dev.c revision a94bc9c46e8e3e1bb5f707e81fd8c60fd93266e6
1/* 2 * Copyright (C) 2005 Marc Kleine-Budde, Pengutronix 3 * Copyright (C) 2006 Andrey Volkov, Varma Electronics 4 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the version 2 of the GNU General Public License 8 * as published by the Free Software Foundation 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, see <http://www.gnu.org/licenses/>. 17 */ 18 19#include <linux/module.h> 20#include <linux/kernel.h> 21#include <linux/slab.h> 22#include <linux/netdevice.h> 23#include <linux/if_arp.h> 24#include <linux/can.h> 25#include <linux/can/dev.h> 26#include <linux/can/skb.h> 27#include <linux/can/netlink.h> 28#include <linux/can/led.h> 29#include <net/rtnetlink.h> 30 31#define MOD_DESC "CAN device driver interface" 32 33MODULE_DESCRIPTION(MOD_DESC); 34MODULE_LICENSE("GPL v2"); 35MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); 36 37/* CAN DLC to real data length conversion helpers */ 38 39static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7, 40 8, 12, 16, 20, 24, 32, 48, 64}; 41 42/* get data length from can_dlc with sanitized can_dlc */ 43u8 can_dlc2len(u8 can_dlc) 44{ 45 return dlc2len[can_dlc & 0x0F]; 46} 47EXPORT_SYMBOL_GPL(can_dlc2len); 48 49static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */ 50 9, 9, 9, 9, /* 9 - 12 */ 51 10, 10, 10, 10, /* 13 - 16 */ 52 11, 11, 11, 11, /* 17 - 20 */ 53 12, 12, 12, 12, /* 21 - 24 */ 54 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */ 55 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */ 56 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */ 57 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */ 58 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */ 59 60/* map the sanitized data length to an appropriate data length code */ 61u8 can_len2dlc(u8 len) 62{ 63 if (unlikely(len > 64)) 64 return 0xF; 65 66 return len2dlc[len]; 67} 68EXPORT_SYMBOL_GPL(can_len2dlc); 69 70#ifdef CONFIG_CAN_CALC_BITTIMING 71#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */ 72 73/* 74 * Bit-timing calculation derived from: 75 * 76 * Code based on LinCAN sources and H8S2638 project 77 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz 78 * Copyright 2005 Stanislav Marek 79 * email: pisa@cmp.felk.cvut.cz 80 * 81 * Calculates proper bit-timing parameters for a specified bit-rate 82 * and sample-point, which can then be used to set the bit-timing 83 * registers of the CAN controller. You can find more information 84 * in the header file linux/can/netlink.h. 85 */ 86static int can_update_spt(const struct can_bittiming_const *btc, 87 int sampl_pt, int tseg, int *tseg1, int *tseg2) 88{ 89 *tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000; 90 if (*tseg2 < btc->tseg2_min) 91 *tseg2 = btc->tseg2_min; 92 if (*tseg2 > btc->tseg2_max) 93 *tseg2 = btc->tseg2_max; 94 *tseg1 = tseg - *tseg2; 95 if (*tseg1 > btc->tseg1_max) { 96 *tseg1 = btc->tseg1_max; 97 *tseg2 = tseg - *tseg1; 98 } 99 return 1000 * (tseg + 1 - *tseg2) / (tseg + 1); 100} 101 102static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt) 103{ 104 struct can_priv *priv = netdev_priv(dev); 105 const struct can_bittiming_const *btc = priv->bittiming_const; 106 long rate, best_rate = 0; 107 long best_error = 1000000000, error = 0; 108 int best_tseg = 0, best_brp = 0, brp = 0; 109 int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0; 110 int spt_error = 1000, spt = 0, sampl_pt; 111 u64 v64; 112 113 if (!priv->bittiming_const) 114 return -ENOTSUPP; 115 116 /* Use CIA recommended sample points */ 117 if (bt->sample_point) { 118 sampl_pt = bt->sample_point; 119 } else { 120 if (bt->bitrate > 800000) 121 sampl_pt = 750; 122 else if (bt->bitrate > 500000) 123 sampl_pt = 800; 124 else 125 sampl_pt = 875; 126 } 127 128 /* tseg even = round down, odd = round up */ 129 for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1; 130 tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) { 