dev.c revision 2e1143742789463c00ed5e7f9bf471f2b707b493
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, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18 */
19
20#include <linux/module.h>
21#include <linux/kernel.h>
22#include <linux/slab.h>
23#include <linux/netdevice.h>
24#include <linux/if_arp.h>
25#include <linux/can.h>
26#include <linux/can/dev.h>
27#include <linux/can/netlink.h>
28#include <net/rtnetlink.h>
29
30#define MOD_DESC "CAN device driver interface"
31
32MODULE_DESCRIPTION(MOD_DESC);
33MODULE_LICENSE("GPL v2");
34MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
35
36#ifdef CONFIG_CAN_CALC_BITTIMING
37#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
38
39/*
40 * Bit-timing calculation derived from:
41 *
42 * Code based on LinCAN sources and H8S2638 project
43 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
44 * Copyright 2005      Stanislav Marek
45 * email: pisa@cmp.felk.cvut.cz
46 *
47 * Calculates proper bit-timing parameters for a specified bit-rate
48 * and sample-point, which can then be used to set the bit-timing
49 * registers of the CAN controller. You can find more information
50 * in the header file linux/can/netlink.h.
51 */
52static int can_update_spt(const struct can_bittiming_const *btc,
53			  int sampl_pt, int tseg, int *tseg1, int *tseg2)
54{
55	*tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000;
56	if (*tseg2 < btc->tseg2_min)
57		*tseg2 = btc->tseg2_min;
58	if (*tseg2 > btc->tseg2_max)
59		*tseg2 = btc->tseg2_max;
60	*tseg1 = tseg - *tseg2;
61	if (*tseg1 > btc->tseg1_max) {
62		*tseg1 = btc->tseg1_max;
63		*tseg2 = tseg - *tseg1;
64	}
65	return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
66}
67
68static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
69{
70	struct can_priv *priv = netdev_priv(dev);
71	const struct can_bittiming_const *btc = priv->bittiming_const;
72	long rate, best_rate = 0;
73	long best_error = 1000000000, error = 0;
74	int best_tseg = 0, best_brp = 0, brp = 0;
75	int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0;
76	int spt_error = 1000, spt = 0, sampl_pt;
77	u64 v64;
78
79	if (!priv->bittiming_const)
80		return -ENOTSUPP;
81
82	/* Use CIA recommended sample points */
83	if (bt->sample_point) {
84		sampl_pt = bt->sample_point;
85	} else {
86		if (bt->bitrate > 800000)
87			sampl_pt = 750;
88		else if (bt->bitrate > 500000)
89			sampl_pt = 800;
90		else
91			sampl_pt = 875;
92	}
93
94	/* tseg even = round down, odd = round up */
95	for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
96	     tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
97		tsegall = 1 + tseg / 2;
98		/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
99		brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
100		/* chose brp step which is possible in system */
101		brp = (brp / btc->brp_inc) * btc->brp_inc;
102		if ((brp < btc->brp_min) || (brp > btc->brp_max))
103			continue;
104		rate = priv->clock.freq / (brp * tsegall);
105		error = bt->bitrate - rate;
106		/* tseg brp biterror */
107		if (error < 0)
108			error = -error;
109		if (error > best_error)
110			continue;
111		best_error = error;
112		if (error == 0) {
113			spt = can_update_spt(btc, sampl_pt, tseg / 2,
114					     &tseg1, &tseg2);
115			error = sampl_pt - spt;
116			if (error < 0)
117				error = -error;
118			if (error > spt_error)
119				continue;
120			spt_error = error;
121		}
122		best_tseg = tseg / 2;
123		best_brp = brp;
124		best_rate = rate;
125		if (error == 0)
126			break;
127	}
128
129	if (best_error) {
130		/* Error in one-tenth of a percent */
131		error = (best_error * 1000) / bt->bitrate;
132		if (error > CAN_CALC_MAX_ERROR) {
133			dev_err(dev->dev.parent,
134				"bitrate error %ld.%ld%% too high\n",
135				error / 10, error % 10);
136			return -EDOM;
137		} else {
138			dev_warn(dev->dev.parent, "bitrate error %ld.%ld%%\n",
139				 error / 10, error % 10);
140		}
141	}
142
143	/* real sample point */
144	bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
