• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * CAN driver for esd CAN-USB/2 and CAN-USB/Micro
4  *
5  * Copyright (C) 2010-2012 Matthias Fuchs <matthias.fuchs@esd.eu>, esd gmbh
6  */
7 #include <linux/signal.h>
8 #include <linux/slab.h>
9 #include <linux/module.h>
10 #include <linux/netdevice.h>
11 #include <linux/usb.h>
12 
13 #include <linux/can.h>
14 #include <linux/can/dev.h>
15 #include <linux/can/error.h>
16 
17 MODULE_AUTHOR("Matthias Fuchs <matthias.fuchs@esd.eu>");
18 MODULE_DESCRIPTION("CAN driver for esd CAN-USB/2 and CAN-USB/Micro interfaces");
19 MODULE_LICENSE("GPL v2");
20 
21 /* Define these values to match your devices */
22 #define USB_ESDGMBH_VENDOR_ID	0x0ab4
23 #define USB_CANUSB2_PRODUCT_ID	0x0010
24 #define USB_CANUSBM_PRODUCT_ID	0x0011
25 
26 #define ESD_USB2_CAN_CLOCK	60000000
27 #define ESD_USBM_CAN_CLOCK	36000000
28 #define ESD_USB2_MAX_NETS	2
29 
30 /* USB2 commands */
31 #define CMD_VERSION		1 /* also used for VERSION_REPLY */
32 #define CMD_CAN_RX		2 /* device to host only */
33 #define CMD_CAN_TX		3 /* also used for TX_DONE */
34 #define CMD_SETBAUD		4 /* also used for SETBAUD_REPLY */
35 #define CMD_TS			5 /* also used for TS_REPLY */
36 #define CMD_IDADD		6 /* also used for IDADD_REPLY */
37 
38 /* esd CAN message flags - dlc field */
39 #define ESD_RTR			0x10
40 
41 /* esd CAN message flags - id field */
42 #define ESD_EXTID		0x20000000
43 #define ESD_EVENT		0x40000000
44 #define ESD_IDMASK		0x1fffffff
45 
46 /* esd CAN event ids used by this driver */
47 #define ESD_EV_CAN_ERROR_EXT	2
48 
49 /* baudrate message flags */
50 #define ESD_USB2_UBR		0x80000000
51 #define ESD_USB2_LOM		0x40000000
52 #define ESD_USB2_NO_BAUDRATE	0x7fffffff
53 #define ESD_USB2_TSEG1_MIN	1
54 #define ESD_USB2_TSEG1_MAX	16
55 #define ESD_USB2_TSEG1_SHIFT	16
56 #define ESD_USB2_TSEG2_MIN	1
57 #define ESD_USB2_TSEG2_MAX	8
58 #define ESD_USB2_TSEG2_SHIFT	20
59 #define ESD_USB2_SJW_MAX	4
60 #define ESD_USB2_SJW_SHIFT	14
61 #define ESD_USBM_SJW_SHIFT	24
62 #define ESD_USB2_BRP_MIN	1
63 #define ESD_USB2_BRP_MAX	1024
64 #define ESD_USB2_BRP_INC	1
65 #define ESD_USB2_3_SAMPLES	0x00800000
66 
67 /* esd IDADD message */
68 #define ESD_ID_ENABLE		0x80
69 #define ESD_MAX_ID_SEGMENT	64
70 
71 /* SJA1000 ECC register (emulated by usb2 firmware) */
72 #define SJA1000_ECC_SEG		0x1F
73 #define SJA1000_ECC_DIR		0x20
74 #define SJA1000_ECC_ERR		0x06
75 #define SJA1000_ECC_BIT		0x00
76 #define SJA1000_ECC_FORM	0x40
77 #define SJA1000_ECC_STUFF	0x80
78 #define SJA1000_ECC_MASK	0xc0
79 
80 /* esd bus state event codes */
81 #define ESD_BUSSTATE_MASK	0xc0
82 #define ESD_BUSSTATE_WARN	0x40
83 #define ESD_BUSSTATE_ERRPASSIVE	0x80
84 #define ESD_BUSSTATE_BUSOFF	0xc0
85 
86 #define RX_BUFFER_SIZE		1024
87 #define MAX_RX_URBS		4
88 #define MAX_TX_URBS		16 /* must be power of 2 */
89 
90 struct header_msg {
91 	u8 len; /* len is always the total message length in 32bit words */
92 	u8 cmd;
93 	u8 rsvd[2];
94 };
95 
96 struct version_msg {
97 	u8 len;
98 	u8 cmd;
99 	u8 rsvd;
100 	u8 flags;
101 	__le32 drv_version;
102 };
103 
104 struct version_reply_msg {
105 	u8 len;
106 	u8 cmd;
107 	u8 nets;
108 	u8 features;
109 	__le32 version;
110 	u8 name[16];
111 	__le32 rsvd;
112 	__le32 ts;
113 };
114 
115 struct rx_msg {
116 	u8 len;
117 	u8 cmd;
118 	u8 net;
119 	u8 dlc;
120 	__le32 ts;
121 	__le32 id; /* upper 3 bits contain flags */
122 	u8 data[8];
123 };
124 
125 struct tx_msg {
126 	u8 len;
127 	u8 cmd;
128 	u8 net;
129 	u8 dlc;
130 	u32 hnd;	/* opaque handle, not used by device */
131 	__le32 id; /* upper 3 bits contain flags */
132 	u8 data[8];
133 };
134 
135 struct tx_done_msg {
136 	u8 len;
137 	u8 cmd;
138 	u8 net;
139 	u8 status;
140 	u32 hnd;	/* opaque handle, not used by device */
141 	__le32 ts;
142 };
143 
144 struct id_filter_msg {
145 	u8 len;
146 	u8 cmd;
147 	u8 net;
148 	u8 option;
