linux/drivers/input/joydev.c
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   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
  29MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  30MODULE_DESCRIPTION("Joystick device interfaces");
  31MODULE_SUPPORTED_DEVICE("input/js");
  32MODULE_LICENSE("GPL");
  33
  34#define JOYDEV_MINOR_BASE       0
  35#define JOYDEV_MINORS           16
  36#define JOYDEV_BUFFER_SIZE      64
  37
  38struct joydev {
  39        int exist;
  40        int open;
  41        int minor;
  42        char name[16];
  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
  50        struct js_corr corr[ABS_MAX + 1];
  51        struct JS_DATA_SAVE_TYPE glue;
  52        int nabs;
  53        int nkey;
  54        __u16 keymap[KEY_MAX - BTN_MISC + 1];
  55        __u16 keypam[KEY_MAX - BTN_MISC + 1];
  56        __u8 absmap[ABS_MAX + 1];
  57        __u8 abspam[ABS_MAX + 1];
  58        __s16 abs[ABS_MAX + 1];
  59};
  60
  61struct joydev_client {
  62        struct js_event buffer[JOYDEV_BUFFER_SIZE];
  63        int head;
  64        int tail;
  65        int startup;
  66        spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  67        struct fasync_struct *fasync;
  68        struct joydev *joydev;
  69        struct list_head node;
  70};
  71
  72static struct joydev *joydev_table[JOYDEV_MINORS];
  73static DEFINE_MUTEX(joydev_table_mutex);
  74
  75static int joydev_correct(int value, struct js_corr *corr)
  76{
  77        switch (corr->type) {
  78
  79        case JS_CORR_NONE:
  80                break;
  81
  82        case JS_CORR_BROKEN:
  83                value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
  84                        ((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
  85                        ((corr->coef[2] * (value - corr->coef[0])) >> 14);
  86                break;
  87
  88        default:
  89                return 0;
  90        }
  91
  92        return value < -32767 ? -32767 : (value > 32767 ? 32767 : value);
  93}
  94
  95static void joydev_pass_event(struct joydev_client *client,
  96                              struct js_event *event)
  97{
  98        struct joydev *joydev = client->joydev;
  99
 100        /*
 101         * IRQs already disabled, just acquire the lock
 102         */
 103        spin_lock(&client->buffer_lock);
 104
 105        client->buffer[client->head] = *event;
 106
 107        if (client->startup == joydev->nabs + joydev->nkey) {
 108                client->head++;
 109                client->head &= JOYDEV_BUFFER_SIZE - 1;
 110                if (client->tail == client->head)
 111                        client->startup = 0;
 112        }
 113
 114        spin_unlock(&client->buffer_lock);
 115
 116        kill_fasync(&client->fasync, SIGIO, POLL_IN);
 117}
 118
 119static void joydev_event(struct input_handle *handle,
 120                         unsigned int type, unsigned int code, int value)
 121{
 122        struct joydev *joydev = handle->private;
 123        struct joydev_client *client;
 124        struct js_event event;
 125
 126        switch (type) {
 127
 128        case EV_KEY:
 129                if (code < BTN_MISC || value == 2)
 130                        return;
 131                event.type = JS_EVENT_BUTTON;
 132                event.number = joydev->keymap[code - BTN_MISC];
 133                event.value = value;
 134                break;
 135
 136        case EV_ABS:
 137                event.type = JS_EVENT_AXIS;
 138                event.number = joydev->absmap[code];
 139                event.value = joydev_correct(value,
 140                                        &joydev->corr[event.number]);
 141                if (event.value == joydev->abs[event.number])
 142                        return;
 143                joydev->abs[event.number] = event.value;
 144                break;
 145
 146        default:
 147                return;
 148        }
 149
 150        event.time = jiffies_to_msecs(jiffies);
 151
 152        rcu_read_lock();
 153        list_for_each_entry_rcu(client, &joydev->client_list, node)
 154                joydev_pass_event(client, &event);
 155        rcu_read_unlock();
 156
 157        wake_up_interruptible(&joydev->wait);
 158}
 159
 160static int joydev_fasync(int fd, struct file *file, int on)
 161{
 162        int retval;
 163        struct joydev_client *client = file->private_data;
 164
 165        retval = fasync_helper(fd, file, on, &client->fasync);
 166
 167        return retval < 0 ? retval : 0;
 168}
 169
 170static void joydev_free(struct device *dev)
 171{
 172        struct joydev *joydev = container_of(dev, struct joydev, dev);
