drivers/net/can/usb/peak_usb/pcan_usb_core.c

   1 /*
   2  * CAN driver for PEAK System USB adapters
   3  * Derived from the PCAN project file driver/src/pcan_usb_core.c
   4  *
   5  * Copyright (C) 2003-2010 PEAK System-Technik GmbH
   6  * Copyright (C) 2010-2012 Stephane Grosjean <s.grosjean@peak-system.com>
   7  *
   8  * Many thanks to Klaus Hitschler <klaus.hitschler@gmx.de>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published
  12  * by the Free Software Foundation; version 2 of the License.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  */
  19 #include <linux/init.h>
  20 #include <linux/signal.h>
  21 #include <linux/slab.h>
  22 #include <linux/module.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/usb.h>
  25
  26 #include <linux/can.h>
  27 #include <linux/can/dev.h>
  28 #include <linux/can/error.h>
  29
  30 #include "pcan_usb_core.h"
  31
  32 MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>");
  33 MODULE_DESCRIPTION("CAN driver for PEAK-System USB adapters");
  34 MODULE_LICENSE("GPL v2");
  35
  36 /* Table of devices that work with this driver */
  37 static struct usb_device_id peak_usb_table[] = {
  38         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USB_PRODUCT_ID)},
  39         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBPRO_PRODUCT_ID)},
  40         {} /* Terminating entry */
  41 };
  42
  43 MODULE_DEVICE_TABLE(usb, peak_usb_table);
  44
  45 /* List of supported PCAN-USB adapters (NULL terminated list) */
  46 static struct peak_usb_adapter *peak_usb_adapters_list[] = {
  47         &pcan_usb,
  48         &pcan_usb_pro,
  49         NULL,
  50 };
  51
  52 /*
  53  * dump memory
  54  */
  55 #define DUMP_WIDTH      16
  56 void pcan_dump_mem(char *prompt, void *p, int l)
  57 {
  58         pr_info("%s dumping %s (%d bytes):\n",
  59                 PCAN_USB_DRIVER_NAME, prompt ? prompt : "memory", l);
  60         print_hex_dump(KERN_INFO, PCAN_USB_DRIVER_NAME " ", DUMP_PREFIX_NONE,
  61                        DUMP_WIDTH, 1, p, l, false);
  62 }
  63
  64 /*
  65  * initialize a time_ref object with usb adapter own settings
  66  */
  67 void peak_usb_init_time_ref(struct peak_time_ref *time_ref,
  68                             struct peak_usb_adapter *adapter)
  69 {
  70         if (time_ref) {
  71                 memset(time_ref, 0, sizeof(struct peak_time_ref));
  72                 time_ref->adapter = adapter;
  73         }
  74 }
  75
  76 static void peak_usb_add_us(struct timeval *tv, u32 delta_us)
  77 {
  78         /* number of s. to add to final time */
  79         u32 delta_s = delta_us / 1000000;
  80
  81         delta_us -= delta_s * 1000000;
  82
  83         tv->tv_usec += delta_us;
  84         if (tv->tv_usec >= 1000000) {
  85                 tv->tv_usec -= 1000000;
  86                 delta_s++;
  87         }
  88         tv->tv_sec += delta_s;
  89 }
  90
  91 /*
  92  * sometimes, another now may be  more recent than current one...
