1// SPDX-License-Identifier: GPL-2.0-only 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 7#include <linux/module.h> 8#include <linux/kernel.h> 9#include <linux/slab.h> 10#include <linux/netdevice.h> 11#include <linux/if_arp.h> 12#include <linux/workqueue.h> 13#include <linux/can.h> 14#include <linux/can/can-ml.h> 15#include <linux/can/dev.h> 16#include <linux/can/skb.h> 17#include <linux/can/netlink.h> 18#include <linux/can/led.h> 19#include <linux/of.h> 20#include <net/rtnetlink.h> 21 22#define MOD_DESC "CAN device driver interface" 23 24MODULE_DESCRIPTION(MOD_DESC); 25MODULE_LICENSE("GPL v2"); 26MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); 27 28/* CAN DLC to real data length conversion helpers */ 29 30static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7, 31 8, 12, 16, 20, 24, 32, 48, 64}; 32 33/* get data length from can_dlc with sanitized can_dlc */ 34u8 can_dlc2len(u8 can_dlc) 35{ 36 return dlc2len[can_dlc & 0x0F]; 37} 38EXPORT_SYMBOL_GPL(can_dlc2len); 39 40static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */ 41 9, 9, 9, 9, /* 9 - 12 */ 42 10, 10, 10, 10, /* 13 - 16 */ 43 11, 11, 11, 11, /* 17 - 20 */ 44 12, 12, 12, 12, /* 21 - 24 */ 45 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */ 46 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */ 47 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */ 48 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */ 49 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */ 50 51/* map the sanitized data length to an appropriate data length code */ 52u8 can_len2dlc(u8 len) 53{ 54 if (unlikely(len > 64)) 55 return 0xF; 56 57 return len2dlc[len]; 58} 59EXPORT_SYMBOL_GPL(can_len2dlc); 60 61#ifdef CONFIG_CAN_CALC_BITTIMING 62#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */ 63 64/* Bit-timing calculation derived from: 65 * 66 * Code based on LinCAN sources and H8S2638 project 67 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz 68 * Copyright 2005 Stanislav Marek 69 * email: pisa@cmp.felk.cvut.cz 70 * 71 * Calculates proper bit-timing parameters for a specified bit-rate 72 * and sample-point, which can then be used to set the bit-timing 73 * registers of the CAN controller. You can find more information 74 * in the header file linux/can/netlink.h. 75 */ 76static int 77can_update_sample_point(const struct can_bittiming_const *btc, 78 unsigned int sample_point_nominal, unsigned int tseg, 79 unsigned int *tseg1_ptr, unsigned int *tseg2_ptr, 80 unsigned int *sample_point_error_ptr) 81{ 82 unsigned int sample_point_error, best_sample_point_error = UINT_MAX; 83 unsigned int sample_point, best_sample_point = 0; 84 unsigned int tseg1, tseg2; 85 int i; 86 87 for (i = 0; i <= 1; i++) { 88 tseg2 = tseg + CAN_SYNC_SEG - 89 (sample_point_nominal * (tseg + CAN_SYNC_SEG)) / 90 1000 - i; 91 tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max); 92 tseg1 = tseg - tseg2; 93 if (tseg1 > btc->tseg1_max) { 94 tseg1 = btc->tseg1_max; 95 tseg2 = tseg - tseg1; 96 } 97 98 sample_point = 1000 * (tseg + CAN_SYNC_SEG - tseg2) / 99 (tseg + CAN_SYNC_SEG); 100 sample_point_error = abs(sample_point_nominal - sample_point); 101 102 if (sample_point <= sample_point_nominal && 103 sample_point_error < best_sample_point_error) { 104 best_sample_point = sample_point; 105 best_sample_point_error = sample_point_error; 106 *tseg1_ptr = tseg1; 107 *tseg2_ptr = tseg2; 108 } 109 } 110 111 if (sample_point_error_ptr) 112 *sample_point_error_ptr = best_sample_point_error; 113 114 return best_sample_point; 115} 116 117static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, 118 const struct can_bittiming_const *btc) 119{ 120 struct can_priv *priv = netdev_priv(dev); 121 unsigned int bitrate; /* current bitrate */ 122 unsigned int bitrate_error; /* difference between current and nominal value */ 123 unsigned int best_bitrate_error = UINT_MAX; 124 unsigned int sample_point_error; /* difference between current and nominal value */ 125 unsigned int best_sample_point_error = UINT_MAX; 126 unsigned int sample_point_nominal; /* nominal sample point */ 127 unsigned int best_tseg = 0; /* current best value for tseg */ 128 unsigned int best_brp = 0; /* current best value for brp */ 129 unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0; 130 u64 v64; 131 132 /* Use CiA recommended sample points */ 133 if (bt->sample_point) { 134 sample_point_nominal = bt->sample_point; 135 } else { 136 if (bt->bitrate > 800000) 137 sample_point_nominal = 750; 138 else if (bt->bitrate > 500000) 139 sample_point_nominal = 800; 140 else 141 sample_point_nominal = 875; 142 } 143 144 /* tseg even = round down, odd = round up */ 145 for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1; 146 tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) { 147 tsegall = CAN_SYNC_SEG + tseg / 2; 148 149 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */ 150 