xref: /linux/drivers/net/can/usb/esd_usb.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * CAN driver for esd electronics gmbh CAN-USB/2, CAN-USB/3 and CAN-USB/Micro
4  *
5  * Copyright (C) 2010-2012 esd electronic system design gmbh, Matthias Fuchs <socketcan@esd.eu>
6  * Copyright (C) 2022-2024 esd electronics gmbh, Frank Jungclaus <frank.jungclaus@esd.eu>
7  */
8 
9 #include <linux/can.h>
10 #include <linux/can/dev.h>
11 #include <linux/can/error.h>
12 #include <linux/err.h>
13 #include <linux/ethtool.h>
14 #include <linux/module.h>
15 #include <linux/netdevice.h>
16 #include <linux/signal.h>
17 #include <linux/slab.h>
18 #include <linux/units.h>
19 #include <linux/usb.h>
20 
21 MODULE_AUTHOR("Matthias Fuchs <socketcan@esd.eu>");
22 MODULE_AUTHOR("Frank Jungclaus <frank.jungclaus@esd.eu>");
23 MODULE_DESCRIPTION("CAN driver for esd electronics gmbh CAN-USB/2, CAN-USB/3 and CAN-USB/Micro interfaces");
24 MODULE_LICENSE("GPL v2");
25 
26 /* USB vendor and product ID */
27 #define ESD_USB_ESDGMBH_VENDOR_ID	0x0ab4
28 #define ESD_USB_CANUSB2_PRODUCT_ID	0x0010
29 #define ESD_USB_CANUSBM_PRODUCT_ID	0x0011
30 #define ESD_USB_CANUSB3_PRODUCT_ID	0x0014
31 
32 /* CAN controller clock frequencies */
33 #define ESD_USB_2_CAN_CLOCK	(60 * MEGA) /* Hz */
34 #define ESD_USB_M_CAN_CLOCK	(36 * MEGA) /* Hz */
35 #define ESD_USB_3_CAN_CLOCK	(80 * MEGA) /* Hz */
36 
37 /* Maximum number of CAN nets */
38 #define ESD_USB_MAX_NETS	2
39 
40 /* USB commands */
41 #define ESD_USB_CMD_VERSION		1 /* also used for VERSION_REPLY */
42 #define ESD_USB_CMD_CAN_RX		2 /* device to host only */
43 #define ESD_USB_CMD_CAN_TX		3 /* also used for TX_DONE */
44 #define ESD_USB_CMD_SETBAUD		4 /* also used for SETBAUD_REPLY */
45 #define ESD_USB_CMD_TS			5 /* also used for TS_REPLY */
46 #define ESD_USB_CMD_IDADD		6 /* also used for IDADD_REPLY */
47 
48 /* esd CAN message flags - dlc field */
49 #define ESD_USB_RTR	BIT(4)
50 #define ESD_USB_NO_BRS	BIT(4)
51 #define ESD_USB_ESI	BIT(5)
52 #define ESD_USB_FD	BIT(7)
53 
54 /* esd CAN message flags - id field */
55 #define ESD_USB_EXTID	BIT(29)
56 #define ESD_USB_EVENT	BIT(30)
57 #define ESD_USB_IDMASK	GENMASK(28, 0)
58 
59 /* esd CAN event ids */
60 #define ESD_USB_EV_CAN_ERROR_EXT	2 /* CAN controller specific diagnostic data */
61 
62 /* baudrate message flags */
63 #define ESD_USB_LOM	BIT(30) /* Listen Only Mode */
64 #define ESD_USB_UBR	BIT(31) /* User Bit Rate (controller BTR) in bits 0..27 */
65 #define ESD_USB_NO_BAUDRATE	GENMASK(30, 0) /* bit rate unconfigured */
66 
67 /* bit timing esd CAN-USB */
68 #define ESD_USB_2_TSEG1_SHIFT	16
69 #define ESD_USB_2_TSEG2_SHIFT	20
70 #define ESD_USB_2_SJW_SHIFT	14
71 #define ESD_USB_M_SJW_SHIFT	24
72 #define ESD_USB_TRIPLE_SAMPLES	BIT(23)
73 
74 /* Transmitter Delay Compensation */
75 #define ESD_USB_3_TDC_MODE_AUTO	0
76 
77 /* esd IDADD message */
78 #define ESD_USB_ID_ENABLE	BIT(7)
79 #define ESD_USB_MAX_ID_SEGMENT	64
80 
81 /* SJA1000 ECC register (emulated by usb firmware) */
82 #define ESD_USB_SJA1000_ECC_SEG		GENMASK(4, 0)
83 #define ESD_USB_SJA1000_ECC_DIR		BIT(5)
84 #define ESD_USB_SJA1000_ECC_ERR		BIT(2, 1)
85 #define ESD_USB_SJA1000_ECC_BIT		0x00
86 #define ESD_USB_SJA1000_ECC_FORM	BIT(6)
87 #define ESD_USB_SJA1000_ECC_STUFF	BIT(7)
88 #define ESD_USB_SJA1000_ECC_MASK	GENMASK(7, 6)
89 
90 /* esd bus state event codes */
91 #define ESD_USB_BUSSTATE_MASK	GENMASK(7, 6)
92 #define ESD_USB_BUSSTATE_WARN	BIT(6)
93 #define ESD_USB_BUSSTATE_ERRPASSIVE	BIT(7)
94 #define ESD_USB_BUSSTATE_BUSOFF	GENMASK(7, 6)
95 
96 #define ESD_USB_RX_BUFFER_SIZE		1024
97 #define ESD_USB_MAX_RX_URBS		4
98 #define ESD_USB_MAX_TX_URBS		16 /* must be power of 2 */
99 
100 /* Modes for CAN-USB/3, to be used for esd_usb_3_set_baudrate_msg_x.mode */
101 #define ESD_USB_3_BAUDRATE_MODE_DISABLE		0 /* remove from bus */
102 #define ESD_USB_3_BAUDRATE_MODE_INDEX		1 /* ESD (CiA) bit rate idx */
103 #define ESD_USB_3_BAUDRATE_MODE_BTR_CTRL	2 /* BTR values (controller)*/
104 #define ESD_USB_3_BAUDRATE_MODE_BTR_CANONICAL	3 /* BTR values (canonical) */
105 #define ESD_USB_3_BAUDRATE_MODE_NUM		4 /* numerical bit rate */
106 #define ESD_USB_3_BAUDRATE_MODE_AUTOBAUD	5 /* autobaud */
107 
108 /* Flags for CAN-USB/3, to be used for esd_usb_3_set_baudrate_msg_x.flags */
109 #define ESD_USB_3_BAUDRATE_FLAG_FD	BIT(0) /* enable CAN FD mode */
110 #define ESD_USB_3_BAUDRATE_FLAG_LOM	BIT(1) /* enable listen only mode */
111 #define ESD_USB_3_BAUDRATE_FLAG_STM	BIT(2) /* enable self test mode */
112 #define ESD_USB_3_BAUDRATE_FLAG_TRS	BIT(3) /* enable triple sampling */
113 #define ESD_USB_3_BAUDRATE_FLAG_TXP	BIT(4) /* enable transmit pause */
114 
115 struct esd_usb_header_msg {
116 	u8 len; /* total message length in 32bit words */
117 	u8 cmd;
118 	u8 rsvd[2];
119 };
120 
121 struct esd_usb_version_msg {
122 	u8 len; /* total message length in 32bit words */
123 	u8 cmd;
124 	u8 rsvd;
125 	u8 flags;
126 	__le32 drv_version;
127 };
128 
129 struct esd_usb_version_reply_msg {
130 	u8 len; /* total message length in 32bit words */
131 	u8 cmd;
132 	u8 nets;
133 	u8 features;
134 	__le32 version;
135 	u8 name[16];
136 	__le32 rsvd;
137 	__le32 ts;
138 };
139 
140 struct esd_usb_rx_msg {
141 	u8 len; /* total message length in 32bit words */
142 	u8 cmd;
143 	u8 net;
144 	u8 dlc;
145 	__le32 ts;
146 	__le32 id; /* upper 3 bits contain flags */
147 	union {
148 		u8 data[CAN_MAX_DLEN];
149 		u8 data_fd[CANFD_MAX_DLEN];
150 		struct {
151 			u8 status; /* CAN Controller Status */
152 			u8 ecc;    /* Error Capture Register */
153 			u8 rec;    /* RX Error Counter */