  93  */
  94 void peak_usb_update_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
  95 {
  96         time_ref->ts_dev_2 = ts_now;
  97
  98         /* should wait at least two passes before computing */
  99         if (time_ref->tv_host.tv_sec > 0) {
 100                 u32 delta_ts = time_ref->ts_dev_2 - time_ref->ts_dev_1;
 101
 102                 if (time_ref->ts_dev_2 < time_ref->ts_dev_1)
 103                         delta_ts &= (1 << time_ref->adapter->ts_used_bits) - 1;
 104
 105                 time_ref->ts_total += delta_ts;
 106         }
 107 }
 108
 109 /*
 110  * register device timestamp as now
 111  */
 112 void peak_usb_set_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
 113 {
 114         if (time_ref->tv_host_0.tv_sec == 0) {
 115                 /* use monotonic clock to correctly compute further deltas */
 116                 time_ref->tv_host_0 = ktime_to_timeval(ktime_get());
 117                 time_ref->tv_host.tv_sec = 0;
 118         } else {
 119                 /*
 120                  * delta_us should not be >= 2^32 => delta_s should be < 4294
 121                  * handle 32-bits wrapping here: if count of s. reaches 4200,
 122                  * reset counters and change time base
 123                  */
 124                 if (time_ref->tv_host.tv_sec != 0) {
 125                         u32 delta_s = time_ref->tv_host.tv_sec
 126                                                 - time_ref->tv_host_0.tv_sec;
 127                         if (delta_s > 4200) {
 128                                 time_ref->tv_host_0 = time_ref->tv_host;
 129                                 time_ref->ts_total = 0;
 130                         }
 131                 }
 132
 133                 time_ref->tv_host = ktime_to_timeval(ktime_get());
 134                 time_ref->tick_count++;
 135         }
 136
 137         time_ref->ts_dev_1 = time_ref->ts_dev_2;
 138         peak_usb_update_ts_now(time_ref, ts_now);
 139 }
 140
 141 /*
 142  * compute timeval according to current ts and time_ref data
 143  */
 144 void peak_usb_get_ts_tv(struct peak_time_ref *time_ref, u32 ts,
 145                         struct timeval *tv)
 146 {
 147         /* protect from getting timeval before setting now */
 148         if (time_ref->tv_host.tv_sec > 0) {
 149                 u64 delta_us;
 150
 151                 delta_us = ts - time_ref->ts_dev_2;
 152                 if (ts < time_ref->ts_dev_2)
 153                         delta_us &= (1 << time_ref->adapter->ts_used_bits) - 1;
 154
 155                 delta_us += time_ref->ts_total;
 156
 157                 delta_us *= time_ref->adapter->us_per_ts_scale;
 158                 delta_us >>= time_ref->adapter->us_per_ts_shift;
 159
 160                 *tv = time_ref->tv_host_0;
 161                 peak_usb_add_us(tv, (u32)delta_us);
 162         } else {
 163                 *tv = ktime_to_timeval(ktime_get());
 164         }
 165 }
 166
 167 /*
 168  * callback for bulk Rx urb
 169  */
 170 static void peak_usb_read_bulk_callback(struct urb *urb)
 171 {
 172         struct peak_usb_device *dev = urb->context;
 173         struct net_device *netdev;
 174         int err;
 175
 176         netdev = dev->netdev;
 177
 178         if (!netif_device_present(netdev))
 179                 return;
 180
 181         /* check reception status */
 182         switch (urb->status) {
 183         case 0:
 184                 /* success */
 185                 break;
 186
 187         case -EILSEQ:
 188         case -ENOENT:
 189         case -ECONNRESET:
 190         case -ESHUTDOWN:
 191                 return;
 192
 193         default:
 194                 if (net_ratelimit())
 195                         netdev_err(netdev,
 196                                    "Rx urb aborted (%d)\n", urb->status);
 197                 goto resubmit_urb;
 198         }
 199
 200         /* protect from any incoming empty msgs */
 201         if ((urb->actual_length > 0) && (dev->adapter->dev_decode_buf)) {
 202                 /* handle these kinds of msgs only if _start callback called */
 203                 if (dev->state & PCAN_USB_STATE_STARTED) {
 204                         err = dev->adapter->dev_decode_buf(dev, urb);
 205                         if (err)
 206                                 pcan_dump_mem("received usb message",
 207                                               urb->transfer_buffer,
 208                                               urb->transfer_buffer_length);
 209                 }
 210         }
 211
 212 resubmit_urb:
 213         usb_fill_bulk_urb(urb, dev->udev,
 214                 usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 215                 urb->transfer_buffer, dev->adapter->rx_buffer_size,
 216                 peak_usb_read_bulk_callback, dev);
 217
 218         usb_anchor_urb(urb, &dev->rx_submitted);
 219         err = usb_submit_urb(urb, GFP_ATOMIC);
 220         if (!err)
 221                 return;