145					  &tseg1, &tseg2);
146
147	v64 = (u64)best_brp * 1000000000UL;
148	do_div(v64, priv->clock.freq);
149	bt->tq = (u32)v64;
150	bt->prop_seg = tseg1 / 2;
151	bt->phase_seg1 = tseg1 - bt->prop_seg;
152	bt->phase_seg2 = tseg2;
153
154	/* check for sjw user settings */
155	if (!bt->sjw || !btc->sjw_max)
156		bt->sjw = 1;
157	else {
158		/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
159		if (bt->sjw > btc->sjw_max)
160			bt->sjw = btc->sjw_max;
161		/* bt->sjw must not be higher than tseg2 */
162		if (tseg2 < bt->sjw)
163			bt->sjw = tseg2;
164	}
165
166	bt->brp = best_brp;
167	/* real bit-rate */
168	bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
169
170	return 0;
171}
172#else /* !CONFIG_CAN_CALC_BITTIMING */
173static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
174{
175	dev_err(dev->dev.parent, "bit-timing calculation not available\n");
176	return -EINVAL;
177}
178#endif /* CONFIG_CAN_CALC_BITTIMING */
179
180/*
181 * Checks the validity of the specified bit-timing parameters prop_seg,
182 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
183 * prescaler value brp. You can find more information in the header
184 * file linux/can/netlink.h.
185 */
186static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt)
187{
188	struct can_priv *priv = netdev_priv(dev);
189	const struct can_bittiming_const *btc = priv->bittiming_const;
190	int tseg1, alltseg;
191	u64 brp64;
192
193	if (!priv->bittiming_const)
194		return -ENOTSUPP;
195
196	tseg1 = bt->prop_seg + bt->phase_seg1;
197	if (!bt->sjw)
198		bt->sjw = 1;
199	if (bt->sjw > btc->sjw_max ||
200	    tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
201	    bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
202		return -ERANGE;
203
204	brp64 = (u64)priv->clock.freq * (u64)bt->tq;
205	if (btc->brp_inc > 1)
206		do_div(brp64, btc->brp_inc);
207	brp64 += 500000000UL - 1;
208	do_div(brp64, 1000000000UL); /* the practicable BRP */
209	if (btc->brp_inc > 1)
210		brp64 *= btc->brp_inc;
211	bt->brp = (u32)brp64;
212
213	if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
214		return -EINVAL;
215
216	alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
217	bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
218	bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
219
220	return 0;
221}
222
223static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt)
224{
225	struct can_priv *priv = netdev_priv(dev);
226	int err;
227
228	/* Check if the CAN device has bit-timing parameters */
229	if (priv->bittiming_const) {
230
231		/* Non-expert mode? Check if the bitrate has been pre-defined */
232		if (!bt->tq)
233			/* Determine bit-timing parameters */
234			err = can_calc_bittiming(dev, bt);
235		else
236			/* Check bit-timing params and calculate proper brp */
237			err = can_fixup_bittiming(dev, bt);
238		if (err)
239			return err;
240	}
241
242	return 0;
243}
244
245/*
246 * Local echo of CAN messages
247 *
248 * CAN network devices *should* support a local echo functionality
249 * (see Documentation/networking/can.txt). To test the handling of CAN
250 * interfaces that do not support the local echo both driver types are
251 * implemented. In the case that the driver does not support the echo
252 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
253 * to perform the echo as a fallback solution.
254 */
255static void can_flush_echo_skb(struct net_device *dev)
256{
257	struct can_priv *priv = netdev_priv(dev);
258	struct net_device_stats *stats = &dev->stats;
259	int i;
260
261	for (i = 0; i < priv->echo_skb_max; i++) {
262		if (priv->echo_skb[i]) {
263			kfree_skb(priv->echo_skb[i]);
264			priv->echo_skb[i] = NULL;
265			stats->tx_dropped++;
266			stats->tx_aborted_errors++;
267		}
268	}
269}
270
271/*
272 * Put the skb on the stack to be looped backed locally lateron
273 *
274 * The function is typically called in the start_xmit function
275 * of the device driver. The driver must protect access to
276 * priv->echo_skb, if necessary.