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2; 151 152 /* choose brp step which is possible in system */ 153 brp = (brp / btc->brp_inc) * btc->brp_inc; 154 if (brp < btc->brp_min || brp > btc->brp_max) 155 continue; 156 157 bitrate = priv->clock.freq / (brp * tsegall); 158 bitrate_error = abs(bt->bitrate - bitrate); 159 160 /* tseg brp biterror */ 161 if (bitrate_error > best_bitrate_error) 162 continue; 163 164 /* reset sample point error if we have a better bitrate */ 165 if (bitrate_error < best_bitrate_error) 166 best_sample_point_error = UINT_MAX; 167 168 can_update_sample_point(btc, sample_point_nominal, tseg / 2, 169 &tseg1, &tseg2, &sample_point_error); 170 if (sample_point_error > best_sample_point_error) 171 continue; 172 173 best_sample_point_error = sample_point_error; 174 best_bitrate_error = bitrate_error; 175 best_tseg = tseg / 2; 176 best_brp = brp; 177 178 if (bitrate_error == 0 && sample_point_error == 0) 179 break; 180 } 181 182 if (best_bitrate_error) { 183 /* Error in one-tenth of a percent */ 184 v64 = (u64)best_bitrate_error * 1000; 185 do_div(v64, bt->bitrate); 186 bitrate_error = (u32)v64; 187 if (bitrate_error > CAN_CALC_MAX_ERROR) { 188 netdev_err(dev, 189 "bitrate error %d.%d%% too high\n", 190 bitrate_error / 10, bitrate_error % 10); 191 return -EDOM; 192 } 193 netdev_warn(dev, "bitrate error %d.%d%%\n", 194 bitrate_error / 10, bitrate_error % 10); 195 } 196 197 /* real sample point */ 198 bt->sample_point = can_update_sample_point(btc, sample_point_nominal, 199 best_tseg, &tseg1, &tseg2, 200 NULL); 201 202 v64 = (u64)best_brp * 1000 * 1000 * 1000; 203 do_div(v64, priv->clock.freq); 204 bt->tq = (u32)v64; 205 bt->prop_seg = tseg1 / 2; 206 bt->phase_seg1 = tseg1 - bt->prop_seg; 207 bt->phase_seg2 = tseg2; 208 209 /* check for sjw user settings */ 210 if (!bt->sjw || !btc->sjw_max) { 211 bt->sjw = 1; 212 } else { 213 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */ 214 if (bt->sjw > btc->sjw_max) 215 bt->sjw = btc->sjw_max; 216 /* bt->sjw must not be higher than tseg2 */ 217 if (tseg2 < bt->sjw) 218 bt->sjw = tseg2; 219 } 220 221 bt->brp = best_brp; 222 223 /* real bitrate */ 224 bt->bitrate = priv->clock.freq / 225 (bt->brp * (CAN_SYNC_SEG + tseg1 + tseg2)); 226 227 return 0; 228} 229#else /* !CONFIG_CAN_CALC_BITTIMING */ 230static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, 231 const struct can_bittiming_const *btc) 232{ 233 netdev_err(dev, "bit-timing calculation not available\n"); 234 return -EINVAL; 235} 236#endif /* CONFIG_CAN_CALC_BITTIMING */ 237 238/* Checks the validity of the specified bit-timing parameters prop_seg, 239 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate 240 * prescaler value brp. You can find more information in the header 241 * file linux/can/netlink.h. 242 */ 243static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt, 244 const struct can_bittiming_const *btc) 245{ 246 struct can_priv *priv = netdev_priv(dev); 247 int tseg1, alltseg; 248 u64 brp64; 249 250 tseg1 = bt->prop_seg + bt->phase_seg1; 251 if (!bt->sjw) 252 bt->sjw = 1; 253 if (bt->sjw > btc->sjw_max || 254 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max || 255 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max) 256 return -ERANGE; 257 258 brp64 = (u64)priv->clock.freq * (u64)bt->tq; 259 if (btc->brp_inc > 1) 260 do_div(brp64, btc->brp_inc); 261 brp64 += 500000000UL - 1; 262 do_div(brp64, 1000000000UL); /* the practicable BRP */ 263 if (btc->brp_inc > 1) 264 brp64 *= btc->brp_inc; 265 bt->brp = (u32)brp64; 266 267 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max) 268 return -EINVAL; 269 270 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1; 271 bt->bitrate = priv->clock.freq / (bt->brp * alltseg); 272 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg; 273 274 return 0; 275} 276 277/* Checks the validity of predefined bitrate settings */ 278static int 279can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt, 280 const u32 *bitrate_const, 281 const unsigned int bitrate_const_cnt) 282{ 283 struct can_priv *priv = netdev_priv(dev); 284 unsigned int i; 285 286 for (i = 0; i < bitrate_const_cnt; i++) { 287 if (bt->bitrate == bitrate_const[i]) 288 break; 289 } 290 291 if (i >= priv->bitrate_const_cnt) 292 return -EINVAL; 293 294 return 0; 295} 296 297static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt, 298 const struct can_bittiming_const *btc, 299 const u32 *bitrate_const, 300 const unsigned int bitrate_const_cnt) 301{ 302 int err; 303 304 /* Depending on the given can_bittiming parameter structure the CAN 305 * timing parameters are calculated based on the provided bitrate OR 306 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are 307 * provided directly which are then checked and fixed up. 308 */ 309 if (!bt->tq && bt->bitrate && btc) 310 err = can_calc_bittiming(dev, bt, btc); 311 else if (bt->tq && !bt->bitrate && btc) 312 err = can_fixup_bittiming(dev, bt, btc); 313 else if (!bt->tq && bt->bitrate && bitrate_const) 314 err = can_validate_bitrate(dev, bt, bitrate_const, 315 bitrate_const_cnt); 316 else 317 err = -EINVAL; 318 319 return err; 320} 321 322static void can_update_state_error_stats(struct net_device *dev, 323 enum can_state new_state) 324{ 325 struct can_priv *priv = netdev_priv(dev); 326 327 if (new_state <= priv->state) 328 return; 329 330 switch (new_state) { 331 case CAN_STATE_ERROR_WARNING: 332 priv->can_stats.error_warning++; 333 break; 334 case CAN_STATE_ERROR_PASSIVE: 335 priv->can_stats.error_passive++; 336 break; 337 case CAN_STATE_BUS_OFF: 338 priv->can_stats.bus_off++; 339 break; 340 default: 341 break; 342 } 343} 344 345static int can_tx_state_to_frame(struct net_device *dev, enum can_state state) 346{ 347 switch (state) { 348 case CAN_STATE_ERROR_ACTIVE: 349 return CAN_ERR_CRTL_ACTIVE; 350 case CAN_STATE_ERROR_WARNING: 351 return CAN_ERR_CRTL_TX_WARNING; 352 case CAN_STATE_ERROR_PASSIVE: 353 return CAN_ERR_CRTL_TX_PASSIVE; 354 default: 355 return 0; 356 } 357} 358 359static int can_rx_state_to_frame(struct net_device *dev, enum can_state state) 360{ 361 switch (state) { 362 case CAN_STATE_ERROR_ACTIVE: 363 return CAN_ERR_CRTL_ACTIVE; 364 case CAN_STATE_ERROR_WARNING: 365 return CAN_ERR_CRTL_RX_WARNING; 366 case CAN_STATE_ERROR_PASSIVE: 367 return CAN_ERR_CRTL_RX_PASSIVE; 368 default: 369 return 0; 370 } 371} 372 373static const char *can_get_state_str(const enum can_state state) 374{ 375 switch (state) { 376 case CAN_STATE_ERROR_ACTIVE: 377 return "Error Active"; 378 case CAN_STATE_ERROR_WARNING: 379 return "Error Warning"; 380 case CAN_STATE_ERROR_PASSIVE: 381 return "Error Passive"; 382 case CAN_STATE_BUS_OFF: 383 return "Bus Off"; 384 case CAN_STATE_STOPPED: 385 return "Stopped"; 386 case CAN_STATE_SLEEPING: 387 return "Sleeping"; 388 default: 389 return "<unknown>"; 390 } 391 392 return "<unknown>"; 393} 394 395void can_change_state(struct net_device *dev, struct can_frame *cf, 396 enum can_state tx_state, enum can_state rx_state) 397{ 398 struct can_priv *priv = netdev_priv(dev); 399 enum can_state new_state = max(tx_state, rx_state); 400 401 if (unlikely(new_state == priv->state)) { 402 netdev_warn(dev, "%s: oops, state did not change", __func__); 403 return; 404 } 405 406 netdev_dbg(dev, "Controller changed from %s State (%d) into %s State (%d).\n", 407 can_get_state_str(priv->state), priv->state, 408 can_get_state_str(new_state), new_state); 409 410 can_update_state_error_stats(dev, new_state); 411 priv->state = new_state; 412 413 if (!cf) 414 return; 415 416 if (unlikely(new_state == CAN_STATE_BUS_OFF)) { 417 cf->can_id |= CAN_ERR_BUSOFF; 418 return; 419 } 420 421 cf->can_id |= CAN_ERR_CRTL; 422 cf->data[1] |= tx_state >= rx_state ? 423 can_tx_state_to_frame(dev, tx_state) : 0; 424 cf->data[1] |= tx_state <= rx_state ? 425 can_rx_state_to_frame(dev, rx_state) : 0; 426} 427EXPORT_SYMBOL_GPL(can_change_state); 428 429/* Local echo of CAN messages 430 * 431 * CAN network devices *should* support a local echo functionality 432 * (see Documentation/networking/can.rst). To test the handling of CAN 433 * interfaces that do not support the local echo both driver types are 434 * implemented. In the case that the driver does not support the echo 435 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core 436 * to perform the echo as a fallback solution. 437 */ 438static void can_flush_echo_skb(struct net_device *dev) 439{ 440 struct can_priv *priv = netdev_priv(dev); 441 struct net_device_stats *stats = &dev->stats; 442 int i; 443 444 for (i = 0; i < priv->echo_skb_max; i++) { 445 if (priv->echo_skb[i]) { 446 kfree_skb(priv->echo_skb[i]); 447 priv->echo_skb[i] = NULL; 448 stats->tx_dropped++; 449 stats->tx_aborted_errors++; 450 } 451 } 452} 453 454/* Put the skb on the stack to be looped backed locally lateron 455 * 456 * The function is typically called in the start_xmit function 457 * of the device driver. The driver must protect access to 458 * priv->echo_skb, if necessary. 459 */ 460int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 461 unsigned int idx) 462{ 463 struct can_priv *priv = netdev_priv(dev); 464 465 BUG_ON(idx >= priv->echo_skb_max); 466 467 /* check flag whether this packet has to be looped back */ 468 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK || 469 (skb->protocol != htons(ETH_P_CAN) && 470 skb->protocol != htons(ETH_P_CANFD))) { 471 kfree_skb(skb); 472 return 0; 473 } 474 475 if (!priv->echo_skb[idx]) { 476 skb = can_create_echo_skb(skb); 477 if (!skb) 478 return -ENOMEM; 479 480 /* make settings for echo to reduce code in irq context */ 481 skb->pkt_type = PACKET_BROADCAST; 482 skb->ip_summed = CHECKSUM_UNNECESSARY; 483 skb->dev = dev; 484 485 /* save this skb for tx interrupt echo handling */ 486 priv->echo_skb[idx] = skb; 487 } else { 488 /* locking problem with netif_stop_queue() ?? */ 489 netdev_err(dev, "%s: BUG! echo_skb %d is occupied!