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->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                /* Userspace expects a long space event before the start of
  47                 * the signal to use as a sync.  This may be done with repeat
  48                 * packets and normal samples.  But if a reset has been sent
  49                 * then we assume that a long time has passed, so we send a
  50                 * space with the maximum time value. */
  51                sample = LIRC_SPACE(LIRC_VALUE_MASK);
  52                IR_dprintk(2, "delivering reset sync space to lirc_dev\n");
  53
  54        /* Carrier reports */
  55        } else if (ev.carrier_report) {
  56                sample = LIRC_FREQUENCY(ev.carrier);
  57                IR_dprintk(2, "carrier report (freq: %d)\n", sample);
  58
  59        /* Packet end */
  60        } else if (ev.timeout) {
  61
  62                if (lirc->gap)
  63                        return 0;
  64
  65                lirc->gap_start = ktime_get();
  66                lirc->gap = true;
  67                lirc->gap_duration = ev.duration;
  68
  69                if (!lirc->send_timeout_reports)
  70                        return 0;
  71
  72                sample = LIRC_TIMEOUT(ev.duration / 1000);
  73                IR_dprintk(2, "timeout report (duration: %d)\n", sample);
  74
  75        /* Normal sample */
  76        } else {
  77
  78                if (lirc->gap) {
  79                        int gap_sample;
  80
  81                        lirc->gap_duration += ktime_to_ns(ktime_sub(ktime_get(),
  82                                lirc->gap_start));
  83
  84                        /* Convert to ms and cap by LIRC_VALUE_MASK */
  85                        do_div(lirc->gap_duration, 1000);
  86                        lirc->gap_duration = min(lirc->gap_duration,
  87                                                        (u64)LIRC_VALUE_MASK);
  88
  89                        gap_sample = LIRC_SPACE(lirc->gap_duration);
  90                        lirc_buffer_write(dev->raw->lirc.drv->rbuf,
  91                                                (unsigned char *) &gap_sample);
  92                        lirc->gap = false;
  93                }
  94
  95                sample = ev.pulse ? LIRC_PULSE(ev.duration / 1000) :
  96                                        LIRC_SPACE(ev.duration / 1000);
  97                IR_dprintk(2, "delivering %uus %s to lirc_dev\n",
  98                           TO_US(ev.duration), TO_STR(ev.pulse));
  99        }
 100
 101        lirc_buffer_write(dev->raw->lirc.drv->rbuf,
 102                          (unsigned char *) &sample);
 103        wake_up(&dev->raw->lirc.drv->rbuf->wait_poll);
 104
 105        return 0;
 106}
 107
 108static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 109                                   size_t n, loff_t *ppos)
 110{
 111        struct lirc_codec *lirc;
 112        struct rc_dev *dev;
 113        unsigned int *txbuf; /* buffer with values to transmit */
 114        ssize_t ret = -EINVAL;
 115        size_t count;
 116        ktime_t start;
 117        s64 towait;
 118        unsigned int duration = 0; /* signal duration in us */
 119        int i;
 120
 121        start = ktime_get();
 122
 123        lirc = lirc_get_pdata(file);
 124        if (!lirc)
 125                return -EFAULT;
 126
 127        if (n < sizeof(unsigned) || n % sizeof(unsigned))
 128                return -EINVAL;
 129
 130        count = n / sizeof(unsigned);
 131        if (count > LIRCBUF_SIZE || count % 2 == 0)
 132                return -EINVAL;
 133
 134        txbuf = memdup_user(buf, n);
 135        if (IS_ERR(txbuf))
 136                return PTR_ERR(txbuf);
 137
 138        dev = lirc->dev;
 139        if (!dev) {
 140                ret = -EFAULT;
 141                goto out;
 142        }
 143
 144        if (!dev->tx_ir) {
 145                ret = -ENOSYS;
 146                goto out;
 147        }
 148
 149        for (i = 0; i < count; i++) {
 150                if (txbuf[i] > IR_MAX_DURATION / 1000 - duration || !txbuf[i]) {
 151                        ret = -EINVAL;
 152                        goto out;
 153                }
 154
 155                duration += txbuf[i];
 156        }
 157
 158        ret = dev->tx_ir(dev, txbuf, count);
 159        if (ret < 0)
 160                goto out;
 161
 162        for (duration = i = 0; i < ret; i++)
 163                duration += txbuf[i];
 164
 165        ret *= sizeof(unsigned int);
 166
 167        /*
 168         * The lircd gap calculation expects the write function to
 169         * wait for the actual IR signal to be transmitted before
 170         * returning.
