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