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                         netdev_err(netdev, "No memory left for USB buffer\n");
 390                         usb_free_urb(urb);
 391                         err = -ENOMEM;
 392                         break;
 393                 }
 394
 395                 usb_fill_bulk_urb(urb, dev->udev,
 396                         usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 397                         buf, dev->adapter->rx_buffer_size,
 398                         peak_usb_read_bulk_callback, dev);
 399
 400                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 401                 urb->transfer_flags |= URB_FREE_BUFFER;
 402                 usb_anchor_urb(urb, &dev->rx_submitted);
 403
 404                 err = usb_submit_urb(urb, GFP_KERNEL);
 405                 if (err) {
 406                         if (err == -ENODEV)
 407                                 netif_device_detach(dev->netdev);
 408
 409                         usb_unanchor_urb(urb);
 410                         kfree(buf);
 411                         usb_free_urb(urb);
 412                         break;
 413                 }
 414
 415                 /* drop reference, USB core will take care of freeing it */
 416                 usb_free_urb(urb);
 417         }
 418
 419         /* did we submit any URBs? Warn if we was not able to submit all urbs */
 420         if (i < PCAN_USB_MAX_RX_URBS) {
 421                 if (i == 0) {
 422                         netdev_err(netdev, "couldn't setup any rx URB\n");
 423                         return err;
 424                 }
 425
 426                 netdev_warn(netdev, "rx performance may be slow\n");
 427         }
 428
 429         /* pre-alloc tx buffers and corresponding urbs */
 430         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 431                 struct peak_tx_urb_context *context;
 432                 struct urb *urb;
 433                 u8 *buf;
 434
 435                 /* create a URB and a buffer for it, to transmit usb messages */
 436                 urb = usb_alloc_urb(0, GFP_KERNEL);
 437                 if (!urb) {
 438                         netdev_err(netdev, "No memory left for URBs\n");
 439                         err = -ENOMEM;
 440                         break;
 441                 }
 442
 443                 buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);
 444                 if (!buf) {
 445                         netdev_err(netdev, "No memory left for USB buffer\n");
 446                         usb_free_urb(urb);
 447                         err = -ENOMEM;
 448                         break;
 449                 }
 450
 451                 context = dev->tx_contexts + i;
 452                 context->dev = dev;
 453                 context->urb = urb;
 454
 455                 usb_fill_bulk_urb(urb, dev->udev,
 456                         usb_sndbulkpipe(dev->udev, dev->ep_msg_out),
 457                         buf, dev->adapter->tx_buffer_size,
 458                         peak_usb_write_bulk_callback, context);
 459
 460                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 461                 urb->transfer_flags |= URB_FREE_BUFFER;
 462         }
 463
 464         /* warn if we were not able to allocate enough tx contexts */
 465         if (i < PCAN_USB_MAX_TX_URBS) {
 466                 if (i == 0) {
 467                         netdev_err(netdev, "couldn't setup any tx URB\n");
 468                         return err;
 469                 }
 470
 471                 netdev_warn(netdev, "tx performance may be slow\n");
 472         }
 473
 474         if (dev->adapter->dev_start) {
 475                 err = dev->adapter->dev_start(dev);
 476                 if (err)
 477                         goto failed;
 478         }
 479
 480         dev->state |= PCAN_USB_STATE_STARTED;
 481
 482         /* can set bus on now */
 483         if (dev->adapter->dev_set_bus) {
 484                 err = dev->adapter->dev_set_bus(dev, 1);
 485                 if (err)
 486                         goto failed;
 487         }
 488
 489         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 490
 491         return 0;
 492
 493 failed:
 494         if (err == -ENODEV)
 495                 netif_device_detach(dev->netdev);
 496
 497         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 498
 499         return err;
 500 }
 501
 502 /*
 503  * called by netdev to open the corresponding CAN interface.
 504  */
 505 static int peak_usb_ndo_open(struct net_device *netdev)
 506 {
 507         struct peak_usb_device *dev = netdev_priv(netdev);
 508         int err;
 509
 510         /* common open */
 511         err = open_candev(netdev);
 512         if (err)
 513                 return err;
 514
 515         /* finally start device */
 516         err = peak_usb_start(dev);
 517         if (err) {
 518                 netdev_err(netdev, "couldn't start device: %d\n", err);
 519                 close_candev(netdev);
 520                 return err;
 521         }
 522
 523         dev->open_time = jiffies;
 524         netif_start_queue(netdev);
 525
 526         return 0;
 527 }
 528
 529 /*
 530  * unlink in-flight Rx and Tx urbs and free their memory.
