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>
31 #include <net/rtnetlink.h>
33 #define MOD_DESC "CAN device driver interface"
35 MODULE_DESCRIPTION(MOD_DESC);
36 MODULE_LICENSE("GPL v2");
37 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
39 /* CAN DLC to real data length conversion helpers */
41 static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
42 8, 12, 16, 20, 24, 32, 48, 64};
44 /* get data length from can_dlc with sanitized can_dlc */
45 u8 can_dlc2len(u8 can_dlc)
47 return dlc2len[can_dlc & 0x0F];
49 EXPORT_SYMBOL_GPL(can_dlc2len);
51 static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */
52 9, 9, 9, 9, /* 9 - 12 */
53 10, 10, 10, 10, /* 13 - 16 */
54 11, 11, 11, 11, /* 17 - 20 */
55 12, 12, 12, 12, /* 21 - 24 */
56 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */
57 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */
58 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */
59 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */
60 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */
62 /* map the sanitized data length to an appropriate data length code */
63 u8 can_len2dlc(u8 len)
65 if (unlikely(len > 64))
70 EXPORT_SYMBOL_GPL(can_len2dlc);
72 #ifdef CONFIG_CAN_CALC_BITTIMING
73 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
74 #define CAN_CALC_SYNC_SEG 1
77 * Bit-timing calculation derived from:
79 * Code based on LinCAN sources and H8S2638 project
80 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
81 * Copyright 2005 Stanislav Marek
82 * email: pisa@cmp.felk.cvut.cz
84 * Calculates proper bit-timing parameters for a specified bit-rate
85 * and sample-point, which can then be used to set the bit-timing
86 * registers of the CAN controller. You can find more information
87 * in the header file linux/can/netlink.h.
89 static int can_update_sample_point(const struct can_bittiming_const *btc,
90 unsigned int sample_point_nominal, unsigned int tseg,
91 unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
92 unsigned int *sample_point_error_ptr)
94 unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
95 unsigned int sample_point, best_sample_point = 0;
96 unsigned int tseg1, tseg2;
99 for (i = 0; i <= 1; i++) {
100 tseg2 = tseg + CAN_CALC_SYNC_SEG - (sample_point_nominal * (tseg + CAN_CALC_SYNC_SEG)) / 1000 - i;
101 tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
102 tseg1 = tseg - tseg2;
103 if (tseg1 > btc->tseg1_max) {
104 tseg1 = btc->tseg1_max;
105 tseg2 = tseg - tseg1;
108 sample_point = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) / (tseg + CAN_CALC_SYNC_SEG);
109 sample_point_error = abs(sample_point_nominal - sample_point);
111 if ((sample_point <= sample_point_nominal) && (sample_point_error < best_sample_point_error)) {
112 best_sample_point = sample_point;
113 best_sample_point_error = sample_point_error;
119 if (sample_point_error_ptr)
120 *sample_point_error_ptr = best_sample_point_error;
122 return best_sample_point;
125 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
126 const struct can_bittiming_const *btc)
128 struct can_priv *priv = netdev_priv(dev);
129 unsigned int bitrate; /* current bitrate */
130 unsigned int bitrate_error; /* difference between current and nominal value */
131 unsigned int best_bitrate_error = UINT_MAX;
132 unsigned int sample_point_error; /* difference between current and nominal value */
133 unsigned int best_sample_point_error = UINT_MAX;
134 unsigned int sample_point_nominal; /* nominal sample point */
135 unsigned int best_tseg = 0; /* current best value for tseg */
136 unsigned int best_brp = 0; /* current best value for brp */
137 unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
140 /* Use CiA recommended sample points */
141 if (bt->sample_point) {
142 sample_point_nominal = bt->sample_point;
144 if (bt->bitrate > 800000)
145 sample_point_nominal = 750;
146 else if (bt->bitrate > 500000)
147 sample_point_nominal = 800;
149 sample_point_nominal = 875;
152 /* tseg even = round down, odd = round up */
153 for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
154 tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
