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                         return err;
 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 failed;
 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 failed;
 485         }
 486
 487         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 488
 489         return 0;
 490
 491 failed:
 492         if (err == -ENODEV)
 493                 netif_device_detach(dev->netdev);
 494
 495         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 496
 497         return err;
 498 }
 499
 500 /*
 501  * called by netdev to open the corresponding CAN interface.
 502  */
 503 static int peak_usb_ndo_open(struct net_device *netdev)
 504 {
 505         struct peak_usb_device *dev = netdev_priv(netdev);
 506         int err;
 507
 508         /* common open */
 509         err = open_candev(netdev);
 510         if (err)
 511                 return err;
 512
 513         /* finally start device */
 514         err = peak_usb_start(dev);
 515         if (err) {
 516                 netdev_err(netdev, "couldn't start device: %d\n", err);
 517                 close_candev(netdev);
 518                 return err;
 519         }
 520
 521         netif_start_queue(netdev);
 522
 523         return 0;
 524 }
 525
 526 /*
 527  * unlink in-flight Rx and Tx urbs and free their memory.
 528  */
 529 static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)
 530 {
 531         int i;
 532
 533         /* free all Rx (submitted) urbs */
 534         usb_kill_anchored_urbs(&dev->rx_submitted);
 535
 536         /* free unsubmitted Tx urbs first */
 537         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 538                 struct urb *urb = dev->tx_contexts[i].urb;
 539
 540                 if (!urb ||
 541                     dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {
 542                         /*
 543                          * this urb is already released or always submitted,
 544                          * let usb core free by itself
 545                          */
 546                         continue;
 547                 }
 548
 549                 usb_free_urb(urb);
 550                 dev->tx_contexts[i].urb = NULL;
 551         }
 552
 553         /* then free all submitted Tx urbs */
 554         usb_kill_anchored_urbs(&dev->tx_submitted);
 555         atomic_set(&dev->active_tx_urbs, 0);
 556 }
 557
 558 /*
 559  * called by netdev to close the corresponding CAN interface.
 560  */
 561 static int peak_usb_ndo_stop(struct net_device *netdev)
 562 {
 563         struct peak_usb_device *dev = netdev_priv(netdev);
 564
 565         dev->state &= ~PCAN_USB_STATE_STARTED;
 566         netif_stop_queue(netdev);
 567
 568         /* unlink all pending urbs and free used memory */
 569         peak_usb_unlink_all_urbs(dev);
 570
 571         if (dev->adapter->dev_stop)
 572                 dev->adapter->dev_stop(dev);
 573
 574         close_candev(netdev);
 575
 576         dev->can.state = CAN_STATE_STOPPED;
 577
 578         /* can set bus off now */
 579         if (dev->adapter->dev_set_bus) {
 580                 int err = dev->adapter->dev_set_bus(dev, 0);
 581                 if (err)
 582                         return err;
 583         }
 584
 585         return 0;
 586 }
 587
 588 /*
 589  * handle end of waiting for the device to reset
 590  */
 591 void peak_usb_restart_complete(struct peak_usb_device *dev)
 592 {
 593         /* finally MUST update can state */
 594         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 595
 596         /* netdev queue can be awaken now */
 597         netif_wake_queue(dev->netdev);
 598 }
 599
 600 void peak_usb_async_complete(struct urb *urb)
 601 {
 602         kfree(urb->transfer_buffer);
 603         usb_free_urb(urb);
 604 }
 605
 606 /*
 607  * device (auto-)restart mechanism runs in a timer context =>
 608  * MUST handle restart with asynchronous usb transfers
 609  */
 610 static int peak_usb_restart(struct peak_usb_device *dev)
 611 {
 612         struct urb *urb;
 613         int err;
 614         u8 *buf;
 615
 616         /*
 617          * if device doesn't define any asynchronous restart handler, simply
 618          * wake the netdev queue up
 619          */
 620         if (!dev->adapter->dev_restart_async) {
 621                 peak_usb_restart_complete(dev);
 622                 return 0;
 623         }
 624
 625         /* first allocate a urb to handle the asynchronous steps */
 626         urb = usb_alloc_urb(0, GFP_ATOMIC);
 627         if (!urb) {
 628                 netdev_err(dev->netdev, "no memory left for urb\n");
 629                 return -ENOMEM;
 630         }
 631
 632         /* also allocate enough space for the commands to send */
 633         buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);
 634         if (!buf) {
 635                 usb_free_urb(urb);
 636                 return -ENOMEM;
 637         }
 638
 639         /* call the device specific handler for the restart */
 640         err = dev->adapter->dev_restart_async(dev, urb, buf);
 641         if (!err)
 642                 return 0;
 643
 644         kfree(buf);
 645         usb_free_urb(urb);
 646
 647         return err;
 648 }
 649
 650 /*
 651  * candev callback used to change CAN mode.
 652  * Warning: this is called from a timer context!
