drivers/net/can/dev.c

   1 /*
   2  * Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
   3  * Copyright (C) 2006 Andrey Volkov, Varma Electronics
   4  * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the version 2 of the GNU General Public License
   8  * as published by the Free Software Foundation
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/slab.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/if_arp.h>
  24 #include <linux/can.h>
  25 #include <linux/can/dev.h>
  26 #include <linux/can/skb.h>
  27 #include <linux/can/netlink.h>
  28 #include <linux/can/led.h>
  29 #include <net/rtnetlink.h>
  30
  31 #define MOD_DESC "CAN device driver interface"
  32
  33 MODULE_DESCRIPTION(MOD_DESC);
  34 MODULE_LICENSE("GPL v2");
  35 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  36
  37 /* CAN DLC to real data length conversion helpers */
  38
  39 static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
  40                              8, 12, 16, 20, 24, 32, 48, 64};
  41
  42 /* get data length from can_dlc with sanitized can_dlc */
  43 u8 can_dlc2len(u8 can_dlc)
  44 {
  45         return dlc2len[can_dlc & 0x0F];
  46 }
  47 EXPORT_SYMBOL_GPL(can_dlc2len);
  48
  49 static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8,         /* 0 - 8 */
  50                              9, 9, 9, 9,                        /* 9 - 12 */
  51                              10, 10, 10, 10,                    /* 13 - 16 */
  52                              11, 11, 11, 11,                    /* 17 - 20 */
  53                              12, 12, 12, 12,                    /* 21 - 24 */
  54                              13, 13, 13, 13, 13, 13, 13, 13,    /* 25 - 32 */
  55                              14, 14, 14, 14, 14, 14, 14, 14,    /* 33 - 40 */
  56                              14, 14, 14, 14, 14, 14, 14, 14,    /* 41 - 48 */
  57                              15, 15, 15, 15, 15, 15, 15, 15,    /* 49 - 56 */
  58                              15, 15, 15, 15, 15, 15, 15, 15};   /* 57 - 64 */
  59
  60 /* map the sanitized data length to an appropriate data length code */
  61 u8 can_len2dlc(u8 len)
  62 {
  63         if (unlikely(len > 64))
  64                 return 0xF;
  65
  66         return len2dlc[len];
  67 }
  68 EXPORT_SYMBOL_GPL(can_len2dlc);
  69
  70 #ifdef CONFIG_CAN_CALC_BITTIMING
  71 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
  72
  73 /*
  74  * Bit-timing calculation derived from:
  75  *
  76  * Code based on LinCAN sources and H8S2638 project
  77  * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
  78  * Copyright 2005      Stanislav Marek
  79  * email: pisa@cmp.felk.cvut.cz
  80  *
  81  * Calculates proper bit-timing parameters for a specified bit-rate
  82  * and sample-point, which can then be used to set the bit-timing
  83  * registers of the CAN controller. You can find more information
  84  * in the header file linux/can/netlink.h.
