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1/*
2 * CAN driver for "8 devices" USB2CAN converter
3 *
4 * Copyright (C) 2012 Bernd Krumboeck (krumboeck@universalnet.at)
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published
8 * by the Free Software Foundation; version 2 of the License.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program.
17 *
18 * This driver is inspired by the 3.2.0 version of drivers/net/can/usb/ems_usb.c
19 * and drivers/net/can/usb/esd_usb2.c
20 *
21 * Many thanks to Gerhard Bertelsmann (info@gerhard-bertelsmann.de)
22 * for testing and fixing this driver. Also many thanks to "8 devices",
23 * who were very cooperative and answered my questions.
24 */
25
26#include <linux/signal.h>
27#include <linux/slab.h>
28#include <linux/module.h>
29#include <linux/netdevice.h>
30#include <linux/usb.h>
31
32#include <linux/can.h>
33#include <linux/can/dev.h>
34#include <linux/can/error.h>
35#include <linux/can/led.h>
36
37/* driver constants */
38#define MAX_RX_URBS 20
39#define MAX_TX_URBS 20
40#define RX_BUFFER_SIZE 64
41
42/* vendor and product id */
43#define USB_8DEV_VENDOR_ID 0x0483
44#define USB_8DEV_PRODUCT_ID 0x1234
45
46/* endpoints */
47enum usb_8dev_endpoint {
48 USB_8DEV_ENDP_DATA_RX = 1,
49 USB_8DEV_ENDP_DATA_TX,
50 USB_8DEV_ENDP_CMD_RX,
51 USB_8DEV_ENDP_CMD_TX
52};
53
54/* device CAN clock */
55#define USB_8DEV_ABP_CLOCK 32000000
56
57/* setup flags */
58#define USB_8DEV_SILENT 0x01
59#define USB_8DEV_LOOPBACK 0x02
60#define USB_8DEV_DISABLE_AUTO_RESTRANS 0x04
61#define USB_8DEV_STATUS_FRAME 0x08
62
63/* commands */
64enum usb_8dev_cmd {
65 USB_8DEV_RESET = 1,
66 USB_8DEV_OPEN,
67 USB_8DEV_CLOSE,
68 USB_8DEV_SET_SPEED,
69 USB_8DEV_SET_MASK_FILTER,
70 USB_8DEV_GET_STATUS,
71 USB_8DEV_GET_STATISTICS,
72 USB_8DEV_GET_SERIAL,
73 USB_8DEV_GET_SOFTW_VER,
74 USB_8DEV_GET_HARDW_VER,
75 USB_8DEV_RESET_TIMESTAMP,
76 USB_8DEV_GET_SOFTW_HARDW_VER
77};
78
79/* command options */
80#define USB_8DEV_BAUD_MANUAL 0x09
81#define USB_8DEV_CMD_START 0x11
82#define USB_8DEV_CMD_END 0x22
83
84#define USB_8DEV_CMD_SUCCESS 0
85#define USB_8DEV_CMD_ERROR 255
86
87#define USB_8DEV_CMD_TIMEOUT 1000
88
89/* frames */
90#define USB_8DEV_DATA_START 0x55
91#define USB_8DEV_DATA_END 0xAA
92
93#define USB_8DEV_TYPE_CAN_FRAME 0
94#define USB_8DEV_TYPE_ERROR_FRAME 3
95
96#define USB_8DEV_EXTID 0x01
97#define USB_8DEV_RTR 0x02
98#define USB_8DEV_ERR_FLAG 0x04
99
100/* status */
101#define USB_8DEV_STATUSMSG_OK 0x00 /* Normal condition. */
102#define USB_8DEV_STATUSMSG_OVERRUN 0x01 /* Overrun occured when sending */
103#define USB_8DEV_STATUSMSG_BUSLIGHT 0x02 /* Error counter has reached 96 */
104#define USB_8DEV_STATUSMSG_BUSHEAVY 0x03 /* Error count. has reached 128 */
105#define USB_8DEV_STATUSMSG_BUSOFF 0x04 /* Device is in BUSOFF */
