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/can.h> 8 #include <linux/can/can-ml.h> 9 #include <linux/can/dev.h> 10 #include <linux/can/skb.h> 11 #include <linux/gpio/consumer.h> 12 #include <linux/if_arp.h> 13 #include <linux/kernel.h> 14 #include <linux/netdevice.h> 15 #include <linux/of.h> 16 #include <linux/slab.h> 17 #include <linux/workqueue.h> 18 19 static void can_update_state_error_stats(struct net_device *dev, 20 enum can_state new_state) 21 { 22 struct can_priv *priv = netdev_priv(dev); 23 24 if (new_state <= priv->state) 25 return; 26 27 switch (new_state) { 28 case CAN_STATE_ERROR_WARNING: 29 priv->can_stats.error_warning++; 30 break; 31 case CAN_STATE_ERROR_PASSIVE: 32 priv->can_stats.error_passive++; 33 break; 34 case CAN_STATE_BUS_OFF: 35 priv->can_stats.bus_off++; 36 break; 37 default: 38 break; 39 } 40 } 41 42 static int can_tx_state_to_frame(struct net_device *dev, enum can_state state) 43 { 44 switch (state) { 45 case CAN_STATE_ERROR_ACTIVE: 46 return CAN_ERR_CRTL_ACTIVE; 47 case CAN_STATE_ERROR_WARNING: 48 return CAN_ERR_CRTL_TX_WARNING; 49 case CAN_STATE_ERROR_PASSIVE: 50 return CAN_ERR_CRTL_TX_PASSIVE; 51 default: 52 return 0; 53 } 54 } 55 56 static int can_rx_state_to_frame(struct net_device *dev, enum can_state state) 57 { 58 switch (state) { 59 case CAN_STATE_ERROR_ACTIVE: 60 return CAN_ERR_CRTL_ACTIVE; 61 case CAN_STATE_ERROR_WARNING: 62 return CAN_ERR_CRTL_RX_WARNING; 63 case CAN_STATE_ERROR_PASSIVE: 64 return CAN_ERR_CRTL_RX_PASSIVE; 65 default: 66 return 0; 67 } 68 } 69 70 const char *can_get_state_str(const enum can_state state) 71 { 72 switch (state) { 73 case CAN_STATE_ERROR_ACTIVE: 74 return "Error Active"; 75 case CAN_STATE_ERROR_WARNING: 76 return "Error Warning"; 77 case CAN_STATE_ERROR_PASSIVE: 78 return "Error Passive"; 79 case CAN_STATE_BUS_OFF: 80 return "Bus Off"; 81 case CAN_STATE_STOPPED: 82 return "Stopped"; 83 case CAN_STATE_SLEEPING: 84 return "Sleeping"; 85 default: 86 return "<unknown>"; 87 } 88 } 89 EXPORT_SYMBOL_GPL(can_get_state_str); 90 91 const char *can_get_ctrlmode_str(u32 ctrlmode) 92 { 93 switch (ctrlmode & ~(ctrlmode - 1)) { 94 case 0: 95 return "(none)"; 96 case CAN_CTRLMODE_LOOPBACK: 97 return "LOOPBACK"; 98 case CAN_CTRLMODE_LISTENONLY: 99 return "LISTEN-ONLY"; 100 case CAN_CTRLMODE_3_SAMPLES: 101 return "TRIPLE-SAMPLING"; 102 case CAN_CTRLMODE_ONE_SHOT: 103 return "ONE-SHOT"; 104 case CAN_CTRLMODE_BERR_REPORTING: 105 return "BERR-REPORTING"; 106 case CAN_CTRLMODE_FD: 107 return "FD"; 108 case CAN_CTRLMODE_PRESUME_ACK: 109 return "PRESUME-ACK"; 110 case CAN_CTRLMODE_FD_NON_ISO: 111 return "FD-NON-ISO"; 112 case CAN_CTRLMODE_CC_LEN8_DLC: 113 return "CC-LEN8-DLC"; 114 case CAN_CTRLMODE_TDC_AUTO: 115 return "TDC-AUTO"; 116 case CAN_CTRLMODE_TDC_MANUAL: 117 return "TDC-MANUAL"; 118 case CAN_CTRLMODE_RESTRICTED: 119 return "RESTRICTED"; 120 case CAN_CTRLMODE_XL: 121 return "XL"; 122 case CAN_CTRLMODE_XL_TDC_AUTO: 123 return "XL-TDC-AUTO"; 124 case CAN_CTRLMODE_XL_TDC_MANUAL: 125 return "XL-TDC-MANUAL"; 126 case CAN_CTRLMODE_XL_TMS: 127 return "TMS"; 128 default: 129 return "<unknown>"; 130 } 131 } 132 EXPORT_SYMBOL_GPL(can_get_ctrlmode_str); 133 134 static enum can_state can_state_err_to_state(u16 err) 135 { 136 if (err < CAN_ERROR_WARNING_THRESHOLD) 137 return CAN_STATE_ERROR_ACTIVE; 138 if (err < CAN_ERROR_PASSIVE_THRESHOLD) 139 return CAN_STATE_ERROR_WARNING; 140 if (err < CAN_BUS_OFF_THRESHOLD) 141 return CAN_STATE_ERROR_PASSIVE; 142 143 return CAN_STATE_BUS_OFF; 144 } 145 146 void can_state_get_by_berr_counter(const struct net_device *dev, 147 const struct can_berr_counter *bec, 148 enum can_state *tx_state, 149 enum can_state *rx_state) 150 { 151 *tx_state = can_state_err_to_state(bec->txerr); 152 *rx_state = can_state_err_to_state(bec->rxerr); 153 } 154 EXPORT_SYMBOL_GPL(can_state_get_by_berr_counter); 155 156 void can_change_state(struct net_device *dev, struct can_frame *cf, 157 enum can_state tx_state, enum can_state rx_state) 158 { 159 struct can_priv *priv = netdev_priv(dev); 160 enum can_state new_state = max(tx_state, rx_state); 161 162 if (unlikely(new_state == priv->state)) { 163 netdev_warn(dev, "%s: oops, state did not change", __func__); 164 return; 165 } 166 167 netdev_dbg(dev, "Controller changed from %s State (%d) into %s State (%d).\n", 168 can_get_state_str(priv->state), priv->state, 169 can_get_state_str(new_state), new_state); 170 171 can_update_state_error_stats(dev, new_state); 172 priv->state = new_state; 173 174 if (!cf) 175 return; 176 177 if (unlikely(new_state == CAN_STATE_BUS_OFF)) { 178 cf->can_id |= CAN_ERR_BUSOFF; 179 return; 180 } 181 182 cf->can_id |= CAN_ERR_CRTL; 183 cf->data[1] |= tx_state >= rx_state ? 184 can_tx_state_to_frame(dev, tx_state) : 0; 185 cf->data[1] |= tx_state <= rx_state ? 186 can_rx_state_to_frame(dev, rx_state) : 0; 187 } 188 EXPORT_SYMBOL_GPL(can_change_state); 189 190 /* CAN device restart for bus-off recovery */ 191 static int can_restart(struct net_device *dev) 192 { 193 struct can_priv *priv = netdev_priv(dev); 194 struct sk_buff *skb; 195 struct can_frame *cf; 196 int err; 197 198 if (!priv->do_set_mode) 199 return -EOPNOTSUPP; 200 201 if (netif_carrier_ok(dev)) 202 netdev_err(dev, "Attempt to restart for bus-off recovery, but carrier is OK?\n"); 203 204 /* No synchronization needed because the device is bus-off and 205 * no messages can come in or go out. 206 */ 207 can_flush_echo_skb(dev); 208 209 /* send restart message upstream */ 210 skb = alloc_can_err_skb(dev, &cf); 211 if (skb) { 212 cf->can_id |= CAN_ERR_RESTARTED; 213 netif_rx(skb); 214 } 215 216 /* Now restart the device */ 217 netif_carrier_on(dev); 218 err = priv->do_set_mode(dev, CAN_MODE_START); 219 if (err) { 220 netdev_err(dev, "Restart failed, error %pe\n", ERR_PTR(err)); 221 netif_carrier_off(dev); 222 223 return err; 224 } else { 225 netdev_dbg(dev, "Restarted\n"); 226 priv->can_stats.restarts++; 227 } 228 229 return 0; 230 } 231 232 static void can_restart_work(struct work_struct *work) 233 { 234 struct