ARM: dts: add 'dr_mode' property to hsotg devices for exynos boards
[linux/fpc-iii.git] / drivers / net / can / dev.c
blob3ec8f6f25e5f979e16838930295fe4cd66b2841c
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>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the version 2 of the GNU General Public License
8 * as published by the Free Software Foundation
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/slab.h>
22 #include <linux/netdevice.h>
23 #include <linux/if_arp.h>
24 #include <linux/can.h>
25 #include <linux/can/dev.h>
26 #include <linux/can/skb.h>
27 #include <linux/can/netlink.h>
28 #include <linux/can/led.h>
29 #include <net/rtnetlink.h>
31 #define MOD_DESC "CAN device driver interface"
33 MODULE_DESCRIPTION(MOD_DESC);
34 MODULE_LICENSE("GPL v2");
35 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
37 /* CAN DLC to real data length conversion helpers */
39 static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
40 8, 12, 16, 20, 24, 32, 48, 64};
42 /* get data length from can_dlc with sanitized can_dlc */
43 u8 can_dlc2len(u8 can_dlc)
45 return dlc2len[can_dlc & 0x0F];
47 EXPORT_SYMBOL_GPL(can_dlc2len);
49 static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */
50 9, 9, 9, 9, /* 9 - 12 */
51 10, 10, 10, 10, /* 13 - 16 */
52 11, 11, 11, 11, /* 17 - 20 */
53 12, 12, 12, 12, /* 21 - 24 */
54 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */
55 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */
56 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */
57 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */
58 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */
60 /* map the sanitized data length to an appropriate data length code */
61 u8 can_len2dlc(u8 len)
63 if (unlikely(len > 64))
64 return 0xF;
66 return len2dlc[len];
68 EXPORT_SYMBOL_GPL(can_len2dlc);
70 #ifdef CONFIG_CAN_CALC_BITTIMING
71 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
74 * Bit-timing calculation derived from:
76 * Code based on LinCAN sources and H8S2638 project
77 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
78 * Copyright 2005 Stanislav Marek
79 * email: pisa@cmp.felk.cvut.cz
81 * Calculates proper bit-timing parameters for a specified bit-rate
82 * and sample-point, which can then be used to set the bit-timing
83 * registers of the CAN controller. You can find more information
84 * in the header file linux/can/netlink.h.
86 static int can_update_spt(const struct can_bittiming_const *btc,
87 int sampl_pt, int tseg, int *tseg1, int *tseg2)
89 *tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000;
90 if (*tseg2 < btc->tseg2_min)
91 *tseg2 = btc->tseg2_min;
92 if (*tseg2 > btc->tseg2_max)
93 *tseg2 = btc->tseg2_max;
94 *tseg1 = tseg - *tseg2;
95 if (*tseg1 > btc->tseg1_max) {
96 *tseg1 = btc->tseg1_max;
97 *tseg2 = tseg - *tseg1;
99 return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
102 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
103 const struct can_bittiming_const *btc)
105 struct can_priv *priv = netdev_priv(dev);
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 long rate;
111 u64 v64;
113 /* Use CiA recommended sample points */
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;
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;
153 best_tseg = tseg / 2;
154 best_brp = brp;
155 if (error == 0)
156 break;
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) {
163 netdev_err(dev,
164 "bitrate error %ld.%ld%% too high\n",
165 error / 10, error % 10);
166 return -EDOM;
167 } else {
168 netdev_warn(dev, "bitrate error %ld.%ld%%\n",
169 error / 10, error % 10);
173 /* real sample point */
174 bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
175 &tseg1, &tseg2);
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;
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;
196 bt->brp = best_brp;
197 /* real bit-rate */
198 bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
200 return 0;
202 #else /* !CONFIG_CAN_CALC_BITTIMING */
203 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
204 const struct can_bittiming_const *btc)
206 netdev_err(dev, "bit-timing calculation not available\n");
207 return -EINVAL;
209 #endif /* CONFIG_CAN_CALC_BITTIMING */
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.
217 static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
218 const struct can_bittiming_const *btc)
220 struct can_priv *priv = netdev_priv(dev);
221 int tseg1, alltseg;
222 u64 brp64;
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;
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;
241 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
242 return -EINVAL;
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;
248 return 0;
251 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
252 const struct can_bittiming_const *btc)
254 int err;
256 /* Check if the CAN device has bit-timing parameters */
257 if (!btc)
258 return -EOPNOTSUPP;
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.
