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Commit | Line | Data |
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39549eef WG |
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 | |
05780d98 | 16 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
39549eef WG |
17 | */ |
18 | ||
19 | #include <linux/module.h> | |
20 | #include <linux/kernel.h> | |
5a0e3ad6 | 21 | #include <linux/slab.h> |
39549eef WG |
22 | #include <linux/netdevice.h> |
23 | #include <linux/if_arp.h> | |
24 | #include <linux/can.h> | |
25 | #include <linux/can/dev.h> | |
156c2bb9 | 26 | #include <linux/can/skb.h> |
39549eef | 27 | #include <linux/can/netlink.h> |
a1ef7bd9 | 28 | #include <linux/can/led.h> |
39549eef WG |
29 | #include <net/rtnetlink.h> |
30 | ||
31 | #define MOD_DESC "CAN device driver interface" | |
32 | ||
33 | MODULE_DESCRIPTION(MOD_DESC); | |
34 | MODULE_LICENSE("GPL v2"); | |
35 | MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); | |
36 | ||
1e0625fa OH |
37 | /* CAN DLC to real data length conversion helpers */ |
38 | ||
39 | static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7, | |
40 | 8, 12, 16, 20, 24, 32, 48, 64}; | |
41 | ||
42 | /* get data length from can_dlc with sanitized can_dlc */ | |
43 | u8 can_dlc2len(u8 can_dlc) | |
44 | { | |
45 | return dlc2len[can_dlc & 0x0F]; | |
46 | } | |
47 | EXPORT_SYMBOL_GPL(can_dlc2len); | |
48 | ||
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 */ | |
59 | ||
60 | /* map the sanitized data length to an appropriate data length code */ | |
61 | u8 can_len2dlc(u8 len) | |
62 | { | |
63 | if (unlikely(len > 64)) | |
64 | return 0xF; | |
65 | ||
66 | return len2dlc[len]; | |
67 | } | |
68 | EXPORT_SYMBOL_GPL(can_len2dlc); | |
69 | ||
39549eef WG |
70 | #ifdef CONFIG_CAN_CALC_BITTIMING |
71 | #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */ | |
72 | ||
73 | /* | |
74 | * Bit-timing calculation derived from: | |
75 | * | |
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 | |
80 | * | |
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. | |
85 | */ | |
86 | static int can_update_spt(const struct can_bittiming_const *btc, | |
87 | int sampl_pt, int tseg, int *tseg1, int *tseg2) | |
88 | { | |
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; | |
98 | } | |
99 | return 1000 * (tseg + 1 - *tseg2) / (tseg + 1); | |
100 | } | |
101 | ||
08da7da4 OH |
102 | static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, |
103 | const struct can_bittiming_const *btc) | |
39549eef WG |
104 | { |
105 | struct can_priv *priv = netdev_priv(dev); | |
39549eef WG |
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; | |
b25a4372 | 110 | long rate; |
39549eef WG |
111 | u64 v64; |
112 | ||
67b5909e | 113 | /* Use CiA recommended sample points */ |
39549eef WG |
114 | if (bt->sample_point) { |
115 | sampl_pt = bt->sample_point; | |
116 | } else { | |
117 | if (bt->bitrate > 800000) | |
118 | sampl_pt = 750; | |
119 | else if (bt->bitrate > 500000) | |
120 | sampl_pt = 800; | |
121 | else | |
122 | sampl_pt = 875; | |
123 | } | |
124 | ||
125 | /* tseg even = round down, odd = round up */ | |
126 | for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1; | |
127 | tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) { | |
128 | tsegall = 1 + tseg / 2; | |
129 | /* Compute all possible tseg choices (tseg=tseg1+tseg2) */ | |
130 | brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2; | |
131 | /* chose brp step which is possible in system */ | |
132 | brp = (brp / btc->brp_inc) * btc->brp_inc; | |
133 | if ((brp < btc->brp_min) || (brp > btc->brp_max)) | |
134 | continue; | |
135 | rate = priv->clock.freq / (brp * tsegall); | |
136 | error = bt->bitrate - rate; | |
137 | /* tseg brp biterror */ | |
138 | if (error < 0) | |
139 | error = -error; | |
140 | if (error > best_error) | |
141 | continue; | |
142 | best_error = error; | |
143 | if (error == 0) { | |
144 | spt = can_update_spt(btc, sampl_pt, tseg / 2, | |
145 | &tseg1, &tseg2); | |
146 | error = sampl_pt - spt; | |
147 | if (error < 0) | |
148 | error = -error; | |
149 | if (error > spt_error) | |
150 | continue; | |
151 | spt_error = error; | |
152 | } | |
153 | best_tseg = tseg / 2; | |
154 | best_brp = brp; | |
39549eef WG |
155 | if (error == 0) |
156 | break; | |
157 | } | |
158 | ||
159 | if (best_error) { | |
160 | /* Error in one-tenth of a percent */ | |
161 | error = (best_error * 1000) / bt->bitrate; | |
