385
 386 static inline int joydev_data_pending(struct joydev_client *client)
 387 {
 388         struct joydev *joydev = client->joydev;
 389
 390         return client->startup < joydev->nabs + joydev->nkey ||
 391                 client->head != client->tail;
 392 }
 393
 394 static ssize_t joydev_read(struct file *file, char __user *buf,
 395                            size_t count, loff_t *ppos)
 396 {
 397         struct joydev_client *client = file->private_data;
 398         struct joydev *joydev = client->joydev;
 399         struct input_dev *input = joydev->handle.dev;
 400         struct js_event event;
 401         int retval;
 402
 403         if (!joydev->exist)
 404                 return -ENODEV;
 405
 406         if (count < sizeof(struct js_event))
 407                 return -EINVAL;
 408
 409         if (count == sizeof(struct JS_DATA_TYPE))
 410                 return joydev_0x_read(client, input, buf);
 411
 412         if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
 413                 return -EAGAIN;
 414
 415         retval = wait_event_interruptible(joydev->wait,
 416                         !joydev->exist || joydev_data_pending(client));
 417         if (retval)
 418                 return retval;
 419
 420         if (!joydev->exist)
 421                 return -ENODEV;
 422
 423         while (retval + sizeof(struct js_event) <= count &&
 424                joydev_generate_startup_event(client, input, &event)) {
 425
 426                 if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 427                         return -EFAULT;
 428
 429                 retval += sizeof(struct js_event);
 430         }
 431
 432         while (retval + sizeof(struct js_event) <= count &&
 433                joydev_fetch_next_event(client, &event)) {
 434
 435                 if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 436                         return -EFAULT;
 437
 438                 retval += sizeof(struct js_event);
 439         }
 440
 441         return retval;
 442 }
 443
 444 /* No kernel lock - fine */
 445 static unsigned int joydev_poll(struct file *file, poll_table *wait)
 446 {
 447         struct joydev_client *client = file->private_data;
 448         struct joydev *joydev = client->joydev;
 449
 450         poll_wait(file, &joydev->wait, wait);
 451         return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
 452                 (joydev->exist ?  0 : (POLLHUP | POLLERR));
 453 }
 454
 455 static int joydev_ioctl_common(struct joydev *joydev,
 456                                 unsigned int cmd, void __user *argp)
 457 {
 458         struct input_dev *dev = joydev->handle.dev;
 459         size_t len;
 460         int i, j;
 461         const char *name;
 462
 463         /* Process fixed-sized commands. */
 464         switch (cmd) {
 465
 466         case JS_SET_CAL:
 467                 return copy_from_user(&joydev->glue.JS_CORR, argp,
 468                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 469
 470         case JS_GET_CAL:
 471                 return copy_to_user(argp, &joydev->glue.JS_CORR,
 472                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 473
 474         case JS_SET_TIMEOUT:
 475                 return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 476
 477         case JS_GET_TIMEOUT:
 478                 return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 479
 480         case JSIOCGVERSION:
 481                 return put_user(JS_VERSION, (__u32 __user *) argp);
 482
 483         case JSIOCGAXES:
 484                 return put_user(joydev->nabs, (__u8 __user *) argp);
 485
 486         case JSIOCGBUTTONS:
 487                 return put_user(joydev->nkey, (__u8 __user *) argp);
 488
 489         case JSIOCSCORR:
 490                 if (copy_from_user(joydev->corr, argp,
 491                               sizeof(joydev->corr[0]) * joydev->nabs))
 492                     return -EFAULT;
 493
 494                 for (i = 0; i < joydev->nabs; i++) {
 495                         j = joydev->abspam[i];
 496                         joydev->abs[i] = joydev_correct(dev->abs[j],
 497                                                         &joydev->corr[i]);
 498                 }
 499                 return 0;
 500
 501         case JSIOCGCORR:
 502                 return copy_to_user(argp, joydev->corr,
 503                         sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
 504
 505         }
 506
 507         /*
 508          * Process variable-sized commands (the axis and button map commands
 509          * are considered variable-sized to decouple them from the values of
 510          * ABS_MAX and KEY_MAX).
 511          */
 512         switch (cmd & ~IOCSIZE_MASK) {
 513
 514         case (JSIOCSAXMAP & ~IOCSIZE_MASK):
 515                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
 516                 /*
 517                  * FIXME: we should not copy into our axis map before
 518                  * validating the data.