266 if (!bt->tq && bt->bitrate)
267 err = can_calc_bittiming(dev, bt, btc);
268 else if (bt->tq && !bt->bitrate)
269 err = can_fixup_bittiming(dev, bt, btc);
270 else
271 err = -EINVAL;
273 return err;
276 static void can_update_state_error_stats(struct net_device *dev,
277 enum can_state new_state)
279 struct can_priv *priv = netdev_priv(dev);
281 if (new_state <= priv->state)
282 return;
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;
297 static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
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;
311 static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
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;
325 void can_change_state(struct net_device *dev, struct can_frame *cf,
326 enum can_state tx_state, enum can_state rx_state)
328 struct can_priv *priv = netdev_priv(dev);
329 enum can_state new_state = max(tx_state, rx_state);
331 if (unlikely(new_state == priv->state)) {
332 netdev_warn(dev, "%s: oops, state did not change", __func__);
333 return;
336 netdev_dbg(dev, "New error state: %d\n", new_state);
338 can_update_state_error_stats(dev, new_state);
339 priv->state = new_state;
341 if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
342 cf->can_id |= CAN_ERR_BUSOFF;
343 return;
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;
352 EXPORT_SYMBOL_GPL(can_change_state);
355 * Local echo of CAN messages
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.
364 static void can_flush_echo_skb(struct net_device *dev)
366 struct can_priv *priv = netdev_priv(dev);
367 struct net_device_stats *stats = &dev->stats;
368 int i;
370 for (i = 0; i < priv->echo_skb_max; i++) {
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++;
381 * Put the skb on the stack to be looped backed locally lateron
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.
387 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
388 unsigned int idx)
390 struct can_priv *priv = netdev_priv(dev);
392 BUG_ON(idx >= priv->echo_skb_max);
394 /* check flag whether this packet has to be looped back */
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))) {
398 kfree_skb(skb);
399 return;
402 if (!priv->echo_skb[idx]) {
404 skb = can_create_echo_skb(skb);
405 if (!skb)
406 return;
408 /* make settings for echo to reduce code in irq context */
409 skb->pkt_type = PACKET_BROADCAST;
410 skb->ip_summed = CHECKSUM_UNNECESSARY;
411 skb->dev = dev;
413 /* save this skb for tx interrupt echo handling */
414 priv->echo_skb[idx] = skb;
415 } else {
416 /* locking problem with netif_stop_queue() ?? */
417 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
418 kfree_skb(skb);
421 EXPORT_SYMBOL_GPL(can_put_echo_skb);
424 * Get the skb from the stack and loop it back locally
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.
430 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
432 struct can_priv *priv = netdev_priv(dev);
434 BUG_ON(idx >= priv->echo_skb_max);
436 if (priv->echo_skb[idx]) {
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;
441 netif_rx(priv->echo_skb[idx]);
442 priv->echo_skb[idx] = NULL;
444 return dlc;
447 return 0;
449 EXPORT_SYMBOL_GPL(can_get_echo_skb);
452 * Remove the skb from the stack and free it.
454 * The function is typically called when TX failed.
456 void can_free_echo_skb(struct net_device *dev, unsigned int idx)
458 struct can_priv *priv = netdev_priv(dev);
460 BUG_ON(idx >= priv->echo_skb_max);
462 if (priv->echo_skb[idx]) {
463 dev_kfree_skb_any(priv->echo_skb[idx]);
464 priv->echo_skb[idx] = NULL;
467 EXPORT_SYMBOL_GPL(can_free_echo_skb);
470 * CAN device restart for bus-off recovery
472 static void can_restart(unsigned long data)
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;
481 BUG_ON(netif_carrier_ok(dev));
484 * No synchronization needed because the device is bus-off and
485 * no messages can come in or go out.
487 can_flush_echo_skb(dev);
489 /* send restart message upstream */
490 skb = alloc_can_err_skb(dev, &cf);
491 if (skb == NULL) {
492 err = -ENOMEM;
493 goto restart;
495 cf->can_id |= CAN_ERR_RESTARTED;
497 netif_rx(skb);
499 stats->rx_packets++;
500 stats->rx_bytes += cf->can_dlc;
502 restart:
503 netdev_dbg(dev, "restarted\n");
504 priv->can_stats.restarts++;
506 /* Now restart the device */
507 err = priv->do_set_mode(dev, CAN_MODE_START);
509 netif_carrier_on(dev);
510 if (err)
511 netdev_err(dev, "Error %d during restart", err);
514 int can_restart_now(struct net_device *dev)
516 struct can_priv *priv = netdev_priv(dev);
519 * A manual restart is only permitted if automatic restart is
520 * disabled and the device is in the bus-off state
522 if (priv->restart_ms)
523 return -EINVAL;
524 if (priv->state != CAN_STATE_BUS_OFF)
525 return -EBUSY;
527 /* Runs as soon as possible in the timer context */
528 mod_timer(&priv->restart_timer, jiffies);
530 return 0;
534 * CAN bus-off
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.
