drivers/net/can/dev.c

   1 /*
   2  * Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
   3  * Copyright (C) 2006 Andrey Volkov, Varma Electronics
   4  * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the version 2 of the GNU General Public License
   8  * as published by the Free Software Foundation
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/slab.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/if_arp.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/can.h>
  26 #include <linux/can/dev.h>
  27 #include <linux/can/skb.h>
  28 #include <linux/can/netlink.h>
  29 #include <linux/can/led.h>
  30 #include <net/rtnetlink.h>
  31
  32 #define MOD_DESC "CAN device driver interface"
  33
  34 MODULE_DESCRIPTION(MOD_DESC);
  35 MODULE_LICENSE("GPL v2");
  36 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  37
  38 /* CAN DLC to real data length conversion helpers */
  39
  40 static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
  41                              8, 12, 16, 20, 24, 32, 48, 64};
  42
  43 /* get data length from can_dlc with sanitized can_dlc */
  44 u8 can_dlc2len(u8 can_dlc)
  45 {
  46         return dlc2len[can_dlc & 0x0F];
  47 }
  48 EXPORT_SYMBOL_GPL(can_dlc2len);
  49
  50 static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8,         /* 0 - 8 */
  51                              9, 9, 9, 9,                        /* 9 - 12 */
  52                              10, 10, 10, 10,                    /* 13 - 16 */
  53                              11, 11, 11, 11,                    /* 17 - 20 */
  54                              12, 12, 12, 12,                    /* 21 - 24 */
  55                              13, 13, 13, 13, 13, 13, 13, 13,    /* 25 - 32 */
  56                              14, 14, 14, 14, 14, 14, 14, 14,    /* 33 - 40 */
  57                              14, 14, 14, 14, 14, 14, 14, 14,    /* 41 - 48 */
  58                              15, 15, 15, 15, 15, 15, 15, 15,    /* 49 - 56 */
  59                              15, 15, 15, 15, 15, 15, 15, 15};   /* 57 - 64 */
  60
  61 /* map the sanitized data length to an appropriate data length code */
  62 u8 can_len2dlc(u8 len)
  63 {
  64         if (unlikely(len > 64))
  65                 return 0xF;
  66
  67         return len2dlc[len];
  68 }
  69 EXPORT_SYMBOL_GPL(can_len2dlc);
  70
  71 #ifdef CONFIG_CAN_CALC_BITTIMING
  72 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
  73 #define CAN_CALC_SYNC_SEG 1
  74
  75 /*
  76  * Bit-timing calculation derived from:
  77  *
  78  * Code based on LinCAN sources and H8S2638 project
  79  * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
  80  * Copyright 2005      Stanislav Marek
  81  * email: pisa@cmp.felk.cvut.cz
  82  *
  83  * Calculates proper bit-timing parameters for a specified bit-rate
  84  * and sample-point, which can then be used to set the bit-timing
  85  * registers of the CAN controller. You can find more information
  86  * in the header file linux/can/netlink.h.
  87  */
  88 static int can_update_sample_point(const struct can_bittiming_const *btc,
  89                           unsigned int sample_point_nominal, unsigned int tseg,
  90                           unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
  91                           unsigned int *sample_point_error_ptr)
  92 {
  93         unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
  94         unsigned int sample_point, best_sample_point = 0;
  95         unsigned int tseg1, tseg2;
  96         int i;
  97
  98         for (i = 0; i <= 1; i++) {
  99                 tseg2 = tseg + CAN_CALC_SYNC_SEG - (sample_point_nominal * (tseg + CAN_CALC_SYNC_SEG)) / 1000 - i;
 100                 tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
 101                 tseg1 = tseg - tseg2;
 102                 if (tseg1 > btc->tseg1_max) {
 103                         tseg1 = btc->tseg1_max;
 104                         tseg2 = tseg - tseg1;
 105                 }
 106
 107                 sample_point = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) / (tseg + CAN_CALC_SYNC_SEG);
 108                 sample_point_error = abs(sample_point_nominal - sample_point);
 109
 110                 if ((sample_point <= sample_point_nominal) && (sample_point_error < best_sample_point_error)) {
 111                         best_sample_point = sample_point;
 112                         best_sample_point_error = sample_point_error;
 113                         *tseg1_ptr = tseg1;
 114                         *tseg2_ptr = tseg2;
 115                 }
 116         }
 117
 118         if (sample_point_error_ptr)
 119                 *sample_point_error_ptr = best_sample_point_error;
 120
 121         return best_sample_point;
 122 }
 123
 124 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 125                               const struct can_bittiming_const *btc)
 126 {
 127         struct can_priv *priv = netdev_priv(dev);
 128         unsigned int bitrate;                   /* current bitrate */
 129         unsigned int bitrate_error;             /* difference between current and nominal value */
 130         unsigned int best_bitrate_error = UINT_MAX;
 131         unsigned int sample_point_error;        /* difference between current and nominal value */
 132         unsigned int best_sample_point_error = UINT_MAX;
 133         unsigned int sample_point_nominal;      /* nominal sample point */
 134         unsigned int best_tseg = 0;             /* current best value for tseg */
 135         unsigned int best_brp = 0;              /* current best value for brp */
 136         unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
 137         u64 v64;
 138
 139         /* Use CiA recommended sample points */
 140         if (bt->sample_point) {
 141                 sample_point_nominal = bt->sample_point;
 142         } else {
 143                 if (bt->bitrate > 800000)
 144                         sample_point_nominal = 750;
 145                 else if (bt->bitrate > 500000)
 146                         sample_point_nominal = 800;
 147                 else
 148                         sample_point_nominal = 875;
 149         }
 150
 151         /* tseg even = round down, odd = round up */
 152         for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
 153              tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
 154                 tsegall = CAN_CALC_SYNC_SEG + tseg / 2;
 155
 156                 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */
 157                 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
 158
 159                 /* choose brp step which is possible in system */
 160                 brp = (brp / btc->brp_inc) * btc->brp_inc;
 161                 if ((brp < btc->brp_min) || (brp > btc->brp_max))
 162                         continue;
 163
 164                 bitrate = priv->clock.freq / (brp * tsegall);
 165                 bitrate_error = abs(bt->bitrate - bitrate);
 166
 167                 /* tseg brp biterror */
 168                 if (bitrate_error > best_bitrate_error)
 169                         continue;
 170
 171                 /* reset sample point error if we have a better bitrate */
 172                 if (bitrate_error < best_bitrate_error)
 173                         best_sample_point_error = UINT_MAX;
 174
 175                 can_update_sample_point(btc, sample_point_nominal, tseg / 2, &tseg1, &tseg2, &sample_point_error);
 176                 if (sample_point_error > best_sample_point_error)
 177                         continue;
 178
 179                 best_sample_point_error = sample_point_error;
 180                 best_bitrate_error = bitrate_error;
 181                 best_tseg = tseg / 2;
 182                 best_brp = brp;
 183
 184                 if (bitrate_error == 0 && sample_point_error == 0)
 185                         break;
 186         }
 187
 188         if (best_bitrate_error) {
 189                 /* Error in one-tenth of a percent */
 190                 v64 = (u64)best_bitrate_error * 1000;
 191                 do_div(v64, bt->bitrate);
 192                 bitrate_error = (u32)v64;
 193                 if (bitrate_error > CAN_CALC_MAX_ERROR) {
 194                         netdev_err(dev,
 195                                    "bitrate error %d.%d%% too high\n",
 196                                    bitrate_error / 10, bitrate_error % 10);
 197                         return -EDOM;
 198                 }
 199                 netdev_warn(dev, "bitrate error %d.%d%%\n",
 200                             bitrate_error / 10, bitrate_error % 10);
 201         }
 202
 203         /* real sample point */
 204         bt->sample_point = can_update_sample_point(btc, sample_point_nominal, best_tseg,
 205                                           &tseg1, &tseg2, NULL);
 206
 207         v64 = (u64)best_brp * 1000 * 1000 * 1000;
 208         do_div(v64, priv->clock.freq);
 209         bt->tq = (u32)v64;
 210         bt->prop_seg = tseg1 / 2;
 211         bt->phase_seg1 = tseg1 - bt->prop_seg;
 212         bt->phase_seg2 = tseg2;
 213
 214         /* check for sjw user settings */
 215         if (!bt->sjw || !btc->sjw_max) {
 216                 bt->sjw = 1;
 217         } else {
 218                 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
 219                 if (bt->sjw > btc->sjw_max)
 220                         bt->sjw = btc->sjw_max;
 221                 /* bt->sjw must not be higher than tseg2 */
 222                 if (tseg2 < bt->sjw)
 223                         bt->sjw = tseg2;
 224         }
 225
 226         bt->brp = best_brp;
 227
 228         /* real bitrate */
 229         bt->bitrate = priv->clock.freq / (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2));
 230
 231         return 0;
 232 }
 233 #else /* !CONFIG_CAN_CALC_BITTIMING */
 234 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 235                               const struct can_bittiming_const *btc)
 236 {
 237         netdev_err(dev, "bit-timing calculation not available\n");
 238         return -EINVAL;
 239 }
 240 #endif /* CONFIG_CAN_CALC_BITTIMING */
 241
 242 /*
 243  * Checks the validity of the specified bit-timing parameters prop_seg,
 244  * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
 245  * prescaler value brp. You can find more information in the header
 246  * file linux/can/netlink.h.
 247  */
 248 static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
 249                                const struct can_bittiming_const *btc)
 250 {
 251         struct can_priv *priv = netdev_priv(dev);
 252         int tseg1, alltseg;
 253         u64 brp64;
 254
 255         tseg1 = bt->prop_seg + bt->phase_seg1;
 256         if (!bt->sjw)
 257                 bt->sjw = 1;
 258         if (bt->sjw > btc->sjw_max ||
 259             tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
 260             bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
 261                 return -ERANGE;
 262
 263         brp64 = (u64)priv->clock.freq * (u64)bt->tq;
 264         if (btc->brp_inc > 1)
 265                 do_div(brp64, btc->brp_inc);
 266         brp64 += 500000000UL - 1;
 267         do_div(brp64, 1000000000UL); /* the practicable BRP */
 268         if (btc->brp_inc > 1)
 269                 brp64 *= btc->brp_inc;
 270         bt->brp = (u32)brp64;
 271
 272         if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
 273                 return -EINVAL;
 274
 275         alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
 276         bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
 277         bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
 278
 279         return 0;
 280 }
 281
 282 /* Checks the validity of predefined bitrate settings */
 283 static int can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
 284                                 const u32 *bitrate_const,
 285                                 const unsigned int bitrate_const_cnt)
 286 {
 287         struct can_priv *priv = netdev_priv(dev);
 288         unsigned int i;
 289
 290         for (i = 0; i < bitrate_const_cnt; i++) {
 291                 if (bt->bitrate == bitrate_const[i])
 292                         break;
 293         }
 294
 295         if (i >= priv->bitrate_const_cnt)
 296                 return -EINVAL;
 297
 298         return 0;
 299 }
 300
 301 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
 302                              const struct can_bittiming_const *btc,
 303                              const u32 *bitrate_const,
 304                              const unsigned int bitrate_const_cnt)
 305 {
 306         int err;
 307
 308         /*
 309          * Depending on the given can_bittiming parameter structure the CAN
 310          * timing parameters are calculated based on the provided bitrate OR
 311          * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
 312          * provided directly which are then checked and fixed up.
