drivers/net/can/dev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   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
   7 #include <linux/module.h>
   8 #include <linux/kernel.h>
   9 #include <linux/slab.h>
  10 #include <linux/netdevice.h>
  11 #include <linux/if_arp.h>
  12 #include <linux/workqueue.h>
  13 #include <linux/can.h>
  14 #include <linux/can/dev.h>
  15 #include <linux/can/skb.h>
  16 #include <linux/can/netlink.h>
  17 #include <linux/can/led.h>
  18 #include <linux/of.h>
  19 #include <net/rtnetlink.h>
  20
  21 #define MOD_DESC "CAN device driver interface"
  22
  23 MODULE_DESCRIPTION(MOD_DESC);
  24 MODULE_LICENSE("GPL v2");
  25 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  26
  27 /* CAN DLC to real data length conversion helpers */
  28
  29 static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
  30                              8, 12, 16, 20, 24, 32, 48, 64};
  31
  32 /* get data length from can_dlc with sanitized can_dlc */
  33 u8 can_dlc2len(u8 can_dlc)
  34 {
  35         return dlc2len[can_dlc & 0x0F];
  36 }
  37 EXPORT_SYMBOL_GPL(can_dlc2len);
  38
  39 static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8,         /* 0 - 8 */
  40                              9, 9, 9, 9,                        /* 9 - 12 */
  41                              10, 10, 10, 10,                    /* 13 - 16 */
  42                              11, 11, 11, 11,                    /* 17 - 20 */
  43                              12, 12, 12, 12,                    /* 21 - 24 */
  44                              13, 13, 13, 13, 13, 13, 13, 13,    /* 25 - 32 */
  45                              14, 14, 14, 14, 14, 14, 14, 14,    /* 33 - 40 */
  46                              14, 14, 14, 14, 14, 14, 14, 14,    /* 41 - 48 */
  47                              15, 15, 15, 15, 15, 15, 15, 15,    /* 49 - 56 */
  48                              15, 15, 15, 15, 15, 15, 15, 15};   /* 57 - 64 */
  49
  50 /* map the sanitized data length to an appropriate data length code */
  51 u8 can_len2dlc(u8 len)
  52 {
  53         if (unlikely(len > 64))
  54                 return 0xF;
  55
  56         return len2dlc[len];
  57 }
  58 EXPORT_SYMBOL_GPL(can_len2dlc);
  59
  60 #ifdef CONFIG_CAN_CALC_BITTIMING
  61 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
  62 #define CAN_CALC_SYNC_SEG 1
  63
  64 /* Bit-timing calculation derived from:
  65  *
  66  * Code based on LinCAN sources and H8S2638 project
  67  * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
  68  * Copyright 2005      Stanislav Marek
  69  * email: pisa@cmp.felk.cvut.cz
  70  *
  71  * Calculates proper bit-timing parameters for a specified bit-rate
  72  * and sample-point, which can then be used to set the bit-timing
  73  * registers of the CAN controller. You can find more information
  74  * in the header file linux/can/netlink.h.
  75  */
  76 static int
  77 can_update_sample_point(const struct can_bittiming_const *btc,
  78                         unsigned int sample_point_nominal, unsigned int tseg,
  79                         unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
  80                         unsigned int *sample_point_error_ptr)
  81 {
  82         unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
  83         unsigned int sample_point, best_sample_point = 0;
  84         unsigned int tseg1, tseg2;
  85         int i;
  86
  87         for (i = 0; i <= 1; i++) {
  88                 tseg2 = tseg + CAN_CALC_SYNC_SEG -
  89                         (sample_point_nominal * (tseg + CAN_CALC_SYNC_SEG)) /
  90                         1000 - i;
  91                 tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
  92                 tseg1 = tseg - tseg2;
  93                 if (tseg1 > btc->tseg1_max) {
  94                         tseg1 = btc->tseg1_max;
  95                         tseg2 = tseg - tseg1;
  96                 }
  97
  98                 sample_point = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) /
  99                         (tseg + CAN_CALC_SYNC_SEG);
 100                 sample_point_error = abs(sample_point_nominal - sample_point);
 101
 102                 if (sample_point <= sample_point_nominal &&
 103                     sample_point_error < best_sample_point_error) {
 104                         best_sample_point = sample_point;
 105                         best_sample_point_error = sample_point_error;
 106                         *tseg1_ptr = tseg1;
 107                         *tseg2_ptr = tseg2;
 108                 }
 109         }
 110
 111         if (sample_point_error_ptr)
 112                 *sample_point_error_ptr = best_sample_point_error;
 113
 114         return best_sample_point;
 115 }
 116
 117 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 118                               const struct can_bittiming_const *btc)
 119 {
 120         struct can_priv *priv = netdev_priv(dev);
 121         unsigned int bitrate;                   /* current bitrate */
 122         unsigned int bitrate_error;             /* difference between current and nominal value */
 123         unsigned int best_bitrate_error = UINT_MAX;
 124         unsigned int sample_point_error;        /* difference between current and nominal value */
 125         unsigned int best_sample_point_error = UINT_MAX;
 126         unsigned int sample_point_nominal;      /* nominal sample point */
 127         unsigned int best_tseg = 0;             /* current best value for tseg */
 128         unsigned int best_brp = 0;              /* current best value for brp */
 129         unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
 130         u64 v64;
 131
 132         /* Use CiA recommended sample points */
 133         if (bt->sample_point) {
 134                 sample_point_nominal = bt->sample_point;
 135         } else {
 136                 if (bt->bitrate > 800000)
 137                         sample_point_nominal = 750;
 138                 else if (bt->bitrate > 500000)
 139                         sample_point_nominal = 800;
 140                 else
 141                         sample_point_nominal = 875;
 142         }
 143
 144         /* tseg even = round down, odd = round up */
 145         for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
 146              tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
 147                 tsegall = CAN_CALC_SYNC_SEG + tseg / 2;
 148
 149                 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */
 150                 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
 151
 152                 /* choose brp step which is possible in system */
 153                 brp = (brp / btc->brp_inc) * btc->brp_inc;
 154                 if (brp < btc->brp_min || brp > btc->brp_max)
 155                         continue;
 156
 157                 bitrate = priv->clock.freq / (brp * tsegall);
 158                 bitrate_error = abs(bt->bitrate - bitrate);
 159
 160                 /* tseg brp biterror */
 161                 if (bitrate_error > best_bitrate_error)
 162                         continue;
 163
 164                 /* reset sample point error if we have a better bitrate */
 165                 if (bitrate_error < best_bitrate_error)
 166                         best_sample_point_error = UINT_MAX;
 167
 168                 can_update_sample_point(btc, sample_point_nominal, tseg / 2,
 169                                         &tseg1, &tseg2, &sample_point_error);
 170                 if (sample_point_error > best_sample_point_error)
 171                         continue;
 172
 173                 best_sample_point_error = sample_point_error;
 174                 best_bitrate_error = bitrate_error;
 175                 best_tseg = tseg / 2;
 176                 best_brp = brp;
 177
 178                 if (bitrate_error == 0 && sample_point_error == 0)
 179                         break;
 180         }
 181
 182         if (best_bitrate_error) {
 183                 /* Error in one-tenth of a percent */
 184                 v64 = (u64)best_bitrate_error * 1000;
 185                 do_div(v64, bt->bitrate);
 186                 bitrate_error = (u32)v64;
 187                 if (bitrate_error > CAN_CALC_MAX_ERROR) {
 188                         netdev_err(dev,
 189                                    "bitrate error %d.%d%% too high\n",
 190                                    bitrate_error / 10, bitrate_error % 10);
 191                         return -EDOM;
 192                 }
 193                 netdev_warn(dev, "bitrate error %d.%d%%\n",
 194                             bitrate_error / 10, bitrate_error % 10);
 195         }
 196
 197         /* real sample point */
 198         bt->sample_point = can_update_sample_point(btc, sample_point_nominal,
 199                                                    best_tseg, &tseg1, &tseg2,
 200                                                    NULL);
 201
 202         v64 = (u64)best_brp * 1000 * 1000 * 1000;
 203         do_div(v64, priv->clock.freq);
 204         bt->tq = (u32)v64;
 205         bt->prop_seg = tseg1 / 2;
 206         bt->phase_seg1 = tseg1 - bt->prop_seg;
 207         bt->phase_seg2 = tseg2;
 208
 209         /* check for sjw user settings */
 210         if (!bt->sjw || !btc->sjw_max) {
 211                 bt->sjw = 1;
 212         } else {
 213                 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
 214                 if (bt->sjw > btc->sjw_max)
 215                         bt->sjw = btc->sjw_max;
 216                 /* bt->sjw must not be higher than tseg2 */
 217                 if (tseg2 < bt->sjw)
 218                         bt->sjw = tseg2;
 219         }
 220
 221         bt->brp = best_brp;
 222
 223         /* real bitrate */
 224         bt->bitrate = priv->clock.freq /
 225                 (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2));
 226
 227         return 0;
 228 }
 229 #else /* !CONFIG_CAN_CALC_BITTIMING */
 230 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 231                               const struct can_bittiming_const *btc)
 232 {
 233         netdev_err(dev, "bit-timing calculation not available\n");
 234         return -EINVAL;
 235 }
 236 #endif /* CONFIG_CAN_CALC_BITTIMING */
 237
 238 /* Checks the validity of the specified bit-timing parameters prop_seg,
 239  * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
 240  * prescaler value brp. You can find more information in the header
 241  * file linux/can/netlink.h.
 242  */
 243 static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
 244                                const struct can_bittiming_const *btc)
 245 {
 246         struct can_priv *priv = netdev_priv(dev);
 247         int tseg1, alltseg;
 248         u64 brp64;
 249
 250         tseg1 = bt->prop_seg + bt->phase_seg1;
 251         if (!bt->sjw)
 252                 bt->sjw = 1;
 253         if (bt->sjw > btc->sjw_max ||
 254             tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
 255             bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
 256                 return -ERANGE;
 257
 258         brp64 = (u64)priv->clock.freq * (u64)bt->tq;
 259         if (btc->brp_inc > 1)
 260                 do_div(brp64, btc->brp_inc);
 261         brp64 += 500000000UL - 1;
 262         do_div(brp64, 1000000000UL); /* the practicable BRP */
 263         if (btc->brp_inc > 1)
 264                 brp64 *= btc->brp_inc;
 265         bt->brp = (u32)brp64;
 266
 267         if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
 268                 return -EINVAL;
 269
 270         alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
 271         bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
 272         bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
 273
 274         return 0;
 275 }
 276
 277 /* Checks the validity of predefined bitrate settings */
 278 static int
 279 can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
 280                      const u32 *bitrate_const,
 281                      const unsigned int bitrate_const_cnt)
 282 {
 283         struct can_priv *priv = netdev_priv(dev);
 284         unsigned int i;
 285
 286         for (i = 0; i < bitrate_const_cnt; i++) {
 287                 if (bt->bitrate == bitrate_const[i])
 288                         break;
 289         }
 290
 291         if (i >= priv->bitrate_const_cnt)
 292                 return -EINVAL;
 293
 294         return 0;
 295 }
 296
 297 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
 298                              const struct can_bittiming_const *btc,
 299                              const u32 *bitrate_const,
 300                              const unsigned int bitrate_const_cnt)
 301 {
 302         int err;
 303
 304         /* Depending on the given can_bittiming parameter structure the CAN
 305          * timing parameters are calculated based on the provided bitrate OR
 306          * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
 307          * provided directly which are then checked and fixed up.