 173
 174        kfree(joydev);
 175}
 176
 177static void joydev_attach_client(struct joydev *joydev,
 178                                 struct joydev_client *client)
 179{
 180        spin_lock(&joydev->client_lock);
 181        list_add_tail_rcu(&client->node, &joydev->client_list);
 182        spin_unlock(&joydev->client_lock);
 183        synchronize_rcu();
 184}
 185
 186static void joydev_detach_client(struct joydev *joydev,
 187                                 struct joydev_client *client)
 188{
 189        spin_lock(&joydev->client_lock);
 190        list_del_rcu(&client->node);
 191        spin_unlock(&joydev->client_lock);
 192        synchronize_rcu();
 193}
 194
 195static int joydev_open_device(struct joydev *joydev)
 196{
 197        int retval;
 198
 199        retval = mutex_lock_interruptible(&joydev->mutex);
 200        if (retval)
 201                return retval;
 202
 203        if (!joydev->exist)
 204                retval = -ENODEV;
 205        else if (!joydev->open++) {
 206                retval = input_open_device(&joydev->handle);
 207                if (retval)
 208                        joydev->open--;
 209        }
 210
 211        mutex_unlock(&joydev->mutex);
 212        return retval;
 213}
 214
 215static void joydev_close_device(struct joydev *joydev)
 216{
 217        mutex_lock(&joydev->mutex);
 218
 219        if (joydev->exist && !--joydev->open)
 220                input_close_device(&joydev->handle);
 221
 222        mutex_unlock(&joydev->mutex);
 223}
 224
 225/*
 226 * Wake up users waiting for IO so they can disconnect from
 227 * dead device.
 228 */
 229static void joydev_hangup(struct joydev *joydev)
 230{
 231        struct joydev_client *client;
 232
 233        spin_lock(&joydev->client_lock);
 234        list_for_each_entry(client, &joydev->client_list, node)
 235                kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 236        spin_unlock(&joydev->client_lock);
 237
 238        wake_up_interruptible(&joydev->wait);
 239}
 240
 241static int joydev_release(struct inode *inode, struct file *file)
 242{
 243        struct joydev_client *client = file->private_data;
 244        struct joydev *joydev = client->joydev;
 245
 246        joydev_fasync(-1, file, 0);
 247        joydev_detach_client(joydev, client);
 248        kfree(client);
 249
 250        joydev_close_device(joydev);
 251        put_device(&joydev->dev);
 252
 253        return 0;
 254}
 255
 256static int joydev_open(struct inode *inode, struct file *file)
 257{
 258        struct joydev_client *client;
 259        struct joydev *joydev;
 260        int i = iminor(inode) - JOYDEV_MINOR_BASE;
 261        int error;
 262
 263        if (i >= JOYDEV_MINORS)
 264                return -ENODEV;
 265
 266        error = mutex_lock_interruptible(&joydev_table_mutex);
 267        if (error)
 268                return error;
 269        joydev = joydev_table[i];
 270        if (joydev)
 271                get_device(&joydev->dev);
 272        mutex_unlock(&joydev_table_mutex);
 273
 274        if (!joydev)
 275                return -ENODEV;
 276
 277        client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
 278        if (!client) {
 279                error = -ENOMEM;
 280                goto err_put_joydev;
 281        }
 282
 283        spin_lock_init(&client->buffer_lock);
 284        client->joydev = joydev;
 285        joydev_attach_client(joydev, client);
 286
 287        error = joydev_open_device(joydev);
 288        if (error)
 289                goto err_free_client;
 290
 291        file->private_data = client;
 292        return 0;
 293
 294 err_free_client:
 295        joydev_detach_client(joydev, client);
 296        kfree(client);
 297 err_put_joydev:
 298        put_device(&joydev->dev);
 299        return error;
 300}
 301
 302static int joydev_generate_startup_event(struct joydev_client *client,
 303                                         struct input_dev *input,
 304                                         struct js_event *event)
 305{
 306        struct joydev *joydev = client->joydev;
 307        int have_event;
 308
 309        spin_lock_irq(&client->buffer_lock);
 310
 311        have_event = client->startup < joydev->nabs + joydev->nkey;
 312
 313        if (have_event) {
 314
 315                event->time = jiffies_to_msecs(jiffies);
 316                if (client->startup < joydev->nkey) {
 317                        event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 318                        event->number = client->startup;
 319                        event->value = !!test_bit(joydev->keypam[event->number],
