drivers/media/rc/lirc_dev.c

   1 /*
   2  * LIRC base driver
   3  *
   4  * by Artur Lipowski <[email protected]>
   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  */
  17
  18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  19
  20 #include <linux/module.h>
  21 #include <linux/kernel.h>
  22 #include <linux/sched/signal.h>
  23 #include <linux/errno.h>
  24 #include <linux/ioctl.h>
  25 #include <linux/fs.h>
  26 #include <linux/poll.h>
  27 #include <linux/completion.h>
  28 #include <linux/mutex.h>
  29 #include <linux/wait.h>
  30 #include <linux/unistd.h>
  31 #include <linux/kthread.h>
  32 #include <linux/bitops.h>
  33 #include <linux/device.h>
  34 #include <linux/cdev.h>
  35
  36 #include <media/rc-core.h>
  37 #include <media/lirc.h>
  38 #include <media/lirc_dev.h>
  39
  40 static bool debug;
  41
  42 #define IRCTL_DEV_NAME  "BaseRemoteCtl"
  43 #define NOPLUG          -1
  44 #define LOGHEAD         "lirc_dev (%s[%d]): "
  45
  46 static dev_t lirc_base_dev;
  47
  48 struct irctl {
  49         struct lirc_driver d;
  50         int attached;
  51         int open;
  52
  53         struct mutex irctl_lock;
  54         struct lirc_buffer *buf;
  55         unsigned int chunk_size;
  56
  57         struct cdev *cdev;
  58
  59         struct task_struct *task;
  60         long jiffies_to_wait;
  61 };
  62
  63 static DEFINE_MUTEX(lirc_dev_lock);
  64
  65 static struct irctl *irctls[MAX_IRCTL_DEVICES];
  66
  67 /* Only used for sysfs but defined to void otherwise */
  68 static struct class *lirc_class;
  69
  70 /*  helper function
  71  *  initializes the irctl structure
  72  */
  73 static void lirc_irctl_init(struct irctl *ir)
  74 {
  75         mutex_init(&ir->irctl_lock);
  76         ir->d.minor = NOPLUG;
  77 }
  78
  79 static void lirc_irctl_cleanup(struct irctl *ir)
  80 {
  81         device_destroy(lirc_class, MKDEV(MAJOR(lirc_base_dev), ir->d.minor));
  82
  83         if (ir->buf != ir->d.rbuf) {
  84                 lirc_buffer_free(ir->buf);
  85                 kfree(ir->buf);
  86         }
  87         ir->buf = NULL;
  88 }
  89
  90 /*  helper function
  91  *  reads key codes from driver and puts them into buffer
  92  *  returns 0 on success
  93  */
  94 static int lirc_add_to_buf(struct irctl *ir)
  95 {
  96         int res;
  97         int got_data = -1;
  98
  99         if (!ir->d.add_to_buf)
 100                 return 0;
 101
 102         /*
 103          * service the device as long as it is returning
 104          * data and we have space
 105          */
 106         do {
 107                 got_data++;
 108                 res = ir->d.add_to_buf(ir->d.data, ir->buf);
 109         } while (!res);
 110
 111         if (res == -ENODEV)
 112                 kthread_stop(ir->task);
 113
 114         return got_data ? 0 : res;
 115 }
 116
 117 /* main function of the polling thread
 118  */
 119 static int lirc_thread(void *irctl)
 120 {
 121         struct irctl *ir = irctl;
 122
 123         do {
 124                 if (ir->open) {
 125                         if (ir->jiffies_to_wait) {
 126                                 set_current_state(TASK_INTERRUPTIBLE);
 127                                 schedule_timeout(ir->jiffies_to_wait);
 128                         }
 129                         if (kthread_should_stop())
 130                                 break;
 131                         if (!lirc_add_to_buf(ir))
 132                                 wake_up_interruptible(&ir->buf->wait_poll);
 133                 } else {
 134                         set_current_state(TASK_INTERRUPTIBLE);
 135                         schedule();
 136                 }