154 			u8 tec;    /* TX Error Counter */
155 		} ev_can_err_ext;  /* For ESD_EV_CAN_ERROR_EXT */
156 	};
157 };
158 
159 struct esd_usb_tx_msg {
160 	u8 len; /* total message length in 32bit words */
161 	u8 cmd;
162 	u8 net;
163 	u8 dlc;
164 	u32 hnd;	/* opaque handle, not used by device */
165 	__le32 id; /* upper 3 bits contain flags */
166 	union {
167 		u8 data[CAN_MAX_DLEN];
168 		u8 data_fd[CANFD_MAX_DLEN];
169 	};
170 };
171 
172 struct esd_usb_tx_done_msg {
173 	u8 len; /* total message length in 32bit words */
174 	u8 cmd;
175 	u8 net;
176 	u8 status;
177 	u32 hnd;	/* opaque handle, not used by device */
178 	__le32 ts;
179 };
180 
181 struct esd_usb_id_filter_msg {
182 	u8 len; /* total message length in 32bit words */
183 	u8 cmd;
184 	u8 net;
185 	u8 option;
186 	__le32 mask[ESD_USB_MAX_ID_SEGMENT + 1]; /* +1 for 29bit extended IDs */
187 };
188 
189 struct esd_usb_set_baudrate_msg {
190 	u8 len; /* total message length in 32bit words */
191 	u8 cmd;
192 	u8 net;
193 	u8 rsvd;
194 	__le32 baud;
195 };
196 
197 /* CAN-USB/3 baudrate configuration, used for nominal as well as for data bit rate */
198 struct esd_usb_3_baudrate_cfg {
199 	__le16 brp;	/* bit rate pre-scaler */
200 	__le16 tseg1;	/* time segment before sample point */
201 	__le16 tseg2;	/* time segment after sample point */
202 	__le16 sjw;	/* synchronization jump Width */
203 };
204 
205 /* In principle, the esd CAN-USB/3 supports Transmitter Delay Compensation (TDC),
206  * but currently only the automatic TDC mode is supported by this driver.
207  * An implementation for manual TDC configuration will follow.
208  *
209  * For information about struct esd_usb_3_tdc_cfg, see
210  * NTCAN Application Developers Manual, 6.2.25 NTCAN_TDC_CFG + related chapters
211  * https://esd.eu/fileadmin/esd/docs/manuals/NTCAN_Part1_Function_API_Manual_en_56.pdf
212  */
213 struct esd_usb_3_tdc_cfg {
214 	u8 tdc_mode;	/* transmitter delay compensation mode  */
215 	u8 ssp_offset;	/* secondary sample point offset in mtq */
216 	s8 ssp_shift;	/* secondary sample point shift in mtq */
217 	u8 tdc_filter;	/* TDC filter in mtq */
218 };
219 
220 /* Extended version of the above set_baudrate_msg for a CAN-USB/3
221  * to define the CAN bit timing configuration of the CAN controller in
222  * CAN FD mode as well as in Classical CAN mode.
223  *
224  * The payload of this command is a NTCAN_BAUDRATE_X structure according to
225  * esd electronics gmbh, NTCAN Application Developers Manual, 6.2.15 NTCAN_BAUDRATE_X
226  * https://esd.eu/fileadmin/esd/docs/manuals/NTCAN_Part1_Function_API_Manual_en_56.pdf
227  */
228 struct esd_usb_3_set_baudrate_msg_x {
229 	u8 len;	/* total message length in 32bit words */
230 	u8 cmd;
231 	u8 net;
232 	u8 rsvd;	/*reserved */
233 	/* Payload ... */
234 	__le16 mode;	/* mode word, see ESD_USB_3_BAUDRATE_MODE_xxx */
235 	__le16 flags;	/* control flags, see ESD_USB_3_BAUDRATE_FLAG_xxx */
236 	struct esd_usb_3_tdc_cfg tdc;	/* TDC configuration */
237 	struct esd_usb_3_baudrate_cfg nom;	/* nominal bit rate */
238 	struct esd_usb_3_baudrate_cfg data;	/* data bit rate */
239 };
240 
241 /* Main message type used between library and application */
242 union __packed esd_usb_msg {
243 	struct esd_usb_header_msg hdr;
244 	struct esd_usb_version_msg version;
245 	struct esd_usb_version_reply_msg version_reply;
246 	struct esd_usb_rx_msg rx;
247 	struct esd_usb_tx_msg tx;
248 	struct esd_usb_tx_done_msg txdone;
249 	struct esd_usb_set_baudrate_msg setbaud;
250 	struct esd_usb_3_set_baudrate_msg_x setbaud_x;
251 	struct esd_usb_id_filter_msg filter;
252 };
253 
254 static struct usb_device_id esd_usb_table[] = {
255 	{USB_DEVICE(ESD_USB_ESDGMBH_VENDOR_ID, ESD_USB_CANUSB2_PRODUCT_ID)},
256 	{USB_DEVICE(ESD_USB_ESDGMBH_VENDOR_ID, ESD_USB_CANUSBM_PRODUCT_ID)},
257 	{USB_DEVICE(ESD_USB_ESDGMBH_VENDOR_ID, ESD_USB_CANUSB3_PRODUCT_ID)},
258 	{}
259 };
260 MODULE_DEVICE_TABLE(usb, esd_usb_table);
261 
262 struct esd_usb_net_priv;
263 
264 struct esd_tx_urb_context {
265 	struct esd_usb_net_priv *priv;
266 	u32 echo_index;
267 };
268 
269 struct esd_usb {
270 	struct usb_device *udev;
271 	struct esd_usb_net_priv *nets[ESD_USB_MAX_NETS];
272 
273 	struct usb_anchor rx_submitted;
274 
275 	int net_count;
276 	u32 version;
277 	int rxinitdone;
278 	int in_usb_disconnect;
279 	void *rxbuf[ESD_USB_MAX_RX_URBS];
280 	dma_addr_t rxbuf_dma[ESD_USB_MAX_RX_URBS];
281 };
282 
283 struct esd_usb_net_priv {
284 	struct can_priv can; /* must be the first member */
285 
286 	atomic_t active_tx_jobs;
287 	struct usb_anchor tx_submitted;
288 	struct esd_tx_urb_context tx_contexts[ESD_USB_MAX_TX_URBS];
289 
290 	struct esd_usb *usb;
291 	struct net_device *netdev;
292 	int index;
293 	u8 old_state;
294 	struct can_berr_counter bec;
295 };
296 
297 static void esd_usb_rx_event(struct esd_usb_net_priv *priv,
298 			     union esd_usb_msg *msg)
299 {
300 	struct net_device_stats *stats = &priv->netdev->stats;
301 	struct can_frame *cf;
302 	struct sk_buff *skb;
303 	u32 id = le32_to_cpu(msg->rx.id) & ESD_USB_IDMASK;
304 
305 	if (id == ESD_USB_EV_CAN_ERROR_EXT) {
306 		u8 state = msg->rx.ev_can_err_ext.status;
307 		u8 ecc = msg->rx.ev_can_err_ext.ecc;
308 
309 		priv->bec.rxerr = msg->rx.ev_can_err_ext.rec;
310 		priv->bec.txerr = msg->rx.ev_can_err_ext.tec;
311 
312 		netdev_dbg(priv->netdev,
313 			   "CAN_ERR_EV_EXT: dlc=%#02x state=%02x ecc=%02x rec=%02x tec=%02x\n",
314 			   msg->rx.dlc, state, ecc,
315 			   priv->bec.rxerr, priv->bec.txerr);
316 
317 		/* if berr-reporting is off, only pass through on state change ... */
318 		if (!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
