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Wolfgang Grandegger39549ee2009-05-15 23:39:29 +00001/*
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
Jeff Kirsher05780d92013-12-06 06:28:45 -080016 * along with this program; if not, see <http://www.gnu.org/licenses/>.
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +000017 */
18
19#include <linux/module.h>
20#include <linux/kernel.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090021#include <linux/slab.h>
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +000022#include <linux/netdevice.h>
23#include <linux/if_arp.h>
24#include <linux/can.h>
25#include <linux/can/dev.h>
Oliver Hartkopp156c2bb2013-01-17 18:43:39 +010026#include <linux/can/skb.h>
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +000027#include <linux/can/netlink.h>
Kurt Van Dijcka1ef7bd2012-12-18 18:50:57 +010028#include <linux/can/led.h>
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +000029#include <net/rtnetlink.h>
30
31#define MOD_DESC "CAN device driver interface"
32
33MODULE_DESCRIPTION(MOD_DESC);
34MODULE_LICENSE("GPL v2");
35MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
36
Oliver Hartkopp1e0625f2012-06-13 20:48:21 +020037/* CAN DLC to real data length conversion helpers */
38
39static 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 */
43u8 can_dlc2len(u8 can_dlc)
44{
45 return dlc2len[can_dlc & 0x0F];
46}
47EXPORT_SYMBOL_GPL(can_dlc2len);
48
49static 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 */
61u8 can_len2dlc(u8 len)
62{
63 if (unlikely(len > 64))
64 return 0xF;
65
66 return len2dlc[len];
67}
68EXPORT_SYMBOL_GPL(can_len2dlc);
69
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +000070#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 */
86static 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
102static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
103{
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;
111 u64 v64;
112
113 if (!priv->bittiming_const)
114 return -ENOTSUPP;
115
116 /* Use CIA recommended sample points */
117 if (bt->sample_point) {
118 sampl_pt = bt->sample_point;
119 } else {
120 if (bt->bitrate > 800000)
121 sampl_pt = 750;
122 else if (bt->bitrate > 500000)
123 sampl_pt = 800;
124 else
125 sampl_pt = 875;
126 }
127
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))
137 continue;
138 rate = priv->clock.freq / (brp * tsegall);
139 error = bt->bitrate - rate;
140 /* tseg brp biterror */
141 if (error < 0)
142 error = -error;
143 if (error > best_error)
144 continue;
145 best_error = error;
146 if (error == 0) {
147 spt = can_update_spt(btc, sampl_pt, tseg / 2,
148 &tseg1, &tseg2);
149 error = sampl_pt - spt;
150 if (error < 0)
151 error = -error;
152 if (error > spt_error)
153 continue;
154 spt_error = error;
155 }
156 best_tseg = tseg / 2;
157 best_brp = brp;
158 best_rate = rate;
159 if (error == 0)
160 break;
161 }
162
163 if (best_error) {
164 /* Error in one-tenth of a percent */
165 error = (best_error * 1000) / bt->bitrate;
166 if (error > CAN_CALC_MAX_ERROR) {
Wolfgang Grandeggeraabdfd62012-02-01 11:02:05 +0100167 netdev_err(dev,
168 "bitrate error %ld.%ld%% too high\n",
169 error / 10, error % 10);
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000170 return -EDOM;
171 } else {
Wolfgang Grandeggeraabdfd62012-02-01 11:02:05 +0100172 netdev_warn(dev, "bitrate error %ld.%ld%%\n",
173 error / 10, error % 10);
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000174 }
175 }
176
177 /* real sample point */
178 bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
179 &tseg1, &tseg2);
180
181 v64 = (u64)best_brp * 1000000000UL;
182 do_div(v64, priv->clock.freq);
183 bt->tq = (u32)v64;
184 bt->prop_seg = tseg1 / 2;
185 bt->phase_seg1 = tseg1 - bt->prop_seg;
186 bt->phase_seg2 = tseg2;
Oliver Hartkopp2e114372011-09-28 02:50:11 +0000187
188 /* check for sjw user settings */
189 if (!bt->sjw || !btc->sjw_max)
190 bt->sjw = 1;
191 else {
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 */
196 if (tseg2 < bt->sjw)
197 bt->sjw = tseg2;
198 }
199
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000200 bt->brp = best_brp;
201 /* real bit-rate */
202 bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
203
204 return 0;
205}
206#else /* !CONFIG_CAN_CALC_BITTIMING */
207static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
208{
Wolfgang Grandeggeraabdfd62012-02-01 11:02:05 +0100209 netdev_err(dev, "bit-timing calculation not available\n");
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000210 return -EINVAL;
211}
212#endif /* CONFIG_CAN_CALC_BITTIMING */
213
214/*
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.
