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                 s64 delta_ts = 0;
 134
 135                 /* General case: dev_ts_1 < dev_ts_2 < ts, with:
 136                  *
 137                  * - dev_ts_1 = previous sync timestamp
 138                  * - dev_ts_2 = last sync timestamp
 139                  * - ts = event timestamp
 140                  * - ts_period = known sync period (theoretical)
 141                  *             ~ dev_ts2 - dev_ts1
 142                  * *but*:
 143                  *
 144                  * - time counters wrap (see adapter->ts_used_bits)
 145                  * - sometimes, dev_ts_1 < ts < dev_ts2
 146                  *
 147                  * "normal" case (sync time counters increase):
 148                  * must take into account case when ts wraps (tsw)
 149                  *
 150                  *      < ts_period > <          >
 151                  *     |             |            |
 152                  *  ---+--------+----+-------0-+--+-->
 153                  *     ts_dev_1 |    ts_dev_2  |
 154                  *              ts             tsw
 155                  */
 156                 if (time_ref->ts_dev_1 < time_ref->ts_dev_2) {
 157                         /* case when event time (tsw) wraps */
 158                         if (ts < time_ref->ts_dev_1)
 159                                 delta_ts = 1 << time_ref->adapter->ts_used_bits;
 160
 161                 /* Otherwise, sync time counter (ts_dev_2) has wrapped:
 162                  * handle case when event time (tsn) hasn't.
 163                  *
 164                  *      < ts_period > <          >
 165                  *     |             |            |
 166                  *  ---+--------+--0-+---------+--+-->
 167                  *     ts_dev_1 |    ts_dev_2  |
 168                  *              tsn            ts
 169                  */
 170                 } else if (time_ref->ts_dev_1 < ts) {
 171                         delta_ts = -(1 << time_ref->adapter->ts_used_bits);
 172                 }
 173
 174                 /* add delay between last sync and event timestamps */
 175                 delta_ts += (signed int)(ts - time_ref->ts_dev_2);
 176
 177                 /* add time from beginning to last sync */
 178                 delta_ts += time_ref->ts_total;
 179
 180                 /* convert ticks number into microseconds */
 181                 delta_us = delta_ts * time_ref->adapter->us_per_ts_scale;
 182                 delta_us >>= time_ref->adapter->us_per_ts_shift;
 183
 184                 *time = ktime_add_us(time_ref->tv_host_0, delta_us);
 185         } else {
 186                 *time = ktime_get();
 187         }
 188 }
 189
 190 /*
 191  * post received skb after having set any hw timestamp
 192  */
 193 int peak_usb_netif_rx(struct sk_buff *skb,
 194                       struct peak_time_ref *time_ref, u32 ts_low)
 195 {
 196         struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
 197
 198         peak_usb_get_ts_time(time_ref, ts_low, &hwts->hwtstamp);
 199
 200         return netif_rx(skb);
 201 }
 202
 203 /*
 204  * callback for bulk Rx urb
 205  */
 206 static void peak_usb_read_bulk_callback(struct urb *urb)
 207 {
 208         struct peak_usb_device *dev = urb->context;
 209         struct net_device *netdev;
 210         int err;
 211
 212         netdev = dev->netdev;
 213
 214         if (!netif_device_present(netdev))
 215                 return;
 216
 217         /* check reception status */
 218         switch (urb->status) {
 219         case 0:
 220                 /* success */
 221                 break;
 222
 223         case -EILSEQ:
 224         case -ENOENT:
 225         case -ECONNRESET:
 226         case -ESHUTDOWN:
 227                 return;
 228
 229         default:
 230                 if (net_ratelimit())
 231                         netdev_err(netdev,
 232                                    "Rx urb aborted (%d)\n", urb->status);
 233                 goto resubmit_urb;
 234         }
 235
 236         /* protect from any incoming empty msgs */
 237         if ((urb->actual_length > 0) && (dev->adapter->dev_decode_buf)) {
 238                 /* handle these kinds of msgs only if _start callback called */
 239                 if (dev->state & PCAN_USB_STATE_STARTED) {
 240                         err = dev->adapter->dev_decode_buf(dev, urb);
 241                         if (err)
 242                                 pcan_dump_mem("received usb message",
 243                                               urb->transfer_buffer,
 244                                               urb->transfer_buffer_length);
 245                 }
 246         }
 247
 248 resubmit_urb:
 249         usb_fill_bulk_urb(urb, dev->udev,
 250                 usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 251                 urb->transfer_buffer, dev->adapter->rx_buffer_size,
 252                 peak_usb_read_bulk_callback, dev);
 253
 254         usb_anchor_urb(urb, &dev->rx_submitted);
 255         err = usb_submit_urb(urb, GFP_ATOMIC);