 222
 223         usb_unanchor_urb(urb);
 224
 225         if (err == -ENODEV)
 226                 netif_device_detach(netdev);
 227         else
 228                 netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
 229                            err);
 230 }
 231
 232 /*
 233  * callback for bulk Tx urb
 234  */
 235 static void peak_usb_write_bulk_callback(struct urb *urb)
 236 {
 237         struct peak_tx_urb_context *context = urb->context;
 238         struct peak_usb_device *dev;
 239         struct net_device *netdev;
 240
 241         BUG_ON(!context);
 242
 243         dev = context->dev;
 244         netdev = dev->netdev;
 245
 246         atomic_dec(&dev->active_tx_urbs);
 247
 248         if (!netif_device_present(netdev))
 249                 return;
 250
 251         /* check tx status */
 252         switch (urb->status) {
 253         case 0:
 254                 /* transmission complete */
 255                 netdev->stats.tx_packets++;
 256                 netdev->stats.tx_bytes += context->dlc;
 257
 258                 /* prevent tx timeout */
 259                 netdev->trans_start = jiffies;
 260                 break;
 261
 262         default:
 263                 if (net_ratelimit())
 264                         netdev_err(netdev, "Tx urb aborted (%d)\n",
 265                                    urb->status);
 266         case -EPROTO:
 267         case -ENOENT:
 268         case -ECONNRESET:
 269         case -ESHUTDOWN:
 270
 271                 break;
 272         }
 273
 274         /* should always release echo skb and corresponding context */
 275         can_get_echo_skb(netdev, context->echo_index);
 276         context->echo_index = PCAN_USB_MAX_TX_URBS;
 277
 278         /* do wakeup tx queue in case of success only */
 279         if (!urb->status)
 280                 netif_wake_queue(netdev);
 281 }
 282
 283 /*
 284  * called by netdev to send one skb on the CAN interface.
 285  */
 286 static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
 287                                            struct net_device *netdev)
 288 {
 289         struct peak_usb_device *dev = netdev_priv(netdev);
 290         struct peak_tx_urb_context *context = NULL;
 291         struct net_device_stats *stats = &netdev->stats;
 292         struct can_frame *cf = (struct can_frame *)skb->data;
 293         struct urb *urb;
 294         u8 *obuf;
 295         int i, err;
 296         size_t size = dev->adapter->tx_buffer_size;
 297
 298         if (can_dropped_invalid_skb(netdev, skb))
 299                 return NETDEV_TX_OK;
 300
 301         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 302                 if (dev->tx_contexts[i].echo_index == PCAN_USB_MAX_TX_URBS) {
 303                         context = dev->tx_contexts + i;
 304                         break;
 305                 }
 306
 307         if (!context) {
 308                 /* should not occur except during restart */
 309                 return NETDEV_TX_BUSY;
 310         }
 311
 312         urb = context->urb;
 313         obuf = urb->transfer_buffer;
 314
 315         err = dev->adapter->dev_encode_msg(dev, skb, obuf, &size);
 316         if (err) {
 317                 if (net_ratelimit())
 318                         netdev_err(netdev, "packet dropped\n");
 319                 dev_kfree_skb(skb);
 320                 stats->tx_dropped++;
 321                 return NETDEV_TX_OK;
 322         }
 323
 324         context->echo_index = i;
 325         context->dlc = cf->can_dlc;
 326
 327         usb_anchor_urb(urb, &dev->tx_submitted);
 328
 329         can_put_echo_skb(skb, netdev, context->echo_index);
 330
 331         atomic_inc(&dev->active_tx_urbs);
 332
 333         err = usb_submit_urb(urb, GFP_ATOMIC);
 334         if (err) {
 335                 can_free_echo_skb(netdev, context->echo_index);
 336
 337                 usb_unanchor_urb(urb);
 338
 339                 /* this context is not used in fact */
 340                 context->echo_index = PCAN_USB_MAX_TX_URBS;
 341
 342                 atomic_dec(&dev->active_tx_urbs);
 343
 344                 switch (err) {
 345                 case -ENODEV:
 346                         netif_device_detach(netdev);
 347                         break;
 348                 default:
 349                         netdev_warn(netdev, "tx urb submitting failed err=%d\n",
 350                                     err);
 351                 case -ENOENT:
 352                         /* cable unplugged */
 353                         stats->tx_dropped++;
 354                 }
 355         } else {
 356                 netdev->trans_start = jiffies;
 357
 358                 /* slow down tx path */
 359                 if (atomic_read(&dev->active_tx_urbs) >= PCAN_USB_MAX_TX_URBS)
 360                         netif_stop_queue(netdev);
 361         }
 362
 363         return NETDEV_TX_OK;
 364 }
 365
 366 /*
 367  * start the CAN interface.
