xref: /linux/drivers/net/can/usb/esd_usb.c (revision 9f2c9170934eace462499ba0bfe042cc72900173)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * CAN driver for esd electronics gmbh CAN-USB/2 and CAN-USB/Micro
4  *
5  * Copyright (C) 2010-2012 esd electronic system design gmbh, Matthias Fuchs <socketcan@esd.eu>
6  * Copyright (C) 2022 esd electronics gmbh, Frank Jungclaus <frank.jungclaus@esd.eu>
7  */
8 #include <linux/ethtool.h>
9 #include <linux/signal.h>
10 #include <linux/slab.h>
11 #include <linux/module.h>
12 #include <linux/netdevice.h>
13 #include <linux/usb.h>
14 
15 #include <linux/can.h>
16 #include <linux/can/dev.h>
17 #include <linux/can/error.h>
18 
19 MODULE_AUTHOR("Matthias Fuchs <socketcan@esd.eu>");
20 MODULE_AUTHOR("Frank Jungclaus <frank.jungclaus@esd.eu>");
21 MODULE_DESCRIPTION("CAN driver for esd electronics gmbh CAN-USB/2 and CAN-USB/Micro interfaces");
22 MODULE_LICENSE("GPL v2");
23 
24 /* USB vendor and product ID */
25 #define USB_ESDGMBH_VENDOR_ID	0x0ab4
26 #define USB_CANUSB2_PRODUCT_ID	0x0010
27 #define USB_CANUSBM_PRODUCT_ID	0x0011
28 
29 /* CAN controller clock frequencies */
30 #define ESD_USB2_CAN_CLOCK	60000000
31 #define ESD_USBM_CAN_CLOCK	36000000
32 
33 /* Maximum number of CAN nets */
34 #define ESD_USB_MAX_NETS	2
35 
36 /* USB commands */
37 #define CMD_VERSION		1 /* also used for VERSION_REPLY */
38 #define CMD_CAN_RX		2 /* device to host only */
39 #define CMD_CAN_TX		3 /* also used for TX_DONE */
40 #define CMD_SETBAUD		4 /* also used for SETBAUD_REPLY */
41 #define CMD_TS			5 /* also used for TS_REPLY */
42 #define CMD_IDADD		6 /* also used for IDADD_REPLY */
43 
44 /* esd CAN message flags - dlc field */
45 #define ESD_RTR			0x10
46 
47 /* esd CAN message flags - id field */
48 #define ESD_EXTID		0x20000000
49 #define ESD_EVENT		0x40000000
50 #define ESD_IDMASK		0x1fffffff
51 
52 /* esd CAN event ids */
53 #define ESD_EV_CAN_ERROR_EXT	2 /* CAN controller specific diagnostic data */
54 
55 /* baudrate message flags */
56 #define ESD_USB_UBR		0x80000000
57 #define ESD_USB_LOM		0x40000000
58 #define ESD_USB_NO_BAUDRATE	0x7fffffff
59 
60 /* bit timing CAN-USB/2 */
61 #define ESD_USB2_TSEG1_MIN	1
62 #define ESD_USB2_TSEG1_MAX	16
63 #define ESD_USB2_TSEG1_SHIFT	16
64 #define ESD_USB2_TSEG2_MIN	1
65 #define ESD_USB2_TSEG2_MAX	8
66 #define ESD_USB2_TSEG2_SHIFT	20
67 #define ESD_USB2_SJW_MAX	4
68 #define ESD_USB2_SJW_SHIFT	14
69 #define ESD_USBM_SJW_SHIFT	24
70 #define ESD_USB2_BRP_MIN	1
71 #define ESD_USB2_BRP_MAX	1024
72 #define ESD_USB2_BRP_INC	1
73 #define ESD_USB2_3_SAMPLES	0x00800000
74 
75 /* esd IDADD message */
76 #define ESD_ID_ENABLE		0x80
77 #define ESD_MAX_ID_SEGMENT	64
78 
79 /* SJA1000 ECC register (emulated by usb firmware) */
80 #define SJA1000_ECC_SEG		0x1F
81 #define SJA1000_ECC_DIR		0x20
82 #define SJA1000_ECC_ERR		0x06
83 #define SJA1000_ECC_BIT		0x00
84 #define SJA1000_ECC_FORM	0x40
85 #define SJA1000_ECC_STUFF	0x80
86 #define SJA1000_ECC_MASK	0xc0
87 
88 /* esd bus state event codes */
89 #define ESD_BUSSTATE_MASK	0xc0
90 #define ESD_BUSSTATE_WARN	0x40
91 #define ESD_BUSSTATE_ERRPASSIVE	0x80
92 #define ESD_BUSSTATE_BUSOFF	0xc0
93 
94 #define RX_BUFFER_SIZE		1024
95 #define MAX_RX_URBS		4
96 #define MAX_TX_URBS		16 /* must be power of 2 */
97 
98 struct header_msg {
99 	u8 len; /* len is always the total message length in 32bit words */
100 	u8 cmd;
101 	u8 rsvd[2];
102 };
103 
104 struct version_msg {
105 	u8 len;
106 	u8 cmd;
107 	u8 rsvd;
108 	u8 flags;
109 	__le32 drv_version;
110 };
111 
112 struct version_reply_msg {
113 	u8 len;
114 	u8 cmd;
115 	u8 nets;
116 	u8 features;
117 	__le32 version;
118 	u8 name[16];
119 	__le32 rsvd;
120 	__le32 ts;
121 };
122 
123 struct rx_msg {
124 	u8 len;
125 	u8 cmd;
126 	u8 net;
127 	u8 dlc;
128 	__le32 ts;
129 	__le32 id; /* upper 3 bits contain flags */
130 	u8 data[8];
131 };
132 
133 struct tx_msg {
134 	u8 len;
135 	u8 cmd;
136 	u8 net;
137 	u8 dlc;
138 	u32 hnd;	/* opaque handle, not used by device */
139 	__le32 id; /* upper 3 bits contain flags */
140 	u8 data[8];
141 };
142 
143 struct tx_done_msg {
144 	u8 len;
145 	u8 cmd;
146 	u8 net;
147 	u8 status;
