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 <asm/system.h>
  17#include <linux/delay.h>
  18#include <linux/errno.h>
  19#include <linux/joystick.h>
  20#include <linux/input.h>
  21#include <linux/kernel.h>
  22#include <linux/major.h>
  23#include <linux/sched.h>
  24#include <linux/slab.h>
  25#include <linux/mm.h>
  26#include <linux/miscdevice.h>
  27#include <linux/module.h>
  28#include <linux/poll.h>
  29#include <linux/init.h>
  30#include <linux/device.h>
  31
  32MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  33MODULE_DESCRIPTION("Joystick device interfaces");
  34MODULE_SUPPORTED_DEVICE("input/js");
  35MODULE_LICENSE("GPL");
  36
  37#define JOYDEV_MINOR_BASE       0
  38#define JOYDEV_MINORS           16
  39#define JOYDEV_BUFFER_SIZE      64
  40
  41struct joydev {
  42        int open;
  43        int minor;
  44        struct input_handle handle;
  45        wait_queue_head_t wait;
  46        struct list_head client_list;
  47        spinlock_t client_lock; /* protects client_list */
  48        struct mutex mutex;
  49        struct device dev;
  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
  63struct 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
  74static struct joydev *joydev_table[JOYDEV_MINORS];
  75static DEFINE_MUTEX(joydev_table_mutex);
  76
  77static int joydev_correct(int value, struct js_corr *corr)
  78{
  79        switch (corr->type) {
  80
  81        case JS_CORR_NONE:
  82                break;
  83
  84        case JS_CORR_BROKEN:
  85                value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
  86                        ((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
  87                        ((corr->coef[2] * (value - corr->coef[0])) >> 14);
  88                break;
  89
  90        default:
  91                return 0;
  92        }
  93
  94        return value < -32767 ? -32767 : (value > 32767 ? 32767 : value);
  95}
  96
  97static void joydev_pass_event(struct joydev_client *client,
  98                              struct js_event *event)
  99{
 100        struct joydev *joydev = client->joydev;
 101
 102        /*
 103         * IRQs already disabled, just acquire the lock
 104         */
 105        spin_lock(&client->buffer_lock);
 106
 107        client->buffer[client->head] = *event;
 108
 109        if (client->startup == joydev->nabs + joydev->nkey) {
 110                client->head++;
 111                client->head &= JOYDEV_BUFFER_SIZE - 1;
 112                if (client->tail == client->head)
 113                        client->startup = 0;
 114        }
 115
 116        spin_unlock(&client->buffer_lock);
 117
 118        kill_fasync(&client->fasync, SIGIO, POLL_IN);
 119}
 120
 121static void joydev_event(struct input_handle *handle,
 122                         unsigned int type, unsigned int code, int value)
 123{
 124        struct joydev *joydev = handle->private;
 125        struct joydev_client *client;
 126        struct js_event event;
 127
 128        switch (type) {
 129
 130        case EV_KEY:
 131                if (code < BTN_MISC || value == 2)
 132                        return;
 133                event.type = JS_EVENT_BUTTON;
 134                event.number = joydev->keymap[code - BTN_MISC];
 135                event.value = value;
 136                break;
 137
 138        case EV_ABS:
 139                event.type = JS_EVENT_AXIS;
 140                event.number = joydev->absmap[code];
 141                event.value = joydev_correct(value,
 142                                        &joydev->corr[event.number]);
 143                if (event.value == joydev->abs[event.number])
 144                        return;
 145                joydev->abs[event.number] = event.value;
 146                break;
 147
 148        default:
 149                return;
 150        }
 151
 152        event.time = jiffies_to_msecs(jiffies);
 153
 154        rcu_read_lock();
 155        list_for_each_entry_rcu(client, &joydev->client_list, node)
 156                joydev_pass_event(client, &event);
 157        rcu_read_unlock();
 158
 159        wake_up_interruptible(&joydev->wait);
 160}
 161
 162static int joydev_fasync(int fd, struct file *file, int on)
 163{
 164        struct joydev_client *client = file->private_data;
 165
 166        return fasync_helper(fd, file, on, &client->fasync);
 167}
 168
 169static void joydev_free(struct device *dev)
 170{
 171        struct joydev *joydev = container_of(dev, struct joydev, dev);