162 | if (error > CAN_CALC_MAX_ERROR) { | |
aabdfd6a WG |
163 | netdev_err(dev, |
164 | "bitrate error %ld.%ld%% too high\n", | |
165 | error / 10, error % 10); | |
39549eef WG |
166 | return -EDOM; |
167 | } else { | |
aabdfd6a WG |
168 | netdev_warn(dev, "bitrate error %ld.%ld%%\n", |
169 | error / 10, error % 10); | |
39549eef WG |
170 | } |
171 | } | |
172 | ||
173 | /* real sample point */ | |
174 | bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg, | |
175 | &tseg1, &tseg2); | |
176 | ||
177 | v64 = (u64)best_brp * 1000000000UL; | |
178 | do_div(v64, priv->clock.freq); | |
179 | bt->tq = (u32)v64; | |
180 | bt->prop_seg = tseg1 / 2; | |
181 | bt->phase_seg1 = tseg1 - bt->prop_seg; | |
182 | bt->phase_seg2 = tseg2; | |
2e114374 OH |
183 | |
184 | /* check for sjw user settings */ | |
185 | if (!bt->sjw || !btc->sjw_max) | |
186 | bt->sjw = 1; | |
187 | else { | |
188 | /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */ | |
189 | if (bt->sjw > btc->sjw_max) | |
190 | bt->sjw = btc->sjw_max; | |
191 | /* bt->sjw must not be higher than tseg2 */ | |
192 | if (tseg2 < bt->sjw) | |
193 | bt->sjw = tseg2; | |
194 | } | |
195 | ||
39549eef WG |
196 | bt->brp = best_brp; |
197 | /* real bit-rate */ | |
198 | bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1)); | |
199 | ||
200 | return 0; | |
201 | } | |
202 | #else /* !CONFIG_CAN_CALC_BITTIMING */ | |
08da7da4 OH |
203 | static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, |
204 | const struct can_bittiming_const *btc) | |
39549eef | 205 | { |
aabdfd6a | 206 | netdev_err(dev, "bit-timing calculation not available\n"); |
39549eef WG |
207 | return -EINVAL; |
208 | } | |
209 | #endif /* CONFIG_CAN_CALC_BITTIMING */ | |
210 | ||
211 | /* | |
212 | * Checks the validity of the specified bit-timing parameters prop_seg, | |
213 | * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate | |
214 | * prescaler value brp. You can find more information in the header | |
215 | * file linux/can/netlink.h. | |
216 | */ | |
08da7da4 OH |
217 | static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt, |
218 | const struct can_bittiming_const *btc) | |
39549eef WG |
219 | { |
220 | struct can_priv *priv = netdev_priv(dev); | |
39549eef WG |
221 | int tseg1, alltseg; |
222 | u64 brp64; | |
223 | ||
39549eef WG |
224 | tseg1 = bt->prop_seg + bt->phase_seg1; |
225 | if (!bt->sjw) | |
226 | bt->sjw = 1; | |
227 | if (bt->sjw > btc->sjw_max || | |
228 | tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max || | |
229 | bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max) | |
230 | return -ERANGE; | |
231 | ||
232 | brp64 = (u64)priv->clock.freq * (u64)bt->tq; | |
233 | if (btc->brp_inc > 1) | |
234 | do_div(brp64, btc->brp_inc); | |
235 | brp64 += 500000000UL - 1; | |
236 | do_div(brp64, 1000000000UL); /* the practicable BRP */ | |
237 | if (btc->brp_inc > 1) | |
238 | brp64 *= btc->brp_inc; | |
239 | bt->brp = (u32)brp64; | |
240 | ||
241 | if (bt->brp < btc->brp_min || bt->brp > btc->brp_max) | |
242 | return -EINVAL; | |
243 | ||
244 | alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1; | |
245 | bt->bitrate = priv->clock.freq / (bt->brp * alltseg); | |
246 | bt->sample_point = ((tseg1 + 1) * 1000) / alltseg; | |
247 | ||
248 | return 0; | |
249 | } | |
250 | ||
08da7da4 OH |
251 | static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt, |
252 | const struct can_bittiming_const *btc) | |
39549eef | 253 | { |
39549eef WG |
254 | int err; |
255 | ||
256 | /* Check if the CAN device has bit-timing parameters */ | |
08da7da4 | 257 | if (!btc) |
d4824432 | 258 | return -EOPNOTSUPP; |
39549eef | 259 | |
d5298dff OH |
260 | /* |
261 | * Depending on the given can_bittiming parameter structure the CAN | |
262 | * timing parameters are calculated based on the provided bitrate OR | |
263 | * alternatively the CAN timing parameters (tq, prop_seg, etc.) are | |
264 | * provided directly which are then checked and fixed up. | |
265 | */ | |
266 | if (!bt->tq && bt->bitrate) | |
08da7da4 | 267 | err = can_calc_bittiming(dev, bt, btc); |
d5298dff | 268 | else if (bt->tq && !bt->bitrate) |
08da7da4 | 269 | err = can_fixup_bittiming(dev, bt, btc); |
d5298dff OH |
270 | else |
271 | err = -EINVAL; | |
39549eef | 272 | |
d5298dff | 273 | return err; |
39549eef WG |
274 | } |
275 | ||
bac78aab AY |
276 | static void can_update_state_error_stats(struct net_device *dev, |
