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->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
 108 static 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
 178 out:
 179         kfree(txbuf);
 180         return ret;
 181 }
 182
 183 static 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                 /* Check for multiply overflow */
 293                 if (val > U32_MAX / 1000)
 294                         return -EINVAL;
 295
 296                 tmp = val * 1000;
 297
 298                 if (tmp < dev->min_timeout || tmp > dev->max_timeout)
 299                         return -EINVAL;
 300
 301                 dev->timeout = tmp;
 302                 break;
 303
 304         case LIRC_SET_REC_TIMEOUT_REPORTS:
 305                 lirc->send_timeout_reports = !!val;
 306                 break;
 307
 308         default:
 309                 return lirc_dev_fop_ioctl(filep, cmd, arg);
 310         }
 311
 312         if (_IOC_DIR(cmd) & _IOC_READ)
 313                 ret = put_user(val, argp);
 314
 315         return ret;
 316 }
 317
 318 static int ir_lirc_open(void *data)
 319 {
 320         return 0;
 321 }
 322
 323 static void ir_lirc_close(void *data)
 324 {
 325         return;
 326 }
 327
 328 static const struct file_operations lirc_fops = {
 329         .owner          = THIS_MODULE,
 330         .write          = ir_lirc_transmit_ir,
 331         .unlocked_ioctl = ir_lirc_ioctl,
 332 #ifdef CONFIG_COMPAT
 333         .compat_ioctl   = ir_lirc_ioctl,
 334 #endif
 335         .read           = lirc_dev_fop_read,
 336         .poll           = lirc_dev_fop_poll,
 337         .open           = lirc_dev_fop_open,
 338         .release        = lirc_dev_fop_close,
 339         .llseek         = no_llseek,
 340 };
 341
 342 static int ir_lirc_register(struct rc_dev *dev)
 343 {
 344         struct lirc_driver *drv;
 345         struct lirc_buffer *rbuf;
 346         int rc = -ENOMEM;
 347         unsigned long features;
 348
 349         drv = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
 350         if (!drv)
 351                 return rc;
 352
 353         rbuf = kzalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
 354         if (!rbuf)
 355                 goto rbuf_alloc_failed;
 356
 357         rc = lirc_buffer_init(rbuf, sizeof(int), LIRCBUF_SIZE);
 358         if (rc)
 359                 goto rbuf_init_failed;
 360
 361         features = LIRC_CAN_REC_MODE2;
 362         if (dev->tx_ir) {
 363                 features |= LIRC_CAN_SEND_PULSE;
 364                 if (dev->s_tx_mask)
 365                         features |= LIRC_CAN_SET_TRANSMITTER_MASK;
 366                 if (dev->s_tx_carrier)
 367                         features |= LIRC_CAN_SET_SEND_CARRIER;
 368                 if (dev->s_tx_duty_cycle)
 369                         features |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
 370         }
 371
 372         if (dev->s_rx_carrier_range)
 373                 features |= LIRC_CAN_SET_REC_CARRIER |
 374                         LIRC_CAN_SET_REC_CARRIER_RANGE;
 375
 376         if (dev->s_learning_mode)
 377                 features |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
 378
 379         if (dev->s_carrier_report)
 380                 features |= LIRC_CAN_MEASURE_CARRIER;
 381
 382         if (dev->max_timeout)
 383                 features |= LIRC_CAN_SET_REC_TIMEOUT;
 384
 385         snprintf(drv->name, sizeof(drv->name), "ir-lirc-codec (%s)",
 386                  dev->driver_name);
 387         drv->minor = -1;
 388         drv->features = features;
 389         drv->data = &dev->raw->lirc;
 390         drv->rbuf = rbuf;
 391         drv->set_use_inc = &ir_lirc_open;
 392         drv->set_use_dec = &ir_lirc_close;
 393         drv->code_length = sizeof(struct ir_raw_event) * 8;
 394         drv->fops = &lirc_fops;
 395         drv->dev = &dev->dev;
 396         drv->rdev = dev;
 397         drv->owner = THIS_MODULE;
 398
 399         drv->minor = lirc_register_driver(drv);
 400         if (drv->minor < 0) {
 401                 rc = -ENODEV;
 402                 goto lirc_register_failed;
 403         }
 404
 405         dev->raw->lirc.drv = drv;
 406         dev->raw->lirc.dev = dev;
 407         return 0;
 408
 409 lirc_register_failed:
 410 rbuf_init_failed:
 411         kfree(rbuf);
 412 rbuf_alloc_failed:
 413         kfree(drv);
 414
 415         return rc;
 416 }
 417
 418 static int ir_lirc_unregister(struct rc_dev *dev)
 419 {
 420         struct lirc_codec *lirc = &dev->raw->lirc;
 421
 422         lirc_unregister_driver(lirc->drv->minor);
 423         lirc_buffer_free(lirc->drv->rbuf);
 424         kfree(lirc->drv);
 425
 426         return 0;
 427 }
 428
 429 static struct ir_raw_handler lirc_handler = {
 430         .protocols      = RC_BIT_LIRC,
 431         .decode         = ir_lirc_decode,
 432         .raw_register   = ir_lirc_register,
 433         .raw_unregister = ir_lirc_unregister,
 434 };
 435
 436 static int __init ir_lirc_codec_init(void)
 437 {
 438         ir_raw_handler_register(&lirc_handler);
 439
 440         printk(KERN_INFO "IR LIRC bridge handler initialized\n");
 441         return 0;
 442 }
 443
 444 static void __exit ir_lirc_codec_exit(void)
 445 {
 446         ir_raw_handler_unregister(&lirc_handler);
 447 }
 448
 449 module_init(ir_lirc_codec_init);
 450 module_exit(ir_lirc_codec_exit);
 451
 452 MODULE_LICENSE("GPL");
 453 MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
 454 MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
 455 MODULE_DESCRIPTION("LIRC IR handler bridge");