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                 s64 delta_ts = 0;
 154
 155                 /* General case: dev_ts_1 < dev_ts_2 < ts, with:
 156                  *
 157                  * - dev_ts_1 = previous sync timestamp
 158                  * - dev_ts_2 = last sync timestamp
 159                  * - ts = event timestamp
 160                  * - ts_period = known sync period (theoretical)
 161                  *             ~ dev_ts2 - dev_ts1
 162                  * *but*:
 163                  *
 164                  * - time counters wrap (see adapter->ts_used_bits)
 165                  * - sometimes, dev_ts_1 < ts < dev_ts2
 166                  *
 167                  * "normal" case (sync time counters increase):
 168                  * must take into account case when ts wraps (tsw)
 169                  *
 170                  *      < ts_period > <          >
 171                  *     |             |            |
 172                  *  ---+--------+----+-------0-+--+-->
 173                  *     ts_dev_1 |    ts_dev_2  |
 174                  *              ts             tsw
 175                  */
 176                 if (time_ref->ts_dev_1 < time_ref->ts_dev_2) {
 177                         /* case when event time (tsw) wraps */
 178                         if (ts < time_ref->ts_dev_1)
 179                                 delta_ts = BIT_ULL(time_ref->adapter->ts_used_bits);
 180
 181                 /* Otherwise, sync time counter (ts_dev_2) has wrapped:
 182                  * handle case when event time (tsn) hasn't.
 183                  *
 184                  *      < ts_period > <          >
 185                  *     |             |            |
 186                  *  ---+--------+--0-+---------+--+-->
 187                  *     ts_dev_1 |    ts_dev_2  |
 188                  *              tsn            ts
 189                  */
 190                 } else if (time_ref->ts_dev_1 < ts) {
 191                         delta_ts = -BIT_ULL(time_ref->adapter->ts_used_bits);
 192                 }
 193
 194                 /* add delay between last sync and event timestamps */
 195                 delta_ts += (signed int)(ts - time_ref->ts_dev_2);
 196
 197                 /* add time from beginning to last sync */
 198                 delta_ts += time_ref->ts_total;
 199
 200                 /* convert ticks number into microseconds */
 201                 delta_us = delta_ts * time_ref->adapter->us_per_ts_scale;
 202                 delta_us >>= time_ref->adapter->us_per_ts_shift;
 203
 204                 *tv = time_ref->tv_host_0;
 205                 peak_usb_add_us(tv, (u32)delta_us);
 206         } else {
 207                 *tv = ktime_to_timeval(ktime_get());
 208         }
 209 }
 210
 211 /*
 212  * post received skb after having set any hw timestamp
 213  */
 214 int peak_usb_netif_rx(struct sk_buff *skb,
 215                       struct peak_time_ref *time_ref, u32 ts_low, u32 ts_high)
 216 {
 217         struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
 218         struct timeval tv;
 219
 220         peak_usb_get_ts_tv(time_ref, ts_low, &tv);
 221         hwts->hwtstamp = timeval_to_ktime(tv);
 222
 223         return netif_rx(skb);
 224 }
 225
 226 /*
 227  * callback for bulk Rx urb
 228  */
 229 static void peak_usb_read_bulk_callback(struct urb *urb)
 230 {
 231         struct peak_usb_device *dev = urb->context;
 232         struct net_device *netdev;
 233         int err;
 234
 235         netdev = dev->netdev;
 236
 237         if (!netif_device_present(netdev))
 238                 return;
