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                 s64 delta_ts = 0;
 158
 159                 /* General case: dev_ts_1 < dev_ts_2 < ts, with:
 160                  *
 161                  * - dev_ts_1 = previous sync timestamp
 162                  * - dev_ts_2 = last sync timestamp
 163                  * - ts = event timestamp
 164                  * - ts_period = known sync period (theoretical)
 165                  *             ~ dev_ts2 - dev_ts1
 166                  * *but*:
 167                  *
 168                  * - time counters wrap (see adapter->ts_used_bits)
 169                  * - sometimes, dev_ts_1 < ts < dev_ts2
 170                  *
 171                  * "normal" case (sync time counters increase):
 172                  * must take into account case when ts wraps (tsw)
 173                  *
 174                  *      < ts_period > <          >
 175                  *     |             |            |
 176                  *  ---+--------+----+-------0-+--+-->
 177                  *     ts_dev_1 |    ts_dev_2  |
 178                  *              ts             tsw
 179                  */
 180                 if (time_ref->ts_dev_1 < time_ref->ts_dev_2) {
 181                         /* case when event time (tsw) wraps */
 182                         if (ts < time_ref->ts_dev_1)
 183                                 delta_ts = BIT_ULL(time_ref->adapter->ts_used_bits);
 184
 185                 /* Otherwise, sync time counter (ts_dev_2) has wrapped:
 186                  * handle case when event time (tsn) hasn't.
 187                  *
 188                  *      < ts_period > <          >
 189                  *     |             |            |
 190                  *  ---+--------+--0-+---------+--+-->
 191                  *     ts_dev_1 |    ts_dev_2  |
 192                  *              tsn            ts
 193                  */
 194                 } else if (time_ref->ts_dev_1 < ts) {
 195                         delta_ts = -BIT_ULL(time_ref->adapter->ts_used_bits);
 196                 }
 197
 198                 /* add delay between last sync and event timestamps */
 199                 delta_ts += (signed int)(ts - time_ref->ts_dev_2);
 200
 201                 /* add time from beginning to last sync */
 202                 delta_ts += time_ref->ts_total;
 203
 204                 /* convert ticks number into microseconds */
 205                 delta_us = delta_ts * time_ref->adapter->us_per_ts_scale;
 206                 delta_us >>= time_ref->adapter->us_per_ts_shift;
 207
 208                 *tv = time_ref->tv_host_0;
 209                 peak_usb_add_us(tv, (u32)delta_us);
 210         } else {
 211                 *tv = ktime_to_timeval(ktime_get());
 212         }
 213 }
 214
 215 /*
 216  * post received skb after having set any hw timestamp
 217  */
 218 int peak_usb_netif_rx(struct sk_buff *skb,
 219                       struct peak_time_ref *time_ref, u32 ts_low, u32 ts_high)
 220 {
 221         struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
 222         struct timeval tv;
 223
 224         peak_usb_get_ts_tv(time_ref, ts_low, &tv);
 225         hwts->hwtstamp = timeval_to_ktime(tv);
 226
 227         return netif_rx(skb);
 228 }
 229
 230 /*
 231  * callback for bulk Rx urb
 232  */
 233 static void peak_usb_read_bulk_callback(struct urb *urb)
 234 {
 235         struct peak_usb_device *dev = urb->context;
 236         struct net_device *netdev;
 237         int err;
 238
 239         netdev = dev->netdev;
 240
 241         if (!netif_device_present(netdev))
 242                 return;
 243
 244         /* check reception status */
 245         switch (urb->status) {
 246         case 0:
 247                 /* success */
 248                 break;
 249
 250         case -EILSEQ:
 251         case -ENOENT:
 252         case -ECONNRESET:
 253         case -ESHUTDOWN:
 254                 return;
 255
 256         default:
 257                 if (net_ratelimit())
 258                         netdev_err(netdev,
 259                                    "Rx urb aborted (%d)\n", urb->status);
 260                 goto resubmit_urb;
 261         }
 262
 263         /* protect from any incoming empty msgs */
 264         if ((urb->actual_length > 0) && (dev->adapter->dev_decode_buf)) {
 265                 /* handle these kinds of msgs only if _start callback called */
 266                 if (dev->state & PCAN_USB_STATE_STARTED) {
 267                         err = dev->adapter->dev_decode_buf(dev, urb);
 268                         if (err)
 269                                 pcan_dump_mem("received usb message",
 270                                               urb->transfer_buffer,
 271                                               urb->transfer_buffer_length);
 272                 }
 273         }
 274
 275 resubmit_urb:
 276         usb_fill_bulk_urb(urb, dev->udev,
 277                 usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 278                 urb->transfer_buffer, dev->adapter->rx_buffer_size,
 279                 peak_usb_read_bulk_callback, dev);
 280
