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
);
560 cf
->can_id
|= CAN_ERR_RESTARTED
;
565 stats
->rx_bytes
+= cf
->can_dlc
;
568 netdev_dbg(dev
, "restarted\n");
569 priv
->can_stats
.restarts
++;
571 /* Now restart the device */
572 err
= priv
->do_set_mode(dev
, CAN_MODE_START
);
574 netif_carrier_on(dev
);
576 netdev_err(dev
, "Error %d during restart", err
);
579 static void can_restart_work(struct work_struct
*work
)
581 struct delayed_work
*dwork
= to_delayed_work(work
);
582 struct can_priv
*priv
= container_of(dwork
, struct can_priv
,
585 can_restart(priv
->dev
);
588 int can_restart_now(struct net_device
*dev
)
590 struct can_priv
*priv
= netdev_priv(dev
);
592 /* A manual restart is only permitted if automatic restart is
593 * disabled and the device is in the bus-off state
595 if (priv
->restart_ms
)
597 if (priv
->state
!= CAN_STATE_BUS_OFF
)
600 cancel_delayed_work_sync(&priv
->restart_work
);
608 * This functions should be called when the device goes bus-off to
609 * tell the netif layer that no more packets can be sent or received.
610 * If enabled, a timer is started to trigger bus-off recovery.
612 void can_bus_off(struct net_device
*dev
)
614 struct can_priv
*priv
= netdev_priv(dev
);
616 netdev_info(dev
, "bus-off\n");
618 netif_carrier_off(dev
);
620 if (priv
->restart_ms
)
621 schedule_delayed_work(&priv
->restart_work
,
622 msecs_to_jiffies(priv
->restart_ms
));
624 EXPORT_SYMBOL_GPL(can_bus_off
);
626 static void can_setup(struct net_device
*dev
)
628 dev
->type
= ARPHRD_CAN
;
630 dev
->hard_header_len
= 0;
632 dev
->tx_queue_len
= 10;
634 /* New-style flags. */
635 dev
->flags
= IFF_NOARP
;
636 dev
->features
= NETIF_F_HW_CSUM
;
639 struct sk_buff
*alloc_can_skb(struct net_device
*dev
, struct can_frame
**cf
)
643 skb
= netdev_alloc_skb(dev
, sizeof(struct can_skb_priv
) +
644 sizeof(struct can_frame
));
648 skb
->protocol
= htons(ETH_P_CAN
);
649 skb
->pkt_type
= PACKET_BROADCAST
;
650 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
652 skb_reset_mac_header(skb
);
653 skb_reset_network_header(skb
);
654 skb_reset_transport_header(skb
);
656 can_skb_reserve(skb
);
657 can_skb_prv(skb
)->ifindex
= dev
->ifindex
;
658 can_skb_prv(skb
)->skbcnt
= 0;
660 *cf
= skb_put_zero(skb
, sizeof(struct can_frame
));
664 EXPORT_SYMBOL_GPL(alloc_can_skb
);
666 struct sk_buff
*alloc_canfd_skb(struct net_device
*dev
,
667 struct canfd_frame
**cfd
)
671 skb
= netdev_alloc_skb(dev
, sizeof(struct can_skb_priv
) +
672 sizeof(struct canfd_frame
));
676 skb
->protocol
= htons(ETH_P_CANFD
);
677 skb
->pkt_type
= PACKET_BROADCAST
;
678 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
680 skb_reset_mac_header(skb
);
681 skb_reset_network_header(skb
);
682 skb_reset_transport_header(skb
);
684 can_skb_reserve(skb
);
685 can_skb_prv(skb
)->ifindex
= dev
->ifindex
;
686 can_skb_prv(skb
)->skbcnt
= 0;
688 *cfd
= skb_put_zero(skb
, sizeof(struct canfd_frame
));
692 EXPORT_SYMBOL_GPL(alloc_canfd_skb
);
694 struct sk_buff
*alloc_can_err_skb(struct net_device
*dev
, struct can_frame
**cf
)
698 skb
= alloc_can_skb(dev
, cf
);
702 (*cf
)->can_id
= CAN_ERR_FLAG
;
703 (*cf
)->can_dlc
= CAN_ERR_DLC
;
707 EXPORT_SYMBOL_GPL(alloc_can_err_skb
);
709 /* Allocate and setup space for the CAN network device */
710 struct net_device
*alloc_candev_mqs(int sizeof_priv
, unsigned int echo_skb_max
,
711 unsigned int txqs
, unsigned int rxqs
)
713 struct net_device
*dev
;
714 struct can_priv
*priv
;
717 /* We put the driver's priv, the CAN mid layer priv and the
718 * echo skb into the netdevice's priv. The memory layout for
719 * the netdev_priv is like this:
721 * +-------------------------+
723 * +-------------------------+
724 * | struct can_ml_priv |
725 * +-------------------------+
726 * | array of struct sk_buff |
727 * +-------------------------+
730 size
= ALIGN(sizeof_priv
, NETDEV_ALIGN
) + sizeof(struct can_ml_priv
);
733 size
= ALIGN(size
, sizeof(struct sk_buff
*)) +
734 echo_skb_max
