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/smp_lock.h>
  28 #include <linux/device.h>
  29
  30 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  31 MODULE_DESCRIPTION("Joystick device interfaces");
  32 MODULE_SUPPORTED_DEVICE("input/js");
  33 MODULE_LICENSE("GPL");
  34
  35 #define JOYDEV_MINOR_BASE       0
  36 #define JOYDEV_MINORS           16
  37 #define JOYDEV_BUFFER_SIZE      64
  38
  39 struct joydev {
  40         int exist;
  41         int open;
  42         int minor;
  43         char name[16];
  44         struct input_handle handle;
  45         wait_queue_head_t wait;
  46         struct list_head list;
  47         struct js_corr corr[ABS_MAX + 1];
  48         struct JS_DATA_SAVE_TYPE glue;
  49         int nabs;
  50         int nkey;
  51         __u16 keymap[KEY_MAX - BTN_MISC + 1];
  52         __u16 keypam[KEY_MAX - BTN_MISC + 1];
  53         __u8 absmap[ABS_MAX + 1];
  54         __u8 abspam[ABS_MAX + 1];
  55         __s16 abs[ABS_MAX + 1];
  56 };
  57
  58 struct joydev_list {
  59         struct js_event buffer[JOYDEV_BUFFER_SIZE];
  60         int head;
  61         int tail;
  62         int startup;
  63         struct fasync_struct *fasync;
  64         struct joydev *joydev;
  65         struct list_head node;
  66 };
  67
  68 static struct joydev *joydev_table[JOYDEV_MINORS];
  69
  70 static int joydev_correct(int value, struct js_corr *corr)
  71 {
  72         switch (corr->type) {
  73                 case JS_CORR_NONE:
  74                         break;
  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                 default:
  81                         return 0;
  82         }
  83
  84         if (value < -32767) return -32767;
  85         if (value >  32767) return  32767;
  86
  87         return value;
  88 }
  89
  90 static void joydev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value)
  91 {
  92         struct joydev *joydev = handle->private;
  93         struct joydev_list *list;
  94         struct js_event event;
  95
  96         switch (type) {
  97
  98                 case EV_KEY:
  99                         if (code < BTN_MISC || value == 2) return;
 100                         event.type = JS_EVENT_BUTTON;
 101                         event.number = joydev->keymap[code - BTN_MISC];
 102                         event.value = value;
 103                         break;
 104
 105                 case EV_ABS:
 106                         event.type = JS_EVENT_AXIS;
 107                         event.number = joydev->absmap[code];
 108                         event.value = joydev_correct(value, joydev->corr + event.number);
 109                         if (event.value == joydev->abs[event.number]) return;
 110                         joydev->abs[event.number] = event.value;
 111                         break;
 112
 113                 default:
 114                         return;
 115         }
 116
 117         event.time = jiffies_to_msecs(jiffies);
 118
 119         list_for_each_entry(list, &joydev->list, node) {
 120
 121                 memcpy(list->buffer + list->head, &event, sizeof(struct js_event));
 122
 123                 if (list->startup == joydev->nabs + joydev->nkey)
 124                         if (list->tail == (list->head = (list->head + 1) & (JOYDEV_BUFFER_SIZE - 1)))
 125                                 list->startup = 0;
 126
 127                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
 128         }
 129
 130         wake_up_interruptible(&joydev->wait);
 131 }
 132
 133 static int joydev_fasync(int fd, struct file *file, int on)
 134 {
 135         int retval;
 136         struct joydev_list *list = file->private_data;
 137         retval = fasync_helper(fd, file, on, &list->fasync);
 138         return retval < 0 ? retval : 0;
 139 }
 140
 141 static void joydev_free(struct joydev *joydev)
 142 {
 143         joydev_table[joydev->minor] = NULL;
 144         kfree(joydev);
 145 }
 146
 147 static int joydev_release(struct inode * inode, struct file * file)
 148 {
 149         struct joydev_list *list = file->private_data;
 150
 151         joydev_fasync(-1, file, 0);
 152
 153         list_del(&list->node);
 154
 155         if (!--list->joydev->open) {
 156                 if (list->joydev->exist)
 157                         input_close_device(&list->joydev->handle);
 158                 else
 159                         joydev_free(list->joydev);
 160         }
 161
 162         kfree(list);
 163         return 0;
 164 }
 165
