dev.c revision 52c793f24054f5dc30d228e37e0e19cc8313f086
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, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 20#include <linux/module.h> 21#include <linux/kernel.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/netlink.h> 27#include <net/rtnetlink.h> 28 29#define MOD_DESC "CAN device driver interface" 30 31MODULE_DESCRIPTION(MOD_DESC); 32MODULE_LICENSE("GPL v2"); 33MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); 34 35#ifdef CONFIG_CAN_CALC_BITTIMING 36#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */ 37 38/* 39 * Bit-timing calculation derived from: 40 * 41 * Code based on LinCAN sources and H8S2638 project 42 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz 43 * Copyright 2005 Stanislav Marek 44 * email: pisa@cmp.felk.cvut.cz 45 * 46 * Calculates proper bit-timing parameters for a specified bit-rate 47 * and sample-point, which can then be used to set the bit-timing 48 * registers of the CAN controller. You can find more information 49 * in the header file linux/can/netlink.h. 50 */ 51static int can_update_spt(const struct can_bittiming_const *btc, 52 int sampl_pt, int tseg, int *tseg1, int *tseg2) 53{ 54 *tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000; 55 if (*tseg2 < btc->tseg2_min) 56 *tseg2 = btc->tseg2_min; 57 if (*tseg2 > btc->tseg2_max) 58 *tseg2 = btc->tseg2_max; 59 *tseg1 = tseg - *tseg2; 60 if (*tseg1 > btc->tseg1_max) { 61 *tseg1 = btc->tseg1_max; 62 *tseg2 = tseg - *tseg1; 63 } 64 return 1000 * (tseg + 1 - *tseg2) / (tseg + 1); 65} 66 67static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt) 68{ 69 struct can_priv *priv = netdev_priv(dev); 70 const struct can_bittiming_const *btc = priv->bittiming_const; 71 long rate, best_rate = 0; 72 long best_error = 1000000000, error = 0; 73 int best_tseg = 0, best_brp = 0, brp = 0; 74 int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0; 75 int spt_error = 1000, spt = 0, sampl_pt; 76 u64 v64; 77 78 if (!priv->bittiming_const) 79 return -ENOTSUPP; 80 81 /* Use CIA recommended sample points */ 82 if (bt->sample_point) { 83 sampl_pt = bt->sample_point; 84 } else { 85 if (bt->bitrate > 800000) 86 sampl_pt = 750; 87 else if (bt->bitrate > 500000) 88 sampl_pt = 800; 89 else 90 sampl_pt = 875; 91 } 92 93 /* tseg even = round down, odd = round up */ 94 for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1; 95 tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) { 96 tsegall = 1 + tseg / 2; 97 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */ 98 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2; 99 /* chose brp step which is possible in system */ 100 brp = (brp / btc->brp_inc) * btc->brp_inc; 101 if ((brp < btc->brp_min) || (brp > btc->brp_max)) 102 continue; 103 rate = priv->clock.freq / (brp * tsegall); 104 error = bt->bitrate - rate; 105 /* tseg brp biterror */ 106 if (error < 0) 107 error = -error; 108 if (error > best_error) 109 continue; 110 best_error = error; 111 if (error == 0) { 112 spt = can_update_spt(btc, sampl_pt, tseg / 2, 113 &tseg1, &tseg2); 114 error = sampl_pt - spt; 115 if (error < 0) 116 error = -error; 117 if (error > spt_error) 118 continue; 119 spt_error = error; 120 } 121 best_tseg = tseg / 2; 122 best_brp = brp; 123 best_rate = rate; 124 if (error == 0) 125 break; 126 } 127 128 if (best_error) { 129 /* Error in one-tenth of a percent */ 130 error = (best_error * 1000) / bt->bitrate; 131 if (error > CAN_CALC_MAX_ERROR) { 132 dev_err(dev->dev.parent, 133 "bitrate error %ld.