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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * CAN driver for "8 devices" USB2CAN converter
4 *
5 * Copyright (C) 2012 Bernd Krumboeck (krumboeck@universalnet.at)
6 *
7 * This driver is inspired by the 3.2.0 version of drivers/net/can/usb/ems_usb.c
8 * and drivers/net/can/usb/esd_usb2.c
9 *
10 * Many thanks to Gerhard Bertelsmann (info@gerhard-bertelsmann.de)
11 * for testing and fixing this driver. Also many thanks to "8 devices",
12 * who were very cooperative and answered my questions.
13 */
14
15#include <linux/signal.h>
16#include <linux/slab.h>
17#include <linux/module.h>
18#include <linux/netdevice.h>
19#include <linux/usb.h>
20
21#include <linux/can.h>
22#include <linux/can/dev.h>
23#include <linux/can/error.h>
24#include <linux/can/led.h>
25
26/* driver constants */
27#define MAX_RX_URBS 20
28#define MAX_TX_URBS 20
29#define RX_BUFFER_SIZE 64
30
31/* vendor and product id */
32#define USB_8DEV_VENDOR_ID 0x0483
33#define USB_8DEV_PRODUCT_ID 0x1234
34
35/* endpoints */
36enum usb_8dev_endpoint {
37 USB_8DEV_ENDP_DATA_RX = 1,
38 USB_8DEV_ENDP_DATA_TX,
39 USB_8DEV_ENDP_CMD_RX,
40 USB_8DEV_ENDP_CMD_TX
41};
42
43/* device CAN clock */
44#define USB_8DEV_ABP_CLOCK 32000000
45
46/* setup flags */
47#define USB_8DEV_SILENT 0x01
48#define USB_8DEV_LOOPBACK 0x02
49#define USB_8DEV_DISABLE_AUTO_RESTRANS 0x04
50#define USB_8DEV_STATUS_FRAME 0x08
51
52/* commands */
53enum usb_8dev_cmd {
54 USB_8DEV_RESET = 1,
55 USB_8DEV_OPEN,
56 USB_8DEV_CLOSE,
57 USB_8DEV_SET_SPEED,
58 USB_8DEV_SET_MASK_FILTER,
59 USB_8DEV_GET_STATUS,
60 USB_8DEV_GET_STATISTICS,
61 USB_8DEV_GET_SERIAL,
62 USB_8DEV_GET_SOFTW_VER,
63 USB_8DEV_GET_HARDW_VER,
64 USB_8DEV_RESET_TIMESTAMP,
65 USB_8DEV_GET_SOFTW_HARDW_VER
66};
67
68/* command options */
69#define USB_8DEV_BAUD_MANUAL 0x09
70#define USB_8DEV_CMD_START 0x11
71#define USB_8DEV_CMD_END 0x22
72
73#define USB_8DEV_CMD_SUCCESS 0
74#define USB_8DEV_CMD_ERROR 255
75
76#define USB_8DEV_CMD_TIMEOUT 1000
77
78/* frames */
79#define USB_8DEV_DATA_START 0x55
80#define USB_8DEV_DATA_END 0xAA
81
82#define USB_8DEV_TYPE_CAN_FRAME 0
83#define USB_8DEV_TYPE_ERROR_FRAME 3
84
85#define USB_8DEV_EXTID 0x01
86#define USB_8DEV_RTR 0x02
87#define USB_8DEV_ERR_FLAG 0x04
88
89/* status */
90#define USB_8DEV_STATUSMSG_OK 0x00 /* Normal condition. */
91#define USB_8DEV_STATUSMSG_OVERRUN 0x01 /* Overrun occured when sending */
92#define USB_8DEV_STATUSMSG_BUSLIGHT 0x02 /* Error counter has reached 96 */
93#define USB_8DEV_STATUSMSG_BUSHEAVY 0x03 /* Error count. has reached 128 */
94#define USB_8DEV_STATUSMSG_BUSOFF 0x04 /* Device is in BUSOFF */
95#define USB_8DEV_STATUSMSG_STUFF 0x20 /* Stuff Error */
96#define USB_8DEV_STATUSMSG_FORM 0x21 /* Form Error */
