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
 247         return 0;
 248 }
 249
 250 static int joydev_open(struct inode *inode, struct file *file)
 251 {
 252         struct joydev *joydev =
 253                         container_of(inode->i_cdev, struct joydev, cdev);
 254         struct joydev_client *client;
 255         int error;
 256
 257         client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
 258         if (!client)
 259                 return -ENOMEM;
 260
 261         spin_lock_init(&client->buffer_lock);
 262         client->joydev = joydev;
 263         joydev_attach_client(joydev, client);
 264
 265         error = joydev_open_device(joydev);
 266         if (error)
 267                 goto err_free_client;
 268
 269         file->private_data = client;
 270         nonseekable_open(inode, file);
 271
 272         return 0;
 273
 274  err_free_client:
 275         joydev_detach_client(joydev, client);
 276         kfree(client);
 277         return error;
 278 }
 279
 280 static int joydev_generate_startup_event(struct joydev_client *client,
 281                                          struct input_dev *input,
 282                                          struct js_event *event)
 283 {
 284         struct joydev *joydev = client->joydev;
 285         int have_event;
 286
 287         spin_lock_irq(&client->buffer_lock);
 288
 289         have_event = client->startup < joydev->nabs + joydev->nkey;
 290
 291         if (have_event) {
 292
 293                 event->time = jiffies_to_msecs(jiffies);
 294                 if (client->startup < joydev->nkey) {
 295                         event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 296                         event->number = client->startup;
 297                         event->value = !!test_bit(joydev->keypam[event->number],
 298                                                   input->key);
 299                 } else {
 300                         event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
 301                         event->number = client->startup - joydev->nkey;
 302                         event->value = joydev->abs[event->number];
 303                 }
 304                 client->startup++;
 305         }
 306
 307         spin_unlock_irq(&client->buffer_lock);
 308
 309         return have_event;
 310 }
 311
 312 static int joydev_fetch_next_event(struct joydev_client *client,
 313                                    struct js_event *event)
 314 {
 315         int have_event;
 316
 317         spin_lock_irq(&client->buffer_lock);
 318
 319         have_event = client->head != client->tail;
 320         if (have_event) {
 321                 *event = client->buffer[client->tail++];
 322                 client->tail &= JOYDEV_BUFFER_SIZE - 1;
 323         }
 324
 325         spin_unlock_irq(&client->buffer_lock);
 326
 327         return have_event;
 328 }
 329
 330 /*
 331  * Old joystick interface
 332  */
 333 static ssize_t joydev_0x_read(struct joydev_client *client,
 334                               struct input_dev *input,
 335                               char __user *buf)
 336 {
 337         struct joydev *joydev = client->joydev;
 338         struct JS_DATA_TYPE data;
 339         int i;
 340
 341         spin_lock_irq(&input->event_lock);
 342
 343         /*
 344          * Get device state
 345          */
 346         for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 347                 data.buttons |=
 348                         test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 349         data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 350         data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
 351
 352         /*
 353          * Reset reader's event queue
 354          */
 355         spin_lock(&client->buffer_lock);
 356         client->startup = 0;
 357         client->tail = client->head;
 358         spin_unlock(&client->buffer_lock);
 359
 360         spin_unlock_irq(&input->event_lock);
 361
 362         if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 363                 return -EFAULT;
 364
 365         return sizeof(struct JS_DATA_TYPE);
 366 }
 367
 368 static inline int joydev_data_pending(struct joydev_client *client)
 369 {
 370         struct joydev *joydev = client->joydev;
 371
 372         return client->startup < joydev->nabs + joydev->nkey ||
 373                 client->head != client->tail;
 374 }
 375
 376 static ssize_t joydev_read(struct file *file, char __user *buf,
 377                            size_t count, loff_t *ppos)
 378 {
 379         struct joydev_client *client = file->private_data;
 380         struct joydev *joydev = client->joydev;
 381         struct input_dev *input = joydev->handle.dev;
 382         struct js_event event;
 383         int retval;
 384
 385         if (!joydev->exist)
 386                 return -ENODEV;
 387
 388         if (count < sizeof(struct js_event))
 389                 return -EINVAL;
 390
 391         if (count == sizeof(struct JS_DATA_TYPE))
 392                 return joydev_0x_read(client, input, buf);
 393
 394         if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
 395                 return -EAGAIN;
 396
 397         retval = wait_event_interruptible(joydev->wait,
 398                         !joydev->exist || joydev_data_pending(client));
 399         if (retval)
 400                 return retval;
 401
 402         if (!joydev->exist)
 403                 return -ENODEV;