 368  * Rx and Tx urbs are allocated here. Rx urbs are submitted here.
 369  */
 370 static int peak_usb_start(struct peak_usb_device *dev)
 371 {
 372         struct net_device *netdev = dev->netdev;
 373         int err, i;
 374
 375         for (i = 0; i < PCAN_USB_MAX_RX_URBS; i++) {
 376                 struct urb *urb;
 377                 u8 *buf;
 378
 379                 /* create a URB, and a buffer for it, to receive usb messages */
 380                 urb = usb_alloc_urb(0, GFP_KERNEL);
 381                 if (!urb) {
 382                         netdev_err(netdev, "No memory left for URBs\n");
 383                         err = -ENOMEM;
 384                         break;
 385                 }
 386
 387                 buf = kmalloc(dev->adapter->rx_buffer_size, GFP_KERNEL);
 388                 if (!buf) {
 389                         usb_free_urb(urb);
 390                         err = -ENOMEM;
 391                         break;
 392                 }
 393
 394                 usb_fill_bulk_urb(urb, dev->udev,
 395                         usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 396                         buf, dev->adapter->rx_buffer_size,
 397                         peak_usb_read_bulk_callback, dev);
 398
 399                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 400                 urb->transfer_flags |= URB_FREE_BUFFER;
 401                 usb_anchor_urb(urb, &dev->rx_submitted);
 402
 403                 err = usb_submit_urb(urb, GFP_KERNEL);
 404                 if (err) {
 405                         if (err == -ENODEV)
 406                                 netif_device_detach(dev->netdev);
 407
 408                         usb_unanchor_urb(urb);
 409                         kfree(buf);
 410                         usb_free_urb(urb);
 411                         break;
 412                 }
 413
 414                 /* drop reference, USB core will take care of freeing it */
 415                 usb_free_urb(urb);
 416         }
 417
 418         /* did we submit any URBs? Warn if we was not able to submit all urbs */
 419         if (i < PCAN_USB_MAX_RX_URBS) {
 420                 if (i == 0) {
 421                         netdev_err(netdev, "couldn't setup any rx URB\n");
 422                         return err;
 423                 }
 424
 425                 netdev_warn(netdev, "rx performance may be slow\n");
 426         }
 427
 428         /* pre-alloc tx buffers and corresponding urbs */
 429         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 430                 struct peak_tx_urb_context *context;
 431                 struct urb *urb;
 432                 u8 *buf;
 433
 434                 /* create a URB and a buffer for it, to transmit usb messages */
 435                 urb = usb_alloc_urb(0, GFP_KERNEL);
 436                 if (!urb) {
 437                         netdev_err(netdev, "No memory left for URBs\n");
 438                         err = -ENOMEM;
 439                         break;
 440                 }
 441
 442                 buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);
 443                 if (!buf) {
 444                         usb_free_urb(urb);
 445                         err = -ENOMEM;
 446                         break;
 447                 }
 448
 449                 context = dev->tx_contexts + i;
 450                 context->dev = dev;
 451                 context->urb = urb;
 452
 453                 usb_fill_bulk_urb(urb, dev->udev,
 454                         usb_sndbulkpipe(dev->udev, dev->ep_msg_out),
 455                         buf, dev->adapter->tx_buffer_size,
