linux/drivers/media/rc/ir-lirc-codec.c
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   1/* ir-lirc-codec.c - rc-core to classic lirc interface bridge
   2 *
   3 * Copyright (C) 2010 by Jarod Wilson <jarod@redhat.com>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 *  it under the terms of the GNU General Public License as published by
   7 *  the Free Software Foundation version 2 of the License.
   8 *
   9 *  This program is distributed in the hope that it will be useful,
  10 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 *  GNU General Public License for more details.
  13 */
  14
  15#include <linux/sched.h>
  16#include <linux/wait.h>
  17#include <linux/module.h>
  18#include <media/lirc.h>
  19#include <media/lirc_dev.h>
  20#include <media/rc-core.h>
  21#include "rc-core-priv.h"
  22
  23#define LIRCBUF_SIZE 256
  24
  25/**
  26 * ir_lirc_decode() - Send raw IR data to lirc_dev to be relayed to the
  27 *                    lircd userspace daemon for decoding.
  28 * @input_dev:  the struct rc_dev descriptor of the device
  29 * @duration:   the struct ir_raw_event descriptor of the pulse/space
  30 *
  31 * This function returns -EINVAL if the lirc interfaces aren't wired up.
  32 */
  33static int ir_lirc_decode(struct rc_dev *dev, struct ir_raw_event ev)
  34{
  35        struct lirc_codec *lirc = &dev->raw->lirc;
  36        int sample;
  37
  38        if (!dev->raw->lirc.drv || !dev->raw->lirc.drv->rbuf)
  39                return -EINVAL;
  40
  41        /* Packet start */
  42        if (ev.reset) {
  43                /* Userspace expects a long space event before the start of
  44                 * the signal to use as a sync.  This may be done with repeat
  45                 * packets and normal samples.  But if a reset has been sent
  46                 * then we assume that a long time has passed, so we send a
  47                 * space with the maximum time value. */
  48                sample = LIRC_SPACE(LIRC_VALUE_MASK);
  49                IR_dprintk(2, "delivering reset sync space to lirc_dev\n");
  50
  51        /* Carrier reports */
  52        } else if (ev.carrier_report) {
  53                sample = LIRC_FREQUENCY(ev.carrier);
  54                IR_dprintk(2, "carrier report (freq: %d)\n", sample);
  55
  56        /* Packet end */
  57        } else if (ev.timeout) {
  58
  59                if (lirc->gap)
  60                        return 0;
  61
  62                lirc->gap_start = ktime_get();
  63                lirc->gap = true;
  64                lirc->gap_duration = ev.duration;
  65
  66                if (!lirc->send_timeout_reports)
  67                        return 0;
  68
  69                sample = LIRC_TIMEOUT(ev.duration / 1000);
  70                IR_dprintk(2, "timeout report (duration: %d)\n", sample);
  71
  72        /* Normal sample */
  73        } else {
  74
  75                if (lirc->gap) {
  76                        int gap_sample;
  77
  78                        lirc->gap_duration += ktime_to_ns(ktime_sub(ktime_get(),
  79                                lirc->gap_start));
  80
  81                        /* Convert to ms and cap by LIRC_VALUE_MASK */
  82                        do_div(lirc->gap_duration, 1000);
  83                        lirc->gap_duration = min(lirc->gap_duration,
  84                                                        (u64)LIRC_VALUE_MASK);
  85
  86                        gap_sample = LIRC_SPACE(lirc->gap_duration);
  87                        lirc_buffer_write(dev->raw->lirc.drv->rbuf,
  88                                                (unsigned char *) &gap_sample);
  89                        lirc->gap = false;
  90                }
  91
  92                sample = ev.pulse ? LIRC_PULSE(ev.duration / 1000) :