 404
 405         while (retval + sizeof(struct js_event) <= count &&
 406                joydev_generate_startup_event(client, input, &event)) {
 407
 408                 if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 409                         return -EFAULT;
 410
 411                 retval += sizeof(struct js_event);
 412         }
 413
 414         while (retval + sizeof(struct js_event) <= count &&
 415                joydev_fetch_next_event(client, &event)) {
 416
 417                 if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 418                         return -EFAULT;
 419
 420                 retval += sizeof(struct js_event);
 421         }
 422
 423         return retval;
 424 }
 425
 426 /* No kernel lock - fine */
 427 static unsigned int joydev_poll(struct file *file, poll_table *wait)
 428 {
 429         struct joydev_client *client = file->private_data;
 430         struct joydev *joydev = client->joydev;
 431
 432         poll_wait(file, &joydev->wait, wait);
 433         return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
 434                 (joydev->exist ?  0 : (POLLHUP | POLLERR));
 435 }
 436
 437 static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
 438                                      void __user *argp, size_t len)
 439 {
 440         __u8 *abspam;
 441         int i;
 442         int retval = 0;
 443
 444         len = min(len, sizeof(joydev->abspam));
 445
 446         /* Validate the map. */
 447         abspam = kmalloc(len, GFP_KERNEL);
 448         if (!abspam)
 449                 return -ENOMEM;
 450
 451         if (copy_from_user(abspam, argp, len)) {
 452                 retval = -EFAULT;
 453                 goto out;
 454         }
 455
 456         for (i = 0; i < joydev->nabs; i++) {
 457                 if (abspam[i] > ABS_MAX) {
 458                         retval = -EINVAL;
 459                         goto out;
 460                 }
 461         }
 462
 463         memcpy(joydev->abspam, abspam, len);
 464
 465         for (i = 0; i < joydev->nabs; i++)
 466                 joydev->absmap[joydev->abspam[i]] = i;
 467
 468  out:
 469         kfree(abspam);
 470         return retval;
 471 }
 472
 473 static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
 474                                       void __user *argp, size_t len)
 475 {
 476         __u16 *keypam;
 477         int i;
 478         int retval = 0;
 479
 480         len = min(len, sizeof(joydev->keypam));
 481
 482         /* Validate the map. */
 483         keypam = kmalloc(len, GFP_KERNEL);
 484         if (!keypam)
 485                 return -ENOMEM;
 486
 487         if (copy_from_user(keypam, argp, len)) {
 488                 retval = -EFAULT;
 489                 goto out;
 490         }
 491
 492         for (i = 0; i < joydev->nkey; i++) {
 493                 if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
 494                         retval = -EINVAL;
 495                         goto out;
 496                 }
 497         }
 498
 499         memcpy(joydev->keypam, keypam, len);
 500
 501         for (i = 0; i < joydev->nkey; i++)
 502                 joydev->keymap[keypam[i] - BTN_MISC] = i;
 503
 504  out:
 505         kfree(keypam);
 506         return retval;
 507 }
 508
 509
 510 static int joydev_ioctl_common(struct joydev *joydev,
 511                                 unsigned int cmd, void __user *argp)
 512 {
 513         struct input_dev *dev = joydev->handle.dev;
 514         size_t len;
 515         int i;
 516         const char *name;
 517
 518         /* Process fixed-sized commands. */
 519         switch (cmd) {
 520
 521         case JS_SET_CAL:
 522                 return copy_from_user(&joydev->glue.JS_CORR, argp,
 523                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 524
 525         case JS_GET_CAL:
 526                 return copy_to_user(argp, &joydev->glue.JS_CORR,
 527                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 528
 529         case JS_SET_TIMEOUT:
 530                 return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 531
 532         case JS_GET_TIMEOUT:
 533                 return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 534
 535         case JSIOCGVERSION:
 536                 return put_user(JS_VERSION, (__u32 __user *) argp);
 537
 538         case JSIOCGAXES:
 539                 return put_user(joydev->nabs, (__u8 __user *) argp);
 540
 541         case JSIOCGBUTTONS:
 542                 return put_user(joydev->nkey, (__u8 __user *) argp);
 543
 544         case JSIOCSCORR:
 545                 if (copy_from_user(joydev->corr, argp,
 546                               sizeof(joydev->corr[0]) * joydev->nabs))
 547                         return -EFAULT;
 548
 549                 for (i = 0; i < joydev->nabs; i++) {
 550                         int val = input_abs_get_val(dev, joydev->abspam[i]);
 551                         joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
 552                 }
 553                 return 0;
 554
 555         case JSIOCGCORR:
 556                 return copy_to_user(argp, joydev->corr,
 557                         sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
 558
 559         }
 560
 561         /*
 562          * Process variable-sized commands (the axis and button map commands
 563          * are considered variable-sized to decouple them from the values of
 564          * ABS_MAX and KEY_MAX).