149 	__le32 mask[ESD_MAX_ID_SEGMENT + 1];
150 };
151 
152 struct set_baudrate_msg {
153 	u8 len;
154 	u8 cmd;
155 	u8 net;
156 	u8 rsvd;
157 	__le32 baud;
158 };
159 
160 /* Main message type used between library and application */
161 struct __attribute__ ((packed)) esd_usb2_msg {
162 	union {
163 		struct header_msg hdr;
164 		struct version_msg version;
165 		struct version_reply_msg version_reply;
166 		struct rx_msg rx;
167 		struct tx_msg tx;
168 		struct tx_done_msg txdone;
169 		struct set_baudrate_msg setbaud;
170 		struct id_filter_msg filter;
171 	} msg;
172 };
173 
174 static struct usb_device_id esd_usb2_table[] = {
175 	{USB_DEVICE(USB_ESDGMBH_VENDOR_ID, USB_CANUSB2_PRODUCT_ID)},
176 	{USB_DEVICE(USB_ESDGMBH_VENDOR_ID, USB_CANUSBM_PRODUCT_ID)},
177 	{}
178 };
179 MODULE_DEVICE_TABLE(usb, esd_usb2_table);
180 
181 struct esd_usb2_net_priv;
182 
183 struct esd_tx_urb_context {
184 	struct esd_usb2_net_priv *priv;
185 	u32 echo_index;
186 	int dlc;
187 };
188 
189 struct esd_usb2 {
190 	struct usb_device *udev;
191 	struct esd_usb2_net_priv *nets[ESD_USB2_MAX_NETS];
192 
193 	struct usb_anchor rx_submitted;
194 
195 	int net_count;
196 	u32 version;
197 	int rxinitdone;
198 	void *rxbuf[MAX_RX_URBS];
199 	dma_addr_t rxbuf_dma[MAX_RX_URBS];
200 };
201 
202 struct esd_usb2_net_priv {
203 	struct can_priv can; /* must be the first member */
204 
205 	atomic_t active_tx_jobs;
206 	struct usb_anchor tx_submitted;
207 	struct esd_tx_urb_context tx_contexts[MAX_TX_URBS];
208 
209 	struct esd_usb2 *usb2;
210 	struct net_device *netdev;
211 	int index;
212 	u8 old_state;
213 	struct can_berr_counter bec;
214 };
215 
esd_usb2_rx_event(struct esd_usb2_net_priv * priv,struct esd_usb2_msg * msg)216 static void esd_usb2_rx_event(struct esd_usb2_net_priv *priv,
217 			      struct esd_usb2_msg *msg)
218 {
219 	struct net_device_stats *stats = &priv->netdev->stats;
220 	struct can_frame *cf;
221 	struct sk_buff *skb;
222 	u32 id = le32_to_cpu(msg->msg.rx.id) & ESD_IDMASK;
223 
224 	if (id == ESD_EV_CAN_ERROR_EXT) {
225 		u8 state = msg->msg.rx.data[0];
226 		u8 ecc = msg->msg.rx.data[1];
227 		u8 rxerr = msg->msg.rx.data[2];
228 		u8 txerr = msg->msg.rx.data[3];
229 
230 		skb = alloc_can_err_skb(priv->netdev, &cf);
231 		if (skb == NULL) {
232 			stats->rx_dropped++;
233 			return;
234 		}
235 
236 		if (state != priv->old_state) {
237 			priv->old_state = state;
238 
239 			switch (state & ESD_BUSSTATE_MASK) {
240 			case ESD_BUSSTATE_BUSOFF:
241 				priv->can.state = CAN_STATE_BUS_OFF;
242 				cf->can_id |= CAN_ERR_BUSOFF;
243 				priv->can.can_stats.bus_off++;
244 				can_bus_off(priv->netdev);
245 				break;
246 			case ESD_BUSSTATE_WARN:
247 				priv->can.state = CAN_STATE_ERROR_WARNING;
248 				priv->can.can_stats.error_warning++;
249 				break;
250 			case ESD_BUSSTATE_ERRPASSIVE:
251 				priv->can.state = CAN_STATE_ERROR_PASSIVE;
252 				priv->can.can_stats.error_passive++;
253 				break;
254 			default:
255 				priv->can.state = CAN_STATE_ERROR_ACTIVE;
256 				break;
257 			}
258 		} else {
259 			priv->can.can_stats.bus_error++;
260 			stats->rx_errors++;
261 
262 			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
263 
264 			switch (ecc & SJA1000_ECC_MASK) {
265 			case SJA1000_ECC_BIT:
266 				cf->data[2] |= CAN_ERR_PROT_BIT;
267 				break;
268 			case SJA1000_ECC_FORM:
269 				cf->data[2] |= CAN_ERR_PROT_FORM;
270 				break;
271 			case SJA1000_ECC_STUFF:
272 				cf->data[2] |= CAN_ERR_PROT_STUFF;
273 				break;
274 			default:
275 				cf->data[3] = ecc & SJA1000_ECC_SEG;
276 				break;
277 			}
278 
279 			/* Error occurred during transmission? */
280 			if (!(ecc & SJA1000_ECC_DIR))
281 				cf->data[2] |= CAN_ERR_PROT_TX;
282 
283 			if (priv->can.state == CAN_STATE_ERROR_WARNING ||
284 			    priv->can.state == CAN_STATE_ERROR_PASSIVE) {
285 				cf->data[1] = (txerr > rxerr) ?