delayed_work *dwork = to_delayed_work(work); 235 struct can_priv *priv = container_of(dwork, struct can_priv, 236 restart_work); 237 238 can_restart(priv->dev); 239 } 240 241 int can_restart_now(struct net_device *dev) 242 { 243 struct can_priv *priv = netdev_priv(dev); 244 245 /* A manual restart is only permitted if automatic restart is 246 * disabled and the device is in the bus-off state 247 */ 248 if (priv->restart_ms) 249 return -EINVAL; 250 if (priv->state != CAN_STATE_BUS_OFF) 251 return -EBUSY; 252 253 cancel_delayed_work_sync(&priv->restart_work); 254 255 return can_restart(dev); 256 } 257 258 /* CAN bus-off 259 * 260 * This functions should be called when the device goes bus-off to 261 * tell the netif layer that no more packets can be sent or received. 262 * If enabled, a timer is started to trigger bus-off recovery. 263 */ 264 void can_bus_off(struct net_device *dev) 265 { 266 struct can_priv *priv = netdev_priv(dev); 267 268 if (priv->restart_ms) 269 netdev_info(dev, "bus-off, scheduling restart in %d ms\n", 270 priv->restart_ms); 271 else 272 netdev_info(dev, "bus-off\n"); 273 274 netif_carrier_off(dev); 275 276 if (priv->restart_ms) 277 schedule_delayed_work(&priv->restart_work, 278 msecs_to_jiffies(priv->restart_ms)); 279 } 280 EXPORT_SYMBOL_GPL(can_bus_off); 281 282 void can_setup(struct net_device *dev) 283 { 284 dev->type = ARPHRD_CAN; 285 dev->mtu = CAN_MTU; 286 dev->min_mtu = CAN_MTU; 287 dev->max_mtu = CAN_MTU; 288 dev->hard_header_len = 0; 289 dev->addr_len = 0; 290 dev->tx_queue_len = 10; 291 292 /* New-style flags. */ 293 dev->flags = IFF_NOARP; 294 dev->features = NETIF_F_HW_CSUM; 295 } 296 297 /* Allocate and setup space for the CAN network device */ 298 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max, 299 unsigned int txqs, unsigned int rxqs) 300 { 301 struct can_ml_priv *can_ml; 302 struct net_device *dev; 303 struct can_priv *priv; 304 int size; 305 306 /* We put the driver's priv, the CAN mid layer priv and the 307 * echo skb into the netdevice's priv. The memory layout for 308 * the netdev_priv is like this: 309 * 310 * +-------------------------+ 311 * | driver's priv | 312 * +-------------------------+ 313 * | struct can_ml_priv | 314 * +-------------------------+ 315 * | array of struct sk_buff | 316 * +-------------------------+ 317 */ 318 319 size = ALIGN(sizeof_priv, NETDEV_ALIGN) + sizeof(struct can_ml_priv); 320 321 if (echo_skb_max) 322 size = ALIGN(size, sizeof(struct sk_buff *)) + 323 echo_skb_max * sizeof(struct sk_buff *); 324 325 dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup, 326 txqs, rxqs); 327 if (!dev) 328 return NULL; 329 330 priv = netdev_priv(dev); 331 priv->dev = dev; 332 333 can_ml = (void *)priv + ALIGN(sizeof_priv, NETDEV_ALIGN); 334 can_set_ml_priv(dev, can_ml); 335 336 if (echo_skb_max) { 337 priv->echo_skb_max = echo_skb_max; 338 priv->echo_skb = (void *)priv + 339 (size - echo_skb_max * sizeof(struct sk_buff *)); 340 } 341 342 priv->state = CAN_STATE_STOPPED; 343 344 