131 tsegall = 1 + tseg / 2; 132 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */ 133 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2; 134 /* chose brp step which is possible in system */ 135 brp = (brp / btc->brp_inc) * btc->brp_inc; 136 if ((brp < btc->brp_min) || (brp > btc->brp_max)) 137 continue; 138 rate = priv->clock.freq / (brp * tsegall); 139 error = bt->bitrate - rate; 140 /* tseg brp biterror */ 141 if (error < 0) 142 error = -error; 143 if (error > best_error) 144 continue; 145 best_error = error; 146 if (error == 0) { 147 spt = can_update_spt(btc, sampl_pt, tseg / 2, 148 &tseg1, &tseg2); 149 error = sampl_pt - spt; 150 if (error < 0) 151 error = -error; 152 if (error > spt_error) 153 continue; 154 spt_error = error; 155 } 156 best_tseg = tseg / 2; 157 best_brp = brp; 158 best_rate = rate; 159 if (error == 0) 160 break; 161 } 162 163 if (best_error) { 164 /* Error in one-tenth of a percent */ 165 error = (best_error * 1000) / bt->bitrate; 166 if (error > CAN_CALC_MAX_ERROR) { 167 netdev_err(dev, 168 "bitrate error %ld.%ld%% too high\n", 169 error / 10, error % 10); 170 return -EDOM; 171 } else { 172 netdev_warn(dev, "bitrate error %ld.%ld%%\n", 173 error / 10, error % 10); 174 } 175 } 176 177 /* real sample point */ 178 bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg, 179 &tseg1, &tseg2); 180 181 v64 = (u64)best_brp * 1000000000UL; 182 do_div(v64, priv->clock.freq); 183 bt->tq = (u32)v64; 184 bt->prop_seg = tseg1 / 2; 185 bt->phase_seg1 = tseg1 - bt->prop_seg; 186 bt->phase_seg2 = tseg2; 187 188 /* check for sjw user settings */ 189 if (!bt->sjw || !btc->sjw_max) 190 bt->sjw = 1; 191 else { 192 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */ 193 if (bt->sjw > btc->sjw_max) 194 bt->sjw = btc->sjw_max; 195 /* bt->sjw must not be higher than tseg2 */ 196 if (tseg2 < bt->sjw) 197 bt->sjw = tseg2; 198 } 199 200 bt->brp = best_brp; 201 /* real bit-rate */ 202 bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1)); 203 204 return 0; 205} 206#else /* !CONFIG_CAN_CALC_BITTIMING */ 207static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt) 208{ 209 netdev_err(dev, "bit-timing calculation not available\n"); 210 return -EINVAL; 211} 212#endif /* CONFIG_CAN_CALC_BITTIMING */ 213 214/* 215 * Checks the validity of the specified bit-timing parameters prop_seg, 216 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate 217 * prescaler value brp. You can find more information in the header 218 * file linux/can/netlink.h. 219 */ 220static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt) 221{ 222 struct can_priv *priv = netdev_priv(dev); 223 const struct can_bittiming_const *btc = priv->bittiming_const; 224 int tseg1, alltseg; 225 u64 brp64; 226 227 if (!priv->bittiming_const) 228 return -ENOTSUPP; 229 230 tseg1 = bt->prop_seg + bt->phase_seg1; 231 if (!bt->sjw) 232 bt->sjw = 1; 233 if (bt->sjw > btc->sjw_max || 234 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max || 235 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max) 236 return -ERANGE; 237 238 brp64 = (u64)priv->clock.freq * (u64)bt->tq; 239 if (btc->brp_inc > 1) 240 do_div(brp64, btc->brp_inc); 241 brp64 += 500000000UL - 1; 242 do_div(brp64, 1000000000UL); /* the practicable BRP */ 243 if (btc->brp_inc > 1) 244 brp64 *= btc->brp_inc; 245 bt->brp = (u32)brp64; 246 247 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max) 248 return -EINVAL; 249 250 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1; 251 bt->bitrate = priv->clock.freq / (bt->brp * alltseg); 252 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg; 253 254 return 0; 255} 256 257static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt) 258{ 259 struct can_priv *priv = netdev_priv(dev); 260 int err; 261 262 /* Check if the CAN device has bit-timing parameters */ 263 if (priv->bittiming_const) { 264 265 /* Non-expert mode? Check if the