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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * CAN driver for PEAK System USB adapters
   4  * Derived from the PCAN project file driver/src/pcan_usb_core.c
   5  *
   6  * Copyright (C) 2003-2010 PEAK System-Technik GmbH
   7  * Copyright (C) 2010-2012 Stephane Grosjean <s.grosjean@peak-system.com>
   8  *
   9  * Many thanks to Klaus Hitschler <klaus.hitschler@gmx.de>
  10  */
  11 #include <linux/init.h>
  12 #include <linux/signal.h>
  13 #include <linux/slab.h>
  14 #include <linux/module.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/usb.h>
  17
  18 #include <linux/can.h>
  19 #include <linux/can/dev.h>
  20 #include <linux/can/error.h>
  21
  22 #include "pcan_usb_core.h"
  23
  24 MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>");
  25 MODULE_DESCRIPTION("CAN driver for PEAK-System USB adapters");
  26 MODULE_LICENSE("GPL v2");
  27
  28 /* Table of devices that work with this driver */
  29 static struct usb_device_id peak_usb_table[] = {
  30         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USB_PRODUCT_ID)},
  31         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBPRO_PRODUCT_ID)},
  32         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBFD_PRODUCT_ID)},
  33         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBPROFD_PRODUCT_ID)},
  34         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBCHIP_PRODUCT_ID)},
  35         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBX6_PRODUCT_ID)},
  36         {} /* Terminating entry */
  37 };
  38
  39 MODULE_DEVICE_TABLE(usb, peak_usb_table);
  40
  41 /* List of supported PCAN-USB adapters (NULL terminated list) */
  42 static const struct peak_usb_adapter *const peak_usb_adapters_list[] = {
  43         &pcan_usb,
  44         &pcan_usb_pro,
  45         &pcan_usb_fd,
  46         &pcan_usb_pro_fd,
  47         &pcan_usb_chip,
  48         &pcan_usb_x6,
  49 };
  50
  51 /*
  52  * dump memory
  53  */
  54 #define DUMP_WIDTH      16
  55 void pcan_dump_mem(char *prompt, void *p, int l)
  56 {
  57         pr_info("%s dumping %s (%d bytes):\n",
  58                 PCAN_USB_DRIVER_NAME, prompt ? prompt : "memory", l);
  59         print_hex_dump(KERN_INFO, PCAN_USB_DRIVER_NAME " ", DUMP_PREFIX_NONE,
  60                        DUMP_WIDTH, 1, p, l, false);
  61 }
  62
  63 /*
  64  * initialize a time_ref object with usb adapter own settings
  65  */
  66 void peak_usb_init_time_ref(struct peak_time_ref *time_ref,
  67                             const struct peak_usb_adapter *adapter)
  68 {
  69         if (time_ref) {
  70                 memset(time_ref, 0, sizeof(struct peak_time_ref));
  71                 time_ref->adapter = adapter;
  72         }
  73 }
  74
  75 /*
  76  * sometimes, another now may be  more recent than current one...