148 	u32 hnd;	/* opaque handle, not used by device */
149 	__le32 ts;
150 };
151 
152 struct id_filter_msg {
153 	u8 len;
154 	u8 cmd;
155 	u8 net;
156 	u8 option;
157 	__le32 mask[ESD_MAX_ID_SEGMENT + 1];
158 };
159 
160 struct set_baudrate_msg {
161 	u8 len;
162 	u8 cmd;
163 	u8 net;
164 	u8 rsvd;
165 	__le32 baud;
166 };
167 
168 /* Main message type used between library and application */
169 struct __packed esd_usb_msg {
170 	union {
171 		struct header_msg hdr;
172 		struct version_msg version;
173 		struct version_reply_msg version_reply;
174 		struct rx_msg rx;
175 		struct tx_msg tx;
176 		struct tx_done_msg txdone;
177 		struct set_baudrate_msg setbaud;
178 		struct id_filter_msg filter;
179 	} msg;
180 };
181 
182 static struct usb_device_id esd_usb_table[] = {
183 	{USB_DEVICE(USB_ESDGMBH_VENDOR_ID, USB_CANUSB2_PRODUCT_ID)},
184 	{USB_DEVICE(USB_ESDGMBH_VENDOR_ID, USB_CANUSBM_PRODUCT_ID)},
185 	{}
186 };
187 MODULE_DEVICE_TABLE(usb, esd_usb_table);
188 
189 struct esd_usb_net_priv;
190 
191 struct esd_tx_urb_context {
192 	struct esd_usb_net_priv *priv;
193 	u32 echo_index;
194 };
195 
196 struct esd_usb {
197 	struct usb_device *udev;
198 	struct esd_usb_net_priv *nets[ESD_USB_MAX_NETS];
199 
200 	struct usb_anchor rx_submitted;
201 
202 	int net_count;
203 	u32 version;
204 	int rxinitdone;
205 	void *rxbuf[MAX_RX_URBS];
206 	dma_addr_t rxbuf_dma[MAX_RX_URBS];
207 };
208 
209 struct esd_usb_net_priv {
210 	struct can_priv can; /* must be the first member */
211 
212 	atomic_t active_tx_jobs;
213 	struct usb_anchor tx_submitted;
214 	struct esd_tx_urb_context tx_contexts[MAX_TX_URBS];
215 
216 	struct esd_usb *usb;
217 	struct net_device *netdev;
218 	int index;
219 	u8 old_state;
220 	struct can_berr_counter bec;
221 };
222 
223 static void esd_usb_rx_event(struct esd_usb_net_priv *priv,
224 			     struct esd_usb_msg *msg)
225 {
226 	struct net_device_stats *stats = &priv->netdev->stats;
227 	struct can_frame *cf;
228 	struct sk_buff *skb;
229 	u32 id = le32_to_cpu(msg->msg.rx.id) & ESD_IDMASK;
230 
231 	if (id == ESD_EV_CAN_ERROR_EXT) {
232 		u8 state = msg->msg.rx.data[0];
233 		u8 ecc = msg->msg.rx.data[1];
234 		u8 rxerr = msg->msg.rx.data[2];
235 		u8 txerr = msg->msg.rx.data[3];
236 
237 		netdev_dbg(priv->netdev,
238 			   "CAN_ERR_EV_EXT: dlc=%#02x state=%02x ecc=%02x rec=%02x tec=%02x\n",
239 			   msg->msg.rx.dlc, state, ecc, rxerr, txerr);
240 
241 		skb = alloc_can_err_skb(priv->netdev, &cf);
242 		if (skb == NULL) {
243 			stats->rx_dropped++;
244 			return;
245 		}
246 
247 		if (state != priv->old_state) {
248 			priv->old_state = state;
249 
250 			switch (state & ESD_BUSSTATE_MASK) {
251 			case ESD_BUSSTATE_BUSOFF:
252 				priv->can.state = CAN_STATE_BUS_OFF;
253 				cf->can_id |= CAN_ERR_BUSOFF;
254 				priv->can.can_stats.bus_off++;
255 				can_bus_off(priv->netdev);
256 				break;
257 			case ESD_BUSSTATE_WARN:
258 				priv->can.state = CAN_STATE_ERROR_WARNING;
259 				priv->can.can_stats.error_warning++;
260 				break;
261 			case ESD_BUSSTATE_ERRPASSIVE:
262 				priv->can.state = CAN_STATE_ERROR_PASSIVE;
263 				priv->can.can_stats.error_passive++;
264 				break;
265 			default:
266 				priv->can.state = CAN_STATE_ERROR_ACTIVE;
267 				txerr = 0;
268 				rxerr = 0;
269 				break;
270 			}
271 		} else {
272 			priv->can.can_stats.bus_error++;
273 			stats->rx_errors++;
274 
275 			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR |
276 				      CAN_ERR_CNT;
277 
278 			switch (ecc & SJA1000_ECC_MASK) {
279 			case SJA1000_ECC_BIT:
280 				cf->data[2] |= CAN_ERR_PROT_BIT;
281 				break;
282 			case SJA1000_ECC_FORM:
283 				cf->data[2] |= CAN_ERR_PROT_FORM;
284 				break;
285 			case SJA1000_ECC_STUFF:
286 				cf->data[2] |= CAN_ERR_PROT_STUFF;
287 				break;
288 			default:
289 				cf->data[3] = ecc & SJA1000_ECC_SEG;
290 				break;
291 			}
292 
293 			/* Error occurred during transmission? */
294 			if (!(ecc & SJA1000_ECC_DIR))
295 				cf->data[2] |= CAN_ERR_PROT_TX;
296 
297 			if (priv->can.state == CAN_STATE_ERROR_WARNING ||
298 			    priv->can.state == CAN_STATE_ERROR_PASSIVE) {
299 				cf->data[1] = (txerr > rxerr) ?
