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         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBFD_PRODUCT_ID)},
  41         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBPROFD_PRODUCT_ID)},
  42         {} /* Terminating entry */
  43 };
  44
  45 MODULE_DEVICE_TABLE(usb, peak_usb_table);
  46
  47 /* List of supported PCAN-USB adapters (NULL terminated list) */
  48 static const struct peak_usb_adapter *const peak_usb_adapters_list[] = {
  49         &pcan_usb,
  50         &pcan_usb_pro,
  51         &pcan_usb_fd,
  52         &pcan_usb_pro_fd,
  53 };
  54
  55 /*
  56  * dump memory
  57  */
  58 #define DUMP_WIDTH      16
  59 void pcan_dump_mem(char *prompt, void *p, int l)
  60 {
  61         pr_info("%s dumping %s (%d bytes):\n",
  62                 PCAN_USB_DRIVER_NAME, prompt ? prompt : "memory", l);
  63         print_hex_dump(KERN_INFO, PCAN_USB_DRIVER_NAME " ", DUMP_PREFIX_NONE,
  64                        DUMP_WIDTH, 1, p, l, false);
  65 }
  66
  67 /*
  68  * initialize a time_ref object with usb adapter own settings
  69  */
  70 void peak_usb_init_time_ref(struct peak_time_ref *time_ref,
  71                             const struct peak_usb_adapter *adapter)
  72 {
  73         if (time_ref) {
  74                 memset(time_ref, 0, sizeof(struct peak_time_ref));
  75                 time_ref->adapter = adapter;
  76         }
  77 }
  78
  79 static void peak_usb_add_us(struct timeval *tv, u32 delta_us)
  80 {
  81         /* number of s. to add to final time */
  82         u32 delta_s = delta_us / 1000000;
  83
  84         delta_us -= delta_s * 1000000;
  85
  86         tv->tv_usec += delta_us;
  87         if (tv->tv_usec >= 1000000) {
  88                 tv->tv_usec -= 1000000;
  89                 delta_s++;
  90         }
  91         tv->tv_sec += delta_s;
  92 }
  93
  94 /*
  95  * sometimes, another now may be  more recent than current one...
  96  */
  97 void peak_usb_update_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
  98 {
  99         time_ref->ts_dev_2 = ts_now;
 100
 101         /* should wait at least two passes before computing */
 102         if (time_ref->tv_host.tv_sec > 0) {
 103                 u32 delta_ts = time_ref->ts_dev_2 - time_ref->ts_dev_1;
 104
 105                 if (time_ref->ts_dev_2 < time_ref->ts_dev_1)
 106                         delta_ts &= (1 << time_ref->adapter->ts_used_bits) - 1;
 107
 108                 time_ref->ts_total += delta_ts;
 109         }
 110 }
 111
 112 /*
 113  * register device timestamp as now
 114  */
 115 void peak_usb_set_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
 116 {
 117         if (time_ref->tv_host_0.tv_sec == 0) {
 118                 /* use monotonic clock to correctly compute further deltas */
 119                 time_ref->tv_host_0 = ktime_to_timeval(ktime_get());
 120                 time_ref->tv_host.tv_sec = 0;
 121         } else {
 122                 /*
 123                  * delta_us should not be >= 2^32 => delta_s should be < 4294
 124                  * handle 32-bits wrapping here: if count of s. reaches 4200,
 125                  * reset counters and change time base
 126                  */
 127                 if (time_ref->tv_host.tv_sec != 0) {
 128                         u32 delta_s = time_ref->tv_host.tv_sec
 129                                                 - time_ref->tv_host_0.tv_sec;
 130                         if (delta_s > 4200) {
 131                                 time_ref->tv_host_0 = time_ref->tv_host;
 132                                 time_ref->ts_total = 0;
 133                         }
 134                 }
 135
 136                 time_ref->tv_host = ktime_to_timeval(ktime_get());
 137                 time_ref->tick_count++;
 138         }
 139
 140         time_ref->ts_dev_1 = time_ref->ts_dev_2;
 141         peak_usb_update_ts_now(time_ref, ts_now);
 142 }
 143
 144 /*
 145  * compute timeval according to current ts and time_ref data
 146  */
 147 void peak_usb_get_ts_tv(struct peak_time_ref *time_ref, u32 ts,
 148                         struct timeval *tv)
 149 {
 150         /* protect from getting timeval before setting now */
 151         if (time_ref->tv_host.tv_sec > 0) {
 152                 u64 delta_us;
 153
 154                 delta_us = ts - time_ref->ts_dev_2;
 155                 if (ts < time_ref->ts_dev_2)
 156                         delta_us &= (1 << time_ref->adapter->ts_used_bits) - 1;
 157
 158                 delta_us += time_ref->ts_total;
 159
 160                 delta_us *= time_ref->adapter->us_per_ts_scale;
 161                 delta_us >>= time_ref->adapter->us_per_ts_shift;