155 tsegall = CAN_CALC_SYNC_SEG + tseg / 2;
157 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */
158 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
160 /* choose brp step which is possible in system */
161 brp = (brp / btc->brp_inc) * btc->brp_inc;
162 if ((brp < btc->brp_min) || (brp > btc->brp_max))
165 bitrate = priv->clock.freq / (brp * tsegall);
166 bitrate_error = abs(bt->bitrate - bitrate);
168 /* tseg brp biterror */
169 if (bitrate_error > best_bitrate_error)
172 /* reset sample point error if we have a better bitrate */
173 if (bitrate_error < best_bitrate_error)
174 best_sample_point_error = UINT_MAX;
176 can_update_sample_point(btc, sample_point_nominal, tseg / 2, &tseg1, &tseg2, &sample_point_error);
177 if (sample_point_error > best_sample_point_error)
180 best_sample_point_error = sample_point_error;
181 best_bitrate_error = bitrate_error;
182 best_tseg = tseg / 2;
185 if (bitrate_error == 0 && sample_point_error == 0)
189 if (best_bitrate_error) {
190 /* Error in one-tenth of a percent */
191 v64 = (u64)best_bitrate_error * 1000;
192 do_div(v64, bt->bitrate);
193 bitrate_error = (u32)v64;
194 if (bitrate_error > CAN_CALC_MAX_ERROR) {
196 "bitrate error %d.%d%% too high\n",
197 bitrate_error / 10, bitrate_error % 10);
200 netdev_warn(dev, "bitrate error %d.%d%%\n",
201 bitrate_error / 10, bitrate_error % 10);
204 /* real sample point */
205 bt->sample_point = can_update_sample_point(btc, sample_point_nominal, best_tseg,
206 &tseg1, &tseg2, NULL);
208 v64 = (u64)best_brp * 1000 * 1000 * 1000;
209 do_div(v64, priv->clock.freq);
211 bt->prop_seg = tseg1 / 2;
212 bt->phase_seg1 = tseg1 - bt->prop_seg;
213 bt->phase_seg2 = tseg2;
215 /* check for sjw user settings */
216 if (!bt->sjw || !btc->sjw_max) {
219 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
220 if (bt->sjw > btc->sjw_max)
221 bt->sjw = btc->sjw_max;
222 /* bt->sjw must not be higher than tseg2 */
230 bt->bitrate = priv->clock.freq / (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2));
234 #else /* !CONFIG_CAN_CALC_BITTIMING */
235 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
236 const struct can_bittiming_const *btc)
238 netdev_err(dev, "bit-timing calculation not available\n");
241 #endif /* CONFIG_CAN_CALC_BITTIMING */
244 * Checks the validity of the specified bit-timing parameters prop_seg,
245 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
246 * prescaler value brp. You can find more information in the header
247 * file linux/can/netlink.h.
249 static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
250 const struct can_bittiming_const *btc)
252 struct can_priv *priv = netdev_priv(dev);
256 tseg1 = bt->prop_seg + bt->phase_seg1;
259 if (bt->sjw > btc->sjw_max ||
260 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
261 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
264 brp64 = (u64)priv->clock.freq * (u64)bt->tq;
265 if (btc->brp_inc > 1)
266 do_div(brp64, btc->brp_inc);
267 brp64 += 500000000UL - 1;
268 do_div(brp64, 1000000000UL); /* the practicable BRP */
269 if (btc->brp_inc > 1)
270 brp64 *= btc->brp_inc;
271 bt->brp = (u32)brp64;
273 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
276 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
277 bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
278 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
283 /* Checks the validity of predefined bitrate settings */
284 static int can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
285 const u32 *bitrate_const,
286 const unsigned int bitrate_const_cnt)
288 struct can_priv *priv = netdev_priv(dev);
291 for (i = 0; i < bitrate_const_cnt; i++) {
292 if (bt->bitrate == bitrate_const[i])
296 if (i >= priv->bitrate_const_cnt)
302 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
303 const struct can_bittiming_const *btc,
304 const u32 *bitrate_const,
305 const unsigned int bitrate_const_cnt)
310 * Depending on the given can_bittiming parameter structure the CAN
311 * timing parameters are calculated based on the provided bitrate OR
312 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
313 * provided directly which are then checked and fixed up.