219 */
220static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt)
221{
222 struct can_priv *priv = netdev_priv(dev);
223 const struct can_bittiming_const *btc = priv->bittiming_const;
224 int tseg1, alltseg;
225 u64 brp64;
226
227 if (!priv->bittiming_const)
228 return -ENOTSUPP;
229
230 tseg1 = bt->prop_seg + bt->phase_seg1;
231 if (!bt->sjw)
232 bt->sjw = 1;
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)
236 return -ERANGE;
237
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;
246
247 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
248 return -EINVAL;
249
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;
253
254 return 0;
255}
256
Thadeu Lima de Souza Cascardo61463a32011-07-21 16:22:31 +0000257static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt)
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000258{
259 struct can_priv *priv = netdev_priv(dev);
260 int err;
261
262 /* Check if the CAN device has bit-timing parameters */
263 if (priv->bittiming_const) {
264
265 /* Non-expert mode? Check if the bitrate has been pre-defined */
266 if (!bt->tq)
267 /* Determine bit-timing parameters */
268 err = can_calc_bittiming(dev, bt);
269 else
270 /* Check bit-timing params and calculate proper brp */
271 err = can_fixup_bittiming(dev, bt);
272 if (err)
273 return err;
274 }
275
276 return 0;
277}
278
279/*
280 * Local echo of CAN messages
281 *
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.
288 */
289static void can_flush_echo_skb(struct net_device *dev)
290{
291 struct can_priv *priv = netdev_priv(dev);
292 struct net_device_stats *stats = &dev->stats;
293 int i;
294
Wolfgang Grandeggera6e4bc52009-10-08 22:17:11 +0000295 for (i = 0; i < priv->echo_skb_max; i++) {
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000296 if (priv->echo_skb[i]) {
297 kfree_skb(priv->echo_skb[i]);
298 priv->echo_skb[i] = NULL;
299 stats->tx_dropped++;
300 stats->tx_aborted_errors++;
301 }
302 }
303}
304
305/*
306 * Put the skb on the stack to be looped backed locally lateron
307 *
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.
311 */
Wolfgang Grandeggera6e4bc52009-10-08 22:17:11 +0000312void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
313 unsigned int idx)
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000314{
315 struct can_priv *priv = netdev_priv(dev);
316
Wolfgang Grandeggera6e4bc52009-10-08 22:17:11 +0000317 BUG_ON(idx >= priv->echo_skb_max);
318
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000319 /* check flag whether this packet has to be looped back */
320 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) {
321 kfree_skb(skb);
322 return;
323 }
324
325 if (!priv->echo_skb[idx]) {
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000326
Oliver Hartkopp0ae89be2014-01-30 10:11:28 +0100327 skb = can_create_echo_skb(skb);
328 if (!skb)
329 return;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000330
331 /* make settings for echo to reduce code in irq context */
332 skb->protocol = htons(ETH_P_CAN);
333 skb->pkt_type = PACKET_BROADCAST;
334 skb->ip_summed = CHECKSUM_UNNECESSARY;
335 skb->dev = dev;
336
337 /* save this skb for tx interrupt echo handling */
338 priv->echo_skb[idx] = skb;
339 } else {
340 /* locking problem with netif_stop_queue() ?? */
Wolfgang Grandeggeraabdfd62012-02-01 11:02:05 +0100341 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000342 kfree_skb(skb);
343 }
344}
345EXPORT_SYMBOL_GPL(can_put_echo_skb);
346
347/*
348 * Get the skb from the stack and loop it back locally
349 *
350 * The function is typically called when the TX done interrupt
351 * is handled in the device driver. The driver must protect
352 * access to priv->echo_skb, if necessary.