 172
 173        input_put_device(joydev->handle.dev);
 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_detach_client(joydev, client);
 247        kfree(client);
 248
 249        joydev_close_device(joydev);
 250        put_device(&joydev->dev);
 251
 252        return 0;
 253}
 254
 255static int joydev_open(struct inode *inode, struct file *file)
 256{
 257        struct joydev_client *client;
 258        struct joydev *joydev;
 259        int i = iminor(inode) - JOYDEV_MINOR_BASE;
 260        int error;
 261
 262        if (i >= JOYDEV_MINORS)
 263                return -ENODEV;
 264
 265        error = mutex_lock_interruptible(&joydev_table_mutex);
 266        if (error)
 267                return error;
 268        joydev = joydev_table[i];
 269        if (joydev)
 270                get_device(&joydev->dev);
 271        mutex_unlock(&joydev_table_mutex);
 272
 273        if (!joydev)
 274                return -ENODEV;
 275
 276        client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
 277        if (!client) {
 278                error = -ENOMEM;
 279                goto err_put_joydev;
 280        }
 281
 282        spin_lock_init(&client->buffer_lock);
 283        client->joydev = joydev;
 284        joydev_attach_client(joydev, client);
 285
 286        error = joydev_open_device(joydev);
 287        if (error)
 288                goto err_free_client;
 289
 290        file->private_data = client;
 291        nonseekable_open(inode, file);
 292
 293        return 0;
 294
 295 err_free_client:
 296        joydev_detach_client(joydev, client);
 297        kfree(client);
 298 err_put_joydev:
 299        put_device(&joydev->dev);
 300        return error;
 301}
 302
 303static int joydev_generate_startup_event(struct joydev_client *client,
 304                                         struct input_dev *input,
 305                                         struct js_event *event)
 306{
 307        struct joydev *joydev = client->joydev;
 308        int have_event;
 309
 310        spin_lock_irq(&client->buffer_lock);
 311
 312        have_event = client->startup < joydev->nabs + joydev->nkey;
 313
 314        if (have_event) {
 315
 316                event->time = jiffies_to_msecs(jiffies);
 317                if (client->startup < joydev->nkey) {
 318                        event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 319                        event->number = client->startup;
 320                        event->value = !!test_bit(joydev->keypam[event->number],
 321                                                  input->key);
 322                } else {
 323                        event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
 324                        event->number = client->startup - joydev->nkey;
 325                        event->value = joydev->abs[event->number];
 326                }
 327                client->startup++;
 328        }
 329
 330        spin_unlock_irq(&client->buffer_lock);
 331
 332        return have_event;
 333}
 334
 335static int joydev_fetch_next_event(struct joydev_client *client,
 336                                   struct js_event *event)
 337{
 338        int have_event;
 339
 340        spin_lock_irq(&client->buffer_lock);
 341
 342        have_event = client->head != client->tail;
 343        if (have_event) {
 344                *event = client->buffer[client->tail++];
 345                client->tail &= JOYDEV_BUFFER_SIZE - 1;
 346        }
 347
 348        spin_unlock_irq(&client->buffer_lock);
 349
 350        return have_event;
 351}
 352
 353/*
 354 * Old joystick interface
 355 */
 356static ssize_t joydev_0x_read(struct joydev_client *client,
 357                              struct input_dev *input,
 358                              char __user *buf)
 359{
 360        struct joydev *joydev = client->joydev;
 361        struct JS_DATA_TYPE data;
 362        int i;
 363
 364        spin_lock_irq(&input->event_lock);
 365
 366        /*
 367         * Get device state
 368         */
 369        for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 370                data.buttons |=
 371                        test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 372        data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 373        data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
 374
 375        /*
 376         * Reset reader's event queue
 377         */
 378        spin_lock(&client->buffer_lock);