  77  */
  78 void peak_usb_update_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
  79 {
  80         time_ref->ts_dev_2 = ts_now;
  81
  82         /* should wait at least two passes before computing */
  83         if (ktime_to_ns(time_ref->tv_host) > 0) {
  84                 u32 delta_ts = time_ref->ts_dev_2 - time_ref->ts_dev_1;
  85
  86                 if (time_ref->ts_dev_2 < time_ref->ts_dev_1)
  87                         delta_ts &= (1 << time_ref->adapter->ts_used_bits) - 1;
  88
  89                 time_ref->ts_total += delta_ts;
  90         }
  91 }
  92
  93 /*
  94  * register device timestamp as now
  95  */
  96 void peak_usb_set_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
  97 {
  98         if (ktime_to_ns(time_ref->tv_host_0) == 0) {
  99                 /* use monotonic clock to correctly compute further deltas */
 100                 time_ref->tv_host_0 = ktime_get();
 101                 time_ref->tv_host = ktime_set(0, 0);
 102         } else {
 103                 /*
 104                  * delta_us should not be >= 2^32 => delta should be < 4294s
 105                  * handle 32-bits wrapping here: if count of s. reaches 4200,
 106                  * reset counters and change time base
 107                  */
 108                 if (ktime_to_ns(time_ref->tv_host)) {
 109                         ktime_t delta = ktime_sub(time_ref->tv_host,
 110                                                   time_ref->tv_host_0);
 111                         if (ktime_to_ns(delta) > (4200ull * NSEC_PER_SEC)) {
 112                                 time_ref->tv_host_0 = time_ref->tv_host;
 113                                 time_ref->ts_total = 0;
 114                         }
 115                 }
 116
 117                 time_ref->tv_host = ktime_get();
 118                 time_ref->tick_count++;
 119         }
 120
 121         time_ref->ts_dev_1 = time_ref->ts_dev_2;
 122         peak_usb_update_ts_now(time_ref, ts_now);
 123 }
 124
 125 /*
 126  * compute time according to current ts and time_ref data
 127  */
 128 void peak_usb_get_ts_time(struct peak_time_ref *time_ref, u32 ts, ktime_t *time)
 129 {
 130         /* protect from getting time before setting now */
 131         if (ktime_to_ns(time_ref->tv_host)) {
 132                 u64 delta_us;
 133
 134                 delta_us = ts - time_ref->ts_dev_2;
 135                 if (ts < time_ref->ts_dev_2)
 136                         delta_us &= (1 << time_ref->adapter->ts_used_bits) - 1;
 137
 138                 delta_us += time_ref->ts_total;
 139
 140                 delta_us *= time_ref->adapter->us_per_ts_scale;
 141                 delta_us >>= time_ref->adapter->us_per_ts_shift;
 142
 143                 *time = ktime_add_us(time_ref->tv_host_0, delta_us);
 144         } else {
 145                 *time = ktime_get();
 146         }
 147 }
 148
 149 /*
 150  * post received skb after having set any hw timestamp
 151  */
 152 int peak_usb_netif_rx(struct sk_buff *skb,
 153                       struct peak_time_ref *time_ref, u32 ts_low)
 154 {
 155         struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
 156
 157         peak_usb_get_ts_time(time_ref, ts_low, &hwts->hwtstamp);
 158
 159         return netif_rx(skb);
 160 }
 161
 162 /*
 163  * callback for bulk Rx urb
 164  */
 165 static void peak_usb_read_bulk_callback(struct urb *urb)
 166 {
 167         struct peak_usb_device *dev = urb->context;
 168         struct net_device *netdev;
 169         int err;
 170
 171         netdev = dev->netdev;
 172
 173         if (!netif_device_present(netdev))
 174                 return;
 175
 176         /* check reception status */
 177         switch (urb->status) {
 178         case 0:
 179                 /* success */
 180                 break;
 181
 182         case -EILSEQ:
 183         case -ENOENT:
 184         case -ECONNRESET:
 185         case -ESHUTDOWN:
 186                 return;
 187
 188         default:
 189                 if (net_ratelimit())
 190                         netdev_err(netdev,
 191                                    "Rx urb aborted (%d)\n", urb->status);
 192                 goto resubmit_urb;
 193         }
 194
 195         /* protect from any incoming empty msgs */
 196         if ((urb->actual_length > 0) && (dev->adapter->dev_decode_buf)) {
 197                 /* handle these kinds of msgs only if _start callback called */
 198                 if (dev->state & PCAN_USB_STATE_STARTED) {
 199                         err = dev->adapter->dev_decode_buf(dev, urb);
 200                         if (err)
 201                                 pcan_dump_mem("received usb message",
 202                                               urb->transfer_buffer,
 203                                               urb->transfer_buffer_length);
 204                 }
 205         }
 206
 207 resubmit_urb:
 208         usb_fill_bulk_urb(urb, dev->udev,
 209                 usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 210                 urb->transfer_buffer, dev->adapter->rx_buffer_size,
 211                 peak_usb_read_bulk_callback, dev);
 212
 213         usb_anchor_urb(urb, &dev->rx_submitted);
