drivers/media/rc/lirc_dev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * LIRC base driver
   4  *
   5  * by Artur Lipowski <alipowski@interia.pl>
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/module.h>
  11 #include <linux/mutex.h>
  12 #include <linux/device.h>
  13 #include <linux/file.h>
  14 #include <linux/idr.h>
  15 #include <linux/poll.h>
  16 #include <linux/sched.h>
  17 #include <linux/wait.h>
  18
  19 #include "rc-core-priv.h"
  20 #include <uapi/linux/lirc.h>
  21
  22 #define LIRCBUF_SIZE    1024
  23
  24 static dev_t lirc_base_dev;
  25
  26 /* Used to keep track of allocated lirc devices */
  27 static DEFINE_IDA(lirc_ida);
  28
  29 /* Only used for sysfs but defined to void otherwise */
  30 static struct class *lirc_class;
  31
  32 /**
  33  * lirc_raw_event() - Send raw IR data to lirc to be relayed to userspace
  34  *
  35  * @dev:        the struct rc_dev descriptor of the device
  36  * @ev:         the struct ir_raw_event descriptor of the pulse/space
  37  */
  38 void lirc_raw_event(struct rc_dev *dev, struct ir_raw_event ev)
  39 {
  40         unsigned long flags;
  41         struct lirc_fh *fh;
  42         int sample;
  43
  44         /* Receiver overflow, data missing */
  45         if (ev.overflow) {
  46                 /*
  47                  * Send lirc overflow message. This message is unknown to
  48                  * lircd, but it will interpret this as a long space as
  49                  * long as the value is set to high value. This resets its
  50                  * decoder state.
  51                  */
  52                 sample = LIRC_OVERFLOW(LIRC_VALUE_MASK);
  53                 dev_dbg(&dev->dev, "delivering overflow to lirc_dev\n");
  54
  55         /* Carrier reports */
  56         } else if (ev.carrier_report) {
  57                 sample = LIRC_FREQUENCY(ev.carrier);
  58                 dev_dbg(&dev->dev, "carrier report (freq: %d)\n", sample);
  59
  60         /* Packet end */
  61         } else if (ev.timeout) {
  62                 dev->gap_start = ktime_get();
  63
  64                 sample = LIRC_TIMEOUT(ev.duration);
  65                 dev_dbg(&dev->dev, "timeout report (duration: %d)\n", sample);
  66
  67         /* Normal sample */
  68         } else {
  69                 if (dev->gap_start) {
  70                         u64 duration = ktime_us_delta(ktime_get(),
  71                                                       dev->gap_start);
  72
  73                         /* Cap by LIRC_VALUE_MASK */
  74                         duration = min_t(u64, duration, LIRC_VALUE_MASK);
  75
  76                         spin_lock_irqsave(&dev->lirc_fh_lock, flags);
  77                         list_for_each_entry(fh, &dev->lirc_fh, list)
  78                                 kfifo_put(&fh->rawir, LIRC_SPACE(duration));
  79                         spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
  80                         dev->gap_start = 0;
  81                 }
  82
  83                 sample = ev.pulse ? LIRC_PULSE(ev.duration) :
  84                                         LIRC_SPACE(ev.duration);
  85                 dev_dbg(&dev->dev, "delivering %uus %s to lirc_dev\n",
  86                         ev.duration, TO_STR(ev.pulse));
  87         }
  88
  89         /*
  90          * bpf does not care about the gap generated above; that exists
  91          * for backwards compatibility
  92          */
  93         lirc_bpf_run(dev, sample);
  94
  95         spin_lock_irqsave(&dev->lirc_fh_lock, flags);
  96         list_for_each_entry(fh, &dev->lirc_fh, list) {
  97                 if (kfifo_put(&fh->rawir, sample))
  98                         wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
  99         }
 100         spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
 101 }
 102
 103 /**
 104  * lirc_scancode_event() - Send scancode data to lirc to be relayed to
 105  *              userspace. This can be called in atomic context.
