linux/drivers/media/rc/lirc_dev.c
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   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
  24static dev_t lirc_base_dev;
  25
  26/* Used to keep track of allocated lirc devices */
  27static DEFINE_IDA(lirc_ida);
  28
  29/* Only used for sysfs but defined to void otherwise */
  30static struct class *lirc_class;
  31
  32/**
  33 * ir_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 */
  38void ir_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        /* Packet start */
  45        if (ev.reset) {
  46                /*
  47                 * Userspace expects a long space event before the start of
  48                 * the signal to use as a sync.  This may be done with repeat
  49                 * packets and normal samples.  But if a reset has been sent
  50                 * then we assume that a long time has passed, so we send a
  51                 * space with the maximum time value.
  52                 */
  53                sample = LIRC_SPACE(LIRC_VALUE_MASK);
  54                dev_dbg(&dev->dev, "delivering reset sync space to lirc_dev\n");
  55
  56        /* Carrier reports */
  57        } else if (ev.carrier_report) {
  58                sample = LIRC_FREQUENCY(ev.carrier);
  59                dev_dbg(&dev->dev, "carrier report (freq: %d)\n", sample);
  60
  61        /* Packet end */
  62        } else if (ev.timeout) {
  63                if (dev->gap)
  64                        return;
  65
  66                dev->gap_start = ktime_get();
  67                dev->gap = true;
  68                dev->gap_duration = ev.duration;
  69
  70                sample = LIRC_TIMEOUT(ev.duration / 1000);
  71                dev_dbg(&dev->dev, "timeout report (duration: %d)\n", sample);
  72
  73        /* Normal sample */
  74        } else {
  75                if (dev->gap) {
  76                        dev->gap_duration += ktime_to_ns(ktime_sub(ktime_get(),
  77                                                         dev->gap_start));
  78
  79                        /* Convert to ms and cap by LIRC_VALUE_MASK */
  80                        do_div(dev->gap_duration, 1000);
  81                        dev->gap_duration = min_t(u64, dev->gap_duration,
  82                                                  LIRC_VALUE_MASK);
  83
  84                        spin_lock_irqsave(&dev->lirc_fh_lock, flags);
  85                        list_for_each_entry(fh, &dev->lirc_fh, list)
  86                                kfifo_put(&fh->rawir,
  87                                          LIRC_SPACE(dev->gap_duration));
  88                        spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
  89                        dev->gap = false;
  90                }
  91
  92                sample = ev.pulse ? LIRC_PULSE(ev.duration / 1000) :
  93                                        LIRC_SPACE(ev.duration / 1000);
  94                dev_dbg(&dev->dev, "delivering %uus %s to lirc_dev\n",
  95                        TO_US(ev.duration), TO_STR(ev.pulse));
  96        }
  97
  98        /*
  99         * bpf does not care about the gap generated above; that exists
 100         * for backwards compatibility
 101         */
 102        lirc_bpf_run(dev, sample);
 103
 104        spin_lock_irqsave(&dev->lirc_fh_lock, flags);
 105        list_for_each_entry(fh, &dev->lirc_fh, list) {
 106                if (LIRC_IS_TIMEOUT(sample) && !fh->send_timeout_reports)
 107                        continue;
 108                if (kfifo_put(&fh->rawir, sample))
 109                        wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
 110        }
 111        spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
 112}
 113
 114/**
 115 * ir_lirc_scancode_event() - Send scancode data to lirc to be relayed to
 116 *              userspace. This can be called in atomic context.