 214         err = usb_submit_urb(urb, GFP_ATOMIC);
 215         if (!err)
 216                 return;
 217
 218         usb_unanchor_urb(urb);
 219
 220         if (err == -ENODEV)
 221                 netif_device_detach(netdev);
 222         else
 223                 netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
 224                            err);
 225 }
 226
 227 /*
 228  * callback for bulk Tx urb
 229  */
 230 static void peak_usb_write_bulk_callback(struct urb *urb)
 231 {
 232         struct peak_tx_urb_context *context = urb->context;
 233         struct peak_usb_device *dev;
 234         struct net_device *netdev;
 235
 236         BUG_ON(!context);
 237
 238         dev = context->dev;
 239         netdev = dev->netdev;
 240
 241         atomic_dec(&dev->active_tx_urbs);
 242
 243         if (!netif_device_present(netdev))
 244                 return;
 245
 246         /* check tx status */
 247         switch (urb->status) {
 248         case 0:
 249                 /* transmission complete */
 250                 netdev->stats.tx_packets++;
 251                 netdev->stats.tx_bytes += context->data_len;
 252
 253                 /* prevent tx timeout */
 254                 netif_trans_update(netdev);
 255                 break;
 256
 257         default:
 258                 if (net_ratelimit())
 259                         netdev_err(netdev, "Tx urb aborted (%d)\n",
 260                                    urb->status);
 261         case -EPROTO:
 262         case -ENOENT:
 263         case -ECONNRESET:
 264         case -ESHUTDOWN:
 265
 266                 break;
 267         }
 268
 269         /* should always release echo skb and corresponding context */
 270         can_get_echo_skb(netdev, context->echo_index);
 271         context->echo_index = PCAN_USB_MAX_TX_URBS;
 272
 273         /* do wakeup tx queue in case of success only */
 274         if (!urb->status)
 275                 netif_wake_queue(netdev);
 276 }
 277
 278 /*
 279  * called by netdev to send one skb on the CAN interface.
 280  */
 281 static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
 282                                            struct net_device *netdev)
 283 {
 284         struct peak_usb_device *dev = netdev_priv(netdev);
 285         struct peak_tx_urb_context *context = NULL;
 286         struct net_device_stats *stats = &netdev->stats;
 287         struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 288         struct urb *urb;
 289         u8 *obuf;
 290         int i, err;
 291         size_t size = dev->adapter->tx_buffer_size;
 292
 293         if (can_dropped_invalid_skb(netdev, skb))
 294                 return NETDEV_TX_OK;
 295
 296         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 297                 if (dev->tx_contexts[i].echo_index == PCAN_USB_MAX_TX_URBS) {
 298                         context = dev->tx_contexts + i;
 299                         break;
 300                 }
 301
 302         if (!context) {
 303                 /* should not occur except during restart */
 304                 return NETDEV_TX_BUSY;
 305         }
 306
 307         urb = context->urb;
 308         obuf = urb->transfer_buffer;
 309
 310         err = dev->adapter->dev_encode_msg(dev, skb, obuf, &size);
 311         if (err) {
 312                 if (net_ratelimit())
 313                         netdev_err(netdev, "packet dropped\n");
 314                 dev_kfree_skb(skb);
 315                 stats->tx_dropped++;
 316                 return NETDEV_TX_OK;
 317         }
 318
 319         context->echo_index = i;
 320
 321         /* Note: this works with CANFD frames too */
 322         context->data_len = cfd->len;
 323
 324         usb_anchor_urb(urb, &dev->tx_submitted);
 325
 326         can_put_echo_skb(skb, netdev, context->echo_index);
 327
 328         atomic_inc(&dev->active_tx_urbs);
 329
 330         err = usb_submit_urb(urb, GFP_ATOMIC);
 331         if (err) {
 332                 can_free_echo_skb(netdev, context->echo_index);
 333
 334                 usb_unanchor_urb(urb);
 335
 336                 /* this context is not used in fact */
 337                 context->echo_index = PCAN_USB_MAX_TX_URBS;
 338
 339                 atomic_dec(&dev->active_tx_urbs);
 340
 341                 switch (err) {
 342                 case -ENODEV:
 343                         netif_device_detach(netdev);
 344                         break;
 345                 default:
 346                         netdev_warn(netdev, "tx urb submitting failed err=%d\n",
 347                                     err);
 348                         /* fall through */
 349                 case -ENOENT:
 350                         /* cable unplugged */
 351                         stats->tx_dropped++;
 352                 }
 353         } else {
 354                 netif_trans_update(netdev);
 355
 356                 /* slow down tx path */
 357                 if (atomic_read(&dev->active_tx_urbs) >= PCAN_USB_MAX_TX_URBS)
 358                         netif_stop_queue(netdev);
 359         }
 360
 361         return NETDEV_TX_OK;
 362 }
 363
 364 /*
 365  * start the CAN interface.
