drivers/media/rc/lirc_dev.c

   1 /*
   2  * LIRC base driver
   3  *
   4  * by Artur Lipowski <alipowski@interia.pl>
   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  */
  21
  22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24 #include <linux/module.h>
  25 #include <linux/kernel.h>
  26 #include <linux/sched.h>
  27 #include <linux/errno.h>
  28 #include <linux/ioctl.h>
  29 #include <linux/fs.h>
  30 #include <linux/poll.h>
  31 #include <linux/completion.h>
  32 #include <linux/mutex.h>
  33 #include <linux/wait.h>
  34 #include <linux/unistd.h>
  35 #include <linux/kthread.h>
  36 #include <linux/bitops.h>
  37 #include <linux/device.h>
  38 #include <linux/cdev.h>
  39
  40 #include <media/rc-core.h>
  41 #include <media/lirc.h>
  42 #include <media/lirc_dev.h>
  43
  44 static bool debug;
  45
  46 #define IRCTL_DEV_NAME  "BaseRemoteCtl"
  47 #define NOPLUG          -1
  48 #define LOGHEAD         "lirc_dev (%s[%d]): "
  49
  50 static dev_t lirc_base_dev;
  51
  52 struct irctl {
  53         struct lirc_driver d;
  54         int attached;
  55         int open;
  56
  57         struct mutex irctl_lock;
  58         struct lirc_buffer *buf;
  59         unsigned int chunk_size;
  60
  61         struct cdev *cdev;
  62
  63         struct task_struct *task;
  64         long jiffies_to_wait;
  65 };
  66
  67 static DEFINE_MUTEX(lirc_dev_lock);
  68
  69 static struct irctl *irctls[MAX_IRCTL_DEVICES];
  70
  71 /* Only used for sysfs but defined to void otherwise */
  72 static struct class *lirc_class;
  73
  74 /*  helper function
  75  *  initializes the irctl structure
  76  */
  77 static void lirc_irctl_init(struct irctl *ir)
  78 {
  79         mutex_init(&ir->irctl_lock);
  80         ir->d.minor = NOPLUG;
  81 }
  82
  83 static void lirc_irctl_cleanup(struct irctl *ir)
  84 {
  85         device_destroy(lirc_class, MKDEV(MAJOR(lirc_base_dev), ir->d.minor));
  86
  87         if (ir->buf != ir->d.rbuf) {
  88                 lirc_buffer_free(ir->buf);
  89                 kfree(ir->buf);
  90         }
  91         ir->buf = NULL;
  92 }
  93
  94 /*  helper function
  95  *  reads key codes from driver and puts them into buffer
  96  *  returns 0 on success
  97  */
  98 static int lirc_add_to_buf(struct irctl *ir)
  99 {
 100         int res;
 101         int got_data = -1;
 102
 103         if (!ir->d.add_to_buf)
 104                 return 0;
 105
 106         /*
 107          * service the device as long as it is returning
 108          * data and we have space
 109          */
 110         do {
 111                 got_data++;
 112                 res = ir->d.add_to_buf(ir->d.data, ir->buf);
 113         } while (!res);
 114
 115         if (res == -ENODEV)
 116                 kthread_stop(ir->task);
 117
 118         return got_data ? 0 : res;
 119 }
 120
 121 /* main function of the polling thread
 122  */
 123 static int lirc_thread(void *irctl)
 124 {
 125         struct irctl *ir = irctl;
 126
 127         do {
 128                 if (ir->open) {
 129                         if (ir->jiffies_to_wait) {
 130                                 set_current_state(TASK_INTERRUPTIBLE);
 131                                 schedule_timeout(ir->jiffies_to_wait);
 132                         }
 133                         if (kthread_should_stop())
 134                                 break;
 135                         if (!lirc_add_to_buf(ir))
 136                                 wake_up_interruptible(&ir->buf->wait_poll);
 137                 } else {
 138                         set_current_state(TASK_INTERRUPTIBLE);
 139                         schedule();
 140                 }
