drivers/net/irda/sir_dev.c

   1 /*********************************************************************
   2  *
   3  *      sir_dev.c:      irda sir network device
   4  *
   5  *      Copyright (c) 2002 Martin Diehl
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License as
   9  *      published by the Free Software Foundation; either version 2 of
  10  *      the License, or (at your option) any later version.
  11  *
  12  ********************************************************************/
  13
  14 #include <linux/module.h>
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/delay.h>
  18
  19 #include <net/irda/irda.h>
  20 #include <net/irda/wrapper.h>
  21 #include <net/irda/irda_device.h>
  22
  23 #include "sir-dev.h"
  24
  25
  26 static struct workqueue_struct *irda_sir_wq;
  27
  28 /* STATE MACHINE */
  29
  30 /* substate handler of the config-fsm to handle the cases where we want
  31  * to wait for transmit completion before changing the port configuration
  32  */
  33
  34 static int sirdev_tx_complete_fsm(struct sir_dev *dev)
  35 {
  36         struct sir_fsm *fsm = &dev->fsm;
  37         unsigned next_state, delay;
  38         unsigned bytes_left;
  39
  40         do {
  41                 next_state = fsm->substate;     /* default: stay in current substate */
  42                 delay = 0;
  43
  44                 switch(fsm->substate) {
  45
  46                 case SIRDEV_STATE_WAIT_XMIT:
  47                         if (dev->drv->chars_in_buffer)
  48                                 bytes_left = dev->drv->chars_in_buffer(dev);
  49                         else
  50                                 bytes_left = 0;
  51                         if (!bytes_left) {
  52                                 next_state = SIRDEV_STATE_WAIT_UNTIL_SENT;
  53                                 break;
  54                         }
  55
  56                         if (dev->speed > 115200)
  57                                 delay = (bytes_left*8*10000) / (dev->speed/100);
  58                         else if (dev->speed > 0)
  59                                 delay = (bytes_left*10*10000) / (dev->speed/100);
  60                         else
  61                                 delay = 0;
  62                         /* expected delay (usec) until remaining bytes are sent */
  63                         if (delay < 100) {
  64                                 udelay(delay);
  65                                 delay = 0;
  66                                 break;
  67                         }
  68                         /* sleep some longer delay (msec) */
  69                         delay = (delay+999) / 1000;
  70                         break;
  71
  72                 case SIRDEV_STATE_WAIT_UNTIL_SENT:
  73                         /* block until underlaying hardware buffer are empty */
  74                         if (dev->drv->wait_until_sent)
  75                                 dev->drv->wait_until_sent(dev);
  76                         next_state = SIRDEV_STATE_TX_DONE;
  77                         break;
  78
  79                 case SIRDEV_STATE_TX_DONE:
  80                         return 0;
  81
  82                 default:
  83                         IRDA_ERROR("%s - undefined state\n", __FUNCTION__);
  84                         return -EINVAL;
  85                 }
  86                 fsm->substate = next_state;
  87         } while (delay == 0);
  88         return delay;
  89 }
  90
  91 /*
  92  * Function sirdev_config_fsm
  93  *
  94  * State machine to handle the configuration of the device (and attached dongle, if any).
  95  * This handler is scheduled for execution in kIrDAd context, so we can sleep.
  96  * however, kIrDAd is shared by all sir_dev devices so we better don't sleep there too
  97  * long. Instead, for longer delays we start a timer to reschedule us later.
  98  * On entry, fsm->sem is always locked and the netdev xmit queue stopped.
  99  * Both must be unlocked/restarted on completion - but only on final exit.
 100  */
 101
 102 static void sirdev_config_fsm(struct work_struct *work)
 103 {
 104         struct sir_dev *dev = container_of(work, struct sir_dev, fsm.work.work);
 105         struct sir_fsm *fsm = &dev->fsm;
 106         int next_state;
 107         int ret = -1;
 108         unsigned delay;
 109
 110         IRDA_DEBUG(2, "%s(), <%ld>\n", __FUNCTION__, jiffies);
 111
 112         do {
 113                 IRDA_DEBUG(3, "%s - state=0x%04x / substate=0x%04x\n",
 114                         __FUNCTION__, fsm->state, fsm->substate);
 115
 116                 next_state = fsm->state;
 117                 delay = 0;
 118
 119                 switch(fsm->state) {
 120
 121                 case SIRDEV_STATE_DONGLE_OPEN:
 122                         if (dev->dongle_drv != NULL) {
 123                                 ret = sirdev_put_dongle(dev);
 124                                 if (ret) {
 125                                         fsm->result = -EINVAL;
 126                                         next_state = SIRDEV_STATE_ERROR;
 127                                         break;
 128                                 }
 129                         }
 130
 131                         /* Initialize dongle */
 132                         ret = sirdev_get_dongle(dev, fsm->param);
 133                         if (ret) {
 134                                 fsm->result = ret;
 135                                 next_state = SIRDEV_STATE_ERROR;
 136                                 break;
 137                         }
 138
 139                         /* Dongles are powered through the modem control lines which
 140                          * were just set during open. Before resetting, let's wait for
 141                          * the power to stabilize. This is what some dongle drivers did
 142                          * in open before, while others didn't - should be safe anyway.