97#define USB_8DEV_STATUSMSG_ACK 0x23 /* Ack Error */
98#define USB_8DEV_STATUSMSG_BIT0 0x24 /* Bit1 Error */
99#define USB_8DEV_STATUSMSG_BIT1 0x25 /* Bit0 Error */
100#define USB_8DEV_STATUSMSG_CRC 0x27 /* CRC Error */
101
102#define USB_8DEV_RP_MASK 0x7F /* Mask for Receive Error Bit */
103
104
105/* table of devices that work with this driver */
106static const struct usb_device_id usb_8dev_table[] = {
107 { USB_DEVICE(USB_8DEV_VENDOR_ID, USB_8DEV_PRODUCT_ID) },
108 { } /* Terminating entry */
109};
110
111MODULE_DEVICE_TABLE(usb, usb_8dev_table);
112
113struct usb_8dev_tx_urb_context {
114 struct usb_8dev_priv *priv;
115
116 u32 echo_index;
117 u8 dlc;
118};
119
120/* Structure to hold all of our device specific stuff */
121struct usb_8dev_priv {
122 struct can_priv can; /* must be the first member */
123
124 struct sk_buff *echo_skb[MAX_TX_URBS];
125
126 struct usb_device *udev;
127 struct net_device *netdev;
128
129 atomic_t active_tx_urbs;
130 struct usb_anchor tx_submitted;
131 struct usb_8dev_tx_urb_context tx_contexts[MAX_TX_URBS];
132
133 struct usb_anchor rx_submitted;
134
135 struct can_berr_counter bec;
136
137 u8 *cmd_msg_buffer;
138
139 struct mutex usb_8dev_cmd_lock;
140
141};
142
143/* tx frame */
144struct __packed usb_8dev_tx_msg {
145 u8 begin;
146 u8 flags; /* RTR and EXT_ID flag */
147 __be32 id; /* upper 3 bits not used */
148 u8 dlc; /* data length code 0-8 bytes */
149 u8 data[8]; /* 64-bit data */
150 u8 end;
151};
152
153/* rx frame */
154struct __packed usb_8dev_rx_msg {
155 u8 begin;
156 u8 type; /* frame type */
157 u8 flags; /* RTR and EXT_ID flag */
158 __be32 id; /* upper 3 bits not used */
159 u8 dlc; /* data length code 0-8 bytes */
160 u8 data[8]; /* 64-bit data */
161 __be32 timestamp; /* 32-bit timestamp */
162 u8 end;
163};
164
165/* command frame */
166struct __packed usb_8dev_cmd_msg {
167 u8 begin;
168 u8 channel; /* unkown - always 0 */
169 u8 command; /* command to execute */
170 u8 opt1; /* optional parameter / return value */
171 u8 opt2; /* optional parameter 2 */
172 u8 data[10]; /* optional parameter and data */
173 u8 end;
174};
175
176static int usb_8dev_send_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size)
177{
178 int actual_length;
179
180 return usb_bulk_msg(priv->udev,
181 usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_TX),
182 msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT);
183}
184
185static int usb_8dev_wait_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size,
186 int *actual_length)
187{
188 return usb_bulk_msg(priv->udev,
189 usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_RX),
190 msg, size, actual_length, USB_8DEV_CMD_TIMEOUT);
191}
192
193/* Send command to device and receive result.
194 * Command was successful when opt1 = 0.