 137         } while (!kthread_should_stop());
 138
 139         return 0;
 140 }
 141
 142
 143 static const struct file_operations lirc_dev_fops = {
 144         .owner          = THIS_MODULE,
 145         .read           = lirc_dev_fop_read,
 146         .write          = lirc_dev_fop_write,
 147         .poll           = lirc_dev_fop_poll,
 148         .unlocked_ioctl = lirc_dev_fop_ioctl,
 149         .open           = lirc_dev_fop_open,
 150         .release        = lirc_dev_fop_close,
 151         .llseek         = noop_llseek,
 152 };
 153
 154 static int lirc_cdev_add(struct irctl *ir)
 155 {
 156         struct lirc_driver *d = &ir->d;
 157         struct cdev *cdev;
 158         int retval;
 159
 160         cdev = cdev_alloc();
 161         if (!cdev)
 162                 return -ENOMEM;
 163
 164         if (d->fops) {
 165                 cdev->ops = d->fops;
 166                 cdev->owner = d->owner;
 167         } else {
 168                 cdev->ops = &lirc_dev_fops;
 169                 cdev->owner = THIS_MODULE;
 170         }
 171         retval = kobject_set_name(&cdev->kobj, "lirc%d", d->minor);
 172         if (retval)
 173                 goto err_out;
 174
 175         retval = cdev_add(cdev, MKDEV(MAJOR(lirc_base_dev), d->minor), 1);
 176         if (retval)
 177                 goto err_out;
 178
 179         ir->cdev = cdev;
 180
 181         return 0;
 182
 183 err_out:
 184         cdev_del(cdev);
 185         return retval;
 186 }
 187
 188 static int lirc_allocate_buffer(struct irctl *ir)
 189 {
 190         int err = 0;
 191         int bytes_in_key;
 192         unsigned int chunk_size;
 193         unsigned int buffer_size;
 194         struct lirc_driver *d = &ir->d;
 195
 196         mutex_lock(&lirc_dev_lock);
 197
 198         bytes_in_key = BITS_TO_LONGS(d->code_length) +
 199                                                 (d->code_length % 8 ? 1 : 0);
 200         buffer_size = d->buffer_size ? d->buffer_size : BUFLEN / bytes_in_key;
 201         chunk_size  = d->chunk_size  ? d->chunk_size  : bytes_in_key;
 202
 203         if (d->rbuf) {
 204                 ir->buf = d->rbuf;
 205         } else {
 206                 ir->buf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
 207                 if (!ir->buf) {
 208                         err = -ENOMEM;
 209                         goto out;
 210                 }
 211
 212                 err = lirc_buffer_init(ir->buf, chunk_size, buffer_size);
 213                 if (err) {
 214                         kfree(ir->buf);
 215                         goto out;
 216                 }
 217         }
 218         ir->chunk_size = ir->buf->chunk_size;
 219
 220 out:
 221         mutex_unlock(&lirc_dev_lock);
 222
 223         return err;
 224 }
 225
 226 static int lirc_allocate_driver(struct lirc_driver *d)
 227 {
 228         struct irctl *ir;
 229         int minor;
 230         int err;
 231
 232         if (!d) {
 233                 pr_err("driver pointer must be not NULL!\n");
 234                 return -EBADRQC;
 235         }
 236
 237         if (!d->dev) {
 238                 pr_err("dev pointer not filled in!\n");
 239                 return -EINVAL;
 240         }
 241
 242         if (d->minor >= MAX_IRCTL_DEVICES) {
 243                 dev_err(d->dev, "minor must be between 0 and %d!\n",
 244                                                 MAX_IRCTL_DEVICES - 1);
 245                 return -EBADRQC;
 246         }
 247
 248         if (d->code_length < 1 || d->code_length > (BUFLEN * 8)) {
 249                 dev_err(d->dev, "code length must be less than %d bits\n",
 250                                                                 BUFLEN * 8);
