xref: /openbmc/linux/drivers/net/can/usb/esd_usb.c (revision c67ce71d)
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/ethtool.h>
13 #include <linux/module.h>
14 #include <linux/netdevice.h>
15 #include <linux/signal.h>
16 #include <linux/slab.h>
17 #include <linux/units.h>
18 #include <linux/usb.h>
19 
20 MODULE_AUTHOR("Matthias Fuchs <socketcan@esd.eu>");
21 MODULE_AUTHOR("Frank Jungclaus <frank.jungclaus@esd.eu>");
22 MODULE_DESCRIPTION("CAN driver for esd electronics gmbh CAN-USB/2, CAN-USB/3 and CAN-USB/Micro interfaces");
23 MODULE_LICENSE("GPL v2");
24 
25 /* USB vendor and product ID */
26 #define ESD_USB_ESDGMBH_VENDOR_ID	0x0ab4
27 #define ESD_USB_CANUSB2_PRODUCT_ID	0x0010
28 #define ESD_USB_CANUSBM_PRODUCT_ID	0x0011
29 #define ESD_USB_CANUSB3_PRODUCT_ID	0x0014
30 
31 /* CAN controller clock frequencies */
32 #define ESD_USB_2_CAN_CLOCK	(60 * MEGA) /* Hz */
33 #define ESD_USB_M_CAN_CLOCK	(36 * MEGA) /* Hz */
34 #define ESD_USB_3_CAN_CLOCK	(80 * MEGA) /* Hz */
35 
36 /* Maximum number of CAN nets */
37 #define ESD_USB_MAX_NETS	2
38 
39 /* USB commands */
40 #define ESD_USB_CMD_VERSION		1 /* also used for VERSION_REPLY */
41 #define ESD_USB_CMD_CAN_RX		2 /* device to host only */
42 #define ESD_USB_CMD_CAN_TX		3 /* also used for TX_DONE */
43 #define ESD_USB_CMD_SETBAUD		4 /* also used for SETBAUD_REPLY */
44 #define ESD_USB_CMD_TS			5 /* also used for TS_REPLY */
45 #define ESD_USB_CMD_IDADD		6 /* also used for IDADD_REPLY */
46 
47 /* esd CAN message flags - dlc field */
48 #define ESD_USB_RTR	BIT(4)
49 #define ESD_USB_NO_BRS	BIT(4)
50 #define ESD_USB_ESI	BIT(5)
51 #define ESD_USB_FD	BIT(7)
52 
53 /* esd CAN message flags - id field */
54 #define ESD_USB_EXTID	BIT(29)
55 #define ESD_USB_EVENT	BIT(30)
56 #define ESD_USB_IDMASK	GENMASK(28, 0)
57 
58 /* esd CAN event ids */
59 #define ESD_USB_EV_CAN_ERROR_EXT	2 /* CAN controller specific diagnostic data */
60 
61 /* baudrate message flags */
62 #define ESD_USB_LOM	BIT(30) /* Listen Only Mode */
63 #define ESD_USB_UBR	BIT(31) /* User Bit Rate (controller BTR) in bits 0..27 */
64 #define ESD_USB_NO_BAUDRATE	GENMASK(30, 0) /* bit rate unconfigured */
65 
66 /* bit timing esd CAN-USB */
67 #define ESD_USB_2_TSEG1_SHIFT	16
68 #define ESD_USB_2_TSEG2_SHIFT	20
69 #define ESD_USB_2_SJW_SHIFT	14
70 #define ESD_USB_M_SJW_SHIFT	24
71 #define ESD_USB_TRIPLE_SAMPLES	BIT(23)
72 
73 /* Transmitter Delay Compensation */
74 #define ESD_USB_3_TDC_MODE_AUTO	0
75 
76 /* esd IDADD message */
77 #define ESD_USB_ID_ENABLE	BIT(7)
78 #define ESD_USB_MAX_ID_SEGMENT	64
79 
80 /* SJA1000 ECC register (emulated by usb firmware) */
81 #define ESD_USB_SJA1000_ECC_SEG		GENMASK(4, 0)
82 #define ESD_USB_SJA1000_ECC_DIR		BIT(5)
83 #define ESD_USB_SJA1000_ECC_ERR		BIT(2, 1)
84 #define ESD_USB_SJA1000_ECC_BIT		0x00
85 #define ESD_USB_SJA1000_ECC_FORM	BIT(6)
86 #define ESD_USB_SJA1000_ECC_STUFF	BIT(7)
87 #define ESD_USB_SJA1000_ECC_MASK	GENMASK(7, 6)
88 
89 /* esd bus state event codes */
90 #define ESD_USB_BUSSTATE_MASK	GENMASK(7, 6)
91 #define ESD_USB_BUSSTATE_WARN	BIT(6)
92 #define ESD_USB_BUSSTATE_ERRPASSIVE	BIT(7)
93 #define ESD_USB_BUSSTATE_BUSOFF	GENMASK(7, 6)
94 
95 #define ESD_USB_RX_BUFFER_SIZE		1024
96 #define ESD_USB_MAX_RX_URBS		4
97 #define ESD_USB_MAX_TX_URBS		16 /* must be power of 2 */
98 
99 /* Modes for CAN-USB/3, to be used for esd_usb_3_set_baudrate_msg_x.mode */
100 #define ESD_USB_3_BAUDRATE_MODE_DISABLE		0 /* remove from bus */
101 #define ESD_USB_3_BAUDRATE_MODE_INDEX		1 /* ESD (CiA) bit rate idx */
102 #define ESD_USB_3_BAUDRATE_MODE_BTR_CTRL	2 /* BTR values (controller)*/
103 #define ESD_USB_3_BAUDRATE_MODE_BTR_CANONICAL	3 /* BTR values (canonical) */
104 #define ESD_USB_3_BAUDRATE_MODE_NUM		4 /* numerical bit rate */
105 #define ESD_USB_3_BAUDRATE_MODE_AUTOBAUD	5 /* autobaud */
106 
107 /* Flags for CAN-USB/3, to be used for esd_usb_3_set_baudrate_msg_x.flags */
108 #define ESD_USB_3_BAUDRATE_FLAG_FD	BIT(0) /* enable CAN FD mode */
109 #define ESD_USB_3_BAUDRATE_FLAG_LOM	BIT(1) /* enable listen only mode */
110 #define ESD_USB_3_BAUDRATE_FLAG_STM	BIT(2) /* enable self test mode */
111 #define ESD_USB_3_BAUDRATE_FLAG_TRS	BIT(3) /* enable triple sampling */
112 #define ESD_USB_3_BAUDRATE_FLAG_TXP	BIT(4) /* enable transmit pause */
113 
114 struct esd_usb_header_msg {
115 	u8 len; /* total message length in 32bit words */
116 	u8 cmd;
117 	u8 rsvd[2];
118 };
119 
120 struct esd_usb_version_msg {
121 	u8 len; /* total message length in 32bit words */
122 	u8 cmd;
123 	u8 rsvd;
124 	u8 flags;
125 	__le32 drv_version;
126 };
127 
128 struct esd_usb_version_reply_msg {
129 	u8 len; /* total message length in 32bit words */
130 	u8 cmd;
131 	u8 nets;
132 	u8 features;
133 	__le32 version;
134 	u8 name[16];
135 	__le32 rsvd;
136 	__le32 ts;
137 };
138 
139 struct esd_usb_rx_msg {
140 	u8 len; /* total message length in 32bit words */
141 	u8 cmd;
142 	u8 net;
143 	u8 dlc;
144 	__le32 ts;
145 	__le32 id; /* upper 3 bits contain flags */
146 	union {
147 		u8 data[CAN_MAX_DLEN];
148 		u8 data_fd[CANFD_MAX_DLEN];
149 		struct {
150 			u8 status; /* CAN Controller Status */
151 			u8 ecc;    /* Error Capture Register */
152 			u8 rec;    /* RX Error Counter */
153 			u8 tec;    /* TX Error Counter */
154 		} ev_can_err_ext;  /* For ESD_EV_CAN_ERROR_EXT */
155 	};
156 };
157 
158 struct esd_usb_tx_msg {
159 	u8 len; /* total message length in 32bit words */
160 	u8 cmd;
161 	u8 net;
162 	u8 dlc;
163 	u32 hnd;	/* opaque handle, not used by device */
