dev.c revision d5298dffebae76810a6a942bc6467f893bc11eee
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 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 return 0; 265 266 /* 267 * Depending on the given can_bittiming parameter structure the CAN 268 * timing parameters are calculated based on the provided bitrate OR 269 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are 270 * provided directly which are then checked and fixed up. 271 */ 272 if (!bt->tq && bt->bitrate) 273 err = can_calc_bittiming(dev, bt); 274 else if (bt->tq && !bt->bitrate) 275 err = can_fixup_bittiming(dev, bt); 276 else 277 err = -EINVAL; 278 279 return err; 280} 281 282/* 283 * Local echo of CAN messages 284 * 285 * CAN network devices *should* support a local echo functionality 286 * (see Documentation/networking/can.txt). To test the handling of CAN 287 * interfaces that do not support the local echo both driver types are 288 * implemented. In the case that the driver does not support the echo 289 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core 290 * to perform the echo as a fallback solution. 291 */ 292static void can_flush_echo_skb(struct net_device *dev) 293{ 294 struct can_priv *priv = netdev_priv(dev); 295 struct net_device_stats *stats = &dev->stats; 296 int i; 297 298 for (i = 0; i < priv->echo_skb_max; i++) { 299 if (priv->echo_skb[i]) { 300 kfree_skb(priv->echo_skb[i]); 301 priv->echo_skb[i] = NULL; 302 stats->tx_dropped++; 303 stats->tx_aborted_errors++; 304 } 305 } 306} 307 308/* 309 * Put the skb on the stack to be looped backed locally lateron 310 * 311 * The function is typically called in the start_xmit function 312 * of the device driver. The driver must protect access to 313 * priv->echo_skb, if necessary. 314 */ 315void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 316 unsigned int idx) 317{ 318 struct can_priv *priv = netdev_priv(dev); 319 320 BUG_ON(idx >= priv->echo_skb_max); 321 322 /* check flag whether this packet has to be looped back */ 323 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK || 324 (skb->protocol != htons(ETH_P_CAN) && 325 skb->protocol != htons(ETH_P_CANFD))) { 326 kfree_skb(skb); 327 return; 328 } 329 330 if (!priv->echo_skb[idx]) { 331 332 skb = can_create_echo_skb(skb); 333 if (!skb) 334 return; 335 336 /* make settings for echo to reduce code in irq context */ 337 skb->pkt_type = PACKET_BROADCAST; 338 skb->ip_summed = CHECKSUM_UNNECESSARY; 339 skb->dev = dev; 340 341 /* save this skb for tx interrupt echo handling */ 342 priv->echo_skb[idx] = skb; 343 } else { 344 /* locking problem with netif_stop_queue() ?? */ 345 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__); 346 kfree_skb(skb); 347 } 348} 349EXPORT_SYMBOL_GPL(can_put_echo_skb); 350 351/* 352 * Get the skb from the stack and loop it back locally 353 * 354 * The function is typically called when the TX done interrupt 355 * is handled in the device driver. The driver must protect 356 * access to priv->echo_skb, if necessary. 357 */ 358unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx) 359{ 360 struct can_priv *priv = netdev_priv(dev); 361 362 BUG_ON(idx >= priv->echo_skb_max); 363 364 if (priv->echo_skb[idx]) { 365 struct sk_buff *skb = priv->echo_skb[idx]; 366 struct can_frame *cf = (struct can_frame *)skb->data; 367 u8 dlc = cf->can_dlc; 368 369 netif_rx(priv->echo_skb[idx]); 370 priv->echo_skb[idx] = NULL; 371 372 return dlc; 373 } 374 375 return 0; 376} 377EXPORT_SYMBOL_GPL(can_get_echo_skb); 378 379/* 380 * Remove the skb from the stack and free it. 381 * 382 * The function is typically called when TX failed. 