 519                  */
 520                 if (copy_from_user(joydev->abspam, argp, len))
 521                         return -EFAULT;
 522
 523                 for (i = 0; i < joydev->nabs; i++) {
 524                         if (joydev->abspam[i] > ABS_MAX)
 525                                 return -EINVAL;
 526                         joydev->absmap[joydev->abspam[i]] = i;
 527                 }
 528                 return 0;
 529
 530         case (JSIOCGAXMAP & ~IOCSIZE_MASK):
 531                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
 532                 return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : 0;
 533
 534         case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
 535                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
 536                 /*
 537                  * FIXME: we should not copy into our keymap before
 538                  * validating the data.
 539                  */
 540                 if (copy_from_user(joydev->keypam, argp, len))
 541                         return -EFAULT;
 542
 543                 for (i = 0; i < joydev->nkey; i++) {
 544                         if (joydev->keypam[i] > KEY_MAX ||
 545                             joydev->keypam[i] < BTN_MISC)
 546                                 return -EINVAL;
 547                         joydev->keymap[joydev->keypam[i] - BTN_MISC] = i;
 548                 }
 549
 550                 return 0;
 551
 552         case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
 553                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
 554                 return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : 0;
 555
 556         case JSIOCGNAME(0):
 557                 name = dev->name;
 558                 if (!name)
 559                         return 0;
 560
 561                 len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
 562                 return copy_to_user(argp, name, len) ? -EFAULT : len;
 563         }
 564
 565         return -EINVAL;
 566 }
 567
 568 #ifdef CONFIG_COMPAT
 569 static long joydev_compat_ioctl(struct file *file,
 570                                 unsigned int cmd, unsigned long arg)
 571 {
 572         struct joydev_client *client = file->private_data;
 573         struct joydev *joydev = client->joydev;
 574         void __user *argp = (void __user *)arg;
 575         s32 tmp32;
 576         struct JS_DATA_SAVE_TYPE_32 ds32;
 577         int retval;
 578
 579         retval = mutex_lock_interruptible(&joydev->mutex);
 580         if (retval)
 581                 return retval;
 582
 583         if (!joydev->exist) {
 584                 retval = -ENODEV;
 585                 goto out;
 586         }
 587
 588         switch (cmd) {
 589
 590         case JS_SET_TIMELIMIT:
 591                 retval = get_user(tmp32, (s32 __user *) arg);
 592                 if (retval == 0)
 593                         joydev->glue.JS_TIMELIMIT = tmp32;
 594                 break;
 595
 596         case JS_GET_TIMELIMIT:
 597                 tmp32 = joydev->glue.JS_TIMELIMIT;
 598                 retval = put_user(tmp32, (s32 __user *) arg);
 599                 break;
 600
 601         case JS_SET_ALL:
 602                 retval = copy_from_user(&ds32, argp,
 603                                         sizeof(ds32)) ? -EFAULT : 0;
 604                 if (retval == 0) {
 605                         joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
 606                         joydev->glue.BUSY          = ds32.BUSY;
 607                         joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
 608                         joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
 609                         joydev->glue.JS_SAVE       = ds32.JS_SAVE;
 610                         joydev->glue.JS_CORR       = ds32.JS_CORR;
 611                 }
 612                 break;
 613
 614         case JS_GET_ALL:
 615                 ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
 616                 ds32.BUSY          = joydev->glue.BUSY;
 617                 ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
 618                 ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
 619                 ds32.JS_SAVE       = joydev->glue.JS_SAVE;
 620                 ds32.JS_CORR       = joydev->glue.JS_CORR;
 621
 622                 retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
 623                 break;
 624
 625         default:
 626                 retval = joydev_ioctl_common(joydev, cmd, argp);
 627                 break;
 628         }
 629
 630  out:
 631         mutex_unlock(&joydev->mutex);
 632         return retval;
 633 }
 634 #endif /* CONFIG_COMPAT */
 635
 636 static long joydev_ioctl(struct file *file,
 637                          unsigned int cmd, unsigned long arg)
 638 {
 639         struct joydev_client *client = file->private_data;
 640         struct joydev *joydev = client->joydev;
 641         void __user *argp = (void __user *)arg;
 642         int retval;
 643
 644         retval = mutex_lock_interruptible(&joydev->mutex);
