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#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
  31MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  32MODULE_DESCRIPTION("Joystick device interfaces");
  33MODULE_SUPPORTED_DEVICE("input/js");
  34MODULE_LICENSE("GPL");
  35
  36#define JOYDEV_MINOR_BASE       0
  37#define JOYDEV_MINORS           16
  38#define JOYDEV_BUFFER_SIZE      64
  39
  40struct joydev {
  41        int open;
  42        int minor;
  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        bool exist;
  50
  51        struct js_corr corr[ABS_CNT];
  52        struct JS_DATA_SAVE_TYPE glue;
  53        int nabs;
  54        int nkey;
  55        __u16 keymap[KEY_MAX - BTN_MISC + 1];
  56        __u16 keypam[KEY_MAX - BTN_MISC + 1];
  57        __u8 absmap[ABS_CNT];
  58        __u8 abspam[ABS_CNT];
  59        __s16 abs[ABS_CNT];
  60};
  61
  62struct joydev_client {
  63        struct js_event buffer[JOYDEV_BUFFER_SIZE];
  64        int head;
  65        int tail;
  66        int startup;
  67        spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  68        struct fasync_struct *fasync;
  69        struct joydev *joydev;
  70        struct list_head node;
  71};
  72
  73static struct joydev *joydev_table[JOYDEV_MINORS];
  74static DEFINE_MUTEX(joydev_table_mutex);
  75
  76static int joydev_correct(int value, struct js_corr *corr)
  77{
  78        switch (corr->type) {
  79
  80        case JS_CORR_NONE:
  81                break;
  82
  83        case JS_CORR_BROKEN:
  84                value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
  85                        ((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
  86                        ((corr->coef[2] * (value - corr->coef[0])) >> 14);
  87                break;
  88
  89        default:
  90                return 0;
  91        }
  92
  93        return value < -32767 ? -32767 : (value > 32767 ? 32767 : value);
  94}
  95
  96static void joydev_pass_event(struct joydev_client *client,
  97                              struct js_event *event)
  98{
  99        struct joydev *joydev = client->joydev;
 100
 101        /*
 102         * IRQs already disabled, just acquire the lock
 103         */
 104        spin_lock(&client->buffer_lock);
 105
 106        client->buffer[client->head] = *event;
 107
 108        if (client->startup == joydev->nabs + joydev->nkey) {
 109                client->head++;
 110                client->head &= JOYDEV_BUFFER_SIZE - 1;
 111                if (client->tail == client->head)
 112                        client->startup = 0;
 113        }
 114
 115        spin_unlock(&client->buffer_lock);
 116
 117        kill_fasync(&client->fasync, SIGIO, POLL_IN);
 118}
 119
 120static void joydev_event(struct input_handle *handle,
 121                         unsigned int type, unsigned int code, int value)
 122{
 123        struct joydev *joydev = handle->private;
 124        struct joydev_client *client;
 125        struct js_event event;
 126
 127        switch (type) {
 128
 129        case EV_KEY:
 130                if (code < BTN_MISC || value == 2)
 131                        return;
 132                event.type = JS_EVENT_BUTTON;
 133                event.number = joydev->keymap[code - BTN_MISC];
 134                event.value = value;
 135                break;
 136
 137        case EV_ABS:
 138                event.type = JS_EVENT_AXIS;
 139                event.number = joydev->absmap[code];
 140                event.value = joydev_correct(value,
 141                                        &joydev->corr[event.number]);
 142                if (event.value == joydev->abs[event.number])
 143                        return;
 144                joydev->abs[event.number] = event.value;
 145                break;
 146
 147        default:
 148                return;
 149        }
 150
 151        event.time = jiffies_to_msecs(jiffies);
 152
 153        rcu_read_lock();
 154        list_for_each_entry_rcu(client, &joydev->client_list, node)
 155                joydev_pass_event(client, &event);
 156        rcu_read_unlock();
 157
 158        wake_up_interruptible(&joydev->wait);
 159}
 160
 161static int joydev_fasync(int fd, struct file *file, int on)
 162{
 163        struct joydev_client *client = file->private_data;
 164
 165        return fasync_helper(fd, file, on, &client->fasync);
 166}
 167
 168static void joydev_free(struct device *dev)
 169{
 170        struct joydev *joydev = container_of(dev, struct joydev, dev);
 171
