drivers/net/can/dev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
   4  * Copyright (C) 2006 Andrey Volkov, Varma Electronics
   5  * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/kernel.h>
  10 #include <linux/slab.h>
  11 #include <linux/netdevice.h>
  12 #include <linux/if_arp.h>
  13 #include <linux/workqueue.h>
  14 #include <linux/can.h>
  15 #include <linux/can/dev.h>
  16 #include <linux/can/skb.h>
  17 #include <linux/can/netlink.h>
  18 #include <linux/can/led.h>
  19 #include <linux/of.h>
  20 #include <net/rtnetlink.h>
  21
  22 #define MOD_DESC "CAN device driver interface"
  23
  24 MODULE_DESCRIPTION(MOD_DESC);
  25 MODULE_LICENSE("GPL v2");
  26 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  27
  28 /* CAN DLC to real data length conversion helpers */
  29
  30 static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
  31                              8, 12, 16, 20, 24, 32, 48, 64};
  32
  33 /* get data length from can_dlc with sanitized can_dlc */
  34 u8 can_dlc2len(u8 can_dlc)
  35 {
  36         return dlc2len[can_dlc & 0x0F];
  37 }
  38 EXPORT_SYMBOL_GPL(can_dlc2len);
  39
  40 static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8,         /* 0 - 8 */
  41                              9, 9, 9, 9,                        /* 9 - 12 */
  42                              10, 10, 10, 10,                    /* 13 - 16 */
  43                              11, 11, 11, 11,                    /* 17 - 20 */
  44                              12, 12, 12, 12,                    /* 21 - 24 */
  45                              13, 13, 13, 13, 13, 13, 13, 13,    /* 25 - 32 */
  46                              14, 14, 14, 14, 14, 14, 14, 14,    /* 33 - 40 */
  47                              14, 14, 14, 14, 14, 14, 14, 14,    /* 41 - 48 */
  48                              15, 15, 15, 15, 15, 15, 15, 15,    /* 49 - 56 */
  49                              15, 15, 15, 15, 15, 15, 15, 15};   /* 57 - 64 */
  50
  51 /* map the sanitized data length to an appropriate data length code */
  52 u8 can_len2dlc(u8 len)
  53 {
  54         if (unlikely(len > 64))
  55                 return 0xF;
  56
  57         return len2dlc[len];
  58 }
  59 EXPORT_SYMBOL_GPL(can_len2dlc);
  60
  61 #ifdef CONFIG_CAN_CALC_BITTIMING
  62 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
  63 #define CAN_CALC_SYNC_SEG 1
  64
  65 /*
  66  * Bit-timing calculation derived from:
  67  *
  68  * Code based on LinCAN sources and H8S2638 project
  69  * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
  70  * Copyright 2005      Stanislav Marek
  71  * email: pisa@cmp.felk.cvut.cz
  72  *
  73  * Calculates proper bit-timing parameters for a specified bit-rate
  74  * and sample-point, which can then be used to set the bit-timing
  75  * registers of the CAN controller. You can find more information
  76  * in the header file linux/can/netlink.h.
  77  */
  78 static int can_update_sample_point(const struct can_bittiming_const *btc,
  79                           unsigned int sample_point_nominal, unsigned int tseg,
  80                           unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
  81                           unsigned int *sample_point_error_ptr)
  82 {
  83         unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
  84         unsigned int sample_point, best_sample_point = 0;
  85         unsigned int tseg1, tseg2;
  86         int i;
  87
  88         for (i = 0; i <= 1; i++) {
  89                 tseg2 = tseg + CAN_CALC_SYNC_SEG - (sample_point_nominal * (tseg + CAN_CALC_SYNC_SEG)) / 1000 - i;
  90                 tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
  91                 tseg1 = tseg - tseg2;
  92                 if (tseg1 > btc->tseg1_max) {
  93                         tseg1 = btc->tseg1_max;
  94                         tseg2 = tseg - tseg1;
  95                 }
  96
  97                 sample_point = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) / (tseg + CAN_CALC_SYNC_SEG);
  98                 sample_point_error = abs(sample_point_nominal - sample_point);
  99
 100                 if ((sample_point <= sample_point_nominal) && (sample_point_error < best_sample_point_error)) {
 101                         best_sample_point = sample_point;
 102                         best_sample_point_error = sample_point_error;
 103                         *tseg1_ptr = tseg1;
 104                         *tseg2_ptr = tseg2;
 105                 }
 106         }
 107
 108         if (sample_point_error_ptr)
 109                 *sample_point_error_ptr = best_sample_point_error;
 110
 111         return best_sample_point;
 112 }
 113
 114 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 115                               const struct can_bittiming_const *btc)
 116 {
 117         struct can_priv *priv = netdev_priv(dev);
 118         unsigned int bitrate;                   /* current bitrate */
 119         unsigned int bitrate_error;             /* difference between current and nominal value */
 120         unsigned int best_bitrate_error = UINT_MAX;
 121         unsigned int sample_point_error;        /* difference between current and nominal value */
 122         unsigned int best_sample_point_error = UINT_MAX;
 123         unsigned int sample_point_nominal;      /* nominal sample point */
 124         unsigned int best_tseg = 0;             /* current best value for tseg */
 125         unsigned int best_brp = 0;              /* current best value for brp */
 126         unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
 127         u64 v64;
 128
 129         /* Use CiA recommended sample points */
 130         if (bt->sample_point) {
 131                 sample_point_nominal = bt->sample_point;
 132         } else {
 133                 if (bt->bitrate > 800000)
 134                         sample_point_nominal = 750;
 135                 else if (bt->bitrate > 500000)
 136                         sample_point_nominal = 800;
 137                 else
 138                         sample_point_nominal = 875;
 139         }
 140
 141         /* tseg even = round down, odd = round up */
 142         for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
 143              tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
 144                 tsegall = CAN_CALC_SYNC_SEG + tseg / 2;
 145
 146                 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */
 147                 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
 148
 149                 /* choose brp step which is possible in system */
 150                 brp = (brp / btc->brp_inc) * btc->brp_inc;
 151                 if ((brp < btc->brp_min) || (brp > btc->brp_max))
 152                         continue;
 153
 154                 bitrate = priv->clock.freq / (brp * tsegall);
 155                 bitrate_error = abs(bt->bitrate - bitrate);
 156
 157                 /* tseg brp biterror */
 158                 if (bitrate_error > best_bitrate_error)
 159                         continue;
 160
 161                 /* reset sample point error if we have a better bitrate */
 162                 if (bitrate_error < best_bitrate_error)
 163                         best_sample_point_error = UINT_MAX;
 164
 165                 can_update_sample_point(btc, sample_point_nominal, tseg / 2, &tseg1, &tseg2, &sample_point_error);
 166                 if (sample_point_error > best_sample_point_error)
 167                         continue;
 168
 169                 best_sample_point_error = sample_point_error;
 170                 best_bitrate_error = bitrate_error;
 171                 best_tseg = tseg / 2;
 172                 best_brp = brp;
 173
 174                 if (bitrate_error == 0 && sample_point_error == 0)
 175                         break;
 176         }
 177
 178         if (best_bitrate_error) {
 179                 /* Error in one-tenth of a percent */
 180                 v64 = (u64)best_bitrate_error * 1000;
 181                 do_div(v64, bt->bitrate);
 182                 bitrate_error = (u32)v64;
 183                 if (bitrate_error > CAN_CALC_MAX_ERROR) {
 184                         netdev_err(dev,
 185                                    "bitrate error %d.%d%% too high\n",
 186                                    bitrate_error / 10, bitrate_error % 10);
 187                         return -EDOM;
 188                 }
 189                 netdev_warn(dev, "bitrate error %d.%d%%\n",
 190                             bitrate_error / 10, bitrate_error % 10);
 191         }
 192
 193         /* real sample point */
 194         bt->sample_point = can_update_sample_point(btc, sample_point_nominal, best_tseg,
 195                                           &tseg1, &tseg2, NULL);
 196
 197         v64 = (u64)best_brp * 1000 * 1000 * 1000;
 198         do_div(v64, priv->clock.freq);
 199         bt->tq = (u32)v64;
 200         bt->prop_seg = tseg1 / 2;
 201         bt->phase_seg1 = tseg1 - bt->prop_seg;
 202         bt->phase_seg2 = tseg2;
 203
 204         /* check for sjw user settings */
 205         if (!bt->sjw || !btc->sjw_max) {
 206                 bt->sjw = 1;
 207         } else {
 208                 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
 209                 if (bt->sjw > btc->sjw_max)
 210                         bt->sjw = btc->sjw_max;
 211                 /* bt->sjw must not be higher than tseg2 */
 212                 if (tseg2 < bt->sjw)
 213                         bt->sjw = tseg2;
 214         }
 215
 216         bt->brp = best_brp;
 217
 218         /* real bitrate */
 219         bt->bitrate = priv->clock.freq / (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2));
 220
 221         return 0;
 222 }
 223 #else /* !CONFIG_CAN_CALC_BITTIMING */
 224 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 225                               const struct can_bittiming_const *btc)
 226 {
 227         netdev_err(dev, "bit-timing calculation not available\n");
 228         return -EINVAL;
 229 }
 230 #endif /* CONFIG_CAN_CALC_BITTIMING */
 231
 232 /*
 233  * Checks the validity of the specified bit-timing parameters prop_seg,
 234  * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
 235  * prescaler value brp. You can find more information in the header
 236  * file linux/can/netlink.h.
 237  */
 238 static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
 239                                const struct can_bittiming_const *btc)
 240 {
 241         struct can_priv *priv = netdev_priv(dev);
 242         int tseg1, alltseg;
 243         u64 brp64;
 244
 245         tseg1 = bt->prop_seg + bt->phase_seg1;
 246         if (!bt->sjw)
 247                 bt->sjw = 1;
 248         if (bt->sjw > btc->sjw_max ||
 249             tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
 250             bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
 251                 return -ERANGE;
 252
 253         brp64 = (u64)priv->clock.freq * (u64)bt->tq;
 254         if (btc->brp_inc > 1)
 255                 do_div(brp64, btc->brp_inc);
 256         brp64 += 500000000UL - 1;
 257         do_div(brp64, 1000000000UL); /* the practicable BRP */
 258         if (btc->brp_inc > 1)
 259                 brp64 *= btc->brp_inc;
 260         bt->brp = (u32)brp64;
 261
 262         if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
 263                 return -EINVAL;
 264
 265         alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
 266         bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
 267         bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
 268
 269         return 0;
 270 }
 271
 272 /* Checks the validity of predefined bitrate settings */
 273 static int can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
 274                                 const u32 *bitrate_const,
 275                                 const unsigned int bitrate_const_cnt)
 276 {
 277         struct can_priv *priv = netdev_priv(dev);
 278         unsigned int i;
 279
 280         for (i = 0; i < bitrate_const_cnt; i++) {
 281                 if (bt->bitrate == bitrate_const[i])
 282                         break;
 283         }
 284
 285         if (i >= priv->bitrate_const_cnt)
 286                 return -EINVAL;
 287
 288         return 0;
 289 }
 290
 291 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
 292                              const struct can_bittiming_const *btc,
 293                              const u32 *bitrate_const,
 294                              const unsigned int bitrate_const_cnt)
 295 {
 296         int err;
 297
 298         /*
 299          * Depending on the given can_bittiming parameter structure the CAN
 300          * timing parameters are calculated based on the provided bitrate OR
 301          * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
 302          * provided directly which are then checked and fixed up.