315 if (!bt->tq && bt->bitrate && btc)
316 err = can_calc_bittiming(dev, bt, btc);
317 else if (bt->tq && !bt->bitrate && btc)
318 err = can_fixup_bittiming(dev, bt, btc);
319 else if (!bt->tq && bt->bitrate && bitrate_const)
320 err = can_validate_bitrate(dev, bt, bitrate_const,
328 static void can_update_state_error_stats(struct net_device *dev,
329 enum can_state new_state)
331 struct can_priv *priv = netdev_priv(dev);
333 if (new_state <= priv->state)
337 case CAN_STATE_ERROR_WARNING:
338 priv->can_stats.error_warning++;
340 case CAN_STATE_ERROR_PASSIVE:
341 priv->can_stats.error_passive++;
343 case CAN_STATE_BUS_OFF:
344 priv->can_stats.bus_off++;
351 static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
354 case CAN_STATE_ERROR_ACTIVE:
355 return CAN_ERR_CRTL_ACTIVE;
356 case CAN_STATE_ERROR_WARNING:
357 return CAN_ERR_CRTL_TX_WARNING;
358 case CAN_STATE_ERROR_PASSIVE:
359 return CAN_ERR_CRTL_TX_PASSIVE;
365 static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
368 case CAN_STATE_ERROR_ACTIVE:
369 return CAN_ERR_CRTL_ACTIVE;
370 case CAN_STATE_ERROR_WARNING:
371 return CAN_ERR_CRTL_RX_WARNING;
372 case CAN_STATE_ERROR_PASSIVE:
373 return CAN_ERR_CRTL_RX_PASSIVE;
379 void can_change_state(struct net_device *dev, struct can_frame *cf,
380 enum can_state tx_state, enum can_state rx_state)
382 struct can_priv *priv = netdev_priv(dev);
383 enum can_state new_state = max(tx_state, rx_state);
385 if (unlikely(new_state == priv->state)) {
386 netdev_warn(dev, "%s: oops, state did not change", __func__);
390 netdev_dbg(dev, "New error state: %d\n", new_state);
392 can_update_state_error_stats(dev, new_state);
393 priv->state = new_state;
398 if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
399 cf->can_id |= CAN_ERR_BUSOFF;
403 cf->can_id |= CAN_ERR_CRTL;
404 cf->data[1] |= tx_state >= rx_state ?
405 can_tx_state_to_frame(dev, tx_state) : 0;
406 cf->data[1] |= tx_state <= rx_state ?
407 can_rx_state_to_frame(dev, rx_state) : 0;
409 EXPORT_SYMBOL_GPL(can_change_state);
412 * Local echo of CAN messages
414 * CAN network devices *should* support a local echo functionality
415 * (see Documentation/networking/can.rst). To test the handling of CAN
416 * interfaces that do not support the local echo both driver types are
417 * implemented. In the case that the driver does not support the echo
418 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
419 * to perform the echo as a fallback solution.
421 static void can_flush_echo_skb(struct net_device *dev)
423 struct can_priv *priv = netdev_priv(dev);
424 struct net_device_stats *stats = &dev->stats;
427 for (i = 0; i < priv->echo_skb_max; i++) {
428 if (priv->echo_skb[i]) {
429 kfree_skb(priv->echo_skb[i]);
430 priv->echo_skb[i] = NULL;
432 stats->tx_aborted_errors++;
438 * Put the skb on the stack to be looped backed locally lateron
440 * The function is typically called in the start_xmit function
441 * of the device driver. The driver must protect access to
442 * priv->echo_skb, if necessary.
444 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
447 struct can_priv *priv = netdev_priv(dev);
449 BUG_ON(idx >= priv->echo_skb_max);
451 /* check flag whether this packet has to be looped back */
452 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
453 (skb->protocol != htons(ETH_P_CAN) &&
454 skb->protocol != htons(ETH_P_CANFD))) {
459 if (!priv->echo_skb[idx]) {
461 skb = can_create_echo_skb(skb);
465 /* make settings for echo to reduce code in irq context */
466 skb->pkt_type = PACKET_BROADCAST;
467 skb->ip_summed = CHECKSUM_UNNECESSARY;
470 /* save this skb for tx interrupt echo handling */
471 priv->echo_skb[idx] = skb;
473 /* locking problem with netif_stop_queue() ?? */
474 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
478 EXPORT_SYMBOL_GPL(can_put_echo_skb);
480 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
482 struct can_priv *priv = netdev_priv(dev);
484 if (idx >= priv->echo_skb_max) {
485 netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
486 __func__, idx, priv->echo_skb_max);
490 if (priv->echo_skb[idx]) {
491 /* Using "struct canfd_frame::len" for the frame
492 * length is supported on both CAN and CANFD frames.
