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