106#define USB_8DEV_STATUSMSG_STUFF 0x20 /* Stuff Error */
107#define USB_8DEV_STATUSMSG_FORM 0x21 /* Form Error */
108#define USB_8DEV_STATUSMSG_ACK 0x23 /* Ack Error */
109#define USB_8DEV_STATUSMSG_BIT0 0x24 /* Bit1 Error */
110#define USB_8DEV_STATUSMSG_BIT1 0x25 /* Bit0 Error */
111#define USB_8DEV_STATUSMSG_CRC 0x27 /* CRC Error */
112
113#define USB_8DEV_RP_MASK 0x7F /* Mask for Receive Error Bit */
114
115
116/* table of devices that work with this driver */
117static const struct usb_device_id usb_8dev_table[] = {
118 { USB_DEVICE(USB_8DEV_VENDOR_ID, USB_8DEV_PRODUCT_ID) },
119 { } /* Terminating entry */
120};
121
122MODULE_DEVICE_TABLE(usb, usb_8dev_table);
123
124struct usb_8dev_tx_urb_context {
125 struct usb_8dev_priv *priv;
126
127 u32 echo_index;
128 u8 dlc;
129};
130
131/* Structure to hold all of our device specific stuff */
132struct usb_8dev_priv {
133 struct can_priv can; /* must be the first member */
134
135 struct sk_buff *echo_skb[MAX_TX_URBS];
136
137 struct usb_device *udev;
138 struct net_device *netdev;
139
140 atomic_t active_tx_urbs;
141 struct usb_anchor tx_submitted;
142 struct usb_8dev_tx_urb_context tx_contexts[MAX_TX_URBS];
143
144 struct usb_anchor rx_submitted;
145
146 struct can_berr_counter bec;
147
148 u8 *cmd_msg_buffer;
149
150 struct mutex usb_8dev_cmd_lock;
151
152};
153
154/* tx frame */
155struct __packed usb_8dev_tx_msg {
156 u8 begin;
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 u8 end;
162};
163
164/* rx frame */
165struct __packed usb_8dev_rx_msg {
166 u8 begin;
167 u8 type; /* frame type */
168 u8 flags; /* RTR and EXT_ID flag */
169 __be32 id; /* upper 3 bits not used */
170 u8 dlc; /* data length code 0-8 bytes */
171 u8 data[8]; /* 64-bit data */
172 __be32 timestamp; /* 32-bit timestamp */
173 u8 end;
174};
175
176/* command frame */
177struct __packed usb_8dev_cmd_msg {
178 u8 begin;
179 u8 channel; /* unkown - always 0 */
180 u8 command; /* command to execute */
181 u8 opt1; /* optional parameter / return value */
182 u8 opt2; /* optional parameter 2 */
183 u8 data[10]; /* optional parameter and data */
184 u8 end;
185};
186
187static int usb_8dev_send_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size)
188{
189 int actual_length;
190
191 return usb_bulk_msg(priv->udev,
192 usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_TX),
193 msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT);
194}
195
196static int usb_8dev_wait_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size,
197 int *actual_length)
198{
199 return usb_bulk_msg(priv->udev,
200 usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_RX),
201 msg, size, actual_length, USB_8DEV_CMD_TIMEOUT);
202}
203
204/* Send command to device and receive result.
205 * Command was successful when opt1 = 0.