 171         */
 172        towait = ktime_us_delta(ktime_add_us(start, duration), ktime_get());
 173        if (towait > 0) {
 174                set_current_state(TASK_INTERRUPTIBLE);
 175                schedule_timeout(usecs_to_jiffies(towait));
 176        }
 177
 178out:
 179        kfree(txbuf);
 180        return ret;
 181}
 182
 183static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
 184                        unsigned long arg)
 185{
 186        struct lirc_codec *lirc;
 187        struct rc_dev *dev;
 188        u32 __user *argp = (u32 __user *)(arg);
 189        int ret = 0;
 190        __u32 val = 0, tmp;
 191
 192        lirc = lirc_get_pdata(filep);
 193        if (!lirc)
 194                return -EFAULT;
 195
 196        dev = lirc->dev;
 197        if (!dev)
 198                return -EFAULT;
 199
 200        if (_IOC_DIR(cmd) & _IOC_WRITE) {
 201                ret = get_user(val, argp);
 202                if (ret)
 203                        return ret;
 204        }
 205
 206        switch (cmd) {
 207
 208        /* legacy support */
 209        case LIRC_GET_SEND_MODE:
 210                val = LIRC_CAN_SEND_PULSE & LIRC_CAN_SEND_MASK;
 211                break;
 212
 213        case LIRC_SET_SEND_MODE:
 214                if (val != (LIRC_MODE_PULSE & LIRC_CAN_SEND_MASK))
 215                        return -EINVAL;
 216                return 0;
 217
 218        /* TX settings */
 219        case LIRC_SET_TRANSMITTER_MASK:
 220                if (!dev->s_tx_mask)
 221                        return -ENOSYS;
 222
 223                return dev->s_tx_mask(dev, val);
 224
 225        case LIRC_SET_SEND_CARRIER:
 226                if (!dev->s_tx_carrier)
 227                        return -ENOSYS;
 228
 229                return dev->s_tx_carrier(dev, val);
 230
 231        case LIRC_SET_SEND_DUTY_CYCLE:
 232                if (!dev->s_tx_duty_cycle)
 233                        return -ENOSYS;
 234
 235                if (val <= 0 || val >= 100)
 236                        return -EINVAL;
 237
 238                return dev->s_tx_duty_cycle(dev, val);
 239
 240        /* RX settings */
 241        case LIRC_SET_REC_CARRIER:
 242                if (!dev->s_rx_carrier_range)
 243                        return -ENOSYS;
 244
 245                if (val <= 0)
 246                        return -EINVAL;
 247
 248                return dev->s_rx_carrier_range(dev,
 249                                               dev->raw->lirc.carrier_low,
 250                                               val);
 251
 252        case LIRC_SET_REC_CARRIER_RANGE:
 253                if (val <= 0)
 254                        return -EINVAL;
 255
 256                dev->raw->lirc.carrier_low = val;
 257                return 0;
 258
 259        case LIRC_GET_REC_RESOLUTION:
 260                val = dev->rx_resolution;
 261                break;
 262
 263        case LIRC_SET_WIDEBAND_RECEIVER:
 264                if (!dev->s_learning_mode)
 265                        return -ENOSYS;
 266
 267                return dev->s_learning_mode(dev, !!val);
 268
 269        case LIRC_SET_MEASURE_CARRIER_MODE:
 270                if (!dev->s_carrier_report)
 271                        return -ENOSYS;
 272
 273                return dev->s_carrier_report(dev, !!val);
 274
 275        /* Generic timeout support */
 276        case LIRC_GET_MIN_TIMEOUT:
 277                if (!dev->max_timeout)
 278                        return -ENOSYS;
 279                val = dev->min_timeout / 1000;
 280                break;
 281
 282        case LIRC_GET_MAX_TIMEOUT:
 283                if (!dev->max_timeout)
 284                        return -ENOSYS;
 285                val = dev->max_timeout / 1000;
 286                break;
 287
 288        case LIRC_SET_REC_TIMEOUT:
 289                if (!dev->max_timeout)
 290                        return -ENOSYS;
 291
 292                tmp = val * 1000;
 293
 294                if (tmp < dev->min_timeout ||
 295                    tmp > dev->max_timeout)
 296                                return -EINVAL;
 297
 298                dev->timeout = tmp;
 299                break;
 300
 301        case LIRC_SET_REC_TIMEOUT_REPORTS:
 302                lirc->send_timeout_reports = !!val;
 303                break;
 304
 305        default:
 306                return lirc_dev_fop_ioctl(filep, cmd, arg);
 307        }
 308
 309        if (_IOC_DIR(cmd) & _IOC_READ)
 310                ret = put_user(val, argp);