319 		    state == priv->old_state)
320 			return;
321 
322 		skb = alloc_can_err_skb(priv->netdev, &cf);
323 		if (!skb)
324 			stats->rx_dropped++;
325 
326 		if (state != priv->old_state) {
327 			enum can_state tx_state, rx_state;
328 			enum can_state new_state = CAN_STATE_ERROR_ACTIVE;
329 
330 			priv->old_state = state;
331 
332 			switch (state & ESD_USB_BUSSTATE_MASK) {
333 			case ESD_USB_BUSSTATE_BUSOFF:
334 				new_state = CAN_STATE_BUS_OFF;
335 				can_bus_off(priv->netdev);
336 				break;
337 			case ESD_USB_BUSSTATE_WARN:
338 				new_state = CAN_STATE_ERROR_WARNING;
339 				break;
340 			case ESD_USB_BUSSTATE_ERRPASSIVE:
341 				new_state = CAN_STATE_ERROR_PASSIVE;
342 				break;
343 			default:
344 				new_state = CAN_STATE_ERROR_ACTIVE;
345 				priv->bec.txerr = 0;
346 				priv->bec.rxerr = 0;
347 				break;
348 			}
349 
350 			if (new_state != priv->can.state) {
351 				tx_state = (priv->bec.txerr >= priv->bec.rxerr) ? new_state : 0;
352 				rx_state = (priv->bec.txerr <= priv->bec.rxerr) ? new_state : 0;
353 				can_change_state(priv->netdev, cf,
354 						 tx_state, rx_state);
355 			}
356 		} else if (skb) {
357 			priv->can.can_stats.bus_error++;
358 			stats->rx_errors++;
359 
360 			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
361 
362 			switch (ecc & ESD_USB_SJA1000_ECC_MASK) {
363 			case ESD_USB_SJA1000_ECC_BIT:
364 				cf->data[2] |= CAN_ERR_PROT_BIT;
365 				break;
366 			case ESD_USB_SJA1000_ECC_FORM:
367 				cf->data[2] |= CAN_ERR_PROT_FORM;
368 				break;
369 			case ESD_USB_SJA1000_ECC_STUFF:
370 				cf->data[2] |= CAN_ERR_PROT_STUFF;
371 				break;
372 			default:
373 				break;
374 			}
375 
376 			/* Error occurred during transmission? */
377 			if (!(ecc & ESD_USB_SJA1000_ECC_DIR))
378 				cf->data[2] |= CAN_ERR_PROT_TX;
379 
380 			/* Bit stream position in CAN frame as the error was detected */
381 			cf->data[3] = ecc & ESD_USB_SJA1000_ECC_SEG;
382 		}
383 
384 		if (skb) {
385 			cf->can_id |= CAN_ERR_CNT;
386 			cf->data[6] = priv->bec.txerr;
387 			cf->data[7] = priv->bec.rxerr;
388 
389 			netif_rx(skb);
390 		}
391 	}
392 }
393 
394 static void esd_usb_rx_can_msg(struct esd_usb_net_priv *priv,
395 			       union esd_usb_msg *msg)
396 {
397 	struct net_device_stats *stats = &priv->netdev->stats;
398 	struct can_frame *cf;
399 	struct canfd_frame *cfd;
400 	struct sk_buff *skb;
401 	u32 id;
402 	u8 len;
403 
404 	if (!netif_device_present(priv->netdev))
405 		return;
406 
407 	id = le32_to_cpu(msg->rx.id);
408 
409 	if (id & ESD_USB_EVENT) {
410 		esd_usb_rx_event(priv, msg);
411 	} else {
412 		if (msg->rx.dlc & ESD_USB_FD) {
413 			skb = alloc_canfd_skb(priv->netdev, &cfd);
414 		} else {
415 			skb = alloc_can_skb(priv->netdev, &cf);
416 			cfd = (struct canfd_frame *)cf;
417 		}
418 
419 		if (skb == NULL) {
420 			stats->rx_dropped++;
421 			return;
422 		}
423 
424 		cfd->can_id = id & ESD_USB_IDMASK;
425 
426 		if (msg->rx.dlc & ESD_USB_FD) {
427 			/* masking by 0x0F is already done within can_fd_dlc2len() */
428 			cfd->len = can_fd_dlc2len(msg->rx.dlc);
429 			len = cfd->len;
430 			if ((msg->rx.dlc & ESD_USB_NO_BRS) == 0)
431 				cfd->flags |= CANFD_BRS;
432 			if (msg->rx.dlc & ESD_USB_ESI)
433 				cfd->flags |= CANFD_ESI;
434 		} else {
435 			can_frame_set_cc_len(cf, msg->rx.dlc & ~ESD_USB_RTR, priv->can.ctrlmode);
436 			len = cf->len;
437 			if (msg->rx.dlc & ESD_USB_RTR) {
438 				cf->can_id |= CAN_RTR_FLAG;
439 				len = 0;
440 			}
441 		}
442 
443 		if (id & ESD_USB_EXTID)
444 			cfd->can_id |= CAN_EFF_FLAG;
445 
446 		memcpy(cfd->data, msg->rx.data_fd, len);
447 		stats->rx_bytes += len;
448 		stats->rx_packets++;
449 
450 		netif_rx(skb);
451 	}
452 }
453 
454 static void esd_usb_tx_done_msg(struct esd_usb_net_priv *priv,
455 				union esd_usb_msg *msg)
456 {
457 	struct net_device_stats *stats = &priv->netdev->stats;
458 	struct net_device *netdev = priv->netdev;
459 	struct esd_tx_urb_context *context;
460 
461 	if (!netif_device_present(netdev))
462 		return;
463 
464 	context = &priv->tx_contexts[msg->txdone.hnd & (ESD_USB_MAX_TX_URBS - 1)];
465 
466 	if (!msg->txdone.status) {
467 		stats->tx_packets++;
468 		stats->tx_bytes += can_get_echo_skb(netdev, context->echo_index,
469 						    NULL);
470 	} else {
471 		stats->tx_errors++;
472 		can_free_echo_skb(netdev, context->echo_index, NULL);
473 	}
474 
475 	/* Release context */
476 	context->echo_index = ESD_USB_MAX_TX_URBS;
477 	atomic_dec(&priv->active_tx_jobs);
478 
479 	netif_wake_queue(netdev);
480 }
481 
482 static void esd_usb_read_bulk_callback(struct urb *urb)
483 {
484 	struct esd_usb *dev = urb->context;
485 	int err;
486 	int pos = 0;
487 	int i;
488 
489 	switch (urb->status) {
490 	case 0: /* success */
491 		break;
492 
493 	case -ENOENT:
494 	case -EPIPE:
495 	case -EPROTO:
496 	case -ESHUTDOWN:
497 		return;
498 
499 	default:
500 		dev_info(dev->udev->dev.parent,
501 			 "Rx URB aborted (%pe)\n", ERR_PTR(urb->status));
502 		goto resubmit_urb;
503 	}
504 
505 	while (pos < urb->actual_length) {
506 		union esd_usb_msg *msg;
507 
508 		msg = (union esd_usb_msg *)(urb->transfer_buffer + pos);
509 
510 		switch (msg->hdr.cmd) {
511 		case ESD_USB_CMD_CAN_RX:
512 			if (msg->rx.net >= dev->net_count) {
513 				dev_err(dev->udev->dev.parent, "format error\n");
514 				break;
515 			}
516 
517 			esd_usb_rx_can_msg(dev->nets[msg->rx.net], msg);
518 			break;
519 
520 		case ESD_USB_CMD_CAN_TX:
521 			if (msg->txdone.net >= dev->net_count) {
522 				dev_err(dev->udev->dev.parent, "format error\n");
523 				break;
524 			}