277 */
278void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
279		      unsigned int idx)
280{
281	struct can_priv *priv = netdev_priv(dev);
282
283	BUG_ON(idx >= priv->echo_skb_max);
284
285	/* check flag whether this packet has to be looped back */
286	if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) {
287		kfree_skb(skb);
288		return;
289	}
290
291	if (!priv->echo_skb[idx]) {
292		struct sock *srcsk = skb->sk;
293
294		if (atomic_read(&skb->users) != 1) {
295			struct sk_buff *old_skb = skb;
296
297			skb = skb_clone(old_skb, GFP_ATOMIC);
298			kfree_skb(old_skb);
299			if (!skb)
300				return;
301		} else
302			skb_orphan(skb);
303
304		skb->sk = srcsk;
305
306		/* make settings for echo to reduce code in irq context */
307		skb->protocol = htons(ETH_P_CAN);
308		skb->pkt_type = PACKET_BROADCAST;
309		skb->ip_summed = CHECKSUM_UNNECESSARY;
310		skb->dev = dev;
311
312		/* save this skb for tx interrupt echo handling */
313		priv->echo_skb[idx] = skb;
314	} else {
315		/* locking problem with netif_stop_queue() ?? */
316		dev_err(dev->dev.parent, "%s: BUG! echo_skb is occupied!\n",
317			__func__);
318		kfree_skb(skb);
319	}
320}
321EXPORT_SYMBOL_GPL(can_put_echo_skb);
322
323/*
324 * Get the skb from the stack and loop it back locally
325 *
326 * The function is typically called when the TX done interrupt
327 * is handled in the device driver. The driver must protect
328 * access to priv->echo_skb, if necessary.
329 */
330void can_get_echo_skb(struct net_device *dev, unsigned int idx)
331{
332	struct can_priv *priv = netdev_priv(dev);
333
334	BUG_ON(idx >= priv->echo_skb_max);
335
336	if (priv->echo_skb[idx]) {
337		netif_rx(priv->echo_skb[idx]);
338		priv->echo_skb[idx] = NULL;
339	}
340}
341EXPORT_SYMBOL_GPL(can_get_echo_skb);
342
343/*
344  * Remove the skb from the stack and free it.
345  *
346  * The function is typically called when TX failed.
347  */
348void can_free_echo_skb(struct net_device *dev, unsigned int idx)
349{
350	struct can_priv *priv = netdev_priv(dev);
351
352	BUG_ON(idx >= priv->echo_skb_max);
353
354	if (priv->echo_skb[idx]) {
355		kfree_skb(priv->echo_skb[idx]);
356		priv->echo_skb[idx] = NULL;
357	}
358}
359EXPORT_SYMBOL_GPL(can_free_echo_skb);
360
361/*
362 * CAN device restart for bus-off recovery
363 */
364void can_restart(unsigned long data)
365{
366	struct net_device *dev = (struct net_device *)data;
367	struct can_priv *priv = netdev_priv(dev);
368	struct net_device_stats *stats = &dev->stats;
369	struct sk_buff *skb;
370	struct can_frame *cf;
371	int err;
372
373	BUG_ON(netif_carrier_ok(dev));
374
375	/*
376	 * No synchronization needed because the device is bus-off and
377	 * no messages can come in or go out.
