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>
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
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.
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/>.
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>
31 #define MOD_DESC "CAN device driver interface"
33 MODULE_DESCRIPTION(MOD_DESC);
34 MODULE_LICENSE("GPL v2");
35 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
37 /* CAN DLC to real data length conversion helpers */
39 static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
40 8, 12, 16, 20, 24, 32, 48, 64};
42 /* get data length from can_dlc with sanitized can_dlc */
43 u8 can_dlc2len(u8 can_dlc)
45 return dlc2len[can_dlc & 0x0F];
47 EXPORT_SYMBOL_GPL(can_dlc2len);
49 static 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 */
60 /* map the sanitized data length to an appropriate data length code */
61 u8 can_len2dlc(u8 len)
63 if (unlikely(len > 64))
68 EXPORT_SYMBOL_GPL(can_len2dlc);
70 #ifdef CONFIG_CAN_CALC_BITTIMING
71 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
74 * Bit-timing calculation derived from:
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
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.
86 static int can_update_spt(const struct can_bittiming_const *btc,
87 int sampl_pt, int tseg, int *tseg1, int *tseg2)
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;
99 return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
102 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
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;
113 if (!priv->bittiming_const)
116 /* Use CIA recommended sample points */
117 if (bt->sample_point) {
118 sampl_pt = bt->sample_point;
120 if (bt->bitrate > 800000)
122 else if (bt->bitrate > 500000)
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))
138 rate = priv->clock.freq / (brp * tsegall);
139 error = bt->bitrate - rate;
140 /* tseg brp biterror */
143 if (error > best_error)
147 spt = can_update_spt(btc, sampl_pt, tseg / 2,
149 error = sampl_pt - spt;
152 if (error > spt_error)
156 best_tseg = tseg / 2;
164 /* Error in one-tenth of a percent */
165 error = (best_error * 1000) / bt->bitrate;
166 if (error > CAN_CALC_MAX_ERROR) {
168 "bitrate error %ld.%ld%% too high\n",
169 error / 10, error % 10);
172 netdev_warn(dev, "bitrate error %ld.%ld%%\n",
173 error / 10, error % 10);
177 /* real sample point */
178 bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
181 v64 = (u64)best_brp * 1000000000UL;
182 do_div(v64, priv->clock.freq);
184 bt->prop_seg = tseg1 / 2;
185 bt->phase_seg1 = tseg1 - bt->prop_seg;
186 bt->phase_seg2 = tseg2;
188 /* check for sjw user settings */
189 if (!bt->sjw || !btc->sjw_max)
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 */
202 bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
206 #else /* !CONFIG_CAN_CALC_BITTIMING */
207 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
209 netdev_err(dev, "bit-timing calculation not available\n");
212 #endif /* CONFIG_CAN_CALC_BITTIMING */
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.
220 static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt)
222 struct can_priv *priv = netdev_priv(dev);
223 const struct can_bittiming_const *btc = priv->bittiming_const;
227 if (!priv->bittiming_const)
230 tseg1 = bt->prop_seg + bt->phase_seg1;
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)
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;
247 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
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;
257 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt)
259 struct can_priv *priv = netdev_priv(dev);
262 /* Check if the CAN device has bit-timing parameters */
263 if (priv->bittiming_const) {
265 /* Non-expert mode? Check if the bitrate has been pre-defined */
267 /* Determine bit-timing parameters */
268 err = can_calc_bittiming(dev, bt);
270 /* Check bit-timing params and calculate proper brp */
271 err = can_fixup_bittiming(dev, bt);
280 * Local echo of CAN messages
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.
289 static void can_flush_echo_skb(struct net_device *dev)
291 struct can_priv *priv = netdev_priv(dev);
292 struct net_device_stats *stats = &dev->stats;
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;
300 stats->tx_aborted_errors++;
306 * Put the skb on the stack to be looped backed locally lateron
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.