 653  */
 654 static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 655 {
 656         struct peak_usb_device *dev = netdev_priv(netdev);
 657         int err = 0;
 658
 659         switch (mode) {
 660         case CAN_MODE_START:
 661                 err = peak_usb_restart(dev);
 662                 if (err)
 663                         netdev_err(netdev, "couldn't start device (err %d)\n",
 664                                    err);
 665                 break;
 666
 667         default:
 668                 return -EOPNOTSUPP;
 669         }
 670
 671         return err;
 672 }
 673
 674 /*
 675  * candev callback used to set device bitrate.
 676  */
 677 static int peak_usb_set_bittiming(struct net_device *netdev)
 678 {
 679         struct peak_usb_device *dev = netdev_priv(netdev);
 680         struct can_bittiming *bt = &dev->can.bittiming;
 681
 682         if (dev->adapter->dev_set_bittiming) {
 683                 int err = dev->adapter->dev_set_bittiming(dev, bt);
 684
 685                 if (err)
 686                         netdev_info(netdev, "couldn't set bitrate (err %d)\n",
 687                                 err);
 688                 return err;
 689         }
 690
 691         return 0;
 692 }
 693
 694 static const struct net_device_ops peak_usb_netdev_ops = {
 695         .ndo_open = peak_usb_ndo_open,
 696         .ndo_stop = peak_usb_ndo_stop,
 697         .ndo_start_xmit = peak_usb_ndo_start_xmit,
 698 };
 699
 700 /*
 701  * create one device which is attached to CAN controller #ctrl_idx of the
 702  * usb adapter.
 703  */
 704 static int peak_usb_create_dev(struct peak_usb_adapter *peak_usb_adapter,
 705                                struct usb_interface *intf, int ctrl_idx)
 706 {
 707         struct usb_device *usb_dev = interface_to_usbdev(intf);
 708         int sizeof_candev = peak_usb_adapter->sizeof_dev_private;
 709         struct peak_usb_device *dev;
 710         struct net_device *netdev;
 711         int i, err;
 712         u16 tmp16;
 713
 714         if (sizeof_candev < sizeof(struct peak_usb_device))
 715                 sizeof_candev = sizeof(struct peak_usb_device);
 716
 717         netdev = alloc_candev(sizeof_candev, PCAN_USB_MAX_TX_URBS);
 718         if (!netdev) {
 719                 dev_err(&intf->dev, "%s: couldn't alloc candev\n",
 720                         PCAN_USB_DRIVER_NAME);
 721                 return -ENOMEM;
 722         }
 723
 724         dev = netdev_priv(netdev);
 725
 726         /* allocate a buffer large enough to send commands */
 727         dev->cmd_buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
 728         if (!dev->cmd_buf) {
 729                 err = -ENOMEM;
 730                 goto lbl_set_intf_data;
 731         }
 732
 733         dev->udev = usb_dev;
 734         dev->netdev = netdev;
 735         dev->adapter = peak_usb_adapter;
 736         dev->ctrl_idx = ctrl_idx;
 737         dev->state = PCAN_USB_STATE_CONNECTED;
 738
 739         dev->ep_msg_in = peak_usb_adapter->ep_msg_in;
 740         dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];
 741
 742         dev->can.clock = peak_usb_adapter->clock;
 743         dev->can.bittiming_const = &peak_usb_adapter->bittiming_const;
 744         dev->can.do_set_bittiming = peak_usb_set_bittiming;
 745         dev->can.do_set_mode = peak_usb_set_mode;
 746         dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
 747                                       CAN_CTRLMODE_LISTENONLY;
 748
 749         netdev->netdev_ops = &peak_usb_netdev_ops;
 750
 751         netdev->flags |= IFF_ECHO; /* we support local echo */
 752
 753         init_usb_anchor(&dev->rx_submitted);
 754
 755         init_usb_anchor(&dev->tx_submitted);
 756         atomic_set(&dev->active_tx_urbs, 0);
 757
 758         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 759                 dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;
 760
 761         dev->prev_siblings = usb_get_intfdata(intf);
 762         usb_set_intfdata(intf, dev);
 763
 764         SET_NETDEV_DEV(netdev, &intf->dev);
 765
 766         err = register_candev(netdev);
 767         if (err) {
 768                 dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
 769                 goto lbl_free_cmd_buf;
 770         }
 771
 772         if (dev->prev_siblings)
 773                 (dev->prev_siblings)->next_siblings = dev;
 774
 775         /* keep hw revision into the netdevice */
 776         tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);
 777         dev->device_rev = tmp16 >> 8;
 778
 779         if (dev->adapter->dev_init) {
 780                 err = dev->adapter->dev_init(dev);
 781                 if (err)
 782                         goto lbl_free_cmd_buf;
 783         }
 784
 785         /* set bus off */
 786         if (dev->adapter->dev_set_bus) {
 787                 err = dev->adapter->dev_set_bus(dev, 0);
 788                 if (err)
 789                         goto lbl_free_cmd_buf;
 790         }
 791
 792         /* get device number early */
 793         if (dev->adapter->dev_get_device_id)
 794                 dev->adapter->dev_get_device_id(dev, &dev->device_number);
 795
