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 #ifdef CONFIG_COMPAT
 154         .compat_ioctl   = lirc_dev_fop_ioctl,
 155 #endif
 156         .open           = lirc_dev_fop_open,
 157         .release        = lirc_dev_fop_close,
 158         .llseek         = noop_llseek,
 159 };
 160
 161 static int lirc_cdev_add(struct irctl *ir)
 162 {
 163         int retval = -ENOMEM;
 164         struct lirc_driver *d = &ir->d;
 165         struct cdev *cdev;
 166
 167         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 168         if (!cdev)
 169                 goto err_out;
 170
 171         if (d->fops) {
 172                 cdev_init(cdev, d->fops);
 173                 cdev->owner = d->owner;
 174         } else {
 175                 cdev_init(cdev, &lirc_dev_fops);
 176                 cdev->owner = THIS_MODULE;
 177         }
 178         retval = kobject_set_name(&cdev->kobj, "lirc%d", d->minor);
 179         if (retval)
 180                 goto err_out;
 181
 182         retval = cdev_add(cdev, MKDEV(MAJOR(lirc_base_dev), d->minor), 1);
 183         if (retval) {
 184                 kobject_put(&cdev->kobj);
 185                 goto err_out;
 186         }
 187
 188         ir->cdev = cdev;
 189
 190         return 0;
 191
 192 err_out:
 193         kfree(cdev);
 194         return retval;
 195 }
 196
 197 static int lirc_allocate_buffer(struct irctl *ir)
 198 {
 199         int err = 0;
 200         int bytes_in_key;
 201         unsigned int chunk_size;
 202         unsigned int buffer_size;
 203         struct lirc_driver *d = &ir->d;
 204
 205         mutex_lock(&lirc_dev_lock);
 206
 207         bytes_in_key = BITS_TO_LONGS(d->code_length) +
 208                                                 (d->code_length % 8 ? 1 : 0);
 209         buffer_size = d->buffer_size ? d->buffer_size : BUFLEN / bytes_in_key;
 210         chunk_size  = d->chunk_size  ? d->chunk_size  : bytes_in_key;
 211
 212         if (d->rbuf) {
 213                 ir->buf = d->rbuf;
 214         } else {
 215                 ir->buf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
 216                 if (!ir->buf) {
 217                         err = -ENOMEM;
 218                         goto out;
 219                 }
 220
 221                 err = lirc_buffer_init(ir->buf, chunk_size, buffer_size);
 222                 if (err) {
 223                         kfree(ir->buf);
 224                         goto out;
 225                 }
 226         }
 227         ir->chunk_size = ir->buf->chunk_size;
 228
 229 out:
 230         mutex_unlock(&lirc_dev_lock);
 231
 232         return err;
 233 }
 234
 235 static int lirc_allocate_driver(struct lirc_driver *d)
 236 {
 237         struct irctl *ir;
 238         int minor;
 239         int err;
 240
 241         if (!d) {
 242                 pr_err("driver pointer must be not NULL!\n");
 243                 return -EBADRQC;
 244         }
 245
 246         if (!d->dev) {
 247                 pr_err("dev pointer not filled in!\n");
 248                 return -EINVAL;
 249         }
 250
 251         if (d->minor >= MAX_IRCTL_DEVICES) {
 252                 dev_err(d->dev, "minor must be between 0 and %d!\n",
 253                                                 MAX_IRCTL_DEVICES - 1);
 254                 return -EBADRQC;
 255         }
 256
 257         if (d->code_length < 1 || d->code_length > (BUFLEN * 8)) {
 258                 dev_err(d->dev, "code length must be less than %d bits\n",
 259                                                                 BUFLEN * 8);
 260                 return -EBADRQC;
 261         }
 262
 263         if (d->sample_rate) {