 251                 return -EBADRQC;
 252         }
 253
 254         if (d->sample_rate) {
 255                 if (2 > d->sample_rate || HZ < d->sample_rate) {
 256                         dev_err(d->dev, "invalid %d sample rate\n",
 257                                                         d->sample_rate);
 258                         return -EBADRQC;
 259                 }
 260                 if (!d->add_to_buf) {
 261                         dev_err(d->dev, "add_to_buf not set\n");
 262                         return -EBADRQC;
 263                 }
 264         } else if (!d->rbuf && !(d->fops && d->fops->read &&
 265                                 d->fops->poll && d->fops->unlocked_ioctl)) {
 266                 dev_err(d->dev, "undefined read, poll, ioctl\n");
 267                 return -EBADRQC;
 268         }
 269
 270         mutex_lock(&lirc_dev_lock);
 271
 272         minor = d->minor;
 273
 274         if (minor < 0) {
 275                 /* find first free slot for driver */
 276                 for (minor = 0; minor < MAX_IRCTL_DEVICES; minor++)
 277                         if (!irctls[minor])
 278                                 break;
 279                 if (minor == MAX_IRCTL_DEVICES) {
 280                         dev_err(d->dev, "no free slots for drivers!\n");
 281                         err = -ENOMEM;
 282                         goto out_lock;
 283                 }
 284         } else if (irctls[minor]) {
 285                 dev_err(d->dev, "minor (%d) just registered!\n", minor);
 286                 err = -EBUSY;
 287                 goto out_lock;
 288         }
 289
 290         ir = kzalloc(sizeof(struct irctl), GFP_KERNEL);
 291         if (!ir) {
 292                 err = -ENOMEM;
 293                 goto out_lock;
 294         }
 295         lirc_irctl_init(ir);
 296         irctls[minor] = ir;
 297         d->minor = minor;
 298
 299         /* some safety check 8-) */
 300         d->name[sizeof(d->name)-1] = '\0';
 301
 302         if (d->features == 0)
 303                 d->features = LIRC_CAN_REC_LIRCCODE;
 304
 305         ir->d = *d;
 306
 307         device_create(lirc_class, ir->d.dev,
 308                       MKDEV(MAJOR(lirc_base_dev), ir->d.minor), NULL,
 309                       "lirc%u", ir->d.minor);
 310
 311         if (d->sample_rate) {
 312                 ir->jiffies_to_wait = HZ / d->sample_rate;
 313
 314                 /* try to fire up polling thread */
 315                 ir->task = kthread_run(lirc_thread, (void *)ir, "lirc_dev");
 316                 if (IS_ERR(ir->task)) {
 317                         dev_err(d->dev, "cannot run thread for minor = %d\n",
 318                                                                 d->minor);
 319                         err = -ECHILD;
 320                         goto out_sysfs;
 321                 }
 322         } else {
 323                 /* it means - wait for external event in task queue */
 324                 ir->jiffies_to_wait = 0;
 325         }
 326
 327         err = lirc_cdev_add(ir);
 328         if (err)
 329                 goto out_sysfs;
 330
 331         ir->attached = 1;
 332         mutex_unlock(&lirc_dev_lock);
 333
 334         dev_info(ir->d.dev, "lirc_dev: driver %s registered at minor = %d\n",
 335                  ir->d.name, ir->d.minor);
 336         return minor;
 337
 338 out_sysfs:
 339         device_destroy(lirc_class, MKDEV(MAJOR(lirc_base_dev), ir->d.minor));
 340 out_lock:
 341         mutex_unlock(&lirc_dev_lock);
 342
 343         return err;
 344 }
 345
 346 int lirc_register_driver(struct lirc_driver *d)
 347 {
 348         int minor, err = 0;
 349
 350         minor = lirc_allocate_driver(d);