 281         usb_anchor_urb(urb, &dev->rx_submitted);
 282         err = usb_submit_urb(urb, GFP_ATOMIC);
 283         if (!err)
 284                 return;
 285
 286         usb_unanchor_urb(urb);
 287
 288         if (err == -ENODEV)
 289                 netif_device_detach(netdev);
 290         else
 291                 netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
 292                            err);
 293 }
 294
 295 /*
 296  * callback for bulk Tx urb
 297  */
 298 static void peak_usb_write_bulk_callback(struct urb *urb)
 299 {
 300         struct peak_tx_urb_context *context = urb->context;
 301         struct peak_usb_device *dev;
 302         struct net_device *netdev;
 303
 304         BUG_ON(!context);
 305
 306         dev = context->dev;
 307         netdev = dev->netdev;
 308
 309         atomic_dec(&dev->active_tx_urbs);
 310
 311         if (!netif_device_present(netdev))
 312                 return;
 313
 314         /* check tx status */
 315         switch (urb->status) {
 316         case 0:
 317                 /* transmission complete */
 318                 netdev->stats.tx_packets++;
 319                 netdev->stats.tx_bytes += context->data_len;
 320
 321                 /* prevent tx timeout */
 322                 netif_trans_update(netdev);
 323                 break;
 324
 325         default:
 326                 if (net_ratelimit())
 327                         netdev_err(netdev, "Tx urb aborted (%d)\n",
 328                                    urb->status);
 329         case -EPROTO:
 330         case -ENOENT:
 331         case -ECONNRESET:
 332         case -ESHUTDOWN:
 333
 334                 break;
 335         }
 336
 337         /* should always release echo skb and corresponding context */
 338         can_get_echo_skb(netdev, context->echo_index);
 339         context->echo_index = PCAN_USB_MAX_TX_URBS;
 340
 341         /* do wakeup tx queue in case of success only */
 342         if (!urb->status)
 343                 netif_wake_queue(netdev);
 344 }
 345
 346 /*
 347  * called by netdev to send one skb on the CAN interface.
 348  */
 349 static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
 350                                            struct net_device *netdev)
 351 {
 352         struct peak_usb_device *dev = netdev_priv(netdev);
 353         struct peak_tx_urb_context *context = NULL;
 354         struct net_device_stats *stats = &netdev->stats;
 355         struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 356         struct urb *urb;
 357         u8 *obuf;
 358         int i, err;
 359         size_t size = dev->adapter->tx_buffer_size;
 360
 361         if (can_dropped_invalid_skb(netdev, skb))
 362                 return NETDEV_TX_OK;
 363
 364         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
 365                 if (dev->tx_contexts[i].echo_index == PCAN_USB_MAX_TX_URBS) {
 366                         context = dev->tx_contexts + i;
 367                         break;
 368                 }
 369
 370         if (!context) {
 371                 /* should not occur except during restart */
 372                 return NETDEV_TX_BUSY;
 373         }
 374
 375         urb = context->urb;
 376         obuf = urb->transfer_buffer;
 377
 378         err = dev->adapter->dev_encode_msg(dev, skb, obuf, &size);
 379         if (err) {
 380                 if (net_ratelimit())
 381                         netdev_err(netdev, "packet dropped\n");
 382                 dev_kfree_skb(skb);
 383                 stats->tx_dropped++;
 384                 return NETDEV_TX_OK;
 385         }
 386
 387         context->echo_index = i;
 388
 389         /* Note: this works with CANFD frames too */
 390         context->data_len = cfd->len;
 391
 392         usb_anchor_urb(urb, &dev->tx_submitted);
 393
 394         can_put_echo_skb(skb, netdev, context->echo_index);
 395
 396         atomic_inc(&dev->active_tx_urbs);
 397
 398         err = usb_submit_urb(urb, GFP_ATOMIC);
 399         if (err) {
 400                 can_free_echo_skb(netdev, context->echo_index);
 401
 402                 usb_unanchor_urb(urb);
 403
 404                 /* this context is not used in fact */
 405                 context->echo_index = PCAN_USB_MAX_TX_URBS;
 406
 407                 atomic_dec(&dev->active_tx_urbs);
 408
 409                 switch (err) {
 410                 case -ENODEV:
 411                         netif_device_detach(netdev);
 412                         break;
 413                 default:
 414                         netdev_warn(netdev, "tx urb submitting failed err=%d\n",
 415                                     err);
 416                 case -ENOENT:
 417                         /* cable unplugged */
 418                         stats->tx_dropped++;
 419                 }
 420         } else {
 421                 netif_trans_update(netdev);
 422
 423                 /* slow down tx path */
 424                 if (atomic_read(&dev->active_tx_urbs) >= PCAN_USB_MAX_TX_URBS)
 425                         netif_stop_queue(netdev);
 426         }
 427
 428         return NETDEV_TX_OK;
 429 }
 430
 431 /*
 432  * start the CAN interface.