 172        input_put_device(joydev->handle.dev);
 173        kfree(joydev);
 174}
 175
 176static void joydev_attach_client(struct joydev *joydev,
 177                                 struct joydev_client *client)
 178{
 179        spin_lock(&joydev->client_lock);
 180        list_add_tail_rcu(&client->node, &joydev->client_list);
 181        spin_unlock(&joydev->client_lock);
 182}
 183
 184static void joydev_detach_client(struct joydev *joydev,
 185                                 struct joydev_client *client)
 186{
 187        spin_lock(&joydev->client_lock);
 188        list_del_rcu(&client->node);
 189        spin_unlock(&joydev->client_lock);
 190        synchronize_rcu();
 191}
 192
 193static int joydev_open_device(struct joydev *joydev)
 194{
 195        int retval;
 196
 197        retval = mutex_lock_interruptible(&joydev->mutex);
 198        if (retval)
 199                return retval;
 200
 201        if (!joydev->exist)
 202                retval = -ENODEV;
 203        else if (!joydev->open++) {
 204                retval = input_open_device(&joydev->handle);
 205                if (retval)
 206                        joydev->open--;
 207        }
 208
 209        mutex_unlock(&joydev->mutex);
 210        return retval;
 211}
 212
 213static void joydev_close_device(struct joydev *joydev)
 214{
 215        mutex_lock(&joydev->mutex);
 216
 217        if (joydev->exist && !--joydev->open)
 218                input_close_device(&joydev->handle);
 219
 220        mutex_unlock(&joydev->mutex);
 221}
 222
 223/*
 224 * Wake up users waiting for IO so they can disconnect from
 225 * dead device.
 226 */
 227static void joydev_hangup(struct joydev *joydev)
 228{
 229        struct joydev_client *client;
 230
 231        spin_lock(&joydev->client_lock);
 232        list_for_each_entry(client, &joydev->client_list, node)
 233                kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 234        spin_unlock(&joydev->client_lock);
 235
 236        wake_up_interruptible(&joydev->wait);
 237}
 238
 239static int joydev_release(struct inode *inode, struct file *file)
 240{
 241        struct joydev_client *client = file->private_data;
 242        struct joydev *joydev = client->joydev;
 243
 244        joydev_detach_client(joydev, client);
 245        kfree(client);
 246
 247        joydev_close_device(joydev);
 248        put_device(&joydev->dev);
 249
 250        return 0;
 251}
 252
 253static int joydev_open(struct inode *inode, struct file *file)
 254{
 255        struct joydev_client *client;
 256        struct joydev *joydev;
 257        int i = iminor(inode) - JOYDEV_MINOR_BASE;
 258        int error;
 259
 260        if (i >= JOYDEV_MINORS)
 261                return -ENODEV;
 262
 263        error = mutex_lock_interruptible(&joydev_table_mutex);
 264        if (error)
 265                return error;
 266        joydev = joydev_table[i];
 267        if (joydev)
 268                get_device(&joydev->dev);
 269        mutex_unlock(&joydev_table_mutex);
 270
 271        if (!joydev)
 272                return -ENODEV;
 273
 274        client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
 275        if (!client) {
 276                error = -ENOMEM;
 277                goto err_put_joydev;
 278        }
 279
 280        spin_lock_init(&client->buffer_lock);
 281        client->joydev = joydev;
 282        joydev_attach_client(joydev, client);
 283
 284        error = joydev_open_device(joydev);
 285        if (error)
 286                goto err_free_client;
 287
 288        file->private_data = client;
 289        nonseekable_open(inode, file);
 290
 291        return 0;
 292
 293 err_free_client:
 294        joydev_detach_client(joydev, client);
 295        kfree(client);
 296 err_put_joydev:
 297        put_device(&joydev->dev);
 298        return error;
 299}
 300
 301static int joydev_generate_startup_event(struct joydev_client *client,
 302                                         struct input_dev *input,
 303                                         struct js_event *event)
 304{
 305        struct joydev *joydev = client->joydev;
 306        int have_event;
 307
 308        spin_lock_irq(&client->buffer_lock);
 309
 310        have_event = client->startup < joydev->nabs + joydev->nkey;
 311
 312        if (have_event) {
 313
 314                event->time = jiffies_to_msecs(jiffies);
 315                if (client->startup < joydev->nkey) {
 316                        event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 317                        event->number = client->startup;