 351         if (minor < 0)
 352                 return minor;
 353
 354         if (LIRC_CAN_REC(d->features)) {
 355                 err = lirc_allocate_buffer(irctls[minor]);
 356                 if (err)
 357                         lirc_unregister_driver(minor);
 358         }
 359
 360         return err ? err : minor;
 361 }
 362 EXPORT_SYMBOL(lirc_register_driver);
 363
 364 int lirc_unregister_driver(int minor)
 365 {
 366         struct irctl *ir;
 367         struct cdev *cdev;
 368
 369         if (minor < 0 || minor >= MAX_IRCTL_DEVICES) {
 370                 pr_err("minor (%d) must be between 0 and %d!\n",
 371                                         minor, MAX_IRCTL_DEVICES - 1);
 372                 return -EBADRQC;
 373         }
 374
 375         ir = irctls[minor];
 376         if (!ir) {
 377                 pr_err("failed to get irctl\n");
 378                 return -ENOENT;
 379         }
 380
 381         cdev = ir->cdev;
 382
 383         mutex_lock(&lirc_dev_lock);
 384
 385         if (ir->d.minor != minor) {
 386                 dev_err(ir->d.dev, "lirc_dev: minor %d device not registered\n",
 387                                                                         minor);
 388                 mutex_unlock(&lirc_dev_lock);
 389                 return -ENOENT;
 390         }
 391
 392         /* end up polling thread */
 393         if (ir->task)
 394                 kthread_stop(ir->task);
 395
 396         dev_dbg(ir->d.dev, "lirc_dev: driver %s unregistered from minor = %d\n",
 397                 ir->d.name, ir->d.minor);
 398
 399         ir->attached = 0;
 400         if (ir->open) {
 401                 dev_dbg(ir->d.dev, LOGHEAD "releasing opened driver\n",
 402                         ir->d.name, ir->d.minor);
 403                 wake_up_interruptible(&ir->buf->wait_poll);
 404                 mutex_lock(&ir->irctl_lock);
 405
 406                 if (ir->d.set_use_dec)
 407                         ir->d.set_use_dec(ir->d.data);
 408
 409                 module_put(cdev->owner);
 410                 mutex_unlock(&ir->irctl_lock);
 411         } else {
 412                 lirc_irctl_cleanup(ir);
 413                 cdev_del(cdev);
 414                 kfree(ir);
 415                 irctls[minor] = NULL;
 416         }
 417
 418         mutex_unlock(&lirc_dev_lock);
 419
 420         return 0;
 421 }
 422 EXPORT_SYMBOL(lirc_unregister_driver);
 423
 424 int lirc_dev_fop_open(struct inode *inode, struct file *file)
 425 {
 426         struct irctl *ir;
 427         struct cdev *cdev;
 428         int retval = 0;
 429
 430         if (iminor(inode) >= MAX_IRCTL_DEVICES) {
 431                 pr_err("open result for %d is -ENODEV\n", iminor(inode));
 432                 return -ENODEV;
 433         }
 434
 435         if (mutex_lock_interruptible(&lirc_dev_lock))
 436                 return -ERESTARTSYS;
 437
 438         ir = irctls[iminor(inode)];
 439         mutex_unlock(&lirc_dev_lock);
 440
 441         if (!ir) {
 442                 retval = -ENODEV;
 443                 goto error;
 444         }
 445
 446         dev_dbg(ir->d.dev, LOGHEAD "open called\n", ir->d.name, ir->d.minor);
 447
 448         if (ir->d.minor == NOPLUG) {
 449                 retval = -ENODEV;
 450                 goto error;
 451         }
 452
 453         if (ir->open) {
 454                 retval = -EBUSY;
 455                 goto error;
 456         }
 457
 458         if (ir->d.rdev) {
 459                 retval = rc_open(ir->d.rdev);
 460                 if (retval)
 461                         goto error;
 462         }
 463
 464         cdev = ir->cdev;
 465         if (try_module_get(cdev->owner)) {
 466                 ir->open++;