 256         if (!err)
 257                 return;
 258
 259         usb_unanchor_urb(urb);
 260
 261         if (err == -ENODEV)
 262                 netif_device_detach(netdev);
 263         else
 264                 netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
 265                            err);
 266 }
 267
 268 /*
 269  * callback for bulk Tx urb
 270  */
 271 static void peak_usb_write_bulk_callback(struct urb *urb)
 272 {
 273         struct peak_tx_urb_context *context = urb->context;
 274         struct peak_usb_device *dev;
 275         struct net_device *netdev;
 276
 277         BUG_ON(!context);
 278
 279         dev = context->dev;
 280         netdev = dev->netdev;
 281
 282         atomic_dec(&dev->active_tx_urbs);
 283
 284         if (!netif_device_present(netdev))
 285                 return;
 286
 287         /* check tx status */
 288         switch (urb->status) {
 289         case 0:
 290                 /* transmission complete */
 291                 netdev->stats.tx_packets++;
 292                 netdev->stats.tx_bytes += context->data_len;
 293
 294                 /* prevent tx timeout */
 295                 netif_trans_update(netdev);
 296                 break;
 297
 298         default:
 299                 if (net_ratelimit())
 300                         netdev_err(netdev, "Tx urb aborted (%d)\n",
 301                                    urb->status);
 302         case -EPROTO:
 303         case -ENOENT:
 304         case -ECONNRESET:
 305         case -ESHUTDOWN:
 306
 307                 break;
 308         }
 309
 310         /* should always release echo skb and corresponding context */
 311         can_get_echo_skb(netdev, context->echo_index);
 312         context->echo_index = PCAN_USB_MAX_TX_URBS;
 313
 314         /* do wakeup tx queue in case of success only */
 315         if (!urb->status)
 316                 netif_wake_queue(netdev);
 317 }
 318
 319 /*
 320  * called by netdev to send one skb on the CAN interface.
 321  */
 322 static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
 323                                            struct net_device *netdev)
 324 {
 325         struct peak_usb_device *dev = netdev_priv(netdev);
 326         struct peak_tx_urb_context *context = NULL;
 327         struct net_device_stats *stats = &netdev->stats;
 328         struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 329         struct urb *urb;
 330         u8 *obuf;
 331         int i, err;
 332         size_t size = dev->adapter->tx_buffer_size;
 333
 334         if (can_dropped_invalid_skb(netdev, skb))
 335                 return NETDEV_TX_OK;
 336
 337         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 338                 if (dev->tx_contexts[i].echo_index == PCAN_USB_MAX_TX_URBS) {
 339                         context = dev->tx_contexts + i;
 340                         break;
 341                 }
 342
 343         if (!context) {
 344                 /* should not occur except during restart */
 345                 return NETDEV_TX_BUSY;
 346         }
 347
 348         urb = context->urb;
 349         obuf = urb->transfer_buffer;
 350
 351         err = dev->adapter->dev_encode_msg(dev, skb, obuf, &size);
 352         if (err) {
 353                 if (net_ratelimit())
 354                         netdev_err(netdev, "packet dropped\n");
 355                 dev_kfree_skb(skb);
 356                 stats->tx_dropped++;
 357                 return NETDEV_TX_OK;
 358         }
 359
 360         context->echo_index = i;
 361
 362         /* Note: this works with CANFD frames too */
 363         context->data_len = cfd->len;
 364
 365         usb_anchor_urb(urb, &dev->tx_submitted);
 366
 367         can_put_echo_skb(skb, netdev, context->echo_index);
 368
 369         atomic_inc(&dev->active_tx_urbs);
 370
 371         err = usb_submit_urb(urb, GFP_ATOMIC);
 372         if (err) {
 373                 can_free_echo_skb(netdev, context->echo_index);
 374
 375                 usb_unanchor_urb(urb);
 376
 377                 /* this context is not used in fact */
 378                 context->echo_index = PCAN_USB_MAX_TX_URBS;
 379
 380                 atomic_dec(&dev->active_tx_urbs);
 381
 382                 switch (err) {
 383                 case -ENODEV:
 384                         netif_device_detach(netdev);
 385                         break;
 386                 default:
 387                         netdev_warn(netdev, "tx urb submitting failed err=%d\n",
 388                                     err);
 389                         fallthrough;
 390                 case -ENOENT:
 391                         /* cable unplugged */
 392                         stats->tx_dropped++;
 393                 }
 394         } else {
 395                 netif_trans_update(netdev);
 396
 397                 /* slow down tx path */
 398                 if (atomic_read(&dev->active_tx_urbs) >= PCAN_USB_MAX_TX_URBS)
 399                         netif_stop_queue(netdev);
 400         }
 401
 402         return NETDEV_TX_OK;
 403 }
 404
 405 /*
 406  * start the CAN interface.