 141         } while (!kthread_should_stop());
 142
 143         return 0;
 144 }
 145
 146
 147 static const struct file_operations lirc_dev_fops = {
 148         .owner          = THIS_MODULE,
 149         .read           = lirc_dev_fop_read,
 150         .write          = lirc_dev_fop_write,
 151         .poll           = lirc_dev_fop_poll,
 152         .unlocked_ioctl = lirc_dev_fop_ioctl,
 153         .open           = lirc_dev_fop_open,
 154         .release        = lirc_dev_fop_close,
 155         .llseek         = noop_llseek,
 156 };
 157
 158 static int lirc_cdev_add(struct irctl *ir)
 159 {
 160         struct lirc_driver *d = &ir->d;
 161         struct cdev *cdev;
 162         int retval;
 163
 164         cdev = cdev_alloc();
 165         if (!cdev)
 166                 return -ENOMEM;
 167
 168         if (d->fops) {
 169                 cdev->ops = d->fops;
 170                 cdev->owner = d->owner;
 171         } else {
 172                 cdev->ops = &lirc_dev_fops;
 173                 cdev->owner = THIS_MODULE;
 174         }
 175         retval = kobject_set_name(&cdev->kobj, "lirc%d", d->minor);
 176         if (retval)
 177                 goto err_out;
 178
 179         retval = cdev_add(cdev, MKDEV(MAJOR(lirc_base_dev), d->minor), 1);
 180         if (retval)
 181                 goto err_out;
 182
 183         ir->cdev = cdev;
 184
 185         return 0;
 186
 187 err_out:
 188         cdev_del(cdev);
 189         return retval;
 190 }
 191
 192 static int lirc_allocate_buffer(struct irctl *ir)
 193 {
 194         int err = 0;
 195         int bytes_in_key;
 196         unsigned int chunk_size;
 197         unsigned int buffer_size;
 198         struct lirc_driver *d = &ir->d;
 199
 200         mutex_lock(&lirc_dev_lock);
 201
 202         bytes_in_key = BITS_TO_LONGS(d->code_length) +
 203                                                 (d->code_length % 8 ? 1 : 0);
 204         buffer_size = d->buffer_size ? d->buffer_size : BUFLEN / bytes_in_key;
 205         chunk_size  = d->chunk_size  ? d->chunk_size  : bytes_in_key;
 206
 207         if (d->rbuf) {
 208                 ir->buf = d->rbuf;
 209         } else {
 210                 ir->buf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
 211                 if (!ir->buf) {
 212                         err = -ENOMEM;
 213                         goto out;
 214                 }
 215
 216                 err = lirc_buffer_init(ir->buf, chunk_size, buffer_size);
 217                 if (err) {
 218                         kfree(ir->buf);
 219                         goto out;
 220                 }
 221         }
 222         ir->chunk_size = ir->buf->chunk_size;
 223
 224 out:
 225         mutex_unlock(&lirc_dev_lock);
 226
 227         return err;
 228 }
 229
 230 static int lirc_allocate_driver(struct lirc_driver *d)
 231 {
 232         struct irctl *ir;
 233         int minor;
 234         int err;
 235
 236         if (!d) {
 237                 pr_err("driver pointer must be not NULL!\n");
 238                 return -EBADRQC;
 239         }
 240
 241         if (!d->dev) {
 242                 pr_err("dev pointer not filled in!\n");
 243                 return -EINVAL;
 244         }
 245
 246         if (d->minor >= MAX_IRCTL_DEVICES) {
 247                 dev_err(d->dev, "minor must be between 0 and %d!\n",
 248                                                 MAX_IRCTL_DEVICES - 1);
 249                 return -EBADRQC;
 250         }
 251
 252         if (d->code_length < 1 || d->code_length > (BUFLEN * 8)) {
 253                 dev_err(d->dev, "code length must be less than %d bits\n",
 254                                                                 BUFLEN * 8);