 313          */
 314         if (!bt->tq && bt->bitrate && btc)
 315                 err = can_calc_bittiming(dev, bt, btc);
 316         else if (bt->tq && !bt->bitrate && btc)
 317                 err = can_fixup_bittiming(dev, bt, btc);
 318         else if (!bt->tq && bt->bitrate && bitrate_const)
 319                 err = can_validate_bitrate(dev, bt, bitrate_const,
 320                                            bitrate_const_cnt);
 321         else
 322                 err = -EINVAL;
 323
 324         return err;
 325 }
 326
 327 static void can_update_state_error_stats(struct net_device *dev,
 328                                          enum can_state new_state)
 329 {
 330         struct can_priv *priv = netdev_priv(dev);
 331
 332         if (new_state <= priv->state)
 333                 return;
 334
 335         switch (new_state) {
 336         case CAN_STATE_ERROR_WARNING:
 337                 priv->can_stats.error_warning++;
 338                 break;
 339         case CAN_STATE_ERROR_PASSIVE:
 340                 priv->can_stats.error_passive++;
 341                 break;
 342         case CAN_STATE_BUS_OFF:
 343                 priv->can_stats.bus_off++;
 344                 break;
 345         default:
 346                 break;
 347         }
 348 }
 349
 350 static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
 351 {
 352         switch (state) {
 353         case CAN_STATE_ERROR_ACTIVE:
 354                 return CAN_ERR_CRTL_ACTIVE;
 355         case CAN_STATE_ERROR_WARNING:
 356                 return CAN_ERR_CRTL_TX_WARNING;
 357         case CAN_STATE_ERROR_PASSIVE:
 358                 return CAN_ERR_CRTL_TX_PASSIVE;
 359         default:
 360                 return 0;
 361         }
 362 }
 363
 364 static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
 365 {
 366         switch (state) {
 367         case CAN_STATE_ERROR_ACTIVE:
 368                 return CAN_ERR_CRTL_ACTIVE;
 369         case CAN_STATE_ERROR_WARNING:
 370                 return CAN_ERR_CRTL_RX_WARNING;
 371         case CAN_STATE_ERROR_PASSIVE:
 372                 return CAN_ERR_CRTL_RX_PASSIVE;
 373         default:
 374                 return 0;
 375         }
 376 }
 377
 378 void can_change_state(struct net_device *dev, struct can_frame *cf,
 379                       enum can_state tx_state, enum can_state rx_state)
 380 {
 381         struct can_priv *priv = netdev_priv(dev);
 382         enum can_state new_state = max(tx_state, rx_state);
 383
 384         if (unlikely(new_state == priv->state)) {
 385                 netdev_warn(dev, "%s: oops, state did not change", __func__);
 386                 return;
 387         }
 388
 389         netdev_dbg(dev, "New error state: %d\n", new_state);
 390
 391         can_update_state_error_stats(dev, new_state);
 392         priv->state = new_state;
 393
 394         if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
 395                 cf->can_id |= CAN_ERR_BUSOFF;
 396                 return;
 397         }
 398
 399         cf->can_id |= CAN_ERR_CRTL;
 400         cf->data[1] |= tx_state >= rx_state ?
 401                        can_tx_state_to_frame(dev, tx_state) : 0;
 402         cf->data[1] |= tx_state <= rx_state ?
 403                        can_rx_state_to_frame(dev, rx_state) : 0;
 404 }
 405 EXPORT_SYMBOL_GPL(can_change_state);
 406
 407 /*
 408  * Local echo of CAN messages
 409  *
 410  * CAN network devices *should* support a local echo functionality
 411  * (see Documentation/networking/can.txt). To test the handling of CAN
 412  * interfaces that do not support the local echo both driver types are
 413  * implemented. In the case that the driver does not support the echo
 414  * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
 415  * to perform the echo as a fallback solution.
 416  */
 417 static void can_flush_echo_skb(struct net_device *dev)
 418 {
 419         struct can_priv *priv = netdev_priv(dev);
 420         struct net_device_stats *stats = &dev->stats;
 421         int i;
 422
 423         for (i = 0; i < priv->echo_skb_max; i++) {
 424                 if (priv->echo_skb[i]) {
 425                         kfree_skb(priv->echo_skb[i]);
 426                         priv->echo_skb[i] = NULL;
 427                         stats->tx_dropped++;
 428                         stats->tx_aborted_errors++;
 429                 }
 430         }
 431 }
 432
 433 /*
 434  * Put the skb on the stack to be looped backed locally lateron
 435  *
 436  * The function is typically called in the start_xmit function
 437  * of the device driver. The driver must protect access to
 438  * priv->echo_skb, if necessary.