  93                                        LIRC_SPACE(ev.duration / 1000);
  94                IR_dprintk(2, "delivering %uus %s to lirc_dev\n",
  95                           TO_US(ev.duration), TO_STR(ev.pulse));
  96        }
  97
  98        lirc_buffer_write(dev->raw->lirc.drv->rbuf,
  99                          (unsigned char *) &sample);
 100        wake_up(&dev->raw->lirc.drv->rbuf->wait_poll);
 101
 102        return 0;
 103}
 104
 105static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 106                                   size_t n, loff_t *ppos)
 107{
 108        struct lirc_codec *lirc;
 109        struct rc_dev *dev;
 110        unsigned int *txbuf; /* buffer with values to transmit */
 111        ssize_t ret = -EINVAL;
 112        size_t count;
 113        ktime_t start;
 114        s64 towait;
 115        unsigned int duration = 0; /* signal duration in us */
 116        int i;
 117
 118        start = ktime_get();
 119
 120        lirc = lirc_get_pdata(file);
 121        if (!lirc)
 122                return -EFAULT;
 123
 124        if (n < sizeof(unsigned) || n % sizeof(unsigned))
 125                return -EINVAL;
 126
 127        count = n / sizeof(unsigned);
 128        if (count > LIRCBUF_SIZE || count % 2 == 0)
 129                return -EINVAL;
 130
 131        txbuf = memdup_user(buf, n);
 132        if (IS_ERR(txbuf))
 133                return PTR_ERR(txbuf);
 134
 135        dev = lirc->dev;
 136        if (!dev) {
 137                ret = -EFAULT;
 138                goto out;
 139        }
 140
 141        if (!dev->tx_ir) {
 142                ret = -ENOSYS;
 143                goto out;
 144        }
 145
 146        for (i = 0; i < count; i++) {
 147                if (txbuf[i] > IR_MAX_DURATION / 1000 - duration || !txbuf[i]) {
 148                        ret = -EINVAL;
 149                        goto out;
 150                }
 151
 152                duration += txbuf[i];
 153        }
 154
 155        ret = dev->tx_ir(dev, txbuf, count);
 156        if (ret < 0)
 157                goto out;
 158
 159        for (duration = i = 0; i < ret; i++)
 160                duration += txbuf[i];
 161
 162        ret *= sizeof(unsigned int);
 163
 164        /*
 165         * The lircd gap calculation expects the write function to
 166         * wait for the actual IR signal to be transmitted before
 167         * returning.
 168         */
 169        towait = ktime_us_delta(ktime_add_us(start, duration), ktime_get());
 170        if (towait > 0) {
 171                set_current_state(TASK_INTERRUPTIBLE);
 172                schedule_timeout(usecs_to_jiffies(towait));
 173        }
 174
 175out:
 176        kfree(txbuf);
 177        return ret;
 178}
 179
 180static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
 181                        unsigned long arg)
 182{
 183        struct lirc_codec *lirc;
 184        struct rc_dev *dev;
 185        u32 __user *argp = (u32 __user *)(arg);
 186        int ret = 0;
 187        __u32 val = 0, tmp;
 188
 189        lirc = lirc_get_pdata(filep);
 190        if (!lirc)
 191                return -EFAULT;
 192
 193        dev = lirc->dev;
 194        if (!dev)
 195                return -EFAULT;
 196
 197        if (_IOC_DIR(cmd) & _IOC_WRITE) {
 198                ret = get_user(val, argp);
 199                if (ret)
 200                        return ret;
 201        }
 202
 203        switch (cmd) {
 204
 205        /* legacy support */
 206        case LIRC_GET_SEND_MODE:
 207                val = LIRC_CAN_SEND_PULSE & LIRC_CAN_SEND_MASK;
 208                break;
 209
 210        case LIRC_SET_SEND_MODE:
 211                if (val != (LIRC_MODE_PULSE & LIRC_CAN_SEND_MASK))
 212                        return -EINVAL;
 213                return 0;
