dev.c revision a1ef7bd9fce8aba8e4701e60208148fb3bc9bdd4
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 <linux/can/led.h> 29#include <net/rtnetlink.h> 30 31#define MOD_DESC "CAN device driver interface" 32 33MODULE_DESCRIPTION(MOD_DESC); 34MODULE_LICENSE("GPL v2"); 35MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); 36 37/* CAN DLC to real data length conversion helpers */ 38 39static 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 */ 43u8 can_dlc2len(u8 can_dlc) 44{ 45 return dlc2len[can_dlc & 0x0F]; 46} 47EXPORT_SYMBOL_GPL(can_dlc2len); 48 49static 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 */ 61u8 can_len2dlc(u8 len) 62{ 63 if (unlikely(len > 64)) 64 return 0xF; 65 66 return len2dlc[len]; 67} 68EXPORT_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 */ 86static 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 102static 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 */ 207static 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 */ 220static 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 257static 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 */ 289static 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 */ 312void 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 struct sock *srcsk = skb->sk; 327 328 if (atomic_read(&skb->users) != 1) { 329 struct sk_buff *old_skb = skb; 330 331 skb = skb_clone(old_skb, GFP_ATOMIC); 332 kfree_skb(old_skb); 333 if (!skb) 334 return; 335 } else 336 skb_orphan(skb); 337 338 skb->sk = srcsk; 339 340 /* make settings for echo to reduce code in irq context */ 341 skb->protocol = htons(ETH_P_CAN); 342 skb->pkt_type = PACKET_BROADCAST; 343 skb->ip_summed = CHECKSUM_UNNECESSARY; 344 skb->dev = dev; 345 346 /* save this skb for tx interrupt echo handling */ 347 priv->echo_skb[idx] = skb; 348 } else { 349 /* locking problem with netif_stop_queue() ?? */ 350 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__); 351 kfree_skb(skb); 352 } 353} 354EXPORT_SYMBOL_GPL(can_put_echo_skb); 355 356/* 357 * Get the skb from the stack and loop it back locally 358 * 359 * The function is typically called when the TX done interrupt 360 * is handled in the device driver. The driver must protect 361 * access to priv->echo_skb, if necessary. 362 */ 363unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx) 364{ 365 struct can_priv *priv = netdev_priv(dev); 366 367 BUG_ON(idx >= priv->echo_skb_max); 368 369 if (priv->echo_skb[idx]) { 370 struct sk_buff *skb = priv->echo_skb[idx]; 371 struct can_frame *cf = (struct can_frame *)skb->data; 372 u8 dlc = cf->can_dlc; 373 374 netif_rx(priv->echo_skb[idx]); 375 priv->echo_skb[idx] = NULL; 376 377 return dlc; 378 } 379 380 return 0; 381} 382EXPORT_SYMBOL_GPL(can_get_echo_skb); 383 384/* 385 * Remove the skb from the stack and free it. 386 * 387 * The function is typically called when TX failed. 388 */ 389void can_free_echo_skb(struct net_device *dev, unsigned int idx) 390{ 391 struct can_priv *priv = netdev_priv(dev); 392 393 BUG_ON(idx >= priv->echo_skb_max); 394 395 if (priv->echo_skb[idx]) { 396 kfree_skb(priv->echo_skb[idx]); 397 priv->echo_skb[idx] = NULL; 398 } 399} 400EXPORT_SYMBOL_GPL(can_free_echo_skb); 401 402/* 403 * CAN device restart for bus-off recovery 404 */ 405static void can_restart(unsigned long data) 406{ 407 struct net_device *dev = (struct net_device *)data; 408 struct can_priv *priv = netdev_priv(dev); 409 struct net_device_stats *stats = &dev->stats; 410 struct sk_buff *skb; 411 struct can_frame *cf; 412 int err; 413 414 BUG_ON(netif_carrier_ok(dev)); 415 416 /* 417 * No synchronization needed because the device is bus-off