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