 439  */
 440 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 441                       unsigned int idx)
 442 {
 443         struct can_priv *priv = netdev_priv(dev);
 444
 445         BUG_ON(idx >= priv->echo_skb_max);
 446
 447         /* check flag whether this packet has to be looped back */
 448         if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
 449             (skb->protocol != htons(ETH_P_CAN) &&
 450              skb->protocol != htons(ETH_P_CANFD))) {
 451                 kfree_skb(skb);
 452                 return;
 453         }
 454
 455         if (!priv->echo_skb[idx]) {
 456
 457                 skb = can_create_echo_skb(skb);
 458                 if (!skb)
 459                         return;
 460
 461                 /* make settings for echo to reduce code in irq context */
 462                 skb->pkt_type = PACKET_BROADCAST;
 463                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 464                 skb->dev = dev;
 465
 466                 /* save this skb for tx interrupt echo handling */
 467                 priv->echo_skb[idx] = skb;
 468         } else {
 469                 /* locking problem with netif_stop_queue() ?? */
 470                 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
 471                 kfree_skb(skb);
 472         }
 473 }
 474 EXPORT_SYMBOL_GPL(can_put_echo_skb);
 475
 476 /*
 477  * Get the skb from the stack and loop it back locally
 478  *
 479  * The function is typically called when the TX done interrupt
 480  * is handled in the device driver. The driver must protect
 481  * access to priv->echo_skb, if necessary.
 482  */
 483 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
 484 {
 485         struct can_priv *priv = netdev_priv(dev);
 486
 487         BUG_ON(idx >= priv->echo_skb_max);
 488
 489         if (priv->echo_skb[idx]) {
 490                 struct sk_buff *skb = priv->echo_skb[idx];
 491                 struct can_frame *cf = (struct can_frame *)skb->data;
 492                 u8 dlc = cf->can_dlc;
 493
 494                 netif_rx(priv->echo_skb[idx]);
 495                 priv->echo_skb[idx] = NULL;
 496
 497                 return dlc;
 498         }
 499
 500         return 0;
 501 }
 502 EXPORT_SYMBOL_GPL(can_get_echo_skb);
 503
 504 /*
 505   * Remove the skb from the stack and free it.
 506   *
 507   * The function is typically called when TX failed.
 508   */
 509 void can_free_echo_skb(struct net_device *dev, unsigned int idx)
 510 {
 511         struct can_priv *priv = netdev_priv(dev);
 512
 513         BUG_ON(idx >= priv->echo_skb_max);
 514
 515         if (priv->echo_skb[idx]) {
 516                 dev_kfree_skb_any(priv->echo_skb[idx]);
 517                 priv->echo_skb[idx] = NULL;
 518         }
 519 }
 520 EXPORT_SYMBOL_GPL(can_free_echo_skb);
 521
 522 /*
 523  * CAN device restart for bus-off recovery
 524  */
 525 static void can_restart(struct net_device *dev)
 526 {
 527         struct can_priv *priv = netdev_priv(dev);
 528         struct net_device_stats *stats = &dev->stats;
 529         struct sk_buff *skb;
 530         struct can_frame *cf;
 531         int err;
 532
 533         BUG_ON(netif_carrier_ok(dev));
 534
 535         /*
 536          * No synchronization needed because the device is bus-off and
 537          * no messages can come in or go out.
 538          */
 539         can_flush_echo_skb(dev);
 540
 541         /* send restart message upstream */
 542         skb = alloc_can_err_skb(dev, &cf);
 543         if (skb == NULL) {
 544                 err = -ENOMEM;
 545                 goto restart;
 546         }
 547         cf->can_id |= CAN_ERR_RESTARTED;
 548
 549         netif_rx(skb);
 550
 551         stats->rx_packets++;
 552         stats->rx_bytes += cf->can_dlc;
 553
 554 restart:
 555         netdev_dbg(dev, "restarted\n");
 556         priv->can_stats.restarts++;
 557
 558         /* Now restart the device */
 559         err = priv->do_set_mode(dev, CAN_MODE_START);
 560
 561         netif_carrier_on(dev);
 562         if (err)
 563                 netdev_err(dev, "Error %d during restart", err);
 564 }
 565
 566 static void can_restart_work(struct work_struct *work)
 567 {
 568         struct delayed_work *dwork = to_delayed_work(work);
 569         struct can_priv *priv = container_of(dwork, struct can_priv, restart_work);
 570
 571         can_restart(priv->dev);
 572 }
 573
 574 int can_restart_now(struct net_device *dev)
 575 {
 576         struct can_priv *priv = netdev_priv(dev);
 577
 578         /*
 579          * A manual restart is only permitted if automatic restart is
 580          * disabled and the device is in the bus-off state
 581          */
 582         if (priv->restart_ms)
 583                 return -EINVAL;
 584         if (priv->state != CAN_STATE_BUS_OFF)
 585                 return -EBUSY;
 586
 587         cancel_delayed_work_sync(&priv->restart_work);
 588         can_restart(dev);
 589
 590         return 0;
 591 }
 592
 593 /*
 594  * CAN bus-off
 595  *
 596  * This functions should be called when the device goes bus-off to
 597  * tell the netif layer that no more packets can be sent or received.
 598  * If enabled, a timer is started to trigger bus-off recovery.