 166 static int joydev_open(struct inode *inode, struct file *file)
 167 {
 168         struct joydev_list *list;
 169         int i = iminor(inode) - JOYDEV_MINOR_BASE;
 170
 171         if (i >= JOYDEV_MINORS || !joydev_table[i])
 172                 return -ENODEV;
 173
 174         if (!(list = kzalloc(sizeof(struct joydev_list), GFP_KERNEL)))
 175                 return -ENOMEM;
 176
 177         list->joydev = joydev_table[i];
 178         list_add_tail(&list->node, &joydev_table[i]->list);
 179         file->private_data = list;
 180
 181         if (!list->joydev->open++)
 182                 if (list->joydev->exist)
 183                         input_open_device(&list->joydev->handle);
 184
 185         return 0;
 186 }
 187
 188 static ssize_t joydev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 189 {
 190         return -EINVAL;
 191 }
 192
 193 static ssize_t joydev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 194 {
 195         struct joydev_list *list = file->private_data;
 196         struct joydev *joydev = list->joydev;
 197         struct input_dev *input = joydev->handle.dev;
 198         int retval = 0;
 199
 200         if (!list->joydev->exist)
 201                 return -ENODEV;
 202
 203         if (count < sizeof(struct js_event))
 204                 return -EINVAL;
 205
 206         if (count == sizeof(struct JS_DATA_TYPE)) {
 207
 208                 struct JS_DATA_TYPE data;
 209                 int i;
 210
 211                 for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 212                         data.buttons |= test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 213                 data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 214                 data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
 215
 216                 if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 217                         return -EFAULT;
 218
 219                 list->startup = 0;
 220                 list->tail = list->head;
 221
 222                 return sizeof(struct JS_DATA_TYPE);
 223         }
 224
 225         if (list->startup == joydev->nabs + joydev->nkey
 226                 && list->head == list->tail && (file->f_flags & O_NONBLOCK))
 227                         return -EAGAIN;
 228
 229         retval = wait_event_interruptible(list->joydev->wait,
 230                                           !list->joydev->exist ||
 231                                           list->startup < joydev->nabs + joydev->nkey ||
 232                                           list->head != list->tail);
 233
 234         if (retval)
 235                 return retval;
 236
 237         if (!list->joydev->exist)
 238                 return -ENODEV;
 239
 240         while (list->startup < joydev->nabs + joydev->nkey && retval + sizeof(struct js_event) <= count) {
 241
 242                 struct js_event event;
 243
 244                 event.time = jiffies_to_msecs(jiffies);
 245
 246                 if (list->startup < joydev->nkey) {
 247                         event.type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 248                         event.number = list->startup;
 249                         event.value = !!test_bit(joydev->keypam[event.number], input->key);
 250                 } else {
 251                         event.type = JS_EVENT_AXIS | JS_EVENT_INIT;
 252                         event.number = list->startup - joydev->nkey;
 253                         event.value = joydev->abs[event.number];
 254                 }
 255
 256                 if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 257                         return -EFAULT;
 258
 259                 list->startup++;
 260                 retval += sizeof(struct js_event);
 261         }
 262
 263         while (list->head != list->tail && retval + sizeof(struct js_event) <= count) {
 264
 265                 if (copy_to_user(buf + retval, list->buffer + list->tail, sizeof(struct js_event)))
 266                         return -EFAULT;
 267
 268                 list->tail = (list->tail + 1) & (JOYDEV_BUFFER_SIZE - 1);
 269                 retval += sizeof(struct js_event);
 270         }
 271
 272         return retval;
 273 }
 274
 275 /* No kernel lock - fine */
 276 static unsigned int joydev_poll(struct file *file, poll_table *wait)
 277 {
 278         struct joydev_list *list = file->private_data;
 279         poll_wait(file, &list->joydev->wait, wait);
 280         return ((list->head != list->tail || list->startup < list->joydev->nabs + list->joydev->nkey) ?
