1 // SPDX-License-Identifier: GPL-2.0-only
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>
7 #include <linux/module.h>
8 #include <linux/kernel.h>
9 #include <linux/slab.h>
10 #include <linux/netdevice.h>
11 #include <linux/if_arp.h>
12 #include <linux/workqueue.h>
13 #include <linux/can.h>
14 #include <linux/can/can-ml.h>
15 #include <linux/can/dev.h>
16 #include <linux/can/skb.h>
17 #include <linux/can/netlink.h>
18 #include <linux/can/led.h>
20 #include <net/rtnetlink.h>
22 #define MOD_DESC "CAN device driver interface"
24 MODULE_DESCRIPTION(MOD_DESC);
25 MODULE_LICENSE("GPL v2");
26 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
28 /* CAN DLC to real data length conversion helpers */
30 static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
31 8, 12, 16, 20, 24, 32, 48, 64};
33 /* get data length from can_dlc with sanitized can_dlc */
34 u8 can_dlc2len(u8 can_dlc)
36 return dlc2len[can_dlc & 0x0F];
38 EXPORT_SYMBOL_GPL(can_dlc2len);
40 static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */
41 9, 9, 9, 9, /* 9 - 12 */
42 10, 10, 10, 10, /* 13 - 16 */
43 11, 11, 11, 11, /* 17 - 20 */
44 12, 12, 12, 12, /* 21 - 24 */
45 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */
46 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */
47 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */
48 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */
49 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */
51 /* map the sanitized data length to an appropriate data length code */
52 u8 can_len2dlc(u8 len)
54 if (unlikely(len > 64))
59 EXPORT_SYMBOL_GPL(can_len2dlc);
61 #ifdef CONFIG_CAN_CALC_BITTIMING
62 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
63 #define CAN_CALC_SYNC_SEG 1
65 /* Bit-timing calculation derived from:
67 * Code based on LinCAN sources and H8S2638 project
68 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
69 * Copyright 2005 Stanislav Marek
70 * email: pisa@cmp.felk.cvut.cz
72 * Calculates proper bit-timing parameters for a specified bit-rate
73 * and sample-point, which can then be used to set the bit-timing
74 * registers of the CAN controller. You can find more information
75 * in the header file linux/can/netlink.h.
78 can_update_sample_point(const struct can_bittiming_const *btc,
79 unsigned int sample_point_nominal, unsigned int tseg,
80 unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
81 unsigned int *sample_point_error_ptr)
83 unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
84 unsigned int sample_point, best_sample_point = 0;
85 unsigned int tseg1, tseg2;
88 for (i = 0; i <= 1; i++) {
89 tseg2 = tseg + CAN_CALC_SYNC_SEG -
90 (sample_point_nominal * (tseg + CAN_CALC_SYNC_SEG)) /
92 tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
94 if (tseg1 > btc->tseg1_max) {
95 tseg1 = btc->tseg1_max;
99 sample_point = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) /
100 (tseg + CAN_CALC_SYNC_SEG);
101 sample_point_error = abs(sample_point_nominal - sample_point);
103 if (sample_point <= sample_point_nominal &&
104 sample_point_error < best_sample_point_error) {
105 best_sample_point = sample_point;
106 best_sample_point_error = sample_point_error;
112 if (sample_point_error_ptr)
113 *sample_point_error_ptr = best_sample_point_error;
115 return best_sample_point;
118 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
119 const struct can_bittiming_const *btc)
121 struct can_priv *priv = netdev_priv(dev);
122 unsigned int bitrate; /* current bitrate */
123 unsigned int bitrate_error; /* difference between current and nominal value */
124 unsigned int best_bitrate_error = UINT_MAX;
125 unsigned int sample_point_error; /* difference between current and nominal value */
126 unsigned int best_sample_point_error = UINT_MAX;
127 unsigned int sample_point_nominal; /* nominal sample point */
128 unsigned int best_tseg = 0; /* current best value for tseg */
129 unsigned int best_brp = 0; /* current best value for brp */
130 unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
133 /* Use CiA recommended sample points */
134 if (bt->sample_point) {
135 sample_point_nominal = bt->sample_point;
137 if (bt->bitrate > 800000)
138 sample_point_nominal = 750;
139 else if (bt->bitrate > 500000)
140 sample_point_nominal = 800;
142 sample_point_nominal = 875;
