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/workqueue.h>
25 #include <linux/can.h>
26 #include <linux/can/dev.h>
27 #include <linux/can/skb.h>
28 #include <linux/can/netlink.h>
29 #include <linux/can/led.h>
30 #include <net/rtnetlink.h>
32 #define MOD_DESC "CAN device driver interface"
34 MODULE_DESCRIPTION(MOD_DESC);
35 MODULE_LICENSE("GPL v2");
36 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
38 /* CAN DLC to real data length conversion helpers */
40 static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
41 8, 12, 16, 20, 24, 32, 48, 64};
43 /* get data length from can_dlc with sanitized can_dlc */
44 u8 can_dlc2len(u8 can_dlc)
46 return dlc2len[can_dlc & 0x0F];
48 EXPORT_SYMBOL_GPL(can_dlc2len);
50 static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */
51 9, 9, 9, 9, /* 9 - 12 */
52 10, 10, 10, 10, /* 13 - 16 */
53 11, 11, 11, 11, /* 17 - 20 */
54 12, 12, 12, 12, /* 21 - 24 */
55 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */
56 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */
57 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */
58 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */
59 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */
61 /* map the sanitized data length to an appropriate data length code */
62 u8 can_len2dlc(u8 len)
64 if (unlikely(len > 64))
69 EXPORT_SYMBOL_GPL(can_len2dlc);
71 #ifdef CONFIG_CAN_CALC_BITTIMING
72 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
73 #define CAN_CALC_SYNC_SEG 1
76 * Bit-timing calculation derived from:
78 * Code based on LinCAN sources and H8S2638 project
79 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
80 * Copyright 2005 Stanislav Marek
81 * email: pisa@cmp.felk.cvut.cz
83 * Calculates proper bit-timing parameters for a specified bit-rate
84 * and sample-point, which can then be used to set the bit-timing
85 * registers of the CAN controller. You can find more information
86 * in the header file linux/can/netlink.h.
88 static int can_update_sample_point(const struct can_bittiming_const *btc,
89 unsigned int sample_point_nominal, unsigned int tseg,
90 unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
91 unsigned int *sample_point_error_ptr)
93 unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
94 unsigned int sample_point, best_sample_point = 0;
95 unsigned int tseg1, tseg2;
98 for (i = 0; i <= 1; i++) {
99 tseg2 = tseg + CAN_CALC_SYNC_SEG - (sample_point_nominal * (tseg + CAN_CALC_SYNC_SEG)) / 1000 - i;
100 tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
101 tseg1 = tseg - tseg2;
102 if (tseg1 > btc->tseg1_max) {
103 tseg1 = btc->tseg1_max;
104 tseg2 = tseg - tseg1;
107 sample_point = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) / (tseg + CAN_CALC_SYNC_SEG);
108 sample_point_error = abs(sample_point_nominal - sample_point);
110 if ((sample_point <= sample_point_nominal) && (sample_point_error < best_sample_point_error)) {
111 best_sample_point = sample_point;
112 best_sample_point_error = sample_point_error;
118 if (sample_point_error_ptr)
119 *sample_point_error_ptr = best_sample_point_error;
121 return best_sample_point;
124 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
125 const struct can_bittiming_const *btc)
127 struct can_priv *priv = netdev_priv(dev);
128 unsigned int bitrate; /* current bitrate */
129 unsigned int bitrate_error; /* difference between current and nominal value */
130 unsigned int best_bitrate_error = UINT_MAX;
131 unsigned int sample_point_error; /* difference between current and nominal value */
132 unsigned int best_sample_point_error = UINT_MAX;
133 unsigned int sample_point_nominal; /* nominal sample point */
134 unsigned int best_tseg = 0; /* current best value for tseg */
135 unsigned int best_brp = 0; /* current best value for brp */
136 unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
139 /* Use CiA recommended sample points */
140 if (bt->sample_point) {
141 sample_point_nominal = bt->sample_point;
143 if (bt->bitrate > 800000)
144 sample_point_nominal = 750;