525 
526 			esd_usb_tx_done_msg(dev->nets[msg->txdone.net],
527 					    msg);
528 			break;
529 		}
530 
531 		pos += msg->hdr.len * sizeof(u32); /* convert to # of bytes */
532 
533 		if (pos > urb->actual_length) {
534 			dev_err(dev->udev->dev.parent, "format error\n");
535 			break;
536 		}
537 	}
538 
539 resubmit_urb:
540 	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
541 			  urb->transfer_buffer, ESD_USB_RX_BUFFER_SIZE,
542 			  esd_usb_read_bulk_callback, dev);
543 
544 	err = usb_submit_urb(urb, GFP_ATOMIC);
545 	if (err == -ENODEV) {
546 		for (i = 0; i < dev->net_count; i++) {
547 			if (dev->nets[i])
548 				netif_device_detach(dev->nets[i]->netdev);
549 		}
550 	} else if (err) {
551 		dev_err(dev->udev->dev.parent,
552 			"failed resubmitting read bulk urb: %pe\n", ERR_PTR(err));
553 	}
554 }
555 
556 /* callback for bulk IN urb */
557 static void esd_usb_write_bulk_callback(struct urb *urb)
558 {
559 	struct esd_tx_urb_context *context = urb->context;
560 	struct esd_usb_net_priv *priv;
561 	struct net_device *netdev;
562 	size_t size = sizeof(union esd_usb_msg);
563 
564 	WARN_ON(!context);
565 
566 	priv = context->priv;
567 	netdev = priv->netdev;
568 
569 	/* free up our allocated buffer */
570 	usb_free_coherent(urb->dev, size,
571 			  urb->transfer_buffer, urb->transfer_dma);
572 
573 	if (!netif_device_present(netdev))
574 		return;
575 
576 	if (urb->status)
577 		netdev_info(netdev, "Tx URB aborted (%pe)\n", ERR_PTR(urb->status));
578 
579 	netif_trans_update(netdev);
580 }
581 
582 static ssize_t firmware_show(struct device *d,
583 			     struct device_attribute *attr, char *buf)
584 {
585 	struct usb_interface *intf = to_usb_interface(d);
586 	struct esd_usb *dev = usb_get_intfdata(intf);
587 
588 	return sprintf(buf, "%d.%d.%d\n",
589 		       (dev->version >> 12) & 0xf,
590 		       (dev->version >> 8) & 0xf,
591 		       dev->version & 0xff);
592 }
593 static DEVICE_ATTR_RO(firmware);
594 
595 static ssize_t hardware_show(struct device *d,
596 			     struct device_attribute *attr, char *buf)
597 {
598 	struct usb_interface *intf = to_usb_interface(d);
599 	struct esd_usb *dev = usb_get_intfdata(intf);
600 
601 	return sprintf(buf, "%d.%d.%d\n",
602 		       (dev->version >> 28) & 0xf,
603 		       (dev->version >> 24) & 0xf,
604 		       (dev->version >> 16) & 0xff);
605 }
606 static DEVICE_ATTR_RO(hardware);
607 
608 static ssize_t nets_show(struct device *d,
609 			 struct device_attribute *attr, char *buf)
610 {
611 	struct usb_interface *intf = to_usb_interface(d);
612 	struct esd_usb *dev = usb_get_intfdata(intf);
613 
614 	return sprintf(buf, "%d", dev->net_count);
615 }
616 static DEVICE_ATTR_RO(nets);
617 
618 static int esd_usb_send_msg(struct esd_usb *dev, union esd_usb_msg *msg)
619 {
620 	int actual_length;
621 
622 	return usb_bulk_msg(dev->udev,
623 			    usb_sndbulkpipe(dev->udev, 2),
624 			    msg,
625 			    msg->hdr.len * sizeof(u32), /* convert to # of bytes */
626 			    &actual_length,
627 			    1000);
628 }
629 
630 static int esd_usb_wait_msg(struct esd_usb *dev,
631 			    union esd_usb_msg *msg)
632 {
633 	int actual_length;
634 
635 	return usb_bulk_msg(dev->udev,
636 			    usb_rcvbulkpipe(dev->udev, 1),
637 			    msg,
638 			    sizeof(*msg),
639 			    &actual_length,
640 			    1000);
641 }
642 
643 static int esd_usb_setup_rx_urbs(struct esd_usb *dev)
644 {
645 	int i, err = 0;
646 
647 	if (dev->rxinitdone)
648 		return 0;
649 
650 	for (i = 0; i < ESD_USB_MAX_RX_URBS; i++) {
651 		struct urb *urb = NULL;
652 		u8 *buf = NULL;
653 		dma_addr_t buf_dma;
654 
655 		/* create a URB, and a buffer for it */
656 		urb = usb_alloc_urb(0, GFP_KERNEL);
657 		if (!urb) {
658 			err = -ENOMEM;
659 			break;
660 		}
661 
662 		buf = usb_alloc_coherent(dev->udev, ESD_USB_RX_BUFFER_SIZE, GFP_KERNEL,
663 					 &buf_dma);
664 		if (!buf) {
665 			dev_warn(dev->udev->dev.parent,
666 				 "No memory left for USB buffer\n");
667 			err = -ENOMEM;
668 			goto freeurb;
669 		}
670 
671 		urb->transfer_dma = buf_dma;
672 
673 		usb_fill_bulk_urb(urb, dev->udev,
674 				  usb_rcvbulkpipe(dev->udev, 1),
675 				  buf, ESD_USB_RX_BUFFER_SIZE,
676 				  esd_usb_read_bulk_callback, dev);
677 		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
678 		usb_anchor_urb(urb, &dev->rx_submitted);
679 
680 		err = usb_submit_urb(urb, GFP_KERNEL);
681 		if (err) {
682 			usb_unanchor_urb(urb);
683 			usb_free_coherent(dev->udev, ESD_USB_RX_BUFFER_SIZE, buf,
684 					  urb->transfer_dma);
685 			goto freeurb;
686 		}
687 
688 		dev->rxbuf[i] = buf;
689 		dev->rxbuf_dma[i] = buf_dma;
690 
691 freeurb:
692 		/* Drop reference, USB core will take care of freeing it */
693 		usb_free_urb(urb);
694 		if (err)
695 			break;
696 	}
697 
698 	/* Did we submit any URBs */
699 	if (i == 0) {
700 		dev_err(dev->udev->dev.parent, "couldn't setup read URBs\n");
701 		return err;
702 	}
703 
704 	/* Warn if we've couldn't transmit all the URBs */
705 	if (i < ESD_USB_MAX_RX_URBS) {
706 		dev_warn(dev->udev->dev.parent,
707 			 "rx performance may be slow\n");
708 	}
709 
710 	dev->rxinitdone = 1;
711 	return 0;
712 }
713 
714 /* Start interface */
715 static int esd_usb_start(struct esd_usb_net_priv *priv)
716 {
717 	struct esd_usb *dev = priv->usb;
718 	struct net_device *netdev = priv->netdev;
719 	union esd_usb_msg *msg;
720 	int err, i;
721 
722 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
723 	if (!msg) {
724 		err = -ENOMEM;
725 		goto out;
726 	}
727 
728 	/* Enable all IDs
729 	 * The IDADD message takes up to 64 32 bit bitmasks (2048 bits).