 318                        event->value = !!test_bit(joydev->keypam[event->number],
 319                                                  input->key);
 320                } else {
 321                        event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
 322                        event->number = client->startup - joydev->nkey;
 323                        event->value = joydev->abs[event->number];
 324                }
 325                client->startup++;
 326        }
 327
 328        spin_unlock_irq(&client->buffer_lock);
 329
 330        return have_event;
 331}
 332
 333static int joydev_fetch_next_event(struct joydev_client *client,
 334                                   struct js_event *event)
 335{
 336        int have_event;
 337
 338        spin_lock_irq(&client->buffer_lock);
 339
 340        have_event = client->head != client->tail;
 341        if (have_event) {
 342                *event = client->buffer[client->tail++];
 343                client->tail &= JOYDEV_BUFFER_SIZE - 1;
 344        }
 345
 346        spin_unlock_irq(&client->buffer_lock);
 347
 348        return have_event;
 349}
 350
 351/*
 352 * Old joystick interface
 353 */
 354static ssize_t joydev_0x_read(struct joydev_client *client,
 355                              struct input_dev *input,
 356                              char __user *buf)
 357{
 358        struct joydev *joydev = client->joydev;
 359        struct JS_DATA_TYPE data;
 360        int i;
 361
 362        spin_lock_irq(&input->event_lock);
 363
 364        /*
 365         * Get device state
 366         */
 367        for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 368                data.buttons |=
 369                        test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 370        data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 371        data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
 372
 373        /*
 374         * Reset reader's event queue
 375         */
 376        spin_lock(&client->buffer_lock);
 377        client->startup = 0;
 378        client->tail = client->head;
 379        spin_unlock(&client->buffer_lock);
 380
 381        spin_unlock_irq(&input->event_lock);
 382
 383        if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 384                return -EFAULT;
 385
 386        return sizeof(struct JS_DATA_TYPE);
 387}
 388
 389static inline int joydev_data_pending(struct joydev_client *client)
 390{
 391        struct joydev *joydev = client->joydev;
 392
 393        return client->startup < joydev->nabs + joydev->nkey ||
 394                client->head != client->tail;
 395}
 396
 397static ssize_t joydev_read(struct file *file, char __user *buf,
 398                           size_t count, loff_t *ppos)
 399{
 400        struct joydev_client *client = file->private_data;
 401        struct joydev *joydev = client->joydev;
 402        struct input_dev *input = joydev->handle.dev;
 403        struct js_event event;
 404        int retval;
 405
 406        if (!joydev->exist)
 407                return -ENODEV;
 408
 409        if (count < sizeof(struct js_event))
 410                return -EINVAL;
 411
 412        if (count == sizeof(struct JS_DATA_TYPE))
 413                return joydev_0x_read(client, input, buf);
 414
 415        if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
 416                return -EAGAIN;
 417
 418        retval = wait_event_interruptible(joydev->wait,
 419                        !joydev->exist || joydev_data_pending(client));
 420        if (retval)
 421                return retval;
 422
 423        if (!joydev->exist)
 424                return -ENODEV;
 425
 426        while (retval + sizeof(struct js_event) <= count &&
 427               joydev_generate_startup_event(client, input, &event)) {
 428
 429                if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 430                        return -EFAULT;
 431
 432                retval += sizeof(struct js_event);
 433        }
 434
 435        while (retval + sizeof(struct js_event) <= count &&
 436               joydev_fetch_next_event(client, &event)) {
 437
 438                if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 439                        return -EFAULT;
 440
 441                retval += sizeof(struct js_event);
 442        }
 443
 444        return retval;
 445}
 446
 447/* No kernel lock - fine */
 448static unsigned int joydev_poll(struct file *file, poll_table *wait)
 449{
 450        struct joydev_client *client = file->private_data;
