drivers/media/rc/ir-lirc-codec.c

   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  * @dev:        the struct rc_dev descriptor of the device
  29  * @ev:         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  */
  33 static 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.ldev || !dev->raw->lirc.ldev->buf)
  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.ldev->buf,
  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.ldev->buf,
  99                           (unsigned char *) &sample);
 100         wake_up(&dev->raw->lirc.ldev->buf->wait_poll);
 101
 102         return 0;
 103 }
 104
 105 static 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 = -EINVAL;
 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
 175 out:
 176         kfree(txbuf);
 177         return ret;
 178 }
 179
 180 static 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                 if (!dev->tx_ir)
 208                         return -ENOTTY;
 209
 210                 val = LIRC_MODE_PULSE;
 211                 break;
 212
 213         case LIRC_SET_SEND_MODE:
 214                 if (!dev->tx_ir)
 215                         return -ENOTTY;
 216
 217                 if (val != LIRC_MODE_PULSE)
 218                         return -EINVAL;
 219                 return 0;
 220
 221         /* TX settings */
 222         case LIRC_SET_TRANSMITTER_MASK:
 223                 if (!dev->s_tx_mask)
 224                         return -ENOTTY;
 225
 226                 return dev->s_tx_mask(dev, val);
 227
 228         case LIRC_SET_SEND_CARRIER:
 229                 if (!dev->s_tx_carrier)
 230                         return -ENOTTY;
 231
 232                 return dev->s_tx_carrier(dev, val);
 233
 234         case LIRC_SET_SEND_DUTY_CYCLE:
 235                 if (!dev->s_tx_duty_cycle)
 236                         return -ENOTTY;
 237
 238                 if (val <= 0 || val >= 100)
 239                         return -EINVAL;
 240
 241                 return dev->s_tx_duty_cycle(dev, val);
 242
 243         /* RX settings */
 244         case LIRC_SET_REC_CARRIER:
 245                 if (!dev->s_rx_carrier_range)
 246                         return -ENOTTY;
 247
 248                 if (val <= 0)
 249                         return -EINVAL;
 250
 251                 return dev->s_rx_carrier_range(dev,
 252                                                dev->raw->lirc.carrier_low,
 253                                                val);
 254
 255         case LIRC_SET_REC_CARRIER_RANGE:
 256                 if (!dev->s_rx_carrier_range)
 257                         return -ENOTTY;
 258
 259                 if (val <= 0)
 260                         return -EINVAL;
 261
 262                 dev->raw->lirc.carrier_low = val;
 263                 return 0;
 264
 265         case LIRC_GET_REC_RESOLUTION:
 266                 if (!dev->rx_resolution)
 267                         return -ENOTTY;
 268
 269                 val = dev->rx_resolution / 1000;
 270                 break;
 271
 272         case LIRC_SET_WIDEBAND_RECEIVER:
 273                 if (!dev->s_learning_mode)
 274                         return -ENOTTY;
 275
 276                 return dev->s_learning_mode(dev, !!val);
 277
 278         case LIRC_SET_MEASURE_CARRIER_MODE:
 279                 if (!dev->s_carrier_report)
 280                         return -ENOTTY;
 281
 282                 return dev->s_carrier_report(dev, !!val);
 283
 284         /* Generic timeout support */
 285         case LIRC_GET_MIN_TIMEOUT:
 286                 if (!dev->max_timeout)
 287                         return -ENOTTY;
 288                 val = DIV_ROUND_UP(dev->min_timeout, 1000);
 289                 break;
 290
 291         case LIRC_GET_MAX_TIMEOUT:
 292                 if (!dev->max_timeout)
 293                         return -ENOTTY;
 294                 val = dev->max_timeout / 1000;
 295                 break;
 296
 297         case LIRC_SET_REC_TIMEOUT:
 298                 if (!dev->max_timeout)
 299                         return -ENOTTY;
 300
 301                 /* Check for multiply overflow */
 302                 if (val > U32_MAX / 1000)
 303                         return -EINVAL;
 304
 305                 tmp = val * 1000;
 306
 307                 if (tmp < dev->min_timeout || tmp > dev->max_timeout)
 308                         return -EINVAL;
 309
 310                 if (dev->s_timeout)
 311                         ret = dev->s_timeout(dev, tmp);
 312                 if (!ret)
