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  * @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  */
  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.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
 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 = -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
 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                 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                 if (dev->s_timeout)
 296                         ret = dev->s_timeout(dev, tmp);
 297                 if (!ret)
 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
 315 static int ir_lirc_open(void *data)
 316 {
 317         return 0;
 318 }
 319
 320 static void ir_lirc_close(void *data)
 321 {
 322         return;
 323 }
 324
 325 static 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
 339 static 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
 406 lirc_register_failed:
 407 rbuf_init_failed:
 408         kfree(rbuf);
 409 rbuf_alloc_failed:
 410         kfree(drv);
 411
 412         return rc;
 413 }
 414
 415 static 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->rbuf);
 422         kfree(lirc->drv);
 423
 424         return 0;
 425 }
 426
 427 static struct ir_raw_handler lirc_handler = {
 428         .protocols      = 0,
 429         .decode         = ir_lirc_decode,
 430         .raw_register   = ir_lirc_register,
 431         .raw_unregister = ir_lirc_unregister,
 432 };
 433
 434 static int __init ir_lirc_codec_init(void)
 435 {
 436         ir_raw_handler_register(&lirc_handler);
 437
 438         printk(KERN_INFO "IR LIRC bridge handler initialized\n");
 439         return 0;
 440 }
 441
 442 static void __exit ir_lirc_codec_exit(void)
 443 {
 444         ir_raw_handler_unregister(&lirc_handler);
 445 }
 446
 447 module_init(ir_lirc_codec_init);
 448 module_exit(ir_lirc_codec_exit);
 449
 450 MODULE_LICENSE("GPL");
 451 MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
 452 MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
 453 MODULE_DESCRIPTION("LIRC IR handler bridge");