 379        client->startup = 0;
 380        client->tail = client->head;
 381        spin_unlock(&client->buffer_lock);
 382
 383        spin_unlock_irq(&input->event_lock);
 384
 385        if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 386                return -EFAULT;
 387
 388        return sizeof(struct JS_DATA_TYPE);
 389}
 390
 391static inline int joydev_data_pending(struct joydev_client *client)
 392{
 393        struct joydev *joydev = client->joydev;
 394
 395        return client->startup < joydev->nabs + joydev->nkey ||
 396                client->head != client->tail;
 397}
 398
 399static ssize_t joydev_read(struct file *file, char __user *buf,
 400                           size_t count, loff_t *ppos)
 401{
 402        struct joydev_client *client = file->private_data;
 403        struct joydev *joydev = client->joydev;
 404        struct input_dev *input = joydev->handle.dev;
 405        struct js_event event;
 406        int retval;
 407
 408        if (!joydev->exist)
 409                return -ENODEV;
 410
 411        if (count < sizeof(struct js_event))
 412                return -EINVAL;
 413
 414        if (count == sizeof(struct JS_DATA_TYPE))
 415                return joydev_0x_read(client, input, buf);
 416
 417        if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
 418                return -EAGAIN;
 419
 420        retval = wait_event_interruptible(joydev->wait,
 421                        !joydev->exist || joydev_data_pending(client));
 422        if (retval)
 423                return retval;
 424
 425        if (!joydev->exist)
 426                return -ENODEV;
 427
 428        while (retval + sizeof(struct js_event) <= count &&
 429               joydev_generate_startup_event(client, input, &event)) {
 430
 431                if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 432                        return -EFAULT;
 433
 434                retval += sizeof(struct js_event);
 435        }
 436
 437        while (retval + sizeof(struct js_event) <= count &&
 438               joydev_fetch_next_event(client, &event)) {
 439
 440                if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 441                        return -EFAULT;
 442
 443                retval += sizeof(struct js_event);
 444        }
 445
 446        return retval;
 447}
 448
 449/* No kernel lock - fine */
 450static unsigned int joydev_poll(struct file *file, poll_table *wait)
 451{
 452        struct joydev_client *client = file->private_data;
 453        struct joydev *joydev = client->joydev;
 454
 455        poll_wait(file, &joydev->wait, wait);
 456        return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
 457                (joydev->exist ?  0 : (POLLHUP | POLLERR));
 458}
 459
 460static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
 461                                     void __user *argp, size_t len)
 462{
 463        __u8 *abspam;
 464        int i;
 465        int retval = 0;
 466
 467        len = min(len, sizeof(joydev->abspam));
 468
 469        /* Validate the map. */
 470        abspam = kmalloc(len, GFP_KERNEL);
 471        if (!abspam)
 472                return -ENOMEM;
 473
 474        if (copy_from_user(abspam, argp, len)) {
 475                retval = -EFAULT;
 476                goto out;
 477        }
 478
 479        for (i = 0; i < joydev->nabs; i++) {
 480                if (abspam[i] > ABS_MAX) {
 481                        retval = -EINVAL;
 482                        goto out;
 483                }
 484        }
 485
 486        memcpy(joydev->abspam, abspam, len);
 487
 488        for (i = 0; i < joydev->nabs; i++)
 489                joydev->absmap[joydev->abspam[i]] = i;
 490
 491 out:
 492        kfree(abspam);
 493        return retval;
 494}
 495
 496static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
 497                                      void __user *argp, size_t len)
 498{
 499        __u16 *keypam;
 500        int i;
 501        int retval = 0;
 502
 503        len = min(len, sizeof(joydev->keypam));
 504
 505        /* Validate the map. */
 506        keypam = kmalloc(len, GFP_KERNEL);
 507        if (!keypam)
 508                return -ENOMEM;
 509
 510        if (copy_from_user(keypam, argp, len)) {
 511                retval = -EFAULT;
 512                goto out;
 513        }
 514
 515        for (i = 0; i < joydev->nkey; i++) {
 516                if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
