dev.c revision dd22586dec4c1444608affd83b1fedd520280ab4
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 const struct can_bittiming_const *btc) 104{ 105 struct can_priv *priv = netdev_priv(dev); 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 /* Use CIA recommended sample points */ 114 if (bt->sample_point) { 115 sampl_pt = bt->sample_point; 116 } else { 117 if (bt->bitrate > 800000) 118 sampl_pt = 750; 119 else if (bt->bitrate > 500000) 120 sampl_pt = 800; 121 else 122 sampl_pt = 875; 123 } 124 125 /* tseg even = round down, odd = round up */ 126 for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1; 127 tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) { 128 tsegall = 1 + tseg / 2; 129 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */ 130 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2; 131 /* chose brp step which is possible in system */ 132 brp = (brp / btc->brp_inc) * btc->brp_inc; 133 if ((brp < btc->brp_min) || (brp > btc->brp_max)) 134 continue; 135 rate = priv->clock.freq / (brp * tsegall); 136 error = bt->bitrate - rate; 137 /* tseg brp biterror */ 138 if (error < 0) 139 error = -error; 140 if (error > best_error) 141 continue; 142 best_error = error; 143 if (error == 0) { 144 spt = can_update_spt(btc, sampl_pt, tseg / 2, 145 &tseg1, &tseg2); 146 error = sampl_pt - spt; 147 if (error < 0) 148 error = -error; 149 if (error > spt_error) 150 continue; 151 spt_error = error; 152 } 153 best_tseg = tseg / 2; 154 best_brp = brp; 155 best_rate = rate; 156 if (error == 0) 157 break; 158 } 159 160 if (best_error) { 161 /* Error in one-tenth of a percent */ 162 error = (best_error * 1000) / bt->bitrate; 163 if (error > CAN_CALC_MAX_ERROR) { 164 netdev_err(dev, 165 "bitrate error %ld.%ld%% too high\n", 166 error / 10, error % 10); 167 return -EDOM; 168 } else { 169 netdev_warn(dev, "bitrate error %ld.%ld%%\n", 170 error / 10, error % 10); 171 } 172 } 173 174 /* real sample point */ 175 bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg, 176 &tseg1, &tseg2); 177 178 v64 = (u64)best_brp * 1000000000UL; 179 do_div(v64, priv->clock.freq); 180 bt->tq = (u32)v64; 181 bt->prop_seg = tseg1 / 2; 182 bt->phase_seg1 = tseg1 - bt->prop_seg; 183 bt->phase_seg2 = tseg2; 184 185 /* check for sjw user settings */ 186 if (!bt->sjw || !btc->sjw_max) 187 bt->sjw = 1; 188 else { 189 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */ 190 if (bt->sjw > btc->sjw_max) 191 bt->sjw = btc->sjw_max; 192 /* bt->sjw must not be higher than tseg2 */ 193 if (tseg2 < bt->sjw) 194 bt->sjw = tseg2; 195 } 196 197 bt->brp = best_brp; 198 /* real bit-rate */ 199 bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1)); 200 201 return 0; 202} 203#else /* !CONFIG_CAN_CALC_BITTIMING */ 204static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, 205 const struct can_bittiming_const *btc) 206{ 207 netdev_err(dev, "bit-timing calculation not available\n"); 208 return -EINVAL; 209} 210#endif /* CONFIG_CAN_CALC_BITTIMING */ 211 212/* 213 * Checks the validity of the specified bit-timing parameters prop_seg, 214 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate 215 * prescaler value brp. You can find more information in the header 216 * file linux/can/netlink.h. 217 */ 218static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt, 219 const struct can_bittiming_const *btc) 220{ 221 struct can_priv *priv = netdev_priv(dev); 222 int tseg1, alltseg; 223 u64 brp64; 224 225 tseg1 = bt->prop_seg + bt->phase_seg1; 226 if (!bt->sjw) 227 bt->sjw = 1; 228 if (bt->sjw > btc->sjw_max || 229 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max || 230 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max) 231 return -ERANGE; 232 233 brp64 = (u64)priv->clock.freq * (u64)bt->tq; 234 if (btc->brp_inc > 1) 235 do_div(brp64, btc->brp_inc); 