494 struct sk_buff *skb = priv->echo_skb[idx];
495 struct canfd_frame *cf = (struct canfd_frame *)skb->data;
497 /* get the real payload length for netdev statistics */
498 if (cf->can_id & CAN_RTR_FLAG)
503 priv->echo_skb[idx] = NULL;
512 * Get the skb from the stack and loop it back locally
514 * The function is typically called when the TX done interrupt
515 * is handled in the device driver. The driver must protect
516 * access to priv->echo_skb, if necessary.
518 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
523 skb = __can_get_echo_skb(dev, idx, &len);
528 if (netif_rx(skb) == NET_RX_SUCCESS)
529 dev_consume_skb_any(skb);
531 dev_kfree_skb_any(skb);
535 EXPORT_SYMBOL_GPL(can_get_echo_skb);
538 * Remove the skb from the stack and free it.
540 * The function is typically called when TX failed.
542 void can_free_echo_skb(struct net_device *dev, unsigned int idx)
544 struct can_priv *priv = netdev_priv(dev);
546 BUG_ON(idx >= priv->echo_skb_max);
548 if (priv->echo_skb[idx]) {
549 dev_kfree_skb_any(priv->echo_skb[idx]);
550 priv->echo_skb[idx] = NULL;
553 EXPORT_SYMBOL_GPL(can_free_echo_skb);
556 * CAN device restart for bus-off recovery
558 static void can_restart(struct net_device *dev)
560 struct can_priv *priv = netdev_priv(dev);
561 struct net_device_stats *stats = &dev->stats;
563 struct can_frame *cf;
566 if (netif_carrier_ok(dev))
567 netdev_err(dev, "Attempt to restart for bus-off recovery, but carrier is OK?\n");
570 * No synchronization needed because the device is bus-off and
571 * no messages can come in or go out.
573 can_flush_echo_skb(dev);
575 /* send restart message upstream */
576 skb = alloc_can_err_skb(dev, &cf);
581 cf->can_id |= CAN_ERR_RESTARTED;
584 stats->rx_bytes += cf->can_dlc;
589 netdev_dbg(dev, "restarted\n");
590 priv->can_stats.restarts++;
592 /* Now restart the device */
593 netif_carrier_on(dev);
594 err = priv->do_set_mode(dev, CAN_MODE_START);
596 netdev_err(dev, "Error %d during restart", err);
597 netif_carrier_off(dev);
601 static void can_restart_work(struct work_struct *work)
603 struct delayed_work *dwork = to_delayed_work(work);
604 struct can_priv *priv = container_of(dwork, struct can_priv, restart_work);
606 can_restart(priv->dev);
609 int can_restart_now(struct net_device *dev)
611 struct can_priv *priv = netdev_priv(dev);
614 * A manual restart is only permitted if automatic restart is
615 * disabled and the device is in the bus-off state
617 if (priv->restart_ms)
619 if (priv->state != CAN_STATE_BUS_OFF)
622 cancel_delayed_work_sync(&priv->restart_work);
631 * This functions should be called when the device goes bus-off to
632 * tell the netif layer that no more packets can be sent or received.
633 * If enabled, a timer is started to trigger bus-off recovery.