 517                        retval = -EINVAL;
 518                        goto out;
 519                }
 520        }
 521
 522        memcpy(joydev->keypam, keypam, len);
 523
 524        for (i = 0; i < joydev->nkey; i++)
 525                joydev->keymap[keypam[i] - BTN_MISC] = i;
 526
 527 out:
 528        kfree(keypam);
 529        return retval;
 530}
 531
 532
 533static int joydev_ioctl_common(struct joydev *joydev,
 534                                unsigned int cmd, void __user *argp)
 535{
 536        struct input_dev *dev = joydev->handle.dev;
 537        size_t len;
 538        int i;
 539        const char *name;
 540
 541        /* Process fixed-sized commands. */
 542        switch (cmd) {
 543
 544        case JS_SET_CAL:
 545                return copy_from_user(&joydev->glue.JS_CORR, argp,
 546                                sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 547
 548        case JS_GET_CAL:
 549                return copy_to_user(argp, &joydev->glue.JS_CORR,
 550                                sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 551
 552        case JS_SET_TIMEOUT:
 553                return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 554
 555        case JS_GET_TIMEOUT:
 556                return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 557
 558        case JSIOCGVERSION:
 559                return put_user(JS_VERSION, (__u32 __user *) argp);
 560
 561        case JSIOCGAXES:
 562                return put_user(joydev->nabs, (__u8 __user *) argp);
 563
 564        case JSIOCGBUTTONS:
 565                return put_user(joydev->nkey, (__u8 __user *) argp);
 566
 567        case JSIOCSCORR:
 568                if (copy_from_user(joydev->corr, argp,
 569                              sizeof(joydev->corr[0]) * joydev->nabs))
 570                        return -EFAULT;
 571
 572                for (i = 0; i < joydev->nabs; i++) {
 573                        int val = input_abs_get_val(dev, joydev->abspam[i]);
 574                        joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
 575                }
 576                return 0;
 577
 578        case JSIOCGCORR:
 579                return copy_to_user(argp, joydev->corr,
 580                        sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
 581
 582        }
 583
 584        /*
 585         * Process variable-sized commands (the axis and button map commands
 586         * are considered variable-sized to decouple them from the values of
 587         * ABS_MAX and KEY_MAX).
 588         */
 589        switch (cmd & ~IOCSIZE_MASK) {
 590
 591        case (JSIOCSAXMAP & ~IOCSIZE_MASK):
 592                return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
 593
 594        case (JSIOCGAXMAP & ~IOCSIZE_MASK):
 595                len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
 596                return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
 597
 598        case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
 599                return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
 600
 601        case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
 602                len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
 603                return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
 604
 605        case JSIOCGNAME(0):
 606                name = dev->name;
 607                if (!name)
 608                        return 0;
 609
 610                len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
 611                return copy_to_user(argp, name, len) ? -EFAULT : len;
 612        }
 613
 614        return -EINVAL;
 615}
 616
 617#ifdef CONFIG_COMPAT
 618static long joydev_compat_ioctl(struct file *file,
 619                                unsigned int cmd, unsigned long arg)
 620{
 621        struct joydev_client *client = file->private_data;
 622        struct joydev *joydev = client->joydev;
 623        void __user *argp = (void __user *)arg;
 624        s32 tmp32;
 625        struct JS_DATA_SAVE_TYPE_32 ds32;
 626        int retval;
 627
 628        retval = mutex_lock_interruptible(&joydev->mutex);
 629        if (retval)
 630                return retval;
 631
 632        if (!joydev->exist) {
 633                retval = -ENODEV;
 634                goto out;
 635        }
 636
 637        switch (cmd) {
 638
 639        case JS_SET_TIMELIMIT:
 640                retval = get_user(tmp32, (s32 __user *) arg);
