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 best_error = 1000000000, error = 0; 107 int best_tseg = 0, best_brp = 0, brp = 0; 108 int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0; 109 int spt_error = 1000, spt = 0, sampl_pt; 110 long rate; 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 if (error == 0) 156 break; 157 } 158 159 if (best_error) { 160 /* Error in one-tenth of a percent */ 161 error = (best_error * 1000) / bt->bitrate; 162 if (error > CAN_CALC_MAX_ERROR) { 163 netdev_err(dev, 164 "bitrate error %ld.%ld%% too high\n", 165 error / 10, error % 10); 166 return -EDOM; 167 } else { 168 netdev_warn(dev, "bitrate error %ld.%ld%%\n", 169 error / 10, error % 10); 170 } 171 } 172 173 /* real sample point */ 174 bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg, 175 &tseg1, &tseg2); 176 177 v64 = (u64)best_brp * 1000000000UL; 178 do_div(v64, priv->clock.freq); 179 bt->tq = (u32)v64; 180 bt->prop_seg = tseg1 / 2; 181 bt->phase_seg1 = tseg1 - bt->prop_seg; 182 bt->phase_seg2 = tseg2; 183 184 /* check for sjw user settings */ 185 if (!bt->sjw || !btc->sjw_max) 186 bt->sjw = 1; 187 else { 188 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */ 189 if (bt->sjw > btc->sjw_max) 190 bt->sjw = btc->sjw_max; 191 /* bt->sjw must not be higher than tseg2 */ 192 if (tseg2 < bt->sjw) 193 bt->sjw = tseg2; 194 } 195 196 bt->brp = best_brp; 197 /* real bit-rate */ 198 bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1)); 199 200 return 0; 201} 202#else /* !CONFIG_CAN_CALC_BITTIMING */ 203static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, 204 const struct can_bittiming_const *btc) 205{ 206 netdev_err(dev, "bit-timing calculation not available\n"); 207 return -EINVAL; 208} 209#endif /* CONFIG_CAN_CALC_BITTIMING */ 210 211/* 212 * Checks the validity of the specified bit-timing parameters prop_seg, 213 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate 214 * prescaler value brp. You can find more information in the header 215 * file linux/can/netlink.h. 216 */ 217static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt, 218 const struct can_bittiming_const *btc) 219{ 220 struct can_priv *priv = netdev_priv(dev); 221 int tseg1, alltseg; 222 u64 brp64; 223 224 tseg1 = bt->prop_seg + bt->phase_seg1; 225 if (!bt->sjw) 226 bt->sjw = 1; 227 if (bt->sjw > btc->sjw_max || 228 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max || 229 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max) 230 return -ERANGE; 231 232 brp64 = (u64)priv->clock.freq * (u64)bt->tq; 233 if (btc->brp_inc > 1) 234 do_div(brp64, btc->brp_inc); 235 brp64 += 500000000UL - 1; 236 do_div(brp64, 1000000000UL); /* the practicable BRP */ 237 if (btc->brp_inc > 1) 238 brp64 *= btc->brp_inc; 239 bt->brp = (u32)brp64; 240 241 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max) 242 return -EINVAL; 243 244 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1; 245 bt->bitrate = priv->clock.freq / (bt->brp * alltseg); 246 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg; 247 248 return 0; 249} 250 251static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt, 252 const struct can_bittiming_const *btc) 253{ 254 int err; 255 256 /* Check if the CAN device has bit-timing parameters */ 257 if (!btc) 258 return -EOPNOTSUPP; 259 260 /* 261 * Depending on the given can_bittiming parameter structure the CAN 262 * timing parameters are calculated based on the provided bitrate OR 263 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are 264 * provided directly which are then checked and fixed up. 265 */ 266 if (!bt->tq && bt->bitrate) 267 err = can_calc_bittiming(dev, bt, btc); 268 else if (bt->tq && !bt->bitrate) 269 err = can_fixup_bittiming(dev, bt, btc); 270 else 271 err = -EINVAL; 272 273 return err; 274} 275 276static void can_update_state_error_stats(struct net_device *dev, 277 enum can_state new_state) 278{ 279 struct can_priv *priv = netdev_priv(dev); 280 281 if (new_state <= priv->state) 282 return; 283 284 switch (new_state) { 285 case CAN_STATE_ERROR_WARNING: 286 priv->can_stats.error_warning++; 287 break; 288 case CAN_STATE_ERROR_PASSIVE: 289 priv->can_stats.error_passive++; 290 break; 291 case CAN_STATE_BUS_OFF: 292 priv->can_stats.bus_off++; 293 break; 294 default: 295 break; 296 } 297} 298 299static int can_tx_state_to_frame(struct net_device *dev, enum can_state state) 300{ 301 switch (state) { 302 case CAN_STATE_ERROR_ACTIVE: 303 return CAN_ERR_CRTL_ACTIVE; 304 case CAN_STATE_ERROR_WARNING: 305 return CAN_ERR_CRTL_TX_WARNING; 306 case CAN_STATE_ERROR_PASSIVE: 307 return CAN_ERR_CRTL_TX_PASSIVE; 308 default: 309 return 0; 310 } 311} 312 313static int can_rx_state_to_frame(struct net_device *dev, enum can_state state) 314{ 315 switch (state) { 316 case CAN_STATE_ERROR_ACTIVE: 317 return CAN_ERR_CRTL_ACTIVE; 318 case CAN_STATE_ERROR_WARNING: 319 return CAN_ERR_CRTL_RX_WARNING; 320 case CAN_STATE_ERROR_PASSIVE: 321 return CAN_ERR_CRTL_RX_PASSIVE; 322 default: 323 return 0; 324 } 325} 326 327void can_change_state(struct net_device *dev, struct can_frame *cf, 328 enum can_state tx_state, enum can_state rx_state) 329{ 330 struct can_priv *priv = netdev_priv(dev); 331 enum can_state new_state = max(tx_state, rx_state); 332 333 if (unlikely(new_state == priv->state)) { 334 netdev_warn(dev, "%s: oops, state did not change", __func__); 335 return; 336 } 337 338 netdev_dbg(dev, "New error state: %d\n", new_state); 339 340 can_update_state_error_stats(dev, new_state); 341 priv->state = new_state; 342 343 if (unlikely(new_state == CAN_STATE_BUS_OFF)) { 344 cf->can_id |= CAN_ERR_BUSOFF; 345 return; 346 } 347 348 cf->can_id |= CAN_ERR_CRTL; 349 cf->data[1] |= tx_state >= rx_state ? 350 can_tx_state_to_frame(dev, tx_state) : 0; 351 cf->data[1] |= tx_state <= rx_state ? 352 can_rx_state_to_frame(dev, rx_state) : 0; 353} 354EXPORT_SYMBOL_GPL(can_change_state); 355 356/* 357 * Local echo of CAN messages 358 * 359 * CAN network devices *should* support a local echo functionality 360 * (see Documentation/networking/can.txt). To test the handling of CAN 361 * interfaces that do not support the local echo both driver types are 362 * implemented. In the case that the driver does not support the echo 363 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core 364 * to perform the echo as a fallback solution. 365 */ 366static void can_flush_echo_skb(struct net_device *dev) 367{ 368 struct can_priv *priv = netdev_priv(dev); 369 struct net_device_stats *stats = &dev->stats; 370 int i; 371 372 for (i = 0; i < priv->echo_skb_max; i++) { 373 if (priv->echo_skb[i]) { 374 kfree_skb(priv->echo_skb[i]); 375 priv->echo_skb[i] = NULL; 376 stats->tx_dropped++; 377 stats->tx_aborted_errors++; 378 } 379 } 380} 381 382/* 383 * Put the skb on the stack to be looped backed locally lateron 384 * 385 * The function is typically called in the start_xmit function 386 * of the device driver. The driver must protect access to 387 * priv->echo_skb, if necessary. 