 143                          */
 144
 145                         delay = 50;
 146                         fsm->substate = SIRDEV_STATE_DONGLE_RESET;
 147                         next_state = SIRDEV_STATE_DONGLE_RESET;
 148
 149                         fsm->param = 9600;
 150
 151                         break;
 152
 153                 case SIRDEV_STATE_DONGLE_CLOSE:
 154                         /* shouldn't we just treat this as success=? */
 155                         if (dev->dongle_drv == NULL) {
 156                                 fsm->result = -EINVAL;
 157                                 next_state = SIRDEV_STATE_ERROR;
 158                                 break;
 159                         }
 160
 161                         ret = sirdev_put_dongle(dev);
 162                         if (ret) {
 163                                 fsm->result = ret;
 164                                 next_state = SIRDEV_STATE_ERROR;
 165                                 break;
 166                         }
 167                         next_state = SIRDEV_STATE_DONE;
 168                         break;
 169
 170                 case SIRDEV_STATE_SET_DTR_RTS:
 171                         ret = sirdev_set_dtr_rts(dev,
 172                                 (fsm->param&0x02) ? TRUE : FALSE,
 173                                 (fsm->param&0x01) ? TRUE : FALSE);
 174                         next_state = SIRDEV_STATE_DONE;
 175                         break;
 176
 177                 case SIRDEV_STATE_SET_SPEED:
 178                         fsm->substate = SIRDEV_STATE_WAIT_XMIT;
 179                         next_state = SIRDEV_STATE_DONGLE_CHECK;
 180                         break;
 181
 182                 case SIRDEV_STATE_DONGLE_CHECK:
 183                         ret = sirdev_tx_complete_fsm(dev);
 184                         if (ret < 0) {
 185                                 fsm->result = ret;
 186                                 next_state = SIRDEV_STATE_ERROR;
 187                                 break;
 188                         }
 189                         if ((delay=ret) != 0)
 190                                 break;
 191
 192                         if (dev->dongle_drv) {
 193                                 fsm->substate = SIRDEV_STATE_DONGLE_RESET;
 194                                 next_state = SIRDEV_STATE_DONGLE_RESET;
 195                         }
 196                         else {
 197                                 dev->speed = fsm->param;
 198                                 next_state = SIRDEV_STATE_PORT_SPEED;
 199                         }
 200                         break;
 201
 202                 case SIRDEV_STATE_DONGLE_RESET:
 203                         if (dev->dongle_drv->reset) {
 204                                 ret = dev->dongle_drv->reset(dev);
 205                                 if (ret < 0) {
 206                                         fsm->result = ret;
 207                                         next_state = SIRDEV_STATE_ERROR;
 208                                         break;
 209                                 }
 210                         }
 211                         else
 212                                 ret = 0;
 213                         if ((delay=ret) == 0) {
 214                                 /* set serial port according to dongle default speed */
 215                                 if (dev->drv->set_speed)
 216                                         dev->drv->set_speed(dev, dev->speed);
 217                                 fsm->substate = SIRDEV_STATE_DONGLE_SPEED;
 218                                 next_state = SIRDEV_STATE_DONGLE_SPEED;
 219                         }
 220                         break;
 221
 222                 case SIRDEV_STATE_DONGLE_SPEED:
 223                         if (dev->dongle_drv->reset) {
 224                                 ret = dev->dongle_drv->set_speed(dev, fsm->param);
 225                                 if (ret < 0) {
 226                                         fsm->result = ret;
 227                                         next_state = SIRDEV_STATE_ERROR;
 228                                         break;
 229                                 }
 230                         }
 231                         else
 232                                 ret = 0;
 233                         if ((delay=ret) == 0)
 234                                 next_state = SIRDEV_STATE_PORT_SPEED;
 235                         break;
 236
 237                 case SIRDEV_STATE_PORT_SPEED:
 238                         /* Finally we are ready to change the serial port speed */
 239                         if (dev->drv->set_speed)
 240                                 dev->drv->set_speed(dev, dev->speed);
 241                         dev->new_speed = 0;
 242                         next_state = SIRDEV_STATE_DONE;
 243                         break;
 244
 245                 case SIRDEV_STATE_DONE:
 246                         /* Signal network layer so it can send more frames */
 247                         netif_wake_queue(dev->netdev);
 248                         next_state = SIRDEV_STATE_COMPLETE;
 249                         break;
 250
 251                 default:
 252                         IRDA_ERROR("%s - undefined state\n", __FUNCTION__);
 253                         fsm->result = -EINVAL;
 254                         /* fall thru */
 255
 256                 case SIRDEV_STATE_ERROR:
 257                         IRDA_ERROR("%s - error: %d\n", __FUNCTION__, fsm->result);
 258
 259 #if 0   /* don't enable this before we have netdev->tx_timeout to recover */
 260                         netif_stop_queue(dev->netdev);
 261 #else
 262                         netif_wake_queue(dev->netdev);
 263 #endif
 264                         /* fall thru */
 265
 266                 case SIRDEV_STATE_COMPLETE:
 267                         /* config change finished, so we are not busy any longer */
 268                         sirdev_enable_rx(dev);
 269                         up(&fsm->sem);
 270                         return;
 271                 }
 272                 fsm->state = next_state;
 273         } while(!delay);
 274
 275         queue_delayed_work(irda_sir_wq, &fsm->work, msecs_to_jiffies(delay));
 276 }
 277
 278 /* schedule some device configuration task for execution by kIrDAd
 279  * on behalf of the above state machine.
