dev.c revision 61463a30f65225e19e68f59dbd7b888bb308ec99
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/slab.h> 23#include <linux/netdevice.h> 24#include <linux/if_arp.h> 25#include <linux/can.h> 26#include <linux/can/dev.h> 27#include <linux/can/netlink.h> 28#include <net/rtnetlink.h> 29 30#define MOD_DESC "CAN device driver interface" 31 32MODULE_DESCRIPTION(MOD_DESC); 33MODULE_LICENSE("GPL v2"); 34MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); 35 36#ifdef CONFIG_CAN_CALC_BITTIMING 37#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */ 38 39/* 40 * Bit-timing calculation derived from: 41 * 42 * Code based on LinCAN sources and H8S2638 project 43 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz 44 * Copyright 2005 Stanislav Marek 45 * email: pisa@cmp.felk.cvut.cz 46 * 47 * Calculates proper bit-timing parameters for a specified bit-rate 48 * and sample-point, which can then be used to set the bit-timing 49 * registers of the CAN controller. You can find more information 50 * in the header file linux/can/netlink.h. 51 */ 52static int can_update_spt(const struct can_bittiming_const *btc, 53 int sampl_pt, int tseg, int *tseg1, int *tseg2) 54{ 55 *tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000; 56 if (*tseg2 < btc->tseg2_min) 57 *tseg2 = btc->tseg2_min; 58 if (*tseg2 > btc->tseg2_max) 59 *tseg2 = btc->tseg2_max; 60 *tseg1 = tseg - *tseg2; 61 if (*tseg1 > btc->tseg1_max) { 62 *tseg1 = btc->tseg1_max; 63 *tseg2 = tseg - *tseg1; 64 } 65 return 1000 * (tseg + 1 - *tseg2) / (tseg + 1); 66} 67 68static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt) 69{ 70 struct can_priv *priv = netdev_priv(dev); 71 const struct can_bittiming_const *btc = priv->bittiming_const; 72 long rate, best_rate = 0; 73 long best_error = 1000000000, error = 0; 74 int best_tseg = 0, best_brp = 0, brp = 0; 75 int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0; 76 int spt_error = 1000, spt = 0, sampl_pt; 77 u64 v64; 78 79 if (!priv->bittiming_const) 80 return -ENOTSUPP; 81 82 /* Use CIA recommended sample points */ 83 if (bt->sample_point) { 84 sampl_pt = bt->sample_point; 85 } else { 86 if (bt->bitrate > 800000) 87 sampl_pt = 750; 88 else if (bt->bitrate > 500000) 89 sampl_pt = 800; 90 else 91 sampl_pt = 875; 92 } 93 94 /* tseg even = round down, odd = round up */ 95 for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1; 96 tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) { 97 tsegall = 1 + tseg / 2; 98 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */ 99 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2; 100 /* chose brp step which is possible in system */ 101 brp = (brp / btc->brp_inc) * btc->brp_inc; 102 if ((brp < btc->brp_min) || (brp > btc->brp_max)) 103 continue; 104 rate = priv->clock.freq / (brp * tsegall); 105 error = bt->bitrate - rate; 106 /* tseg brp biterror */ 107 if (error < 0) 108 error = -error; 109 if (error > best_error) 110 continue; 111 best_error = error; 112 if (error == 0) { 113 spt = can_update_spt(btc, sampl_pt, tseg / 2, 114 &tseg1, &tseg2); 115 error = sampl_pt - spt; 116 if (error < 0) 117 error = -error; 118 if (error > spt_error) 119 continue; 120 spt_error = error; 121 } 122 best_tseg = tseg / 2; 123 best_brp = brp; 124 best_rate = rate; 125 if (error == 0) 126 break; 127 } 128 129 if (best_error) { 130 /* Error in one-tenth of a percent */ 131 error = (best_error * 1000) / bt->bitrate; 132 if (error > CAN_CALC_MAX_ERROR) { 133 dev_err(dev->dev.parent, 134 "bitrate error %ld.