dev.c revision 77fc95a356cd07d247bbe42a66596ba7b8486920 
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/* CAN DLC to real data length conversion helpers */
37
38static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
39			     8, 12, 16, 20, 24, 32, 48, 64};
40
41/* get data length from can_dlc with sanitized can_dlc */
42u8 can_dlc2len(u8 can_dlc)
43{
44	return dlc2len[can_dlc & 0x0F];
45}
46EXPORT_SYMBOL_GPL(can_dlc2len);
47
48static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8,		/* 0 - 8 */
49			     9, 9, 9, 9,			/* 9 - 12 */
50			     10, 10, 10, 10,			/* 13 - 16 */
51			     11, 11, 11, 11,			/* 17 - 20 */
52			     12, 12, 12, 12,			/* 21 - 24 */
53			     13, 13, 13, 13, 13, 13, 13, 13,	/* 25 - 32 */
54			     14, 14, 14, 14, 14, 14, 14, 14,	/* 33 - 40 */
55			     14, 14, 14, 14, 14, 14, 14, 14,	/* 41 - 48 */
56			     15, 15, 15, 15, 15, 15, 15, 15,	/* 49 - 56 */
57			     15, 15, 15, 15, 15, 15, 15, 15};	/* 57 - 64 */
58
59/* map the sanitized data length to an appropriate data length code */
60u8 can_len2dlc(u8 len)
61{
62	if (unlikely(len > 64))
63		return 0xF;
64
65	return len2dlc[len];
66}
67EXPORT_SYMBOL_GPL(can_len2dlc);
68
69#ifdef CONFIG_CAN_CALC_BITTIMING
70#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
71
72/*
73 * Bit-timing calculation derived from:
74 *
75 * Code based on LinCAN sources and H8S2638 project
76 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
77 * Copyright 2005      Stanislav Marek
78 * email: pisa@cmp.felk.cvut.cz
79 *
80 * Calculates proper bit-timing parameters for a specified bit-rate
81 * and sample-point, which can then be used to set the bit-timing
82 * registers of the CAN controller. You can find more information
83 * in the header file linux/can/netlink.h.
84 */
85static int can_update_spt(const struct can_bittiming_const *btc,
86			  int sampl_pt, int tseg, int *tseg1, int *tseg2)
87{
88	*tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000;
89	if (*tseg2 < btc->tseg2_min)
90		*tseg2 = btc->tseg2_min;
91	if (*tseg2 > btc->tseg2_max)
92		*tseg2 = btc->tseg2_max;
93	*tseg1 = tseg - *tseg2;
94	if (*tseg1 > btc->tseg1_max) {
95		*tseg1 = btc->tseg1_max;
96		*tseg2 = tseg - *tseg1;
97	}
98	return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
99}
100
101static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
102{
103	struct can_priv *priv = netdev_priv(dev);
104	const struct can_bittiming_const *btc = priv->bittiming_const;
105	long rate, best_rate = 0;
106	long best_error = 1000000000, error = 0;
107	int best_tseg = 0, best_brp = 0, brp = 0;
108	int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0;
109	int spt_error = 1000, spt = 0, sampl_pt;
110	u64 v64;
111
112	if (!priv->bittiming_const)
113		return -ENOTSUPP;
114
115	/* Use CIA recommended sample points */
116	if (bt->sample_point) {
117		sampl_pt = bt->sample_point;
118	} else {
119		if (bt->bitrate > 800000)
120			sampl_pt = 750;
121		else if (bt->bitrate > 500000)
122			sampl_pt = 800;
123		else
124			sampl_pt = 875;
125	}
126
127	/* tseg even = round down, odd = round up */
128	for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
129	     tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
130		tsegall = 1 + tseg / 2;
131		/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
132		brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
133		/* chose brp step which is possible in system */
134		brp = (brp / btc->brp_inc) * btc->brp_inc;
135		if ((brp < btc->brp_min) || (brp > btc->brp_max))
136			continue;
137		rate = priv->clock.freq / (brp * tsegall);
138		error = bt->bitrate - rate;
139		/* tseg brp biterror */
140		if (error < 0)
141			error = -error;
142		if (error > best_error)
143			continue;
144		best_error = error;
145		if (error == 0) {
146			spt = can_update_spt(btc, sampl_pt, tseg / 2,
147					     &tseg1, &tseg2);
148			error = sampl_pt - spt;
149			if (error < 0)
150				error = -error;
151			if (error > spt_error)
152				continue;