 280  * can be called from process or interrupt/tasklet context.
 281  */
 282
 283 int sirdev_schedule_request(struct sir_dev *dev, int initial_state, unsigned param)
 284 {
 285         struct sir_fsm *fsm = &dev->fsm;
 286
 287         IRDA_DEBUG(2, "%s - state=0x%04x / param=%u\n", __FUNCTION__, initial_state, param);
 288
 289         if (down_trylock(&fsm->sem)) {
 290                 if (in_interrupt()  ||  in_atomic()  ||  irqs_disabled()) {
 291                         IRDA_DEBUG(1, "%s(), state machine busy!\n", __FUNCTION__);
 292                         return -EWOULDBLOCK;
 293                 } else
 294                         down(&fsm->sem);
 295         }
 296
 297         if (fsm->state == SIRDEV_STATE_DEAD) {
 298                 /* race with sirdev_close should never happen */
 299                 IRDA_ERROR("%s(), instance staled!\n", __FUNCTION__);
 300                 up(&fsm->sem);
 301                 return -ESTALE;         /* or better EPIPE? */
 302         }
 303
 304         netif_stop_queue(dev->netdev);
 305         atomic_set(&dev->enable_rx, 0);
 306
 307         fsm->state = initial_state;
 308         fsm->param = param;
 309         fsm->result = 0;
 310
 311         INIT_DELAYED_WORK(&fsm->work, sirdev_config_fsm);
 312         queue_delayed_work(irda_sir_wq, &fsm->work, 0);
 313         return 0;
 314 }
 315
 316
 317 /***************************************************************************/
 318
 319 void sirdev_enable_rx(struct sir_dev *dev)
 320 {
 321         if (unlikely(atomic_read(&dev->enable_rx)))
 322                 return;
 323
 324         /* flush rx-buffer - should also help in case of problems with echo cancelation */
 325         dev->rx_buff.data = dev->rx_buff.head;
 326         dev->rx_buff.len = 0;
 327         dev->rx_buff.in_frame = FALSE;
 328         dev->rx_buff.state = OUTSIDE_FRAME;
 329         atomic_set(&dev->enable_rx, 1);
 330 }
 331
 332 static int sirdev_is_receiving(struct sir_dev *dev)
 333 {
 334         if (!atomic_read(&dev->enable_rx))
 335                 return 0;
 336
 337         return (dev->rx_buff.state != OUTSIDE_FRAME);
 338 }
 339
 340 int sirdev_set_dongle(struct sir_dev *dev, IRDA_DONGLE type)
 341 {
 342         int err;
 343
 344         IRDA_DEBUG(3, "%s : requesting dongle %d.\n", __FUNCTION__, type);
 345
 346         err = sirdev_schedule_dongle_open(dev, type);
 347         if (unlikely(err))
 348                 return err;
 349         down(&dev->fsm.sem);            /* block until config change completed */
 350         err = dev->fsm.result;
 351         up(&dev->fsm.sem);
 352         return err;
 353 }
 354 EXPORT_SYMBOL(sirdev_set_dongle);
 355
 356 /* used by dongle drivers for dongle programming */
 357
 358 int sirdev_raw_write(struct sir_dev *dev, const char *buf, int len)
 359 {
 360         unsigned long flags;
 361         int ret;
 362
 363         if (unlikely(len > dev->tx_buff.truesize))
 364                 return -ENOSPC;
 365
 366         spin_lock_irqsave(&dev->tx_lock, flags);        /* serialize with other tx operations */
 367         while (dev->tx_buff.len > 0) {                  /* wait until tx idle */
 368                 spin_unlock_irqrestore(&dev->tx_lock, flags);
 369                 msleep(10);
 370                 spin_lock_irqsave(&dev->tx_lock, flags);
 371         }
 372
 373         dev->tx_buff.data = dev->tx_buff.head;
 374         memcpy(dev->tx_buff.data, buf, len);
 375         dev->tx_buff.len = len;
 376
 377         ret = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
 378         if (ret > 0) {
 379                 IRDA_DEBUG(3, "%s(), raw-tx started\n", __FUNCTION__);
 380
 381                 dev->tx_buff.data += ret;
 382                 dev->tx_buff.len -= ret;
 383                 dev->raw_tx = 1;
 384                 ret = len;              /* all data is going to be sent */
 385         }
 386         spin_unlock_irqrestore(&dev->tx_lock, flags);
 387         return ret;
 388 }
 389 EXPORT_SYMBOL(sirdev_raw_write);
 390