 467                 if (ir->d.set_use_inc)
 468                         retval = ir->d.set_use_inc(ir->d.data);
 469
 470                 if (retval) {
 471                         module_put(cdev->owner);
 472                         ir->open--;
 473                 } else if (ir->buf) {
 474                         lirc_buffer_clear(ir->buf);
 475                 }
 476                 if (ir->task)
 477                         wake_up_process(ir->task);
 478         }
 479
 480 error:
 481         nonseekable_open(inode, file);
 482
 483         return retval;
 484 }
 485 EXPORT_SYMBOL(lirc_dev_fop_open);
 486
 487 int lirc_dev_fop_close(struct inode *inode, struct file *file)
 488 {
 489         struct irctl *ir = irctls[iminor(inode)];
 490         struct cdev *cdev;
 491         int ret;
 492
 493         if (!ir) {
 494                 pr_err("called with invalid irctl\n");
 495                 return -EINVAL;
 496         }
 497
 498         cdev = ir->cdev;
 499
 500         ret = mutex_lock_killable(&lirc_dev_lock);
 501         WARN_ON(ret);
 502
 503         rc_close(ir->d.rdev);
 504
 505         ir->open--;
 506         if (ir->attached) {
 507                 if (ir->d.set_use_dec)
 508                         ir->d.set_use_dec(ir->d.data);
 509                 module_put(cdev->owner);
 510         } else {
 511                 lirc_irctl_cleanup(ir);
 512                 cdev_del(cdev);
 513                 irctls[ir->d.minor] = NULL;
 514                 kfree(ir);
 515         }
 516
 517         if (!ret)
 518                 mutex_unlock(&lirc_dev_lock);
 519
 520         return 0;
 521 }
 522 EXPORT_SYMBOL(lirc_dev_fop_close);
 523
 524 unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait)
 525 {
 526         struct irctl *ir = irctls[iminor(file_inode(file))];
 527         unsigned int ret;
 528
 529         if (!ir) {
 530                 pr_err("called with invalid irctl\n");
 531                 return POLLERR;
 532         }
 533
 534         if (!ir->attached)
 535                 return POLLERR;
 536
 537         if (ir->buf) {
 538                 poll_wait(file, &ir->buf->wait_poll, wait);
 539
 540                 if (lirc_buffer_empty(ir->buf))
 541                         ret = 0;
 542                 else
 543                         ret = POLLIN | POLLRDNORM;
 544         } else
 545                 ret = POLLERR;
 546
 547         dev_dbg(ir->d.dev, LOGHEAD "poll result = %d\n",
 548                 ir->d.name, ir->d.minor, ret);
 549
 550         return ret;
 551 }
 552 EXPORT_SYMBOL(lirc_dev_fop_poll);
 553
 554 long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 555 {
 556         __u32 mode;
 557         int result = 0;
 558         struct irctl *ir = irctls[iminor(file_inode(file))];
 559
 560         if (!ir) {
 561                 pr_err("no irctl found!\n");
 562                 return -ENODEV;
 563         }
 564
 565         dev_dbg(ir->d.dev, LOGHEAD "ioctl called (0x%x)\n",
 566                 ir->d.name, ir->d.minor, cmd);
 567
 568         if (ir->d.minor == NOPLUG || !ir->attached) {
 569                 dev_err(ir->d.dev, LOGHEAD "ioctl result = -ENODEV\n",
 570                         ir->d.name, ir->d.minor);
 571                 return -ENODEV;
 572         }
 573
 574         mutex_lock(&ir->irctl_lock);
 575
 576         switch (cmd) {
 577         case LIRC_GET_FEATURES:
 578                 result = put_user(ir->d.features, (__u32 __user *)arg);
 579                 break;
 580         case LIRC_GET_REC_MODE:
 581                 if (!LIRC_CAN_REC(ir->d.features)) {
 582                         result = -ENOTTY;
 583                         break;
 584                 }