145 /* tseg even = round down, odd = round up */
146 for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
147 tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
148 tsegall = CAN_CALC_SYNC_SEG + tseg / 2;
150 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */
151 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
153 /* choose brp step which is possible in system */
154 brp = (brp / btc->brp_inc) * btc->brp_inc;
155 if (brp < btc->brp_min || brp > btc->brp_max)
158 bitrate = priv->clock.freq / (brp * tsegall);
159 bitrate_error = abs(bt->bitrate - bitrate);
161 /* tseg brp biterror */
162 if (bitrate_error > best_bitrate_error)
165 /* reset sample point error if we have a better bitrate */
166 if (bitrate_error < best_bitrate_error)
167 best_sample_point_error = UINT_MAX;
169 can_update_sample_point(btc, sample_point_nominal, tseg / 2,
170 &tseg1, &tseg2, &sample_point_error);
171 if (sample_point_error > best_sample_point_error)
174 best_sample_point_error = sample_point_error;
175 best_bitrate_error = bitrate_error;
176 best_tseg = tseg / 2;
179 if (bitrate_error == 0 && sample_point_error == 0)
183 if (best_bitrate_error) {
184 /* Error in one-tenth of a percent */
185 v64 = (u64)best_bitrate_error * 1000;
186 do_div(v64, bt->bitrate);
187 bitrate_error = (u32)v64;
188 if (bitrate_error > CAN_CALC_MAX_ERROR) {
190 "bitrate error %d.%d%% too high\n",
191 bitrate_error / 10, bitrate_error % 10);
194 netdev_warn(dev, "bitrate error %d.%d%%\n",
195 bitrate_error / 10, bitrate_error % 10);
198 /* real sample point */
199 bt->sample_point = can_update_sample_point(btc, sample_point_nominal,
200 best_tseg, &tseg1, &tseg2,
203 v64 = (u64)best_brp * 1000 * 1000 * 1000;
204 do_div(v64, priv->clock.freq);
206 bt->prop_seg = tseg1 / 2;
207 bt->phase_seg1 = tseg1 - bt->prop_seg;
208 bt->phase_seg2 = tseg2;
210 /* check for sjw user settings */
211 if (!bt->sjw || !btc->sjw_max) {
214 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
215 if (bt->sjw > btc->sjw_max)
216 bt->sjw = btc->sjw_max;
217 /* bt->sjw must not be higher than tseg2 */
225 bt->bitrate = priv->clock.freq /
226 (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2));
230 #else /* !CONFIG_CAN_CALC_BITTIMING */
231 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
232 const struct can_bittiming_const *btc)
234 netdev_err(dev, "bit-timing calculation not available\n");
237 #endif /* CONFIG_CAN_CALC_BITTIMING */
239 /* Checks the validity of the specified bit-timing parameters prop_seg,
240 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
241 * prescaler value brp. You can find more information in the header
242 * file linux/can/netlink.h.
244 static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
245 const struct can_bittiming_const *btc)
247 struct can_priv *priv = netdev_priv(dev);
251 tseg1 = bt->prop_seg + bt->phase_seg1;
254 if (bt->sjw > btc->sjw_max ||
255 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
256 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
259 brp64 = (u64)priv->clock.freq * (u64)bt->tq;
260 if (btc->brp_inc > 1)
261 do_div(brp64, btc->brp_inc);
262 brp64 += 500000000UL - 1;
263 do_div(brp64, 1000000000UL); /* the practicable BRP */
264 if (btc->brp_inc > 1)
265 brp64 *= btc->brp_inc;
266 bt->brp = (u32)brp64;
268 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
271 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
272 bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
273 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
278 /* Checks the validity of predefined bitrate settings */
280 can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
281 const u32 *bitrate_const,
282 const unsigned int bitrate_const_cnt)
284 struct can_priv *priv = netdev_priv(dev);
287 for (i = 0; i < bitrate_const_cnt; i++) {
288 if (bt->bitrate == bitrate_const[i])
292 if (i >= priv->bitrate_const_cnt)
298 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
299 const struct can_bittiming_const *btc,
300 const u32 *bitrate_const,
301 const unsigned int bitrate_const_cnt)
305 /* Depending on the given can_bittiming parameter structure the CAN
306 * timing parameters are calculated based on the provided bitrate OR
307 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
308 * provided directly which are then checked and fixed up.