%ld%% too high\n", 135 error / 10, error % 10); 136 return -EDOM; 137 } else { 138 dev_warn(dev->dev.parent, "bitrate error %ld.%ld%%\n", 139 error / 10, error % 10); 140 } 141 } 142 143 /* real sample point */ 144 bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg, 145 &tseg1, &tseg2); 146 147 v64 = (u64)best_brp * 1000000000UL; 148 do_div(v64, priv->clock.freq); 149 bt->tq = (u32)v64; 150 bt->prop_seg = tseg1 / 2; 151 bt->phase_seg1 = tseg1 - bt->prop_seg; 152 bt->phase_seg2 = tseg2; 153 bt->sjw = 1; 154 bt->brp = best_brp; 155 /* real bit-rate */ 156 bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1)); 157 158 return 0; 159} 160#else /* !CONFIG_CAN_CALC_BITTIMING */ 161static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt) 162{ 163 dev_err(dev->dev.parent, "bit-timing calculation not available\n"); 164 return -EINVAL; 165} 166#endif /* CONFIG_CAN_CALC_BITTIMING */ 167 168/* 169 * Checks the validity of the specified bit-timing parameters prop_seg, 170 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate 171 * prescaler value brp. You can find more information in the header 172 * file linux/can/netlink.h. 173 */ 174static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt) 175{ 176 struct can_priv *priv = netdev_priv(dev); 177 const struct can_bittiming_const *btc = priv->bittiming_const; 178 int tseg1, alltseg; 179 u64 brp64; 180 181 if (!priv->bittiming_const) 182 return -ENOTSUPP; 183 184 tseg1 = bt->prop_seg + bt->phase_seg1; 185 if (!bt->sjw) 186 bt->sjw = 1; 187 if (bt->sjw > btc->sjw_max || 188 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max || 189 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max) 190 return -ERANGE; 191 192 brp64 = (u64)priv->clock.freq * (u64)bt->tq; 193 if (btc->brp_inc > 1) 194 do_div(brp64, btc->brp_inc); 195 brp64 += 500000000UL - 1; 196 do_div(brp64, 1000000000UL); /* the practicable BRP */ 197 if (btc->brp_inc > 1) 198 brp64 *= btc->brp_inc; 199 bt->brp = (u32)brp64; 200 201 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max) 202 return -EINVAL; 203 204 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1; 205 bt->bitrate = priv->clock.freq / (bt->brp * alltseg); 206 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg; 207 208 return 0; 209} 210 211static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt) 212{ 213 struct can_priv *priv = netdev_priv(dev); 214 int err; 215 216 /* Check if the CAN device has bit-timing parameters */ 217 if (priv->bittiming_const) { 218 219 /* Non-expert mode? Check if the bitrate has been pre-defined */ 220 if (!bt->tq) 221 /* Determine bit-timing parameters */ 222 err = can_calc_bittiming(dev, bt); 223 else 224 /* Check bit-timing params and calculate proper brp */ 225 err = can_fixup_bittiming(dev, bt); 226 if (err) 227 return err; 228 } 229 230 return 0; 231} 232 233/* 234 * Local echo of CAN messages 235 * 236 * CAN network devices *should* support a local echo functionality 237 * (see Documentation/networking/can.txt). To test the handling of CAN 238 * interfaces that do not support the local echo both driver types are 239 * implemented. In the case that the driver does not support the echo 240 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core 241 * to perform the echo as a fallback solution. 