 585
 586                 result = put_user(LIRC_REC2MODE
 587                                   (ir->d.features & LIRC_CAN_REC_MASK),
 588                                   (__u32 __user *)arg);
 589                 break;
 590         case LIRC_SET_REC_MODE:
 591                 if (!LIRC_CAN_REC(ir->d.features)) {
 592                         result = -ENOTTY;
 593                         break;
 594                 }
 595
 596                 result = get_user(mode, (__u32 __user *)arg);
 597                 if (!result && !(LIRC_MODE2REC(mode) & ir->d.features))
 598                         result = -EINVAL;
 599                 /*
 600                  * FIXME: We should actually set the mode somehow but
 601                  * for now, lirc_serial doesn't support mode changing either
 602                  */
 603                 break;
 604         case LIRC_GET_LENGTH:
 605                 result = put_user(ir->d.code_length, (__u32 __user *)arg);
 606                 break;
 607         case LIRC_GET_MIN_TIMEOUT:
 608                 if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) ||
 609                     ir->d.min_timeout == 0) {
 610                         result = -ENOTTY;
 611                         break;
 612                 }
 613
 614                 result = put_user(ir->d.min_timeout, (__u32 __user *)arg);
 615                 break;
 616         case LIRC_GET_MAX_TIMEOUT:
 617                 if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) ||
 618                     ir->d.max_timeout == 0) {
 619                         result = -ENOTTY;
 620                         break;
 621                 }
 622
 623                 result = put_user(ir->d.max_timeout, (__u32 __user *)arg);
 624                 break;
 625         default:
 626                 result = -EINVAL;
 627         }
 628
 629         mutex_unlock(&ir->irctl_lock);
 630
 631         return result;
 632 }
 633 EXPORT_SYMBOL(lirc_dev_fop_ioctl);
 634
 635 ssize_t lirc_dev_fop_read(struct file *file,
 636                           char __user *buffer,
 637                           size_t length,
 638                           loff_t *ppos)
 639 {
 640         struct irctl *ir = irctls[iminor(file_inode(file))];
 641         unsigned char *buf;
 642         int ret = 0, written = 0;
 643         DECLARE_WAITQUEUE(wait, current);
 644
 645         if (!ir) {
 646                 pr_err("called with invalid irctl\n");
 647                 return -ENODEV;
 648         }
 649
 650         if (!LIRC_CAN_REC(ir->d.features))
 651                 return -EINVAL;
 652
 653         dev_dbg(ir->d.dev, LOGHEAD "read called\n", ir->d.name, ir->d.minor);
 654
 655         buf = kzalloc(ir->chunk_size, GFP_KERNEL);
 656         if (!buf)
 657                 return -ENOMEM;
 658
 659         if (mutex_lock_interruptible(&ir->irctl_lock)) {
 660                 ret = -ERESTARTSYS;
 661                 goto out_unlocked;
 662         }
 663         if (!ir->attached) {
 664                 ret = -ENODEV;
 665                 goto out_locked;
 666         }
 667
 668         if (length % ir->chunk_size) {
 669                 ret = -EINVAL;
 670                 goto out_locked;
 671         }
 672
 673         /*
 674          * we add ourselves to the task queue before buffer check
 675          * to avoid losing scan code (in case when queue is awaken somewhere
 676          * between while condition checking and scheduling)
 677          */
 678         add_wait_queue(&ir->buf->wait_poll, &wait);
 679
 680         /*
 681          * while we didn't provide 'length' bytes, device is opened in blocking
 682          * mode and 'copy_to_user' is happy, wait for data.