 303          */
 304         if (!bt->tq && bt->bitrate && btc)
 305                 err = can_calc_bittiming(dev, bt, btc);
 306         else if (bt->tq && !bt->bitrate && btc)
 307                 err = can_fixup_bittiming(dev, bt, btc);
 308         else if (!bt->tq && bt->bitrate && bitrate_const)
 309                 err = can_validate_bitrate(dev, bt, bitrate_const,
 310                                            bitrate_const_cnt);
 311         else
 312                 err = -EINVAL;
 313
 314         return err;
 315 }
 316
 317 static void can_update_state_error_stats(struct net_device *dev,
 318                                          enum can_state new_state)
 319 {
 320         struct can_priv *priv = netdev_priv(dev);
 321
 322         if (new_state <= priv->state)
 323                 return;
 324
 325         switch (new_state) {
 326         case CAN_STATE_ERROR_WARNING:
 327                 priv->can_stats.error_warning++;
 328                 break;
 329         case CAN_STATE_ERROR_PASSIVE:
 330                 priv->can_stats.error_passive++;
 331                 break;
 332         case CAN_STATE_BUS_OFF:
 333                 priv->can_stats.bus_off++;
 334                 break;
 335         default:
 336                 break;
 337         }
 338 }
 339
 340 static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
 341 {
 342         switch (state) {
 343         case CAN_STATE_ERROR_ACTIVE:
 344                 return CAN_ERR_CRTL_ACTIVE;
 345         case CAN_STATE_ERROR_WARNING:
 346                 return CAN_ERR_CRTL_TX_WARNING;
 347         case CAN_STATE_ERROR_PASSIVE:
 348                 return CAN_ERR_CRTL_TX_PASSIVE;
 349         default:
 350                 return 0;
 351         }
 352 }
 353
 354 static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
 355 {
 356         switch (state) {
 357         case CAN_STATE_ERROR_ACTIVE:
 358                 return CAN_ERR_CRTL_ACTIVE;
 359         case CAN_STATE_ERROR_WARNING:
 360                 return CAN_ERR_CRTL_RX_WARNING;
 361         case CAN_STATE_ERROR_PASSIVE:
 362                 return CAN_ERR_CRTL_RX_PASSIVE;
 363         default:
 364                 return 0;
 365         }
 366 }
 367
 368 void can_change_state(struct net_device *dev, struct can_frame *cf,
 369                       enum can_state tx_state, enum can_state rx_state)
 370 {
 371         struct can_priv *priv = netdev_priv(dev);
 372         enum can_state new_state = max(tx_state, rx_state);
 373
 374         if (unlikely(new_state == priv->state)) {
 375                 netdev_warn(dev, "%s: oops, state did not change", __func__);
 376                 return;
 377         }
 378
 379         netdev_dbg(dev, "New error state: %d\n", new_state);
 380
 381         can_update_state_error_stats(dev, new_state);
 382         priv->state = new_state;
 383
 384         if (!cf)
 385                 return;
 386
 387         if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
 388                 cf->can_id |= CAN_ERR_BUSOFF;
 389                 return;
 390         }
 391
 392         cf->can_id |= CAN_ERR_CRTL;
 393         cf->data[1] |= tx_state >= rx_state ?
 394                        can_tx_state_to_frame(dev, tx_state) : 0;
 395         cf->data[1] |= tx_state <= rx_state ?
 396                        can_rx_state_to_frame(dev, rx_state) : 0;
 397 }
 398 EXPORT_SYMBOL_GPL(can_change_state);
 399
 400 /*
 401  * Local echo of CAN messages
 402  *
 403  * CAN network devices *should* support a local echo functionality
 404  * (see Documentation/networking/can.rst). To test the handling of CAN
 405  * interfaces that do not support the local echo both driver types are
 406  * implemented. In the case that the driver does not support the echo
 407  * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
 408  * to perform the echo as a fallback solution.
 409  */
 410 static void can_flush_echo_skb(struct net_device *dev)
 411 {
 412         struct can_priv *priv = netdev_priv(dev);
 413         struct net_device_stats *stats = &dev->stats;
 414         int i;
 415
 416         for (i = 0; i < priv->echo_skb_max; i++) {
 417                 if (priv->echo_skb[i]) {
 418                         kfree_skb(priv->echo_skb[i]);
 419                         priv->echo_skb[i] = NULL;
 420                         stats->tx_dropped++;
 421                         stats->tx_aborted_errors++;
 422                 }
 423         }
 424 }
 425
 426 /*
 427  * Put the skb on the stack to be looped backed locally lateron
 428  *
 429  * The function is typically called in the start_xmit function
 430  * of the device driver. The driver must protect access to
 431  * priv->echo_skb, if necessary.
 432  */
 433 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 434                       unsigned int idx)
 435 {
 436         struct can_priv *priv = netdev_priv(dev);
 437
 438         BUG_ON(idx >= priv->echo_skb_max);
 439
 440         /* check flag whether this packet has to be looped back */
 441         if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
 442             (skb->protocol != htons(ETH_P_CAN) &&
 443              skb->protocol != htons(ETH_P_CANFD))) {
 444                 kfree_skb(skb);
 445                 return;
 446         }
 447
 448         if (!priv->echo_skb[idx]) {
 449
 450                 skb = can_create_echo_skb(skb);
 451                 if (!skb)
 452                         return;
 453
 454                 /* make settings for echo to reduce code in irq context */
 455                 skb->pkt_type = PACKET_BROADCAST;
 456                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 457                 skb->dev = dev;
 458
 459                 /* save this skb for tx interrupt echo handling */
 460                 priv->echo_skb[idx] = skb;
 461         } else {
 462                 /* locking problem with netif_stop_queue() ?? */
 463                 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
 464                 kfree_skb(skb);
 465         }
 466 }
 467 EXPORT_SYMBOL_GPL(can_put_echo_skb);
 468
 469 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
 470 {
 471         struct can_priv *priv = netdev_priv(dev);
 472
 473         if (idx >= priv->echo_skb_max) {
 474                 netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
 475                            __func__, idx, priv->echo_skb_max);
 476                 return NULL;
 477         }
 478
 479         if (priv->echo_skb[idx]) {
 480                 /* Using "struct canfd_frame::len" for the frame
 481                  * length is supported on both CAN and CANFD frames.