286 					CAN_ERR_CRTL_TX_PASSIVE :
287 					CAN_ERR_CRTL_RX_PASSIVE;
288 			}
289 			cf->data[6] = txerr;
290 			cf->data[7] = rxerr;
291 		}
292 
293 		priv->bec.txerr = txerr;
294 		priv->bec.rxerr = rxerr;
295 
296 		stats->rx_packets++;
297 		stats->rx_bytes += cf->can_dlc;
298 		netif_rx(skb);
299 	}
300 }
301 
esd_usb2_rx_can_msg(struct esd_usb2_net_priv * priv,struct esd_usb2_msg * msg)302 static void esd_usb2_rx_can_msg(struct esd_usb2_net_priv *priv,
303 				struct esd_usb2_msg *msg)
304 {
305 	struct net_device_stats *stats = &priv->netdev->stats;
306 	struct can_frame *cf;
307 	struct sk_buff *skb;
308 	int i;
309 	u32 id;
310 
311 	if (!netif_device_present(priv->netdev))
312 		return;
313 
314 	id = le32_to_cpu(msg->msg.rx.id);
315 
316 	if (id & ESD_EVENT) {
317 		esd_usb2_rx_event(priv, msg);
318 	} else {
319 		skb = alloc_can_skb(priv->netdev, &cf);
320 		if (skb == NULL) {
321 			stats->rx_dropped++;
322 			return;
323 		}
324 
325 		cf->can_id = id & ESD_IDMASK;
326 		cf->can_dlc = get_can_dlc(msg->msg.rx.dlc & ~ESD_RTR);
327 
328 		if (id & ESD_EXTID)
329 			cf->can_id |= CAN_EFF_FLAG;
330 
331 		if (msg->msg.rx.dlc & ESD_RTR) {
332 			cf->can_id |= CAN_RTR_FLAG;
333 		} else {
334 			for (i = 0; i < cf->can_dlc; i++)
335 				cf->data[i] = msg->msg.rx.data[i];
336 		}
337 
338 		stats->rx_packets++;
339 		stats->rx_bytes += cf->can_dlc;
340 		netif_rx(skb);
341 	}
342 
343 	return;
344 }
345 
esd_usb2_tx_done_msg(struct esd_usb2_net_priv * priv,struct esd_usb2_msg * msg)346 static void esd_usb2_tx_done_msg(struct esd_usb2_net_priv *priv,
347 				 struct esd_usb2_msg *msg)
348 {
349 	struct net_device_stats *stats = &priv->netdev->stats;
350 	struct net_device *netdev = priv->netdev;
351 	struct esd_tx_urb_context *context;
352 
353 	if (!netif_device_present(netdev))
354 		return;
355 
356 	context = &priv->tx_contexts[msg->msg.txdone.hnd & (MAX_TX_URBS - 1)];
357 
358 	if (!msg->msg.txdone.status) {
359 		stats->tx_packets++;
360 		stats->tx_bytes += context->dlc;
361 		can_get_echo_skb(netdev, context->echo_index);
362 	} else {
363 		stats->tx_errors++;
364 		can_free_echo_skb(netdev, context->echo_index);
365 	}
366 
367 	/* Release context */
368 	context->echo_index = MAX_TX_URBS;
369 	atomic_dec(&priv->active_tx_jobs);
370 
371 	netif_wake_queue(netdev);
372 }
373 
esd_usb2_read_bulk_callback(struct urb * urb)374 static void esd_usb2_read_bulk_callback(struct urb *urb)
375 {
376 	struct esd_usb2 *dev = urb->context;
377 	int retval;
378 	int pos = 0;
379 	int i;
380 
381 	switch (urb->status) {
382 	case 0: /* success */
383 		break;
384 
385 	case -ENOENT:
386 	case -EPIPE:
387 	case -EPROTO:
388 	case -ESHUTDOWN:
389 		return;
390 
391 	default:
392 		dev_info(dev->udev->dev.parent,
393 			 "Rx URB aborted (%d)\n", urb->status);
394 		goto resubmit_urb;
395 	}
396 
397 	while (pos < urb->actual_length) {
398 		struct esd_usb2_msg *msg;
399 
400 		msg = (struct esd_usb2_msg *)(urb->transfer_buffer + pos);
401 
402 		switch (msg->msg.hdr.cmd) {
403 		case CMD_CAN_RX:
404 			if (msg->msg.rx.net >= dev->net_count) {
405 				dev_err(dev->udev->dev.parent, "format error\n");
406 				break;
407 			}
408 
409 			esd_usb2_rx_can_msg(dev->nets[msg->msg.rx.net], msg);
410 			break;
411 
412 		case CMD_CAN_TX:
413 			if (msg->msg.txdone.net >= dev->net_count) {
414 				dev_err(dev->udev->dev.parent, "format error\n");
415 				break;
416 			}
417 
418 			esd_usb2_tx_done_msg(dev->nets[msg->msg.txdone.net],
419 					     msg);
420 			break;
421 		}
422 
423 		pos += msg->msg.hdr.len << 2;
424 
425 		if (pos > urb->actual_length) {
426 			dev_err(dev->udev->dev.parent, "format error\n");
427 			break;
428 		}
429 	}
430 
431 resubmit_urb:
432 	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
433 			  urb->transfer_buffer, RX_BUFFER_SIZE,
434 			  esd_usb2_read_bulk_callback, dev);
435 