153			spt_error = error;
154		}
155		best_tseg = tseg / 2;
156		best_brp = brp;
157		best_rate = rate;
158		if (error == 0)
159			break;
160	}
161
162	if (best_error) {
163		/* Error in one-tenth of a percent */
164		error = (best_error * 1000) / bt->bitrate;
165		if (error > CAN_CALC_MAX_ERROR) {
166			netdev_err(dev,
167				   "bitrate error %ld.%ld%% too high\n",
168				   error / 10, error % 10);
169			return -EDOM;
170		} else {
171			netdev_warn(dev, "bitrate error %ld.%ld%%\n",
172				    error / 10, error % 10);
173		}
174	}
175
176	/* real sample point */
177	bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
178					  &tseg1, &tseg2);
179
180	v64 = (u64)best_brp * 1000000000UL;
181	do_div(v64, priv->clock.freq);
182	bt->tq = (u32)v64;
183	bt->prop_seg = tseg1 / 2;
184	bt->phase_seg1 = tseg1 - bt->prop_seg;
185	bt->phase_seg2 = tseg2;
186
187	/* check for sjw user settings */
188	if (!bt->sjw || !btc->sjw_max)
189		bt->sjw = 1;
190	else {
191		/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
192		if (bt->sjw > btc->sjw_max)
193			bt->sjw = btc->sjw_max;
194		/* bt->sjw must not be higher than tseg2 */
195		if (tseg2 < bt->sjw)
196			bt->sjw = tseg2;
197	}
198
199	bt->brp = best_brp;
200	/* real bit-rate */
201	bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
202
203	return 0;
204}
205#else /* !CONFIG_CAN_CALC_BITTIMING */
206static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
207{
208	netdev_err(dev, "bit-timing calculation not available\n");
209	return -EINVAL;
210}
211#endif /* CONFIG_CAN_CALC_BITTIMING */
212
213/*
214 * Checks the validity of the specified bit-timing parameters prop_seg,
215 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
216 * prescaler value brp. You can find more information in the header
217 * file linux/can/netlink.h.
218 */
219static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt)
220{
221	struct can_priv *priv = netdev_priv(dev);
222	const struct can_bittiming_const *btc = priv->bittiming_const;
223	int tseg1, alltseg;
224	u64 brp64;
225
226	if (!priv->bittiming_const)
227		return -ENOTSUPP;
228
229	tseg1 = bt->prop_seg + bt->phase_seg1;
230	if (!bt->sjw)
231		bt->sjw = 1;
232	if (bt->sjw > btc->sjw_max ||
233	    tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
234	    bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
235		return -ERANGE;
236
237	brp64 = (u64)priv->clock.freq * (u64)bt->tq;
238	if (btc->brp_inc > 1)
239		do_div(brp64, btc->brp_inc);
240	brp64 += 500000000UL - 1;
241	do_div(brp64, 1000000000UL); /* the practicable BRP */
242	if (btc->brp_inc > 1)
243		brp64 *= btc->brp_inc;
244	bt->brp = (u32)brp64;
245
246	if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
247		return -EINVAL;
248
249	alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
250	bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
251	bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
252
253	return 0;
254}
255
256static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt)
257{
258	struct can_priv *priv = netdev_priv(dev);
259	int err;
260
261	/* Check if the CAN device has bit-timing parameters */
262	if (priv->bittiming_const) {
263
264		/* Non-expert mode? Check if the bitrate has been pre-defined */
265		if (!bt->tq)
266			/* Determine bit-timing parameters */
267			err = can_calc_bittiming(dev, bt);
268		else
269			/* Check bit-timing params and calculate proper brp */
270			err = can_fixup_bittiming(dev, bt);
271		if (err)
272			return err;
273	}
274
275	return 0;
276}
277
278/*
279 * Local echo of CAN messages
280 *
281 * CAN network devices *should* support a local echo functionality
282 * (see Documentation/networking/can.txt). To test the handling of CAN
283 * interfaces that do not support the local echo both driver types are
284 * implemented. In the case that the driver does not support the echo
285 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
286 * to perform the echo as a fallback solution.