* sizeof(struct sk_buff
*);
736 dev
= alloc_netdev_mqs(size
, "can%d", NET_NAME_UNKNOWN
, can_setup
,
741 priv
= netdev_priv(dev
);
744 dev
->ml_priv
= (void *)priv
+ ALIGN(sizeof_priv
, NETDEV_ALIGN
);
747 priv
->echo_skb_max
= echo_skb_max
;
748 priv
->echo_skb
= (void *)priv
+
749 (size
- echo_skb_max
* sizeof(struct sk_buff
*));
752 priv
->state
= CAN_STATE_STOPPED
;
754 INIT_DELAYED_WORK(&priv
->restart_work
, can_restart_work
);
758 EXPORT_SYMBOL_GPL(alloc_candev_mqs
);
760 /* Free space of the CAN network device */
761 void free_candev(struct net_device
*dev
)
765 EXPORT_SYMBOL_GPL(free_candev
);
767 /* changing MTU and control mode for CAN/CANFD devices */
768 int can_change_mtu(struct net_device
*dev
, int new_mtu
)
770 struct can_priv
*priv
= netdev_priv(dev
);
772 /* Do not allow changing the MTU while running */
773 if (dev
->flags
& IFF_UP
)
776 /* allow change of MTU according to the CANFD ability of the device */
779 /* 'CANFD-only' controllers can not switch to CAN_MTU */
780 if (priv
->ctrlmode_static
& CAN_CTRLMODE_FD
)
783 priv
->ctrlmode
&= ~CAN_CTRLMODE_FD
;
787 /* check for potential CANFD ability */
788 if (!(priv
->ctrlmode_supported
& CAN_CTRLMODE_FD
) &&
789 !(priv
->ctrlmode_static
& CAN_CTRLMODE_FD
))
792 priv
->ctrlmode
|= CAN_CTRLMODE_FD
;
802 EXPORT_SYMBOL_GPL(can_change_mtu
);
804 /* Common open function when the device gets opened.
806 * This function should be called in the open function of the device
809 int open_candev(struct net_device
*dev
)
811 struct can_priv
*priv
= netdev_priv(dev
);
813 if (!priv
->bittiming
.bitrate
) {
814 netdev_err(dev
, "bit-timing not yet defined\n");
818 /* For CAN FD the data bitrate has to be >= the arbitration bitrate */
819 if ((priv
->ctrlmode
& CAN_CTRLMODE_FD
) &&
820 (!priv
->data_bittiming
.bitrate
||
821 priv
->data_bittiming
.bitrate
< priv
->bittiming
.bitrate
)) {
822 netdev_err(dev
, "incorrect/missing data bit-timing\n");
826 /* Switch carrier on if device was stopped while in bus-off state */
827 if (!netif_carrier_ok(dev
))
828 netif_carrier_on(dev
);
832 EXPORT_SYMBOL_GPL(open_candev
);
835 /* Common function that can be used to understand the limitation of
836 * a transceiver when it provides no means to determine these limitations
839 void of_can_transceiver(struct net_device
*dev
)
841 struct device_node
*dn
;
842 struct can_priv
*priv
= netdev_priv(dev
);
843 struct device_node
*np
= dev
->dev
.parent
->of_node
;
846 dn
= of_get_child_by_name(np
, "can-transceiver");
850 ret
= of_property_read_u32(dn
, "max-bitrate", &priv
->bitrate_max
);
852 if ((ret
&& ret
!= -EINVAL
) || (!ret
&& !priv
->bitrate_max
))
853 netdev_warn(dev
, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n");
855 EXPORT_SYMBOL_GPL(of_can_transceiver
);
858 /* Common close function for cleanup before the device gets closed.
860 * This function should be called in the close function of the device
863 void close_candev(struct net_device
*dev
)
865 struct can_priv
*priv
= netdev_priv(dev
);
867 cancel_delayed_work_sync(&priv
->restart_work
);
868 can_flush_echo_skb(dev
);
870 EXPORT_SYMBOL_GPL(close_candev
);
872 /* CAN netlink interface */
873 static const struct nla_policy can_policy
[IFLA_CAN_MAX
+ 1] = {
874 [IFLA_CAN_STATE
] = { .type
= NLA_U32
},
875 [IFLA_CAN_CTRLMODE
] = { .len
= sizeof(struct can_ctrlmode
) },
876 [IFLA_CAN_RESTART_MS
] = { .type
= NLA_U32
},
877 [IFLA_CAN_RESTART
] = { .type
= NLA_U32
},
878 [IFLA_CAN_BITTIMING
] = { .len
= sizeof(struct can_bittiming
) },
879 [IFLA_CAN_BITTIMING_CONST
]
880 = { .len
= sizeof(struct can_bittiming_const
) },
881 [IFLA_CAN_CLOCK
] = { .len
= sizeof(struct can_clock
) },
882 [IFLA_CAN_BERR_COUNTER
] = { .len
= sizeof(struct can_berr_counter
) },
883 [IFLA_CAN_DATA_BITTIMING
]
884 = { .len
= sizeof(struct can_bittiming
) },
885 [IFLA_CAN_DATA_BITTIMING_CONST
]
886 = { .len
= sizeof(struct can_bittiming_const
) },
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");