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         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBCHIP_PRODUCT_ID)},
  43         {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBX6_PRODUCT_ID)},
  44         {} /* Terminating entry */
  45 };
  46
  47 MODULE_DEVICE_TABLE(usb, peak_usb_table);
  48
  49 /* List of supported PCAN-USB adapters (NULL terminated list) */
  50 static const struct peak_usb_adapter *const peak_usb_adapters_list[] = {
  51         &pcan_usb,
  52         &pcan_usb_pro,
  53         &pcan_usb_fd,
  54         &pcan_usb_pro_fd,
  55         &pcan_usb_chip,
  56         &pcan_usb_x6,
  57 };
  58
  59 /*
  60  * dump memory
  61  */
  62 #define DUMP_WIDTH      16
  63 void pcan_dump_mem(char *prompt, void *p, int l)
  64 {
  65         pr_info("%s dumping %s (%d bytes):\n",
  66                 PCAN_USB_DRIVER_NAME, prompt ? prompt : "memory", l);
  67         print_hex_dump(KERN_INFO, PCAN_USB_DRIVER_NAME " ", DUMP_PREFIX_NONE,
  68                        DUMP_WIDTH, 1, p, l, false);
  69 }
  70
  71 /*
  72  * initialize a time_ref object with usb adapter own settings
  73  */
  74 void peak_usb_init_time_ref(struct peak_time_ref *time_ref,
  75                             const struct peak_usb_adapter *adapter)
  76 {
  77         if (time_ref) {
  78                 memset(time_ref, 0, sizeof(struct peak_time_ref));
  79                 time_ref->adapter = adapter;
  80         }
  81 }
  82
  83 static void peak_usb_add_us(struct timeval *tv, u32 delta_us)
  84 {
  85         /* number of s. to add to final time */
  86         u32 delta_s = delta_us / 1000000;
  87
  88         delta_us -= delta_s * 1000000;
  89
  90         tv->tv_usec += delta_us;
  91         if (tv->tv_usec >= 1000000) {
  92                 tv->tv_usec -= 1000000;
  93                 delta_s++;
  94         }
  95         tv->tv_sec += delta_s;
  96 }
  97
  98 /*
  99  * sometimes, another now may be  more recent than current one...
 100  */
 101 void peak_usb_update_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
 102 {
 103         time_ref->ts_dev_2 = ts_now;
 104
 105         /* should wait at least two passes before computing */
 106         if (time_ref->tv_host.tv_sec > 0) {
 107                 u32 delta_ts = time_ref->ts_dev_2 - time_ref->ts_dev_1;
 108
 109                 if (time_ref->ts_dev_2 < time_ref->ts_dev_1)
 110                         delta_ts &= (1 << time_ref->adapter->ts_used_bits) - 1;
 111
 112                 time_ref->ts_total += delta_ts;
 113         }
 114 }
 115
 116 /*
 117  * register device timestamp as now
 118  */
 119 void peak_usb_set_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
 120 {
 121         if (time_ref->tv_host_0.tv_sec == 0) {
 122                 /* use monotonic clock to correctly compute further deltas */
 123                 time_ref->tv_host_0 = ktime_to_timeval(ktime_get());
 124                 time_ref->tv_host.tv_sec = 0;
 125         } else {
 126                 /*
 127                  * delta_us should not be >= 2^32 => delta_s should be < 4294
 128                  * handle 32-bits wrapping here: if count of s. reaches 4200,
 129                  * reset counters and change time base
 130                  */
 131                 if (time_ref->tv_host.tv_sec != 0) {
 132                         u32 delta_s = time_ref->tv_host.tv_sec
 133                                                 - time_ref->tv_host_0.tv_sec;
 134                         if (delta_s > 4200) {
 135                                 time_ref->tv_host_0 = time_ref->tv_host;
 136                                 time_ref->ts_total = 0;
 137                         }
 138                 }
 139
 140                 time_ref->tv_host = ktime_to_timeval(ktime_get());
 141                 time_ref->tick_count++;
 142         }
 143
 144         time_ref->ts_dev_1 = time_ref->ts_dev_2;
 145         peak_usb_update_ts_now(time_ref, ts_now);
 146 }
 147
 148 /*
 149  * compute timeval according to current ts and time_ref data
 150  */
 151 void peak_usb_get_ts_tv(struct peak_time_ref *time_ref, u32 ts,
 152                         struct timeval *tv)
 153 {
 154         /* protect from getting timeval before setting now */
 155         if (time_ref->tv_host.tv_sec > 0) {
 156                 u64 delta_us;
 157
 158                 delta_us = ts - time_ref->ts_dev_2;
 159                 if (ts < time_ref->ts_dev_2)
 160                         delta_us &= (1 << time_ref->adapter->ts_used_bits) - 1;
 161
 162                 delta_us += time_ref->ts_total;
 163
 164                 delta_us *= time_ref->adapter->us_per_ts_scale;
 165                 delta_us >>= time_ref->adapter->us_per_ts_shift;