 255                 return -EBADRQC;
 256         }
 257
 258         if (d->sample_rate) {
 259                 if (2 > d->sample_rate || HZ < d->sample_rate) {
 260                         dev_err(d->dev, "invalid %d sample rate\n",
 261                                                         d->sample_rate);
 262                         return -EBADRQC;
 263                 }
 264                 if (!d->add_to_buf) {
 265                         dev_err(d->dev, "add_to_buf not set\n");
 266                         return -EBADRQC;
 267                 }
 268         } else if (!d->rbuf && !(d->fops && d->fops->read &&
 269                                 d->fops->poll && d->fops->unlocked_ioctl)) {
 270                 dev_err(d->dev, "undefined read, poll, ioctl\n");
 271                 return -EBADRQC;
 272         }
 273
 274         mutex_lock(&lirc_dev_lock);
 275
 276         minor = d->minor;
 277
 278         if (minor < 0) {
 279                 /* find first free slot for driver */
 280                 for (minor = 0; minor < MAX_IRCTL_DEVICES; minor++)
 281                         if (!irctls[minor])
 282                                 break;
 283                 if (minor == MAX_IRCTL_DEVICES) {
 284                         dev_err(d->dev, "no free slots for drivers!\n");
 285                         err = -ENOMEM;
 286                         goto out_lock;
 287                 }
 288         } else if (irctls[minor]) {
 289                 dev_err(d->dev, "minor (%d) just registered!\n", minor);
 290                 err = -EBUSY;
 291                 goto out_lock;
 292         }
 293
 294         ir = kzalloc(sizeof(struct irctl), GFP_KERNEL);
 295         if (!ir) {
 296                 err = -ENOMEM;
 297                 goto out_lock;
 298         }
 299         lirc_irctl_init(ir);
 300         irctls[minor] = ir;
 301         d->minor = minor;
 302
 303         /* some safety check 8-) */
 304         d->name[sizeof(d->name)-1] = '\0';
 305
 306         if (d->features == 0)
 307                 d->features = LIRC_CAN_REC_LIRCCODE;
 308
 309         ir->d = *d;
 310
 311         device_create(lirc_class, ir->d.dev,
 312                       MKDEV(MAJOR(lirc_base_dev), ir->d.minor), NULL,
 313                       "lirc%u", ir->d.minor);
 314
 315         if (d->sample_rate) {
 316                 ir->jiffies_to_wait = HZ / d->sample_rate;
 317
 318                 /* try to fire up polling thread */
 319                 ir->task = kthread_run(lirc_thread, (void *)ir, "lirc_dev");
 320                 if (IS_ERR(ir->task)) {
 321                         dev_err(d->dev, "cannot run thread for minor = %d\n",
 322                                                                 d->minor);
 323                         err = -ECHILD;
 324                         goto out_sysfs;
 325                 }
 326         } else {
 327                 /* it means - wait for external event in task queue */
 328                 ir->jiffies_to_wait = 0;
 329         }
 330
 331         err = lirc_cdev_add(ir);
 332         if (err)
 333                 goto out_sysfs;
 334
 335         ir->attached = 1;
 336         mutex_unlock(&lirc_dev_lock);
 337
 338         dev_info(ir->d.dev, "lirc_dev: driver %s registered at minor = %d\n",
 339                  ir->d.name, ir->d.minor);
 340         return minor;
 341
 342 out_sysfs:
 343         device_destroy(lirc_class, MKDEV(MAJOR(lirc_base_dev), ir->d.minor));
 344 out_lock:
 345         mutex_unlock(&lirc_dev_lock);
 346
 347         return err;
 348 }
 349
 350 int lirc_register_driver(struct lirc_driver *d)
 351 {
 352         int minor, err = 0;
 353