 320                                                  input->key);
 321                } else {
 322                        event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
 323                        event->number = client->startup - joydev->nkey;
 324                        event->value = joydev->abs[event->number];
 325                }
 326                client->startup++;
 327        }
 328
 329        spin_unlock_irq(&client->buffer_lock);
 330
 331        return have_event;
 332}
 333
 334static int joydev_fetch_next_event(struct joydev_client *client,
 335                                   struct js_event *event)
 336{
 337        int have_event;
 338
 339        spin_lock_irq(&client->buffer_lock);
 340
 341        have_event = client->head != client->tail;
 342        if (have_event) {
 343                *event = client->buffer[client->tail++];
 344                client->tail &= JOYDEV_BUFFER_SIZE - 1;
 345        }
 346
 347        spin_unlock_irq(&client->buffer_lock);
 348
 349        return have_event;
 350}
 351
 352/*
 353 * Old joystick interface
 354 */
 355static ssize_t joydev_0x_read(struct joydev_client *client,
 356                              struct input_dev *input,
 357                              char __user *buf)
 358{
 359        struct joydev *joydev = client->joydev;
 360        struct JS_DATA_TYPE data;
 361        int i;
 362
 363        spin_lock_irq(&input->event_lock);
 364
 365        /*
 366         * Get device state
 367         */
 368        for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 369                data.buttons |=
 370                        test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 371        data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 372        data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
 373
 374        /*
 375         * Reset reader's event queue
 376         */
 377        spin_lock(&client->buffer_lock);
 378        client->startup = 0;
 379        client->tail = client->head;
 380        spin_unlock(&client->buffer_lock);
 381
 382        spin_unlock_irq(&input->event_lock);
 383
 384        if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 385                return -EFAULT;
 386
 387        return sizeof(struct JS_DATA_TYPE);
 388}
 389
 390static inline int joydev_data_pending(struct joydev_client *client)
 391{
 392        struct joydev *joydev = client->joydev;
 393
 394        return client->startup < joydev->nabs + joydev->nkey ||
 395                client->head != client->tail;
 396}
 397
 398static ssize_t joydev_read(struct file *file, char __user *buf,
 399                           size_t count, loff_t *ppos)
 400{
 401        struct joydev_client *client = file->private_data;
 402        struct joydev *joydev = client->joydev;
 403        struct input_dev *input = joydev->handle.dev;
 404        struct js_event event;
 405        int retval;
 406
 407        if (!joydev->exist)
 408                return -ENODEV;
 409
 410        if (count < sizeof(struct js_event))
 411                return -EINVAL;
 412
 413        if (count == sizeof(struct JS_DATA_TYPE))
 414                return joydev_0x_read(client, input, buf);
 415
 416        if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
 417                return -EAGAIN;
 418
 419        retval = wait_event_interruptible(joydev->wait,
 420                        !joydev->exist || joydev_data_pending(client));
 421        if (retval)
 422                return retval;
 423
 424        if (!joydev->exist)
 425                return -ENODEV;
 426
 427        while (retval + sizeof(struct js_event) <= count &&
 428               joydev_generate_startup_event(client, input, &event)) {
 429
 430                if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 431                        return -EFAULT;
 432
 433                retval += sizeof(struct js_event);
 434        }
 435
 436        while (retval + sizeof(struct js_event) <= count &&
 437               joydev_fetch_next_event(client, &event)) {
 438
 439                if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 440                        return -EFAULT;
 441
 442                retval += sizeof(struct js_event);
 443        }
 444
 445        return retval;
 446}
 447
 448/* No kernel lock - fine */
 449static unsigned int joydev_poll(struct file *file, poll_table *wait)
 450{
 451        struct joydev_client *client = file->private_data;
 452        struct joydev *joydev = client->joydev;
 453
 454        poll_wait(file, &joydev->wait, wait);
 455        return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