 599  */
 600 void can_bus_off(struct net_device *dev)
 601 {
 602         struct can_priv *priv = netdev_priv(dev);
 603
 604         netdev_dbg(dev, "bus-off\n");
 605
 606         netif_carrier_off(dev);
 607
 608         if (priv->restart_ms)
 609                 schedule_delayed_work(&priv->restart_work,
 610                                       msecs_to_jiffies(priv->restart_ms));
 611 }
 612 EXPORT_SYMBOL_GPL(can_bus_off);
 613
 614 static void can_setup(struct net_device *dev)
 615 {
 616         dev->type = ARPHRD_CAN;
 617         dev->mtu = CAN_MTU;
 618         dev->hard_header_len = 0;
 619         dev->addr_len = 0;
 620         dev->tx_queue_len = 10;
 621
 622         /* New-style flags. */
 623         dev->flags = IFF_NOARP;
 624         dev->features = NETIF_F_HW_CSUM;
 625 }
 626
 627 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
 628 {
 629         struct sk_buff *skb;
 630
 631         skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
 632                                sizeof(struct can_frame));
 633         if (unlikely(!skb))
 634                 return NULL;
 635
 636         skb->protocol = htons(ETH_P_CAN);
 637         skb->pkt_type = PACKET_BROADCAST;
 638         skb->ip_summed = CHECKSUM_UNNECESSARY;
 639
 640         skb_reset_mac_header(skb);
 641         skb_reset_network_header(skb);
 642         skb_reset_transport_header(skb);
 643
 644         can_skb_reserve(skb);
 645         can_skb_prv(skb)->ifindex = dev->ifindex;
 646         can_skb_prv(skb)->skbcnt = 0;
 647
 648         *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
 649         memset(*cf, 0, sizeof(struct can_frame));
 650
 651         return skb;
 652 }
 653 EXPORT_SYMBOL_GPL(alloc_can_skb);
 654
 655 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 656                                 struct canfd_frame **cfd)
 657 {
 658         struct sk_buff *skb;
 659
 660         skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
 661                                sizeof(struct canfd_frame));
 662         if (unlikely(!skb))
 663                 return NULL;
 664
 665         skb->protocol = htons(ETH_P_CANFD);
 666         skb->pkt_type = PACKET_BROADCAST;
 667         skb->ip_summed = CHECKSUM_UNNECESSARY;
 668
 669         skb_reset_mac_header(skb);
 670         skb_reset_network_header(skb);
 671         skb_reset_transport_header(skb);
 672
 673         can_skb_reserve(skb);
 674         can_skb_prv(skb)->ifindex = dev->ifindex;
 675         can_skb_prv(skb)->skbcnt = 0;
 676
 677         *cfd = (struct canfd_frame *)skb_put(skb, sizeof(struct canfd_frame));
 678         memset(*cfd, 0, sizeof(struct canfd_frame));
 679
 680         return skb;
 681 }
 682 EXPORT_SYMBOL_GPL(alloc_canfd_skb);
 683
 684 struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
 685 {
 686         struct sk_buff *skb;
 687
 688         skb = alloc_can_skb(dev, cf);
 689         if (unlikely(!skb))
 690                 return NULL;
 691
 692         (*cf)->can_id = CAN_ERR_FLAG;
 693         (*cf)->can_dlc = CAN_ERR_DLC;
 694
 695         return skb;
 696 }
 697 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
 698
 699 /*
 700  * Allocate and setup space for the CAN network device
 701  */
 702 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
 703 {
 704         struct net_device *dev;
 705         struct can_priv *priv;
 706         int size;
 707
 708         if (echo_skb_max)
 709                 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
 710                         echo_skb_max * sizeof(struct sk_buff *);
 711         else
 712                 size = sizeof_priv;
 713
 714         dev = alloc_netdev(size, "can%d", NET_NAME_UNKNOWN, can_setup);
 715         if (!dev)
 716                 return NULL;
 717
 718         priv = netdev_priv(dev);
 719         priv->dev = dev;
 720
 721         if (echo_skb_max) {
 722                 priv->echo_skb_max = echo_skb_max;
 723                 priv->echo_skb = (void *)priv +
 724                         ALIGN(sizeof_priv, sizeof(struct sk_buff *));
 725         }
 726
 727         priv->state = CAN_STATE_STOPPED;
 728
 729         INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
 730
 731         return dev;
 732 }
 733 EXPORT_SYMBOL_GPL(alloc_candev);
 734
 735 /*
 736  * Free space of the CAN network device
 737  */
 738 void free_candev(struct net_device *dev)
 739 {
 740         free_netdev(dev);
 741 }
 742 EXPORT_SYMBOL_GPL(free_candev);
 743
 744 /*
 745  * changing MTU and control mode for CAN/CANFD devices
 746  */
 747 int can_change_mtu(struct net_device *dev, int new_mtu)
 748 {
 749         struct can_priv *priv = netdev_priv(dev);
 750
 751         /* Do not allow changing the MTU while running */
 752         if (dev->flags & IFF_UP)
 753                 return -EBUSY;
 754
 755         /* allow change of MTU according to the CANFD ability of the device */
 756         switch (new_mtu) {
 757         case CAN_MTU:
 758                 /* 'CANFD-only' controllers can not switch to CAN_MTU */
 759                 if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
 760                         return -EINVAL;
 761
 762                 priv->ctrlmode &= ~CAN_CTRLMODE_FD;
 763                 break;
 764
 765         case CANFD_MTU:
 766                 /* check for potential CANFD ability */
 767                 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
 768                     !(priv->ctrlmode_static & CAN_CTRLMODE_FD))
 769                         return -EINVAL;
 770
 771                 priv->ctrlmode |= CAN_CTRLMODE_FD;
 772                 break;
 773
 774         default:
 775                 return -EINVAL;
 776         }
 777
 778         dev->mtu = new_mtu;
 779         return 0;
 780 }
 781 EXPORT_SYMBOL_GPL(can_change_mtu);
 782
 783 /*
 784  * Common open function when the device gets opened.
 785  *
 786  * This function should be called in the open function of the device
 787  * driver.