 117 * @dev:        the struct rc_dev descriptor of the device
 118 * @lsc:        the struct lirc_scancode describing the decoded scancode
 119 */
 120void ir_lirc_scancode_event(struct rc_dev *dev, struct lirc_scancode *lsc)
 121{
 122        unsigned long flags;
 123        struct lirc_fh *fh;
 124
 125        lsc->timestamp = ktime_get_ns();
 126
 127        spin_lock_irqsave(&dev->lirc_fh_lock, flags);
 128        list_for_each_entry(fh, &dev->lirc_fh, list) {
 129                if (kfifo_put(&fh->scancodes, *lsc))
 130                        wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
 131        }
 132        spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
 133}
 134EXPORT_SYMBOL_GPL(ir_lirc_scancode_event);
 135
 136static int ir_lirc_open(struct inode *inode, struct file *file)
 137{
 138        struct rc_dev *dev = container_of(inode->i_cdev, struct rc_dev,
 139                                          lirc_cdev);
 140        struct lirc_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
 141        unsigned long flags;
 142        int retval;
 143
 144        if (!fh)
 145                return -ENOMEM;
 146
 147        get_device(&dev->dev);
 148
 149        if (!dev->registered) {
 150                retval = -ENODEV;
 151                goto out_fh;
 152        }
 153
 154        if (dev->driver_type == RC_DRIVER_IR_RAW) {
 155                if (kfifo_alloc(&fh->rawir, MAX_IR_EVENT_SIZE, GFP_KERNEL)) {
 156                        retval = -ENOMEM;
 157                        goto out_fh;
 158                }
 159        }
 160
 161        if (dev->driver_type != RC_DRIVER_IR_RAW_TX) {
 162                if (kfifo_alloc(&fh->scancodes, 32, GFP_KERNEL)) {
 163                        retval = -ENOMEM;
 164                        goto out_rawir;
 165                }
 166        }
 167
 168        fh->send_mode = LIRC_MODE_PULSE;
 169        fh->rc = dev;
 170        fh->send_timeout_reports = true;
 171
 172        if (dev->driver_type == RC_DRIVER_SCANCODE)
 173                fh->rec_mode = LIRC_MODE_SCANCODE;
 174        else
 175                fh->rec_mode = LIRC_MODE_MODE2;
 176
 177        retval = rc_open(dev);
 178        if (retval)
 179                goto out_kfifo;
 180
 181        init_waitqueue_head(&fh->wait_poll);
 182
 183        file->private_data = fh;
 184        spin_lock_irqsave(&dev->lirc_fh_lock, flags);
 185        list_add(&fh->list, &dev->lirc_fh);
 186        spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
 187
 188        stream_open(inode, file);
 189
 190        return 0;
 191out_kfifo:
 192        if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
 193                kfifo_free(&fh->scancodes);
 194out_rawir:
 195        if (dev->driver_type == RC_DRIVER_IR_RAW)
 196                kfifo_free(&fh->rawir);
 197out_fh:
 198        kfree(fh);
 199        put_device(&dev->dev);
 200
 201        return retval;
 202}
 203
 204static int ir_lirc_close(struct inode *inode, struct file *file)
 205{
 206        struct lirc_fh *fh = file->private_data;
 207        struct rc_dev *dev = fh->rc;
 208        unsigned long flags;
 209
 210        spin_lock_irqsave(&dev->lirc_fh_lock, flags);
 211        list_del(&fh->list);
 212        spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
 213
 214        if (dev->driver_type == RC_DRIVER_IR_RAW)
 215                kfifo_free(&fh->rawir);
 216        if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
 217                kfifo_free(&fh->scancodes);
 218        kfree(fh);
 219
 220        rc_close(dev);
 221        put_device(&dev->dev);
 222
 223        return 0;
 224}
 225
 226static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 227                                   size_t n, loff_t *ppos)
 228{
 229        struct lirc_fh *fh = file->private_data;
 230        struct rc_dev *dev = fh->rc;
 231        unsigned int *txbuf;
 232        struct ir_raw_event *raw = NULL;
 233        ssize_t ret;
 234        size_t count;
 235        ktime_t start;
 236        s64 towait;
 237        unsigned int duration = 0; /* signal duration in us */
 238        int i;
 239
 240        ret = mutex_lock_interruptible(&dev->lock);
 241        if (ret)
 242                return ret;
 243
 244        if (!dev->registered) {
 245                ret = -ENODEV;
 246                goto out_unlock;
 247        }
 248
 249        if (!dev->tx_ir) {
 250                ret = -EINVAL;
 251                goto out_unlock;
 252        }
 253
 254        if (fh->send_mode == LIRC_MODE_SCANCODE) {
 255                struct lirc_scancode scan;
 256
 257                if (n != sizeof(scan)) {
 258                        ret = -EINVAL;
 259                        goto out_unlock;
 260                }
 261
 262                if (copy_from_user(&scan, buf, sizeof(scan))) {
 263                        ret = -EFAULT;
 264                        goto out_unlock;
 265                }
 266
 267                if (scan.flags || scan.keycode || scan.timestamp) {
 268                        ret = -EINVAL;
 269                        goto out_unlock;
 270                }
 271
 272                /*
 273                 * The scancode field in lirc_scancode is 64-bit simply
 274                 * to future-proof it, since there are IR protocols encode
 275                 * use more than 32 bits. For now only 32-bit protocols
 276                 * are supported.