INIT_DELAYED_WORK(&priv->restart_work, can_restart_work); 345 346 return dev; 347 } 348 EXPORT_SYMBOL_GPL(alloc_candev_mqs); 349 350 /* Free space of the CAN network device */ 351 void free_candev(struct net_device *dev) 352 { 353 free_netdev(dev); 354 } 355 EXPORT_SYMBOL_GPL(free_candev); 356 357 void can_set_default_mtu(struct net_device *dev) 358 { 359 struct can_priv *priv = netdev_priv(dev); 360 361 if (priv->ctrlmode & CAN_CTRLMODE_XL) { 362 if (can_is_canxl_dev_mtu(dev->mtu)) 363 return; 364 dev->mtu = CANXL_MTU; 365 dev->min_mtu = CANXL_MIN_MTU; 366 dev->max_mtu = CANXL_MAX_MTU; 367 } else if (priv->ctrlmode & CAN_CTRLMODE_FD) { 368 dev->mtu = CANFD_MTU; 369 dev->min_mtu = CANFD_MTU; 370 dev->max_mtu = CANFD_MTU; 371 } else { 372 dev->mtu = CAN_MTU; 373 dev->min_mtu = CAN_MTU; 374 dev->max_mtu = CAN_MTU; 375 } 376 } 377 378 /* helper to define static CAN controller features at device creation time */ 379 int can_set_static_ctrlmode(struct net_device *dev, u32 static_mode) 380 { 381 struct can_priv *priv = netdev_priv(dev); 382 383 /* alloc_candev() succeeded => netdev_priv() is valid at this point */ 384 if (priv->ctrlmode_supported & static_mode) { 385 netdev_warn(dev, 386 "Controller features can not be supported and static at the same time\n"); 387 return -EINVAL; 388 } 389 priv->ctrlmode = static_mode; 390 391 /* override MTU which was set by default in can_setup()? */ 392 can_set_default_mtu(dev); 393 394 return 0; 395 } 396 EXPORT_SYMBOL_GPL(can_set_static_ctrlmode); 397 398 /* generic implementation of netdev_ops::ndo_hwtstamp_get for CAN devices 399 * supporting hardware timestamps 400 */ 401 int can_hwtstamp_get(struct net_device *netdev, 402 struct kernel_hwtstamp_config *cfg) 403 { 404 cfg->tx_type = HWTSTAMP_TX_ON; 405 cfg->rx_filter = HWTSTAMP_FILTER_ALL; 406 407 return 0; 408 } 409 EXPORT_SYMBOL(can_hwtstamp_get); 410 411 /* generic implementation of netdev_ops::ndo_hwtstamp_set for CAN devices 412 * supporting hardware timestamps 413 */ 414 int can_hwtstamp_set(struct net_device *netdev, 415 struct kernel_hwtstamp_config *cfg, 416 struct netlink_ext_ack *extack) 417 { 418 if (cfg->tx_type == HWTSTAMP_TX_ON && 419 cfg->rx_filter == HWTSTAMP_FILTER_ALL) 420 return 0; 421 NL_SET_ERR_MSG_MOD(extack, "Only TX on and RX all packets filter supported"); 422 return -ERANGE; 423 } 424 EXPORT_SYMBOL(can_hwtstamp_set); 425 426 /* generic implementation of ethtool_ops::get_ts_info for CAN devices 427 * supporting hardware timestamps 428 */ 429 int can_ethtool_op_get_ts_info_hwts(struct net_device *dev, 430 struct kernel_ethtool_ts_info *info) 431 { 432 info->so_timestamping = 433 SOF_TIMESTAMPING_TX_SOFTWARE | 434 SOF_TIMESTAMPING_TX_HARDWARE | 435 SOF_TIMESTAMPING_RX_HARDWARE | 436 SOF_TIMESTAMPING_RAW_HARDWARE; 437 info->tx_types = BIT(HWTSTAMP_TX_ON); 438 info->rx_filters = BIT(HWTSTAMP_FILTER_ALL); 439 440 return 0; 441 } 442 EXPORT_SYMBOL(can_ethtool_op_get_ts_info_hwts); 443 444 /* Common open function when the device gets opened. 