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->enabled_protocols & RC_TYPE_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 = 0;
 115         size_t count;
 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 = dev->tx_ir(dev, txbuf, count);
 140
 141         if (ret > 0)
 142                 ret *= sizeof(unsigned);
 143
 144 out:
 145         kfree(txbuf);
 146         return ret;
 147 }
 148
 149 static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
 150                         unsigned long arg)
 151 {
 152         struct lirc_codec *lirc;
 153         struct rc_dev *dev;
 154         u32 __user *argp = (u32 __user *)(arg);
 155         int ret = 0;
 156         __u32 val = 0, tmp;
 157
 158         lirc = lirc_get_pdata(filep);
 159         if (!lirc)
 160                 return -EFAULT;
 161
 162         dev = lirc->dev;
 163         if (!dev)
 164                 return -EFAULT;
 165
 166         if (_IOC_DIR(cmd) & _IOC_WRITE) {
 167                 ret = get_user(val, argp);
 168                 if (ret)
 169                         return ret;
 170         }
 171
 172         switch (cmd) {
 173
 174         /* legacy support */
 175         case LIRC_GET_SEND_MODE:
 176                 val = LIRC_CAN_SEND_PULSE & LIRC_CAN_SEND_MASK;
 177                 break;
 178
 179         case LIRC_SET_SEND_MODE:
 180                 if (val != (LIRC_MODE_PULSE & LIRC_CAN_SEND_MASK))
 181                         return -EINVAL;
 182                 return 0;
 183
 184         /* TX settings */
 185         case LIRC_SET_TRANSMITTER_MASK:
 186                 if (!dev->s_tx_mask)
 187                         return -EINVAL;
 188
 189                 return dev->s_tx_mask(dev, val);
 190
 191         case LIRC_SET_SEND_CARRIER:
 192                 if (!dev->s_tx_carrier)
 193                         return -EINVAL;
 194
 195                 return dev->s_tx_carrier(dev, val);
 196
 197         case LIRC_SET_SEND_DUTY_CYCLE:
 198                 if (!dev->s_tx_duty_cycle)
 199                         return -ENOSYS;
 200
 201                 if (val <= 0 || val >= 100)
 202                         return -EINVAL;
 203
 204                 return dev->s_tx_duty_cycle(dev, val);
 205
 206         /* RX settings */
 207         case LIRC_SET_REC_CARRIER:
 208                 if (!dev->s_rx_carrier_range)
 209                         return -ENOSYS;
 210
 211                 if (val <= 0)
 212                         return -EINVAL;
 213
 214                 return dev->s_rx_carrier_range(dev,
 215                                                dev->raw->lirc.carrier_low,
 216                                                val);
 217
 218         case LIRC_SET_REC_CARRIER_RANGE:
 219                 if (val <= 0)
 220                         return -EINVAL;
 221
 222                 dev->raw->lirc.carrier_low = val;
 223                 return 0;
 224
 225         case LIRC_GET_REC_RESOLUTION:
 226                 val = dev->rx_resolution;
 227                 break;
 228
 229         case LIRC_SET_WIDEBAND_RECEIVER:
 230                 if (!dev->s_learning_mode)
 231                         return -ENOSYS;
 232
 233                 return dev->s_learning_mode(dev, !!val);
 234
 235         case LIRC_SET_MEASURE_CARRIER_MODE:
 236                 if (!dev->s_carrier_report)
 237                         return -ENOSYS;
 238
 239                 return dev->s_carrier_report(dev, !!val);
 240
 241         /* Generic timeout support */
 242         case LIRC_GET_MIN_TIMEOUT:
 243                 if (!dev->max_timeout)
 244                         return -ENOSYS;
 245                 val = dev->min_timeout / 1000;
 246                 break;
 247
 248         case LIRC_GET_MAX_TIMEOUT:
 249                 if (!dev->max_timeout)
 250                         return -ENOSYS;
 251                 val = dev->max_timeout / 1000;
 252                 break;
 253
 254         case LIRC_SET_REC_TIMEOUT:
 255                 if (!dev->max_timeout)
 256                         return -ENOSYS;
 257
 258                 tmp = val * 1000;
 259
 260                 if (tmp < dev->min_timeout ||
 261                     tmp > dev->max_timeout)
 262                                 return -EINVAL;
 263
 264                 dev->timeout = tmp;
 265                 break;
 266
 267         case LIRC_SET_REC_TIMEOUT_REPORTS:
 268                 lirc->send_timeout_reports = !!val;
 269                 break;
 270
 271         default:
 272                 return lirc_dev_fop_ioctl(filep, cmd, arg);
 273         }
 274
 275         if (_IOC_DIR(cmd) & _IOC_READ)