 277                 */
 278                if (scan.scancode > U32_MAX ||
 279                    !rc_validate_scancode(scan.rc_proto, scan.scancode)) {
 280                        ret = -EINVAL;
 281                        goto out_unlock;
 282                }
 283
 284                raw = kmalloc_array(LIRCBUF_SIZE, sizeof(*raw), GFP_KERNEL);
 285                if (!raw) {
 286                        ret = -ENOMEM;
 287                        goto out_unlock;
 288                }
 289
 290                ret = ir_raw_encode_scancode(scan.rc_proto, scan.scancode,
 291                                             raw, LIRCBUF_SIZE);
 292                if (ret < 0)
 293                        goto out_kfree_raw;
 294
 295                count = ret;
 296
 297                txbuf = kmalloc_array(count, sizeof(unsigned int), GFP_KERNEL);
 298                if (!txbuf) {
 299                        ret = -ENOMEM;
 300                        goto out_kfree_raw;
 301                }
 302
 303                for (i = 0; i < count; i++)
 304                        /* Convert from NS to US */
 305                        txbuf[i] = DIV_ROUND_UP(raw[i].duration, 1000);
 306
 307                if (dev->s_tx_carrier) {
 308                        int carrier = ir_raw_encode_carrier(scan.rc_proto);
 309
 310                        if (carrier > 0)
 311                                dev->s_tx_carrier(dev, carrier);
 312                }
 313        } else {
 314                if (n < sizeof(unsigned int) || n % sizeof(unsigned int)) {
 315                        ret = -EINVAL;
 316                        goto out_unlock;
 317                }
 318
 319                count = n / sizeof(unsigned int);
 320                if (count > LIRCBUF_SIZE || count % 2 == 0) {
 321                        ret = -EINVAL;
 322                        goto out_unlock;
 323                }
 324
 325                txbuf = memdup_user(buf, n);
 326                if (IS_ERR(txbuf)) {
 327                        ret = PTR_ERR(txbuf);
 328                        goto out_unlock;
 329                }
 330        }
 331
 332        for (i = 0; i < count; i++) {
 333                if (txbuf[i] > IR_MAX_DURATION / 1000 - duration || !txbuf[i]) {
 334                        ret = -EINVAL;
 335                        goto out_kfree;
 336                }
 337
 338                duration += txbuf[i];
 339        }
 340
 341        start = ktime_get();
 342
 343        ret = dev->tx_ir(dev, txbuf, count);
 344        if (ret < 0)
 345                goto out_kfree;
 346
 347        kfree(txbuf);
 348        kfree(raw);
 349        mutex_unlock(&dev->lock);
 350
 351        /*
 352         * The lircd gap calculation expects the write function to
 353         * wait for the actual IR signal to be transmitted before
 354         * returning.