353 */
Marc Kleine-Buddecf5046b2011-10-10 23:43:53 +0200354unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000355{
356 struct can_priv *priv = netdev_priv(dev);
357
Wolfgang Grandeggera6e4bc52009-10-08 22:17:11 +0000358 BUG_ON(idx >= priv->echo_skb_max);
359
Wolfgang Grandegger39e3ab62009-09-01 05:26:12 +0000360 if (priv->echo_skb[idx]) {
Marc Kleine-Buddecf5046b2011-10-10 23:43:53 +0200361 struct sk_buff *skb = priv->echo_skb[idx];
362 struct can_frame *cf = (struct can_frame *)skb->data;
363 u8 dlc = cf->can_dlc;
364
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000365 netif_rx(priv->echo_skb[idx]);
366 priv->echo_skb[idx] = NULL;
Marc Kleine-Buddecf5046b2011-10-10 23:43:53 +0200367
368 return dlc;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000369 }
Marc Kleine-Buddecf5046b2011-10-10 23:43:53 +0200370
371 return 0;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000372}
373EXPORT_SYMBOL_GPL(can_get_echo_skb);
374
375/*
Wolfgang Grandegger39e3ab62009-09-01 05:26:12 +0000376 * Remove the skb from the stack and free it.
377 *
378 * The function is typically called when TX failed.
379 */
Wolfgang Grandeggera6e4bc52009-10-08 22:17:11 +0000380void can_free_echo_skb(struct net_device *dev, unsigned int idx)
Wolfgang Grandegger39e3ab62009-09-01 05:26:12 +0000381{
382 struct can_priv *priv = netdev_priv(dev);
383
Wolfgang Grandeggera6e4bc52009-10-08 22:17:11 +0000384 BUG_ON(idx >= priv->echo_skb_max);
385
Wolfgang Grandegger39e3ab62009-09-01 05:26:12 +0000386 if (priv->echo_skb[idx]) {
387 kfree_skb(priv->echo_skb[idx]);
388 priv->echo_skb[idx] = NULL;
389 }
390}
391EXPORT_SYMBOL_GPL(can_free_echo_skb);
392
393/*
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000394 * CAN device restart for bus-off recovery
395 */
Marc Kleine-Budde77fc95a2012-02-06 22:21:13 +0100396static void can_restart(unsigned long data)
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000397{
398 struct net_device *dev = (struct net_device *)data;
399 struct can_priv *priv = netdev_priv(dev);
400 struct net_device_stats *stats = &dev->stats;
401 struct sk_buff *skb;
402 struct can_frame *cf;
403 int err;
404
405 BUG_ON(netif_carrier_ok(dev));
406
407 /*
408 * No synchronization needed because the device is bus-off and
409 * no messages can come in or go out.