312 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
315 struct can_priv *priv = netdev_priv(dev);
317 BUG_ON(idx >= priv->echo_skb_max);
319 /* check flag whether this packet has to be looped back */
320 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) {
325 if (!priv->echo_skb[idx]) {
326 struct sock *srcsk = skb->sk;
328 if (atomic_read(&skb->users) != 1) {
329 struct sk_buff *old_skb = skb;
331 skb = skb_clone(old_skb, GFP_ATOMIC);
340 /* make settings for echo to reduce code in irq context */
341 skb->protocol = htons(ETH_P_CAN);
342 skb->pkt_type = PACKET_BROADCAST;
343 skb->ip_summed = CHECKSUM_UNNECESSARY;
346 /* save this skb for tx interrupt echo handling */
347 priv->echo_skb[idx] = skb;
349 /* locking problem with netif_stop_queue() ?? */
350 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
354 EXPORT_SYMBOL_GPL(can_put_echo_skb);
357 * Get the skb from the stack and loop it back locally
359 * The function is typically called when the TX done interrupt
360 * is handled in the device driver. The driver must protect
361 * access to priv->echo_skb, if necessary.
363 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
365 struct can_priv *priv = netdev_priv(dev);
367 BUG_ON(idx >= priv->echo_skb_max);
369 if (priv->echo_skb[idx]) {
370 struct sk_buff *skb = priv->echo_skb[idx];
371 struct can_frame *cf = (struct can_frame *)skb->data;
372 u8 dlc = cf->can_dlc;
374 netif_rx(priv->echo_skb[idx]);
375 priv->echo_skb[idx] = NULL;
382 EXPORT_SYMBOL_GPL(can_get_echo_skb);
385 * Remove the skb from the stack and free it.
387 * The function is typically called when TX failed.
389 void can_free_echo_skb(struct net_device *dev, unsigned int idx)
391 struct can_priv *priv = netdev_priv(dev);
393 BUG_ON(idx >= priv->echo_skb_max);
395 if (priv->echo_skb[idx]) {
396 kfree_skb(priv->echo_skb[idx]);
397 priv->echo_skb[idx] = NULL;
400 EXPORT_SYMBOL_GPL(can_free_echo_skb);
403 * CAN device restart for bus-off recovery
405 static void can_restart(unsigned long data)
407 struct net_device *dev = (struct net_device *)data;
408 struct can_priv *priv = netdev_priv(dev);
409 struct net_device_stats *stats = &dev->stats;
411 struct can_frame *cf;
414 BUG_ON(netif_carrier_ok(dev));
417 * No synchronization needed because the device is bus-off and
418 * no messages can come in or go out.
420 can_flush_echo_skb(dev);
422 /* send restart message upstream */
423 skb = alloc_can_err_skb(dev, &cf);
428 cf->can_id |= CAN_ERR_RESTARTED;
433 stats->rx_bytes += cf->can_dlc;
436 netdev_dbg(dev, "restarted\n");
437 priv->can_stats.restarts++;
439 /* Now restart the device */
440 err = priv->do_set_mode(dev, CAN_MODE_START);
442 netif_carrier_on(dev);
444 netdev_err(dev, "Error %d during restart", err);
447 int can_restart_now(struct net_device *dev)
449 struct can_priv *priv = netdev_priv(dev);
452 * A manual restart is only permitted if automatic restart is
453 * disabled and the device is in the bus-off state
455 if (priv->restart_ms)
457 if (priv->state != CAN_STATE_BUS_OFF)
460 /* Runs as soon as possible in the timer context */
461 mod_timer(&priv->restart_timer, jiffies);
469 * This functions should be called when the device goes bus-off to
470 * tell the netif layer that no more packets can be sent or received.
471 * If enabled, a timer is started to trigger bus-off recovery.