164 	__le32 id; /* upper 3 bits contain flags */
165 	union {
166 		u8 data[CAN_MAX_DLEN];
167 		u8 data_fd[CANFD_MAX_DLEN];
168 	};
169 };
170 
171 struct esd_usb_tx_done_msg {
172 	u8 len; /* total message length in 32bit words */
173 	u8 cmd;
174 	u8 net;
175 	u8 status;
176 	u32 hnd;	/* opaque handle, not used by device */
177 	__le32 ts;
178 };
179 
180 struct esd_usb_id_filter_msg {
181 	u8 len; /* total message length in 32bit words */
182 	u8 cmd;
183 	u8 net;
184 	u8 option;
185 	__le32 mask[ESD_USB_MAX_ID_SEGMENT + 1]; /* +1 for 29bit extended IDs */
186 };
187 
188 struct esd_usb_set_baudrate_msg {
189 	u8 len; /* total message length in 32bit words */
190 	u8 cmd;
191 	u8 net;
192 	u8 rsvd;
193 	__le32 baud;
194 };
195 
196 /* CAN-USB/3 baudrate configuration, used for nominal as well as for data bit rate */
197 struct esd_usb_3_baudrate_cfg {
198 	__le16 brp;	/* bit rate pre-scaler */
199 	__le16 tseg1;	/* time segment before sample point */
200 	__le16 tseg2;	/* time segment after sample point */
201 	__le16 sjw;	/* synchronization jump Width */
202 };
203 
204 /* In principle, the esd CAN-USB/3 supports Transmitter Delay Compensation (TDC),
205  * but currently only the automatic TDC mode is supported by this driver.
206  * An implementation for manual TDC configuration will follow.
207  *
208  * For information about struct esd_usb_3_tdc_cfg, see
209  * NTCAN Application Developers Manual, 6.2.25 NTCAN_TDC_CFG + related chapters
210  * https://esd.eu/fileadmin/esd/docs/manuals/NTCAN_Part1_Function_API_Manual_en_56.pdf
211  */
212 struct esd_usb_3_tdc_cfg {
213 	u8 tdc_mode;	/* transmitter delay compensation mode  */
214 	u8 ssp_offset;	/* secondary sample point offset in mtq */
215 	s8 ssp_shift;	/* secondary sample point shift in mtq */
216 	u8 tdc_filter;	/* TDC filter in mtq */
217 };
218 
219 /* Extended version of the above set_baudrate_msg for a CAN-USB/3
220  * to define the CAN bit timing configuration of the CAN controller in
221  * CAN FD mode as well as in Classical CAN mode.
222  *
223  * The payload of this command is a NTCAN_BAUDRATE_X structure according to
224  * esd electronics gmbh, NTCAN Application Developers Manual, 6.2.15 NTCAN_BAUDRATE_X
225  * https://esd.eu/fileadmin/esd/docs/manuals/NTCAN_Part1_Function_API_Manual_en_56.pdf
226  */
227 struct esd_usb_3_set_baudrate_msg_x {
228 	u8 len;	/* total message length in 32bit words */
229 	u8 cmd;
230 	u8 net;
231 	u8 rsvd;	/*reserved */
232 	/* Payload ... */
233 	__le16 mode;	/* mode word, see ESD_USB_3_BAUDRATE_MODE_xxx */
234 	__le16 flags;	/* control flags, see ESD_USB_3_BAUDRATE_FLAG_xxx */
235 	struct esd_usb_3_tdc_cfg tdc;	/* TDC configuration */
236 	struct esd_usb_3_baudrate_cfg nom;	/* nominal bit rate */
237 	struct esd_usb_3_baudrate_cfg data;	/* data bit rate */
238 };
239 
240 /* Main message type used between library and application */
241 union __packed esd_usb_msg {
242 	struct esd_usb_header_msg hdr;
243 	struct esd_usb_version_msg version;
244 	struct esd_usb_version_reply_msg version_reply;
245 	struct esd_usb_rx_msg rx;
246 	struct esd_usb_tx_msg tx;
247 	struct esd_usb_tx_done_msg txdone;
248 	struct esd_usb_set_baudrate_msg setbaud;
249 	struct esd_usb_3_set_baudrate_msg_x setbaud_x;
250 	struct esd_usb_id_filter_msg filter;
251 };
252 
253 static struct usb_device_id esd_usb_table[] = {
254 	{USB_DEVICE(ESD_USB_ESDGMBH_VENDOR_ID, ESD_USB_CANUSB2_PRODUCT_ID)},
255 	{USB_DEVICE(ESD_USB_ESDGMBH_VENDOR_ID, ESD_USB_CANUSBM_PRODUCT_ID)},
256 	{USB_DEVICE(ESD_USB_ESDGMBH_VENDOR_ID, ESD_USB_CANUSB3_PRODUCT_ID)},
257 	{}
258 };
259 MODULE_DEVICE_TABLE(usb, esd_usb_table);
260 
261 struct esd_usb_net_priv;
262 
263 struct esd_tx_urb_context {
264 	struct esd_usb_net_priv *priv;
265 	u32 echo_index;
266 };
267 
268 struct esd_usb {
269 	struct usb_device *udev;
270 	struct esd_usb_net_priv *nets[ESD_USB_MAX_NETS];
271 
272 	struct usb_anchor rx_submitted;
273 
274 	int net_count;
275 	u32 version;
276 	int rxinitdone;
277 	void *rxbuf[ESD_USB_MAX_RX_URBS];
278 	dma_addr_t rxbuf_dma[ESD_USB_MAX_RX_URBS];
279 };
280 
281 struct esd_usb_net_priv {
282 	struct can_priv can; /* must be the first member */
283 
284 	atomic_t active_tx_jobs;
285 	struct usb_anchor tx_submitted;
286 	struct esd_tx_urb_context tx_contexts[ESD_USB_MAX_TX_URBS];
287 
288 	struct esd_usb *usb;
289 	struct net_device *netdev;
290 	int index;
291 	u8 old_state;
292 	struct can_berr_counter bec;
293 };
294 
295 static void esd_usb_rx_event(struct esd_usb_net_priv *priv,
296 			     union esd_usb_msg *msg)
297 {
298 	struct net_device_stats *stats = &priv->netdev->stats;
299 	struct can_frame *cf;
300 	struct sk_buff *skb;
301 	u32 id = le32_to_cpu(msg->rx.id) & ESD_USB_IDMASK;
302 
303 	if (id == ESD_USB_EV_CAN_ERROR_EXT) {
304 		u8 state = msg->rx.ev_can_err_ext.status;
305 		u8 ecc = msg->rx.ev_can_err_ext.ecc;
306 
307 		priv->bec.rxerr = msg->rx.ev_can_err_ext.rec;
308 		priv->bec.txerr = msg->rx.ev_can_err_ext.tec;
309 
310 		netdev_dbg(priv->netdev,
311 			   "CAN_ERR_EV_EXT: dlc=%#02x state=%02x ecc=%02x rec=%02x tec=%02x\n",
312 			   msg->rx.dlc, state, ecc,
313 			   priv->bec.rxerr, priv->bec.txerr);
314 
315 		/* if berr-reporting is off, only pass through on state change ... */
316 		if (!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
317 		    state == priv->old_state)
318 			return;
319 
320 		skb = alloc_can_err_skb(priv->netdev, &cf);
321 		if (!skb)
322 			stats->rx_dropped++;
323 