 354         minor = lirc_allocate_driver(d);
 355         if (minor < 0)
 356                 return minor;
 357
 358         if (LIRC_CAN_REC(d->features)) {
 359                 err = lirc_allocate_buffer(irctls[minor]);
 360                 if (err)
 361                         lirc_unregister_driver(minor);
 362         }
 363
 364         return err ? err : minor;
 365 }
 366 EXPORT_SYMBOL(lirc_register_driver);
 367
 368 int lirc_unregister_driver(int minor)
 369 {
 370         struct irctl *ir;
 371         struct cdev *cdev;
 372
 373         if (minor < 0 || minor >= MAX_IRCTL_DEVICES) {
 374                 pr_err("minor (%d) must be between 0 and %d!\n",
 375                                         minor, MAX_IRCTL_DEVICES - 1);
 376                 return -EBADRQC;
 377         }
 378
 379         ir = irctls[minor];
 380         if (!ir) {
 381                 pr_err("failed to get irctl\n");
 382                 return -ENOENT;
 383         }
 384
 385         cdev = ir->cdev;
 386
 387         mutex_lock(&lirc_dev_lock);
 388
 389         if (ir->d.minor != minor) {
 390                 dev_err(ir->d.dev, "lirc_dev: minor %d device not registered\n",
 391                                                                         minor);
 392                 mutex_unlock(&lirc_dev_lock);
 393                 return -ENOENT;
 394         }
 395
 396         /* end up polling thread */
 397         if (ir->task)
 398                 kthread_stop(ir->task);
 399
 400         dev_dbg(ir->d.dev, "lirc_dev: driver %s unregistered from minor = %d\n",
 401                 ir->d.name, ir->d.minor);
 402
 403         ir->attached = 0;
 404         if (ir->open) {
 405                 dev_dbg(ir->d.dev, LOGHEAD "releasing opened driver\n",
 406                         ir->d.name, ir->d.minor);
 407                 wake_up_interruptible(&ir->buf->wait_poll);
 408                 mutex_lock(&ir->irctl_lock);
 409
 410                 if (ir->d.set_use_dec)
 411                         ir->d.set_use_dec(ir->d.data);
 412
 413                 module_put(cdev->owner);
 414                 mutex_unlock(&ir->irctl_lock);
 415         } else {
 416                 lirc_irctl_cleanup(ir);
 417                 cdev_del(cdev);
 418                 kfree(ir);
 419                 irctls[minor] = NULL;
 420         }
 421
 422         mutex_unlock(&lirc_dev_lock);
 423
 424         return 0;
 425 }
 426 EXPORT_SYMBOL(lirc_unregister_driver);
 427
 428 int lirc_dev_fop_open(struct inode *inode, struct file *file)
 429 {
 430         struct irctl *ir;
 431         struct cdev *cdev;
 432         int retval = 0;
 433
 434         if (iminor(inode) >= MAX_IRCTL_DEVICES) {
 435                 pr_err("open result for %d is -ENODEV\n", iminor(inode));
 436                 return -ENODEV;
 437         }
 438
 439         if (mutex_lock_interruptible(&lirc_dev_lock))
 440                 return -ERESTARTSYS;
 441
 442         ir = irctls[iminor(inode)];
 443         if (!ir) {
 444                 retval = -ENODEV;
 445                 goto error;
 446         }
 447
 448         dev_dbg(ir->d.dev, LOGHEAD "open called\n", ir->d.name, ir->d.minor);
 449
 450         if (ir->d.minor == NOPLUG) {
 451                 retval = -ENODEV;
 452                 goto error;
 453         }
 454
 455         if (ir->open) {
 456                 retval = -EBUSY;
 457                 goto error;
 458         }
 459
 460         if (ir->d.rdev) {
 461                 retval = rc_open(ir->d.rdev);
 462                 if (retval)
 463                         goto error;
 464         }
 465
 466         cdev = ir->cdev;
 467         if (try_module_get(cdev->owner)) {