 391 /* seems some dongle drivers may need this */
 392
 393 int sirdev_raw_read(struct sir_dev *dev, char *buf, int len)
 394 {
 395         int count;
 396
 397         if (atomic_read(&dev->enable_rx))
 398                 return -EIO;            /* fail if we expect irda-frames */
 399
 400         count = (len < dev->rx_buff.len) ? len : dev->rx_buff.len;
 401
 402         if (count > 0) {
 403                 memcpy(buf, dev->rx_buff.data, count);
 404                 dev->rx_buff.data += count;
 405                 dev->rx_buff.len -= count;
 406         }
 407
 408         /* remaining stuff gets flushed when re-enabling normal rx */
 409
 410         return count;
 411 }
 412 EXPORT_SYMBOL(sirdev_raw_read);
 413
 414 int sirdev_set_dtr_rts(struct sir_dev *dev, int dtr, int rts)
 415 {
 416         int ret = -ENXIO;
 417         if (dev->drv->set_dtr_rts != 0)
 418                 ret =  dev->drv->set_dtr_rts(dev, dtr, rts);
 419         return ret;
 420 }
 421 EXPORT_SYMBOL(sirdev_set_dtr_rts);
 422
 423 /**********************************************************************/
 424
 425 /* called from client driver - likely with bh-context - to indicate
 426  * it made some progress with transmission. Hence we send the next
 427  * chunk, if any, or complete the skb otherwise
 428  */
 429
 430 void sirdev_write_complete(struct sir_dev *dev)
 431 {
 432         unsigned long flags;
 433         struct sk_buff *skb;
 434         int actual = 0;
 435         int err;
 436
 437         spin_lock_irqsave(&dev->tx_lock, flags);
 438
 439         IRDA_DEBUG(3, "%s() - dev->tx_buff.len = %d\n",
 440                    __FUNCTION__, dev->tx_buff.len);
 441
 442         if (likely(dev->tx_buff.len > 0))  {
 443                 /* Write data left in transmit buffer */
 444                 actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
 445
 446                 if (likely(actual>0)) {
 447                         dev->tx_buff.data += actual;
 448                         dev->tx_buff.len  -= actual;
 449                 }
 450                 else if (unlikely(actual<0)) {
 451                         /* could be dropped later when we have tx_timeout to recover */
 452                         IRDA_ERROR("%s: drv->do_write failed (%d)\n",
 453                                    __FUNCTION__, actual);
 454                         if ((skb=dev->tx_skb) != NULL) {
 455                                 dev->tx_skb = NULL;
 456                                 dev_kfree_skb_any(skb);
 457                                 dev->stats.tx_errors++;
 458                                 dev->stats.tx_dropped++;
 459                         }
 460                         dev->tx_buff.len = 0;
 461                 }
 462                 if (dev->tx_buff.len > 0)
 463                         goto done;      /* more data to send later */
 464         }
 465
 466         if (unlikely(dev->raw_tx != 0)) {
 467                 /* in raw mode we are just done now after the buffer was sent
 468                  * completely. Since this was requested by some dongle driver
 469                  * running under the control of the irda-thread we must take
 470                  * care here not to re-enable the queue. The queue will be
 471                  * restarted when the irda-thread has completed the request.
 472                  */
 473
 474                 IRDA_DEBUG(3, "%s(), raw-tx done\n", __FUNCTION__);
 475                 dev->raw_tx = 0;
 476                 goto done;      /* no post-frame handling in raw mode */
 477         }
 478
 479         /* we have finished now sending this skb.
 480          * update statistics and free the skb.
 481          * finally we check and trigger a pending speed change, if any.
 482          * if not we switch to rx mode and wake the queue for further
 483          * packets.
 484          * note the scheduled speed request blocks until the lower
 485          * client driver and the corresponding hardware has really
 486          * finished sending all data (xmit fifo drained f.e.)