 166
 167                 *tv = time_ref->tv_host_0;
 168                 peak_usb_add_us(tv, (u32)delta_us);
 169         } else {
 170                 *tv = ktime_to_timeval(ktime_get());
 171         }
 172 }
 173
 174 /*
 175  * post received skb after having set any hw timestamp
 176  */
 177 int peak_usb_netif_rx(struct sk_buff *skb,
 178                       struct peak_time_ref *time_ref, u32 ts_low, u32 ts_high)
 179 {
 180         struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
 181         struct timeval tv;
 182
 183         peak_usb_get_ts_tv(time_ref, ts_low, &tv);
 184         hwts->hwtstamp = timeval_to_ktime(tv);
 185
 186         return netif_rx(skb);
 187 }
 188
 189 /*
 190  * callback for bulk Rx urb
 191  */
 192 static void peak_usb_read_bulk_callback(struct urb *urb)
 193 {
 194         struct peak_usb_device *dev = urb->context;
 195         struct net_device *netdev;
 196         int err;
 197
 198         netdev = dev->netdev;
 199
 200         if (!netif_device_present(netdev))
 201                 return;
 202
 203         /* check reception status */
 204         switch (urb->status) {
 205         case 0:
 206                 /* success */
 207                 break;
 208
 209         case -EILSEQ:
 210         case -ENOENT:
 211         case -ECONNRESET:
 212         case -ESHUTDOWN:
 213                 return;
 214
 215         default:
 216                 if (net_ratelimit())
 217                         netdev_err(netdev,
 218                                    "Rx urb aborted (%d)\n", urb->status);
 219                 goto resubmit_urb;
 220         }
 221
 222         /* protect from any incoming empty msgs */
 223         if ((urb->actual_length > 0) && (dev->adapter->dev_decode_buf)) {
 224                 /* handle these kinds of msgs only if _start callback called */
 225                 if (dev->state & PCAN_USB_STATE_STARTED) {
 226                         err = dev->adapter->dev_decode_buf(dev, urb);
 227                         if (err)
 228                                 pcan_dump_mem("received usb message",
 229                                               urb->transfer_buffer,
 230                                               urb->transfer_buffer_length);
 231                 }
 232         }
 233
 234 resubmit_urb:
 235         usb_fill_bulk_urb(urb, dev->udev,
 236                 usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 237                 urb->transfer_buffer, dev->adapter->rx_buffer_size,
 238                 peak_usb_read_bulk_callback, dev);
 239
 240         usb_anchor_urb(urb, &dev->rx_submitted);
 241         err = usb_submit_urb(urb, GFP_ATOMIC);
 242         if (!err)
 243                 return;
 244
 245         usb_unanchor_urb(urb);
 246
 247         if (err == -ENODEV)
 248                 netif_device_detach(netdev);
 249         else
 250                 netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
 251                            err);
 252 }
 253
 254 /*
 255  * callback for bulk Tx urb
 256  */
 257 static void peak_usb_write_bulk_callback(struct urb *urb)
 258 {
 259         struct peak_tx_urb_context *context = urb->context;
 260         struct peak_usb_device *dev;
 261         struct net_device *netdev;
 262
 263         BUG_ON(!context);
 264
 265         dev = context->dev;
 266         netdev = dev->netdev;
 267
 268         atomic_dec(&dev->active_tx_urbs);
 269
 270         if (!netif_device_present(netdev))
 271                 return;
 272
 273         /* check tx status */
 274         switch (urb->status) {
 275         case 0:
 276                 /* transmission complete */
 277                 netdev->stats.tx_packets++;
 278                 netdev->stats.tx_bytes += context->data_len;
 279
 280                 /* prevent tx timeout */
 281                 netif_trans_update(netdev);
 282                 break;
 283
 284         default:
 285                 if (net_ratelimit())
 286                         netdev_err(netdev, "Tx urb aborted (%d)\n",
 287                                    urb->status);
 288         case -EPROTO:
 289         case -ENOENT:
 290         case -ECONNRESET:
 291         case -ESHUTDOWN:
 292
 293                 break;
 294         }
 295
 296         /* should always release echo skb and corresponding context */
 297         can_get_echo_skb(netdev, context->echo_index);
 298         context->echo_index = PCAN_USB_MAX_TX_URBS;
 299
 300         /* do wakeup tx queue in case of success only */
 301         if (!urb->status)
 302                 netif_wake_queue(netdev);
 303 }
 304
 305 /*
 306  * called by netdev to send one skb on the CAN interface.