  85  */
  86 static int can_update_spt(const struct can_bittiming_const *btc,
  87                           int sampl_pt, int tseg, int *tseg1, int *tseg2)
  88 {
  89         *tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000;
  90         if (*tseg2 < btc->tseg2_min)
  91                 *tseg2 = btc->tseg2_min;
  92         if (*tseg2 > btc->tseg2_max)
  93                 *tseg2 = btc->tseg2_max;
  94         *tseg1 = tseg - *tseg2;
  95         if (*tseg1 > btc->tseg1_max) {
  96                 *tseg1 = btc->tseg1_max;
  97                 *tseg2 = tseg - *tseg1;
  98         }
  99         return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
 100 }
 101
 102 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
 103 {
 104         struct can_priv *priv = netdev_priv(dev);
 105         const struct can_bittiming_const *btc = priv->bittiming_const;
 106         long rate, best_rate = 0;
 107         long best_error = 1000000000, error = 0;
 108         int best_tseg = 0, best_brp = 0, brp = 0;
 109         int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0;
 110         int spt_error = 1000, spt = 0, sampl_pt;
 111         u64 v64;
 112
 113         if (!priv->bittiming_const)
 114                 return -ENOTSUPP;
 115
 116         /* Use CIA recommended sample points */
 117         if (bt->sample_point) {
 118                 sampl_pt = bt->sample_point;
 119         } else {
 120                 if (bt->bitrate > 800000)
 121                         sampl_pt = 750;
 122                 else if (bt->bitrate > 500000)
 123                         sampl_pt = 800;
 124                 else
 125                         sampl_pt = 875;
 126         }
 127
 128         /* tseg even = round down, odd = round up */
 129         for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
 130              tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
 131                 tsegall = 1 + tseg / 2;
 132                 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */
 133                 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
 134                 /* chose brp step which is possible in system */
 135                 brp = (brp / btc->brp_inc) * btc->brp_inc;
 136                 if ((brp < btc->brp_min) || (brp > btc->brp_max))
 137                         continue;
 138                 rate = priv->clock.freq / (brp * tsegall);
 139                 error = bt->bitrate - rate;
 140                 /* tseg brp biterror */
 141                 if (error < 0)
 142                         error = -error;
 143                 if (error > best_error)
 144                         continue;
 145                 best_error = error;
 146                 if (error == 0) {
 147                         spt = can_update_spt(btc, sampl_pt, tseg / 2,
 148                                              &tseg1, &tseg2);
 149                         error = sampl_pt - spt;
 150                         if (error < 0)
 151                                 error = -error;
 152                         if (error > spt_error)
 153                                 continue;
 154                         spt_error = error;
 155                 }
 156                 best_tseg = tseg / 2;
 157                 best_brp = brp;
 158                 best_rate = rate;
 159                 if (error == 0)
 160                         break;
 161         }
 162
 163         if (best_error) {
 164                 /* Error in one-tenth of a percent */
 165                 error = (best_error * 1000) / bt->bitrate;
 166                 if (error > CAN_CALC_MAX_ERROR) {
 167                         netdev_err(dev,
 168                                    "bitrate error %ld.%ld%% too high\n",
 169                                    error / 10, error % 10);
 170                         return -EDOM;
 171                 } else {
 172                         netdev_warn(dev, "bitrate error %ld.%ld%%\n",
 173                                     error / 10, error % 10);
 174                 }
 175         }
 176
 177         /* real sample point */
 178         bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
 179                                           &tseg1, &tseg2);
 180
 181         v64 = (u64)best_brp * 1000000000UL;
 182         do_div(v64, priv->clock.freq);
 183         bt->tq = (u32)v64;
 184         bt->prop_seg = tseg1 / 2;
 185         bt->phase_seg1 = tseg1 - bt->prop_seg;
 186         bt->phase_seg2 = tseg2;
 187
 188         /* check for sjw user settings */
 189         if (!bt->sjw || !btc->sjw_max)
 190                 bt->sjw = 1;
 191         else {
 192                 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
 193                 if (bt->sjw > btc->sjw_max)
 194                         bt->sjw = btc->sjw_max;
 195                 /* bt->sjw must not be higher than tseg2 */
 196                 if (tseg2 < bt->sjw)
 197                         bt->sjw = tseg2;
 198         }
 199
 200         bt->brp = best_brp;
 201         /* real bit-rate */
 202         bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
 203
 204         return 0;
 205 }
 206 #else /* !CONFIG_CAN_CALC_BITTIMING */
 207 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
 208 {
 209         netdev_err(dev, "bit-timing calculation not available\n");
 210         return -EINVAL;
 211 }
 212 #endif /* CONFIG_CAN_CALC_BITTIMING */
 213
 214 /*
 215  * Checks the validity of the specified bit-timing parameters prop_seg,
 216  * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
 217  * prescaler value brp. You can find more information in the header
 218  * file linux/can/netlink.h.