 355         */
 356        towait = ktime_us_delta(ktime_add_us(start, duration),
 357                                ktime_get());
 358        if (towait > 0) {
 359                set_current_state(TASK_INTERRUPTIBLE);
 360                schedule_timeout(usecs_to_jiffies(towait));
 361        }
 362
 363        return n;
 364out_kfree:
 365        kfree(txbuf);
 366out_kfree_raw:
 367        kfree(raw);
 368out_unlock:
 369        mutex_unlock(&dev->lock);
 370        return ret;
 371}
 372
 373static long ir_lirc_ioctl(struct file *file, unsigned int cmd,
 374                          unsigned long arg)
 375{
 376        struct lirc_fh *fh = file->private_data;
 377        struct rc_dev *dev = fh->rc;
 378        u32 __user *argp = (u32 __user *)(arg);
 379        u32 val = 0;
 380        int ret;
 381
 382        if (_IOC_DIR(cmd) & _IOC_WRITE) {
 383                ret = get_user(val, argp);
 384                if (ret)
 385                        return ret;
 386        }
 387
 388        ret = mutex_lock_interruptible(&dev->lock);
 389        if (ret)
 390                return ret;
 391
 392        if (!dev->registered) {
 393                ret = -ENODEV;
 394                goto out;
 395        }
 396
 397        switch (cmd) {
 398        case LIRC_GET_FEATURES:
 399                if (dev->driver_type == RC_DRIVER_SCANCODE)
 400                        val |= LIRC_CAN_REC_SCANCODE;
 401
 402                if (dev->driver_type == RC_DRIVER_IR_RAW) {
 403                        val |= LIRC_CAN_REC_MODE2;
 404                        if (dev->rx_resolution)
 405                                val |= LIRC_CAN_GET_REC_RESOLUTION;
 406                }
 407
 408                if (dev->tx_ir) {
 409                        val |= LIRC_CAN_SEND_PULSE;
 410                        if (dev->s_tx_mask)
 411                                val |= LIRC_CAN_SET_TRANSMITTER_MASK;
 412                        if (dev->s_tx_carrier)
 413                                val |= LIRC_CAN_SET_SEND_CARRIER;
 414                        if (dev->s_tx_duty_cycle)
 415                                val |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
 416                }
 417
 418                if (dev->s_rx_carrier_range)
 419                        val |= LIRC_CAN_SET_REC_CARRIER |
 420                                LIRC_CAN_SET_REC_CARRIER_RANGE;
 421
 422                if (dev->s_learning_mode)
 423                        val |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
 424
 425                if (dev->s_carrier_report)
 426                        val |= LIRC_CAN_MEASURE_CARRIER;
 427
 428                if (dev->max_timeout)
 429                        val |= LIRC_CAN_SET_REC_TIMEOUT;
 430
 431                break;
 432
 433        /* mode support */
 434        case LIRC_GET_REC_MODE:
 435                if (dev->driver_type == RC_DRIVER_IR_RAW_TX)
 436                        ret = -ENOTTY;
 437                else
 438                        val = fh->rec_mode;
 439                break;
 440
 441        case LIRC_SET_REC_MODE:
 442                switch (dev->driver_type) {
 443                case RC_DRIVER_IR_RAW_TX:
 444                        ret = -ENOTTY;
 445                        break;
 446                case RC_DRIVER_SCANCODE:
 447                        if (val != LIRC_MODE_SCANCODE)
 448                                ret = -EINVAL;
 449                        break;
 450                case RC_DRIVER_IR_RAW:
 451                        if (!(val == LIRC_MODE_MODE2 ||
 452                              val == LIRC_MODE_SCANCODE))
 453                                ret = -EINVAL;
 454                        break;
 455                }
 456
 457                if (!ret)
 458                        fh->rec_mode = val;
 459                break;
 460
 461        case LIRC_GET_SEND_MODE:
 462                if (!dev->tx_ir)
 463                        ret = -ENOTTY;
 464                else
 465                        val = fh->send_mode;
 466                break;
 467
 468        case LIRC_SET_SEND_MODE:
 469                if (!dev->tx_ir)
 470                        ret = -ENOTTY;
 471                else if (!(val == LIRC_MODE_PULSE || val == LIRC_MODE_SCANCODE))
 472                        ret = -EINVAL;
 473                else
 474                        fh->send_mode = val;
 475                break;
 476
 477        /* TX settings */
 478        case LIRC_SET_TRANSMITTER_MASK:
 479                if (!dev->s_tx_mask)
 480                        ret = -ENOTTY;
 481                else
 482                        ret = dev->s_tx_mask(dev, val);
 483                break;
 484
 485        case LIRC_SET_SEND_CARRIER:
 486                if (!dev->s_tx_carrier)
 487                        ret = -ENOTTY;
 488                else
 489                        ret = dev->s_tx_carrier(dev, val);
 490                break;
 491
 492        case LIRC_SET_SEND_DUTY_CYCLE:
 493                if (!dev->s_tx_duty_cycle)
 494                        ret = -ENOTTY;
 495                else if (val <= 0 || val >= 100)
 496                        ret = -EINVAL;
 497                else
 498                        ret = dev->s_tx_duty_cycle(dev, val);
 499                break;
 500
 501        /* RX settings */
 502        case LIRC_SET_REC_CARRIER:
 503                if (!dev->s_rx_carrier_range)
 504                        ret = -ENOTTY;
 505                else if (val <= 0)
 506                        ret = -EINVAL;
 507                else
 508                        ret = dev->s_rx_carrier_range(dev, fh->carrier_low,
 509                                                      val);
 510                break;
 511
 512        case LIRC_SET_REC_CARRIER_RANGE:
 513                if (!dev->s_rx_carrier_range)
 514                        ret = -ENOTTY;
 515                else if (val <= 0)
 516                        ret = -EINVAL;
 517                else
 518                        fh->carrier_low = val;
 519                break;
 520
 521        case LIRC_GET_REC_RESOLUTION:
 522                if (!dev->rx_resolution)
 523                        ret = -ENOTTY;
 524                else
 525                        val = dev->rx_resolution / 1000;
 526                break;
 527
 528        case LIRC_SET_WIDEBAND_RECEIVER:
 529                if (!dev->s_learning_mode)
 530                        ret = -ENOTTY;
 531                else
 532                        ret = dev->s_learning_mode(dev, !!val);
 533                break;
 534
 535        case LIRC_SET_MEASURE_CARRIER_MODE:
 536                if (!dev->s_carrier_report)
 537                        ret = -ENOTTY;
 538                else
 539                        ret = dev->s_carrier_report(dev, !!val);
 540                break;
 541
 542        /* Generic timeout support */
 543        case LIRC_GET_MIN_TIMEOUT:
 544                if (!dev->max_timeout)
 545                        ret = -ENOTTY;
 546                else
 547                        val = DIV_ROUND_UP(dev->min_timeout, 1000);
 548                break;
 549
 550        case LIRC_GET_MAX_TIMEOUT:
 551                if (!dev->max_timeout)
 552                        ret = -ENOTTY;
 553                else
 554                        val = dev->max_timeout / 1000;
 555                break;
 556
 557        case LIRC_SET_REC_TIMEOUT:
 558                if (!dev->max_timeout) {
 559                        ret = -ENOTTY;
 560                } else if (val > U32_MAX / 1000) {
 561                        /* Check for multiply overflow */
 562                        ret = -EINVAL;
 563                } else {
 564                        u32 tmp = val * 1000;
 565
 566                        if (tmp < dev->min_timeout || tmp > dev->max_timeout)
 567                                ret = -EINVAL;
 568                        else if (dev->s_timeout)
 569                                ret = dev->s_timeout(dev, tmp);
 570                        else
 571                                dev->timeout = tmp;
 572                }
 573                break;
 574
 575        case LIRC_GET_REC_TIMEOUT:
 576                if (!dev->timeout)
 577                        ret = -ENOTTY;
 578                else
 579                        val = DIV_ROUND_UP(dev->timeout, 1000);
 580                break;
 581
 582        case LIRC_SET_REC_TIMEOUT_REPORTS:
 583                if (dev->driver_type != RC_DRIVER_IR_RAW)
 584                        ret = -ENOTTY;
 585                else
 586                        fh->send_timeout_reports = !!val;
 587                break;
 588
 589        default:
 590                ret = -ENOTTY;
 591        }
 592
 593        if (!ret && _IOC_DIR(cmd) & _IOC_READ)
 594                ret = put_user(val, argp);
 595
 596out:
 597        mutex_unlock(&dev->lock);
 598        return ret;
 599}
 600