445 * 446 * This function should be called in the open function of the device 447 * driver. 448 */ 449 int open_candev(struct net_device *dev) 450 { 451 struct can_priv *priv = netdev_priv(dev); 452 453 if (!priv->bittiming.bitrate) { 454 netdev_err(dev, "bit-timing not yet defined\n"); 455 return -EINVAL; 456 } 457 458 /* For CAN FD the data bitrate has to be >= the arbitration bitrate */ 459 if ((priv->ctrlmode & CAN_CTRLMODE_FD) && 460 (!priv->fd.data_bittiming.bitrate || 461 priv->fd.data_bittiming.bitrate < priv->bittiming.bitrate)) { 462 netdev_err(dev, "incorrect/missing data bit-timing\n"); 463 return -EINVAL; 464 } 465 466 /* Switch carrier on if device was stopped while in bus-off state */ 467 if (!netif_carrier_ok(dev)) 468 netif_carrier_on(dev); 469 470 return 0; 471 } 472 EXPORT_SYMBOL_GPL(open_candev); 473 474 #ifdef CONFIG_OF 475 /* Common function that can be used to understand the limitation of 476 * a transceiver when it provides no means to determine these limitations 477 * at runtime. 478 */ 479 void of_can_transceiver(struct net_device *dev) 480 { 481 struct device_node *dn; 482 struct can_priv *priv = netdev_priv(dev); 483 struct device_node *np = dev->dev.parent->of_node; 484 int ret; 485 486 dn = of_get_child_by_name(np, "can-transceiver"); 487 if (!dn) 488 return; 489 490 ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max); 491 of_node_put(dn); 492 if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max)) 493 netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n"); 494 } 495 EXPORT_SYMBOL_GPL(of_can_transceiver); 496 #endif 497 498 /* Common close function for cleanup before the device gets closed. 499 * 500 * This function should be called in the close function of the device 501 * driver. 502 */ 503 void close_candev(struct net_device *dev) 504 { 505 struct can_priv *priv = netdev_priv(dev); 506 507 cancel_delayed_work_sync(&priv->restart_work); 508 can_flush_echo_skb(dev); 509 } 510 EXPORT_SYMBOL_GPL(close_candev); 511 512 static int can_set_termination(struct net_device *ndev, u16 term) 513 { 514 struct can_priv *priv = netdev_priv(ndev); 515 int set; 516 517 if (term == priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_ENABLED]) 518 set = 1; 519 else 520 set = 0; 521 522 gpiod_set_value_cansleep(priv->termination_gpio, set); 523 524 return 0; 525 } 526 527 static int can_get_termination(struct net_device *ndev) 528 { 529 struct can_priv *priv = netdev_priv(ndev); 530 struct device *dev = ndev->dev.parent; 531 struct gpio_desc *gpio; 532 u32 term; 533 int ret; 534 535 /* Disabling termination by default is the safe choice: Else if many 536 * bus participants enable it, no communication is possible at all. 537 */ 538 gpio = devm_gpiod_get_optional(dev, "termination", GPIOD_OUT_LOW); 539 if (IS_ERR(gpio)) 540 return dev_err_probe(dev, PTR_ERR(gpio), 541 "Cannot get termination-gpios\n"); 542 543 if (!gpio) 544 return 0; 545 546 ret = device_property_read_u32(dev, "termination-ohms", &term); 547 if (ret) { 548 netdev_err(ndev, "Cannot get