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/slab.h>
  17 #include <linux/init.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", __func__);
  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", __func__, jiffies);
 112
 113         do {
 114                 IRDA_DEBUG(3, "%s - state=0x%04x / substate=0x%04x\n",
 115                         __func__, 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", __func__);
 254                         fsm->result = -EINVAL;
 255                         /* fall thru */
 256
 257                 case SIRDEV_STATE_ERROR:
 258                         IRDA_ERROR("%s - error: %d\n", __func__, 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", __func__,
 289                         initial_state, param);
 290
 291         if (down_trylock(&fsm->sem)) {
 292                 if (in_interrupt()  ||  in_atomic()  ||  irqs_disabled()) {
 293                         IRDA_DEBUG(1, "%s(), state machine busy!\n", __func__);
 294                         return -EWOULDBLOCK;
 295                 } else
 296                         down(&fsm->sem);
 297         }
 298
 299         if (fsm->state == SIRDEV_STATE_DEAD) {
 300                 /* race with sirdev_close should never happen */
 301                 IRDA_ERROR("%s(), instance staled!\n", __func__);
 302                 up(&fsm->sem);
 303                 return -ESTALE;         /* or better EPIPE? */
 304         }
 305
 306         netif_stop_queue(dev->netdev);
 307         atomic_set(&dev->enable_rx, 0);
 308
 309         fsm->state = initial_state;
 310         fsm->param = param;
 311         fsm->result = 0;
 312
 313         INIT_DELAYED_WORK(&fsm->work, sirdev_config_fsm);
 314         queue_delayed_work(irda_sir_wq, &fsm->work, 0);
 315         return 0;
 316 }
 317
 318
 319 /***************************************************************************/
 320
 321 void sirdev_enable_rx(struct sir_dev *dev)
 322 {
 323         if (unlikely(atomic_read(&dev->enable_rx)))
 324                 return;
 325
 326         /* flush rx-buffer - should also help in case of problems with echo cancelation */
 327         dev->rx_buff.data = dev->rx_buff.head;
 328         dev->rx_buff.len = 0;
 329         dev->rx_buff.in_frame = FALSE;
 330         dev->rx_buff.state = OUTSIDE_FRAME;
 331         atomic_set(&dev->enable_rx, 1);
 332 }
 333
 334 static int sirdev_is_receiving(struct sir_dev *dev)
 335 {
 336         if (!atomic_read(&dev->enable_rx))
 337                 return 0;
 338
 339         return (dev->rx_buff.state != OUTSIDE_FRAME);
 340 }
 341
 342 int sirdev_set_dongle(struct sir_dev *dev, IRDA_DONGLE type)
 343 {
 344         int err;
 345
 346         IRDA_DEBUG(3, "%s : requesting dongle %d.\n", __func__, type);
 347
 348         err = sirdev_schedule_dongle_open(dev, type);
 349         if (unlikely(err))
 350                 return err;
 351         down(&dev->fsm.sem);            /* block until config change completed */
 352         err = dev->fsm.result;
 353         up(&dev->fsm.sem);
 354         return err;
 355 }
 356 EXPORT_SYMBOL(sirdev_set_dongle);
 357
 358 /* used by dongle drivers for dongle programming */
 359
 360 int sirdev_raw_write(struct sir_dev *dev, const char *buf, int len)
 361 {
 362         unsigned long flags;
 363         int ret;
 364
 365         if (unlikely(len > dev->tx_buff.truesize))
 366                 return -ENOSPC;
 367
 368         spin_lock_irqsave(&dev->tx_lock, flags);        /* serialize with other tx operations */
 369         while (dev->tx_buff.len > 0) {                  /* wait until tx idle */
 370                 spin_unlock_irqrestore(&dev->tx_lock, flags);
 371                 msleep(10);
 372                 spin_lock_irqsave(&dev->tx_lock, flags);
 373         }
 374
 375         dev->tx_buff.data = dev->tx_buff.head;
 376         memcpy(dev->tx_buff.data, buf, len);
 377         dev->tx_buff.len = len;
 378
 379         ret = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
 380         if (ret > 0) {
 381                 IRDA_DEBUG(3, "%s(), raw-tx started\n", __func__);
 382
 383                 dev->tx_buff.data += ret;
 384                 dev->tx_buff.len -= ret;
 385                 dev->raw_tx = 1;
 386                 ret = len;              /* all data is going to be sent */