 219  */
 220 static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt)
 221 {
 222         struct can_priv *priv = netdev_priv(dev);
 223         const struct can_bittiming_const *btc = priv->bittiming_const;
 224         int tseg1, alltseg;
 225         u64 brp64;
 226
 227         if (!priv->bittiming_const)
 228                 return -ENOTSUPP;
 229
 230         tseg1 = bt->prop_seg + bt->phase_seg1;
 231         if (!bt->sjw)
 232                 bt->sjw = 1;
 233         if (bt->sjw > btc->sjw_max ||
 234             tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
 235             bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
 236                 return -ERANGE;
 237
 238         brp64 = (u64)priv->clock.freq * (u64)bt->tq;
 239         if (btc->brp_inc > 1)
 240                 do_div(brp64, btc->brp_inc);
 241         brp64 += 500000000UL - 1;
 242         do_div(brp64, 1000000000UL); /* the practicable BRP */
 243         if (btc->brp_inc > 1)
 244                 brp64 *= btc->brp_inc;
 245         bt->brp = (u32)brp64;
 246
 247         if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
 248                 return -EINVAL;
 249
 250         alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
 251         bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
 252         bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
 253
 254         return 0;
 255 }
 256
 257 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt)
 258 {
 259         struct can_priv *priv = netdev_priv(dev);
 260         int err;
 261
 262         /* Check if the CAN device has bit-timing parameters */
 263         if (priv->bittiming_const) {
 264
 265                 /* Non-expert mode? Check if the bitrate has been pre-defined */
 266                 if (!bt->tq)
 267                         /* Determine bit-timing parameters */
 268                         err = can_calc_bittiming(dev, bt);
 269                 else
 270                         /* Check bit-timing params and calculate proper brp */
 271                         err = can_fixup_bittiming(dev, bt);
 272                 if (err)
 273                         return err;
 274         }
 275
 276         return 0;
 277 }
 278
 279 /*
 280  * Local echo of CAN messages
 281  *
 282  * CAN network devices *should* support a local echo functionality
 283  * (see Documentation/networking/can.txt). To test the handling of CAN
 284  * interfaces that do not support the local echo both driver types are
 285  * implemented. In the case that the driver does not support the echo
 286  * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
 287  * to perform the echo as a fallback solution.
 288  */
 289 static void can_flush_echo_skb(struct net_device *dev)
 290 {
 291         struct can_priv *priv = netdev_priv(dev);
 292         struct net_device_stats *stats = &dev->stats;
 293         int i;
 294
 295         for (i = 0; i < priv->echo_skb_max; i++) {
 296                 if (priv->echo_skb[i]) {
 297                         kfree_skb(priv->echo_skb[i]);
 298                         priv->echo_skb[i] = NULL;
 299                         stats->tx_dropped++;
 300                         stats->tx_aborted_errors++;
 301                 }
 302         }
 303 }
 304
 305 /*
 306  * Put the skb on the stack to be looped backed locally lateron
 307  *
 308  * The function is typically called in the start_xmit function
 309  * of the device driver. The driver must protect access to
 310  * priv->echo_skb, if necessary.
 311  */
 312 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 313                       unsigned int idx)
 314 {
 315         struct can_priv *priv = netdev_priv(dev);
 316
 317         BUG_ON(idx >= priv->echo_skb_max);
 318
 319         /* check flag whether this packet has to be looped back */
 320         if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) {
 321                 kfree_skb(skb);
 322                 return;
 323         }
 324
 325         if (!priv->echo_skb[idx]) {
 326
 327                 skb = can_create_echo_skb(skb);
 328                 if (!skb)
 329                         return;
 330
 331                 /* make settings for echo to reduce code in irq context */
 332                 skb->protocol = htons(ETH_P_CAN);
 333                 skb->pkt_type = PACKET_BROADCAST;
 334                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 335                 skb->dev = dev;
 336
 337                 /* save this skb for tx interrupt echo handling */
 338                 priv->echo_skb[idx] = skb;
 339         } else {
 340                 /* locking problem with netif_stop_queue() ?? */
 341                 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
 342                 kfree_skb(skb);
 343         }
 344 }
 345 EXPORT_SYMBOL_GPL(can_put_echo_skb);
 346
 347 /*
 348  * Get the skb from the stack and loop it back locally
 349  *
 350  * The function is typically called when the TX done interrupt
 351  * is handled in the device driver. The driver must protect
 352  * access to priv->echo_skb, if necessary.