%ld%% too high\n", 134 error / 10, error % 10); 135 return -EDOM; 136 } else { 137 dev_warn(dev->dev.parent, "bitrate error %ld.%ld%%\n", 138 error / 10, error % 10); 139 } 140 } 141 142 /* real sample point */ 143 bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg, 144 &tseg1, &tseg2); 145 146 v64 = (u64)best_brp * 1000000000UL; 147 do_div(v64, priv->clock.freq); 148 bt->tq = (u32)v64; 149 bt->prop_seg = tseg1 / 2; 150 bt->phase_seg1 = tseg1 - bt->prop_seg; 151 bt->phase_seg2 = tseg2; 152 bt->sjw = 1; 153 bt->brp = best_brp; 154 /* real bit-rate */ 155 bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1)); 156 157 return 0; 158} 159#else /* !CONFIG_CAN_CALC_BITTIMING */ 160static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt) 161{ 162 dev_err(dev->dev.parent, "bit-timing calculation not available\n"); 163 return -EINVAL; 164} 165#endif /* CONFIG_CAN_CALC_BITTIMING */ 166 167/* 168 * Checks the validity of the specified bit-timing parameters prop_seg, 169 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate 170 * prescaler value brp. You can find more information in the header 171 * file linux/can/netlink.h. 172 */ 173static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt) 174{ 175 struct can_priv *priv = netdev_priv(dev); 176 const struct can_bittiming_const *btc = priv->bittiming_const; 177 int tseg1, alltseg; 178 u64 brp64; 179 180 if (!priv->bittiming_const) 181 return -ENOTSUPP; 182 183 tseg1 = bt->prop_seg + bt->phase_seg1; 184 if (!bt->sjw) 185 bt->sjw = 1; 186 if (bt->sjw > btc->sjw_max || 187 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max || 188 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max) 189 return -ERANGE; 190 191 brp64 = (u64)priv->clock.freq * (u64)bt->tq; 192 if (btc->brp_inc > 1) 193 do_div(brp64, btc->brp_inc); 194 brp64 += 500000000UL - 1; 195 do_div(brp64, 1000000000UL); /* the practicable BRP */ 196 if (btc->brp_inc > 1) 197 brp64 *= btc->brp_inc; 198 bt->brp = (u32)brp64; 199 200 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max) 201 return -EINVAL; 202 203 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1; 204 bt->bitrate = priv->clock.freq / (bt->brp * alltseg); 205 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg; 206 207 return 0; 208} 209 210int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt) 211{ 212 struct can_priv *priv = netdev_priv(dev); 213 int err; 214 215 /* Check if the CAN device has bit-timing parameters */ 216 if (priv->bittiming_const) { 217 218 /* Non-expert mode? Check if the bitrate has been pre-defined */ 219 if (!bt->tq) 220 /* Determine bit-timing parameters */ 221 err = can_calc_bittiming(dev, bt); 222 else 223 /* Check bit-timing params and calculate proper brp */ 224 err = can_fixup_bittiming(dev, bt); 225 if (err) 226 return err; 227 } 228 229 return 0; 230} 231 232/* 233 * Local echo of CAN messages 234 * 235 * CAN network devices *should* support a local echo functionality 236 * (see Documentation/networking/can.txt). To test the handling of CAN 237 * interfaces that do not support the local echo both driver types are 238 * implemented. In the case that the driver does not support the echo 239 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core 240 * to perform the echo as a fallback solution. 