730 	 * Each bit represents one 11 bit CAN identifier. A set bit
731 	 * enables reception of the corresponding CAN identifier. A cleared
732 	 * bit disabled this identifier. An additional bitmask value
733 	 * following the CAN 2.0A bits is used to enable reception of
734 	 * extended CAN frames. Only the LSB of this final mask is checked
735 	 * for the complete 29 bit ID range. The IDADD message also allows
736 	 * filter configuration for an ID subset. In this case you can add
737 	 * the number of the starting bitmask (0..64) to the filter.option
738 	 * field followed by only some bitmasks.
739 	 */
740 	msg->hdr.cmd = ESD_USB_CMD_IDADD;
741 	msg->hdr.len = sizeof(struct esd_usb_id_filter_msg) / sizeof(u32); /* # of 32bit words */
742 	msg->filter.net = priv->index;
743 	msg->filter.option = ESD_USB_ID_ENABLE; /* start with segment 0 */
744 	for (i = 0; i < ESD_USB_MAX_ID_SEGMENT; i++)
745 		msg->filter.mask[i] = cpu_to_le32(GENMASK(31, 0));
746 	/* enable 29bit extended IDs */
747 	msg->filter.mask[ESD_USB_MAX_ID_SEGMENT] = cpu_to_le32(BIT(0));
748 
749 	err = esd_usb_send_msg(dev, msg);
750 	if (err)
751 		goto out;
752 
753 	err = esd_usb_setup_rx_urbs(dev);
754 	if (err)
755 		goto out;
756 
757 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
758 
759 out:
760 	if (err == -ENODEV)
761 		netif_device_detach(netdev);
762 	if (err)
763 		netdev_err(netdev, "couldn't start device: %pe\n", ERR_PTR(err));
764 
765 	kfree(msg);
766 	return err;
767 }
768 
769 static void unlink_all_urbs(struct esd_usb *dev)
770 {
771 	struct esd_usb_net_priv *priv;
772 	int i, j;
773 
774 	usb_kill_anchored_urbs(&dev->rx_submitted);
775 
776 	for (i = 0; i < ESD_USB_MAX_RX_URBS; ++i)
777 		usb_free_coherent(dev->udev, ESD_USB_RX_BUFFER_SIZE,
778 				  dev->rxbuf[i], dev->rxbuf_dma[i]);
779 
780 	for (i = 0; i < dev->net_count; i++) {
781 		priv = dev->nets[i];
782 		if (priv) {
783 			usb_kill_anchored_urbs(&priv->tx_submitted);
784 			atomic_set(&priv->active_tx_jobs, 0);
785 
786 			for (j = 0; j < ESD_USB_MAX_TX_URBS; j++)
787 				priv->tx_contexts[j].echo_index = ESD_USB_MAX_TX_URBS;
788 		}
789 	}
790 }
791 
792 static int esd_usb_open(struct net_device *netdev)
793 {
794 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
795 	int err;
796 
797 	/* common open */
798 	err = open_candev(netdev);
799 	if (err)
800 		return err;
801 
802 	/* finally start device */
803 	err = esd_usb_start(priv);
804 	if (err) {
805 		close_candev(netdev);
806 		return err;
807 	}
808 
809 	netif_start_queue(netdev);
810 
811 	return 0;
812 }
813 
814 static netdev_tx_t esd_usb_start_xmit(struct sk_buff *skb,
815 				      struct net_device *netdev)
816 {
817 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
818 	struct esd_usb *dev = priv->usb;
819 	struct esd_tx_urb_context *context = NULL;
820 	struct net_device_stats *stats = &netdev->stats;
821 	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
822 	union esd_usb_msg *msg;
823 	struct urb *urb;
824 	u8 *buf;
825 	int i, err;
826 	int ret = NETDEV_TX_OK;
827 	size_t size = sizeof(union esd_usb_msg);
828 
829 	if (can_dev_dropped_skb(netdev, skb))
830 		return NETDEV_TX_OK;
831 
832 	/* create a URB, and a buffer for it, and copy the data to the URB */
833 	urb = usb_alloc_urb(0, GFP_ATOMIC);
834 	if (!urb) {
835 		stats->tx_dropped++;
836 		dev_kfree_skb(skb);
837 		goto nourbmem;
838 	}
839 
840 	buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC,
841 				 &urb->transfer_dma);
842 	if (!buf) {
843 		netdev_err(netdev, "No memory left for USB buffer\n");
844 		stats->tx_dropped++;
845 		dev_kfree_skb(skb);
846 		goto nobufmem;
847 	}
848 
849 	msg = (union esd_usb_msg *)buf;
850 
851 	/* minimal length as # of 32bit words */
852 	msg->hdr.len = offsetof(struct esd_usb_tx_msg, data) / sizeof(u32);
853 	msg->hdr.cmd = ESD_USB_CMD_CAN_TX;
854 	msg->tx.net = priv->index;
855 
856 	if (can_is_canfd_skb(skb)) {
857 		msg->tx.dlc = can_fd_len2dlc(cfd->len);
858 		msg->tx.dlc |= ESD_USB_FD;
859 
860 		if ((cfd->flags & CANFD_BRS) == 0)
861 			msg->tx.dlc |= ESD_USB_NO_BRS;
862 	} else {
863 		msg->tx.dlc = can_get_cc_dlc((struct can_frame *)cfd, priv->can.ctrlmode);
864 
865 		if (cfd->can_id & CAN_RTR_FLAG)
866 			msg->tx.dlc |= ESD_USB_RTR;
867 	}
868 
869 	msg->tx.id = cpu_to_le32(cfd->can_id & CAN_ERR_MASK);
870 
871 	if (cfd->can_id & CAN_EFF_FLAG)
872 		msg->tx.id |= cpu_to_le32(ESD_USB_EXTID);
873 
874 	memcpy(msg->tx.data_fd, cfd->data, cfd->len);
875 
876 	/* round up, then divide by 4 to add the payload length as # of 32bit words */
877 	msg->hdr.len += DIV_ROUND_UP(cfd->len, sizeof(u32));
878 
879 	for (i = 0; i < ESD_USB_MAX_TX_URBS; i++) {
880 		if (priv->tx_contexts[i].echo_index == ESD_USB_MAX_TX_URBS) {
881 			context = &priv->tx_contexts[i];
882 			break;
883 		}
884 	}
885 
886 	/* This may never happen */
887 	if (!context) {
888 		netdev_warn(netdev, "couldn't find free context\n");
889 		ret = NETDEV_TX_BUSY;
890 		goto releasebuf;
891 	}
892 
893 	context->priv = priv;
894 	context->echo_index = i;
895 
896 	/* hnd must not be 0 - MSB is stripped in txdone handling */
897 	msg->tx.hnd = BIT(31) | i; /* returned in TX done message */