 307  */
 308 static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
 309                                            struct net_device *netdev)
 310 {
 311         struct peak_usb_device *dev = netdev_priv(netdev);
 312         struct peak_tx_urb_context *context = NULL;
 313         struct net_device_stats *stats = &netdev->stats;
 314         struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 315         struct urb *urb;
 316         u8 *obuf;
 317         int i, err;
 318         size_t size = dev->adapter->tx_buffer_size;
 319
 320         if (can_dropped_invalid_skb(netdev, skb))
 321                 return NETDEV_TX_OK;
 322
 323         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 324                 if (dev->tx_contexts[i].echo_index == PCAN_USB_MAX_TX_URBS) {
 325                         context = dev->tx_contexts + i;
 326                         break;
 327                 }
 328
 329         if (!context) {
 330                 /* should not occur except during restart */
 331                 return NETDEV_TX_BUSY;
 332         }
 333
 334         urb = context->urb;
 335         obuf = urb->transfer_buffer;
 336
 337         err = dev->adapter->dev_encode_msg(dev, skb, obuf, &size);
 338         if (err) {
 339                 if (net_ratelimit())
 340                         netdev_err(netdev, "packet dropped\n");
 341                 dev_kfree_skb(skb);
 342                 stats->tx_dropped++;
 343                 return NETDEV_TX_OK;
 344         }
 345
 346         context->echo_index = i;
 347
 348         /* Note: this works with CANFD frames too */
 349         context->data_len = cfd->len;
 350
 351         usb_anchor_urb(urb, &dev->tx_submitted);
 352
 353         can_put_echo_skb(skb, netdev, context->echo_index);
 354
 355         atomic_inc(&dev->active_tx_urbs);
 356
 357         err = usb_submit_urb(urb, GFP_ATOMIC);
 358         if (err) {
 359                 can_free_echo_skb(netdev, context->echo_index);
 360
 361                 usb_unanchor_urb(urb);
 362
 363                 /* this context is not used in fact */
 364                 context->echo_index = PCAN_USB_MAX_TX_URBS;
 365
 366                 atomic_dec(&dev->active_tx_urbs);
 367
 368                 switch (err) {
 369                 case -ENODEV:
 370                         netif_device_detach(netdev);
 371                         break;
 372                 default:
 373                         netdev_warn(netdev, "tx urb submitting failed err=%d\n",
 374                                     err);
 375                 case -ENOENT:
 376                         /* cable unplugged */
 377                         stats->tx_dropped++;
 378                 }
 379         } else {
 380                 netif_trans_update(netdev);
 381
 382                 /* slow down tx path */
 383                 if (atomic_read(&dev->active_tx_urbs) >= PCAN_USB_MAX_TX_URBS)
 384                         netif_stop_queue(netdev);
 385         }
 386
 387         return NETDEV_TX_OK;
 388 }
 389
 390 /*
 391  * start the CAN interface.
 392  * Rx and Tx urbs are allocated here. Rx urbs are submitted here.