 162
 163                 *tv = time_ref->tv_host_0;
 164                 peak_usb_add_us(tv, (u32)delta_us);
 165         } else {
 166                 *tv = ktime_to_timeval(ktime_get());
 167         }
 168 }
 169
 170 /*
 171  * post received skb after having set any hw timestamp
 172  */
 173 int peak_usb_netif_rx(struct sk_buff *skb,
 174                       struct peak_time_ref *time_ref, u32 ts_low, u32 ts_high)
 175 {
 176         struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
 177         struct timeval tv;
 178
 179         peak_usb_get_ts_tv(time_ref, ts_low, &tv);
 180         hwts->hwtstamp = timeval_to_ktime(tv);
 181
 182         return netif_rx(skb);
 183 }
 184
 185 /*
 186  * callback for bulk Rx urb
 187  */
 188 static void peak_usb_read_bulk_callback(struct urb *urb)
 189 {
 190         struct peak_usb_device *dev = urb->context;
 191         struct net_device *netdev;
 192         int err;
 193
 194         netdev = dev->netdev;
 195
 196         if (!netif_device_present(netdev))
 197                 return;
 198
 199         /* check reception status */
 200         switch (urb->status) {
 201         case 0:
 202                 /* success */
 203                 break;
 204
 205         case -EILSEQ:
 206         case -ENOENT:
 207         case -ECONNRESET:
 208         case -ESHUTDOWN:
 209                 return;
 210
 211         default:
 212                 if (net_ratelimit())
 213                         netdev_err(netdev,
 214                                    "Rx urb aborted (%d)\n", urb->status);
 215                 goto resubmit_urb;
 216         }
 217
 218         /* protect from any incoming empty msgs */
 219         if ((urb->actual_length > 0) && (dev->adapter->dev_decode_buf)) {
 220                 /* handle these kinds of msgs only if _start callback called */
 221                 if (dev->state & PCAN_USB_STATE_STARTED) {
 222                         err = dev->adapter->dev_decode_buf(dev, urb);
 223                         if (err)
 224                                 pcan_dump_mem("received usb message",
 225                                               urb->transfer_buffer,
 226                                               urb->transfer_buffer_length);
 227                 }
 228         }
 229
 230 resubmit_urb:
 231         usb_fill_bulk_urb(urb, dev->udev,
 232                 usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 233                 urb->transfer_buffer, dev->adapter->rx_buffer_size,
 234                 peak_usb_read_bulk_callback, dev);
 235
 236         usb_anchor_urb(urb, &dev->rx_submitted);
 237         err = usb_submit_urb(urb, GFP_ATOMIC);
 238         if (!err)
 239                 return;
 240
 241         usb_unanchor_urb(urb);
 242
 243         if (err == -ENODEV)
 244                 netif_device_detach(netdev);
 245         else
 246                 netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
 247                            err);
 248 }
 249
 250 /*
 251  * callback for bulk Tx urb
 252  */
 253 static void peak_usb_write_bulk_callback(struct urb *urb)
 254 {
 255         struct peak_tx_urb_context *context = urb->context;
 256         struct peak_usb_device *dev;
 257         struct net_device *netdev;
 258
 259         BUG_ON(!context);
 260
 261         dev = context->dev;
 262         netdev = dev->netdev;
 263
 264         atomic_dec(&dev->active_tx_urbs);
 265
 266         if (!netif_device_present(netdev))
 267                 return;
 268
 269         /* check tx status */
 270         switch (urb->status) {
 271         case 0:
 272                 /* transmission complete */
 273                 netdev->stats.tx_packets++;
 274                 netdev->stats.tx_bytes += context->data_len;
 275
 276                 /* prevent tx timeout */
 277                 netif_trans_update(netdev);
 278                 break;
 279
 280         default:
 281                 if (net_ratelimit())
 282                         netdev_err(netdev, "Tx urb aborted (%d)\n",
 283                                    urb->status);
 284         case -EPROTO:
 285         case -ENOENT:
 286         case -ECONNRESET:
 287         case -ESHUTDOWN:
 288
 289                 break;
 290         }
 291
 292         /* should always release echo skb and corresponding context */
 293         can_get_echo_skb(netdev, context->echo_index);
 294         context->echo_index = PCAN_USB_MAX_TX_URBS;
 295
 296         /* do wakeup tx queue in case of success only */
 297         if (!urb->status)
 298                 netif_wake_queue(netdev);
 299 }
 300
 301 /*
 302  * called by netdev to send one skb on the CAN interface.