 456                (joydev->exist ?  0 : (POLLHUP | POLLERR));
 457}
 458
 459static int joydev_ioctl_common(struct joydev *joydev,
 460                                unsigned int cmd, void __user *argp)
 461{
 462        struct input_dev *dev = joydev->handle.dev;
 463        int i, j;
 464
 465        switch (cmd) {
 466
 467        case JS_SET_CAL:
 468                return copy_from_user(&joydev->glue.JS_CORR, argp,
 469                                sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 470
 471        case JS_GET_CAL:
 472                return copy_to_user(argp, &joydev->glue.JS_CORR,
 473                                sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 474
 475        case JS_SET_TIMEOUT:
 476                return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 477
 478        case JS_GET_TIMEOUT:
 479                return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 480
 481        case JSIOCGVERSION:
 482                return put_user(JS_VERSION, (__u32 __user *) argp);
 483
 484        case JSIOCGAXES:
 485                return put_user(joydev->nabs, (__u8 __user *) argp);
 486
 487        case JSIOCGBUTTONS:
 488                return put_user(joydev->nkey, (__u8 __user *) argp);
 489
 490        case JSIOCSCORR:
 491                if (copy_from_user(joydev->corr, argp,
 492                              sizeof(joydev->corr[0]) * joydev->nabs))
 493                    return -EFAULT;
 494
 495                for (i = 0; i < joydev->nabs; i++) {
 496                        j = joydev->abspam[i];
 497                        joydev->abs[i] = joydev_correct(dev->abs[j],
 498                                                        &joydev->corr[i]);
 499                }
 500                return 0;
 501
 502        case JSIOCGCORR:
 503                return copy_to_user(argp, joydev->corr,
 504                        sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
 505
 506        case JSIOCSAXMAP:
 507                if (copy_from_user(joydev->abspam, argp,
 508                                   sizeof(__u8) * (ABS_MAX + 1)))
 509                        return -EFAULT;
 510
 511                for (i = 0; i < joydev->nabs; i++) {
 512                        if (joydev->abspam[i] > ABS_MAX)
 513                                return -EINVAL;
 514                        joydev->absmap[joydev->abspam[i]] = i;
 515                }
 516                return 0;
 517
 518        case JSIOCGAXMAP:
 519                return copy_to_user(argp, joydev->abspam,
 520                        sizeof(__u8) * (ABS_MAX + 1)) ? -EFAULT : 0;
 521
 522        case JSIOCSBTNMAP:
 523                if (copy_from_user(joydev->keypam, argp,
 524                                   sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)))
 525                        return -EFAULT;
 526
 527                for (i = 0; i < joydev->nkey; i++) {
 528                        if (joydev->keypam[i] > KEY_MAX ||
 529                            joydev->keypam[i] < BTN_MISC)
 530                                return -EINVAL;
 531                        joydev->keymap[joydev->keypam[i] - BTN_MISC] = i;
 532                }
 533
 534                return 0;
 535
 536        case JSIOCGBTNMAP:
 537                return copy_to_user(argp, joydev->keypam,
 538                        sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)) ? -EFAULT : 0;
 539
 540        default:
 541                if ((cmd & ~IOCSIZE_MASK) == JSIOCGNAME(0)) {
 542                        int len;
 543                        if (!dev->name)
 544                                return 0;
 545                        len = strlen(dev->name) + 1;
 546                        if (len > _IOC_SIZE(cmd))
 547                                len = _IOC_SIZE(cmd);
 548                        if (copy_to_user(argp, dev->name, len))
 549                                return -EFAULT;
 550                        return len;
 551                }
 552        }
 553        return -EINVAL;
 554}
 555
 556#ifdef CONFIG_COMPAT
 557static long joydev_compat_ioctl(struct file *file,
 558                                unsigned int cmd, unsigned long arg)
 559{
 560        struct joydev_client *client = file->private_data;
 561        struct joydev *joydev = client->joydev;
 562        void __user *argp = (void __user *)arg;
 563        s32 tmp32;
 564        struct JS_DATA_SAVE_TYPE_32 ds32;
 565        int retval;
 566
 567        retval = mutex_lock_interruptible(&joydev->mutex);
 568        if (retval)
 569                return retval;
 570
 571        if (!joydev->exist) {