540 void can_bus_off(struct net_device *dev)
542 struct can_priv *priv = netdev_priv(dev);
544 netdev_dbg(dev, "bus-off\n");
546 netif_carrier_off(dev);
547 priv->can_stats.bus_off++;
549 if (priv->restart_ms)
550 mod_timer(&priv->restart_timer,
551 jiffies + (priv->restart_ms * HZ) / 1000);
553 EXPORT_SYMBOL_GPL(can_bus_off);
555 static void can_setup(struct net_device *dev)
557 dev->type = ARPHRD_CAN;
558 dev->mtu = CAN_MTU;
559 dev->hard_header_len = 0;
560 dev->addr_len = 0;
561 dev->tx_queue_len = 10;
563 /* New-style flags. */
564 dev->flags = IFF_NOARP;
565 dev->features = NETIF_F_HW_CSUM;
568 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
570 struct sk_buff *skb;
572 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
573 sizeof(struct can_frame));
574 if (unlikely(!skb))
575 return NULL;
577 skb->protocol = htons(ETH_P_CAN);
578 skb->pkt_type = PACKET_BROADCAST;
579 skb->ip_summed = CHECKSUM_UNNECESSARY;
581 can_skb_reserve(skb);
582 can_skb_prv(skb)->ifindex = dev->ifindex;
584 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
585 memset(*cf, 0, sizeof(struct can_frame));
587 return skb;
589 EXPORT_SYMBOL_GPL(alloc_can_skb);
591 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
592 struct canfd_frame **cfd)
594 struct sk_buff *skb;
596 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
597 sizeof(struct canfd_frame));
598 if (unlikely(!skb))
599 return NULL;
601 skb->protocol = htons(ETH_P_CANFD);
602 skb->pkt_type = PACKET_BROADCAST;
603 skb->ip_summed = CHECKSUM_UNNECESSARY;
605 can_skb_reserve(skb);
606 can_skb_prv(skb)->ifindex = dev->ifindex;
608 *cfd = (struct canfd_frame *)skb_put(skb, sizeof(struct canfd_frame));
609 memset(*cfd, 0, sizeof(struct canfd_frame));
611 return skb;
613 EXPORT_SYMBOL_GPL(alloc_canfd_skb);
615 struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
617 struct sk_buff *skb;
619 skb = alloc_can_skb(dev, cf);
620 if (unlikely(!skb))
621 return NULL;
623 (*cf)->can_id = CAN_ERR_FLAG;
624 (*cf)->can_dlc = CAN_ERR_DLC;
626 return skb;
628 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
631 * Allocate and setup space for the CAN network device
633 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
635 struct net_device *dev;
636 struct can_priv *priv;
637 int size;
639 if (echo_skb_max)
640 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
641 echo_skb_max * sizeof(struct sk_buff *);
642 else
643 size = sizeof_priv;
645 dev = alloc_netdev(size, "can%d", NET_NAME_UNKNOWN, can_setup);
646 if (!dev)
647 return NULL;
649 priv = netdev_priv(dev);
651 if (echo_skb_max) {
652 priv->echo_skb_max = echo_skb_max;
653 priv->echo_skb = (void *)priv +
654 ALIGN(sizeof_priv, sizeof(struct sk_buff *));
657 priv->state = CAN_STATE_STOPPED;
659 init_timer(&priv->restart_timer);
661 return dev;
663 EXPORT_SYMBOL_GPL(alloc_candev);
666 * Free space of the CAN network device
668 void free_candev(struct net_device *dev)
670 free_netdev(dev);
672 EXPORT_SYMBOL_GPL(free_candev);
675 * changing MTU and control mode for CAN/CANFD devices
677 int can_change_mtu(struct net_device *dev, int new_mtu)
679 struct can_priv *priv = netdev_priv(dev);
681 /* Do not allow changing the MTU while running */
682 if (dev->flags & IFF_UP)
683 return -EBUSY;
685 /* allow change of MTU according to the CANFD ability of the device */
686 switch (new_mtu) {
687 case CAN_MTU:
688 priv->ctrlmode &= ~CAN_CTRLMODE_FD;
689 break;
691 case CANFD_MTU:
692 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD))
693 return -EINVAL;
695 priv->ctrlmode |= CAN_CTRLMODE_FD;
696 break;
698 default:
699 return -EINVAL;
702 dev->mtu = new_mtu;
703 return 0;
705 EXPORT_SYMBOL_GPL(can_change_mtu);
708 * Common open function when the device gets opened.