 239
 240         /* check reception status */
 241         switch (urb->status) {
 242         case 0:
 243                 /* success */
 244                 break;
 245
 246         case -EILSEQ:
 247         case -ENOENT:
 248         case -ECONNRESET:
 249         case -ESHUTDOWN:
 250                 return;
 251
 252         default:
 253                 if (net_ratelimit())
 254                         netdev_err(netdev,
 255                                    "Rx urb aborted (%d)\n", urb->status);
 256                 goto resubmit_urb;
 257         }
 258
 259         /* protect from any incoming empty msgs */
 260         if ((urb->actual_length > 0) && (dev->adapter->dev_decode_buf)) {
 261                 /* handle these kinds of msgs only if _start callback called */
 262                 if (dev->state & PCAN_USB_STATE_STARTED) {
 263                         err = dev->adapter->dev_decode_buf(dev, urb);
 264                         if (err)
 265                                 pcan_dump_mem("received usb message",
 266                                               urb->transfer_buffer,
 267                                               urb->transfer_buffer_length);
 268                 }
 269         }
 270
 271 resubmit_urb:
 272         usb_fill_bulk_urb(urb, dev->udev,
 273                 usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 274                 urb->transfer_buffer, dev->adapter->rx_buffer_size,
 275                 peak_usb_read_bulk_callback, dev);
 276
 277         usb_anchor_urb(urb, &dev->rx_submitted);
 278         err = usb_submit_urb(urb, GFP_ATOMIC);
 279         if (!err)
 280                 return;
 281
 282         usb_unanchor_urb(urb);
 283
 284         if (err == -ENODEV)
 285                 netif_device_detach(netdev);
 286         else
 287                 netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
 288                            err);
 289 }
 290
 291 /*
 292  * callback for bulk Tx urb
 293  */
 294 static void peak_usb_write_bulk_callback(struct urb *urb)
 295 {
 296         struct peak_tx_urb_context *context = urb->context;
 297         struct peak_usb_device *dev;
 298         struct net_device *netdev;
 299
 300         BUG_ON(!context);
 301
 302         dev = context->dev;
 303         netdev = dev->netdev;
 304
 305         atomic_dec(&dev->active_tx_urbs);
 306
 307         if (!netif_device_present(netdev))
 308                 return;
 309
 310         /* check tx status */
 311         switch (urb->status) {
 312         case 0:
 313                 /* transmission complete */
 314                 netdev->stats.tx_packets++;
 315                 netdev->stats.tx_bytes += context->data_len;
 316
 317                 /* prevent tx timeout */
 318                 netdev->trans_start = jiffies;
 319                 break;
 320
 321         default:
 322                 if (net_ratelimit())
 323                         netdev_err(netdev, "Tx urb aborted (%d)\n",
 324                                    urb->status);
 325         case -EPROTO:
 326         case -ENOENT:
 327         case -ECONNRESET:
 328         case -ESHUTDOWN:
 329
 330                 break;
 331         }
 332
 333         /* should always release echo skb and corresponding context */
 334         can_get_echo_skb(netdev, context->echo_index);
 335         context->echo_index = PCAN_USB_MAX_TX_URBS;
 336
 337         /* do wakeup tx queue in case of success only */
 338         if (!urb->status)
 339                 netif_wake_queue(netdev);
 340 }
 341
 342 /*
 343  * called by netdev to send one skb on the CAN interface.