 106  * @dev:        the struct rc_dev descriptor of the device
 107  * @lsc:        the struct lirc_scancode describing the decoded scancode
 108  */
 109 void lirc_scancode_event(struct rc_dev *dev, struct lirc_scancode *lsc)
 110 {
 111         unsigned long flags;
 112         struct lirc_fh *fh;
 113
 114         lsc->timestamp = ktime_get_ns();
 115
 116         spin_lock_irqsave(&dev->lirc_fh_lock, flags);
 117         list_for_each_entry(fh, &dev->lirc_fh, list) {
 118                 if (kfifo_put(&fh->scancodes, *lsc))
 119                         wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
 120         }
 121         spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
 122 }
 123 EXPORT_SYMBOL_GPL(lirc_scancode_event);
 124
 125 static int lirc_open(struct inode *inode, struct file *file)
 126 {
 127         struct rc_dev *dev = container_of(inode->i_cdev, struct rc_dev,
 128                                           lirc_cdev);
 129         struct lirc_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
 130         unsigned long flags;
 131         int retval;
 132
 133         if (!fh)
 134                 return -ENOMEM;
 135
 136         get_device(&dev->dev);
 137
 138         if (!dev->registered) {
 139                 retval = -ENODEV;
 140                 goto out_fh;
 141         }
 142
 143         if (dev->driver_type == RC_DRIVER_IR_RAW) {
 144                 if (kfifo_alloc(&fh->rawir, MAX_IR_EVENT_SIZE, GFP_KERNEL)) {
 145                         retval = -ENOMEM;
 146                         goto out_fh;
 147                 }
 148         }
 149
 150         if (dev->driver_type != RC_DRIVER_IR_RAW_TX) {
 151                 if (kfifo_alloc(&fh->scancodes, 32, GFP_KERNEL)) {
 152                         retval = -ENOMEM;
 153                         goto out_rawir;
 154                 }
 155         }
 156
 157         fh->send_mode = LIRC_MODE_PULSE;
 158         fh->rc = dev;
 159
 160         if (dev->driver_type == RC_DRIVER_SCANCODE)
 161                 fh->rec_mode = LIRC_MODE_SCANCODE;
 162         else
 163                 fh->rec_mode = LIRC_MODE_MODE2;
 164
 165         retval = rc_open(dev);
 166         if (retval)
 167                 goto out_kfifo;
 168
 169         init_waitqueue_head(&fh->wait_poll);
 170
 171         file->private_data = fh;
 172         spin_lock_irqsave(&dev->lirc_fh_lock, flags);
 173         list_add(&fh->list, &dev->lirc_fh);
 174         spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
 175
 176         stream_open(inode, file);
 177
 178         return 0;
 179 out_kfifo:
 180         if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
 181                 kfifo_free(&fh->scancodes);
 182 out_rawir:
 183         if (dev->driver_type == RC_DRIVER_IR_RAW)
 184                 kfifo_free(&fh->rawir);
 185 out_fh:
 186         kfree(fh);
 187         put_device(&dev->dev);
 188
 189         return retval;
 190 }
 191
 192 static int lirc_close(struct inode *inode, struct file *file)
 193 {
 194         struct lirc_fh *fh = file->private_data;
 195         struct rc_dev *dev = fh->rc;
 196         unsigned long flags;
 197
 198         spin_lock_irqsave(&dev->lirc_fh_lock, flags);
 199         list_del(&fh->list);
 200         spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
 201
 202         if (dev->driver_type == RC_DRIVER_IR_RAW)
 203                 kfifo_free(&fh->rawir);
 204         if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
 205                 kfifo_free(&fh->scancodes);
 206         kfree(fh);
 207
 208         rc_close(dev);
 209         put_device(&dev->dev);
 210
 211         return 0;
 212 }
 213
 214 static ssize_t lirc_transmit(struct file *file, const char __user *buf,
 215                              size_t n, loff_t *ppos)
 216 {
 217         struct lirc_fh *fh = file->private_data;
 218         struct rc_dev *dev = fh->rc;
 219         unsigned int *txbuf;
 220         struct ir_raw_event *raw = NULL;
 221         ssize_t ret;
 222         size_t count;
 223         ktime_t start;
 224         s64 towait;
 225         unsigned int duration = 0; /* signal duration in us */