 308          */
 309         if (!bt->tq && bt->bitrate && btc)
 310                 err = can_calc_bittiming(dev, bt, btc);
 311         else if (bt->tq && !bt->bitrate && btc)
 312                 err = can_fixup_bittiming(dev, bt, btc);
 313         else if (!bt->tq && bt->bitrate && bitrate_const)
 314                 err = can_validate_bitrate(dev, bt, bitrate_const,
 315                                            bitrate_const_cnt);
 316         else
 317                 err = -EINVAL;
 318
 319         return err;
 320 }
 321
 322 static void can_update_state_error_stats(struct net_device *dev,
 323                                          enum can_state new_state)
 324 {
 325         struct can_priv *priv = netdev_priv(dev);
 326
 327         if (new_state <= priv->state)
 328                 return;
 329
 330         switch (new_state) {
 331         case CAN_STATE_ERROR_WARNING:
 332                 priv->can_stats.error_warning++;
 333                 break;
 334         case CAN_STATE_ERROR_PASSIVE:
 335                 priv->can_stats.error_passive++;
 336                 break;
 337         case CAN_STATE_BUS_OFF:
 338                 priv->can_stats.bus_off++;
 339                 break;
 340         default:
 341                 break;
 342         }
 343 }
 344
 345 static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
 346 {
 347         switch (state) {
 348         case CAN_STATE_ERROR_ACTIVE:
 349                 return CAN_ERR_CRTL_ACTIVE;
 350         case CAN_STATE_ERROR_WARNING:
 351                 return CAN_ERR_CRTL_TX_WARNING;
 352         case CAN_STATE_ERROR_PASSIVE:
 353                 return CAN_ERR_CRTL_TX_PASSIVE;
 354         default:
 355                 return 0;
 356         }
 357 }
 358
 359 static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
 360 {
 361         switch (state) {
 362         case CAN_STATE_ERROR_ACTIVE:
 363                 return CAN_ERR_CRTL_ACTIVE;
 364         case CAN_STATE_ERROR_WARNING:
 365                 return CAN_ERR_CRTL_RX_WARNING;
 366         case CAN_STATE_ERROR_PASSIVE:
 367                 return CAN_ERR_CRTL_RX_PASSIVE;
 368         default:
 369                 return 0;
 370         }
 371 }
 372
 373 void can_change_state(struct net_device *dev, struct can_frame *cf,
 374                       enum can_state tx_state, enum can_state rx_state)
 375 {
 376         struct can_priv *priv = netdev_priv(dev);
 377         enum can_state new_state = max(tx_state, rx_state);
 378
 379         if (unlikely(new_state == priv->state)) {
 380                 netdev_warn(dev, "%s: oops, state did not change", __func__);
 381                 return;
 382         }
 383
 384         netdev_dbg(dev, "New error state: %d\n", new_state);
 385
 386         can_update_state_error_stats(dev, new_state);
 387         priv->state = new_state;
 388
 389         if (!cf)
 390                 return;
 391
 392         if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
 393                 cf->can_id |= CAN_ERR_BUSOFF;
 394                 return;
 395         }
 396
 397         cf->can_id |= CAN_ERR_CRTL;
 398         cf->data[1] |= tx_state >= rx_state ?
 399                        can_tx_state_to_frame(dev, tx_state) : 0;
 400         cf->data[1] |= tx_state <= rx_state ?
 401                        can_rx_state_to_frame(dev, rx_state) : 0;
 402 }
 403 EXPORT_SYMBOL_GPL(can_change_state);
 404
 405 /* Local echo of CAN messages
 406  *
 407  * CAN network devices *should* support a local echo functionality
 408  * (see Documentation/networking/can.rst). To test the handling of CAN
 409  * interfaces that do not support the local echo both driver types are
 410  * implemented. In the case that the driver does not support the echo
 411  * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
 412  * to perform the echo as a fallback solution.
 413  */
 414 static void can_flush_echo_skb(struct net_device *dev)
 415 {
 416         struct can_priv *priv = netdev_priv(dev);
 417         struct net_device_stats *stats = &dev->stats;
 418         int i;
 419
 420         for (i = 0; i < priv->echo_skb_max; i++) {
 421                 if (priv->echo_skb[i]) {
 422                         kfree_skb(priv->echo_skb[i]);
 423                         priv->echo_skb[i] = NULL;
 424                         stats->tx_dropped++;
 425                         stats->tx_aborted_errors++;
 426                 }
 427         }
 428 }
 429
 430 /* Put the skb on the stack to be looped backed locally lateron
 431  *
 432  * The function is typically called in the start_xmit function
 433  * of the device driver. The driver must protect access to
 434  * priv->echo_skb, if necessary.
 435  */
 436 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 437                       unsigned int idx)
 438 {
 439         struct can_priv *priv = netdev_priv(dev);
 440
 441         BUG_ON(idx >= priv->echo_skb_max);
 442
 443         /* check flag whether this packet has to be looped back */
 444         if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
 445             (skb->protocol != htons(ETH_P_CAN) &&
 446              skb->protocol != htons(ETH_P_CANFD))) {
 447                 kfree_skb(skb);
 448                 return;
 449         }
 450
 451         if (!priv->echo_skb[idx]) {
 452
 453                 skb = can_create_echo_skb(skb);
 454                 if (!skb)
 455                         return;
 456
 457                 /* make settings for echo to reduce code in irq context */
 458                 skb->pkt_type = PACKET_BROADCAST;
 459                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 460                 skb->dev = dev;
 461
 462                 /* save this skb for tx interrupt echo handling */
 463                 priv->echo_skb[idx] = skb;
 464         } else {
 465                 /* locking problem with netif_stop_queue() ?? */
 466                 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
 467                 kfree_skb(skb);
 468         }
 469 }
 470 EXPORT_SYMBOL_GPL(can_put_echo_skb);
 471
 472 struct sk_buff *
 473 __can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
 474 {
 475         struct can_priv *priv = netdev_priv(dev);
 476
 477         if (idx >= priv->echo_skb_max) {
 478                 netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
 479                            __func__, idx, priv->echo_skb_max);
 480                 return NULL;
 481         }
 482
 483         if (priv->echo_skb[idx]) {
 484                 /* Using "struct canfd_frame::len" for the frame
 485                  * length is supported on both CAN and CANFD frames.