 487          * before the speed change gets finally done and the queue
 488          * re-activated.
 489          */
 490
 491         IRDA_DEBUG(5, "%s(), finished with frame!\n", __FUNCTION__);
 492
 493         if ((skb=dev->tx_skb) != NULL) {
 494                 dev->tx_skb = NULL;
 495                 dev->stats.tx_packets++;
 496                 dev->stats.tx_bytes += skb->len;
 497                 dev_kfree_skb_any(skb);
 498         }
 499
 500         if (unlikely(dev->new_speed > 0)) {
 501                 IRDA_DEBUG(5, "%s(), Changing speed!\n", __FUNCTION__);
 502                 err = sirdev_schedule_speed(dev, dev->new_speed);
 503                 if (unlikely(err)) {
 504                         /* should never happen
 505                          * forget the speed change and hope the stack recovers
 506                          */
 507                         IRDA_ERROR("%s - schedule speed change failed: %d\n",
 508                                    __FUNCTION__, err);
 509                         netif_wake_queue(dev->netdev);
 510                 }
 511                 /* else: success
 512                  *      speed change in progress now
 513                  *      on completion dev->new_speed gets cleared,
 514                  *      rx-reenabled and the queue restarted
 515                  */
 516         }
 517         else {
 518                 sirdev_enable_rx(dev);
 519                 netif_wake_queue(dev->netdev);
 520         }
 521
 522 done:
 523         spin_unlock_irqrestore(&dev->tx_lock, flags);
 524 }
 525 EXPORT_SYMBOL(sirdev_write_complete);
 526
 527 /* called from client driver - likely with bh-context - to give us
 528  * some more received bytes. We put them into the rx-buffer,
 529  * normally unwrapping and building LAP-skb's (unless rx disabled)
 530  */
 531
 532 int sirdev_receive(struct sir_dev *dev, const unsigned char *cp, size_t count)
 533 {
 534         if (!dev || !dev->netdev) {
 535                 IRDA_WARNING("%s(), not ready yet!\n", __FUNCTION__);
 536                 return -1;
 537         }
 538
 539         if (!dev->irlap) {
 540                 IRDA_WARNING("%s - too early: %p / %zd!\n",
 541                              __FUNCTION__, cp, count);
 542                 return -1;
 543         }
 544
 545         if (cp==NULL) {
 546                 /* error already at lower level receive
 547                  * just update stats and set media busy
 548                  */
 549                 irda_device_set_media_busy(dev->netdev, TRUE);
 550                 dev->stats.rx_dropped++;
 551                 IRDA_DEBUG(0, "%s; rx-drop: %zd\n", __FUNCTION__, count);
 552                 return 0;
 553         }
 554
 555         /* Read the characters into the buffer */
 556         if (likely(atomic_read(&dev->enable_rx))) {
 557                 while (count--)
 558                         /* Unwrap and destuff one byte */
 559                         async_unwrap_char(dev->netdev, &dev->stats,
 560                                           &dev->rx_buff, *cp++);
 561         } else {
 562                 while (count--) {
 563                         /* rx not enabled: save the raw bytes and never
 564                          * trigger any netif_rx. The received bytes are flushed
 565                          * later when we re-enable rx but might be read meanwhile
 566                          * by the dongle driver.
 567                          */
 568                         dev->rx_buff.data[dev->rx_buff.len++] = *cp++;
 569
 570                         /* What should we do when the buffer is full? */
 571                         if (unlikely(dev->rx_buff.len == dev->rx_buff.truesize))
 572                                 dev->rx_buff.len = 0;
 573                 }
 574         }
 575
 576         return 0;
 577 }
 578 EXPORT_SYMBOL(sirdev_receive);
 579
 580 /**********************************************************************/
 581
 582 /* callbacks from network layer */
 583
 584 static struct net_device_stats *sirdev_get_stats(struct net_device *ndev)
 585 {
 586         struct sir_dev *dev = ndev->priv;
 587
 588         return (dev) ? &dev->stats : NULL;
 589 }
 590
 591 static int sirdev_hard_xmit(struct sk_buff *skb, struct net_device *ndev)
 592 {
 593         struct sir_dev *dev = ndev->priv;
 594         unsigned long flags;
 595         int actual = 0;
 596         int err;
 597         s32 speed;
 598
 599         IRDA_ASSERT(dev != NULL, return 0;);
 600
 601         netif_stop_queue(ndev);
 602
 603         IRDA_DEBUG(3, "%s(), skb->len = %d\n", __FUNCTION__, skb->len);
 604
 605         speed = irda_get_next_speed(skb);
 606         if ((speed != dev->speed) && (speed != -1)) {
 607                 if (!skb->len) {
 608                         err = sirdev_schedule_speed(dev, speed);
 609                         if (unlikely(err == -EWOULDBLOCK)) {
 610                                 /* Failed to initiate the speed change, likely the fsm
 611                                  * is still busy (pretty unlikely, but...)