 468                 ir->open++;
 469                 if (ir->d.set_use_inc)
 470                         retval = ir->d.set_use_inc(ir->d.data);
 471
 472                 if (retval) {
 473                         module_put(cdev->owner);
 474                         ir->open--;
 475                 } else {
 476                         lirc_buffer_clear(ir->buf);
 477                 }
 478                 if (ir->task)
 479                         wake_up_process(ir->task);
 480         }
 481
 482 error:
 483         mutex_unlock(&lirc_dev_lock);
 484
 485         nonseekable_open(inode, file);
 486
 487         return retval;
 488 }
 489 EXPORT_SYMBOL(lirc_dev_fop_open);
 490
 491 int lirc_dev_fop_close(struct inode *inode, struct file *file)
 492 {
 493         struct irctl *ir = irctls[iminor(inode)];
 494         struct cdev *cdev;
 495         int ret;
 496
 497         if (!ir) {
 498                 pr_err("called with invalid irctl\n");
 499                 return -EINVAL;
 500         }
 501
 502         cdev = ir->cdev;
 503
 504         ret = mutex_lock_killable(&lirc_dev_lock);
 505         WARN_ON(ret);
 506
 507         rc_close(ir->d.rdev);
 508
 509         ir->open--;
 510         if (ir->attached) {
 511                 if (ir->d.set_use_dec)
 512                         ir->d.set_use_dec(ir->d.data);
 513                 module_put(cdev->owner);
 514         } else {
 515                 lirc_irctl_cleanup(ir);
 516                 cdev_del(cdev);
 517                 irctls[ir->d.minor] = NULL;
 518                 kfree(ir);
 519         }
 520
 521         if (!ret)
 522                 mutex_unlock(&lirc_dev_lock);
 523
 524         return 0;
 525 }
 526 EXPORT_SYMBOL(lirc_dev_fop_close);
 527
 528 unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait)
 529 {
 530         struct irctl *ir = irctls[iminor(file_inode(file))];
 531         unsigned int ret;
 532
 533         if (!ir) {
 534                 pr_err("called with invalid irctl\n");
 535                 return POLLERR;
 536         }
 537
 538         if (!ir->attached)
 539                 return POLLERR;
 540
 541         if (ir->buf) {
 542                 poll_wait(file, &ir->buf->wait_poll, wait);
 543
 544                 if (lirc_buffer_empty(ir->buf))
 545                         ret = 0;
 546                 else
 547                         ret = POLLIN | POLLRDNORM;
 548         } else
 549                 ret = POLLERR;
 550
 551         dev_dbg(ir->d.dev, LOGHEAD "poll result = %d\n",
 552                 ir->d.name, ir->d.minor, ret);
 553
 554         return ret;
 555 }
 556 EXPORT_SYMBOL(lirc_dev_fop_poll);
 557
 558 long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 559 {
 560         __u32 mode;
 561         int result = 0;
 562         struct irctl *ir = irctls[iminor(file_inode(file))];
 563
 564         if (!ir) {
 565                 pr_err("no irctl found!\n");
 566                 return -ENODEV;
 567         }
 568
 569         dev_dbg(ir->d.dev, LOGHEAD "ioctl called (0x%x)\n",
 570                 ir->d.name, ir->d.minor, cmd);
 571
 572         if (ir->d.minor == NOPLUG || !ir->attached) {
 573                 dev_err(ir->d.dev, LOGHEAD "ioctl result = -ENODEV\n",
 574                         ir->d.name, ir->d.minor);
 575                 return -ENODEV;
 576         }
 577
 578         mutex_lock(&ir->irctl_lock);
 579
 580         switch (cmd) {
 581         case LIRC_GET_FEATURES:
 582                 result = put_user(ir->d.features, (__u32 __user *)arg);
 583                 break;
 584         case LIRC_GET_REC_MODE:
 585                 if (LIRC_CAN_REC(ir->d.features)) {
 586                         result = -ENOTTY;