 486                  */
 487                 struct sk_buff *skb = priv->echo_skb[idx];
 488                 struct canfd_frame *cf = (struct canfd_frame *)skb->data;
 489                 u8 len = cf->len;
 490
 491                 *len_ptr = len;
 492                 priv->echo_skb[idx] = NULL;
 493
 494                 return skb;
 495         }
 496
 497         return NULL;
 498 }
 499
 500 /* Get the skb from the stack and loop it back locally
 501  *
 502  * The function is typically called when the TX done interrupt
 503  * is handled in the device driver. The driver must protect
 504  * access to priv->echo_skb, if necessary.
 505  */
 506 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
 507 {
 508         struct sk_buff *skb;
 509         u8 len;
 510
 511         skb = __can_get_echo_skb(dev, idx, &len);
 512         if (!skb)
 513                 return 0;
 514
 515         netif_rx(skb);
 516
 517         return len;
 518 }
 519 EXPORT_SYMBOL_GPL(can_get_echo_skb);
 520
 521 /* Remove the skb from the stack and free it.
 522  *
 523  * The function is typically called when TX failed.
 524  */
 525 void can_free_echo_skb(struct net_device *dev, unsigned int idx)
 526 {
 527         struct can_priv *priv = netdev_priv(dev);
 528
 529         BUG_ON(idx >= priv->echo_skb_max);
 530
 531         if (priv->echo_skb[idx]) {
 532                 dev_kfree_skb_any(priv->echo_skb[idx]);
 533                 priv->echo_skb[idx] = NULL;
 534         }
 535 }
 536 EXPORT_SYMBOL_GPL(can_free_echo_skb);
 537
 538 /* CAN device restart for bus-off recovery */
 539 static void can_restart(struct net_device *dev)
 540 {
 541         struct can_priv *priv = netdev_priv(dev);
 542         struct net_device_stats *stats = &dev->stats;
 543         struct sk_buff *skb;
 544         struct can_frame *cf;
 545         int err;
 546
 547         BUG_ON(netif_carrier_ok(dev));
 548
 549         /* No synchronization needed because the device is bus-off and
 550          * no messages can come in or go out.
 551          */
 552         can_flush_echo_skb(dev);
 553
 554         /* send restart message upstream */
 555         skb = alloc_can_err_skb(dev, &cf);
 556         if (skb == NULL) {
 557                 err = -ENOMEM;
 558                 goto restart;
 559         }
 560         cf->can_id |= CAN_ERR_RESTARTED;
 561
 562         netif_rx(skb);
 563
 564         stats->rx_packets++;
 565         stats->rx_bytes += cf->can_dlc;
 566
 567 restart:
 568         netdev_dbg(dev, "restarted\n");
 569         priv->can_stats.restarts++;
 570
 571         /* Now restart the device */
 572         err = priv->do_set_mode(dev, CAN_MODE_START);
 573
 574         netif_carrier_on(dev);
 575         if (err)
 576                 netdev_err(dev, "Error %d during restart", err);
 577 }
 578
 579 static void can_restart_work(struct work_struct *work)
 580 {
 581         struct delayed_work *dwork = to_delayed_work(work);
 582         struct can_priv *priv = container_of(dwork, struct can_priv,
 583                                              restart_work);
 584
 585         can_restart(priv->dev);
 586 }
 587
 588 int can_restart_now(struct net_device *dev)
 589 {
 590         struct can_priv *priv = netdev_priv(dev);
 591
 592         /* A manual restart is only permitted if automatic restart is
 593          * disabled and the device is in the bus-off state
 594          */
 595         if (priv->restart_ms)
 596                 return -EINVAL;
 597         if (priv->state != CAN_STATE_BUS_OFF)
 598                 return -EBUSY;
 599
 600         cancel_delayed_work_sync(&priv->restart_work);
 601         can_restart(dev);
 602
 603         return 0;
 604 }
 605
 606 /* CAN bus-off
 607  *
 608  * This functions should be called when the device goes bus-off to
 609  * tell the netif layer that no more packets can be sent or received.
 610  * If enabled, a timer is started to trigger bus-off recovery.