898 
899 	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
900 			  msg->hdr.len * sizeof(u32), /* convert to # of bytes */
901 			  esd_usb_write_bulk_callback, context);
902 
903 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
904 
905 	usb_anchor_urb(urb, &priv->tx_submitted);
906 
907 	can_put_echo_skb(skb, netdev, context->echo_index, 0);
908 
909 	atomic_inc(&priv->active_tx_jobs);
910 
911 	/* Slow down tx path */
912 	if (atomic_read(&priv->active_tx_jobs) >= ESD_USB_MAX_TX_URBS)
913 		netif_stop_queue(netdev);
914 
915 	err = usb_submit_urb(urb, GFP_ATOMIC);
916 	if (err) {
917 		can_free_echo_skb(netdev, context->echo_index, NULL);
918 
919 		atomic_dec(&priv->active_tx_jobs);
920 		usb_unanchor_urb(urb);
921 
922 		stats->tx_dropped++;
923 
924 		if (err == -ENODEV)
925 			netif_device_detach(netdev);
926 		else
927 			netdev_warn(netdev, "failed tx_urb %pe\n", ERR_PTR(err));
928 
929 		goto releasebuf;
930 	}
931 
932 	netif_trans_update(netdev);
933 
934 	/* Release our reference to this URB, the USB core will eventually free
935 	 * it entirely.
936 	 */
937 	usb_free_urb(urb);
938 
939 	return NETDEV_TX_OK;
940 
941 releasebuf:
942 	usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
943 
944 nobufmem:
945 	usb_free_urb(urb);
946 
947 nourbmem:
948 	return ret;
949 }
950 
951 /* Stop interface */
952 static int esd_usb_stop(struct esd_usb_net_priv *priv)
953 {
954 	union esd_usb_msg *msg;
955 	int err;
956 	int i;
957 
958 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
959 	if (!msg)
960 		return -ENOMEM;
961 
962 	/* Disable all IDs (see esd_usb_start()) */
963 	msg->hdr.cmd = ESD_USB_CMD_IDADD;
964 	msg->hdr.len = sizeof(struct esd_usb_id_filter_msg) / sizeof(u32);/* # of 32bit words */
965 	msg->filter.net = priv->index;
966 	msg->filter.option = ESD_USB_ID_ENABLE; /* start with segment 0 */
967 	for (i = 0; i <= ESD_USB_MAX_ID_SEGMENT; i++)
968 		msg->filter.mask[i] = 0;
969 	err = esd_usb_send_msg(priv->usb, msg);
970 	if (err < 0) {
971 		netdev_err(priv->netdev, "sending idadd message failed: %pe\n", ERR_PTR(err));
972 		goto bail;
973 	}
974 
975 	/* set CAN controller to reset mode */
976 	msg->hdr.len = sizeof(struct esd_usb_set_baudrate_msg) / sizeof(u32); /* # of 32bit words */
977 	msg->hdr.cmd = ESD_USB_CMD_SETBAUD;
978 	msg->setbaud.net = priv->index;
979 	msg->setbaud.rsvd = 0;
980 	msg->setbaud.baud = cpu_to_le32(ESD_USB_NO_BAUDRATE);
981 	err = esd_usb_send_msg(priv->usb, msg);
982 	if (err < 0)
983 		netdev_err(priv->netdev, "sending setbaud message failed: %pe\n", ERR_PTR(err));
984 
985 bail:
986 	kfree(msg);
987 
988 	return err;
989 }
990 
991 static int esd_usb_close(struct net_device *netdev)
992 {
993 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
994 	int err = 0;
995 
996 	if (!priv->usb->in_usb_disconnect) {
997 		/* It's moot to try this in usb_disconnect()! */
998 		err = esd_usb_stop(priv);
999 	}
1000 
1001 	priv->can.state = CAN_STATE_STOPPED;
1002 
1003 	netif_stop_queue(netdev);
1004 
1005 	close_candev(netdev);
1006 
1007 	return err;
1008 }
1009 
1010 static const struct net_device_ops esd_usb_netdev_ops = {
1011 	.ndo_open = esd_usb_open,
1012 	.ndo_stop = esd_usb_close,
1013 	.ndo_start_xmit = esd_usb_start_xmit,
1014 	.ndo_change_mtu = can_change_mtu,
1015 };
1016 
1017 static const struct ethtool_ops esd_usb_ethtool_ops = {
1018 	.get_ts_info = ethtool_op_get_ts_info,
1019 };
1020 
1021 static const struct can_bittiming_const esd_usb_2_bittiming_const = {
1022 	.name = "esd_usb_2",
1023 	.tseg1_min = 1,
1024 	.tseg1_max = 16,
1025 	.tseg2_min = 1,
1026 	.tseg2_max = 8,
1027 	.sjw_max = 4,
1028 	.brp_min = 1,
1029 	.brp_max = 1024,
1030 	.brp_inc = 1,
1031 };
1032 
1033 static int esd_usb_2_set_bittiming(struct net_device *netdev)
1034 {
1035 	const struct can_bittiming_const *btc = &esd_usb_2_bittiming_const;
1036 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
1037 	struct can_bittiming *bt = &priv->can.bittiming;
1038 	union esd_usb_msg *msg;
1039 	int err;
1040 	u32 canbtr;
1041 	int sjw_shift;
1042 
1043 	canbtr = ESD_USB_UBR;
1044 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
1045 		canbtr |= ESD_USB_LOM;
1046 
1047 	canbtr |= (bt->brp - 1) & (btc->brp_max - 1);
1048 
1049 	if (le16_to_cpu(priv->usb->udev->descriptor.idProduct) ==
1050 	    ESD_USB_CANUSBM_PRODUCT_ID)
1051 		sjw_shift = ESD_USB_M_SJW_SHIFT;
1052 	else
1053 		sjw_shift = ESD_USB_2_SJW_SHIFT;
1054 
1055 	canbtr |= ((bt->sjw - 1) & (btc->sjw_max - 1))
1056 		<< sjw_shift;
1057 	canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
1058 		   & (btc->tseg1_max - 1))
1059 		<< ESD_USB_2_TSEG1_SHIFT;
1060 	canbtr |= ((bt->phase_seg2 - 1) & (btc->tseg2_max - 1))
1061 		<< ESD_USB_2_TSEG2_SHIFT;
1062 	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
1063 		canbtr |= ESD_USB_TRIPLE_SAMPLES;
1064 
1065 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
1066 	if (!msg)
1067 		return -ENOMEM;
1068 
1069 	msg->hdr.len = sizeof(struct esd_usb_set_baudrate_msg) / sizeof(u32); /* # of 32bit words */
1070 	msg->hdr.cmd = ESD_USB_CMD_SETBAUD;
1071 	msg->setbaud.net = priv->index;
1072 	msg->setbaud.rsvd = 0;