 303  */
 304 static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
 305                                            struct net_device *netdev)
 306 {
 307         struct peak_usb_device *dev = netdev_priv(netdev);
 308         struct peak_tx_urb_context *context = NULL;
 309         struct net_device_stats *stats = &netdev->stats;
 310         struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 311         struct urb *urb;
 312         u8 *obuf;
 313         int i, err;
 314         size_t size = dev->adapter->tx_buffer_size;
 315
 316         if (can_dropped_invalid_skb(netdev, skb))
 317                 return NETDEV_TX_OK;
 318
 319         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 320                 if (dev->tx_contexts[i].echo_index == PCAN_USB_MAX_TX_URBS) {
 321                         context = dev->tx_contexts + i;
 322                         break;
 323                 }
 324
 325         if (!context) {
 326                 /* should not occur except during restart */
 327                 return NETDEV_TX_BUSY;
 328         }
 329
 330         urb = context->urb;
 331         obuf = urb->transfer_buffer;
 332
 333         err = dev->adapter->dev_encode_msg(dev, skb, obuf, &size);
 334         if (err) {
 335                 if (net_ratelimit())
 336                         netdev_err(netdev, "packet dropped\n");
 337                 dev_kfree_skb(skb);
 338                 stats->tx_dropped++;
 339                 return NETDEV_TX_OK;
 340         }
 341
 342         context->echo_index = i;
 343
 344         /* Note: this works with CANFD frames too */
 345         context->data_len = cfd->len;
 346
 347         usb_anchor_urb(urb, &dev->tx_submitted);
 348
 349         can_put_echo_skb(skb, netdev, context->echo_index);
 350
 351         atomic_inc(&dev->active_tx_urbs);
 352
 353         err = usb_submit_urb(urb, GFP_ATOMIC);
 354         if (err) {
 355                 can_free_echo_skb(netdev, context->echo_index);
 356
 357                 usb_unanchor_urb(urb);
 358
 359                 /* this context is not used in fact */
 360                 context->echo_index = PCAN_USB_MAX_TX_URBS;
 361
 362                 atomic_dec(&dev->active_tx_urbs);
 363
 364                 switch (err) {
 365                 case -ENODEV:
 366                         netif_device_detach(netdev);
 367                         break;
 368                 default:
 369                         netdev_warn(netdev, "tx urb submitting failed err=%d\n",
 370                                     err);
 371                 case -ENOENT:
 372                         /* cable unplugged */
 373                         stats->tx_dropped++;
 374                 }
 375         } else {
 376                 netif_trans_update(netdev);
 377
 378                 /* slow down tx path */
 379                 if (atomic_read(&dev->active_tx_urbs) >= PCAN_USB_MAX_TX_URBS)
 380                         netif_stop_queue(netdev);
 381         }
 382
 383         return NETDEV_TX_OK;
 384 }
 385
 386 /*
 387  * start the CAN interface.
 388  * Rx and Tx urbs are allocated here. Rx urbs are submitted here.