378	 */
379	can_flush_echo_skb(dev);
380
381	/* send restart message upstream */
382	skb = alloc_can_err_skb(dev, &cf);
383	if (skb == NULL) {
384		err = -ENOMEM;
385		goto restart;
386	}
387	cf->can_id |= CAN_ERR_RESTARTED;
388
389	netif_rx(skb);
390
391	stats->rx_packets++;
392	stats->rx_bytes += cf->can_dlc;
393
394restart:
395	dev_dbg(dev->dev.parent, "restarted\n");
396	priv->can_stats.restarts++;
397
398	/* Now restart the device */
399	err = priv->do_set_mode(dev, CAN_MODE_START);
400
401	netif_carrier_on(dev);
402	if (err)
403		dev_err(dev->dev.parent, "Error %d during restart", err);
404}
405
406int can_restart_now(struct net_device *dev)
407{
408	struct can_priv *priv = netdev_priv(dev);
409
410	/*
411	 * A manual restart is only permitted if automatic restart is
412	 * disabled and the device is in the bus-off state
413	 */
414	if (priv->restart_ms)
415		return -EINVAL;
416	if (priv->state != CAN_STATE_BUS_OFF)
417		return -EBUSY;
418
419	/* Runs as soon as possible in the timer context */
420	mod_timer(&priv->restart_timer, jiffies);
421
422	return 0;
423}
424
425/*
426 * CAN bus-off
427 *
428 * This functions should be called when the device goes bus-off to
429 * tell the netif layer that no more packets can be sent or received.
430 * If enabled, a timer is started to trigger bus-off recovery.
431 */
432void can_bus_off(struct net_device *dev)
433{
434	struct can_priv *priv = netdev_priv(dev);
435
436	dev_dbg(dev->dev.parent, "bus-off\n");
437
438	netif_carrier_off(dev);
439	priv->can_stats.bus_off++;
440
441	if (priv->restart_ms)
442		mod_timer(&priv->restart_timer,
443			  jiffies + (priv->restart_ms * HZ) / 1000);
444}
445EXPORT_SYMBOL_GPL(can_bus_off);
446
447static void can_setup(struct net_device *dev)
448{
449	dev->type = ARPHRD_CAN;
450	dev->mtu = sizeof(struct can_frame);
451	dev->hard_header_len = 0;
452	dev->addr_len = 0;
453	dev->tx_queue_len = 10;
454
455	/* New-style flags. */
456	dev->flags = IFF_NOARP;
457	dev->features = NETIF_F_NO_CSUM;
458}
459
460struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
461{
462	struct sk_buff *skb;
463
464	skb = netdev_alloc_skb(dev, sizeof(struct can_frame));
465	if (unlikely(!skb))
466		return NULL;
467
468	skb->protocol = htons(ETH_P_CAN);
469	skb->pkt_type = PACKET_BROADCAST;
470	skb->ip_summed = CHECKSUM_UNNECESSARY;
471	*cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
472	memset(*cf, 0, sizeof(struct can_frame));
473
474	return skb;
475}
476EXPORT_SYMBOL_GPL(alloc_can_skb);
477
478struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
479{
480	struct sk_buff *skb;
481
482	skb = alloc_can_skb(dev, cf);
483	if (unlikely(!skb))
484		return NULL;
485
486	(*cf)->can_id = CAN_ERR_FLAG;
487	(*cf)->can_dlc = CAN_ERR_DLC;
488
489	return skb;
490}
491EXPORT_SYMBOL_GPL(alloc_can_err_skb);
492
493/*
494 * Allocate and setup space for the CAN network device
495 */
496struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
497{
498	struct net_device *dev;
499	struct can_priv *priv;
500	int size;
501
502	if (echo_skb_max)
503		size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
504			echo_skb_max * sizeof(struct sk_buff *);
505	else
506		size = sizeof_priv;
507
508	dev = alloc_netdev(size, "can%d", can_setup);
509	if (!dev)
510		return NULL;
511
512	priv = netdev_priv(dev);
513
514	if (echo_skb_max) {
515		priv->echo_skb_max = echo_skb_max;
516		priv->echo_skb = (void *)priv +
517			ALIGN(sizeof_priv, sizeof(struct sk_buff *));
518	}
519
520	priv->state = CAN_STATE_STOPPED;
521
522	init_timer(&priv->restart_timer);
523
524	return dev;
525}
526EXPORT_SYMBOL_GPL(alloc_candev);
527
528/*
529 * Free space of the CAN network device
530 */
531void free_candev(struct net_device *dev)
532{
533	free_netdev(dev);
534}
535EXPORT_SYMBOL_GPL(free_candev);
536
537/*
538 * Common open function when the device gets opened.