 226         int i;
 227
 228         ret = mutex_lock_interruptible(&dev->lock);
 229         if (ret)
 230                 return ret;
 231
 232         if (!dev->registered) {
 233                 ret = -ENODEV;
 234                 goto out_unlock;
 235         }
 236
 237         if (!dev->tx_ir) {
 238                 ret = -EINVAL;
 239                 goto out_unlock;
 240         }
 241
 242         if (fh->send_mode == LIRC_MODE_SCANCODE) {
 243                 struct lirc_scancode scan;
 244
 245                 if (n != sizeof(scan)) {
 246                         ret = -EINVAL;
 247                         goto out_unlock;
 248                 }
 249
 250                 if (copy_from_user(&scan, buf, sizeof(scan))) {
 251                         ret = -EFAULT;
 252                         goto out_unlock;
 253                 }
 254
 255                 if (scan.flags || scan.keycode || scan.timestamp ||
 256                     scan.rc_proto > RC_PROTO_MAX) {
 257                         ret = -EINVAL;
 258                         goto out_unlock;
 259                 }
 260
 261                 /* We only have encoders for 32-bit protocols. */
 262                 if (scan.scancode > U32_MAX ||
 263                     !rc_validate_scancode(scan.rc_proto, scan.scancode)) {
 264                         ret = -EINVAL;
 265                         goto out_unlock;
 266                 }
 267
 268                 raw = kmalloc_array(LIRCBUF_SIZE, sizeof(*raw), GFP_KERNEL);
 269                 if (!raw) {
 270                         ret = -ENOMEM;
 271                         goto out_unlock;
 272                 }
 273
 274                 ret = ir_raw_encode_scancode(scan.rc_proto, scan.scancode,
 275                                              raw, LIRCBUF_SIZE);
 276                 if (ret < 0)
 277                         goto out_kfree_raw;
 278
 279                 /* drop trailing space */
 280                 if (!(ret % 2))
 281                         count = ret - 1;
 282                 else
 283                         count = ret;
 284
 285                 txbuf = kmalloc_array(count, sizeof(unsigned int), GFP_KERNEL);
 286                 if (!txbuf) {
 287                         ret = -ENOMEM;
 288                         goto out_kfree_raw;
 289                 }
 290
 291                 for (i = 0; i < count; i++)
 292                         txbuf[i] = raw[i].duration;
 293
 294                 if (dev->s_tx_carrier) {
 295                         int carrier = ir_raw_encode_carrier(scan.rc_proto);
 296
 297                         if (carrier > 0)
 298                                 dev->s_tx_carrier(dev, carrier);
 299                 }
 300         } else {
 301                 if (n < sizeof(unsigned int) || n % sizeof(unsigned int)) {
 302                         ret = -EINVAL;
 303                         goto out_unlock;
 304                 }
 305
 306                 count = n / sizeof(unsigned int);
 307                 if (count > LIRCBUF_SIZE || count % 2 == 0) {
 308                         ret = -EINVAL;
 309                         goto out_unlock;
 310                 }
 311
 312                 txbuf = memdup_user(buf, n);
 313                 if (IS_ERR(txbuf)) {
 314                         ret = PTR_ERR(txbuf);
 315                         goto out_unlock;
 316                 }
 317         }
 318
 319         for (i = 0; i < count; i++) {
 320                 if (txbuf[i] > IR_MAX_DURATION - duration || !txbuf[i]) {
 321                         ret = -EINVAL;
 322                         goto out_kfree;
 323                 }
 324
 325                 duration += txbuf[i];
 326         }
 327
 328         start = ktime_get();
 329
 330         ret = dev->tx_ir(dev, txbuf, count);
 331         if (ret < 0)
 332                 goto out_kfree;
 333
 334         kfree(txbuf);
 335         kfree(raw);
 336         mutex_unlock(&dev->lock);
 337
 338         /*
 339          * The lircd gap calculation expects the write function to
 340          * wait for the actual IR signal to be transmitted before
 341          * returning.