383 */ 384void can_free_echo_skb(struct net_device *dev, unsigned int idx) 385{ 386 struct can_priv *priv = netdev_priv(dev); 387 388 BUG_ON(idx >= priv->echo_skb_max); 389 390 if (priv->echo_skb[idx]) { 391 kfree_skb(priv->echo_skb[idx]); 392 priv->echo_skb[idx] = NULL; 393 } 394} 395EXPORT_SYMBOL_GPL(can_free_echo_skb); 396 397/* 398 * CAN device restart for bus-off recovery 399 */ 400static void can_restart(unsigned long data) 401{ 402 struct net_device *dev = (struct net_device *)data; 403 struct can_priv *priv = netdev_priv(dev); 404 struct net_device_stats *stats = &dev->stats; 405 struct sk_buff *skb; 406 struct can_frame *cf; 407 int err; 408 409 BUG_ON(netif_carrier_ok(dev)); 410 411 /* 412 * No synchronization needed because the device is bus-off and 413 * no messages can come in or go out. 414 */ 415 can_flush_echo_skb(dev); 416 417 /* send restart message upstream */ 418 skb = alloc_can_err_skb(dev, &cf); 419 if (skb == NULL) { 420 err = -ENOMEM; 421 goto restart; 422 } 423 cf->can_id |= CAN_ERR_RESTARTED; 424 425 netif_rx(skb); 426 427 stats->rx_packets++; 428 stats->rx_bytes += cf->can_dlc; 429 430restart: 431 netdev_dbg(dev, "restarted\n"); 432 priv->can_stats.restarts++; 433 434 /* Now restart the device */ 435 err = priv->do_set_mode(dev, CAN_MODE_START); 436 437 netif_carrier_on(dev); 438 if (err) 439 netdev_err(dev, "Error %d during restart", err); 440} 441 442int can_restart_now(struct net_device *dev) 443{ 444 struct can_priv *priv = netdev_priv(dev); 445 446 /* 447 * A manual restart is only permitted if automatic restart is 448 * disabled and the device is in the bus-off state 449 */ 450 if (priv->restart_ms) 451 return -EINVAL; 452 if (priv->state != CAN_STATE_BUS_OFF) 453 return -EBUSY; 454 455 /* Runs as soon as possible in the timer context */ 456 mod_timer(&priv->restart_timer, jiffies); 457 458 return 0; 459} 460 461/* 462 * CAN bus-off 463 * 464 * This functions should be called when the device goes bus-off to 465 * tell the netif layer that no more packets can be sent or received. 466 * If enabled, a timer is started to trigger bus-off recovery. 467 */ 468void can_bus_off(struct net_device *dev) 469{ 470 struct can_priv *priv = netdev_priv(dev); 471 472 netdev_dbg(dev, "bus-off\n"); 473 474 netif_carrier_off(dev); 475 priv->can_stats.bus_off++; 476 477 if (priv->restart_ms) 478 mod_timer(&priv->restart_timer, 479 jiffies + (priv->restart_ms * HZ) / 1000); 480} 481EXPORT_SYMBOL_GPL(can_bus_off); 482 483static void can_setup(struct net_device *dev) 484{ 485 dev->type = ARPHRD_CAN; 486 dev->mtu = CAN_MTU; 487 dev->hard_header_len = 0; 488 dev->addr_len = 0; 489 dev->tx_queue_len = 10; 490 491 /* New-style flags. */ 492 dev->flags = IFF_NOARP; 493 dev->features = NETIF_F_HW_CSUM; 494} 495 496struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) 497{ 498 struct sk_buff *skb; 499 500 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + 501 sizeof(struct can_frame)); 502 if (unlikely(!skb)) 503 return NULL; 504 505 skb->protocol = htons(ETH_P_CAN); 506 skb->pkt_type = PACKET_BROADCAST; 507 skb->ip_summed = CHECKSUM_UNNECESSARY; 508 509 can_skb_reserve(skb); 510 can_skb_prv(skb)->ifindex = dev->ifindex; 511 512 *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_canfd_skb(struct net_device *dev, 520 struct canfd_frame **cfd) 521{ 522 struct sk_buff *skb; 523 524 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + 525 sizeof(struct canfd_frame)); 526 if (unlikely(!skb)) 527 return NULL; 528 529 skb->protocol = htons(ETH_P_CANFD); 530 skb->pkt_type = PACKET_BROADCAST; 531 skb->ip_summed = CHECKSUM_UNNECESSARY; 532 533 can_skb_reserve(skb); 534 can_skb_prv(skb)->ifindex = dev->ifindex; 535 536 *cfd = (struct canfd_frame *)skb_put(skb, sizeof(struct canfd_frame)); 537 memset(*cfd, 0, sizeof(struct canfd_frame)); 538 539 return skb; 540} 541EXPORT_SYMBOL_GPL(alloc_canfd_skb); 542 543struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) 544{ 545 struct sk_buff *skb; 546 547 skb = alloc_can_skb(dev, cf); 548 if (unlikely(!skb)) 549 return NULL; 550 551 (*cf)->can_id = CAN_ERR_FLAG; 552 (*cf)->can_dlc = CAN_ERR_DLC; 553 554 return skb; 555} 556EXPORT_SYMBOL_GPL(alloc_can_err_skb); 557 558/* 559 * Allocate and setup space for the CAN network device 560 */ 561struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) 