 611  */
 612 void can_bus_off(struct net_device *dev)
 613 {
 614         struct can_priv *priv = netdev_priv(dev);
 615
 616         netdev_info(dev, "bus-off\n");
 617
 618         netif_carrier_off(dev);
 619
 620         if (priv->restart_ms)
 621                 schedule_delayed_work(&priv->restart_work,
 622                                       msecs_to_jiffies(priv->restart_ms));
 623 }
 624 EXPORT_SYMBOL_GPL(can_bus_off);
 625
 626 static void can_setup(struct net_device *dev)
 627 {
 628         dev->type = ARPHRD_CAN;
 629         dev->mtu = CAN_MTU;
 630         dev->hard_header_len = 0;
 631         dev->addr_len = 0;
 632         dev->tx_queue_len = 10;
 633
 634         /* New-style flags. */
 635         dev->flags = IFF_NOARP;
 636         dev->features = NETIF_F_HW_CSUM;
 637 }
 638
 639 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
 640 {
 641         struct sk_buff *skb;
 642
 643         skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
 644                                sizeof(struct can_frame));
 645         if (unlikely(!skb))
 646                 return NULL;
 647
 648         skb->protocol = htons(ETH_P_CAN);
 649         skb->pkt_type = PACKET_BROADCAST;
 650         skb->ip_summed = CHECKSUM_UNNECESSARY;
 651
 652         skb_reset_mac_header(skb);
 653         skb_reset_network_header(skb);
 654         skb_reset_transport_header(skb);
 655
 656         can_skb_reserve(skb);
 657         can_skb_prv(skb)->ifindex = dev->ifindex;
 658         can_skb_prv(skb)->skbcnt = 0;
 659
 660         *cf = skb_put_zero(skb, sizeof(struct can_frame));
 661
 662         return skb;
 663 }
 664 EXPORT_SYMBOL_GPL(alloc_can_skb);
 665
 666 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 667                                 struct canfd_frame **cfd)
 668 {
 669         struct sk_buff *skb;
 670
 671         skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
 672                                sizeof(struct canfd_frame));
 673         if (unlikely(!skb))
 674                 return NULL;
 675
 676         skb->protocol = htons(ETH_P_CANFD);
 677         skb->pkt_type = PACKET_BROADCAST;
 678         skb->ip_summed = CHECKSUM_UNNECESSARY;
 679
 680         skb_reset_mac_header(skb);
 681         skb_reset_network_header(skb);
 682         skb_reset_transport_header(skb);
 683
 684         can_skb_reserve(skb);
 685         can_skb_prv(skb)->ifindex = dev->ifindex;
 686         can_skb_prv(skb)->skbcnt = 0;
 687
 688         *cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
 689
 690         return skb;
 691 }
 692 EXPORT_SYMBOL_GPL(alloc_canfd_skb);
 693
 694 struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
 695 {
 696         struct sk_buff *skb;
 697
 698         skb = alloc_can_skb(dev, cf);
 699         if (unlikely(!skb))
 700                 return NULL;
 701
 702         (*cf)->can_id = CAN_ERR_FLAG;
 703         (*cf)->can_dlc = CAN_ERR_DLC;
 704
 705         return skb;
 706 }
 707 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
 708
 709 /* Allocate and setup space for the CAN network device */
 710 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 711                                     unsigned int txqs, unsigned int rxqs)
 712 {
 713         struct net_device *dev;
 714         struct can_priv *priv;
 715         int size;
 716
 717         if (echo_skb_max)
 718                 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
 719                         echo_skb_max * sizeof(struct sk_buff *);
 720         else
 721                 size = sizeof_priv;
 722
 723         dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup,
 724                                txqs, rxqs);
 725         if (!dev)
 726                 return NULL;
 727
 728         priv = netdev_priv(dev);
 729         priv->dev = dev;
 730
 731         if (echo_skb_max) {
 732                 priv->echo_skb_max = echo_skb_max;
 733                 priv->echo_skb = (void *)priv +
 734                         ALIGN(sizeof_priv, sizeof(struct sk_buff *));
 735         }
 736
 737         priv->state = CAN_STATE_STOPPED;
 738
 739         INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
 740
 741         return dev;
 742 }
 743 EXPORT_SYMBOL_GPL(alloc_candev_mqs);
 744
 745 /* Free space of the CAN network device */
 746 void free_candev(struct net_device *dev)
 747 {
 748         free_netdev(dev);
 749 }
 750 EXPORT_SYMBOL_GPL(free_candev);
 751
 752 /* changing MTU and control mode for CAN/CANFD devices */
 753 int can_change_mtu(struct net_device *dev, int new_mtu)
 754 {
 755         struct can_priv *priv = netdev_priv(dev);
 756
 757         /* Do not allow changing the MTU while running */
 758         if (dev->flags & IFF_UP)
 759                 return -EBUSY;
 760
 761         /* allow change of MTU according to the CANFD ability of the device */
 762         switch (new_mtu) {
 763         case CAN_MTU:
 764                 /* 'CANFD-only' controllers can not switch to CAN_MTU */
 765                 if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
 766                         return -EINVAL;
 767
 768                 priv->ctrlmode &= ~CAN_CTRLMODE_FD;
 769                 break;
 770
 771         case CANFD_MTU:
 772                 /* check for potential CANFD ability */
 773                 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
 774                     !(priv->ctrlmode_static & CAN_CTRLMODE_FD))
 775                         return -EINVAL;
 776
 777                 priv->ctrlmode |= CAN_CTRLMODE_FD;
 778                 break;
 779
 780         default:
 781                 return -EINVAL;
 782         }
 783
 784         dev->mtu = new_mtu;
 785         return 0;
 786 }
 787 EXPORT_SYMBOL_GPL(can_change_mtu);
 788
 789 /* Common open function when the device gets opened.
 790  *
 791  * This function should be called in the open function of the device
 792  * driver.
 793  */
 794 int open_candev(struct net_device *dev)
 795 {
 796         struct can_priv *priv = netdev_priv(dev);
 797
 798         if (!priv->bittiming.bitrate) {
 799                 netdev_err(dev, "bit-timing not yet defined\n");
 800                 return -EINVAL;
 801         }
 802
 803         /* For CAN FD the data bitrate has to be >= the arbitration bitrate */
 804         if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
 805             (!priv->data_bittiming.bitrate ||
 806              priv->data_bittiming.bitrate < priv->bittiming.bitrate)) {
 807                 netdev_err(dev, "incorrect/missing data bit-timing\n");
 808                 return -EINVAL;
 809         }
 810
 811         /* Switch carrier on if device was stopped while in bus-off state */
 812         if (!netif_carrier_ok(dev))
 813                 netif_carrier_on(dev);
 814
 815         return 0;
 816 }
 817 EXPORT_SYMBOL_GPL(open_candev);
 818
 819 #ifdef CONFIG_OF
 820 /* Common function that can be used to understand the limitation of
 821  * a transceiver when it provides no means to determine these limitations
 822  * at runtime.