206 */
207static int usb_8dev_send_cmd(struct usb_8dev_priv *priv,
208 struct usb_8dev_cmd_msg *out,
209 struct usb_8dev_cmd_msg *in)
210{
211 int err;
212 int num_bytes_read;
213 struct net_device *netdev;
214
215 netdev = priv->netdev;
216
217 out->begin = USB_8DEV_CMD_START;
218 out->end = USB_8DEV_CMD_END;
219
220 mutex_lock(&priv->usb_8dev_cmd_lock);
221
222 memcpy(priv->cmd_msg_buffer, out,
223 sizeof(struct usb_8dev_cmd_msg));
224
225 err = usb_8dev_send_cmd_msg(priv, priv->cmd_msg_buffer,
226 sizeof(struct usb_8dev_cmd_msg));
227 if (err < 0) {
228 netdev_err(netdev, "sending command message failed\n");
229 goto failed;
230 }
231
232 err = usb_8dev_wait_cmd_msg(priv, priv->cmd_msg_buffer,
233 sizeof(struct usb_8dev_cmd_msg),
234 &num_bytes_read);
235 if (err < 0) {
236 netdev_err(netdev, "no command message answer\n");
237 goto failed;
238 }
239
240 memcpy(in, priv->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg));
241
242 if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END ||
243 num_bytes_read != 16 || in->opt1 != 0)
244 err = -EPROTO;
245
246failed:
247 mutex_unlock(&priv->usb_8dev_cmd_lock);
248 return err;
249}
250
251/* Send open command to device */
252static int usb_8dev_cmd_open(struct usb_8dev_priv *priv)
253{
254 struct can_bittiming *bt = &priv->can.bittiming;
255 struct usb_8dev_cmd_msg outmsg;
256 struct usb_8dev_cmd_msg inmsg;
257 u32 ctrlmode = priv->can.ctrlmode;
258 u32 flags = USB_8DEV_STATUS_FRAME;
259 __be32 beflags;
260 __be16 bebrp;
261
262 memset(&outmsg, 0, sizeof(outmsg));
263 outmsg.command = USB_8DEV_OPEN;
264 outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
265 outmsg.data[0] = bt->prop_seg + bt->phase_seg1;
266 outmsg.data[1] = bt->phase_seg2;
267 outmsg.data[2] = bt->sjw;
268
269 /* BRP */
270 bebrp = cpu_to_be16((u16)bt->brp);
271 memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp));
272
273 /* flags */
274 if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
275 flags |= USB_8DEV_LOOPBACK;
276 if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
277 flags |= USB_8DEV_SILENT;
278 if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
279 flags |= USB_8DEV_DISABLE_AUTO_RESTRANS;
280
281 beflags = cpu_to_be32(flags);
282 memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
283
284 return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
285}
286
287/* Send close command to device */
288static int usb_8dev_cmd_close(struct usb_8dev_priv *priv)
289{
290 struct usb_8dev_cmd_msg inmsg;
291 struct usb_8dev_cmd_msg outmsg = {
292 .channel = 0,
293 .command = USB_8DEV_CLOSE,
294 .opt1 = 0,
295 .opt2 = 0
296 };
297
298 return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
299}
300
301/* Get firmware and hardware version */
302static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, u32 *res)
303{
304 struct usb_8dev_cmd_msg inmsg;
305 struct usb_8dev_cmd_msg outmsg = {
306 .channel = 0,
307 .command = USB_8DEV_GET_SOFTW_HARDW_VER,
308 .opt1 = 0,
309 .opt2 = 0
310 };
311
312 int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg);
313 if (err)
314 return err;
315
316 *res = be32_to_cpup((__be32 *)inmsg.data);
317
318 return err;
319}
320
321/* Set network device mode
322 *
323 * Maybe we should leave this function empty, because the device
324 * set mode variable with open command.
