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