195 */
196static int usb_8dev_send_cmd(struct usb_8dev_priv *priv,
197 struct usb_8dev_cmd_msg *out,
198 struct usb_8dev_cmd_msg *in)
199{
200 int err;
201 int num_bytes_read;
202 struct net_device *netdev;
203
204 netdev = priv->netdev;
205
206 out->begin = USB_8DEV_CMD_START;
207 out->end = USB_8DEV_CMD_END;
208
209 mutex_lock(&priv->usb_8dev_cmd_lock);
210
211 memcpy(priv->cmd_msg_buffer, out,
212 sizeof(struct usb_8dev_cmd_msg));
213
214 err = usb_8dev_send_cmd_msg(priv, priv->cmd_msg_buffer,
215 sizeof(struct usb_8dev_cmd_msg));
216 if (err < 0) {
217 netdev_err(netdev, "sending command message failed\n");
218 goto failed;
219 }
220
221 err = usb_8dev_wait_cmd_msg(priv, priv->cmd_msg_buffer,
222 sizeof(struct usb_8dev_cmd_msg),
223 &num_bytes_read);
224 if (err < 0) {
225 netdev_err(netdev, "no command message answer\n");
226 goto failed;
227 }
228
229 memcpy(in, priv->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg));
230
231 if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END ||
232 num_bytes_read != 16 || in->opt1 != 0)
233 err = -EPROTO;
234
235failed:
236 mutex_unlock(&priv->usb_8dev_cmd_lock);
237 return err;
238}
239
240/* Send open command to device */
241static int usb_8dev_cmd_open(struct usb_8dev_priv *priv)
242{
243 struct can_bittiming *bt = &priv->can.bittiming;
244 struct usb_8dev_cmd_msg outmsg;
245 struct usb_8dev_cmd_msg inmsg;
246 u32 ctrlmode = priv->can.ctrlmode;
247 u32 flags = USB_8DEV_STATUS_FRAME;
248 __be32 beflags;
249 __be16 bebrp;
250
251 memset(&outmsg, 0, sizeof(outmsg));
252 outmsg.command = USB_8DEV_OPEN;
253 outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
254 outmsg.data[0] = bt->prop_seg + bt->phase_seg1;
255 outmsg.data[1] = bt->phase_seg2;
256 outmsg.data[2] = bt->sjw;
257
258 /* BRP */
259 bebrp = cpu_to_be16((u16)bt->brp);
260 memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp));
261
262 /* flags */
263 if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
264 flags |= USB_8DEV_LOOPBACK;
265 if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
266 flags |= USB_8DEV_SILENT;
267 if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
268 flags |= USB_8DEV_DISABLE_AUTO_RESTRANS;
269
270 beflags = cpu_to_be32(flags);
271 memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
272
273 return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
274}
275
276/* Send close command to device */
277static int usb_8dev_cmd_close(struct usb_8dev_priv *priv)
278{
279 struct usb_8dev_cmd_msg inmsg;
280 struct usb_8dev_cmd_msg outmsg = {
281 .channel = 0,
282 .command = USB_8DEV_CLOSE,
283 .opt1 = 0,
284 .opt2 = 0
285 };
286
287 return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
288}
289
290/* Get firmware and hardware version */
291static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, u32 *res)
292{
293 struct usb_8dev_cmd_msg inmsg;
294 struct usb_8dev_cmd_msg outmsg = {
295 .channel = 0,
296 .command = USB_8DEV_GET_SOFTW_HARDW_VER,
297 .opt1 = 0,
298 .opt2 = 0
299 };
300
301 int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg);
302 if (err)
303 return err;
304
305 *res = be32_to_cpup((__be32 *)inmsg.data);
306
307 return err;
308}
309
310/* Set network device mode
311 *
312 * Maybe we should leave this function empty, because the device
313 * set mode variable with open command.