325 */
326static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode)
327{
328 struct usb_8dev_priv *priv = netdev_priv(netdev);
329 int err = 0;
330
331 switch (mode) {
332 case CAN_MODE_START:
333 err = usb_8dev_cmd_open(priv);
334 if (err)
335 netdev_warn(netdev, "couldn't start device");
336 break;
337
338 default:
339 return -EOPNOTSUPP;
340 }
341
342 return err;
343}
344
345/* Read error/status frames */
346static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
347 struct usb_8dev_rx_msg *msg)
348{
349 struct can_frame *cf;
350 struct sk_buff *skb;
351 struct net_device_stats *stats = &priv->netdev->stats;
352
353 /* Error message:
354 * byte 0: Status
355 * byte 1: bit 7: Receive Passive
356 * byte 1: bit 0-6: Receive Error Counter
357 * byte 2: Transmit Error Counter
358 * byte 3: Always 0 (maybe reserved for future use)
359 */
360
361 u8 state = msg->data[0];
362 u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
363 u8 txerr = msg->data[2];
364 int rx_errors = 0;
365 int tx_errors = 0;
366
367 skb = alloc_can_err_skb(priv->netdev, &cf);
368 if (!skb)
369 return;
370
371 switch (state) {
372 case USB_8DEV_STATUSMSG_OK:
373 priv->can.state = CAN_STATE_ERROR_ACTIVE;
374 cf->can_id |= CAN_ERR_PROT;
375 cf->data[2] = CAN_ERR_PROT_ACTIVE;
376 break;
377 case USB_8DEV_STATUSMSG_BUSOFF:
378 priv->can.state = CAN_STATE_BUS_OFF;
379 cf->can_id |= CAN_ERR_BUSOFF;
380 priv->can.can_stats.bus_off++;
381 can_bus_off(priv->netdev);
382 break;
383 case USB_8DEV_STATUSMSG_OVERRUN:
384 case USB_8DEV_STATUSMSG_BUSLIGHT:
385 case USB_8DEV_STATUSMSG_BUSHEAVY:
386 cf->can_id |= CAN_ERR_CRTL;
387 break;
388 default:
389 priv->can.state = CAN_STATE_ERROR_WARNING;
390 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
391 priv->can.can_stats.bus_error++;
392 break;
393 }
394
395 switch (state) {
396 case USB_8DEV_STATUSMSG_OK:
397 case USB_8DEV_STATUSMSG_BUSOFF:
398 break;
399 case USB_8DEV_STATUSMSG_ACK:
400 cf->can_id |= CAN_ERR_ACK;
401 tx_errors = 1;
402 break;
403 case USB_8DEV_STATUSMSG_CRC:
404 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
405 rx_errors = 1;
406 break;
407 case USB_8DEV_STATUSMSG_BIT0:
408 cf->data[2] |= CAN_ERR_PROT_BIT0;
409 tx_errors = 1;
410 break;
411 case USB_8DEV_STATUSMSG_BIT1:
412 cf->data[2] |= CAN_ERR_PROT_BIT1;
413 tx_errors = 1;
414 break;
415 case USB_8DEV_STATUSMSG_FORM:
416 cf->data[2] |= CAN_ERR_PROT_FORM;
417 rx_errors = 1;
418 break;
419 case USB_8DEV_STATUSMSG_STUFF:
420 cf->data[2] |= CAN_ERR_PROT_STUFF;
421 rx_errors = 1;
422 break;
423 case USB_8DEV_STATUSMSG_OVERRUN:
424 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
425 stats->rx_over_errors++;
426 rx_errors = 1;
427 break;
428 case USB_8DEV_STATUSMSG_BUSLIGHT:
429 priv->can.state = CAN_STATE_ERROR_WARNING;
430 cf->data[1] = (txerr > rxerr) ?
431 CAN_ERR_CRTL_TX_WARNING :
432 CAN_ERR_CRTL_RX_WARNING;
433 priv->can.can_stats.error_warning++;
434 break;
435 case USB_8DEV_STATUSMSG_BUSHEAVY:
436 priv->can.state = CAN_STATE_ERROR_PASSIVE;
437 cf->data[1] = (txerr > rxerr) ?
438 CAN_ERR_CRTL_TX_PASSIVE :
439 CAN_ERR_CRTL_RX_PASSIVE;
440 priv->can.can_stats.error_passive++;
441 break;
442 default:
443 netdev_warn(priv->netdev,
444 "Unknown status/error message (%d)\n", state);
445 break;
446 }
447
448 if (tx_errors) {
449 cf->data[2] |= CAN_ERR_PROT_TX;
450 stats->tx_errors++;
451 }
452
453 if (rx_errors)
454 stats->rx_errors++;
455
456 cf->data[6] = txerr;
457 cf->data[7] = rxerr;
458
459 priv->bec.txerr = txerr;
460 priv->bec.rxerr = rxerr;
461
462 stats->rx_packets++;
463 stats->rx_bytes += cf->can_dlc;
464 netif_rx(skb);
465}
466
467/* Read data and status frames */
468static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
469 struct usb_8dev_rx_msg *msg)
470{
471 struct can_frame *cf;
472 struct sk_buff *skb;
473 struct net_device_stats *stats = &priv->netdev->stats;
474
475 if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
476 msg->flags == USB_8DEV_ERR_FLAG) {
477 usb_8dev_rx_err_msg(priv, msg);
478 } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
479 skb = alloc_can_skb(priv->netdev, &cf);
480 if (!skb)
481 return;
482
483 cf->can_id = be32_to_cpu(msg->id);
484 cf->can_dlc = get_can_dlc(msg->dlc & 0xF);
485
486 if (msg->flags & USB_8DEV_EXTID)
487 cf->can_id |= CAN_EFF_FLAG;
488
489 if (msg->flags & USB_8DEV_RTR)
490 cf->can_id |= CAN_RTR_FLAG;
491 else
492 memcpy(cf->data, msg->data, cf->can_dlc);
493
494 stats->rx_packets++;
495 stats->rx_bytes += cf->can_dlc;
496 netif_rx(skb);
497
498 can_led_event(priv->netdev, CAN_LED_EVENT_RX);
499 } else {
500 netdev_warn(priv->netdev, "frame type %d unknown",
501 msg->type);
502 }
503
504}
505
506/* Callback for reading data from device
507 *
508 * Check urb status, call read function and resubmit urb read operation.