 342          */
 343         towait = ktime_us_delta(ktime_add_us(start, duration),
 344                                 ktime_get());
 345         if (towait > 0) {
 346                 set_current_state(TASK_INTERRUPTIBLE);
 347                 schedule_timeout(usecs_to_jiffies(towait));
 348         }
 349
 350         return n;
 351 out_kfree:
 352         kfree(txbuf);
 353 out_kfree_raw:
 354         kfree(raw);
 355 out_unlock:
 356         mutex_unlock(&dev->lock);
 357         return ret;
 358 }
 359
 360 static long lirc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 361 {
 362         struct lirc_fh *fh = file->private_data;
 363         struct rc_dev *dev = fh->rc;
 364         u32 __user *argp = (u32 __user *)(arg);
 365         u32 val = 0;
 366         int ret;
 367
 368         if (_IOC_DIR(cmd) & _IOC_WRITE) {
 369                 ret = get_user(val, argp);
 370                 if (ret)
 371                         return ret;
 372         }
 373
 374         ret = mutex_lock_interruptible(&dev->lock);
 375         if (ret)
 376                 return ret;
 377
 378         if (!dev->registered) {
 379                 ret = -ENODEV;
 380                 goto out;
 381         }
 382
 383         switch (cmd) {
 384         case LIRC_GET_FEATURES:
 385                 if (dev->driver_type == RC_DRIVER_SCANCODE)
 386                         val |= LIRC_CAN_REC_SCANCODE;
 387
 388                 if (dev->driver_type == RC_DRIVER_IR_RAW) {
 389                         val |= LIRC_CAN_REC_MODE2;
 390                         if (dev->rx_resolution)
 391                                 val |= LIRC_CAN_GET_REC_RESOLUTION;
 392                 }
 393
 394                 if (dev->tx_ir) {
 395                         val |= LIRC_CAN_SEND_PULSE;
 396                         if (dev->s_tx_mask)
 397                                 val |= LIRC_CAN_SET_TRANSMITTER_MASK;
 398                         if (dev->s_tx_carrier)
 399                                 val |= LIRC_CAN_SET_SEND_CARRIER;
 400                         if (dev->s_tx_duty_cycle)
 401                                 val |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
 402                 }
 403
 404                 if (dev->s_rx_carrier_range)
 405                         val |= LIRC_CAN_SET_REC_CARRIER |
 406                                 LIRC_CAN_SET_REC_CARRIER_RANGE;
 407
 408                 if (dev->s_wideband_receiver)
 409                         val |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
 410
 411                 if (dev->s_carrier_report)
 412                         val |= LIRC_CAN_MEASURE_CARRIER;
 413
 414                 if (dev->max_timeout)
 415                         val |= LIRC_CAN_SET_REC_TIMEOUT;
 416
 417                 break;
 418
 419         /* mode support */
 420         case LIRC_GET_REC_MODE:
 421                 if (dev->driver_type == RC_DRIVER_IR_RAW_TX)
 422                         ret = -ENOTTY;
 423                 else
 424                         val = fh->rec_mode;
 425                 break;
 426
 427         case LIRC_SET_REC_MODE:
 428                 switch (dev->driver_type) {
 429                 case RC_DRIVER_IR_RAW_TX:
 430                         ret = -ENOTTY;
 431                         break;
 432                 case RC_DRIVER_SCANCODE:
 433                         if (val != LIRC_MODE_SCANCODE)
 434                                 ret = -EINVAL;
 435                         break;
 436                 case RC_DRIVER_IR_RAW:
 437                         if (!(val == LIRC_MODE_MODE2 ||
 438                               val == LIRC_MODE_SCANCODE))
 439                                 ret = -EINVAL;
 440                         break;
 441                 }
 442
 443                 if (!ret)
 444                         fh->rec_mode = val;
 445                 break;
 446
 447         case LIRC_GET_SEND_MODE:
 448                 if (!dev->tx_ir)
 449                         ret = -ENOTTY;
 450                 else
 451                         val = fh->send_mode;
 452                 break;
 453
 454         case LIRC_SET_SEND_MODE:
 455                 if (!dev->tx_ir)
 456                         ret = -ENOTTY;
 457                 else if (!(val == LIRC_MODE_PULSE || val == LIRC_MODE_SCANCODE))
 458                         ret = -EINVAL;
 459                 else
 460                         fh->send_mode = val;
 461                 break;