145 else if (bt->bitrate > 500000)
146 sample_point_nominal = 800;
148 sample_point_nominal = 875;
151 /* tseg even = round down, odd = round up */
152 for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
153 tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
154 tsegall = CAN_CALC_SYNC_SEG + tseg / 2;
156 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */
157 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
159 /* choose brp step which is possible in system */
160 brp = (brp / btc->brp_inc) * btc->brp_inc;
161 if ((brp < btc->brp_min) || (brp > btc->brp_max))
164 bitrate = priv->clock.freq / (brp * tsegall);
165 bitrate_error = abs(bt->bitrate - bitrate);
167 /* tseg brp biterror */
168 if (bitrate_error > best_bitrate_error)
171 /* reset sample point error if we have a better bitrate */
172 if (bitrate_error < best_bitrate_error)
173 best_sample_point_error = UINT_MAX;
175 can_update_sample_point(btc, sample_point_nominal, tseg / 2, &tseg1, &tseg2, &sample_point_error);
176 if (sample_point_error > best_sample_point_error)
179 best_sample_point_error = sample_point_error;
180 best_bitrate_error = bitrate_error;
181 best_tseg = tseg / 2;
184 if (bitrate_error == 0 && sample_point_error == 0)
188 if (best_bitrate_error) {
189 /* Error in one-tenth of a percent */
190 v64 = (u64)best_bitrate_error * 1000;
191 do_div(v64, bt->bitrate);
192 bitrate_error = (u32)v64;
193 if (bitrate_error > CAN_CALC_MAX_ERROR) {
195 "bitrate error %d.%d%% too high\n",
196 bitrate_error / 10, bitrate_error % 10);
199 netdev_warn(dev, "bitrate error %d.%d%%\n",
200 bitrate_error / 10, bitrate_error % 10);
203 /* real sample point */
204 bt->sample_point = can_update_sample_point(btc, sample_point_nominal, best_tseg,
205 &tseg1, &tseg2, NULL);
207 v64 = (u64)best_brp * 1000 * 1000 * 1000;
208 do_div(v64, priv->clock.freq);
210 bt->prop_seg = tseg1 / 2;
211 bt->phase_seg1 = tseg1 - bt->prop_seg;
212 bt->phase_seg2 = tseg2;
214 /* check for sjw user settings */
215 if (!bt->sjw || !btc->sjw_max) {
218 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
219 if (bt->sjw > btc->sjw_max)
220 bt->sjw = btc->sjw_max;
221 /* bt->sjw must not be higher than tseg2 */
229 bt->bitrate = priv->clock.freq / (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2));
233 #else /* !CONFIG_CAN_CALC_BITTIMING */
234 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
235 const struct can_bittiming_const *btc)
237 netdev_err(dev, "bit-timing calculation not available\n");
240 #endif /* CONFIG_CAN_CALC_BITTIMING */
243 * Checks the validity of the specified bit-timing parameters prop_seg,
244 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
245 * prescaler value brp. You can find more information in the header
246 * file linux/can/netlink.h.
248 static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
249 const struct can_bittiming_const *btc)
251 struct can_priv *priv = netdev_priv(dev);
255 tseg1 = bt->prop_seg + bt->phase_seg1;
258 if (bt->sjw > btc->sjw_max ||
259 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
260 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
263 brp64 = (u64)priv->clock.freq * (u64)bt->tq;
264 if (btc->brp_inc > 1)
265 do_div(brp64, btc->brp_inc);
266 brp64 += 500000000UL - 1;
267 do_div(brp64, 1000000000UL); /* the practicable BRP */
268 if (btc->brp_inc > 1)
269 brp64 *= btc->brp_inc;
270 bt->brp = (u32)brp64;
272 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
275 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
276 bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
277 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
282 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
283 const struct can_bittiming_const *btc)
287 /* Check if the CAN device has bit-timing parameters */
292 * Depending on the given can_bittiming parameter structure the CAN
293 * timing parameters are calculated based on the provided bitrate OR
294 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
295 * provided directly which are then checked and fixed up.