 482                  */
 483                 struct sk_buff *skb = priv->echo_skb[idx];
 484                 struct canfd_frame *cf = (struct canfd_frame *)skb->data;
 485                 u8 len = cf->len;
 486
 487                 *len_ptr = len;
 488                 priv->echo_skb[idx] = NULL;
 489
 490                 return skb;
 491         }
 492
 493         return NULL;
 494 }
 495
 496 /*
 497  * Get the skb from the stack and loop it back locally
 498  *
 499  * The function is typically called when the TX done interrupt
 500  * is handled in the device driver. The driver must protect
 501  * access to priv->echo_skb, if necessary.
 502  */
 503 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
 504 {
 505         struct sk_buff *skb;
 506         u8 len;
 507
 508         skb = __can_get_echo_skb(dev, idx, &len);
 509         if (!skb)
 510                 return 0;
 511
 512         netif_rx(skb);
 513
 514         return len;
 515 }
 516 EXPORT_SYMBOL_GPL(can_get_echo_skb);
 517
 518 /*
 519   * Remove the skb from the stack and free it.
 520   *
 521   * The function is typically called when TX failed.
 522   */
 523 void can_free_echo_skb(struct net_device *dev, unsigned int idx)
 524 {
 525         struct can_priv *priv = netdev_priv(dev);
 526
 527         BUG_ON(idx >= priv->echo_skb_max);
 528
 529         if (priv->echo_skb[idx]) {
 530                 dev_kfree_skb_any(priv->echo_skb[idx]);
 531                 priv->echo_skb[idx] = NULL;
 532         }
 533 }
 534 EXPORT_SYMBOL_GPL(can_free_echo_skb);
 535
 536 /*
 537  * CAN device restart for bus-off recovery
 538  */
 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         /*
 550          * No synchronization needed because the device is bus-off and
 551          * no messages can come in or go out.
 552          */
 553         can_flush_echo_skb(dev);
 554
 555         /* send restart message upstream */
 556         skb = alloc_can_err_skb(dev, &cf);
 557         if (skb == NULL) {
 558                 err = -ENOMEM;
 559                 goto restart;
 560         }
 561         cf->can_id |= CAN_ERR_RESTARTED;
 562
 563         netif_rx(skb);
 564
 565         stats->rx_packets++;
 566         stats->rx_bytes += cf->can_dlc;
 567
 568 restart:
 569         netdev_dbg(dev, "restarted\n");
 570         priv->can_stats.restarts++;
 571
 572         /* Now restart the device */
 573         err = priv->do_set_mode(dev, CAN_MODE_START);
 574
 575         netif_carrier_on(dev);
 576         if (err)
 577                 netdev_err(dev, "Error %d during restart", err);
 578 }
 579
 580 static void can_restart_work(struct work_struct *work)
 581 {
 582         struct delayed_work *dwork = to_delayed_work(work);
 583         struct can_priv *priv = container_of(dwork, struct can_priv, 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         /*
 593          * A manual restart is only permitted if automatic restart is
 594          * disabled and the device is in the bus-off state
 595          */
 596         if (priv->restart_ms)
 597                 return -EINVAL;
 598         if (priv->state != CAN_STATE_BUS_OFF)
 599                 return -EBUSY;
 600
 601         cancel_delayed_work_sync(&priv->restart_work);
 602         can_restart(dev);
 603
 604         return 0;
 605 }
 606
 607 /*
 608  * CAN bus-off
 609  *
 610  * This functions should be called when the device goes bus-off to
 611  * tell the netif layer that no more packets can be sent or received.
 612  * If enabled, a timer is started to trigger bus-off recovery.