388 */ 389void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 390 unsigned int idx) 391{ 392 struct can_priv *priv = netdev_priv(dev); 393 394 BUG_ON(idx >= priv->echo_skb_max); 395 396 /* check flag whether this packet has to be looped back */ 397 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK || 398 (skb->protocol != htons(ETH_P_CAN) && 399 skb->protocol != htons(ETH_P_CANFD))) { 400 kfree_skb(skb); 401 return; 402 } 403 404 if (!priv->echo_skb[idx]) { 405 406 skb = can_create_echo_skb(skb); 407 if (!skb) 408 return; 409 410 /* make settings for echo to reduce code in irq context */ 411 skb->pkt_type = PACKET_BROADCAST; 412 skb->ip_summed = CHECKSUM_UNNECESSARY; 413 skb->dev = dev; 414 415 /* save this skb for tx interrupt echo handling */ 416 priv->echo_skb[idx] = skb; 417 } else { 418 /* locking problem with netif_stop_queue() ?? */ 419 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__); 420 kfree_skb(skb); 421 } 422} 423EXPORT_SYMBOL_GPL(can_put_echo_skb); 424 425/* 426 * Get the skb from the stack and loop it back locally 427 * 428 * The function is typically called when the TX done interrupt 429 * is handled in the device driver. The driver must protect 430 * access to priv->echo_skb, if necessary. 431 */ 432unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx) 433{ 434 struct can_priv *priv = netdev_priv(dev); 435 436 BUG_ON(idx >= priv->echo_skb_max); 437 438 if (priv->echo_skb[idx]) { 439 struct sk_buff *skb = priv->echo_skb[idx]; 440 struct can_frame *cf = (struct can_frame *)skb->data; 441 u8 dlc = cf->can_dlc; 442 443 netif_rx(priv->echo_skb[idx]); 444 priv->echo_skb[idx] = NULL; 445 446 return dlc; 447 } 448 449 return 0; 450} 451EXPORT_SYMBOL_GPL(can_get_echo_skb); 452 453/* 454 * Remove the skb from the stack and free it. 455 * 456 * The function is typically called when TX failed. 457 */ 458void can_free_echo_skb(struct net_device *dev, unsigned int idx) 459{ 460 struct can_priv *priv = netdev_priv(dev); 461 462 BUG_ON(idx >= priv->echo_skb_max); 463 464 if (priv->echo_skb[idx]) { 465 dev_kfree_skb_any(priv->echo_skb[idx]); 466 priv->echo_skb[idx] = NULL; 467 } 468} 469EXPORT_SYMBOL_GPL(can_free_echo_skb); 470 471/* 472 * CAN device restart for bus-off recovery 473 */ 474static void can_restart(unsigned long data) 475{ 476 struct net_device *dev = (struct net_device *)data; 477 struct can_priv *priv = netdev_priv(dev); 478 struct net_device_stats *stats = &dev->stats; 479 struct sk_buff *skb; 480 struct can_frame *cf; 481 int err; 482 483 BUG_ON(netif_carrier_ok(dev)); 484 485 /* 486 * No synchronization needed because the device is bus-off and 487 * no messages can come in or go out. 488 */ 489 can_flush_echo_skb(dev); 490 491 /* send restart message upstream */ 492 skb = alloc_can_err_skb(dev, &cf); 493 if (skb == NULL) { 494 err = -ENOMEM; 495 goto restart; 496 } 497 cf->can_id |= CAN_ERR_RESTARTED; 498 499 netif_rx(skb); 500 501 stats->rx_packets++; 502 stats->rx_bytes += cf->can_dlc; 503 504restart: 505 netdev_dbg(dev, "restarted\n"); 506 priv->can_stats.restarts++; 507 508 /* Now restart the device */ 509 err = priv->do_set_mode(dev, CAN_MODE_START); 510 511 netif_carrier_on(dev); 512 if (err) 513 netdev_err(dev, "Error %d during restart", err); 514} 515 516int can_restart_now(struct net_device *dev) 517{ 518 struct can_priv *priv = netdev_priv(dev); 519 520 /* 521 * A manual restart is only permitted if automatic restart is 522 * disabled and the device is in the bus-off state 523 */ 524 if (priv->restart_ms) 525 return -EINVAL; 526 if (priv->state != CAN_STATE_BUS_OFF) 527 return -EBUSY; 528 529 /* Runs as soon as possible in the timer context */ 530 mod_timer(&priv->restart_timer, jiffies); 531 532 return 0; 533} 534 535/* 536 * CAN bus-off 537 * 538 * This functions should be called when the device goes bus-off to 539 * tell the netif layer that no more packets can be sent or received. 540 * If enabled, a timer is started to trigger bus-off recovery. 