 531  */
 532 static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)
 533 {
 534         int i;
 535
 536         /* free all Rx (submitted) urbs */
 537         usb_kill_anchored_urbs(&dev->rx_submitted);
 538
 539         /* free unsubmitted Tx urbs first */
 540         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 541                 struct urb *urb = dev->tx_contexts[i].urb;
 542
 543                 if (!urb ||
 544                     dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {
 545                         /*
 546                          * this urb is already released or always submitted,
 547                          * let usb core free by itself
 548                          */
 549                         continue;
 550                 }
 551
 552                 usb_free_urb(urb);
 553                 dev->tx_contexts[i].urb = NULL;
 554         }
 555
 556         /* then free all submitted Tx urbs */
 557         usb_kill_anchored_urbs(&dev->tx_submitted);
 558         atomic_set(&dev->active_tx_urbs, 0);
 559 }
 560
 561 /*
 562  * called by netdev to close the corresponding CAN interface.
 563  */
 564 static int peak_usb_ndo_stop(struct net_device *netdev)
 565 {
 566         struct peak_usb_device *dev = netdev_priv(netdev);
 567
 568         dev->state &= ~PCAN_USB_STATE_STARTED;
 569         netif_stop_queue(netdev);
 570
 571         /* unlink all pending urbs and free used memory */
 572         peak_usb_unlink_all_urbs(dev);
 573
 574         if (dev->adapter->dev_stop)
 575                 dev->adapter->dev_stop(dev);
 576
 577         close_candev(netdev);
 578
 579         dev->open_time = 0;
 580         dev->can.state = CAN_STATE_STOPPED;
 581
 582         /* can set bus off now */
 583         if (dev->adapter->dev_set_bus) {
 584                 int err = dev->adapter->dev_set_bus(dev, 0);
 585                 if (err)
 586                         return err;
 587         }
 588
 589         return 0;
 590 }
 591
 592 /*
 593  * handle end of waiting for the device to reset
 594  */
 595 void peak_usb_restart_complete(struct peak_usb_device *dev)
 596 {
 597         /* finally MUST update can state */
 598         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 599
 600         /* netdev queue can be awaken now */
 601         netif_wake_queue(dev->netdev);
 602 }
 603
 604 void peak_usb_async_complete(struct urb *urb)
 605 {
 606         kfree(urb->transfer_buffer);
 607         usb_free_urb(urb);
 608 }
 609
 610 /*
 611  * device (auto-)restart mechanism runs in a timer context =>
 612  * MUST handle restart with asynchronous usb transfers
 613  */
 614 static int peak_usb_restart(struct peak_usb_device *dev)
 615 {
 616         struct urb *urb;
 617         int err;
 618         u8 *buf;
 619
 620         /*
 621          * if device doesn't define any asynchronous restart handler, simply
 622          * wake the netdev queue up
 623          */
 624         if (!dev->adapter->dev_restart_async) {
 625                 peak_usb_restart_complete(dev);
 626                 return 0;
 627         }
 628
 629         /* first allocate a urb to handle the asynchronous steps */
 630         urb = usb_alloc_urb(0, GFP_ATOMIC);
 631         if (!urb) {
 632                 netdev_err(dev->netdev, "no memory left for urb\n");
 633                 return -ENOMEM;
 634         }
 635
 636         /* also allocate enough space for the commands to send */
 637         buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);
 638         if (!buf) {
 639                 netdev_err(dev->netdev, "no memory left for async cmd\n");
 640                 usb_free_urb(urb);
 641                 return -ENOMEM;
 642         }
 643
 644         /* call the device specific handler for the restart */
 645         err = dev->adapter->dev_restart_async(dev, urb, buf);
 646         if (!err)
 647                 return 0;
 648
 649         kfree(buf);
 650         usb_free_urb(urb);
 651
 652         return err;
 653 }
 654
 655 /*
 656  * candev callback used to change CAN mode.
 657  * Warning: this is called from a timer context!
 658  */
 659 static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 660 {
 661         struct peak_usb_device *dev = netdev_priv(netdev);
 662         int err = 0;
 663
 664         if (!dev->open_time)
 665                 return -EINVAL;
 666
 667         switch (mode) {
 668         case CAN_MODE_START:
 669                 err = peak_usb_restart(dev);
 670                 if (err)
 671                         netdev_err(netdev, "couldn't start device (err %d)\n",
 672                                    err);
 673                 break;
 674
 675         default:
 676                 return -EOPNOTSUPP;
 677         }
 678
 679         return err;
 680 }
 681
 682 /*
 683  * candev callback used to set device bitrate.