 565          */
 566         switch (cmd & ~IOCSIZE_MASK) {
 567
 568         case (JSIOCSAXMAP & ~IOCSIZE_MASK):
 569                 return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
 570
 571         case (JSIOCGAXMAP & ~IOCSIZE_MASK):
 572                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
 573                 return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
 574
 575         case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
 576                 return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
 577
 578         case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
 579                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
 580                 return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
 581
 582         case JSIOCGNAME(0):
 583                 name = dev->name;
 584                 if (!name)
 585                         return 0;
 586
 587                 len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
 588                 return copy_to_user(argp, name, len) ? -EFAULT : len;
 589         }
 590
 591         return -EINVAL;
 592 }
 593
 594 #ifdef CONFIG_COMPAT
 595 static long joydev_compat_ioctl(struct file *file,
 596                                 unsigned int cmd, unsigned long arg)
 597 {
 598         struct joydev_client *client = file->private_data;
 599         struct joydev *joydev = client->joydev;
 600         void __user *argp = (void __user *)arg;
 601         s32 tmp32;
 602         struct JS_DATA_SAVE_TYPE_32 ds32;
 603         int retval;
 604
 605         retval = mutex_lock_interruptible(&joydev->mutex);
 606         if (retval)
 607                 return retval;
 608
 609         if (!joydev->exist) {
 610                 retval = -ENODEV;
 611                 goto out;
 612         }
 613
 614         switch (cmd) {
 615
 616         case JS_SET_TIMELIMIT:
 617                 retval = get_user(tmp32, (s32 __user *) arg);
 618                 if (retval == 0)
 619                         joydev->glue.JS_TIMELIMIT = tmp32;
 620                 break;
 621
 622         case JS_GET_TIMELIMIT:
 623                 tmp32 = joydev->glue.JS_TIMELIMIT;
 624                 retval = put_user(tmp32, (s32 __user *) arg);
 625                 break;
 626
 627         case JS_SET_ALL:
 628                 retval = copy_from_user(&ds32, argp,
 629                                         sizeof(ds32)) ? -EFAULT : 0;
 630                 if (retval == 0) {
 631                         joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
 632                         joydev->glue.BUSY          = ds32.BUSY;
 633                         joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
 634                         joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
 635                         joydev->glue.JS_SAVE       = ds32.JS_SAVE;
 636                         joydev->glue.JS_CORR       = ds32.JS_CORR;
 637                 }
 638                 break;
 639
 640         case JS_GET_ALL:
 641                 ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
 642                 ds32.BUSY          = joydev->glue.BUSY;
 643                 ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
 644                 ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
 645                 ds32.JS_SAVE       = joydev->glue.JS_SAVE;
 646                 ds32.JS_CORR       = joydev->glue.JS_CORR;
 647
 648                 retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
 649                 break;
 650
 651         default:
 652                 retval = joydev_ioctl_common(joydev, cmd, argp);
 653                 break;
 654         }
 655
 656  out:
 657         mutex_unlock(&joydev->mutex);
 658         return retval;
 659 }
 660 #endif /* CONFIG_COMPAT */
 661
 662 static long joydev_ioctl(struct file *file,
 663                          unsigned int cmd, unsigned long arg)
 664 {
 665         struct joydev_client *client = file->private_data;
 666         struct joydev *joydev = client->joydev;
 667         void __user *argp = (void __user *)arg;
 668         int retval;
 669
 670         retval = mutex_lock_interruptible(&joydev->mutex);
 671         if (retval)
 672                 return retval;
 673
 674         if (!joydev->exist) {
 675                 retval = -ENODEV;
 676                 goto out;
 677         }
 678
 679         switch (cmd) {
 680
 681         case JS_SET_TIMELIMIT:
 682                 retval = get_user(joydev->glue.JS_TIMELIMIT,
 683                                   (long __user *) arg);
 684                 break;
 685
 686         case JS_GET_TIMELIMIT:
 687                 retval = put_user(joydev->glue.JS_TIMELIMIT,
 688                                   (long __user *) arg);
 689                 break;
 690
 691         case JS_SET_ALL:
 692                 retval = copy_from_user(&joydev->glue, argp,
 693                                         sizeof(joydev->glue)) ? -EFAULT : 0;