310 if (!bt->tq && bt->bitrate && btc)
311 err = can_calc_bittiming(dev, bt, btc);
312 else if (bt->tq && !bt->bitrate && btc)
313 err = can_fixup_bittiming(dev, bt, btc);
314 else if (!bt->tq && bt->bitrate && bitrate_const)
315 err = can_validate_bitrate(dev, bt, bitrate_const,
323 static void can_update_state_error_stats(struct net_device *dev,
324 enum can_state new_state)
326 struct can_priv *priv = netdev_priv(dev);
328 if (new_state <= priv->state)
332 case CAN_STATE_ERROR_WARNING:
333 priv->can_stats.error_warning++;
335 case CAN_STATE_ERROR_PASSIVE:
336 priv->can_stats.error_passive++;
338 case CAN_STATE_BUS_OFF:
339 priv->can_stats.bus_off++;
346 static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
349 case CAN_STATE_ERROR_ACTIVE:
350 return CAN_ERR_CRTL_ACTIVE;
351 case CAN_STATE_ERROR_WARNING:
352 return CAN_ERR_CRTL_TX_WARNING;
353 case CAN_STATE_ERROR_PASSIVE:
354 return CAN_ERR_CRTL_TX_PASSIVE;
360 static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
363 case CAN_STATE_ERROR_ACTIVE:
364 return CAN_ERR_CRTL_ACTIVE;
365 case CAN_STATE_ERROR_WARNING:
366 return CAN_ERR_CRTL_RX_WARNING;
367 case CAN_STATE_ERROR_PASSIVE:
368 return CAN_ERR_CRTL_RX_PASSIVE;
374 void can_change_state(struct net_device *dev, struct can_frame *cf,
375 enum can_state tx_state, enum can_state rx_state)
377 struct can_priv *priv = netdev_priv(dev);
378 enum can_state new_state = max(tx_state, rx_state);
380 if (unlikely(new_state == priv->state)) {
381 netdev_warn(dev, "%s: oops, state did not change", __func__);
385 netdev_dbg(dev, "New error state: %d\n", new_state);
387 can_update_state_error_stats(dev, new_state);
388 priv->state = new_state;
393 if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
394 cf->can_id |= CAN_ERR_BUSOFF;
398 cf->can_id |= CAN_ERR_CRTL;
399 cf->data[1] |= tx_state >= rx_state ?
400 can_tx_state_to_frame(dev, tx_state) : 0;
401 cf->data[1] |= tx_state <= rx_state ?
402 can_rx_state_to_frame(dev, rx_state) : 0;
404 EXPORT_SYMBOL_GPL(can_change_state);
406 /* Local echo of CAN messages
408 * CAN network devices *should* support a local echo functionality
409 * (see Documentation/networking/can.rst). To test the handling of CAN
410 * interfaces that do not support the local echo both driver types are
411 * implemented. In the case that the driver does not support the echo
412 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
413 * to perform the echo as a fallback solution.
415 static void can_flush_echo_skb(struct net_device *dev)
417 struct can_priv *priv = netdev_priv(dev);
418 struct net_device_stats *stats = &dev->stats;
421 for (i = 0; i < priv->echo_skb_max; i++) {
422 if (priv->echo_skb[i]) {
423 kfree_skb(priv->echo_skb[i]);
424 priv->echo_skb[i] = NULL;
426 stats->tx_aborted_errors++;
431 /* Put the skb on the stack to be looped backed locally lateron
433 * The function is typically called in the start_xmit function
434 * of the device driver. The driver must protect access to
435 * priv->echo_skb, if necessary.