277 | enum can_state new_state) | |
278 | { | |
279 | struct can_priv *priv = netdev_priv(dev); | |
280 | ||
281 | if (new_state <= priv->state) | |
282 | return; | |
283 | ||
284 | switch (new_state) { | |
285 | case CAN_STATE_ERROR_WARNING: | |
286 | priv->can_stats.error_warning++; | |
287 | break; | |
288 | case CAN_STATE_ERROR_PASSIVE: | |
289 | priv->can_stats.error_passive++; | |
290 | break; | |
291 | case CAN_STATE_BUS_OFF: | |
292 | default: | |
293 | break; | |
294 | }; | |
295 | } | |
296 | ||
297 | static int can_tx_state_to_frame(struct net_device *dev, enum can_state state) | |
298 | { | |
299 | switch (state) { | |
300 | case CAN_STATE_ERROR_ACTIVE: | |
301 | return CAN_ERR_CRTL_ACTIVE; | |
302 | case CAN_STATE_ERROR_WARNING: | |
303 | return CAN_ERR_CRTL_TX_WARNING; | |
304 | case CAN_STATE_ERROR_PASSIVE: | |
305 | return CAN_ERR_CRTL_TX_PASSIVE; | |
306 | default: | |
307 | return 0; | |
308 | } | |
309 | } | |
310 | ||
311 | static int can_rx_state_to_frame(struct net_device *dev, enum can_state state) | |
312 | { | |
313 | switch (state) { | |
314 | case CAN_STATE_ERROR_ACTIVE: | |
315 | return CAN_ERR_CRTL_ACTIVE; | |
316 | case CAN_STATE_ERROR_WARNING: | |
317 | return CAN_ERR_CRTL_RX_WARNING; | |
318 | case CAN_STATE_ERROR_PASSIVE: | |
319 | return CAN_ERR_CRTL_RX_PASSIVE; | |
320 | default: | |
321 | return 0; | |
322 | } | |
323 | } | |
324 | ||
325 | void can_change_state(struct net_device *dev, struct can_frame *cf, | |
326 | enum can_state tx_state, enum can_state rx_state) | |
327 | { | |
328 | struct can_priv *priv = netdev_priv(dev); | |
329 | enum can_state new_state = max(tx_state, rx_state); | |
330 | ||
331 | if (unlikely(new_state == priv->state)) { | |
332 | netdev_warn(dev, "%s: oops, state did not change", __func__); | |
333 | return; | |
334 | } | |
335 | ||
336 | netdev_dbg(dev, "New error state: %d\n", new_state); | |
337 | ||
338 | can_update_state_error_stats(dev, new_state); | |
339 | priv->state = new_state; | |
340 | ||
341 | if (unlikely(new_state == CAN_STATE_BUS_OFF)) { | |
342 | cf->can_id |= CAN_ERR_BUSOFF; | |
343 | return; | |
344 | } | |
345 | ||
346 | cf->can_id |= CAN_ERR_CRTL; | |
347 | cf->data[1] |= tx_state >= rx_state ? | |
348 | can_tx_state_to_frame(dev, tx_state) : 0; | |
349 | cf->data[1] |= tx_state <= rx_state ? | |
350 | can_rx_state_to_frame(dev, rx_state) : 0; | |
351 | } | |
352 | EXPORT_SYMBOL_GPL(can_change_state); | |
353 | ||
39549eef WG |
354 | /* |
355 | * Local echo of CAN messages | |
356 | * | |
357 | * CAN network devices *should* support a local echo functionality | |
358 | * (see Documentation/networking/can.txt). To test the handling of CAN | |
359 | * interfaces that do not support the local echo both driver types are | |
360 | * implemented. In the case that the driver does not support the echo | |
361 | * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core | |
362 | * to perform the echo as a fallback solution. | |
363 | */ | |
364 | static void can_flush_echo_skb(struct net_device *dev) | |
365 | { | |
366 | struct can_priv *priv = netdev_priv(dev); | |
367 | struct net_device_stats *stats = &dev->stats; | |
368 | int i; | |
369 | ||
a6e4bc53 | 370 | for (i = 0; i < priv->echo_skb_max; i++) { |
39549eef WG |
371 | if (priv->echo_skb[i]) { |
372 | kfree_skb(priv->echo_skb[i]); | |
373 | priv->echo_skb[i] = NULL; | |
374 | stats->tx_dropped++; | |
375 | stats->tx_aborted_errors++; | |
376 | } | |
377 | } | |
378 | } | |
379 | ||
380 | /* | |
381 | * Put the skb on the stack to be looped backed locally lateron | |
382 | * | |
383 | * The function is typically called in the start_xmit function | |
384 | * of the device driver. The driver must protect access to | |
385 | * priv->echo_skb, if necessary. | |
386 | */ | |
a6e4bc53 WG |
387 | void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, |
388 | unsigned int idx) | |
39549eef WG |
389 | { |
390 | struct can_priv *priv = netdev_priv(dev); | |
391 | ||
a6e4bc53 WG |
392 | BUG_ON(idx >= priv->echo_skb_max); |
393 | ||
39549eef | 394 | /* check flag whether this packet has to be looped back */ |
a94bc9c4 OH |
395 | if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK || |
396 | (skb->protocol != htons(ETH_P_CAN) && | |
397 | skb->protocol != htons(ETH_P_CANFD))) { | |
39549eef WG |
398 | kfree_skb(skb); |
399 | return; | |
400 | } | |
401 | ||
402 | if (!priv->echo_skb[idx]) { | |
39549eef | 403 | |
0ae89beb OH |