and 418 * no messages can come in or go out. 419 */ 420 can_flush_echo_skb(dev); 421 422 /* send restart message upstream */ 423 skb = alloc_can_err_skb(dev, &cf); 424 if (skb == NULL) { 425 err = -ENOMEM; 426 goto restart; 427 } 428 cf->can_id |= CAN_ERR_RESTARTED; 429 430 netif_rx(skb); 431 432 stats->rx_packets++; 433 stats->rx_bytes += cf->can_dlc; 434 435restart: 436 netdev_dbg(dev, "restarted\n"); 437 priv->can_stats.restarts++; 438 439 /* Now restart the device */ 440 err = priv->do_set_mode(dev, CAN_MODE_START); 441 442 netif_carrier_on(dev); 443 if (err) 444 netdev_err(dev, "Error %d during restart", err); 445} 446 447int can_restart_now(struct net_device *dev) 448{ 449 struct can_priv *priv = netdev_priv(dev); 450 451 /* 452 * A manual restart is only permitted if automatic restart is 453 * disabled and the device is in the bus-off state 454 */ 455 if (priv->restart_ms) 456 return -EINVAL; 457 if (priv->state != CAN_STATE_BUS_OFF) 458 return -EBUSY; 459 460 /* Runs as soon as possible in the timer context */ 461 mod_timer(&priv->restart_timer, jiffies); 462 463 return 0; 464} 465 466/* 467 * CAN bus-off 468 * 469 * This functions should be called when the device goes bus-off to 470 * tell the netif layer that no more packets can be sent or received. 471 * If enabled, a timer is started to trigger bus-off recovery. 472 */ 473void can_bus_off(struct net_device *dev) 474{ 475 struct can_priv *priv = netdev_priv(dev); 476 477 netdev_dbg(dev, "bus-off\n"); 478 479 netif_carrier_off(dev); 480 priv->can_stats.bus_off++; 481 482 if (priv->restart_ms) 483 mod_timer(&priv->restart_timer, 484 jiffies + (priv->restart_ms * HZ) / 1000); 485} 486EXPORT_SYMBOL_GPL(can_bus_off); 487 488static void can_setup(struct net_device *dev) 489{ 490 dev->type = ARPHRD_CAN; 491 dev->mtu = CAN_MTU; 492 dev->hard_header_len = 0; 493 dev->addr_len = 0; 494 dev->tx_queue_len = 10; 495 496 /* New-style flags. */ 497 dev->flags = IFF_NOARP; 498 dev->features = NETIF_F_HW_CSUM; 499} 500 501struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) 502{ 503 struct sk_buff *skb; 504 505 skb = netdev_alloc_skb(dev, sizeof(struct can_frame)); 506 if (unlikely(!skb)) 507 return NULL; 508 509 skb->protocol = htons(ETH_P_CAN); 510 skb->pkt_type = PACKET_BROADCAST; 511 skb->ip_summed = CHECKSUM_UNNECESSARY; 512 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); 513 memset(*cf, 0, sizeof(struct can_frame)); 514 515 return skb; 516} 517EXPORT_SYMBOL_GPL(alloc_can_skb); 518 519struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) 520{ 521 struct sk_buff *skb; 522 523 skb = alloc_can_skb(dev, cf); 524 if (unlikely(!skb)) 525 return NULL; 526 527 (*cf)->can_id = CAN_ERR_FLAG; 528 (*cf)->can_dlc = CAN_ERR_DLC; 529 530 return skb; 531} 532EXPORT_SYMBOL_GPL(alloc_can_err_skb); 533 534/* 535 * Allocate and setup space for the CAN network device 536 */ 537struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) 538{ 539 struct net_device *dev; 540 struct can_priv *priv; 541 int size; 542 543 if (echo_skb_max) 544 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) + 545 echo_skb_max * sizeof(struct sk_buff *); 546 else 547 size = sizeof_priv; 548 549 dev = alloc_netdev(size, "can%d", can_setup); 550 if (!dev) 551 return NULL; 552 553 priv = netdev_priv(dev); 554 555 if (echo_skb_max) { 556 priv->echo_skb_max = echo_skb_max; 557 priv->echo_skb = (void *)priv + 558 ALIGN(sizeof_priv, sizeof(struct sk_buff *)); 559 } 560 561 priv->state = CAN_STATE_STOPPED; 562 563 init_timer(&priv->restart_timer); 564 565 return dev; 566} 567EXPORT_SYMBOL_GPL(alloc_candev); 568 569/* 570 * Free space of the CAN network device 571 */ 572void free_candev(struct net_device *dev) 573{ 574 free_netdev(dev); 575} 576EXPORT_SYMBOL_GPL(free_candev); 577 578/* 579 * Common open function when the device gets opened. 