1073 	msg->setbaud.baud = cpu_to_le32(canbtr);
1074 
1075 	netdev_dbg(netdev, "setting BTR=%#x\n", canbtr);
1076 
1077 	err = esd_usb_send_msg(priv->usb, msg);
1078 
1079 	kfree(msg);
1080 	return err;
1081 }
1082 
1083 /* Nominal bittiming constants, see
1084  * Microchip SAM E70/S70/V70/V71, Data Sheet, Rev. G - 07/2022
1085  * 48.6.8 MCAN Nominal Bit Timing and Prescaler Register
1086  */
1087 static const struct can_bittiming_const esd_usb_3_nom_bittiming_const = {
1088 	.name = "esd_usb_3",
1089 	.tseg1_min = 2,
1090 	.tseg1_max = 256,
1091 	.tseg2_min = 2,
1092 	.tseg2_max = 128,
1093 	.sjw_max = 128,
1094 	.brp_min = 1,
1095 	.brp_max = 512,
1096 	.brp_inc = 1,
1097 };
1098 
1099 /* Data bittiming constants, see
1100  * Microchip SAM E70/S70/V70/V71, Data Sheet, Rev. G - 07/2022
1101  * 48.6.4 MCAN Data Bit Timing and Prescaler Register
1102  */
1103 static const struct can_bittiming_const esd_usb_3_data_bittiming_const = {
1104 	.name = "esd_usb_3",
1105 	.tseg1_min = 2,
1106 	.tseg1_max = 32,
1107 	.tseg2_min = 1,
1108 	.tseg2_max = 16,
1109 	.sjw_max = 8,
1110 	.brp_min = 1,
1111 	.brp_max = 32,
1112 	.brp_inc = 1,
1113 };
1114 
1115 static int esd_usb_3_set_bittiming(struct net_device *netdev)
1116 {
1117 	const struct can_bittiming_const *nom_btc = &esd_usb_3_nom_bittiming_const;
1118 	const struct can_bittiming_const *data_btc = &esd_usb_3_data_bittiming_const;
1119 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
1120 	struct can_bittiming *nom_bt = &priv->can.bittiming;
1121 	struct can_bittiming *data_bt = &priv->can.fd.data_bittiming;
1122 	struct esd_usb_3_set_baudrate_msg_x *baud_x;
1123 	union esd_usb_msg *msg;
1124 	u16 flags = 0;
1125 	int err;
1126 
1127 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
1128 	if (!msg)
1129 		return -ENOMEM;
1130 
1131 	baud_x = &msg->setbaud_x;
1132 
1133 	/* Canonical is the most reasonable mode for SocketCAN on CAN-USB/3 ... */
1134 	baud_x->mode = cpu_to_le16(ESD_USB_3_BAUDRATE_MODE_BTR_CANONICAL);
1135 
1136 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
1137 		flags |= ESD_USB_3_BAUDRATE_FLAG_LOM;
1138 
1139 	baud_x->nom.brp = cpu_to_le16(nom_bt->brp & (nom_btc->brp_max - 1));
1140 	baud_x->nom.sjw = cpu_to_le16(nom_bt->sjw & (nom_btc->sjw_max - 1));
1141 	baud_x->nom.tseg1 = cpu_to_le16((nom_bt->prop_seg + nom_bt->phase_seg1)
1142 					& (nom_btc->tseg1_max - 1));
1143 	baud_x->nom.tseg2 = cpu_to_le16(nom_bt->phase_seg2 & (nom_btc->tseg2_max - 1));
1144 
1145 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1146 		baud_x->data.brp = cpu_to_le16(data_bt->brp & (data_btc->brp_max - 1));
1147 		baud_x->data.sjw = cpu_to_le16(data_bt->sjw & (data_btc->sjw_max - 1));
1148 		baud_x->data.tseg1 = cpu_to_le16((data_bt->prop_seg + data_bt->phase_seg1)
1149 						 & (data_btc->tseg1_max - 1));
1150 		baud_x->data.tseg2 = cpu_to_le16(data_bt->phase_seg2 & (data_btc->tseg2_max - 1));
1151 		flags |= ESD_USB_3_BAUDRATE_FLAG_FD;
1152 	}
1153 
1154 	/* Currently this driver only supports the automatic TDC mode */
1155 	baud_x->tdc.tdc_mode = ESD_USB_3_TDC_MODE_AUTO;
1156 	baud_x->tdc.ssp_offset = 0;
1157 	baud_x->tdc.ssp_shift = 0;
1158 	baud_x->tdc.tdc_filter = 0;
1159 
1160 	baud_x->flags = cpu_to_le16(flags);
1161 	baud_x->net = priv->index;
1162 	baud_x->rsvd = 0;
1163 
1164 	/* set len as # of 32bit words */
1165 	msg->hdr.len = sizeof(struct esd_usb_3_set_baudrate_msg_x) / sizeof(u32);
1166 	msg->hdr.cmd = ESD_USB_CMD_SETBAUD;
1167 
1168 	netdev_dbg(netdev,
1169 		   "ctrlmode=%#x/%#x, esd-net=%u, esd-mode=%#x, esd-flags=%#x\n",
1170 		   priv->can.ctrlmode, priv->can.ctrlmode_supported,
1171 		   priv->index, le16_to_cpu(baud_x->mode), flags);
1172 
1173 	err = esd_usb_send_msg(priv->usb, msg);
1174 
1175 	kfree(msg);
1176 	return err;
1177 }
1178 
1179 static int esd_usb_get_berr_counter(const struct net_device *netdev,
1180 				    struct can_berr_counter *bec)
1181 {
1182 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
1183 
1184 	bec->txerr = priv->bec.txerr;
1185 	bec->rxerr = priv->bec.rxerr;
1186 
1187 	return 0;
1188 }
1189 
1190 static int esd_usb_set_mode(struct net_device *netdev, enum can_mode mode)
1191 {
1192 	switch (mode) {
1193 	case CAN_MODE_START:
1194 		netif_wake_queue(netdev);
1195 		break;
1196 
1197 	default:
1198 		return -EOPNOTSUPP;
1199 	}
1200 
1201 	return 0;
1202 }
1203 
1204 static int esd_usb_probe_one_net(struct usb_interface *intf, int index)
1205 {
1206 	struct esd_usb *dev = usb_get_intfdata(intf);
1207 	struct net_device *netdev;
1208 	struct esd_usb_net_priv *priv;
1209 	int err = 0;
1210 	int i;
1211 
1212 	netdev = alloc_candev(sizeof(*priv), ESD_USB_MAX_TX_URBS);
1213 	if (!netdev) {
1214 		dev_err(&intf->dev, "couldn't alloc candev\n");
1215 		err = -ENOMEM;
1216 		goto done;
1217 	}
1218 
1219 	priv = netdev_priv(netdev);
1220 
1221 	init_usb_anchor(&priv->tx_submitted);
1222 	atomic_set(&priv->active_tx_jobs, 0);
1223 
1224 	for (i = 0; i < ESD_USB_MAX_TX_URBS; i++)
1225 		priv->tx_contexts[i].echo_index = ESD_USB_MAX_TX_URBS;
1226 
1227 	priv->usb = dev;
1228 	priv->netdev = netdev;
1229 	priv->index = index;
1230 
1231 	priv->can.state = CAN_STATE_STOPPED;