 433  * Rx and Tx urbs are allocated here. Rx urbs are submitted here.
 434  */
 435 static int peak_usb_start(struct peak_usb_device *dev)
 436 {
 437         struct net_device *netdev = dev->netdev;
 438         int err, i;
 439
 440         for (i = 0; i < PCAN_USB_MAX_RX_URBS; i++) {
 441                 struct urb *urb;
 442                 u8 *buf;
 443
 444                 /* create a URB, and a buffer for it, to receive usb messages */
 445                 urb = usb_alloc_urb(0, GFP_KERNEL);
 446                 if (!urb) {
 447                         err = -ENOMEM;
 448                         break;
 449                 }
 450
 451                 buf = kmalloc(dev->adapter->rx_buffer_size, GFP_KERNEL);
 452                 if (!buf) {
 453                         usb_free_urb(urb);
 454                         err = -ENOMEM;
 455                         break;
 456                 }
 457
 458                 usb_fill_bulk_urb(urb, dev->udev,
 459                         usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
 460                         buf, dev->adapter->rx_buffer_size,
 461                         peak_usb_read_bulk_callback, dev);
 462
 463                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 464                 urb->transfer_flags |= URB_FREE_BUFFER;
 465                 usb_anchor_urb(urb, &dev->rx_submitted);
 466
 467                 err = usb_submit_urb(urb, GFP_KERNEL);
 468                 if (err) {
 469                         if (err == -ENODEV)
 470                                 netif_device_detach(dev->netdev);
 471
 472                         usb_unanchor_urb(urb);
 473                         kfree(buf);
 474                         usb_free_urb(urb);
 475                         break;
 476                 }
 477
 478                 /* drop reference, USB core will take care of freeing it */
 479                 usb_free_urb(urb);
 480         }
 481
 482         /* did we submit any URBs? Warn if we was not able to submit all urbs */
 483         if (i < PCAN_USB_MAX_RX_URBS) {
 484                 if (i == 0) {
 485                         netdev_err(netdev, "couldn't setup any rx URB\n");
 486                         return err;
 487                 }
 488
 489                 netdev_warn(netdev, "rx performance may be slow\n");
 490         }
 491
 492         /* pre-alloc tx buffers and corresponding urbs */
 493         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 494                 struct peak_tx_urb_context *context;
 495                 struct urb *urb;
 496                 u8 *buf;
 497
 498                 /* create a URB and a buffer for it, to transmit usb messages */
 499                 urb = usb_alloc_urb(0, GFP_KERNEL);
 500                 if (!urb) {
 501                         err = -ENOMEM;
 502                         break;
 503                 }
 504
 505                 buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);
 506                 if (!buf) {
 507                         usb_free_urb(urb);
 508                         err = -ENOMEM;
 509                         break;
 510                 }
 511
 512                 context = dev->tx_contexts + i;
 513                 context->dev = dev;
 514                 context->urb = urb;
 515
 516                 usb_fill_bulk_urb(urb, dev->udev,
 517                         usb_sndbulkpipe(dev->udev, dev->ep_msg_out),
 518                         buf, dev->adapter->tx_buffer_size,
 519                         peak_usb_write_bulk_callback, context);
 520
