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   1 /*
   2  *  User level driver support for input subsystem
   3  *
   4  * Heavily based on evdev.c by Vojtech Pavlik
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  *
  20  * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
  21  *
  22  * Changes/Revisions:
  23  *      0.3     09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>)
  24  *              - updated ff support for the changes in kernel interface
  25  *              - added MODULE_VERSION
  26  *      0.2     16/10/2004 (Micah Dowty <micah@navi.cx>)
  27  *              - added force feedback support
  28  *              - added UI_SET_PHYS
  29  *      0.1     20/06/2002
  30  *              - first public version
  31  */
  32 #include <linux/poll.h>
  33 #include <linux/slab.h>
  34 #include <linux/module.h>
  35 #include <linux/init.h>
  36 #include <linux/smp_lock.h>
  37 #include <linux/fs.h>
  38 #include <linux/miscdevice.h>
  39 #include <linux/uinput.h>
  40
  41 static int uinput_dev_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
  42 {
  43         struct uinput_device    *udev = input_get_drvdata(dev);
  44
  45         udev->buff[udev->head].type = type;
  46         udev->buff[udev->head].code = code;
  47         udev->buff[udev->head].value = value;
  48         do_gettimeofday(&udev->buff[udev->head].time);
  49         udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
  50
  51         wake_up_interruptible(&udev->waitq);
  52
  53         return 0;
  54 }
  55
  56 static int uinput_request_alloc_id(struct uinput_device *udev, struct uinput_request *request)
  57 {
  58         /* Atomically allocate an ID for the given request. Returns 0 on success. */
  59         int id;
  60         int err = -1;
  61
  62         spin_lock(&udev->requests_lock);
  63
  64         for (id = 0; id < UINPUT_NUM_REQUESTS; id++)
  65                 if (!udev->requests[id]) {
  66                         request->id = id;
  67                         udev->requests[id] = request;
  68                         err = 0;
  69                         break;
  70                 }
  71
  72         spin_unlock(&udev->requests_lock);
  73         return err;
  74 }
  75
  76 static struct uinput_request* uinput_request_find(struct uinput_device *udev, int id)
  77 {
  78         /* Find an input request, by ID. Returns NULL if the ID isn't valid. */
  79         if (id >= UINPUT_NUM_REQUESTS || id < 0)
  80                 return NULL;
  81         return udev->requests[id];
  82 }
  83
  84 static inline int uinput_request_reserve_slot(struct uinput_device *udev, struct uinput_request *request)
  85 {
  86         /* Allocate slot. If none are available right away, wait. */
  87         return wait_event_interruptible(udev->requests_waitq,
  88                                         !uinput_request_alloc_id(udev, request));
  89 }
  90
  91 static void uinput_request_done(struct uinput_device *udev, struct uinput_request *request)
  92 {
  93         /* Mark slot as available */
  94         udev->requests[request->id] = NULL;
  95         wake_up(&udev->requests_waitq);
  96
  97         complete(&request->done);
  98 }
  99
 100 static int uinput_request_submit(struct input_dev *dev, struct uinput_request *request)
 101 {
 102         /* Tell our userspace app about this new request by queueing an input event */
 103         uinput_dev_event(dev, EV_UINPUT, request->code, request->id);
 104
 105         /* Wait for the request to complete */
 106         wait_for_completion(&request->done);
 107         return request->retval;
 108 }
 109
 110 static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
 111 {
 112         uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
 113 }
 114
 115 static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
 116 {
 117         uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
 118 }
 119
 120 static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
 121 {
 122         return uinput_dev_event(dev, EV_FF, effect_id, value);
 123 }
 124
 125 static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect, struct ff_effect *old)
 126 {
 127         struct uinput_request request;
 128         int retval;
