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