 389  */
 390 static int peak_usb_start(struct peak_usb_device *dev)
 391 {
 392         struct net_device *netdev = dev->netdev;
 393         int err, i;
 394
 395         for (i = 0; i < PCAN_USB_MAX_RX_URBS; i++) {
 396                 struct urb *urb;
 397                 u8 *buf;
 398
 399                 /* create a URB, and a buffer for it, to receive usb messages */
 400                 urb = usb_alloc_urb(0, GFP_KERNEL);
 401                 if (!urb) {
 402                         err = -ENOMEM;
 403                         break;
 404                 }
 405
 406                 buf = kmalloc(dev->adapter->rx_buffer_size, GFP_KERNEL);
 407                 if (!buf) {
 408                         usb_free_urb(urb);
 409                         err = -ENOMEM;
 410                         break;
 411                 }
 412
 413                 usb_fill_bulk_urb(urb, dev->udev,
 414                         usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 415                         buf, dev->adapter->rx_buffer_size,
 416                         peak_usb_read_bulk_callback, dev);
 417
 418                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 419                 urb->transfer_flags |= URB_FREE_BUFFER;
 420                 usb_anchor_urb(urb, &dev->rx_submitted);
 421
 422                 err = usb_submit_urb(urb, GFP_KERNEL);
 423                 if (err) {
 424                         if (err == -ENODEV)
 425                                 netif_device_detach(dev->netdev);
 426
 427                         usb_unanchor_urb(urb);
 428                         kfree(buf);
 429                         usb_free_urb(urb);
 430                         break;
 431                 }
 432
 433                 /* drop reference, USB core will take care of freeing it */
 434                 usb_free_urb(urb);
 435         }
 436
 437         /* did we submit any URBs? Warn if we was not able to submit all urbs */
 438         if (i < PCAN_USB_MAX_RX_URBS) {
 439                 if (i == 0) {
 440                         netdev_err(netdev, "couldn't setup any rx URB\n");
 441                         return err;
 442                 }
 443
 444                 netdev_warn(netdev, "rx performance may be slow\n");
 445         }
 446
 447         /* pre-alloc tx buffers and corresponding urbs */
 448         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 449                 struct peak_tx_urb_context *context;
 450                 struct urb *urb;
 451                 u8 *buf;
 452
 453                 /* create a URB and a buffer for it, to transmit usb messages */
 454                 urb = usb_alloc_urb(0, GFP_KERNEL);
 455                 if (!urb) {
 456                         err = -ENOMEM;
 457                         break;
 458                 }
 459
 460                 buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);
 461                 if (!buf) {
 462                         usb_free_urb(urb);
 463                         err = -ENOMEM;
 464                         break;
 465                 }
 466
 467                 context = dev->tx_contexts + i;
 468                 context->dev = dev;
 469                 context->urb = urb;
 470
 471                 usb_fill_bulk_urb(urb, dev->udev,
 472                         usb_sndbulkpipe(dev->udev, dev->ep_msg_out),
 473                         buf, dev->adapter->tx_buffer_size,
 474                         peak_usb_write_bulk_callback, context);
 475
 476                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 477                 urb->transfer_flags |= URB_FREE_BUFFER;
 478         }
 479
 480         /* warn if we were not able to allocate enough tx contexts */
 481         if (i < PCAN_USB_MAX_TX_URBS) {
 482                 if (i == 0) {
 483                         netdev_err(netdev, "couldn't setup any tx URB\n");
 484                         goto err_tx;
 485                 }
 486
 487                 netdev_warn(netdev, "tx performance may be slow\n");
 488         }
 489
 490         if (dev->adapter->dev_start) {
 491                 err = dev->adapter->dev_start(dev);
 492                 if (err)
 493                         goto err_adapter;
 494         }
 495
 496         dev->state |= PCAN_USB_STATE_STARTED;
 497
 498         /* can set bus on now */
 499         if (dev->adapter->dev_set_bus) {
 500                 err = dev->adapter->dev_set_bus(dev, 1);
 501                 if (err)
 502                         goto err_adapter;
 503         }
 504
 505         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 506
 507         return 0;
 508
 509 err_adapter:
 510         if (err == -ENODEV)
 511                 netif_device_detach(dev->netdev);
 512
 513         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 514
 515         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 516                 usb_free_urb(dev->tx_contexts[i].urb);
 517                 dev->tx_contexts[i].urb = NULL;
 518         }
 519 err_tx:
 520         usb_kill_anchored_urbs(&dev->rx_submitted);
 521
 522         return err;
 523 }
 524
 525 /*
 526  * called by netdev to open the corresponding CAN interface.