436 	retval = usb_submit_urb(urb, GFP_ATOMIC);
437 	if (retval == -ENODEV) {
438 		for (i = 0; i < dev->net_count; i++) {
439 			if (dev->nets[i])
440 				netif_device_detach(dev->nets[i]->netdev);
441 		}
442 	} else if (retval) {
443 		dev_err(dev->udev->dev.parent,
444 			"failed resubmitting read bulk urb: %d\n", retval);
445 	}
446 
447 	return;
448 }
449 
450 /*
451  * callback for bulk IN urb
452  */
esd_usb2_write_bulk_callback(struct urb * urb)453 static void esd_usb2_write_bulk_callback(struct urb *urb)
454 {
455 	struct esd_tx_urb_context *context = urb->context;
456 	struct esd_usb2_net_priv *priv;
457 	struct net_device *netdev;
458 	size_t size = sizeof(struct esd_usb2_msg);
459 
460 	WARN_ON(!context);
461 
462 	priv = context->priv;
463 	netdev = priv->netdev;
464 
465 	/* free up our allocated buffer */
466 	usb_free_coherent(urb->dev, size,
467 			  urb->transfer_buffer, urb->transfer_dma);
468 
469 	if (!netif_device_present(netdev))
470 		return;
471 
472 	if (urb->status)
473 		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
474 
475 	netif_trans_update(netdev);
476 }
477 
show_firmware(struct device * d,struct device_attribute * attr,char * buf)478 static ssize_t show_firmware(struct device *d,
479 			     struct device_attribute *attr, char *buf)
480 {
481 	struct usb_interface *intf = to_usb_interface(d);
482 	struct esd_usb2 *dev = usb_get_intfdata(intf);
483 
484 	return sprintf(buf, "%d.%d.%d\n",
485 		       (dev->version >> 12) & 0xf,
486 		       (dev->version >> 8) & 0xf,
487 		       dev->version & 0xff);
488 }
489 static DEVICE_ATTR(firmware, 0444, show_firmware, NULL);
490 
show_hardware(struct device * d,struct device_attribute * attr,char * buf)491 static ssize_t show_hardware(struct device *d,
492 			     struct device_attribute *attr, char *buf)
493 {
494 	struct usb_interface *intf = to_usb_interface(d);
495 	struct esd_usb2 *dev = usb_get_intfdata(intf);
496 
497 	return sprintf(buf, "%d.%d.%d\n",
498 		       (dev->version >> 28) & 0xf,
499 		       (dev->version >> 24) & 0xf,
500 		       (dev->version >> 16) & 0xff);
501 }
502 static DEVICE_ATTR(hardware, 0444, show_hardware, NULL);
503 
show_nets(struct device * d,struct device_attribute * attr,char * buf)504 static ssize_t show_nets(struct device *d,
505 			 struct device_attribute *attr, char *buf)
506 {
507 	struct usb_interface *intf = to_usb_interface(d);
508 	struct esd_usb2 *dev = usb_get_intfdata(intf);
509 
510 	return sprintf(buf, "%d", dev->net_count);
511 }
512 static DEVICE_ATTR(nets, 0444, show_nets, NULL);
513 
esd_usb2_send_msg(struct esd_usb2 * dev,struct esd_usb2_msg * msg)514 static int esd_usb2_send_msg(struct esd_usb2 *dev, struct esd_usb2_msg *msg)
515 {
516 	int actual_length;
517 
518 	return usb_bulk_msg(dev->udev,
519 			    usb_sndbulkpipe(dev->udev, 2),
520 			    msg,
521 			    msg->msg.hdr.len << 2,
522 			    &actual_length,
523 			    1000);
524 }
525 
esd_usb2_wait_msg(struct esd_usb2 * dev,struct esd_usb2_msg * msg)526 static int esd_usb2_wait_msg(struct esd_usb2 *dev,
527 			     struct esd_usb2_msg *msg)
528 {
529 	int actual_length;
530 
531 	return usb_bulk_msg(dev->udev,
532 			    usb_rcvbulkpipe(dev->udev, 1),
533 			    msg,
534 			    sizeof(*msg),
535 			    &actual_length,
536 			    1000);
537 }
538 
esd_usb2_setup_rx_urbs(struct esd_usb2 * dev)539 static int esd_usb2_setup_rx_urbs(struct esd_usb2 *dev)
540 {
541 	int i, err = 0;
542 
543 	if (dev->rxinitdone)
544 		return 0;
545 
546 	for (i = 0; i < MAX_RX_URBS; i++) {
547 		struct urb *urb = NULL;
548 		u8 *buf = NULL;
549 		dma_addr_t buf_dma;
550 
551 		/* create a URB, and a buffer for it */
552 		urb = usb_alloc_urb(0, GFP_KERNEL);
553 		if (!urb) {
554 			err = -ENOMEM;
555 			break;
556 		}
557 
558 		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
559 					 &buf_dma);
560 		if (!buf) {
561 			dev_warn(dev->udev->dev.parent,