 276                 ret = put_user(val, argp);
 277
 278         return ret;
 279 }
 280
 281 static int ir_lirc_open(void *data)
 282 {
 283         return 0;
 284 }
 285
 286 static void ir_lirc_close(void *data)
 287 {
 288         return;
 289 }
 290
 291 static struct file_operations lirc_fops = {
 292         .owner          = THIS_MODULE,
 293         .write          = ir_lirc_transmit_ir,
 294         .unlocked_ioctl = ir_lirc_ioctl,
 295 #ifdef CONFIG_COMPAT
 296         .compat_ioctl   = ir_lirc_ioctl,
 297 #endif
 298         .read           = lirc_dev_fop_read,
 299         .poll           = lirc_dev_fop_poll,
 300         .open           = lirc_dev_fop_open,
 301         .release        = lirc_dev_fop_close,
 302         .llseek         = no_llseek,
 303 };
 304
 305 static int ir_lirc_register(struct rc_dev *dev)
 306 {
 307         struct lirc_driver *drv;
 308         struct lirc_buffer *rbuf;
 309         int rc = -ENOMEM;
 310         unsigned long features;
 311
 312         drv = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
 313         if (!drv)
 314                 return rc;
 315
 316         rbuf = kzalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
 317         if (!rbuf)
 318                 goto rbuf_alloc_failed;
 319
 320         rc = lirc_buffer_init(rbuf, sizeof(int), LIRCBUF_SIZE);
 321         if (rc)
 322                 goto rbuf_init_failed;
 323
 324         features = LIRC_CAN_REC_MODE2;
 325         if (dev->tx_ir) {
 326                 features |= LIRC_CAN_SEND_PULSE;
 327                 if (dev->s_tx_mask)
 328                         features |= LIRC_CAN_SET_TRANSMITTER_MASK;
 329                 if (dev->s_tx_carrier)
 330                         features |= LIRC_CAN_SET_SEND_CARRIER;
 331                 if (dev->s_tx_duty_cycle)
 332                         features |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
 333         }
 334
 335         if (dev->s_rx_carrier_range)
 336                 features |= LIRC_CAN_SET_REC_CARRIER |
 337                         LIRC_CAN_SET_REC_CARRIER_RANGE;
 338
 339         if (dev->s_learning_mode)
 340                 features |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
 341
 342         if (dev->s_carrier_report)
 343                 features |= LIRC_CAN_MEASURE_CARRIER;
 344
 345         if (dev->max_timeout)
 346                 features |= LIRC_CAN_SET_REC_TIMEOUT;
 347
 348         snprintf(drv->name, sizeof(drv->name), "ir-lirc-codec (%s)",
 349                  dev->driver_name);
 350         drv->minor = -1;
 351         drv->features = features;
 352         drv->data = &dev->raw->lirc;
 353         drv->rbuf = rbuf;
 354         drv->set_use_inc = &ir_lirc_open;
 355         drv->set_use_dec = &ir_lirc_close;
 356         drv->code_length = sizeof(struct ir_raw_event) * 8;
 357         drv->fops = &lirc_fops;
 358         drv->dev = &dev->dev;
 359         drv->owner = THIS_MODULE;
 360
 361         drv->minor = lirc_register_driver(drv);
 362         if (drv->minor < 0) {
 363                 rc = -ENODEV;
 364                 goto lirc_register_failed;
 365         }
 366
 367         dev->raw->lirc.drv = drv;
 368         dev->raw->lirc.dev = dev;
 369         return 0;
 370
 371 lirc_register_failed:
 372 rbuf_init_failed:
 373         kfree(rbuf);
 374 rbuf_alloc_failed:
 375         kfree(drv);
 376
 377         return rc;
 378 }
 379
 380 static int ir_lirc_unregister(struct rc_dev *dev)
 381 {
 382         struct lirc_codec *lirc = &dev->raw->lirc;
 383
 384         lirc_unregister_driver(lirc->drv->minor);
 385         lirc_buffer_free(lirc->drv->rbuf);
 386         kfree(lirc->drv);
 387
 388         return 0;
 389 }
 390
 391 static struct ir_raw_handler lirc_handler = {
 392         .protocols      = RC_TYPE_LIRC,
 393         .decode         = ir_lirc_decode,
 394         .raw_register   = ir_lirc_register,
 395         .raw_unregister = ir_lirc_unregister,
 396 };
 397
 398 static int __init ir_lirc_codec_init(void)
 399 {
 400         ir_raw_handler_register(&lirc_handler);
 401
 402         printk(KERN_INFO "IR LIRC bridge handler initialized\n");
 403         return 0;
 404 }
 405
 406 static void __exit ir_lirc_codec_exit(void)
 407 {
 408         ir_raw_handler_unregister(&lirc_handler);
 409 }
 410
 411 module_init(ir_lirc_codec_init);
 412 module_exit(ir_lirc_codec_exit);
 413
 414 MODULE_LICENSE("GPL");
 415 MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
 416 MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
 417 MODULE_DESCRIPTION("LIRC IR handler bridge");