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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 ([email protected])
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 ([email protected])
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/ethtool.h>
16#include <linux/signal.h>
17#include <linux/slab.h>
18#include <linux/module.h>
19#include <linux/netdevice.h>
20#include <linux/usb.h>
21
22#include <linux/can.h>
23#include <linux/can/dev.h>
24#include <linux/can/error.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 occurred 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};
118
119/* Structure to hold all of our device specific stuff */
120struct usb_8dev_priv {
121 struct can_priv can; /* must be the first member */
122
123 struct usb_device *udev;
124 struct net_device *netdev;
125
126 atomic_t active_tx_urbs;
127 struct usb_anchor tx_submitted;
128 struct usb_8dev_tx_urb_context tx_contexts[MAX_TX_URBS];
129
130 struct usb_anchor rx_submitted;
131
132 struct can_berr_counter bec;
133
134 u8 *cmd_msg_buffer;
135
136 struct mutex usb_8dev_cmd_lock;
137 void *rxbuf[MAX_RX_URBS];
138 dma_addr_t rxbuf_dma[MAX_RX_URBS];
139};
140
141/* tx frame */
142struct __packed usb_8dev_tx_msg {
143 u8 begin;
144 u8 flags; /* RTR and EXT_ID flag */
145 __be32 id; /* upper 3 bits not used */
146 u8 dlc; /* data length code 0-8 bytes */
147 u8 data[8]; /* 64-bit data */
148 u8 end;
149};
150
151/* rx frame */
152struct __packed usb_8dev_rx_msg {
153 u8 begin;
154 u8 type; /* frame type */
155 u8 flags; /* RTR and EXT_ID flag */
156 __be32 id; /* upper 3 bits not used */
157 u8 dlc; /* data length code 0-8 bytes */
158 u8 data[8]; /* 64-bit data */
159 __be32 timestamp; /* 32-bit timestamp */
160 u8 end;
161};
162
163/* command frame */
164struct __packed usb_8dev_cmd_msg {
165 u8 begin;
166 u8 channel; /* unknown - always 0 */
167 u8 command; /* command to execute */
168 u8 opt1; /* optional parameter / return value */
169 u8 opt2; /* optional parameter 2 */
170 u8 data[10]; /* optional parameter and data */
171 u8 end;
172};
173
174static int usb_8dev_send_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size)
175{
176 int actual_length;
177
178 return usb_bulk_msg(priv->udev,
179 usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_TX),
180 msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT);
181}
182
183static int usb_8dev_wait_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size,
184 int *actual_length)
185{
186 return usb_bulk_msg(priv->udev,
187 usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_RX),
188 msg, size, actual_length, USB_8DEV_CMD_TIMEOUT);
189}
190
191/* Send command to device and receive result.
192 * Command was successful when opt1 = 0.
193 */
194static int usb_8dev_send_cmd(struct usb_8dev_priv *priv,
195 struct usb_8dev_cmd_msg *out,
196 struct usb_8dev_cmd_msg *in)
197{
198 int err;
199 int num_bytes_read;
200 struct net_device *netdev;
201
202 netdev = priv->netdev;
203
204 out->begin = USB_8DEV_CMD_START;
205 out->end = USB_8DEV_CMD_END;
206
207 mutex_lock(&priv->usb_8dev_cmd_lock);
208
209 memcpy(priv->cmd_msg_buffer, out,
210 sizeof(struct usb_8dev_cmd_msg));
211
212 err = usb_8dev_send_cmd_msg(priv, priv->cmd_msg_buffer,
213 sizeof(struct usb_8dev_cmd_msg));
214 if (err < 0) {
215 netdev_err(netdev, "sending command message failed\n");
216 goto failed;
217 }
218
219 err = usb_8dev_wait_cmd_msg(priv, priv->cmd_msg_buffer,
220 sizeof(struct usb_8dev_cmd_msg),
221 &num_bytes_read);
222 if (err < 0) {
223 netdev_err(netdev, "no command message answer\n");
224 goto failed;
225 }
226