562 				 "No memory left for USB buffer\n");
563 			err = -ENOMEM;
564 			goto freeurb;
565 		}
566 
567 		urb->transfer_dma = buf_dma;
568 
569 		usb_fill_bulk_urb(urb, dev->udev,
570 				  usb_rcvbulkpipe(dev->udev, 1),
571 				  buf, RX_BUFFER_SIZE,
572 				  esd_usb2_read_bulk_callback, dev);
573 		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
574 		usb_anchor_urb(urb, &dev->rx_submitted);
575 
576 		err = usb_submit_urb(urb, GFP_KERNEL);
577 		if (err) {
578 			usb_unanchor_urb(urb);
579 			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
580 					  urb->transfer_dma);
581 			goto freeurb;
582 		}
583 
584 		dev->rxbuf[i] = buf;
585 		dev->rxbuf_dma[i] = buf_dma;
586 
587 freeurb:
588 		/* Drop reference, USB core will take care of freeing it */
589 		usb_free_urb(urb);
590 		if (err)
591 			break;
592 	}
593 
594 	/* Did we submit any URBs */
595 	if (i == 0) {
596 		dev_err(dev->udev->dev.parent, "couldn't setup read URBs\n");
597 		return err;
598 	}
599 
600 	/* Warn if we've couldn't transmit all the URBs */
601 	if (i < MAX_RX_URBS) {
602 		dev_warn(dev->udev->dev.parent,
603 			 "rx performance may be slow\n");
604 	}
605 
606 	dev->rxinitdone = 1;
607 	return 0;
608 }
609 
610 /*
611  * Start interface
612  */
esd_usb2_start(struct esd_usb2_net_priv * priv)613 static int esd_usb2_start(struct esd_usb2_net_priv *priv)
614 {
615 	struct esd_usb2 *dev = priv->usb2;
616 	struct net_device *netdev = priv->netdev;
617 	struct esd_usb2_msg *msg;
618 	int err, i;
619 
620 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
621 	if (!msg) {
622 		err = -ENOMEM;
623 		goto out;
624 	}
625 
626 	/*
627 	 * Enable all IDs
628 	 * The IDADD message takes up to 64 32 bit bitmasks (2048 bits).
629 	 * Each bit represents one 11 bit CAN identifier. A set bit
630 	 * enables reception of the corresponding CAN identifier. A cleared
631 	 * bit disabled this identifier. An additional bitmask value
632 	 * following the CAN 2.0A bits is used to enable reception of
633 	 * extended CAN frames. Only the LSB of this final mask is checked
634 	 * for the complete 29 bit ID range. The IDADD message also allows
635 	 * filter configuration for an ID subset. In this case you can add
636 	 * the number of the starting bitmask (0..64) to the filter.option
637 	 * field followed by only some bitmasks.
638 	 */
639 	msg->msg.hdr.cmd = CMD_IDADD;
640 	msg->msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
641 	msg->msg.filter.net = priv->index;
642 	msg->msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
643 	for (i = 0; i < ESD_MAX_ID_SEGMENT; i++)
644 		msg->msg.filter.mask[i] = cpu_to_le32(0xffffffff);
645 	/* enable 29bit extended IDs */
646 	msg->msg.filter.mask[ESD_MAX_ID_SEGMENT] = cpu_to_le32(0x00000001);
647 
648 	err = esd_usb2_send_msg(dev, msg);
649 	if (err)
650 		goto out;
651 
652 	err = esd_usb2_setup_rx_urbs(dev);
653 	if (err)
654 		goto out;
655 
656 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
657 
658 out:
659 	if (err == -ENODEV)
660 		netif_device_detach(netdev);
661 	if (err)
662 		netdev_err(netdev, "couldn't start device: %d\n", err);
663 
664 	kfree(msg);
665 	return err;
666 }
667 
unlink_all_urbs(struct esd_usb2 * dev)668 static void unlink_all_urbs(struct esd_usb2 *dev)
669 {
670 	struct esd_usb2_net_priv *priv;
671 	int i, j;
672 
673 	usb_kill_anchored_urbs(&dev->rx_submitted);
674 
675 	for (i = 0; i < MAX_RX_URBS; ++i)
676 		usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
677 				  dev->rxbuf[i], dev->rxbuf_dma[i]);
678 
679 	for (i = 0; i < dev->net_count; i++) {
680 		priv = dev->nets[i];
681 		if (priv) {
682 			usb_kill_anchored_urbs(&priv->tx_submitted);
683 			atomic_set(&priv->active_tx_jobs, 0);
684 
685 			for (j = 0; j < MAX_TX_URBS; j++)
686 				priv->tx_contexts[j].echo_index = MAX_TX_URBS;
687 		}
688 	}
689 }
690 