541 */ 542void can_bus_off(struct net_device *dev) 543{ 544 struct can_priv *priv = netdev_priv(dev); 545 546 netdev_dbg(dev, "bus-off\n"); 547 548 netif_carrier_off(dev); 549 550 if (priv->restart_ms) 551 mod_timer(&priv->restart_timer, 552 jiffies + (priv->restart_ms * HZ) / 1000); 553} 554EXPORT_SYMBOL_GPL(can_bus_off); 555 556static void can_setup(struct net_device *dev) 557{ 558 dev->type = ARPHRD_CAN; 559 dev->mtu = CAN_MTU; 560 dev->hard_header_len = 0; 561 dev->addr_len = 0; 562 dev->tx_queue_len = 10; 563 564 /* New-style flags. */ 565 dev->flags = IFF_NOARP; 566 dev->features = NETIF_F_HW_CSUM; 567} 568 569struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) 570{ 571 struct sk_buff *skb; 572 573 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + 574 sizeof(struct can_frame)); 575 if (unlikely(!skb)) 576 return NULL; 577 578 skb->protocol = htons(ETH_P_CAN); 579 skb->pkt_type = PACKET_BROADCAST; 580 skb->ip_summed = CHECKSUM_UNNECESSARY; 581 582 skb_reset_mac_header(skb); 583 skb_reset_network_header(skb); 584 skb_reset_transport_header(skb); 585 586 can_skb_reserve(skb); 587 can_skb_prv(skb)->ifindex = dev->ifindex; 588 can_skb_prv(skb)->skbcnt = 0; 589 590 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); 591 memset(*cf, 0, sizeof(struct can_frame)); 592 593 return skb; 594} 595EXPORT_SYMBOL_GPL(alloc_can_skb); 596 597struct sk_buff *alloc_canfd_skb(struct net_device *dev, 598 struct canfd_frame **cfd) 599{ 600 struct sk_buff *skb; 601 602 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + 603 sizeof(struct canfd_frame)); 604 if (unlikely(!skb)) 605 return NULL; 606 607 skb->protocol = htons(ETH_P_CANFD); 608 skb->pkt_type = PACKET_BROADCAST; 609 skb->ip_summed = CHECKSUM_UNNECESSARY; 610 611 skb_reset_mac_header(skb); 612 skb_reset_network_header(skb); 613 skb_reset_transport_header(skb); 614 615 can_skb_reserve(skb); 616 can_skb_prv(skb)->ifindex = dev->ifindex; 617 can_skb_prv(skb)->skbcnt = 0; 618 619 *cfd = (struct canfd_frame *)skb_put(skb, sizeof(struct canfd_frame)); 620 memset(*cfd, 0, sizeof(struct canfd_frame)); 621 622 return skb; 623} 624EXPORT_SYMBOL_GPL(alloc_canfd_skb); 625 626struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) 627{ 628 struct sk_buff *skb; 629 630 skb = alloc_can_skb(dev, cf); 631 if (unlikely(!skb)) 632 return NULL; 633 634 (*cf)->can_id = CAN_ERR_FLAG; 635 (*cf)->can_dlc = CAN_ERR_DLC; 636 637 return skb; 638} 639EXPORT_SYMBOL_GPL(alloc_can_err_skb); 640 641/* 642 * Allocate and setup space for the CAN network device 643 */ 644struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) 645{ 646 struct net_device *dev; 647 struct can_priv *priv; 648 int size; 649 650 if (echo_skb_max) 651 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) + 652 echo_skb_max * sizeof(struct sk_buff *); 653 else 654 size = sizeof_priv; 655 656 dev = alloc_netdev(size, "can%d", NET_NAME_UNKNOWN, can_setup); 657 if (!dev) 658 return NULL; 659 660 priv = netdev_priv(dev); 661 662 if (echo_skb_max) { 663 priv->echo_skb_max = echo_skb_max; 664 priv->echo_skb = (void *)priv + 665 ALIGN(sizeof_priv, sizeof(struct sk_buff *)); 666 } 667 668 priv->state = CAN_STATE_STOPPED; 669 670 init_timer(&priv->restart_timer); 671 672 return dev; 673} 674EXPORT_SYMBOL_GPL(alloc_candev); 675 676/* 677 * Free space of the CAN network device 678 */ 679void free_candev(struct net_device *dev) 680{ 681 free_netdev(dev); 682} 683EXPORT_SYMBOL_GPL(free_candev); 684 685/* 686 * changing MTU and control mode for CAN/CANFD devices 687 */ 688int can_change_mtu(struct net_device *dev, int new_mtu) 689{ 690 struct can_priv *priv = netdev_priv(dev); 691 692 /* Do not allow changing the MTU while running */ 693 if (dev->flags & IFF_UP) 694 return -EBUSY; 695 696 /* allow change of MTU according to the CANFD ability of the device */ 697 switch (new_mtu) { 698 case CAN_MTU: 699 /* 'CANFD-only' controllers can not switch to CAN_MTU */ 700 if (priv->ctrlmode_static & CAN_CTRLMODE_FD) 701 return -EINVAL; 702 703 priv->ctrlmode &= ~CAN_CTRLMODE_FD; 704 break; 705 706 case CANFD_MTU: 707 /* check for potential CANFD ability */ 708 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) && 709 !