562{ 563 struct net_device *dev; 564 struct can_priv *priv; 565 int size; 566 567 if (echo_skb_max) 568 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) + 569 echo_skb_max * sizeof(struct sk_buff *); 570 else 571 size = sizeof_priv; 572 573 dev = alloc_netdev(size, "can%d", can_setup); 574 if (!dev) 575 return NULL; 576 577 priv = netdev_priv(dev); 578 579 if (echo_skb_max) { 580 priv->echo_skb_max = echo_skb_max; 581 priv->echo_skb = (void *)priv + 582 ALIGN(sizeof_priv, sizeof(struct sk_buff *)); 583 } 584 585 priv->state = CAN_STATE_STOPPED; 586 587 init_timer(&priv->restart_timer); 588 589 return dev; 590} 591EXPORT_SYMBOL_GPL(alloc_candev); 592 593/* 594 * Free space of the CAN network device 595 */ 596void free_candev(struct net_device *dev) 597{ 598 free_netdev(dev); 599} 600EXPORT_SYMBOL_GPL(free_candev); 601 602/* 603 * Common open function when the device gets opened. 604 * 605 * This function should be called in the open function of the device 606 * driver. 607 */ 608int open_candev(struct net_device *dev) 609{ 610 struct can_priv *priv = netdev_priv(dev); 611 612 if (!priv->bittiming.bitrate) { 613 netdev_err(dev, "bit-timing not yet defined\n"); 614 return -EINVAL; 615 } 616 617 /* Switch carrier on if device was stopped while in bus-off state */ 618 if (!netif_carrier_ok(dev)) 619 netif_carrier_on(dev); 620 621 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); 622 623 return 0; 624} 625EXPORT_SYMBOL_GPL(open_candev); 626 627/* 628 * Common close function for cleanup before the device gets closed. 629 * 630 * This function should be called in the close function of the device 631 * driver. 632 */ 633void close_candev(struct net_device *dev) 634{ 635 struct can_priv *priv = netdev_priv(dev); 636 637 del_timer_sync(&priv->restart_timer); 638 can_flush_echo_skb(dev); 639} 640EXPORT_SYMBOL_GPL(close_candev); 641 642/* 643 * CAN netlink interface 644 */ 645static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { 646 [IFLA_CAN_STATE] = { .type = NLA_U32 }, 647 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, 648 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, 649 [IFLA_CAN_RESTART] = { .type = NLA_U32 }, 650 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, 651 [IFLA_CAN_BITTIMING_CONST] 652 = { .len = sizeof(struct can_bittiming_const) }, 653 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, 654 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, 655}; 656 657static int can_changelink(struct net_device *dev, 658 struct nlattr *tb[], struct nlattr *data[]) 659{ 660 struct can_priv *priv = netdev_priv(dev); 661 int err; 662 663 /* We need synchronization with dev->stop() */ 664 ASSERT_RTNL(); 665 666 if (data[IFLA_CAN_BITTIMING]) { 667 struct can_bittiming bt; 668 669 /* Do not allow changing bittiming while running */ 670 if (dev->flags & IFF_UP) 671 return -EBUSY; 672 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); 673 err = can_get_bittiming(dev, &bt); 674 if (err) 675 return err; 676 memcpy(&priv->bittiming, &bt, sizeof(bt)); 677 678 if (priv->do_set_bittiming) { 679 /* Finally, set the bit-timing registers */ 680 err = priv->do_set_bittiming(dev); 681 if (err) 682 return err; 683 } 684 } 685 686 if (data[IFLA_CAN_CTRLMODE]) { 687 struct can_ctrlmode *cm; 688 689 /* Do not allow changing controller mode while running */ 690 if (dev->flags & IFF_UP) 691 return -EBUSY; 692 cm = nla_data(data[IFLA_CAN_CTRLMODE]); 693 if (cm->flags & ~priv->ctrlmode_supported) 694 return -EOPNOTSUPP; 695 priv->ctrlmode &= ~cm->mask; 696 priv->ctrlmode |= cm->flags; 697 } 698 699 if (data[IFLA_CAN_RESTART_MS]) { 700 /* Do not allow changing restart delay while running */ 701 if (dev->flags & IFF_UP) 702 return -EBUSY; 703 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); 704 } 705 706 if (data[IFLA_CAN_RESTART]) { 707 /* Do not allow a restart while not running */ 708 if (!