635 void can_bus_off(struct net_device *dev)
637 struct can_priv *priv = netdev_priv(dev);
639 netdev_info(dev, "bus-off\n");
641 netif_carrier_off(dev);
643 if (priv->restart_ms)
644 schedule_delayed_work(&priv->restart_work,
645 msecs_to_jiffies(priv->restart_ms));
647 EXPORT_SYMBOL_GPL(can_bus_off);
649 static void can_setup(struct net_device *dev)
651 dev->type = ARPHRD_CAN;
653 dev->hard_header_len = 0;
655 dev->tx_queue_len = 10;
657 /* New-style flags. */
658 dev->flags = IFF_NOARP;
659 dev->features = NETIF_F_HW_CSUM;
662 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
666 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
667 sizeof(struct can_frame));
671 skb->protocol = htons(ETH_P_CAN);
672 skb->pkt_type = PACKET_BROADCAST;
673 skb->ip_summed = CHECKSUM_UNNECESSARY;
675 skb_reset_mac_header(skb);
676 skb_reset_network_header(skb);
677 skb_reset_transport_header(skb);
679 can_skb_reserve(skb);
680 can_skb_prv(skb)->ifindex = dev->ifindex;
681 can_skb_prv(skb)->skbcnt = 0;
683 *cf = skb_put_zero(skb, sizeof(struct can_frame));
687 EXPORT_SYMBOL_GPL(alloc_can_skb);
689 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
690 struct canfd_frame **cfd)
694 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
695 sizeof(struct canfd_frame));
699 skb->protocol = htons(ETH_P_CANFD);
700 skb->pkt_type = PACKET_BROADCAST;
701 skb->ip_summed = CHECKSUM_UNNECESSARY;
703 skb_reset_mac_header(skb);
704 skb_reset_network_header(skb);
705 skb_reset_transport_header(skb);
707 can_skb_reserve(skb);
708 can_skb_prv(skb)->ifindex = dev->ifindex;
709 can_skb_prv(skb)->skbcnt = 0;
711 *cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
715 EXPORT_SYMBOL_GPL(alloc_canfd_skb);
717 struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
721 skb = alloc_can_skb(dev, cf);
725 (*cf)->can_id = CAN_ERR_FLAG;
726 (*cf)->can_dlc = CAN_ERR_DLC;
730 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
733 * Allocate and setup space for the CAN network device
735 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
736 unsigned int txqs, unsigned int rxqs)
738 struct net_device *dev;
739 struct can_priv *priv;
743 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
744 echo_skb_max * sizeof(struct sk_buff *);
748 dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup,
753 priv = netdev_priv(dev);
757 priv->echo_skb_max = echo_skb_max;
758 priv->echo_skb = (void *)priv +
759 ALIGN(sizeof_priv, sizeof(struct sk_buff *));
762 priv->state = CAN_STATE_STOPPED;
764 INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
768 EXPORT_SYMBOL_GPL(alloc_candev_mqs);
771 * Free space of the CAN network device
773 void free_candev(struct net_device *dev)
777 EXPORT_SYMBOL_GPL(free_candev);
780 * changing MTU and control mode for CAN/CANFD devices
782 int can_change_mtu(struct net_device *dev, int new_mtu)
784 struct can_priv *priv = netdev_priv(dev);
786 /* Do not allow changing the MTU while running */
787 if (dev->flags & IFF_UP)
790 /* allow change of MTU according to the CANFD ability of the device */
793 /* 'CANFD-only' controllers can not switch to CAN_MTU */
794 if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
797 priv->ctrlmode &= ~CAN_CTRLMODE_FD;
801 /* check for potential CANFD ability */
802 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
803 !(priv->ctrlmode_static & CAN_CTRLMODE_FD))
806 priv->ctrlmode |= CAN_CTRLMODE_FD;
816 EXPORT_SYMBOL_GPL(can_change_mtu);
819 * Common open function when the device gets opened.