 601static __poll_t ir_lirc_poll(struct file *file, struct poll_table_struct *wait)
 602{
 603        struct lirc_fh *fh = file->private_data;
 604        struct rc_dev *rcdev = fh->rc;
 605        __poll_t events = 0;
 606
 607        poll_wait(file, &fh->wait_poll, wait);
 608
 609        if (!rcdev->registered) {
 610                events = EPOLLHUP | EPOLLERR;
 611        } else if (rcdev->driver_type != RC_DRIVER_IR_RAW_TX) {
 612                if (fh->rec_mode == LIRC_MODE_SCANCODE &&
 613                    !kfifo_is_empty(&fh->scancodes))
 614                        events = EPOLLIN | EPOLLRDNORM;
 615
 616                if (fh->rec_mode == LIRC_MODE_MODE2 &&
 617                    !kfifo_is_empty(&fh->rawir))
 618                        events = EPOLLIN | EPOLLRDNORM;
 619        }
 620
 621        return events;
 622}
 623
 624static ssize_t ir_lirc_read_mode2(struct file *file, char __user *buffer,
 625                                  size_t length)
 626{
 627        struct lirc_fh *fh = file->private_data;
 628        struct rc_dev *rcdev = fh->rc;
 629        unsigned int copied;
 630        int ret;
 631
 632        if (length < sizeof(unsigned int) || length % sizeof(unsigned int))
 633                return -EINVAL;
 634
 635        do {
 636                if (kfifo_is_empty(&fh->rawir)) {
 637                        if (file->f_flags & O_NONBLOCK)
 638                                return -EAGAIN;
 639
 640                        ret = wait_event_interruptible(fh->wait_poll,
 641                                        !kfifo_is_empty(&fh->rawir) ||
 642                                        !rcdev->registered);
 643                        if (ret)
 644                                return ret;
 645                }
 646
 647                if (!rcdev->registered)
 648                        return -ENODEV;
 649
 650                ret = mutex_lock_interruptible(&rcdev->lock);
 651                if (ret)
 652                        return ret;
 653                ret = kfifo_to_user(&fh->rawir, buffer, length, &copied);
 654                mutex_unlock(&rcdev->lock);
 655                if (ret)
 656                        return ret;
 657        } while (copied == 0);
 658
 659        return copied;
 660}
 661
 662static ssize_t ir_lirc_read_scancode(struct file *file, char __user *buffer,
 663                                     size_t length)
 664{
 665        struct lirc_fh *fh = file->private_data;
 666        struct rc_dev *rcdev = fh->rc;
 667        unsigned int copied;
 668        int ret;
 669
 670        if (length < sizeof(struct lirc_scancode) ||
 671            length % sizeof(struct lirc_scancode))
 672                return -EINVAL;
 673
 674        do {
 675                if (kfifo_is_empty(&fh->scancodes)) {
 676                        if (file->f_flags & O_NONBLOCK)
 677                                return -EAGAIN;
 678
 679                        ret = wait_event_interruptible(fh->wait_poll,
 680                                        !kfifo_is_empty(&fh->scancodes) ||
 681                                        !rcdev->registered);
 682                        if (ret)
 683                                return ret;
 684                }
 685
 686                if (!rcdev->registered)
 687                        return -ENODEV;
 688
 689                ret = mutex_lock_interruptible(&rcdev->lock);
 690                if (ret)
 691                        return ret;
 692                ret = kfifo_to_user(&fh->scancodes, buffer, length, &copied);
 693                mutex_unlock(&rcdev->lock);
 694                if (ret)
 695                        return ret;
 696        } while (copied == 0);
 697
 698        return copied;
 699}
 700
 701static ssize_t ir_lirc_read(struct file *file, char __user *buffer,
 702                            size_t length, loff_t *ppos)
 703{
 704        struct lirc_fh *fh = file->private_data;
 705        struct rc_dev *rcdev = fh->rc;
 706
 707        if (rcdev->driver_type == RC_DRIVER_IR_RAW_TX)
 708                return -EINVAL;
 709
 710        if (!rcdev->registered)
 711                return -ENODEV;
 712
 713        if (fh->rec_mode == LIRC_MODE_MODE2)
 714                return ir_lirc_read_mode2(file, buffer, length);
 715        else /* LIRC_MODE_SCANCODE */
 716                return ir_lirc_read_scancode(file, buffer, length);
 717}
 718
 719static const struct file_operations lirc_fops = {
 720        .owner          = THIS_MODULE,