236 brp64 += 500000000UL - 1; 237 do_div(brp64, 1000000000UL); /* the practicable BRP */ 238 if (btc->brp_inc > 1) 239 brp64 *= btc->brp_inc; 240 bt->brp = (u32)brp64; 241 242 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max) 243 return -EINVAL; 244 245 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1; 246 bt->bitrate = priv->clock.freq / (bt->brp * alltseg); 247 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg; 248 249 return 0; 250} 251 252static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt, 253 const struct can_bittiming_const *btc) 254{ 255 int err; 256 257 /* Check if the CAN device has bit-timing parameters */ 258 if (!btc) 259 return -ENOTSUPP; 260 261 /* 262 * Depending on the given can_bittiming parameter structure the CAN 263 * timing parameters are calculated based on the provided bitrate OR 264 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are 265 * provided directly which are then checked and fixed up. 266 */ 267 if (!bt->tq && bt->bitrate) 268 err = can_calc_bittiming(dev, bt, btc); 269 else if (bt->tq && !bt->bitrate) 270 err = can_fixup_bittiming(dev, bt, btc); 271 else 272 err = -EINVAL; 273 274 return err; 275} 276 277/* 278 * Local echo of CAN messages 279 * 280 * CAN network devices *should* support a local echo functionality 281 * (see Documentation/networking/can.txt). To test the handling of CAN 282 * interfaces that do not support the local echo both driver types are 283 * implemented. In the case that the driver does not support the echo 284 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core 285 * to perform the echo as a fallback solution. 286 */ 287static void can_flush_echo_skb(struct net_device *dev) 288{ 289 struct can_priv *priv = netdev_priv(dev); 290 struct net_device_stats *stats = &dev->stats; 291 int i; 292 293 for (i = 0; i < priv->echo_skb_max; i++) { 294 if (priv->echo_skb[i]) { 295 kfree_skb(priv->echo_skb[i]); 296 priv->echo_skb[i] = NULL; 297 stats->tx_dropped++; 298 stats->tx_aborted_errors++; 299 } 300 } 301} 302 303/* 304 * Put the skb on the stack to be looped backed locally lateron 305 * 306 * The function is typically called in the start_xmit function 307 * of the device driver. The driver must protect access to 308 * priv->echo_skb, if necessary. 309 */ 310void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 311 unsigned int idx) 312{ 313 struct can_priv *priv = netdev_priv(dev); 314 315 BUG_ON(idx >= priv->echo_skb_max); 316 317 /* check flag whether this packet has to be looped back */ 318 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK || 319 (skb->protocol != htons(ETH_P_CAN) && 320 skb->protocol != htons(ETH_P_CANFD))) { 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->pkt_type = PACKET_BROADCAST; 333 skb->ip_summed = CHECKSUM_UNNECESSARY; 334 skb->dev = dev; 335 336 /* save this skb for tx interrupt echo handling */ 337 priv->echo_skb[idx] = skb; 338 } else { 339 /* locking problem with netif_stop_queue() ?? */ 340 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__); 341 kfree_skb(skb); 342 } 343} 344EXPORT_SYMBOL_GPL(can_put_echo_skb); 345 346/* 347 * Get the skb from the stack and loop it back locally 348 * 349 * The function is typically called when the TX done interrupt 350 * is handled in the device driver. The driver must protect 351 * access to priv->echo_skb, if necessary. 352 */ 353unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx) 354{ 355 struct can_priv *priv = netdev_priv(dev); 356 357 BUG_ON(idx >= priv->echo_skb_max); 358 359 if (priv->echo_skb[idx]) { 360 struct sk_buff *skb = priv->echo_skb[idx]; 361 struct can_frame *cf = (struct can_frame *)skb->data; 362 u8 dlc = cf->can_dlc; 363 364 netif_rx(priv->echo_skb[idx]); 365 priv->echo_skb[idx] = NULL; 366 367 return dlc; 368 } 369 370 return 0; 371} 372EXPORT_SYMBOL_GPL(can_get_echo_skb); 373 374/* 375 * Remove the skb from the stack and free it. 376 * 377 * The function is typically called when TX failed. 