710 * This function should be called in the open function of the device
711 * driver.
713 int open_candev(struct net_device *dev)
715 struct can_priv *priv = netdev_priv(dev);
717 if (!priv->bittiming.bitrate) {
718 netdev_err(dev, "bit-timing not yet defined\n");
719 return -EINVAL;
722 /* For CAN FD the data bitrate has to be >= the arbitration bitrate */
723 if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
724 (!priv->data_bittiming.bitrate ||
725 (priv->data_bittiming.bitrate < priv->bittiming.bitrate))) {
726 netdev_err(dev, "incorrect/missing data bit-timing\n");
727 return -EINVAL;
730 /* Switch carrier on if device was stopped while in bus-off state */
731 if (!netif_carrier_ok(dev))
732 netif_carrier_on(dev);
734 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
736 return 0;
738 EXPORT_SYMBOL_GPL(open_candev);
741 * Common close function for cleanup before the device gets closed.
743 * This function should be called in the close function of the device
744 * driver.
746 void close_candev(struct net_device *dev)
748 struct can_priv *priv = netdev_priv(dev);
750 del_timer_sync(&priv->restart_timer);
751 can_flush_echo_skb(dev);
753 EXPORT_SYMBOL_GPL(close_candev);
756 * CAN netlink interface
758 static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
759 [IFLA_CAN_STATE] = { .type = NLA_U32 },
760 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
761 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
762 [IFLA_CAN_RESTART] = { .type = NLA_U32 },
763 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
764 [IFLA_CAN_BITTIMING_CONST]
765 = { .len = sizeof(struct can_bittiming_const) },
766 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
767 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
768 [IFLA_CAN_DATA_BITTIMING]
769 = { .len = sizeof(struct can_bittiming) },
770 [IFLA_CAN_DATA_BITTIMING_CONST]
771 = { .len = sizeof(struct can_bittiming_const) },
774 static int can_changelink(struct net_device *dev,
775 struct nlattr *tb[], struct nlattr *data[])
777 struct can_priv *priv = netdev_priv(dev);
778 int err;
780 /* We need synchronization with dev->stop() */
781 ASSERT_RTNL();
783 if (data[IFLA_CAN_BITTIMING]) {
784 struct can_bittiming bt;
786 /* Do not allow changing bittiming while running */
787 if (dev->flags & IFF_UP)
788 return -EBUSY;
789 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
790 err = can_get_bittiming(dev, &bt, priv->bittiming_const);
791 if (err)
792 return err;
793 memcpy(&priv->bittiming, &bt, sizeof(bt));
795 if (priv->do_set_bittiming) {
796 /* Finally, set the bit-timing registers */
797 err = priv->do_set_bittiming(dev);
798 if (err)
799 return err;
803 if (data[IFLA_CAN_CTRLMODE]) {
804 struct can_ctrlmode *cm;
806 /* Do not allow changing controller mode while running */
807 if (dev->flags & IFF_UP)
808 return -EBUSY;
809 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
810 if (cm->flags & ~priv->ctrlmode_supported)
811 return -EOPNOTSUPP;
812 priv->ctrlmode &= ~cm->mask;
813 priv->ctrlmode |= cm->flags;
815 /* CAN_CTRLMODE_FD can only be set when driver supports FD */
816 if (priv->ctrlmode & CAN_CTRLMODE_FD)
817 dev->mtu = CANFD_MTU;
818 else
819 dev->mtu = CAN_MTU;
822 if (data[IFLA_CAN_RESTART_MS]) {
823 /* Do not allow changing restart delay while running */
824 if (dev->flags & IFF_UP)
825 return -EBUSY;
826 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
829 if (data[IFLA_CAN_RESTART]) {
830 /* Do not allow a restart while not running */
831 if (!(dev->flags & IFF_UP))
832 return -EINVAL;
833 err = can_restart_now(dev);
834 if (err)
835 return err;
838 if (data[IFLA_CAN_DATA_BITTIMING]) {
839 struct can_bittiming dbt;
841 /* Do not allow changing bittiming while running */
842 if (dev->flags & IFF_UP)
843 return -EBUSY;
844 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
845 sizeof(dbt));
846 err = can_get_bittiming(dev, &dbt, priv->data_bittiming_const);
847 if (err)
848 return err;
849 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
851 if (priv->do_set_data_bittiming) {
852 /* Finally, set the bit-timing registers */
853 err = priv->do_set_data_bittiming(dev);
854 if (err)
855 return err;
859 return 0;