509 */
510static void usb_8dev_read_bulk_callback(struct urb *urb)
511{
512 struct usb_8dev_priv *priv = urb->context;
513 struct net_device *netdev;
514 int retval;
515 int pos = 0;
516
517 netdev = priv->netdev;
518
519 if (!netif_device_present(netdev))
520 return;
521
522 switch (urb->status) {
523 case 0: /* success */
524 break;
525
526 case -ENOENT:
527 case -ESHUTDOWN:
528 return;
529
530 default:
531 netdev_info(netdev, "Rx URB aborted (%d)\n",
532 urb->status);
533 goto resubmit_urb;
534 }
535
536 while (pos < urb->actual_length) {
537 struct usb_8dev_rx_msg *msg;
538
539 if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
540 netdev_err(priv->netdev, "format error\n");
541 break;
542 }
543
544 msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
545 usb_8dev_rx_can_msg(priv, msg);
546
547 pos += sizeof(struct usb_8dev_rx_msg);
548 }
549
550resubmit_urb:
551 usb_fill_bulk_urb(urb, priv->udev,
552 usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
553 urb->transfer_buffer, RX_BUFFER_SIZE,
554 usb_8dev_read_bulk_callback, priv);
555
556 retval = usb_submit_urb(urb, GFP_ATOMIC);
557
558 if (retval == -ENODEV)
559 netif_device_detach(netdev);
560 else if (retval)
561 netdev_err(netdev,
562 "failed resubmitting read bulk urb: %d\n", retval);
563}
564
565/* Callback handler for write operations
566 *
567 * Free allocated buffers, check transmit status and
568 * calculate statistic.
569 */
570static void usb_8dev_write_bulk_callback(struct urb *urb)
571{
572 struct usb_8dev_tx_urb_context *context = urb->context;
573 struct usb_8dev_priv *priv;
574 struct net_device *netdev;
575
576 BUG_ON(!context);
577
578 priv = context->priv;
579 netdev = priv->netdev;
580
581 /* free up our allocated buffer */
582 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
583 urb->transfer_buffer, urb->transfer_dma);
584
585 atomic_dec(&priv->active_tx_urbs);
586
587 if (!netif_device_present(netdev))
588 return;
589
590 if (urb->status)
591 netdev_info(netdev, "Tx URB aborted (%d)\n",
592 urb->status);
593
594 netdev->stats.tx_packets++;
595 netdev->stats.tx_bytes += context->dlc;
596
597 can_get_echo_skb(netdev, context->echo_index);
598
599 can_led_event(netdev, CAN_LED_EVENT_TX);
600
601 /* Release context */
602 context->echo_index = MAX_TX_URBS;
603
604 netif_wake_queue(netdev);
605}
606
607/* Send data to device */
608static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
609 struct net_device *netdev)
610{
611 struct usb_8dev_priv *priv = netdev_priv(netdev);
612 struct net_device_stats *stats = &netdev->stats;
613 struct can_frame *cf = (struct can_frame *) skb->data;
614 struct usb_8dev_tx_msg *msg;
615 struct urb *urb;
616 struct usb_8dev_tx_urb_context *context = NULL;
617 u8 *buf;
618 int i, err;
619 size_t size = sizeof(struct usb_8dev_tx_msg);
620
621 if (can_dropped_invalid_skb(netdev, skb))
622 return NETDEV_TX_OK;
623
624 /* create a URB, and a buffer for it, and copy the data to the URB */
625 urb = usb_alloc_urb(0, GFP_ATOMIC);
626 if (!urb)
627 goto nomem;
628
629 buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
630 &urb->transfer_dma);
631 if (!buf) {
632 netdev_err(netdev, "No memory left for USB buffer\n");