bitrate has been pre-defined */ 266 if (!bt->tq) 267 /* Determine bit-timing parameters */ 268 err = can_calc_bittiming(dev, bt); 269 else 270 /* Check bit-timing params and calculate proper brp */ 271 err = can_fixup_bittiming(dev, bt); 272 if (err) 273 return err; 274 } 275 276 return 0; 277} 278 279/* 280 * Local echo of CAN messages 281 * 282 * CAN network devices *should* support a local echo functionality 283 * (see Documentation/networking/can.txt). To test the handling of CAN 284 * interfaces that do not support the local echo both driver types are 285 * implemented. In the case that the driver does not support the echo 286 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core 287 * to perform the echo as a fallback solution. 288 */ 289static void can_flush_echo_skb(struct net_device *dev) 290{ 291 struct can_priv *priv = netdev_priv(dev); 292 struct net_device_stats *stats = &dev->stats; 293 int i; 294 295 for (i = 0; i < priv->echo_skb_max; i++) { 296 if (priv->echo_skb[i]) { 297 kfree_skb(priv->echo_skb[i]); 298 priv->echo_skb[i] = NULL; 299 stats->tx_dropped++; 300 stats->tx_aborted_errors++; 301 } 302 } 303} 304 305/* 306 * Put the skb on the stack to be looped backed locally lateron 307 * 308 * The function is typically called in the start_xmit function 309 * of the device driver. The driver must protect access to 310 * priv->echo_skb, if necessary. 311 */ 312void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 313 unsigned int idx) 314{ 315 struct can_priv *priv = netdev_priv(dev); 316 317 BUG_ON(idx >= priv->echo_skb_max); 318 319 /* check flag whether this packet has to be looped back */ 320 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK || 321 (skb->protocol != htons(ETH_P_CAN) && 322 skb->protocol != htons(ETH_P_CANFD))) { 323 kfree_skb(skb); 324 return; 325 } 326 327 if (!priv->echo_skb[idx]) { 328 329 skb = can_create_echo_skb(skb); 330 if (!skb) 331 return; 332 333 /* make settings for echo to reduce code in irq context */ 334 skb->pkt_type = PACKET_BROADCAST; 335 skb->ip_summed = CHECKSUM_UNNECESSARY; 336 skb->dev = dev; 337 338 /* save this skb for tx interrupt echo handling */ 339 priv->echo_skb[idx] = skb; 340 } else { 341 /* locking problem with netif_stop_queue() ?? */ 342 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__); 343 kfree_skb(skb); 344 } 345} 346EXPORT_SYMBOL_GPL(can_put_echo_skb); 347 348/* 349 * Get the skb from the stack and loop it back locally 350 * 351 * The function is typically called when the TX done interrupt 352 * is handled in the device driver. The driver must protect 353 * access to priv->echo_skb, if necessary. 354 */ 355unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx) 356{ 357 struct can_priv *priv = netdev_priv(dev); 358 359 BUG_ON(idx >= priv->echo_skb_max); 360 361 if (priv->echo_skb[idx]) { 362 struct sk_buff *skb = priv->echo_skb[idx]; 363 struct can_frame *cf = (struct can_frame *)skb->data; 364 u8 dlc = cf->can_dlc; 365 366 netif_rx(priv->echo_skb[idx]); 367 priv->echo_skb[idx] = NULL; 368 369 return dlc; 370 } 371 372 return 0; 373} 374EXPORT_SYMBOL_GPL(can_get_echo_skb); 375 376/* 377 * Remove the skb from the stack and free it. 378 * 379 * The function is typically called when TX failed. 380 */ 381void can_free_echo_skb(struct net_device *dev, unsigned int idx) 382{ 383 struct can_priv *priv = netdev_priv(dev); 384 385 BUG_ON(idx >= priv->echo_skb_max); 386 387 if (priv->echo_skb[idx]) { 388 kfree_skb(priv->echo_skb[idx]); 389 priv->echo_skb[idx] = NULL; 390 } 391} 392EXPORT_SYMBOL_GPL(can_free_echo_skb); 393 394/* 395 * CAN device restart for bus-off recovery 396 */ 397static void can_restart(unsigned long data) 398{ 399 struct net_device *dev = (struct net_device *)data; 400 struct can_priv *priv = netdev_priv(dev); 401 struct net_device_stats *stats = &dev->stats; 402 struct sk_buff *skb; 403 struct can_frame *cf; 404 int err; 405 406 