 129
 130         request.id = -1;
 131         init_completion(&request.done);
 132         request.code = UI_FF_UPLOAD;
 133         request.u.upload.effect = effect;
 134         request.u.upload.old = old;
 135
 136         retval = uinput_request_reserve_slot(input_get_drvdata(dev), &request);
 137         if (!retval)
 138                 retval = uinput_request_submit(dev, &request);
 139
 140         return retval;
 141 }
 142
 143 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
 144 {
 145         struct uinput_request request;
 146         int retval;
 147
 148         if (!test_bit(EV_FF, dev->evbit))
 149                 return -ENOSYS;
 150
 151         request.id = -1;
 152         init_completion(&request.done);
 153         request.code = UI_FF_ERASE;
 154         request.u.effect_id = effect_id;
 155
 156         retval = uinput_request_reserve_slot(input_get_drvdata(dev), &request);
 157         if (!retval)
 158                 retval = uinput_request_submit(dev, &request);
 159
 160         return retval;
 161 }
 162
 163 static void uinput_destroy_device(struct uinput_device *udev)
 164 {
 165         const char *name, *phys;
 166
 167         if (udev->dev) {
 168                 name = udev->dev->name;
 169                 phys = udev->dev->phys;
 170                 if (udev->state == UIST_CREATED)
 171                         input_unregister_device(udev->dev);
 172                 else
 173                         input_free_device(udev->dev);
 174                 kfree(name);
 175                 kfree(phys);
 176                 udev->dev = NULL;
 177         }
 178
 179         udev->state = UIST_NEW_DEVICE;
 180 }
 181
 182 static int uinput_create_device(struct uinput_device *udev)
 183 {
 184         struct input_dev *dev = udev->dev;
 185         int error;
 186
 187         if (udev->state != UIST_SETUP_COMPLETE) {
 188                 printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
 189                 return -EINVAL;
 190         }
 191
 192         if (udev->ff_effects_max) {
 193                 error = input_ff_create(dev, udev->ff_effects_max);
 194                 if (error)
 195                         goto fail1;
 196
 197                 dev->ff->upload = uinput_dev_upload_effect;
 198                 dev->ff->erase = uinput_dev_erase_effect;
 199                 dev->ff->playback = uinput_dev_playback;
 200                 dev->ff->set_gain = uinput_dev_set_gain;
 201                 dev->ff->set_autocenter = uinput_dev_set_autocenter;
 202         }
 203
 204         error = input_register_device(udev->dev);
 205         if (error)
 206                 goto fail2;
 207
 208         udev->state = UIST_CREATED;
 209
 210         return 0;
 211
 212  fail2: input_ff_destroy(dev);
 213  fail1: uinput_destroy_device(udev);
 214         return error;
 215 }
 216
 217 static int uinput_open(struct inode *inode, struct file *file)
 218 {
 219         struct uinput_device *newdev;
 220
 221         newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
 222         if (!newdev)
 223                 return -ENOMEM;
 224
 225         lock_kernel();
 226         mutex_init(&newdev->mutex);
 227         spin_lock_init(&newdev->requests_lock);
 228         init_waitqueue_head(&newdev->requests_waitq);
 229         init_waitqueue_head(&newdev->waitq);
 230         newdev->state = UIST_NEW_DEVICE;
 231
 232         file->private_data = newdev;
 233         unlock_kernel();
 234
 235         return 0;
 236 }
 237
 238 static int uinput_validate_absbits(struct input_dev *dev)
 239 {
 240         unsigned int cnt;
 241         int retval = 0;
 242
 243         for (cnt = 0; cnt < ABS_MAX + 1; cnt++) {
 244                 if (!test_bit(cnt, dev->absbit))
 245                         continue;
 246
 247                 if ((dev->absmax[cnt] <= dev->absmin[cnt])) {
 248                         printk(KERN_DEBUG
 249                                 "%s: invalid abs[%02x] min:%d max:%d\n",
 250                                 UINPUT_NAME, cnt,
 251                                 dev->absmin[cnt], dev->absmax[cnt]);
 252                         retval = -EINVAL;
 253                         break;
 254                 }
 255