 527  */
 528 static int peak_usb_ndo_open(struct net_device *netdev)
 529 {
 530         struct peak_usb_device *dev = netdev_priv(netdev);
 531         int err;
 532
 533         /* common open */
 534         err = open_candev(netdev);
 535         if (err)
 536                 return err;
 537
 538         /* finally start device */
 539         err = peak_usb_start(dev);
 540         if (err) {
 541                 netdev_err(netdev, "couldn't start device: %d\n", err);
 542                 close_candev(netdev);
 543                 return err;
 544         }
 545
 546         netif_start_queue(netdev);
 547
 548         return 0;
 549 }
 550
 551 /*
 552  * unlink in-flight Rx and Tx urbs and free their memory.
 553  */
 554 static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)
 555 {
 556         int i;
 557
 558         /* free all Rx (submitted) urbs */
 559         usb_kill_anchored_urbs(&dev->rx_submitted);
 560
 561         /* free unsubmitted Tx urbs first */
 562         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 563                 struct urb *urb = dev->tx_contexts[i].urb;
 564
 565                 if (!urb ||
 566                     dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {
 567                         /*
 568                          * this urb is already released or always submitted,
 569                          * let usb core free by itself
 570                          */
 571                         continue;
 572                 }
 573
 574                 usb_free_urb(urb);
 575                 dev->tx_contexts[i].urb = NULL;
 576         }
 577
 578         /* then free all submitted Tx urbs */
 579         usb_kill_anchored_urbs(&dev->tx_submitted);
 580         atomic_set(&dev->active_tx_urbs, 0);
 581 }
 582
 583 /*
 584  * called by netdev to close the corresponding CAN interface.
 585  */
 586 static int peak_usb_ndo_stop(struct net_device *netdev)
 587 {
 588         struct peak_usb_device *dev = netdev_priv(netdev);
 589
 590         dev->state &= ~PCAN_USB_STATE_STARTED;
 591         netif_stop_queue(netdev);
 592
 593         /* unlink all pending urbs and free used memory */
 594         peak_usb_unlink_all_urbs(dev);
 595
 596         if (dev->adapter->dev_stop)
 597                 dev->adapter->dev_stop(dev);
 598
 599         close_candev(netdev);
 600
 601         dev->can.state = CAN_STATE_STOPPED;
 602
 603         /* can set bus off now */
 604         if (dev->adapter->dev_set_bus) {
 605                 int err = dev->adapter->dev_set_bus(dev, 0);
 606                 if (err)
 607                         return err;
 608         }
 609
 610         return 0;
 611 }
 612
 613 /*
 614  * handle end of waiting for the device to reset
 615  */
 616 void peak_usb_restart_complete(struct peak_usb_device *dev)
 617 {
 618         /* finally MUST update can state */
 619         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 620
 621         /* netdev queue can be awaken now */
 622         netif_wake_queue(dev->netdev);
 623 }
 624
 625 void peak_usb_async_complete(struct urb *urb)
 626 {
 627         kfree(urb->transfer_buffer);
 628         usb_free_urb(urb);
 629 }
 630
 631 /*
 632  * device (auto-)restart mechanism runs in a timer context =>
 633  * MUST handle restart with asynchronous usb transfers
 634  */
 635 static int peak_usb_restart(struct peak_usb_device *dev)
 636 {
 637         struct urb *urb;
 638         int err;
 639         u8 *buf;
 640
 641         /*
 642          * if device doesn't define any asynchronous restart handler, simply
 643          * wake the netdev queue up
 644          */
 645         if (!dev->adapter->dev_restart_async) {
 646                 peak_usb_restart_complete(dev);
 647                 return 0;
 648         }
 649
 650         /* first allocate a urb to handle the asynchronous steps */
 651         urb = usb_alloc_urb(0, GFP_ATOMIC);
 652         if (!urb)
 653                 return -ENOMEM;
 654
 655         /* also allocate enough space for the commands to send */
 656         buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);
 657         if (!buf) {
 658                 usb_free_urb(urb);
 659                 return -ENOMEM;
 660         }
 661
 662         /* call the device specific handler for the restart */
 663         err = dev->adapter->dev_restart_async(dev, urb, buf);
 664         if (!err)
 665                 return 0;
 666
 667         kfree(buf);
 668         usb_free_urb(urb);
 669
 670         return err;
 671 }
 672
 673 /*
 674  * candev callback used to change CAN mode.