 393  */
 394 static int peak_usb_start(struct peak_usb_device *dev)
 395 {
 396         struct net_device *netdev = dev->netdev;
 397         int err, i;
 398
 399         for (i = 0; i < PCAN_USB_MAX_RX_URBS; i++) {
 400                 struct urb *urb;
 401                 u8 *buf;
 402
 403                 /* create a URB, and a buffer for it, to receive usb messages */
 404                 urb = usb_alloc_urb(0, GFP_KERNEL);
 405                 if (!urb) {
 406                         err = -ENOMEM;
 407                         break;
 408                 }
 409
 410                 buf = kmalloc(dev->adapter->rx_buffer_size, GFP_KERNEL);
 411                 if (!buf) {
 412                         usb_free_urb(urb);
 413                         err = -ENOMEM;
 414                         break;
 415                 }
 416
 417                 usb_fill_bulk_urb(urb, dev->udev,
 418                         usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 419                         buf, dev->adapter->rx_buffer_size,
 420                         peak_usb_read_bulk_callback, dev);
 421
 422                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 423                 urb->transfer_flags |= URB_FREE_BUFFER;
 424                 usb_anchor_urb(urb, &dev->rx_submitted);
 425
 426                 err = usb_submit_urb(urb, GFP_KERNEL);
 427                 if (err) {
 428                         if (err == -ENODEV)
 429                                 netif_device_detach(dev->netdev);
 430
 431                         usb_unanchor_urb(urb);
 432                         kfree(buf);
 433                         usb_free_urb(urb);
 434                         break;
 435                 }
 436
 437                 /* drop reference, USB core will take care of freeing it */
 438                 usb_free_urb(urb);
 439         }
 440
 441         /* did we submit any URBs? Warn if we was not able to submit all urbs */
 442         if (i < PCAN_USB_MAX_RX_URBS) {
 443                 if (i == 0) {
 444                         netdev_err(netdev, "couldn't setup any rx URB\n");
 445                         return err;
 446                 }
 447
 448                 netdev_warn(netdev, "rx performance may be slow\n");
 449         }
 450
 451         /* pre-alloc tx buffers and corresponding urbs */
 452         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 453                 struct peak_tx_urb_context *context;
 454                 struct urb *urb;
 455                 u8 *buf;
 456
 457                 /* create a URB and a buffer for it, to transmit usb messages */
 458                 urb = usb_alloc_urb(0, GFP_KERNEL);
 459                 if (!urb) {
 460                         err = -ENOMEM;
 461                         break;
 462                 }
 463
 464                 buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);
 465                 if (!buf) {
 466                         usb_free_urb(urb);
 467                         err = -ENOMEM;
 468                         break;
 469                 }
 470
 471                 context = dev->tx_contexts + i;
 472                 context->dev = dev;
 473                 context->urb = urb;
 474
 475                 usb_fill_bulk_urb(urb, dev->udev,
 476                         usb_sndbulkpipe(dev->udev, dev->ep_msg_out),
 477                         buf, dev->adapter->tx_buffer_size,
 478                         peak_usb_write_bulk_callback, context);
 479
 480                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 481                 urb->transfer_flags |= URB_FREE_BUFFER;
 482         }
 483
 484         /* warn if we were not able to allocate enough tx contexts */
 485         if (i < PCAN_USB_MAX_TX_URBS) {
 486                 if (i == 0) {
 487                         netdev_err(netdev, "couldn't setup any tx URB\n");
 488                         goto err_tx;
 489                 }
 490
 491                 netdev_warn(netdev, "tx performance may be slow\n");
 492         }
 493
 494         if (dev->adapter->dev_start) {
 495                 err = dev->adapter->dev_start(dev);
 496                 if (err)
 497                         goto err_adapter;
 498         }
 499
 500         dev->state |= PCAN_USB_STATE_STARTED;
 501
 502         /* can set bus on now */
 503         if (dev->adapter->dev_set_bus) {
 504                 err = dev->adapter->dev_set_bus(dev, 1);
 505                 if (err)
 506                         goto err_adapter;
 507         }
 508
 509         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 510
 511         return 0;
 512
 513 err_adapter:
 514         if (err == -ENODEV)
 515                 netif_device_detach(dev->netdev);
 516
 517         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 518
 519         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 520                 usb_free_urb(dev->tx_contexts[i].urb);
 521                 dev->tx_contexts[i].urb = NULL;
 522         }
 523 err_tx:
 524         usb_kill_anchored_urbs(&dev->rx_submitted);
 525
 526         return err;
 527 }
 528
 529 /*
 530  * called by netdev to open the corresponding CAN interface.