404 | skb = can_create_echo_skb(skb); |
405 | if (!skb) | |
406 | return; | |
39549eef WG |
407 | |
408 | /* make settings for echo to reduce code in irq context */ | |
39549eef WG |
409 | skb->pkt_type = PACKET_BROADCAST; |
410 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
411 | skb->dev = dev; | |
412 | ||
413 | /* save this skb for tx interrupt echo handling */ | |
414 | priv->echo_skb[idx] = skb; | |
415 | } else { | |
416 | /* locking problem with netif_stop_queue() ?? */ | |
aabdfd6a | 417 | netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__); |
39549eef WG |
418 | kfree_skb(skb); |
419 | } | |
420 | } | |
421 | EXPORT_SYMBOL_GPL(can_put_echo_skb); | |
422 | ||
423 | /* | |
424 | * Get the skb from the stack and loop it back locally | |
425 | * | |
426 | * The function is typically called when the TX done interrupt | |
427 | * is handled in the device driver. The driver must protect | |
428 | * access to priv->echo_skb, if necessary. | |
429 | */ | |
cf5046b3 | 430 | unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx) |
39549eef WG |
431 | { |
432 | struct can_priv *priv = netdev_priv(dev); | |
433 | ||
a6e4bc53 WG |
434 | BUG_ON(idx >= priv->echo_skb_max); |
435 | ||
39e3ab6f | 436 | if (priv->echo_skb[idx]) { |
cf5046b3 MKB |
437 | struct sk_buff *skb = priv->echo_skb[idx]; |
438 | struct can_frame *cf = (struct can_frame *)skb->data; | |
439 | u8 dlc = cf->can_dlc; | |
440 | ||
39549eef WG |
441 | netif_rx(priv->echo_skb[idx]); |
442 | priv->echo_skb[idx] = NULL; | |
cf5046b3 MKB |
443 | |
444 | return dlc; | |
39549eef | 445 | } |
cf5046b3 MKB |
446 | |
447 | return 0; | |
39549eef WG |
448 | } |
449 | EXPORT_SYMBOL_GPL(can_get_echo_skb); | |
450 | ||
39e3ab6f WG |
451 | /* |
452 | * Remove the skb from the stack and free it. | |
453 | * | |
454 | * The function is typically called when TX failed. | |
455 | */ | |
a6e4bc53 | 456 | void can_free_echo_skb(struct net_device *dev, unsigned int idx) |
39e3ab6f WG |
457 | { |
458 | struct can_priv *priv = netdev_priv(dev); | |
459 | ||
a6e4bc53 WG |
460 | BUG_ON(idx >= priv->echo_skb_max); |
461 | ||
39e3ab6f | 462 | if (priv->echo_skb[idx]) { |
5247a589 | 463 | dev_kfree_skb_any(priv->echo_skb[idx]); |
39e3ab6f WG |
464 | priv->echo_skb[idx] = NULL; |
465 | } | |
466 | } | |
467 | EXPORT_SYMBOL_GPL(can_free_echo_skb); | |
468 | ||
39549eef WG |
469 | /* |
470 | * CAN device restart for bus-off recovery | |
471 | */ | |
77fc95a3 | 472 | static void can_restart(unsigned long data) |
39549eef WG |
473 | { |
474 | struct net_device *dev = (struct net_device *)data; | |
475 | struct can_priv *priv = netdev_priv(dev); | |
476 | struct net_device_stats *stats = &dev->stats; | |
477 | struct sk_buff *skb; | |
478 | struct can_frame *cf; | |
479 | int err; | |
480 | ||
481 | BUG_ON(netif_carrier_ok(dev)); | |
482 | ||
483 | /* | |
484 | * No synchronization needed because the device is bus-off and | |
485 | * no messages can come in or go out. | |
486 | */ | |
487 | can_flush_echo_skb(dev); | |
488 | ||
489 | /* send restart message upstream */ | |
7b6856a0 | 490 | skb = alloc_can_err_skb(dev, &cf); |
39549eef WG |
491 | if (skb == NULL) { |
492 | err = -ENOMEM; | |
b3d0df7c | 493 | goto restart; |
39549eef | 494 | } |
7b6856a0 | 495 | cf->can_id |= CAN_ERR_RESTARTED; |
39549eef WG |
496 | |
497 | netif_rx(skb); | |
498 | ||
39549eef WG |
499 | stats->rx_packets++; |
500 | stats->rx_bytes += cf->can_dlc; | |
501 | ||
b3d0df7c | 502 | restart: |
aabdfd6a | 503 | netdev_dbg(dev, "restarted\n"); |
39549eef WG |
504 | priv->can_stats.restarts++; |
505 | ||
506 | /* Now restart the device */ | |
507 | err = priv->do_set_mode(dev, CAN_MODE_START); | |
508 | ||
39549eef WG |
509 | netif_carrier_on(dev); |
510 | if (err) | |
aabdfd6a | 511 | netdev_err(dev, "Error %d during restart", err); |
39549eef WG |
512 | } |
513 | ||
514 | int can_restart_now(struct net_device *dev) | |
515 | { | |
516 | struct can_priv *priv = netdev_priv(dev); | |
517 | ||
518 | /* | |
519 | * A manual restart is only permitted if automatic restart is | |
520 | * disabled and the device is in the bus-off state | |
521 | */ | |
522 | if (priv->restart_ms) | |
523 | return -EINVAL; | |
524 | if (priv->state != CAN_STATE_BUS_OFF) | |
525 | return -EBUSY; | |
526 | ||
527 | /* Runs as soon as possible in the timer context */ | |
528 | mod_timer(&priv->restart_timer, jiffies); | |
529 | ||
530 | return 0; | |