 572                retval = -ENODEV;
 573                goto out;
 574        }
 575
 576        switch (cmd) {
 577
 578        case JS_SET_TIMELIMIT:
 579                retval = get_user(tmp32, (s32 __user *) arg);
 580                if (retval == 0)
 581                        joydev->glue.JS_TIMELIMIT = tmp32;
 582                break;
 583
 584        case JS_GET_TIMELIMIT:
 585                tmp32 = joydev->glue.JS_TIMELIMIT;
 586                retval = put_user(tmp32, (s32 __user *) arg);
 587                break;
 588
 589        case JS_SET_ALL:
 590                retval = copy_from_user(&ds32, argp,
 591                                        sizeof(ds32)) ? -EFAULT : 0;
 592                if (retval == 0) {
 593                        joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
 594                        joydev->glue.BUSY          = ds32.BUSY;
 595                        joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
 596                        joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
 597                        joydev->glue.JS_SAVE       = ds32.JS_SAVE;
 598                        joydev->glue.JS_CORR       = ds32.JS_CORR;
 599                }
 600                break;
 601
 602        case JS_GET_ALL:
 603                ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
 604                ds32.BUSY          = joydev->glue.BUSY;
 605                ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
 606                ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
 607                ds32.JS_SAVE       = joydev->glue.JS_SAVE;
 608                ds32.JS_CORR       = joydev->glue.JS_CORR;
 609
 610                retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
 611                break;
 612
 613        default:
 614                retval = joydev_ioctl_common(joydev, cmd, argp);
 615                break;
 616        }
 617
 618 out:
 619        mutex_unlock(&joydev->mutex);
 620        return retval;
 621}
 622#endif /* CONFIG_COMPAT */
 623
 624static long joydev_ioctl(struct file *file,
 625                         unsigned int cmd, unsigned long arg)
 626{
 627        struct joydev_client *client = file->private_data;
 628        struct joydev *joydev = client->joydev;
 629        void __user *argp = (void __user *)arg;
 630        int retval;
 631
 632        retval = mutex_lock_interruptible(&joydev->mutex);
 633        if (retval)
 634                return retval;
 635
 636        if (!joydev->exist) {
 637                retval = -ENODEV;
 638                goto out;
 639        }
 640
 641        switch (cmd) {
 642
 643        case JS_SET_TIMELIMIT:
 644                retval = get_user(joydev->glue.JS_TIMELIMIT,
 645                                  (long __user *) arg);
 646                break;
 647
 648        case JS_GET_TIMELIMIT:
 649                retval = put_user(joydev->glue.JS_TIMELIMIT,
 650                                  (long __user *) arg);
 651                break;
 652
 653        case JS_SET_ALL:
 654                retval = copy_from_user(&joydev->glue, argp,
 655                                        sizeof(joydev->glue)) ? -EFAULT: 0;
 656                break;
 657
 658        case JS_GET_ALL:
 659                retval = copy_to_user(argp, &joydev->glue,
 660                                      sizeof(joydev->glue)) ? -EFAULT : 0;
 661                break;
 662
 663        default:
 664                retval = joydev_ioctl_common(joydev, cmd, argp);
 665                break;
 666        }
 667 out:
 668        mutex_unlock(&joydev->mutex);
 669        return retval;
 670}
 671
 672static const struct file_operations joydev_fops = {
 673        .owner          = THIS_MODULE,
 674        .read           = joydev_read,
 675        .poll           = joydev_poll,
 676        .open           = joydev_open,
 677        .release        = joydev_release,
 678        .unlocked_ioctl = joydev_ioctl,
 679#ifdef CONFIG_COMPAT
 680        .compat_ioctl   = joydev_compat_ioctl,
 681#endif
 682        .fasync         = joydev_fasync,
 683};
 684
 685static int joydev_install_chrdev(struct joydev *joydev)
 686{
 687        joydev_table[joydev->minor] = joydev;
 688        return 0;
 689}
 690
 691static void joydev_remove_chrdev(struct joydev *joydev)
 692{
 693        mutex_lock(&joydev_table_mutex);
 694        joydev_table[joydev->minor] = NULL;
 695        mutex_unlock(&joydev_table_mutex);
 696}
 697
 698/*
 699 * Mark device non-existant. This disables writes, ioctls and
 700 * prevents new users from opening the device. Already posted
 701 * blocking reads will stay, however new ones will fail.