 675  * Warning: this is called from a timer context!
 676  */
 677 static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 678 {
 679         struct peak_usb_device *dev = netdev_priv(netdev);
 680         int err = 0;
 681
 682         switch (mode) {
 683         case CAN_MODE_START:
 684                 err = peak_usb_restart(dev);
 685                 if (err)
 686                         netdev_err(netdev, "couldn't start device (err %d)\n",
 687                                    err);
 688                 break;
 689
 690         default:
 691                 return -EOPNOTSUPP;
 692         }
 693
 694         return err;
 695 }
 696
 697 /*
 698  * candev callback used to set device nominal/arbitration bitrate.
 699  */
 700 static int peak_usb_set_bittiming(struct net_device *netdev)
 701 {
 702         struct peak_usb_device *dev = netdev_priv(netdev);
 703         const struct peak_usb_adapter *pa = dev->adapter;
 704
 705         if (pa->dev_set_bittiming) {
 706                 struct can_bittiming *bt = &dev->can.bittiming;
 707                 int err = pa->dev_set_bittiming(dev, bt);
 708
 709                 if (err)
 710                         netdev_info(netdev, "couldn't set bitrate (err %d)\n",
 711                                     err);
 712                 return err;
 713         }
 714
 715         return 0;
 716 }
 717
 718 /*
 719  * candev callback used to set device data bitrate.
 720  */
 721 static int peak_usb_set_data_bittiming(struct net_device *netdev)
 722 {
 723         struct peak_usb_device *dev = netdev_priv(netdev);
 724         const struct peak_usb_adapter *pa = dev->adapter;
 725
 726         if (pa->dev_set_data_bittiming) {
 727                 struct can_bittiming *bt = &dev->can.data_bittiming;
 728                 int err = pa->dev_set_data_bittiming(dev, bt);
 729
 730                 if (err)
 731                         netdev_info(netdev,
 732                                     "couldn't set data bitrate (err %d)\n",
 733                                     err);
 734
 735                 return err;
 736         }
 737
 738         return 0;
 739 }
 740
 741 static const struct net_device_ops peak_usb_netdev_ops = {
 742         .ndo_open = peak_usb_ndo_open,
 743         .ndo_stop = peak_usb_ndo_stop,
 744         .ndo_start_xmit = peak_usb_ndo_start_xmit,
 745         .ndo_change_mtu = can_change_mtu,
 746 };
 747
 748 /*
 749  * create one device which is attached to CAN controller #ctrl_idx of the
 750  * usb adapter.