 721        .write          = ir_lirc_transmit_ir,
 722        .unlocked_ioctl = ir_lirc_ioctl,
 723#ifdef CONFIG_COMPAT
 724        .compat_ioctl   = ir_lirc_ioctl,
 725#endif
 726        .read           = ir_lirc_read,
 727        .poll           = ir_lirc_poll,
 728        .open           = ir_lirc_open,
 729        .release        = ir_lirc_close,
 730        .llseek         = no_llseek,
 731};
 732
 733static void lirc_release_device(struct device *ld)
 734{
 735        struct rc_dev *rcdev = container_of(ld, struct rc_dev, lirc_dev);
 736
 737        put_device(&rcdev->dev);
 738}
 739
 740int ir_lirc_register(struct rc_dev *dev)
 741{
 742        const char *rx_type, *tx_type;
 743        int err, minor;
 744
 745        minor = ida_simple_get(&lirc_ida, 0, RC_DEV_MAX, GFP_KERNEL);
 746        if (minor < 0)
 747                return minor;
 748
 749        device_initialize(&dev->lirc_dev);
 750        dev->lirc_dev.class = lirc_class;
 751        dev->lirc_dev.parent = &dev->dev;
 752        dev->lirc_dev.release = lirc_release_device;
 753        dev->lirc_dev.devt = MKDEV(MAJOR(lirc_base_dev), minor);
 754        dev_set_name(&dev->lirc_dev, "lirc%d", minor);
 755
 756        INIT_LIST_HEAD(&dev->lirc_fh);
 757        spin_lock_init(&dev->lirc_fh_lock);
 758
 759        cdev_init(&dev->lirc_cdev, &lirc_fops);
 760
 761        err = cdev_device_add(&dev->lirc_cdev, &dev->lirc_dev);
 762        if (err)
 763                goto out_ida;
 764
 765        get_device(&dev->dev);
 766
 767        switch (dev->driver_type) {
 768        case RC_DRIVER_SCANCODE:
 769                rx_type = "scancode";
 770                break;
 771        case RC_DRIVER_IR_RAW:
 772                rx_type = "raw IR";
 773                break;
 774        default:
 775                rx_type = "no";
 776                break;
 777        }
 778
 779        if (dev->tx_ir)
 780                tx_type = "raw IR";
 781        else
 782                tx_type = "no";
 783
 784        dev_info(&dev->dev, "lirc_dev: driver %s registered at minor = %d, %s receiver, %s transmitter",
 785                 dev->driver_name, minor, rx_type, tx_type);
 786
 787        return 0;
 788
 789out_ida:
 790        ida_simple_remove(&lirc_ida, minor);
 791        return err;
 792}
 793
 794void ir_lirc_unregister(struct rc_dev *dev)
 795{
 796        unsigned long flags;
 797        struct lirc_fh *fh;
 798
 799        dev_dbg(&dev->dev, "lirc_dev: driver %s unregistered from minor = %d\n",
 800                dev->driver_name, MINOR(dev->lirc_dev.devt));
 801
 802        spin_lock_irqsave(&dev->lirc_fh_lock, flags);
 803        list_for_each_entry(fh, &dev->lirc_fh, list)
 804                wake_up_poll(&fh->wait_poll, EPOLLHUP | EPOLLERR);
 805        spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
 806
 807        cdev_device_del(&dev->lirc_cdev, &dev->lirc_dev);
 808        ida_simple_remove(&lirc_ida, MINOR(dev->lirc_dev.devt));
 809}
 810
 811int __init lirc_dev_init(void)
 812{
 813        int retval;
 814
 815        lirc_class = class_create(THIS_MODULE, "lirc");
 816        if (IS_ERR(lirc_class)) {
 817                pr_err("class_create failed\n");
 818                return PTR_ERR(lirc_class);
 819        }
 820
 821        retval = alloc_chrdev_region(&lirc_base_dev, 0, RC_DEV_MAX,
 822                                     "BaseRemoteCtl");
 823        if (retval) {
 824                class_destroy(lirc_class);
 825                pr_err("alloc_chrdev_region failed\n");
 826                return retval;
 827        }
 828
 829        pr_debug("IR Remote Control driver registered, major %d\n",
 830                 MAJOR(lirc_base_dev));
 831
 832        return 0;
 833}
 834
 835void __exit lirc_dev_exit(void)
 836{
 837        class_destroy(lirc_class);
 838        unregister_chrdev_region(lirc_base_dev, RC_DEV_MAX);
 839}
 840
 841struct rc_dev *rc_dev_get_from_fd(int fd)
 842{
 843        struct fd f = fdget(fd);
 844        struct lirc_fh *fh;
 845        struct rc_dev *dev;
 846
 847        if (!f.file)
 848                return ERR_PTR(-EBADF);
 849
 850        if (f.file->f_op != &lirc_fops) {
 851                fdput(f);
 852                return ERR_PTR(-EINVAL);
 853        }
 854
 855        fh = f.file->private_data;
 856        dev = fh->rc;
 857
 858        get_device(&dev->dev);
 859        fdput(f);
 860
 861        return dev;
 862}
 863
 864MODULE_ALIAS("lirc_dev");
 865