 456                         peak_usb_write_bulk_callback, context);
 457
 458                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 459                 urb->transfer_flags |= URB_FREE_BUFFER;
 460         }
 461
 462         /* warn if we were not able to allocate enough tx contexts */
 463         if (i < PCAN_USB_MAX_TX_URBS) {
 464                 if (i == 0) {
 465                         netdev_err(netdev, "couldn't setup any tx URB\n");
 466                         goto err_tx;
 467                 }
 468
 469                 netdev_warn(netdev, "tx performance may be slow\n");
 470         }
 471
 472         if (dev->adapter->dev_start) {
 473                 err = dev->adapter->dev_start(dev);
 474                 if (err)
 475                         goto err_adapter;
 476         }
 477
 478         dev->state |= PCAN_USB_STATE_STARTED;
 479
 480         /* can set bus on now */
 481         if (dev->adapter->dev_set_bus) {
 482                 err = dev->adapter->dev_set_bus(dev, 1);
 483                 if (err)
 484                         goto err_adapter;
 485         }
 486
 487         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 488
 489         return 0;
 490
 491 err_adapter:
 492         if (err == -ENODEV)
 493                 netif_device_detach(dev->netdev);
 494
 495         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 496
 497         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 498                 usb_free_urb(dev->tx_contexts[i].urb);
 499                 dev->tx_contexts[i].urb = NULL;
 500         }
 501 err_tx:
 502         usb_kill_anchored_urbs(&dev->rx_submitted);
 503
 504         return err;
 505 }
 506
 507 /*
 508  * called by netdev to open the corresponding CAN interface.
 509  */
 510 static int peak_usb_ndo_open(struct net_device *netdev)
 511 {
 512         struct peak_usb_device *dev = netdev_priv(netdev);
 513         int err;
 514
 515         /* common open */
 516         err = open_candev(netdev);
 517         if (err)
 518                 return err;
 519
 520         /* finally start device */
 521         err = peak_usb_start(dev);
 522         if (err) {
 523                 netdev_err(netdev, "couldn't start device: %d\n", err);
 524                 close_candev(netdev);
 525                 return err;
 526         }
 527
 528         netif_start_queue(netdev);
 529
 530         return 0;
 531 }
 532
 533 /*
 534  * unlink in-flight Rx and Tx urbs and free their memory.
 535  */
 536 static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)
 537 {
 538         int i;
 539
 540         /* free all Rx (submitted) urbs */
 541         usb_kill_anchored_urbs(&dev->rx_submitted);
 542
 543         /* free unsubmitted Tx urbs first */
 544         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 545                 struct urb *urb = dev->tx_contexts[i].urb;
 546
 547                 if (!urb ||
 548                     dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {
 549                         /*
 550                          * this urb is already released or always submitted,
 551                          * let usb core free by itself
 552                          */
 553                         continue;
 554                 }
 555
 556                 usb_free_urb(urb);
 557                 dev->tx_contexts[i].urb = NULL;
 558         }
 559
 560         /* then free all submitted Tx urbs */
 561         usb_kill_anchored_urbs(&dev->tx_submitted);
 562         atomic_set(&dev->active_tx_urbs, 0);
 563 }
 564
 565 /*
 566  * called by netdev to close the corresponding CAN interface.