 264                 if (2 > d->sample_rate || HZ < d->sample_rate) {
 265                         dev_err(d->dev, "invalid %d sample rate\n",
 266                                                         d->sample_rate);
 267                         return -EBADRQC;
 268                 }
 269                 if (!d->add_to_buf) {
 270                         dev_err(d->dev, "add_to_buf not set\n");
 271                         return -EBADRQC;
 272                 }
 273         } else if (!d->rbuf && !(d->fops && d->fops->read &&
 274                                 d->fops->poll && d->fops->unlocked_ioctl)) {
 275                 dev_err(d->dev, "undefined read, poll, ioctl\n");
 276                 return -EBADRQC;
 277         }
 278
 279         mutex_lock(&lirc_dev_lock);
 280
 281         minor = d->minor;
 282
 283         if (minor < 0) {
 284                 /* find first free slot for driver */
 285                 for (minor = 0; minor < MAX_IRCTL_DEVICES; minor++)
 286                         if (!irctls[minor])
 287                                 break;
 288                 if (minor == MAX_IRCTL_DEVICES) {
 289                         dev_err(d->dev, "no free slots for drivers!\n");
 290                         err = -ENOMEM;
 291                         goto out_lock;
 292                 }
 293         } else if (irctls[minor]) {
 294                 dev_err(d->dev, "minor (%d) just registered!\n", minor);
 295                 err = -EBUSY;
 296                 goto out_lock;
 297         }
 298
 299         ir = kzalloc(sizeof(struct irctl), GFP_KERNEL);
 300         if (!ir) {
 301                 err = -ENOMEM;
 302                 goto out_lock;
 303         }
 304         lirc_irctl_init(ir);
 305         irctls[minor] = ir;
 306         d->minor = minor;
 307
 308         /* some safety check 8-) */
 309         d->name[sizeof(d->name)-1] = '\0';
 310
 311         if (d->features == 0)
 312                 d->features = LIRC_CAN_REC_LIRCCODE;
 313
 314         ir->d = *d;
 315
 316         device_create(lirc_class, ir->d.dev,
 317                       MKDEV(MAJOR(lirc_base_dev), ir->d.minor), NULL,
 318                       "lirc%u", ir->d.minor);
 319
 320         if (d->sample_rate) {
 321                 ir->jiffies_to_wait = HZ / d->sample_rate;
 322
 323                 /* try to fire up polling thread */
 324                 ir->task = kthread_run(lirc_thread, (void *)ir, "lirc_dev");
 325                 if (IS_ERR(ir->task)) {
 326                         dev_err(d->dev, "cannot run thread for minor = %d\n",
 327                                                                 d->minor);
 328                         err = -ECHILD;
 329                         goto out_sysfs;
 330                 }
 331         } else {
 332                 /* it means - wait for external event in task queue */
 333                 ir->jiffies_to_wait = 0;
 334         }
 335
 336         err = lirc_cdev_add(ir);
 337         if (err)
 338                 goto out_sysfs;
 339
 340         ir->attached = 1;
 341         mutex_unlock(&lirc_dev_lock);
 342
 343         dev_info(ir->d.dev, "lirc_dev: driver %s registered at minor = %d\n",
 344                  ir->d.name, ir->d.minor);
 345         return minor;
 346
 347 out_sysfs:
 348         device_destroy(lirc_class, MKDEV(MAJOR(lirc_base_dev), ir->d.minor));
 349 out_lock:
 350         mutex_unlock(&lirc_dev_lock);
 351
 352         return err;
 353 }
 354
 355 int lirc_register_driver(struct lirc_driver *d)
 356 {
 357         int minor, err = 0;
 358
 359         minor = lirc_allocate_driver(d);
 360         if (minor < 0)
 361                 return minor;
 362