531 | } | |
532 | ||
533 | /* | |
534 | * CAN bus-off | |
535 | * | |
536 | * This functions should be called when the device goes bus-off to | |
537 | * tell the netif layer that no more packets can be sent or received. | |
538 | * If enabled, a timer is started to trigger bus-off recovery. | |
539 | */ | |
540 | void can_bus_off(struct net_device *dev) | |
541 | { | |
542 | struct can_priv *priv = netdev_priv(dev); | |
543 | ||
aabdfd6a | 544 | netdev_dbg(dev, "bus-off\n"); |
39549eef WG |
545 | |
546 | netif_carrier_off(dev); | |
547 | priv->can_stats.bus_off++; | |
548 | ||
549 | if (priv->restart_ms) | |
550 | mod_timer(&priv->restart_timer, | |
551 | jiffies + (priv->restart_ms * HZ) / 1000); | |
552 | } | |
553 | EXPORT_SYMBOL_GPL(can_bus_off); | |
554 | ||
555 | static void can_setup(struct net_device *dev) | |
556 | { | |
557 | dev->type = ARPHRD_CAN; | |
1e0625fa | 558 | dev->mtu = CAN_MTU; |
39549eef WG |
559 | dev->hard_header_len = 0; |
560 | dev->addr_len = 0; | |
561 | dev->tx_queue_len = 10; | |
562 | ||
563 | /* New-style flags. */ | |
564 | dev->flags = IFF_NOARP; | |
34324dc2 | 565 | dev->features = NETIF_F_HW_CSUM; |
39549eef WG |
566 | } |
567 | ||
7b6856a0 WG |
568 | struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) |
569 | { | |
570 | struct sk_buff *skb; | |
571 | ||
156c2bb9 OH |
572 | skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + |
573 | sizeof(struct can_frame)); | |
7b6856a0 WG |
574 | if (unlikely(!skb)) |
575 | return NULL; | |
576 | ||
577 | skb->protocol = htons(ETH_P_CAN); | |
578 | skb->pkt_type = PACKET_BROADCAST; | |
579 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
156c2bb9 | 580 | |
1db8d025 OH |
581 | skb_reset_mac_header(skb); |
582 | skb_reset_network_header(skb); | |
583 | skb_reset_transport_header(skb); | |
584 | ||
2bf3440d OH |
585 | can_skb_reserve(skb); |
586 | can_skb_prv(skb)->ifindex = dev->ifindex; | |
156c2bb9 | 587 | |
7b6856a0 WG |
588 | *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); |
589 | memset(*cf, 0, sizeof(struct can_frame)); | |
590 | ||
591 | return skb; | |
592 | } | |
593 | EXPORT_SYMBOL_GPL(alloc_can_skb); | |
594 | ||
cb2518ca SG |
595 | struct sk_buff *alloc_canfd_skb(struct net_device *dev, |
596 | struct canfd_frame **cfd) | |
597 | { | |
598 | struct sk_buff *skb; | |
599 | ||
600 | skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + | |
601 | sizeof(struct canfd_frame)); | |
602 | if (unlikely(!skb)) | |
603 | return NULL; | |
604 | ||
605 | skb->protocol = htons(ETH_P_CANFD); | |
606 | skb->pkt_type = PACKET_BROADCAST; | |
607 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
608 | ||
1db8d025 OH |
609 | skb_reset_mac_header(skb); |
610 | skb_reset_network_header(skb); | |
611 | skb_reset_transport_header(skb); | |
612 | ||
cb2518ca SG |
613 | can_skb_reserve(skb); |
614 | can_skb_prv(skb)->ifindex = dev->ifindex; | |
615 | ||
616 | *cfd = (struct canfd_frame *)skb_put(skb, sizeof(struct canfd_frame)); | |
617 | memset(*cfd, 0, sizeof(struct canfd_frame)); | |
618 | ||
619 | return skb; | |
620 | } | |
621 | EXPORT_SYMBOL_GPL(alloc_canfd_skb); | |
622 | ||
7b6856a0 WG |
623 | struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) |
624 | { | |
625 | struct sk_buff *skb; | |
626 | ||
627 | skb = alloc_can_skb(dev, cf); | |
628 | if (unlikely(!skb)) | |
629 | return NULL; | |
630 | ||
631 | (*cf)->can_id = CAN_ERR_FLAG; | |
632 | (*cf)->can_dlc = CAN_ERR_DLC; | |
633 | ||
634 | return skb; | |
635 | } | |
636 | EXPORT_SYMBOL_GPL(alloc_can_err_skb); | |
637 | ||
39549eef WG |
638 | /* |
639 | * Allocate and setup space for the CAN network device | |
640 | */ | |
a6e4bc53 | 641 | struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) |
39549eef WG |
642 | { |
643 | struct net_device *dev; | |
644 | struct can_priv *priv; | |
a6e4bc53 | 645 | int size; |
39549eef | 646 | |
a6e4bc53 WG |
647 | if (echo_skb_max) |
648 | size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) + | |
649 | echo_skb_max * sizeof(struct sk_buff *); | |
650 | else | |
651 | size = sizeof_priv; | |
652 | ||
c835a677 | 653 | dev = alloc_netdev(size, "can%d", NET_NAME_UNKNOWN, can_setup); |
39549eef WG |
654 | if (!dev) |
655 | return NULL; | |
656 | ||
657 | priv = netdev_priv(dev); | |
658 | ||
a6e4bc53 WG |
659 | if (echo_skb_max) { |
660 | priv->echo_skb_max = echo_skb_max; | |
661 | priv->echo_skb = (void *)priv + | |
662 | ALIGN(sizeof_priv, sizeof(struct sk_buff *)); | |