378 */ 379void can_free_echo_skb(struct net_device *dev, unsigned int idx) 380{ 381 struct can_priv *priv = netdev_priv(dev); 382 383 BUG_ON(idx >= priv->echo_skb_max); 384 385 if (priv->echo_skb[idx]) { 386 kfree_skb(priv->echo_skb[idx]); 387 priv->echo_skb[idx] = NULL; 388 } 389} 390EXPORT_SYMBOL_GPL(can_free_echo_skb); 391 392/* 393 * CAN device restart for bus-off recovery 394 */ 395static void can_restart(unsigned long data) 396{ 397 struct net_device *dev = (struct net_device *)data; 398 struct can_priv *priv = netdev_priv(dev); 399 struct net_device_stats *stats = &dev->stats; 400 struct sk_buff *skb; 401 struct can_frame *cf; 402 int err; 403 404 BUG_ON(netif_carrier_ok(dev)); 405 406 /* 407 * No synchronization needed because the device is bus-off and 408 * no messages can come in or go out. 409 */ 410 can_flush_echo_skb(dev); 411 412 /* send restart message upstream */ 413 skb = alloc_can_err_skb(dev, &cf); 414 if (skb == NULL) { 415 err = -ENOMEM; 416 goto restart; 417 } 418 cf->can_id |= CAN_ERR_RESTARTED; 419 420 netif_rx(skb); 421 422 stats->rx_packets++; 423 stats->rx_bytes += cf->can_dlc; 424 425restart: 426 netdev_dbg(dev, "restarted\n"); 427 priv->can_stats.restarts++; 428 429 /* Now restart the device */ 430 err = priv->do_set_mode(dev, CAN_MODE_START); 431 432 netif_carrier_on(dev); 433 if (err) 434 netdev_err(dev, "Error %d during restart", err); 435} 436 437int can_restart_now(struct net_device *dev) 438{ 439 struct can_priv *priv = netdev_priv(dev); 440 441 /* 442 * A manual restart is only permitted if automatic restart is 443 * disabled and the device is in the bus-off state 444 */ 445 if (priv->restart_ms) 446 return -EINVAL; 447 if (priv->state != CAN_STATE_BUS_OFF) 448 return -EBUSY; 449 450 /* Runs as soon as possible in the timer context */ 451 mod_timer(&priv->restart_timer, jiffies); 452 453 return 0; 454} 455 456/* 457 * CAN bus-off 458 * 459 * This functions should be called when the device goes bus-off to 460 * tell the netif layer that no more packets can be sent or received. 461 * If enabled, a timer is started to trigger bus-off recovery. 462 */ 463void can_bus_off(struct net_device *dev) 464{ 465 struct can_priv *priv = netdev_priv(dev); 466 467 netdev_dbg(dev, "bus-off\n"); 468 469 netif_carrier_off(dev); 470 priv->can_stats.bus_off++; 471 472 if (priv->restart_ms) 473 mod_timer(&priv->restart_timer, 474 jiffies + (priv->restart_ms * HZ) / 1000); 475} 476EXPORT_SYMBOL_GPL(can_bus_off); 477 478static void can_setup(struct net_device *dev) 479{ 480 dev->type = ARPHRD_CAN; 481 dev->mtu = CAN_MTU; 482 dev->hard_header_len = 0; 483 dev->addr_len = 0; 484 dev->tx_queue_len = 10; 485 486 /* New-style flags. */ 487 dev->flags = IFF_NOARP; 488 dev->features = NETIF_F_HW_CSUM; 489} 490 491struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) 492{ 493 struct sk_buff *skb; 494 495 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + 496 sizeof(struct can_frame)); 497 if (unlikely(!skb)) 498 return NULL; 499 500 skb->protocol = htons(ETH_P_CAN); 501 skb->pkt_type = PACKET_BROADCAST; 502 skb->ip_summed = CHECKSUM_UNNECESSARY; 503 504 can_skb_reserve(skb); 505 can_skb_prv(skb)->ifindex = dev->ifindex; 506 507 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); 508 memset(*cf, 0, sizeof(struct can_frame)); 509 510 return skb; 511} 512EXPORT_SYMBOL_GPL(alloc_can_skb); 513 514struct sk_buff *alloc_canfd_skb(struct net_device *dev, 515 struct canfd_frame **cfd) 516{ 517 struct sk_buff *skb; 518 519 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + 520 sizeof(struct canfd_frame)); 521 if (unlikely(!skb)) 522 