 521                 /* ask last usb_free_urb() to also kfree() transfer_buffer */
 522                 urb->transfer_flags |= URB_FREE_BUFFER;
 523         }
 524
 525         /* warn if we were not able to allocate enough tx contexts */
 526         if (i < PCAN_USB_MAX_TX_URBS) {
 527                 if (i == 0) {
 528                         netdev_err(netdev, "couldn't setup any tx URB\n");
 529                         goto err_tx;
 530                 }
 531
 532                 netdev_warn(netdev, "tx performance may be slow\n");
 533         }
 534
 535         if (dev->adapter->dev_start) {
 536                 err = dev->adapter->dev_start(dev);
 537                 if (err)
 538                         goto err_adapter;
 539         }
 540
 541         dev->state |= PCAN_USB_STATE_STARTED;
 542
 543         /* can set bus on now */
 544         if (dev->adapter->dev_set_bus) {
 545                 err = dev->adapter->dev_set_bus(dev, 1);
 546                 if (err)
 547                         goto err_adapter;
 548         }
 549
 550         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 551
 552         return 0;
 553
 554 err_adapter:
 555         if (err == -ENODEV)
 556                 netif_device_detach(dev->netdev);
 557
 558         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 559
 560         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 561                 usb_free_urb(dev->tx_contexts[i].urb);
 562                 dev->tx_contexts[i].urb = NULL;
 563         }
 564 err_tx:
 565         usb_kill_anchored_urbs(&dev->rx_submitted);
 566
 567         return err;
 568 }
 569
 570 /*
 571  * called by netdev to open the corresponding CAN interface.
 572  */
 573 static int peak_usb_ndo_open(struct net_device *netdev)
 574 {
 575         struct peak_usb_device *dev = netdev_priv(netdev);
 576         int err;
 577
 578         /* common open */
 579         err = open_candev(netdev);
 580         if (err)
 581                 return err;
 582
 583         /* finally start device */
 584         err = peak_usb_start(dev);
 585         if (err) {
 586                 netdev_err(netdev, "couldn't start device: %d\n", err);
 587                 close_candev(netdev);
 588                 return err;
 589         }
 590
 591         netif_start_queue(netdev);
 592
 593         return 0;
 594 }
 595
 596 /*
 597  * unlink in-flight Rx and Tx urbs and free their memory.
 598  */
 599 static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)
 600 {
 601         int i;
 602
 603         /* free all Rx (submitted) urbs */
 604         usb_kill_anchored_urbs(&dev->rx_submitted);
 605
 606         /* free unsubmitted Tx urbs first */
 607         for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
 608                 struct urb *urb = dev->tx_contexts[i].urb;
 609
 610                 if (!urb ||
 611                     dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {
 612                         /*
 613                          * this urb is already released or always submitted,
 614                          * let usb core free by itself
 615                          */
 616                         continue;
 617                 }
 618
 619                 usb_free_urb(urb);
 620                 dev->tx_contexts[i].urb = NULL;
 621         }
 622
 623         /* then free all submitted Tx urbs */
 624         usb_kill_anchored_urbs(&dev->tx_submitted);
 625         atomic_set(&dev->active_tx_urbs, 0);
 626 }
 627
 628 /*
 629  * called by netdev to close the corresponding CAN interface.