287 */
288static void can_flush_echo_skb(struct net_device *dev)
289{
290	struct can_priv *priv = netdev_priv(dev);
291	struct net_device_stats *stats = &dev->stats;
292	int i;
293
294	for (i = 0; i < priv->echo_skb_max; i++) {
295		if (priv->echo_skb[i]) {
296			kfree_skb(priv->echo_skb[i]);
297			priv->echo_skb[i] = NULL;
298			stats->tx_dropped++;
299			stats->tx_aborted_errors++;
300		}
301	}
302}
303
304/*
305 * Put the skb on the stack to be looped backed locally lateron
306 *
307 * The function is typically called in the start_xmit function
308 * of the device driver. The driver must protect access to
309 * priv->echo_skb, if necessary.
310 */
311void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
312		      unsigned int idx)
313{
314	struct can_priv *priv = netdev_priv(dev);
315
316	BUG_ON(idx >= priv->echo_skb_max);
317
318	/* check flag whether this packet has to be looped back */
319	if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) {
320		kfree_skb(skb);
321		return;
322	}
323
324	if (!priv->echo_skb[idx]) {
325		struct sock *srcsk = skb->sk;
326
327		if (atomic_read(&skb->users) != 1) {
328			struct sk_buff *old_skb = skb;
329
330			skb = skb_clone(old_skb, GFP_ATOMIC);
331			kfree_skb(old_skb);
332			if (!skb)
333				return;
334		} else
335			skb_orphan(skb);
336
337		skb->sk = srcsk;
338
339		/* make settings for echo to reduce code in irq context */
340		skb->protocol = htons(ETH_P_CAN);
341		skb->pkt_type = PACKET_BROADCAST;
342		skb->ip_summed = CHECKSUM_UNNECESSARY;
343		skb->dev = dev;
344
345		/* save this skb for tx interrupt echo handling */
346		priv->echo_skb[idx] = skb;
347	} else {
348		/* locking problem with netif_stop_queue() ?? */
349		netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
350		kfree_skb(skb);
351	}
352}
353EXPORT_SYMBOL_GPL(can_put_echo_skb);
354
355/*
356 * Get the skb from the stack and loop it back locally
357 *
358 * The function is typically called when the TX done interrupt
359 * is handled in the device driver. The driver must protect
360 * access to priv->echo_skb, if necessary.
361 */
362unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
363{
364	struct can_priv *priv = netdev_priv(dev);
365
366	BUG_ON(idx >= priv->echo_skb_max);
367
368	if (priv->echo_skb[idx]) {
369		struct sk_buff *skb = priv->echo_skb[idx];
370		struct can_frame *cf = (struct can_frame *)skb->data;
371		u8 dlc = cf->can_dlc;
372
373		netif_rx(priv->echo_skb[idx]);
374		priv->echo_skb[idx] = NULL;
375
376		return dlc;
377	}
378
379	return 0;
380}
381EXPORT_SYMBOL_GPL(can_get_echo_skb);
382
383/*
384  * Remove the skb from the stack and free it.
385  *
386  * The function is typically called when TX failed.
387  */
388void can_free_echo_skb(struct net_device *dev, unsigned int idx)
389{
390	struct can_priv *priv = netdev_priv(dev);
391
392	BUG_ON(idx >= priv->echo_skb_max);
393
394	if (priv->echo_skb[idx]) {
395		kfree_skb(priv->echo_skb[idx]);
396		priv->echo_skb[idx] = NULL;
397	}
398}
399EXPORT_SYMBOL_GPL(can_free_echo_skb);
400
401/*
402 * CAN device restart for bus-off recovery
403 */
404static void can_restart(unsigned long data)
405{
406	struct net_device *dev = (struct net_device *)data;
407	struct can_priv *priv = netdev_priv(dev);
408	struct net_device_stats *stats = &dev->stats;
409	struct sk_buff *skb;
410	struct can_frame *cf;
411	int err;
412
413	BUG_ON(netif_carrier_ok(dev));
414
415	/*
416	 * No synchronization needed because the device is bus-off and
417	 * no messages can come in or go out.