return NULL; 523 524 skb->protocol = htons(ETH_P_CANFD); 525 skb->pkt_type = PACKET_BROADCAST; 526 skb->ip_summed = CHECKSUM_UNNECESSARY; 527 528 can_skb_reserve(skb); 529 can_skb_prv(skb)->ifindex = dev->ifindex; 530 531 *cfd = (struct canfd_frame *)skb_put(skb, sizeof(struct canfd_frame)); 532 memset(*cfd, 0, sizeof(struct canfd_frame)); 533 534 return skb; 535} 536EXPORT_SYMBOL_GPL(alloc_canfd_skb); 537 538struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) 539{ 540 struct sk_buff *skb; 541 542 skb = alloc_can_skb(dev, cf); 543 if (unlikely(!skb)) 544 return NULL; 545 546 (*cf)->can_id = CAN_ERR_FLAG; 547 (*cf)->can_dlc = CAN_ERR_DLC; 548 549 return skb; 550} 551EXPORT_SYMBOL_GPL(alloc_can_err_skb); 552 553/* 554 * Allocate and setup space for the CAN network device 555 */ 556struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) 557{ 558 struct net_device *dev; 559 struct can_priv *priv; 560 int size; 561 562 if (echo_skb_max) 563 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) + 564 echo_skb_max * sizeof(struct sk_buff *); 565 else 566 size = sizeof_priv; 567 568 dev = alloc_netdev(size, "can%d", can_setup); 569 if (!dev) 570 return NULL; 571 572 priv = netdev_priv(dev); 573 574 if (echo_skb_max) { 575 priv->echo_skb_max = echo_skb_max; 576 priv->echo_skb = (void *)priv + 577 ALIGN(sizeof_priv, sizeof(struct sk_buff *)); 578 } 579 580 priv->state = CAN_STATE_STOPPED; 581 582 init_timer(&priv->restart_timer); 583 584 return dev; 585} 586EXPORT_SYMBOL_GPL(alloc_candev); 587 588/* 589 * Free space of the CAN network device 590 */ 591void free_candev(struct net_device *dev) 592{ 593 free_netdev(dev); 594} 595EXPORT_SYMBOL_GPL(free_candev); 596 597/* 598 * changing MTU and control mode for CAN/CANFD devices 599 */ 600int can_change_mtu(struct net_device *dev, int new_mtu) 601{ 602 struct can_priv *priv = netdev_priv(dev); 603 604 /* Do not allow changing the MTU while running */ 605 if (dev->flags & IFF_UP) 606 return -EBUSY; 607 608 /* allow change of MTU according to the CANFD ability of the device */ 609 switch (new_mtu) { 610 case CAN_MTU: 611 priv->ctrlmode &= ~CAN_CTRLMODE_FD; 612 break; 613 614 case CANFD_MTU: 615 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD)) 616 return -EINVAL; 617 618 priv->ctrlmode |= CAN_CTRLMODE_FD; 619 break; 620 621 default: 622 return -EINVAL; 623 } 624 625 dev->mtu = new_mtu; 626 return 0; 627} 628EXPORT_SYMBOL_GPL(can_change_mtu); 629 630/* 631 * Common open function when the device gets opened. 632 * 633 * This function should be called in the open function of the device 634 * driver. 635 */ 636int open_candev(struct net_device *dev) 637{ 638 struct can_priv *priv = netdev_priv(dev); 639 640 if (!priv->bittiming.bitrate) { 641 netdev_err(dev, "bit-timing not yet defined\n"); 642 return -EINVAL; 643 } 644 645 /* For CAN FD the data bitrate has to be >= the arbitration bitrate */ 646 if ((priv->ctrlmode & CAN_CTRLMODE_FD) && 647 (!priv->data_bittiming.bitrate || 648 (priv->data_bittiming.bitrate < priv->bittiming.bitrate))) { 649 netdev_err(dev, "incorrect/missing data bit-timing\n"); 650 return -EINVAL; 651 } 652 653 /* Switch carrier on if device was stopped while in bus-off state */ 654 if (!netif_carrier_ok(dev)) 655 netif_carrier_on(dev); 656 657 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); 658 659 return 0; 660} 661EXPORT_SYMBOL_GPL(open_candev); 662 663/* 664 * Common close function for cleanup before the device gets closed. 665 * 666 * This function should be called in the close function of the device 667 * driver. 