 613  */
 614 void can_bus_off(struct net_device *dev)
 615 {
 616         struct can_priv *priv = netdev_priv(dev);
 617
 618         netdev_info(dev, "bus-off\n");
 619
 620         netif_carrier_off(dev);
 621
 622         if (priv->restart_ms)
 623                 schedule_delayed_work(&priv->restart_work,
 624                                       msecs_to_jiffies(priv->restart_ms));
 625 }
 626 EXPORT_SYMBOL_GPL(can_bus_off);
 627
 628 static void can_setup(struct net_device *dev)
 629 {
 630         dev->type = ARPHRD_CAN;
 631         dev->mtu = CAN_MTU;
 632         dev->hard_header_len = 0;
 633         dev->addr_len = 0;
 634         dev->tx_queue_len = 10;
 635
 636         /* New-style flags. */
 637         dev->flags = IFF_NOARP;
 638         dev->features = NETIF_F_HW_CSUM;
 639 }
 640
 641 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
 642 {
 643         struct sk_buff *skb;
 644
 645         skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
 646                                sizeof(struct can_frame));
 647         if (unlikely(!skb))
 648                 return NULL;
 649
 650         skb->protocol = htons(ETH_P_CAN);
 651         skb->pkt_type = PACKET_BROADCAST;
 652         skb->ip_summed = CHECKSUM_UNNECESSARY;
 653
 654         skb_reset_mac_header(skb);
 655         skb_reset_network_header(skb);
 656         skb_reset_transport_header(skb);
 657
 658         can_skb_reserve(skb);
 659         can_skb_prv(skb)->ifindex = dev->ifindex;
 660         can_skb_prv(skb)->skbcnt = 0;
 661
 662         *cf = skb_put_zero(skb, sizeof(struct can_frame));
 663
 664         return skb;
 665 }
 666 EXPORT_SYMBOL_GPL(alloc_can_skb);
 667
 668 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 669                                 struct canfd_frame **cfd)
 670 {
 671         struct sk_buff *skb;
 672
 673         skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
 674                                sizeof(struct canfd_frame));
 675         if (unlikely(!skb))
 676                 return NULL;
 677
 678         skb->protocol = htons(ETH_P_CANFD);
 679         skb->pkt_type = PACKET_BROADCAST;
 680         skb->ip_summed = CHECKSUM_UNNECESSARY;
 681
 682         skb_reset_mac_header(skb);
 683         skb_reset_network_header(skb);
 684         skb_reset_transport_header(skb);
 685
 686         can_skb_reserve(skb);
 687         can_skb_prv(skb)->ifindex = dev->ifindex;
 688         can_skb_prv(skb)->skbcnt = 0;
 689
 690         *cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
 691
 692         return skb;
 693 }
 694 EXPORT_SYMBOL_GPL(alloc_canfd_skb);
 695
 696 struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
 697 {
 698         struct sk_buff *skb;
 699
 700         skb = alloc_can_skb(dev, cf);
 701         if (unlikely(!skb))
 702                 return NULL;
 703
 704         (*cf)->can_id = CAN_ERR_FLAG;
 705         (*cf)->can_dlc = CAN_ERR_DLC;
 706
 707         return skb;
 708 }
 709 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
 710
 711 /*
 712  * Allocate and setup space for the CAN network device
 713  */
 714 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 715                                     unsigned int txqs, unsigned int rxqs)
 716 {
 717         struct net_device *dev;
 718         struct can_priv *priv;
 719         int size;
 720
 721         if (echo_skb_max)
 722                 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
 723                         echo_skb_max * sizeof(struct sk_buff *);
 724         else
 725                 size = sizeof_priv;
 726
 727         dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup,
 728                                txqs, rxqs);
 729         if (!dev)
 730                 return NULL;
 731
 732         priv = netdev_priv(dev);
 733         priv->dev = dev;
 734
 735         if (echo_skb_max) {
 736                 priv->echo_skb_max = echo_skb_max;
 737                 priv->echo_skb = (void *)priv +
 738                         ALIGN(sizeof_priv, sizeof(struct sk_buff *));
 739         }
 740
 741         priv->state = CAN_STATE_STOPPED;
 742
 743         INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
 744
 745         return dev;
 746 }
 747 EXPORT_SYMBOL_GPL(alloc_candev_mqs);
 748
 749 /*
 750  * Free space of the CAN network device
 751  */
 752 void free_candev(struct net_device *dev)
 753 {
 754         free_netdev(dev);
 755 }
 756 EXPORT_SYMBOL_GPL(free_candev);
 757
 758 /*
 759  * changing MTU and control mode for CAN/CANFD devices
 760  */
 761 int can_change_mtu(struct net_device *dev, int new_mtu)
 762 {
 763         struct can_priv *priv = netdev_priv(dev);
 764
 765         /* Do not allow changing the MTU while running */
 766         if (dev->flags & IFF_UP)
 767                 return -EBUSY;
 768
 769         /* allow change of MTU according to the CANFD ability of the device */
 770         switch (new_mtu) {
 771         case CAN_MTU:
 772                 /* 'CANFD-only' controllers can not switch to CAN_MTU */
 773                 if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
 774                         return -EINVAL;
 775
 776                 priv->ctrlmode &= ~CAN_CTRLMODE_FD;
 777                 break;
 778
 779         case CANFD_MTU:
 780                 /* check for potential CANFD ability */
 781                 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
 782                     !(priv->ctrlmode_static & CAN_CTRLMODE_FD))
 783                         return -EINVAL;
 784
 785                 priv->ctrlmode |= CAN_CTRLMODE_FD;
 786                 break;
 787
 788         default:
 789                 return -EINVAL;
 790         }
 791
 792         dev->mtu = new_mtu;
 793         return 0;
 794 }
 795 EXPORT_SYMBOL_GPL(can_change_mtu);
 796
 797 /*
 798  * Common open function when the device gets opened.
 799  *
 800  * This function should be called in the open function of the device
 801  * driver.
 802  */
 803 int open_candev(struct net_device *dev)
 804 {
 805         struct can_priv *priv = netdev_priv(dev);
 806
 807         if (!priv->bittiming.bitrate) {
 808                 netdev_err(dev, "bit-timing not yet defined\n");
 809                 return -EINVAL;
 810         }
 811
 812         /* For CAN FD the data bitrate has to be >= the arbitration bitrate */
 813         if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
 814             (!priv->data_bittiming.bitrate ||
 815              (priv->data_bittiming.bitrate < priv->bittiming.bitrate))) {
 816                 netdev_err(dev, "incorrect/missing data bit-timing\n");
 817                 return -EINVAL;
 818         }
 819
 820         /* Switch carrier on if device was stopped while in bus-off state */
 821         if (!netif_carrier_ok(dev))
 822                 netif_carrier_on(dev);
 823
 824         return 0;
 825 }
 826 EXPORT_SYMBOL_GPL(open_candev);
 827
 828 #ifdef CONFIG_OF
 829 /* Common function that can be used to understand the limitation of
 830  * a transceiver when it provides no means to determine these limitations
 831  * at runtime.