297 if (!bt->tq && bt->bitrate)
298 err = can_calc_bittiming(dev, bt, btc);
299 else if (bt->tq && !bt->bitrate)
300 err = can_fixup_bittiming(dev, bt, btc);
307 static void can_update_state_error_stats(struct net_device *dev,
308 enum can_state new_state)
310 struct can_priv *priv = netdev_priv(dev);
312 if (new_state <= priv->state)
316 case CAN_STATE_ERROR_WARNING:
317 priv->can_stats.error_warning++;
319 case CAN_STATE_ERROR_PASSIVE:
320 priv->can_stats.error_passive++;
322 case CAN_STATE_BUS_OFF:
323 priv->can_stats.bus_off++;
330 static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
333 case CAN_STATE_ERROR_ACTIVE:
334 return CAN_ERR_CRTL_ACTIVE;
335 case CAN_STATE_ERROR_WARNING:
336 return CAN_ERR_CRTL_TX_WARNING;
337 case CAN_STATE_ERROR_PASSIVE:
338 return CAN_ERR_CRTL_TX_PASSIVE;
344 static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
347 case CAN_STATE_ERROR_ACTIVE:
348 return CAN_ERR_CRTL_ACTIVE;
349 case CAN_STATE_ERROR_WARNING:
350 return CAN_ERR_CRTL_RX_WARNING;
351 case CAN_STATE_ERROR_PASSIVE:
352 return CAN_ERR_CRTL_RX_PASSIVE;
358 void can_change_state(struct net_device *dev, struct can_frame *cf,
359 enum can_state tx_state, enum can_state rx_state)
361 struct can_priv *priv = netdev_priv(dev);
362 enum can_state new_state = max(tx_state, rx_state);
364 if (unlikely(new_state == priv->state)) {
365 netdev_warn(dev, "%s: oops, state did not change", __func__);
369 netdev_dbg(dev, "New error state: %d\n", new_state);
371 can_update_state_error_stats(dev, new_state);
372 priv->state = new_state;
374 if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
375 cf->can_id |= CAN_ERR_BUSOFF;
379 cf->can_id |= CAN_ERR_CRTL;
380 cf->data[1] |= tx_state >= rx_state ?
381 can_tx_state_to_frame(dev, tx_state) : 0;
382 cf->data[1] |= tx_state <= rx_state ?
383 can_rx_state_to_frame(dev, rx_state) : 0;
385 EXPORT_SYMBOL_GPL(can_change_state);
388 * Local echo of CAN messages
390 * CAN network devices *should* support a local echo functionality
391 * (see Documentation/networking/can.txt). To test the handling of CAN
392 * interfaces that do not support the local echo both driver types are
393 * implemented. In the case that the driver does not support the echo
394 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
395 * to perform the echo as a fallback solution.
397 static void can_flush_echo_skb(struct net_device *dev)
399 struct can_priv *priv = netdev_priv(dev);
400 struct net_device_stats *stats = &dev->stats;
403 for (i = 0; i < priv->echo_skb_max; i++) {
404 if (priv->echo_skb[i]) {
405 kfree_skb(priv->echo_skb[i]);
406 priv->echo_skb[i] = NULL;
408 stats->tx_aborted_errors++;
414 * Put the skb on the stack to be looped backed locally lateron
416 * The function is typically called in the start_xmit function
417 * of the device driver. The driver must protect access to
418 * priv->echo_skb, if necessary.
420 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
423 struct can_priv *priv = netdev_priv(dev);
425 BUG_ON(idx >= priv->echo_skb_max);
427 /* check flag whether this packet has to be looped back */
428 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
429 (skb->protocol != htons(ETH_P_CAN) &&
430 skb->protocol != htons(ETH_P_CANFD))) {
435 if (!priv->echo_skb[idx]) {
437 skb = can_create_echo_skb(skb);
441 /* make settings for echo to reduce code in irq context */
442 skb->pkt_type = PACKET_BROADCAST;
443 skb->ip_summed = CHECKSUM_UNNECESSARY;
446 /* save this skb for tx interrupt echo handling */
447 priv->echo_skb[idx] = skb;
449 /* locking problem with netif_stop_queue() ?? */
450 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
454 EXPORT_SYMBOL_GPL(can_put_echo_skb);
456 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
458 struct can_priv *priv = netdev_priv(dev);
460 if (idx >= priv->echo_skb_max) {
461 netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
462 __func__, idx, priv->echo_skb_max);
466 if (priv->echo_skb[idx]) {
467 /* Using "struct canfd_frame::len" for the frame
468 * length is supported on both CAN and CANFD frames.