668 */ 669void close_candev(struct net_device *dev) 670{ 671 struct can_priv *priv = netdev_priv(dev); 672 673 del_timer_sync(&priv->restart_timer); 674 can_flush_echo_skb(dev); 675} 676EXPORT_SYMBOL_GPL(close_candev); 677 678/* 679 * CAN netlink interface 680 */ 681static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { 682 [IFLA_CAN_STATE] = { .type = NLA_U32 }, 683 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, 684 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, 685 [IFLA_CAN_RESTART] = { .type = NLA_U32 }, 686 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, 687 [IFLA_CAN_BITTIMING_CONST] 688 = { .len = sizeof(struct can_bittiming_const) }, 689 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, 690 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, 691 [IFLA_CAN_DATA_BITTIMING] 692 = { .len = sizeof(struct can_bittiming) }, 693 [IFLA_CAN_DATA_BITTIMING_CONST] 694 = { .len = sizeof(struct can_bittiming_const) }, 695}; 696 697static int can_changelink(struct net_device *dev, 698 struct nlattr *tb[], struct nlattr *data[]) 699{ 700 struct can_priv *priv = netdev_priv(dev); 701 int err; 702 703 /* We need synchronization with dev->stop() */ 704 ASSERT_RTNL(); 705 706 if (data[IFLA_CAN_BITTIMING]) { 707 struct can_bittiming bt; 708 709 /* Do not allow changing bittiming while running */ 710 if (dev->flags & IFF_UP) 711 return -EBUSY; 712 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); 713 err = can_get_bittiming(dev, &bt, priv->bittiming_const); 714 if (err) 715 return err; 716 memcpy(&priv->bittiming, &bt, sizeof(bt)); 717 718 if (priv->do_set_bittiming) { 719 /* Finally, set the bit-timing registers */ 720 err = priv->do_set_bittiming(dev); 721 if (err) 722 return err; 723 } 724 } 725 726 if (data[IFLA_CAN_CTRLMODE]) { 727 struct can_ctrlmode *cm; 728 729 /* Do not allow changing controller mode while running */ 730 if (dev->flags & IFF_UP) 731 return -EBUSY; 732 cm = nla_data(data[IFLA_CAN_CTRLMODE]); 733 if (cm->flags & ~priv->ctrlmode_supported) 734 return -EOPNOTSUPP; 735 priv->ctrlmode &= ~cm->mask; 736 priv->ctrlmode |= cm->flags; 737 738 /* CAN_CTRLMODE_FD can only be set when driver supports FD */ 739 if (priv->ctrlmode & CAN_CTRLMODE_FD) 740 dev->mtu = CANFD_MTU; 741 else 742 dev->mtu = CAN_MTU; 743 } 744 745 if (data[IFLA_CAN_RESTART_MS]) { 746 /* Do not allow changing restart delay while running */ 747 if (dev->flags & IFF_UP) 748 return -EBUSY; 749 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); 750 } 751 752 if (data[IFLA_CAN_RESTART]) { 753 /* Do not allow a restart while not running */ 754 if (!(dev->flags & IFF_UP)) 755 return -EINVAL; 756 err = can_restart_now(dev); 757 if (err) 758 return err; 759 } 760 761 if (data[IFLA_CAN_DATA_BITTIMING]) { 762 struct can_bittiming dbt; 763 764 /* Do not allow changing bittiming while running */ 765 if (dev->flags & IFF_UP) 766 return -EBUSY; 767 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]), 768 sizeof(dbt)); 769 err = can_get_bittiming(dev, &dbt, priv->data_bittiming_const); 770 if (err) 771 return err; 772 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt)); 773 774 if (priv->do_set_data_bittiming) { 775 /* Finally, set the bit-timing registers */ 776 err = priv->do_set_data_bittiming(dev); 777 if (err) 778 return err; 779 } 780 } 781 782 return 0; 783} 784 785static size_t can_get_size(const struct net_device *dev) 786{ 787 struct can_priv *priv = netdev_priv(dev); 788 size_t size = 0; 789 790 if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */ 791 size += nla_total_size(sizeof(struct can_bittiming)); 792 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ 793 size += nla_total_size(sizeof(struct can_bittiming_const)); 794 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */ 795 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ 796 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */ 797 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ 798 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ 799 size += nla_total_size(sizeof(struct can_berr_counter)); 800 if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */ 801 size += nla_total_size(sizeof(struct can_bittiming)); 802 if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */ 803 size += nla_total_size(sizeof(struct can_bittiming_const)); 804 805 return size; 806} 807 808static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) 809{ 810 struct can_priv *priv = netdev_priv(dev); 811 struct can_ctrlmode cm = {.flags = priv->ctrlmode}; 812 struct can_berr_counter bec; 813 enum can_state state = priv->state; 814 815 if (priv->do_get_state) 816 priv->do_get_state(dev, &state); 817 818 if ((priv->bittiming.bitrate && 819 nla_put(skb, IFLA_CAN_BITTIMING, 820 sizeof(priv->bittiming), &priv->bittiming)) || 821 822 (priv->bittiming_const && 823 nla_put(skb, IFLA_CAN_BITTIMING_CONST, 824 sizeof(*priv->bittiming_const), priv->bittiming_const)) || 825 826 nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) || 827 nla_put_u32(skb, IFLA_CAN_STATE, state) || 828 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) || 829 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) || 830 831 (priv->do_get_berr_counter && 832 !priv->do_get_berr_counter(dev, &bec) && 833 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) || 834 835 (priv->data_bittiming.bitrate && 836 nla_put(skb, IFLA_CAN_DATA_BITTIMING, 837 sizeof(priv->data_bittiming), &priv->data_bittiming)) || 838 839 (priv->data_bittiming_const && 840 nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST, 841 sizeof(*priv->data_bittiming_const), 842 priv->data_bittiming_const))) 843 return -EMSGSIZE; 844 845 return 0; 846} 847 848static size_t can_get_xstats_size(const struct net_device *dev) 849{ 850 return sizeof(struct can_device_stats); 851} 852 853static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) 854{ 855 struct can_priv *priv = netdev_priv(dev); 856 857 if (nla_put(skb, IFLA_INFO_XSTATS, 858 sizeof(priv->can_stats), &priv->can_stats)) 859 goto nla_put_failure; 860 return 0; 861 862nla_put_failure: 863 return -EMSGSIZE; 864} 865 866static int can_newlink(struct net *src_net, struct net_device *dev, 867 struct nlattr *tb[], struct nlattr *data[]) 868{ 869 return -EOPNOTSUPP; 870} 871 872static struct rtnl_link_ops can_link_ops __read_mostly = { 873 .kind = "can", 874 .maxtype = IFLA_CAN_MAX, 875 .policy = can_policy, 876 .setup = can_setup, 877 .newlink = can_newlink, 878 .changelink = can_changelink, 879 .get_size = can_get_size, 880 .fill_info = can_fill_info, 881 .get_xstats_size = can_get_xstats_size, 882 .fill_xstats = can_fill_xstats, 883}; 884 885/* 886 * Register the CAN network device 887 */ 888int register_candev(struct net_device *dev) 889{ 890 dev->rtnl_link_ops = &can_link_ops; 891 return register_netdev(dev); 892} 893EXPORT_SYMBOL_GPL(register_candev); 894 895/* 896 * Unregister the CAN network device 897 */ 898void unregister_candev(struct net_device *dev) 899{ 900 unregister_netdev(dev); 901} 902EXPORT_SYMBOL_GPL(unregister_candev); 903 904/* 905 * Test if a network device is a candev based device 906 * and return the can_priv* if so. 907 */ 908struct can_priv *safe_candev_priv(struct net_device *dev) 909{ 910 if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops)) 911 return NULL; 912 913 return netdev_priv(dev); 914} 915EXPORT_SYMBOL_GPL(safe_candev_priv); 916 917static __init int can_dev_init(void) 918{ 919 int err; 920 921 can_led_notifier_init(); 922 923 err = rtnl_link_register(&can_link_ops); 924 if (!err) 925 printk(KERN_INFO MOD_DESC "\n"); 926 927 return err; 928} 929module_init(can_dev_init); 930 931static __exit void can_dev_exit(void) 932{ 933 rtnl_link_unregister(&can_link_ops); 934 935 can_led_notifier_exit(); 936} 937module_exit(can_dev_exit); 938 939MODULE_ALIAS_RTNL_LINK("can"); 940