 363         if (LIRC_CAN_REC(d->features)) {
 364                 err = lirc_allocate_buffer(irctls[minor]);
 365                 if (err)
 366                         lirc_unregister_driver(minor);
 367         }
 368
 369         return err ? err : minor;
 370 }
 371 EXPORT_SYMBOL(lirc_register_driver);
 372
 373 int lirc_unregister_driver(int minor)
 374 {
 375         struct irctl *ir;
 376         struct cdev *cdev;
 377
 378         if (minor < 0 || minor >= MAX_IRCTL_DEVICES) {
 379                 pr_err("minor (%d) must be between 0 and %d!\n",
 380                                         minor, MAX_IRCTL_DEVICES - 1);
 381                 return -EBADRQC;
 382         }
 383
 384         ir = irctls[minor];
 385         if (!ir) {
 386                 pr_err("failed to get irctl\n");
 387                 return -ENOENT;
 388         }
 389
 390         cdev = ir->cdev;
 391
 392         mutex_lock(&lirc_dev_lock);
 393
 394         if (ir->d.minor != minor) {
 395                 dev_err(ir->d.dev, "lirc_dev: minor %d device not registered\n",
 396                                                                         minor);
 397                 mutex_unlock(&lirc_dev_lock);
 398                 return -ENOENT;
 399         }
 400
 401         /* end up polling thread */
 402         if (ir->task)
 403                 kthread_stop(ir->task);
 404
 405         dev_dbg(ir->d.dev, "lirc_dev: driver %s unregistered from minor = %d\n",
 406                 ir->d.name, ir->d.minor);
 407
 408         ir->attached = 0;
 409         if (ir->open) {
 410                 dev_dbg(ir->d.dev, LOGHEAD "releasing opened driver\n",
 411                         ir->d.name, ir->d.minor);
 412                 wake_up_interruptible(&ir->buf->wait_poll);
 413                 mutex_lock(&ir->irctl_lock);
 414
 415                 if (ir->d.set_use_dec)
 416                         ir->d.set_use_dec(ir->d.data);
 417
 418                 module_put(cdev->owner);
 419                 mutex_unlock(&ir->irctl_lock);
 420         } else {
 421                 lirc_irctl_cleanup(ir);
 422                 cdev_del(cdev);
 423                 kfree(cdev);
 424                 kfree(ir);
 425                 irctls[minor] = NULL;
 426         }
 427
 428         mutex_unlock(&lirc_dev_lock);
 429
 430         return 0;
 431 }
 432 EXPORT_SYMBOL(lirc_unregister_driver);
 433
 434 int lirc_dev_fop_open(struct inode *inode, struct file *file)
 435 {
 436         struct irctl *ir;
 437         struct cdev *cdev;
 438         int retval = 0;
 439
 440         if (iminor(inode) >= MAX_IRCTL_DEVICES) {
 441                 pr_err("open result for %d is -ENODEV\n", iminor(inode));
 442                 return -ENODEV;
 443         }
 444
 445         if (mutex_lock_interruptible(&lirc_dev_lock))
 446                 return -ERESTARTSYS;
 447
 448         ir = irctls[iminor(inode)];
 449         mutex_unlock(&lirc_dev_lock);
 450
 451         if (!ir) {
 452                 retval = -ENODEV;
 453                 goto error;
 454         }
 455
 456         dev_dbg(ir->d.dev, LOGHEAD "open called\n", ir->d.name, ir->d.minor);
 457
 458         if (ir->d.minor == NOPLUG) {
 459                 retval = -ENODEV;
 460                 goto error;
 461         }
 462
 463         if (ir->open) {
 464                 retval = -EBUSY;
 465                 goto error;
 466         }
 467
 468         if (ir->d.rdev) {
 469                 retval = rc_open(ir->d.rdev);
 470                 if (retval)
 471                         goto error;
 472         }
 473
 474         cdev = ir->cdev;
 475         if (try_module_get(cdev->owner)) {
 476                 ir->open++;