 567  */
 568 static int peak_usb_ndo_stop(struct net_device *netdev)
 569 {
 570         struct peak_usb_device *dev = netdev_priv(netdev);
 571
 572         dev->state &= ~PCAN_USB_STATE_STARTED;
 573         netif_stop_queue(netdev);
 574
 575         /* unlink all pending urbs and free used memory */
 576         peak_usb_unlink_all_urbs(dev);
 577
 578         if (dev->adapter->dev_stop)
 579                 dev->adapter->dev_stop(dev);
 580
 581         close_candev(netdev);
 582
 583         dev->can.state = CAN_STATE_STOPPED;
 584
 585         /* can set bus off now */
 586         if (dev->adapter->dev_set_bus) {
 587                 int err = dev->adapter->dev_set_bus(dev, 0);
 588                 if (err)
 589                         return err;
 590         }
 591
 592         return 0;
 593 }
 594
 595 /*
 596  * handle end of waiting for the device to reset
 597  */
 598 void peak_usb_restart_complete(struct peak_usb_device *dev)
 599 {
 600         /* finally MUST update can state */
 601         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 602
 603         /* netdev queue can be awaken now */
 604         netif_wake_queue(dev->netdev);
 605 }
 606
 607 void peak_usb_async_complete(struct urb *urb)
 608 {
 609         kfree(urb->transfer_buffer);
 610         usb_free_urb(urb);
 611 }
 612
 613 /*
 614  * device (auto-)restart mechanism runs in a timer context =>
 615  * MUST handle restart with asynchronous usb transfers
 616  */
 617 static int peak_usb_restart(struct peak_usb_device *dev)
 618 {
 619         struct urb *urb;
 620         int err;
 621         u8 *buf;
 622
 623         /*
 624          * if device doesn't define any asynchronous restart handler, simply
 625          * wake the netdev queue up
 626          */
 627         if (!dev->adapter->dev_restart_async) {
 628                 peak_usb_restart_complete(dev);
 629                 return 0;
 630         }
 631
 632         /* first allocate a urb to handle the asynchronous steps */
 633         urb = usb_alloc_urb(0, GFP_ATOMIC);
 634         if (!urb) {
 635                 netdev_err(dev->netdev, "no memory left for urb\n");
 636                 return -ENOMEM;
 637         }
 638
 639         /* also allocate enough space for the commands to send */
 640         buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);
 641         if (!buf) {
 642                 usb_free_urb(urb);
 643                 return -ENOMEM;
 644         }
 645
 646         /* call the device specific handler for the restart */
 647         err = dev->adapter->dev_restart_async(dev, urb, buf);
 648         if (!err)
 649                 return 0;
 650
 651         kfree(buf);
 652         usb_free_urb(urb);
 653
 654         return err;
 655 }
 656
 657 /*
 658  * candev callback used to change CAN mode.
 659  * Warning: this is called from a timer context!
 660  */
 661 static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 662 {
 663         struct peak_usb_device *dev = netdev_priv(netdev);
 664         int err = 0;
 665
 666         switch (mode) {
 667         case CAN_MODE_START:
 668                 err = peak_usb_restart(dev);
 669                 if (err)
 670                         netdev_err(netdev, "couldn't start device (err %d)\n",
 671                                    err);
 672                 break;
 673
 674         default:
 675                 return -EOPNOTSUPP;
 676         }
 677
 678         return err;
 679 }
 680
 681 /*
 682  * candev callback used to set device bitrate.
 683  */
 684 static int peak_usb_set_bittiming(struct net_device *netdev)
 685 {
 686         struct peak_usb_device *dev = netdev_priv(netdev);
 687         struct can_bittiming *bt = &dev->can.bittiming;
 688
 689         if (dev->adapter->dev_set_bittiming) {
 690                 int err = dev->adapter->dev_set_bittiming(dev, bt);
 691
 692                 if (err)
 693                         netdev_info(netdev, "couldn't set bitrate (err %d)\n",
 694                                 err);
 695                 return err;
 696         }
 697
 698         return 0;
 699 }
 700
 701 static const struct net_device_ops peak_usb_netdev_ops = {
 702         .ndo_open = peak_usb_ndo_open,
 703         .ndo_stop = peak_usb_ndo_stop,
 704         .ndo_start_xmit = peak_usb_ndo_start_xmit,
 705         .ndo_change_mtu = can_change_mtu,
 706 };
 707
 708 /*
 709  * create one device which is attached to CAN controller #ctrl_idx of the
 710  * usb adapter.