1232 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY |
1233 		CAN_CTRLMODE_CC_LEN8_DLC |
1234 		CAN_CTRLMODE_BERR_REPORTING;
1235 
1236 	switch (le16_to_cpu(dev->udev->descriptor.idProduct)) {
1237 	case ESD_USB_CANUSB3_PRODUCT_ID:
1238 		priv->can.clock.freq = ESD_USB_3_CAN_CLOCK;
1239 		priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
1240 		priv->can.bittiming_const = &esd_usb_3_nom_bittiming_const;
1241 		priv->can.fd.data_bittiming_const = &esd_usb_3_data_bittiming_const;
1242 		priv->can.do_set_bittiming = esd_usb_3_set_bittiming;
1243 		priv->can.fd.do_set_data_bittiming = esd_usb_3_set_bittiming;
1244 		break;
1245 
1246 	case ESD_USB_CANUSBM_PRODUCT_ID:
1247 		priv->can.clock.freq = ESD_USB_M_CAN_CLOCK;
1248 		priv->can.bittiming_const = &esd_usb_2_bittiming_const;
1249 		priv->can.do_set_bittiming = esd_usb_2_set_bittiming;
1250 		break;
1251 
1252 	case ESD_USB_CANUSB2_PRODUCT_ID:
1253 	default:
1254 		priv->can.clock.freq = ESD_USB_2_CAN_CLOCK;
1255 		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1256 		priv->can.bittiming_const = &esd_usb_2_bittiming_const;
1257 		priv->can.do_set_bittiming = esd_usb_2_set_bittiming;
1258 		break;
1259 	}
1260 
1261 	priv->can.do_set_mode = esd_usb_set_mode;
1262 	priv->can.do_get_berr_counter = esd_usb_get_berr_counter;
1263 
1264 	netdev->flags |= IFF_ECHO; /* we support local echo */
1265 
1266 	netdev->netdev_ops = &esd_usb_netdev_ops;
1267 	netdev->ethtool_ops = &esd_usb_ethtool_ops;
1268 
1269 	SET_NETDEV_DEV(netdev, &intf->dev);
1270 	netdev->dev_id = index;
1271 
1272 	err = register_candev(netdev);
1273 	if (err) {
1274 		dev_err(&intf->dev, "couldn't register CAN device: %pe\n", ERR_PTR(err));
1275 		free_candev(netdev);
1276 		err = -ENOMEM;
1277 		goto done;
1278 	}
1279 
1280 	dev->nets[index] = priv;
1281 	netdev_info(netdev, "registered\n");
1282 
1283 done:
1284 	return err;
1285 }
1286 
1287 /* probe function for new USB devices
1288  *
1289  * check version information and number of available
1290  * CAN interfaces
1291  */
1292 static int esd_usb_probe(struct usb_interface *intf,
1293 			 const struct usb_device_id *id)
1294 {
1295 	struct esd_usb *dev;
1296 	union esd_usb_msg *msg;
1297 	int i, err;
1298 
1299 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1300 	if (!dev) {
1301 		err = -ENOMEM;
1302 		goto done;
1303 	}
1304 
1305 	dev->udev = interface_to_usbdev(intf);
1306 
1307 	init_usb_anchor(&dev->rx_submitted);
1308 
1309 	usb_set_intfdata(intf, dev);
1310 
1311 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
1312 	if (!msg) {
1313 		err = -ENOMEM;
1314 		goto free_msg;
1315 	}
1316 
1317 	/* query number of CAN interfaces (nets) */
1318 	msg->hdr.cmd = ESD_USB_CMD_VERSION;
1319 	msg->hdr.len = sizeof(struct esd_usb_version_msg) / sizeof(u32); /* # of 32bit words */
1320 	msg->version.rsvd = 0;
1321 	msg->version.flags = 0;
1322 	msg->version.drv_version = 0;
1323 
1324 	err = esd_usb_send_msg(dev, msg);
1325 	if (err < 0) {
1326 		dev_err(&intf->dev, "sending version message failed\n");
1327 		goto free_msg;
1328 	}
1329 
1330 	err = esd_usb_wait_msg(dev, msg);
1331 	if (err < 0) {
1332 		dev_err(&intf->dev, "no version message answer\n");
1333 		goto free_msg;
1334 	}
1335 
1336 	dev->net_count = (int)msg->version_reply.nets;
1337 	dev->version = le32_to_cpu(msg->version_reply.version);
1338 
1339 	if (device_create_file(&intf->dev, &dev_attr_firmware))
1340 		dev_err(&intf->dev,
1341 			"Couldn't create device file for firmware\n");
1342 
1343 	if (device_create_file(&intf->dev, &dev_attr_hardware))
1344 		dev_err(&intf->dev,
1345 			"Couldn't create device file for hardware\n");
1346 
1347 	if (device_create_file(&intf->dev, &dev_attr_nets))
1348 		dev_err(&intf->dev,
1349 			"Couldn't create device file for nets\n");
1350 
1351 	/* do per device probing */
1352 	for (i = 0; i < dev->net_count; i++)
1353 		esd_usb_probe_one_net(intf, i);
1354 
1355 free_msg:
1356 	kfree(msg);
1357 	if (err)
1358 		kfree(dev);
1359 done:
1360 	return err;
1361 }
1362 
1363 /* called by the usb core when the device is removed from the system */
1364 static void esd_usb_disconnect(struct usb_interface *intf)
1365 {
1366 	struct esd_usb *dev = usb_get_intfdata(intf);
1367 	struct net_device *netdev;
1368 	int i;
1369 
1370 	device_remove_file(&intf->dev, &dev_attr_firmware);
1371 	device_remove_file(&intf->dev, &dev_attr_hardware);
1372 	device_remove_file(&intf->dev, &dev_attr_nets);
1373 
1374 	usb_set_intfdata(intf, NULL);
1375 
1376 	if (dev) {
1377 		dev->in_usb_disconnect = 1;
1378 		for (i = 0; i < dev->net_count; i++) {
1379 			if (dev->nets[i]) {
1380 				netdev = dev->nets[i]->netdev;
1381 				netdev_info(netdev, "unregister\n");
1382 				unregister_netdev(netdev);
1383 				free_candev(netdev);
1384 			}
1385 		}
1386 		unlink_all_urbs(dev);
1387 		kfree(dev);
1388 	}
1389 }
1390 
1391 /* usb specific object needed to register this driver with the usb subsystem */
1392 static struct usb_driver esd_usb_driver = {
1393 	.name = KBUILD_MODNAME,
1394 	.probe = esd_usb_probe,
1395 	.disconnect = esd_usb_disconnect,
1396 	.id_table = esd_usb_table,
1397 };
1398 
1399 module_usb_driver(esd_usb_driver);
1400