324 		if (state != priv->old_state) {
325 			enum can_state tx_state, rx_state;
326 			enum can_state new_state = CAN_STATE_ERROR_ACTIVE;
327 
328 			priv->old_state = state;
329 
330 			switch (state & ESD_USB_BUSSTATE_MASK) {
331 			case ESD_USB_BUSSTATE_BUSOFF:
332 				new_state = CAN_STATE_BUS_OFF;
333 				can_bus_off(priv->netdev);
334 				break;
335 			case ESD_USB_BUSSTATE_WARN:
336 				new_state = CAN_STATE_ERROR_WARNING;
337 				break;
338 			case ESD_USB_BUSSTATE_ERRPASSIVE:
339 				new_state = CAN_STATE_ERROR_PASSIVE;
340 				break;
341 			default:
342 				new_state = CAN_STATE_ERROR_ACTIVE;
343 				priv->bec.txerr = 0;
344 				priv->bec.rxerr = 0;
345 				break;
346 			}
347 
348 			if (new_state != priv->can.state) {
349 				tx_state = (priv->bec.txerr >= priv->bec.rxerr) ? new_state : 0;
350 				rx_state = (priv->bec.txerr <= priv->bec.rxerr) ? new_state : 0;
351 				can_change_state(priv->netdev, cf,
352 						 tx_state, rx_state);
353 			}
354 		} else if (skb) {
355 			priv->can.can_stats.bus_error++;
356 			stats->rx_errors++;
357 
358 			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
359 
360 			switch (ecc & ESD_USB_SJA1000_ECC_MASK) {
361 			case ESD_USB_SJA1000_ECC_BIT:
362 				cf->data[2] |= CAN_ERR_PROT_BIT;
363 				break;
364 			case ESD_USB_SJA1000_ECC_FORM:
365 				cf->data[2] |= CAN_ERR_PROT_FORM;
366 				break;
367 			case ESD_USB_SJA1000_ECC_STUFF:
368 				cf->data[2] |= CAN_ERR_PROT_STUFF;
369 				break;
370 			default:
371 				break;
372 			}
373 
374 			/* Error occurred during transmission? */
375 			if (!(ecc & ESD_USB_SJA1000_ECC_DIR))
376 				cf->data[2] |= CAN_ERR_PROT_TX;
377 
378 			/* Bit stream position in CAN frame as the error was detected */
379 			cf->data[3] = ecc & ESD_USB_SJA1000_ECC_SEG;
380 		}
381 
382 		if (skb) {
383 			cf->can_id |= CAN_ERR_CNT;
384 			cf->data[6] = priv->bec.txerr;
385 			cf->data[7] = priv->bec.rxerr;
386 
387 			netif_rx(skb);
388 		}
389 	}
390 }
391 
392 static void esd_usb_rx_can_msg(struct esd_usb_net_priv *priv,
393 			       union esd_usb_msg *msg)
394 {
395 	struct net_device_stats *stats = &priv->netdev->stats;
396 	struct can_frame *cf;
397 	struct canfd_frame *cfd;
398 	struct sk_buff *skb;
399 	u32 id;
400 	u8 len;
401 
402 	if (!netif_device_present(priv->netdev))
403 		return;
404 
405 	id = le32_to_cpu(msg->rx.id);
406 
407 	if (id & ESD_USB_EVENT) {
408 		esd_usb_rx_event(priv, msg);
409 	} else {
410 		if (msg->rx.dlc & ESD_USB_FD) {
411 			skb = alloc_canfd_skb(priv->netdev, &cfd);
412 		} else {
413 			skb = alloc_can_skb(priv->netdev, &cf);
414 			cfd = (struct canfd_frame *)cf;
415 		}
416 
417 		if (skb == NULL) {
418 			stats->rx_dropped++;
419 			return;
420 		}
421 
422 		cfd->can_id = id & ESD_USB_IDMASK;
423 
424 		if (msg->rx.dlc & ESD_USB_FD) {
425 			/* masking by 0x0F is already done within can_fd_dlc2len() */
426 			cfd->len = can_fd_dlc2len(msg->rx.dlc);
427 			len = cfd->len;
428 			if ((msg->rx.dlc & ESD_USB_NO_BRS) == 0)
429 				cfd->flags |= CANFD_BRS;
430 			if (msg->rx.dlc & ESD_USB_ESI)
431 				cfd->flags |= CANFD_ESI;
432 		} else {
433 			can_frame_set_cc_len(cf, msg->rx.dlc & ~ESD_USB_RTR, priv->can.ctrlmode);
434 			len = cf->len;
435 			if (msg->rx.dlc & ESD_USB_RTR) {
436 				cf->can_id |= CAN_RTR_FLAG;
437 				len = 0;
438 			}
439 		}
440 
441 		if (id & ESD_USB_EXTID)
442 			cfd->can_id |= CAN_EFF_FLAG;
443 
444 		memcpy(cfd->data, msg->rx.data_fd, len);
445 		stats->rx_bytes += len;
446 		stats->rx_packets++;
447 
448 		netif_rx(skb);
449 	}
450 }
451 
452 static void esd_usb_tx_done_msg(struct esd_usb_net_priv *priv,
453 				union esd_usb_msg *msg)
454 {
455 	struct net_device_stats *stats = &priv->netdev->stats;
456 	struct net_device *netdev = priv->netdev;
457 	struct esd_tx_urb_context *context;
458 
459 	if (!netif_device_present(netdev))
460 		return;
461 
462 	context = &priv->tx_contexts[msg->txdone.hnd & (ESD_USB_MAX_TX_URBS - 1)];
463 
464 	if (!msg->txdone.status) {
465 		stats->tx_packets++;
466 		stats->tx_bytes += can_get_echo_skb(netdev, context->echo_index,
467 						    NULL);
468 	} else {
469 		stats->tx_errors++;
470 		can_free_echo_skb(netdev, context->echo_index, NULL);
471 	}
472 
473 	/* Release context */
474 	context->echo_index = ESD_USB_MAX_TX_URBS;
475 	atomic_dec(&priv->active_tx_jobs);
476 
477 	netif_wake_queue(netdev);
478 }
479 
480 static void esd_usb_read_bulk_callback(struct urb *urb)
481 {
482 	struct esd_usb *dev = urb->context;
483 	int retval;
484 	int pos = 0;
485 	int i;
486 
487 	switch (urb->status) {
488 	case 0: /* success */
489 		break;
490 
491 	case -ENOENT:
492 	case -EPIPE:
493 	case -EPROTO:
494 	case -ESHUTDOWN:
495 		return;
496 
497 	default:
498 		dev_info(dev->udev->dev.parent,
499 			 "Rx URB aborted (%d)\n", urb->status);
500 		goto resubmit_urb;
501 	}
502 
503 	while (pos < urb->actual_length) {
504 		union esd_usb_msg *msg;
505 
506 		msg = (union esd_usb_msg *)(urb->transfer_buffer + pos);
507 
508 		switch (msg->hdr.cmd) {
509 		case ESD_USB_CMD_CAN_RX:
510 			if (msg->rx.net >= dev->net_count) {
511 				dev_err(dev->udev->dev.parent, "format error\n");
512 				break;
513 			}
514 
515 			esd_usb_rx_can_msg(dev->nets[msg->rx.net], msg);
516 			break;
517 
518 		case ESD_USB_CMD_CAN_TX:
519 			if (msg->txdone.net >= dev->net_count) {
520 				dev_err(dev->udev->dev.parent, "format error\n");
521 				break;
522 			}
523 
524 			esd_usb_tx_done_msg(dev->nets[msg->txdone.net],
525 					    msg);
526 			break;