BUG_ON(netif_carrier_ok(dev)); 407 408 /* 409 * No synchronization needed because the device is bus-off and 410 * no messages can come in or go out. 411 */ 412 can_flush_echo_skb(dev); 413 414 /* send restart message upstream */ 415 skb = alloc_can_err_skb(dev, &cf); 416 if (skb == NULL) { 417 err = -ENOMEM; 418 goto restart; 419 } 420 cf->can_id |= CAN_ERR_RESTARTED; 421 422 netif_rx(skb); 423 424 stats->rx_packets++; 425 stats->rx_bytes += cf->can_dlc; 426 427restart: 428 netdev_dbg(dev, "restarted\n"); 429 priv->can_stats.restarts++; 430 431 /* Now restart the device */ 432 err = priv->do_set_mode(dev, CAN_MODE_START); 433 434 netif_carrier_on(dev); 435 if (err) 436 netdev_err(dev, "Error %d during restart", err); 437} 438 439int can_restart_now(struct net_device *dev) 440{ 441 struct can_priv *priv = netdev_priv(dev); 442 443 /* 444 * A manual restart is only permitted if automatic restart is 445 * disabled and the device is in the bus-off state 446 */ 447 if (priv->restart_ms) 448 return -EINVAL; 449 if (priv->state != CAN_STATE_BUS_OFF) 450 return -EBUSY; 451 452 /* Runs as soon as possible in the timer context */ 453 mod_timer(&priv->restart_timer, jiffies); 454 455 return 0; 456} 457 458/* 459 * CAN bus-off 460 * 461 * This functions should be called when the device goes bus-off to 462 * tell the netif layer that no more packets can be sent or received. 463 * If enabled, a timer is started to trigger bus-off recovery. 464 */ 465void can_bus_off(struct net_device *dev) 466{ 467 struct can_priv *priv = netdev_priv(dev); 468 469 netdev_dbg(dev, "bus-off\n"); 470 471 netif_carrier_off(dev); 472 priv->can_stats.bus_off++; 473 474 if (priv->restart_ms) 475 mod_timer(&priv->restart_timer, 476 jiffies + (priv->restart_ms * HZ) / 1000); 477} 478EXPORT_SYMBOL_GPL(can_bus_off); 479 480static void can_setup(struct net_device *dev) 481{ 482 dev->type = ARPHRD_CAN; 483 dev->mtu = CAN_MTU; 484 dev->hard_header_len = 0; 485 dev->addr_len = 0; 486 dev->tx_queue_len = 10; 487 488 /* New-style flags. */ 489 dev->flags = IFF_NOARP; 490 dev->features = NETIF_F_HW_CSUM; 491} 492 493struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) 494{ 495 struct sk_buff *skb; 496 497 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + 498 sizeof(struct can_frame)); 499 if (unlikely(!skb)) 500 return NULL; 501 502 skb->protocol = htons(ETH_P_CAN); 503 skb->pkt_type = PACKET_BROADCAST; 504 skb->ip_summed = CHECKSUM_UNNECESSARY; 505 506 can_skb_reserve(skb); 507 can_skb_prv(skb)->ifindex = dev->ifindex; 508 509 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); 510 memset(*cf, 0, sizeof(struct can_frame)); 511 512 return skb; 513} 514EXPORT_SYMBOL_GPL(alloc_can_skb); 515 516struct sk_buff *alloc_canfd_skb(struct net_device *dev, 517 struct canfd_frame **cfd) 518{ 519 struct sk_buff *skb; 520 521 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + 522 sizeof(struct canfd_frame)); 523 if (unlikely(!skb)) 524 return NULL; 525 526 skb->protocol = htons(ETH_P_CANFD); 527 skb->pkt_type = PACKET_BROADCAST; 528 skb->ip_summed = CHECKSUM_UNNECESSARY; 529 530 can_skb_reserve(skb); 531 can_skb_prv(skb)->ifindex = dev->ifindex; 532 533 *cfd = (struct canfd_frame *)skb_put(skb, sizeof(struct canfd_frame)); 534 memset(*cfd, 0, sizeof(struct canfd_frame)); 535 536 return skb; 537} 538EXPORT_SYMBOL_GPL(alloc_canfd_skb); 539 540struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) 541{ 542 struct sk_buff *skb; 543 544 skb = alloc_can_skb(dev, cf); 545 if (unlikely(!skb)) 546 return NULL; 547 548 (*cf)->can_id = CAN_ERR_FLAG; 549 (*cf)->can_dlc = CAN_ERR_DLC; 550 551 return skb; 552} 553EXPORT_SYMBOL_GPL(alloc_can_err_skb); 554 555/* 556 * Allocate and setup space for the CAN network device 557 */ 558struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) 559{ 560 struct net_device *dev; 561 struct can_priv *priv; 562 int size; 563 564 if (echo_skb_max) 565 