 531  */
 532 static int peak_usb_ndo_open(struct net_device *netdev)
 533 {
 534         struct peak_usb_device *dev = netdev_priv(netdev);
 535         int err;
 536
 537         /* common open */
 538         err = open_candev(netdev);
 539         if (err)
 540                 return err;
 541
 542         /* finally start device */
 543         err = peak_usb_start(dev);
 544         if (err) {
 545                 netdev_err(netdev, "couldn't start device: %d\n", err);
 546                 close_candev(netdev);
 547                 return err;
 548         }
 549
 550         netif_start_queue(netdev);
 551
 552         return 0;
 553 }
 554
 555 /*
 556  * unlink in-flight Rx and Tx urbs and free their memory.
 557  */
 558 static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)
 559 {
 560         int i;
 561
 562         /* free all Rx (submitted) urbs */
 563         usb_kill_anchored_urbs(&dev->rx_submitted);
 564
 565         /* free unsubmitted Tx urbs first */
 566         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 567                 struct urb *urb = dev->tx_contexts[i].urb;
 568
 569                 if (!urb ||
 570                     dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {
 571                         /*
 572                          * this urb is already released or always submitted,
 573                          * let usb core free by itself
 574                          */
 575                         continue;
 576                 }
 577
 578                 usb_free_urb(urb);
 579                 dev->tx_contexts[i].urb = NULL;
 580         }
 581
 582         /* then free all submitted Tx urbs */
 583         usb_kill_anchored_urbs(&dev->tx_submitted);
 584         atomic_set(&dev->active_tx_urbs, 0);
 585 }
 586
 587 /*
 588  * called by netdev to close the corresponding CAN interface.
 589  */
 590 static int peak_usb_ndo_stop(struct net_device *netdev)
 591 {
 592         struct peak_usb_device *dev = netdev_priv(netdev);
 593
 594         dev->state &= ~PCAN_USB_STATE_STARTED;
 595         netif_stop_queue(netdev);
 596
 597         /* unlink all pending urbs and free used memory */
 598         peak_usb_unlink_all_urbs(dev);
 599
 600         if (dev->adapter->dev_stop)
 601                 dev->adapter->dev_stop(dev);
 602
 603         close_candev(netdev);
 604
 605         dev->can.state = CAN_STATE_STOPPED;
 606
 607         /* can set bus off now */
 608         if (dev->adapter->dev_set_bus) {
 609                 int err = dev->adapter->dev_set_bus(dev, 0);
 610                 if (err)
 611                         return err;
 612         }
 613
 614         return 0;
 615 }
 616
 617 /*
 618  * handle end of waiting for the device to reset
 619  */
 620 void peak_usb_restart_complete(struct peak_usb_device *dev)
 621 {
 622         /* finally MUST update can state */
 623         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 624
 625         /* netdev queue can be awaken now */
 626         netif_wake_queue(dev->netdev);
 627 }
 628
 629 void peak_usb_async_complete(struct urb *urb)
 630 {
 631         kfree(urb->transfer_buffer);
 632         usb_free_urb(urb);
 633 }
 634
 635 /*
 636  * device (auto-)restart mechanism runs in a timer context =>
 637  * MUST handle restart with asynchronous usb transfers
 638  */
 639 static int peak_usb_restart(struct peak_usb_device *dev)
 640 {
 641         struct urb *urb;
 642         int err;
 643         u8 *buf;
 644
 645         /*
 646          * if device doesn't define any asynchronous restart handler, simply
 647          * wake the netdev queue up
 648          */
 649         if (!dev->adapter->dev_restart_async) {
 650                 peak_usb_restart_complete(dev);
 651                 return 0;
 652         }
 653
 654         /* first allocate a urb to handle the asynchronous steps */
 655         urb = usb_alloc_urb(0, GFP_ATOMIC);
 656         if (!urb)
 657                 return -ENOMEM;
 658
 659         /* also allocate enough space for the commands to send */
 660         buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);
 661         if (!buf) {
 662                 usb_free_urb(urb);
 663                 return -ENOMEM;
 664         }
 665
 666         /* call the device specific handler for the restart */
 667         err = dev->adapter->dev_restart_async(dev, urb, buf);
 668         if (!err)
 669                 return 0;
 670
 671         kfree(buf);
 672         usb_free_urb(urb);
 673
 674         return err;
 675 }
 676
 677 /*
 678  * candev callback used to change CAN mode.