 387         }
 388         spin_unlock_irqrestore(&dev->tx_lock, flags);
 389         return ret;
 390 }
 391 EXPORT_SYMBOL(sirdev_raw_write);
 392
 393 /* seems some dongle drivers may need this */
 394
 395 int sirdev_raw_read(struct sir_dev *dev, char *buf, int len)
 396 {
 397         int count;
 398
 399         if (atomic_read(&dev->enable_rx))
 400                 return -EIO;            /* fail if we expect irda-frames */
 401
 402         count = (len < dev->rx_buff.len) ? len : dev->rx_buff.len;
 403
 404         if (count > 0) {
 405                 memcpy(buf, dev->rx_buff.data, count);
 406                 dev->rx_buff.data += count;
 407                 dev->rx_buff.len -= count;
 408         }
 409
 410         /* remaining stuff gets flushed when re-enabling normal rx */
 411
 412         return count;
 413 }
 414 EXPORT_SYMBOL(sirdev_raw_read);
 415
 416 int sirdev_set_dtr_rts(struct sir_dev *dev, int dtr, int rts)
 417 {
 418         int ret = -ENXIO;
 419         if (dev->drv->set_dtr_rts)
 420                 ret =  dev->drv->set_dtr_rts(dev, dtr, rts);
 421         return ret;
 422 }
 423 EXPORT_SYMBOL(sirdev_set_dtr_rts);
 424
 425 /**********************************************************************/
 426
 427 /* called from client driver - likely with bh-context - to indicate
 428  * it made some progress with transmission. Hence we send the next
 429  * chunk, if any, or complete the skb otherwise
 430  */
 431
 432 void sirdev_write_complete(struct sir_dev *dev)
 433 {
 434         unsigned long flags;
 435         struct sk_buff *skb;
 436         int actual = 0;
 437         int err;
 438
 439         spin_lock_irqsave(&dev->tx_lock, flags);
 440
 441         IRDA_DEBUG(3, "%s() - dev->tx_buff.len = %d\n",
 442                    __func__, dev->tx_buff.len);
 443
 444         if (likely(dev->tx_buff.len > 0))  {
 445                 /* Write data left in transmit buffer */
 446                 actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
 447
 448                 if (likely(actual>0)) {
 449                         dev->tx_buff.data += actual;
 450                         dev->tx_buff.len  -= actual;
 451                 }
 452                 else if (unlikely(actual<0)) {
 453                         /* could be dropped later when we have tx_timeout to recover */
 454                         IRDA_ERROR("%s: drv->do_write failed (%d)\n",
 455                                    __func__, actual);
 456                         if ((skb=dev->tx_skb) != NULL) {
 457                                 dev->tx_skb = NULL;
 458                                 dev_kfree_skb_any(skb);
 459                                 dev->netdev->stats.tx_errors++;
 460                                 dev->netdev->stats.tx_dropped++;
 461                         }
 462                         dev->tx_buff.len = 0;
 463                 }
 464                 if (dev->tx_buff.len > 0)
 465                         goto done;      /* more data to send later */
 466         }
 467
 468         if (unlikely(dev->raw_tx != 0)) {
 469                 /* in raw mode we are just done now after the buffer was sent
 470                  * completely. Since this was requested by some dongle driver
 471                  * running under the control of the irda-thread we must take
 472                  * care here not to re-enable the queue. The queue will be
 473                  * restarted when the irda-thread has completed the request.
 474                  */
 475
 476                 IRDA_DEBUG(3, "%s(), raw-tx done\n", __func__);
 477                 dev->raw_tx = 0;
 478                 goto done;      /* no post-frame handling in raw mode */
 479         }
 480
 481         /* we have finished now sending this skb.
 482          * update statistics and free the skb.
 483          * finally we check and trigger a pending speed change, if any.
 484          * if not we switch to rx mode and wake the queue for further
 485          * packets.
 486          * note the scheduled speed request blocks until the lower
 487          * client driver and the corresponding hardware has really
 488          * finished sending all data (xmit fifo drained f.e.)
 489          * before the speed change gets finally done and the queue
 490          * re-activated.