242 */ 243static void can_flush_echo_skb(struct net_device *dev) 244{ 245 struct can_priv *priv = netdev_priv(dev); 246 struct net_device_stats *stats = &dev->stats; 247 int i; 248 249 for (i = 0; i < priv->echo_skb_max; i++) { 250 if (priv->echo_skb[i]) { 251 kfree_skb(priv->echo_skb[i]); 252 priv->echo_skb[i] = NULL; 253 stats->tx_dropped++; 254 stats->tx_aborted_errors++; 255 } 256 } 257} 258 259/* 260 * Put the skb on the stack to be looped backed locally lateron 261 * 262 * The function is typically called in the start_xmit function 263 * of the device driver. The driver must protect access to 264 * priv->echo_skb, if necessary. 265 */ 266void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 267 unsigned int idx) 268{ 269 struct can_priv *priv = netdev_priv(dev); 270 271 BUG_ON(idx >= priv->echo_skb_max); 272 273 /* check flag whether this packet has to be looped back */ 274 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) { 275 kfree_skb(skb); 276 return; 277 } 278 279 if (!priv->echo_skb[idx]) { 280 struct sock *srcsk = skb->sk; 281 282 if (atomic_read(&skb->users) != 1) { 283 struct sk_buff *old_skb = skb; 284 285 skb = skb_clone(old_skb, GFP_ATOMIC); 286 kfree_skb(old_skb); 287 if (!skb) 288 return; 289 } else 290 skb_orphan(skb); 291 292 skb->sk = srcsk; 293 294 /* make settings for echo to reduce code in irq context */ 295 skb->protocol = htons(ETH_P_CAN); 296 skb->pkt_type = PACKET_BROADCAST; 297 skb->ip_summed = CHECKSUM_UNNECESSARY; 298 skb->dev = dev; 299 300 /* save this skb for tx interrupt echo handling */ 301 priv->echo_skb[idx] = skb; 302 } else { 303 /* locking problem with netif_stop_queue() ?? */ 304 dev_err(dev->dev.parent, "%s: BUG! echo_skb is occupied!\n", 305 __func__); 306 kfree_skb(skb); 307 } 308} 309EXPORT_SYMBOL_GPL(can_put_echo_skb); 310 311/* 312 * Get the skb from the stack and loop it back locally 313 * 314 * The function is typically called when the TX done interrupt 315 * is handled in the device driver. The driver must protect 316 * access to priv->echo_skb, if necessary. 317 */ 318void can_get_echo_skb(struct net_device *dev, unsigned int idx) 319{ 320 struct can_priv *priv = netdev_priv(dev); 321 322 BUG_ON(idx >= priv->echo_skb_max); 323 324 if (priv->echo_skb[idx]) { 325 netif_rx(priv->echo_skb[idx]); 326 priv->echo_skb[idx] = NULL; 327 } 328} 329EXPORT_SYMBOL_GPL(can_get_echo_skb); 330 331/* 332 * Remove the skb from the stack and free it. 333 * 334 * The function is typically called when TX failed. 335 */ 336void can_free_echo_skb(struct net_device *dev, unsigned int idx) 337{ 338 struct can_priv *priv = netdev_priv(dev); 339 340 BUG_ON(idx >= priv->echo_skb_max); 341 342 if (priv->echo_skb[idx]) { 343 kfree_skb(priv->echo_skb[idx]); 344 priv->echo_skb[idx] = NULL; 345 } 346} 347EXPORT_SYMBOL_GPL(can_free_echo_skb); 348 349/* 350 * CAN device restart for bus-off recovery 351 */ 352void can_restart(unsigned long data) 353{ 354 struct net_device *dev = (struct net_device *)data; 355 struct can_priv *priv = netdev_priv(dev); 356 struct net_device_stats *stats = &dev->stats; 357 struct sk_buff *skb; 358 struct can_frame *cf; 359 int err; 360 361 BUG_ON(netif_carrier_ok(dev)); 362 363 /* 364 * No synchronization needed because the device is bus-off and 365 * no messages can come in or go out. 366 */ 367 can_flush_echo_skb(dev); 368 369 /* send restart message upstream */ 370 skb = alloc_can_err_skb(dev, &cf); 371 if (skb == NULL) { 372 err = -ENOMEM; 373 goto restart; 374 } 375 cf->can_id |= CAN_ERR_RESTARTED; 376 377 netif_rx(skb); 378 379 stats->rx_packets++; 380 stats->rx_bytes += cf->can_dlc; 381 382restart: 383 dev_dbg(dev->dev.parent, "restarted\n"); 384 priv->can_stats.restarts++; 385 386 /* Now restart the device */ 387 err = priv->do_set_mode(dev, CAN_MODE_START); 388 389 netif_carrier_on(dev); 390 if (err) 391 dev_err(dev->dev.parent, "Error %d during restart", err); 392} 393 394int can_restart_now(struct net_device *dev) 395{ 396 struct can_priv *priv = netdev_priv(dev); 397 398 /* 399 * A manual restart is only permitted if automatic restart is 400 * disabled and the device is in the bus-off state 401 */ 402 if (priv->restart_ms) 403 return -EINVAL; 404 if (priv->state != CAN_STATE_BUS_OFF) 405 return -EBUSY; 406 407 /* Runs as soon as possible in the timer context */ 408 mod_timer(&priv->restart_timer, jiffies); 409 410 return 0; 411} 412 413/* 414 * CAN bus-off 415 * 416 * This functions should be called when the device goes bus-off to 417 * tell the netif layer that no more packets can be sent or received. 418 * If enabled, a timer is started to trigger bus-off recovery. 419 */ 420void can_bus_off(struct net_device *dev) 421{ 422 struct can_priv *priv = netdev_priv(dev); 423 424 dev_dbg(dev->dev.parent, "bus-off\n"); 425 426 netif_carrier_off(dev); 427 priv->can_stats.bus_off++; 428 429 if (priv->restart_ms) 430 mod_timer(&priv->restart_timer, 431 jiffies + (priv->restart_ms * HZ) / 1000); 432} 433EXPORT_SYMBOL_GPL(can_bus_off); 434 435static void can_setup(struct net_device *dev) 436{ 437 dev->type = ARPHRD_CAN; 438 dev->mtu = sizeof(struct can_frame); 439 dev->hard_header_len = 0; 440 dev->addr_len = 0; 441 dev->tx_queue_len = 10; 442 443 /* New-style flags. */ 444 dev->flags = IFF_NOARP; 445 dev->features = NETIF_F_NO_CSUM; 446} 447 448struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) 449{ 450 struct sk_buff *skb; 451 452 skb = netdev_alloc_skb(dev, sizeof(struct can_frame)); 453 if (unlikely(!skb)) 454 return NULL; 455 456 skb->protocol = htons(ETH_P_CAN); 457 skb->pkt_type = PACKET_BROADCAST; 458 skb->ip_summed = CHECKSUM_UNNECESSARY; 459 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); 460 memset(*cf, 0, sizeof(struct can_frame)); 461 462 return skb; 463} 464EXPORT_SYMBOL_GPL(alloc_can_skb); 465 466struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) 467{ 468 struct sk_buff *skb; 469 470 skb = alloc_can_skb(dev, cf); 471 if (unlikely(!skb)) 472 return NULL; 473 474 (*cf)->can_id = CAN_ERR_FLAG; 475 (*cf)->can_dlc = CAN_ERR_DLC; 476 477 return skb; 478} 479EXPORT_SYMBOL_GPL(alloc_can_err_skb); 480 481/* 482 * Allocate and setup space for the CAN network device 483 */ 484struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) 485{ 486 struct net_device *dev; 487 struct can_priv *priv; 488 int size; 489 490 if (echo_skb_max) 491 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) + 492 echo_skb_max * sizeof(struct sk_buff *); 493 else 494 size = sizeof_priv; 495 496 dev = alloc_netdev(size, "can%d", can_setup); 497 if (!dev) 498 return NULL; 499 500 priv = netdev_priv(dev); 501 502 if (echo_skb_max) { 503 priv->echo_skb_max = echo_skb_max; 504 priv->echo_skb = (void *)priv + 505 ALIGN(sizeof_priv, sizeof(struct sk_buff *)); 506 } 507 508 priv->state = CAN_STATE_STOPPED; 509 510 init_timer(&priv->restart_timer); 511 512 return dev; 513} 514EXPORT_SYMBOL_GPL(alloc_candev); 515 516/* 517 * Free space of the CAN network device 518 */ 519void free_candev(struct net_device *dev) 520{ 521 free_netdev(dev); 522} 523EXPORT_SYMBOL_GPL(free_candev); 524 525/* 526 * Common open function when the device gets opened. 