470 struct sk_buff *skb = priv->echo_skb[idx];
471 struct canfd_frame *cf = (struct canfd_frame *)skb->data;
473 /* get the real payload length for netdev statistics */
474 if (cf->can_id & CAN_RTR_FLAG)
479 priv->echo_skb[idx] = NULL;
488 * Get the skb from the stack and loop it back locally
490 * The function is typically called when the TX done interrupt
491 * is handled in the device driver. The driver must protect
492 * access to priv->echo_skb, if necessary.
494 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
499 skb = __can_get_echo_skb(dev, idx, &len);
504 if (netif_rx(skb) == NET_RX_SUCCESS)
505 dev_consume_skb_any(skb);
507 dev_kfree_skb_any(skb);
511 EXPORT_SYMBOL_GPL(can_get_echo_skb);
514 * Remove the skb from the stack and free it.
516 * The function is typically called when TX failed.
518 void can_free_echo_skb(struct net_device *dev, unsigned int idx)
520 struct can_priv *priv = netdev_priv(dev);
522 BUG_ON(idx >= priv->echo_skb_max);
524 if (priv->echo_skb[idx]) {
525 dev_kfree_skb_any(priv->echo_skb[idx]);
526 priv->echo_skb[idx] = NULL;
529 EXPORT_SYMBOL_GPL(can_free_echo_skb);
532 * CAN device restart for bus-off recovery
534 static void can_restart(struct net_device *dev)
536 struct can_priv *priv = netdev_priv(dev);
537 struct net_device_stats *stats = &dev->stats;
539 struct can_frame *cf;
542 BUG_ON(netif_carrier_ok(dev));
545 * No synchronization needed because the device is bus-off and
546 * no messages can come in or go out.
548 can_flush_echo_skb(dev);
550 /* send restart message upstream */
551 skb = alloc_can_err_skb(dev, &cf);
556 cf->can_id |= CAN_ERR_RESTARTED;
559 stats->rx_bytes += cf->can_dlc;
564 netdev_dbg(dev, "restarted\n");
565 priv->can_stats.restarts++;
567 /* Now restart the device */
568 err = priv->do_set_mode(dev, CAN_MODE_START);
570 netif_carrier_on(dev);
572 netdev_err(dev, "Error %d during restart", err);
575 static void can_restart_work(struct work_struct *work)
577 struct delayed_work *dwork = to_delayed_work(work);
578 struct can_priv *priv = container_of(dwork, struct can_priv, restart_work);
580 can_restart(priv->dev);
583 int can_restart_now(struct net_device *dev)
585 struct can_priv *priv = netdev_priv(dev);
588 * A manual restart is only permitted if automatic restart is
589 * disabled and the device is in the bus-off state
591 if (priv->restart_ms)
593 if (priv->state != CAN_STATE_BUS_OFF)
596 cancel_delayed_work_sync(&priv->restart_work);
605 * This functions should be called when the device goes bus-off to
606 * tell the netif layer that no more packets can be sent or received.
607 * If enabled, a timer is started to trigger bus-off recovery.