314 */
315static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode)
316{
317 struct usb_8dev_priv *priv = netdev_priv(netdev);
318 int err = 0;
319
320 switch (mode) {
321 case CAN_MODE_START:
322 err = usb_8dev_cmd_open(priv);
323 if (err)
324 netdev_warn(netdev, "couldn't start device");
325 break;
326
327 default:
328 return -EOPNOTSUPP;
329 }
330
331 return err;
332}
333
334/* Read error/status frames */
335static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
336 struct usb_8dev_rx_msg *msg)
337{
338 struct can_frame *cf;
339 struct sk_buff *skb;
340 struct net_device_stats *stats = &priv->netdev->stats;
341
342 /* Error message:
343 * byte 0: Status
344 * byte 1: bit 7: Receive Passive
345 * byte 1: bit 0-6: Receive Error Counter
346 * byte 2: Transmit Error Counter
347 * byte 3: Always 0 (maybe reserved for future use)
348 */
349
350 u8 state = msg->data[0];
351 u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
352 u8 txerr = msg->data[2];
353 int rx_errors = 0;
354 int tx_errors = 0;
355
356 skb = alloc_can_err_skb(priv->netdev, &cf);
357 if (!skb)
358 return;
359
360 switch (state) {
361 case USB_8DEV_STATUSMSG_OK:
362 priv->can.state = CAN_STATE_ERROR_ACTIVE;
363 cf->can_id |= CAN_ERR_PROT;
364 cf->data[2] = CAN_ERR_PROT_ACTIVE;
365 break;
366 case USB_8DEV_STATUSMSG_BUSOFF:
367 priv->can.state = CAN_STATE_BUS_OFF;
368 cf->can_id |= CAN_ERR_BUSOFF;
369 priv->can.can_stats.bus_off++;
370 can_bus_off(priv->netdev);
371 break;
372 case USB_8DEV_STATUSMSG_OVERRUN:
373 case USB_8DEV_STATUSMSG_BUSLIGHT:
374 case USB_8DEV_STATUSMSG_BUSHEAVY:
375 cf->can_id |= CAN_ERR_CRTL;
376 break;
377 default:
378 priv->can.state = CAN_STATE_ERROR_WARNING;
379 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
380 priv->can.can_stats.bus_error++;
381 break;
382 }
383
384 switch (state) {
385 case USB_8DEV_STATUSMSG_OK:
386 case USB_8DEV_STATUSMSG_BUSOFF:
387 break;
388 case USB_8DEV_STATUSMSG_ACK:
389 cf->can_id |= CAN_ERR_ACK;
390 tx_errors = 1;
391 break;
392 case USB_8DEV_STATUSMSG_CRC:
393 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
394 rx_errors = 1;
395 break;
396 case USB_8DEV_STATUSMSG_BIT0:
397 cf->data[2] |= CAN_ERR_PROT_BIT0;
398 tx_errors = 1;
399 break;
400 case USB_8DEV_STATUSMSG_BIT1:
401 cf->data[2] |= CAN_ERR_PROT_BIT1;
402 tx_errors = 1;
403 break;
404 case USB_8DEV_STATUSMSG_FORM:
405 cf->data[2] |= CAN_ERR_PROT_FORM;
406 rx_errors = 1;
407 break;
408 case USB_8DEV_STATUSMSG_STUFF:
409 cf->data[2] |= CAN_ERR_PROT_STUFF;
410 rx_errors = 1;
411 break;
412 case USB_8DEV_STATUSMSG_OVERRUN:
413 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
414 stats->rx_over_errors++;
415 rx_errors = 1;
416 break;
417 case USB_8DEV_STATUSMSG_BUSLIGHT:
418 priv->can.state = CAN_STATE_ERROR_WARNING;
419 cf->data[1] = (txerr > rxerr) ?
420 CAN_ERR_CRTL_TX_WARNING :
421 CAN_ERR_CRTL_RX_WARNING;
422 priv->can.can_stats.error_warning++;
423 break;
424 case USB_8DEV_STATUSMSG_BUSHEAVY:
425 priv->can.state = CAN_STATE_ERROR_PASSIVE;
426 cf->data[1] = (txerr > rxerr) ?