527 		}
528 
529 		pos += msg->hdr.len * sizeof(u32); /* convert to # of bytes */
530 
531 		if (pos > urb->actual_length) {
532 			dev_err(dev->udev->dev.parent, "format error\n");
533 			break;
534 		}
535 	}
536 
537 resubmit_urb:
538 	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
539 			  urb->transfer_buffer, ESD_USB_RX_BUFFER_SIZE,
540 			  esd_usb_read_bulk_callback, dev);
541 
542 	retval = usb_submit_urb(urb, GFP_ATOMIC);
543 	if (retval == -ENODEV) {
544 		for (i = 0; i < dev->net_count; i++) {
545 			if (dev->nets[i])
546 				netif_device_detach(dev->nets[i]->netdev);
547 		}
548 	} else if (retval) {
549 		dev_err(dev->udev->dev.parent,
550 			"failed resubmitting read bulk urb: %d\n", retval);
551 	}
552 }
553 
554 /* callback for bulk IN urb */
555 static void esd_usb_write_bulk_callback(struct urb *urb)
556 {
557 	struct esd_tx_urb_context *context = urb->context;
558 	struct esd_usb_net_priv *priv;
559 	struct net_device *netdev;
560 	size_t size = sizeof(union esd_usb_msg);
561 
562 	WARN_ON(!context);
563 
564 	priv = context->priv;
565 	netdev = priv->netdev;
566 
567 	/* free up our allocated buffer */
568 	usb_free_coherent(urb->dev, size,
569 			  urb->transfer_buffer, urb->transfer_dma);
570 
571 	if (!netif_device_present(netdev))
572 		return;
573 
574 	if (urb->status)
575 		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
576 
577 	netif_trans_update(netdev);
578 }
579 
580 static ssize_t firmware_show(struct device *d,
581 			     struct device_attribute *attr, char *buf)
582 {
583 	struct usb_interface *intf = to_usb_interface(d);
584 	struct esd_usb *dev = usb_get_intfdata(intf);
585 
586 	return sprintf(buf, "%d.%d.%d\n",
587 		       (dev->version >> 12) & 0xf,
588 		       (dev->version >> 8) & 0xf,
589 		       dev->version & 0xff);
590 }
591 static DEVICE_ATTR_RO(firmware);
592 
593 static ssize_t hardware_show(struct device *d,
594 			     struct device_attribute *attr, char *buf)
595 {
596 	struct usb_interface *intf = to_usb_interface(d);
597 	struct esd_usb *dev = usb_get_intfdata(intf);
598 
599 	return sprintf(buf, "%d.%d.%d\n",
600 		       (dev->version >> 28) & 0xf,
601 		       (dev->version >> 24) & 0xf,
602 		       (dev->version >> 16) & 0xff);
603 }
604 static DEVICE_ATTR_RO(hardware);
605 
606 static ssize_t nets_show(struct device *d,
607 			 struct device_attribute *attr, char *buf)
608 {
609 	struct usb_interface *intf = to_usb_interface(d);
610 	struct esd_usb *dev = usb_get_intfdata(intf);
611 
612 	return sprintf(buf, "%d", dev->net_count);
613 }
614 static DEVICE_ATTR_RO(nets);
615 
616 static int esd_usb_send_msg(struct esd_usb *dev, union esd_usb_msg *msg)
617 {
618 	int actual_length;
619 
620 	return usb_bulk_msg(dev->udev,
621 			    usb_sndbulkpipe(dev->udev, 2),
622 			    msg,
623 			    msg->hdr.len * sizeof(u32), /* convert to # of bytes */
624 			    &actual_length,
625 			    1000);
626 }
627 
628 static int esd_usb_wait_msg(struct esd_usb *dev,
629 			    union esd_usb_msg *msg)
630 {
631 	int actual_length;
632 
633 	return usb_bulk_msg(dev->udev,
634 			    usb_rcvbulkpipe(dev->udev, 1),
635 			    msg,
636 			    sizeof(*msg),
637 			    &actual_length,
638 			    1000);
639 }
640 
641 static int esd_usb_setup_rx_urbs(struct esd_usb *dev)
642 {
643 	int i, err = 0;
644 
645 	if (dev->rxinitdone)
646 		return 0;
647 
648 	for (i = 0; i < ESD_USB_MAX_RX_URBS; i++) {
649 		struct urb *urb = NULL;
650 		u8 *buf = NULL;
651 		dma_addr_t buf_dma;
652 
653 		/* create a URB, and a buffer for it */
654 		urb = usb_alloc_urb(0, GFP_KERNEL);
655 		if (!urb) {
656 			err = -ENOMEM;
657 			break;
658 		}
659 
660 		buf = usb_alloc_coherent(dev->udev, ESD_USB_RX_BUFFER_SIZE, GFP_KERNEL,
661 					 &buf_dma);
662 		if (!buf) {
663 			dev_warn(dev->udev->dev.parent,
664 				 "No memory left for USB buffer\n");
665 			err = -ENOMEM;
666 			goto freeurb;
667 		}
668 
669 		urb->transfer_dma = buf_dma;
670 
671 		usb_fill_bulk_urb(urb, dev->udev,
672 				  usb_rcvbulkpipe(dev->udev, 1),
673 				  buf, ESD_USB_RX_BUFFER_SIZE,
674 				  esd_usb_read_bulk_callback, dev);
675 		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
676 		usb_anchor_urb(urb, &dev->rx_submitted);
677 
678 		err = usb_submit_urb(urb, GFP_KERNEL);
679 		if (err) {
680 			usb_unanchor_urb(urb);
681 			usb_free_coherent(dev->udev, ESD_USB_RX_BUFFER_SIZE, buf,
682 					  urb->transfer_dma);
683 			goto freeurb;
684 		}
685 
686 		dev->rxbuf[i] = buf;
687 		dev->rxbuf_dma[i] = buf_dma;
688 
689 freeurb:
690 		/* Drop reference, USB core will take care of freeing it */
691 		usb_free_urb(urb);
692 		if (err)
693 			break;
694 	}
695 
696 	/* Did we submit any URBs */
697 	if (i == 0) {
698 		dev_err(dev->udev->dev.parent, "couldn't setup read URBs\n");
699 		return err;
700 	}
701 
702 	/* Warn if we've couldn't transmit all the URBs */
703 	if (i < ESD_USB_MAX_RX_URBS) {
704 		dev_warn(dev->udev->dev.parent,
705 			 "rx performance may be slow\n");
706 	}
707 
708 	dev->rxinitdone = 1;
709 	return 0;
710 }
711 
712 /* Start interface */
713 static int esd_usb_start(struct esd_usb_net_priv *priv)
714 {
715 	struct esd_usb *dev = priv->usb;
716 	struct net_device *netdev = priv->netdev;
717 	union esd_usb_msg *msg;
718 	int err, i;
719 
720 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
721 	if (!msg) {
722 		err = -ENOMEM;
723 		goto out;
724 	}
725 
726 	/* Enable all IDs
727 	 * The IDADD message takes up to 64 32 bit bitmasks (2048 bits).