 256                 if (dev->absflat[cnt] > (dev->absmax[cnt] - dev->absmin[cnt])) {
 257                         printk(KERN_DEBUG
 258                                 "%s: absflat[%02x] out of range: %d "
 259                                 "(min:%d/max:%d)\n",
 260                                 UINPUT_NAME, cnt, dev->absflat[cnt],
 261                                 dev->absmin[cnt], dev->absmax[cnt]);
 262                         retval = -EINVAL;
 263                         break;
 264                 }
 265         }
 266         return retval;
 267 }
 268
 269 static int uinput_allocate_device(struct uinput_device *udev)
 270 {
 271         udev->dev = input_allocate_device();
 272         if (!udev->dev)
 273                 return -ENOMEM;
 274
 275         udev->dev->event = uinput_dev_event;
 276         input_set_drvdata(udev->dev, udev);
 277
 278         return 0;
 279 }
 280
 281 static int uinput_setup_device(struct uinput_device *udev, const char __user *buffer, size_t count)
 282 {
 283         struct uinput_user_dev  *user_dev;
 284         struct input_dev        *dev;
 285         char                    *name;
 286         int                     size;
 287         int                     retval;
 288
 289         if (count != sizeof(struct uinput_user_dev))
 290                 return -EINVAL;
 291
 292         if (!udev->dev) {
 293                 retval = uinput_allocate_device(udev);
 294                 if (retval)
 295                         return retval;
 296         }
 297
 298         dev = udev->dev;
 299
 300         user_dev = kmalloc(sizeof(struct uinput_user_dev), GFP_KERNEL);
 301         if (!user_dev)
 302                 return -ENOMEM;
 303
 304         if (copy_from_user(user_dev, buffer, sizeof(struct uinput_user_dev))) {
 305                 retval = -EFAULT;
 306                 goto exit;
 307         }
 308
 309         udev->ff_effects_max = user_dev->ff_effects_max;
 310
 311         size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE) + 1;
 312         if (!size) {
 313                 retval = -EINVAL;
 314                 goto exit;
 315         }
 316
 317         kfree(dev->name);
 318         dev->name = name = kmalloc(size, GFP_KERNEL);
 319         if (!name) {
 320                 retval = -ENOMEM;
 321                 goto exit;
 322         }
 323         strlcpy(name, user_dev->name, size);
 324
 325         dev->id.bustype = user_dev->id.bustype;
 326         dev->id.vendor  = user_dev->id.vendor;
 327         dev->id.product = user_dev->id.product;
 328         dev->id.version = user_dev->id.version;
 329
 330         size = sizeof(int) * (ABS_MAX + 1);
 331         memcpy(dev->absmax, user_dev->absmax, size);
 332         memcpy(dev->absmin, user_dev->absmin, size);
 333         memcpy(dev->absfuzz, user_dev->absfuzz, size);
 334         memcpy(dev->absflat, user_dev->absflat, size);
 335
 336         /* check if absmin/absmax/absfuzz/absflat are filled as
 337          * told in Documentation/input/input-programming.txt */
 338         if (test_bit(EV_ABS, dev->evbit)) {
 339                 retval = uinput_validate_absbits(dev);
 340                 if (retval < 0)
 341                         goto exit;
 342         }
 343
 344         udev->state = UIST_SETUP_COMPLETE;
 345         retval = count;
 346
 347  exit:
 348         kfree(user_dev);
 349         return retval;
 350 }
 351
 352 static inline ssize_t uinput_inject_event(struct uinput_device *udev, const char __user *buffer, size_t count)
 353 {
 354         struct input_event ev;
 355
 356         if (count != sizeof(struct input_event))
 357                 return -EINVAL;
 358
 359         if (copy_from_user(&ev, buffer, sizeof(struct input_event)))
 360                 return -EFAULT;
 361
 362         input_event(udev->dev, ev.type, ev.code, ev.value);
 363
 364         return sizeof(struct input_event);
 365 }
 366
 367 static ssize_t uinput_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 368 {
 369         struct uinput_device *udev = file->private_data;
 370         int retval;
 371
 372         retval = mutex_lock_interruptible(&udev->mutex);
 373         if (retval)
 374                 return retval;
 375
 376         retval = udev->state == UIST_CREATED ?