437 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
440 struct can_priv *priv = netdev_priv(dev);
442 BUG_ON(idx >= priv->echo_skb_max);
444 /* check flag whether this packet has to be looped back */
445 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
446 (skb->protocol != htons(ETH_P_CAN) &&
447 skb->protocol != htons(ETH_P_CANFD))) {
452 if (!priv->echo_skb[idx]) {
453 skb = can_create_echo_skb(skb);
457 /* make settings for echo to reduce code in irq context */
458 skb->pkt_type = PACKET_BROADCAST;
459 skb->ip_summed = CHECKSUM_UNNECESSARY;
462 /* save this skb for tx interrupt echo handling */
463 priv->echo_skb[idx] = skb;
465 /* locking problem with netif_stop_queue() ?? */
466 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
470 EXPORT_SYMBOL_GPL(can_put_echo_skb);
473 __can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
475 struct can_priv *priv = netdev_priv(dev);
477 if (idx >= priv->echo_skb_max) {
478 netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
479 __func__, idx, priv->echo_skb_max);
483 if (priv->echo_skb[idx]) {
484 /* Using "struct canfd_frame::len" for the frame
485 * length is supported on both CAN and CANFD frames.
487 struct sk_buff *skb = priv->echo_skb[idx];
488 struct canfd_frame *cf = (struct canfd_frame *)skb->data;
492 priv->echo_skb[idx] = NULL;
500 /* Get the skb from the stack and loop it back locally
502 * The function is typically called when the TX done interrupt
503 * is handled in the device driver. The driver must protect
504 * access to priv->echo_skb, if necessary.
506 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
511 skb = __can_get_echo_skb(dev, idx, &len);
519 EXPORT_SYMBOL_GPL(can_get_echo_skb);
521 /* Remove the skb from the stack and free it.
523 * The function is typically called when TX failed.
525 void can_free_echo_skb(struct net_device *dev, unsigned int idx)
527 struct can_priv *priv = netdev_priv(dev);
529 BUG_ON(idx >= priv->echo_skb_max);
531 if (priv->echo_skb[idx]) {
532 dev_kfree_skb_any(priv->echo_skb[idx]);
533 priv->echo_skb[idx] = NULL;
536 EXPORT_SYMBOL_GPL(can_free_echo_skb);
538 /* CAN device restart for bus-off recovery */
539 static void can_restart(struct net_device *dev)
541 struct can_priv *priv = netdev_priv(dev);
542 struct net_device_stats *stats = &dev->stats;
544 struct can_frame *cf;
547 BUG_ON(netif_carrier_ok(dev));
549 /* No synchronization needed because the device is bus-off and
550 * no messages can come in or go out.
552 can_flush_echo_skb(dev);
554 /* send restart message upstream */
555 skb = alloc_can_err_skb(dev, &cf);
559 cf->can_id |= CAN_ERR_RESTARTED;
564 stats->rx_bytes += cf->can_dlc;
567 netdev_dbg(dev, "restarted\n");
568 priv->can_stats.restarts++;
570 /* Now restart the device */
571 err = priv->do_set_mode(dev, CAN_MODE_START);
573 netif_carrier_on(dev);
575 netdev_err(dev, "Error %d during restart", err);
578 static void can_restart_work(struct work_struct *work)
580 struct delayed_work *dwork = to_delayed_work(work);
581 struct can_priv *priv = container_of(dwork, struct can_priv,
584 can_restart(priv->dev);
587 int can_restart_now(struct net_device *dev)
589 struct can_priv *priv = netdev_priv(dev);
591 /* A manual restart is only permitted if automatic restart is
592 * disabled and the device is in the bus-off state
594 if (priv->restart_ms)
596 if (priv->state != CAN_STATE_BUS_OFF)
599 cancel_delayed_work_sync(&priv->restart_work);
607 * This functions should be called when the device goes bus-off to
608 * tell the netif layer that no more packets can be sent or received.
609 * If enabled, a timer is started to trigger bus-off recovery.