 702 */
 703static void joydev_mark_dead(struct joydev *joydev)
 704{
 705        mutex_lock(&joydev->mutex);
 706        joydev->exist = 0;
 707        mutex_unlock(&joydev->mutex);
 708}
 709
 710static void joydev_cleanup(struct joydev *joydev)
 711{
 712        struct input_handle *handle = &joydev->handle;
 713
 714        joydev_mark_dead(joydev);
 715        joydev_hangup(joydev);
 716        joydev_remove_chrdev(joydev);
 717
 718        /* joydev is marked dead so noone else accesses joydev->open */
 719        if (joydev->open)
 720                input_close_device(handle);
 721}
 722
 723static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 724                          const struct input_device_id *id)
 725{
 726        struct joydev *joydev;
 727        int i, j, t, minor;
 728        int error;
 729
 730        for (minor = 0; minor < JOYDEV_MINORS; minor++)
 731                if (!joydev_table[minor])
 732                        break;
 733
 734        if (minor == JOYDEV_MINORS) {
 735                printk(KERN_ERR "joydev: no more free joydev devices\n");
 736                return -ENFILE;
 737        }
 738
 739        joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
 740        if (!joydev)
 741                return -ENOMEM;
 742
 743        INIT_LIST_HEAD(&joydev->client_list);
 744        spin_lock_init(&joydev->client_lock);
 745        mutex_init(&joydev->mutex);
 746        init_waitqueue_head(&joydev->wait);
 747
 748        snprintf(joydev->name, sizeof(joydev->name), "js%d", minor);
 749        joydev->exist = 1;
 750        joydev->minor = minor;
 751
 752        joydev->exist = 1;
 753        joydev->handle.dev = dev;
 754        joydev->handle.name = joydev->name;
 755        joydev->handle.handler = handler;
 756        joydev->handle.private = joydev;
 757
 758        for (i = 0; i < ABS_MAX + 1; i++)
 759                if (test_bit(i, dev->absbit)) {
 760                        joydev->absmap[i] = joydev->nabs;
 761                        joydev->abspam[joydev->nabs] = i;
 762                        joydev->nabs++;
 763                }
 764
 765        for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 766                if (test_bit(i + BTN_MISC, dev->keybit)) {
 767                        joydev->keymap[i] = joydev->nkey;
 768                        joydev->keypam[joydev->nkey] = i + BTN_MISC;
 769                        joydev->nkey++;
 770                }
 771
 772        for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 773                if (test_bit(i + BTN_MISC, dev->keybit)) {
 774                        joydev->keymap[i] = joydev->nkey;
 775                        joydev->keypam[joydev->nkey] = i + BTN_MISC;
 776                        joydev->nkey++;
 777                }
 778
 779        for (i = 0; i < joydev->nabs; i++) {
 780                j = joydev->abspam[i];
 781                if (dev->absmax[j] == dev->absmin[j]) {
 782                        joydev->corr[i].type = JS_CORR_NONE;
 783                        joydev->abs[i] = dev->abs[j];
 784                        continue;
 785                }
 786                joydev->corr[i].type = JS_CORR_BROKEN;
 787                joydev->corr[i].prec = dev->absfuzz[j];
 788                joydev->corr[i].coef[0] =
 789                        (dev->absmax[j] + dev->absmin[j]) / 2 - dev->absflat[j];
 790                joydev->corr[i].coef[1] =
 791                        (dev->absmax[j] + dev->absmin[j]) / 2 + dev->absflat[j];
 792
 793                t = (dev->absmax[j] - dev->absmin[j]) / 2 - 2 * dev->absflat[j];
 794                if (t) {
 795                        joydev->corr[i].coef[2] = (1 << 29) / t;