418	 */
419	can_flush_echo_skb(dev);
420
421	/* send restart message upstream */
422	skb = alloc_can_err_skb(dev, &cf);
423	if (skb == NULL) {
424		err = -ENOMEM;
425		goto restart;
426	}
427	cf->can_id |= CAN_ERR_RESTARTED;
428
429	netif_rx(skb);
430
431	stats->rx_packets++;
432	stats->rx_bytes += cf->can_dlc;
433
434restart:
435	netdev_dbg(dev, "restarted\n");
436	priv->can_stats.restarts++;
437
438	/* Now restart the device */
439	err = priv->do_set_mode(dev, CAN_MODE_START);
440
441	netif_carrier_on(dev);
442	if (err)
443		netdev_err(dev, "Error %d during restart", err);
444}
445
446int can_restart_now(struct net_device *dev)
447{
448	struct can_priv *priv = netdev_priv(dev);
449
450	/*
451	 * A manual restart is only permitted if automatic restart is
452	 * disabled and the device is in the bus-off state
453	 */
454	if (priv->restart_ms)
455		return -EINVAL;
456	if (priv->state != CAN_STATE_BUS_OFF)
457		return -EBUSY;
458
459	/* Runs as soon as possible in the timer context */
460	mod_timer(&priv->restart_timer, jiffies);
461
462	return 0;
463}
464
465/*
466 * CAN bus-off
467 *
468 * This functions should be called when the device goes bus-off to
469 * tell the netif layer that no more packets can be sent or received.
470 * If enabled, a timer is started to trigger bus-off recovery.
471 */
472void can_bus_off(struct net_device *dev)
473{
474	struct can_priv *priv = netdev_priv(dev);
475
476	netdev_dbg(dev, "bus-off\n");
477
478	netif_carrier_off(dev);
479	priv->can_stats.bus_off++;
480
481	if (priv->restart_ms)
482		mod_timer(&priv->restart_timer,
483			  jiffies + (priv->restart_ms * HZ) / 1000);
484}
485EXPORT_SYMBOL_GPL(can_bus_off);
486
487static void can_setup(struct net_device *dev)
488{
489	dev->type = ARPHRD_CAN;
490	dev->mtu = CAN_MTU;
491	dev->hard_header_len = 0;
492	dev->addr_len = 0;
493	dev->tx_queue_len = 10;
494
495	/* New-style flags. */
496	dev->flags = IFF_NOARP;
497	dev->features = NETIF_F_HW_CSUM;
498}
499
500struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
501{
502	struct sk_buff *skb;
503
504	skb = netdev_alloc_skb(dev, sizeof(struct can_frame));
505	if (unlikely(!skb))
506		return NULL;
507
508	skb->protocol = htons(ETH_P_CAN);
509	skb->pkt_type = PACKET_BROADCAST;
510	skb->ip_summed = CHECKSUM_UNNECESSARY;
511	*cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
512	memset(*cf, 0, sizeof(struct can_frame));
513
514	return skb;
515}
516EXPORT_SYMBOL_GPL(alloc_can_skb);
517
518struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
519{
520	struct sk_buff *skb;
521
522	skb = alloc_can_skb(dev, cf);
523	if (unlikely(!skb))
524		return NULL;
525
526	(*cf)->can_id = CAN_ERR_FLAG;
527	(*cf)->can_dlc = CAN_ERR_DLC;
528
529	return skb;
530}
531EXPORT_SYMBOL_GPL(alloc_can_err_skb);
532
533/*
534 * Allocate and setup space for the CAN network device
535 */
536struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
537{
538	struct net_device *dev;
539	struct can_priv *priv;
540	int size;
541
542	if (echo_skb_max)
543		size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
544			echo_skb_max * sizeof(struct sk_buff *);
545	else
546		size = sizeof_priv;
547
548	dev = alloc_netdev(size, "can%d", can_setup);
549	if (!dev)
550		return NULL;
551
552	priv = netdev_priv(dev);
553
554	if (echo_skb_max) {
555		priv->echo_skb_max = echo_skb_max;
556		priv->echo_skb = (void *)priv +
557			ALIGN(sizeof_priv, sizeof(struct sk_buff *));
558	}
559
560	priv->state = CAN_STATE_STOPPED;
561
562	init_timer(&priv->restart_timer);
563
564	return dev;
565}
566EXPORT_SYMBOL_GPL(alloc_candev);
567
568/*
569 * Free space of the CAN network device
570 */
571void free_candev(struct net_device *dev)
572{
573	free_netdev(dev);
574}
575EXPORT_SYMBOL_GPL(free_candev);
576
577/*
578 * Common open function when the device gets opened.