410 */
411 can_flush_echo_skb(dev);
412
413 /* send restart message upstream */
Wolfgang Grandegger7b6856a2009-10-20 00:08:01 -0700414 skb = alloc_can_err_skb(dev, &cf);
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000415 if (skb == NULL) {
416 err = -ENOMEM;
Wolfgang Grandeggerb3d0df72009-07-20 04:06:40 +0000417 goto restart;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000418 }
Wolfgang Grandegger7b6856a2009-10-20 00:08:01 -0700419 cf->can_id |= CAN_ERR_RESTARTED;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000420
421 netif_rx(skb);
422
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000423 stats->rx_packets++;
424 stats->rx_bytes += cf->can_dlc;
425
Wolfgang Grandeggerb3d0df72009-07-20 04:06:40 +0000426restart:
Wolfgang Grandeggeraabdfd62012-02-01 11:02:05 +0100427 netdev_dbg(dev, "restarted\n");
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000428 priv->can_stats.restarts++;
429
430 /* Now restart the device */
431 err = priv->do_set_mode(dev, CAN_MODE_START);
432
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000433 netif_carrier_on(dev);
434 if (err)
Wolfgang Grandeggeraabdfd62012-02-01 11:02:05 +0100435 netdev_err(dev, "Error %d during restart", err);
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000436}
437
438int can_restart_now(struct net_device *dev)
439{
440 struct can_priv *priv = netdev_priv(dev);
441
442 /*
443 * A manual restart is only permitted if automatic restart is
444 * disabled and the device is in the bus-off state
445 */
446 if (priv->restart_ms)
447 return -EINVAL;
448 if (priv->state != CAN_STATE_BUS_OFF)
449 return -EBUSY;
450
451 /* Runs as soon as possible in the timer context */
452 mod_timer(&priv->restart_timer, jiffies);
453
454 return 0;
455}
456
457/*
458 * CAN bus-off
459 *
460 * This functions should be called when the device goes bus-off to
461 * tell the netif layer that no more packets can be sent or received.
462 * If enabled, a timer is started to trigger bus-off recovery.
463 */
464void can_bus_off(struct net_device *dev)
465{
466 struct can_priv *priv = netdev_priv(dev);
467
Wolfgang Grandeggeraabdfd62012-02-01 11:02:05 +0100468 netdev_dbg(dev, "bus-off\n");
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000469
470 netif_carrier_off(dev);
471 priv->can_stats.bus_off++;
472
473 if (priv->restart_ms)
474 mod_timer(&priv->restart_timer,
475 jiffies + (priv->restart_ms * HZ) / 1000);
476}
477EXPORT_SYMBOL_GPL(can_bus_off);
478
479static void can_setup(struct net_device *dev)
480{
481 dev->type = ARPHRD_CAN;
Oliver Hartkopp1e0625f2012-06-13 20:48:21 +0200482 dev->mtu = CAN_MTU;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000483 dev->hard_header_len = 0;
484 dev->addr_len = 0;
485 dev->tx_queue_len = 10;
486
487 /* New-style flags. */
488 dev->flags = IFF_NOARP;
Michał Mirosław34324dc2011-11-15 15:29:55 +0000489 dev->features = NETIF_F_HW_CSUM;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000490}
491
Wolfgang Grandegger7b6856a2009-10-20 00:08:01 -0700492struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
493{
494 struct sk_buff *skb;
495
Oliver Hartkopp156c2bb2013-01-17 18:43:39 +0100496 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
497 sizeof(struct can_frame));
Wolfgang Grandegger7b6856a2009-10-20 00:08:01 -0700498 if (unlikely(!skb))
499 return NULL;
500
501 skb->protocol = htons(ETH_P_CAN);