 587                         break;
 588                 }
 589
 590                 result = put_user(LIRC_REC2MODE
 591                                   (ir->d.features & LIRC_CAN_REC_MASK),
 592                                   (__u32 __user *)arg);
 593                 break;
 594         case LIRC_SET_REC_MODE:
 595                 if (LIRC_CAN_REC(ir->d.features)) {
 596                         result = -ENOTTY;
 597                         break;
 598                 }
 599
 600                 result = get_user(mode, (__u32 __user *)arg);
 601                 if (!result && !(LIRC_MODE2REC(mode) & ir->d.features))
 602                         result = -EINVAL;
 603                 /*
 604                  * FIXME: We should actually set the mode somehow but
 605                  * for now, lirc_serial doesn't support mode changing either
 606                  */
 607                 break;
 608         case LIRC_GET_LENGTH:
 609                 result = put_user(ir->d.code_length, (__u32 __user *)arg);
 610                 break;
 611         case LIRC_GET_MIN_TIMEOUT:
 612                 if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) ||
 613                     ir->d.min_timeout == 0) {
 614                         result = -ENOTTY;
 615                         break;
 616                 }
 617
 618                 result = put_user(ir->d.min_timeout, (__u32 __user *)arg);
 619                 break;
 620         case LIRC_GET_MAX_TIMEOUT:
 621                 if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) ||
 622                     ir->d.max_timeout == 0) {
 623                         result = -ENOTTY;
 624                         break;
 625                 }
 626
 627                 result = put_user(ir->d.max_timeout, (__u32 __user *)arg);
 628                 break;
 629         default:
 630                 result = -EINVAL;
 631         }
 632
 633         mutex_unlock(&ir->irctl_lock);
 634
 635         return result;
 636 }
 637 EXPORT_SYMBOL(lirc_dev_fop_ioctl);
 638
 639 ssize_t lirc_dev_fop_read(struct file *file,
 640                           char __user *buffer,
 641                           size_t length,
 642                           loff_t *ppos)
 643 {
 644         struct irctl *ir = irctls[iminor(file_inode(file))];
 645         unsigned char *buf;
 646         int ret = 0, written = 0;
 647         DECLARE_WAITQUEUE(wait, current);
 648
 649         if (!ir) {
 650                 pr_err("called with invalid irctl\n");
 651                 return -ENODEV;
 652         }
 653
 654         dev_dbg(ir->d.dev, LOGHEAD "read called\n", ir->d.name, ir->d.minor);
 655
 656         buf = kzalloc(ir->chunk_size, GFP_KERNEL);
 657         if (!buf)
 658                 return -ENOMEM;
 659
 660         if (mutex_lock_interruptible(&ir->irctl_lock)) {
 661                 ret = -ERESTARTSYS;
 662                 goto out_unlocked;
 663         }
 664         if (!ir->attached) {
 665                 ret = -ENODEV;
 666                 goto out_locked;
 667         }
 668
 669         if (length % ir->chunk_size) {
 670                 ret = -EINVAL;
 671                 goto out_locked;
 672         }
 673
 674         /*
 675          * we add ourselves to the task queue before buffer check
 676          * to avoid losing scan code (in case when queue is awaken somewhere
 677          * between while condition checking and scheduling)
 678          */
 679         add_wait_queue(&ir->buf->wait_poll, &wait);
 680
 681         /*
 682          * while we didn't provide 'length' bytes, device is opened in blocking
 683          * mode and 'copy_to_user' is happy, wait for data.