300 					CAN_ERR_CRTL_TX_PASSIVE :
301 					CAN_ERR_CRTL_RX_PASSIVE;
302 			}
303 			cf->data[6] = txerr;
304 			cf->data[7] = rxerr;
305 		}
306 
307 		priv->bec.txerr = txerr;
308 		priv->bec.rxerr = rxerr;
309 
310 		netif_rx(skb);
311 	}
312 }
313 
314 static void esd_usb_rx_can_msg(struct esd_usb_net_priv *priv,
315 			       struct esd_usb_msg *msg)
316 {
317 	struct net_device_stats *stats = &priv->netdev->stats;
318 	struct can_frame *cf;
319 	struct sk_buff *skb;
320 	int i;
321 	u32 id;
322 
323 	if (!netif_device_present(priv->netdev))
324 		return;
325 
326 	id = le32_to_cpu(msg->msg.rx.id);
327 
328 	if (id & ESD_EVENT) {
329 		esd_usb_rx_event(priv, msg);
330 	} else {
331 		skb = alloc_can_skb(priv->netdev, &cf);
332 		if (skb == NULL) {
333 			stats->rx_dropped++;
334 			return;
335 		}
336 
337 		cf->can_id = id & ESD_IDMASK;
338 		can_frame_set_cc_len(cf, msg->msg.rx.dlc & ~ESD_RTR,
339 				     priv->can.ctrlmode);
340 
341 		if (id & ESD_EXTID)
342 			cf->can_id |= CAN_EFF_FLAG;
343 
344 		if (msg->msg.rx.dlc & ESD_RTR) {
345 			cf->can_id |= CAN_RTR_FLAG;
346 		} else {
347 			for (i = 0; i < cf->len; i++)
348 				cf->data[i] = msg->msg.rx.data[i];
349 
350 			stats->rx_bytes += cf->len;
351 		}
352 		stats->rx_packets++;
353 
354 		netif_rx(skb);
355 	}
356 }
357 
358 static void esd_usb_tx_done_msg(struct esd_usb_net_priv *priv,
359 				struct esd_usb_msg *msg)
360 {
361 	struct net_device_stats *stats = &priv->netdev->stats;
362 	struct net_device *netdev = priv->netdev;
363 	struct esd_tx_urb_context *context;
364 
365 	if (!netif_device_present(netdev))
366 		return;
367 
368 	context = &priv->tx_contexts[msg->msg.txdone.hnd & (MAX_TX_URBS - 1)];
369 
370 	if (!msg->msg.txdone.status) {
371 		stats->tx_packets++;
372 		stats->tx_bytes += can_get_echo_skb(netdev, context->echo_index,
373 						    NULL);
374 	} else {
375 		stats->tx_errors++;
376 		can_free_echo_skb(netdev, context->echo_index, NULL);
377 	}
378 
379 	/* Release context */
380 	context->echo_index = MAX_TX_URBS;
381 	atomic_dec(&priv->active_tx_jobs);
382 
383 	netif_wake_queue(netdev);
384 }
385 
386 static void esd_usb_read_bulk_callback(struct urb *urb)
387 {
388 	struct esd_usb *dev = urb->context;
389 	int retval;
390 	int pos = 0;
391 	int i;
392 
393 	switch (urb->status) {
394 	case 0: /* success */
395 		break;
396 
397 	case -ENOENT:
398 	case -EPIPE:
399 	case -EPROTO:
400 	case -ESHUTDOWN:
401 		return;
402 
403 	default:
404 		dev_info(dev->udev->dev.parent,
405 			 "Rx URB aborted (%d)\n", urb->status);
406 		goto resubmit_urb;
407 	}
408 
409 	while (pos < urb->actual_length) {
410 		struct esd_usb_msg *msg;
411 
412 		msg = (struct esd_usb_msg *)(urb->transfer_buffer + pos);
413 
414 		switch (msg->msg.hdr.cmd) {
415 		case CMD_CAN_RX:
416 			if (msg->msg.rx.net >= dev->net_count) {
417 				dev_err(dev->udev->dev.parent, "format error\n");
418 				break;
419 			}
420 
421 			esd_usb_rx_can_msg(dev->nets[msg->msg.rx.net], msg);
422 			break;
423 
424 		case CMD_CAN_TX:
425 			if (msg->msg.txdone.net >= dev->net_count) {
426 				dev_err(dev->udev->dev.parent, "format error\n");
427 				break;
428 			}
429 
430 			esd_usb_tx_done_msg(dev->nets[msg->msg.txdone.net],
431 					    msg);
432 			break;
433 		}
434 
435 		pos += msg->msg.hdr.len << 2;
436 
437 		if (pos > urb->actual_length) {
438 			dev_err(dev->udev->dev.parent, "format error\n");
439 			break;
440 		}
441 	}
442 
443 resubmit_urb:
444 	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
445 			  urb->transfer_buffer, RX_BUFFER_SIZE,
446 			  esd_usb_read_bulk_callback, dev);
447 