 796                        joydev->corr[i].coef[3] = (1 << 29) / t;
 797
 798                        joydev->abs[i] = joydev_correct(dev->abs[j],
 799                                                        joydev->corr + i);
 800                }
 801        }
 802
 803        strlcpy(joydev->dev.bus_id, joydev->name, sizeof(joydev->dev.bus_id));
 804        joydev->dev.devt = MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor);
 805        joydev->dev.class = &input_class;
 806        joydev->dev.parent = &dev->dev;
 807        joydev->dev.release = joydev_free;
 808        device_initialize(&joydev->dev);
 809
 810        error = input_register_handle(&joydev->handle);
 811        if (error)
 812                goto err_free_joydev;
 813
 814        error = joydev_install_chrdev(joydev);
 815        if (error)
 816                goto err_unregister_handle;
 817
 818        error = device_add(&joydev->dev);
 819        if (error)
 820                goto err_cleanup_joydev;
 821
 822        return 0;
 823
 824 err_cleanup_joydev:
 825        joydev_cleanup(joydev);
 826 err_unregister_handle:
 827        input_unregister_handle(&joydev->handle);
 828 err_free_joydev:
 829        put_device(&joydev->dev);
 830        return error;
 831}
 832
 833static void joydev_disconnect(struct input_handle *handle)
 834{
 835        struct joydev *joydev = handle->private;
 836
 837        device_del(&joydev->dev);
 838        joydev_cleanup(joydev);
 839        input_unregister_handle(handle);
 840        put_device(&joydev->dev);
 841}
 842
 843static const struct input_device_id joydev_blacklist[] = {
 844        {
 845                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 846                                INPUT_DEVICE_ID_MATCH_KEYBIT,
 847                .evbit = { BIT_MASK(EV_KEY) },
 848                .keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
 849        },      /* Avoid itouchpads, touchscreens and tablets */
 850        { }     /* Terminating entry */
 851};
 852
 853static const struct input_device_id joydev_ids[] = {
 854        {
 855                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 856                                INPUT_DEVICE_ID_MATCH_ABSBIT,
 857                .evbit = { BIT_MASK(EV_ABS) },
 858                .absbit = { BIT_MASK(ABS_X) },
 859        },
 860        {
 861                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 862                                INPUT_DEVICE_ID_MATCH_ABSBIT,
 863                .evbit = { BIT_MASK(EV_ABS) },
 864                .absbit = { BIT_MASK(ABS_WHEEL) },
 865        },
 866        {
 867                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 868                                INPUT_DEVICE_ID_MATCH_ABSBIT,
 869                .evbit = { BIT_MASK(EV_ABS) },
 870                .absbit = { BIT_MASK(ABS_THROTTLE) },
 871        },
 872        { }     /* Terminating entry */
 873};
 874
 875MODULE_DEVICE_TABLE(input, joydev_ids);
 876
 877static struct input_handler joydev_handler = {
 878        .event          = joydev_event,
 879        .connect        = joydev_connect,
 880        .disconnect     = joydev_disconnect,
 881        .fops           = &joydev_fops,
 882        .minor          = JOYDEV_MINOR_BASE,
 883        .name           = "joydev",
 884        .id_table       = joydev_ids,
 885        .blacklist      = joydev_blacklist,
 886};
 887
 888static int __init joydev_init(void)
 889{
 890        return input_register_handler(&joydev_handler);
 891}
 892
 893static void __exit joydev_exit(void)
 894{
 895        input_unregister_handler(&joydev_handler);
 896}
 897
 898module_init(joydev_init);
 899module_exit(joydev_exit);
 900