esd_usb2_open(struct net_device * netdev)691 static int esd_usb2_open(struct net_device *netdev)
692 {
693 	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
694 	int err;
695 
696 	/* common open */
697 	err = open_candev(netdev);
698 	if (err)
699 		return err;
700 
701 	/* finally start device */
702 	err = esd_usb2_start(priv);
703 	if (err) {
704 		netdev_warn(netdev, "couldn't start device: %d\n", err);
705 		close_candev(netdev);
706 		return err;
707 	}
708 
709 	netif_start_queue(netdev);
710 
711 	return 0;
712 }
713 
esd_usb2_start_xmit(struct sk_buff * skb,struct net_device * netdev)714 static netdev_tx_t esd_usb2_start_xmit(struct sk_buff *skb,
715 				      struct net_device *netdev)
716 {
717 	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
718 	struct esd_usb2 *dev = priv->usb2;
719 	struct esd_tx_urb_context *context = NULL;
720 	struct net_device_stats *stats = &netdev->stats;
721 	struct can_frame *cf = (struct can_frame *)skb->data;
722 	struct esd_usb2_msg *msg;
723 	struct urb *urb;
724 	u8 *buf;
725 	int i, err;
726 	int ret = NETDEV_TX_OK;
727 	size_t size = sizeof(struct esd_usb2_msg);
728 
729 	if (can_dropped_invalid_skb(netdev, skb))
730 		return NETDEV_TX_OK;
731 
732 	/* create a URB, and a buffer for it, and copy the data to the URB */
733 	urb = usb_alloc_urb(0, GFP_ATOMIC);
734 	if (!urb) {
735 		stats->tx_dropped++;
736 		dev_kfree_skb(skb);
737 		goto nourbmem;
738 	}
739 
740 	buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC,
741 				 &urb->transfer_dma);
742 	if (!buf) {
743 		netdev_err(netdev, "No memory left for USB buffer\n");
744 		stats->tx_dropped++;
745 		dev_kfree_skb(skb);
746 		goto nobufmem;
747 	}
748 
749 	msg = (struct esd_usb2_msg *)buf;
750 
751 	msg->msg.hdr.len = 3; /* minimal length */
752 	msg->msg.hdr.cmd = CMD_CAN_TX;
753 	msg->msg.tx.net = priv->index;
754 	msg->msg.tx.dlc = cf->can_dlc;
755 	msg->msg.tx.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
756 
757 	if (cf->can_id & CAN_RTR_FLAG)
758 		msg->msg.tx.dlc |= ESD_RTR;
759 
760 	if (cf->can_id & CAN_EFF_FLAG)
761 		msg->msg.tx.id |= cpu_to_le32(ESD_EXTID);
762 
763 	for (i = 0; i < cf->can_dlc; i++)
764 		msg->msg.tx.data[i] = cf->data[i];
765 
766 	msg->msg.hdr.len += (cf->can_dlc + 3) >> 2;
767 
768 	for (i = 0; i < MAX_TX_URBS; i++) {
769 		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
770 			context = &priv->tx_contexts[i];
771 			break;
772 		}
773 	}
774 
775 	/*
776 	 * This may never happen.
777 	 */
778 	if (!context) {
779 		netdev_warn(netdev, "couldn't find free context\n");
780 		ret = NETDEV_TX_BUSY;
781 		goto releasebuf;
782 	}
783 
784 	context->priv = priv;
785 	context->echo_index = i;
786 	context->dlc = cf->can_dlc;
787 
788 	/* hnd must not be 0 - MSB is stripped in txdone handling */
789 	msg->msg.tx.hnd = 0x80000000 | i; /* returned in TX done message */
790 
791 	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
792 			  msg->msg.hdr.len << 2,
793 			  esd_usb2_write_bulk_callback, context);
794 
795 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
796 
797 	usb_anchor_urb(urb, &priv->tx_submitted);
798 
799 	can_put_echo_skb(skb, netdev, context->echo_index);
800 
801 	atomic_inc(&priv->active_tx_jobs);
802 
803 	/* Slow down tx path */
804 	if (atomic_read(&priv->active_tx_jobs) >= MAX_TX_URBS)
805 		netif_stop_queue(netdev);
806 
807 	err = usb_submit_urb(urb, GFP_ATOMIC);
808 	if (err) {
809 		can_free_echo_skb(netdev, context->echo_index);
810 
811 		atomic_dec(&priv->active_tx_jobs);
812 		usb_unanchor_urb(urb);
813 
814 		stats->tx_dropped++;
815 
816 		if (err == -ENODEV)
817 			netif_device_detach(netdev);
818 		else
819 			netdev_warn(netdev, "failed tx_urb %d\n", err);
820 
821 		goto releasebuf;
822 	}
823 
824 	netif_trans_update(netdev);
825 
826 	/*
827 	 * Release our reference to this URB, the USB core will eventually free
828 	 * it entirely.