241 */ 242static void can_flush_echo_skb(struct net_device *dev) 243{ 244 struct can_priv *priv = netdev_priv(dev); 245 struct net_device_stats *stats = &dev->stats; 246 int i; 247 248 for (i = 0; i < priv->echo_skb_max; i++) { 249 if (priv->echo_skb[i]) { 250 kfree_skb(priv->echo_skb[i]); 251 priv->echo_skb[i] = NULL; 252 stats->tx_dropped++; 253 stats->tx_aborted_errors++; 254 } 255 } 256} 257 258/* 259 * Put the skb on the stack to be looped backed locally lateron 260 * 261 * The function is typically called in the start_xmit function 262 * of the device driver. The driver must protect access to 263 * priv->echo_skb, if necessary. 264 */ 265void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 266 unsigned int idx) 267{ 268 struct can_priv *priv = netdev_priv(dev); 269 270 BUG_ON(idx >= priv->echo_skb_max); 271 272 /* check flag whether this packet has to be looped back */ 273 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) { 274 kfree_skb(skb); 275 return; 276 } 277 278 if (!priv->echo_skb[idx]) { 279 struct sock *srcsk = skb->sk; 280 281 if (atomic_read(&skb->users) != 1) { 282 struct sk_buff *old_skb = skb; 283 284 skb = skb_clone(old_skb, GFP_ATOMIC); 285 kfree_skb(old_skb); 286 if (!skb) 287 return; 288 } else 289 skb_orphan(skb); 290 291 skb->sk = srcsk; 292 293 /* make settings for echo to reduce code in irq context */ 294 skb->protocol = htons(ETH_P_CAN); 295 skb->pkt_type = PACKET_BROADCAST; 296 skb->ip_summed = CHECKSUM_UNNECESSARY; 297 skb->dev = dev; 298 299 /* save this skb for tx interrupt echo handling */ 300 priv->echo_skb[idx] = skb; 301 } else { 302 /* locking problem with netif_stop_queue() ?? */ 303 dev_err(dev->dev.parent, "%s: BUG! echo_skb is occupied!\n", 304 __func__); 305 kfree_skb(skb); 306 } 307} 308EXPORT_SYMBOL_GPL(can_put_echo_skb); 309 310/* 311 * Get the skb from the stack and loop it back locally 312 * 313 * The function is typically called when the TX done interrupt 314 * is handled in the device driver. The driver must protect 315 * access to priv->echo_skb, if necessary. 316 */ 317void can_get_echo_skb(struct net_device *dev, unsigned int idx) 318{ 319 struct can_priv *priv = netdev_priv(dev); 320 321 BUG_ON(idx >= priv->echo_skb_max); 322 323 if (priv->echo_skb[idx]) { 324 netif_rx(priv->echo_skb[idx]); 325 priv->echo_skb[idx] = NULL; 326 } 327} 328EXPORT_SYMBOL_GPL(can_get_echo_skb); 329 330/* 331 * Remove the skb from the stack and free it. 332 * 333 * The function is typically called when TX failed. 334 */ 335void can_free_echo_skb(struct net_device *dev, unsigned int idx) 336{ 337 struct can_priv *priv = netdev_priv(dev); 338 339 BUG_ON(idx >= priv->echo_skb_max); 340 341 if (priv->echo_skb[idx]) { 342 kfree_skb(priv->echo_skb[idx]); 343 priv->echo_skb[idx] = NULL; 344 } 345} 346EXPORT_SYMBOL_GPL(can_free_echo_skb); 347 348/* 349 * CAN device restart for bus-off recovery 350 */ 351void can_restart(unsigned long data) 352{ 353 struct net_device *dev = (struct net_device *)data; 354 struct can_priv *priv = netdev_priv(dev); 355 struct net_device_stats *stats = &dev->stats; 356 struct sk_buff *skb; 357 struct can_frame *cf; 358 int err; 359 360 BUG_ON(netif_carrier_ok(dev)); 361 362 /* 363 * No synchronization needed because the device is bus-off and 364 * no messages can come in or go out. 365 */ 366 can_flush_echo_skb(dev); 367 368 /* send restart message upstream */ 369 skb = alloc_can_err_skb(dev, &cf); 370 if (skb == NULL) { 371 err = -ENOMEM; 372 goto restart; 373 } 374 cf->can_id |= CAN_ERR_RESTARTED; 375 376 netif_rx(skb); 377 378 stats->rx_packets++; 379 stats->rx_bytes += cf->can_dlc; 380 381restart: 382 dev_dbg(dev->dev.parent, "restarted\n"); 383 priv->can_stats.restarts++; 384 385 /* Now restart the device */ 386 err = priv->do_set_mode(dev, CAN_MODE_START); 387 388 netif_carrier_on(dev); 389 if (err) 390 dev_err(dev->dev.parent, "Error %d during restart", err); 391} 392 393int can_restart_now(struct net_device *dev) 394{ 395 struct can_priv *priv = netdev_priv(dev); 396 397 /* 398 * A manual restart is only permitted if automatic restart is 399 * disabled and the device is in the bus-off state 400 */ 401 if (priv->restart_ms) 402 return -EINVAL; 403 if (priv->state != CAN_STATE_BUS_OFF) 404 return -EBUSY; 405 406 /* Runs as soon as possible in the timer context */ 407 mod_timer(&priv->restart_timer, jiffies); 408 409 return 0; 410} 411 412/* 413 * CAN bus-off 414 * 415 * This functions should be called when the device goes bus-off to 416 * tell the netif layer that no more packets can be sent or received. 417 * If enabled, a timer is started to trigger bus-off recovery. 418 */ 419void can_bus_off(struct net_device *dev) 420{ 421 struct can_priv *priv = netdev_priv(dev); 422 423 dev_dbg(dev->dev.parent, "bus-off\n"); 424 425 netif_carrier_off(dev); 426 priv->can_stats.bus_off++; 427 428 if (priv->restart_ms) 429 mod_timer(&priv->restart_timer, 430 jiffies + (priv->restart_ms * HZ) / 1000); 431} 432EXPORT_SYMBOL_GPL(can_bus_off); 433 434static void can_setup(struct net_device *dev) 435{ 436 dev->type = ARPHRD_CAN; 437 dev->mtu = sizeof(struct can_frame); 438 dev->hard_header_len = 0; 439 dev->addr_len = 0; 440 dev->tx_queue_len = 10; 441 442 /* New-style flags. */ 443 dev->flags = IFF_NOARP; 444 dev->features = NETIF_F_NO_CSUM; 445} 446 447struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) 448{ 449 struct sk_buff *skb; 450 451 skb = netdev_alloc_skb(dev, sizeof(struct can_frame)); 452 if (unlikely(!skb)) 453 return NULL; 454 455 skb->protocol = htons(ETH_P_CAN); 456 skb->pkt_type = PACKET_BROADCAST; 457 skb->ip_summed = CHECKSUM_UNNECESSARY; 458 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); 459 memset(*cf, 0, sizeof(struct can_frame)); 460 461 return skb; 462} 463EXPORT_SYMBOL_GPL(alloc_can_skb); 464 465struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) 466{ 467 struct sk_buff *skb; 468 469 skb = alloc_can_skb(dev, cf); 470 if (unlikely(!skb)) 471 return NULL; 472 473 (*cf)->can_id = CAN_ERR_FLAG; 474 (*cf)->can_dlc = CAN_ERR_DLC; 475 476 return skb; 477} 478EXPORT_SYMBOL_GPL(alloc_can_err_skb); 479 480/* 481 * Allocate and setup space for the CAN network device 482 */ 483struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) 484{ 485 struct net_device *dev; 486 struct can_priv *priv; 487 int size; 488 489 if (echo_skb_max) 490 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) + 491 echo_skb_max * sizeof(struct sk_buff *); 492 else 493 size = sizeof_priv; 494 495 dev = alloc_netdev(size, "can%d", can_setup); 496 if (!dev) 497 return NULL; 498 499 priv = netdev_priv(dev); 500 501 if (echo_skb_max) { 502 priv->echo_skb_max = echo_skb_max; 503 priv->echo_skb = (void *)priv + 504 ALIGN(sizeof_priv, sizeof(struct sk_buff *)); 505 } 506 507 priv->state = CAN_STATE_STOPPED; 508 509 init_timer(&priv->restart_timer); 510 511 return dev; 512} 513EXPORT_SYMBOL_GPL(alloc_candev); 514 515/* 516 * Free space of the CAN network device 517 */ 518void free_candev(struct net_device *dev) 519{ 520 free_netdev(dev); 521} 522EXPORT_SYMBOL_GPL(free_candev); 523 524/* 525 * Common open function when the device gets opened. 