 491          */
 492
 493         IRDA_DEBUG(5, "%s(), finished with frame!\n", __func__);
 494
 495         if ((skb=dev->tx_skb) != NULL) {
 496                 dev->tx_skb = NULL;
 497                 dev->netdev->stats.tx_packets++;
 498                 dev->netdev->stats.tx_bytes += skb->len;
 499                 dev_kfree_skb_any(skb);
 500         }
 501
 502         if (unlikely(dev->new_speed > 0)) {
 503                 IRDA_DEBUG(5, "%s(), Changing speed!\n", __func__);
 504                 err = sirdev_schedule_speed(dev, dev->new_speed);
 505                 if (unlikely(err)) {
 506                         /* should never happen
 507                          * forget the speed change and hope the stack recovers
 508                          */
 509                         IRDA_ERROR("%s - schedule speed change failed: %d\n",
 510                                    __func__, err);
 511                         netif_wake_queue(dev->netdev);
 512                 }
 513                 /* else: success
 514                  *      speed change in progress now
 515                  *      on completion dev->new_speed gets cleared,
 516                  *      rx-reenabled and the queue restarted
 517                  */
 518         }
 519         else {
 520                 sirdev_enable_rx(dev);
 521                 netif_wake_queue(dev->netdev);
 522         }
 523
 524 done:
 525         spin_unlock_irqrestore(&dev->tx_lock, flags);
 526 }
 527 EXPORT_SYMBOL(sirdev_write_complete);
 528
 529 /* called from client driver - likely with bh-context - to give us
 530  * some more received bytes. We put them into the rx-buffer,
 531  * normally unwrapping and building LAP-skb's (unless rx disabled)
 532  */
 533
 534 int sirdev_receive(struct sir_dev *dev, const unsigned char *cp, size_t count)
 535 {
 536         if (!dev || !dev->netdev) {
 537                 IRDA_WARNING("%s(), not ready yet!\n", __func__);
 538                 return -1;
 539         }
 540
 541         if (!dev->irlap) {
 542                 IRDA_WARNING("%s - too early: %p / %zd!\n",
 543                              __func__, cp, count);
 544                 return -1;
 545         }
 546
 547         if (cp==NULL) {
 548                 /* error already at lower level receive
 549                  * just update stats and set media busy
 550                  */
 551                 irda_device_set_media_busy(dev->netdev, TRUE);
 552                 dev->netdev->stats.rx_dropped++;
 553                 IRDA_DEBUG(0, "%s; rx-drop: %zd\n", __func__, count);
 554                 return 0;
 555         }
 556
 557         /* Read the characters into the buffer */
 558         if (likely(atomic_read(&dev->enable_rx))) {
 559                 while (count--)
 560                         /* Unwrap and destuff one byte */
 561                         async_unwrap_char(dev->netdev, &dev->netdev->stats,
 562                                           &dev->rx_buff, *cp++);
 563         } else {
 564                 while (count--) {
 565                         /* rx not enabled: save the raw bytes and never
 566                          * trigger any netif_rx. The received bytes are flushed
 567                          * later when we re-enable rx but might be read meanwhile
 568                          * by the dongle driver.
 569                          */
 570                         dev->rx_buff.data[dev->rx_buff.len++] = *cp++;
 571
 572                         /* What should we do when the buffer is full? */
 573                         if (unlikely(dev->rx_buff.len == dev->rx_buff.truesize))
 574                                 dev->rx_buff.len = 0;
 575                 }
 576         }
 577
 578         return 0;
 579 }
 580 EXPORT_SYMBOL(sirdev_receive);
 581
 582 /**********************************************************************/
 583
 584 /* callbacks from network layer */
 585
 586 static netdev_tx_t sirdev_hard_xmit(struct sk_buff *skb,
 587                                           struct net_device *ndev)
 588 {
 589         struct sir_dev *dev = netdev_priv(ndev);
 590         unsigned long flags;
 591         int actual = 0;
 592         int err;
 593         s32 speed;
 594
 595         IRDA_ASSERT(dev != NULL, return NETDEV_TX_OK;);
 596
 597         netif_stop_queue(ndev);
 598
 599         IRDA_DEBUG(3, "%s(), skb->len = %d\n", __func__, skb->len);
 600
 601         speed = irda_get_next_speed(skb);
 602         if ((speed != dev->speed) && (speed != -1)) {
 603                 if (!skb->len) {
 604                         err = sirdev_schedule_speed(dev, speed);
 605                         if (unlikely(err == -EWOULDBLOCK)) {
 606                                 /* Failed to initiate the speed change, likely the fsm
 607                                  * is still busy (pretty unlikely, but...)