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) + 566 echo_skb_max * sizeof(struct sk_buff *); 567 else 568 size = sizeof_priv; 569 570 dev = alloc_netdev(size, "can%d", can_setup); 571 if (!dev) 572 return NULL; 573 574 priv = netdev_priv(dev); 575 576 if (echo_skb_max) { 577 priv->echo_skb_max = echo_skb_max; 578 priv->echo_skb = (void *)priv + 579 ALIGN(sizeof_priv, sizeof(struct sk_buff *)); 580 } 581 582 priv->state = CAN_STATE_STOPPED; 583 584 init_timer(&priv->restart_timer); 585 586 return dev; 587} 588EXPORT_SYMBOL_GPL(alloc_candev); 589 590/* 591 * Free space of the CAN network device 592 */ 593void free_candev(struct net_device *dev) 594{ 595 free_netdev(dev); 596} 597EXPORT_SYMBOL_GPL(free_candev); 598 599/* 600 * Common open function when the device gets opened. 601 * 602 * This function should be called in the open function of the device 603 * driver. 604 */ 605int open_candev(struct net_device *dev) 606{ 607 struct can_priv *priv = netdev_priv(dev); 608 609 if (!priv->bittiming.tq && !priv->bittiming.bitrate) { 610 netdev_err(dev, "bit-timing not yet defined\n"); 611 return -EINVAL; 612 } 613 614 /* Switch carrier on if device was stopped while in bus-off state */ 615 if (!netif_carrier_ok(dev)) 616 netif_carrier_on(dev); 617 618 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); 619 620 return 0; 621} 622EXPORT_SYMBOL_GPL(open_candev); 623 624/* 625 * Common close function for cleanup before the device gets closed. 626 * 627 * This function should be called in the close function of the device 628 * driver. 629 */ 630void close_candev(struct net_device *dev) 631{ 632 struct can_priv *priv = netdev_priv(dev); 633 634 del_timer_sync(&priv->restart_timer); 635 can_flush_echo_skb(dev); 636} 637EXPORT_SYMBOL_GPL(close_candev); 638 639/* 640 * CAN netlink interface 641 */ 642static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { 643 [IFLA_CAN_STATE] = { .type = NLA_U32 }, 644 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, 645 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, 646 [IFLA_CAN_RESTART] = { .type = NLA_U32 }, 647 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, 648 [IFLA_CAN_BITTIMING_CONST] 649 = { .len = sizeof(struct can_bittiming_const) }, 650 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, 651 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, 652}; 653 654static int can_changelink(struct net_device *dev, 655 struct nlattr *tb[], struct nlattr *data[]) 656{ 657 struct can_priv *priv = netdev_priv(dev); 658 int err; 659 660 /* We need synchronization with dev->stop() */ 661 ASSERT_RTNL(); 662 663 if (data[IFLA_CAN_BITTIMING]) { 664 struct can_bittiming bt; 665 666 /* Do not allow changing bittiming while running */ 667 if (dev->flags & IFF_UP) 668 return -EBUSY; 669 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); 670 if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq)) 671 return -EINVAL; 672 err = can_get_bittiming(dev, &bt); 673 if (err) 674 return err; 675 memcpy(&priv->bittiming, &bt, sizeof(bt)); 676 677 if (priv->do_set_bittiming) { 678 /* Finally, set the bit-timing registers */ 679 err = priv->do_set_bittiming(dev); 680 if (err) 681 return err; 682 } 683 } 684 685 if (data[IFLA_CAN_CTRLMODE]) { 686 struct can_ctrlmode *cm; 687 688 /* Do not allow changing controller mode while running */ 689 if (dev->flags & IFF_UP) 690 return -EBUSY; 691 cm = nla_data(data[IFLA_CAN_CTRLMODE]); 692 if (cm->flags & ~priv->ctrlmode_supported) 693 return -EOPNOTSUPP; 694 priv->ctrlmode &= ~cm->mask; 695 priv->ctrlmode |= cm->flags; 696 } 697 698 if (data[IFLA_CAN_RESTART_MS]) { 699 /* Do not allow changing restart delay while running */ 700 if (dev->flags & IFF_UP) 701 return -EBUSY; 702 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); 703 } 704 705 if (data[IFLA_CAN_RESTART]) { 706 /* Do not allow a restart while not running */ 707 if (!