 451        struct joydev *joydev = client->joydev;
 452
 453        poll_wait(file, &joydev->wait, wait);
 454        return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
 455                (joydev->exist ?  0 : (POLLHUP | POLLERR));
 456}
 457
 458static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
 459                                     void __user *argp, size_t len)
 460{
 461        __u8 *abspam;
 462        int i;
 463        int retval = 0;
 464
 465        len = min(len, sizeof(joydev->abspam));
 466
 467        /* Validate the map. */
 468        abspam = kmalloc(len, GFP_KERNEL);
 469        if (!abspam)
 470                return -ENOMEM;
 471
 472        if (copy_from_user(abspam, argp, len)) {
 473                retval = -EFAULT;
 474                goto out;
 475        }
 476
 477        for (i = 0; i < joydev->nabs; i++) {
 478                if (abspam[i] > ABS_MAX) {
 479                        retval = -EINVAL;
 480                        goto out;
 481                }
 482        }
 483
 484        memcpy(joydev->abspam, abspam, len);
 485
 486        for (i = 0; i < joydev->nabs; i++)
 487                joydev->absmap[joydev->abspam[i]] = i;
 488
 489 out:
 490        kfree(abspam);
 491        return retval;
 492}
 493
 494static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
 495                                      void __user *argp, size_t len)
 496{
 497        __u16 *keypam;
 498        int i;
 499        int retval = 0;
 500
 501        len = min(len, sizeof(joydev->keypam));
 502
 503        /* Validate the map. */
 504        keypam = kmalloc(len, GFP_KERNEL);
 505        if (!keypam)
 506                return -ENOMEM;
 507
 508        if (copy_from_user(keypam, argp, len)) {
 509                retval = -EFAULT;
 510                goto out;
 511        }
 512
 513        for (i = 0; i < joydev->nkey; i++) {
 514                if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
 515                        retval = -EINVAL;
 516                        goto out;
 517                }
 518        }
 519
 520        memcpy(joydev->keypam, keypam, len);
 521
 522        for (i = 0; i < joydev->nkey; i++)
 523                joydev->keymap[keypam[i] - BTN_MISC] = i;
 524
 525 out:
 526        kfree(keypam);
 527        return retval;
 528}
 529
 530
 531static int joydev_ioctl_common(struct joydev *joydev,
 532                                unsigned int cmd, void __user *argp)
 533{
 534        struct input_dev *dev = joydev->handle.dev;
 535        size_t len;
 536        int i;
 537        const char *name;
 538
 539        /* Process fixed-sized commands. */
 540        switch (cmd) {
 541
 542        case JS_SET_CAL:
 543                return copy_from_user(&joydev->glue.JS_CORR, argp,
 544                                sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 545
 546        case JS_GET_CAL:
 547                return copy_to_user(argp, &joydev->glue.JS_CORR,
 548                                sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 549
 550        case JS_SET_TIMEOUT:
 551                return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 552
 553        case JS_GET_TIMEOUT:
 554                return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 555
 556        case JSIOCGVERSION:
 557                return put_user(JS_VERSION, (__u32 __user *) argp);
 558
 559        case JSIOCGAXES:
 560                return put_user(joydev->nabs, (__u8 __user *) argp);
 561
 562        case JSIOCGBUTTONS:
 563                return put_user(joydev->nkey, (__u8 __user *) argp);
 564
 565        case JSIOCSCORR:
 566                if (copy_from_user(joydev->corr, argp,
 567                              sizeof(joydev->corr[0]) * joydev->nabs))
 568                        return -EFAULT;
 569
 570                for (i = 0; i < joydev->nabs; i++) {
 571                        int val = input_abs_get_val(dev, joydev->abspam[i]);
 572                        joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
 573                }
 574                return 0;
 575
 576        case JSIOCGCORR:
 577                return copy_to_user(argp, joydev->corr,
 578                        sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
 579
 580        }
 581
 582        /*
 583         * Process variable-sized commands (the axis and button map commands
 584         * are considered variable-sized to decouple them from the values of
 585         * ABS_MAX and KEY_MAX).