 612                                  * We refuse to accept the skb and return with the queue
 613                                  * stopped so the network layer will retry after the
 614                                  * fsm completes and wakes the queue.
 615                                  */
 616                                  return 1;
 617                         }
 618                         else if (unlikely(err)) {
 619                                 /* other fatal error - forget the speed change and
 620                                  * hope the stack will recover somehow
 621                                  */
 622                                  netif_start_queue(ndev);
 623                         }
 624                         /* else: success
 625                          *      speed change in progress now
 626                          *      on completion the queue gets restarted
 627                          */
 628
 629                         dev_kfree_skb_any(skb);
 630                         return 0;
 631                 } else
 632                         dev->new_speed = speed;
 633         }
 634
 635         /* Init tx buffer*/
 636         dev->tx_buff.data = dev->tx_buff.head;
 637
 638         /* Check problems */
 639         if(spin_is_locked(&dev->tx_lock)) {
 640                 IRDA_DEBUG(3, "%s(), write not completed\n", __FUNCTION__);
 641         }
 642
 643         /* serialize with write completion */
 644         spin_lock_irqsave(&dev->tx_lock, flags);
 645
 646         /* Copy skb to tx_buff while wrapping, stuffing and making CRC */
 647         dev->tx_buff.len = async_wrap_skb(skb, dev->tx_buff.data, dev->tx_buff.truesize);
 648
 649         /* transmission will start now - disable receive.
 650          * if we are just in the middle of an incoming frame,
 651          * treat it as collision. probably it's a good idea to
 652          * reset the rx_buf OUTSIDE_FRAME in this case too?
 653          */
 654         atomic_set(&dev->enable_rx, 0);
 655         if (unlikely(sirdev_is_receiving(dev)))
 656                 dev->stats.collisions++;
 657
 658         actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
 659
 660         if (likely(actual > 0)) {
 661                 dev->tx_skb = skb;
 662                 ndev->trans_start = jiffies;
 663                 dev->tx_buff.data += actual;
 664                 dev->tx_buff.len -= actual;
 665         }
 666         else if (unlikely(actual < 0)) {
 667                 /* could be dropped later when we have tx_timeout to recover */
 668                 IRDA_ERROR("%s: drv->do_write failed (%d)\n",
 669                            __FUNCTION__, actual);
 670                 dev_kfree_skb_any(skb);
 671                 dev->stats.tx_errors++;
 672                 dev->stats.tx_dropped++;
 673                 netif_wake_queue(ndev);
 674         }
 675         spin_unlock_irqrestore(&dev->tx_lock, flags);
 676
 677         return 0;
 678 }
 679
 680 /* called from network layer with rtnl hold */
 681
 682 static int sirdev_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
 683 {
 684         struct if_irda_req *irq = (struct if_irda_req *) rq;
 685         struct sir_dev *dev = ndev->priv;
 686         int ret = 0;
 687
 688         IRDA_ASSERT(dev != NULL, return -1;);
 689
 690         IRDA_DEBUG(3, "%s(), %s, (cmd=0x%X)\n", __FUNCTION__, ndev->name, cmd);
 691
 692         switch (cmd) {
 693         case SIOCSBANDWIDTH: /* Set bandwidth */
 694                 if (!capable(CAP_NET_ADMIN))
 695                         ret = -EPERM;
 696                 else
 697                         ret = sirdev_schedule_speed(dev, irq->ifr_baudrate);
 698                 /* cannot sleep here for completion
 699                  * we are called from network layer with rtnl hold
 700                  */
 701                 break;
 702
 703         case SIOCSDONGLE: /* Set dongle */
 704                 if (!capable(CAP_NET_ADMIN))
 705                         ret = -EPERM;
 706                 else
 707                         ret = sirdev_schedule_dongle_open(dev, irq->ifr_dongle);
 708                 /* cannot sleep here for completion
 709                  * we are called from network layer with rtnl hold
 710                  */
 711                 break;
 712
 713         case SIOCSMEDIABUSY: /* Set media busy */
 714                 if (!capable(CAP_NET_ADMIN))
 715                         ret = -EPERM;
 716                 else
 717                         irda_device_set_media_busy(dev->netdev, TRUE);
 718                 break;
 719
 720         case SIOCGRECEIVING: /* Check if we are receiving right now */
 721                 irq->ifr_receiving = sirdev_is_receiving(dev);
 722                 break;
 723
 724         case SIOCSDTRRTS:
 725                 if (!capable(CAP_NET_ADMIN))
 726                         ret = -EPERM;
 727                 else
 728                         ret = sirdev_schedule_dtr_rts(dev, irq->ifr_dtr, irq->ifr_rts);
 729                 /* cannot sleep here for completion