862 static size_t can_get_size(const struct net_device *dev)
864 struct can_priv *priv = netdev_priv(dev);
865 size_t size = 0;
867 if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */
868 size += nla_total_size(sizeof(struct can_bittiming));
869 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
870 size += nla_total_size(sizeof(struct can_bittiming_const));
871 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
872 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
873 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
874 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
875 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
876 size += nla_total_size(sizeof(struct can_berr_counter));
877 if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */
878 size += nla_total_size(sizeof(struct can_bittiming));
879 if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */
880 size += nla_total_size(sizeof(struct can_bittiming_const));
882 return size;
885 static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
887 struct can_priv *priv = netdev_priv(dev);
888 struct can_ctrlmode cm = {.flags = priv->ctrlmode};
889 struct can_berr_counter bec;
890 enum can_state state = priv->state;
892 if (priv->do_get_state)
893 priv->do_get_state(dev, &state);
895 if ((priv->bittiming.bitrate &&
896 nla_put(skb, IFLA_CAN_BITTIMING,
897 sizeof(priv->bittiming), &priv->bittiming)) ||
899 (priv->bittiming_const &&
900 nla_put(skb, IFLA_CAN_BITTIMING_CONST,
901 sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
903 nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) ||
904 nla_put_u32(skb, IFLA_CAN_STATE, state) ||
905 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
906 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
908 (priv->do_get_berr_counter &&
909 !priv->do_get_berr_counter(dev, &bec) &&
910 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
912 (priv->data_bittiming.bitrate &&
913 nla_put(skb, IFLA_CAN_DATA_BITTIMING,
914 sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
916 (priv->data_bittiming_const &&
917 nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
918 sizeof(*priv->data_bittiming_const),
919 priv->data_bittiming_const)))
920 return -EMSGSIZE;
922 return 0;
925 static size_t can_get_xstats_size(const struct net_device *dev)
927 return sizeof(struct can_device_stats);
930 static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
932 struct can_priv *priv = netdev_priv(dev);
934 if (nla_put(skb, IFLA_INFO_XSTATS,
935 sizeof(priv->can_stats), &priv->can_stats))
936 goto nla_put_failure;
937 return 0;
939 nla_put_failure:
940 return -EMSGSIZE;
943 static int can_newlink(struct net *src_net, struct net_device *dev,
944 struct nlattr *tb[], struct nlattr *data[])
946 return -EOPNOTSUPP;
949 static struct rtnl_link_ops can_link_ops __read_mostly = {
950 .kind = "can",
951 .maxtype = IFLA_CAN_MAX,
952 .policy = can_policy,
953 .setup = can_setup,
954 .newlink = can_newlink,
955 .changelink = can_changelink,
956 .get_size = can_get_size,
957 .fill_info = can_fill_info,
958 .get_xstats_size = can_get_xstats_size,
959 .fill_xstats = can_fill_xstats,
963 * Register the CAN network device
965 int register_candev(struct net_device *dev)
967 dev->rtnl_link_ops = &can_link_ops;
968 return register_netdev(dev);
970 EXPORT_SYMBOL_GPL(register_candev);
973 * Unregister the CAN network device
975 void unregister_candev(struct net_device *dev)
977 unregister_netdev(dev);
979 EXPORT_SYMBOL_GPL(unregister_candev);
982 * Test if a network device is a candev based device
983 * and return the can_priv* if so.
985 struct can_priv *safe_candev_priv(struct net_device *dev)
987 if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
988 return NULL;
990 return netdev_priv(dev);
992 EXPORT_SYMBOL_GPL(safe_candev_priv);
994 static __init int can_dev_init(void)
996 int err;
998 can_led_notifier_init();
1000 err = rtnl_link_register(&can_link_ops);
1001 if (!err)
1002 printk(KERN_INFO MOD_DESC "\n");
1004 return err;
1006 module_init(can_dev_init);
1008 static __exit void can_dev_exit(void)
1010 rtnl_link_unregister(&can_link_ops);
1012 can_led_notifier_exit();
1014 module_exit(can_dev_exit);
1016 MODULE_ALIAS_RTNL_LINK("can");