 684  */
 685 static int peak_usb_set_bittiming(struct net_device *netdev)
 686 {
 687         struct peak_usb_device *dev = netdev_priv(netdev);
 688         struct can_bittiming *bt = &dev->can.bittiming;
 689
 690         if (dev->adapter->dev_set_bittiming) {
 691                 int err = dev->adapter->dev_set_bittiming(dev, bt);
 692
 693                 if (err)
 694                         netdev_info(netdev, "couldn't set bitrate (err %d)\n",
 695                                 err);
 696                 return err;
 697         }
 698
 699         return 0;
 700 }
 701
 702 static const struct net_device_ops peak_usb_netdev_ops = {
 703         .ndo_open = peak_usb_ndo_open,
 704         .ndo_stop = peak_usb_ndo_stop,
 705         .ndo_start_xmit = peak_usb_ndo_start_xmit,
 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                 dev_err(&intf->dev, "%s: couldn't alloc cmd buffer\n",
 738                         PCAN_USB_DRIVER_NAME);
 739                 err = -ENOMEM;
 740                 goto lbl_set_intf_data;
 741         }
 742
 743         dev->udev = usb_dev;
 744         dev->netdev = netdev;
 745         dev->adapter = peak_usb_adapter;
 746         dev->ctrl_idx = ctrl_idx;
 747         dev->state = PCAN_USB_STATE_CONNECTED;
 748
 749         dev->ep_msg_in = peak_usb_adapter->ep_msg_in;
 750         dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];
 751
 752         dev->can.clock = peak_usb_adapter->clock;
 753         dev->can.bittiming_const = &peak_usb_adapter->bittiming_const;
 754         dev->can.do_set_bittiming = peak_usb_set_bittiming;
 755         dev->can.do_set_mode = peak_usb_set_mode;
 756         dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
 757                                       CAN_CTRLMODE_LISTENONLY;
 758
 759         netdev->netdev_ops = &peak_usb_netdev_ops;
 760
 761         netdev->flags |= IFF_ECHO; /* we support local echo */
 762
 763         init_usb_anchor(&dev->rx_submitted);
 764
 765         init_usb_anchor(&dev->tx_submitted);
 766         atomic_set(&dev->active_tx_urbs, 0);
 767
 768         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 769                 dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;
 770
 771         dev->prev_siblings = usb_get_intfdata(intf);
 772         usb_set_intfdata(intf, dev);
 773
 774         SET_NETDEV_DEV(netdev, &intf->dev);
 775
 776         err = register_candev(netdev);
 777         if (err) {
 778                 dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
 779                 goto lbl_free_cmd_buf;
 780         }
 781
 782         if (dev->prev_siblings)
 783                 (dev->prev_siblings)->next_siblings = dev;
 784
 785         /* keep hw revision into the netdevice */
 786         tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);
 787         dev->device_rev = tmp16 >> 8;
 788
 789         if (dev->adapter->dev_init) {
 790                 err = dev->adapter->dev_init(dev);
 791                 if (err)
 792                         goto lbl_free_cmd_buf;
 793         }
 794
 795         /* set bus off */
 796         if (dev->adapter->dev_set_bus) {
 797                 err = dev->adapter->dev_set_bus(dev, 0);
 798                 if (err)
 799                         goto lbl_free_cmd_buf;
 800         }
 801
 802         /* get device number early */
 803         if (dev->adapter->dev_get_device_id)
 804                 dev->adapter->dev_get_device_id(dev, &dev->device_number);
 805
 806         netdev_info(netdev, "attached to %s channel %u (device %u)\n",
 807                         peak_usb_adapter->name, ctrl_idx, dev->device_number);
 808
 809         return 0;
 810
 811 lbl_free_cmd_buf:
 812         kfree(dev->cmd_buf);
 813
 814 lbl_set_intf_data:
 815         usb_set_intfdata(intf, dev->prev_siblings);
 816         free_candev(netdev);
 817
 818         return err;
 819 }
 820
 821 /*
 822  * called by the usb core when the device is unplugged from the system
 823  */
 824 static void peak_usb_disconnect(struct usb_interface *intf)
 825 {
 826         struct peak_usb_device *dev;
 827
 828         /* unregister as many netdev devices as siblings */
 829         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
 830                 struct net_device *netdev = dev->netdev;
 831                 char name[IFNAMSIZ];
