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