609 void can_bus_off(struct net_device *dev)
611 struct can_priv *priv = netdev_priv(dev);
613 netdev_dbg(dev, "bus-off\n");
615 netif_carrier_off(dev);
617 if (priv->restart_ms)
618 schedule_delayed_work(&priv->restart_work,
619 msecs_to_jiffies(priv->restart_ms));
621 EXPORT_SYMBOL_GPL(can_bus_off);
623 static void can_setup(struct net_device *dev)
625 dev->type = ARPHRD_CAN;
627 dev->hard_header_len = 0;
629 dev->tx_queue_len = 10;
631 /* New-style flags. */
632 dev->flags = IFF_NOARP;
633 dev->features = NETIF_F_HW_CSUM;
636 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
640 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
641 sizeof(struct can_frame));
645 skb->protocol = htons(ETH_P_CAN);
646 skb->pkt_type = PACKET_BROADCAST;
647 skb->ip_summed = CHECKSUM_UNNECESSARY;
649 skb_reset_mac_header(skb);
650 skb_reset_network_header(skb);
651 skb_reset_transport_header(skb);
653 can_skb_reserve(skb);
654 can_skb_prv(skb)->ifindex = dev->ifindex;
655 can_skb_prv(skb)->skbcnt = 0;
657 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
658 memset(*cf, 0, sizeof(struct can_frame));
662 EXPORT_SYMBOL_GPL(alloc_can_skb);
664 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
665 struct canfd_frame **cfd)
669 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
670 sizeof(struct canfd_frame));
674 skb->protocol = htons(ETH_P_CANFD);
675 skb->pkt_type = PACKET_BROADCAST;
676 skb->ip_summed = CHECKSUM_UNNECESSARY;
678 skb_reset_mac_header(skb);
679 skb_reset_network_header(skb);
680 skb_reset_transport_header(skb);
682 can_skb_reserve(skb);
683 can_skb_prv(skb)->ifindex = dev->ifindex;
684 can_skb_prv(skb)->skbcnt = 0;
686 *cfd = (struct canfd_frame *)skb_put(skb, sizeof(struct canfd_frame));
687 memset(*cfd, 0, sizeof(struct canfd_frame));
691 EXPORT_SYMBOL_GPL(alloc_canfd_skb);
693 struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
697 skb = alloc_can_skb(dev, cf);
701 (*cf)->can_id = CAN_ERR_FLAG;
702 (*cf)->can_dlc = CAN_ERR_DLC;
706 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
709 * Allocate and setup space for the CAN network device
711 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
713 struct net_device *dev;
714 struct can_priv *priv;
718 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
719 echo_skb_max * sizeof(struct sk_buff *);
723 dev = alloc_netdev(size, "can%d", NET_NAME_UNKNOWN, can_setup);
727 priv = netdev_priv(dev);
731 priv->echo_skb_max = echo_skb_max;
732 priv->echo_skb = (void *)priv +
733 ALIGN(sizeof_priv, sizeof(struct sk_buff *));
736 priv->state = CAN_STATE_STOPPED;
738 INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
742 EXPORT_SYMBOL_GPL(alloc_candev);
745 * Free space of the CAN network device
747 void free_candev(struct net_device *dev)
751 EXPORT_SYMBOL_GPL(free_candev);
754 * changing MTU and control mode for CAN/CANFD devices
756 int can_change_mtu(struct net_device *dev, int new_mtu)
758 struct can_priv *priv = netdev_priv(dev);
760 /* Do not allow changing the MTU while running */
761 if (dev->flags & IFF_UP)
764 /* allow change of MTU according to the CANFD ability of the device */
767 /* 'CANFD-only' controllers can not switch to CAN_MTU */
768 if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
771 priv->ctrlmode &= ~CAN_CTRLMODE_FD;
775 /* check for potential CANFD ability */
776 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
777 !(priv->ctrlmode_static & CAN_CTRLMODE_FD))
780 priv->ctrlmode |= CAN_CTRLMODE_FD;
790 EXPORT_SYMBOL_GPL(can_change_mtu);
793 * Common open function when the device gets opened.
795 * This function should be called in the open function of the device
798 int open_candev(struct net_device *dev)
800 struct can_priv *priv = netdev_priv(dev);
802 if (!priv->bittiming.bitrate) {
803 netdev_err(dev, "bit-timing not yet defined\n");
807 /* For CAN FD the data bitrate has to be >= the arbitration bitrate */
808 if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
809 (!priv->data_bittiming.bitrate ||
810 (priv->data_bittiming.bitrate < priv->bittiming.bitrate))) {
811 netdev_err(dev, "incorrect/missing data bit-timing\n");
815 /* Switch carrier on if device was stopped while in bus-off state */
816 if (!netif_carrier_ok(dev))
817 netif_carrier_on(dev);
821 EXPORT_SYMBOL_GPL(open_candev);
824 * Common close function for cleanup before the device gets closed.