 751  */
 752 static int peak_usb_create_dev(const struct peak_usb_adapter *peak_usb_adapter,
 753                                struct usb_interface *intf, int ctrl_idx)
 754 {
 755         struct usb_device *usb_dev = interface_to_usbdev(intf);
 756         int sizeof_candev = peak_usb_adapter->sizeof_dev_private;
 757         struct peak_usb_device *dev;
 758         struct net_device *netdev;
 759         int i, err;
 760         u16 tmp16;
 761
 762         if (sizeof_candev < sizeof(struct peak_usb_device))
 763                 sizeof_candev = sizeof(struct peak_usb_device);
 764
 765         netdev = alloc_candev(sizeof_candev, PCAN_USB_MAX_TX_URBS);
 766         if (!netdev) {
 767                 dev_err(&intf->dev, "%s: couldn't alloc candev\n",
 768                         PCAN_USB_DRIVER_NAME);
 769                 return -ENOMEM;
 770         }
 771
 772         dev = netdev_priv(netdev);
 773
 774         /* allocate a buffer large enough to send commands */
 775         dev->cmd_buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
 776         if (!dev->cmd_buf) {
 777                 err = -ENOMEM;
 778                 goto lbl_free_candev;
 779         }
 780
 781         dev->udev = usb_dev;
 782         dev->netdev = netdev;
 783         dev->adapter = peak_usb_adapter;
 784         dev->ctrl_idx = ctrl_idx;
 785         dev->state = PCAN_USB_STATE_CONNECTED;
 786
 787         dev->ep_msg_in = peak_usb_adapter->ep_msg_in;
 788         dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];
 789
 790         dev->can.clock = peak_usb_adapter->clock;
 791         dev->can.bittiming_const = peak_usb_adapter->bittiming_const;
 792         dev->can.do_set_bittiming = peak_usb_set_bittiming;
 793         dev->can.data_bittiming_const = peak_usb_adapter->data_bittiming_const;
 794         dev->can.do_set_data_bittiming = peak_usb_set_data_bittiming;
 795         dev->can.do_set_mode = peak_usb_set_mode;
 796         dev->can.do_get_berr_counter = peak_usb_adapter->do_get_berr_counter;
 797         dev->can.ctrlmode_supported = peak_usb_adapter->ctrlmode_supported;
 798
 799         netdev->netdev_ops = &peak_usb_netdev_ops;
 800
 801         netdev->flags |= IFF_ECHO; /* we support local echo */
 802
 803         init_usb_anchor(&dev->rx_submitted);
 804
 805         init_usb_anchor(&dev->tx_submitted);
 806         atomic_set(&dev->active_tx_urbs, 0);
 807
 808         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 809                 dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;
 810
 811         dev->prev_siblings = usb_get_intfdata(intf);
 812         usb_set_intfdata(intf, dev);
 813
 814         SET_NETDEV_DEV(netdev, &intf->dev);
 815         netdev->dev_id = ctrl_idx;
 816
 817         err = register_candev(netdev);
 818         if (err) {
 819                 dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
 820                 goto lbl_restore_intf_data;
 821         }
 822
 823         if (dev->prev_siblings)
 824                 (dev->prev_siblings)->next_siblings = dev;
 825
 826         /* keep hw revision into the netdevice */
 827         tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);
 828         dev->device_rev = tmp16 >> 8;
 829
 830         if (dev->adapter->dev_init) {
 831                 err = dev->adapter->dev_init(dev);
 832                 if (err)
 833                         goto lbl_unregister_candev;
 834         }
 835
 836         /* set bus off */
 837         if (dev->adapter->dev_set_bus) {
 838                 err = dev->adapter->dev_set_bus(dev, 0);
 839                 if (err)
 840                         goto lbl_unregister_candev;
 841         }
 842
 843         /* get device number early */
 844         if (dev->adapter->dev_get_device_id)
 845                 dev->adapter->dev_get_device_id(dev, &dev->device_number);
 846
 847         netdev_info(netdev, "attached to %s channel %u (device %u)\n",
 848                         peak_usb_adapter->name, ctrl_idx, dev->device_number);
 849
 850         return 0;
 851
 852 lbl_unregister_candev:
 853         unregister_candev(netdev);
 854
 855 lbl_restore_intf_data:
 856         usb_set_intfdata(intf, dev->prev_siblings);
 857         kfree(dev->cmd_buf);
 858
 859 lbl_free_candev:
 860         free_candev(netdev);
 861
 862         return err;
 863 }
 864
 865 /*
 866  * called by the usb core when the device is unplugged from the system
 867  */
 868 static void peak_usb_disconnect(struct usb_interface *intf)
 869 {
 870         struct peak_usb_device *dev;
 871
 872         /* unregister as many netdev devices as siblings */