 796         netdev_info(netdev, "attached to %s channel %u (device %u)\n",
 797                         peak_usb_adapter->name, ctrl_idx, dev->device_number);
 798
 799         return 0;
 800
 801 lbl_free_cmd_buf:
 802         kfree(dev->cmd_buf);
 803
 804 lbl_set_intf_data:
 805         usb_set_intfdata(intf, dev->prev_siblings);
 806         free_candev(netdev);
 807
 808         return err;
 809 }
 810
 811 /*
 812  * called by the usb core when the device is unplugged from the system
 813  */
 814 static void peak_usb_disconnect(struct usb_interface *intf)
 815 {
 816         struct peak_usb_device *dev;
 817
 818         /* unregister as many netdev devices as siblings */
 819         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
 820                 struct net_device *netdev = dev->netdev;
 821                 char name[IFNAMSIZ];
 822
 823                 dev->state &= ~PCAN_USB_STATE_CONNECTED;
 824                 strncpy(name, netdev->name, IFNAMSIZ);
 825
 826                 unregister_netdev(netdev);
 827                 free_candev(netdev);
 828
 829                 kfree(dev->cmd_buf);
 830                 dev->next_siblings = NULL;
 831                 if (dev->adapter->dev_free)
 832                         dev->adapter->dev_free(dev);
 833
 834                 dev_info(&intf->dev, "%s removed\n", name);
 835         }
 836
 837         usb_set_intfdata(intf, NULL);
 838 }
 839
 840 /*
 841  * probe function for new PEAK-System devices
 842  */
 843 static int peak_usb_probe(struct usb_interface *intf,
 844                           const struct usb_device_id *id)
 845 {
 846         struct usb_device *usb_dev = interface_to_usbdev(intf);
 847         struct peak_usb_adapter *peak_usb_adapter, **pp;
 848         int i, err = -ENOMEM;
 849
 850         usb_dev = interface_to_usbdev(intf);
 851
 852         /* get corresponding PCAN-USB adapter */
 853         for (pp = peak_usb_adapters_list; *pp; pp++)
 854                 if ((*pp)->device_id == usb_dev->descriptor.idProduct)
 855                         break;
 856
 857         peak_usb_adapter = *pp;
 858         if (!peak_usb_adapter) {
 859                 /* should never come except device_id bad usage in this file */
 860                 pr_err("%s: didn't find device id. 0x%x in devices list\n",
 861                         PCAN_USB_DRIVER_NAME, usb_dev->descriptor.idProduct);
 862                 return -ENODEV;
 863         }
 864
 865         /* got corresponding adapter: check if it handles current interface */
 866         if (peak_usb_adapter->intf_probe) {
 867                 err = peak_usb_adapter->intf_probe(intf);
 868                 if (err)
 869                         return err;
 870         }
 871
 872         for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
 873                 err = peak_usb_create_dev(peak_usb_adapter, intf, i);
 874                 if (err) {
 875                         /* deregister already created devices */
 876                         peak_usb_disconnect(intf);
 877                         break;
 878                 }
 879         }
 880
 881         return err;
 882 }
 883
 884 /* usb specific object needed to register this driver with the usb subsystem */
 885 static struct usb_driver peak_usb_driver = {
 886         .name = PCAN_USB_DRIVER_NAME,
 887         .disconnect = peak_usb_disconnect,
 888         .probe = peak_usb_probe,
 889         .id_table = peak_usb_table,
 890 };
 891
 892 static int __init peak_usb_init(void)
 893 {
 894         int err;
 895
 896         /* register this driver with the USB subsystem */
 897         err = usb_register(&peak_usb_driver);
 898         if (err)
 899                 pr_err("%s: usb_register failed (err %d)\n",
 900                         PCAN_USB_DRIVER_NAME, err);
 901
 902         return err;
 903 }
 904
 905 static int peak_usb_do_device_exit(struct device *d, void *arg)
 906 {
 907         struct usb_interface *intf = to_usb_interface(d);
 908         struct peak_usb_device *dev;
 909
 910         /* stop as many netdev devices as siblings */
 911         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
 912                 struct net_device *netdev = dev->netdev;
 913
 914                 if (netif_device_present(netdev))
 915                         if (dev->adapter->dev_exit)
 916                                 dev->adapter->dev_exit(dev);
 917         }
 918
 919         return 0;
 920 }
 921
 922 static void __exit peak_usb_exit(void)
 923 {
 924         int err;
 925
 926         /* last chance do send any synchronous commands here */
 927         err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
 928                                      NULL, peak_usb_do_device_exit);
 929         if (err)
 930                 pr_err("%s: failed to stop all can devices (err %d)\n",
 931                         PCAN_USB_DRIVER_NAME, err);
 932
 933         /* deregister this driver with the USB subsystem */
 934         usb_deregister(&peak_usb_driver);
 935
 936         pr_info("%s: PCAN-USB interfaces driver unloaded\n",
 937                 PCAN_USB_DRIVER_NAME);
 938 }
 939
 940 module_init(peak_usb_init);
 941 module_exit(peak_usb_exit);