 462
 463         /* TX settings */
 464         case LIRC_SET_TRANSMITTER_MASK:
 465                 if (!dev->s_tx_mask)
 466                         ret = -ENOTTY;
 467                 else
 468                         ret = dev->s_tx_mask(dev, val);
 469                 break;
 470
 471         case LIRC_SET_SEND_CARRIER:
 472                 if (!dev->s_tx_carrier)
 473                         ret = -ENOTTY;
 474                 else
 475                         ret = dev->s_tx_carrier(dev, val);
 476                 break;
 477
 478         case LIRC_SET_SEND_DUTY_CYCLE:
 479                 if (!dev->s_tx_duty_cycle)
 480                         ret = -ENOTTY;
 481                 else if (val <= 0 || val >= 100)
 482                         ret = -EINVAL;
 483                 else
 484                         ret = dev->s_tx_duty_cycle(dev, val);
 485                 break;
 486
 487         /* RX settings */
 488         case LIRC_SET_REC_CARRIER:
 489                 if (!dev->s_rx_carrier_range)
 490                         ret = -ENOTTY;
 491                 else if (val <= 0)
 492                         ret = -EINVAL;
 493                 else
 494                         ret = dev->s_rx_carrier_range(dev, fh->carrier_low,
 495                                                       val);
 496                 break;
 497
 498         case LIRC_SET_REC_CARRIER_RANGE:
 499                 if (!dev->s_rx_carrier_range)
 500                         ret = -ENOTTY;
 501                 else if (val <= 0)
 502                         ret = -EINVAL;
 503                 else
 504                         fh->carrier_low = val;
 505                 break;
 506
 507         case LIRC_GET_REC_RESOLUTION:
 508                 if (!dev->rx_resolution)
 509                         ret = -ENOTTY;
 510                 else
 511                         val = dev->rx_resolution;
 512                 break;
 513
 514         case LIRC_SET_WIDEBAND_RECEIVER:
 515                 if (!dev->s_wideband_receiver)
 516                         ret = -ENOTTY;
 517                 else
 518                         ret = dev->s_wideband_receiver(dev, !!val);
 519                 break;
 520
 521         case LIRC_SET_MEASURE_CARRIER_MODE:
 522                 if (!dev->s_carrier_report)
 523                         ret = -ENOTTY;
 524                 else
 525                         ret = dev->s_carrier_report(dev, !!val);
 526                 break;
 527
 528         /* Generic timeout support */
 529         case LIRC_GET_MIN_TIMEOUT:
 530                 if (!dev->max_timeout)
 531                         ret = -ENOTTY;
 532                 else
 533                         val = dev->min_timeout;
 534                 break;
 535
 536         case LIRC_GET_MAX_TIMEOUT:
 537                 if (!dev->max_timeout)
 538                         ret = -ENOTTY;
 539                 else
 540                         val = dev->max_timeout;
 541                 break;
 542
 543         case LIRC_SET_REC_TIMEOUT:
 544                 if (!dev->max_timeout) {
 545                         ret = -ENOTTY;
 546                 } else {
 547                         if (val < dev->min_timeout || val > dev->max_timeout)
 548                                 ret = -EINVAL;
 549                         else if (dev->s_timeout)
 550                                 ret = dev->s_timeout(dev, val);
 551                         else
 552                                 dev->timeout = val;
 553                 }
 554                 break;
 555
 556         case LIRC_GET_REC_TIMEOUT:
 557                 if (!dev->timeout)
 558                         ret = -ENOTTY;
 559                 else
 560                         val = dev->timeout;
 561                 break;
 562
 563         case LIRC_SET_REC_TIMEOUT_REPORTS:
 564                 if (dev->driver_type != RC_DRIVER_IR_RAW)
 565                         ret = -ENOTTY;
 566                 break;
 567
 568         default:
 569                 ret = -ENOTTY;
 570         }
 571
 572         if (!ret && _IOC_DIR(cmd) & _IOC_READ)
 573                 ret = put_user(val, argp);
 574
 575 out:
 576         mutex_unlock(&dev->lock);
 577         return ret;
 578 }
 579
 580 static __poll_t lirc_poll(struct file *file, struct poll_table_struct *wait)
 581 {
 582         struct lirc_fh *fh = file->private_data;
 583         struct rc_dev *rcdev = fh->rc;