 586         */
 587        switch (cmd & ~IOCSIZE_MASK) {
 588
 589        case (JSIOCSAXMAP & ~IOCSIZE_MASK):
 590                return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
 591
 592        case (JSIOCGAXMAP & ~IOCSIZE_MASK):
 593                len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
 594                return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
 595
 596        case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
 597                return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
 598
 599        case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
 600                len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
 601                return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
 602
 603        case JSIOCGNAME(0):
 604                name = dev->name;
 605                if (!name)
 606                        return 0;
 607
 608                len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
 609                return copy_to_user(argp, name, len) ? -EFAULT : len;
 610        }
 611
 612        return -EINVAL;
 613}
 614
 615#ifdef CONFIG_COMPAT
 616static long joydev_compat_ioctl(struct file *file,
 617                                unsigned int cmd, unsigned long arg)
 618{
 619        struct joydev_client *client = file->private_data;
 620        struct joydev *joydev = client->joydev;
 621        void __user *argp = (void __user *)arg;
 622        s32 tmp32;
 623        struct JS_DATA_SAVE_TYPE_32 ds32;
 624        int retval;
 625
 626        retval = mutex_lock_interruptible(&joydev->mutex);
 627        if (retval)
 628                return retval;
 629
 630        if (!joydev->exist) {
 631                retval = -ENODEV;
 632                goto out;
 633        }
 634
 635        switch (cmd) {
 636
 637        case JS_SET_TIMELIMIT:
 638                retval = get_user(tmp32, (s32 __user *) arg);
 639                if (retval == 0)
 640                        joydev->glue.JS_TIMELIMIT = tmp32;
 641                break;
 642
 643        case JS_GET_TIMELIMIT:
 644                tmp32 = joydev->glue.JS_TIMELIMIT;
 645                retval = put_user(tmp32, (s32 __user *) arg);
 646                break;
 647
 648        case JS_SET_ALL:
 649                retval = copy_from_user(&ds32, argp,
 650                                        sizeof(ds32)) ? -EFAULT : 0;
 651                if (retval == 0) {
 652                        joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
 653                        joydev->glue.BUSY          = ds32.BUSY;
 654                        joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
 655                        joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
 656                        joydev->glue.JS_SAVE       = ds32.JS_SAVE;
 657                        joydev->glue.JS_CORR       = ds32.JS_CORR;
 658                }
 659                break;
 660
 661        case JS_GET_ALL:
 662                ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
 663                ds32.BUSY          = joydev->glue.BUSY;
 664                ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
 665                ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
 666                ds32.JS_SAVE       = joydev->glue.JS_SAVE;
 667                ds32.JS_CORR       = joydev->glue.JS_CORR;
 668
 669                retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
 670                break;
 671
 672        default:
 673                retval = joydev_ioctl_common(joydev, cmd, argp);
 674                break;
 675        }
 676
 677 out:
 678        mutex_unlock(&joydev->mutex);
 679        return retval;
 680}
 681#endif /* CONFIG_COMPAT */
 682
 683static long joydev_ioctl(struct file *file,
 684                         unsigned int cmd, unsigned long arg)
 685{
 686        struct joydev_client *client = file->private_data;
 687        struct joydev *joydev = client->joydev;
 688        void __user *argp = (void __user *)arg;
 689        int retval;
 690
 691        retval = mutex_lock_interruptible(&joydev->mutex);
 692        if (retval)
 693                return retval;
 694
 695        if (!joydev->exist) {
 696                retval = -ENODEV;
 697                goto out;
 698        }
 699
 700        switch (cmd) {
 701
 702        case JS_SET_TIMELIMIT:
 703                retval = get_user(joydev->glue.JS_TIMELIMIT,
 704                                  (long __user *) arg);
 705                break;
 706
 707        case JS_GET_TIMELIMIT:
 708                retval = put_user(joydev->glue.JS_TIMELIMIT,
 709                                  (long __user *) arg);
 710                break;
 711
 712        case JS_SET_ALL:
 713                retval = copy_from_user(&joydev->glue, argp,
 714                                        sizeof(joydev->glue)) ? -EFAULT: 0;
 715                break;
 716
 717        case JS_GET_ALL:
 718                retval = copy_to_user(argp, &joydev->glue,
 719                                      sizeof(joydev->glue)) ? -EFAULT : 0;
 720                break;
 721
 722        default:
 723                retval = joydev_ioctl_common(joydev, cmd, argp);
 724                break;
 725        }
 726 out:
 727        mutex_unlock(&joydev->mutex);
 728        return retval;
 729}
 730
 731static const struct file_operations joydev_fops = {
 732        .owner          = THIS_MODULE,
 733        .read           = joydev_read,
 734        .poll           = joydev_poll,
 735        .open           = joydev_open,
 736        .release        = joydev_release,
 737        .unlocked_ioctl = joydev_ioctl,
 738#ifdef CONFIG_COMPAT
 739        .compat_ioctl   = joydev_compat_ioctl,
 740#endif
 741        .fasync         = joydev_fasync,
 742        .llseek         = no_llseek,
 743};
 744
 745static int joydev_install_chrdev(struct joydev *joydev)
 746{
 747        joydev_table[joydev->minor] = joydev;
 748        return 0;
 749}
 750
 751static void joydev_remove_chrdev(struct joydev *joydev)
 752{
 753        mutex_lock(&joydev_table_mutex);
 754        joydev_table[joydev->minor] = NULL;
 755        mutex_unlock(&joydev_table_mutex);
 756}
 757
 758/*
 759 * Mark device non-existent. This disables writes, ioctls and
 760 * prevents new users from opening the device. Already posted
 761 * blocking reads will stay, however new ones will fail.