 645         if (retval)
 646                 return retval;
 647
 648         if (!joydev->exist) {
 649                 retval = -ENODEV;
 650                 goto out;
 651         }
 652
 653         switch (cmd) {
 654
 655         case JS_SET_TIMELIMIT:
 656                 retval = get_user(joydev->glue.JS_TIMELIMIT,
 657                                   (long __user *) arg);
 658                 break;
 659
 660         case JS_GET_TIMELIMIT:
 661                 retval = put_user(joydev->glue.JS_TIMELIMIT,
 662                                   (long __user *) arg);
 663                 break;
 664
 665         case JS_SET_ALL:
 666                 retval = copy_from_user(&joydev->glue, argp,
 667                                         sizeof(joydev->glue)) ? -EFAULT: 0;
 668                 break;
 669
 670         case JS_GET_ALL:
 671                 retval = copy_to_user(argp, &joydev->glue,
 672                                       sizeof(joydev->glue)) ? -EFAULT : 0;
 673                 break;
 674
 675         default:
 676                 retval = joydev_ioctl_common(joydev, cmd, argp);
 677                 break;
 678         }
 679  out:
 680         mutex_unlock(&joydev->mutex);
 681         return retval;
 682 }
 683
 684 static const struct file_operations joydev_fops = {
 685         .owner          = THIS_MODULE,
 686         .read           = joydev_read,
 687         .poll           = joydev_poll,
 688         .open           = joydev_open,
 689         .release        = joydev_release,
 690         .unlocked_ioctl = joydev_ioctl,
 691 #ifdef CONFIG_COMPAT
 692         .compat_ioctl   = joydev_compat_ioctl,
 693 #endif
 694         .fasync         = joydev_fasync,
 695 };
 696
 697 static int joydev_install_chrdev(struct joydev *joydev)
 698 {
 699         joydev_table[joydev->minor] = joydev;
 700         return 0;
 701 }
 702
 703 static void joydev_remove_chrdev(struct joydev *joydev)
 704 {
 705         mutex_lock(&joydev_table_mutex);
 706         joydev_table[joydev->minor] = NULL;
 707         mutex_unlock(&joydev_table_mutex);
 708 }
 709
 710 /*
 711  * Mark device non-existant. This disables writes, ioctls and
 712  * prevents new users from opening the device. Already posted
 713  * blocking reads will stay, however new ones will fail.
 714  */
 715 static void joydev_mark_dead(struct joydev *joydev)
 716 {
 717         mutex_lock(&joydev->mutex);
 718         joydev->exist = 0;
 719         mutex_unlock(&joydev->mutex);
 720 }
 721
 722 static void joydev_cleanup(struct joydev *joydev)
 723 {
 724         struct input_handle *handle = &joydev->handle;
 725
 726         joydev_mark_dead(joydev);
 727         joydev_hangup(joydev);
 728         joydev_remove_chrdev(joydev);
 729
 730         /* joydev is marked dead so noone else accesses joydev->open */
 731         if (joydev->open)
 732                 input_close_device(handle);
 733 }
 734
 735 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 736                           const struct input_device_id *id)
 737 {
 738         struct joydev *joydev;
 739         int i, j, t, minor;
 740         int error;
 741
 742         for (minor = 0; minor < JOYDEV_MINORS; minor++)
 743                 if (!joydev_table[minor])
 744                         break;
 745
 746         if (minor == JOYDEV_MINORS) {
 747                 printk(KERN_ERR "joydev: no more free joydev devices\n");
 748                 return -ENFILE;
 749         }
 750
 751         joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
 752         if (!joydev)
 753                 return -ENOMEM;
 754
 755         INIT_LIST_HEAD(&joydev->client_list);
 756         spin_lock_init(&joydev->client_lock);
 757         mutex_init(&joydev->mutex);
 758         init_waitqueue_head(&joydev->wait);
 759
 760         dev_set_name(&joydev->dev, "js%d", minor);
 761         joydev->exist = 1;
 762         joydev->minor = minor;
 763
 764         joydev->exist = 1;
 765         joydev->handle.dev = input_get_device(dev);
 766         joydev->handle.name = dev_name(&joydev->dev);
 767         joydev->handle.handler = handler;
 768         joydev->handle.private = joydev;
 769
 770         for (i = 0; i < ABS_MAX + 1; i++)
 771                 if (test_bit(i, dev->absbit)) {
 772                         joydev->absmap[i] = joydev->nabs;
 773                         joydev->abspam[joydev->nabs] = i;
 774                         joydev->nabs++;
 775                 }
 776
 777         for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 778                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 779                         joydev->keymap[i] = joydev->nkey;
 780                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 781                         joydev->nkey++;
 782                 }
 783
 784         for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 785                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 786                         joydev->keymap[i] = joydev->nkey;