 832  */
 833 void of_can_transceiver(struct net_device *dev)
 834 {
 835         struct device_node *dn;
 836         struct can_priv *priv = netdev_priv(dev);
 837         struct device_node *np = dev->dev.parent->of_node;
 838         int ret;
 839
 840         dn = of_get_child_by_name(np, "can-transceiver");
 841         if (!dn)
 842                 return;
 843
 844         ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max);
 845         if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max))
 846                 netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n");
 847 }
 848 EXPORT_SYMBOL_GPL(of_can_transceiver);
 849 #endif
 850
 851 /*
 852  * Common close function for cleanup before the device gets closed.
 853  *
 854  * This function should be called in the close function of the device
 855  * driver.
 856  */
 857 void close_candev(struct net_device *dev)
 858 {
 859         struct can_priv *priv = netdev_priv(dev);
 860
 861         cancel_delayed_work_sync(&priv->restart_work);
 862         can_flush_echo_skb(dev);
 863 }
 864 EXPORT_SYMBOL_GPL(close_candev);
 865
 866 /*
 867  * CAN netlink interface
 868  */
 869 static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
 870         [IFLA_CAN_STATE]        = { .type = NLA_U32 },
 871         [IFLA_CAN_CTRLMODE]     = { .len = sizeof(struct can_ctrlmode) },
 872         [IFLA_CAN_RESTART_MS]   = { .type = NLA_U32 },
 873         [IFLA_CAN_RESTART]      = { .type = NLA_U32 },
 874         [IFLA_CAN_BITTIMING]    = { .len = sizeof(struct can_bittiming) },
 875         [IFLA_CAN_BITTIMING_CONST]
 876                                 = { .len = sizeof(struct can_bittiming_const) },
 877         [IFLA_CAN_CLOCK]        = { .len = sizeof(struct can_clock) },
 878         [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
 879         [IFLA_CAN_DATA_BITTIMING]
 880                                 = { .len = sizeof(struct can_bittiming) },
 881         [IFLA_CAN_DATA_BITTIMING_CONST]
 882                                 = { .len = sizeof(struct can_bittiming_const) },
 883 };
 884
 885 static int can_validate(struct nlattr *tb[], struct nlattr *data[],
 886                         struct netlink_ext_ack *extack)
 887 {
 888         bool is_can_fd = false;
 889
 890         /* Make sure that valid CAN FD configurations always consist of
 891          * - nominal/arbitration bittiming
 892          * - data bittiming
 893          * - control mode with CAN_CTRLMODE_FD set
 894          */
 895
 896         if (!data)
 897                 return 0;
 898
 899         if (data[IFLA_CAN_CTRLMODE]) {
 900                 struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
 901
 902                 is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
 903         }
 904
 905         if (is_can_fd) {
 906                 if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
 907                         return -EOPNOTSUPP;
 908         }
 909
 910         if (data[IFLA_CAN_DATA_BITTIMING]) {
 911                 if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
 912                         return -EOPNOTSUPP;
 913         }
 914
 915         return 0;
 916 }
 917
 918 static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 919                           struct nlattr *data[],
 920                           struct netlink_ext_ack *extack)
 921 {
 922         struct can_priv *priv = netdev_priv(dev);
 923         int err;
 924
 925         /* We need synchronization with dev->stop() */
 926         ASSERT_RTNL();
 927
 928         if (data[IFLA_CAN_BITTIMING]) {
 929                 struct can_bittiming bt;
 930
 931                 /* Do not allow changing bittiming while running */
 932                 if (dev->flags & IFF_UP)
 933                         return -EBUSY;
 934
 935                 /* Calculate bittiming parameters based on
 936                  * bittiming_const if set, otherwise pass bitrate
 937                  * directly via do_set_bitrate(). Bail out if neither
 938                  * is given.
 939                  */
 940                 if (!priv->bittiming_const && !priv->do_set_bittiming)
 941                         return -EOPNOTSUPP;
 942
 943                 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
 944                 err = can_get_bittiming(dev, &bt,
 945                                         priv->bittiming_const,
 946                                         priv->bitrate_const,
 947                                         priv->bitrate_const_cnt);
 948                 if (err)
 949                         return err;
 950
 951                 if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) {
 952                         netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n",
 953                                    priv->bitrate_max);
 954                         return -EINVAL;
 955                 }
 956
 957                 memcpy(&priv->bittiming, &bt, sizeof(bt));
 958
 959                 if (priv->do_set_bittiming) {
 960                         /* Finally, set the bit-timing registers */
 961                         err = priv->do_set_bittiming(dev);
 962                         if (err)
 963                                 return err;
 964                 }
 965         }
 966
 967         if (data[IFLA_CAN_CTRLMODE]) {
 968                 struct can_ctrlmode *cm;
 969                 u32 ctrlstatic;
 970                 u32 maskedflags;
 971
 972                 /* Do not allow changing controller mode while running */
 973                 if (dev->flags & IFF_UP)
 974                         return -EBUSY;
 975                 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
 976                 ctrlstatic = priv->ctrlmode_static;
 977                 maskedflags = cm->flags & cm->mask;
 978
 979                 /* check whether provided bits are allowed to be passed */
 980                 if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
 981                         return -EOPNOTSUPP;
 982
 983                 /* do not check for static fd-non-iso if 'fd' is disabled */
 984                 if (!(maskedflags & CAN_CTRLMODE_FD))
 985                         ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
 986
 987                 /* make sure static options are provided by configuration */
 988                 if ((maskedflags & ctrlstatic) != ctrlstatic)
 989                         return -EOPNOTSUPP;
 990
 991                 /* clear bits to be modified and copy the flag values */
 992                 priv->ctrlmode &= ~cm->mask;
 993                 priv->ctrlmode |= maskedflags;
 994
 995                 /* CAN_CTRLMODE_FD can only be set when driver supports FD */
 996                 if (priv->ctrlmode & CAN_CTRLMODE_FD)
 997                         dev->mtu = CANFD_MTU;
 998                 else
 999                         dev->mtu = CAN_MTU;
1000         }
1001
1002         if (data[IFLA_CAN_RESTART_MS]) {
1003                 /* Do not allow changing restart delay while running */
1004                 if (dev->flags & IFF_UP)
1005                         return -EBUSY;
1006                 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
1007         }
1008
1009         if (data[IFLA_CAN_RESTART]) {
1010                 /* Do not allow a restart while not running */
1011                 if (!(dev->flags & IFF_UP))
1012                         return -EINVAL;
1013                 err = can_restart_now(dev);
1014                 if (err)
1015                         return err;
1016         }
1017
1018         if (data[IFLA_CAN_DATA_BITTIMING]) {
1019                 struct can_bittiming dbt;
1020
1021                 /* Do not allow changing bittiming while running */
1022                 if (dev->flags & IFF_UP)
1023                         return -EBUSY;
1024
1025                 /* Calculate bittiming parameters based on
1026                  * data_bittiming_const if set, otherwise pass bitrate
1027                  * directly via do_set_bitrate(). Bail out if neither
1028                  * is given.