 353  */
 354 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
 355 {
 356         struct can_priv *priv = netdev_priv(dev);
 357
 358         BUG_ON(idx >= priv->echo_skb_max);
 359
 360         if (priv->echo_skb[idx]) {
 361                 struct sk_buff *skb = priv->echo_skb[idx];
 362                 struct can_frame *cf = (struct can_frame *)skb->data;
 363                 u8 dlc = cf->can_dlc;
 364
 365                 netif_rx(priv->echo_skb[idx]);
 366                 priv->echo_skb[idx] = NULL;
 367
 368                 return dlc;
 369         }
 370
 371         return 0;
 372 }
 373 EXPORT_SYMBOL_GPL(can_get_echo_skb);
 374
 375 /*
 376   * Remove the skb from the stack and free it.
 377   *
 378   * The function is typically called when TX failed.
 379   */
 380 void can_free_echo_skb(struct net_device *dev, unsigned int idx)
 381 {
 382         struct can_priv *priv = netdev_priv(dev);
 383
 384         BUG_ON(idx >= priv->echo_skb_max);
 385
 386         if (priv->echo_skb[idx]) {
 387                 kfree_skb(priv->echo_skb[idx]);
 388                 priv->echo_skb[idx] = NULL;
 389         }
 390 }
 391 EXPORT_SYMBOL_GPL(can_free_echo_skb);
 392
 393 /*
 394  * CAN device restart for bus-off recovery
 395  */
 396 static void can_restart(unsigned long data)
 397 {
 398         struct net_device *dev = (struct net_device *)data;
 399         struct can_priv *priv = netdev_priv(dev);
 400         struct net_device_stats *stats = &dev->stats;
 401         struct sk_buff *skb;
 402         struct can_frame *cf;
 403         int err;
 404
 405         BUG_ON(netif_carrier_ok(dev));
 406
 407         /*
 408          * No synchronization needed because the device is bus-off and
 409          * no messages can come in or go out.
 410          */
 411         can_flush_echo_skb(dev);
 412
 413         /* send restart message upstream */
 414         skb = alloc_can_err_skb(dev, &cf);
 415         if (skb == NULL) {
 416                 err = -ENOMEM;
 417                 goto restart;
 418         }
 419         cf->can_id |= CAN_ERR_RESTARTED;
 420
 421         netif_rx(skb);
 422
 423         stats->rx_packets++;
 424         stats->rx_bytes += cf->can_dlc;
 425
 426 restart:
 427         netdev_dbg(dev, "restarted\n");
 428         priv->can_stats.restarts++;
 429
 430         /* Now restart the device */
 431         err = priv->do_set_mode(dev, CAN_MODE_START);
 432
 433         netif_carrier_on(dev);
 434         if (err)
 435                 netdev_err(dev, "Error %d during restart", err);
 436 }
 437
 438 int can_restart_now(struct net_device *dev)
 439 {
 440         struct can_priv *priv = netdev_priv(dev);
 441
 442         /*
 443          * A manual restart is only permitted if automatic restart is
 444          * disabled and the device is in the bus-off state
 445          */
 446         if (priv->restart_ms)
 447                 return -EINVAL;
 448         if (priv->state != CAN_STATE_BUS_OFF)
 449                 return -EBUSY;
 450
 451         /* Runs as soon as possible in the timer context */
 452         mod_timer(&priv->restart_timer, jiffies);
 453
 454         return 0;
 455 }
 456
 457 /*
 458  * CAN bus-off
 459  *
 460  * This functions should be called when the device goes bus-off to
 461  * tell the netif layer that no more packets can be sent or received.
 462  * If enabled, a timer is started to trigger bus-off recovery.