448 	retval = usb_submit_urb(urb, GFP_ATOMIC);
449 	if (retval == -ENODEV) {
450 		for (i = 0; i < dev->net_count; i++) {
451 			if (dev->nets[i])
452 				netif_device_detach(dev->nets[i]->netdev);
453 		}
454 	} else if (retval) {
455 		dev_err(dev->udev->dev.parent,
456 			"failed resubmitting read bulk urb: %d\n", retval);
457 	}
458 }
459 
460 /* callback for bulk IN urb */
461 static void esd_usb_write_bulk_callback(struct urb *urb)
462 {
463 	struct esd_tx_urb_context *context = urb->context;
464 	struct esd_usb_net_priv *priv;
465 	struct net_device *netdev;
466 	size_t size = sizeof(struct esd_usb_msg);
467 
468 	WARN_ON(!context);
469 
470 	priv = context->priv;
471 	netdev = priv->netdev;
472 
473 	/* free up our allocated buffer */
474 	usb_free_coherent(urb->dev, size,
475 			  urb->transfer_buffer, urb->transfer_dma);
476 
477 	if (!netif_device_present(netdev))
478 		return;
479 
480 	if (urb->status)
481 		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
482 
483 	netif_trans_update(netdev);
484 }
485 
486 static ssize_t firmware_show(struct device *d,
487 			     struct device_attribute *attr, char *buf)
488 {
489 	struct usb_interface *intf = to_usb_interface(d);
490 	struct esd_usb *dev = usb_get_intfdata(intf);
491 
492 	return sprintf(buf, "%d.%d.%d\n",
493 		       (dev->version >> 12) & 0xf,
494 		       (dev->version >> 8) & 0xf,
495 		       dev->version & 0xff);
496 }
497 static DEVICE_ATTR_RO(firmware);
498 
499 static ssize_t hardware_show(struct device *d,
500 			     struct device_attribute *attr, char *buf)
501 {
502 	struct usb_interface *intf = to_usb_interface(d);
503 	struct esd_usb *dev = usb_get_intfdata(intf);
504 
505 	return sprintf(buf, "%d.%d.%d\n",
506 		       (dev->version >> 28) & 0xf,
507 		       (dev->version >> 24) & 0xf,
508 		       (dev->version >> 16) & 0xff);
509 }
510 static DEVICE_ATTR_RO(hardware);
511 
512 static ssize_t nets_show(struct device *d,
513 			 struct device_attribute *attr, char *buf)
514 {
515 	struct usb_interface *intf = to_usb_interface(d);
516 	struct esd_usb *dev = usb_get_intfdata(intf);
517 
518 	return sprintf(buf, "%d", dev->net_count);
519 }
520 static DEVICE_ATTR_RO(nets);
521 
522 static int esd_usb_send_msg(struct esd_usb *dev, struct esd_usb_msg *msg)
523 {
524 	int actual_length;
525 
526 	return usb_bulk_msg(dev->udev,
527 			    usb_sndbulkpipe(dev->udev, 2),
528 			    msg,
529 			    msg->msg.hdr.len << 2,
530 			    &actual_length,
531 			    1000);
532 }
533 
534 static int esd_usb_wait_msg(struct esd_usb *dev,
535 			    struct esd_usb_msg *msg)
536 {
537 	int actual_length;
538 
539 	return usb_bulk_msg(dev->udev,
540 			    usb_rcvbulkpipe(dev->udev, 1),
541 			    msg,
542 			    sizeof(*msg),
543 			    &actual_length,
544 			    1000);
545 }
546 
547 static int esd_usb_setup_rx_urbs(struct esd_usb *dev)
548 {
549 	int i, err = 0;
550 
551 	if (dev->rxinitdone)
552 		return 0;
553 
554 	for (i = 0; i < MAX_RX_URBS; i++) {
555 		struct urb *urb = NULL;
556 		u8 *buf = NULL;
557 		dma_addr_t buf_dma;
558 
559 		/* create a URB, and a buffer for it */
560 		urb = usb_alloc_urb(0, GFP_KERNEL);
561 		if (!urb) {
562 			err = -ENOMEM;
563 			break;
564 		}
565 
566 		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
567 					 &buf_dma);
568 		if (!buf) {
569 			dev_warn(dev->udev->dev.parent,
570 				 "No memory left for USB buffer\n");
571 			err = -ENOMEM;
572 			goto freeurb;
573 		}
574 
575 		urb->transfer_dma = buf_dma;
576 
577 		usb_fill_bulk_urb(urb, dev->udev,
578 				  usb_rcvbulkpipe(dev->udev, 1),
579 				  buf, RX_BUFFER_SIZE,