227 memcpy(in, priv->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg));
228
229 if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END ||
230 num_bytes_read != 16 || in->opt1 != 0)
231 err = -EPROTO;
232
233failed:
234 mutex_unlock(&priv->usb_8dev_cmd_lock);
235 return err;
236}
237
238/* Send open command to device */
239static int usb_8dev_cmd_open(struct usb_8dev_priv *priv)
240{
241 struct can_bittiming *bt = &priv->can.bittiming;
242 struct usb_8dev_cmd_msg outmsg;
243 struct usb_8dev_cmd_msg inmsg;
244 u32 ctrlmode = priv->can.ctrlmode;
245 u32 flags = USB_8DEV_STATUS_FRAME;
246 __be32 beflags;
247 __be16 bebrp;
248
249 memset(&outmsg, 0, sizeof(outmsg));
250 outmsg.command = USB_8DEV_OPEN;
251 outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
252 outmsg.data[0] = bt->prop_seg + bt->phase_seg1;
253 outmsg.data[1] = bt->phase_seg2;
254 outmsg.data[2] = bt->sjw;
255
256 /* BRP */
257 bebrp = cpu_to_be16((u16)bt->brp);
258 memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp));
259
260 /* flags */
261 if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
262 flags |= USB_8DEV_LOOPBACK;
263 if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
264 flags |= USB_8DEV_SILENT;
265 if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
266 flags |= USB_8DEV_DISABLE_AUTO_RESTRANS;
267
268 beflags = cpu_to_be32(flags);
269 memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
270
271 return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
272}
273
274/* Send close command to device */
275static int usb_8dev_cmd_close(struct usb_8dev_priv *priv)
276{
277 struct usb_8dev_cmd_msg inmsg;
278 struct usb_8dev_cmd_msg outmsg = {
279 .channel = 0,
280 .command = USB_8DEV_CLOSE,
281 .opt1 = 0,
282 .opt2 = 0
283 };
284
285 return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
286}
287
288/* Get firmware and hardware version */
289static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, u32 *res)
290{
291 struct usb_8dev_cmd_msg inmsg;
292 struct usb_8dev_cmd_msg outmsg = {
293 .channel = 0,
294 .command = USB_8DEV_GET_SOFTW_HARDW_VER,
295 .opt1 = 0,
296 .opt2 = 0
297 };
298
299 int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg);
300 if (err)
301 return err;
302
303 *res = be32_to_cpup((__be32 *)inmsg.data);
304
305 return err;
306}
307
308/* Set network device mode
309 *
310 * Maybe we should leave this function empty, because the device
311 * set mode variable with open command.
312 */
313static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode)
314{
315 struct usb_8dev_priv *priv = netdev_priv(netdev);
316 int err = 0;
317
318 switch (mode) {
319 case CAN_MODE_START:
320 err = usb_8dev_cmd_open(priv);
321 if (err)
322 netdev_warn(netdev, "couldn't start device");
323 break;
324
325 default:
326 return -EOPNOTSUPP;
327 }
328
329 return err;
330}
331
332/* Read error/status frames */
333static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
334 struct usb_8dev_rx_msg *msg)
335{
336 struct can_frame *cf;
337 struct sk_buff *skb;
338 struct net_device_stats *stats = &priv->netdev->stats;
339
340 /* Error message:
341 * byte 0: Status
342 * byte 1: bit 7: Receive Passive
343 * byte 1: bit 0-6: Receive Error Counter
344 * byte 2: Transmit Error Counter
345 * byte 3: Always 0 (maybe reserved for future use)
346 */
347
348 u8 state = msg->data[0];
349 u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
350 u8 txerr = msg->data[2];
351 int rx_errors = 0;
352 int tx_errors = 0;
353
354 skb = alloc_can_err_skb(priv->netdev, &cf);
355 if (!skb)
356 return;
357
358 switch (state) {
359 case USB_8DEV_STATUSMSG_OK:
360 priv->can.state = CAN_STATE_ERROR_ACTIVE;
361 cf->can_id |= CAN_ERR_PROT;
362 cf->data[2] = CAN_ERR_PROT_ACTIVE;
363 break;
364 case USB_8DEV_STATUSMSG_BUSOFF:
365 priv->can.state = CAN_STATE_BUS_OFF;
366 cf->can_id |= CAN_ERR_BUSOFF;
367 priv->can.can_stats.bus_off++;
368 can_bus_off(priv->netdev);
369 break;
370 case USB_8DEV_STATUSMSG_OVERRUN:
371 case USB_8DEV_STATUSMSG_BUSLIGHT:
372 case USB_8DEV_STATUSMSG_BUSHEAVY:
373 cf->can_id |= CAN_ERR_CRTL;
374 break;
375 default:
376 priv->can.state = CAN_STATE_ERROR_WARNING;
377 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
378 priv->can.can_stats.bus_error++;
379 break;
380 }
381
382 switch (state) {
383 case USB_8DEV_STATUSMSG_OK:
384 case USB_8DEV_STATUSMSG_BUSOFF:
385 break;
386 case USB_8DEV_STATUSMSG_ACK:
387 cf->can_id |= CAN_ERR_ACK;
388 tx_errors = 1;
389 break;
390 case USB_8DEV_STATUSMSG_CRC:
391 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
392 rx_errors = 1;
393 break;
394 case USB_8DEV_STATUSMSG_BIT0:
395 cf->data[2] |= CAN_ERR_PROT_BIT0;
396 tx_errors = 1;
397 break;
398 case USB_8DEV_STATUSMSG_BIT1:
399 cf->data[2] |= CAN_ERR_PROT_BIT1;
400 tx_errors = 1;
401 break;
402 case USB_8DEV_STATUSMSG_FORM:
403 cf->data[2] |= CAN_ERR_PROT_FORM;
404 rx_errors = 1;
405 break;
406 case USB_8DEV_STATUSMSG_STUFF:
407 cf->data[2] |= CAN_ERR_PROT_STUFF;
408 rx_errors = 1;
409 break;
410 case USB_8DEV_STATUSMSG_OVERRUN:
411 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
412 stats->rx_over_errors++;
413 rx_errors = 1;
414 break;
415 case USB_8DEV_STATUSMSG_BUSLIGHT:
416 priv->can.state = CAN_STATE_ERROR_WARNING;
417 cf->data[1] = (txerr > rxerr) ?
418 CAN_ERR_CRTL_TX_WARNING :
419 CAN_ERR_CRTL_RX_WARNING;
420 priv->can.can_stats.error_warning++;
421 break;
422 case USB_8DEV_STATUSMSG_BUSHEAVY:
423 priv->can.state = CAN_STATE_ERROR_PASSIVE;
424 cf->data[1] = (txerr > rxerr) ?
425 CAN_ERR_CRTL_TX_PASSIVE :
426 CAN_ERR_CRTL_RX_PASSIVE;
427 priv->can.can_stats.error_passive++;
428 break;
429 default:
430 netdev_warn(priv->netdev,
431 "Unknown status/error message (%d)\n", state);
432 break;
433 }
434
435 if (tx_errors) {
436 cf->data[2] |= CAN_ERR_PROT_TX;
437 stats->tx_errors++;
438 }
439
440 if (rx_errors)
441 stats->rx_errors++;
442 if (priv->can.state != CAN_STATE_BUS_OFF) {
443 cf->can_id |= CAN_ERR_CNT;
444 cf->data[6] = txerr;
445 cf->data[7] = rxerr;
446 }
447
448 priv->bec.txerr = txerr;
449 priv->bec.rxerr = rxerr;
450
451 netif_rx(skb);
452}
453
454/* Read data and status frames */
455static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
456 struct usb_8dev_rx_msg *msg)
457{
458 struct can_frame *cf;
459 struct sk_buff *skb;
460 struct net_device_stats *stats = &priv->netdev->stats;
461
462 if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
463 msg->flags == USB_8DEV_ERR_FLAG) {
464 usb_8dev_rx_err_msg(priv, msg);
465 } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
466 skb = alloc_can_skb(priv->netdev, &cf);
467 if (!skb)
468 return;
469
470 cf->can_id = be32_to_cpu(msg->id);
471 can_frame_set_cc_len(cf, msg->dlc & 0xF, priv->can.ctrlmode);
472
473 if (msg->flags & USB_8DEV_EXTID)
474 cf->can_id |= CAN_EFF_FLAG;
475
476 if (msg->flags & USB_8DEV_RTR) {
477 cf->can_id |= CAN_RTR_FLAG;
478 } else {
479 memcpy(cf->data, msg->data, cf->len);
480 stats->rx_bytes += cf->len;
481 }
482 stats->rx_packets++;
483
484 netif_rx(skb);
485 } else {
486 netdev_warn(priv->netdev, "frame type %d unknown",
487 msg->type);
488 }
489
490}
491
492/* Callback for reading data from device
493 *
494 * Check urb status, call read function and resubmit urb read operation.