821 * This function should be called in the open function of the device
824 int open_candev(struct net_device *dev)
826 struct can_priv *priv = netdev_priv(dev);
828 if (!priv->bittiming.bitrate) {
829 netdev_err(dev, "bit-timing not yet defined\n");
833 /* For CAN FD the data bitrate has to be >= the arbitration bitrate */
834 if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
835 (!priv->data_bittiming.bitrate ||
836 (priv->data_bittiming.bitrate < priv->bittiming.bitrate))) {
837 netdev_err(dev, "incorrect/missing data bit-timing\n");
841 /* Switch carrier on if device was stopped while in bus-off state */
842 if (!netif_carrier_ok(dev))
843 netif_carrier_on(dev);
847 EXPORT_SYMBOL_GPL(open_candev);
850 /* Common function that can be used to understand the limitation of
851 * a transceiver when it provides no means to determine these limitations
854 void of_can_transceiver(struct net_device *dev)
856 struct device_node *dn;
857 struct can_priv *priv = netdev_priv(dev);
858 struct device_node *np = dev->dev.parent->of_node;
861 dn = of_get_child_by_name(np, "can-transceiver");
865 ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max);
867 if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max))
868 netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n");
870 EXPORT_SYMBOL_GPL(of_can_transceiver);
874 * Common close function for cleanup before the device gets closed.
876 * This function should be called in the close function of the device
879 void close_candev(struct net_device *dev)
881 struct can_priv *priv = netdev_priv(dev);
883 cancel_delayed_work_sync(&priv->restart_work);
884 can_flush_echo_skb(dev);
886 EXPORT_SYMBOL_GPL(close_candev);
889 * CAN netlink interface
891 static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
892 [IFLA_CAN_STATE] = { .type = NLA_U32 },
893 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
894 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
895 [IFLA_CAN_RESTART] = { .type = NLA_U32 },
896 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
897 [IFLA_CAN_BITTIMING_CONST]
898 = { .len = sizeof(struct can_bittiming_const) },
899 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
900 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
901 [IFLA_CAN_DATA_BITTIMING]
902 = { .len = sizeof(struct can_bittiming) },
903 [IFLA_CAN_DATA_BITTIMING_CONST]
904 = { .len = sizeof(struct can_bittiming_const) },
905 [IFLA_CAN_TERMINATION] = { .type = NLA_U16 },
908 static int can_validate(struct nlattr *tb[], struct nlattr *data[],
909 struct netlink_ext_ack *extack)
911 bool is_can_fd = false;
913 /* Make sure that valid CAN FD configurations always consist of
914 * - nominal/arbitration bittiming
916 * - control mode with CAN_CTRLMODE_FD set
922 if (data[IFLA_CAN_CTRLMODE]) {
923 struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
925 is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
929 if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
933 if (data[IFLA_CAN_DATA_BITTIMING]) {
934 if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
941 static int can_changelink(struct net_device *dev, struct nlattr *tb[],
942 struct nlattr *data[],
943 struct netlink_ext_ack *extack)
945 struct can_priv *priv = netdev_priv(dev);
948 /* We need synchronization with dev->stop() */
951 if (data[IFLA_CAN_BITTIMING]) {
952 struct can_bittiming bt;
954 /* Do not allow changing bittiming while running */
955 if (dev->flags & IFF_UP)
958 /* Calculate bittiming parameters based on
959 * bittiming_const if set, otherwise pass bitrate
960 * directly via do_set_bitrate(). Bail out if neither
963 if (!priv->bittiming_const && !priv->do_set_bittiming)
966 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
967 err = can_get_bittiming(dev, &bt,
968 priv->bittiming_const,
970 priv->bitrate_const_cnt);
974 if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) {
975 netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n",
980 memcpy(&priv->bittiming, &bt, sizeof(bt));
982 if (priv->do_set_bittiming) {
983 /* Finally, set the bit-timing registers */
984 err = priv->do_set_bittiming(dev);
990 if (data[IFLA_CAN_CTRLMODE]) {
991 struct can_ctrlmode *cm;
995 /* Do not allow changing controller mode while running */
996 if (dev->flags & IFF_UP)