 463  */
 464 void can_bus_off(struct net_device *dev)
 465 {
 466         struct can_priv *priv = netdev_priv(dev);
 467
 468         netdev_dbg(dev, "bus-off\n");
 469
 470         netif_carrier_off(dev);
 471         priv->can_stats.bus_off++;
 472
 473         if (priv->restart_ms)
 474                 mod_timer(&priv->restart_timer,
 475                           jiffies + (priv->restart_ms * HZ) / 1000);
 476 }
 477 EXPORT_SYMBOL_GPL(can_bus_off);
 478
 479 static void can_setup(struct net_device *dev)
 480 {
 481         dev->type = ARPHRD_CAN;
 482         dev->mtu = CAN_MTU;
 483         dev->hard_header_len = 0;
 484         dev->addr_len = 0;
 485         dev->tx_queue_len = 10;
 486
 487         /* New-style flags. */
 488         dev->flags = IFF_NOARP;
 489         dev->features = NETIF_F_HW_CSUM;
 490 }
 491
 492 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
 493 {
 494         struct sk_buff *skb;
 495
 496         skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
 497                                sizeof(struct can_frame));
 498         if (unlikely(!skb))
 499                 return NULL;
 500
 501         skb->protocol = htons(ETH_P_CAN);
 502         skb->pkt_type = PACKET_BROADCAST;
 503         skb->ip_summed = CHECKSUM_UNNECESSARY;
 504
 505         can_skb_reserve(skb);
 506         can_skb_prv(skb)->ifindex = dev->ifindex;
 507
 508         *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
 509         memset(*cf, 0, sizeof(struct can_frame));
 510
 511         return skb;
 512 }
 513 EXPORT_SYMBOL_GPL(alloc_can_skb);
 514
 515 struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
 516 {
 517         struct sk_buff *skb;
 518
 519         skb = alloc_can_skb(dev, cf);
 520         if (unlikely(!skb))
 521                 return NULL;
 522
 523         (*cf)->can_id = CAN_ERR_FLAG;
 524         (*cf)->can_dlc = CAN_ERR_DLC;
 525
 526         return skb;
 527 }
 528 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
 529
 530 /*
 531  * Allocate and setup space for the CAN network device
 532  */
 533 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
 534 {
 535         struct net_device *dev;
 536         struct can_priv *priv;
 537         int size;
 538
 539         if (echo_skb_max)
 540                 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
 541                         echo_skb_max * sizeof(struct sk_buff *);
 542         else
 543                 size = sizeof_priv;
 544
 545         dev = alloc_netdev(size, "can%d", can_setup);
 546         if (!dev)
 547                 return NULL;
 548
 549         priv = netdev_priv(dev);
 550
 551         if (echo_skb_max) {
 552                 priv->echo_skb_max = echo_skb_max;
 553                 priv->echo_skb = (void *)priv +
 554                         ALIGN(sizeof_priv, sizeof(struct sk_buff *));
 555         }
 556
 557         priv->state = CAN_STATE_STOPPED;
 558
 559         init_timer(&priv->restart_timer);
 560
 561         return dev;
 562 }
 563 EXPORT_SYMBOL_GPL(alloc_candev);
 564
 565 /*
 566  * Free space of the CAN network device
 567  */
 568 void free_candev(struct net_device *dev)
 569 {
 570         free_netdev(dev);
 571 }
 572 EXPORT_SYMBOL_GPL(free_candev);
 573
 574 /*
 575  * Common open function when the device gets opened.
 576  *
 577  * This function should be called in the open function of the device
 578  * driver.
 579  */
 580 int open_candev(struct net_device *dev)
 581 {
 582         struct can_priv *priv = netdev_priv(dev);
 583
 584         if (!priv->bittiming.tq && !priv->bittiming.bitrate) {
 585                 netdev_err(dev, "bit-timing not yet defined\n");
 586                 return -EINVAL;
 587         }
 588
 589         /* Switch carrier on if device was stopped while in bus-off state */
 590         if (!netif_carrier_ok(dev))
 591                 netif_carrier_on(dev);
 592
 593         setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
 594
 595         return 0;
 596 }
 597 EXPORT_SYMBOL_GPL(open_candev);
 598
 599 /*
 600  * Common close function for cleanup before the device gets closed.
 601  *
 602  * This function should be called in the close function of the device
 603  * driver.