 344  */
 345 static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
 346                                            struct net_device *netdev)
 347 {
 348         struct peak_usb_device *dev = netdev_priv(netdev);
 349         struct peak_tx_urb_context *context = NULL;
 350         struct net_device_stats *stats = &netdev->stats;
 351         struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 352         struct urb *urb;
 353         u8 *obuf;
 354         int i, err;
 355         size_t size = dev->adapter->tx_buffer_size;
 356
 357         if (can_dropped_invalid_skb(netdev, skb))
 358                 return NETDEV_TX_OK;
 359
 360         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 361                 if (dev->tx_contexts[i].echo_index == PCAN_USB_MAX_TX_URBS) {
 362                         context = dev->tx_contexts + i;
 363                         break;
 364                 }
 365
 366         if (!context) {
 367                 /* should not occur except during restart */
 368                 return NETDEV_TX_BUSY;
 369         }
 370
 371         urb = context->urb;
 372         obuf = urb->transfer_buffer;
 373
 374         err = dev->adapter->dev_encode_msg(dev, skb, obuf, &size);
 375         if (err) {
 376                 if (net_ratelimit())
 377                         netdev_err(netdev, "packet dropped\n");
 378                 dev_kfree_skb(skb);
 379                 stats->tx_dropped++;
 380                 return NETDEV_TX_OK;
 381         }
 382
 383         context->echo_index = i;
 384
 385         /* Note: this works with CANFD frames too */
 386         context->data_len = cfd->len;
 387
 388         usb_anchor_urb(urb, &dev->tx_submitted);
 389
 390         can_put_echo_skb(skb, netdev, context->echo_index);
 391
 392         atomic_inc(&dev->active_tx_urbs);
 393
 394         err = usb_submit_urb(urb, GFP_ATOMIC);
 395         if (err) {
 396                 can_free_echo_skb(netdev, context->echo_index);
 397
 398                 usb_unanchor_urb(urb);
 399
 400                 /* this context is not used in fact */
 401                 context->echo_index = PCAN_USB_MAX_TX_URBS;
 402
 403                 atomic_dec(&dev->active_tx_urbs);
 404
 405                 switch (err) {
 406                 case -ENODEV:
 407                         netif_device_detach(netdev);
 408                         break;
 409                 default:
 410                         netdev_warn(netdev, "tx urb submitting failed err=%d\n",
 411                                     err);
 412                 case -ENOENT:
 413                         /* cable unplugged */
 414                         stats->tx_dropped++;
 415                 }
 416         } else {
 417                 netdev->trans_start = jiffies;
 418
 419                 /* slow down tx path */
 420                 if (atomic_read(&dev->active_tx_urbs) >= PCAN_USB_MAX_TX_URBS)
 421                         netif_stop_queue(netdev);
 422         }
 423
 424         return NETDEV_TX_OK;
 425 }
 426
 427 /*
 428  * start the CAN interface.
 429  * Rx and Tx urbs are allocated here. Rx urbs are submitted here.
 430  */
 431 static int peak_usb_start(struct peak_usb_device *dev)
 432 {
 433         struct net_device *netdev = dev->netdev;
 434         int err, i;
 435
 436         for (i = 0; i < PCAN_USB_MAX_RX_URBS; i++) {
 437                 struct urb *urb;
 438                 u8 *buf;
 439
 440                 /* create a URB, and a buffer for it, to receive usb messages */
 441                 urb = usb_alloc_urb(0, GFP_KERNEL);
 442                 if (!urb) {
 443                         netdev_err(netdev, "No memory left for URBs\n");
 444                         err = -ENOMEM;
 445                         break;
 446                 }
 447
 448                 buf = kmalloc(dev->adapter->rx_buffer_size, GFP_KERNEL);
 449                 if (!buf) {
 450                         usb_free_urb(urb);
 451                         err = -ENOMEM;
 452                         break;
 453                 }
 454
 455                 usb_fill_bulk_urb(urb, dev->udev,
 456                         usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 457                         buf, dev->adapter->rx_buffer_size,
 458                         peak_usb_read_bulk_callback, dev);
 459
 460                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 461                 urb->transfer_flags |= URB_FREE_BUFFER;
 462                 usb_anchor_urb(urb, &dev->rx_submitted);
 463
 464                 err = usb_submit_urb(urb, GFP_KERNEL);