663 | } | |
664 | ||
39549eef WG |
665 | priv->state = CAN_STATE_STOPPED; |
666 | ||
667 | init_timer(&priv->restart_timer); | |
668 | ||
669 | return dev; | |
670 | } | |
671 | EXPORT_SYMBOL_GPL(alloc_candev); | |
672 | ||
673 | /* | |
674 | * Free space of the CAN network device | |
675 | */ | |
676 | void free_candev(struct net_device *dev) | |
677 | { | |
678 | free_netdev(dev); | |
679 | } | |
680 | EXPORT_SYMBOL_GPL(free_candev); | |
681 | ||
bc05a894 OH |
682 | /* |
683 | * changing MTU and control mode for CAN/CANFD devices | |
684 | */ | |
685 | int can_change_mtu(struct net_device *dev, int new_mtu) | |
686 | { | |
687 | struct can_priv *priv = netdev_priv(dev); | |
688 | ||
689 | /* Do not allow changing the MTU while running */ | |
690 | if (dev->flags & IFF_UP) | |
691 | return -EBUSY; | |
692 | ||
693 | /* allow change of MTU according to the CANFD ability of the device */ | |
694 | switch (new_mtu) { | |
695 | case CAN_MTU: | |
696 | priv->ctrlmode &= ~CAN_CTRLMODE_FD; | |
697 | break; | |
698 | ||
699 | case CANFD_MTU: | |
700 | if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD)) | |
701 | return -EINVAL; | |
702 | ||
703 | priv->ctrlmode |= CAN_CTRLMODE_FD; | |
704 | break; | |
705 | ||
706 | default: | |
707 | return -EINVAL; | |
708 | } | |
709 | ||
710 | dev->mtu = new_mtu; | |
711 | return 0; | |
712 | } | |
713 | EXPORT_SYMBOL_GPL(can_change_mtu); | |
714 | ||
39549eef WG |
715 | /* |
716 | * Common open function when the device gets opened. | |
717 | * | |
718 | * This function should be called in the open function of the device | |
719 | * driver. | |
720 | */ | |
721 | int open_candev(struct net_device *dev) | |
722 | { | |
723 | struct can_priv *priv = netdev_priv(dev); | |
724 | ||
b30749fd | 725 | if (!priv->bittiming.bitrate) { |
aabdfd6a | 726 | netdev_err(dev, "bit-timing not yet defined\n"); |
39549eef WG |
727 | return -EINVAL; |
728 | } | |
729 | ||
dd22586d OH |
730 | /* For CAN FD the data bitrate has to be >= the arbitration bitrate */ |
731 | if ((priv->ctrlmode & CAN_CTRLMODE_FD) && | |
732 | (!priv->data_bittiming.bitrate || | |
733 | (priv->data_bittiming.bitrate < priv->bittiming.bitrate))) { | |
734 | netdev_err(dev, "incorrect/missing data bit-timing\n"); | |
735 | return -EINVAL; | |
736 | } | |
737 | ||
1b0d9224 WG |
738 | /* Switch carrier on if device was stopped while in bus-off state */ |
739 | if (!netif_carrier_ok(dev)) | |
740 | netif_carrier_on(dev); | |
741 | ||
39549eef WG |
742 | setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); |
743 | ||
744 | return 0; | |
745 | } | |
128ced8f | 746 | EXPORT_SYMBOL_GPL(open_candev); |
39549eef WG |
747 | |
748 | /* | |
749 | * Common close function for cleanup before the device gets closed. | |
750 | * | |
751 | * This function should be called in the close function of the device | |
752 | * driver. | |
753 | */ | |
754 | void close_candev(struct net_device *dev) | |
755 | { | |
756 | struct can_priv *priv = netdev_priv(dev); | |
757 | ||
ab48b03e | 758 | del_timer_sync(&priv->restart_timer); |
39549eef WG |
759 | can_flush_echo_skb(dev); |
760 | } | |
761 | EXPORT_SYMBOL_GPL(close_candev); | |
762 | ||
763 | /* | |
764 | * CAN netlink interface | |
765 | */ | |
766 | static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { | |
767 | [IFLA_CAN_STATE] = { .type = NLA_U32 }, | |
768 | [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, | |
769 | [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, | |
770 | [IFLA_CAN_RESTART] = { .type = NLA_U32 }, | |
771 | [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, | |
772 | [IFLA_CAN_BITTIMING_CONST] | |
773 | = { .len = sizeof(struct can_bittiming_const) }, | |
774 | [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, | |
52c793f2 | 775 | [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, |
9859ccd2 OH |
776 | [IFLA_CAN_DATA_BITTIMING] |
777 | = { .len = sizeof(struct can_bittiming) }, | |
778 | [IFLA_CAN_DATA_BITTIMING_CONST] | |
779 | = { .len = sizeof(struct can_bittiming_const) }, | |
39549eef WG |
780 | }; |
781 | ||
782 | static int can_changelink(struct net_device *dev, | |
783 | struct nlattr *tb[], struct nlattr *data[]) | |
784 | { | |
785 | struct can_priv *priv = netdev_priv(dev); | |
786 | int err; | |
787 | ||
788 | /* We need synchronization with dev->stop() */ | |
789 | ASSERT_RTNL(); | |
790 | ||
39549eef WG |