502 skb->pkt_type = PACKET_BROADCAST;
503 skb->ip_summed = CHECKSUM_UNNECESSARY;
Oliver Hartkopp156c2bb2013-01-17 18:43:39 +0100504
Oliver Hartkopp2bf34402013-01-28 08:33:33 +0000505 can_skb_reserve(skb);
506 can_skb_prv(skb)->ifindex = dev->ifindex;
Oliver Hartkopp156c2bb2013-01-17 18:43:39 +0100507
Wolfgang Grandegger7b6856a2009-10-20 00:08:01 -0700508 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
509 memset(*cf, 0, sizeof(struct can_frame));
510
511 return skb;
512}
513EXPORT_SYMBOL_GPL(alloc_can_skb);
514
515struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
516{
517 struct sk_buff *skb;
518
519 skb = alloc_can_skb(dev, cf);
520 if (unlikely(!skb))
521 return NULL;
522
523 (*cf)->can_id = CAN_ERR_FLAG;
524 (*cf)->can_dlc = CAN_ERR_DLC;
525
526 return skb;
527}
528EXPORT_SYMBOL_GPL(alloc_can_err_skb);
529
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000530/*
531 * Allocate and setup space for the CAN network device
532 */
Wolfgang Grandeggera6e4bc52009-10-08 22:17:11 +0000533struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000534{
535 struct net_device *dev;
536 struct can_priv *priv;
Wolfgang Grandeggera6e4bc52009-10-08 22:17:11 +0000537 int size;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000538
Wolfgang Grandeggera6e4bc52009-10-08 22:17:11 +0000539 if (echo_skb_max)
540 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
541 echo_skb_max * sizeof(struct sk_buff *);
542 else
543 size = sizeof_priv;
544
545 dev = alloc_netdev(size, "can%d", can_setup);
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000546 if (!dev)
547 return NULL;
548
549 priv = netdev_priv(dev);
550
Wolfgang Grandeggera6e4bc52009-10-08 22:17:11 +0000551 if (echo_skb_max) {
552 priv->echo_skb_max = echo_skb_max;
553 priv->echo_skb = (void *)priv +
554 ALIGN(sizeof_priv, sizeof(struct sk_buff *));
555 }
556
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000557 priv->state = CAN_STATE_STOPPED;
558
559 init_timer(&priv->restart_timer);
560
561 return dev;
562}
563EXPORT_SYMBOL_GPL(alloc_candev);
564
565/*
566 * Free space of the CAN network device
567 */
568void free_candev(struct net_device *dev)
569{
570 free_netdev(dev);
571}
572EXPORT_SYMBOL_GPL(free_candev);
573
574/*
575 * Common open function when the device gets opened.
576 *
577 * This function should be called in the open function of the device
578 * driver.
579 */
580int open_candev(struct net_device *dev)
581{
582 struct can_priv *priv = netdev_priv(dev);
583
584 if (!priv->bittiming.tq && !priv->bittiming.bitrate) {
Wolfgang Grandeggeraabdfd62012-02-01 11:02:05 +0100585 netdev_err(dev, "bit-timing not yet defined\n");
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000586 return -EINVAL;
587 }
588
Wolfgang Grandegger1b0d9222009-07-20 04:06:41 +0000589 /* Switch carrier on if device was stopped while in bus-off state */
590 if (!netif_carrier_ok(dev))
591 netif_carrier_on(dev);
592
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000593 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
594
595 return 0;
596}
Wolfgang Grandegger128ced82009-05-30 07:55:48 +0000597EXPORT_SYMBOL_GPL(open_candev);
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000598
599/*
600 * Common close function for cleanup before the device gets closed.
601 *
602 * This function should be called in the close function of the device
603 * driver.