495 */
496static void usb_8dev_read_bulk_callback(struct urb *urb)
497{
498 struct usb_8dev_priv *priv = urb->context;
499 struct net_device *netdev;
500 int retval;
501 int pos = 0;
502
503 netdev = priv->netdev;
504
505 if (!netif_device_present(netdev))
506 return;
507
508 switch (urb->status) {
509 case 0: /* success */
510 break;
511
512 case -ENOENT:
513 case -EPIPE:
514 case -EPROTO:
515 case -ESHUTDOWN:
516 return;
517
518 default:
519 netdev_info(netdev, "Rx URB aborted (%d)\n",
520 urb->status);
521 goto resubmit_urb;
522 }
523
524 while (pos < urb->actual_length) {
525 struct usb_8dev_rx_msg *msg;
526
527 if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
528 netdev_err(priv->netdev, "format error\n");
529 break;
530 }
531
532 msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
533 usb_8dev_rx_can_msg(priv, msg);
534
535 pos += sizeof(struct usb_8dev_rx_msg);
536 }
537
538resubmit_urb:
539 usb_fill_bulk_urb(urb, priv->udev,
540 usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
541 urb->transfer_buffer, RX_BUFFER_SIZE,
542 usb_8dev_read_bulk_callback, priv);
543
544 usb_anchor_urb(urb, &priv->rx_submitted);
545
546 retval = usb_submit_urb(urb, GFP_ATOMIC);
547 if (!retval)
548 return;
549
550 usb_unanchor_urb(urb);
551
552 if (retval == -ENODEV)
553 netif_device_detach(netdev);
554 else
555 netdev_err(netdev,
556 "failed resubmitting read bulk urb: %d\n", retval);
557}
558
559/* Callback handler for write operations
560 *
561 * Free allocated buffers, check transmit status and
562 * calculate statistic.
563 */
564static void usb_8dev_write_bulk_callback(struct urb *urb)
565{
566 struct usb_8dev_tx_urb_context *context = urb->context;
567 struct usb_8dev_priv *priv;
568 struct net_device *netdev;
569
570 BUG_ON(!context);
571
572 priv = context->priv;
573 netdev = priv->netdev;
574
575 /* free up our allocated buffer */
576 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
577 urb->transfer_buffer, urb->transfer_dma);
578
579 atomic_dec(&priv->active_tx_urbs);
580
581 if (!netif_device_present(netdev))
582 return;
583
584 if (urb->status)
585 netdev_info(netdev, "Tx URB aborted (%d)\n",
586 urb->status);
587
588 netdev->stats.tx_packets++;
589 netdev->stats.tx_bytes += can_get_echo_skb(netdev, context->echo_index, NULL);
590
591 /* Release context */
592 context->echo_index = MAX_TX_URBS;
593
594 netif_wake_queue(netdev);
595}
596
597/* Send data to device */
598static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
599 struct net_device *netdev)
600{
601 struct usb_8dev_priv *priv = netdev_priv(netdev);
602 struct net_device_stats *stats = &netdev->stats;
603 struct can_frame *cf = (struct can_frame *) skb->data;
604 struct usb_8dev_tx_msg *msg;
605 struct urb *urb;
606 struct usb_8dev_tx_urb_context *context = NULL;
607 u8 *buf;
608 int i, err;
609 size_t size = sizeof(struct usb_8dev_tx_msg);
610
611 if (can_dev_dropped_skb(netdev, skb))
612 return NETDEV_TX_OK;
613
614 /* create a URB, and a buffer for it, and copy the data to the URB */
615 urb = usb_alloc_urb(0, GFP_ATOMIC);
616 if (!urb)
617 goto nomem;
618
619 buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
620 &urb->transfer_dma);
621 if (!buf) {
622 netdev_err(netdev, "No memory left for USB buffer\n");
623 goto nomembuf;
624 }
625
626 memset(buf, 0, size);
627
628 msg = (struct usb_8dev_tx_msg *)buf;
629 msg->begin = USB_8DEV_DATA_START;
630 msg->flags = 0x00;
631
632 if (cf->can_id & CAN_RTR_FLAG)
633 msg->flags |= USB_8DEV_RTR;
634
635 if (cf->can_id & CAN_EFF_FLAG)
636 msg->flags |= USB_8DEV_EXTID;
637
638 msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
639 msg->dlc = can_get_cc_dlc(cf, priv->can.ctrlmode);
640 memcpy(msg->data, cf->data, cf->len);
641 msg->end = USB_8DEV_DATA_END;
642
643 for (i = 0; i < MAX_TX_URBS; i++) {
644 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
645 context = &priv->tx_contexts[i];
646 break;
647 }
648 }
649
650 /* May never happen! When this happens we'd more URBs in flight as
651 * allowed (MAX_TX_URBS).