633 goto nomembuf;
634 }
635
636 memset(buf, 0, size);
637
638 msg = (struct usb_8dev_tx_msg *)buf;
639 msg->begin = USB_8DEV_DATA_START;
640 msg->flags = 0x00;
641
642 if (cf->can_id & CAN_RTR_FLAG)
643 msg->flags |= USB_8DEV_RTR;
644
645 if (cf->can_id & CAN_EFF_FLAG)
646 msg->flags |= USB_8DEV_EXTID;
647
648 msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
649 msg->dlc = cf->can_dlc;
650 memcpy(msg->data, cf->data, cf->can_dlc);
651 msg->end = USB_8DEV_DATA_END;
652
653 for (i = 0; i < MAX_TX_URBS; i++) {
654 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
655 context = &priv->tx_contexts[i];
656 break;
657 }
658 }
659
660 /* May never happen! When this happens we'd more URBs in flight as
661 * allowed (MAX_TX_URBS).
662 */
663 if (!context)
664 goto nofreecontext;
665
666 context->priv = priv;
667 context->echo_index = i;
668 context->dlc = cf->can_dlc;
669
670 usb_fill_bulk_urb(urb, priv->udev,
671 usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
672 buf, size, usb_8dev_write_bulk_callback, context);
673 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
674 usb_anchor_urb(urb, &priv->tx_submitted);
675
676 can_put_echo_skb(skb, netdev, context->echo_index);
677
678 atomic_inc(&priv->active_tx_urbs);
679
680 err = usb_submit_urb(urb, GFP_ATOMIC);
681 if (unlikely(err))
682 goto failed;
683 else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
684 /* Slow down tx path */
685 netif_stop_queue(netdev);
686
687 /* Release our reference to this URB, the USB core will eventually free
688 * it entirely.
689 */
690 usb_free_urb(urb);
691
692 return NETDEV_TX_OK;
693
694nofreecontext:
695 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
696 usb_free_urb(urb);
697
698 netdev_warn(netdev, "couldn't find free context");
699
700 return NETDEV_TX_BUSY;
701
702failed:
703 can_free_echo_skb(netdev, context->echo_index);
704
705 usb_unanchor_urb(urb);
706 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
707
708 atomic_dec(&priv->active_tx_urbs);
709
710 if (err == -ENODEV)
711 netif_device_detach(netdev);
712 else
713 netdev_warn(netdev, "failed tx_urb %d\n", err);
714
715nomembuf:
716 usb_free_urb(urb);
717
718nomem:
719 dev_kfree_skb(skb);
720 stats->tx_dropped++;
721
722 return NETDEV_TX_OK;
723}
724
725static int usb_8dev_get_berr_counter(const struct net_device *netdev,
726 struct can_berr_counter *bec)
727{
728 struct usb_8dev_priv *priv = netdev_priv(netdev);
729
730 bec->txerr = priv->bec.txerr;
731 bec->rxerr = priv->bec.rxerr;
732
733 return 0;
734}
735
736/* Start USB device */
737static int usb_8dev_start(struct usb_8dev_priv *priv)
738{
739 struct net_device *netdev = priv->netdev;
740 int err, i;
741
742 for (i = 0; i < MAX_RX_URBS; i++) {
743 struct urb *urb = NULL;
744 u8 *buf;
745
746 /* create a URB, and a buffer for it */
747 urb = usb_alloc_urb(0, GFP_KERNEL);
748 if (!urb) {
749 err = -ENOMEM;
750 break;
751 }
752
753 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
754 &urb->transfer_dma);
755 if (!buf) {
756 netdev_err(netdev, "No memory left for USB buffer\n");
757 usb_free_urb(urb);
758 err = -ENOMEM;
759 break;
760 }
761
762 usb_fill_bulk_urb(urb, priv->udev,