 313                         dev->timeout = tmp;
 314                 break;
 315
 316         case LIRC_SET_REC_TIMEOUT_REPORTS:
 317                 if (!dev->timeout)
 318                         return -ENOTTY;
 319
 320                 lirc->send_timeout_reports = !!val;
 321                 break;
 322
 323         default:
 324                 return lirc_dev_fop_ioctl(filep, cmd, arg);
 325         }
 326
 327         if (_IOC_DIR(cmd) & _IOC_READ)
 328                 ret = put_user(val, argp);
 329
 330         return ret;
 331 }
 332
 333 static const struct file_operations lirc_fops = {
 334         .owner          = THIS_MODULE,
 335         .write          = ir_lirc_transmit_ir,
 336         .unlocked_ioctl = ir_lirc_ioctl,
 337 #ifdef CONFIG_COMPAT
 338         .compat_ioctl   = ir_lirc_ioctl,
 339 #endif
 340         .read           = lirc_dev_fop_read,
 341         .poll           = lirc_dev_fop_poll,
 342         .open           = lirc_dev_fop_open,
 343         .release        = lirc_dev_fop_close,
 344         .llseek         = no_llseek,
 345 };
 346
 347 static int ir_lirc_register(struct rc_dev *dev)
 348 {
 349         struct lirc_dev *ldev;
 350         int rc = -ENOMEM;
 351         unsigned long features = 0;
 352
 353         ldev = lirc_allocate_device();
 354         if (!ldev)
 355                 return rc;
 356
 357         if (dev->driver_type != RC_DRIVER_IR_RAW_TX) {
 358                 features |= LIRC_CAN_REC_MODE2;
 359                 if (dev->rx_resolution)
 360                         features |= LIRC_CAN_GET_REC_RESOLUTION;
 361         }
 362
 363         if (dev->tx_ir) {
 364                 features |= LIRC_CAN_SEND_PULSE;
 365                 if (dev->s_tx_mask)
 366                         features |= LIRC_CAN_SET_TRANSMITTER_MASK;
 367                 if (dev->s_tx_carrier)
 368                         features |= LIRC_CAN_SET_SEND_CARRIER;
 369                 if (dev->s_tx_duty_cycle)
 370                         features |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
 371         }
 372
 373         if (dev->s_rx_carrier_range)
 374                 features |= LIRC_CAN_SET_REC_CARRIER |
 375                         LIRC_CAN_SET_REC_CARRIER_RANGE;
 376
 377         if (dev->s_learning_mode)
 378                 features |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
 379
 380         if (dev->s_carrier_report)
 381                 features |= LIRC_CAN_MEASURE_CARRIER;
 382
 383         if (dev->max_timeout)
 384                 features |= LIRC_CAN_SET_REC_TIMEOUT;
 385
 386         snprintf(ldev->name, sizeof(ldev->name), "ir-lirc-codec (%s)",
 387                  dev->driver_name);
 388         ldev->features = features;
 389         ldev->data = &dev->raw->lirc;
 390         ldev->buf = NULL;
 391         ldev->code_length = sizeof(struct ir_raw_event) * 8;
 392         ldev->chunk_size = sizeof(int);
 393         ldev->buffer_size = LIRCBUF_SIZE;
 394         ldev->fops = &lirc_fops;
 395         ldev->dev.parent = &dev->dev;
 396         ldev->rdev = dev;
 397         ldev->owner = THIS_MODULE;
 398
 399         rc = lirc_register_device(ldev);
 400         if (rc < 0)
 401                 goto out;
 402
 403         dev->raw->lirc.ldev = ldev;
 404         dev->raw->lirc.dev = dev;
 405         return 0;
 406
 407 out:
 408         lirc_free_device(ldev);
 409         return rc;
 410 }
 411
 412 static int ir_lirc_unregister(struct rc_dev *dev)
 413 {
 414         struct lirc_codec *lirc = &dev->raw->lirc;
 415
 416         lirc_unregister_device(lirc->ldev);
 417         lirc->ldev = NULL;
 418
 419         return 0;
 420 }
 421
 422 static struct ir_raw_handler lirc_handler = {
 423         .protocols      = 0,
 424         .decode         = ir_lirc_decode,
 425         .raw_register   = ir_lirc_register,
 426         .raw_unregister = ir_lirc_unregister,
 427 };
 428
 429 static int __init ir_lirc_codec_init(void)
 430 {
 431         ir_raw_handler_register(&lirc_handler);
 432
 433         printk(KERN_INFO "IR LIRC bridge handler initialized\n");
 434         return 0;
 435 }
 436
 437 static void __exit ir_lirc_codec_exit(void)
 438 {
 439         ir_raw_handler_unregister(&lirc_handler);
 440 }
 441
 442 module_init(ir_lirc_codec_init);
 443 module_exit(ir_lirc_codec_exit);
 444
 445 MODULE_LICENSE("GPL");
 446 MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
 447 MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
 448 MODULE_DESCRIPTION("LIRC IR handler bridge");