539 *
540 * This function should be called in the open function of the device
541 * driver.
542 */
543int open_candev(struct net_device *dev)
544{
545	struct can_priv *priv = netdev_priv(dev);
546
547	if (!priv->bittiming.tq && !priv->bittiming.bitrate) {
548		dev_err(dev->dev.parent, "bit-timing not yet defined\n");
549		return -EINVAL;
550	}
551
552	/* Switch carrier on if device was stopped while in bus-off state */
553	if (!netif_carrier_ok(dev))
554		netif_carrier_on(dev);
555
556	setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
557
558	return 0;
559}
560EXPORT_SYMBOL_GPL(open_candev);
561
562/*
563 * Common close function for cleanup before the device gets closed.
564 *
565 * This function should be called in the close function of the device
566 * driver.
567 */
568void close_candev(struct net_device *dev)
569{
570	struct can_priv *priv = netdev_priv(dev);
571
572	if (del_timer_sync(&priv->restart_timer))
573		dev_put(dev);
574	can_flush_echo_skb(dev);
575}
576EXPORT_SYMBOL_GPL(close_candev);
577
578/*
579 * CAN netlink interface
580 */
581static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
582	[IFLA_CAN_STATE]	= { .type = NLA_U32 },
583	[IFLA_CAN_CTRLMODE]	= { .len = sizeof(struct can_ctrlmode) },
584	[IFLA_CAN_RESTART_MS]	= { .type = NLA_U32 },
585	[IFLA_CAN_RESTART]	= { .type = NLA_U32 },
586	[IFLA_CAN_BITTIMING]	= { .len = sizeof(struct can_bittiming) },
587	[IFLA_CAN_BITTIMING_CONST]
588				= { .len = sizeof(struct can_bittiming_const) },
589	[IFLA_CAN_CLOCK]	= { .len = sizeof(struct can_clock) },
590	[IFLA_CAN_BERR_COUNTER]	= { .len = sizeof(struct can_berr_counter) },
591};
592
593static int can_changelink(struct net_device *dev,
594			  struct nlattr *tb[], struct nlattr *data[])
595{
596	struct can_priv *priv = netdev_priv(dev);
597	int err;
598
599	/* We need synchronization with dev->stop() */
600	ASSERT_RTNL();
601
602	if (data[IFLA_CAN_CTRLMODE]) {
603		struct can_ctrlmode *cm;
604
605		/* Do not allow changing controller mode while running */
606		if (dev->flags & IFF_UP)
607			return -EBUSY;
608		cm = nla_data(data[IFLA_CAN_CTRLMODE]);
609		if (cm->flags & ~priv->ctrlmode_supported)
610			return -EOPNOTSUPP;
611		priv->ctrlmode &= ~cm->mask;
612		priv->ctrlmode |= cm->flags;
613	}
614
615	if (data[IFLA_CAN_BITTIMING]) {
616		struct can_bittiming bt;
617
618		/* Do not allow changing bittiming while running */
619		if (dev->flags & IFF_UP)
620			return -EBUSY;
621		memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
622		if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq))
623			return -EINVAL;
624		err = can_get_bittiming(dev, &bt);
625		if (err)
626			return err;
627		memcpy(&priv->bittiming, &bt, sizeof(bt));
628
629		if (priv->do_set_bittiming) {
630			/* Finally, set the bit-timing registers */
631			err = priv->do_set_bittiming(dev);
632			if (err)
633				return err;
634		}
635	}
636
637	if (data[IFLA_CAN_RESTART_MS]) {
638		/* Do not allow changing restart delay while running */
639		if (dev->flags & IFF_UP)
640			return -EBUSY;
641		priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
642	}
643
644	if (data[IFLA_CAN_RESTART]) {
645		/* Do not allow a restart while not running */
646		if (!(dev->flags & IFF_UP))
647			return -EINVAL;
648		err = can_restart_now(dev);
649		if (err)
650			return err;
651	}
652
653	return 0;
654}
655
656static size_t can_get_size(const struct net_device *dev)