 281                 (POLLIN | POLLRDNORM) : 0) | (list->joydev->exist ? 0 : (POLLHUP | POLLERR));
 282 }
 283
 284 static int joydev_ioctl_common(struct joydev *joydev, unsigned int cmd, void __user *argp)
 285 {
 286         struct input_dev *dev = joydev->handle.dev;
 287         int i, j;
 288
 289         switch (cmd) {
 290
 291                 case JS_SET_CAL:
 292                         return copy_from_user(&joydev->glue.JS_CORR, argp,
 293                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 294                 case JS_GET_CAL:
 295                         return copy_to_user(argp, &joydev->glue.JS_CORR,
 296                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 297                 case JS_SET_TIMEOUT:
 298                         return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 299                 case JS_GET_TIMEOUT:
 300                         return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 301
 302                 case JSIOCGVERSION:
 303                         return put_user(JS_VERSION, (__u32 __user *) argp);
 304                 case JSIOCGAXES:
 305                         return put_user(joydev->nabs, (__u8 __user *) argp);
 306                 case JSIOCGBUTTONS:
 307                         return put_user(joydev->nkey, (__u8 __user *) argp);
 308                 case JSIOCSCORR:
 309                         if (copy_from_user(joydev->corr, argp,
 310                                       sizeof(joydev->corr[0]) * joydev->nabs))
 311                             return -EFAULT;
 312                         for (i = 0; i < joydev->nabs; i++) {
 313                                 j = joydev->abspam[i];
 314                                 joydev->abs[i] = joydev_correct(dev->abs[j], joydev->corr + i);
 315                         }
 316                         return 0;
 317                 case JSIOCGCORR:
 318                         return copy_to_user(argp, joydev->corr,
 319                                                 sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
 320                 case JSIOCSAXMAP:
 321                         if (copy_from_user(joydev->abspam, argp, sizeof(__u8) * (ABS_MAX + 1)))
 322                                 return -EFAULT;
 323                         for (i = 0; i < joydev->nabs; i++) {
 324                                 if (joydev->abspam[i] > ABS_MAX) return -EINVAL;
 325                                 joydev->absmap[joydev->abspam[i]] = i;
 326                         }
 327                         return 0;
 328                 case JSIOCGAXMAP:
 329                         return copy_to_user(argp, joydev->abspam,
 330                                                 sizeof(__u8) * (ABS_MAX + 1)) ? -EFAULT : 0;
 331                 case JSIOCSBTNMAP:
 332                         if (copy_from_user(joydev->keypam, argp, sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)))
 333                                 return -EFAULT;
 334                         for (i = 0; i < joydev->nkey; i++) {
 335                                 if (joydev->keypam[i] > KEY_MAX || joydev->keypam[i] < BTN_MISC) return -EINVAL;
 336                                 joydev->keymap[joydev->keypam[i] - BTN_MISC] = i;
 337                         }
 338                         return 0;
 339                 case JSIOCGBTNMAP:
 340                         return copy_to_user(argp, joydev->keypam,
 341                                                 sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)) ? -EFAULT : 0;
 342                 default:
 343                         if ((cmd & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT)) == JSIOCGNAME(0)) {
 344                                 int len;
 345                                 if (!dev->name) return 0;
 346                                 len = strlen(dev->name) + 1;
 347                                 if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
 348                                 if (copy_to_user(argp, dev->name, len)) return -EFAULT;
 349                                 return len;
 350                         }
 351         }
 352         return -EINVAL;
 353 }
 354
 355 #ifdef CONFIG_COMPAT
 356 static long joydev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 357 {
 358         struct joydev_list *list = file->private_data;
 359         struct joydev *joydev = list->joydev;
 360         void __user *argp = (void __user *)arg;
 361         s32 tmp32;
 362         struct JS_DATA_SAVE_TYPE_32 ds32;
 363         int err;
 364
 365         if (!joydev->exist) return -ENODEV;
 366         switch(cmd) {
 367         case JS_SET_TIMELIMIT:
 368                 err = get_user(tmp32, (s32 __user *) arg);
 369                 if (err == 0)