 407  * Rx and Tx urbs are allocated here. Rx urbs are submitted here.
 408  */
 409 static int peak_usb_start(struct peak_usb_device *dev)
 410 {
 411         struct net_device *netdev = dev->netdev;
 412         int err, i;
 413
 414         for (i = 0; i < PCAN_USB_MAX_RX_URBS; i++) {
 415                 struct urb *urb;
 416                 u8 *buf;
 417
 418                 /* create a URB, and a buffer for it, to receive usb messages */
 419                 urb = usb_alloc_urb(0, GFP_KERNEL);
 420                 if (!urb) {
 421                         err = -ENOMEM;
 422                         break;
 423                 }
 424
 425                 buf = kmalloc(dev->adapter->rx_buffer_size, GFP_KERNEL);
 426                 if (!buf) {
 427                         usb_free_urb(urb);
 428                         err = -ENOMEM;
 429                         break;
 430                 }
 431
 432                 usb_fill_bulk_urb(urb, dev->udev,
 433                         usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 434                         buf, dev->adapter->rx_buffer_size,
 435                         peak_usb_read_bulk_callback, dev);
 436
 437                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 438                 urb->transfer_flags |= URB_FREE_BUFFER;
 439                 usb_anchor_urb(urb, &dev->rx_submitted);
 440
 441                 err = usb_submit_urb(urb, GFP_KERNEL);
 442                 if (err) {
 443                         if (err == -ENODEV)
 444                                 netif_device_detach(dev->netdev);
 445
 446                         usb_unanchor_urb(urb);
 447                         kfree(buf);
 448                         usb_free_urb(urb);
 449                         break;
 450                 }
 451
 452                 /* drop reference, USB core will take care of freeing it */
 453                 usb_free_urb(urb);
 454         }
 455
 456         /* did we submit any URBs? Warn if we was not able to submit all urbs */
 457         if (i < PCAN_USB_MAX_RX_URBS) {
 458                 if (i == 0) {
 459                         netdev_err(netdev, "couldn't setup any rx URB\n");
 460                         return err;
 461                 }
 462
 463                 netdev_warn(netdev, "rx performance may be slow\n");
 464         }
 465
 466         /* pre-alloc tx buffers and corresponding urbs */
 467         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 468                 struct peak_tx_urb_context *context;
 469                 struct urb *urb;
 470                 u8 *buf;
 471
 472                 /* create a URB and a buffer for it, to transmit usb messages */
 473                 urb = usb_alloc_urb(0, GFP_KERNEL);
 474                 if (!urb) {
 475                         err = -ENOMEM;
 476                         break;
 477                 }
 478
 479                 buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);
 480                 if (!buf) {
 481                         usb_free_urb(urb);
 482                         err = -ENOMEM;
 483                         break;
 484                 }
 485
 486                 context = dev->tx_contexts + i;
 487                 context->dev = dev;
 488                 context->urb = urb;
 489
 490                 usb_fill_bulk_urb(urb, dev->udev,
 491                         usb_sndbulkpipe(dev->udev, dev->ep_msg_out),
 492                         buf, dev->adapter->tx_buffer_size,
 493                         peak_usb_write_bulk_callback, context);
 494
 495                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 496                 urb->transfer_flags |= URB_FREE_BUFFER;
 497         }
 498
 499         /* warn if we were not able to allocate enough tx contexts */
 500         if (i < PCAN_USB_MAX_TX_URBS) {
 501                 if (i == 0) {
 502                         netdev_err(netdev, "couldn't setup any tx URB\n");
 503                         goto err_tx;
 504                 }
 505
 506                 netdev_warn(netdev, "tx performance may be slow\n");
 507         }
 508
 509         if (dev->adapter->dev_start) {
 510                 err = dev->adapter->dev_start(dev);
 511                 if (err)
 512                         goto err_adapter;
 513         }
 514
 515         dev->state |= PCAN_USB_STATE_STARTED;
 516
 517         /* can set bus on now */
 518         if (dev->adapter->dev_set_bus) {
 519                 err = dev->adapter->dev_set_bus(dev, 1);
 520                 if (err)
 521                         goto err_adapter;
 522         }
 523
 524         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 525
 526         return 0;
 527
 528 err_adapter:
 529         if (err == -ENODEV)
 530                 netif_device_detach(dev->netdev);
 531
 532         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 533
 534         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 535                 usb_free_urb(dev->tx_contexts[i].urb);
 536                 dev->tx_contexts[i].urb = NULL;
 537         }
 538 err_tx:
 539         usb_kill_anchored_urbs(&dev->rx_submitted);
 540
 541         return err;
 542 }
 543
 544 /*
 545  * called by netdev to open the corresponding CAN interface.