 366  * Rx and Tx urbs are allocated here. Rx urbs are submitted here.
 367  */
 368 static int peak_usb_start(struct peak_usb_device *dev)
 369 {
 370         struct net_device *netdev = dev->netdev;
 371         int err, i;
 372
 373         for (i = 0; i < PCAN_USB_MAX_RX_URBS; i++) {
 374                 struct urb *urb;
 375                 u8 *buf;
 376
 377                 /* create a URB, and a buffer for it, to receive usb messages */
 378                 urb = usb_alloc_urb(0, GFP_KERNEL);
 379                 if (!urb) {
 380                         err = -ENOMEM;
 381                         break;
 382                 }
 383
 384                 buf = kmalloc(dev->adapter->rx_buffer_size, GFP_KERNEL);
 385                 if (!buf) {
 386                         usb_free_urb(urb);
 387                         err = -ENOMEM;
 388                         break;
 389                 }
 390
 391                 usb_fill_bulk_urb(urb, dev->udev,
 392                         usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 393                         buf, dev->adapter->rx_buffer_size,
 394                         peak_usb_read_bulk_callback, dev);
 395
 396                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 397                 urb->transfer_flags |= URB_FREE_BUFFER;
 398                 usb_anchor_urb(urb, &dev->rx_submitted);
 399
 400                 err = usb_submit_urb(urb, GFP_KERNEL);
 401                 if (err) {
 402                         if (err == -ENODEV)
 403                                 netif_device_detach(dev->netdev);
 404
 405                         usb_unanchor_urb(urb);
 406                         kfree(buf);
 407                         usb_free_urb(urb);
 408                         break;
 409                 }
 410
 411                 /* drop reference, USB core will take care of freeing it */
 412                 usb_free_urb(urb);
 413         }
 414
 415         /* did we submit any URBs? Warn if we was not able to submit all urbs */
 416         if (i < PCAN_USB_MAX_RX_URBS) {
 417                 if (i == 0) {
 418                         netdev_err(netdev, "couldn't setup any rx URB\n");
 419                         return err;
 420                 }
 421
 422                 netdev_warn(netdev, "rx performance may be slow\n");
 423         }
 424
 425         /* pre-alloc tx buffers and corresponding urbs */
 426         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 427                 struct peak_tx_urb_context *context;
 428                 struct urb *urb;
 429                 u8 *buf;
 430
 431                 /* create a URB and a buffer for it, to transmit usb messages */
 432                 urb = usb_alloc_urb(0, GFP_KERNEL);
 433                 if (!urb) {
 434                         err = -ENOMEM;
 435                         break;
 436                 }
 437
 438                 buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);
 439                 if (!buf) {
 440                         usb_free_urb(urb);
 441                         err = -ENOMEM;
 442                         break;
 443                 }
 444
 445                 context = dev->tx_contexts + i;
 446                 context->dev = dev;
 447                 context->urb = urb;
 448
 449                 usb_fill_bulk_urb(urb, dev->udev,
 450                         usb_sndbulkpipe(dev->udev, dev->ep_msg_out),
 451                         buf, dev->adapter->tx_buffer_size,
 452                         peak_usb_write_bulk_callback, context);
 453
 454                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 455                 urb->transfer_flags |= URB_FREE_BUFFER;
 456         }
 457
 458         /* warn if we were not able to allocate enough tx contexts */
 459         if (i < PCAN_USB_MAX_TX_URBS) {
 460                 if (i == 0) {
 461                         netdev_err(netdev, "couldn't setup any tx URB\n");
 462                         goto err_tx;
 463                 }
 464
 465                 netdev_warn(netdev, "tx performance may be slow\n");
 466         }
 467
 468         if (dev->adapter->dev_start) {
 469                 err = dev->adapter->dev_start(dev);