(priv->ctrlmode_static & CAN_CTRLMODE_FD)) 710 return -EINVAL; 711 712 priv->ctrlmode |= CAN_CTRLMODE_FD; 713 break; 714 715 default: 716 return -EINVAL; 717 } 718 719 dev->mtu = new_mtu; 720 return 0; 721} 722EXPORT_SYMBOL_GPL(can_change_mtu); 723 724/* 725 * Common open function when the device gets opened. 726 * 727 * This function should be called in the open function of the device 728 * driver. 729 */ 730int open_candev(struct net_device *dev) 731{ 732 struct can_priv *priv = netdev_priv(dev); 733 734 if (!priv->bittiming.bitrate) { 735 netdev_err(dev, "bit-timing not yet defined\n"); 736 return -EINVAL; 737 } 738 739 /* For CAN FD the data bitrate has to be >= the arbitration bitrate */ 740 if ((priv->ctrlmode & CAN_CTRLMODE_FD) && 741 (!priv->data_bittiming.bitrate || 742 (priv->data_bittiming.bitrate < priv->bittiming.bitrate))) { 743 netdev_err(dev, "incorrect/missing data bit-timing\n"); 744 return -EINVAL; 745 } 746 747 /* Switch carrier on if device was stopped while in bus-off state */ 748 if (!netif_carrier_ok(dev)) 749 netif_carrier_on(dev); 750 751 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); 752 753 return 0; 754} 755EXPORT_SYMBOL_GPL(open_candev); 756 757/* 758 * Common close function for cleanup before the device gets closed. 759 * 760 * This function should be called in the close function of the device 761 * driver. 762 */ 763void close_candev(struct net_device *dev) 764{ 765 struct can_priv *priv = netdev_priv(dev); 766 767 del_timer_sync(&priv->restart_timer); 768 can_flush_echo_skb(dev); 769} 770EXPORT_SYMBOL_GPL(close_candev); 771 772/* 773 * CAN netlink interface 774 */ 775static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { 776 [IFLA_CAN_STATE] = { .type = NLA_U32 }, 777 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, 778 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, 779 [IFLA_CAN_RESTART] = { .type = NLA_U32 }, 780 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, 781 [IFLA_CAN_BITTIMING_CONST] 782 = { .len = sizeof(struct can_bittiming_const) }, 783 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, 784 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, 785 [IFLA_CAN_DATA_BITTIMING] 786 = { .len = sizeof(struct can_bittiming) }, 787 [IFLA_CAN_DATA_BITTIMING_CONST] 788 = { .len = sizeof(struct can_bittiming_const) }, 789}; 790 791static int can_validate(struct nlattr *tb[], struct nlattr *data[]) 792{ 793 bool is_can_fd = false; 794 795 /* Make sure that valid CAN FD configurations always consist of 796 * - nominal/arbitration bittiming 797 * - data bittiming 798 * - control mode with CAN_CTRLMODE_FD set 799 */ 800 801 if (data[IFLA_CAN_CTRLMODE]) { 802 struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]); 803 804 is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD; 805 } 806 807 if (is_can_fd) { 808 if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING]) 809 return -EOPNOTSUPP; 810 } 811 812 if (data[IFLA_CAN_DATA_BITTIMING]) { 813 if (!is_can_fd || !data[IFLA_CAN_BITTIMING]) 814 return -EOPNOTSUPP; 815 } 816 817 return 0; 818} 819 820static int can_changelink(struct net_device *dev, 821 struct nlattr *tb[], struct nlattr *data[]) 822{ 823 struct can_priv *priv = netdev_priv(dev); 824 int err; 825 826 /* We need synchronization