 377                         uinput_inject_event(udev, buffer, count) :
 378                         uinput_setup_device(udev, buffer, count);
 379
 380         mutex_unlock(&udev->mutex);
 381
 382         return retval;
 383 }
 384
 385 static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 386 {
 387         struct uinput_device *udev = file->private_data;
 388         int retval = 0;
 389
 390         if (udev->state != UIST_CREATED)
 391                 return -ENODEV;
 392
 393         if (udev->head == udev->tail && (file->f_flags & O_NONBLOCK))
 394                 return -EAGAIN;
 395
 396         retval = wait_event_interruptible(udev->waitq,
 397                         udev->head != udev->tail || udev->state != UIST_CREATED);
 398         if (retval)
 399                 return retval;
 400
 401         retval = mutex_lock_interruptible(&udev->mutex);
 402         if (retval)
 403                 return retval;
 404
 405         if (udev->state != UIST_CREATED) {
 406                 retval = -ENODEV;
 407                 goto out;
 408         }
 409
 410         while (udev->head != udev->tail && retval + sizeof(struct input_event) <= count) {
 411                 if (copy_to_user(buffer + retval, &udev->buff[udev->tail], sizeof(struct input_event))) {
 412                         retval = -EFAULT;
 413                         goto out;
 414                 }
 415                 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 416                 retval += sizeof(struct input_event);
 417         }
 418
 419  out:
 420         mutex_unlock(&udev->mutex);
 421
 422         return retval;
 423 }
 424
 425 static unsigned int uinput_poll(struct file *file, poll_table *wait)
 426 {
 427         struct uinput_device *udev = file->private_data;
 428
 429         poll_wait(file, &udev->waitq, wait);
 430
 431         if (udev->head != udev->tail)
 432                 return POLLIN | POLLRDNORM;
 433
 434         return 0;
 435 }
 436
 437 static int uinput_release(struct inode *inode, struct file *file)
 438 {
 439         struct uinput_device *udev = file->private_data;
 440
 441         uinput_destroy_device(udev);
 442         kfree(udev);
 443
 444         return 0;
 445 }
 446
 447 #define uinput_set_bit(_arg, _bit, _max)                \
 448 ({                                                      \
 449         int __ret = 0;                                  \
 450         if (udev->state == UIST_CREATED)                \
 451                 __ret =  -EINVAL;                       \
 452         else if ((_arg) > (_max))                       \
 453                 __ret = -EINVAL;                        \
 454         else set_bit((_arg), udev->dev->_bit);          \
 455         __ret;                                          \
 456 })
 457
 458 static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 459 {
 460         int                     retval;
 461         struct uinput_device    *udev;
 462         void __user             *p = (void __user *)arg;
 463         struct uinput_ff_upload ff_up;
 464         struct uinput_ff_erase  ff_erase;
 465         struct uinput_request   *req;
 466         int                     length;
 467         char                    *phys;
 468
 469         udev = file->private_data;
 470
 471         retval = mutex_lock_interruptible(&udev->mutex);
 472         if (retval)
 473                 return retval;
 474
 475         if (!udev->dev) {
 476                 retval = uinput_allocate_device(udev);
 477                 if (retval)
 478                         goto out;
 479         }
 480
 481         switch (cmd) {
 482                 case UI_DEV_CREATE:
 483                         retval = uinput_create_device(udev);
 484                         break;
 485
 486                 case UI_DEV_DESTROY:
 487                         uinput_destroy_device(udev);
 488                         break;
 489
 490                 case UI_SET_EVBIT:
 491                         retval = uinput_set_bit(arg, evbit, EV_MAX);
 492                         break;
 493
 494                 case UI_SET_KEYBIT:
 495                         retval = uinput_set_bit(arg, keybit, KEY_MAX);
 496                         break;
 497
 498                 case UI_SET_RELBIT:
 499                         retval = uinput_set_bit(arg, relbit, REL_MAX);
 500                         break;
 501
 502                 case UI_SET_ABSBIT:
 503                         retval = uinput_set_bit(arg, absbit, ABS_MAX);
 504                         break;
 505
 506                 case UI_SET_MSCBIT:
 507                         retval = uinput_set_bit(arg, mscbit, MSC_MAX);
 508                         break;
 509
 510                 case UI_SET_LEDBIT:
 511                         retval = uinput_set_bit(arg, ledbit, LED_MAX);
 512                         break;
 513
 514                 case UI_SET_SNDBIT:
 515                         retval = uinput_set_bit(arg, sndbit, SND_MAX);
 516                         break;
 517
 518                 case UI_SET_FFBIT:
 519                         retval = uinput_set_bit(arg, ffbit, FF_MAX);
 520                         break;
 521
 522                 case UI_SET_SWBIT:
 523                         retval = uinput_set_bit(arg, swbit, SW_MAX);
 524                         break;
 525
 526                 case UI_SET_PHYS:
 527                         if (udev->state == UIST_CREATED) {
 528                                 retval = -EINVAL;
 529                                 goto out;
 530                         }
 531                         length = strnlen_user(p, 1024);