580 * 581 * This function should be called in the open function of the device 582 * driver. 583 */ 584int open_candev(struct net_device *dev) 585{ 586 struct can_priv *priv = netdev_priv(dev); 587 588 if (!priv->bittiming.tq && !priv->bittiming.bitrate) { 589 netdev_err(dev, "bit-timing not yet defined\n"); 590 return -EINVAL; 591 } 592 593 /* Switch carrier on if device was stopped while in bus-off state */ 594 if (!netif_carrier_ok(dev)) 595 netif_carrier_on(dev); 596 597 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); 598 599 return 0; 600} 601EXPORT_SYMBOL_GPL(open_candev); 602 603/* 604 * Common close function for cleanup before the device gets closed. 605 * 606 * This function should be called in the close function of the device 607 * driver. 608 */ 609void close_candev(struct net_device *dev) 610{ 611 struct can_priv *priv = netdev_priv(dev); 612 613 del_timer_sync(&priv->restart_timer); 614 can_flush_echo_skb(dev); 615} 616EXPORT_SYMBOL_GPL(close_candev); 617 618/* 619 * CAN netlink interface 620 */ 621static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { 622 [IFLA_CAN_STATE] = { .type = NLA_U32 }, 623 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, 624 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, 625 [IFLA_CAN_RESTART] = { .type = NLA_U32 }, 626 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, 627 [IFLA_CAN_BITTIMING_CONST] 628 = { .len = sizeof(struct can_bittiming_const) }, 629 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, 630 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, 631}; 632 633static int can_changelink(struct net_device *dev, 634 struct nlattr *tb[], struct nlattr *data[]) 635{ 636 struct can_priv *priv = netdev_priv(dev); 637 int err; 638 639 /* We need synchronization with dev->stop() */ 640 ASSERT_RTNL(); 641 642 if (data[IFLA_CAN_CTRLMODE]) { 643 struct can_ctrlmode *cm; 644 645 /* Do not allow changing controller mode while running */ 646 if (dev->flags & IFF_UP) 647 return -EBUSY; 648 cm = nla_data(data[IFLA_CAN_CTRLMODE]); 649 if (cm->flags & ~priv->ctrlmode_supported) 650 return -EOPNOTSUPP; 651 priv->ctrlmode &= ~cm->mask; 652 priv->ctrlmode |= cm->flags; 653 } 654 655 if (data[IFLA_CAN_BITTIMING]) { 656 struct can_bittiming bt; 657 658 /* Do not allow changing bittiming while running */ 659 if (dev->flags & IFF_UP) 660 return -EBUSY; 661 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); 662 if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq)) 663 return -EINVAL; 664 err = can_get_bittiming(dev, &bt); 665 if (err) 666 return err; 667 memcpy(&priv->bittiming, &bt, sizeof(bt)); 668 669 if (priv->do_set_bittiming) { 670 /* Finally, set the bit-timing registers */ 671 err = priv->do_set_bittiming(dev); 672 if (err) 673 return err; 674 } 675 } 676 677 if (data[IFLA_CAN_RESTART_MS]) { 678 /* Do not allow changing restart delay while running */ 679 if (dev->flags & IFF_UP) 680 return -EBUSY; 681 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); 682 } 683 684 if (data[IFLA_CAN_RESTART]) { 685 /* Do not allow a restart while not running */ 686 if (!