611 void can_bus_off(struct net_device *dev)
613 struct can_priv *priv = netdev_priv(dev);
615 netdev_info(dev, "bus-off\n");
617 netif_carrier_off(dev);
619 if (priv->restart_ms)
620 schedule_delayed_work(&priv->restart_work,
621 msecs_to_jiffies(priv->restart_ms));
623 EXPORT_SYMBOL_GPL(can_bus_off);
625 static void can_setup(struct net_device *dev)
627 dev->type = ARPHRD_CAN;
629 dev->hard_header_len = 0;
631 dev->tx_queue_len = 10;
633 /* New-style flags. */
634 dev->flags = IFF_NOARP;
635 dev->features = NETIF_F_HW_CSUM;
638 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
642 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
643 sizeof(struct can_frame));
647 skb->protocol = htons(ETH_P_CAN);
648 skb->pkt_type = PACKET_BROADCAST;
649 skb->ip_summed = CHECKSUM_UNNECESSARY;
651 skb_reset_mac_header(skb);
652 skb_reset_network_header(skb);
653 skb_reset_transport_header(skb);
655 can_skb_reserve(skb);
656 can_skb_prv(skb)->ifindex = dev->ifindex;
657 can_skb_prv(skb)->skbcnt = 0;
659 *cf = skb_put_zero(skb, sizeof(struct can_frame));
663 EXPORT_SYMBOL_GPL(alloc_can_skb);
665 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
666 struct canfd_frame **cfd)
670 skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
671 sizeof(struct canfd_frame));
675 skb->protocol = htons(ETH_P_CANFD);
676 skb->pkt_type = PACKET_BROADCAST;
677 skb->ip_summed = CHECKSUM_UNNECESSARY;
679 skb_reset_mac_header(skb);
680 skb_reset_network_header(skb);
681 skb_reset_transport_header(skb);
683 can_skb_reserve(skb);
684 can_skb_prv(skb)->ifindex = dev->ifindex;
685 can_skb_prv(skb)->skbcnt = 0;
687 *cfd = skb_put_zero(skb, 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);
708 /* Allocate and setup space for the CAN network device */
709 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
710 unsigned int txqs, unsigned int rxqs)
712 struct net_device *dev;
713 struct can_priv *priv;
716 /* We put the driver's priv, the CAN mid layer priv and the
717 * echo skb into the netdevice's priv. The memory layout for
718 * the netdev_priv is like this:
720 * +-------------------------+
722 * +-------------------------+
723 * | struct can_ml_priv |
724 * +-------------------------+
725 * | array of struct sk_buff |
726 * +-------------------------+
729 size = ALIGN(sizeof_priv, NETDEV_ALIGN) + sizeof(struct can_ml_priv);
732 size = ALIGN(size, sizeof(struct sk_buff *)) +
733 echo_skb_max * sizeof(struct sk_buff *);
735 dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup,
740 priv = netdev_priv(dev);
743 dev->ml_priv = (void *)priv + ALIGN(sizeof_priv, NETDEV_ALIGN);
746 priv->echo_skb_max = echo_skb_max;
747 priv->echo_skb = (void *)priv +
748 (size - echo_skb_max * sizeof(struct sk_buff *));
751 priv->state = CAN_STATE_STOPPED;
753 INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
757 EXPORT_SYMBOL_GPL(alloc_candev_mqs);
759 /* Free space of the CAN network device */
760 void free_candev(struct net_device *dev)
764 EXPORT_SYMBOL_GPL(free_candev);
766 /* changing MTU and control mode for CAN/CANFD devices */
767 int can_change_mtu(struct net_device *dev, int new_mtu)
769 struct can_priv *priv = netdev_priv(dev);
771 /* Do not allow changing the MTU while running */
772 if (dev->flags & IFF_UP)
775 /* allow change of MTU according to the CANFD ability of the device */
778 /* 'CANFD-only' controllers can not switch to CAN_MTU */
779 if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
782 priv->ctrlmode &= ~CAN_CTRLMODE_FD;
786 /* check for potential CANFD ability */
787 if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
788 !(priv->ctrlmode_static & CAN_CTRLMODE_FD))
791 priv->ctrlmode |= CAN_CTRLMODE_FD;
801 EXPORT_SYMBOL_GPL(can_change_mtu);
803 /* Common open function when the device gets opened.