 470                 if (err)
 471                         goto err_adapter;
 472         }
 473
 474         dev->state |= PCAN_USB_STATE_STARTED;
 475
 476         /* can set bus on now */
 477         if (dev->adapter->dev_set_bus) {
 478                 err = dev->adapter->dev_set_bus(dev, 1);
 479                 if (err)
 480                         goto err_adapter;
 481         }
 482
 483         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 484
 485         return 0;
 486
 487 err_adapter:
 488         if (err == -ENODEV)
 489                 netif_device_detach(dev->netdev);
 490
 491         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 492
 493         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 494                 usb_free_urb(dev->tx_contexts[i].urb);
 495                 dev->tx_contexts[i].urb = NULL;
 496         }
 497 err_tx:
 498         usb_kill_anchored_urbs(&dev->rx_submitted);
 499
 500         return err;
 501 }
 502
 503 /*
 504  * called by netdev to open the corresponding CAN interface.
 505  */
 506 static int peak_usb_ndo_open(struct net_device *netdev)
 507 {
 508         struct peak_usb_device *dev = netdev_priv(netdev);
 509         int err;
 510
 511         /* common open */
 512         err = open_candev(netdev);
 513         if (err)
 514                 return err;
 515
 516         /* finally start device */
 517         err = peak_usb_start(dev);
 518         if (err) {
 519                 netdev_err(netdev, "couldn't start device: %d\n", err);
 520                 close_candev(netdev);
 521                 return err;
 522         }
 523
 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         close_candev(netdev);
 572
 573         dev->can.state = CAN_STATE_STOPPED;
 574
 575         /* unlink all pending urbs and free used memory */
 576         peak_usb_unlink_all_urbs(dev);
 577
 578         if (dev->adapter->dev_stop)
 579                 dev->adapter->dev_stop(dev);
 580
 581         /* can set bus off now */
 582         if (dev->adapter->dev_set_bus) {
 583                 int err = dev->adapter->dev_set_bus(dev, 0);
 584                 if (err)
 585                         return err;
 586         }
 587
 588         return 0;
 589 }
 590
 591 /*
 592  * handle end of waiting for the device to reset
 593  */
 594 void peak_usb_restart_complete(struct peak_usb_device *dev)
 595 {
 596         /* finally MUST update can state */
 597         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 598
 599         /* netdev queue can be awaken now */
 600         netif_wake_queue(dev->netdev);
 601 }
 602
 603 void peak_usb_async_complete(struct urb *urb)
 604 {
 605         kfree(urb->transfer_buffer);
 606         usb_free_urb(urb);
 607 }
 608
 609 /*
 610  * device (auto-)restart mechanism runs in a timer context =>
 611  * MUST handle restart with asynchronous usb transfers
 612  */
 613 static int peak_usb_restart(struct peak_usb_device *dev)
 614 {
 615         struct urb *urb;
 616         int err;
 617         u8 *buf;
 618
 619         /*
 620          * if device doesn't define any asynchronous restart handler, simply
 621          * wake the netdev queue up
 622          */
 623         if (!dev->adapter->dev_restart_async) {
 624                 peak_usb_restart_complete(dev);
 625                 return 0;
 626         }
 627
 628         /* first allocate a urb to handle the asynchronous steps */
 629         urb = usb_alloc_urb(0, GFP_ATOMIC);
 630         if (!urb)
 631                 return -ENOMEM;
 632
 633         /* also allocate enough space for the commands to send */
 634         buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);
 635         if (!buf) {
 636                 usb_free_urb(urb);
 637                 return -ENOMEM;
 638         }
 639
 640         /* call the device specific handler for the restart */
 641         err = dev->adapter->dev_restart_async(dev, urb, buf);
 642         if (!err)
 643                 return 0;
 644
 645         kfree(buf);
 646         usb_free_urb(urb);
 647
 648         return err;
 649 }
 650
 651 /*
 652  * candev callback used to change CAN mode.