 370                         joydev->glue.JS_TIMELIMIT = tmp32;
 371                 break;
 372         case JS_GET_TIMELIMIT:
 373                 tmp32 = joydev->glue.JS_TIMELIMIT;
 374                 err = put_user(tmp32, (s32 __user *) arg);
 375                 break;
 376
 377         case JS_SET_ALL:
 378                 err = copy_from_user(&ds32, argp,
 379                                      sizeof(ds32)) ? -EFAULT : 0;
 380                 if (err == 0) {
 381                         joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
 382                         joydev->glue.BUSY          = ds32.BUSY;
 383                         joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
 384                         joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
 385                         joydev->glue.JS_SAVE       = ds32.JS_SAVE;
 386                         joydev->glue.JS_CORR       = ds32.JS_CORR;
 387                 }
 388                 break;
 389
 390         case JS_GET_ALL:
 391                 ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
 392                 ds32.BUSY          = joydev->glue.BUSY;
 393                 ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
 394                 ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
 395                 ds32.JS_SAVE       = joydev->glue.JS_SAVE;
 396                 ds32.JS_CORR       = joydev->glue.JS_CORR;
 397
 398                 err = copy_to_user(argp, &ds32,
 399                                           sizeof(ds32)) ? -EFAULT : 0;
 400                 break;
 401
 402         default:
 403                 err = joydev_ioctl_common(joydev, cmd, argp);
 404         }
 405         return err;
 406 }
 407 #endif /* CONFIG_COMPAT */
 408
 409 static int joydev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 410 {
 411         struct joydev_list *list = file->private_data;
 412         struct joydev *joydev = list->joydev;
 413         void __user *argp = (void __user *)arg;
 414
 415         if (!joydev->exist) return -ENODEV;
 416
 417         switch(cmd) {
 418                 case JS_SET_TIMELIMIT:
 419                         return get_user(joydev->glue.JS_TIMELIMIT, (long __user *) arg);
 420                 case JS_GET_TIMELIMIT:
 421                         return put_user(joydev->glue.JS_TIMELIMIT, (long __user *) arg);
 422                 case JS_SET_ALL:
 423                         return copy_from_user(&joydev->glue, argp,
 424                                                 sizeof(joydev->glue)) ? -EFAULT : 0;
 425                 case JS_GET_ALL:
 426                         return copy_to_user(argp, &joydev->glue,
 427                                                 sizeof(joydev->glue)) ? -EFAULT : 0;
 428                 default:
 429                         return joydev_ioctl_common(joydev, cmd, argp);
 430         }
 431 }
 432
 433 static struct file_operations joydev_fops = {
 434         .owner =        THIS_MODULE,
 435         .read =         joydev_read,
 436         .write =        joydev_write,
 437         .poll =         joydev_poll,
 438         .open =         joydev_open,
 439         .release =      joydev_release,
 440         .ioctl =        joydev_ioctl,
 441 #ifdef CONFIG_COMPAT
 442         .compat_ioctl = joydev_compat_ioctl,
 443 #endif
 444         .fasync =       joydev_fasync,
 445 };
 446
 447 static struct input_handle *joydev_connect(struct input_handler *handler, struct input_dev *dev, struct input_device_id *id)
 448 {
 449         struct joydev *joydev;
 450         struct class_device *cdev;
 451         int i, j, t, minor;
 452
 453         for (minor = 0; minor < JOYDEV_MINORS && joydev_table[minor]; minor++);
 454         if (minor == JOYDEV_MINORS) {
 455                 printk(KERN_ERR "joydev: no more free joydev devices\n");
 456                 return NULL;
 457         }
 458
 459         if (!(joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL)))
 460                 return NULL;
 461
 462         INIT_LIST_HEAD(&joydev->list);
 463         init_waitqueue_head(&joydev->wait);
 464
 465         joydev->minor = minor;
 466         joydev->exist = 1;
 467         joydev->handle.dev = dev;
 468         joydev->handle.name = joydev->name;
 469         joydev->handle.handler = handler;
 470         joydev->handle.private = joydev;
 471         sprintf(joydev->name, "js%d", minor);
 472
 473         for (i = 0; i < ABS_MAX + 1; i++)
 474                 if (test_bit(i, dev->absbit)) {
 475                         joydev->absmap[i] = joydev->nabs;
 476                         joydev->abspam[joydev->nabs] = i;
 477                         joydev->nabs++;
 478                 }
 479