657{
658	struct can_priv *priv = netdev_priv(dev);
659	size_t size;
660
661	size = nla_total_size(sizeof(u32));   /* IFLA_CAN_STATE */
662	size += sizeof(struct can_ctrlmode);  /* IFLA_CAN_CTRLMODE */
663	size += nla_total_size(sizeof(u32));  /* IFLA_CAN_RESTART_MS */
664	size += sizeof(struct can_bittiming); /* IFLA_CAN_BITTIMING */
665	size += sizeof(struct can_clock);     /* IFLA_CAN_CLOCK */
666	if (priv->do_get_berr_counter)        /* IFLA_CAN_BERR_COUNTER */
667		size += sizeof(struct can_berr_counter);
668	if (priv->bittiming_const)	      /* IFLA_CAN_BITTIMING_CONST */
669		size += sizeof(struct can_bittiming_const);
670
671	return size;
672}
673
674static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
675{
676	struct can_priv *priv = netdev_priv(dev);
677	struct can_ctrlmode cm = {.flags = priv->ctrlmode};
678	struct can_berr_counter bec;
679	enum can_state state = priv->state;
680
681	if (priv->do_get_state)
682		priv->do_get_state(dev, &state);
683	NLA_PUT_U32(skb, IFLA_CAN_STATE, state);
684	NLA_PUT(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm);
685	NLA_PUT_U32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms);
686	NLA_PUT(skb, IFLA_CAN_BITTIMING,
687		sizeof(priv->bittiming), &priv->bittiming);
688	NLA_PUT(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock);
689	if (priv->do_get_berr_counter && !priv->do_get_berr_counter(dev, &bec))
690		NLA_PUT(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec);
691	if (priv->bittiming_const)
692		NLA_PUT(skb, IFLA_CAN_BITTIMING_CONST,
693			sizeof(*priv->bittiming_const), priv->bittiming_const);
694
695	return 0;
696
697nla_put_failure:
698	return -EMSGSIZE;
699}
700
701static size_t can_get_xstats_size(const struct net_device *dev)
702{
703	return sizeof(struct can_device_stats);
704}
705
706static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
707{
708	struct can_priv *priv = netdev_priv(dev);
709
710	NLA_PUT(skb, IFLA_INFO_XSTATS,
711		sizeof(priv->can_stats), &priv->can_stats);
712
713	return 0;
714
715nla_put_failure:
716	return -EMSGSIZE;
717}
718
719static int can_newlink(struct net *src_net, struct net_device *dev,
720		       struct nlattr *tb[], struct nlattr *data[])
721{
722	return -EOPNOTSUPP;
723}
724
725static struct rtnl_link_ops can_link_ops __read_mostly = {
726	.kind		= "can",
727	.maxtype	= IFLA_CAN_MAX,
728	.policy		= can_policy,
729	.setup		= can_setup,
730	.newlink	= can_newlink,
731	.changelink	= can_changelink,
732	.get_size	= can_get_size,
733	.fill_info	= can_fill_info,
734	.get_xstats_size = can_get_xstats_size,
735	.fill_xstats	= can_fill_xstats,
736};
737
738/*
739 * Register the CAN network device
740 */
741int register_candev(struct net_device *dev)
742{
743	dev->rtnl_link_ops = &can_link_ops;
744	return register_netdev(dev);
745}
746EXPORT_SYMBOL_GPL(register_candev);
747
748/*
749 * Unregister the CAN network device
750 */
751void unregister_candev(struct net_device *dev)
752{
753	unregister_netdev(dev);
754}
755EXPORT_SYMBOL_GPL(unregister_candev);
756
757static __init int can_dev_init(void)
758{
759	int err;
760
761	err = rtnl_link_register(&can_link_ops);
762	if (!err)
763		printk(KERN_INFO MOD_DESC "\n");
764
765	return err;
766}
767module_init(can_dev_init);
768
769static __exit void can_dev_exit(void)
770{
771	rtnl_link_unregister(&can_link_ops);
772}
773module_exit(can_dev_exit);
774
775MODULE_ALIAS_RTNL_LINK("can");
776