 546  */
 547 static int peak_usb_ndo_open(struct net_device *netdev)
 548 {
 549         struct peak_usb_device *dev = netdev_priv(netdev);
 550         int err;
 551
 552         /* common open */
 553         err = open_candev(netdev);
 554         if (err)
 555                 return err;
 556
 557         /* finally start device */
 558         err = peak_usb_start(dev);
 559         if (err) {
 560                 netdev_err(netdev, "couldn't start device: %d\n", err);
 561                 close_candev(netdev);
 562                 return err;
 563         }
 564
 565         netif_start_queue(netdev);
 566
 567         return 0;
 568 }
 569
 570 /*
 571  * unlink in-flight Rx and Tx urbs and free their memory.
 572  */
 573 static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)
 574 {
 575         int i;
 576
 577         /* free all Rx (submitted) urbs */
 578         usb_kill_anchored_urbs(&dev->rx_submitted);
 579
 580         /* free unsubmitted Tx urbs first */
 581         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 582                 struct urb *urb = dev->tx_contexts[i].urb;
 583
 584                 if (!urb ||
 585                     dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {
 586                         /*
 587                          * this urb is already released or always submitted,
 588                          * let usb core free by itself
 589                          */
 590                         continue;
 591                 }
 592
 593                 usb_free_urb(urb);
 594                 dev->tx_contexts[i].urb = NULL;
 595         }
 596
 597         /* then free all submitted Tx urbs */
 598         usb_kill_anchored_urbs(&dev->tx_submitted);
 599         atomic_set(&dev->active_tx_urbs, 0);
 600 }
 601
 602 /*
 603  * called by netdev to close the corresponding CAN interface.
 604  */
 605 static int peak_usb_ndo_stop(struct net_device *netdev)
 606 {
 607         struct peak_usb_device *dev = netdev_priv(netdev);
 608
 609         dev->state &= ~PCAN_USB_STATE_STARTED;
 610         netif_stop_queue(netdev);
 611
 612         close_candev(netdev);
 613
 614         dev->can.state = CAN_STATE_STOPPED;
 615
 616         /* unlink all pending urbs and free used memory */
 617         peak_usb_unlink_all_urbs(dev);
 618
 619         if (dev->adapter->dev_stop)
 620                 dev->adapter->dev_stop(dev);
 621
 622         /* can set bus off now */
 623         if (dev->adapter->dev_set_bus) {
 624                 int err = dev->adapter->dev_set_bus(dev, 0);
 625                 if (err)
 626                         return err;
 627         }
 628
 629         return 0;
 630 }
 631
 632 /*
 633  * handle end of waiting for the device to reset
 634  */
 635 void peak_usb_restart_complete(struct peak_usb_device *dev)
 636 {
 637         /* finally MUST update can state */
 638         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 639
 640         /* netdev queue can be awaken now */
 641         netif_wake_queue(dev->netdev);
 642 }
 643
 644 void peak_usb_async_complete(struct urb *urb)
 645 {
 646         kfree(urb->transfer_buffer);
 647         usb_free_urb(urb);
 648 }
 649
 650 /*
 651  * device (auto-)restart mechanism runs in a timer context =>
 652  * MUST handle restart with asynchronous usb transfers
 653  */
 654 static int peak_usb_restart(struct peak_usb_device *dev)
 655 {
 656         struct urb *urb;
 657         int err;
 658         u8 *buf;
 659
 660         /*
 661          * if device doesn't define any asynchronous restart handler, simply
 662          * wake the netdev queue up
 663          */
 664         if (!dev->adapter->dev_restart_async) {
 665                 peak_usb_restart_complete(dev);
 666                 return 0;
 667         }
 668
 669         /* first allocate a urb to handle the asynchronous steps */
 670         urb = usb_alloc_urb(0, GFP_ATOMIC);
 671         if (!urb)
 672                 return -ENOMEM;
 673
 674         /* also allocate enough space for the commands to send */
 675         buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);
 676         if (!buf) {
 677                 usb_free_urb(urb);
 678                 return -ENOMEM;
 679         }
 680
 681         /* call the device specific handler for the restart */
 682         err = dev->adapter->dev_restart_async(dev, urb, buf);
 683         if (!err)
 684                 return 0;
 685
 686         kfree(buf);
 687         usb_free_urb(urb);
 688
 689         return err;
 690 }
 691
 692 /*
 693  * candev callback used to change CAN mode.