998 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
999 ctrlstatic = priv->ctrlmode_static;
1000 maskedflags = cm->flags & cm->mask;
1002 /* check whether provided bits are allowed to be passed */
1003 if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
1006 /* do not check for static fd-non-iso if 'fd' is disabled */
1007 if (!(maskedflags & CAN_CTRLMODE_FD))
1008 ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
1010 /* make sure static options are provided by configuration */
1011 if ((maskedflags & ctrlstatic) != ctrlstatic)
1014 /* clear bits to be modified and copy the flag values */
1015 priv->ctrlmode &= ~cm->mask;
1016 priv->ctrlmode |= maskedflags;
1018 /* CAN_CTRLMODE_FD can only be set when driver supports FD */
1019 if (priv->ctrlmode & CAN_CTRLMODE_FD)
1020 dev->mtu = CANFD_MTU;
1025 if (data[IFLA_CAN_RESTART_MS]) {
1026 /* Do not allow changing restart delay while running */
1027 if (dev->flags & IFF_UP)
1029 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
1032 if (data[IFLA_CAN_RESTART]) {
1033 /* Do not allow a restart while not running */
1034 if (!(dev->flags & IFF_UP))
1036 err = can_restart_now(dev);
1041 if (data[IFLA_CAN_DATA_BITTIMING]) {
1042 struct can_bittiming dbt;
1044 /* Do not allow changing bittiming while running */
1045 if (dev->flags & IFF_UP)
1048 /* Calculate bittiming parameters based on
1049 * data_bittiming_const if set, otherwise pass bitrate
1050 * directly via do_set_bitrate(). Bail out if neither
1053 if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
1056 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
1058 err = can_get_bittiming(dev, &dbt,
1059 priv->data_bittiming_const,
1060 priv->data_bitrate_const,
1061 priv->data_bitrate_const_cnt);
1065 if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
1066 netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n",
1071 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
1073 if (priv->do_set_data_bittiming) {
1074 /* Finally, set the bit-timing registers */
1075 err = priv->do_set_data_bittiming(dev);
1081 if (data[IFLA_CAN_TERMINATION]) {
1082 const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
1083 const unsigned int num_term = priv->termination_const_cnt;
1086 if (!priv->do_set_termination)
1089 /* check whether given value is supported by the interface */
1090 for (i = 0; i < num_term; i++) {
1091 if (termval == priv->termination_const[i])
1097 /* Finally, set the termination value */
1098 err = priv->do_set_termination(dev, termval);
1102 priv->termination = termval;
1108 static size_t can_get_size(const struct net_device *dev)
1110 struct can_priv *priv = netdev_priv(dev);
1113 if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */
1114 size += nla_total_size(sizeof(struct can_bittiming));
1115 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
1116 size += nla_total_size(sizeof(struct can_bittiming_const));
1117 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
1118 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
1119 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
1120 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
1121 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
1122 size += nla_total_size(sizeof(struct can_berr_counter));
1123 if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */
1124 size += nla_total_size(sizeof(struct can_bittiming));
1125 if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */
1126 size += nla_total_size(sizeof(struct can_bittiming_const));
1127 if (priv->termination_const) {
1128 size += nla_total_size(sizeof(priv->termination)); /* IFLA_CAN_TERMINATION */
1129 size += nla_total_size(sizeof(*priv->termination_const) * /* IFLA_CAN_TERMINATION_CONST */
1130 priv->termination_const_cnt);
1132 if (priv->bitrate_const) /* IFLA_CAN_BITRATE_CONST */
1133 size += nla_total_size(sizeof(*priv->bitrate_const) *
1134 priv->bitrate_const_cnt);
1135 if (priv->data_bitrate_const) /* IFLA_CAN_DATA_BITRATE_CONST */
1136 size += nla_total_size(sizeof(*priv->data_bitrate_const) *
1137 priv->data_bitrate_const_cnt);
1138 size += sizeof(priv->bitrate_max); /* IFLA_CAN_BITRATE_MAX */
1143 static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
1145 struct can_priv *priv = netdev_priv(dev);
1146 struct can_ctrlmode cm = {.flags = priv->ctrlmode};