 711  */
 712 static int peak_usb_create_dev(struct peak_usb_adapter *peak_usb_adapter,
 713                                struct usb_interface *intf, int ctrl_idx)
 714 {
 715         struct usb_device *usb_dev = interface_to_usbdev(intf);
 716         int sizeof_candev = peak_usb_adapter->sizeof_dev_private;
 717         struct peak_usb_device *dev;
 718         struct net_device *netdev;
 719         int i, err;
 720         u16 tmp16;
 721
 722         if (sizeof_candev < sizeof(struct peak_usb_device))
 723                 sizeof_candev = sizeof(struct peak_usb_device);
 724
 725         netdev = alloc_candev(sizeof_candev, PCAN_USB_MAX_TX_URBS);
 726         if (!netdev) {
 727                 dev_err(&intf->dev, "%s: couldn't alloc candev\n",
 728                         PCAN_USB_DRIVER_NAME);
 729                 return -ENOMEM;
 730         }
 731
 732         dev = netdev_priv(netdev);
 733
 734         /* allocate a buffer large enough to send commands */
 735         dev->cmd_buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
 736         if (!dev->cmd_buf) {
 737                 err = -ENOMEM;
 738                 goto lbl_set_intf_data;
 739         }
 740
 741         dev->udev = usb_dev;
 742         dev->netdev = netdev;
 743         dev->adapter = peak_usb_adapter;
 744         dev->ctrl_idx = ctrl_idx;
 745         dev->state = PCAN_USB_STATE_CONNECTED;
 746
 747         dev->ep_msg_in = peak_usb_adapter->ep_msg_in;
 748         dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];
 749
 750         dev->can.clock = peak_usb_adapter->clock;
 751         dev->can.bittiming_const = &peak_usb_adapter->bittiming_const;
 752         dev->can.do_set_bittiming = peak_usb_set_bittiming;
 753         dev->can.do_set_mode = peak_usb_set_mode;
 754         dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
 755                                       CAN_CTRLMODE_LISTENONLY;
 756
 757         netdev->netdev_ops = &peak_usb_netdev_ops;
 758
 759         netdev->flags |= IFF_ECHO; /* we support local echo */
 760
 761         init_usb_anchor(&dev->rx_submitted);
 762
 763         init_usb_anchor(&dev->tx_submitted);
 764         atomic_set(&dev->active_tx_urbs, 0);
 765
 766         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 767                 dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;
 768
 769         dev->prev_siblings = usb_get_intfdata(intf);
 770         usb_set_intfdata(intf, dev);
 771
 772         SET_NETDEV_DEV(netdev, &intf->dev);
 773
 774         err = register_candev(netdev);
 775         if (err) {
 776                 dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
 777                 goto lbl_free_cmd_buf;
 778         }
 779
 780         if (dev->prev_siblings)
 781                 (dev->prev_siblings)->next_siblings = dev;
 782
 783         /* keep hw revision into the netdevice */
 784         tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);
 785         dev->device_rev = tmp16 >> 8;
 786
 787         if (dev->adapter->dev_init) {
 788                 err = dev->adapter->dev_init(dev);
 789                 if (err)
 790                         goto lbl_free_cmd_buf;
 791         }
 792
 793         /* set bus off */
 794         if (dev->adapter->dev_set_bus) {
 795                 err = dev->adapter->dev_set_bus(dev, 0);
 796                 if (err)
 797                         goto lbl_free_cmd_buf;
 798         }
 799
 800         /* get device number early */
 801         if (dev->adapter->dev_get_device_id)
 802                 dev->adapter->dev_get_device_id(dev, &dev->device_number);
 803
 804         netdev_info(netdev, "attached to %s channel %u (device %u)\n",
 805                         peak_usb_adapter->name, ctrl_idx, dev->device_number);
 806
 807         return 0;
 808
 809 lbl_free_cmd_buf:
 810         kfree(dev->cmd_buf);
 811
 812 lbl_set_intf_data:
 813         usb_set_intfdata(intf, dev->prev_siblings);
 814         free_candev(netdev);
 815
 816         return err;
 817 }
 818
 819 /*
 820  * called by the usb core when the device is unplugged from the system
 821  */
 822 static void peak_usb_disconnect(struct usb_interface *intf)
 823 {
 824         struct peak_usb_device *dev;
 825
 826         /* unregister as many netdev devices as siblings */
 827         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
 828                 struct net_device *netdev = dev->netdev;