 694  * Warning: this is called from a timer context!
 695  */
 696 static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 697 {
 698         struct peak_usb_device *dev = netdev_priv(netdev);
 699         int err = 0;
 700
 701         switch (mode) {
 702         case CAN_MODE_START:
 703                 err = peak_usb_restart(dev);
 704                 if (err)
 705                         netdev_err(netdev, "couldn't start device (err %d)\n",
 706                                    err);
 707                 break;
 708
 709         default:
 710                 return -EOPNOTSUPP;
 711         }
 712
 713         return err;
 714 }
 715
 716 /*
 717  * candev callback used to set device nominal/arbitration bitrate.
 718  */
 719 static int peak_usb_set_bittiming(struct net_device *netdev)
 720 {
 721         struct peak_usb_device *dev = netdev_priv(netdev);
 722         const struct peak_usb_adapter *pa = dev->adapter;
 723
 724         if (pa->dev_set_bittiming) {
 725                 struct can_bittiming *bt = &dev->can.bittiming;
 726                 int err = pa->dev_set_bittiming(dev, bt);
 727
 728                 if (err)
 729                         netdev_info(netdev, "couldn't set bitrate (err %d)\n",
 730                                     err);
 731                 return err;
 732         }
 733
 734         return 0;
 735 }
 736
 737 /*
 738  * candev callback used to set device data bitrate.
 739  */
 740 static int peak_usb_set_data_bittiming(struct net_device *netdev)
 741 {
 742         struct peak_usb_device *dev = netdev_priv(netdev);
 743         const struct peak_usb_adapter *pa = dev->adapter;
 744
 745         if (pa->dev_set_data_bittiming) {
 746                 struct can_bittiming *bt = &dev->can.data_bittiming;
 747                 int err = pa->dev_set_data_bittiming(dev, bt);
 748
 749                 if (err)
 750                         netdev_info(netdev,
 751                                     "couldn't set data bitrate (err %d)\n",
 752                                     err);
 753
 754                 return err;
 755         }
 756
 757         return 0;
 758 }
 759
 760 static const struct net_device_ops peak_usb_netdev_ops = {
 761         .ndo_open = peak_usb_ndo_open,
 762         .ndo_stop = peak_usb_ndo_stop,
 763         .ndo_start_xmit = peak_usb_ndo_start_xmit,
 764         .ndo_change_mtu = can_change_mtu,
 765 };
 766
 767 /*
 768  * create one device which is attached to CAN controller #ctrl_idx of the
 769  * usb adapter.