829 	 */
830 	usb_free_urb(urb);
831 
832 	return NETDEV_TX_OK;
833 
834 releasebuf:
835 	usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
836 
837 nobufmem:
838 	usb_free_urb(urb);
839 
840 nourbmem:
841 	return ret;
842 }
843 
esd_usb2_close(struct net_device * netdev)844 static int esd_usb2_close(struct net_device *netdev)
845 {
846 	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
847 	struct esd_usb2_msg *msg;
848 	int i;
849 
850 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
851 	if (!msg)
852 		return -ENOMEM;
853 
854 	/* Disable all IDs (see esd_usb2_start()) */
855 	msg->msg.hdr.cmd = CMD_IDADD;
856 	msg->msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
857 	msg->msg.filter.net = priv->index;
858 	msg->msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
859 	for (i = 0; i <= ESD_MAX_ID_SEGMENT; i++)
860 		msg->msg.filter.mask[i] = 0;
861 	if (esd_usb2_send_msg(priv->usb2, msg) < 0)
862 		netdev_err(netdev, "sending idadd message failed\n");
863 
864 	/* set CAN controller to reset mode */
865 	msg->msg.hdr.len = 2;
866 	msg->msg.hdr.cmd = CMD_SETBAUD;
867 	msg->msg.setbaud.net = priv->index;
868 	msg->msg.setbaud.rsvd = 0;
869 	msg->msg.setbaud.baud = cpu_to_le32(ESD_USB2_NO_BAUDRATE);
870 	if (esd_usb2_send_msg(priv->usb2, msg) < 0)
871 		netdev_err(netdev, "sending setbaud message failed\n");
872 
873 	priv->can.state = CAN_STATE_STOPPED;
874 
875 	netif_stop_queue(netdev);
876 
877 	close_candev(netdev);
878 
879 	kfree(msg);
880 
881 	return 0;
882 }
883 
884 static const struct net_device_ops esd_usb2_netdev_ops = {
885 	.ndo_open = esd_usb2_open,
886 	.ndo_stop = esd_usb2_close,
887 	.ndo_start_xmit = esd_usb2_start_xmit,
888 	.ndo_change_mtu = can_change_mtu,
889 };
890 
891 static const struct can_bittiming_const esd_usb2_bittiming_const = {
892 	.name = "esd_usb2",
893 	.tseg1_min = ESD_USB2_TSEG1_MIN,
894 	.tseg1_max = ESD_USB2_TSEG1_MAX,
895 	.tseg2_min = ESD_USB2_TSEG2_MIN,
896 	.tseg2_max = ESD_USB2_TSEG2_MAX,
897 	.sjw_max = ESD_USB2_SJW_MAX,
898 	.brp_min = ESD_USB2_BRP_MIN,
899 	.brp_max = ESD_USB2_BRP_MAX,
900 	.brp_inc = ESD_USB2_BRP_INC,
901 };
902 
esd_usb2_set_bittiming(struct net_device * netdev)903 static int esd_usb2_set_bittiming(struct net_device *netdev)
904 {
905 	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
906 	struct can_bittiming *bt = &priv->can.bittiming;
907 	struct esd_usb2_msg *msg;
908 	int err;
909 	u32 canbtr;
910 	int sjw_shift;
911 
912 	canbtr = ESD_USB2_UBR;
913 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
914 		canbtr |= ESD_USB2_LOM;
915 
916 	canbtr |= (bt->brp - 1) & (ESD_USB2_BRP_MAX - 1);
917 
918 	if (le16_to_cpu(priv->usb2->udev->descriptor.idProduct) ==
919 	    USB_CANUSBM_PRODUCT_ID)
920 		sjw_shift = ESD_USBM_SJW_SHIFT;
921 	else
922 		sjw_shift = ESD_USB2_SJW_SHIFT;
923 
924 	canbtr |= ((bt->sjw - 1) & (ESD_USB2_SJW_MAX - 1))
925 		<< sjw_shift;
926 	canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
927 		   & (ESD_USB2_TSEG1_MAX - 1))
928 		<< ESD_USB2_TSEG1_SHIFT;
929 	canbtr |= ((bt->phase_seg2 - 1) & (ESD_USB2_TSEG2_MAX - 1))
930 		<< ESD_USB2_TSEG2_SHIFT;
931 	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
932 		canbtr |= ESD_USB2_3_SAMPLES;
933 
934 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
935 	if (!msg)
936 		return -ENOMEM;
937 
938 	msg->msg.hdr.len = 2;
939 	msg->msg.hdr.cmd = CMD_SETBAUD;
940 	msg->msg.setbaud.net = priv->index;
941 	msg->msg.setbaud.rsvd = 0;
942 	msg->msg.setbaud.baud = cpu_to_le32(canbtr);
943 
944 	netdev_info(netdev, "setting BTR=%#x\n", canbtr);
945 
946 	err = esd_usb2_send_msg(priv->usb2, msg);
947 
948 	kfree(msg);
949 	return err;
950 }
951 
esd_usb2_get_berr_counter(const struct net_device * netdev,struct can_berr_counter * bec)952 static int esd_usb2_get_berr_counter(const struct net_device *netdev,
953 				     struct can_berr_counter *bec)
954 {
955 	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
956 
957 	bec->txerr = priv->bec.txerr;
958 	bec->rxerr = priv->bec.rxerr;
959 
960 	return 0;
961 }
962 
esd_usb2_set_mode(struct net_device * netdev,enum can_mode mode)963 static int esd_usb2_set_mode(struct net_device *netdev, enum can_mode mode)
964 {
965 	switch (mode) {
966 	case CAN_MODE_START:
967 		netif_wake_queue(netdev);
968 		break;
969 
970 	default:
971 		return -EOPNOTSUPP;
972 	}
973 
974 	return 0;
975 }
976 
esd_usb2_probe_one_net(struct usb_interface * intf,int index)977 static int esd_usb2_probe_one_net(struct usb_interface *intf, int index)
978 {
979 	struct esd_usb2 *dev = usb_get_intfdata(intf);
980 	struct net_device *netdev;
981 	struct esd_usb2_net_priv *priv;
982 	int err = 0;
983 	int i;
984 
985 	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
986 	if (!netdev) {
987 		dev_err(&intf->dev, "couldn't alloc candev\n");
988 		err = -ENOMEM;