 679  * Warning: this is called from a timer context!
 680  */
 681 static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 682 {
 683         struct peak_usb_device *dev = netdev_priv(netdev);
 684         int err = 0;
 685
 686         switch (mode) {
 687         case CAN_MODE_START:
 688                 err = peak_usb_restart(dev);
 689                 if (err)
 690                         netdev_err(netdev, "couldn't start device (err %d)\n",
 691                                    err);
 692                 break;
 693
 694         default:
 695                 return -EOPNOTSUPP;
 696         }
 697
 698         return err;
 699 }
 700
 701 /*
 702  * candev callback used to set device nominal/arbitration bitrate.
 703  */
 704 static int peak_usb_set_bittiming(struct net_device *netdev)
 705 {
 706         struct peak_usb_device *dev = netdev_priv(netdev);
 707         const struct peak_usb_adapter *pa = dev->adapter;
 708
 709         if (pa->dev_set_bittiming) {
 710                 struct can_bittiming *bt = &dev->can.bittiming;
 711                 int err = pa->dev_set_bittiming(dev, bt);
 712
 713                 if (err)
 714                         netdev_info(netdev, "couldn't set bitrate (err %d)\n",
 715                                     err);
 716                 return err;
 717         }
 718
 719         return 0;
 720 }
 721
 722 /*
 723  * candev callback used to set device data bitrate.
 724  */
 725 static int peak_usb_set_data_bittiming(struct net_device *netdev)
 726 {
 727         struct peak_usb_device *dev = netdev_priv(netdev);
 728         const struct peak_usb_adapter *pa = dev->adapter;
 729
 730         if (pa->dev_set_data_bittiming) {
 731                 struct can_bittiming *bt = &dev->can.data_bittiming;
 732                 int err = pa->dev_set_data_bittiming(dev, bt);
 733
 734                 if (err)
 735                         netdev_info(netdev,
 736                                     "couldn't set data bitrate (err %d)\n",
 737                                     err);
 738
 739                 return err;
 740         }
 741
 742         return 0;
 743 }
 744
 745 static const struct net_device_ops peak_usb_netdev_ops = {
 746         .ndo_open = peak_usb_ndo_open,
 747         .ndo_stop = peak_usb_ndo_stop,
 748         .ndo_start_xmit = peak_usb_ndo_start_xmit,
 749         .ndo_change_mtu = can_change_mtu,
 750 };
 751
 752 /*
 753  * create one device which is attached to CAN controller #ctrl_idx of the
 754  * usb adapter.