 762 */
 763static void joydev_mark_dead(struct joydev *joydev)
 764{
 765        mutex_lock(&joydev->mutex);
 766        joydev->exist = false;
 767        mutex_unlock(&joydev->mutex);
 768}
 769
 770static void joydev_cleanup(struct joydev *joydev)
 771{
 772        struct input_handle *handle = &joydev->handle;
 773
 774        joydev_mark_dead(joydev);
 775        joydev_hangup(joydev);
 776        joydev_remove_chrdev(joydev);
 777
 778        /* joydev is marked dead so no one else accesses joydev->open */
 779        if (joydev->open)
 780                input_close_device(handle);
 781}
 782
 783
 784static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
 785{
 786        /* Avoid touchpads and touchscreens */
 787        if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_TOUCH, dev->keybit))
 788                return false;
 789
 790        /* Avoid tablets, digitisers and similar devices */
 791        if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
 792                return false;
 793
 794        return true;
 795}
 796
 797static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 798                          const struct input_device_id *id)
 799{
 800        struct joydev *joydev;
 801        int i, j, t, minor;
 802        int error;
 803
 804        for (minor = 0; minor < JOYDEV_MINORS; minor++)
 805                if (!joydev_table[minor])
 806                        break;
 807
 808        if (minor == JOYDEV_MINORS) {
 809                pr_err("no more free joydev devices\n");
 810                return -ENFILE;
 811        }
 812
 813        joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
 814        if (!joydev)
 815                return -ENOMEM;
 816
 817        INIT_LIST_HEAD(&joydev->client_list);
 818        spin_lock_init(&joydev->client_lock);
 819        mutex_init(&joydev->mutex);
 820        init_waitqueue_head(&joydev->wait);
 821
 822        dev_set_name(&joydev->dev, "js%d", minor);
 823        joydev->exist = true;
 824        joydev->minor = minor;
 825
 826        joydev->handle.dev = input_get_device(dev);
 827        joydev->handle.name = dev_name(&joydev->dev);
 828        joydev->handle.handler = handler;
 829        joydev->handle.private = joydev;
 830
 831        for (i = 0; i < ABS_CNT; i++)
 832                if (test_bit(i, dev->absbit)) {
 833                        joydev->absmap[i] = joydev->nabs;
 834                        joydev->abspam[joydev->nabs] = i;
 835                        joydev->nabs++;
 836                }
 837
 838        for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 839                if (test_bit(i + BTN_MISC, dev->keybit)) {
 840                        joydev->keymap[i] = joydev->nkey;
 841                        joydev->keypam[joydev->nkey] = i + BTN_MISC;
 842                        joydev->nkey++;
 843                }
 844
 845        for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 846                if (test_bit(i + BTN_MISC, dev->keybit)) {
 847                        joydev->keymap[i] = joydev->nkey;
 848                        joydev->keypam[joydev->nkey] = i + BTN_MISC;
 849                        joydev->nkey++;
 850                }
 851
 852        for (i = 0; i < joydev->nabs; i++) {
 853                j = joydev->abspam[i];
 854                if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
 855                        joydev->corr[i].type = JS_CORR_NONE;
 856                        joydev->abs[i] = input_abs_get_val(dev, j);
 857                        continue;
 858                }
 859                joydev->corr[i].type = JS_CORR_BROKEN;
 860                joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
 861
 862                t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
 863                joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
 864                joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
 865
 866                t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
 867                        - 2 * input_abs_get_flat(dev, j);
 868                if (t) {
 869                        joydev->corr[i].coef[2] = (1 << 29) / t;