427 CAN_ERR_CRTL_TX_PASSIVE :
428 CAN_ERR_CRTL_RX_PASSIVE;
429 priv->can.can_stats.error_passive++;
430 break;
431 default:
432 netdev_warn(priv->netdev,
433 "Unknown status/error message (%d)\n", state);
434 break;
435 }
436
437 if (tx_errors) {
438 cf->data[2] |= CAN_ERR_PROT_TX;
439 stats->tx_errors++;
440 }
441
442 if (rx_errors)
443 stats->rx_errors++;
444
445 cf->data[6] = txerr;
446 cf->data[7] = rxerr;
447
448 priv->bec.txerr = txerr;
449 priv->bec.rxerr = rxerr;
450
451 stats->rx_packets++;
452 stats->rx_bytes += cf->can_dlc;
453 netif_rx(skb);
454}
455
456/* Read data and status frames */
457static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
458 struct usb_8dev_rx_msg *msg)
459{
460 struct can_frame *cf;
461 struct sk_buff *skb;
462 struct net_device_stats *stats = &priv->netdev->stats;
463
464 if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
465 msg->flags == USB_8DEV_ERR_FLAG) {
466 usb_8dev_rx_err_msg(priv, msg);
467 } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
468 skb = alloc_can_skb(priv->netdev, &cf);
469 if (!skb)
470 return;
471
472 cf->can_id = be32_to_cpu(msg->id);
473 cf->can_dlc = get_can_dlc(msg->dlc & 0xF);
474
475 if (msg->flags & USB_8DEV_EXTID)
476 cf->can_id |= CAN_EFF_FLAG;
477
478 if (msg->flags & USB_8DEV_RTR)
479 cf->can_id |= CAN_RTR_FLAG;
480 else
481 memcpy(cf->data, msg->data, cf->can_dlc);
482
483 stats->rx_packets++;
484 stats->rx_bytes += cf->can_dlc;
485 netif_rx(skb);
486
487 can_led_event(priv->netdev, CAN_LED_EVENT_RX);
488 } else {
489 netdev_warn(priv->netdev, "frame type %d unknown",
490 msg->type);
491 }
492
493}
494
495/* Callback for reading data from device
496 *
497 * Check urb status, call read function and resubmit urb read operation.
498 */
499static void usb_8dev_read_bulk_callback(struct urb *urb)
500{
501 struct usb_8dev_priv *priv = urb->context;
502 struct net_device *netdev;
503 int retval;
504 int pos = 0;
505
506 netdev = priv->netdev;
507
508 if (!netif_device_present(netdev))
509 return;
510
511 switch (urb->status) {
512 case 0: /* success */
513 break;
514
515 case -ENOENT:
516 case -EPIPE:
517 case -EPROTO:
518 case -ESHUTDOWN:
519 return;
520
521 default:
522 netdev_info(netdev, "Rx URB aborted (%d)\n",
523 urb->status);
524 goto resubmit_urb;
525 }
526
527 while (pos < urb->actual_length) {
528 struct usb_8dev_rx_msg *msg;
529
530 if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
531 netdev_err(priv->netdev, "format error\n");
532 break;
533 }
534
535 msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
536 usb_8dev_rx_can_msg(priv, msg);
537
538 pos += sizeof(struct usb_8dev_rx_msg);
539 }
540
541resubmit_urb:
542 usb_fill_bulk_urb(urb, priv->udev,
543 usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
544 urb->transfer_buffer, RX_BUFFER_SIZE,
545 usb_8dev_read_bulk_callback, priv);
546
547 retval = usb_submit_urb(urb, GFP_ATOMIC);
548
549 if (retval == -ENODEV)
550 netif_device_detach(netdev);
551 else if (retval)
552 netdev_err(netdev,
553 "failed resubmitting read bulk urb: %d\n", retval);
554}
555
556/* Callback handler for write operations
557 *
558 * Free allocated buffers, check transmit status and
559 * calculate statistic.
560 */
561static void usb_8dev_write_bulk_callback(struct urb *urb)
562{
563 struct usb_8dev_tx_urb_context *context = urb->context;
564 struct usb_8dev_priv *priv;
565 struct net_device *netdev;
566
567 BUG_ON(!context);
568
569 priv = context->priv;
570 netdev = priv->netdev;
571
572 /* free up our allocated buffer */
573 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
574 urb->transfer_buffer, urb->transfer_dma);
575
576 atomic_dec(&priv->active_tx_urbs);
577
578 if (!netif_device_present(netdev))
579 return;
580
581 if (urb->status)