526 * 527 * This function should be called in the open function of the device 528 * driver. 529 */ 530int open_candev(struct net_device *dev) 531{ 532 struct can_priv *priv = netdev_priv(dev); 533 534 if (!priv->bittiming.tq && !priv->bittiming.bitrate) { 535 dev_err(dev->dev.parent, "bit-timing not yet defined\n"); 536 return -EINVAL; 537 } 538 539 /* Switch carrier on if device was stopped while in bus-off state */ 540 if (!netif_carrier_ok(dev)) 541 netif_carrier_on(dev); 542 543 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); 544 545 return 0; 546} 547EXPORT_SYMBOL_GPL(open_candev); 548 549/* 550 * Common close function for cleanup before the device gets closed. 551 * 552 * This function should be called in the close function of the device 553 * driver. 554 */ 555void close_candev(struct net_device *dev) 556{ 557 struct can_priv *priv = netdev_priv(dev); 558 559 if (del_timer_sync(&priv->restart_timer)) 560 dev_put(dev); 561 can_flush_echo_skb(dev); 562} 563EXPORT_SYMBOL_GPL(close_candev); 564 565/* 566 * CAN netlink interface 567 */ 568static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { 569 [IFLA_CAN_STATE] = { .type = NLA_U32 }, 570 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, 571 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, 572 [IFLA_CAN_RESTART] = { .type = NLA_U32 }, 573 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, 574 [IFLA_CAN_BITTIMING_CONST] 575 = { .len = sizeof(struct can_bittiming_const) }, 576 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, 577 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, 578}; 579 580static int can_changelink(struct net_device *dev, 581 struct nlattr *tb[], struct nlattr *data[]) 582{ 583 struct can_priv *priv = netdev_priv(dev); 584 int err; 585 586 /* We need synchronization with dev->stop() */ 587 ASSERT_RTNL(); 588 589 if (data[IFLA_CAN_CTRLMODE]) { 590 struct can_ctrlmode *cm; 591 592 /* Do not allow changing controller mode while running */ 593 if (dev->flags & IFF_UP) 594 return -EBUSY; 595 cm = nla_data(data[IFLA_CAN_CTRLMODE]); 596 if (cm->flags & ~priv->ctrlmode_supported) 597 return -EOPNOTSUPP; 598 priv->ctrlmode &= ~cm->mask; 599 priv->ctrlmode |= cm->flags; 600 } 601 602 if (data[IFLA_CAN_BITTIMING]) { 603 struct can_bittiming bt; 604 605 /* Do not allow changing bittiming while running */ 606 if (dev->flags & IFF_UP) 607 return -EBUSY; 608 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); 609 if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq)) 610 return -EINVAL; 611 err = can_get_bittiming(dev, &bt); 612 if (err) 613 return err; 614 memcpy(&priv->bittiming, &bt, sizeof(bt)); 615 616 if (priv->do_set_bittiming) { 617 /* Finally, set the bit-timing registers */ 618 err = priv->do_set_bittiming(dev); 619 if (err) 620 return err; 621 } 622 } 623 624 if (data[IFLA_CAN_RESTART_MS]) { 625 /* Do not allow changing restart delay while running */ 626 if (dev->flags & IFF_UP) 627 return -EBUSY; 628 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); 629 } 630 631 if (data[IFLA_CAN_RESTART]) { 632 /* Do not allow a restart while not running */ 633 if (!