604 */
605void close_candev(struct net_device *dev)
606{
607 struct can_priv *priv = netdev_priv(dev);
608
Alexander Steinab48b032012-11-27 08:52:34 +0100609 del_timer_sync(&priv->restart_timer);
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000610 can_flush_echo_skb(dev);
611}
612EXPORT_SYMBOL_GPL(close_candev);
613
614/*
615 * CAN netlink interface
616 */
617static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
618 [IFLA_CAN_STATE] = { .type = NLA_U32 },
619 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
620 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
621 [IFLA_CAN_RESTART] = { .type = NLA_U32 },
622 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
623 [IFLA_CAN_BITTIMING_CONST]
624 = { .len = sizeof(struct can_bittiming_const) },
625 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
Wolfgang Grandegger52c793f2010-02-22 22:21:17 +0000626 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000627};
628
629static int can_changelink(struct net_device *dev,
630 struct nlattr *tb[], struct nlattr *data[])
631{
632 struct can_priv *priv = netdev_priv(dev);
633 int err;
634
635 /* We need synchronization with dev->stop() */
636 ASSERT_RTNL();
637
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000638 if (data[IFLA_CAN_BITTIMING]) {
639 struct can_bittiming bt;
640
641 /* Do not allow changing bittiming while running */
642 if (dev->flags & IFF_UP)
643 return -EBUSY;
644 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
645 if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq))
646 return -EINVAL;
647 err = can_get_bittiming(dev, &bt);
648 if (err)
649 return err;
650 memcpy(&priv->bittiming, &bt, sizeof(bt));
651
652 if (priv->do_set_bittiming) {
653 /* Finally, set the bit-timing registers */
654 err = priv->do_set_bittiming(dev);
655 if (err)
656 return err;
657 }
658 }
659
Marc Kleine-Budde49cb5c02013-10-04 15:40:22 +0200660 if (data[IFLA_CAN_CTRLMODE]) {
661 struct can_ctrlmode *cm;
662
663 /* Do not allow changing controller mode while running */
664 if (dev->flags & IFF_UP)
665 return -EBUSY;
666 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
667 if (cm->flags & ~priv->ctrlmode_supported)
668 return -EOPNOTSUPP;
669 priv->ctrlmode &= ~cm->mask;
670 priv->ctrlmode |= cm->flags;
671 }
672
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000673 if (data[IFLA_CAN_RESTART_MS]) {
674 /* Do not allow changing restart delay while running */
675 if (dev->flags & IFF_UP)
676 return -EBUSY;
677 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
678 }
679
680 if (data[IFLA_CAN_RESTART]) {
681 /* Do not allow a restart while not running */
682 if (!(dev->flags & IFF_UP))
683 return -EINVAL;
684 err = can_restart_now(dev);
685 if (err)
686 return err;
687 }
688
689 return 0;
690}
691
Wolfgang Grandegger53a0ef862009-11-06 23:53:13 +0000692static size_t can_get_size(const struct net_device *dev)
693{
694 struct can_priv *priv = netdev_priv(dev);
Marc Kleine-Buddec13c64d2013-10-05 20:34:47 +0200695 size_t size = 0;
Wolfgang Grandegger53a0ef862009-11-06 23:53:13 +0000696
Marc Kleine-Buddec13c64d2013-10-05 20:34:47 +0200697 size += nla_total_size(sizeof(struct can_bittiming)); /* IFLA_CAN_BITTIMING */
698 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
Marc Kleine-Buddefe119a02013-10-05 21:25:17 +0200699 size += nla_total_size(sizeof(struct can_bittiming_const));
Marc Kleine-Buddec13c64d2013-10-05 20:34:47 +0200700 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
701 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
702 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
703 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
704 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
705 size += nla_total_size(sizeof(struct can_berr_counter));
Wolfgang Grandegger53a0ef862009-11-06 23:53:13 +0000706
707 return size;
708}
709
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000710static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
711{
712 struct can_priv *priv = netdev_priv(dev);
713 struct can_ctrlmode cm = {.flags = priv->ctrlmode};
Wolfgang Grandegger52c793f2010-02-22 22:21:17 +0000714 struct can_berr_counter bec;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000715 enum can_state state = priv->state;