580 				  esd_usb_read_bulk_callback, dev);
581 		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
582 		usb_anchor_urb(urb, &dev->rx_submitted);
583 
584 		err = usb_submit_urb(urb, GFP_KERNEL);
585 		if (err) {
586 			usb_unanchor_urb(urb);
587 			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
588 					  urb->transfer_dma);
589 			goto freeurb;
590 		}
591 
592 		dev->rxbuf[i] = buf;
593 		dev->rxbuf_dma[i] = buf_dma;
594 
595 freeurb:
596 		/* Drop reference, USB core will take care of freeing it */
597 		usb_free_urb(urb);
598 		if (err)
599 			break;
600 	}
601 
602 	/* Did we submit any URBs */
603 	if (i == 0) {
604 		dev_err(dev->udev->dev.parent, "couldn't setup read URBs\n");
605 		return err;
606 	}
607 
608 	/* Warn if we've couldn't transmit all the URBs */
609 	if (i < MAX_RX_URBS) {
610 		dev_warn(dev->udev->dev.parent,
611 			 "rx performance may be slow\n");
612 	}
613 
614 	dev->rxinitdone = 1;
615 	return 0;
616 }
617 
618 /* Start interface */
619 static int esd_usb_start(struct esd_usb_net_priv *priv)
620 {
621 	struct esd_usb *dev = priv->usb;
622 	struct net_device *netdev = priv->netdev;
623 	struct esd_usb_msg *msg;
624 	int err, i;
625 
626 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
627 	if (!msg) {
628 		err = -ENOMEM;
629 		goto out;
630 	}
631 
632 	/* Enable all IDs
633 	 * The IDADD message takes up to 64 32 bit bitmasks (2048 bits).
634 	 * Each bit represents one 11 bit CAN identifier. A set bit
635 	 * enables reception of the corresponding CAN identifier. A cleared
636 	 * bit disabled this identifier. An additional bitmask value
637 	 * following the CAN 2.0A bits is used to enable reception of
638 	 * extended CAN frames. Only the LSB of this final mask is checked
639 	 * for the complete 29 bit ID range. The IDADD message also allows
640 	 * filter configuration for an ID subset. In this case you can add
641 	 * the number of the starting bitmask (0..64) to the filter.option
642 	 * field followed by only some bitmasks.
643 	 */
644 	msg->msg.hdr.cmd = CMD_IDADD;
645 	msg->msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
646 	msg->msg.filter.net = priv->index;
647 	msg->msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
648 	for (i = 0; i < ESD_MAX_ID_SEGMENT; i++)
649 		msg->msg.filter.mask[i] = cpu_to_le32(0xffffffff);
650 	/* enable 29bit extended IDs */
651 	msg->msg.filter.mask[ESD_MAX_ID_SEGMENT] = cpu_to_le32(0x00000001);
652 
653 	err = esd_usb_send_msg(dev, msg);
654 	if (err)
655 		goto out;
656 
657 	err = esd_usb_setup_rx_urbs(dev);
658 	if (err)
659 		goto out;
660 
661 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
662 
663 out:
664 	if (err == -ENODEV)
665 		netif_device_detach(netdev);
666 	if (err)
667 		netdev_err(netdev, "couldn't start device: %d\n", err);
668 
669 	kfree(msg);
670 	return err;
671 }
672 
673 static void unlink_all_urbs(struct esd_usb *dev)
674 {
675 	struct esd_usb_net_priv *priv;
676 	int i, j;
677 
678 	usb_kill_anchored_urbs(&dev->rx_submitted);
679 
680 	for (i = 0; i < MAX_RX_URBS; ++i)
681 		usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
682 				  dev->rxbuf[i], dev->rxbuf_dma[i]);
683 
684 	for (i = 0; i < dev->net_count; i++) {
685 		priv = dev->nets[i];
686 		if (priv) {
687 			usb_kill_anchored_urbs(&priv->tx_submitted);
688 			atomic_set(&priv->active_tx_jobs, 0);
689 
690 			for (j = 0; j < MAX_TX_URBS; j++)
691 				priv->tx_contexts[j].echo_index = MAX_TX_URBS;
692 		}
693 	}
694 }
695 
696 static int esd_usb_open(struct net_device *netdev)
697 {
698 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
699 	int err;
700 