(dev->flags & IFF_UP)) 687 return -EINVAL; 688 err = can_restart_now(dev); 689 if (err) 690 return err; 691 } 692 693 return 0; 694} 695 696static size_t can_get_size(const struct net_device *dev) 697{ 698 struct can_priv *priv = netdev_priv(dev); 699 size_t size; 700 701 size = nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ 702 size += sizeof(struct can_ctrlmode); /* IFLA_CAN_CTRLMODE */ 703 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ 704 size += sizeof(struct can_bittiming); /* IFLA_CAN_BITTIMING */ 705 size += sizeof(struct can_clock); /* IFLA_CAN_CLOCK */ 706 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ 707 size += sizeof(struct can_berr_counter); 708 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ 709 size += sizeof(struct can_bittiming_const); 710 711 return size; 712} 713 714static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) 715{ 716 struct can_priv *priv = netdev_priv(dev); 717 struct can_ctrlmode cm = {.flags = priv->ctrlmode}; 718 struct can_berr_counter bec; 719 enum can_state state = priv->state; 720 721 if (priv->do_get_state) 722 priv->do_get_state(dev, &state); 723 if (nla_put_u32(skb, IFLA_CAN_STATE, state) || 724 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) || 725 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) || 726 nla_put(skb, IFLA_CAN_BITTIMING, 727 sizeof(priv->bittiming), &priv->bittiming) || 728 nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) || 729 (priv->do_get_berr_counter && 730 !priv->do_get_berr_counter(dev, &bec) && 731 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) || 732 (priv->bittiming_const && 733 nla_put(skb, IFLA_CAN_BITTIMING_CONST, 734 sizeof(*priv->bittiming_const), priv->bittiming_const))) 735 goto nla_put_failure; 736 return 0; 737 738nla_put_failure: 739 return -EMSGSIZE; 740} 741 742static size_t can_get_xstats_size(const struct net_device *dev) 743{ 744 return sizeof(struct can_device_stats); 745} 746 747static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) 748{ 749 struct can_priv *priv = netdev_priv(dev); 750 751 if (nla_put(skb, IFLA_INFO_XSTATS, 752 sizeof(priv->can_stats), &priv->can_stats)) 753 goto nla_put_failure; 754 return 0; 755 756nla_put_failure: 757 return -EMSGSIZE; 758} 759 760static int can_newlink(struct net *src_net, struct net_device *dev, 761 struct nlattr *tb[], struct nlattr *data[]) 762{ 763 return -EOPNOTSUPP; 764} 765 766static struct rtnl_link_ops can_link_ops __read_mostly = { 767 .kind = "can", 768 .maxtype = IFLA_CAN_MAX, 769 .policy = can_policy, 770 .setup = can_setup, 771 .newlink = can_newlink, 772 .changelink = can_changelink, 773 .get_size = can_get_size, 774 .fill_info = can_fill_info, 775 .get_xstats_size = can_get_xstats_size, 776 .fill_xstats = can_fill_xstats, 777}; 778 779/* 780 * Register the CAN network device 781 */ 782int register_candev(struct net_device *dev) 783{ 784 dev->rtnl_link_ops = &can_link_ops; 785 return register_netdev(dev); 786} 787EXPORT_SYMBOL_GPL(register_candev); 788 789/* 790 * Unregister the CAN network device 791 */ 792void unregister_candev(struct net_device *dev) 793{ 794 unregister_netdev(dev); 795} 796EXPORT_SYMBOL_GPL(unregister_candev); 797 798/* 799 * Test if a network device is a candev based device 800 * and return the can_priv* if so. 801 */ 802struct can_priv *safe_candev_priv(struct net_device *dev) 803{ 804 if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops)) 805 return NULL; 806 807 return netdev_priv(dev); 808} 809EXPORT_SYMBOL_GPL(safe_candev_priv); 810 811static __init int can_dev_init(void) 812{ 813 int err; 814 815 can_led_notifier_init(); 816 817 err = rtnl_link_register(&can_link_ops); 818 if (!err) 819 printk(KERN_INFO MOD_DESC "\n"); 820 821 return err; 822} 823module_init(can_dev_init); 824 825static __exit void can_dev_exit(void) 826{ 827 rtnl_link_unregister(&can_link_ops); 828 829 can_led_notifier_exit(); 830} 831module_exit(can_dev_exit); 832 833MODULE_ALIAS_RTNL_LINK("can"); 834