 823  */
 824 void of_can_transceiver(struct net_device *dev)
 825 {
 826         struct device_node *dn;
 827         struct can_priv *priv = netdev_priv(dev);
 828         struct device_node *np = dev->dev.parent->of_node;
 829         int ret;
 830
 831         dn = of_get_child_by_name(np, "can-transceiver");
 832         if (!dn)
 833                 return;
 834
 835         ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max);
 836         if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max))
 837                 netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n");
 838 }
 839 EXPORT_SYMBOL_GPL(of_can_transceiver);
 840 #endif
 841
 842 /* Common close function for cleanup before the device gets closed.
 843  *
 844  * This function should be called in the close function of the device
 845  * driver.
 846  */
 847 void close_candev(struct net_device *dev)
 848 {
 849         struct can_priv *priv = netdev_priv(dev);
 850
 851         cancel_delayed_work_sync(&priv->restart_work);
 852         can_flush_echo_skb(dev);
 853 }
 854 EXPORT_SYMBOL_GPL(close_candev);
 855
 856 /* CAN netlink interface */
 857 static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
 858         [IFLA_CAN_STATE]        = { .type = NLA_U32 },
 859         [IFLA_CAN_CTRLMODE]     = { .len = sizeof(struct can_ctrlmode) },
 860         [IFLA_CAN_RESTART_MS]   = { .type = NLA_U32 },
 861         [IFLA_CAN_RESTART]      = { .type = NLA_U32 },
 862         [IFLA_CAN_BITTIMING]    = { .len = sizeof(struct can_bittiming) },
 863         [IFLA_CAN_BITTIMING_CONST]
 864                                 = { .len = sizeof(struct can_bittiming_const) },
 865         [IFLA_CAN_CLOCK]        = { .len = sizeof(struct can_clock) },
 866         [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
 867         [IFLA_CAN_DATA_BITTIMING]
 868                                 = { .len = sizeof(struct can_bittiming) },
 869         [IFLA_CAN_DATA_BITTIMING_CONST]
 870                                 = { .len = sizeof(struct can_bittiming_const) },
 871 };
 872
 873 static int can_validate(struct nlattr *tb[], struct nlattr *data[],
 874                         struct netlink_ext_ack *extack)
 875 {
 876         bool is_can_fd = false;
 877
 878         /* Make sure that valid CAN FD configurations always consist of
 879          * - nominal/arbitration bittiming
 880          * - data bittiming
 881          * - control mode with CAN_CTRLMODE_FD set
 882          */
 883
 884         if (!data)
 885                 return 0;
 886
 887         if (data[IFLA_CAN_CTRLMODE]) {
 888                 struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
 889
 890                 is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
 891         }
 892
 893         if (is_can_fd) {
 894                 if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
 895                         return -EOPNOTSUPP;
 896         }
 897
 898         if (data[IFLA_CAN_DATA_BITTIMING]) {
 899                 if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
 900                         return -EOPNOTSUPP;
 901         }
 902
 903         return 0;
 904 }
 905
 906 static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 907                           struct nlattr *data[],
 908                           struct netlink_ext_ack *extack)
 909 {
 910         struct can_priv *priv = netdev_priv(dev);
 911         int err;
 912
 913         /* We need synchronization with dev->stop() */
 914         ASSERT_RTNL();
 915
 916         if (data[IFLA_CAN_BITTIMING]) {
 917                 struct can_bittiming bt;
 918
 919                 /* Do not allow changing bittiming while running */
 920                 if (dev->flags & IFF_UP)
 921                         return -EBUSY;
 922
 923                 /* Calculate bittiming parameters based on
 924                  * bittiming_const if set, otherwise pass bitrate
 925                  * directly via do_set_bitrate(). Bail out if neither
 926                  * is given.
 927                  */
 928                 if (!priv->bittiming_const && !priv->do_set_bittiming)
 929                         return -EOPNOTSUPP;
 930
 931                 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
 932                 err = can_get_bittiming(dev, &bt,
 933                                         priv->bittiming_const,
 934                                         priv->bitrate_const,
 935                                         priv->bitrate_const_cnt);
 936                 if (err)
 937                         return err;
 938
 939                 if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) {
 940                         netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n",
 941                                    priv->bitrate_max);
 942                         return -EINVAL;
 943                 }
 944
 945                 memcpy(&priv->bittiming, &bt, sizeof(bt));
 946
 947                 if (priv->do_set_bittiming) {
 948                         /* Finally, set the bit-timing registers */
 949                         err = priv->do_set_bittiming(dev);
 950                         if (err)
 951                                 return err;
 952                 }
 953         }
 954
 955         if (data[IFLA_CAN_CTRLMODE]) {
 956                 struct can_ctrlmode *cm;
 957                 u32 ctrlstatic;
 958                 u32 maskedflags;
 959
 960                 /* Do not allow changing controller mode while running */
 961                 if (dev->flags & IFF_UP)
 962                         return -EBUSY;
 963                 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
 964                 ctrlstatic = priv->ctrlmode_static;
 965                 maskedflags = cm->flags & cm->mask;
 966
 967                 /* check whether provided bits are allowed to be passed */
 968                 if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
 969                         return -EOPNOTSUPP;
 970
 971                 /* do not check for static fd-non-iso if 'fd' is disabled */
 972                 if (!(maskedflags & CAN_CTRLMODE_FD))
 973                         ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
 974
 975                 /* make sure static options are provided by configuration */
 976                 if ((maskedflags & ctrlstatic) != ctrlstatic)
 977                         return -EOPNOTSUPP;
 978
 979                 /* clear bits to be modified and copy the flag values */
 980                 priv->ctrlmode &= ~cm->mask;
 981                 priv->ctrlmode |= maskedflags;
 982
 983                 /* CAN_CTRLMODE_FD can only be set when driver supports FD */
 984                 if (priv->ctrlmode & CAN_CTRLMODE_FD)
 985                         dev->mtu = CANFD_MTU;
 986                 else
 987                         dev->mtu = CAN_MTU;
 988         }
 989
 990         if (data[IFLA_CAN_RESTART_MS]) {
 991                 /* Do not allow changing restart delay while running */
 992                 if (dev->flags & IFF_UP)
 993                         return -EBUSY;
 994                 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
 995         }
 996
 997         if (data[IFLA_CAN_RESTART]) {
 998                 /* Do not allow a restart while not running */
 999                 if (!(dev->flags & IFF_UP))
1000                         return -EINVAL;
1001                 err = can_restart_now(dev);
1002                 if (err)
1003                         return err;
1004         }
1005
1006         if (data[IFLA_CAN_DATA_BITTIMING]) {
1007                 struct can_bittiming dbt;
1008
1009                 /* Do not allow changing bittiming while running */
1010                 if (dev->flags & IFF_UP)
1011                         return -EBUSY;
1012
1013                 /* Calculate bittiming parameters based on
1014                  * data_bittiming_const if set, otherwise pass bitrate
1015                  * directly via do_set_bitrate(). Bail out if neither
1016                  * is given.