989 		goto done;
990 	}
991 
992 	priv = netdev_priv(netdev);
993 
994 	init_usb_anchor(&priv->tx_submitted);
995 	atomic_set(&priv->active_tx_jobs, 0);
996 
997 	for (i = 0; i < MAX_TX_URBS; i++)
998 		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
999 
1000 	priv->usb2 = dev;
1001 	priv->netdev = netdev;
1002 	priv->index = index;
1003 
1004 	priv->can.state = CAN_STATE_STOPPED;
1005 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY;
1006 
1007 	if (le16_to_cpu(dev->udev->descriptor.idProduct) ==
1008 	    USB_CANUSBM_PRODUCT_ID)
1009 		priv->can.clock.freq = ESD_USBM_CAN_CLOCK;
1010 	else {
1011 		priv->can.clock.freq = ESD_USB2_CAN_CLOCK;
1012 		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1013 	}
1014 
1015 	priv->can.bittiming_const = &esd_usb2_bittiming_const;
1016 	priv->can.do_set_bittiming = esd_usb2_set_bittiming;
1017 	priv->can.do_set_mode = esd_usb2_set_mode;
1018 	priv->can.do_get_berr_counter = esd_usb2_get_berr_counter;
1019 
1020 	netdev->flags |= IFF_ECHO; /* we support local echo */
1021 
1022 	netdev->netdev_ops = &esd_usb2_netdev_ops;
1023 
1024 	SET_NETDEV_DEV(netdev, &intf->dev);
1025 	netdev->dev_id = index;
1026 
1027 	err = register_candev(netdev);
1028 	if (err) {
1029 		dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
1030 		free_candev(netdev);
1031 		err = -ENOMEM;
1032 		goto done;
1033 	}
1034 
1035 	dev->nets[index] = priv;
1036 	netdev_info(netdev, "device %s registered\n", netdev->name);
1037 
1038 done:
1039 	return err;
1040 }
1041 
1042 /*
1043  * probe function for new USB2 devices
1044  *
1045  * check version information and number of available
1046  * CAN interfaces
1047  */
esd_usb2_probe(struct usb_interface * intf,const struct usb_device_id * id)1048 static int esd_usb2_probe(struct usb_interface *intf,
1049 			 const struct usb_device_id *id)
1050 {
1051 	struct esd_usb2 *dev;
1052 	struct esd_usb2_msg *msg;
1053 	int i, err;
1054 
1055 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1056 	if (!dev) {
1057 		err = -ENOMEM;
1058 		goto done;
1059 	}
1060 
1061 	dev->udev = interface_to_usbdev(intf);
1062 
1063 	init_usb_anchor(&dev->rx_submitted);
1064 
1065 	usb_set_intfdata(intf, dev);
1066 
1067 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
1068 	if (!msg) {
1069 		err = -ENOMEM;
1070 		goto free_msg;
1071 	}
1072 
1073 	/* query number of CAN interfaces (nets) */
1074 	msg->msg.hdr.cmd = CMD_VERSION;
1075 	msg->msg.hdr.len = 2;
1076 	msg->msg.version.rsvd = 0;
1077 	msg->msg.version.flags = 0;
1078 	msg->msg.version.drv_version = 0;
1079 
1080 	err = esd_usb2_send_msg(dev, msg);
1081 	if (err < 0) {
1082 		dev_err(&intf->dev, "sending version message failed\n");
1083 		goto free_msg;
1084 	}
1085 
1086 	err = esd_usb2_wait_msg(dev, msg);
1087 	if (err < 0) {
1088 		dev_err(&intf->dev, "no version message answer\n");
1089 		goto free_msg;
1090 	}
1091 
1092 	dev->net_count = (int)msg->msg.version_reply.nets;
1093 	dev->version = le32_to_cpu(msg->msg.version_reply.version);
1094 
1095 	if (device_create_file(&intf->dev, &dev_attr_firmware))
1096 		dev_err(&intf->dev,
1097 			"Couldn't create device file for firmware\n");
1098 
1099 	if (device_create_file(&intf->dev, &dev_attr_hardware))
1100 		dev_err(&intf->dev,
1101 			"Couldn't create device file for hardware\n");
1102 
1103 	if (device_create_file(&intf->dev, &dev_attr_nets))
1104 		dev_err(&intf->dev,
1105 			"Couldn't create device file for nets\n");
1106 
1107 	/* do per device probing */
1108 	for (i = 0; i < dev->net_count; i++)
1109 		esd_usb2_probe_one_net(intf, i);
1110 
1111 free_msg:
1112 	kfree(msg);
1113 	if (err)
1114 		kfree(dev);
1115 done:
1116 	return err;
1117 }
1118 
1119 /*
1120  * called by the usb core when the device is removed from the system
1121  */
esd_usb2_disconnect(struct usb_interface * intf)1122 static void esd_usb2_disconnect(struct usb_interface *intf)
1123 {
1124 	struct esd_usb2 *dev = usb_get_intfdata(intf);
1125 	struct net_device *netdev;
1126 	int i;
1127 
1128 	device_remove_file(&intf->dev, &dev_attr_firmware);
1129 	device_remove_file(&intf->dev, &dev_attr_hardware);
1130 	device_remove_file(&intf->dev, &dev_attr_nets);
1131 
1132 	usb_set_intfdata(intf, NULL);
1133 
1134 	if (dev) {
1135 		for (i = 0; i < dev->net_count; i++) {
1136 			if (dev->nets[i]) {
1137 				netdev = dev->nets[i]->netdev;
1138 				unregister_netdev(netdev);
1139 				free_candev(netdev);
1140 			}
1141 		}
1142 		unlink_all_urbs(dev);
1143 		kfree(dev);
1144 	}
1145 }
1146 
1147 /* usb specific object needed to register this driver with the usb subsystem */
1148 static struct usb_driver esd_usb2_driver = {
1149 	.name = "esd_usb2",
1150 	.probe = esd_usb2_probe,
1151 	.disconnect = esd_usb2_disconnect,
1152 	.id_table = esd_usb2_table,
1153 };
1154 
1155 module_usb_driver(esd_usb2_driver);
1156