701 	/* common open */
702 	err = open_candev(netdev);
703 	if (err)
704 		return err;
705 
706 	/* finally start device */
707 	err = esd_usb_start(priv);
708 	if (err) {
709 		netdev_warn(netdev, "couldn't start device: %d\n", err);
710 		close_candev(netdev);
711 		return err;
712 	}
713 
714 	netif_start_queue(netdev);
715 
716 	return 0;
717 }
718 
719 static netdev_tx_t esd_usb_start_xmit(struct sk_buff *skb,
720 				      struct net_device *netdev)
721 {
722 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
723 	struct esd_usb *dev = priv->usb;
724 	struct esd_tx_urb_context *context = NULL;
725 	struct net_device_stats *stats = &netdev->stats;
726 	struct can_frame *cf = (struct can_frame *)skb->data;
727 	struct esd_usb_msg *msg;
728 	struct urb *urb;
729 	u8 *buf;
730 	int i, err;
731 	int ret = NETDEV_TX_OK;
732 	size_t size = sizeof(struct esd_usb_msg);
733 
734 	if (can_dev_dropped_skb(netdev, skb))
735 		return NETDEV_TX_OK;
736 
737 	/* create a URB, and a buffer for it, and copy the data to the URB */
738 	urb = usb_alloc_urb(0, GFP_ATOMIC);
739 	if (!urb) {
740 		stats->tx_dropped++;
741 		dev_kfree_skb(skb);
742 		goto nourbmem;
743 	}
744 
745 	buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC,
746 				 &urb->transfer_dma);
747 	if (!buf) {
748 		netdev_err(netdev, "No memory left for USB buffer\n");
749 		stats->tx_dropped++;
750 		dev_kfree_skb(skb);
751 		goto nobufmem;
752 	}
753 
754 	msg = (struct esd_usb_msg *)buf;
755 
756 	msg->msg.hdr.len = 3; /* minimal length */
757 	msg->msg.hdr.cmd = CMD_CAN_TX;
758 	msg->msg.tx.net = priv->index;
759 	msg->msg.tx.dlc = can_get_cc_dlc(cf, priv->can.ctrlmode);
760 	msg->msg.tx.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
761 
762 	if (cf->can_id & CAN_RTR_FLAG)
763 		msg->msg.tx.dlc |= ESD_RTR;
764 
765 	if (cf->can_id & CAN_EFF_FLAG)
766 		msg->msg.tx.id |= cpu_to_le32(ESD_EXTID);
767 
768 	for (i = 0; i < cf->len; i++)
769 		msg->msg.tx.data[i] = cf->data[i];
770 
771 	msg->msg.hdr.len += (cf->len + 3) >> 2;
772 
773 	for (i = 0; i < MAX_TX_URBS; i++) {
774 		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
775 			context = &priv->tx_contexts[i];
776 			break;
777 		}
778 	}
779 
780 	/* This may never happen */
781 	if (!context) {
782 		netdev_warn(netdev, "couldn't find free context\n");
783 		ret = NETDEV_TX_BUSY;
784 		goto releasebuf;
785 	}
786 
787 	context->priv = priv;
788 	context->echo_index = i;
789 
790 	/* hnd must not be 0 - MSB is stripped in txdone handling */
791 	msg->msg.tx.hnd = 0x80000000 | i; /* returned in TX done message */
792 
793 	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
794 			  msg->msg.hdr.len << 2,
795 			  esd_usb_write_bulk_callback, context);
796 
797 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
798 
799 	usb_anchor_urb(urb, &priv->tx_submitted);
800 
801 	can_put_echo_skb(skb, netdev, context->echo_index, 0);
802 
803 	atomic_inc(&priv->active_tx_jobs);
804 
805 	/* Slow down tx path */
806 	if (atomic_read(&priv->active_tx_jobs) >= MAX_TX_URBS)
807 		netif_stop_queue(netdev);
808 
809 	err = usb_submit_urb(urb, GFP_ATOMIC);
810 	if (err) {
811 		can_free_echo_skb(netdev, context->echo_index, NULL);
812 
813 		atomic_dec(&priv->active_tx_jobs);
814 		usb_unanchor_urb(urb);
815 
816 		stats->tx_dropped++;
817 
818 		if (err == -ENODEV)
819 			netif_device_detach(netdev);
820 		else
821 			netdev_warn(netdev, "failed tx_urb %d\n", err);
822 
823 		goto releasebuf;
824 	}
825 
826 	netif_trans_update(netdev);
827 
828 	/* Release our reference to this URB, the USB core will eventually free
829 	 * it entirely.