 608                                  * We refuse to accept the skb and return with the queue
 609                                  * stopped so the network layer will retry after the
 610                                  * fsm completes and wakes the queue.
 611                                  */
 612                                  return NETDEV_TX_BUSY;
 613                         }
 614                         else if (unlikely(err)) {
 615                                 /* other fatal error - forget the speed change and
 616                                  * hope the stack will recover somehow
 617                                  */
 618                                  netif_start_queue(ndev);
 619                         }
 620                         /* else: success
 621                          *      speed change in progress now
 622                          *      on completion the queue gets restarted
 623                          */
 624
 625                         dev_kfree_skb_any(skb);
 626                         return NETDEV_TX_OK;
 627                 } else
 628                         dev->new_speed = speed;
 629         }
 630
 631         /* Init tx buffer*/
 632         dev->tx_buff.data = dev->tx_buff.head;
 633
 634         /* Check problems */
 635         if(spin_is_locked(&dev->tx_lock)) {
 636                 IRDA_DEBUG(3, "%s(), write not completed\n", __func__);
 637         }
 638
 639         /* serialize with write completion */
 640         spin_lock_irqsave(&dev->tx_lock, flags);
 641
 642         /* Copy skb to tx_buff while wrapping, stuffing and making CRC */
 643         dev->tx_buff.len = async_wrap_skb(skb, dev->tx_buff.data, dev->tx_buff.truesize);
 644
 645         /* transmission will start now - disable receive.
 646          * if we are just in the middle of an incoming frame,
 647          * treat it as collision. probably it's a good idea to
 648          * reset the rx_buf OUTSIDE_FRAME in this case too?
 649          */
 650         atomic_set(&dev->enable_rx, 0);
 651         if (unlikely(sirdev_is_receiving(dev)))
 652                 dev->netdev->stats.collisions++;
 653
 654         actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
 655
 656         if (likely(actual > 0)) {
 657                 dev->tx_skb = skb;
 658                 dev->tx_buff.data += actual;
 659                 dev->tx_buff.len -= actual;
 660         }
 661         else if (unlikely(actual < 0)) {
 662                 /* could be dropped later when we have tx_timeout to recover */
 663                 IRDA_ERROR("%s: drv->do_write failed (%d)\n",
 664                            __func__, actual);
 665                 dev_kfree_skb_any(skb);
 666                 dev->netdev->stats.tx_errors++;
 667                 dev->netdev->stats.tx_dropped++;
 668                 netif_wake_queue(ndev);
 669         }
 670         spin_unlock_irqrestore(&dev->tx_lock, flags);
 671
 672         return NETDEV_TX_OK;
 673 }
 674
 675 /* called from network layer with rtnl hold */
 676
 677 static int sirdev_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
 678 {
 679         struct if_irda_req *irq = (struct if_irda_req *) rq;
 680         struct sir_dev *dev = netdev_priv(ndev);
 681         int ret = 0;
 682
 683         IRDA_ASSERT(dev != NULL, return -1;);
 684
 685         IRDA_DEBUG(3, "%s(), %s, (cmd=0x%X)\n", __func__, ndev->name, cmd);
 686
 687         switch (cmd) {
 688         case SIOCSBANDWIDTH: /* Set bandwidth */
 689                 if (!capable(CAP_NET_ADMIN))
 690                         ret = -EPERM;
 691                 else
 692                         ret = sirdev_schedule_speed(dev, irq->ifr_baudrate);
 693                 /* cannot sleep here for completion
 694                  * we are called from network layer with rtnl hold
 695                  */
 696                 break;
 697
 698         case SIOCSDONGLE: /* Set dongle */
 699                 if (!capable(CAP_NET_ADMIN))
 700                         ret = -EPERM;
 701                 else