 465                 if (err) {
 466                         if (err == -ENODEV)
 467                                 netif_device_detach(dev->netdev);
 468
 469                         usb_unanchor_urb(urb);
 470                         kfree(buf);
 471                         usb_free_urb(urb);
 472                         break;
 473                 }
 474
 475                 /* drop reference, USB core will take care of freeing it */
 476                 usb_free_urb(urb);
 477         }
 478
 479         /* did we submit any URBs? Warn if we was not able to submit all urbs */
 480         if (i < PCAN_USB_MAX_RX_URBS) {
 481                 if (i == 0) {
 482                         netdev_err(netdev, "couldn't setup any rx URB\n");
 483                         return err;
 484                 }
 485
 486                 netdev_warn(netdev, "rx performance may be slow\n");
 487         }
 488
 489         /* pre-alloc tx buffers and corresponding urbs */
 490         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 491                 struct peak_tx_urb_context *context;
 492                 struct urb *urb;
 493                 u8 *buf;
 494
 495                 /* create a URB and a buffer for it, to transmit usb messages */
 496                 urb = usb_alloc_urb(0, GFP_KERNEL);
 497                 if (!urb) {
 498                         netdev_err(netdev, "No memory left for URBs\n");
 499                         err = -ENOMEM;
 500                         break;
 501                 }
 502
 503                 buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);
 504                 if (!buf) {
 505                         usb_free_urb(urb);
 506                         err = -ENOMEM;
 507                         break;
 508                 }
 509
 510                 context = dev->tx_contexts + i;
 511                 context->dev = dev;
 512                 context->urb = urb;
 513
 514                 usb_fill_bulk_urb(urb, dev->udev,
 515                         usb_sndbulkpipe(dev->udev, dev->ep_msg_out),
 516                         buf, dev->adapter->tx_buffer_size,
 517                         peak_usb_write_bulk_callback, context);
 518
 519                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 520                 urb->transfer_flags |= URB_FREE_BUFFER;
 521         }
 522
 523         /* warn if we were not able to allocate enough tx contexts */
 524         if (i < PCAN_USB_MAX_TX_URBS) {
 525                 if (i == 0) {
 526                         netdev_err(netdev, "couldn't setup any tx URB\n");
 527                         goto err_tx;
 528                 }
 529
 530                 netdev_warn(netdev, "tx performance may be slow\n");
 531         }
 532
 533         if (dev->adapter->dev_start) {
 534                 err = dev->adapter->dev_start(dev);
 535                 if (err)
 536                         goto err_adapter;
 537         }
 538
 539         dev->state |= PCAN_USB_STATE_STARTED;
 540
 541         /* can set bus on now */
 542         if (dev->adapter->dev_set_bus) {
 543                 err = dev->adapter->dev_set_bus(dev, 1);
 544                 if (err)
 545                         goto err_adapter;
 546         }
 547
 548         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 549
 550         return 0;
 551
 552 err_adapter:
 553         if (err == -ENODEV)
 554                 netif_device_detach(dev->netdev);
 555
 556         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 557
 558         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 559                 usb_free_urb(dev->tx_contexts[i].urb);
 560                 dev->tx_contexts[i].urb = NULL;
 561         }
 562 err_tx:
 563         usb_kill_anchored_urbs(&dev->rx_submitted);
 564
 565         return err;
 566 }
 567
 568 /*
 569  * called by netdev to open the corresponding CAN interface.
 570  */
 571 static int peak_usb_ndo_open(struct net_device *netdev)
 572 {
 573         struct peak_usb_device *dev = netdev_priv(netdev);
 574         int err;
 575
 576         /* common open */
 577         err = open_candev(netdev);
 578         if (err)
 579                 return err;
 580
 581         /* finally start device */
 582         err = peak_usb_start(dev);
 583         if (err) {
 584                 netdev_err(netdev, "couldn't start device: %d\n", err);
 585                 close_candev(netdev);
 586                 return err;
 587         }
 588
 589         netif_start_queue(netdev);
 590
 591         return 0;
 592 }
 593
 594 /*
 595  * unlink in-flight Rx and Tx urbs and free their memory.