 653  * Warning: this is called from a timer context!
 654  */
 655 static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 656 {
 657         struct peak_usb_device *dev = netdev_priv(netdev);
 658         int err = 0;
 659
 660         switch (mode) {
 661         case CAN_MODE_START:
 662                 err = peak_usb_restart(dev);
 663                 if (err)
 664                         netdev_err(netdev, "couldn't start device (err %d)\n",
 665                                    err);
 666                 break;
 667
 668         default:
 669                 return -EOPNOTSUPP;
 670         }
 671
 672         return err;
 673 }
 674
 675 /*
 676  * candev callback used to set device nominal/arbitration bitrate.
 677  */
 678 static int peak_usb_set_bittiming(struct net_device *netdev)
 679 {
 680         struct peak_usb_device *dev = netdev_priv(netdev);
 681         const struct peak_usb_adapter *pa = dev->adapter;
 682
 683         if (pa->dev_set_bittiming) {
 684                 struct can_bittiming *bt = &dev->can.bittiming;
 685                 int err = pa->dev_set_bittiming(dev, bt);
 686
 687                 if (err)
 688                         netdev_info(netdev, "couldn't set bitrate (err %d)\n",
 689                                     err);
 690                 return err;
 691         }
 692
 693         return 0;
 694 }
 695
 696 /*
 697  * candev callback used to set device data bitrate.
 698  */
 699 static int peak_usb_set_data_bittiming(struct net_device *netdev)
 700 {
 701         struct peak_usb_device *dev = netdev_priv(netdev);
 702         const struct peak_usb_adapter *pa = dev->adapter;
 703
 704         if (pa->dev_set_data_bittiming) {
 705                 struct can_bittiming *bt = &dev->can.data_bittiming;
 706                 int err = pa->dev_set_data_bittiming(dev, bt);
 707
 708                 if (err)
 709                         netdev_info(netdev,
 710                                     "couldn't set data bitrate (err %d)\n",
 711                                     err);
 712
 713                 return err;
 714         }
 715
 716         return 0;
 717 }
 718
 719 static const struct net_device_ops peak_usb_netdev_ops = {
 720         .ndo_open = peak_usb_ndo_open,
 721         .ndo_stop = peak_usb_ndo_stop,
 722         .ndo_start_xmit = peak_usb_ndo_start_xmit,
 723         .ndo_change_mtu = can_change_mtu,
 724 };
 725
 726 /*
 727  * create one device which is attached to CAN controller #ctrl_idx of the
 728  * usb adapter.
 729  */
 730 static int peak_usb_create_dev(const struct peak_usb_adapter *peak_usb_adapter,
 731                                struct usb_interface *intf, int ctrl_idx)
 732 {
 733         struct usb_device *usb_dev = interface_to_usbdev(intf);
 734         int sizeof_candev = peak_usb_adapter->sizeof_dev_private;
 735         struct peak_usb_device *dev;
 736         struct net_device *netdev;
 737         int i, err;
 738         u16 tmp16;
 739
 740         if (sizeof_candev < sizeof(struct peak_usb_device))
 741                 sizeof_candev = sizeof(struct peak_usb_device);
 742
 743         netdev = alloc_candev(sizeof_candev, PCAN_USB_MAX_TX_URBS);
 744         if (!netdev) {
 745                 dev_err(&intf->dev, "%s: couldn't alloc candev\n",
 746                         PCAN_USB_DRIVER_NAME);
 747                 return -ENOMEM;
 748         }
 749
 750         dev = netdev_priv(netdev);
 751
 752         /* allocate a buffer large enough to send commands */
 753         dev->cmd_buf = kzalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
 754         if (!dev->cmd_buf) {
 755                 err = -ENOMEM;
 756                 goto lbl_free_candev;
 757         }
 758
 759         dev->udev = usb_dev;
 760         dev->netdev = netdev;
 761         dev->adapter = peak_usb_adapter;
 762         dev->ctrl_idx = ctrl_idx;
 763         dev->state = PCAN_USB_STATE_CONNECTED;
 764
 765         dev->ep_msg_in = peak_usb_adapter->ep_msg_in;