1029                  */
1030                 if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
1031                         return -EOPNOTSUPP;
1032
1033                 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
1034                        sizeof(dbt));
1035                 err = can_get_bittiming(dev, &dbt,
1036                                         priv->data_bittiming_const,
1037                                         priv->data_bitrate_const,
1038                                         priv->data_bitrate_const_cnt);
1039                 if (err)
1040                         return err;
1041
1042                 if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
1043                         netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n",
1044                                    priv->bitrate_max);
1045                         return -EINVAL;
1046                 }
1047
1048                 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
1049
1050                 if (priv->do_set_data_bittiming) {
1051                         /* Finally, set the bit-timing registers */
1052                         err = priv->do_set_data_bittiming(dev);
1053                         if (err)
1054                                 return err;
1055                 }
1056         }
1057
1058         if (data[IFLA_CAN_TERMINATION]) {
1059                 const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
1060                 const unsigned int num_term = priv->termination_const_cnt;
1061                 unsigned int i;
1062
1063                 if (!priv->do_set_termination)
1064                         return -EOPNOTSUPP;
1065
1066                 /* check whether given value is supported by the interface */
1067                 for (i = 0; i < num_term; i++) {
1068                         if (termval == priv->termination_const[i])
1069                                 break;
1070                 }
1071                 if (i >= num_term)
1072                         return -EINVAL;
1073
1074                 /* Finally, set the termination value */
1075                 err = priv->do_set_termination(dev, termval);
1076                 if (err)
1077                         return err;
1078
1079                 priv->termination = termval;
1080         }
1081
1082         return 0;
1083 }
1084
1085 static size_t can_get_size(const struct net_device *dev)
1086 {
1087         struct can_priv *priv = netdev_priv(dev);
1088         size_t size = 0;
1089
1090         if (priv->bittiming.bitrate)                            /* IFLA_CAN_BITTIMING */
1091                 size += nla_total_size(sizeof(struct can_bittiming));
1092         if (priv->bittiming_const)                              /* IFLA_CAN_BITTIMING_CONST */
1093                 size += nla_total_size(sizeof(struct can_bittiming_const));
1094         size += nla_total_size(sizeof(struct can_clock));       /* IFLA_CAN_CLOCK */
1095         size += nla_total_size(sizeof(u32));                    /* IFLA_CAN_STATE */
1096         size += nla_total_size(sizeof(struct can_ctrlmode));    /* IFLA_CAN_CTRLMODE */
1097         size += nla_total_size(sizeof(u32));                    /* IFLA_CAN_RESTART_MS */
1098         if (priv->do_get_berr_counter)                          /* IFLA_CAN_BERR_COUNTER */
1099                 size += nla_total_size(sizeof(struct can_berr_counter));
1100         if (priv->data_bittiming.bitrate)                       /* IFLA_CAN_DATA_BITTIMING */
1101                 size += nla_total_size(sizeof(struct can_bittiming));
1102         if (priv->data_bittiming_const)                         /* IFLA_CAN_DATA_BITTIMING_CONST */
1103                 size += nla_total_size(sizeof(struct can_bittiming_const));
1104         if (priv->termination_const) {
1105                 size += nla_total_size(sizeof(priv->termination));              /* IFLA_CAN_TERMINATION */
1106                 size += nla_total_size(sizeof(*priv->termination_const) *       /* IFLA_CAN_TERMINATION_CONST */
1107                                        priv->termination_const_cnt);
1108         }
1109         if (priv->bitrate_const)                                /* IFLA_CAN_BITRATE_CONST */
1110                 size += nla_total_size(sizeof(*priv->bitrate_const) *
1111                                        priv->bitrate_const_cnt);
1112         if (priv->data_bitrate_const)                           /* IFLA_CAN_DATA_BITRATE_CONST */
1113                 size += nla_total_size(sizeof(*priv->data_bitrate_const) *
1114                                        priv->data_bitrate_const_cnt);
1115         size += sizeof(priv->bitrate_max);                      /* IFLA_CAN_BITRATE_MAX */
1116
1117         return size;
1118 }
1119
1120 static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
1121 {
1122         struct can_priv *priv = netdev_priv(dev);
1123         struct can_ctrlmode cm = {.flags = priv->ctrlmode};
1124         struct can_berr_counter bec;
1125         enum can_state state = priv->state;
1126
1127         if (priv->do_get_state)
1128                 priv->do_get_state(dev, &state);
1129
1130         if ((priv->bittiming.bitrate &&
1131              nla_put(skb, IFLA_CAN_BITTIMING,
1132                      sizeof(priv->bittiming), &priv->bittiming)) ||
1133
1134             (priv->bittiming_const &&
1135              nla_put(skb, IFLA_CAN_BITTIMING_CONST,
1136                      sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
1137
1138             nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