 477                 if (ir->d.set_use_inc)
 478                         retval = ir->d.set_use_inc(ir->d.data);
 479
 480                 if (retval) {
 481                         module_put(cdev->owner);
 482                         ir->open--;
 483                 } else {
 484                         lirc_buffer_clear(ir->buf);
 485                 }
 486                 if (ir->task)
 487                         wake_up_process(ir->task);
 488         }
 489
 490 error:
 491         nonseekable_open(inode, file);
 492
 493         return retval;
 494 }
 495 EXPORT_SYMBOL(lirc_dev_fop_open);
 496
 497 int lirc_dev_fop_close(struct inode *inode, struct file *file)
 498 {
 499         struct irctl *ir = irctls[iminor(inode)];
 500         struct cdev *cdev;
 501         int ret;
 502
 503         if (!ir) {
 504                 pr_err("called with invalid irctl\n");
 505                 return -EINVAL;
 506         }
 507
 508         cdev = ir->cdev;
 509
 510         ret = mutex_lock_killable(&lirc_dev_lock);
 511         WARN_ON(ret);
 512
 513         rc_close(ir->d.rdev);
 514
 515         ir->open--;
 516         if (ir->attached) {
 517                 if (ir->d.set_use_dec)
 518                         ir->d.set_use_dec(ir->d.data);
 519                 module_put(cdev->owner);
 520         } else {
 521                 lirc_irctl_cleanup(ir);
 522                 cdev_del(cdev);
 523                 irctls[ir->d.minor] = NULL;
 524                 kfree(cdev);
 525                 kfree(ir);
 526         }
 527
 528         if (!ret)
 529                 mutex_unlock(&lirc_dev_lock);
 530
 531         return 0;
 532 }
 533 EXPORT_SYMBOL(lirc_dev_fop_close);
 534
 535 unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait)
 536 {
 537         struct irctl *ir = irctls[iminor(file_inode(file))];
 538         unsigned int ret;
 539
 540         if (!ir) {
 541                 pr_err("called with invalid irctl\n");
 542                 return POLLERR;
 543         }
 544
 545         if (!ir->attached)
 546                 return POLLERR;
 547
 548         if (ir->buf) {
 549                 poll_wait(file, &ir->buf->wait_poll, wait);
 550
 551                 if (lirc_buffer_empty(ir->buf))
 552                         ret = 0;
 553                 else
 554                         ret = POLLIN | POLLRDNORM;
 555         } else
 556                 ret = POLLERR;
 557
 558         dev_dbg(ir->d.dev, LOGHEAD "poll result = %d\n",
 559                 ir->d.name, ir->d.minor, ret);
 560
 561         return ret;
 562 }
 563 EXPORT_SYMBOL(lirc_dev_fop_poll);
 564
 565 long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 566 {
 567         __u32 mode;
 568         int result = 0;
 569         struct irctl *ir = irctls[iminor(file_inode(file))];
 570
 571         if (!ir) {
 572                 pr_err("no irctl found!\n");
 573                 return -ENODEV;
 574         }
 575
 576         dev_dbg(ir->d.dev, LOGHEAD "ioctl called (0x%x)\n",
 577                 ir->d.name, ir->d.minor, cmd);
 578
 579         if (ir->d.minor == NOPLUG || !ir->attached) {
 580                 dev_err(ir->d.dev, LOGHEAD "ioctl result = -ENODEV\n",
 581                         ir->d.name, ir->d.minor);
 582                 return -ENODEV;
 583         }
 584
 585         mutex_lock(&ir->irctl_lock);
 586
 587         switch (cmd) {
 588         case LIRC_GET_FEATURES:
 589                 result = put_user(ir->d.features, (__u32 __user *)arg);
 590                 break;
 591         case LIRC_GET_REC_MODE:
 592                 if (!LIRC_CAN_REC(ir->d.features)) {
 593                         result = -ENOTTY;
 594                         break;