 788  */
 789 int open_candev(struct net_device *dev)
 790 {
 791         struct can_priv *priv = netdev_priv(dev);
 792
 793         if (!priv->bittiming.bitrate) {
 794                 netdev_err(dev, "bit-timing not yet defined\n");
 795                 return -EINVAL;
 796         }
 797
 798         /* For CAN FD the data bitrate has to be >= the arbitration bitrate */
 799         if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
 800             (!priv->data_bittiming.bitrate ||
 801              (priv->data_bittiming.bitrate < priv->bittiming.bitrate))) {
 802                 netdev_err(dev, "incorrect/missing data bit-timing\n");
 803                 return -EINVAL;
 804         }
 805
 806         /* Switch carrier on if device was stopped while in bus-off state */
 807         if (!netif_carrier_ok(dev))
 808                 netif_carrier_on(dev);
 809
 810         return 0;
 811 }
 812 EXPORT_SYMBOL_GPL(open_candev);
 813
 814 /*
 815  * Common close function for cleanup before the device gets closed.
 816  *
 817  * This function should be called in the close function of the device
 818  * driver.
 819  */
 820 void close_candev(struct net_device *dev)
 821 {
 822         struct can_priv *priv = netdev_priv(dev);
 823
 824         cancel_delayed_work_sync(&priv->restart_work);
 825         can_flush_echo_skb(dev);
 826 }
 827 EXPORT_SYMBOL_GPL(close_candev);
 828
 829 /*
 830  * CAN netlink interface
 831  */
 832 static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
 833         [IFLA_CAN_STATE]        = { .type = NLA_U32 },
 834         [IFLA_CAN_CTRLMODE]     = { .len = sizeof(struct can_ctrlmode) },
 835         [IFLA_CAN_RESTART_MS]   = { .type = NLA_U32 },
 836         [IFLA_CAN_RESTART]      = { .type = NLA_U32 },
 837         [IFLA_CAN_BITTIMING]    = { .len = sizeof(struct can_bittiming) },
 838         [IFLA_CAN_BITTIMING_CONST]
 839                                 = { .len = sizeof(struct can_bittiming_const) },
 840         [IFLA_CAN_CLOCK]        = { .len = sizeof(struct can_clock) },
 841         [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
 842         [IFLA_CAN_DATA_BITTIMING]
 843                                 = { .len = sizeof(struct can_bittiming) },
 844         [IFLA_CAN_DATA_BITTIMING_CONST]
 845                                 = { .len = sizeof(struct can_bittiming_const) },
 846 };
 847
 848 static int can_validate(struct nlattr *tb[], struct nlattr *data[])
 849 {
 850         bool is_can_fd = false;
 851
 852         /* Make sure that valid CAN FD configurations always consist of
 853          * - nominal/arbitration bittiming
 854          * - data bittiming
 855          * - control mode with CAN_CTRLMODE_FD set
 856          */
 857
 858         if (!data)
 859                 return 0;
 860
 861         if (data[IFLA_CAN_CTRLMODE]) {
 862                 struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
 863
 864                 is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
 865         }
 866
 867         if (is_can_fd) {
 868                 if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
 869                         return -EOPNOTSUPP;
 870         }
 871
 872         if (data[IFLA_CAN_DATA_BITTIMING]) {
 873                 if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
 874                         return -EOPNOTSUPP;
 875         }
 876
 877         return 0;
 878 }
 879
 880 static int can_changelink(struct net_device *dev,
 881                           struct nlattr *tb[], struct nlattr *data[])
 882 {
 883         struct can_priv *priv = netdev_priv(dev);
 884         int err;
 885
 886         /* We need synchronization with dev->stop() */
 887         ASSERT_RTNL();
 888
 889         if (data[IFLA_CAN_BITTIMING]) {
 890                 struct can_bittiming bt;
 891
 892                 /* Do not allow changing bittiming while running */
 893                 if (dev->flags & IFF_UP)
 894                         return -EBUSY;
 895
 896                 /* Calculate bittiming parameters based on
 897                  * bittiming_const if set, otherwise pass bitrate
 898                  * directly via do_set_bitrate(). Bail out if neither
 899                  * is given.
 900                  */
 901                 if (!priv->bittiming_const && !priv->do_set_bittiming)
 902                         return -EOPNOTSUPP;
 903
 904                 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
 905                 err = can_get_bittiming(dev, &bt,
 906                                         priv->bittiming_const,
 907                                         priv->bitrate_const,
 908                                         priv->bitrate_const_cnt);
 909                 if (err)
 910                         return err;
 911                 memcpy(&priv->bittiming, &bt, sizeof(bt));
 912
 913                 if (priv->do_set_bittiming) {
 914                         /* Finally, set the bit-timing registers */
 915                         err = priv->do_set_bittiming(dev);
 916                         if (err)
 917                                 return err;
 918                 }
 919         }
 920
 921         if (data[IFLA_CAN_CTRLMODE]) {
 922                 struct can_ctrlmode *cm;
 923                 u32 ctrlstatic;
 924                 u32 maskedflags;
 925
 926                 /* Do not allow changing controller mode while running */
 927                 if (dev->flags & IFF_UP)
 928                         return -EBUSY;
 929                 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
 930                 ctrlstatic = priv->ctrlmode_static;
 931                 maskedflags = cm->flags & cm->mask;
 932
 933                 /* check whether provided bits are allowed to be passed */
 934                 if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
 935                         return -EOPNOTSUPP;
 936
 937                 /* do not check for static fd-non-iso if 'fd' is disabled */
 938                 if (!(maskedflags & CAN_CTRLMODE_FD))
 939                         ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
 940
 941                 /* make sure static options are provided by configuration */
 942                 if ((maskedflags & ctrlstatic) != ctrlstatic)
 943                         return -EOPNOTSUPP;
 944
 945                 /* clear bits to be modified and copy the flag values */
 946                 priv->ctrlmode &= ~cm->mask;
 947                 priv->ctrlmode |= maskedflags;
 948
 949                 /* CAN_CTRLMODE_FD can only be set when driver supports FD */
 950                 if (priv->ctrlmode & CAN_CTRLMODE_FD)
 951                         dev->mtu = CANFD_MTU;
 952                 else
 953                         dev->mtu = CAN_MTU;
 954         }
 955
 956         if (data[IFLA_CAN_RESTART_MS]) {
 957                 /* Do not allow changing restart delay while running */
 958                 if (dev->flags & IFF_UP)
 959                         return -EBUSY;
 960                 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
 961         }
 962
 963         if (data[IFLA_CAN_RESTART]) {
 964                 /* Do not allow a restart while not running */
 965                 if (!(dev->flags & IFF_UP))
 966                         return -EINVAL;
 967                 err = can_restart_now(dev);
 968                 if (err)
 969                         return err;
 970         }
 971
 972         if (data[IFLA_CAN_DATA_BITTIMING]) {
 973                 struct can_bittiming dbt;
 974
 975                 /* Do not allow changing bittiming while running */
 976                 if (dev->flags & IFF_UP)
 977                         return -EBUSY;
 978
 979                 /* Calculate bittiming parameters based on
 980                  * data_bittiming_const if set, otherwise pass bitrate
 981                  * directly via do_set_bitrate(). Bail out if neither
 982                  * is given.