728 	 * Each bit represents one 11 bit CAN identifier. A set bit
729 	 * enables reception of the corresponding CAN identifier. A cleared
730 	 * bit disabled this identifier. An additional bitmask value
731 	 * following the CAN 2.0A bits is used to enable reception of
732 	 * extended CAN frames. Only the LSB of this final mask is checked
733 	 * for the complete 29 bit ID range. The IDADD message also allows
734 	 * filter configuration for an ID subset. In this case you can add
735 	 * the number of the starting bitmask (0..64) to the filter.option
736 	 * field followed by only some bitmasks.
737 	 */
738 	msg->hdr.cmd = ESD_USB_CMD_IDADD;
739 	msg->hdr.len = sizeof(struct esd_usb_id_filter_msg) / sizeof(u32); /* # of 32bit words */
740 	msg->filter.net = priv->index;
741 	msg->filter.option = ESD_USB_ID_ENABLE; /* start with segment 0 */
742 	for (i = 0; i < ESD_USB_MAX_ID_SEGMENT; i++)
743 		msg->filter.mask[i] = cpu_to_le32(GENMASK(31, 0));
744 	/* enable 29bit extended IDs */
745 	msg->filter.mask[ESD_USB_MAX_ID_SEGMENT] = cpu_to_le32(BIT(0));
746 
747 	err = esd_usb_send_msg(dev, msg);
748 	if (err)
749 		goto out;
750 
751 	err = esd_usb_setup_rx_urbs(dev);
752 	if (err)
753 		goto out;
754 
755 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
756 
757 out:
758 	if (err == -ENODEV)
759 		netif_device_detach(netdev);
760 	if (err)
761 		netdev_err(netdev, "couldn't start device: %d\n", err);
762 
763 	kfree(msg);
764 	return err;
765 }
766 
767 static void unlink_all_urbs(struct esd_usb *dev)
768 {
769 	struct esd_usb_net_priv *priv;
770 	int i, j;
771 
772 	usb_kill_anchored_urbs(&dev->rx_submitted);
773 
774 	for (i = 0; i < ESD_USB_MAX_RX_URBS; ++i)
775 		usb_free_coherent(dev->udev, ESD_USB_RX_BUFFER_SIZE,
776 				  dev->rxbuf[i], dev->rxbuf_dma[i]);
777 
778 	for (i = 0; i < dev->net_count; i++) {
779 		priv = dev->nets[i];
780 		if (priv) {
781 			usb_kill_anchored_urbs(&priv->tx_submitted);
782 			atomic_set(&priv->active_tx_jobs, 0);
783 
784 			for (j = 0; j < ESD_USB_MAX_TX_URBS; j++)
785 				priv->tx_contexts[j].echo_index = ESD_USB_MAX_TX_URBS;
786 		}
787 	}
788 }
789 
790 static int esd_usb_open(struct net_device *netdev)
791 {
792 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
793 	int err;
794 
795 	/* common open */
796 	err = open_candev(netdev);
797 	if (err)
798 		return err;
799 
800 	/* finally start device */
801 	err = esd_usb_start(priv);
802 	if (err) {
803 		netdev_warn(netdev, "couldn't start device: %d\n", err);
804 		close_candev(netdev);
805 		return err;
806 	}
807 
808 	netif_start_queue(netdev);
809 
810 	return 0;
811 }
812 
813 static netdev_tx_t esd_usb_start_xmit(struct sk_buff *skb,
814 				      struct net_device *netdev)
815 {
816 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
817 	struct esd_usb *dev = priv->usb;
818 	struct esd_tx_urb_context *context = NULL;
819 	struct net_device_stats *stats = &netdev->stats;
820 	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
821 	union esd_usb_msg *msg;
822 	struct urb *urb;
823 	u8 *buf;
824 	int i, err;
825 	int ret = NETDEV_TX_OK;
826 	size_t size = sizeof(union esd_usb_msg);
827 
828 	if (can_dev_dropped_skb(netdev, skb))
829 		return NETDEV_TX_OK;
830 
831 	/* create a URB, and a buffer for it, and copy the data to the URB */
832 	urb = usb_alloc_urb(0, GFP_ATOMIC);
833 	if (!urb) {
834 		stats->tx_dropped++;
835 		dev_kfree_skb(skb);
836 		goto nourbmem;
837 	}
838 
839 	buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC,
840 				 &urb->transfer_dma);
841 	if (!buf) {
842 		netdev_err(netdev, "No memory left for USB buffer\n");
843 		stats->tx_dropped++;
844 		dev_kfree_skb(skb);
845 		goto nobufmem;
846 	}
847 
848 	msg = (union esd_usb_msg *)buf;
849 
850 	/* minimal length as # of 32bit words */
851 	msg->hdr.len = offsetof(struct esd_usb_tx_msg, data) / sizeof(u32);
852 	msg->hdr.cmd = ESD_USB_CMD_CAN_TX;
853 	msg->tx.net = priv->index;
854 
855 	if (can_is_canfd_skb(skb)) {
856 		msg->tx.dlc = can_fd_len2dlc(cfd->len);
857 		msg->tx.dlc |= ESD_USB_FD;
858 
859 		if ((cfd->flags & CANFD_BRS) == 0)
860 			msg->tx.dlc |= ESD_USB_NO_BRS;
861 	} else {
862 		msg->tx.dlc = can_get_cc_dlc((struct can_frame *)cfd, priv->can.ctrlmode);
863 
864 		if (cfd->can_id & CAN_RTR_FLAG)
865 			msg->tx.dlc |= ESD_USB_RTR;
866 	}
867 
868 	msg->tx.id = cpu_to_le32(cfd->can_id & CAN_ERR_MASK);
869 
870 	if (cfd->can_id & CAN_EFF_FLAG)
871 		msg->tx.id |= cpu_to_le32(ESD_USB_EXTID);
872 
873 	memcpy(msg->tx.data_fd, cfd->data, cfd->len);
874 
875 	/* round up, then divide by 4 to add the payload length as # of 32bit words */
876 	msg->hdr.len += DIV_ROUND_UP(cfd->len, sizeof(u32));
877 
878 	for (i = 0; i < ESD_USB_MAX_TX_URBS; i++) {
879 		if (priv->tx_contexts[i].echo_index == ESD_USB_MAX_TX_URBS) {
880 			context = &priv->tx_contexts[i];
881 			break;
882 		}
883 	}
884 
885 	/* This may never happen */
886 	if (!context) {
887 		netdev_warn(netdev, "couldn't find free context\n");
888 		ret = NETDEV_TX_BUSY;
889 		goto releasebuf;
890 	}
891 