 702                         ret = sirdev_schedule_dongle_open(dev, irq->ifr_dongle);
 703                 /* cannot sleep here for completion
 704                  * we are called from network layer with rtnl hold
 705                  */
 706                 break;
 707
 708         case SIOCSMEDIABUSY: /* Set media busy */
 709                 if (!capable(CAP_NET_ADMIN))
 710                         ret = -EPERM;
 711                 else
 712                         irda_device_set_media_busy(dev->netdev, TRUE);
 713                 break;
 714
 715         case SIOCGRECEIVING: /* Check if we are receiving right now */
 716                 irq->ifr_receiving = sirdev_is_receiving(dev);
 717                 break;
 718
 719         case SIOCSDTRRTS:
 720                 if (!capable(CAP_NET_ADMIN))
 721                         ret = -EPERM;
 722                 else
 723                         ret = sirdev_schedule_dtr_rts(dev, irq->ifr_dtr, irq->ifr_rts);
 724                 /* cannot sleep here for completion
 725                  * we are called from network layer with rtnl hold
 726                  */
 727                 break;
 728
 729         case SIOCSMODE:
 730 #if 0
 731                 if (!capable(CAP_NET_ADMIN))
 732                         ret = -EPERM;
 733                 else
 734                         ret = sirdev_schedule_mode(dev, irq->ifr_mode);
 735                 /* cannot sleep here for completion
 736                  * we are called from network layer with rtnl hold
 737                  */
 738                 break;
 739 #endif
 740         default:
 741                 ret = -EOPNOTSUPP;
 742         }
 743
 744         return ret;
 745 }
 746
 747 /* ----------------------------------------------------------------------------- */
 748
 749 #define SIRBUF_ALLOCSIZE 4269   /* worst case size of a wrapped IrLAP frame */
 750
 751 static int sirdev_alloc_buffers(struct sir_dev *dev)
 752 {
 753         dev->tx_buff.truesize = SIRBUF_ALLOCSIZE;
 754         dev->rx_buff.truesize = IRDA_SKB_MAX_MTU;
 755
 756         /* Bootstrap ZeroCopy Rx */
 757         dev->rx_buff.skb = __netdev_alloc_skb(dev->netdev, dev->rx_buff.truesize,
 758                                               GFP_KERNEL);
 759         if (dev->rx_buff.skb == NULL)
 760                 return -ENOMEM;
 761         skb_reserve(dev->rx_buff.skb, 1);
 762         dev->rx_buff.head = dev->rx_buff.skb->data;
 763
 764         dev->tx_buff.head = kmalloc(dev->tx_buff.truesize, GFP_KERNEL);
 765         if (dev->tx_buff.head == NULL) {
 766                 kfree_skb(dev->rx_buff.skb);
 767                 dev->rx_buff.skb = NULL;
 768                 dev->rx_buff.head = NULL;
 769                 return -ENOMEM;
 770         }
 771
 772         dev->tx_buff.data = dev->tx_buff.head;
 773         dev->rx_buff.data = dev->rx_buff.head;
 774         dev->tx_buff.len = 0;
 775         dev->rx_buff.len = 0;
 776
 777         dev->rx_buff.in_frame = FALSE;
 778         dev->rx_buff.state = OUTSIDE_FRAME;
 779         return 0;
 780 };
 781
 782 static void sirdev_free_buffers(struct sir_dev *dev)
 783 {
 784         kfree_skb(dev->rx_buff.skb);
 785         kfree(dev->tx_buff.head);
 786         dev->rx_buff.head = dev->tx_buff.head = NULL;
 787         dev->rx_buff.skb = NULL;
 788 }
 789
 790 static int sirdev_open(struct net_device *ndev)
 791 {
 792         struct sir_dev *dev = netdev_priv(ndev);
 793         const struct sir_driver *drv = dev->drv;
 794
 795         if (!drv)
 796                 return -ENODEV;
 797
 798         /* increase the reference count of the driver module before doing serious stuff */
 799         if (!try_module_get(drv->owner))
 800                 return -ESTALE;
 801
 802         IRDA_DEBUG(2, "%s()\n", __func__);
 803
 804         if (sirdev_alloc_buffers(dev))
 805                 goto errout_dec;
 806
 807         if (!dev->drv->start_dev  ||  dev->drv->start_dev(dev))
 808                 goto errout_free;
 809
 810         sirdev_enable_rx(dev);
 811         dev->raw_tx = 0;
 812