1017                  */
1018                 if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
1019                         return -EOPNOTSUPP;
1020
1021                 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
1022                        sizeof(dbt));
1023                 err = can_get_bittiming(dev, &dbt,
1024                                         priv->data_bittiming_const,
1025                                         priv->data_bitrate_const,
1026                                         priv->data_bitrate_const_cnt);
1027                 if (err)
1028                         return err;
1029
1030                 if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
1031                         netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n",
1032                                    priv->bitrate_max);
1033                         return -EINVAL;
1034                 }
1035
1036                 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
1037
1038                 if (priv->do_set_data_bittiming) {
1039                         /* Finally, set the bit-timing registers */
1040                         err = priv->do_set_data_bittiming(dev);
1041                         if (err)
1042                                 return err;
1043                 }
1044         }
1045
1046         if (data[IFLA_CAN_TERMINATION]) {
1047                 const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
1048                 const unsigned int num_term = priv->termination_const_cnt;
1049                 unsigned int i;
1050
1051                 if (!priv->do_set_termination)
1052                         return -EOPNOTSUPP;
1053
1054                 /* check whether given value is supported by the interface */
1055                 for (i = 0; i < num_term; i++) {
1056                         if (termval == priv->termination_const[i])
1057                                 break;
1058                 }
1059                 if (i >= num_term)
1060                         return -EINVAL;
1061
1062                 /* Finally, set the termination value */
1063                 err = priv->do_set_termination(dev, termval);
1064                 if (err)
1065                         return err;
1066
1067                 priv->termination = termval;
1068         }
1069
1070         return 0;
1071 }
1072
1073 static size_t can_get_size(const struct net_device *dev)
1074 {
1075         struct can_priv *priv = netdev_priv(dev);
1076         size_t size = 0;
1077
1078         if (priv->bittiming.bitrate)                            /* IFLA_CAN_BITTIMING */
1079                 size += nla_total_size(sizeof(struct can_bittiming));
1080         if (priv->bittiming_const)                              /* IFLA_CAN_BITTIMING_CONST */
1081                 size += nla_total_size(sizeof(struct can_bittiming_const));
1082         size += nla_total_size(sizeof(struct can_clock));       /* IFLA_CAN_CLOCK */
1083         size += nla_total_size(sizeof(u32));                    /* IFLA_CAN_STATE */
1084         size += nla_total_size(sizeof(struct can_ctrlmode));    /* IFLA_CAN_CTRLMODE */
1085         size += nla_total_size(sizeof(u32));                    /* IFLA_CAN_RESTART_MS */
1086         if (priv->do_get_berr_counter)                          /* IFLA_CAN_BERR_COUNTER */
1087                 size += nla_total_size(sizeof(struct can_berr_counter));
1088         if (priv->data_bittiming.bitrate)                       /* IFLA_CAN_DATA_BITTIMING */
1089                 size += nla_total_size(sizeof(struct can_bittiming));
1090         if (priv->data_bittiming_const)                         /* IFLA_CAN_DATA_BITTIMING_CONST */
1091                 size += nla_total_size(sizeof(struct can_bittiming_const));
1092         if (priv->termination_const) {
1093                 size += nla_total_size(sizeof(priv->termination));              /* IFLA_CAN_TERMINATION */
1094                 size += nla_total_size(sizeof(*priv->termination_const) *       /* IFLA_CAN_TERMINATION_CONST */
1095                                        priv->termination_const_cnt);
1096         }
1097         if (priv->bitrate_const)                                /* IFLA_CAN_BITRATE_CONST */
1098                 size += nla_total_size(sizeof(*priv->bitrate_const) *
1099                                        priv->bitrate_const_cnt);
1100         if (priv->data_bitrate_const)                           /* IFLA_CAN_DATA_BITRATE_CONST */
1101                 size += nla_total_size(sizeof(*priv->data_bitrate_const) *
1102                                        priv->data_bitrate_const_cnt);
1103         size += sizeof(priv->bitrate_max);                      /* IFLA_CAN_BITRATE_MAX */
1104
1105         return size;
1106 }
1107
1108 static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
1109 {
1110         struct can_priv *priv = netdev_priv(dev);
1111         struct can_ctrlmode cm = {.flags = priv->ctrlmode};
1112         struct can_berr_counter bec;
1113         enum can_state state = priv->state;
1114
1115         if (priv->do_get_state)
1116                 priv->do_get_state(dev, &state);
1117
1118         if ((priv->bittiming.bitrate &&
1119              nla_put(skb, IFLA_CAN_BITTIMING,
1120                      sizeof(priv->bittiming), &priv->bittiming)) ||
1121
1122             (priv->bittiming_const &&
1123              nla_put(skb, IFLA_CAN_BITTIMING_CONST,
1124                      sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
1125
1126             nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
