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