 755  */
 756 static int peak_usb_create_dev(const struct peak_usb_adapter *peak_usb_adapter,
 757                                struct usb_interface *intf, int ctrl_idx)
 758 {
 759         struct usb_device *usb_dev = interface_to_usbdev(intf);
 760         int sizeof_candev = peak_usb_adapter->sizeof_dev_private;
 761         struct peak_usb_device *dev;
 762         struct net_device *netdev;
 763         int i, err;
 764         u16 tmp16;
 765
 766         if (sizeof_candev < sizeof(struct peak_usb_device))
 767                 sizeof_candev = sizeof(struct peak_usb_device);
 768
 769         netdev = alloc_candev(sizeof_candev, PCAN_USB_MAX_TX_URBS);
 770         if (!netdev) {
 771                 dev_err(&intf->dev, "%s: couldn't alloc candev\n",
 772                         PCAN_USB_DRIVER_NAME);
 773                 return -ENOMEM;
 774         }
 775
 776         dev = netdev_priv(netdev);
 777
 778         /* allocate a buffer large enough to send commands */
 779         dev->cmd_buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
 780         if (!dev->cmd_buf) {
 781                 err = -ENOMEM;
 782                 goto lbl_free_candev;
 783         }
 784
 785         dev->udev = usb_dev;
 786         dev->netdev = netdev;
 787         dev->adapter = peak_usb_adapter;
 788         dev->ctrl_idx = ctrl_idx;
 789         dev->state = PCAN_USB_STATE_CONNECTED;
 790
 791         dev->ep_msg_in = peak_usb_adapter->ep_msg_in;
 792         dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];
 793
 794         dev->can.clock = peak_usb_adapter->clock;
 795         dev->can.bittiming_const = peak_usb_adapter->bittiming_const;
 796         dev->can.do_set_bittiming = peak_usb_set_bittiming;
 797         dev->can.data_bittiming_const = peak_usb_adapter->data_bittiming_const;
 798         dev->can.do_set_data_bittiming = peak_usb_set_data_bittiming;
 799         dev->can.do_set_mode = peak_usb_set_mode;
 800         dev->can.do_get_berr_counter = peak_usb_adapter->do_get_berr_counter;
 801         dev->can.ctrlmode_supported = peak_usb_adapter->ctrlmode_supported;
 802
 803         netdev->netdev_ops = &peak_usb_netdev_ops;
 804
 805         netdev->flags |= IFF_ECHO; /* we support local echo */
 806
 807         init_usb_anchor(&dev->rx_submitted);
 808
 809         init_usb_anchor(&dev->tx_submitted);
 810         atomic_set(&dev->active_tx_urbs, 0);
 811
 812         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 813                 dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;
 814
 815         dev->prev_siblings = usb_get_intfdata(intf);
 816         usb_set_intfdata(intf, dev);
 817
 818         SET_NETDEV_DEV(netdev, &intf->dev);
 819         netdev->dev_id = ctrl_idx;
 820
 821         err = register_candev(netdev);
 822         if (err) {
 823                 dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
 824                 goto lbl_restore_intf_data;
 825         }
 826
 827         if (dev->prev_siblings)
 828                 (dev->prev_siblings)->next_siblings = dev;
 829
 830         /* keep hw revision into the netdevice */
 831         tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);
 832         dev->device_rev = tmp16 >> 8;
 833
 834         if (dev->adapter->dev_init) {
 835                 err = dev->adapter->dev_init(dev);
 836                 if (err)
 837                         goto lbl_unregister_candev;
 838         }
 839
 840         /* set bus off */
 841         if (dev->adapter->dev_set_bus) {
 842                 err = dev->adapter->dev_set_bus(dev, 0);
 843                 if (err)
 844                         goto lbl_unregister_candev;
 845         }
 846
 847         /* get device number early */
 848         if (dev->adapter->dev_get_device_id)
 849                 dev->adapter->dev_get_device_id(dev, &dev->device_number);
 850
 851         netdev_info(netdev, "attached to %s channel %u (device %u)\n",
 852                         peak_usb_adapter->name, ctrl_idx, dev->device_number);
 853
 854         return 0;
 855
 856 lbl_unregister_candev:
 857         unregister_candev(netdev);
 858
 859 lbl_restore_intf_data:
 860         usb_set_intfdata(intf, dev->prev_siblings);
 861         kfree(dev->cmd_buf);
 862
 863 lbl_free_candev:
 864         free_candev(netdev);
 865
 866         return err;
 867 }
 868
 869 /*
 870  * called by the usb core when the device is unplugged from the system
 871  */
 872 static void peak_usb_disconnect(struct usb_interface *intf)
 873 {
 874         struct peak_usb_device *dev;
 875         struct peak_usb_device *dev_prev_siblings;
 876
 877         /* unregister as many netdev devices as siblings */