 694                 break;
 695
 696         case JS_GET_ALL:
 697                 retval = copy_to_user(argp, &joydev->glue,
 698                                       sizeof(joydev->glue)) ? -EFAULT : 0;
 699                 break;
 700
 701         default:
 702                 retval = joydev_ioctl_common(joydev, cmd, argp);
 703                 break;
 704         }
 705  out:
 706         mutex_unlock(&joydev->mutex);
 707         return retval;
 708 }
 709
 710 static const struct file_operations joydev_fops = {
 711         .owner          = THIS_MODULE,
 712         .read           = joydev_read,
 713         .poll           = joydev_poll,
 714         .open           = joydev_open,
 715         .release        = joydev_release,
 716         .unlocked_ioctl = joydev_ioctl,
 717 #ifdef CONFIG_COMPAT
 718         .compat_ioctl   = joydev_compat_ioctl,
 719 #endif
 720         .fasync         = joydev_fasync,
 721         .llseek         = no_llseek,
 722 };
 723
 724 /*
 725  * Mark device non-existent. This disables writes, ioctls and
 726  * prevents new users from opening the device. Already posted
 727  * blocking reads will stay, however new ones will fail.
 728  */
 729 static void joydev_mark_dead(struct joydev *joydev)
 730 {
 731         mutex_lock(&joydev->mutex);
 732         joydev->exist = false;
 733         mutex_unlock(&joydev->mutex);
 734 }
 735
 736 static void joydev_cleanup(struct joydev *joydev)
 737 {
 738         struct input_handle *handle = &joydev->handle;
 739
 740         joydev_mark_dead(joydev);
 741         joydev_hangup(joydev);
 742
 743         cdev_del(&joydev->cdev);
 744
 745         /* joydev is marked dead so no one else accesses joydev->open */
 746         if (joydev->open)
 747                 input_close_device(handle);
 748 }
 749
 750
 751 static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
 752 {
 753         /* Avoid touchpads and touchscreens */
 754         if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_TOUCH, dev->keybit))
 755                 return false;
 756
 757         /* Avoid tablets, digitisers and similar devices */
 758         if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
 759                 return false;
 760
 761         return true;
 762 }
 763
 764 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 765                           const struct input_device_id *id)
 766 {
 767         struct joydev *joydev;
 768         int i, j, t, minor, dev_no;
 769         int error;
 770
 771         minor = input_get_new_minor(JOYDEV_MINOR_BASE, JOYDEV_MINORS, true);
 772         if (minor < 0) {
 773                 error = minor;
 774                 pr_err("failed to reserve new minor: %d\n", error);
 775                 return error;
 776         }
 777
 778         joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
 779         if (!joydev) {
 780                 error = -ENOMEM;
 781                 goto err_free_minor;
 782         }
 783
 784         INIT_LIST_HEAD(&joydev->client_list);
 785         spin_lock_init(&joydev->client_lock);
 786         mutex_init(&joydev->mutex);
 787         init_waitqueue_head(&joydev->wait);
 788         joydev->exist = true;
 789
 790         dev_no = minor;
 791         /* Normalize device number if it falls into legacy range */
 792         if (dev_no < JOYDEV_MINOR_BASE + JOYDEV_MINORS)
 793                 dev_no -= JOYDEV_MINOR_BASE;
 794         dev_set_name(&joydev->dev, "js%d", dev_no);
 795
 796         joydev->handle.dev = input_get_device(dev);
 797         joydev->handle.name = dev_name(&joydev->dev);
 798         joydev->handle.handler = handler;
 799         joydev->handle.private = joydev;
 800
 801         for (i = 0; i < ABS_CNT; i++)
 802                 if (test_bit(i, dev->absbit)) {
 803                         joydev->absmap[i] = joydev->nabs;
 804                         joydev->abspam[joydev->nabs] = i;
 805                         joydev->nabs++;
 806                 }
 807
 808         for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 809                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 810                         joydev->keymap[i] = joydev->nkey;
 811                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 812                         joydev->nkey++;
 813                 }
 814
 815         for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 816                 if (test_bit(i + BTN_MISC, dev->keybit)) {
 817                         joydev->keymap[i] = joydev->nkey;
 818                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
 819                         joydev->nkey++;
 820                 }
 821
 822         for (i = 0; i < joydev->nabs; i++) {
 823                 j = joydev->abspam[i];
 824                 if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
 825                         joydev->corr[i].type = JS_CORR_NONE;
 826                         joydev->abs[i] = input_abs_get_val(dev, j);
 827                         continue;
 828                 }