826 * This function should be called in the close function of the device
829 void close_candev(struct net_device *dev)
831 struct can_priv *priv = netdev_priv(dev);
833 cancel_delayed_work_sync(&priv->restart_work);
834 can_flush_echo_skb(dev);
836 EXPORT_SYMBOL_GPL(close_candev);
839 * CAN netlink interface
841 static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
842 [IFLA_CAN_STATE] = { .type = NLA_U32 },
843 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
844 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
845 [IFLA_CAN_RESTART] = { .type = NLA_U32 },
846 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
847 [IFLA_CAN_BITTIMING_CONST]
848 = { .len = sizeof(struct can_bittiming_const) },
849 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
850 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
851 [IFLA_CAN_DATA_BITTIMING]
852 = { .len = sizeof(struct can_bittiming) },
853 [IFLA_CAN_DATA_BITTIMING_CONST]
854 = { .len = sizeof(struct can_bittiming_const) },
857 static int can_validate(struct nlattr *tb[], struct nlattr *data[])
859 bool is_can_fd = false;
861 /* Make sure that valid CAN FD configurations always consist of
862 * - nominal/arbitration bittiming
864 * - control mode with CAN_CTRLMODE_FD set
870 if (data[IFLA_CAN_CTRLMODE]) {
871 struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
873 is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
877 if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
881 if (data[IFLA_CAN_DATA_BITTIMING]) {
882 if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
889 static int can_changelink(struct net_device *dev,
890 struct nlattr *tb[], struct nlattr *data[])
892 struct can_priv *priv = netdev_priv(dev);
895 /* We need synchronization with dev->stop() */
898 if (data[IFLA_CAN_BITTIMING]) {
899 struct can_bittiming bt;
901 /* Do not allow changing bittiming while running */
902 if (dev->flags & IFF_UP)
904 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
905 err = can_get_bittiming(dev, &bt, priv->bittiming_const);
908 memcpy(&priv->bittiming, &bt, sizeof(bt));
910 if (priv->do_set_bittiming) {
911 /* Finally, set the bit-timing registers */
912 err = priv->do_set_bittiming(dev);
918 if (data[IFLA_CAN_CTRLMODE]) {
919 struct can_ctrlmode *cm;
923 /* Do not allow changing controller mode while running */
924 if (dev->flags & IFF_UP)
926 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
927 ctrlstatic = priv->ctrlmode_static;
928 maskedflags = cm->flags & cm->mask;
930 /* check whether provided bits are allowed to be passed */
931 if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
934 /* do not check for static fd-non-iso if 'fd' is disabled */
935 if (!(maskedflags & CAN_CTRLMODE_FD))
936 ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
938 /* make sure static options are provided by configuration */
939 if ((maskedflags & ctrlstatic) != ctrlstatic)
942 /* clear bits to be modified and copy the flag values */
943 priv->ctrlmode &= ~cm->mask;
944 priv->ctrlmode |= maskedflags;
946 /* CAN_CTRLMODE_FD can only be set when driver supports FD */
947 if (priv->ctrlmode & CAN_CTRLMODE_FD)
948 dev->mtu = CANFD_MTU;
953 if (data[IFLA_CAN_RESTART_MS]) {
954 /* Do not allow changing restart delay while running */
955 if (dev->flags & IFF_UP)
957 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
960 if (data[IFLA_CAN_RESTART]) {
961 /* Do not allow a restart while not running */
962 if (!(dev->flags & IFF_UP))
964 err = can_restart_now(dev);
969 if (data[IFLA_CAN_DATA_BITTIMING]) {
970 struct can_bittiming dbt;
972 /* Do not allow changing bittiming while running */
973 if (dev->flags & IFF_UP)
975 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
977 err = can_get_bittiming(dev, &dbt, priv->data_bittiming_const);
980 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
982 if (priv->do_set_data_bittiming) {
983 /* Finally, set the bit-timing registers */
984 err = priv->do_set_data_bittiming(dev);
993 static size_t can_get_size(const struct net_device *dev)
995 struct can_priv *priv = netdev_priv(dev);