 766         dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];
 767
 768         dev->can.clock = peak_usb_adapter->clock;
 769         dev->can.bittiming_const = peak_usb_adapter->bittiming_const;
 770         dev->can.do_set_bittiming = peak_usb_set_bittiming;
 771         dev->can.data_bittiming_const = peak_usb_adapter->data_bittiming_const;
 772         dev->can.do_set_data_bittiming = peak_usb_set_data_bittiming;
 773         dev->can.do_set_mode = peak_usb_set_mode;
 774         dev->can.do_get_berr_counter = peak_usb_adapter->do_get_berr_counter;
 775         dev->can.ctrlmode_supported = peak_usb_adapter->ctrlmode_supported;
 776
 777         netdev->netdev_ops = &peak_usb_netdev_ops;
 778
 779         netdev->flags |= IFF_ECHO; /* we support local echo */
 780
 781         init_usb_anchor(&dev->rx_submitted);
 782
 783         init_usb_anchor(&dev->tx_submitted);
 784         atomic_set(&dev->active_tx_urbs, 0);
 785
 786         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 787                 dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;
 788
 789         dev->prev_siblings = usb_get_intfdata(intf);
 790         usb_set_intfdata(intf, dev);
 791
 792         SET_NETDEV_DEV(netdev, &intf->dev);
 793         netdev->dev_id = ctrl_idx;
 794
 795         err = register_candev(netdev);
 796         if (err) {
 797                 dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
 798                 goto lbl_restore_intf_data;
 799         }
 800
 801         if (dev->prev_siblings)
 802                 (dev->prev_siblings)->next_siblings = dev;
 803
 804         /* keep hw revision into the netdevice */
 805         tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);
 806         dev->device_rev = tmp16 >> 8;
 807
 808         if (dev->adapter->dev_init) {
 809                 err = dev->adapter->dev_init(dev);
 810                 if (err)
 811                         goto lbl_unregister_candev;
 812         }
 813
 814         /* set bus off */
 815         if (dev->adapter->dev_set_bus) {
 816                 err = dev->adapter->dev_set_bus(dev, 0);
 817                 if (err)
 818                         goto lbl_unregister_candev;
 819         }
 820
 821         /* get device number early */
 822         if (dev->adapter->dev_get_device_id)
 823                 dev->adapter->dev_get_device_id(dev, &dev->device_number);
 824
 825         netdev_info(netdev, "attached to %s channel %u (device %u)\n",
 826                         peak_usb_adapter->name, ctrl_idx, dev->device_number);
 827
 828         return 0;
 829
 830 lbl_unregister_candev:
 831         unregister_candev(netdev);
 832
 833 lbl_restore_intf_data:
 834         usb_set_intfdata(intf, dev->prev_siblings);
 835         kfree(dev->cmd_buf);
 836
 837 lbl_free_candev:
 838         free_candev(netdev);
 839
 840         return err;
 841 }
 842
 843 /*
 844  * called by the usb core when the device is unplugged from the system
 845  */
 846 static void peak_usb_disconnect(struct usb_interface *intf)
 847 {
 848         struct peak_usb_device *dev;
 849         struct peak_usb_device *dev_prev_siblings;
 850
 851         /* unregister as many netdev devices as siblings */
 852         for (dev = usb_get_intfdata(intf); dev; dev = dev_prev_siblings) {
 853                 struct net_device *netdev = dev->netdev;
 854                 char name[IFNAMSIZ];
 855
 856                 dev_prev_siblings = dev->prev_siblings;
 857                 dev->state &= ~PCAN_USB_STATE_CONNECTED;
 858                 strlcpy(name, netdev->name, IFNAMSIZ);
 859
 860                 unregister_netdev(netdev);
 861
 862                 kfree(dev->cmd_buf);
 863                 dev->next_siblings = NULL;
 864                 if (dev->adapter->dev_free)
 865                         dev->adapter->dev_free(dev);
 866
 867                 free_candev(netdev);
 868                 dev_info(&intf->dev, "%s removed\n", name);