763 usb_rcvbulkpipe(priv->udev,
764 USB_8DEV_ENDP_DATA_RX),
765 buf, RX_BUFFER_SIZE,
766 usb_8dev_read_bulk_callback, priv);
767 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
768 usb_anchor_urb(urb, &priv->rx_submitted);
769
770 err = usb_submit_urb(urb, GFP_KERNEL);
771 if (err) {
772 usb_unanchor_urb(urb);
773 usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
774 urb->transfer_dma);
775 usb_free_urb(urb);
776 break;
777 }
778
779 /* Drop reference, USB core will take care of freeing it */
780 usb_free_urb(urb);
781 }
782
783 /* Did we submit any URBs */
784 if (i == 0) {
785 netdev_warn(netdev, "couldn't setup read URBs\n");
786 return err;
787 }
788
789 /* Warn if we've couldn't transmit all the URBs */
790 if (i < MAX_RX_URBS)
791 netdev_warn(netdev, "rx performance may be slow\n");
792
793 err = usb_8dev_cmd_open(priv);
794 if (err)
795 goto failed;
796
797 priv->can.state = CAN_STATE_ERROR_ACTIVE;
798
799 return 0;
800
801failed:
802 if (err == -ENODEV)
803 netif_device_detach(priv->netdev);
804
805 netdev_warn(netdev, "couldn't submit control: %d\n", err);
806
807 return err;
808}
809
810/* Open USB device */
811static int usb_8dev_open(struct net_device *netdev)
812{
813 struct usb_8dev_priv *priv = netdev_priv(netdev);
814 int err;
815
816 /* common open */
817 err = open_candev(netdev);
818 if (err)
819 return err;
820
821 can_led_event(netdev, CAN_LED_EVENT_OPEN);
822
823 /* finally start device */
824 err = usb_8dev_start(priv);
825 if (err) {
826 if (err == -ENODEV)
827 netif_device_detach(priv->netdev);
828
829 netdev_warn(netdev, "couldn't start device: %d\n",
830 err);
831
832 close_candev(netdev);
833
834 return err;
835 }
836
837 netif_start_queue(netdev);
838
839 return 0;
840}
841
842static void unlink_all_urbs(struct usb_8dev_priv *priv)
843{
844 int i;
845
846 usb_kill_anchored_urbs(&priv->rx_submitted);
847
848 usb_kill_anchored_urbs(&priv->tx_submitted);
849 atomic_set(&priv->active_tx_urbs, 0);
850
851 for (i = 0; i < MAX_TX_URBS; i++)
852 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
853}
854
855/* Close USB device */
856static int usb_8dev_close(struct net_device *netdev)
857{
858 struct usb_8dev_priv *priv = netdev_priv(netdev);
859 int err = 0;
860
861 /* Send CLOSE command to CAN controller */
862 err = usb_8dev_cmd_close(priv);
863 if (err)
864 netdev_warn(netdev, "couldn't stop device");
865
866 priv->can.state = CAN_STATE_STOPPED;
867
868 netif_stop_queue(netdev);
869
870 /* Stop polling */
871 unlink_all_urbs(priv);
872
873 close_candev(netdev);
874
875 can_led_event(netdev, CAN_LED_EVENT_STOP);
876
877 return err;
878}
879
880static const struct net_device_ops usb_8dev_netdev_ops = {
881 .ndo_open = usb_8dev_open,
882 .ndo_stop = usb_8dev_close,
883 .ndo_start_xmit = usb_8dev_start_xmit,
884 .ndo_change_mtu = can_change_mtu,
885};
886
887static const struct can_bittiming_const usb_8dev_bittiming_const = {
888 .name = "usb_8dev",
889 .tseg1_min = 1,
890 .tseg1_max = 16,
891 .tseg2_min = 1,
892 .tseg2_max = 8,
893 .sjw_max = 4,
894 .brp_min = 1,
895 .brp_max = 1024,
896 .brp_inc = 1,
897};
898
899/* Probe USB device
900 *
901 * Check device and firmware.