579 *
580 * This function should be called in the open function of the device
581 * driver.
582 */
583int open_candev(struct net_device *dev)
584{
585	struct can_priv *priv = netdev_priv(dev);
586
587	if (!priv->bittiming.tq && !priv->bittiming.bitrate) {
588		netdev_err(dev, "bit-timing not yet defined\n");
589		return -EINVAL;
590	}
591
592	/* Switch carrier on if device was stopped while in bus-off state */
593	if (!netif_carrier_ok(dev))
594		netif_carrier_on(dev);
595
596	setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
597
598	return 0;
599}
600EXPORT_SYMBOL_GPL(open_candev);
601
602/*
603 * Common close function for cleanup before the device gets closed.
604 *
605 * This function should be called in the close function of the device
606 * driver.
607 */
608void close_candev(struct net_device *dev)
609{
610	struct can_priv *priv = netdev_priv(dev);
611
612	if (del_timer_sync(&priv->restart_timer))
613		dev_put(dev);
614	can_flush_echo_skb(dev);
615}
616EXPORT_SYMBOL_GPL(close_candev);
617
618/*
619 * CAN netlink interface
620 */
621static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
622	[IFLA_CAN_STATE]	= { .type = NLA_U32 },
623	[IFLA_CAN_CTRLMODE]	= { .len = sizeof(struct can_ctrlmode) },
624	[IFLA_CAN_RESTART_MS]	= { .type = NLA_U32 },
625	[IFLA_CAN_RESTART]	= { .type = NLA_U32 },
626	[IFLA_CAN_BITTIMING]	= { .len = sizeof(struct can_bittiming) },
627	[IFLA_CAN_BITTIMING_CONST]
628				= { .len = sizeof(struct can_bittiming_const) },
629	[IFLA_CAN_CLOCK]	= { .len = sizeof(struct can_clock) },
630	[IFLA_CAN_BERR_COUNTER]	= { .len = sizeof(struct can_berr_counter) },
631};
632
633static int can_changelink(struct net_device *dev,
634			  struct nlattr *tb[], struct nlattr *data[])
635{
636	struct can_priv *priv = netdev_priv(dev);
637	int err;
638
639	/* We need synchronization with dev->stop() */
640	ASSERT_RTNL();
641
642	if (data[IFLA_CAN_CTRLMODE]) {
643		struct can_ctrlmode *cm;
644
645		/* Do not allow changing controller mode while running */
646		if (dev->flags & IFF_UP)
647			return -EBUSY;
648		cm = nla_data(data[IFLA_CAN_CTRLMODE]);
649		if (cm->flags & ~priv->ctrlmode_supported)
650			return -EOPNOTSUPP;
651		priv->ctrlmode &= ~cm->mask;
652		priv->ctrlmode |= cm->flags;
653	}
654
655	if (data[IFLA_CAN_BITTIMING]) {
656		struct can_bittiming bt;
657
658		/* Do not allow changing bittiming while running */
659		if (dev->flags & IFF_UP)
660			return -EBUSY;
661		memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
662		if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq))
663			return -EINVAL;
664		err = can_get_bittiming(dev, &bt);
665		if (err)
666			return err;
667		memcpy(&priv->bittiming, &bt, sizeof(bt));
668
669		if (priv->do_set_bittiming) {
670			/* Finally, set the bit-timing registers */
671			err = priv->do_set_bittiming(dev);
672			if (err)
673				return err;
674		}
675	}
676
677	if (data[IFLA_CAN_RESTART_MS]) {
678		/* Do not allow changing restart delay while running */
679		if (dev->flags & IFF_UP)
680			return -EBUSY;
681		priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
682	}
683
684	if (data[IFLA_CAN_RESTART]) {
685		/* Do not allow a restart while not running */
686		if (!(dev->flags & IFF_UP))
687			return -EINVAL;
688		err = can_restart_now(dev);
689		if (err)
690			return err;
691	}
692
693	return 0;
694}
695
696static size_t can_get_size(const struct net_device *dev)
697{
698	struct can_priv *priv = netdev_priv(dev);