473 void can_bus_off(struct net_device *dev)
475 struct can_priv *priv = netdev_priv(dev);
477 netdev_dbg(dev, "bus-off\n");
479 netif_carrier_off(dev);
480 priv->can_stats.bus_off++;
482 if (priv->restart_ms)
483 mod_timer(&priv->restart_timer,
484 jiffies + (priv->restart_ms * HZ) / 1000);
486 EXPORT_SYMBOL_GPL(can_bus_off);
488 static void can_setup(struct net_device *dev)
490 dev->type = ARPHRD_CAN;
492 dev->hard_header_len = 0;
494 dev->tx_queue_len = 10;
496 /* New-style flags. */
497 dev->flags = IFF_NOARP;
498 dev->features = NETIF_F_HW_CSUM;
501 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
505 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
506 sizeof(struct can_frame));
510 skb->protocol = htons(ETH_P_CAN);
511 skb->pkt_type = PACKET_BROADCAST;
512 skb->ip_summed = CHECKSUM_UNNECESSARY;
514 can_skb_reserve(skb);
515 can_skb_prv(skb)->ifindex = dev->ifindex;
517 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
518 memset(*cf, 0, sizeof(struct can_frame));
522 EXPORT_SYMBOL_GPL(alloc_can_skb);
524 struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
528 skb = alloc_can_skb(dev, cf);
532 (*cf)->can_id = CAN_ERR_FLAG;
533 (*cf)->can_dlc = CAN_ERR_DLC;
537 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
540 * Allocate and setup space for the CAN network device
542 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
544 struct net_device *dev;
545 struct can_priv *priv;
549 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
550 echo_skb_max * sizeof(struct sk_buff *);
554 dev = alloc_netdev(size, "can%d", can_setup);
558 priv = netdev_priv(dev);
561 priv->echo_skb_max = echo_skb_max;
562 priv->echo_skb = (void *)priv +
563 ALIGN(sizeof_priv, sizeof(struct sk_buff *));
566 priv->state = CAN_STATE_STOPPED;
568 init_timer(&priv->restart_timer);
572 EXPORT_SYMBOL_GPL(alloc_candev);
575 * Free space of the CAN network device
577 void free_candev(struct net_device *dev)
581 EXPORT_SYMBOL_GPL(free_candev);
584 * Common open function when the device gets opened.
586 * This function should be called in the open function of the device
589 int open_candev(struct net_device *dev)
591 struct can_priv *priv = netdev_priv(dev);
593 if (!priv->bittiming.tq && !priv->bittiming.bitrate) {
594 netdev_err(dev, "bit-timing not yet defined\n");
598 /* Switch carrier on if device was stopped while in bus-off state */
599 if (!netif_carrier_ok(dev))
600 netif_carrier_on(dev);
602 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
606 EXPORT_SYMBOL_GPL(open_candev);
609 * Common close function for cleanup before the device gets closed.
611 * This function should be called in the close function of the device
614 void close_candev(struct net_device *dev)
616 struct can_priv *priv = netdev_priv(dev);
618 del_timer_sync(&priv->restart_timer);
619 can_flush_echo_skb(dev);
621 EXPORT_SYMBOL_GPL(close_candev);
624 * CAN netlink interface
626 static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
627 [IFLA_CAN_STATE] = { .type = NLA_U32 },
628 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
629 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
630 [IFLA_CAN_RESTART] = { .type = NLA_U32 },
631 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
632 [IFLA_CAN_BITTIMING_CONST]
633 = { .len = sizeof(struct can_bittiming_const) },
634 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
635 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
638 static int can_changelink(struct net_device *dev,
639 struct nlattr *tb[], struct nlattr *data[])
641 struct can_priv *priv = netdev_priv(dev);
644 /* We need synchronization with dev->stop() */
647 if (data[IFLA_CAN_BITTIMING]) {
648 struct can_bittiming bt;
650 /* Do not allow changing bittiming while running */
651 if (dev->flags & IFF_UP)
653 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
654 if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq))
656 err = can_get_bittiming(dev, &bt);
659 memcpy(&priv->bittiming, &bt, sizeof(bt));
661 if (priv->do_set_bittiming) {
662 /* Finally, set the bit-timing registers */