791 | if (data[IFLA_CAN_BITTIMING]) { |
792 | struct can_bittiming bt; | |
793 | ||
794 | /* Do not allow changing bittiming while running */ | |
795 | if (dev->flags & IFF_UP) | |
796 | return -EBUSY; | |
797 | memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); | |
08da7da4 | 798 | err = can_get_bittiming(dev, &bt, priv->bittiming_const); |
39549eef WG |
799 | if (err) |
800 | return err; | |
801 | memcpy(&priv->bittiming, &bt, sizeof(bt)); | |
802 | ||
803 | if (priv->do_set_bittiming) { | |
804 | /* Finally, set the bit-timing registers */ | |
805 | err = priv->do_set_bittiming(dev); | |
806 | if (err) | |
807 | return err; | |
808 | } | |
809 | } | |
810 | ||
49cb5c0e MKB |
811 | if (data[IFLA_CAN_CTRLMODE]) { |
812 | struct can_ctrlmode *cm; | |
813 | ||
814 | /* Do not allow changing controller mode while running */ | |
815 | if (dev->flags & IFF_UP) | |
816 | return -EBUSY; | |
817 | cm = nla_data(data[IFLA_CAN_CTRLMODE]); | |
9b1087aa OH |
818 | |
819 | /* check whether changed bits are allowed to be modified */ | |
820 | if (cm->mask & ~priv->ctrlmode_supported) | |
49cb5c0e | 821 | return -EOPNOTSUPP; |
9b1087aa OH |
822 | |
823 | /* clear bits to be modified and copy the flag values */ | |
49cb5c0e | 824 | priv->ctrlmode &= ~cm->mask; |
9b1087aa | 825 | priv->ctrlmode |= (cm->flags & cm->mask); |
bc05a894 OH |
826 | |
827 | /* CAN_CTRLMODE_FD can only be set when driver supports FD */ | |
828 | if (priv->ctrlmode & CAN_CTRLMODE_FD) | |
829 | dev->mtu = CANFD_MTU; | |
830 | else | |
831 | dev->mtu = CAN_MTU; | |
49cb5c0e MKB |
832 | } |
833 | ||
39549eef WG |
834 | if (data[IFLA_CAN_RESTART_MS]) { |
835 | /* Do not allow changing restart delay while running */ | |
836 | if (dev->flags & IFF_UP) | |
837 | return -EBUSY; | |
838 | priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); | |
839 | } | |
840 | ||
841 | if (data[IFLA_CAN_RESTART]) { | |
842 | /* Do not allow a restart while not running */ | |
843 | if (!(dev->flags & IFF_UP)) | |
844 | return -EINVAL; | |
845 | err = can_restart_now(dev); | |
846 | if (err) | |
847 | return err; | |
848 | } | |
849 | ||
9859ccd2 OH |
850 | if (data[IFLA_CAN_DATA_BITTIMING]) { |
851 | struct can_bittiming dbt; | |
852 | ||
853 | /* Do not allow changing bittiming while running */ | |
854 | if (dev->flags & IFF_UP) | |
855 | return -EBUSY; | |
856 | memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]), | |
857 | sizeof(dbt)); | |
858 | err = can_get_bittiming(dev, &dbt, priv->data_bittiming_const); | |
859 | if (err) | |
860 | return err; | |
861 | memcpy(&priv->data_bittiming, &dbt, sizeof(dbt)); | |
862 | ||
863 | if (priv->do_set_data_bittiming) { | |
864 | /* Finally, set the bit-timing registers */ | |
865 | err = priv->do_set_data_bittiming(dev); | |
866 | if (err) | |
867 | return err; | |
868 | } | |
869 | } | |
870 | ||
39549eef WG |
871 | return 0; |
872 | } | |
873 | ||
53a0ef86 WG |
874 | static size_t can_get_size(const struct net_device *dev) |
875 | { | |
876 | struct can_priv *priv = netdev_priv(dev); | |
c13c64d8 MKB |
877 | size_t size = 0; |
878 | ||
b30749fd OH |
879 | if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */ |
880 | size += nla_total_size(sizeof(struct can_bittiming)); | |
c13c64d8 | 881 | if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ |
fe119a05 | 882 | size += nla_total_size(sizeof(struct can_bittiming_const)); |
c13c64d8 MKB |
883 | size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */ |
884 | size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ | |
885 | size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */ | |
886 | size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ | |
887 | if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ | |
888 | size += nla_total_size(sizeof(struct can_berr_counter)); | |
9859ccd2 OH |
889 | if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */ |
890 | size += nla_total_size(sizeof(struct can_bittiming)); | |
891 | if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */ | |
892 | size += nla_total_size(sizeof(struct can_bittiming_const)); | |
53a0ef86 WG |
893 | |
894 | return size; | |
895 | } | |
896 | ||
39549eef WG |
897 | static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) |
898 | { | |
899 | struct can_priv *priv = netdev_priv(dev); | |
900 | struct can_ctrlmode cm = {.flags = priv->ctrlmode}; | |
52c793f2 | 901 | struct can_berr_counter bec; |
39549eef WG |