998 if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */
999 size += nla_total_size(sizeof(struct can_bittiming));
1000 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
1001 size += nla_total_size(sizeof(struct can_bittiming_const));
1002 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
1003 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
1004 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
1005 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
1006 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
1007 size += nla_total_size(sizeof(struct can_berr_counter));
1008 if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */
1009 size += nla_total_size(sizeof(struct can_bittiming));
1010 if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */
1011 size += nla_total_size(sizeof(struct can_bittiming_const));
1016 static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
1018 struct can_priv *priv = netdev_priv(dev);
1019 struct can_ctrlmode cm = {.flags = priv->ctrlmode};
1020 struct can_berr_counter bec = { };
1021 enum can_state state = priv->state;
1023 if (priv->do_get_state)
1024 priv->do_get_state(dev, &state);
1026 if ((priv->bittiming.bitrate &&
1027 nla_put(skb, IFLA_CAN_BITTIMING,
1028 sizeof(priv->bittiming), &priv->bittiming)) ||
1030 (priv->bittiming_const &&
1031 nla_put(skb, IFLA_CAN_BITTIMING_CONST,
1032 sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
1034 nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
1035 nla_put_u32(skb, IFLA_CAN_STATE, state) ||
1036 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
1037 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
1039 (priv->do_get_berr_counter &&
1040 !priv->do_get_berr_counter(dev, &bec) &&
1041 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
1043 (priv->data_bittiming.bitrate &&
1044 nla_put(skb, IFLA_CAN_DATA_BITTIMING,
1045 sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
1047 (priv->data_bittiming_const &&
1048 nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
1049 sizeof(*priv->data_bittiming_const),
1050 priv->data_bittiming_const)))
1056 static size_t can_get_xstats_size(const struct net_device *dev)
1058 return sizeof(struct can_device_stats);
1061 static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
1063 struct can_priv *priv = netdev_priv(dev);
1065 if (nla_put(skb, IFLA_INFO_XSTATS,
1066 sizeof(priv->can_stats), &priv->can_stats))
1067 goto nla_put_failure;
1074 static int can_newlink(struct net *src_net, struct net_device *dev,
1075 struct nlattr *tb[], struct nlattr *data[])
1080 static void can_dellink(struct net_device *dev, struct list_head *head)
1085 static struct rtnl_link_ops can_link_ops __read_mostly = {
1087 .netns_refund = true,
1088 .maxtype = IFLA_CAN_MAX,
1089 .policy = can_policy,
1091 .validate = can_validate,
1092 .newlink = can_newlink,
1093 .changelink = can_changelink,
1094 .dellink = can_dellink,
1095 .get_size = can_get_size,
1096 .fill_info = can_fill_info,
1097 .get_xstats_size = can_get_xstats_size,
1098 .fill_xstats = can_fill_xstats,
1102 * Register the CAN network device
1104 int register_candev(struct net_device *dev)
1106 dev->rtnl_link_ops = &can_link_ops;
1107 netif_carrier_off(dev);
1109 return register_netdev(dev);
1111 EXPORT_SYMBOL_GPL(register_candev);
1114 * Unregister the CAN network device
1116 void unregister_candev(struct net_device *dev)
1118 unregister_netdev(dev);
1120 EXPORT_SYMBOL_GPL(unregister_candev);
1123 * Test if a network device is a candev based device
1124 * and return the can_priv* if so.
1126 struct can_priv *safe_candev_priv(struct net_device *dev)
1128 if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
1131 return netdev_priv(dev);
1133 EXPORT_SYMBOL_GPL(safe_candev_priv);
1135 static __init int can_dev_init(void)
1139 can_led_notifier_init();
1141 err = rtnl_link_register(&can_link_ops);
1143 printk(KERN_INFO MOD_DESC "\n");
1147 module_init(can_dev_init);
1149 static __exit void can_dev_exit(void)
1151 rtnl_link_unregister(&can_link_ops);
1153 can_led_notifier_exit();
1155 module_exit(can_dev_exit);
1157 MODULE_ALIAS_RTNL_LINK("can");