1147 struct can_berr_counter bec = { };
1148 enum can_state state = priv->state;
1150 if (priv->do_get_state)
1151 priv->do_get_state(dev, &state);
1153 if ((priv->bittiming.bitrate &&
1154 nla_put(skb, IFLA_CAN_BITTIMING,
1155 sizeof(priv->bittiming), &priv->bittiming)) ||
1157 (priv->bittiming_const &&
1158 nla_put(skb, IFLA_CAN_BITTIMING_CONST,
1159 sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
1161 nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
1162 nla_put_u32(skb, IFLA_CAN_STATE, state) ||
1163 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
1164 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
1166 (priv->do_get_berr_counter &&
1167 !priv->do_get_berr_counter(dev, &bec) &&
1168 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
1170 (priv->data_bittiming.bitrate &&
1171 nla_put(skb, IFLA_CAN_DATA_BITTIMING,
1172 sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
1174 (priv->data_bittiming_const &&
1175 nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
1176 sizeof(*priv->data_bittiming_const),
1177 priv->data_bittiming_const)) ||
1179 (priv->termination_const &&
1180 (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
1181 nla_put(skb, IFLA_CAN_TERMINATION_CONST,
1182 sizeof(*priv->termination_const) *
1183 priv->termination_const_cnt,
1184 priv->termination_const))) ||
1186 (priv->bitrate_const &&
1187 nla_put(skb, IFLA_CAN_BITRATE_CONST,
1188 sizeof(*priv->bitrate_const) *
1189 priv->bitrate_const_cnt,
1190 priv->bitrate_const)) ||
1192 (priv->data_bitrate_const &&
1193 nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
1194 sizeof(*priv->data_bitrate_const) *
1195 priv->data_bitrate_const_cnt,
1196 priv->data_bitrate_const)) ||
1198 (nla_put(skb, IFLA_CAN_BITRATE_MAX,
1199 sizeof(priv->bitrate_max),
1200 &priv->bitrate_max))
1208 static size_t can_get_xstats_size(const struct net_device *dev)
1210 return sizeof(struct can_device_stats);
1213 static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
1215 struct can_priv *priv = netdev_priv(dev);
1217 if (nla_put(skb, IFLA_INFO_XSTATS,
1218 sizeof(priv->can_stats), &priv->can_stats))
1219 goto nla_put_failure;
1226 static int can_newlink(struct net *src_net, struct net_device *dev,
1227 struct nlattr *tb[], struct nlattr *data[],
1228 struct netlink_ext_ack *extack)
1233 static void can_dellink(struct net_device *dev, struct list_head *head)
1238 static struct rtnl_link_ops can_link_ops __read_mostly = {
1240 .netns_refund = true,
1241 .maxtype = IFLA_CAN_MAX,
1242 .policy = can_policy,
1244 .validate = can_validate,
1245 .newlink = can_newlink,
1246 .changelink = can_changelink,
1247 .dellink = can_dellink,
1248 .get_size = can_get_size,
1249 .fill_info = can_fill_info,
1250 .get_xstats_size = can_get_xstats_size,
1251 .fill_xstats = can_fill_xstats,
1255 * Register the CAN network device
1257 int register_candev(struct net_device *dev)
1259 struct can_priv *priv = netdev_priv(dev);
1261 /* Ensure termination_const, termination_const_cnt and
1262 * do_set_termination consistency. All must be either set or
1265 if ((!priv->termination_const != !priv->termination_const_cnt) ||
1266 (!priv->termination_const != !priv->do_set_termination))
1269 if (!priv->bitrate_const != !priv->bitrate_const_cnt)
1272 if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt)
1275 dev->rtnl_link_ops = &can_link_ops;
1276 netif_carrier_off(dev);
1278 return register_netdev(dev);
1280 EXPORT_SYMBOL_GPL(register_candev);
1283 * Unregister the CAN network device
1285 void unregister_candev(struct net_device *dev)
1287 unregister_netdev(dev);
1289 EXPORT_SYMBOL_GPL(unregister_candev);
1292 * Test if a network device is a candev based device
1293 * and return the can_priv* if so.
1295 struct can_priv *safe_candev_priv(struct net_device *dev)
1297 if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
1300 return netdev_priv(dev);
1302 EXPORT_SYMBOL_GPL(safe_candev_priv);
1304 static __init int can_dev_init(void)
1308 can_led_notifier_init();
1310 err = rtnl_link_register(&can_link_ops);
1312 printk(KERN_INFO MOD_DESC "\n");
1316 module_init(can_dev_init);
1318 static __exit void can_dev_exit(void)
1320 rtnl_link_unregister(&can_link_ops);
1322 can_led_notifier_exit();
1324 module_exit(can_dev_exit);
1326 MODULE_ALIAS_RTNL_LINK("can");