 584         __poll_t events = 0;
 585
 586         poll_wait(file, &fh->wait_poll, wait);
 587
 588         if (!rcdev->registered) {
 589                 events = EPOLLHUP | EPOLLERR;
 590         } else if (rcdev->driver_type != RC_DRIVER_IR_RAW_TX) {
 591                 if (fh->rec_mode == LIRC_MODE_SCANCODE &&
 592                     !kfifo_is_empty(&fh->scancodes))
 593                         events = EPOLLIN | EPOLLRDNORM;
 594
 595                 if (fh->rec_mode == LIRC_MODE_MODE2 &&
 596                     !kfifo_is_empty(&fh->rawir))
 597                         events = EPOLLIN | EPOLLRDNORM;
 598         }
 599
 600         return events;
 601 }
 602
 603 static ssize_t lirc_read_mode2(struct file *file, char __user *buffer,
 604                                size_t length)
 605 {
 606         struct lirc_fh *fh = file->private_data;
 607         struct rc_dev *rcdev = fh->rc;
 608         unsigned int copied;
 609         int ret;
 610
 611         if (length < sizeof(unsigned int) || length % sizeof(unsigned int))
 612                 return -EINVAL;
 613
 614         do {
 615                 if (kfifo_is_empty(&fh->rawir)) {
 616                         if (file->f_flags & O_NONBLOCK)
 617                                 return -EAGAIN;
 618
 619                         ret = wait_event_interruptible(fh->wait_poll,
 620                                         !kfifo_is_empty(&fh->rawir) ||
 621                                         !rcdev->registered);
 622                         if (ret)
 623                                 return ret;
 624                 }
 625
 626                 if (!rcdev->registered)
 627                         return -ENODEV;
 628
 629                 ret = mutex_lock_interruptible(&rcdev->lock);
 630                 if (ret)
 631                         return ret;
 632                 ret = kfifo_to_user(&fh->rawir, buffer, length, &copied);
 633                 mutex_unlock(&rcdev->lock);
 634                 if (ret)
 635                         return ret;
 636         } while (copied == 0);
 637
 638         return copied;
 639 }
 640
 641 static ssize_t lirc_read_scancode(struct file *file, char __user *buffer,
 642                                   size_t length)
 643 {
 644         struct lirc_fh *fh = file->private_data;
 645         struct rc_dev *rcdev = fh->rc;
 646         unsigned int copied;
 647         int ret;
 648
 649         if (length < sizeof(struct lirc_scancode) ||
 650             length % sizeof(struct lirc_scancode))
 651                 return -EINVAL;
 652
 653         do {
 654                 if (kfifo_is_empty(&fh->scancodes)) {
 655                         if (file->f_flags & O_NONBLOCK)
 656                                 return -EAGAIN;
 657
 658                         ret = wait_event_interruptible(fh->wait_poll,
 659                                         !kfifo_is_empty(&fh->scancodes) ||
 660                                         !rcdev->registered);
 661                         if (ret)
 662                                 return ret;
 663                 }
 664
 665                 if (!rcdev->registered)
 666                         return -ENODEV;
 667
 668                 ret = mutex_lock_interruptible(&rcdev->lock);
 669                 if (ret)
 670                         return ret;
 671                 ret = kfifo_to_user(&fh->scancodes, buffer, length, &copied);
 672                 mutex_unlock(&rcdev->lock);
 673                 if (ret)
 674                         return ret;
 675         } while (copied == 0);
 676
 677         return copied;
 678 }
 679
 680 static ssize_t lirc_read(struct file *file, char __user *buffer, size_t length,
 681                          loff_t *ppos)
 682 {
 683         struct lirc_fh *fh = file->private_data;
 684         struct rc_dev *rcdev = fh->rc;
 685
 686         if (rcdev->driver_type == RC_DRIVER_IR_RAW_TX)
 687                 return -EINVAL;
 688
 689         if (!rcdev->registered)
 690                 return -ENODEV;
 691
 692         if (fh->rec_mode == LIRC_MODE_MODE2)
 693                 return lirc_read_mode2(file, buffer, length);
 694         else /* LIRC_MODE_SCANCODE */
 695                 return lirc_read_scancode(file, buffer, length);
 696 }
 697
 698 static const struct file_operations lirc_fops = {
 699         .owner          = THIS_MODULE,
 700         .write          = lirc_transmit,
 701         .unlocked_ioctl = lirc_ioctl,
