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