 595                 }
 596
 597                 result = put_user(LIRC_REC2MODE
 598                                   (ir->d.features & LIRC_CAN_REC_MASK),
 599                                   (__u32 __user *)arg);
 600                 break;
 601         case LIRC_SET_REC_MODE:
 602                 if (!LIRC_CAN_REC(ir->d.features)) {
 603                         result = -ENOTTY;
 604                         break;
 605                 }
 606
 607                 result = get_user(mode, (__u32 __user *)arg);
 608                 if (!result && !(LIRC_MODE2REC(mode) & ir->d.features))
 609                         result = -EINVAL;
 610                 /*
 611                  * FIXME: We should actually set the mode somehow but
 612                  * for now, lirc_serial doesn't support mode changing either
 613                  */
 614                 break;
 615         case LIRC_GET_LENGTH:
 616                 result = put_user(ir->d.code_length, (__u32 __user *)arg);
 617                 break;
 618         case LIRC_GET_MIN_TIMEOUT:
 619                 if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) ||
 620                     ir->d.min_timeout == 0) {
 621                         result = -ENOTTY;
 622                         break;
 623                 }
 624
 625                 result = put_user(ir->d.min_timeout, (__u32 __user *)arg);
 626                 break;
 627         case LIRC_GET_MAX_TIMEOUT:
 628                 if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) ||
 629                     ir->d.max_timeout == 0) {
 630                         result = -ENOTTY;
 631                         break;
 632                 }
 633
 634                 result = put_user(ir->d.max_timeout, (__u32 __user *)arg);
 635                 break;
 636         default:
 637                 result = -EINVAL;
 638         }
 639
 640         mutex_unlock(&ir->irctl_lock);
 641
 642         return result;
 643 }
 644 EXPORT_SYMBOL(lirc_dev_fop_ioctl);
 645
 646 ssize_t lirc_dev_fop_read(struct file *file,
 647                           char __user *buffer,
 648                           size_t length,
 649                           loff_t *ppos)
 650 {
 651         struct irctl *ir = irctls[iminor(file_inode(file))];
 652         unsigned char *buf;
 653         int ret = 0, written = 0;
 654         DECLARE_WAITQUEUE(wait, current);
 655
 656         if (!ir) {
 657                 pr_err("called with invalid irctl\n");
 658                 return -ENODEV;
 659         }
 660
 661         dev_dbg(ir->d.dev, LOGHEAD "read called\n", ir->d.name, ir->d.minor);
 662
 663         buf = kzalloc(ir->chunk_size, GFP_KERNEL);
 664         if (!buf)
 665                 return -ENOMEM;
 666
 667         if (mutex_lock_interruptible(&ir->irctl_lock)) {
 668                 ret = -ERESTARTSYS;
 669                 goto out_unlocked;
 670         }
 671         if (!ir->attached) {
 672                 ret = -ENODEV;
 673                 goto out_locked;
 674         }
 675
 676         if (length % ir->chunk_size) {
 677                 ret = -EINVAL;
 678                 goto out_locked;
 679         }
 680
 681         /*
 682          * we add ourselves to the task queue before buffer check
 683          * to avoid losing scan code (in case when queue is awaken somewhere
 684          * between while condition checking and scheduling)
 685          */
 686         add_wait_queue(&ir->buf->wait_poll, &wait);
 687         set_current_state(TASK_INTERRUPTIBLE);
 688
 689         /*
 690          * while we didn't provide 'length' bytes, device is opened in blocking
 691          * mode and 'copy_to_user' is happy, wait for data.