652 */
653 if (!context)
654 goto nofreecontext;
655
656 context->priv = priv;
657 context->echo_index = i;
658
659 usb_fill_bulk_urb(urb, priv->udev,
660 usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
661 buf, size, usb_8dev_write_bulk_callback, context);
662 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
663 usb_anchor_urb(urb, &priv->tx_submitted);
664
665 can_put_echo_skb(skb, netdev, context->echo_index, 0);
666
667 atomic_inc(&priv->active_tx_urbs);
668
669 err = usb_submit_urb(urb, GFP_ATOMIC);
670 if (unlikely(err)) {
671 can_free_echo_skb(netdev, context->echo_index, NULL);
672
673 usb_unanchor_urb(urb);
674 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
675
676 atomic_dec(&priv->active_tx_urbs);
677
678 if (err == -ENODEV)
679 netif_device_detach(netdev);
680 else
681 netdev_warn(netdev, "failed tx_urb %d\n", err);
682 stats->tx_dropped++;
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
702nomembuf:
703 usb_free_urb(urb);
704
705nomem:
706 dev_kfree_skb(skb);
707 stats->tx_dropped++;
708
709 return NETDEV_TX_OK;
710}
711
712static int usb_8dev_get_berr_counter(const struct net_device *netdev,
713 struct can_berr_counter *bec)
714{
715 struct usb_8dev_priv *priv = netdev_priv(netdev);
716
717 bec->txerr = priv->bec.txerr;
718 bec->rxerr = priv->bec.rxerr;
719
720 return 0;
721}
722
723/* Start USB device */
724static int usb_8dev_start(struct usb_8dev_priv *priv)
725{
726 struct net_device *netdev = priv->netdev;
727 int err, i;
728
729 for (i = 0; i < MAX_RX_URBS; i++) {
730 struct urb *urb = NULL;
731 u8 *buf;
732 dma_addr_t buf_dma;
733
734 /* create a URB, and a buffer for it */
735 urb = usb_alloc_urb(0, GFP_KERNEL);
736 if (!urb) {
737 err = -ENOMEM;
738 break;
739 }
740
741 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
742 &buf_dma);
743 if (!buf) {
744 netdev_err(netdev, "No memory left for USB buffer\n");
745 usb_free_urb(urb);
746 err = -ENOMEM;
747 break;
748 }
749
750 urb->transfer_dma = buf_dma;
751
752 usb_fill_bulk_urb(urb, priv->udev,
753 usb_rcvbulkpipe(priv->udev,
754 USB_8DEV_ENDP_DATA_RX),
755 buf, RX_BUFFER_SIZE,
756 usb_8dev_read_bulk_callback, priv);
757 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
758 usb_anchor_urb(urb, &priv->rx_submitted);
759
760 err = usb_submit_urb(urb, GFP_KERNEL);
761 if (err) {
762 usb_unanchor_urb(urb);
763 usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
764 urb->transfer_dma);
765 usb_free_urb(urb);
766 break;
767 }
768
769 priv->rxbuf[i] = buf;
770 priv->rxbuf_dma[i] = buf_dma;
771
772 /* Drop reference, USB core will take care of freeing it */
773 usb_free_urb(urb);
774 }
775
776 /* Did we submit any URBs */
777 if (i == 0) {
778 netdev_warn(netdev, "couldn't setup read URBs\n");
779 return err;
780 }
781
782 /* Warn if we've couldn't transmit all the URBs */
783 if (i < MAX_RX_URBS)
784 netdev_warn(netdev, "rx performance may be slow\n");
785
786 err = usb_8dev_cmd_open(priv);
787 if (err)
788 goto failed;
789
790 priv->can.state = CAN_STATE_ERROR_ACTIVE;