 641                if (retval == 0)
 642                        joydev->glue.JS_TIMELIMIT = tmp32;
 643                break;
 644
 645        case JS_GET_TIMELIMIT:
 646                tmp32 = joydev->glue.JS_TIMELIMIT;
 647                retval = put_user(tmp32, (s32 __user *) arg);
 648                break;
 649
 650        case JS_SET_ALL:
 651                retval = copy_from_user(&ds32, argp,
 652                                        sizeof(ds32)) ? -EFAULT : 0;
 653                if (retval == 0) {
 654                        joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
 655                        joydev->glue.BUSY          = ds32.BUSY;
 656                        joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
 657                        joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
 658                        joydev->glue.JS_SAVE       = ds32.JS_SAVE;
 659                        joydev->glue.JS_CORR       = ds32.JS_CORR;
 660                }
 661                break;
 662
 663        case JS_GET_ALL:
 664                ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
 665                ds32.BUSY          = joydev->glue.BUSY;
 666                ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
 667                ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
 668                ds32.JS_SAVE       = joydev->glue.JS_SAVE;
 669                ds32.JS_CORR       = joydev->glue.JS_CORR;
 670
 671                retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
 672                break;
 673
 674        default:
 675                retval = joydev_ioctl_common(joydev, cmd, argp);
 676                break;
 677        }
 678
 679 out:
 680        mutex_unlock(&joydev->mutex);
 681        return retval;
 682}
 683#endif /* CONFIG_COMPAT */
 684
 685static long joydev_ioctl(struct file *file,
 686                         unsigned int cmd, unsigned long arg)
 687{
 688        struct joydev_client *client = file->private_data;
 689        struct joydev *joydev = client->joydev;
 690        void __user *argp = (void __user *)arg;
 691        int retval;
 692
 693        retval = mutex_lock_interruptible(&joydev->mutex);
 694        if (retval)
 695                return retval;
 696
 697        if (!joydev->exist) {
 698                retval = -ENODEV;
 699                goto out;
 700        }
 701
 702        switch (cmd) {
 703
 704        case JS_SET_TIMELIMIT:
 705                retval = get_user(joydev->glue.JS_TIMELIMIT,
 706                                  (long __user *) arg);
 707                break;
 708
 709        case JS_GET_TIMELIMIT:
 710                retval = put_user(joydev->glue.JS_TIMELIMIT,
 711                                  (long __user *) arg);
 712                break;
 713
 714        case JS_SET_ALL:
 715                retval = copy_from_user(&joydev->glue, argp,
 716                                        sizeof(joydev->glue)) ? -EFAULT: 0;
 717                break;
 718
 719        case JS_GET_ALL:
 720                retval = copy_to_user(argp, &joydev->glue,
 721                                      sizeof(joydev->glue)) ? -EFAULT : 0;
 722                break;
 723
 724        default:
 725                retval = joydev_ioctl_common(joydev, cmd, argp);
 726                break;
 727        }
 728 out:
 729        mutex_unlock(&joydev->mutex);
 730        return retval;
 731}
 732
 733static const struct file_operations joydev_fops = {
 734        .owner          = THIS_MODULE,
 735        .read           = joydev_read,
 736        .poll           = joydev_poll,
 737        .open           = joydev_open,
 738        .release        = joydev_release,
 739        .unlocked_ioctl = joydev_ioctl,
 740#ifdef CONFIG_COMPAT
 741        .compat_ioctl   = joydev_compat_ioctl,
 742#endif
 743        .fasync         = joydev_fasync,
 744        .llseek         = no_llseek,
 745};
 746
 747static int joydev_install_chrdev(struct joydev *joydev)
 748{
 749        joydev_table[joydev->minor] = joydev;
 750        return 0;
 751}
 752
 753static void joydev_remove_chrdev(struct joydev *joydev)
 754{
 755        mutex_lock(&joydev_table_mutex);
 756        joydev_table[joydev->minor] = NULL;
 757        mutex_unlock(&joydev_table_mutex);
 758}
 759
 760/*
 761 * Mark device non-existant. This disables writes, ioctls and
 762 * prevents new users from opening the device. Already posted
 763 * blocking reads will stay, however new ones will fail.