 692          */
 693         while (written < length && ret == 0) {
 694                 if (lirc_buffer_empty(ir->buf)) {
 695                         /* According to the read(2) man page, 'written' can be
 696                          * returned as less than 'length', instead of blocking
 697                          * again, returning -EWOULDBLOCK, or returning
 698                          * -ERESTARTSYS
 699                          */
 700                         if (written)
 701                                 break;
 702                         if (file->f_flags & O_NONBLOCK) {
 703                                 ret = -EWOULDBLOCK;
 704                                 break;
 705                         }
 706                         if (signal_pending(current)) {
 707                                 ret = -ERESTARTSYS;
 708                                 break;
 709                         }
 710
 711                         mutex_unlock(&ir->irctl_lock);
 712                         schedule();
 713                         set_current_state(TASK_INTERRUPTIBLE);
 714
 715                         if (mutex_lock_interruptible(&ir->irctl_lock)) {
 716                                 ret = -ERESTARTSYS;
 717                                 remove_wait_queue(&ir->buf->wait_poll, &wait);
 718                                 set_current_state(TASK_RUNNING);
 719                                 goto out_unlocked;
 720                         }
 721
 722                         if (!ir->attached) {
 723                                 ret = -ENODEV;
 724                                 break;
 725                         }
 726                 } else {
 727                         lirc_buffer_read(ir->buf, buf);
 728                         ret = copy_to_user((void __user *)buffer+written, buf,
 729                                            ir->buf->chunk_size);
 730                         if (!ret)
 731                                 written += ir->buf->chunk_size;
 732                         else
 733                                 ret = -EFAULT;
 734                 }
 735         }
 736
 737         remove_wait_queue(&ir->buf->wait_poll, &wait);
 738         set_current_state(TASK_RUNNING);
 739
 740 out_locked:
 741         mutex_unlock(&ir->irctl_lock);
 742
 743 out_unlocked:
 744         kfree(buf);
 745
 746         return ret ? ret : written;
 747 }
 748 EXPORT_SYMBOL(lirc_dev_fop_read);
 749
 750 void *lirc_get_pdata(struct file *file)
 751 {
 752         return irctls[iminor(file_inode(file))]->d.data;
 753 }
 754 EXPORT_SYMBOL(lirc_get_pdata);
 755
 756
 757 ssize_t lirc_dev_fop_write(struct file *file, const char __user *buffer,
 758                            size_t length, loff_t *ppos)
 759 {
 760         struct irctl *ir = irctls[iminor(file_inode(file))];
 761
 762         if (!ir) {
 763                 pr_err("called with invalid irctl\n");
 764                 return -ENODEV;
 765         }
 766
 767         if (!ir->attached)
 768                 return -ENODEV;
 769
 770         return -EINVAL;
 771 }
 772 EXPORT_SYMBOL(lirc_dev_fop_write);
 773
 774
 775 static int __init lirc_dev_init(void)
 776 {
 777         int retval;
 778
 779         lirc_class = class_create(THIS_MODULE, "lirc");
 780         if (IS_ERR(lirc_class)) {
 781                 pr_err("class_create failed\n");
 782                 return PTR_ERR(lirc_class);
 783         }
 784
 785         retval = alloc_chrdev_region(&lirc_base_dev, 0, MAX_IRCTL_DEVICES,
 786                                      IRCTL_DEV_NAME);
 787         if (retval) {
 788                 class_destroy(lirc_class);
 789                 pr_err("alloc_chrdev_region failed\n");
 790                 return retval;
 791         }
 792
 793
 794         pr_info("IR Remote Control driver registered, major %d\n",
 795                                                 MAJOR(lirc_base_dev));
 796
 797         return 0;
 798 }
 799
 800
 801
 802 static void __exit lirc_dev_exit(void)
 803 {
 804         class_destroy(lirc_class);
 805         unregister_chrdev_region(lirc_base_dev, MAX_IRCTL_DEVICES);
 806         pr_info("module unloaded\n");
 807 }
 808
 809 module_init(lirc_dev_init);
 810 module_exit(lirc_dev_exit);
 811
 812 MODULE_DESCRIPTION("LIRC base driver module");
 813 MODULE_AUTHOR("Artur Lipowski");
 814 MODULE_LICENSE("GPL");
 815
 816 module_param(debug, bool, S_IRUGO | S_IWUSR);
 817 MODULE_PARM_DESC(debug, "Enable debugging messages");