1139             nla_put_u32(skb, IFLA_CAN_STATE, state) ||
1140             nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
1141             nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
1142
1143             (priv->do_get_berr_counter &&
1144              !priv->do_get_berr_counter(dev, &bec) &&
1145              nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
1146
1147             (priv->data_bittiming.bitrate &&
1148              nla_put(skb, IFLA_CAN_DATA_BITTIMING,
1149                      sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
1150
1151             (priv->data_bittiming_const &&
1152              nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
1153                      sizeof(*priv->data_bittiming_const),
1154                      priv->data_bittiming_const)) ||
1155
1156             (priv->termination_const &&
1157              (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
1158               nla_put(skb, IFLA_CAN_TERMINATION_CONST,
1159                       sizeof(*priv->termination_const) *
1160                       priv->termination_const_cnt,
1161                       priv->termination_const))) ||
1162
1163             (priv->bitrate_const &&
1164              nla_put(skb, IFLA_CAN_BITRATE_CONST,
1165                      sizeof(*priv->bitrate_const) *
1166                      priv->bitrate_const_cnt,
1167                      priv->bitrate_const)) ||
1168
1169             (priv->data_bitrate_const &&
1170              nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
1171                      sizeof(*priv->data_bitrate_const) *
1172                      priv->data_bitrate_const_cnt,
1173                      priv->data_bitrate_const)) ||
1174
1175             (nla_put(skb, IFLA_CAN_BITRATE_MAX,
1176                      sizeof(priv->bitrate_max),
1177                      &priv->bitrate_max))
1178             )
1179
1180                 return -EMSGSIZE;
1181
1182         return 0;
1183 }
1184
1185 static size_t can_get_xstats_size(const struct net_device *dev)
1186 {
1187         return sizeof(struct can_device_stats);
1188 }
1189
1190 static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
1191 {
1192         struct can_priv *priv = netdev_priv(dev);
1193
1194         if (nla_put(skb, IFLA_INFO_XSTATS,
1195                     sizeof(priv->can_stats), &priv->can_stats))
1196                 goto nla_put_failure;
1197         return 0;
1198
1199 nla_put_failure:
1200         return -EMSGSIZE;
1201 }
1202
1203 static int can_newlink(struct net *src_net, struct net_device *dev,
1204                        struct nlattr *tb[], struct nlattr *data[],
1205                        struct netlink_ext_ack *extack)
1206 {
1207         return -EOPNOTSUPP;
1208 }
1209
1210 static void can_dellink(struct net_device *dev, struct list_head *head)
1211 {
1212         return;
1213 }
1214
1215 static struct rtnl_link_ops can_link_ops __read_mostly = {
1216         .kind           = "can",
1217         .maxtype        = IFLA_CAN_MAX,
1218         .policy         = can_policy,
1219         .setup          = can_setup,
1220         .validate       = can_validate,
1221         .newlink        = can_newlink,
1222         .changelink     = can_changelink,
1223         .dellink        = can_dellink,
1224         .get_size       = can_get_size,
1225         .fill_info      = can_fill_info,
1226         .get_xstats_size = can_get_xstats_size,
1227         .fill_xstats    = can_fill_xstats,
1228 };
1229
1230 /*
1231  * Register the CAN network device
1232  */
1233 int register_candev(struct net_device *dev)
1234 {
1235         struct can_priv *priv = netdev_priv(dev);
1236
1237         /* Ensure termination_const, termination_const_cnt and
1238          * do_set_termination consistency. All must be either set or
1239          * unset.
1240          */
1241         if ((!priv->termination_const != !priv->termination_const_cnt) ||
1242             (!priv->termination_const != !priv->do_set_termination))
1243                 return -EINVAL;
1244
1245         if (!priv->bitrate_const != !priv->bitrate_const_cnt)
1246                 return -EINVAL;
1247
1248         if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt)
1249                 return -EINVAL;
1250
1251         dev->rtnl_link_ops = &can_link_ops;
1252         return register_netdev(dev);
1253 }
1254 EXPORT_SYMBOL_GPL(register_candev);
1255
1256 /*
1257  * Unregister the CAN network device
1258  */
1259 void unregister_candev(struct net_device *dev)
1260 {
1261         unregister_netdev(dev);
1262 }
1263 EXPORT_SYMBOL_GPL(unregister_candev);
1264
1265 /*
1266  * Test if a network device is a candev based device
1267  * and return the can_priv* if so.
1268  */
1269 struct can_priv *safe_candev_priv(struct net_device *dev)
1270 {
1271         if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
1272                 return NULL;
1273
1274         return netdev_priv(dev);
1275 }
1276 EXPORT_SYMBOL_GPL(safe_candev_priv);
1277
1278 static __init int can_dev_init(void)
1279 {
1280         int err;
1281
1282         can_led_notifier_init();
1283
1284         err = rtnl_link_register(&can_link_ops);
1285         if (!err)
1286                 printk(KERN_INFO MOD_DESC "\n");
1287
1288         return err;
1289 }
1290 module_init(can_dev_init);
1291
1292 static __exit void can_dev_exit(void)
1293 {
1294         rtnl_link_unregister(&can_link_ops);
1295
1296         can_led_notifier_exit();
1297 }
1298 module_exit(can_dev_exit);
1299
1300 MODULE_ALIAS_RTNL_LINK("can");