527 * 528 * This function should be called in the open function of the device 529 * driver. 530 */ 531int open_candev(struct net_device *dev) 532{ 533 struct can_priv *priv = netdev_priv(dev); 534 535 if (!priv->bittiming.tq && !priv->bittiming.bitrate) { 536 dev_err(dev->dev.parent, "bit-timing not yet defined\n"); 537 return -EINVAL; 538 } 539 540 /* Switch carrier on if device was stopped while in bus-off state */ 541 if (!netif_carrier_ok(dev)) 542 netif_carrier_on(dev); 543 544 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); 545 546 return 0; 547} 548EXPORT_SYMBOL_GPL(open_candev); 549 550/* 551 * Common close function for cleanup before the device gets closed. 552 * 553 * This function should be called in the close function of the device 554 * driver. 555 */ 556void close_candev(struct net_device *dev) 557{ 558 struct can_priv *priv = netdev_priv(dev); 559 560 if (del_timer_sync(&priv->restart_timer)) 561 dev_put(dev); 562 can_flush_echo_skb(dev); 563} 564EXPORT_SYMBOL_GPL(close_candev); 565 566/* 567 * CAN netlink interface 568 */ 569static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { 570 [IFLA_CAN_STATE] = { .type = NLA_U32 }, 571 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, 572 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, 573 [IFLA_CAN_RESTART] = { .type = NLA_U32 }, 574 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, 575 [IFLA_CAN_BITTIMING_CONST] 576 = { .len = sizeof(struct can_bittiming_const) }, 577 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, 578 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, 579}; 580 581static int can_changelink(struct net_device *dev, 582 struct nlattr *tb[], struct nlattr *data[]) 583{ 584 struct can_priv *priv = netdev_priv(dev); 585 int err; 586 587 /* We need synchronization with dev->stop() */ 588 ASSERT_RTNL(); 589 590 if (data[IFLA_CAN_CTRLMODE]) { 591 struct can_ctrlmode *cm; 592 593 /* Do not allow changing controller mode while running */ 594 if (dev->flags & IFF_UP) 595 return -EBUSY; 596 cm = nla_data(data[IFLA_CAN_CTRLMODE]); 597 if (cm->flags & ~priv->ctrlmode_supported) 598 return -EOPNOTSUPP; 599 priv->ctrlmode &= ~cm->mask; 600 priv->ctrlmode |= cm->flags; 601 } 602 603 if (data[IFLA_CAN_BITTIMING]) { 604 struct can_bittiming bt; 605 606 /* Do not allow changing bittiming while running */ 607 if (dev->flags & IFF_UP) 608 return -EBUSY; 609 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); 610 if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq)) 611 return -EINVAL; 612 err = can_get_bittiming(dev, &bt); 613 if (err) 614 return err; 615 memcpy(&priv->bittiming, &bt, sizeof(bt)); 616 617 if (priv->do_set_bittiming) { 618 /* Finally, set the bit-timing registers */ 619 err = priv->do_set_bittiming(dev); 620 if (err) 621 return err; 622 } 623 } 624 625 if (data[IFLA_CAN_RESTART_MS]) { 626 /* Do not allow changing restart delay while running */ 627 if (dev->flags & IFF_UP) 628 return -EBUSY; 629 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); 630 } 631 632 if (data[IFLA_CAN_RESTART]) { 633 /* Do not allow a restart while not running */ 634 if (!