 787                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 788                         joydev->nkey++;
 789                 }
 790
 791         for (i = 0; i < joydev->nabs; i++) {
 792                 j = joydev->abspam[i];
 793                 if (dev->absmax[j] == dev->absmin[j]) {
 794                         joydev->corr[i].type = JS_CORR_NONE;
 795                         joydev->abs[i] = dev->abs[j];
 796                         continue;
 797                 }
 798                 joydev->corr[i].type = JS_CORR_BROKEN;
 799                 joydev->corr[i].prec = dev->absfuzz[j];
 800                 joydev->corr[i].coef[0] =
 801                         (dev->absmax[j] + dev->absmin[j]) / 2 - dev->absflat[j];
 802                 joydev->corr[i].coef[1] =
 803                         (dev->absmax[j] + dev->absmin[j]) / 2 + dev->absflat[j];
 804
 805                 t = (dev->absmax[j] - dev->absmin[j]) / 2 - 2 * dev->absflat[j];
 806                 if (t) {
 807                         joydev->corr[i].coef[2] = (1 << 29) / t;
 808                         joydev->corr[i].coef[3] = (1 << 29) / t;
 809
 810                         joydev->abs[i] = joydev_correct(dev->abs[j],
 811                                                         joydev->corr + i);
 812                 }
 813         }
 814
 815         joydev->dev.devt = MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor);
 816         joydev->dev.class = &input_class;
 817         joydev->dev.parent = &dev->dev;
 818         joydev->dev.release = joydev_free;
 819         device_initialize(&joydev->dev);
 820
 821         error = input_register_handle(&joydev->handle);
 822         if (error)
 823                 goto err_free_joydev;
 824
 825         error = joydev_install_chrdev(joydev);
 826         if (error)
 827                 goto err_unregister_handle;
 828
 829         error = device_add(&joydev->dev);
 830         if (error)
 831                 goto err_cleanup_joydev;
 832
 833         return 0;
 834
 835  err_cleanup_joydev:
 836         joydev_cleanup(joydev);
 837  err_unregister_handle:
 838         input_unregister_handle(&joydev->handle);
 839  err_free_joydev:
 840         put_device(&joydev->dev);
 841         return error;
 842 }
 843
 844 static void joydev_disconnect(struct input_handle *handle)
 845 {
 846         struct joydev *joydev = handle->private;
 847
 848         device_del(&joydev->dev);
 849         joydev_cleanup(joydev);
 850         input_unregister_handle(handle);
 851         put_device(&joydev->dev);
 852 }
 853
 854 static const struct input_device_id joydev_blacklist[] = {
 855         {
 856                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 857                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 858                 .evbit = { BIT_MASK(EV_KEY) },
 859                 .keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
 860         },      /* Avoid itouchpads and touchscreens */
 861         {
 862                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 863                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 864                 .evbit = { BIT_MASK(EV_KEY) },
 865                 .keybit = { [BIT_WORD(BTN_DIGI)] = BIT_MASK(BTN_DIGI) },
 866         },      /* Avoid tablets, digitisers and similar devices */
 867         { }     /* Terminating entry */
 868 };
 869
 870 static const struct input_device_id joydev_ids[] = {
 871         {
 872                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 873                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 874                 .evbit = { BIT_MASK(EV_ABS) },
 875                 .absbit = { BIT_MASK(ABS_X) },
 876         },
 877         {
 878                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 879                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 880                 .evbit = { BIT_MASK(EV_ABS) },
 881                 .absbit = { BIT_MASK(ABS_WHEEL) },
 882         },
 883         {
 884                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 885                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 886                 .evbit = { BIT_MASK(EV_ABS) },
 887                 .absbit = { BIT_MASK(ABS_THROTTLE) },
 888         },
 889         { }     /* Terminating entry */
 890 };
 891
 892 MODULE_DEVICE_TABLE(input, joydev_ids);
 893
 894 static struct input_handler joydev_handler = {
 895         .event          = joydev_event,
 896         .connect        = joydev_connect,
 897         .disconnect     = joydev_disconnect,
 898         .fops           = &joydev_fops,
 899         .minor          = JOYDEV_MINOR_BASE,
 900         .name           = "joydev",
 901         .id_table       = joydev_ids,
 902         .blacklist      = joydev_blacklist,
 903 };
 904
 905 static int __init joydev_init(void)
 906 {
 907         return input_register_handler(&joydev_handler);
 908 }
 909
 910 static void __exit joydev_exit(void)
 911 {
 912         input_unregister_handler(&joydev_handler);
 913 }
 914
 915 module_init(joydev_init);
 916 module_exit(joydev_exit);