\n", __func__, idx); 490 kfree_skb(skb); 491 return -EBUSY; 492 } 493 494 return 0; 495} 496EXPORT_SYMBOL_GPL(can_put_echo_skb); 497 498struct sk_buff * 499__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr) 500{ 501 struct can_priv *priv = netdev_priv(dev); 502 503 if (idx >= priv->echo_skb_max) { 504 netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n", 505 __func__, idx, priv->echo_skb_max); 506 return NULL; 507 } 508 509 if (priv->echo_skb[idx]) { 510 /* Using "struct canfd_frame::len" for the frame 511 * length is supported on both CAN and CANFD frames. 512 */ 513 struct sk_buff *skb = priv->echo_skb[idx]; 514 struct canfd_frame *cf = (struct canfd_frame *)skb->data; 515 516 /* get the real payload length for netdev statistics */ 517 if (cf->can_id & CAN_RTR_FLAG) 518 *len_ptr = 0; 519 else 520 *len_ptr = cf->len; 521 522 priv->echo_skb[idx] = NULL; 523 524 return skb; 525 } 526 527 return NULL; 528} 529 530/* Get the skb from the stack and loop it back locally 531 * 532 * The function is typically called when the TX done interrupt 533 * is handled in the device driver. The driver must protect 534 * access to priv->echo_skb, if necessary. 535 */ 536unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx) 537{ 538 struct sk_buff *skb; 539 u8 len; 540 541 skb = __can_get_echo_skb(dev, idx, &len); 542 if (!skb) 543 return 0; 544 545 skb_get(skb); 546 if (netif_rx(skb) == NET_RX_SUCCESS) 547 dev_consume_skb_any(skb); 548 else 549 dev_kfree_skb_any(skb); 550 551 return len; 552} 553EXPORT_SYMBOL_GPL(can_get_echo_skb); 554 555/* Remove the skb from the stack and free it. 556 * 557 * The function is typically called when TX failed. 558 */ 559void can_free_echo_skb(struct net_device *dev, unsigned int idx) 560{ 561 struct can_priv *priv = netdev_priv(dev); 562 563 BUG_ON(idx >= priv->echo_skb_max); 564 565 if (priv->echo_skb[idx]) { 566 dev_kfree_skb_any(priv->echo_skb[idx]); 567 priv->echo_skb[idx] = NULL; 568 } 569} 570EXPORT_SYMBOL_GPL(can_free_echo_skb); 571 572/* CAN device restart for bus-off recovery */ 573static void can_restart(struct net_device *dev) 574{ 575 struct can_priv *priv = netdev_priv(dev); 576 struct net_device_stats *stats = &dev->stats; 577 struct sk_buff *skb; 578 struct can_frame *cf; 579 int err; 580 581 if (netif_carrier_ok(dev)) 582 netdev_err(dev, "Attempt to restart for bus-off recovery, but carrier is OK?\n"); 583 584 /* No synchronization needed because the device is bus-off and 585 * no messages can come in or go out. 586 */ 587 can_flush_echo_skb(dev); 588 589 /* send restart message upstream */ 590 skb = alloc_can_err_skb(dev, &cf); 591 if (!skb) 592 goto restart; 593 594 cf->can_id |= CAN_ERR_RESTARTED; 595 596 stats->rx_packets++; 597 stats->rx_bytes += cf->can_dlc; 598 599 netif_rx_ni(skb); 600 601restart: 602 netdev_dbg(dev, "restarted\n"); 603 priv->can_stats.restarts++; 604 605 /* Now restart the device */ 606 netif_carrier_on(dev); 607 err = priv->do_set_mode(dev, CAN_MODE_START); 608 if (err) { 609 netdev_err(dev, "Error %d during restart", err); 610 netif_carrier_off(dev); 611 } 612} 613 614static void can_restart_work(struct work_struct *work) 615{ 616 struct delayed_work *dwork = to_delayed_work(work); 617 struct can_priv *priv = container_of(dwork, struct can_priv, 618 restart_work); 619 620 can_restart(priv->dev); 621} 622 623int can_restart_now(struct net_device *dev) 624{ 625 struct can_priv *priv = netdev_priv(dev); 626 627 /* A manual restart is only permitted if automatic restart is 628 * disabled and the device is in the bus-off state 629 */ 630 if (priv->restart_ms) 631 return -EINVAL; 632 if (priv->state != CAN_STATE_BUS_OFF) 633 return -EBUSY; 634 635 cancel_delayed_work_sync(&priv->restart_work); 636 can_restart(dev); 637 638 return 0; 639} 640 641/* CAN bus-off 642 * 643 * This functions should be called when the device goes bus-off to 644 * tell the netif layer that no more packets can be sent or received. 645 * If enabled, a timer is started to trigger bus-off recovery. 646 */ 647void can_bus_off(struct net_device *dev) 648{ 649 struct can_priv *priv = netdev_priv(dev); 650 651 if (priv->restart_ms) 652 netdev_info(dev, "bus-off, scheduling restart in %d ms\n", 653 priv->restart_ms); 654 else 655 netdev_info(dev, "bus-off\n"); 656 657 netif_carrier_off(dev); 658 659 if (priv->restart_ms) 660 schedule_delayed_work(&priv->restart_work, 661 msecs_to_jiffies(priv->restart_ms)); 662} 663EXPORT_SYMBOL_GPL(can_bus_off); 664 665static void can_setup(struct net_device *dev) 666{ 667 dev->type = ARPHRD_CAN; 668 dev->mtu = CAN_MTU; 669 dev->hard_header_len = 0; 670 dev->addr_len = 0; 671 dev->tx_queue_len = 10; 672 673 /* New-style flags. */ 674 dev->flags = IFF_NOARP; 675 dev->features = NETIF_F_HW_CSUM; 676} 677 678struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) 679{ 680 struct sk_buff *skb; 681 682 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + 683 sizeof(struct can_frame)); 684 if (unlikely(!skb)) 685 return NULL; 686 687 skb->protocol = htons(ETH_P_CAN); 688 skb->pkt_type = PACKET_BROADCAST; 689 skb->ip_summed = CHECKSUM_UNNECESSARY; 690 691 skb_reset_mac_header(skb); 692 skb_reset_network_header(skb); 693 skb_reset_transport_header(skb); 694 695 can_skb_reserve(skb); 696 can_skb_prv(skb)->ifindex = dev->ifindex; 697 can_skb_prv(skb)->skbcnt = 0; 698 699 *cf = skb_put_zero(skb, sizeof(struct can_frame)); 700 701 return skb; 702} 703EXPORT_SYMBOL_GPL(alloc_can_skb); 704 705struct sk_buff *alloc_canfd_skb(struct net_device *dev, 706 struct canfd_frame **cfd) 707{ 708 struct sk_buff *skb; 709 710 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + 711 sizeof(struct canfd_frame)); 712 if (unlikely(!skb)) 713 return NULL; 714 715 skb->protocol = htons(ETH_P_CANFD); 716 skb->pkt_type = PACKET_BROADCAST; 717 skb->ip_summed = CHECKSUM_UNNECESSARY; 718 719 skb_reset_mac_header(skb); 720 skb_reset_network_header(skb); 721 skb_reset_transport_header(skb); 722 723 can_skb_reserve(skb); 724 can_skb_prv(skb)->ifindex = dev->ifindex; 725 can_skb_prv(skb)->skbcnt = 0; 726 727 *cfd = skb_put_zero(skb, sizeof(struct canfd_frame)); 728 729 return skb; 730} 731EXPORT_SYMBOL_GPL(alloc_canfd_skb); 732 733struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) 734{ 735 struct sk_buff *skb; 736 737 skb = alloc_can_skb(dev, cf); 738 if (unlikely(!skb)) 739 return NULL; 740 741 (*cf)->can_id = CAN_ERR_FLAG; 742 (*cf)->can_dlc = CAN_ERR_DLC; 743 744 return skb; 745} 746EXPORT_SYMBOL_GPL(alloc_can_err_skb); 747 748/* Allocate and setup space for the CAN network device */ 749struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max, 750 unsigned int txqs, unsigned int rxqs) 751{ 752 struct can_ml_priv *can_ml; 753 struct net_device *dev; 754 struct can_priv *priv; 755 int size; 756 757 /* We put the driver's priv, the CAN mid layer priv and the 758 * echo skb into the netdevice's priv. The memory layout for 759 * the netdev_priv is like this: 760 * 761 * +-------------------------+ 762 * | driver's priv | 763 * +-------------------------+ 764 * | struct can_ml_priv | 765 * +-------------------------+ 766 * | array of struct sk_buff | 767 * +-------------------------+ 768 */ 769 770 size = ALIGN(sizeof_priv, NETDEV_ALIGN) + sizeof(struct can_ml_priv); 771 772 if (echo_skb_max) 773 size = ALIGN(size, sizeof(struct sk_buff *)) + 774 echo_skb_max * sizeof(struct sk_buff *); 775 776 dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup, 777 txqs, rxqs); 778 if (!dev) 779 return NULL; 780 781 priv = netdev_priv(dev); 782 priv->dev = dev; 783 784 can_ml = (void *)priv + ALIGN(sizeof_priv, NETDEV_ALIGN); 785 can_set_ml_priv(dev, can_ml); 786 787 if (echo_skb_max) { 788 priv->echo_skb_max = echo_skb_max; 789 priv->echo_skb = (void *)priv + 790 (size - echo_skb_max * sizeof(struct sk_buff *)); 791 } 792 793 priv->state = CAN_STATE_STOPPED; 794 795 INIT_DELAYED_WORK(&priv->restart_work, can_restart_work); 796 797 return dev; 798} 799EXPORT_SYMBOL_GPL(alloc_candev_mqs); 800 801/* Free space of the CAN network device */ 802void free_candev(struct net_device *dev) 803{ 804 free_netdev(dev); 805} 806EXPORT_SYMBOL_GPL(free_candev); 807 808/* changing MTU and control mode for CAN/CANFD devices */ 809int can_change_mtu(struct net_device *dev, int new_mtu) 810{ 811 struct can_priv *priv = netdev_priv(dev); 812 813 /* Do not allow changing the MTU while running */ 814 if (dev->flags & IFF_UP) 815 return -EBUSY; 816 817 /* allow change of MTU according to the CANFD ability of the device */ 818 switch (new_mtu) { 819 case CAN_MTU: 820 /* 'CANFD-only' controllers can not switch to CAN_MTU */ 821 if (priv->ctrlmode_static & CAN_CTRLMODE_FD) 822 return -EINVAL; 823 824 priv->ctrlmode &= ~CAN_CTRLMODE_FD; 825 break; 826 827 case CANFD_MTU: 828 /* check for potential CANFD ability */ 829 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) && 830 !(priv->ctrlmode_static & CAN_CTRLMODE_FD)) 831 return -EINVAL; 832 833 priv->ctrlmode |= CAN_CTRLMODE_FD; 834 break; 835 836 default: 837 return -EINVAL; 838 } 839 840 dev->mtu = new_mtu; 841 return 0; 842} 843EXPORT_SYMBOL_GPL(can_change_mtu); 844 845/* Common open function when the device gets opened. 846 * 847 * This function should be called in the open function of the device 848 * driver. 