(dev->flags & IFF_UP)) 709 return -EINVAL; 710 err = can_restart_now(dev); 711 if (err) 712 return err; 713 } 714 715 return 0; 716} 717 718static size_t can_get_size(const struct net_device *dev) 719{ 720 struct can_priv *priv = netdev_priv(dev); 721 size_t size = 0; 722 723 if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */ 724 size += nla_total_size(sizeof(struct can_bittiming)); 725 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ 726 size += nla_total_size(sizeof(struct can_bittiming_const)); 727 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */ 728 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ 729 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */ 730 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ 731 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ 732 size += nla_total_size(sizeof(struct can_berr_counter)); 733 734 return size; 735} 736 737static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) 738{ 739 struct can_priv *priv = netdev_priv(dev); 740 struct can_ctrlmode cm = {.flags = priv->ctrlmode}; 741 struct can_berr_counter bec; 742 enum can_state state = priv->state; 743 744 if (priv->do_get_state) 745 priv->do_get_state(dev, &state); 746 if ((priv->bittiming.bitrate && 747 nla_put(skb, IFLA_CAN_BITTIMING, 748 sizeof(priv->bittiming), &priv->bittiming)) || 749 (priv->bittiming_const && 750 nla_put(skb, IFLA_CAN_BITTIMING_CONST, 751 sizeof(*priv->bittiming_const), priv->bittiming_const)) || 752 nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) || 753 nla_put_u32(skb, IFLA_CAN_STATE, state) || 754 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) || 755 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) || 756 (priv->do_get_berr_counter && 757 !priv->do_get_berr_counter(dev, &bec) && 758 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec))) 759 return -EMSGSIZE; 760 return 0; 761} 762 763static size_t can_get_xstats_size(const struct net_device *dev) 764{ 765 return sizeof(struct can_device_stats); 766} 767 768static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) 769{ 770 struct can_priv *priv = netdev_priv(dev); 771 772 if (nla_put(skb, IFLA_INFO_XSTATS, 773 sizeof(priv->can_stats), &priv->can_stats)) 774 goto nla_put_failure; 775 return 0; 776 777nla_put_failure: 778 return -EMSGSIZE; 779} 780 781static int can_newlink(struct net *src_net, struct net_device *dev, 782 struct nlattr *tb[], struct nlattr *data[]) 783{ 784 return -EOPNOTSUPP; 785} 786 787static struct rtnl_link_ops can_link_ops __read_mostly = { 788 .kind = "can", 789 .maxtype = IFLA_CAN_MAX, 790 .policy = can_policy, 791 .setup = can_setup, 792 .newlink = can_newlink, 793 .changelink = can_changelink, 794 .get_size = can_get_size, 795 .fill_info = can_fill_info, 796 .get_xstats_size = can_get_xstats_size, 797 .fill_xstats = can_fill_xstats, 798}; 799 800/* 801 * Register the CAN network device 802 */ 803int register_candev(struct net_device *dev) 804{ 805 dev->rtnl_link_ops = &can_link_ops; 806 return register_netdev(dev); 807} 808EXPORT_SYMBOL_GPL(register_candev); 809 810/* 811 * Unregister the CAN network device 812 */ 813void unregister_candev(struct net_device *dev) 814{ 815 unregister_netdev(dev); 816} 817EXPORT_SYMBOL_GPL(unregister_candev); 818 819/* 820 * Test if a network device is a candev based device 821 * and return the can_priv* if so. 822 */ 823struct can_priv *safe_candev_priv(struct net_device *dev) 824{ 825 if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops)) 826 return NULL; 827 828 return netdev_priv(dev); 829} 830EXPORT_SYMBOL_GPL(safe_candev_priv); 831 832static __init int can_dev_init(void) 833{ 834 int err; 835 836 can_led_notifier_init(); 837 838 err = rtnl_link_register(&can_link_ops); 839 if (!err) 840 printk(KERN_INFO MOD_DESC "\n"); 841 842 return err; 843} 844module_init(can_dev_init); 845 846static __exit void can_dev_exit(void) 847{ 848 rtnl_link_unregister(&can_link_ops); 849 850 can_led_notifier_exit(); 851} 852module_exit(can_dev_exit); 853 854MODULE_ALIAS_RTNL_LINK("can"); 855