892 	context->priv = priv;
893 	context->echo_index = i;
894 
895 	/* hnd must not be 0 - MSB is stripped in txdone handling */
896 	msg->tx.hnd = BIT(31) | i; /* returned in TX done message */
897 
898 	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
899 			  msg->hdr.len * sizeof(u32), /* convert to # of bytes */
900 			  esd_usb_write_bulk_callback, context);
901 
902 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
903 
904 	usb_anchor_urb(urb, &priv->tx_submitted);
905 
906 	can_put_echo_skb(skb, netdev, context->echo_index, 0);
907 
908 	atomic_inc(&priv->active_tx_jobs);
909 
910 	/* Slow down tx path */
911 	if (atomic_read(&priv->active_tx_jobs) >= ESD_USB_MAX_TX_URBS)
912 		netif_stop_queue(netdev);
913 
914 	err = usb_submit_urb(urb, GFP_ATOMIC);
915 	if (err) {
916 		can_free_echo_skb(netdev, context->echo_index, NULL);
917 
918 		atomic_dec(&priv->active_tx_jobs);
919 		usb_unanchor_urb(urb);
920 
921 		stats->tx_dropped++;
922 
923 		if (err == -ENODEV)
924 			netif_device_detach(netdev);
925 		else
926 			netdev_warn(netdev, "failed tx_urb %d\n", err);
927 
928 		goto releasebuf;
929 	}
930 
931 	netif_trans_update(netdev);
932 
933 	/* Release our reference to this URB, the USB core will eventually free
934 	 * it entirely.
935 	 */
936 	usb_free_urb(urb);
937 
938 	return NETDEV_TX_OK;
939 
940 releasebuf:
941 	usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
942 
943 nobufmem:
944 	usb_free_urb(urb);
945 
946 nourbmem:
947 	return ret;
948 }
949 
950 static int esd_usb_close(struct net_device *netdev)
951 {
952 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
953 	union esd_usb_msg *msg;
954 	int i;
955 
956 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
957 	if (!msg)
958 		return -ENOMEM;
959 
960 	/* Disable all IDs (see esd_usb_start()) */
961 	msg->hdr.cmd = ESD_USB_CMD_IDADD;
962 	msg->hdr.len = sizeof(struct esd_usb_id_filter_msg) / sizeof(u32);/* # of 32bit words */
963 	msg->filter.net = priv->index;
964 	msg->filter.option = ESD_USB_ID_ENABLE; /* start with segment 0 */
965 	for (i = 0; i <= ESD_USB_MAX_ID_SEGMENT; i++)
966 		msg->filter.mask[i] = 0;
967 	if (esd_usb_send_msg(priv->usb, msg) < 0)
968 		netdev_err(netdev, "sending idadd message failed\n");
969 
970 	/* set CAN controller to reset mode */
971 	msg->hdr.len = sizeof(struct esd_usb_set_baudrate_msg) / sizeof(u32); /* # of 32bit words */
972 	msg->hdr.cmd = ESD_USB_CMD_SETBAUD;
973 	msg->setbaud.net = priv->index;
974 	msg->setbaud.rsvd = 0;
975 	msg->setbaud.baud = cpu_to_le32(ESD_USB_NO_BAUDRATE);
976 	if (esd_usb_send_msg(priv->usb, msg) < 0)
977 		netdev_err(netdev, "sending setbaud message failed\n");
978 
979 	priv->can.state = CAN_STATE_STOPPED;
980 
981 	netif_stop_queue(netdev);
982 
983 	close_candev(netdev);
984 
985 	kfree(msg);
986 
987 	return 0;
988 }
989 
990 static const struct net_device_ops esd_usb_netdev_ops = {
991 	.ndo_open = esd_usb_open,
992 	.ndo_stop = esd_usb_close,
993 	.ndo_start_xmit = esd_usb_start_xmit,
994 	.ndo_change_mtu = can_change_mtu,
995 };
996 
997 static const struct ethtool_ops esd_usb_ethtool_ops = {
998 	.get_ts_info = ethtool_op_get_ts_info,
999 };
1000 
1001 static const struct can_bittiming_const esd_usb_2_bittiming_const = {
1002 	.name = "esd_usb_2",
1003 	.tseg1_min = 1,
1004 	.tseg1_max = 16,
1005 	.tseg2_min = 1,
1006 	.tseg2_max = 8,
1007 	.sjw_max = 4,
1008 	.brp_min = 1,
1009 	.brp_max = 1024,
1010 	.brp_inc = 1,
1011 };
1012 
1013 static int esd_usb_2_set_bittiming(struct net_device *netdev)
1014 {
1015 	const struct can_bittiming_const *btc = &esd_usb_2_bittiming_const;
1016 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
1017 	struct can_bittiming *bt = &priv->can.bittiming;
1018 	union esd_usb_msg *msg;
1019 	int err;
1020 	u32 canbtr;
1021 	int sjw_shift;
1022 
1023 	canbtr = ESD_USB_UBR;
1024 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
1025 		canbtr |= ESD_USB_LOM;
1026 
1027 	canbtr |= (bt->brp - 1) & (btc->brp_max - 1);
1028 
1029 	if (le16_to_cpu(priv->usb->udev->descriptor.idProduct) ==
1030 	    ESD_USB_CANUSBM_PRODUCT_ID)
1031 		sjw_shift = ESD_USB_M_SJW_SHIFT;
1032 	else
1033 		sjw_shift = ESD_USB_2_SJW_SHIFT;
1034 
1035 	canbtr |= ((bt->sjw - 1) & (btc->sjw_max - 1))
1036 		<< sjw_shift;
1037 	canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
1038 		   & (btc->tseg1_max - 1))
1039 		<< ESD_USB_2_TSEG1_SHIFT;
1040 	canbtr |= ((bt->phase_seg2 - 1) & (btc->tseg2_max - 1))
1041 		<< ESD_USB_2_TSEG2_SHIFT;
1042 	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
1043 		canbtr |= ESD_USB_TRIPLE_SAMPLES;
1044 
1045 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
1046 	if (!msg)
1047 		return -ENOMEM;
1048 
1049 	msg->hdr.len = sizeof(struct esd_usb_set_baudrate_msg) / sizeof(u32); /* # of 32bit words */
1050 	msg->hdr.cmd = ESD_USB_CMD_SETBAUD;
1051 	msg->setbaud.net = priv->index;
1052 	msg->setbaud.rsvd = 0;
1053 	msg->setbaud.baud = cpu_to_le32(canbtr);
1054 
1055 	netdev_dbg(netdev, "setting BTR=%#x\n", canbtr);
1056 
1057 	err = esd_usb_send_msg(priv->usb, msg);