849 */ 850int open_candev(struct net_device *dev) 851{ 852 struct can_priv *priv = netdev_priv(dev); 853 854 if (!priv->bittiming.bitrate) { 855 netdev_err(dev, "bit-timing not yet defined\n"); 856 return -EINVAL; 857 } 858 859 /* For CAN FD the data bitrate has to be >= the arbitration bitrate */ 860 if ((priv->ctrlmode & CAN_CTRLMODE_FD) && 861 (!priv->data_bittiming.bitrate || 862 priv->data_bittiming.bitrate < priv->bittiming.bitrate)) { 863 netdev_err(dev, "incorrect/missing data bit-timing\n"); 864 return -EINVAL; 865 } 866 867 /* Switch carrier on if device was stopped while in bus-off state */ 868 if (!netif_carrier_ok(dev)) 869 netif_carrier_on(dev); 870 871 return 0; 872} 873EXPORT_SYMBOL_GPL(open_candev); 874 875#ifdef CONFIG_OF 876/* Common function that can be used to understand the limitation of 877 * a transceiver when it provides no means to determine these limitations 878 * at runtime. 879 */ 880void of_can_transceiver(struct net_device *dev) 881{ 882 struct device_node *dn; 883 struct can_priv *priv = netdev_priv(dev); 884 struct device_node *np = dev->dev.parent->of_node; 885 int ret; 886 887 dn = of_get_child_by_name(np, "can-transceiver"); 888 if (!dn) 889 return; 890 891 ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max); 892 of_node_put(dn); 893 if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max)) 894 netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n"); 895} 896EXPORT_SYMBOL_GPL(of_can_transceiver); 897#endif 898 899/* Common close function for cleanup before the device gets closed. 900 * 901 * This function should be called in the close function of the device 902 * driver. 903 */ 904void close_candev(struct net_device *dev) 905{ 906 struct can_priv *priv = netdev_priv(dev); 907 908 cancel_delayed_work_sync(&priv->restart_work); 909 can_flush_echo_skb(dev); 910} 911EXPORT_SYMBOL_GPL(close_candev); 912 913/* CAN netlink interface */ 914static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { 915 [IFLA_CAN_STATE] = { .type = NLA_U32 }, 916 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, 917 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, 918 [IFLA_CAN_RESTART] = { .type = NLA_U32 }, 919 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, 920 [IFLA_CAN_BITTIMING_CONST] 921 = { .len = sizeof(struct can_bittiming_const) }, 922 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, 923 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, 924 [IFLA_CAN_DATA_BITTIMING] 925 = { .len = sizeof(struct can_bittiming) }, 926 [IFLA_CAN_DATA_BITTIMING_CONST] 927 = { .len = sizeof(struct can_bittiming_const) }, 928 [IFLA_CAN_TERMINATION] = { .type = NLA_U16 }, 929}; 930 931static int can_validate(struct nlattr *tb[], struct nlattr *data[], 932 struct netlink_ext_ack *extack) 933{ 934 bool is_can_fd = false; 935 936 /* Make sure that valid CAN FD configurations always consist of 937 * - nominal/arbitration bittiming 938 * - data bittiming 939 * - control mode with CAN_CTRLMODE_FD set 940 */ 941 942 if (!data) 943 return 0; 944 945 if (data[IFLA_CAN_CTRLMODE]) { 946 struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]); 947 948 is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD; 949 } 950 951 if (is_can_fd) { 952 if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING]) 953 return -EOPNOTSUPP; 954 } 955 956 if (data[IFLA_CAN_DATA_BITTIMING]) { 957 if (!is_can_fd || !data[IFLA_CAN_BITTIMING]) 958 return -EOPNOTSUPP; 959 } 960 961 return 0; 962} 963 964static int can_changelink(struct net_device *dev, struct nlattr *tb[], 965 struct nlattr *data[], 966 struct netlink_ext_ack *extack) 967{ 968 struct can_priv *priv = netdev_priv(dev); 969 int err; 970 971 /* We need synchronization with dev->stop() */ 972 ASSERT_RTNL(); 973 974 if (data[IFLA_CAN_BITTIMING]) { 975 struct can_bittiming bt; 976 977 /* Do not allow changing bittiming while running */ 978 if (dev->flags & IFF_UP) 979 return -EBUSY; 980 981 /* Calculate bittiming parameters based on 982 * bittiming_const if set, otherwise pass bitrate 983 * directly via do_set_bitrate(). Bail out if neither 984 * is given. 985 */ 986 if (!priv->bittiming_const && !priv->do_set_bittiming) 987 return -EOPNOTSUPP; 988 989 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); 990 err = can_get_bittiming(dev, &bt, 991 priv->bittiming_const, 992 priv->bitrate_const, 993 priv->bitrate_const_cnt); 994 if (err) 995 return err; 996 997 if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) { 998 netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n", 999 priv->bitrate_max); 1000 return -EINVAL; 1001 } 1002 1003 memcpy(&priv->bittiming, &bt, sizeof(bt)); 1004 1005 if (priv->do_set_bittiming) { 1006 /* Finally, set the bit-timing registers */ 1007 err = priv->do_set_bittiming(dev); 1008 if (err) 1009 return err; 1010 } 1011 } 1012 1013 if (data[IFLA_CAN_CTRLMODE]) { 1014 struct can_ctrlmode *cm; 1015 u32 ctrlstatic; 1016 u32 maskedflags; 1017 1018 /* Do not allow changing controller mode while running */ 1019 if (dev->flags & IFF_UP) 1020 return -EBUSY; 1021 cm = nla_data(data[IFLA_CAN_CTRLMODE]); 1022 ctrlstatic = priv->ctrlmode_static; 1023 maskedflags = cm->flags & cm->mask; 1024 1025 /* check whether provided bits are allowed to be passed */ 1026 if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic)) 1027 return -EOPNOTSUPP; 1028 1029 /* do not check for static fd-non-iso if 'fd' is disabled */ 1030 if (!