 683          */
 684         while (written < length && ret == 0) {
 685                 if (lirc_buffer_empty(ir->buf)) {
 686                         /* According to the read(2) man page, 'written' can be
 687                          * returned as less than 'length', instead of blocking
 688                          * again, returning -EWOULDBLOCK, or returning
 689                          * -ERESTARTSYS
 690                          */
 691                         if (written)
 692                                 break;
 693                         if (file->f_flags & O_NONBLOCK) {
 694                                 ret = -EWOULDBLOCK;
 695                                 break;
 696                         }
 697                         if (signal_pending(current)) {
 698                                 ret = -ERESTARTSYS;
 699                                 break;
 700                         }
 701
 702                         mutex_unlock(&ir->irctl_lock);
 703                         set_current_state(TASK_INTERRUPTIBLE);
 704                         schedule();
 705                         set_current_state(TASK_RUNNING);
 706
 707                         if (mutex_lock_interruptible(&ir->irctl_lock)) {
 708                                 ret = -ERESTARTSYS;
 709                                 remove_wait_queue(&ir->buf->wait_poll, &wait);
 710                                 goto out_unlocked;
 711                         }
 712
 713                         if (!ir->attached) {
 714                                 ret = -ENODEV;
 715                                 goto out_locked;
 716                         }
 717                 } else {
 718                         lirc_buffer_read(ir->buf, buf);
 719                         ret = copy_to_user((void __user *)buffer+written, buf,
 720                                            ir->buf->chunk_size);
 721                         if (!ret)
 722                                 written += ir->buf->chunk_size;
 723                         else
 724                                 ret = -EFAULT;
 725                 }
 726         }
 727
 728         remove_wait_queue(&ir->buf->wait_poll, &wait);
 729
 730 out_locked:
 731         mutex_unlock(&ir->irctl_lock);
 732
 733 out_unlocked:
 734         kfree(buf);
 735
 736         return ret ? ret : written;
 737 }
 738 EXPORT_SYMBOL(lirc_dev_fop_read);
 739
 740 void *lirc_get_pdata(struct file *file)
 741 {
 742         return irctls[iminor(file_inode(file))]->d.data;
 743 }
 744 EXPORT_SYMBOL(lirc_get_pdata);
 745
 746
 747 ssize_t lirc_dev_fop_write(struct file *file, const char __user *buffer,
 748                            size_t length, loff_t *ppos)
 749 {
 750         struct irctl *ir = irctls[iminor(file_inode(file))];
 751
 752         if (!ir) {
 753                 pr_err("called with invalid irctl\n");
 754                 return -ENODEV;
 755         }
 756
 757         if (!ir->attached)
 758                 return -ENODEV;
 759
 760         return -EINVAL;
 761 }
 762 EXPORT_SYMBOL(lirc_dev_fop_write);
 763
 764
 765 static int __init lirc_dev_init(void)
 766 {
 767         int retval;
 768
 769         lirc_class = class_create(THIS_MODULE, "lirc");
 770         if (IS_ERR(lirc_class)) {
 771                 pr_err("class_create failed\n");
 772                 return PTR_ERR(lirc_class);
 773         }
 774
 775         retval = alloc_chrdev_region(&lirc_base_dev, 0, MAX_IRCTL_DEVICES,
 776                                      IRCTL_DEV_NAME);
 777         if (retval) {
 778                 class_destroy(lirc_class);
 779                 pr_err("alloc_chrdev_region failed\n");
 780                 return retval;
 781         }
 782
 783
 784         pr_info("IR Remote Control driver registered, major %d\n",
 785                                                 MAJOR(lirc_base_dev));
 786
 787         return 0;
 788 }
 789
 790
 791
 792 static void __exit lirc_dev_exit(void)
 793 {
 794         class_destroy(lirc_class);
 795         unregister_chrdev_region(lirc_base_dev, MAX_IRCTL_DEVICES);
 796         pr_info("module unloaded\n");
 797 }
 798
 799 module_init(lirc_dev_init);
 800 module_exit(lirc_dev_exit);
 801
 802 MODULE_DESCRIPTION("LIRC base driver module");
 803 MODULE_AUTHOR("Artur Lipowski");
 804 MODULE_LICENSE("GPL");
 805
 806 module_param(debug, bool, S_IRUGO | S_IWUSR);
 807 MODULE_PARM_DESC(debug, "Enable debugging messages");