 311
 312        return ret;
 313}
 314
 315static int ir_lirc_open(void *data)
 316{
 317        return 0;
 318}
 319
 320static void ir_lirc_close(void *data)
 321{
 322        return;
 323}
 324
 325static const struct file_operations lirc_fops = {
 326        .owner          = THIS_MODULE,
 327        .write          = ir_lirc_transmit_ir,
 328        .unlocked_ioctl = ir_lirc_ioctl,
 329#ifdef CONFIG_COMPAT
 330        .compat_ioctl   = ir_lirc_ioctl,
 331#endif
 332        .read           = lirc_dev_fop_read,
 333        .poll           = lirc_dev_fop_poll,
 334        .open           = lirc_dev_fop_open,
 335        .release        = lirc_dev_fop_close,
 336        .llseek         = no_llseek,
 337};
 338
 339static int ir_lirc_register(struct rc_dev *dev)
 340{
 341        struct lirc_driver *drv;
 342        struct lirc_buffer *rbuf;
 343        int rc = -ENOMEM;
 344        unsigned long features;
 345
 346        drv = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
 347        if (!drv)
 348                return rc;
 349
 350        rbuf = kzalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
 351        if (!rbuf)
 352                goto rbuf_alloc_failed;
 353
 354        rc = lirc_buffer_init(rbuf, sizeof(int), LIRCBUF_SIZE);
 355        if (rc)
 356                goto rbuf_init_failed;
 357
 358        features = LIRC_CAN_REC_MODE2;
 359        if (dev->tx_ir) {
 360                features |= LIRC_CAN_SEND_PULSE;
 361                if (dev->s_tx_mask)
 362                        features |= LIRC_CAN_SET_TRANSMITTER_MASK;
 363                if (dev->s_tx_carrier)
 364                        features |= LIRC_CAN_SET_SEND_CARRIER;
 365                if (dev->s_tx_duty_cycle)
 366                        features |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
 367        }
 368
 369        if (dev->s_rx_carrier_range)
 370                features |= LIRC_CAN_SET_REC_CARRIER |
 371                        LIRC_CAN_SET_REC_CARRIER_RANGE;
 372
 373        if (dev->s_learning_mode)
 374                features |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
 375
 376        if (dev->s_carrier_report)
 377                features |= LIRC_CAN_MEASURE_CARRIER;
 378
 379        if (dev->max_timeout)
 380                features |= LIRC_CAN_SET_REC_TIMEOUT;
 381
 382        snprintf(drv->name, sizeof(drv->name), "ir-lirc-codec (%s)",
 383                 dev->driver_name);
 384        drv->minor = -1;
 385        drv->features = features;
 386        drv->data = &dev->raw->lirc;
 387        drv->rbuf = rbuf;
 388        drv->set_use_inc = &ir_lirc_open;
 389        drv->set_use_dec = &ir_lirc_close;
 390        drv->code_length = sizeof(struct ir_raw_event) * 8;
 391        drv->fops = &lirc_fops;
 392        drv->dev = &dev->dev;
 393        drv->rdev = dev;
 394        drv->owner = THIS_MODULE;
 395
 396        drv->minor = lirc_register_driver(drv);
 397        if (drv->minor < 0) {
 398                rc = -ENODEV;
 399                goto lirc_register_failed;
 400        }
 401
 402        dev->raw->lirc.drv = drv;
 403        dev->raw->lirc.dev = dev;
 404        return 0;
 405
 406lirc_register_failed:
 407rbuf_init_failed:
 408        kfree(rbuf);
 409rbuf_alloc_failed:
 410        kfree(drv);
 411
 412        return rc;
 413}
 414
 415static int ir_lirc_unregister(struct rc_dev *dev)
 416{
 417        struct lirc_codec *lirc = &dev->raw->lirc;
 418
 419        lirc_unregister_driver(lirc->drv->minor);
 420        lirc_buffer_free(lirc->drv->rbuf);
 421        kfree(lirc->drv);
 422
 423        return 0;
 424}
 425
 426static struct ir_raw_handler lirc_handler = {
 427        .protocols      = RC_BIT_LIRC,
 428        .decode         = ir_lirc_decode,
 429        .raw_register   = ir_lirc_register,
 430        .raw_unregister = ir_lirc_unregister,
 431};
 432
 433static int __init ir_lirc_codec_init(void)
 434{
 435        ir_raw_handler_register(&lirc_handler);
 436
 437        printk(KERN_INFO "IR LIRC bridge handler initialized\n");
 438        return 0;
 439}
 440
 441static void __exit ir_lirc_codec_exit(void)
 442{
 443        ir_raw_handler_unregister(&lirc_handler);
 444}
 445
 446module_init(ir_lirc_codec_init);
 447module_exit(ir_lirc_codec_exit);
 448
 449MODULE_LICENSE("GPL");
 450MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
 451MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
 452MODULE_DESCRIPTION("LIRC IR handler bridge");
 453