582 netdev_info(netdev, "Tx URB aborted (%d)\n",
583 urb->status);
584
585 netdev->stats.tx_packets++;
586 netdev->stats.tx_bytes += context->dlc;
587
588 can_get_echo_skb(netdev, context->echo_index);
589
590 can_led_event(netdev, CAN_LED_EVENT_TX);
591
592 /* Release context */
593 context->echo_index = MAX_TX_URBS;
594
595 netif_wake_queue(netdev);
596}
597
598/* Send data to device */
599static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
600 struct net_device *netdev)
601{
602 struct usb_8dev_priv *priv = netdev_priv(netdev);
603 struct net_device_stats *stats = &netdev->stats;
604 struct can_frame *cf = (struct can_frame *) skb->data;
605 struct usb_8dev_tx_msg *msg;
606 struct urb *urb;
607 struct usb_8dev_tx_urb_context *context = NULL;
608 u8 *buf;
609 int i, err;
610 size_t size = sizeof(struct usb_8dev_tx_msg);
611
612 if (can_dropped_invalid_skb(netdev, skb))
613 return NETDEV_TX_OK;
614
615 /* create a URB, and a buffer for it, and copy the data to the URB */
616 urb = usb_alloc_urb(0, GFP_ATOMIC);
617 if (!urb)
618 goto nomem;
619
620 buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
621 &urb->transfer_dma);
622 if (!buf) {
623 netdev_err(netdev, "No memory left for USB buffer\n");
624 goto nomembuf;
625 }
626
627 memset(buf, 0, size);
628
629 msg = (struct usb_8dev_tx_msg *)buf;
630 msg->begin = USB_8DEV_DATA_START;
631 msg->flags = 0x00;
632
633 if (cf->can_id & CAN_RTR_FLAG)
634 msg->flags |= USB_8DEV_RTR;
635
636 if (cf->can_id & CAN_EFF_FLAG)
637 msg->flags |= USB_8DEV_EXTID;
638
639 msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
640 msg->dlc = cf->can_dlc;
641 memcpy(msg->data, cf->data, cf->can_dlc);
642 msg->end = USB_8DEV_DATA_END;
643
644 for (i = 0; i < MAX_TX_URBS; i++) {
645 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
646 context = &priv->tx_contexts[i];
647 break;
648 }
649 }
650
651 /* May never happen! When this happens we'd more URBs in flight as
652 * allowed (MAX_TX_URBS).
653 */
654 if (!context)
655 goto nofreecontext;
656
657 context->priv = priv;
658 context->echo_index = i;
659 context->dlc = cf->can_dlc;
660
661 usb_fill_bulk_urb(urb, priv->udev,
662 usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
663 buf, size, usb_8dev_write_bulk_callback, context);
664 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
665 usb_anchor_urb(urb, &priv->tx_submitted);
666
667 can_put_echo_skb(skb, netdev, context->echo_index);
668
669 atomic_inc(&priv->active_tx_urbs);
670
671 err = usb_submit_urb(urb, GFP_ATOMIC);
672 if (unlikely(err))
673 goto failed;
674 else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
675 /* Slow down tx path */
676 netif_stop_queue(netdev);
677
678 /* Release our reference to this URB, the USB core will eventually free
679 * it entirely.
680 */
681 usb_free_urb(urb);
682
683 return NETDEV_TX_OK;
684
685nofreecontext:
686 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
687 usb_free_urb(urb);
688
689 netdev_warn(netdev, "couldn't find free context");
690
691 return NETDEV_TX_BUSY;
692
693failed:
694 can_free_echo_skb(netdev, context->echo_index);
695
696 usb_unanchor_urb(urb);
697 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
698
699 atomic_dec(&priv->active_tx_urbs);
700
701 if (err == -ENODEV)
702 netif_device_detach(netdev);
703 else
704 netdev_warn(netdev, "failed tx_urb %d\n", err);
705
706nomembuf:
707 usb_free_urb(urb);
708
709nomem:
710 dev_kfree_skb(skb);
711 stats->tx_dropped++;
712
713 return NETDEV_TX_OK;
714}
715
716static int usb_8dev_get_berr_counter(const struct net_device *netdev,
717 struct can_berr_counter *bec)
718{
719 struct usb_8dev_priv *priv = netdev_priv(netdev);
720
721 bec->txerr = priv->bec.txerr;
722 bec->rxerr = priv->bec.rxerr;
723
724 return 0;
725}
726
727/* Start USB device */