termination-ohms: %pe\n", 549 ERR_PTR(ret)); 550 return ret; 551 } 552 553 if (term > U16_MAX) { 554 netdev_err(ndev, "Invalid termination-ohms value (%u > %u)\n", 555 term, U16_MAX); 556 return -EINVAL; 557 } 558 559 priv->termination_const_cnt = ARRAY_SIZE(priv->termination_gpio_ohms); 560 priv->termination_const = priv->termination_gpio_ohms; 561 priv->termination_gpio = gpio; 562 priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_DISABLED] = 563 CAN_TERMINATION_DISABLED; 564 priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_ENABLED] = term; 565 priv->do_set_termination = can_set_termination; 566 567 return 0; 568 } 569 570 static bool 571 can_bittiming_const_valid(const struct can_bittiming_const *btc) 572 { 573 if (!btc) 574 return true; 575 576 if (!btc->sjw_max) 577 return false; 578 579 return true; 580 } 581 582 /* Register the CAN network device */ 583 int register_candev(struct net_device *dev) 584 { 585 struct can_priv *priv = netdev_priv(dev); 586 int err; 587 588 /* Ensure termination_const, termination_const_cnt and 589 * do_set_termination consistency. All must be either set or 590 * unset. 591 */ 592 if ((!priv->termination_const != !priv->termination_const_cnt) || 593 (!priv->termination_const != !priv->do_set_termination)) 594 return -EINVAL; 595 596 if (!priv->bitrate_const != !priv->bitrate_const_cnt) 597 return -EINVAL; 598 599 if (!priv->fd.data_bitrate_const != !priv->fd.data_bitrate_const_cnt) 600 return -EINVAL; 601 602 /* We only support either fixed bit rates or bit timing const. */ 603 if ((priv->bitrate_const || priv->fd.data_bitrate_const) && 604 (priv->bittiming_const || priv->fd.data_bittiming_const)) 605 return -EINVAL; 606 607 if (!can_bittiming_const_valid(priv->bittiming_const) || 608 !can_bittiming_const_valid(priv->fd.data_bittiming_const)) 609 return -EINVAL; 610 611 if (!priv->termination_const) { 612 err = can_get_termination(dev); 613 if (err) 614 return err; 615 } 616 617 dev->rtnl_link_ops = &can_link_ops; 618 netif_carrier_off(dev); 619 620 return register_netdev(dev); 621 } 622 EXPORT_SYMBOL_GPL(register_candev); 623 624 /* Unregister the CAN network device */ 625 void unregister_candev(struct net_device *dev) 626 { 627 unregister_netdev(dev); 628 } 629 EXPORT_SYMBOL_GPL(unregister_candev); 630 631 /* Test if a network device is a candev based device 632 * and return the can_priv* if so. 633 */ 634 struct can_priv *safe_candev_priv(struct net_device *dev) 635 { 636 if (dev->type != ARPHRD_CAN || dev->rtnl_link_ops != &can_link_ops) 637 return NULL; 638 639 return netdev_priv(dev); 640 } 641 EXPORT_SYMBOL_GPL(safe_candev_priv); 642 643 static __init int can_dev_init(void) 644 { 645 int err; 646 647 err = can_netlink_register(); 648 if (!err) 649 pr_info("CAN device driver interface\n"); 650 651 return err; 652 } 653 module_init(can_dev_init); 654 655 static __exit void can_dev_exit(void) 656 { 657 can_netlink_unregister(); 658 } 659 module_exit(can_dev_exit); 660 661 MODULE_ALIAS_RTNL_LINK("can"); 662