 480         for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 481                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 482                         joydev->keymap[i] = joydev->nkey;
 483                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 484                         joydev->nkey++;
 485                 }
 486
 487         for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 488                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 489                         joydev->keymap[i] = joydev->nkey;
 490                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 491                         joydev->nkey++;
 492                 }
 493
 494         for (i = 0; i < joydev->nabs; i++) {
 495                 j = joydev->abspam[i];
 496                 if (dev->absmax[j] == dev->absmin[j]) {
 497                         joydev->corr[i].type = JS_CORR_NONE;
 498                         joydev->abs[i] = dev->abs[j];
 499                         continue;
 500                 }
 501                 joydev->corr[i].type = JS_CORR_BROKEN;
 502                 joydev->corr[i].prec = dev->absfuzz[j];
 503                 joydev->corr[i].coef[0] = (dev->absmax[j] + dev->absmin[j]) / 2 - dev->absflat[j];
 504                 joydev->corr[i].coef[1] = (dev->absmax[j] + dev->absmin[j]) / 2 + dev->absflat[j];
 505                 if (!(t = ((dev->absmax[j] - dev->absmin[j]) / 2 - 2 * dev->absflat[j])))
 506                         continue;
 507                 joydev->corr[i].coef[2] = (1 << 29) / t;
 508                 joydev->corr[i].coef[3] = (1 << 29) / t;
 509
 510                 joydev->abs[i] = joydev_correct(dev->abs[j], joydev->corr + i);
 511         }
 512
 513         joydev_table[minor] = joydev;
 514
 515         cdev = class_device_create(&input_class, &dev->cdev,
 516                         MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor),
 517                         dev->cdev.dev, joydev->name);
 518
 519         /* temporary symlink to keep userspace happy */
 520         sysfs_create_link(&input_class.subsys.kset.kobj, &cdev->kobj,
 521                           joydev->name);
 522
 523         return &joydev->handle;
 524 }
 525
 526 static void joydev_disconnect(struct input_handle *handle)
 527 {
 528         struct joydev *joydev = handle->private;
 529         struct joydev_list *list;
 530
 531         sysfs_remove_link(&input_class.subsys.kset.kobj, joydev->name);
 532         class_device_destroy(&input_class, MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + joydev->minor));
 533         joydev->exist = 0;
 534
 535         if (joydev->open) {
 536                 input_close_device(handle);
 537                 wake_up_interruptible(&joydev->wait);
 538                 list_for_each_entry(list, &joydev->list, node)
 539                         kill_fasync(&list->fasync, SIGIO, POLL_HUP);
 540         } else
 541                 joydev_free(joydev);
 542 }
 543
 544 static struct input_device_id joydev_blacklist[] = {
 545         {
 546                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
 547                 .evbit = { BIT(EV_KEY) },
 548                 .keybit = { [LONG(BTN_TOUCH)] = BIT(BTN_TOUCH) },
 549         },      /* Avoid itouchpads, touchscreens and tablets */
 550         { },    /* Terminating entry */
 551 };
 552
 553 static struct input_device_id joydev_ids[] = {
 554         {
 555                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 556                 .evbit = { BIT(EV_ABS) },
 557                 .absbit = { BIT(ABS_X) },
 558         },
 559         {
 560                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 561                 .evbit = { BIT(EV_ABS) },
 562                 .absbit = { BIT(ABS_WHEEL) },
 563         },
 564         {
 565                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 566                 .evbit = { BIT(EV_ABS) },
 567                 .absbit = { BIT(ABS_THROTTLE) },
 568         },
 569         { },    /* Terminating entry */
 570 };
 571
 572 MODULE_DEVICE_TABLE(input, joydev_ids);
 573
 574 static struct input_handler joydev_handler = {
 575         .event =        joydev_event,
 576         .connect =      joydev_connect,
 577         .disconnect =   joydev_disconnect,
 578         .fops =         &joydev_fops,
 579         .minor =        JOYDEV_MINOR_BASE,
 580         .name =         "joydev",
 581         .id_table =     joydev_ids,
 582         .blacklist =    joydev_blacklist,
 583 };
 584
 585 static int __init joydev_init(void)
 586 {
 587         input_register_handler(&joydev_handler);
 588         return 0;
 589 }
 590
 591 static void __exit joydev_exit(void)
 592 {
 593         input_unregister_handler(&joydev_handler);
 594 }
 595
 596 module_init(joydev_init);
 597 module_exit(joydev_exit);