 829                 joydev->corr[i].type = JS_CORR_BROKEN;
 830                 joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
 831
 832                 t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
 833                 joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
 834                 joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
 835
 836                 t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
 837                         - 2 * input_abs_get_flat(dev, j);
 838                 if (t) {
 839                         joydev->corr[i].coef[2] = (1 << 29) / t;
 840                         joydev->corr[i].coef[3] = (1 << 29) / t;
 841
 842                         joydev->abs[i] =
 843                                 joydev_correct(input_abs_get_val(dev, j),
 844                                                joydev->corr + i);
 845                 }
 846         }
 847
 848         joydev->dev.devt = MKDEV(INPUT_MAJOR, minor);
 849         joydev->dev.class = &input_class;
 850         joydev->dev.parent = &dev->dev;
 851         joydev->dev.release = joydev_free;
 852         device_initialize(&joydev->dev);
 853
 854         error = input_register_handle(&joydev->handle);
 855         if (error)
 856                 goto err_free_joydev;
 857
 858         cdev_init(&joydev->cdev, &joydev_fops);
 859         joydev->cdev.kobj.parent = &joydev->dev.kobj;
 860         error = cdev_add(&joydev->cdev, joydev->dev.devt, 1);
 861         if (error)
 862                 goto err_unregister_handle;
 863
 864         error = device_add(&joydev->dev);
 865         if (error)
 866                 goto err_cleanup_joydev;
 867
 868         return 0;
 869
 870  err_cleanup_joydev:
 871         joydev_cleanup(joydev);
 872  err_unregister_handle:
 873         input_unregister_handle(&joydev->handle);
 874  err_free_joydev:
 875         put_device(&joydev->dev);
 876  err_free_minor:
 877         input_free_minor(minor);
 878         return error;
 879 }
 880
 881 static void joydev_disconnect(struct input_handle *handle)
 882 {
 883         struct joydev *joydev = handle->private;
 884
 885         device_del(&joydev->dev);
 886         joydev_cleanup(joydev);
 887         input_free_minor(MINOR(joydev->dev.devt));
 888         input_unregister_handle(handle);
 889         put_device(&joydev->dev);
 890 }
 891
 892 static const struct input_device_id joydev_ids[] = {
 893         {
 894                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 895                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 896                 .evbit = { BIT_MASK(EV_ABS) },
 897                 .absbit = { BIT_MASK(ABS_X) },
 898         },
 899         {
 900                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 901                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 902                 .evbit = { BIT_MASK(EV_ABS) },
 903                 .absbit = { BIT_MASK(ABS_WHEEL) },
 904         },
 905         {
 906                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 907                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
 908                 .evbit = { BIT_MASK(EV_ABS) },
 909                 .absbit = { BIT_MASK(ABS_THROTTLE) },
 910         },
 911         {
 912                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 913                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 914                 .evbit = { BIT_MASK(EV_KEY) },
 915                 .keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
 916         },
 917         {
 918                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 919                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 920                 .evbit = { BIT_MASK(EV_KEY) },
 921                 .keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
 922         },
 923         {
 924                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 925                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
 926                 .evbit = { BIT_MASK(EV_KEY) },
 927                 .keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
 928         },
 929         { }     /* Terminating entry */
 930 };
 931
 932 MODULE_DEVICE_TABLE(input, joydev_ids);
 933
 934 static struct input_handler joydev_handler = {
 935         .event          = joydev_event,
 936         .match          = joydev_match,
 937         .connect        = joydev_connect,
 938         .disconnect     = joydev_disconnect,
 939         .legacy_minors  = true,
 940         .minor          = JOYDEV_MINOR_BASE,
 941         .name           = "joydev",
 942         .id_table       = joydev_ids,
 943 };
 944
 945 static int __init joydev_init(void)
 946 {
 947         return input_register_handler(&joydev_handler);
 948 }
 949
 950 static void __exit joydev_exit(void)
 951 {
 952         input_unregister_handler(&joydev_handler);
 953 }
 954
 955 module_init(joydev_init);
 956 module_exit(joydev_exit);