699	size_t size;
700
701	size = nla_total_size(sizeof(u32));   /* IFLA_CAN_STATE */
702	size += sizeof(struct can_ctrlmode);  /* IFLA_CAN_CTRLMODE */
703	size += nla_total_size(sizeof(u32));  /* IFLA_CAN_RESTART_MS */
704	size += sizeof(struct can_bittiming); /* IFLA_CAN_BITTIMING */
705	size += sizeof(struct can_clock);     /* IFLA_CAN_CLOCK */
706	if (priv->do_get_berr_counter)        /* IFLA_CAN_BERR_COUNTER */
707		size += sizeof(struct can_berr_counter);
708	if (priv->bittiming_const)	      /* IFLA_CAN_BITTIMING_CONST */
709		size += sizeof(struct can_bittiming_const);
710
711	return size;
712}
713
714static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
715{
716	struct can_priv *priv = netdev_priv(dev);
717	struct can_ctrlmode cm = {.flags = priv->ctrlmode};
718	struct can_berr_counter bec;
719	enum can_state state = priv->state;
720
721	if (priv->do_get_state)
722		priv->do_get_state(dev, &state);
723	if (nla_put_u32(skb, IFLA_CAN_STATE, state) ||
724	    nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
725	    nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
726	    nla_put(skb, IFLA_CAN_BITTIMING,
727		    sizeof(priv->bittiming), &priv->bittiming) ||
728	    nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) ||
729	    (priv->do_get_berr_counter &&
730	     !priv->do_get_berr_counter(dev, &bec) &&
731	     nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
732	    (priv->bittiming_const &&
733	     nla_put(skb, IFLA_CAN_BITTIMING_CONST,
734		     sizeof(*priv->bittiming_const), priv->bittiming_const)))
735		goto nla_put_failure;
736	return 0;
737
738nla_put_failure:
739	return -EMSGSIZE;
740}
741
742static size_t can_get_xstats_size(const struct net_device *dev)
743{
744	return sizeof(struct can_device_stats);
745}
746
747static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
748{
749	struct can_priv *priv = netdev_priv(dev);
750
751	if (nla_put(skb, IFLA_INFO_XSTATS,
752		    sizeof(priv->can_stats), &priv->can_stats))
753		goto nla_put_failure;
754	return 0;
755
756nla_put_failure:
757	return -EMSGSIZE;
758}
759
760static int can_newlink(struct net *src_net, struct net_device *dev,
761		       struct nlattr *tb[], struct nlattr *data[])
762{
763	return -EOPNOTSUPP;
764}
765
766static struct rtnl_link_ops can_link_ops __read_mostly = {
767	.kind		= "can",
768	.maxtype	= IFLA_CAN_MAX,
769	.policy		= can_policy,
770	.setup		= can_setup,
771	.newlink	= can_newlink,
772	.changelink	= can_changelink,
773	.get_size	= can_get_size,
774	.fill_info	= can_fill_info,
775	.get_xstats_size = can_get_xstats_size,
776	.fill_xstats	= can_fill_xstats,
777};
778
779/*
780 * Register the CAN network device
781 */
782int register_candev(struct net_device *dev)
783{
784	dev->rtnl_link_ops = &can_link_ops;
785	return register_netdev(dev);
786}
787EXPORT_SYMBOL_GPL(register_candev);
788
789/*
790 * Unregister the CAN network device
791 */
792void unregister_candev(struct net_device *dev)
793{
794	unregister_netdev(dev);
795}
796EXPORT_SYMBOL_GPL(unregister_candev);
797
798static __init int can_dev_init(void)
799{
800	int err;
801
802	err = rtnl_link_register(&can_link_ops);
803	if (!err)
804		printk(KERN_INFO MOD_DESC "\n");
805
806	return err;
807}
808module_init(can_dev_init);
809
810static __exit void can_dev_exit(void)
811{
812	rtnl_link_unregister(&can_link_ops);
813}
814module_exit(can_dev_exit);
815
816MODULE_ALIAS_RTNL_LINK("can");
817