 870                        joydev->corr[i].coef[3] = (1 << 29) / t;
 871
 872                        joydev->abs[i] =
 873                                joydev_correct(input_abs_get_val(dev, j),
 874                                               joydev->corr + i);
 875                }
 876        }
 877
 878        joydev->dev.devt = MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor);
 879        joydev->dev.class = &input_class;
 880        joydev->dev.parent = &dev->dev;
 881        joydev->dev.release = joydev_free;
 882        device_initialize(&joydev->dev);
 883
 884        error = input_register_handle(&joydev->handle);
 885        if (error)
 886                goto err_free_joydev;
 887
 888        error = joydev_install_chrdev(joydev);
 889        if (error)
 890                goto err_unregister_handle;
 891
 892        error = device_add(&joydev->dev);
 893        if (error)
 894                goto err_cleanup_joydev;
 895
 896        return 0;
 897
 898 err_cleanup_joydev:
 899        joydev_cleanup(joydev);
 900 err_unregister_handle:
 901        input_unregister_handle(&joydev->handle);
 902 err_free_joydev:
 903        put_device(&joydev->dev);
 904        return error;
 905}
 906
 907static void joydev_disconnect(struct input_handle *handle)
 908{
 909        struct joydev *joydev = handle->private;
 910
 911        device_del(&joydev->dev);
 912        joydev_cleanup(joydev);
 913        input_unregister_handle(handle);
 914        put_device(&joydev->dev);
 915}
 916
 917static const struct input_device_id joydev_ids[] = {
 918        {
 919                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 920                                INPUT_DEVICE_ID_MATCH_ABSBIT,
 921                .evbit = { BIT_MASK(EV_ABS) },
 922                .absbit = { BIT_MASK(ABS_X) },
 923        },
 924        {
 925                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 926                                INPUT_DEVICE_ID_MATCH_ABSBIT,
 927                .evbit = { BIT_MASK(EV_ABS) },
 928                .absbit = { BIT_MASK(ABS_WHEEL) },
 929        },
 930        {
 931                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 932                                INPUT_DEVICE_ID_MATCH_ABSBIT,
 933                .evbit = { BIT_MASK(EV_ABS) },
 934                .absbit = { BIT_MASK(ABS_THROTTLE) },
 935        },
 936        {
 937                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 938                                INPUT_DEVICE_ID_MATCH_KEYBIT,
 939                .evbit = { BIT_MASK(EV_KEY) },
 940                .keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
 941        },
 942        {
 943                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 944                                INPUT_DEVICE_ID_MATCH_KEYBIT,
 945                .evbit = { BIT_MASK(EV_KEY) },
 946                .keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
 947        },
 948        {
 949                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 950                                INPUT_DEVICE_ID_MATCH_KEYBIT,
 951                .evbit = { BIT_MASK(EV_KEY) },
 952                .keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
 953        },
 954        { }     /* Terminating entry */
 955};
 956
 957MODULE_DEVICE_TABLE(input, joydev_ids);
 958
 959static struct input_handler joydev_handler = {
 960        .event          = joydev_event,
 961        .match          = joydev_match,
 962        .connect        = joydev_connect,
 963        .disconnect     = joydev_disconnect,
 964        .fops           = &joydev_fops,
 965        .minor          = JOYDEV_MINOR_BASE,
 966        .name           = "joydev",
 967        .id_table       = joydev_ids,
 968};
 969
 970static int __init joydev_init(void)
 971{
 972        return input_register_handler(&joydev_handler);
 973}
 974
 975static void __exit joydev_exit(void)
 976{
 977        input_unregister_handler(&joydev_handler);
 978}
 979
 980module_init(joydev_init);
 981module_exit(joydev_exit);
 982
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