805 * This function should be called in the open function of the device
808 int open_candev(struct net_device *dev)
810 struct can_priv *priv = netdev_priv(dev);
812 if (!priv->bittiming.bitrate) {
813 netdev_err(dev, "bit-timing not yet defined\n");
817 /* For CAN FD the data bitrate has to be >= the arbitration bitrate */
818 if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
819 (!priv->data_bittiming.bitrate ||
820 priv->data_bittiming.bitrate < priv->bittiming.bitrate)) {
821 netdev_err(dev, "incorrect/missing data bit-timing\n");
825 /* Switch carrier on if device was stopped while in bus-off state */
826 if (!netif_carrier_ok(dev))
827 netif_carrier_on(dev);
831 EXPORT_SYMBOL_GPL(open_candev);
834 /* Common function that can be used to understand the limitation of
835 * a transceiver when it provides no means to determine these limitations
838 void of_can_transceiver(struct net_device *dev)
840 struct device_node *dn;
841 struct can_priv *priv = netdev_priv(dev);
842 struct device_node *np = dev->dev.parent->of_node;
845 dn = of_get_child_by_name(np, "can-transceiver");
849 ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max);
851 if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max))
852 netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n");
854 EXPORT_SYMBOL_GPL(of_can_transceiver);
857 /* Common close function for cleanup before the device gets closed.
859 * This function should be called in the close function of the device
862 void close_candev(struct net_device *dev)
864 struct can_priv *priv = netdev_priv(dev);
866 cancel_delayed_work_sync(&priv->restart_work);
867 can_flush_echo_skb(dev);
869 EXPORT_SYMBOL_GPL(close_candev);
871 /* CAN netlink interface */
872 static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
873 [IFLA_CAN_STATE] = { .type = NLA_U32 },
874 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
875 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
876 [IFLA_CAN_RESTART] = { .type = NLA_U32 },
877 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
878 [IFLA_CAN_BITTIMING_CONST]
879 = { .len = sizeof(struct can_bittiming_const) },
880 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
881 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
882 [IFLA_CAN_DATA_BITTIMING]
883 = { .len = sizeof(struct can_bittiming) },
884 [IFLA_CAN_DATA_BITTIMING_CONST]
885 = { .len = sizeof(struct can_bittiming_const) },
886 [IFLA_CAN_TERMINATION] = { .type = NLA_U16 },
889 static int can_validate(struct nlattr *tb[], struct nlattr *data[],
890 struct netlink_ext_ack *extack)
892 bool is_can_fd = false;
894 /* Make sure that valid CAN FD configurations always consist of
895 * - nominal/arbitration bittiming
897 * - control mode with CAN_CTRLMODE_FD set
903 if (data[IFLA_CAN_CTRLMODE]) {
904 struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
906 is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
910 if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
914 if (data[IFLA_CAN_DATA_BITTIMING]) {
915 if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
922 static int can_changelink(struct net_device *dev, struct nlattr *tb[],
923 struct nlattr *data[],
924 struct netlink_ext_ack *extack)
926 struct can_priv *priv = netdev_priv(dev);
929 /* We need synchronization with dev->stop() */
932 if (data[IFLA_CAN_BITTIMING]) {
933 struct can_bittiming bt;
935 /* Do not allow changing bittiming while running */
936 if (dev->flags & IFF_UP)
939 /* Calculate bittiming parameters based on
940 * bittiming_const if set, otherwise pass bitrate
941 * directly via do_set_bitrate(). Bail out if neither
944 if (!priv->bittiming_const && !priv->do_set_bittiming)
947 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
948 err = can_get_bittiming(dev, &bt,
949 priv->bittiming_const,
951 priv->bitrate_const_cnt);
955 if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) {
956 netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n",
961 memcpy(&priv->bittiming, &bt, sizeof(bt));
963 if (priv->do_set_bittiming) {
964 /* Finally, set the bit-timing registers */
965 err = priv->do_set_bittiming(dev);
971 if (data[IFLA_CAN_CTRLMODE]) {
972 struct can_ctrlmode *cm;
976 /* Do not allow changing controller mode while running */
977 if (dev->flags & IFF_UP)