 730                  * we are called from network layer with rtnl hold
 731                  */
 732                 break;
 733
 734         case SIOCSMODE:
 735 #if 0
 736                 if (!capable(CAP_NET_ADMIN))
 737                         ret = -EPERM;
 738                 else
 739                         ret = sirdev_schedule_mode(dev, irq->ifr_mode);
 740                 /* cannot sleep here for completion
 741                  * we are called from network layer with rtnl hold
 742                  */
 743                 break;
 744 #endif
 745         default:
 746                 ret = -EOPNOTSUPP;
 747         }
 748
 749         return ret;
 750 }
 751
 752 /* ----------------------------------------------------------------------------- */
 753
 754 #define SIRBUF_ALLOCSIZE 4269   /* worst case size of a wrapped IrLAP frame */
 755
 756 static int sirdev_alloc_buffers(struct sir_dev *dev)
 757 {
 758         dev->tx_buff.truesize = SIRBUF_ALLOCSIZE;
 759         dev->rx_buff.truesize = IRDA_SKB_MAX_MTU;
 760
 761         /* Bootstrap ZeroCopy Rx */
 762         dev->rx_buff.skb = __dev_alloc_skb(dev->rx_buff.truesize, GFP_KERNEL);
 763         if (dev->rx_buff.skb == NULL)
 764                 return -ENOMEM;
 765         skb_reserve(dev->rx_buff.skb, 1);
 766         dev->rx_buff.head = dev->rx_buff.skb->data;
 767
 768         dev->tx_buff.head = kmalloc(dev->tx_buff.truesize, GFP_KERNEL);
 769         if (dev->tx_buff.head == NULL) {
 770                 kfree_skb(dev->rx_buff.skb);
 771                 dev->rx_buff.skb = NULL;
 772                 dev->rx_buff.head = NULL;
 773                 return -ENOMEM;
 774         }
 775
 776         dev->tx_buff.data = dev->tx_buff.head;
 777         dev->rx_buff.data = dev->rx_buff.head;
 778         dev->tx_buff.len = 0;
 779         dev->rx_buff.len = 0;
 780
 781         dev->rx_buff.in_frame = FALSE;
 782         dev->rx_buff.state = OUTSIDE_FRAME;
 783         return 0;
 784 };
 785
 786 static void sirdev_free_buffers(struct sir_dev *dev)
 787 {
 788         if (dev->rx_buff.skb)
 789                 kfree_skb(dev->rx_buff.skb);
 790         kfree(dev->tx_buff.head);
 791         dev->rx_buff.head = dev->tx_buff.head = NULL;
 792         dev->rx_buff.skb = NULL;
 793 }
 794
 795 static int sirdev_open(struct net_device *ndev)
 796 {
 797         struct sir_dev *dev = ndev->priv;
 798         const struct sir_driver *drv = dev->drv;
 799
 800         if (!drv)
 801                 return -ENODEV;
 802
 803         /* increase the reference count of the driver module before doing serious stuff */
 804         if (!try_module_get(drv->owner))
 805                 return -ESTALE;
 806
 807         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
 808
 809         if (sirdev_alloc_buffers(dev))
 810                 goto errout_dec;
 811
 812         if (!dev->drv->start_dev  ||  dev->drv->start_dev(dev))
 813                 goto errout_free;
 814
 815         sirdev_enable_rx(dev);
 816         dev->raw_tx = 0;
 817
 818         netif_start_queue(ndev);
 819         dev->irlap = irlap_open(ndev, &dev->qos, dev->hwname);
 820         if (!dev->irlap)
 821                 goto errout_stop;
 822
 823         netif_wake_queue(ndev);
 824
 825         IRDA_DEBUG(2, "%s - done, speed = %d\n", __FUNCTION__, dev->speed);
 826
 827         return 0;
 828
 829 errout_stop:
 830         atomic_set(&dev->enable_rx, 0);
 831         if (dev->drv->stop_dev)
 832                 dev->drv->stop_dev(dev);
 833 errout_free:
 834         sirdev_free_buffers(dev);
 835 errout_dec:
 836         module_put(drv->owner);
 837         return -EAGAIN;
 838 }
 839
 840 static int sirdev_close(struct net_device *ndev)
 841 {
 842         struct sir_dev *dev = ndev->priv;
 843         const struct sir_driver *drv;
 844
 845 //      IRDA_DEBUG(0, "%s\n", __FUNCTION__);
 846
 847         netif_stop_queue(ndev);
 848
 849         down(&dev->fsm.sem);            /* block on pending config completion */
 850
 851         atomic_set(&dev->enable_rx, 0);
 852
 853         if (unlikely(!dev->irlap))
 854                 goto out;
 855         irlap_close(dev->irlap);
 856         dev->irlap = NULL;
 857
 858         drv = dev->drv;
 859         if (unlikely(!drv  ||  !dev->priv))
 860                 goto out;
 861
 862         if (drv->stop_dev)
 863                 drv->stop_dev(dev);
 864
 865         sirdev_free_buffers(dev);
 866         module_put(drv->owner);
 867
 868 out:
 869         dev->speed = 0;
 870         up(&dev->fsm.sem);
 871         return 0;
 872 }
 873
 874 /* ----------------------------------------------------------------------------- */
 875
 876 struct sir_dev * sirdev_get_instance(const struct sir_driver *drv, const char *name)
 877 {
 878         struct net_device *ndev;
 879         struct sir_dev *dev;
 880
 881         IRDA_DEBUG(0, "%s - %s\n", __FUNCTION__, name);
 882
 883         /* instead of adding tests to protect against drv->do_write==NULL
 884          * at several places we refuse to create a sir_dev instance for
 885          * drivers which don't implement do_write.