 604  */
 605 void close_candev(struct net_device *dev)
 606 {
 607         struct can_priv *priv = netdev_priv(dev);
 608
 609         del_timer_sync(&priv->restart_timer);
 610         can_flush_echo_skb(dev);
 611 }
 612 EXPORT_SYMBOL_GPL(close_candev);
 613
 614 /*
 615  * CAN netlink interface
 616  */
 617 static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
 618         [IFLA_CAN_STATE]        = { .type = NLA_U32 },
 619         [IFLA_CAN_CTRLMODE]     = { .len = sizeof(struct can_ctrlmode) },
 620         [IFLA_CAN_RESTART_MS]   = { .type = NLA_U32 },
 621         [IFLA_CAN_RESTART]      = { .type = NLA_U32 },
 622         [IFLA_CAN_BITTIMING]    = { .len = sizeof(struct can_bittiming) },
 623         [IFLA_CAN_BITTIMING_CONST]
 624                                 = { .len = sizeof(struct can_bittiming_const) },
 625         [IFLA_CAN_CLOCK]        = { .len = sizeof(struct can_clock) },
 626         [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
 627 };
 628
 629 static int can_changelink(struct net_device *dev,
 630                           struct nlattr *tb[], struct nlattr *data[])
 631 {
 632         struct can_priv *priv = netdev_priv(dev);
 633         int err;
 634
 635         /* We need synchronization with dev->stop() */
 636         ASSERT_RTNL();
 637
 638         if (data[IFLA_CAN_BITTIMING]) {
 639                 struct can_bittiming bt;
 640
 641                 /* Do not allow changing bittiming while running */
 642                 if (dev->flags & IFF_UP)
 643                         return -EBUSY;
 644                 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
 645                 if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq))
 646                         return -EINVAL;
 647                 err = can_get_bittiming(dev, &bt);
 648                 if (err)
 649                         return err;
 650                 memcpy(&priv->bittiming, &bt, sizeof(bt));
 651
 652                 if (priv->do_set_bittiming) {
 653                         /* Finally, set the bit-timing registers */
 654                         err = priv->do_set_bittiming(dev);
 655                         if (err)
 656                                 return err;
 657                 }
 658         }
 659
 660         if (data[IFLA_CAN_CTRLMODE]) {
 661                 struct can_ctrlmode *cm;
 662
 663                 /* Do not allow changing controller mode while running */
 664                 if (dev->flags & IFF_UP)
 665                         return -EBUSY;
 666                 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
 667                 if (cm->flags & ~priv->ctrlmode_supported)
 668                         return -EOPNOTSUPP;
 669                 priv->ctrlmode &= ~cm->mask;
 670                 priv->ctrlmode |= cm->flags;
 671         }
 672
 673         if (data[IFLA_CAN_RESTART_MS]) {
 674                 /* Do not allow changing restart delay while running */
 675                 if (dev->flags & IFF_UP)
 676                         return -EBUSY;
 677                 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
 678         }
 679
 680         if (data[IFLA_CAN_RESTART]) {
 681                 /* Do not allow a restart while not running */
 682                 if (!(dev->flags & IFF_UP))
 683                         return -EINVAL;
 684                 err = can_restart_now(dev);
 685                 if (err)
 686                         return err;
 687         }
 688
 689         return 0;
 690 }
 691
 692 static size_t can_get_size(const struct net_device *dev)
 693 {
 694         struct can_priv *priv = netdev_priv(dev);
 695         size_t size = 0;
 696
 697         size += nla_total_size(sizeof(struct can_bittiming));   /* IFLA_CAN_BITTIMING */
 698         if (priv->bittiming_const)                              /* IFLA_CAN_BITTIMING_CONST */
 699                 size += nla_total_size(sizeof(struct can_bittiming_const));
 700         size += nla_total_size(sizeof(struct can_clock));       /* IFLA_CAN_CLOCK */
 701         size += nla_total_size(sizeof(u32));                    /* IFLA_CAN_STATE */
 702         size += nla_total_size(sizeof(struct can_ctrlmode));    /* IFLA_CAN_CTRLMODE */