 983                  */
 984                 if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
 985                         return -EOPNOTSUPP;
 986
 987                 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
 988                        sizeof(dbt));
 989                 err = can_get_bittiming(dev, &dbt,
 990                                         priv->data_bittiming_const,
 991                                         priv->data_bitrate_const,
 992                                         priv->data_bitrate_const_cnt);
 993                 if (err)
 994                         return err;
 995                 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
 996
 997                 if (priv->do_set_data_bittiming) {
 998                         /* Finally, set the bit-timing registers */
 999                         err = priv->do_set_data_bittiming(dev);
1000                         if (err)
1001                                 return err;
1002                 }
1003         }
1004
1005         if (data[IFLA_CAN_TERMINATION]) {
1006                 const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
1007                 const unsigned int num_term = priv->termination_const_cnt;
1008                 unsigned int i;
1009
1010                 if (!priv->do_set_termination)
1011                         return -EOPNOTSUPP;
1012
1013                 /* check whether given value is supported by the interface */
1014                 for (i = 0; i < num_term; i++) {
1015                         if (termval == priv->termination_const[i])
1016                                 break;
1017                 }
1018                 if (i >= num_term)
1019                         return -EINVAL;
1020
1021                 /* Finally, set the termination value */
1022                 err = priv->do_set_termination(dev, termval);
1023                 if (err)
1024                         return err;
1025
1026                 priv->termination = termval;
1027         }
1028
1029         return 0;
1030 }
1031
1032 static size_t can_get_size(const struct net_device *dev)
1033 {
1034         struct can_priv *priv = netdev_priv(dev);
1035         size_t size = 0;
1036
1037         if (priv->bittiming.bitrate)                            /* IFLA_CAN_BITTIMING */
1038                 size += nla_total_size(sizeof(struct can_bittiming));
1039         if (priv->bittiming_const)                              /* IFLA_CAN_BITTIMING_CONST */
1040                 size += nla_total_size(sizeof(struct can_bittiming_const));
1041         size += nla_total_size(sizeof(struct can_clock));       /* IFLA_CAN_CLOCK */
1042         size += nla_total_size(sizeof(u32));                    /* IFLA_CAN_STATE */
1043         size += nla_total_size(sizeof(struct can_ctrlmode));    /* IFLA_CAN_CTRLMODE */
1044         size += nla_total_size(sizeof(u32));                    /* IFLA_CAN_RESTART_MS */
1045         if (priv->do_get_berr_counter)                          /* IFLA_CAN_BERR_COUNTER */
1046                 size += nla_total_size(sizeof(struct can_berr_counter));
1047         if (priv->data_bittiming.bitrate)                       /* IFLA_CAN_DATA_BITTIMING */
1048                 size += nla_total_size(sizeof(struct can_bittiming));
1049         if (priv->data_bittiming_const)                         /* IFLA_CAN_DATA_BITTIMING_CONST */
1050                 size += nla_total_size(sizeof(struct can_bittiming_const));
1051         if (priv->termination_const) {
1052                 size += nla_total_size(sizeof(priv->termination));              /* IFLA_CAN_TERMINATION */
1053                 size += nla_total_size(sizeof(*priv->termination_const) *       /* IFLA_CAN_TERMINATION_CONST */
1054                                        priv->termination_const_cnt);
1055         }
1056         if (priv->bitrate_const)                                /* IFLA_CAN_BITRATE_CONST */
1057                 size += nla_total_size(sizeof(*priv->bitrate_const) *
1058                                        priv->bitrate_const_cnt);
1059         if (priv->data_bitrate_const)                           /* IFLA_CAN_DATA_BITRATE_CONST */
1060                 size += nla_total_size(sizeof(*priv->data_bitrate_const) *
1061                                        priv->data_bitrate_const_cnt);
1062
1063         return size;
1064 }
1065
1066 static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
1067 {
1068         struct can_priv *priv = netdev_priv(dev);
1069         struct can_ctrlmode cm = {.flags = priv->ctrlmode};
1070         struct can_berr_counter bec;
1071         enum can_state state = priv->state;
1072
1073         if (priv->do_get_state)
1074                 priv->do_get_state(dev, &state);
1075
1076         if ((priv->bittiming.bitrate &&
1077              nla_put(skb, IFLA_CAN_BITTIMING,
1078                      sizeof(priv->bittiming), &priv->bittiming)) ||
1079
1080             (priv->bittiming_const &&
1081              nla_put(skb, IFLA_CAN_BITTIMING_CONST,
1082                      sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
1083
1084             nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
1085             nla_put_u32(skb, IFLA_CAN_STATE, state) ||