(dev->flags & IFF_UP)) 634 return -EINVAL; 635 err = can_restart_now(dev); 636 if (err) 637 return err; 638 } 639 640 return 0; 641} 642 643static size_t can_get_size(const struct net_device *dev) 644{ 645 struct can_priv *priv = netdev_priv(dev); 646 size_t size; 647 648 size = nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ 649 size += sizeof(struct can_ctrlmode); /* IFLA_CAN_CTRLMODE */ 650 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ 651 size += sizeof(struct can_bittiming); /* IFLA_CAN_BITTIMING */ 652 size += sizeof(struct can_clock); /* IFLA_CAN_CLOCK */ 653 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ 654 size += sizeof(struct can_berr_counter); 655 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ 656 size += sizeof(struct can_bittiming_const); 657 658 return size; 659} 660 661static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) 662{ 663 struct can_priv *priv = netdev_priv(dev); 664 struct can_ctrlmode cm = {.flags = priv->ctrlmode}; 665 struct can_berr_counter bec; 666 enum can_state state = priv->state; 667 668 if (priv->do_get_state) 669 priv->do_get_state(dev, &state); 670 NLA_PUT_U32(skb, IFLA_CAN_STATE, state); 671 NLA_PUT(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm); 672 NLA_PUT_U32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms); 673 NLA_PUT(skb, IFLA_CAN_BITTIMING, 674 sizeof(priv->bittiming), &priv->bittiming); 675 NLA_PUT(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock); 676 if (priv->do_get_berr_counter && !priv->do_get_berr_counter(dev, &bec)) 677 NLA_PUT(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec); 678 if (priv->bittiming_const) 679 NLA_PUT(skb, IFLA_CAN_BITTIMING_CONST, 680 sizeof(*priv->bittiming_const), priv->bittiming_const); 681 682 return 0; 683 684nla_put_failure: 685 return -EMSGSIZE; 686} 687 688static size_t can_get_xstats_size(const struct net_device *dev) 689{ 690 return sizeof(struct can_device_stats); 691} 692 693static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) 694{ 695 struct can_priv *priv = netdev_priv(dev); 696 697 NLA_PUT(skb, IFLA_INFO_XSTATS, 698 sizeof(priv->can_stats), &priv->can_stats); 699 700 return 0; 701 702nla_put_failure: 703 return -EMSGSIZE; 704} 705 706static int can_newlink(struct net *src_net, struct net_device *dev, 707 struct nlattr *tb[], struct nlattr *data[]) 708{ 709 return -EOPNOTSUPP; 710} 711 712static struct rtnl_link_ops can_link_ops __read_mostly = { 713 .kind = "can", 714 .maxtype = IFLA_CAN_MAX, 715 .policy = can_policy, 716 .setup = can_setup, 717 .newlink = can_newlink, 718 .changelink = can_changelink, 719 .get_size = can_get_size, 720 .fill_info = can_fill_info, 721 .get_xstats_size = can_get_xstats_size, 722 .fill_xstats = can_fill_xstats, 723}; 724 725/* 726 * Register the CAN network device 727 */ 728int register_candev(struct net_device *dev) 729{ 730 dev->rtnl_link_ops = &can_link_ops; 731 return register_netdev(dev); 732} 733EXPORT_SYMBOL_GPL(register_candev); 734 735/* 736 * Unregister the CAN network device 737 */ 738void unregister_candev(struct net_device *dev) 739{ 740 unregister_netdev(dev); 741} 742EXPORT_SYMBOL_GPL(unregister_candev); 743 744static __init int can_dev_init(void) 745{ 746 int err; 747 748 err = rtnl_link_register(&can_link_ops); 749 if (!err) 750 printk(KERN_INFO MOD_DESC "\n"); 751 752 return err; 753} 754module_init(can_dev_init); 755 756static __exit void can_dev_exit(void) 757{ 758 rtnl_link_unregister(&can_link_ops); 759} 760module_exit(can_dev_exit); 761 762MODULE_ALIAS_RTNL_LINK("can"); 763