1058 
1059 	kfree(msg);
1060 	return err;
1061 }
1062 
1063 /* Nominal bittiming constants, see
1064  * Microchip SAM E70/S70/V70/V71, Data Sheet, Rev. G - 07/2022
1065  * 48.6.8 MCAN Nominal Bit Timing and Prescaler Register
1066  */
1067 static const struct can_bittiming_const esd_usb_3_nom_bittiming_const = {
1068 	.name = "esd_usb_3",
1069 	.tseg1_min = 2,
1070 	.tseg1_max = 256,
1071 	.tseg2_min = 2,
1072 	.tseg2_max = 128,
1073 	.sjw_max = 128,
1074 	.brp_min = 1,
1075 	.brp_max = 512,
1076 	.brp_inc = 1,
1077 };
1078 
1079 /* Data bittiming constants, see
1080  * Microchip SAM E70/S70/V70/V71, Data Sheet, Rev. G - 07/2022
1081  * 48.6.4 MCAN Data Bit Timing and Prescaler Register
1082  */
1083 static const struct can_bittiming_const esd_usb_3_data_bittiming_const = {
1084 	.name = "esd_usb_3",
1085 	.tseg1_min = 2,
1086 	.tseg1_max = 32,
1087 	.tseg2_min = 1,
1088 	.tseg2_max = 16,
1089 	.sjw_max = 8,
1090 	.brp_min = 1,
1091 	.brp_max = 32,
1092 	.brp_inc = 1,
1093 };
1094 
1095 static int esd_usb_3_set_bittiming(struct net_device *netdev)
1096 {
1097 	const struct can_bittiming_const *nom_btc = &esd_usb_3_nom_bittiming_const;
1098 	const struct can_bittiming_const *data_btc = &esd_usb_3_data_bittiming_const;
1099 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
1100 	struct can_bittiming *nom_bt = &priv->can.bittiming;
1101 	struct can_bittiming *data_bt = &priv->can.data_bittiming;
1102 	struct esd_usb_3_set_baudrate_msg_x *baud_x;
1103 	union esd_usb_msg *msg;
1104 	u16 flags = 0;
1105 	int err;
1106 
1107 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
1108 	if (!msg)
1109 		return -ENOMEM;
1110 
1111 	baud_x = &msg->setbaud_x;
1112 
1113 	/* Canonical is the most reasonable mode for SocketCAN on CAN-USB/3 ... */
1114 	baud_x->mode = cpu_to_le16(ESD_USB_3_BAUDRATE_MODE_BTR_CANONICAL);
1115 
1116 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
1117 		flags |= ESD_USB_3_BAUDRATE_FLAG_LOM;
1118 
1119 	baud_x->nom.brp = cpu_to_le16(nom_bt->brp & (nom_btc->brp_max - 1));
1120 	baud_x->nom.sjw = cpu_to_le16(nom_bt->sjw & (nom_btc->sjw_max - 1));
1121 	baud_x->nom.tseg1 = cpu_to_le16((nom_bt->prop_seg + nom_bt->phase_seg1)
1122 					& (nom_btc->tseg1_max - 1));
1123 	baud_x->nom.tseg2 = cpu_to_le16(nom_bt->phase_seg2 & (nom_btc->tseg2_max - 1));
1124 
1125 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1126 		baud_x->data.brp = cpu_to_le16(data_bt->brp & (data_btc->brp_max - 1));
1127 		baud_x->data.sjw = cpu_to_le16(data_bt->sjw & (data_btc->sjw_max - 1));
1128 		baud_x->data.tseg1 = cpu_to_le16((data_bt->prop_seg + data_bt->phase_seg1)
1129 						 & (data_btc->tseg1_max - 1));
1130 		baud_x->data.tseg2 = cpu_to_le16(data_bt->phase_seg2 & (data_btc->tseg2_max - 1));
1131 		flags |= ESD_USB_3_BAUDRATE_FLAG_FD;
1132 	}
1133 
1134 	/* Currently this driver only supports the automatic TDC mode */
1135 	baud_x->tdc.tdc_mode = ESD_USB_3_TDC_MODE_AUTO;
1136 	baud_x->tdc.ssp_offset = 0;
1137 	baud_x->tdc.ssp_shift = 0;
1138 	baud_x->tdc.tdc_filter = 0;
1139 
1140 	baud_x->flags = cpu_to_le16(flags);
1141 	baud_x->net = priv->index;
1142 	baud_x->rsvd = 0;
1143 
1144 	/* set len as # of 32bit words */
1145 	msg->hdr.len = sizeof(struct esd_usb_3_set_baudrate_msg_x) / sizeof(u32);
1146 	msg->hdr.cmd = ESD_USB_CMD_SETBAUD;
1147 
1148 	netdev_dbg(netdev,
1149 		   "ctrlmode=%#x/%#x, esd-net=%u, esd-mode=%#x, esd-flags=%#x\n",
1150 		   priv->can.ctrlmode, priv->can.ctrlmode_supported,
1151 		   priv->index, le16_to_cpu(baud_x->mode), flags);
1152 
1153 	err = esd_usb_send_msg(priv->usb, msg);
1154 
1155 	kfree(msg);
1156 	return err;
1157 }
1158 
1159 static int esd_usb_get_berr_counter(const struct net_device *netdev,
1160 				    struct can_berr_counter *bec)
1161 {
1162 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
1163 
1164 	bec->txerr = priv->bec.txerr;
1165 	bec->rxerr = priv->bec.rxerr;
1166 
1167 	return 0;
1168 }
1169 
1170 static int esd_usb_set_mode(struct net_device *netdev, enum can_mode mode)
1171 {
1172 	switch (mode) {
1173 	case CAN_MODE_START:
1174 		netif_wake_queue(netdev);
1175 		break;
1176 
1177 	default:
1178 		return -EOPNOTSUPP;
1179 	}
1180 
1181 	return 0;
1182 }
1183 
1184 static int esd_usb_probe_one_net(struct usb_interface *intf, int index)
1185 {
1186 	struct esd_usb *dev = usb_get_intfdata(intf);
1187 	struct net_device *netdev;
1188 	struct esd_usb_net_priv *priv;
1189 	int err = 0;
1190 	int i;
1191 
1192 	netdev = alloc_candev(sizeof(*priv), ESD_USB_MAX_TX_URBS);
1193 	if (!netdev) {
1194 		dev_err(&intf->dev, "couldn't alloc candev\n");
1195 		err = -ENOMEM;
1196 		goto done;
1197 	}
1198 
1199 	priv = netdev_priv(netdev);
1200 
1201 	init_usb_anchor(&priv->tx_submitted);
1202 	atomic_set(&priv->active_tx_jobs, 0);
1203 
1204 	for (i = 0; i < ESD_USB_MAX_TX_URBS; i++)
1205 		priv->tx_contexts[i].echo_index = ESD_USB_MAX_TX_URBS;
1206 
1207 	priv->usb = dev;
1208 	priv->netdev = netdev;
1209 	priv->index = index;
1210 
1211 	priv->can.state = CAN_STATE_STOPPED;
1212 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY |
1213 		CAN_CTRLMODE_CC_LEN8_DLC |
1214 		CAN_CTRLMODE_BERR_REPORTING;
1215 
1216 	switch (le16_to_cpu(dev->udev->descriptor.idProduct)) {
1217 	case ESD_USB_CANUSB3_PRODUCT_ID:
1218 		priv->can.clock.freq = ESD_USB_3_CAN_CLOCK;
1219 		priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
1220 		priv->can.bittiming_const = &esd_usb_3_nom_bittiming_const;
1221 		priv->can.data_bittiming_const = &esd_usb_3_data_bittiming_const;
1222 		priv->can.do_set_bittiming = esd_usb_3_set_bittiming;
1223 		priv->can.do_set_data_bittiming = esd_usb_3_set_bittiming;
1224 		break;
1225 
1226 	case ESD_USB_CANUSBM_PRODUCT_ID:
1227 		priv->can.clock.freq = ESD_USB_M_CAN_CLOCK;
1228 		priv->can.bittiming_const = &esd_usb_2_bittiming_const;
1229 		priv->can.do_set_bittiming = esd_usb_2_set_bittiming;
1230 		break;
1231 
1232 	case ESD_USB_CANUSB2_PRODUCT_ID:
1233 	default:
1234 		priv->can.clock.freq = ESD_USB_2_CAN_CLOCK;
1235 		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1236 		priv->can.bittiming_const = &esd_usb_2_bittiming_const;
1237 		priv->can.do_set_bittiming = esd_usb_2_set_bittiming;
1238 		break;
1239 	}
1240 
1241 	priv->can.do_set_mode = esd_usb_set_mode;
1242 	priv->can.do_get_berr_counter = esd_usb_get_berr_counter;
1243 
1244 	netdev->flags |= IFF_ECHO; /* we support local echo */
1245 
1246 	netdev->netdev_ops = &esd_usb_netdev_ops;
1247 	netdev->ethtool_ops = &esd_usb_ethtool_ops;
1248 
1249 	SET_NETDEV_DEV(netdev, &intf->dev);
1250 	netdev->dev_id = index;
1251 
1252 	err = register_candev(netdev);
1253 	if (err) {
1254 		dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
1255 		free_candev(netdev);
1256 		err = -ENOMEM;
1257 		goto done;
1258 	}
1259 
1260 	dev->nets[index] = priv;
1261 	netdev_info(netdev, "device %s registered\n", netdev->name);
1262 
1263 done:
1264 	return err;
1265 }
1266 
1267 /* probe function for new USB devices
1268  *
1269  * check version information and number of available
1270  * CAN interfaces
1271  */
1272 static int esd_usb_probe(struct usb_interface *intf,
1273 			 const struct usb_device_id *id)
1274 {
1275 	struct esd_usb *dev;
1276 	union esd_usb_msg *msg;
1277 	int i, err;
1278 
1279 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1280 	if (!dev) {
1281 		err = -ENOMEM;
1282 		goto done;
1283 	}
1284 
1285 	dev->udev = interface_to_usbdev(intf);
1286 
1287 	init_usb_anchor(&dev->rx_submitted);
1288 
1289 	usb_set_intfdata(intf, dev);
1290 
1291 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
1292 	if (!msg) {
1293 		err = -ENOMEM;
1294 		goto free_msg;
1295 	}
1296 
1297 	/* query number of CAN interfaces (nets) */
1298 	msg->hdr.cmd = ESD_USB_CMD_VERSION;
1299 	msg->hdr.len = sizeof(struct esd_usb_version_msg) / sizeof(u32); /* # of 32bit words */
1300 	msg->version.rsvd = 0;
1301 	msg->version.flags = 0;
1302 	msg->version.drv_version = 0;
1303 
1304 	err = esd_usb_send_msg(dev, msg);
1305 	if (err < 0) {
1306 		dev_err(&intf->dev, "sending version message failed\n");
1307 		goto free_msg;
1308 	}
1309 
1310 	err = esd_usb_wait_msg(dev, msg);
1311 	if (err < 0) {
1312 		dev_err(&intf->dev, "no version message answer\n");
1313 		goto free_msg;
1314 	}
1315 
1316 	dev->net_count = (int)msg->version_reply.nets;
1317 	dev->version = le32_to_cpu(msg->version_reply.version);
1318 
1319 	if (device_create_file(&intf->dev, &dev_attr_firmware))
1320 		dev_err(&intf->dev,
1321 			"Couldn't create device file for firmware\n");
1322 
1323 	if (device_create_file(&intf->dev, &dev_attr_hardware))
1324 		dev_err(&intf->dev,
1325 			"Couldn't create device file for hardware\n");
1326 
1327 	if (device_create_file(&intf->dev, &dev_attr_nets))
1328 		dev_err(&intf->dev,
1329 			"Couldn't create device file for nets\n");
1330 
1331 	/* do per device probing */
1332 	for (i = 0; i < dev->net_count; i++)
1333 		esd_usb_probe_one_net(intf, i);
1334 
1335 free_msg:
1336 	kfree(msg);
1337 	if (err)
1338 		kfree(dev);
1339 done:
1340 	return err;
1341 }
1342 
1343 /* called by the usb core when the device is removed from the system */
1344 static void esd_usb_disconnect(struct usb_interface *intf)
1345 {
1346 	struct esd_usb *dev = usb_get_intfdata(intf);
1347 	struct net_device *netdev;
1348 	int i;
1349 
1350 	device_remove_file(&intf->dev, &dev_attr_firmware);
1351 	device_remove_file(&intf->dev, &dev_attr_hardware);
1352 	device_remove_file(&intf->dev, &dev_attr_nets);
1353 
1354 	usb_set_intfdata(intf, NULL);
1355 
1356 	if (dev) {
1357 		for (i = 0; i < dev->net_count; i++) {
1358 			if (dev->nets[i]) {
1359 				netdev = dev->nets[i]->netdev;
1360 				unregister_netdev(netdev);
1361 				free_candev(netdev);
1362 			}
1363 		}
1364 		unlink_all_urbs(dev);
1365 		kfree(dev);
1366 	}
1367 }
1368 
1369 /* usb specific object needed to register this driver with the usb subsystem */
1370 static struct usb_driver esd_usb_driver = {
1371 	.name = KBUILD_MODNAME,
1372 	.probe = esd_usb_probe,
1373 	.disconnect = esd_usb_disconnect,
1374 	.id_table = esd_usb_table,
1375 };
1376 
1377 module_usb_driver(esd_usb_driver);
1378