 630  */
 631 static int peak_usb_ndo_stop(struct net_device *netdev)
 632 {
 633         struct peak_usb_device *dev = netdev_priv(netdev);
 634
 635         dev->state &= ~PCAN_USB_STATE_STARTED;
 636         netif_stop_queue(netdev);
 637
 638         close_candev(netdev);
 639
 640         dev->can.state = CAN_STATE_STOPPED;
 641
 642         /* unlink all pending urbs and free used memory */
 643         peak_usb_unlink_all_urbs(dev);
 644
 645         if (dev->adapter->dev_stop)
 646                 dev->adapter->dev_stop(dev);
 647
 648         /* can set bus off now */
 649         if (dev->adapter->dev_set_bus) {
 650                 int err = dev->adapter->dev_set_bus(dev, 0);
 651                 if (err)
 652                         return err;
 653         }
 654
 655         return 0;
 656 }
 657
 658 /*
 659  * handle end of waiting for the device to reset
 660  */
 661 void peak_usb_restart_complete(struct peak_usb_device *dev)
 662 {
 663         /* finally MUST update can state */
 664         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 665
 666         /* netdev queue can be awaken now */
 667         netif_wake_queue(dev->netdev);
 668 }
 669
 670 void peak_usb_async_complete(struct urb *urb)
 671 {
 672         kfree(urb->transfer_buffer);
 673         usb_free_urb(urb);
 674 }
 675
 676 /*
 677  * device (auto-)restart mechanism runs in a timer context =>
 678  * MUST handle restart with asynchronous usb transfers
 679  */
 680 static int peak_usb_restart(struct peak_usb_device *dev)
 681 {
 682         struct urb *urb;
 683         int err;
 684         u8 *buf;
 685
 686         /*
 687          * if device doesn't define any asynchronous restart handler, simply
 688          * wake the netdev queue up
 689          */
 690         if (!dev->adapter->dev_restart_async) {
 691                 peak_usb_restart_complete(dev);
 692                 return 0;
 693         }
 694
 695         /* first allocate a urb to handle the asynchronous steps */
 696         urb = usb_alloc_urb(0, GFP_ATOMIC);
 697         if (!urb)
 698                 return -ENOMEM;
 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         /* get corresponding PCAN-USB adapter */
 957         for (i = 0; i < ARRAY_SIZE(peak_usb_adapters_list); i++)
 958                 if (peak_usb_adapters_list[i]->device_id == usb_id_product) {
 959                         peak_usb_adapter = peak_usb_adapters_list[i];
 960                         break;
 961                 }
 962
 963         if (!peak_usb_adapter) {
 964                 /* should never come except device_id bad usage in this file */
 965                 pr_err("%s: didn't find device id. 0x%x in devices list\n",
 966                         PCAN_USB_DRIVER_NAME, usb_id_product);
 967                 return -ENODEV;
 968         }
 969
 970         /* got corresponding adapter: check if it handles current interface */
 971         if (peak_usb_adapter->intf_probe) {
 972                 err = peak_usb_adapter->intf_probe(intf);
 973                 if (err)
 974                         return err;
 975         }
 976
 977         for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
 978                 err = peak_usb_create_dev(peak_usb_adapter, intf, i);
 979                 if (err) {
 980                         /* deregister already created devices */
 981                         peak_usb_disconnect(intf);
 982                         break;
 983                 }
 984         }
 985
 986         return err;
 987 }
 988
 989 /* usb specific object needed to register this driver with the usb subsystem */
 990 static struct usb_driver peak_usb_driver = {
 991         .name = PCAN_USB_DRIVER_NAME,
 992         .disconnect = peak_usb_disconnect,
 993         .probe = peak_usb_probe,
 994         .id_table = peak_usb_table,
 995 };
 996
 997 static int __init peak_usb_init(void)
 998 {
 999         int err;
1000
1001         /* register this driver with the USB subsystem */
1002         err = usb_register(&peak_usb_driver);
1003         if (err)
1004                 pr_err("%s: usb_register failed (err %d)\n",
1005                         PCAN_USB_DRIVER_NAME, err);
1006
1007         return err;
1008 }
1009
1010 static int peak_usb_do_device_exit(struct device *d, void *arg)
1011 {
1012         struct usb_interface *intf = to_usb_interface(d);
1013         struct peak_usb_device *dev;
1014
1015         /* stop as many netdev devices as siblings */
1016         for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
1017                 struct net_device *netdev = dev->netdev;
1018
1019                 if (netif_device_present(netdev))
1020                         if (dev->adapter->dev_exit)
1021                                 dev->adapter->dev_exit(dev);
1022         }
1023
1024         return 0;
1025 }
1026
1027 static void __exit peak_usb_exit(void)
1028 {
1029         int err;
1030
1031         /* last chance do send any synchronous commands here */
1032         err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
1033                                      NULL, peak_usb_do_device_exit);
1034         if (err)
1035                 pr_err("%s: failed to stop all can devices (err %d)\n",
1036                         PCAN_USB_DRIVER_NAME, err);
1037
1038         /* deregister this driver with the USB subsystem */
1039         usb_deregister(&peak_usb_driver);
1040
1041         pr_info("%s: PCAN-USB interfaces driver unloaded\n",
1042                 PCAN_USB_DRIVER_NAME);
1043 }
1044
1045 module_init(peak_usb_init);
1046 module_exit(peak_usb_exit);