 214
 215        /* TX settings */
 216        case LIRC_SET_TRANSMITTER_MASK:
 217                if (!dev->s_tx_mask)
 218                        return -ENOSYS;
 219
 220                return dev->s_tx_mask(dev, val);
 221
 222        case LIRC_SET_SEND_CARRIER:
 223                if (!dev->s_tx_carrier)
 224                        return -ENOSYS;
 225
 226                return dev->s_tx_carrier(dev, val);
 227
 228        case LIRC_SET_SEND_DUTY_CYCLE:
 229                if (!dev->s_tx_duty_cycle)
 230                        return -ENOSYS;
 231
 232                if (val <= 0 || val >= 100)
 233                        return -EINVAL;
 234
 235                return dev->s_tx_duty_cycle(dev, val);
 236
 237        /* RX settings */
 238        case LIRC_SET_REC_CARRIER:
 239                if (!dev->s_rx_carrier_range)
 240                        return -ENOSYS;
 241
 242                if (val <= 0)
 243                        return -EINVAL;
 244
 245                return dev->s_rx_carrier_range(dev,
 246                                               dev->raw->lirc.carrier_low,
 247                                               val);
 248
 249        case LIRC_SET_REC_CARRIER_RANGE:
 250                if (val <= 0)
 251                        return -EINVAL;
 252
 253                dev->raw->lirc.carrier_low = val;
 254                return 0;
 255
 256        case LIRC_GET_REC_RESOLUTION:
 257                val = dev->rx_resolution;
 258                break;
 259
 260        case LIRC_SET_WIDEBAND_RECEIVER:
 261                if (!dev->s_learning_mode)
 262                        return -ENOSYS;
 263
 264                return dev->s_learning_mode(dev, !!val);
 265
 266        case LIRC_SET_MEASURE_CARRIER_MODE:
 267                if (!dev->s_carrier_report)
 268                        return -ENOSYS;
 269
 270                return dev->s_carrier_report(dev, !!val);
 271
 272        /* Generic timeout support */
 273        case LIRC_GET_MIN_TIMEOUT:
 274                if (!dev->max_timeout)
 275                        return -ENOSYS;
 276                val = dev->min_timeout / 1000;
 277                break;
 278
 279        case LIRC_GET_MAX_TIMEOUT:
 280                if (!dev->max_timeout)
 281                        return -ENOSYS;
 282                val = dev->max_timeout / 1000;
 283                break;
 284
 285        case LIRC_SET_REC_TIMEOUT:
 286                if (!dev->max_timeout)
 287                        return -ENOSYS;
 288
 289                tmp = val * 1000;
 290
 291                if (tmp < dev->min_timeout ||
 292                    tmp > dev->max_timeout)
 293                                return -EINVAL;
 294
 295                dev->timeout = tmp;
 296                break;
 297
 298        case LIRC_SET_REC_TIMEOUT_REPORTS:
 299                lirc->send_timeout_reports = !!val;
 300                break;
 301
 302        default:
 303                return lirc_dev_fop_ioctl(filep, cmd, arg);
 304        }
 305
 306        if (_IOC_DIR(cmd) & _IOC_READ)
 307                ret = put_user(val, argp);
 308
 309        return ret;
 310}
 311
 312static int ir_lirc_open(void *data)
 313{
 314        return 0;
 315}
 316
 317static void ir_lirc_close(void *data)
 318{
 319        return;
 320}
 321
 322static const struct file_operations lirc_fops = {
 323        .owner          = THIS_MODULE,
 324        .write          = ir_lirc_transmit_ir,
 325        .unlocked_ioctl = ir_lirc_ioctl,
 326#ifdef CONFIG_COMPAT
 327        .compat_ioctl   = ir_lirc_ioctl,
 328#endif
 329        .read           = lirc_dev_fop_read,
 330        .poll           = lirc_dev_fop_poll,
 331        .open           = lirc_dev_fop_open,
 332        .release        = lirc_dev_fop_close,
 333        .llseek         = no_llseek,