728static int usb_8dev_start(struct usb_8dev_priv *priv)
729{
730 struct net_device *netdev = priv->netdev;
731 int err, i;
732
733 for (i = 0; i < MAX_RX_URBS; i++) {
734 struct urb *urb = NULL;
735 u8 *buf;
736
737 /* create a URB, and a buffer for it */
738 urb = usb_alloc_urb(0, GFP_KERNEL);
739 if (!urb) {
740 err = -ENOMEM;
741 break;
742 }
743
744 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
745 &urb->transfer_dma);
746 if (!buf) {
747 netdev_err(netdev, "No memory left for USB buffer\n");
748 usb_free_urb(urb);
749 err = -ENOMEM;
750 break;
751 }
752
753 usb_fill_bulk_urb(urb, priv->udev,
754 usb_rcvbulkpipe(priv->udev,
755 USB_8DEV_ENDP_DATA_RX),
756 buf, RX_BUFFER_SIZE,
757 usb_8dev_read_bulk_callback, priv);
758 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
759 usb_anchor_urb(urb, &priv->rx_submitted);
760
761 err = usb_submit_urb(urb, GFP_KERNEL);
762 if (err) {
763 usb_unanchor_urb(urb);
764 usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
765 urb->transfer_dma);
766 usb_free_urb(urb);
767 break;
768 }
769
770 /* Drop reference, USB core will take care of freeing it */
771 usb_free_urb(urb);
772 }
773
774 /* Did we submit any URBs */
775 if (i == 0) {
776 netdev_warn(netdev, "couldn't setup read URBs\n");
777 return err;
778 }
779
780 /* Warn if we've couldn't transmit all the URBs */
781 if (i < MAX_RX_URBS)
782 netdev_warn(netdev, "rx performance may be slow\n");
783
784 err = usb_8dev_cmd_open(priv);
785 if (err)
786 goto failed;
787
788 priv->can.state = CAN_STATE_ERROR_ACTIVE;
789
790 return 0;
791
792failed:
793 if (err == -ENODEV)
794 netif_device_detach(priv->netdev);
795
796 netdev_warn(netdev, "couldn't submit control: %d\n", err);
797
798 return err;
799}
800
801/* Open USB device */
802static int usb_8dev_open(struct net_device *netdev)
803{
804 struct usb_8dev_priv *priv = netdev_priv(netdev);
805 int err;
806
807 /* common open */
808 err = open_candev(netdev);
809 if (err)
810 return err;
811
812 can_led_event(netdev, CAN_LED_EVENT_OPEN);
813
814 /* finally start device */
815 err = usb_8dev_start(priv);
816 if (err) {
817 if (err == -ENODEV)
818 netif_device_detach(priv->netdev);
819
820 netdev_warn(netdev, "couldn't start device: %d\n",
821 err);
822
823 close_candev(netdev);
824
825 return err;
826 }
827
828 netif_start_queue(netdev);
829
830 return 0;
831}
832
833static void unlink_all_urbs(struct usb_8dev_priv *priv)
834{
835 int i;
836
837 usb_kill_anchored_urbs(&priv->rx_submitted);
838
839 usb_kill_anchored_urbs(&priv->tx_submitted);
840 atomic_set(&priv->active_tx_urbs, 0);
841
842 for (i = 0; i < MAX_TX_URBS; i++)
843 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
844}
845
846/* Close USB device */
847static int usb_8dev_close(struct net_device *netdev)
848{
849 struct usb_8dev_priv *priv = netdev_priv(netdev);
850 int err = 0;
851
852 /* Send CLOSE command to CAN controller */
853 err = usb_8dev_cmd_close(priv);
854 if (err)
855 netdev_warn(netdev, "couldn't stop device");
856
857 priv->can.state = CAN_STATE_STOPPED;
858
859 netif_stop_queue(netdev);
860
861 /* Stop polling */
862 unlink_all_urbs(priv);
863
864 close_candev(netdev);
865
866 can_led_event(netdev, CAN_LED_EVENT_STOP);
867
868 return err;
869}
870
871static const struct net_device_ops usb_8dev_netdev_ops = {
872 .ndo_open = usb_8dev_open,
873 .ndo_stop = usb_8dev_close,
874 .ndo_start_xmit = usb_8dev_start_xmit,
875 .ndo_change_mtu = can_change_mtu,
876};
877
878static const struct can_bittiming_const usb_8dev_bittiming_const = {
879 .name = "usb_8dev",
880 .tseg1_min = 1,
881 .tseg1_max = 16,
882 .tseg2_min = 1,
883 .tseg2_max = 8,
884 .sjw_max = 4,
885 .brp_min = 1,
886 .brp_max = 1024,
887 .brp_inc = 1,
888};
889
890/* Probe USB device
891 *
892 * Check device and firmware.