(dev->flags & IFF_UP)) 635 return -EINVAL; 636 err = can_restart_now(dev); 637 if (err) 638 return err; 639 } 640 641 return 0; 642} 643 644static size_t can_get_size(const struct net_device *dev) 645{ 646 struct can_priv *priv = netdev_priv(dev); 647 size_t size; 648 649 size = nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ 650 size += sizeof(struct can_ctrlmode); /* IFLA_CAN_CTRLMODE */ 651 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ 652 size += sizeof(struct can_bittiming); /* IFLA_CAN_BITTIMING */ 653 size += sizeof(struct can_clock); /* IFLA_CAN_CLOCK */ 654 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ 655 size += sizeof(struct can_berr_counter); 656 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ 657 size += sizeof(struct can_bittiming_const); 658 659 return size; 660} 661 662static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) 663{ 664 struct can_priv *priv = netdev_priv(dev); 665 struct can_ctrlmode cm = {.flags = priv->ctrlmode}; 666 struct can_berr_counter bec; 667 enum can_state state = priv->state; 668 669 if (priv->do_get_state) 670 priv->do_get_state(dev, &state); 671 NLA_PUT_U32(skb, IFLA_CAN_STATE, state); 672 NLA_PUT(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm); 673 NLA_PUT_U32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms); 674 NLA_PUT(skb, IFLA_CAN_BITTIMING, 675 sizeof(priv->bittiming), &priv->bittiming); 676 NLA_PUT(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock); 677 if (priv->do_get_berr_counter && !priv->do_get_berr_counter(dev, &bec)) 678 NLA_PUT(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec); 679 if (priv->bittiming_const) 680 NLA_PUT(skb, IFLA_CAN_BITTIMING_CONST, 681 sizeof(*priv->bittiming_const), priv->bittiming_const); 682 683 return 0; 684 685nla_put_failure: 686 return -EMSGSIZE; 687} 688 689static size_t can_get_xstats_size(const struct net_device *dev) 690{ 691 return sizeof(struct can_device_stats); 692} 693 694static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) 695{ 696 struct can_priv *priv = netdev_priv(dev); 697 698 NLA_PUT(skb, IFLA_INFO_XSTATS, 699 sizeof(priv->can_stats), &priv->can_stats); 700 701 return 0; 702 703nla_put_failure: 704 return -EMSGSIZE; 705} 706 707static int can_newlink(struct net *src_net, struct net_device *dev, 708 struct nlattr *tb[], struct nlattr *data[]) 709{ 710 return -EOPNOTSUPP; 711} 712 713static struct rtnl_link_ops can_link_ops __read_mostly = { 714 .kind = "can", 715 .maxtype = IFLA_CAN_MAX, 716 .policy = can_policy, 717 .setup = can_setup, 718 .newlink = can_newlink, 719 .changelink = can_changelink, 720 .get_size = can_get_size, 721 .fill_info = can_fill_info, 722 .get_xstats_size = can_get_xstats_size, 723 .fill_xstats = can_fill_xstats, 724}; 725 726/* 727 * Register the CAN network device 728 */ 729int register_candev(struct net_device *dev) 730{ 731 dev->rtnl_link_ops = &can_link_ops; 732 return register_netdev(dev); 733} 734EXPORT_SYMBOL_GPL(register_candev); 735 736/* 737 * Unregister the CAN network device 738 */ 739void unregister_candev(struct net_device *dev) 740{ 741 unregister_netdev(dev); 742} 743EXPORT_SYMBOL_GPL(unregister_candev); 744 745static __init int can_dev_init(void) 746{ 747 int err; 748 749 err = rtnl_link_register(&can_link_ops); 750 if (!err) 751 printk(KERN_INFO MOD_DESC "\n"); 752 753 return err; 754} 755module_init(can_dev_init); 756 757static __exit void can_dev_exit(void) 758{ 759 rtnl_link_unregister(&can_link_ops); 760} 761module_exit(can_dev_exit); 762 763MODULE_ALIAS_RTNL_LINK("can"); 764