(dev->flags & IFF_UP)) 708 return -EINVAL; 709 err = can_restart_now(dev); 710 if (err) 711 return err; 712 } 713 714 return 0; 715} 716 717static size_t can_get_size(const struct net_device *dev) 718{ 719 struct can_priv *priv = netdev_priv(dev); 720 size_t size = 0; 721 722 size += nla_total_size(sizeof(struct can_bittiming)); /* IFLA_CAN_BITTIMING */ 723 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ 724 size += nla_total_size(sizeof(struct can_bittiming_const)); 725 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */ 726 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ 727 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */ 728 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ 729 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ 730 size += nla_total_size(sizeof(struct can_berr_counter)); 731 732 return size; 733} 734 735static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) 736{ 737 struct can_priv *priv = netdev_priv(dev); 738 struct can_ctrlmode cm = {.flags = priv->ctrlmode}; 739 struct can_berr_counter bec; 740 enum can_state state = priv->state; 741 742 if (priv->do_get_state) 743 priv->do_get_state(dev, &state); 744 if (nla_put(skb, IFLA_CAN_BITTIMING, 745 sizeof(priv->bittiming), &priv->bittiming) || 746 (priv->bittiming_const && 747 nla_put(skb, IFLA_CAN_BITTIMING_CONST, 748 sizeof(*priv->bittiming_const), priv->bittiming_const)) || 749 nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) || 750 nla_put_u32(skb, IFLA_CAN_STATE, state) || 751 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) || 752 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) || 753 (priv->do_get_berr_counter && 754 !priv->do_get_berr_counter(dev, &bec) && 755 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec))) 756 return -EMSGSIZE; 757 return 0; 758} 759 760static size_t can_get_xstats_size(const struct net_device *dev) 761{ 762 return sizeof(struct can_device_stats); 763} 764 765static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) 766{ 767 struct can_priv *priv = netdev_priv(dev); 768 769 if (nla_put(skb, IFLA_INFO_XSTATS, 770 sizeof(priv->can_stats), &priv->can_stats)) 771 goto nla_put_failure; 772 return 0; 773 774nla_put_failure: 775 return -EMSGSIZE; 776} 777 778static int can_newlink(struct net *src_net, struct net_device *dev, 779 struct nlattr *tb[], struct nlattr *data[]) 780{ 781 return -EOPNOTSUPP; 782} 783 784static struct rtnl_link_ops can_link_ops __read_mostly = { 785 .kind = "can", 786 .maxtype = IFLA_CAN_MAX, 787 .policy = can_policy, 788 .setup = can_setup, 789 .newlink = can_newlink, 790 .changelink = can_changelink, 791 .get_size = can_get_size, 792 .fill_info = can_fill_info, 793 .get_xstats_size = can_get_xstats_size, 794 .fill_xstats = can_fill_xstats, 795}; 796 797/* 798 * Register the CAN network device 799 */ 800int register_candev(struct net_device *dev) 801{ 802 dev->rtnl_link_ops = &can_link_ops; 803 return register_netdev(dev); 804} 805EXPORT_SYMBOL_GPL(register_candev); 806 807/* 808 * Unregister the CAN network device 809 */ 810void unregister_candev(struct net_device *dev) 811{ 812 unregister_netdev(dev); 813} 814EXPORT_SYMBOL_GPL(unregister_candev); 815 816/* 817 * Test if a network device is a candev based device 818 * and return the can_priv* if so. 819 */ 820struct can_priv *safe_candev_priv(struct net_device *dev) 821{ 822 if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops)) 823 return NULL; 824 825 return netdev_priv(dev); 826} 827EXPORT_SYMBOL_GPL(safe_candev_priv); 828 829static __init int can_dev_init(void) 830{ 831 int err; 832 833 can_led_notifier_init(); 834 835 err = rtnl_link_register(&can_link_ops); 836 if (!err) 837 printk(KERN_INFO MOD_DESC "\n"); 838 839 return err; 840} 841module_init(can_dev_init); 842 843static __exit void can_dev_exit(void) 844{ 845 rtnl_link_unregister(&can_link_ops); 846 847 can_led_notifier_exit(); 848} 849module_exit(can_dev_exit); 850 851MODULE_ALIAS_RTNL_LINK("can"); 852