 764 */
 765static void joydev_mark_dead(struct joydev *joydev)
 766{
 767        mutex_lock(&joydev->mutex);
 768        joydev->exist = false;
 769        mutex_unlock(&joydev->mutex);
 770}
 771
 772static void joydev_cleanup(struct joydev *joydev)
 773{
 774        struct input_handle *handle = &joydev->handle;
 775
 776        joydev_mark_dead(joydev);
 777        joydev_hangup(joydev);
 778        joydev_remove_chrdev(joydev);
 779
 780        /* joydev is marked dead so noone else accesses joydev->open */
 781        if (joydev->open)
 782                input_close_device(handle);
 783}
 784
 785
 786static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
 787{
 788        /* Avoid touchpads and touchscreens */
 789        if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_TOUCH, dev->keybit))
 790                return false;
 791
 792        /* Avoid tablets, digitisers and similar devices */
 793        if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
 794                return false;
 795
 796        return true;
 797}
 798
 799static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 800                          const struct input_device_id *id)
 801{
 802        struct joydev *joydev;
 803        int i, j, t, minor;
 804        int error;
 805
 806        for (minor = 0; minor < JOYDEV_MINORS; minor++)
 807                if (!joydev_table[minor])
 808                        break;
 809
 810        if (minor == JOYDEV_MINORS) {
 811                pr_err("no more free joydev devices\n");
 812                return -ENFILE;
 813        }
 814
 815        joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
 816        if (!joydev)
 817                return -ENOMEM;
 818
 819        INIT_LIST_HEAD(&joydev->client_list);
 820        spin_lock_init(&joydev->client_lock);
 821        mutex_init(&joydev->mutex);
 822        init_waitqueue_head(&joydev->wait);
 823
 824        dev_set_name(&joydev->dev, "js%d", minor);
 825        joydev->exist = true;
 826        joydev->minor = minor;
 827
 828        joydev->handle.dev = input_get_device(dev);
 829        joydev->handle.name = dev_name(&joydev->dev);
 830        joydev->handle.handler = handler;
 831        joydev->handle.private = joydev;
 832
 833        for (i = 0; i < ABS_CNT; i++)
 834                if (test_bit(i, dev->absbit)) {
 835                        joydev->absmap[i] = joydev->nabs;
 836                        joydev->abspam[joydev->nabs] = i;
 837                        joydev->nabs++;
 838                }
 839
 840        for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 841                if (test_bit(i + BTN_MISC, dev->keybit)) {
 842                        joydev->keymap[i] = joydev->nkey;
 843                        joydev->keypam[joydev->nkey] = i + BTN_MISC;
 844                        joydev->nkey++;
 845                }
 846
 847        for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 848                if (test_bit(i + BTN_MISC, dev->keybit)) {
 849                        joydev->keymap[i] = joydev->nkey;
 850                        joydev->keypam[joydev->nkey] = i + BTN_MISC;
 851                        joydev->nkey++;
 852                }
 853
 854        for (i = 0; i < joydev->nabs; i++) {
 855                j = joydev->abspam[i];
 856                if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
 857                        joydev->corr[i].type = JS_CORR_NONE;
 858                        joydev->abs[i] = input_abs_get_val(dev, j);
 859                        continue;
 860                }
 861                joydev->corr[i].type = JS_CORR_BROKEN;
 862                joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
 863
 864                t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
 865                joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
 866                joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
 867
 868                t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
 869                        - 2 * input_abs_get_flat(dev, j);
 870                if (t) {