1086             nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
1087             nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
1088
1089             (priv->do_get_berr_counter &&
1090              !priv->do_get_berr_counter(dev, &bec) &&
1091              nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
1092
1093             (priv->data_bittiming.bitrate &&
1094              nla_put(skb, IFLA_CAN_DATA_BITTIMING,
1095                      sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
1096
1097             (priv->data_bittiming_const &&
1098              nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
1099                      sizeof(*priv->data_bittiming_const),
1100                      priv->data_bittiming_const)) ||
1101
1102             (priv->termination_const &&
1103              (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
1104               nla_put(skb, IFLA_CAN_TERMINATION_CONST,
1105                       sizeof(*priv->termination_const) *
1106                       priv->termination_const_cnt,
1107                       priv->termination_const))) ||
1108
1109             (priv->bitrate_const &&
1110              nla_put(skb, IFLA_CAN_BITRATE_CONST,
1111                      sizeof(*priv->bitrate_const) *
1112                      priv->bitrate_const_cnt,
1113                      priv->bitrate_const)) ||
1114
1115             (priv->data_bitrate_const &&
1116              nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
1117                      sizeof(*priv->data_bitrate_const) *
1118                      priv->data_bitrate_const_cnt,
1119                      priv->data_bitrate_const))
1120             )
1121
1122                 return -EMSGSIZE;
1123
1124         return 0;
1125 }
1126
1127 static size_t can_get_xstats_size(const struct net_device *dev)
1128 {
1129         return sizeof(struct can_device_stats);
1130 }
1131
1132 static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
1133 {
1134         struct can_priv *priv = netdev_priv(dev);
1135
1136         if (nla_put(skb, IFLA_INFO_XSTATS,
1137                     sizeof(priv->can_stats), &priv->can_stats))
1138                 goto nla_put_failure;
1139         return 0;
1140
1141 nla_put_failure:
1142         return -EMSGSIZE;
1143 }
1144
1145 static int can_newlink(struct net *src_net, struct net_device *dev,
1146                        struct nlattr *tb[], struct nlattr *data[])
1147 {
1148         return -EOPNOTSUPP;
1149 }
1150
1151 static void can_dellink(struct net_device *dev, struct list_head *head)
1152 {
1153         return;
1154 }
1155
1156 static struct rtnl_link_ops can_link_ops __read_mostly = {
1157         .kind           = "can",
1158         .maxtype        = IFLA_CAN_MAX,
1159         .policy         = can_policy,
1160         .setup          = can_setup,
1161         .validate       = can_validate,
1162         .newlink        = can_newlink,
1163         .changelink     = can_changelink,
1164         .dellink        = can_dellink,
1165         .get_size       = can_get_size,
1166         .fill_info      = can_fill_info,
1167         .get_xstats_size = can_get_xstats_size,
1168         .fill_xstats    = can_fill_xstats,
1169 };
1170
1171 /*
1172  * Register the CAN network device
1173  */
1174 int register_candev(struct net_device *dev)
1175 {
1176         struct can_priv *priv = netdev_priv(dev);
1177
1178         /* Ensure termination_const, termination_const_cnt and
1179          * do_set_termination consistency. All must be either set or
1180          * unset.
1181          */
1182         if ((!priv->termination_const != !priv->termination_const_cnt) ||
1183             (!priv->termination_const != !priv->do_set_termination))
1184                 return -EINVAL;
1185
1186         if (!priv->bitrate_const != !priv->bitrate_const_cnt)
1187                 return -EINVAL;
1188
1189         if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt)
1190                 return -EINVAL;
1191
1192         dev->rtnl_link_ops = &can_link_ops;
1193         return register_netdev(dev);
1194 }
1195 EXPORT_SYMBOL_GPL(register_candev);
1196
1197 /*
1198  * Unregister the CAN network device
1199  */
1200 void unregister_candev(struct net_device *dev)
1201 {
1202         unregister_netdev(dev);
1203 }
1204 EXPORT_SYMBOL_GPL(unregister_candev);
1205
1206 /*
1207  * Test if a network device is a candev based device
1208  * and return the can_priv* if so.
1209  */
1210 struct can_priv *safe_candev_priv(struct net_device *dev)
1211 {
1212         if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
1213                 return NULL;
1214
1215         return netdev_priv(dev);
1216 }
1217 EXPORT_SYMBOL_GPL(safe_candev_priv);
1218
1219 static __init int can_dev_init(void)
1220 {
1221         int err;
1222
1223         can_led_notifier_init();
1224
1225         err = rtnl_link_register(&can_link_ops);
1226         if (!err)
1227                 printk(KERN_INFO MOD_DESC "\n");
1228
1229         return err;
1230 }
1231 module_init(can_dev_init);
1232
1233 static __exit void can_dev_exit(void)
1234 {
1235         rtnl_link_unregister(&can_link_ops);
1236
1237         can_led_notifier_exit();
1238 }
1239 module_exit(can_dev_exit);
1240
1241 MODULE_ALIAS_RTNL_LINK("can");