1127             nla_put_u32(skb, IFLA_CAN_STATE, state) ||
1128             nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
1129             nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
1130
1131             (priv->do_get_berr_counter &&
1132              !priv->do_get_berr_counter(dev, &bec) &&
1133              nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
1134
1135             (priv->data_bittiming.bitrate &&
1136              nla_put(skb, IFLA_CAN_DATA_BITTIMING,
1137                      sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
1138
1139             (priv->data_bittiming_const &&
1140              nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
1141                      sizeof(*priv->data_bittiming_const),
1142                      priv->data_bittiming_const)) ||
1143
1144             (priv->termination_const &&
1145              (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
1146               nla_put(skb, IFLA_CAN_TERMINATION_CONST,
1147                       sizeof(*priv->termination_const) *
1148                       priv->termination_const_cnt,
1149                       priv->termination_const))) ||
1150
1151             (priv->bitrate_const &&
1152              nla_put(skb, IFLA_CAN_BITRATE_CONST,
1153                      sizeof(*priv->bitrate_const) *
1154                      priv->bitrate_const_cnt,
1155                      priv->bitrate_const)) ||
1156
1157             (priv->data_bitrate_const &&
1158              nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
1159                      sizeof(*priv->data_bitrate_const) *
1160                      priv->data_bitrate_const_cnt,
1161                      priv->data_bitrate_const)) ||
1162
1163             (nla_put(skb, IFLA_CAN_BITRATE_MAX,
1164                      sizeof(priv->bitrate_max),
1165                      &priv->bitrate_max))
1166             )
1167
1168                 return -EMSGSIZE;
1169
1170         return 0;
1171 }
1172
1173 static size_t can_get_xstats_size(const struct net_device *dev)
1174 {
1175         return sizeof(struct can_device_stats);
1176 }
1177
1178 static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
1179 {
1180         struct can_priv *priv = netdev_priv(dev);
1181
1182         if (nla_put(skb, IFLA_INFO_XSTATS,
1183                     sizeof(priv->can_stats), &priv->can_stats))
1184                 goto nla_put_failure;
1185         return 0;
1186
1187 nla_put_failure:
1188         return -EMSGSIZE;
1189 }
1190
1191 static int can_newlink(struct net *src_net, struct net_device *dev,
1192                        struct nlattr *tb[], struct nlattr *data[],
1193                        struct netlink_ext_ack *extack)
1194 {
1195         return -EOPNOTSUPP;
1196 }
1197
1198 static void can_dellink(struct net_device *dev, struct list_head *head)
1199 {
1200         return;
1201 }
1202
1203 static struct rtnl_link_ops can_link_ops __read_mostly = {
1204         .kind           = "can",
1205         .maxtype        = IFLA_CAN_MAX,
1206         .policy         = can_policy,
1207         .setup          = can_setup,
1208         .validate       = can_validate,
1209         .newlink        = can_newlink,
1210         .changelink     = can_changelink,
1211         .dellink        = can_dellink,
1212         .get_size       = can_get_size,
1213         .fill_info      = can_fill_info,
1214         .get_xstats_size = can_get_xstats_size,
1215         .fill_xstats    = can_fill_xstats,
1216 };
1217
1218 /* Register the CAN network device */
1219 int register_candev(struct net_device *dev)
1220 {
1221         struct can_priv *priv = netdev_priv(dev);
1222
1223         /* Ensure termination_const, termination_const_cnt and
1224          * do_set_termination consistency. All must be either set or
1225          * unset.
1226          */
1227         if ((!priv->termination_const != !priv->termination_const_cnt) ||
1228             (!priv->termination_const != !priv->do_set_termination))
1229                 return -EINVAL;
1230
1231         if (!priv->bitrate_const != !priv->bitrate_const_cnt)
1232                 return -EINVAL;
1233
1234         if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt)
1235                 return -EINVAL;
1236
1237         dev->rtnl_link_ops = &can_link_ops;
1238         netif_carrier_off(dev);
1239
1240         return register_netdev(dev);
1241 }
1242 EXPORT_SYMBOL_GPL(register_candev);
1243
1244 /* Unregister the CAN network device */
1245 void unregister_candev(struct net_device *dev)
1246 {
1247         unregister_netdev(dev);
1248 }
1249 EXPORT_SYMBOL_GPL(unregister_candev);
1250
1251 /* Test if a network device is a candev based device
1252  * and return the can_priv* if so.
1253  */
1254 struct can_priv *safe_candev_priv(struct net_device *dev)
1255 {
1256         if (dev->type != ARPHRD_CAN || dev->rtnl_link_ops != &can_link_ops)
1257                 return NULL;
1258
1259         return netdev_priv(dev);
1260 }
1261 EXPORT_SYMBOL_GPL(safe_candev_priv);
1262
1263 static __init int can_dev_init(void)
1264 {
1265         int err;
1266
1267         can_led_notifier_init();
1268
1269         err = rtnl_link_register(&can_link_ops);
1270         if (!err)
1271                 printk(KERN_INFO MOD_DESC "\n");
1272
1273         return err;
1274 }
1275 module_init(can_dev_init);
1276
1277 static __exit void can_dev_exit(void)
1278 {
1279         rtnl_link_unregister(&can_link_ops);
1280
1281         can_led_notifier_exit();
1282 }
1283 module_exit(can_dev_exit);
1284
1285 MODULE_ALIAS_RTNL_LINK("can");