 703         size += nla_total_size(sizeof(u32));                    /* IFLA_CAN_RESTART_MS */
 704         if (priv->do_get_berr_counter)                          /* IFLA_CAN_BERR_COUNTER */
 705                 size += nla_total_size(sizeof(struct can_berr_counter));
 706
 707         return size;
 708 }
 709
 710 static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
 711 {
 712         struct can_priv *priv = netdev_priv(dev);
 713         struct can_ctrlmode cm = {.flags = priv->ctrlmode};
 714         struct can_berr_counter bec;
 715         enum can_state state = priv->state;
 716
 717         if (priv->do_get_state)
 718                 priv->do_get_state(dev, &state);
 719         if (nla_put(skb, IFLA_CAN_BITTIMING,
 720                     sizeof(priv->bittiming), &priv->bittiming) ||
 721             (priv->bittiming_const &&
 722              nla_put(skb, IFLA_CAN_BITTIMING_CONST,
 723                      sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
 724             nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) ||
 725             nla_put_u32(skb, IFLA_CAN_STATE, state) ||
 726             nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
 727             nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
 728             (priv->do_get_berr_counter &&
 729              !priv->do_get_berr_counter(dev, &bec) &&
 730              nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)))
 731                 return -EMSGSIZE;
 732         return 0;
 733 }
 734
 735 static size_t can_get_xstats_size(const struct net_device *dev)
 736 {
 737         return sizeof(struct can_device_stats);
 738 }
 739
 740 static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
 741 {
 742         struct can_priv *priv = netdev_priv(dev);
 743
 744         if (nla_put(skb, IFLA_INFO_XSTATS,
 745                     sizeof(priv->can_stats), &priv->can_stats))
 746                 goto nla_put_failure;
 747         return 0;
 748
 749 nla_put_failure:
 750         return -EMSGSIZE;
 751 }
 752
 753 static int can_newlink(struct net *src_net, struct net_device *dev,
 754                        struct nlattr *tb[], struct nlattr *data[])
 755 {
 756         return -EOPNOTSUPP;
 757 }
 758
 759 static struct rtnl_link_ops can_link_ops __read_mostly = {
 760         .kind           = "can",
 761         .maxtype        = IFLA_CAN_MAX,
 762         .policy         = can_policy,
 763         .setup          = can_setup,
 764         .newlink        = can_newlink,
 765         .changelink     = can_changelink,
 766         .get_size       = can_get_size,
 767         .fill_info      = can_fill_info,
 768         .get_xstats_size = can_get_xstats_size,
 769         .fill_xstats    = can_fill_xstats,
 770 };
 771
 772 /*
 773  * Register the CAN network device
 774  */
 775 int register_candev(struct net_device *dev)
 776 {
 777         dev->rtnl_link_ops = &can_link_ops;
 778         return register_netdev(dev);
 779 }
 780 EXPORT_SYMBOL_GPL(register_candev);
 781
 782 /*
 783  * Unregister the CAN network device
 784  */
 785 void unregister_candev(struct net_device *dev)
 786 {
 787         unregister_netdev(dev);
 788 }
 789 EXPORT_SYMBOL_GPL(unregister_candev);
 790
 791 /*
 792  * Test if a network device is a candev based device
 793  * and return the can_priv* if so.
 794  */
 795 struct can_priv *safe_candev_priv(struct net_device *dev)
 796 {
 797         if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
 798                 return NULL;
 799
 800         return netdev_priv(dev);
 801 }
 802 EXPORT_SYMBOL_GPL(safe_candev_priv);
 803
 804 static __init int can_dev_init(void)
 805 {
 806         int err;
 807
 808         can_led_notifier_init();
 809
 810         err = rtnl_link_register(&can_link_ops);
 811         if (!err)
 812                 printk(KERN_INFO MOD_DESC "\n");
 813
 814         return err;
 815 }
 816 module_init(can_dev_init);
 817
 818 static __exit void can_dev_exit(void)
 819 {
 820         rtnl_link_unregister(&can_link_ops);
 821
 822         can_led_notifier_exit();
 823 }
 824 module_exit(can_dev_exit);
 825
 826 MODULE_ALIAS_RTNL_LINK("can");