(maskedflags & CAN_CTRLMODE_FD)) 1031 ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO; 1032 1033 /* make sure static options are provided by configuration */ 1034 if ((maskedflags & ctrlstatic) != ctrlstatic) 1035 return -EOPNOTSUPP; 1036 1037 /* clear bits to be modified and copy the flag values */ 1038 priv->ctrlmode &= ~cm->mask; 1039 priv->ctrlmode |= maskedflags; 1040 1041 /* CAN_CTRLMODE_FD can only be set when driver supports FD */ 1042 if (priv->ctrlmode & CAN_CTRLMODE_FD) 1043 dev->mtu = CANFD_MTU; 1044 else 1045 dev->mtu = CAN_MTU; 1046 } 1047 1048 if (data[IFLA_CAN_RESTART_MS]) { 1049 /* Do not allow changing restart delay while running */ 1050 if (dev->flags & IFF_UP) 1051 return -EBUSY; 1052 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); 1053 } 1054 1055 if (data[IFLA_CAN_RESTART]) { 1056 /* Do not allow a restart while not running */ 1057 if (!(dev->flags & IFF_UP)) 1058 return -EINVAL; 1059 err = can_restart_now(dev); 1060 if (err) 1061 return err; 1062 } 1063 1064 if (data[IFLA_CAN_DATA_BITTIMING]) { 1065 struct can_bittiming dbt; 1066 1067 /* Do not allow changing bittiming while running */ 1068 if (dev->flags & IFF_UP) 1069 return -EBUSY; 1070 1071 /* Calculate bittiming parameters based on 1072 * data_bittiming_const if set, otherwise pass bitrate 1073 * directly via do_set_bitrate(). Bail out if neither 1074 * is given. 1075 */ 1076 if (!priv->data_bittiming_const && !priv->do_set_data_bittiming) 1077 return -EOPNOTSUPP; 1078 1079 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]), 1080 sizeof(dbt)); 1081 err = can_get_bittiming(dev, &dbt, 1082 priv->data_bittiming_const, 1083 priv->data_bitrate_const, 1084 priv->data_bitrate_const_cnt); 1085 if (err) 1086 return err; 1087 1088 if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) { 1089 netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n", 1090 priv->bitrate_max); 1091 return -EINVAL; 1092 } 1093 1094 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt)); 1095 1096 if (priv->do_set_data_bittiming) { 1097 /* Finally, set the bit-timing registers */ 1098 err = priv->do_set_data_bittiming(dev); 1099 if (err) 1100 return err; 1101 } 1102 } 1103 1104 if (data[IFLA_CAN_TERMINATION]) { 1105 const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]); 1106 const unsigned int num_term = priv->termination_const_cnt; 1107 unsigned int i; 1108 1109 if (!priv->do_set_termination) 1110 return -EOPNOTSUPP; 1111 1112 /* check whether given value is supported by the interface */ 1113 for (i = 0; i < num_term; i++) { 1114 if (termval == priv->termination_const[i]) 1115 break; 1116 } 1117 if (i >= num_term) 1118 return -EINVAL; 1119 1120 /* Finally, set the termination value */ 1121 err = priv->do_set_termination(dev, termval); 1122 if (err) 1123 return err; 1124 1125 priv->termination = termval; 1126 } 1127 1128 return 0; 1129} 1130 1131static size_t can_get_size(const struct net_device *dev) 1132{ 1133 struct can_priv *priv = netdev_priv(dev); 1134 size_t size = 0; 1135 1136 if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */ 1137 size += nla_total_size(sizeof(struct can_bittiming)); 1138 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ 1139 size += nla_total_size(sizeof(struct can_bittiming_const)); 1140 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */ 1141 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ 1142 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */ 1143 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ 1144 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ 1145 size += nla_total_size(sizeof(struct can_berr_counter)); 1146 if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */ 1147 size += nla_total_size(sizeof(struct can_bittiming)); 1148 if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */ 1149 size += nla_total_size(sizeof(struct can_bittiming_const)); 1150 if (priv->termination_const) { 1151 size += nla_total_size(sizeof(priv->termination)); /* IFLA_CAN_TERMINATION */ 1152 size += nla_total_size(sizeof(*priv->termination_const) * /* IFLA_CAN_TERMINATION_CONST */ 1153 priv->termination_const_cnt); 1154 } 1155 if (priv->bitrate_const) /* IFLA_CAN_BITRATE_CONST */ 1156 size += nla_total_size(sizeof(*priv->bitrate_const) * 1157 priv->bitrate_const_cnt); 1158 if (priv->data_bitrate_const) /* IFLA_CAN_DATA_BITRATE_CONST */ 1159 size += nla_total_size(sizeof(*priv->data_bitrate_const) * 1160 priv->data_bitrate_const_cnt); 1161 size += sizeof(priv->bitrate_max); /* IFLA_CAN_BITRATE_MAX */ 1162 1163 return size; 1164} 1165 1166static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) 1167{ 1168 struct can_priv *priv = netdev_priv(dev); 1169 struct can_ctrlmode cm = {.flags = priv->ctrlmode}; 1170 struct can_berr_counter bec = { }; 1171 enum can_state state = priv->state; 1172 1173 if (priv->do_get_state) 1174 priv->do_get_state(dev, &state); 1175 1176 if ((priv->bittiming.bitrate && 1177 nla_put(skb, IFLA_CAN_BITTIMING, 1178 sizeof(priv->bittiming), &priv->bittiming)) || 1179 1180 (priv->bittiming_const && 1181 nla_put(skb, IFLA_CAN_BITTIMING_CONST, 1182 sizeof(*priv->bittiming_const), priv->bittiming_const)) || 1183 1184 nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) || 1185 nla_put_u32(skb, IFLA_CAN_STATE, state) || 1186 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) || 1187 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) || 1188 1189 (priv->do_get_berr_counter && 1190 !priv->do_get_berr_counter(dev, &bec) && 1191 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) || 1192 1193 (priv->data_bittiming.bitrate && 1194 nla_put(skb, IFLA_CAN_DATA_BITTIMING, 1195 sizeof(priv->data_bittiming), &priv->data_bittiming)) || 1196 1197 (priv->data_bittiming_const && 1198 nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST, 1199 sizeof(*priv->data_bittiming_const), 1200 priv->data_bittiming_const)) || 1201 1202 (priv->termination_const && 1203 (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) || 1204 nla_put(skb, IFLA_CAN_TERMINATION_CONST, 1205 sizeof(*priv->termination_const) * 1206 priv->termination_const_cnt, 1207 priv->termination_const))) || 1208 1209 (priv->bitrate_const && 1210 nla_put(skb, IFLA_CAN_BITRATE_CONST, 1211 sizeof(*priv->bitrate_const) * 1212 priv->bitrate_const_cnt, 1213 priv->bitrate_const)) || 1214 1215 (priv->data_bitrate_const && 1216 nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST, 1217 sizeof(*priv->data_bitrate_const) * 1218 priv->data_bitrate_const_cnt, 1219 priv->data_bitrate_const)) || 1220 1221 (nla_put(skb, IFLA_CAN_BITRATE_MAX, 1222 sizeof(priv->bitrate_max), 1223 &priv->bitrate_max)) 1224 ) 1225 1226 return -EMSGSIZE; 1227 1228 return 0; 1229} 1230 1231static size_t can_get_xstats_size(const struct net_device *dev) 1232{ 1233 return sizeof(struct can_device_stats); 1234} 1235 1236static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) 1237{ 1238 struct can_priv *priv = netdev_priv(dev); 1239 1240 if (nla_put(skb, IFLA_INFO_XSTATS, 1241 sizeof(priv->can_stats), &priv->can_stats)) 1242 goto nla_put_failure; 1243 return 0; 1244 1245nla_put_failure: 1246 return -EMSGSIZE; 1247} 1248 1249static int can_newlink(struct net *src_net, struct net_device *dev, 1250 struct nlattr *tb[], struct nlattr *data[], 1251 struct netlink_ext_ack *extack) 1252{ 1253 return -EOPNOTSUPP; 1254} 1255 1256static void can_dellink(struct net_device *dev, struct list_head *head) 1257{ 1258} 1259 1260static struct rtnl_link_ops can_link_ops __read_mostly = { 1261 .kind = "can", 1262 .netns_refund = true, 1263 .maxtype = IFLA_CAN_MAX, 1264 .policy = can_policy, 1265 .setup = can_setup, 1266 .validate = can_validate, 1267 .newlink = can_newlink, 1268 .changelink = can_changelink, 1269 .dellink = can_dellink, 1270 .get_size = can_get_size, 1271 .fill_info = can_fill_info, 1272 .get_xstats_size = can_get_xstats_size, 1273 .fill_xstats = can_fill_xstats, 1274}; 1275 1276/* Register the CAN network device */ 1277int register_candev(struct net_device *dev) 1278{ 1279 struct can_priv *priv = netdev_priv(dev); 1280 1281 /* Ensure termination_const, termination_const_cnt and 1282 * do_set_termination consistency. All must be either set or 1283 * unset. 1284 */ 1285 if ((!priv->termination_const != !priv->termination_const_cnt) || 1286 (!priv->termination_const != !priv->do_set_termination)) 1287 return -EINVAL; 1288 1289 if (!priv->bitrate_const != !priv->bitrate_const_cnt) 1290 return -EINVAL; 1291 1292 if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt) 1293 return -EINVAL; 1294 1295 dev->rtnl_link_ops = &can_link_ops; 1296 netif_carrier_off(dev); 1297 1298 return register_netdev(dev); 1299} 1300EXPORT_SYMBOL_GPL(register_candev); 1301 1302/* Unregister the CAN network device */ 1303void unregister_candev(struct net_device *dev) 1304{ 1305 unregister_netdev(dev); 1306} 1307EXPORT_SYMBOL_GPL(unregister_candev); 1308 1309/* Test if a network device is a candev based device 1310 * and return the can_priv* if so. 1311 */ 1312struct can_priv *safe_candev_priv(struct net_device *dev) 1313{ 1314 if (dev->type != ARPHRD_CAN || dev->rtnl_link_ops != &can_link_ops) 1315 return NULL; 1316 1317 return netdev_priv(dev); 1318} 1319EXPORT_SYMBOL_GPL(safe_candev_priv); 1320 1321static __init int can_dev_init(void) 1322{ 1323 int err; 1324 1325 can_led_notifier_init(); 1326 1327 err = rtnl_link_register(&can_link_ops); 1328 if (!err) 1329 pr_info(MOD_DESC "\n"); 1330 1331 return err; 1332} 1333module_init(can_dev_init); 1334 1335static __exit void can_dev_exit(void) 1336{ 1337 rtnl_link_unregister(&can_link_ops); 1338 1339 can_led_notifier_exit(); 1340} 1341module_exit(can_dev_exit); 1342 1343MODULE_ALIAS_RTNL_LINK("can"); 1344