 770  */
 771 static int peak_usb_create_dev(const struct peak_usb_adapter *peak_usb_adapter,
 772                                struct usb_interface *intf, int ctrl_idx)
 773 {
 774         struct usb_device *usb_dev = interface_to_usbdev(intf);
 775         int sizeof_candev = peak_usb_adapter->sizeof_dev_private;
 776         struct peak_usb_device *dev;
 777         struct net_device *netdev;
 778         int i, err;
 779         u16 tmp16;
 780
 781         if (sizeof_candev < sizeof(struct peak_usb_device))
 782                 sizeof_candev = sizeof(struct peak_usb_device);
 783
 784         netdev = alloc_candev(sizeof_candev, PCAN_USB_MAX_TX_URBS);
 785         if (!netdev) {
 786                 dev_err(&intf->dev, "%s: couldn't alloc candev\n",
 787                         PCAN_USB_DRIVER_NAME);
 788                 return -ENOMEM;
 789         }
 790
 791         dev = netdev_priv(netdev);
 792
 793         /* allocate a buffer large enough to send commands */
 794         dev->cmd_buf = kzalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
 795         if (!dev->cmd_buf) {
 796                 err = -ENOMEM;
 797                 goto lbl_free_candev;
 798         }
 799
 800         dev->udev = usb_dev;
 801         dev->netdev = netdev;
 802         dev->adapter = peak_usb_adapter;
 803         dev->ctrl_idx = ctrl_idx;
 804         dev->state = PCAN_USB_STATE_CONNECTED;
 805
 806         dev->ep_msg_in = peak_usb_adapter->ep_msg_in;
 807         dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];
 808
 809         dev->can.clock = peak_usb_adapter->clock;
 810         dev->can.bittiming_const = peak_usb_adapter->bittiming_const;
 811         dev->can.do_set_bittiming = peak_usb_set_bittiming;
 812         dev->can.data_bittiming_const = peak_usb_adapter->data_bittiming_const;
 813         dev->can.do_set_data_bittiming = peak_usb_set_data_bittiming;
 814         dev->can.do_set_mode = peak_usb_set_mode;
 815         dev->can.do_get_berr_counter = peak_usb_adapter->do_get_berr_counter;
 816         dev->can.ctrlmode_supported = peak_usb_adapter->ctrlmode_supported;
 817
 818         netdev->netdev_ops = &peak_usb_netdev_ops;
 819
 820         netdev->flags |= IFF_ECHO; /* we support local echo */
 821
 822         init_usb_anchor(&dev->rx_submitted);
 823
 824         init_usb_anchor(&dev->tx_submitted);
 825         atomic_set(&dev->active_tx_urbs, 0);
 826
 827         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 828                 dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;
 829
 830         dev->prev_siblings = usb_get_intfdata(intf);
 831         usb_set_intfdata(intf, dev);
 832
 833         SET_NETDEV_DEV(netdev, &intf->dev);
 834         netdev->dev_id = ctrl_idx;
 835
 836         err = register_candev(netdev);
 837         if (err) {
 838                 dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
 839                 goto lbl_restore_intf_data;
 840         }
 841
 842         if (dev->prev_siblings)
 843                 (dev->prev_siblings)->next_siblings = dev;
 844
 845         /* keep hw revision into the netdevice */
 846         tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);
 847         dev->device_rev = tmp16 >> 8;
 848
 849         if (dev->adapter->dev_init) {
 850                 err = dev->adapter->dev_init(dev);
 851                 if (err)
 852                         goto lbl_unregister_candev;
 853         }
 854
 855         /* set bus off */
 856         if (dev->adapter->dev_set_bus) {
 857                 err = dev->adapter->dev_set_bus(dev, 0);
 858                 if (err)
 859                         goto lbl_unregister_candev;
 860         }
 861
 862         /* get device number early */
 863         if (dev->adapter->dev_get_device_id)
 864                 dev->adapter->dev_get_device_id(dev, &dev->device_number);
 865
 866         netdev_info(netdev, "attached to %s channel %u (device %u)\n",
 867                         peak_usb_adapter->name, ctrl_idx, dev->device_number);
 868
 869         return 0;
 870
 871 lbl_unregister_candev:
 872         unregister_candev(netdev);
 873
 874 lbl_restore_intf_data:
 875         usb_set_intfdata(intf, dev->prev_siblings);
 876         kfree(dev->cmd_buf);
 877
 878 lbl_free_candev:
 879         free_candev(netdev);
 880
 881         return err;
 882 }
 883
 884 /*
 885  * called by the usb core when the device is unplugged from the system
 886  */
 887 static void peak_usb_disconnect(struct usb_interface *intf)
 888 {
 889         struct peak_usb_device *dev;
 890         struct peak_usb_device *dev_prev_siblings;
 891
 892         /* unregister as many netdev devices as siblings */