 813         netif_start_queue(ndev);
 814         dev->irlap = irlap_open(ndev, &dev->qos, dev->hwname);
 815         if (!dev->irlap)
 816                 goto errout_stop;
 817
 818         netif_wake_queue(ndev);
 819
 820         IRDA_DEBUG(2, "%s - done, speed = %d\n", __func__, dev->speed);
 821
 822         return 0;
 823
 824 errout_stop:
 825         atomic_set(&dev->enable_rx, 0);
 826         if (dev->drv->stop_dev)
 827                 dev->drv->stop_dev(dev);
 828 errout_free:
 829         sirdev_free_buffers(dev);
 830 errout_dec:
 831         module_put(drv->owner);
 832         return -EAGAIN;
 833 }
 834
 835 static int sirdev_close(struct net_device *ndev)
 836 {
 837         struct sir_dev *dev = netdev_priv(ndev);
 838         const struct sir_driver *drv;
 839
 840 //      IRDA_DEBUG(0, "%s\n", __func__);
 841
 842         netif_stop_queue(ndev);
 843
 844         down(&dev->fsm.sem);            /* block on pending config completion */
 845
 846         atomic_set(&dev->enable_rx, 0);
 847
 848         if (unlikely(!dev->irlap))
 849                 goto out;
 850         irlap_close(dev->irlap);
 851         dev->irlap = NULL;
 852
 853         drv = dev->drv;
 854         if (unlikely(!drv  ||  !dev->priv))
 855                 goto out;
 856
 857         if (drv->stop_dev)
 858                 drv->stop_dev(dev);
 859
 860         sirdev_free_buffers(dev);
 861         module_put(drv->owner);
 862
 863 out:
 864         dev->speed = 0;
 865         up(&dev->fsm.sem);
 866         return 0;
 867 }
 868
 869 static const struct net_device_ops sirdev_ops = {
 870         .ndo_start_xmit = sirdev_hard_xmit,
 871         .ndo_open       = sirdev_open,
 872         .ndo_stop       = sirdev_close,
 873         .ndo_do_ioctl   = sirdev_ioctl,
 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", __func__, 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", __func__);
 897                 goto out;
 898         }
 899         dev = netdev_priv(ndev);
 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         sema_init(&dev->fsm.sem, 1);
 913
 914         dev->drv = drv;
 915         dev->netdev = ndev;
 916
 917         /* Override the network functions we need to use */
 918         ndev->netdev_ops = &sirdev_ops;
 919
 920         if (register_netdev(ndev)) {
 921                 IRDA_ERROR("%s(), register_netdev() failed!\n", __func__);
 922                 goto out_freenetdev;
 923         }
 924
 925         return dev;
 926
 927 out_freenetdev:
 928         free_netdev(ndev);
 929 out:
 930         return NULL;
 931 }
 932 EXPORT_SYMBOL(sirdev_get_instance);
 933
 934 int sirdev_put_instance(struct sir_dev *dev)
 935 {
 936         int err = 0;
 937
 938         IRDA_DEBUG(0, "%s\n", __func__);
 939
 940         atomic_set(&dev->enable_rx, 0);
 941
 942         netif_carrier_off(dev->netdev);
 943         netif_device_detach(dev->netdev);
 944
 945         if (dev->dongle_drv)
 946                 err = sirdev_schedule_dongle_close(dev);
 947         if (err)
 948                 IRDA_ERROR("%s - error %d\n", __func__, err);
 949
 950         sirdev_close(dev->netdev);
 951
 952         down(&dev->fsm.sem);
 953         dev->fsm.state = SIRDEV_STATE_DEAD;     /* mark staled */
 954         dev->dongle_drv = NULL;
 955         dev->priv = NULL;
 956         up(&dev->fsm.sem);
 957
 958         /* Remove netdevice */
 959         unregister_netdev(dev->netdev);
 960
 961         free_netdev(dev->netdev);
 962
 963         return 0;
 964 }
 965 EXPORT_SYMBOL(sirdev_put_instance);
 966
 967 static int __init sir_wq_init(void)
 968 {
 969         irda_sir_wq = create_singlethread_workqueue("irda_sir_wq");
 970         if (!irda_sir_wq)
 971                 return -ENOMEM;
 972         return 0;
 973 }
 974
 975 static void __exit sir_wq_exit(void)
 976 {
 977         destroy_workqueue(irda_sir_wq);
 978 }
 979
 980 module_init(sir_wq_init);
 981 module_exit(sir_wq_exit);
 982
 983 MODULE_AUTHOR("Martin Diehl <info@mdiehl.de>");
 984 MODULE_DESCRIPTION("IrDA SIR core");
 985 MODULE_LICENSE("GPL");