 871                        joydev->corr[i].coef[2] = (1 << 29) / t;
 872                        joydev->corr[i].coef[3] = (1 << 29) / t;
 873
 874                        joydev->abs[i] =
 875                                joydev_correct(input_abs_get_val(dev, j),
 876                                               joydev->corr + i);
 877                }
 878        }
 879
 880        joydev->dev.devt = MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor);
 881        joydev->dev.class = &input_class;
 882        joydev->dev.parent = &dev->dev;
 883        joydev->dev.release = joydev_free;
 884        device_initialize(&joydev->dev);
 885
 886        error = input_register_handle(&joydev->handle);
 887        if (error)
 888                goto err_free_joydev;
 889
 890        error = joydev_install_chrdev(joydev);
 891        if (error)
 892                goto err_unregister_handle;
 893
 894        error = device_add(&joydev->dev);
 895        if (error)
 896                goto err_cleanup_joydev;
 897
 898        return 0;
 899
 900 err_cleanup_joydev:
 901        joydev_cleanup(joydev);
 902 err_unregister_handle:
 903        input_unregister_handle(&joydev->handle);
 904 err_free_joydev:
 905        put_device(&joydev->dev);
 906        return error;
 907}
 908
 909static void joydev_disconnect(struct input_handle *handle)
 910{
 911        struct joydev *joydev = handle->private;
 912
 913        device_del(&joydev->dev);
 914        joydev_cleanup(joydev);
 915        input_unregister_handle(handle);
 916        put_device(&joydev->dev);
 917}
 918
 919static const struct input_device_id joydev_ids[] = {
 920        {
 921                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 922                                INPUT_DEVICE_ID_MATCH_ABSBIT,
 923                .evbit = { BIT_MASK(EV_ABS) },
 924                .absbit = { BIT_MASK(ABS_X) },
 925        },
 926        {
 927                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 928                                INPUT_DEVICE_ID_MATCH_ABSBIT,
 929                .evbit = { BIT_MASK(EV_ABS) },
 930                .absbit = { BIT_MASK(ABS_WHEEL) },
 931        },
 932        {
 933                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 934                                INPUT_DEVICE_ID_MATCH_ABSBIT,
 935                .evbit = { BIT_MASK(EV_ABS) },
 936                .absbit = { BIT_MASK(ABS_THROTTLE) },
 937        },
 938        {
 939                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 940                                INPUT_DEVICE_ID_MATCH_KEYBIT,
 941                .evbit = { BIT_MASK(EV_KEY) },
 942                .keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
 943        },
 944        {
 945                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 946                                INPUT_DEVICE_ID_MATCH_KEYBIT,
 947                .evbit = { BIT_MASK(EV_KEY) },
 948                .keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
 949        },
 950        {
 951                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 952                                INPUT_DEVICE_ID_MATCH_KEYBIT,
 953                .evbit = { BIT_MASK(EV_KEY) },
 954                .keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
 955        },
 956        { }     /* Terminating entry */
 957};
 958
 959MODULE_DEVICE_TABLE(input, joydev_ids);
 960
 961static struct input_handler joydev_handler = {
 962        .event          = joydev_event,
 963        .match          = joydev_match,
 964        .connect        = joydev_connect,
 965        .disconnect     = joydev_disconnect,
 966        .fops           = &joydev_fops,
 967        .minor          = JOYDEV_MINOR_BASE,
 968        .name           = "joydev",
 969        .id_table       = joydev_ids,
 970};
 971
 972static int __init joydev_init(void)
 973{
 974        return input_register_handler(&joydev_handler);
 975}
 976
 977static void __exit joydev_exit(void)
 978{
 979        input_unregister_handler(&joydev_handler);
 980}
 981
 982module_init(joydev_init);
 983module_exit(joydev_exit);
 984