with dev->stop() */ 827 ASSERT_RTNL(); 828 829 if (data[IFLA_CAN_BITTIMING]) { 830 struct can_bittiming bt; 831 832 /* Do not allow changing bittiming while running */ 833 if (dev->flags & IFF_UP) 834 return -EBUSY; 835 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); 836 err = can_get_bittiming(dev, &bt, priv->bittiming_const); 837 if (err) 838 return err; 839 memcpy(&priv->bittiming, &bt, sizeof(bt)); 840 841 if (priv->do_set_bittiming) { 842 /* Finally, set the bit-timing registers */ 843 err = priv->do_set_bittiming(dev); 844 if (err) 845 return err; 846 } 847 } 848 849 if (data[IFLA_CAN_CTRLMODE]) { 850 struct can_ctrlmode *cm; 851 u32 ctrlstatic; 852 u32 maskedflags; 853 854 /* Do not allow changing controller mode while running */ 855 if (dev->flags & IFF_UP) 856 return -EBUSY; 857 cm = nla_data(data[IFLA_CAN_CTRLMODE]); 858 ctrlstatic = priv->ctrlmode_static; 859 maskedflags = cm->flags & cm->mask; 860 861 /* check whether provided bits are allowed to be passed */ 862 if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic)) 863 return -EOPNOTSUPP; 864 865 /* do not check for static fd-non-iso if 'fd' is disabled */ 866 if (!(maskedflags & CAN_CTRLMODE_FD)) 867 ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO; 868 869 /* make sure static options are provided by configuration */ 870 if ((maskedflags & ctrlstatic) != ctrlstatic) 871 return -EOPNOTSUPP; 872 873 /* clear bits to be modified and copy the flag values */ 874 priv->ctrlmode &= ~cm->mask; 875 priv->ctrlmode |= maskedflags; 876 877 /* CAN_CTRLMODE_FD can only be set when driver supports FD */ 878 if (priv->ctrlmode & CAN_CTRLMODE_FD) 879 dev->mtu = CANFD_MTU; 880 else 881 dev->mtu = CAN_MTU; 882 } 883 884 if (data[IFLA_CAN_RESTART_MS]) { 885 /* Do not allow changing restart delay while running */ 886 if (dev->flags & IFF_UP) 887 return -EBUSY; 888 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); 889 } 890 891 if (data[IFLA_CAN_RESTART]) { 892 /* Do not allow a restart while not running */ 893 if (!(dev->flags & IFF_UP)) 894 return -EINVAL; 895 err = can_restart_now(dev); 896 if (err) 897 return err; 898 } 899 900 if (data[IFLA_CAN_DATA_BITTIMING]) { 901 struct can_bittiming dbt; 902 903 /* Do not allow changing bittiming while running */ 904 if (dev->flags & IFF_UP) 905 return -EBUSY; 906 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]), 907 sizeof(dbt)); 908 err = can_get_bittiming(dev, &dbt, priv->data_bittiming_const); 909 if (err) 910 return err; 911 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt)); 912 913 if (priv->do_set_data_bittiming) { 914 /* Finally, set the bit-timing registers */ 915 err = priv->do_set_data_bittiming(dev); 916 if (err) 917 return err; 918 } 919 } 920 921 return 0; 922} 923 924static size_t can_get_size(const struct net_device *dev) 925{ 926 struct can_priv *priv = netdev_priv(dev); 927 size_t size = 0; 928 929 if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */ 930 size += nla_total_size(sizeof(struct can_bittiming)); 931 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ 932 size += nla_total_size(sizeof(struct can_bittiming_const)); 933 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */ 934 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ 935 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */ 936 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ 937 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ 938 size += nla_total_size(sizeof(struct can_berr_counter)); 939 if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */ 940 size += nla_total_size(sizeof(struct can_bittiming)); 941 if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */ 942 size += nla_total_size(sizeof(struct can_bittiming_const)); 943 944 return size; 945} 946 947static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) 948{ 949 struct can_priv *priv = netdev_priv(dev); 950 struct can_ctrlmode cm = {.flags = priv->ctrlmode}; 951 struct can_berr_counter bec; 952 enum can_state state = priv->state; 953 954 if (priv->do_get_state) 955 priv->do_get_state(dev, &state); 956 957 if ((priv->bittiming.bitrate && 958 nla_put(skb, IFLA_CAN_BITTIMING, 959 sizeof(priv->bittiming), &priv->bittiming)) || 960 961 (priv->bittiming_const && 962 nla_put(skb, IFLA_CAN_BITTIMING_CONST, 963 sizeof(*priv->bittiming_const), priv->bittiming_const)) || 964 965 nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) || 966 nla_put_u32(skb, IFLA_CAN_STATE, state) || 967 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) || 968 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) || 969 970 (priv->do_get_berr_counter && 971 !priv->do_get_berr_counter(dev, &bec) && 972 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) || 973 974 (priv->data_bittiming.bitrate && 975 nla_put(skb, IFLA_CAN_DATA_BITTIMING, 976 sizeof(priv->data_bittiming), &priv->data_bittiming)) || 977 978 (priv->data_bittiming_const && 979 nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST, 980 sizeof(*priv->data_bittiming_const), 981 priv->data_bittiming_const))) 982 return -EMSGSIZE; 983 984 return 0; 985} 986 987static size_t can_get_xstats_size(const struct net_device *dev) 988{ 989 return sizeof(struct can_device_stats); 990} 991 992static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) 993{ 994 struct can_priv *priv = netdev_priv(dev); 995 996 if (nla_put(skb, IFLA_INFO_XSTATS, 997 sizeof(priv->can_stats), &priv->can_stats)) 998 goto nla_put_failure; 999 return 0; 1000 1001nla_put_failure: 1002 return -EMSGSIZE; 1003} 1004 1005static int can_newlink(struct net *src_net, struct net_device *dev, 1006 struct nlattr *tb[], struct nlattr *data[]) 1007{ 1008 return -EOPNOTSUPP; 1009} 1010 1011static struct rtnl_link_ops can_link_ops __read_mostly = { 1012 .kind = "can", 1013 .maxtype = IFLA_CAN_MAX, 1014 .policy = can_policy, 1015 .setup = can_setup, 1016 .validate = can_validate, 1017 .newlink = can_newlink, 1018 .changelink = can_changelink, 1019 .get_size = can_get_size, 1020 .fill_info = can_fill_info, 1021 .get_xstats_size = can_get_xstats_size, 1022 .fill_xstats = can_fill_xstats, 1023}; 1024 1025/* 1026 * Register the CAN network device 1027 */ 1028int register_candev(struct net_device *dev) 1029{ 1030 dev->rtnl_link_ops = &can_link_ops; 1031 return register_netdev(dev); 1032} 1033EXPORT_SYMBOL_GPL(register_candev); 1034 1035/* 1036 * Unregister the CAN network device 1037 */ 1038void unregister_candev(struct net_device *dev) 1039{ 1040 unregister_netdev(dev); 1041} 1042EXPORT_SYMBOL_GPL(unregister_candev); 1043 1044/* 1045 * Test if a network device is a candev based device 1046 * and return the can_priv* if so. 1047 */ 1048struct can_priv *safe_candev_priv(struct net_device *dev) 1049{ 1050 if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops)) 1051 return NULL; 1052 1053 return netdev_priv(dev); 1054} 1055EXPORT_SYMBOL_GPL(safe_candev_priv); 1056 1057static __init int can_dev_init(void) 1058{ 1059 int err; 1060 1061 can_led_notifier_init(); 1062 1063 err = rtnl_link_register(&can_link_ops); 1064 if (!err) 1065 printk(KERN_INFO MOD_DESC "\n"); 1066 1067 return err; 1068} 1069module_init(can_dev_init); 1070 1071static __exit void can_dev_exit(void) 1072{ 1073 rtnl_link_unregister(&can_link_ops); 1074 1075 can_led_notifier_exit(); 1076} 1077module_exit(can_dev_exit); 1078 1079MODULE_ALIAS_RTNL_LINK("can"); 1080