979 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
980 ctrlstatic = priv->ctrlmode_static;
981 maskedflags = cm->flags & cm->mask;
983 /* check whether provided bits are allowed to be passed */
984 if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
987 /* do not check for static fd-non-iso if 'fd' is disabled */
988 if (!(maskedflags & CAN_CTRLMODE_FD))
989 ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
991 /* make sure static options are provided by configuration */
992 if ((maskedflags & ctrlstatic) != ctrlstatic)
995 /* clear bits to be modified and copy the flag values */
996 priv->ctrlmode &= ~cm->mask;
997 priv->ctrlmode |= maskedflags;
999 /* CAN_CTRLMODE_FD can only be set when driver supports FD */
1000 if (priv->ctrlmode & CAN_CTRLMODE_FD)
1001 dev->mtu = CANFD_MTU;
1006 if (data[IFLA_CAN_RESTART_MS]) {
1007 /* Do not allow changing restart delay while running */
1008 if (dev->flags & IFF_UP)
1010 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
1013 if (data[IFLA_CAN_RESTART]) {
1014 /* Do not allow a restart while not running */
1015 if (!(dev->flags & IFF_UP))
1017 err = can_restart_now(dev);
1022 if (data[IFLA_CAN_DATA_BITTIMING]) {
1023 struct can_bittiming dbt;
1025 /* Do not allow changing bittiming while running */
1026 if (dev->flags & IFF_UP)
1029 /* Calculate bittiming parameters based on
1030 * data_bittiming_const if set, otherwise pass bitrate
1031 * directly via do_set_bitrate(). Bail out if neither
1034 if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
1037 memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
1039 err = can_get_bittiming(dev, &dbt,
1040 priv->data_bittiming_const,
1041 priv->data_bitrate_const,
1042 priv->data_bitrate_const_cnt);
1046 if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
1047 netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n",
1052 memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
1054 if (priv->do_set_data_bittiming) {
1055 /* Finally, set the bit-timing registers */
1056 err = priv->do_set_data_bittiming(dev);
1062 if (data[IFLA_CAN_TERMINATION]) {
1063 const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
1064 const unsigned int num_term = priv->termination_const_cnt;
1067 if (!priv->do_set_termination)
1070 /* check whether given value is supported by the interface */
1071 for (i = 0; i < num_term; i++) {
1072 if (termval == priv->termination_const[i])
1078 /* Finally, set the termination value */
1079 err = priv->do_set_termination(dev, termval);
1083 priv->termination = termval;
1089 static size_t can_get_size(const struct net_device *dev)
1091 struct can_priv *priv = netdev_priv(dev);
1094 if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */
1095 size += nla_total_size(sizeof(struct can_bittiming));
1096 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
1097 size += nla_total_size(sizeof(struct can_bittiming_const));
1098 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
1099 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
1100 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
1101 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
1102 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
1103 size += nla_total_size(sizeof(struct can_berr_counter));
1104 if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */
1105 size += nla_total_size(sizeof(struct can_bittiming));
1106 if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */
1107 size += nla_total_size(sizeof(struct can_bittiming_const));
1108 if (priv->termination_const) {
1109 size += nla_total_size(sizeof(priv->termination)); /* IFLA_CAN_TERMINATION */
1110 size += nla_total_size(sizeof(*priv->termination_const) * /* IFLA_CAN_TERMINATION_CONST */
1111 priv->termination_const_cnt);
1113 if (priv->bitrate_const) /* IFLA_CAN_BITRATE_CONST */
1114 size += nla_total_size(sizeof(*priv->bitrate_const) *
1115 priv->bitrate_const_cnt);
1116 if (priv->data_bitrate_const) /* IFLA_CAN_DATA_BITRATE_CONST */
1117 size += nla_total_size(sizeof(*priv->data_bitrate_const) *
1118 priv->data_bitrate_const_cnt);
1119 size += sizeof(priv->bitrate_max); /* IFLA_CAN_BITRATE_MAX */
1124 static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
1126 struct can_priv *priv = netdev_priv(dev);
1127 struct can_ctrlmode cm = {.flags = priv->ctrlmode};