 878         for (dev = usb_get_intfdata(intf); dev; dev = dev_prev_siblings) {
 879                 struct net_device *netdev = dev->netdev;
 880                 char name[IFNAMSIZ];
 881
 882                 dev_prev_siblings = dev->prev_siblings;
 883                 dev->state &= ~PCAN_USB_STATE_CONNECTED;
 884                 strncpy(name, netdev->name, IFNAMSIZ);
 885
 886                 unregister_netdev(netdev);
 887
 888                 kfree(dev->cmd_buf);
 889                 dev->next_siblings = NULL;
 890                 if (dev->adapter->dev_free)
 891                         dev->adapter->dev_free(dev);
 892
 893                 free_candev(netdev);
 894                 dev_info(&intf->dev, "%s removed\n", name);
 895         }
 896
 897         usb_set_intfdata(intf, NULL);
 898 }
 899
 900 /*
 901  * probe function for new PEAK-System devices
 902  */
 903 static int peak_usb_probe(struct usb_interface *intf,
 904                           const struct usb_device_id *id)
 905 {
 906         struct usb_device *usb_dev = interface_to_usbdev(intf);
 907         const u16 usb_id_product = le16_to_cpu(usb_dev->descriptor.idProduct);
 908         const struct peak_usb_adapter *peak_usb_adapter = NULL;
 909         int i, err = -ENOMEM;
 910
 911         /* get corresponding PCAN-USB adapter */
 912         for (i = 0; i < ARRAY_SIZE(peak_usb_adapters_list); i++)
 913                 if (peak_usb_adapters_list[i]->device_id == usb_id_product) {
 914                         peak_usb_adapter = peak_usb_adapters_list[i];
 915                         break;
 916                 }
 917
 918         if (!peak_usb_adapter) {
 919                 /* should never come except device_id bad usage in this file */
 920                 pr_err("%s: didn't find device id. 0x%x in devices list\n",
 921                         PCAN_USB_DRIVER_NAME, usb_id_product);
 922                 return -ENODEV;
 923         }
 924
 925         /* got corresponding adapter: check if it handles current interface */
 926         if (peak_usb_adapter->intf_probe) {
 927                 err = peak_usb_adapter->intf_probe(intf);
 928                 if (err)
 929                         return err;
 930         }
 931
 932         for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
 933                 err = peak_usb_create_dev(peak_usb_adapter, intf, i);
 934                 if (err) {
 935                         /* deregister already created devices */
 936                         peak_usb_disconnect(intf);
 937                         break;
 938                 }
 939         }
 940
 941         return err;
 942 }
 943
 944 /* usb specific object needed to register this driver with the usb subsystem */
 945 static struct usb_driver peak_usb_driver = {
 946         .name = PCAN_USB_DRIVER_NAME,
 947         .disconnect = peak_usb_disconnect,
 948         .probe = peak_usb_probe,
 949         .id_table = peak_usb_table,
 950 };
 951
 952 static int __init peak_usb_init(void)
 953 {
 954         int err;
 955
 956         /* register this driver with the USB subsystem */
 957         err = usb_register(&peak_usb_driver);
 958         if (err)
 959                 pr_err("%s: usb_register failed (err %d)\n",
 960                         PCAN_USB_DRIVER_NAME, err);
 961
 962         return err;
 963 }
 964
 965 static int peak_usb_do_device_exit(struct device *d, void *arg)
 966 {
 967         struct usb_interface *intf = to_usb_interface(d);
 968         struct peak_usb_device *dev;
 969
 970         /* stop as many netdev devices as siblings */
 971         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
 972                 struct net_device *netdev = dev->netdev;
 973
 974                 if (netif_device_present(netdev))
 975                         if (dev->adapter->dev_exit)
 976                                 dev->adapter->dev_exit(dev);
 977         }
 978
 979         return 0;
 980 }
 981
 982 static void __exit peak_usb_exit(void)
 983 {
 984         int err;
 985
 986         /* last chance do send any synchronous commands here */
 987         err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
 988                                      NULL, peak_usb_do_device_exit);
 989         if (err)
 990                 pr_err("%s: failed to stop all can devices (err %d)\n",
 991                         PCAN_USB_DRIVER_NAME, err);
 992
 993         /* deregister this driver with the USB subsystem */
 994         usb_deregister(&peak_usb_driver);
 995
 996         pr_info("%s: PCAN-USB interfaces driver unloaded\n",
 997                 PCAN_USB_DRIVER_NAME);
 998 }
 999
1000 module_init(peak_usb_init);
1001 module_exit(peak_usb_exit);