830 	 */
831 	usb_free_urb(urb);
832 
833 	return NETDEV_TX_OK;
834 
835 releasebuf:
836 	usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
837 
838 nobufmem:
839 	usb_free_urb(urb);
840 
841 nourbmem:
842 	return ret;
843 }
844 
845 static int esd_usb_close(struct net_device *netdev)
846 {
847 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
848 	struct esd_usb_msg *msg;
849 	int i;
850 
851 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
852 	if (!msg)
853 		return -ENOMEM;
854 
855 	/* Disable all IDs (see esd_usb_start()) */
856 	msg->msg.hdr.cmd = CMD_IDADD;
857 	msg->msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
858 	msg->msg.filter.net = priv->index;
859 	msg->msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
860 	for (i = 0; i <= ESD_MAX_ID_SEGMENT; i++)
861 		msg->msg.filter.mask[i] = 0;
862 	if (esd_usb_send_msg(priv->usb, msg) < 0)
863 		netdev_err(netdev, "sending idadd message failed\n");
864 
865 	/* set CAN controller to reset mode */
866 	msg->msg.hdr.len = 2;
867 	msg->msg.hdr.cmd = CMD_SETBAUD;
868 	msg->msg.setbaud.net = priv->index;
869 	msg->msg.setbaud.rsvd = 0;
870 	msg->msg.setbaud.baud = cpu_to_le32(ESD_USB_NO_BAUDRATE);
871 	if (esd_usb_send_msg(priv->usb, msg) < 0)
872 		netdev_err(netdev, "sending setbaud message failed\n");
873 
874 	priv->can.state = CAN_STATE_STOPPED;
875 
876 	netif_stop_queue(netdev);
877 
878 	close_candev(netdev);
879 
880 	kfree(msg);
881 
882 	return 0;
883 }
884 
885 static const struct net_device_ops esd_usb_netdev_ops = {
886 	.ndo_open = esd_usb_open,
887 	.ndo_stop = esd_usb_close,
888 	.ndo_start_xmit = esd_usb_start_xmit,
889 	.ndo_change_mtu = can_change_mtu,
890 };
891 
892 static const struct ethtool_ops esd_usb_ethtool_ops = {
893 	.get_ts_info = ethtool_op_get_ts_info,
894 };
895 
896 static const struct can_bittiming_const esd_usb2_bittiming_const = {
897 	.name = "esd_usb2",
898 	.tseg1_min = ESD_USB2_TSEG1_MIN,
899 	.tseg1_max = ESD_USB2_TSEG1_MAX,
900 	.tseg2_min = ESD_USB2_TSEG2_MIN,
901 	.tseg2_max = ESD_USB2_TSEG2_MAX,
902 	.sjw_max = ESD_USB2_SJW_MAX,
903 	.brp_min = ESD_USB2_BRP_MIN,
904 	.brp_max = ESD_USB2_BRP_MAX,
905 	.brp_inc = ESD_USB2_BRP_INC,
906 };
907 
908 static int esd_usb2_set_bittiming(struct net_device *netdev)
909 {
910 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
911 	struct can_bittiming *bt = &priv->can.bittiming;
912 	struct esd_usb_msg *msg;
913 	int err;
914 	u32 canbtr;
915 	int sjw_shift;
916 
917 	canbtr = ESD_USB_UBR;
918 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
919 		canbtr |= ESD_USB_LOM;
920 
921 	canbtr |= (bt->brp - 1) & (ESD_USB2_BRP_MAX - 1);
922 
923 	if (le16_to_cpu(priv->usb->udev->descriptor.idProduct) ==
924 	    USB_CANUSBM_PRODUCT_ID)
925 		sjw_shift = ESD_USBM_SJW_SHIFT;
926 	else
927 		sjw_shift = ESD_USB2_SJW_SHIFT;
928 
929 	canbtr |= ((bt->sjw - 1) & (ESD_USB2_SJW_MAX - 1))
930 		<< sjw_shift;
931 	canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
932 		   & (ESD_USB2_TSEG1_MAX - 1))
933 		<< ESD_USB2_TSEG1_SHIFT;
934 	canbtr |= ((bt->phase_seg2 - 1) & (ESD_USB2_TSEG2_MAX - 1))
935 		<< ESD_USB2_TSEG2_SHIFT;
936 	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
937 		canbtr |= ESD_USB2_3_SAMPLES;
938 
939 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
940 	if (!msg)
941 		return -ENOMEM;
942 
943 	msg->msg.hdr.len = 2;
944 	msg->msg.hdr.cmd = CMD_SETBAUD;
945 	msg->msg.setbaud.net = priv->index;
946 	msg->msg.setbaud.rsvd = 0;
947 	msg->msg.setbaud.baud = cpu_to_le32(canbtr);
948 
949 	netdev_info(netdev, "setting BTR=%#x\n", canbtr);
950 
951 	err = esd_usb_send_msg(priv->usb, msg);
952 
953 	kfree(msg);
954 	return err;
955 }
956 
957 static int esd_usb_get_berr_counter(const struct net_device *netdev,
958 				    struct can_berr_counter *bec)
959 {
960 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
961 
962 	bec->txerr = priv->bec.txerr;
963 	bec->rxerr = priv->bec.rxerr;
964 
965 	return 0;
966 }
967 
968 static int esd_usb_set_mode(struct net_device *netdev, enum can_mode mode)
969 {
970 	switch (mode) {
971 	case CAN_MODE_START:
972 		netif_wake_queue(netdev);
973 		break;
974 
975 	default:
976 		return -EOPNOTSUPP;
977 	}
978 
979 	return 0;
980 }
981 
982 static int esd_usb_probe_one_net(struct usb_interface *intf, int index)
983 {
984 	struct esd_usb *dev = usb_get_intfdata(intf);
985 	struct net_device *netdev;
986 	struct esd_usb_net_priv *priv;
987 	int err = 0;
988 	int i;
989 
990 	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
991 	if (!netdev) {
992 		dev_err(&intf->dev, "couldn't alloc candev\n");
993 		err = -ENOMEM;
994 		goto done;
995 	}
996 
997 	priv = netdev_priv(netdev);
998 