 596  */
 597 static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)
 598 {
 599         int i;
 600
 601         /* free all Rx (submitted) urbs */
 602         usb_kill_anchored_urbs(&dev->rx_submitted);
 603
 604         /* free unsubmitted Tx urbs first */
 605         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 606                 struct urb *urb = dev->tx_contexts[i].urb;
 607
 608                 if (!urb ||
 609                     dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {
 610                         /*
 611                          * this urb is already released or always submitted,
 612                          * let usb core free by itself
 613                          */
 614                         continue;
 615                 }
 616
 617                 usb_free_urb(urb);
 618                 dev->tx_contexts[i].urb = NULL;
 619         }
 620
 621         /* then free all submitted Tx urbs */
 622         usb_kill_anchored_urbs(&dev->tx_submitted);
 623         atomic_set(&dev->active_tx_urbs, 0);
 624 }
 625
 626 /*
 627  * called by netdev to close the corresponding CAN interface.
 628  */
 629 static int peak_usb_ndo_stop(struct net_device *netdev)
 630 {
 631         struct peak_usb_device *dev = netdev_priv(netdev);
 632
 633         dev->state &= ~PCAN_USB_STATE_STARTED;
 634         netif_stop_queue(netdev);
 635
 636         close_candev(netdev);
 637
 638         dev->can.state = CAN_STATE_STOPPED;
 639
 640         /* unlink all pending urbs and free used memory */
 641         peak_usb_unlink_all_urbs(dev);
 642
 643         if (dev->adapter->dev_stop)
 644                 dev->adapter->dev_stop(dev);
 645
 646         /* can set bus off now */
 647         if (dev->adapter->dev_set_bus) {
 648                 int err = dev->adapter->dev_set_bus(dev, 0);
 649                 if (err)
 650                         return err;
 651         }
 652
 653         return 0;
 654 }
 655
 656 /*
 657  * handle end of waiting for the device to reset
 658  */
 659 void peak_usb_restart_complete(struct peak_usb_device *dev)
 660 {
 661         /* finally MUST update can state */
 662         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 663
 664         /* netdev queue can be awaken now */
 665         netif_wake_queue(dev->netdev);
 666 }
 667
 668 void peak_usb_async_complete(struct urb *urb)
 669 {
 670         kfree(urb->transfer_buffer);
 671         usb_free_urb(urb);
 672 }
 673
 674 /*
 675  * device (auto-)restart mechanism runs in a timer context =>
 676  * MUST handle restart with asynchronous usb transfers
 677  */
 678 static int peak_usb_restart(struct peak_usb_device *dev)
 679 {
 680         struct urb *urb;
 681         int err;
 682         u8 *buf;
 683
 684         /*
 685          * if device doesn't define any asynchronous restart handler, simply
 686          * wake the netdev queue up
 687          */
 688         if (!dev->adapter->dev_restart_async) {
 689                 peak_usb_restart_complete(dev);
 690                 return 0;
 691         }
 692
 693         /* first allocate a urb to handle the asynchronous steps */
 694         urb = usb_alloc_urb(0, GFP_ATOMIC);
 695         if (!urb) {
 696                 netdev_err(dev->netdev, "no memory left for urb\n");
 697                 return -ENOMEM;
 698         }
 699
 700         /* also allocate enough space for the commands to send */
 701         buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);
 702         if (!buf) {
 703                 usb_free_urb(urb);
 704                 return -ENOMEM;
 705         }
 706
 707         /* call the device specific handler for the restart */
 708         err = dev->adapter->dev_restart_async(dev, urb, buf);
 709         if (!err)
 710                 return 0;
 711
 712         kfree(buf);
 713         usb_free_urb(urb);
 714
 715         return err;
 716 }
 717
 718 /*
 719  * candev callback used to change CAN mode.
 720  * Warning: this is called from a timer context!
 721  */
 722 static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 723 {
 724         struct peak_usb_device *dev = netdev_priv(netdev);
 725         int err = 0;
 726
 727         switch (mode) {
 728         case CAN_MODE_START:
 729                 err = peak_usb_restart(dev);
 730                 if (err)
 731                         netdev_err(netdev, "couldn't start device (err %d)\n",
 732                                    err);
 733                 break;
 734
 735         default:
 736                 return -EOPNOTSUPP;
 737         }
 738
 739         return err;
 740 }
 741
 742 /*
 743  * candev callback used to set device nominal/arbitration bitrate.