1128 struct can_berr_counter bec;
1129 enum can_state state = priv->state;
1131 if (priv->do_get_state)
1132 priv->do_get_state(dev, &state);
1134 if ((priv->bittiming.bitrate &&
1135 nla_put(skb, IFLA_CAN_BITTIMING,
1136 sizeof(priv->bittiming), &priv->bittiming)) ||
1138 (priv->bittiming_const &&
1139 nla_put(skb, IFLA_CAN_BITTIMING_CONST,
1140 sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
1142 nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
1143 nla_put_u32(skb, IFLA_CAN_STATE, state) ||
1144 nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
1145 nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
1147 (priv->do_get_berr_counter &&
1148 !priv->do_get_berr_counter(dev, &bec) &&
1149 nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
1151 (priv->data_bittiming.bitrate &&
1152 nla_put(skb, IFLA_CAN_DATA_BITTIMING,
1153 sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
1155 (priv->data_bittiming_const &&
1156 nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
1157 sizeof(*priv->data_bittiming_const),
1158 priv->data_bittiming_const)) ||
1160 (priv->termination_const &&
1161 (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
1162 nla_put(skb, IFLA_CAN_TERMINATION_CONST,
1163 sizeof(*priv->termination_const) *
1164 priv->termination_const_cnt,
1165 priv->termination_const))) ||
1167 (priv->bitrate_const &&
1168 nla_put(skb, IFLA_CAN_BITRATE_CONST,
1169 sizeof(*priv->bitrate_const) *
1170 priv->bitrate_const_cnt,
1171 priv->bitrate_const)) ||
1173 (priv->data_bitrate_const &&
1174 nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
1175 sizeof(*priv->data_bitrate_const) *
1176 priv->data_bitrate_const_cnt,
1177 priv->data_bitrate_const)) ||
1179 (nla_put(skb, IFLA_CAN_BITRATE_MAX,
1180 sizeof(priv->bitrate_max),
1181 &priv->bitrate_max))
1189 static size_t can_get_xstats_size(const struct net_device *dev)
1191 return sizeof(struct can_device_stats);
1194 static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
1196 struct can_priv *priv = netdev_priv(dev);
1198 if (nla_put(skb, IFLA_INFO_XSTATS,
1199 sizeof(priv->can_stats), &priv->can_stats))
1200 goto nla_put_failure;
1207 static int can_newlink(struct net *src_net, struct net_device *dev,
1208 struct nlattr *tb[], struct nlattr *data[],
1209 struct netlink_ext_ack *extack)
1214 static void can_dellink(struct net_device *dev, struct list_head *head)
1218 static struct rtnl_link_ops can_link_ops __read_mostly = {
1220 .maxtype = IFLA_CAN_MAX,
1221 .policy = can_policy,
1223 .validate = can_validate,
1224 .newlink = can_newlink,
1225 .changelink = can_changelink,
1226 .dellink = can_dellink,
1227 .get_size = can_get_size,
1228 .fill_info = can_fill_info,
1229 .get_xstats_size = can_get_xstats_size,
1230 .fill_xstats = can_fill_xstats,
1233 /* Register the CAN network device */
1234 int register_candev(struct net_device *dev)
1236 struct can_priv *priv = netdev_priv(dev);
1238 /* Ensure termination_const, termination_const_cnt and
1239 * do_set_termination consistency. All must be either set or
1242 if ((!priv->termination_const != !priv->termination_const_cnt) ||
1243 (!priv->termination_const != !priv->do_set_termination))
1246 if (!priv->bitrate_const != !priv->bitrate_const_cnt)
1249 if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt)
1252 dev->rtnl_link_ops = &can_link_ops;
1253 netif_carrier_off(dev);
1255 return register_netdev(dev);
1257 EXPORT_SYMBOL_GPL(register_candev);
1259 /* Unregister the CAN network device */
1260 void unregister_candev(struct net_device *dev)
1262 unregister_netdev(dev);
1264 EXPORT_SYMBOL_GPL(unregister_candev);
1266 /* Test if a network device is a candev based device
1267 * and return the can_priv* if so.
1269 struct can_priv *safe_candev_priv(struct net_device *dev)
1271 if (dev->type != ARPHRD_CAN || dev->rtnl_link_ops != &can_link_ops)
1274 return netdev_priv(dev);
1276 EXPORT_SYMBOL_GPL(safe_candev_priv);
1278 static __init int can_dev_init(void)
1282 can_led_notifier_init();
1284 err = rtnl_link_register(&can_link_ops);
1286 pr_info(MOD_DESC "\n");
1290 module_init(can_dev_init);
1292 static __exit void can_dev_exit(void)
1294 rtnl_link_unregister(&can_link_ops);
1296 can_led_notifier_exit();
1298 module_exit(can_dev_exit);
1300 MODULE_ALIAS_RTNL_LINK("can");