 684          */
 685         while (written < length && ret == 0) {
 686                 if (lirc_buffer_empty(ir->buf)) {
 687                         /* According to the read(2) man page, 'written' can be
 688                          * returned as less than 'length', instead of blocking
 689                          * again, returning -EWOULDBLOCK, or returning
 690                          * -ERESTARTSYS
 691                          */
 692                         if (written)
 693                                 break;
 694                         if (file->f_flags & O_NONBLOCK) {
 695                                 ret = -EWOULDBLOCK;
 696                                 break;
 697                         }
 698                         if (signal_pending(current)) {
 699                                 ret = -ERESTARTSYS;
 700                                 break;
 701                         }
 702
 703                         mutex_unlock(&ir->irctl_lock);
 704                         set_current_state(TASK_INTERRUPTIBLE);
 705                         schedule();
 706                         set_current_state(TASK_RUNNING);
 707
 708                         if (mutex_lock_interruptible(&ir->irctl_lock)) {
 709                                 ret = -ERESTARTSYS;
 710                                 remove_wait_queue(&ir->buf->wait_poll, &wait);
 711                                 goto out_unlocked;
 712                         }
 713
 714                         if (!ir->attached) {
 715                                 ret = -ENODEV;
 716                                 goto out_locked;
 717                         }
 718                 } else {
 719                         lirc_buffer_read(ir->buf, buf);
 720                         ret = copy_to_user((void __user *)buffer+written, buf,
 721                                            ir->buf->chunk_size);
 722                         if (!ret)
 723                                 written += ir->buf->chunk_size;
 724                         else
 725                                 ret = -EFAULT;
 726                 }
 727         }
 728
 729         remove_wait_queue(&ir->buf->wait_poll, &wait);
 730
 731 out_locked:
 732         mutex_unlock(&ir->irctl_lock);
 733
 734 out_unlocked:
 735         kfree(buf);
 736
 737         return ret ? ret : written;
 738 }
 739 EXPORT_SYMBOL(lirc_dev_fop_read);
 740
 741 void *lirc_get_pdata(struct file *file)
 742 {
 743         return irctls[iminor(file_inode(file))]->d.data;
 744 }
 745 EXPORT_SYMBOL(lirc_get_pdata);
 746
 747
 748 ssize_t lirc_dev_fop_write(struct file *file, const char __user *buffer,
 749                            size_t length, loff_t *ppos)
 750 {
 751         struct irctl *ir = irctls[iminor(file_inode(file))];
 752
 753         if (!ir) {
 754                 pr_err("called with invalid irctl\n");
 755                 return -ENODEV;
 756         }
 757
 758         if (!ir->attached)
 759                 return -ENODEV;
 760
 761         return -EINVAL;
 762 }
 763 EXPORT_SYMBOL(lirc_dev_fop_write);
 764
 765
 766 static int __init lirc_dev_init(void)
 767 {
 768         int retval;
 769
 770         lirc_class = class_create(THIS_MODULE, "lirc");
 771         if (IS_ERR(lirc_class)) {
 772                 pr_err("class_create failed\n");
 773                 return PTR_ERR(lirc_class);
 774         }
 775
 776         retval = alloc_chrdev_region(&lirc_base_dev, 0, MAX_IRCTL_DEVICES,
 777                                      IRCTL_DEV_NAME);
 778         if (retval) {
 779                 class_destroy(lirc_class);
 780                 pr_err("alloc_chrdev_region failed\n");
 781                 return retval;
 782         }
 783
 784
 785         pr_info("IR Remote Control driver registered, major %d\n",
 786                                                 MAJOR(lirc_base_dev));
 787
 788         return 0;
 789 }
 790
 791
 792
 793 static void __exit lirc_dev_exit(void)
 794 {
 795         class_destroy(lirc_class);
 796         unregister_chrdev_region(lirc_base_dev, MAX_IRCTL_DEVICES);
 797         pr_info("module unloaded\n");
 798 }
 799
 800 module_init(lirc_dev_init);
 801 module_exit(lirc_dev_exit);
 802
 803 MODULE_DESCRIPTION("LIRC base driver module");
 804 MODULE_AUTHOR("Artur Lipowski");
 805 MODULE_LICENSE("GPL");
 806
 807 module_param(debug, bool, S_IRUGO | S_IWUSR);
 808 MODULE_PARM_DESC(debug, "Enable debugging messages");