902 | enum can_state state = priv->state; |
903 | ||
904 | if (priv->do_get_state) | |
905 | priv->do_get_state(dev, &state); | |
9859ccd2 | 906 | |
b30749fd OH |
907 | if ((priv->bittiming.bitrate && |
908 | nla_put(skb, IFLA_CAN_BITTIMING, | |
909 | sizeof(priv->bittiming), &priv->bittiming)) || | |
9859ccd2 | 910 | |
57a59b9e MKB |
911 | (priv->bittiming_const && |
912 | nla_put(skb, IFLA_CAN_BITTIMING_CONST, | |
913 | sizeof(*priv->bittiming_const), priv->bittiming_const)) || | |
9859ccd2 | 914 | |
31e0e328 | 915 | nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) || |
57a59b9e MKB |
916 | nla_put_u32(skb, IFLA_CAN_STATE, state) || |
917 | nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) || | |
918 | nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) || | |
9859ccd2 | 919 | |
31e0e328 DM |
920 | (priv->do_get_berr_counter && |
921 | !priv->do_get_berr_counter(dev, &bec) && | |
9859ccd2 OH |
922 | nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) || |
923 | ||
924 | (priv->data_bittiming.bitrate && | |
925 | nla_put(skb, IFLA_CAN_DATA_BITTIMING, | |
926 | sizeof(priv->data_bittiming), &priv->data_bittiming)) || | |
927 | ||
928 | (priv->data_bittiming_const && | |
929 | nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST, | |
930 | sizeof(*priv->data_bittiming_const), | |
931 | priv->data_bittiming_const))) | |
57a59b9e | 932 | return -EMSGSIZE; |
9859ccd2 | 933 | |
39549eef | 934 | return 0; |
39549eef WG |
935 | } |
936 | ||
55369c0a WG |
937 | static size_t can_get_xstats_size(const struct net_device *dev) |
938 | { | |
939 | return sizeof(struct can_device_stats); | |
940 | } | |
941 | ||
39549eef WG |
942 | static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) |
943 | { | |
944 | struct can_priv *priv = netdev_priv(dev); | |
945 | ||
31e0e328 DM |
946 | if (nla_put(skb, IFLA_INFO_XSTATS, |
947 | sizeof(priv->can_stats), &priv->can_stats)) | |
948 | goto nla_put_failure; | |
39549eef WG |
949 | return 0; |
950 | ||
951 | nla_put_failure: | |
952 | return -EMSGSIZE; | |
953 | } | |
954 | ||
81adee47 | 955 | static int can_newlink(struct net *src_net, struct net_device *dev, |
993e6f2f OH |
956 | struct nlattr *tb[], struct nlattr *data[]) |
957 | { | |
958 | return -EOPNOTSUPP; | |
959 | } | |
960 | ||
39549eef WG |
961 | static struct rtnl_link_ops can_link_ops __read_mostly = { |
962 | .kind = "can", | |
963 | .maxtype = IFLA_CAN_MAX, | |
964 | .policy = can_policy, | |
965 | .setup = can_setup, | |
993e6f2f | 966 | .newlink = can_newlink, |
39549eef | 967 | .changelink = can_changelink, |
53a0ef86 | 968 | .get_size = can_get_size, |
39549eef | 969 | .fill_info = can_fill_info, |
55369c0a | 970 | .get_xstats_size = can_get_xstats_size, |
39549eef WG |
971 | .fill_xstats = can_fill_xstats, |
972 | }; | |
973 | ||
974 | /* | |
975 | * Register the CAN network device | |
976 | */ | |
977 | int register_candev(struct net_device *dev) | |
978 | { | |
979 | dev->rtnl_link_ops = &can_link_ops; | |
980 | return register_netdev(dev); | |
981 | } | |
982 | EXPORT_SYMBOL_GPL(register_candev); | |
983 | ||
984 | /* | |
985 | * Unregister the CAN network device | |
986 | */ | |
987 | void unregister_candev(struct net_device *dev) | |
988 | { | |
989 | unregister_netdev(dev); | |
990 | } | |
991 | EXPORT_SYMBOL_GPL(unregister_candev); | |
992 | ||
bf03a537 KVD |
993 | /* |
994 | * Test if a network device is a candev based device | |
995 | * and return the can_priv* if so. | |
996 | */ | |
997 | struct can_priv *safe_candev_priv(struct net_device *dev) | |
998 | { | |
999 | if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops)) | |
1000 | return NULL; | |
1001 | ||
1002 | return netdev_priv(dev); | |
1003 | } | |
1004 | EXPORT_SYMBOL_GPL(safe_candev_priv); | |
1005 | ||
39549eef WG |
1006 | static __init int can_dev_init(void) |
1007 | { | |
1008 | int err; | |
1009 | ||
a1ef7bd9 KVD |
1010 | can_led_notifier_init(); |
1011 | ||
39549eef WG |
1012 | err = rtnl_link_register(&can_link_ops); |
1013 | if (!err) | |
1014 | printk(KERN_INFO MOD_DESC "\n"); | |
1015 | ||
1016 | return err; | |
1017 | } | |
1018 | module_init(can_dev_init); | |
1019 | ||
1020 | static __exit void can_dev_exit(void) | |
1021 | { | |
1022 | rtnl_link_unregister(&can_link_ops); | |
a1ef7bd9 KVD |
1023 | |
1024 | can_led_notifier_exit(); | |
39549eef WG |
1025 | } |
1026 | module_exit(can_dev_exit); | |
1027 | ||
1028 | MODULE_ALIAS_RTNL_LINK("can"); |