 893         for (dev = usb_get_intfdata(intf); dev; dev = dev_prev_siblings) {
 894                 struct net_device *netdev = dev->netdev;
 895                 char name[IFNAMSIZ];
 896
 897                 dev_prev_siblings = dev->prev_siblings;
 898                 dev->state &= ~PCAN_USB_STATE_CONNECTED;
 899                 strlcpy(name, netdev->name, IFNAMSIZ);
 900
 901                 unregister_netdev(netdev);
 902
 903                 kfree(dev->cmd_buf);
 904                 dev->next_siblings = NULL;
 905                 if (dev->adapter->dev_free)
 906                         dev->adapter->dev_free(dev);
 907
 908                 free_candev(netdev);
 909                 dev_info(&intf->dev, "%s removed\n", name);
 910         }
 911
 912         usb_set_intfdata(intf, NULL);
 913 }
 914
 915 /*
 916  * probe function for new PEAK-System devices
 917  */
 918 static int peak_usb_probe(struct usb_interface *intf,
 919                           const struct usb_device_id *id)
 920 {
 921         struct usb_device *usb_dev = interface_to_usbdev(intf);
 922         const u16 usb_id_product = le16_to_cpu(usb_dev->descriptor.idProduct);
 923         const struct peak_usb_adapter *peak_usb_adapter = NULL;
 924         int i, err = -ENOMEM;
 925
 926         /* get corresponding PCAN-USB adapter */
 927         for (i = 0; i < ARRAY_SIZE(peak_usb_adapters_list); i++)
 928                 if (peak_usb_adapters_list[i]->device_id == usb_id_product) {
 929                         peak_usb_adapter = peak_usb_adapters_list[i];
 930                         break;
 931                 }
 932
 933         if (!peak_usb_adapter) {
 934                 /* should never come except device_id bad usage in this file */
 935                 pr_err("%s: didn't find device id. 0x%x in devices list\n",
 936                         PCAN_USB_DRIVER_NAME, usb_id_product);
 937                 return -ENODEV;
 938         }
 939
 940         /* got corresponding adapter: check if it handles current interface */
 941         if (peak_usb_adapter->intf_probe) {
 942                 err = peak_usb_adapter->intf_probe(intf);
 943                 if (err)
 944                         return err;
 945         }
 946
 947         for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
 948                 err = peak_usb_create_dev(peak_usb_adapter, intf, i);
 949                 if (err) {
 950                         /* deregister already created devices */
 951                         peak_usb_disconnect(intf);
 952                         break;
 953                 }
 954         }
 955
 956         return err;
 957 }
 958
 959 /* usb specific object needed to register this driver with the usb subsystem */
 960 static struct usb_driver peak_usb_driver = {
 961         .name = PCAN_USB_DRIVER_NAME,
 962         .disconnect = peak_usb_disconnect,
 963         .probe = peak_usb_probe,
 964         .id_table = peak_usb_table,
 965 };
 966
 967 static int __init peak_usb_init(void)
 968 {
 969         int err;
 970
 971         /* register this driver with the USB subsystem */
 972         err = usb_register(&peak_usb_driver);
 973         if (err)
 974                 pr_err("%s: usb_register failed (err %d)\n",
 975                         PCAN_USB_DRIVER_NAME, err);
 976
 977         return err;
 978 }
 979
 980 static int peak_usb_do_device_exit(struct device *d, void *arg)
 981 {
 982         struct usb_interface *intf = to_usb_interface(d);
 983         struct peak_usb_device *dev;
 984
 985         /* stop as many netdev devices as siblings */
 986         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
 987                 struct net_device *netdev = dev->netdev;
 988
 989                 if (netif_device_present(netdev))
 990                         if (dev->adapter->dev_exit)
 991                                 dev->adapter->dev_exit(dev);
 992         }
 993
 994         return 0;
 995 }
 996
 997 static void __exit peak_usb_exit(void)
 998 {
 999         int err;
1000
1001         /* last chance do send any synchronous commands here */
1002         err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
1003                                      NULL, peak_usb_do_device_exit);
1004         if (err)
1005                 pr_err("%s: failed to stop all can devices (err %d)\n",
1006                         PCAN_USB_DRIVER_NAME, err);
1007
1008         /* deregister this driver with the USB subsystem */
1009         usb_deregister(&peak_usb_driver);
1010
1011         pr_info("%s: PCAN-USB interfaces driver unloaded\n",
1012                 PCAN_USB_DRIVER_NAME);
1013 }
1014
1015 module_init(peak_usb_init);
1016 module_exit(peak_usb_exit);