 744  */
 745 static int peak_usb_set_bittiming(struct net_device *netdev)
 746 {
 747         struct peak_usb_device *dev = netdev_priv(netdev);
 748         const struct peak_usb_adapter *pa = dev->adapter;
 749
 750         if (pa->dev_set_bittiming) {
 751                 struct can_bittiming *bt = &dev->can.bittiming;
 752                 int err = pa->dev_set_bittiming(dev, bt);
 753
 754                 if (err)
 755                         netdev_info(netdev, "couldn't set bitrate (err %d)\n",
 756                                     err);
 757                 return err;
 758         }
 759
 760         return 0;
 761 }
 762
 763 /*
 764  * candev callback used to set device data bitrate.
 765  */
 766 static int peak_usb_set_data_bittiming(struct net_device *netdev)
 767 {
 768         struct peak_usb_device *dev = netdev_priv(netdev);
 769         const struct peak_usb_adapter *pa = dev->adapter;
 770
 771         if (pa->dev_set_data_bittiming) {
 772                 struct can_bittiming *bt = &dev->can.data_bittiming;
 773                 int err = pa->dev_set_data_bittiming(dev, bt);
 774
 775                 if (err)
 776                         netdev_info(netdev,
 777                                     "couldn't set data bitrate (err %d)\n",
 778                                     err);
 779
 780                 return err;
 781         }
 782
 783         return 0;
 784 }
 785
 786 static const struct net_device_ops peak_usb_netdev_ops = {
 787         .ndo_open = peak_usb_ndo_open,
 788         .ndo_stop = peak_usb_ndo_stop,
 789         .ndo_start_xmit = peak_usb_ndo_start_xmit,
 790         .ndo_change_mtu = can_change_mtu,
 791 };
 792
 793 /*
 794  * create one device which is attached to CAN controller #ctrl_idx of the
 795  * usb adapter.
 796  */
 797 static int peak_usb_create_dev(const struct peak_usb_adapter *peak_usb_adapter,
 798                                struct usb_interface *intf, int ctrl_idx)
 799 {
 800         struct usb_device *usb_dev = interface_to_usbdev(intf);
 801         int sizeof_candev = peak_usb_adapter->sizeof_dev_private;
 802         struct peak_usb_device *dev;
 803         struct net_device *netdev;
 804         int i, err;
 805         u16 tmp16;
 806
 807         if (sizeof_candev < sizeof(struct peak_usb_device))
 808                 sizeof_candev = sizeof(struct peak_usb_device);
 809
 810         netdev = alloc_candev(sizeof_candev, PCAN_USB_MAX_TX_URBS);
 811         if (!netdev) {
 812                 dev_err(&intf->dev, "%s: couldn't alloc candev\n",
 813                         PCAN_USB_DRIVER_NAME);
 814                 return -ENOMEM;
 815         }
 816
 817         dev = netdev_priv(netdev);
 818
 819         /* allocate a buffer large enough to send commands */
 820         dev->cmd_buf = kzalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
 821         if (!dev->cmd_buf) {
 822                 err = -ENOMEM;
 823                 goto lbl_free_candev;
 824         }
 825
 826         dev->udev = usb_dev;
 827         dev->netdev = netdev;
 828         dev->adapter = peak_usb_adapter;
 829         dev->ctrl_idx = ctrl_idx;
 830         dev->state = PCAN_USB_STATE_CONNECTED;
 831
 832         dev->ep_msg_in = peak_usb_adapter->ep_msg_in;
 833         dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];
 834
 835         dev->can.clock = peak_usb_adapter->clock;
 836         dev->can.bittiming_const = peak_usb_adapter->bittiming_const;
 837         dev->can.do_set_bittiming = peak_usb_set_bittiming;
 838         dev->can.data_bittiming_const = peak_usb_adapter->data_bittiming_const;
 839         dev->can.do_set_data_bittiming = peak_usb_set_data_bittiming;
 840         dev->can.do_set_mode = peak_usb_set_mode;
 841         dev->can.do_get_berr_counter = peak_usb_adapter->do_get_berr_counter;