 702         .compat_ioctl   = compat_ptr_ioctl,
 703         .read           = lirc_read,
 704         .poll           = lirc_poll,
 705         .open           = lirc_open,
 706         .release        = lirc_close,
 707         .llseek         = no_llseek,
 708 };
 709
 710 static void lirc_release_device(struct device *ld)
 711 {
 712         struct rc_dev *rcdev = container_of(ld, struct rc_dev, lirc_dev);
 713
 714         put_device(&rcdev->dev);
 715 }
 716
 717 int lirc_register(struct rc_dev *dev)
 718 {
 719         const char *rx_type, *tx_type;
 720         int err, minor;
 721
 722         minor = ida_alloc_max(&lirc_ida, RC_DEV_MAX - 1, GFP_KERNEL);
 723         if (minor < 0)
 724                 return minor;
 725
 726         device_initialize(&dev->lirc_dev);
 727         dev->lirc_dev.class = lirc_class;
 728         dev->lirc_dev.parent = &dev->dev;
 729         dev->lirc_dev.release = lirc_release_device;
 730         dev->lirc_dev.devt = MKDEV(MAJOR(lirc_base_dev), minor);
 731         dev_set_name(&dev->lirc_dev, "lirc%d", minor);
 732
 733         INIT_LIST_HEAD(&dev->lirc_fh);
 734         spin_lock_init(&dev->lirc_fh_lock);
 735
 736         cdev_init(&dev->lirc_cdev, &lirc_fops);
 737
 738         err = cdev_device_add(&dev->lirc_cdev, &dev->lirc_dev);
 739         if (err)
 740                 goto out_ida;
 741
 742         get_device(&dev->dev);
 743
 744         switch (dev->driver_type) {
 745         case RC_DRIVER_SCANCODE:
 746                 rx_type = "scancode";
 747                 break;
 748         case RC_DRIVER_IR_RAW:
 749                 rx_type = "raw IR";
 750                 break;
 751         default:
 752                 rx_type = "no";
 753                 break;
 754         }
 755
 756         if (dev->tx_ir)
 757                 tx_type = "raw IR";
 758         else
 759                 tx_type = "no";
 760
 761         dev_info(&dev->dev, "lirc_dev: driver %s registered at minor = %d, %s receiver, %s transmitter",
 762                  dev->driver_name, minor, rx_type, tx_type);
 763
 764         return 0;
 765
 766 out_ida:
 767         ida_free(&lirc_ida, minor);
 768         return err;
 769 }
 770
 771 void lirc_unregister(struct rc_dev *dev)
 772 {
 773         unsigned long flags;
 774         struct lirc_fh *fh;
 775
 776         dev_dbg(&dev->dev, "lirc_dev: driver %s unregistered from minor = %d\n",
 777                 dev->driver_name, MINOR(dev->lirc_dev.devt));
 778
 779         spin_lock_irqsave(&dev->lirc_fh_lock, flags);
 780         list_for_each_entry(fh, &dev->lirc_fh, list)
 781                 wake_up_poll(&fh->wait_poll, EPOLLHUP | EPOLLERR);
 782         spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
 783
 784         cdev_device_del(&dev->lirc_cdev, &dev->lirc_dev);
 785         ida_free(&lirc_ida, MINOR(dev->lirc_dev.devt));
 786 }
 787
 788 int __init lirc_dev_init(void)
 789 {
 790         int retval;
 791
 792         lirc_class = class_create("lirc");
 793         if (IS_ERR(lirc_class)) {
 794                 pr_err("class_create failed\n");
 795                 return PTR_ERR(lirc_class);
 796         }
 797
 798         retval = alloc_chrdev_region(&lirc_base_dev, 0, RC_DEV_MAX, "lirc");
 799         if (retval) {
 800                 class_destroy(lirc_class);
 801                 pr_err("alloc_chrdev_region failed\n");
 802                 return retval;
 803         }
 804
 805         pr_debug("IR Remote Control driver registered, major %d\n",
 806                  MAJOR(lirc_base_dev));
 807
 808         return 0;
 809 }
 810
 811 void __exit lirc_dev_exit(void)
 812 {
 813         class_destroy(lirc_class);
 814         unregister_chrdev_region(lirc_base_dev, RC_DEV_MAX);
 815 }
 816
 817 struct rc_dev *rc_dev_get_from_fd(int fd, bool write)
 818 {
 819         struct fd f = fdget(fd);
 820         struct lirc_fh *fh;
 821         struct rc_dev *dev;
 822
 823         if (!f.file)
 824                 return ERR_PTR(-EBADF);
 825
 826         if (f.file->f_op != &lirc_fops) {
 827                 fdput(f);
 828                 return ERR_PTR(-EINVAL);
 829         }
 830
 831         if (write && !(f.file->f_mode & FMODE_WRITE))
 832                 return ERR_PTR(-EPERM);
 833
 834         fh = f.file->private_data;
 835         dev = fh->rc;
 836
 837         get_device(&dev->dev);
 838         fdput(f);
 839
 840         return dev;
 841 }
 842
 843 MODULE_ALIAS("lirc_dev");