716
717 if (priv->do_get_state)
718 priv->do_get_state(dev, &state);
Marc Kleine-Budde57a59b92013-10-04 13:35:57 +0200719 if (nla_put(skb, IFLA_CAN_BITTIMING,
David S. Miller31e0e322012-04-01 20:21:11 -0400720 sizeof(priv->bittiming), &priv->bittiming) ||
David S. Miller31e0e322012-04-01 20:21:11 -0400721 (priv->bittiming_const &&
722 nla_put(skb, IFLA_CAN_BITTIMING_CONST,
Marc Kleine-Budde57a59b92013-10-04 13:35:57 +0200723 sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
724 nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) ||
725 nla_put_u32(skb, IFLA_CAN_STATE, state) ||
726 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
727 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
728 (priv->do_get_berr_counter &&
729 !priv->do_get_berr_counter(dev, &bec) &&
730 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)))
731 return -EMSGSIZE;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000732 return 0;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000733}
734
Wolfgang Grandegger55369c02009-11-12 05:34:05 +0000735static size_t can_get_xstats_size(const struct net_device *dev)
736{
737 return sizeof(struct can_device_stats);
738}
739
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000740static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
741{
742 struct can_priv *priv = netdev_priv(dev);
743
David S. Miller31e0e322012-04-01 20:21:11 -0400744 if (nla_put(skb, IFLA_INFO_XSTATS,
745 sizeof(priv->can_stats), &priv->can_stats))
746 goto nla_put_failure;
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000747 return 0;
748
749nla_put_failure:
750 return -EMSGSIZE;
751}
752
Eric W. Biederman81adee42009-11-08 00:53:51 -0800753static int can_newlink(struct net *src_net, struct net_device *dev,
Oliver Hartkopp993e6f22009-08-11 02:41:24 +0000754 struct nlattr *tb[], struct nlattr *data[])
755{
756 return -EOPNOTSUPP;
757}
758
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000759static struct rtnl_link_ops can_link_ops __read_mostly = {
760 .kind = "can",
761 .maxtype = IFLA_CAN_MAX,
762 .policy = can_policy,
763 .setup = can_setup,
Oliver Hartkopp993e6f22009-08-11 02:41:24 +0000764 .newlink = can_newlink,
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000765 .changelink = can_changelink,
Wolfgang Grandegger53a0ef862009-11-06 23:53:13 +0000766 .get_size = can_get_size,
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000767 .fill_info = can_fill_info,
Wolfgang Grandegger55369c02009-11-12 05:34:05 +0000768 .get_xstats_size = can_get_xstats_size,
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000769 .fill_xstats = can_fill_xstats,
770};
771
772/*
773 * Register the CAN network device
774 */
775int register_candev(struct net_device *dev)
776{
777 dev->rtnl_link_ops = &can_link_ops;
778 return register_netdev(dev);
779}
780EXPORT_SYMBOL_GPL(register_candev);
781
782/*
783 * Unregister the CAN network device
784 */
785void unregister_candev(struct net_device *dev)
786{
787 unregister_netdev(dev);
788}
789EXPORT_SYMBOL_GPL(unregister_candev);
790
Kurt Van Dijckbf03a532012-12-18 18:50:56 +0100791/*
792 * Test if a network device is a candev based device
793 * and return the can_priv* if so.
794 */
795struct can_priv *safe_candev_priv(struct net_device *dev)
796{
797 if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
798 return NULL;
799
800 return netdev_priv(dev);
801}
802EXPORT_SYMBOL_GPL(safe_candev_priv);
803
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000804static __init int can_dev_init(void)
805{
806 int err;
807
Kurt Van Dijcka1ef7bd2012-12-18 18:50:57 +0100808 can_led_notifier_init();
809
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000810 err = rtnl_link_register(&can_link_ops);
811 if (!err)
812 printk(KERN_INFO MOD_DESC "\n");
813
814 return err;
815}
816module_init(can_dev_init);
817
818static __exit void can_dev_exit(void)
819{
820 rtnl_link_unregister(&can_link_ops);
Kurt Van Dijcka1ef7bd2012-12-18 18:50:57 +0100821
822 can_led_notifier_exit();
Wolfgang Grandegger39549ee2009-05-15 23:39:29 +0000823}
824module_exit(can_dev_exit);
825
826MODULE_ALIAS_RTNL_LINK("can");