 873         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
 874                 struct net_device *netdev = dev->netdev;
 875                 char name[IFNAMSIZ];
 876
 877                 dev->state &= ~PCAN_USB_STATE_CONNECTED;
 878                 strncpy(name, netdev->name, IFNAMSIZ);
 879
 880                 unregister_netdev(netdev);
 881                 free_candev(netdev);
 882
 883                 kfree(dev->cmd_buf);
 884                 dev->next_siblings = NULL;
 885                 if (dev->adapter->dev_free)
 886                         dev->adapter->dev_free(dev);
 887
 888                 dev_info(&intf->dev, "%s removed\n", name);
 889         }
 890
 891         usb_set_intfdata(intf, NULL);
 892 }
 893
 894 /*
 895  * probe function for new PEAK-System devices
 896  */
 897 static int peak_usb_probe(struct usb_interface *intf,
 898                           const struct usb_device_id *id)
 899 {
 900         struct usb_device *usb_dev = interface_to_usbdev(intf);
 901         const u16 usb_id_product = le16_to_cpu(usb_dev->descriptor.idProduct);
 902         const struct peak_usb_adapter *peak_usb_adapter = NULL;
 903         int i, err = -ENOMEM;
 904
 905         usb_dev = interface_to_usbdev(intf);
 906
 907         /* get corresponding PCAN-USB adapter */
 908         for (i = 0; i < ARRAY_SIZE(peak_usb_adapters_list); i++)
 909                 if (peak_usb_adapters_list[i]->device_id == usb_id_product) {
 910                         peak_usb_adapter = peak_usb_adapters_list[i];
 911                         break;
 912                 }
 913
 914         if (!peak_usb_adapter) {
 915                 /* should never come except device_id bad usage in this file */
 916                 pr_err("%s: didn't find device id. 0x%x in devices list\n",
 917                         PCAN_USB_DRIVER_NAME, usb_dev->descriptor.idProduct);
 918                 return -ENODEV;
 919         }
 920
 921         /* got corresponding adapter: check if it handles current interface */
 922         if (peak_usb_adapter->intf_probe) {
 923                 err = peak_usb_adapter->intf_probe(intf);
 924                 if (err)
 925                         return err;
 926         }
 927
 928         for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
 929                 err = peak_usb_create_dev(peak_usb_adapter, intf, i);
 930                 if (err) {
 931                         /* deregister already created devices */
 932                         peak_usb_disconnect(intf);
 933                         break;
 934                 }
 935         }
 936
 937         return err;
 938 }
 939
 940 /* usb specific object needed to register this driver with the usb subsystem */
 941 static struct usb_driver peak_usb_driver = {
 942         .name = PCAN_USB_DRIVER_NAME,
 943         .disconnect = peak_usb_disconnect,
 944         .probe = peak_usb_probe,
 945         .id_table = peak_usb_table,
 946 };
 947
 948 static int __init peak_usb_init(void)
 949 {
 950         int err;
 951
 952         /* register this driver with the USB subsystem */
 953         err = usb_register(&peak_usb_driver);
 954         if (err)
 955                 pr_err("%s: usb_register failed (err %d)\n",
 956                         PCAN_USB_DRIVER_NAME, err);
 957
 958         return err;
 959 }
 960
 961 static int peak_usb_do_device_exit(struct device *d, void *arg)
 962 {
 963         struct usb_interface *intf = to_usb_interface(d);
 964         struct peak_usb_device *dev;
 965
 966         /* stop as many netdev devices as siblings */
 967         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
 968                 struct net_device *netdev = dev->netdev;
 969
 970                 if (netif_device_present(netdev))
 971                         if (dev->adapter->dev_exit)
 972                                 dev->adapter->dev_exit(dev);
 973         }
 974
 975         return 0;
 976 }
 977
 978 static void __exit peak_usb_exit(void)
 979 {
 980         int err;
 981
 982         /* last chance do send any synchronous commands here */
 983         err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
 984                                      NULL, peak_usb_do_device_exit);
 985         if (err)
 986                 pr_err("%s: failed to stop all can devices (err %d)\n",
 987                         PCAN_USB_DRIVER_NAME, err);
 988
 989         /* deregister this driver with the USB subsystem */
 990         usb_deregister(&peak_usb_driver);
 991
 992         pr_info("%s: PCAN-USB interfaces driver unloaded\n",
 993                 PCAN_USB_DRIVER_NAME);
 994 }
 995
 996 module_init(peak_usb_init);
 997 module_exit(peak_usb_exit);