 832
 833                 dev->state &= ~PCAN_USB_STATE_CONNECTED;
 834                 strncpy(name, netdev->name, IFNAMSIZ);
 835
 836                 unregister_netdev(netdev);
 837                 free_candev(netdev);
 838
 839                 kfree(dev->cmd_buf);
 840                 dev->next_siblings = NULL;
 841                 if (dev->adapter->dev_free)
 842                         dev->adapter->dev_free(dev);
 843
 844                 dev_info(&intf->dev, "%s removed\n", name);
 845         }
 846
 847         usb_set_intfdata(intf, NULL);
 848 }
 849
 850 /*
 851  * probe function for new PEAK-System devices
 852  */
 853 static int peak_usb_probe(struct usb_interface *intf,
 854                           const struct usb_device_id *id)
 855 {
 856         struct usb_device *usb_dev = interface_to_usbdev(intf);
 857         struct peak_usb_adapter *peak_usb_adapter, **pp;
 858         int i, err = -ENOMEM;
 859
 860         usb_dev = interface_to_usbdev(intf);
 861
 862         /* get corresponding PCAN-USB adapter */
 863         for (pp = peak_usb_adapters_list; *pp; pp++)
 864                 if ((*pp)->device_id == usb_dev->descriptor.idProduct)
 865                         break;
 866
 867         peak_usb_adapter = *pp;
 868         if (!peak_usb_adapter) {
 869                 /* should never come except device_id bad usage in this file */
 870                 pr_err("%s: didn't find device id. 0x%x in devices list\n",
 871                         PCAN_USB_DRIVER_NAME, usb_dev->descriptor.idProduct);
 872                 return -ENODEV;
 873         }
 874
 875         /* got corresponding adapter: check if it handles current interface */
 876         if (peak_usb_adapter->intf_probe) {
 877                 err = peak_usb_adapter->intf_probe(intf);
 878                 if (err)
 879                         return err;
 880         }
 881
 882         for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
 883                 err = peak_usb_create_dev(peak_usb_adapter, intf, i);
 884                 if (err) {
 885                         /* deregister already created devices */
 886                         peak_usb_disconnect(intf);
 887                         break;
 888                 }
 889         }
 890
 891         return err;
 892 }
 893
 894 /* usb specific object needed to register this driver with the usb subsystem */
 895 static struct usb_driver peak_usb_driver = {
 896         .name = PCAN_USB_DRIVER_NAME,
 897         .disconnect = peak_usb_disconnect,
 898         .probe = peak_usb_probe,
 899         .id_table = peak_usb_table,
 900 };
 901
 902 static int __init peak_usb_init(void)
 903 {
 904         int err;
 905
 906         /* register this driver with the USB subsystem */
 907         err = usb_register(&peak_usb_driver);
 908         if (err)
 909                 pr_err("%s: usb_register failed (err %d)\n",
 910                         PCAN_USB_DRIVER_NAME, err);
 911
 912         return err;
 913 }
 914
 915 static int peak_usb_do_device_exit(struct device *d, void *arg)
 916 {
 917         struct usb_interface *intf = to_usb_interface(d);
 918         struct peak_usb_device *dev;
 919
 920         /* stop as many netdev devices as siblings */
 921         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
 922                 struct net_device *netdev = dev->netdev;
 923
 924                 if (netif_device_present(netdev))
 925                         if (dev->adapter->dev_exit)
 926                                 dev->adapter->dev_exit(dev);
 927         }
 928
 929         return 0;
 930 }
 931
 932 static void __exit peak_usb_exit(void)
 933 {
 934         int err;
 935
 936         /* last chance do send any synchronous commands here */
 937         err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
 938                                      NULL, peak_usb_do_device_exit);
 939         if (err)
 940                 pr_err("%s: failed to stop all can devices (err %d)\n",
 941                         PCAN_USB_DRIVER_NAME, err);
 942
 943         /* deregister this driver with the USB subsystem */
 944         usb_deregister(&peak_usb_driver);
 945
 946         pr_info("%s: PCAN-USB interfaces driver unloaded\n",
 947                 PCAN_USB_DRIVER_NAME);
 948 }
 949
 950 module_init(peak_usb_init);
 951 module_exit(peak_usb_exit);