 842         dev->can.ctrlmode_supported = peak_usb_adapter->ctrlmode_supported;
 843
 844         netdev->netdev_ops = &peak_usb_netdev_ops;
 845
 846         netdev->flags |= IFF_ECHO; /* we support local echo */
 847
 848         init_usb_anchor(&dev->rx_submitted);
 849
 850         init_usb_anchor(&dev->tx_submitted);
 851         atomic_set(&dev->active_tx_urbs, 0);
 852
 853         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 854                 dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;
 855
 856         dev->prev_siblings = usb_get_intfdata(intf);
 857         usb_set_intfdata(intf, dev);
 858
 859         SET_NETDEV_DEV(netdev, &intf->dev);
 860         netdev->dev_id = ctrl_idx;
 861
 862         err = register_candev(netdev);
 863         if (err) {
 864                 dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
 865                 goto lbl_restore_intf_data;
 866         }
 867
 868         if (dev->prev_siblings)
 869                 (dev->prev_siblings)->next_siblings = dev;
 870
 871         /* keep hw revision into the netdevice */
 872         tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);
 873         dev->device_rev = tmp16 >> 8;
 874
 875         if (dev->adapter->dev_init) {
 876                 err = dev->adapter->dev_init(dev);
 877                 if (err)
 878                         goto lbl_unregister_candev;
 879         }
 880
 881         /* set bus off */
 882         if (dev->adapter->dev_set_bus) {
 883                 err = dev->adapter->dev_set_bus(dev, 0);
 884                 if (err)
 885                         goto adap_dev_free;
 886         }
 887
 888         /* get device number early */
 889         if (dev->adapter->dev_get_device_id)
 890                 dev->adapter->dev_get_device_id(dev, &dev->device_number);
 891
 892         netdev_info(netdev, "attached to %s channel %u (device %u)\n",
 893                         peak_usb_adapter->name, ctrl_idx, dev->device_number);
 894
 895         return 0;
 896
 897 adap_dev_free:
 898         if (dev->adapter->dev_free)
 899                 dev->adapter->dev_free(dev);
 900
 901 lbl_unregister_candev:
 902         unregister_candev(netdev);
 903
 904 lbl_restore_intf_data:
 905         usb_set_intfdata(intf, dev->prev_siblings);
 906         kfree(dev->cmd_buf);
 907
 908 lbl_free_candev:
 909         free_candev(netdev);
 910
 911         return err;
 912 }
 913
 914 /*
 915  * called by the usb core when the device is unplugged from the system
 916  */
 917 static void peak_usb_disconnect(struct usb_interface *intf)
 918 {
 919         struct peak_usb_device *dev;
 920         struct peak_usb_device *dev_prev_siblings;
 921
 922         /* unregister as many netdev devices as siblings */
 923         for (dev = usb_get_intfdata(intf); dev; dev = dev_prev_siblings) {
 924                 struct net_device *netdev = dev->netdev;
 925                 char name[IFNAMSIZ];
 926
 927                 dev_prev_siblings = dev->prev_siblings;
 928                 dev->state &= ~PCAN_USB_STATE_CONNECTED;
 929                 strlcpy(name, netdev->name, IFNAMSIZ);
 930
 931                 unregister_netdev(netdev);
 932
 933                 kfree(dev->cmd_buf);
 934                 dev->next_siblings = NULL;
 935                 if (dev->adapter->dev_free)
 936                         dev->adapter->dev_free(dev);
 937
 938                 free_candev(netdev);
 939                 dev_info(&intf->dev, "%s removed\n", name);
 940         }
 941
 942         usb_set_intfdata(intf, NULL);
 943 }
 944
 945 /*
 946  * probe function for new PEAK-System devices
 947  */
 948 static int peak_usb_probe(struct usb_interface *intf,
 949                           const struct usb_device_id *id)