 886          */
 887         if (!drv ||  !drv->do_write)
 888                 return NULL;
 889
 890         /*
 891          *  Allocate new instance of the device
 892          */
 893         ndev = alloc_irdadev(sizeof(*dev));
 894         if (ndev == NULL) {
 895                 IRDA_ERROR("%s - Can't allocate memory for IrDA control block!\n", __FUNCTION__);
 896                 goto out;
 897         }
 898         dev = ndev->priv;
 899
 900         irda_init_max_qos_capabilies(&dev->qos);
 901         dev->qos.baud_rate.bits = IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
 902         dev->qos.min_turn_time.bits = drv->qos_mtt_bits;
 903         irda_qos_bits_to_value(&dev->qos);
 904
 905         strncpy(dev->hwname, name, sizeof(dev->hwname)-1);
 906
 907         atomic_set(&dev->enable_rx, 0);
 908         dev->tx_skb = NULL;
 909
 910         spin_lock_init(&dev->tx_lock);
 911         init_MUTEX(&dev->fsm.sem);
 912
 913         dev->drv = drv;
 914         dev->netdev = ndev;
 915
 916         SET_MODULE_OWNER(ndev);
 917
 918         /* Override the network functions we need to use */
 919         ndev->hard_start_xmit = sirdev_hard_xmit;
 920         ndev->open = sirdev_open;
 921         ndev->stop = sirdev_close;
 922         ndev->get_stats = sirdev_get_stats;
 923         ndev->do_ioctl = sirdev_ioctl;
 924
 925         if (register_netdev(ndev)) {
 926                 IRDA_ERROR("%s(), register_netdev() failed!\n", __FUNCTION__);
 927                 goto out_freenetdev;
 928         }
 929
 930         return dev;
 931
 932 out_freenetdev:
 933         free_netdev(ndev);
 934 out:
 935         return NULL;
 936 }
 937 EXPORT_SYMBOL(sirdev_get_instance);
 938
 939 int sirdev_put_instance(struct sir_dev *dev)
 940 {
 941         int err = 0;
 942
 943         IRDA_DEBUG(0, "%s\n", __FUNCTION__);
 944
 945         atomic_set(&dev->enable_rx, 0);
 946
 947         netif_carrier_off(dev->netdev);
 948         netif_device_detach(dev->netdev);
 949
 950         if (dev->dongle_drv)
 951                 err = sirdev_schedule_dongle_close(dev);
 952         if (err)
 953                 IRDA_ERROR("%s - error %d\n", __FUNCTION__, err);
 954
 955         sirdev_close(dev->netdev);
 956
 957         down(&dev->fsm.sem);
 958         dev->fsm.state = SIRDEV_STATE_DEAD;     /* mark staled */
 959         dev->dongle_drv = NULL;
 960         dev->priv = NULL;
 961         up(&dev->fsm.sem);
 962
 963         /* Remove netdevice */
 964         unregister_netdev(dev->netdev);
 965
 966         free_netdev(dev->netdev);
 967
 968         return 0;
 969 }
 970 EXPORT_SYMBOL(sirdev_put_instance);
 971
 972 static int __init sir_wq_init(void)
 973 {
 974         irda_sir_wq = create_singlethread_workqueue("irda_sir_wq");
 975         if (!irda_sir_wq)
 976                 return -ENOMEM;
 977         return 0;
 978 }
 979
 980 static void __exit sir_wq_exit(void)
 981 {
 982         destroy_workqueue(irda_sir_wq);
 983 }
 984
 985 module_init(sir_wq_init);
 986 module_exit(sir_wq_exit);
 987
 988 MODULE_AUTHOR("Martin Diehl <info@mdiehl.de>");
 989 MODULE_DESCRIPTION("IrDA SIR core");
 990 MODULE_LICENSE("GPL");