663 err = priv->do_set_bittiming(dev);
669 if (data[IFLA_CAN_CTRLMODE]) {
670 struct can_ctrlmode *cm;
672 /* Do not allow changing controller mode while running */
673 if (dev->flags & IFF_UP)
675 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
676 if (cm->flags & ~priv->ctrlmode_supported)
678 priv->ctrlmode &= ~cm->mask;
679 priv->ctrlmode |= cm->flags;
682 if (data[IFLA_CAN_RESTART_MS]) {
683 /* Do not allow changing restart delay while running */
684 if (dev->flags & IFF_UP)
686 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
689 if (data[IFLA_CAN_RESTART]) {
690 /* Do not allow a restart while not running */
691 if (!(dev->flags & IFF_UP))
693 err = can_restart_now(dev);
701 static size_t can_get_size(const struct net_device *dev)
703 struct can_priv *priv = netdev_priv(dev);
706 size += nla_total_size(sizeof(struct can_bittiming)); /* IFLA_CAN_BITTIMING */
707 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
708 size += nla_total_size(sizeof(struct can_bittiming_const));
709 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
710 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
711 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
712 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
713 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
714 size += nla_total_size(sizeof(struct can_berr_counter));
719 static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
721 struct can_priv *priv = netdev_priv(dev);
722 struct can_ctrlmode cm = {.flags = priv->ctrlmode};
723 struct can_berr_counter bec;
724 enum can_state state = priv->state;
726 if (priv->do_get_state)
727 priv->do_get_state(dev, &state);
728 if (nla_put(skb, IFLA_CAN_BITTIMING,
729 sizeof(priv->bittiming), &priv->bittiming) ||
730 (priv->bittiming_const &&
731 nla_put(skb, IFLA_CAN_BITTIMING_CONST,
732 sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
733 nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) ||
734 nla_put_u32(skb, IFLA_CAN_STATE, state) ||
735 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
736 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
737 (priv->do_get_berr_counter &&
738 !priv->do_get_berr_counter(dev, &bec) &&
739 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)))
744 static size_t can_get_xstats_size(const struct net_device *dev)
746 return sizeof(struct can_device_stats);
749 static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
751 struct can_priv *priv = netdev_priv(dev);
753 if (nla_put(skb, IFLA_INFO_XSTATS,
754 sizeof(priv->can_stats), &priv->can_stats))
755 goto nla_put_failure;
762 static int can_newlink(struct net *src_net, struct net_device *dev,
763 struct nlattr *tb[], struct nlattr *data[])
768 static struct rtnl_link_ops can_link_ops __read_mostly = {
770 .maxtype = IFLA_CAN_MAX,
771 .policy = can_policy,
773 .newlink = can_newlink,
774 .changelink = can_changelink,
775 .get_size = can_get_size,
776 .fill_info = can_fill_info,
777 .get_xstats_size = can_get_xstats_size,
778 .fill_xstats = can_fill_xstats,
782 * Register the CAN network device
784 int register_candev(struct net_device *dev)
786 dev->rtnl_link_ops = &can_link_ops;
787 return register_netdev(dev);
789 EXPORT_SYMBOL_GPL(register_candev);
792 * Unregister the CAN network device
794 void unregister_candev(struct net_device *dev)
796 unregister_netdev(dev);
798 EXPORT_SYMBOL_GPL(unregister_candev);
801 * Test if a network device is a candev based device
802 * and return the can_priv* if so.
804 struct can_priv *safe_candev_priv(struct net_device *dev)
806 if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
809 return netdev_priv(dev);
811 EXPORT_SYMBOL_GPL(safe_candev_priv);
813 static __init int can_dev_init(void)
817 can_led_notifier_init();
819 err = rtnl_link_register(&can_link_ops);
821 printk(KERN_INFO MOD_DESC "\n");
825 module_init(can_dev_init);
827 static __exit void can_dev_exit(void)
829 rtnl_link_unregister(&can_link_ops);
831 can_led_notifier_exit();
833 module_exit(can_dev_exit);
835 MODULE_ALIAS_RTNL_LINK("can");