902 * Set supported modes and bittiming constants.
903 * Allocate some memory.
904 */
905static int usb_8dev_probe(struct usb_interface *intf,
906 const struct usb_device_id *id)
907{
908 struct net_device *netdev;
909 struct usb_8dev_priv *priv;
910 int i, err = -ENOMEM;
911 u32 version;
912 char buf[18];
913 struct usb_device *usbdev = interface_to_usbdev(intf);
914
915 /* product id looks strange, better we also check iProduct string */
916 if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
917 sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
918 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
919 return -ENODEV;
920 }
921
922 netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
923 if (!netdev) {
924 dev_err(&intf->dev, "Couldn't alloc candev\n");
925 return -ENOMEM;
926 }
927
928 priv = netdev_priv(netdev);
929
930 priv->udev = usbdev;
931 priv->netdev = netdev;
932
933 priv->can.state = CAN_STATE_STOPPED;
934 priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
935 priv->can.bittiming_const = &usb_8dev_bittiming_const;
936 priv->can.do_set_mode = usb_8dev_set_mode;
937 priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
938 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
939 CAN_CTRLMODE_LISTENONLY |
940 CAN_CTRLMODE_ONE_SHOT;
941
942 netdev->netdev_ops = &usb_8dev_netdev_ops;
943
944 netdev->flags |= IFF_ECHO; /* we support local echo */
945
946 init_usb_anchor(&priv->rx_submitted);
947
948 init_usb_anchor(&priv->tx_submitted);
949 atomic_set(&priv->active_tx_urbs, 0);
950
951 for (i = 0; i < MAX_TX_URBS; i++)
952 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
953
954 priv->cmd_msg_buffer = devm_kzalloc(&intf->dev, sizeof(struct usb_8dev_cmd_msg),
955 GFP_KERNEL);
956 if (!priv->cmd_msg_buffer)
957 goto cleanup_candev;
958
959 usb_set_intfdata(intf, priv);
960
961 SET_NETDEV_DEV(netdev, &intf->dev);
962
963 mutex_init(&priv->usb_8dev_cmd_lock);
964
965 err = register_candev(netdev);
966 if (err) {
967 netdev_err(netdev,
968 "couldn't register CAN device: %d\n", err);
969 goto cleanup_candev;
970 }
971
972 err = usb_8dev_cmd_version(priv, &version);
973 if (err) {
974 netdev_err(netdev, "can't get firmware version\n");
975 goto cleanup_unregister_candev;
976 } else {
977 netdev_info(netdev,
978 "firmware: %d.%d, hardware: %d.%d\n",
979 (version>>24) & 0xff, (version>>16) & 0xff,
980 (version>>8) & 0xff, version & 0xff);
981 }
982
983 devm_can_led_init(netdev);
984
985 return 0;
986
987cleanup_unregister_candev:
988 unregister_netdev(priv->netdev);
989
990cleanup_candev:
991 free_candev(netdev);
992
993 return err;
994
995}
996
997/* Called by the usb core when driver is unloaded or device is removed */
998static void usb_8dev_disconnect(struct usb_interface *intf)
999{
1000 struct usb_8dev_priv *priv = usb_get_intfdata(intf);
1001
1002 usb_set_intfdata(intf, NULL);
1003
1004 if (priv) {
1005 netdev_info(priv->netdev, "device disconnected\n");
1006
1007 unregister_netdev(priv->netdev);
1008 free_candev(priv->netdev);
1009
1010 unlink_all_urbs(priv);
1011 }
1012
1013}
1014
1015static struct usb_driver usb_8dev_driver = {
1016 .name = "usb_8dev",
1017 .probe = usb_8dev_probe,
1018 .disconnect = usb_8dev_disconnect,
1019 .id_table = usb_8dev_table,
1020};
1021
1022module_usb_driver(usb_8dev_driver);
1023
1024MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>");
1025MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
1026MODULE_LICENSE("GPL v2");