999 	init_usb_anchor(&priv->tx_submitted);
1000 	atomic_set(&priv->active_tx_jobs, 0);
1001 
1002 	for (i = 0; i < MAX_TX_URBS; i++)
1003 		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
1004 
1005 	priv->usb = dev;
1006 	priv->netdev = netdev;
1007 	priv->index = index;
1008 
1009 	priv->can.state = CAN_STATE_STOPPED;
1010 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY |
1011 		CAN_CTRLMODE_CC_LEN8_DLC;
1012 
1013 	if (le16_to_cpu(dev->udev->descriptor.idProduct) ==
1014 	    USB_CANUSBM_PRODUCT_ID)
1015 		priv->can.clock.freq = ESD_USBM_CAN_CLOCK;
1016 	else {
1017 		priv->can.clock.freq = ESD_USB2_CAN_CLOCK;
1018 		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1019 	}
1020 
1021 	priv->can.bittiming_const = &esd_usb2_bittiming_const;
1022 	priv->can.do_set_bittiming = esd_usb2_set_bittiming;
1023 	priv->can.do_set_mode = esd_usb_set_mode;
1024 	priv->can.do_get_berr_counter = esd_usb_get_berr_counter;
1025 
1026 	netdev->flags |= IFF_ECHO; /* we support local echo */
1027 
1028 	netdev->netdev_ops = &esd_usb_netdev_ops;
1029 	netdev->ethtool_ops = &esd_usb_ethtool_ops;
1030 
1031 	SET_NETDEV_DEV(netdev, &intf->dev);
1032 	netdev->dev_id = index;
1033 
1034 	err = register_candev(netdev);
1035 	if (err) {
1036 		dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
1037 		free_candev(netdev);
1038 		err = -ENOMEM;
1039 		goto done;
1040 	}
1041 
1042 	dev->nets[index] = priv;
1043 	netdev_info(netdev, "device %s registered\n", netdev->name);
1044 
1045 done:
1046 	return err;
1047 }
1048 
1049 /* probe function for new USB devices
1050  *
1051  * check version information and number of available
1052  * CAN interfaces
1053  */
1054 static int esd_usb_probe(struct usb_interface *intf,
1055 			 const struct usb_device_id *id)
1056 {
1057 	struct esd_usb *dev;
1058 	struct esd_usb_msg *msg;
1059 	int i, err;
1060 
1061 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1062 	if (!dev) {
1063 		err = -ENOMEM;
1064 		goto done;
1065 	}
1066 
1067 	dev->udev = interface_to_usbdev(intf);
1068 
1069 	init_usb_anchor(&dev->rx_submitted);
1070 
1071 	usb_set_intfdata(intf, dev);
1072 
1073 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
1074 	if (!msg) {
1075 		err = -ENOMEM;
1076 		goto free_msg;
1077 	}
1078 
1079 	/* query number of CAN interfaces (nets) */
1080 	msg->msg.hdr.cmd = CMD_VERSION;
1081 	msg->msg.hdr.len = 2;
1082 	msg->msg.version.rsvd = 0;
1083 	msg->msg.version.flags = 0;
1084 	msg->msg.version.drv_version = 0;
1085 
1086 	err = esd_usb_send_msg(dev, msg);
1087 	if (err < 0) {
1088 		dev_err(&intf->dev, "sending version message failed\n");
1089 		goto free_msg;
1090 	}
1091 
1092 	err = esd_usb_wait_msg(dev, msg);
1093 	if (err < 0) {
1094 		dev_err(&intf->dev, "no version message answer\n");
1095 		goto free_msg;
1096 	}
1097 
1098 	dev->net_count = (int)msg->msg.version_reply.nets;
1099 	dev->version = le32_to_cpu(msg->msg.version_reply.version);
1100 
1101 	if (device_create_file(&intf->dev, &dev_attr_firmware))
1102 		dev_err(&intf->dev,
1103 			"Couldn't create device file for firmware\n");
1104 
1105 	if (device_create_file(&intf->dev, &dev_attr_hardware))
1106 		dev_err(&intf->dev,
1107 			"Couldn't create device file for hardware\n");
1108 
1109 	if (device_create_file(&intf->dev, &dev_attr_nets))
1110 		dev_err(&intf->dev,
1111 			"Couldn't create device file for nets\n");
1112 
1113 	/* do per device probing */
1114 	for (i = 0; i < dev->net_count; i++)
1115 		esd_usb_probe_one_net(intf, i);
1116 
1117 free_msg:
1118 	kfree(msg);
1119 	if (err)
1120 		kfree(dev);
1121 done:
1122 	return err;
1123 }
1124 
1125 /* called by the usb core when the device is removed from the system */
1126 static void esd_usb_disconnect(struct usb_interface *intf)
1127 {
1128 	struct esd_usb *dev = usb_get_intfdata(intf);
1129 	struct net_device *netdev;
1130 	int i;
1131 
1132 	device_remove_file(&intf->dev, &dev_attr_firmware);
1133 	device_remove_file(&intf->dev, &dev_attr_hardware);
1134 	device_remove_file(&intf->dev, &dev_attr_nets);
1135 
1136 	usb_set_intfdata(intf, NULL);
1137 
1138 	if (dev) {
1139 		for (i = 0; i < dev->net_count; i++) {
1140 			if (dev->nets[i]) {
1141 				netdev = dev->nets[i]->netdev;
1142 				unregister_netdev(netdev);
1143 				free_candev(netdev);
1144 			}
1145 		}
1146 		unlink_all_urbs(dev);
1147 		kfree(dev);
1148 	}
1149 }
1150 
1151 /* usb specific object needed to register this driver with the usb subsystem */
1152 static struct usb_driver esd_usb_driver = {
1153 	.name = KBUILD_MODNAME,
1154 	.probe = esd_usb_probe,
1155 	.disconnect = esd_usb_disconnect,
1156 	.id_table = esd_usb_table,
1157 };
1158 
1159 module_usb_driver(esd_usb_driver);
1160