 532                         if (length <= 0) {
 533                                 retval = -EFAULT;
 534                                 break;
 535                         }
 536                         kfree(udev->dev->phys);
 537                         udev->dev->phys = phys = kmalloc(length, GFP_KERNEL);
 538                         if (!phys) {
 539                                 retval = -ENOMEM;
 540                                 break;
 541                         }
 542                         if (copy_from_user(phys, p, length)) {
 543                                 udev->dev->phys = NULL;
 544                                 kfree(phys);
 545                                 retval = -EFAULT;
 546                                 break;
 547                         }
 548                         phys[length - 1] = '\0';
 549                         break;
 550
 551                 case UI_BEGIN_FF_UPLOAD:
 552                         if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 553                                 retval = -EFAULT;
 554                                 break;
 555                         }
 556                         req = uinput_request_find(udev, ff_up.request_id);
 557                         if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
 558                                 retval = -EINVAL;
 559                                 break;
 560                         }
 561                         ff_up.retval = 0;
 562                         memcpy(&ff_up.effect, req->u.upload.effect, sizeof(struct ff_effect));
 563                         if (req->u.upload.old)
 564                                 memcpy(&ff_up.old, req->u.upload.old, sizeof(struct ff_effect));
 565                         else
 566                                 memset(&ff_up.old, 0, sizeof(struct ff_effect));
 567
 568                         if (copy_to_user(p, &ff_up, sizeof(ff_up))) {
 569                                 retval = -EFAULT;
 570                                 break;
 571                         }
 572                         break;
 573
 574                 case UI_BEGIN_FF_ERASE:
 575                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 576                                 retval = -EFAULT;
 577                                 break;
 578                         }
 579                         req = uinput_request_find(udev, ff_erase.request_id);
 580                         if (!(req && req->code == UI_FF_ERASE)) {
 581                                 retval = -EINVAL;
 582                                 break;
 583                         }
 584                         ff_erase.retval = 0;
 585                         ff_erase.effect_id = req->u.effect_id;
 586                         if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
 587                                 retval = -EFAULT;
 588                                 break;
 589                         }
 590                         break;
 591
 592                 case UI_END_FF_UPLOAD:
 593                         if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 594                                 retval = -EFAULT;
 595                                 break;
 596                         }
 597                         req = uinput_request_find(udev, ff_up.request_id);
 598                         if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
 599                                 retval = -EINVAL;
 600                                 break;
 601                         }
 602                         req->retval = ff_up.retval;
 603                         uinput_request_done(udev, req);
 604                         break;
 605
 606                 case UI_END_FF_ERASE:
 607                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 608                                 retval = -EFAULT;
 609                                 break;
 610                         }
 611                         req = uinput_request_find(udev, ff_erase.request_id);
 612                         if (!(req && req->code == UI_FF_ERASE)) {
 613                                 retval = -EINVAL;
 614                                 break;
 615                         }
 616                         req->retval = ff_erase.retval;
 617                         uinput_request_done(udev, req);
 618                         break;
 619
 620                 default:
 621                         retval = -EINVAL;
 622         }
 623
 624  out:
 625         mutex_unlock(&udev->mutex);
 626         return retval;
 627 }
 628
 629 static const struct file_operations uinput_fops = {
 630         .owner          = THIS_MODULE,
 631         .open           = uinput_open,
 632         .release        = uinput_release,
 633         .read           = uinput_read,
 634         .write          = uinput_write,
 635         .poll           = uinput_poll,
 636         .unlocked_ioctl = uinput_ioctl,
 637 };
 638
 639 static struct miscdevice uinput_misc = {
 640         .fops           = &uinput_fops,
 641         .minor          = UINPUT_MINOR,
 642         .name           = UINPUT_NAME,
 643 };
 644
 645 static int __init uinput_init(void)
 646 {
 647         return misc_register(&uinput_misc);
 648 }
 649
 650 static void __exit uinput_exit(void)
 651 {
 652         misc_deregister(&uinput_misc);
 653 }
 654
 655 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
 656 MODULE_DESCRIPTION("User level driver support for input subsystem");
 657 MODULE_LICENSE("GPL");
 658 MODULE_VERSION("0.3");
 659
 660 module_init(uinput_init);
 661 module_exit(uinput_exit);
 662