 869         }
 870
 871         usb_set_intfdata(intf, NULL);
 872 }
 873
 874 /*
 875  * probe function for new PEAK-System devices
 876  */
 877 static int peak_usb_probe(struct usb_interface *intf,
 878                           const struct usb_device_id *id)
 879 {
 880         struct usb_device *usb_dev = interface_to_usbdev(intf);
 881         const u16 usb_id_product = le16_to_cpu(usb_dev->descriptor.idProduct);
 882         const struct peak_usb_adapter *peak_usb_adapter = NULL;
 883         int i, err = -ENOMEM;
 884
 885         /* get corresponding PCAN-USB adapter */
 886         for (i = 0; i < ARRAY_SIZE(peak_usb_adapters_list); i++)
 887                 if (peak_usb_adapters_list[i]->device_id == usb_id_product) {
 888                         peak_usb_adapter = peak_usb_adapters_list[i];
 889                         break;
 890                 }
 891
 892         if (!peak_usb_adapter) {
 893                 /* should never come except device_id bad usage in this file */
 894                 pr_err("%s: didn't find device id. 0x%x in devices list\n",
 895                         PCAN_USB_DRIVER_NAME, usb_id_product);
 896                 return -ENODEV;
 897         }
 898
 899         /* got corresponding adapter: check if it handles current interface */
 900         if (peak_usb_adapter->intf_probe) {
 901                 err = peak_usb_adapter->intf_probe(intf);
 902                 if (err)
 903                         return err;
 904         }
 905
 906         for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
 907                 err = peak_usb_create_dev(peak_usb_adapter, intf, i);
 908                 if (err) {
 909                         /* deregister already created devices */
 910                         peak_usb_disconnect(intf);
 911                         break;
 912                 }
 913         }
 914
 915         return err;
 916 }
 917
 918 /* usb specific object needed to register this driver with the usb subsystem */
 919 static struct usb_driver peak_usb_driver = {
 920         .name = PCAN_USB_DRIVER_NAME,
 921         .disconnect = peak_usb_disconnect,
 922         .probe = peak_usb_probe,
 923         .id_table = peak_usb_table,
 924 };
 925
 926 static int __init peak_usb_init(void)
 927 {
 928         int err;
 929
 930         /* register this driver with the USB subsystem */
 931         err = usb_register(&peak_usb_driver);
 932         if (err)
 933                 pr_err("%s: usb_register failed (err %d)\n",
 934                         PCAN_USB_DRIVER_NAME, err);
 935
 936         return err;
 937 }
 938
 939 static int peak_usb_do_device_exit(struct device *d, void *arg)
 940 {
 941         struct usb_interface *intf = to_usb_interface(d);
 942         struct peak_usb_device *dev;
 943
 944         /* stop as many netdev devices as siblings */
 945         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
 946                 struct net_device *netdev = dev->netdev;
 947
 948                 if (netif_device_present(netdev))
 949                         if (dev->adapter->dev_exit)
 950                                 dev->adapter->dev_exit(dev);
 951         }
 952
 953         return 0;
 954 }
 955
 956 static void __exit peak_usb_exit(void)
 957 {
 958         int err;
 959
 960         /* last chance do send any synchronous commands here */
 961         err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
 962                                      NULL, peak_usb_do_device_exit);
 963         if (err)
 964                 pr_err("%s: failed to stop all can devices (err %d)\n",
 965                         PCAN_USB_DRIVER_NAME, err);
 966
 967         /* deregister this driver with the USB subsystem */
 968         usb_deregister(&peak_usb_driver);
 969
 970         pr_info("%s: PCAN-USB interfaces driver unloaded\n",
 971                 PCAN_USB_DRIVER_NAME);
 972 }
 973
 974 module_init(peak_usb_init);
 975 module_exit(peak_usb_exit);