893 * Set supported modes and bittiming constants.
894 * Allocate some memory.
895 */
896static int usb_8dev_probe(struct usb_interface *intf,
897 const struct usb_device_id *id)
898{
899 struct net_device *netdev;
900 struct usb_8dev_priv *priv;
901 int i, err = -ENOMEM;
902 u32 version;
903 char buf[18];
904 struct usb_device *usbdev = interface_to_usbdev(intf);
905
906 /* product id looks strange, better we also check iProduct string */
907 if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
908 sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
909 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
910 return -ENODEV;
911 }
912
913 netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
914 if (!netdev) {
915 dev_err(&intf->dev, "Couldn't alloc candev\n");
916 return -ENOMEM;
917 }
918
919 priv = netdev_priv(netdev);
920
921 priv->udev = usbdev;
922 priv->netdev = netdev;
923
924 priv->can.state = CAN_STATE_STOPPED;
925 priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
926 priv->can.bittiming_const = &usb_8dev_bittiming_const;
927 priv->can.do_set_mode = usb_8dev_set_mode;
928 priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
929 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
930 CAN_CTRLMODE_LISTENONLY |
931 CAN_CTRLMODE_ONE_SHOT;
932
933 netdev->netdev_ops = &usb_8dev_netdev_ops;
934
935 netdev->flags |= IFF_ECHO; /* we support local echo */
936
937 init_usb_anchor(&priv->rx_submitted);
938
939 init_usb_anchor(&priv->tx_submitted);
940 atomic_set(&priv->active_tx_urbs, 0);
941
942 for (i = 0; i < MAX_TX_URBS; i++)
943 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
944
945 priv->cmd_msg_buffer = devm_kzalloc(&intf->dev, sizeof(struct usb_8dev_cmd_msg),
946 GFP_KERNEL);
947 if (!priv->cmd_msg_buffer)
948 goto cleanup_candev;
949
950 usb_set_intfdata(intf, priv);
951
952 SET_NETDEV_DEV(netdev, &intf->dev);
953
954 mutex_init(&priv->usb_8dev_cmd_lock);
955
956 err = register_candev(netdev);
957 if (err) {
958 netdev_err(netdev,
959 "couldn't register CAN device: %d\n", err);
960 goto cleanup_candev;
961 }
962
963 err = usb_8dev_cmd_version(priv, &version);
964 if (err) {
965 netdev_err(netdev, "can't get firmware version\n");
966 goto cleanup_unregister_candev;
967 } else {
968 netdev_info(netdev,
969 "firmware: %d.%d, hardware: %d.%d\n",
970 (version>>24) & 0xff, (version>>16) & 0xff,
971 (version>>8) & 0xff, version & 0xff);
972 }
973
974 devm_can_led_init(netdev);
975
976 return 0;
977
978cleanup_unregister_candev:
979 unregister_netdev(priv->netdev);
980
981cleanup_candev:
982 free_candev(netdev);
983
984 return err;
985
986}
987
988/* Called by the usb core when driver is unloaded or device is removed */
989static void usb_8dev_disconnect(struct usb_interface *intf)
990{
991 struct usb_8dev_priv *priv = usb_get_intfdata(intf);
992
993 usb_set_intfdata(intf, NULL);
994
995 if (priv) {
996 netdev_info(priv->netdev, "device disconnected\n");
997
998 unregister_netdev(priv->netdev);
999 unlink_all_urbs(priv);
1000 free_candev(priv->netdev);
1001 }
1002
1003}
1004
1005static struct usb_driver usb_8dev_driver = {
1006 .name = "usb_8dev",
1007 .probe = usb_8dev_probe,
1008 .disconnect = usb_8dev_disconnect,
1009 .id_table = usb_8dev_table,
1010};
1011
1012module_usb_driver(usb_8dev_driver);
1013
1014MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>");
1015MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
1016MODULE_LICENSE("GPL v2");