 334};
 335
 336static int ir_lirc_register(struct rc_dev *dev)
 337{
 338        struct lirc_driver *drv;
 339        struct lirc_buffer *rbuf;
 340        int rc = -ENOMEM;
 341        unsigned long features;
 342
 343        drv = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
 344        if (!drv)
 345                return rc;
 346
 347        rbuf = kzalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
 348        if (!rbuf)
 349                goto rbuf_alloc_failed;
 350
 351        rc = lirc_buffer_init(rbuf, sizeof(int), LIRCBUF_SIZE);
 352        if (rc)
 353                goto rbuf_init_failed;
 354
 355        features = LIRC_CAN_REC_MODE2;
 356        if (dev->tx_ir) {
 357                features |= LIRC_CAN_SEND_PULSE;
 358                if (dev->s_tx_mask)
 359                        features |= LIRC_CAN_SET_TRANSMITTER_MASK;
 360                if (dev->s_tx_carrier)
 361                        features |= LIRC_CAN_SET_SEND_CARRIER;
 362                if (dev->s_tx_duty_cycle)
 363                        features |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
 364        }
 365
 366        if (dev->s_rx_carrier_range)
 367                features |= LIRC_CAN_SET_REC_CARRIER |
 368                        LIRC_CAN_SET_REC_CARRIER_RANGE;
 369
 370        if (dev->s_learning_mode)
 371                features |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
 372
 373        if (dev->s_carrier_report)
 374                features |= LIRC_CAN_MEASURE_CARRIER;
 375
 376        if (dev->max_timeout)
 377                features |= LIRC_CAN_SET_REC_TIMEOUT;
 378
 379        snprintf(drv->name, sizeof(drv->name), "ir-lirc-codec (%s)",
 380                 dev->driver_name);
 381        drv->minor = -1;
 382        drv->features = features;
 383        drv->data = &dev->raw->lirc;
 384        drv->rbuf = rbuf;
 385        drv->set_use_inc = &ir_lirc_open;
 386        drv->set_use_dec = &ir_lirc_close;
 387        drv->code_length = sizeof(struct ir_raw_event) * 8;
 388        drv->fops = &lirc_fops;
 389        drv->dev = &dev->dev;
 390        drv->rdev = dev;
 391        drv->owner = THIS_MODULE;
 392
 393        drv->minor = lirc_register_driver(drv);
 394        if (drv->minor < 0) {
 395                rc = -ENODEV;
 396                goto lirc_register_failed;
 397        }
 398
 399        dev->raw->lirc.drv = drv;
 400        dev->raw->lirc.dev = dev;
 401        return 0;
 402
 403lirc_register_failed:
 404rbuf_init_failed:
 405        kfree(rbuf);
 406rbuf_alloc_failed:
 407        kfree(drv);
 408
 409        return rc;
 410}
 411
 412static int ir_lirc_unregister(struct rc_dev *dev)
 413{
 414        struct lirc_codec *lirc = &dev->raw->lirc;
 415
 416        lirc_unregister_driver(lirc->drv->minor);
 417        lirc_buffer_free(lirc->drv->rbuf);
 418        kfree(lirc->drv->rbuf);
 419        kfree(lirc->drv);
 420
 421        return 0;
 422}
 423
 424static struct ir_raw_handler lirc_handler = {
 425        .protocols      = 0,
 426        .decode         = ir_lirc_decode,
 427        .raw_register   = ir_lirc_register,
 428        .raw_unregister = ir_lirc_unregister,
 429};
 430
 431static int __init ir_lirc_codec_init(void)
 432{
 433        ir_raw_handler_register(&lirc_handler);
 434
 435        printk(KERN_INFO "IR LIRC bridge handler initialized\n");
 436        return 0;
 437}
 438
 439static void __exit ir_lirc_codec_exit(void)
 440{
 441        ir_raw_handler_unregister(&lirc_handler);
 442}
 443
 444module_init(ir_lirc_codec_init);
 445module_exit(ir_lirc_codec_exit);
 446
 447MODULE_LICENSE("GPL");
 448MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
 449MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
 450MODULE_DESCRIPTION("LIRC IR handler bridge");
 451