 829                 char name[IFNAMSIZ];
 830
 831                 dev->state &= ~PCAN_USB_STATE_CONNECTED;
 832                 strncpy(name, netdev->name, IFNAMSIZ);
 833
 834                 unregister_netdev(netdev);
 835                 free_candev(netdev);
 836
 837                 kfree(dev->cmd_buf);
 838                 dev->next_siblings = NULL;
 839                 if (dev->adapter->dev_free)
 840                         dev->adapter->dev_free(dev);
 841
 842                 dev_info(&intf->dev, "%s removed\n", name);
 843         }
 844
 845         usb_set_intfdata(intf, NULL);
 846 }
 847
 848 /*
 849  * probe function for new PEAK-System devices
 850  */
 851 static int peak_usb_probe(struct usb_interface *intf,
 852                           const struct usb_device_id *id)
 853 {
 854         struct usb_device *usb_dev = interface_to_usbdev(intf);
 855         struct peak_usb_adapter *peak_usb_adapter, **pp;
 856         int i, err = -ENOMEM;
 857
 858         usb_dev = interface_to_usbdev(intf);
 859
 860         /* get corresponding PCAN-USB adapter */
 861         for (pp = peak_usb_adapters_list; *pp; pp++)
 862                 if ((*pp)->device_id == usb_dev->descriptor.idProduct)
 863                         break;
 864
 865         peak_usb_adapter = *pp;
 866         if (!peak_usb_adapter) {
 867                 /* should never come except device_id bad usage in this file */
 868                 pr_err("%s: didn't find device id. 0x%x in devices list\n",
 869                         PCAN_USB_DRIVER_NAME, usb_dev->descriptor.idProduct);
 870                 return -ENODEV;
 871         }
 872
 873         /* got corresponding adapter: check if it handles current interface */
 874         if (peak_usb_adapter->intf_probe) {
 875                 err = peak_usb_adapter->intf_probe(intf);
 876                 if (err)
 877                         return err;
 878         }
 879
 880         for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
 881                 err = peak_usb_create_dev(peak_usb_adapter, intf, i);
 882                 if (err) {
 883                         /* deregister already created devices */
 884                         peak_usb_disconnect(intf);
 885                         break;
 886                 }
 887         }
 888
 889         return err;
 890 }
 891
 892 /* usb specific object needed to register this driver with the usb subsystem */
 893 static struct usb_driver peak_usb_driver = {
 894         .name = PCAN_USB_DRIVER_NAME,
 895         .disconnect = peak_usb_disconnect,
 896         .probe = peak_usb_probe,
 897         .id_table = peak_usb_table,
 898 };
 899
 900 static int __init peak_usb_init(void)
 901 {
 902         int err;
 903
 904         /* register this driver with the USB subsystem */
 905         err = usb_register(&peak_usb_driver);
 906         if (err)
 907                 pr_err("%s: usb_register failed (err %d)\n",
 908                         PCAN_USB_DRIVER_NAME, err);
 909
 910         return err;
 911 }
 912
 913 static int peak_usb_do_device_exit(struct device *d, void *arg)
 914 {
 915         struct usb_interface *intf = to_usb_interface(d);
 916         struct peak_usb_device *dev;
 917
 918         /* stop as many netdev devices as siblings */
 919         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
 920                 struct net_device *netdev = dev->netdev;
 921
 922                 if (netif_device_present(netdev))
 923                         if (dev->adapter->dev_exit)
 924                                 dev->adapter->dev_exit(dev);
 925         }
 926
 927         return 0;
 928 }
 929
 930 static void __exit peak_usb_exit(void)
 931 {
 932         int err;
 933
 934         /* last chance do send any synchronous commands here */
 935         err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
 936                                      NULL, peak_usb_do_device_exit);
 937         if (err)
 938                 pr_err("%s: failed to stop all can devices (err %d)\n",
 939                         PCAN_USB_DRIVER_NAME, err);
 940
 941         /* deregister this driver with the USB subsystem */
 942         usb_deregister(&peak_usb_driver);
 943
 944         pr_info("%s: PCAN-USB interfaces driver unloaded\n",
 945                 PCAN_USB_DRIVER_NAME);
 946 }
 947
 948 module_init(peak_usb_init);
 949 module_exit(peak_usb_exit);