 950 {
 951         struct usb_device *usb_dev = interface_to_usbdev(intf);
 952         const u16 usb_id_product = le16_to_cpu(usb_dev->descriptor.idProduct);
 953         const struct peak_usb_adapter *peak_usb_adapter = NULL;
 954         int i, err = -ENOMEM;
 955
 956         usb_dev = interface_to_usbdev(intf);
 957
 958         /* get corresponding PCAN-USB adapter */
 959         for (i = 0; i < ARRAY_SIZE(peak_usb_adapters_list); i++)
 960                 if (peak_usb_adapters_list[i]->device_id == usb_id_product) {
 961                         peak_usb_adapter = peak_usb_adapters_list[i];
 962                         break;
 963                 }
 964
 965         if (!peak_usb_adapter) {
 966                 /* should never come except device_id bad usage in this file */
 967                 pr_err("%s: didn't find device id. 0x%x in devices list\n",
 968                         PCAN_USB_DRIVER_NAME, usb_dev->descriptor.idProduct);
 969                 return -ENODEV;
 970         }
 971
 972         /* got corresponding adapter: check if it handles current interface */
 973         if (peak_usb_adapter->intf_probe) {
 974                 err = peak_usb_adapter->intf_probe(intf);
 975                 if (err)
 976                         return err;
 977         }
 978
 979         for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
 980                 err = peak_usb_create_dev(peak_usb_adapter, intf, i);
 981                 if (err) {
 982                         /* deregister already created devices */
 983                         peak_usb_disconnect(intf);
 984                         break;
 985                 }
 986         }
 987
 988         return err;
 989 }
 990
 991 /* usb specific object needed to register this driver with the usb subsystem */
 992 static struct usb_driver peak_usb_driver = {
 993         .name = PCAN_USB_DRIVER_NAME,
 994         .disconnect = peak_usb_disconnect,
 995         .probe = peak_usb_probe,
 996         .id_table = peak_usb_table,
 997 };
 998
 999 static int __init peak_usb_init(void)
1000 {
1001         int err;
1002
1003         /* register this driver with the USB subsystem */
1004         err = usb_register(&peak_usb_driver);
1005         if (err)
1006                 pr_err("%s: usb_register failed (err %d)\n",
1007                         PCAN_USB_DRIVER_NAME, err);
1008
1009         return err;
1010 }
1011
1012 static int peak_usb_do_device_exit(struct device *d, void *arg)
1013 {
1014         struct usb_interface *intf = to_usb_interface(d);
1015         struct peak_usb_device *dev;
1016
1017         /* stop as many netdev devices as siblings */
1018         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
1019                 struct net_device *netdev = dev->netdev;
1020
1021                 if (netif_device_present(netdev))
1022                         if (dev->adapter->dev_exit)
1023                                 dev->adapter->dev_exit(dev);
1024         }
1025
1026         return 0;
1027 }
1028
1029 static void __exit peak_usb_exit(void)
1030 {
1031         int err;
1032
1033         /* last chance do send any synchronous commands here */
1034         err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
1035                                      NULL, peak_usb_do_device_exit);
1036         if (err)
1037                 pr_err("%s: failed to stop all can devices (err %d)\n",
1038                         PCAN_USB_DRIVER_NAME, err);
1039
1040         /* deregister this driver with the USB subsystem */
1041         usb_deregister(&peak_usb_driver);
1042
1043         pr_info("%s: PCAN-USB interfaces driver unloaded\n",
1044                 PCAN_USB_DRIVER_NAME);
1045 }
1046
1047 module_init(peak_usb_init);
1048 module_exit(peak_usb_exit);