791
792 return 0;
793
794failed:
795 if (err == -ENODEV)
796 netif_device_detach(priv->netdev);
797
798 netdev_warn(netdev, "couldn't submit control: %d\n", err);
799
800 return err;
801}
802
803/* Open USB device */
804static int usb_8dev_open(struct net_device *netdev)
805{
806 struct usb_8dev_priv *priv = netdev_priv(netdev);
807 int err;
808
809 /* common open */
810 err = open_candev(netdev);
811 if (err)
812 return err;
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 for (i = 0; i < MAX_RX_URBS; ++i)
840 usb_free_coherent(priv->udev, RX_BUFFER_SIZE,
841 priv->rxbuf[i], priv->rxbuf_dma[i]);
842
843 usb_kill_anchored_urbs(&priv->tx_submitted);
844 atomic_set(&priv->active_tx_urbs, 0);
845
846 for (i = 0; i < MAX_TX_URBS; i++)
847 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
848}
849
850/* Close USB device */
851static int usb_8dev_close(struct net_device *netdev)
852{
853 struct usb_8dev_priv *priv = netdev_priv(netdev);
854 int err = 0;
855
856 /* Send CLOSE command to CAN controller */
857 err = usb_8dev_cmd_close(priv);
858 if (err)
859 netdev_warn(netdev, "couldn't stop device");
860
861 priv->can.state = CAN_STATE_STOPPED;
862
863 netif_stop_queue(netdev);
864
865 /* Stop polling */
866 unlink_all_urbs(priv);
867
868 close_candev(netdev);
869
870 return err;
871}
872
873static const struct net_device_ops usb_8dev_netdev_ops = {
874 .ndo_open = usb_8dev_open,
875 .ndo_stop = usb_8dev_close,
876 .ndo_start_xmit = usb_8dev_start_xmit,
877};
878
879static const struct ethtool_ops usb_8dev_ethtool_ops = {
880 .get_ts_info = ethtool_op_get_ts_info,
881};
882
883static const struct can_bittiming_const usb_8dev_bittiming_const = {
884 .name = KBUILD_MODNAME,
885 .tseg1_min = 1,
886 .tseg1_max = 16,
887 .tseg2_min = 1,
888 .tseg2_max = 8,
889 .sjw_max = 4,
890 .brp_min = 1,
891 .brp_max = 1024,
892 .brp_inc = 1,
893};
894
895/* Probe USB device
896 *
897 * Check device and firmware.
898 * Set supported modes and bittiming constants.
899 * Allocate some memory.
900 */
901static int usb_8dev_probe(struct usb_interface *intf,
902 const struct usb_device_id *id)
903{
904 struct net_device *netdev;
905 struct usb_8dev_priv *priv;
906 int i, err = -ENOMEM;
907 u32 version;
908 char buf[18];
909 struct usb_device *usbdev = interface_to_usbdev(intf);
910
911 /* product id looks strange, better we also check iProduct string */
912 if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
913 sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
914 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
915 return -ENODEV;
916 }
917
918 netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
919 if (!netdev) {
920 dev_err(&intf->dev, "Couldn't alloc candev\n");
921 return -ENOMEM;
922 }
923
924 priv = netdev_priv(netdev);
925
926 priv->udev = usbdev;
927 priv->netdev = netdev;
928
929 priv->can.state = CAN_STATE_STOPPED;
930 priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
931 priv->can.bittiming_const = &usb_8dev_bittiming_const;
932 priv->can.do_set_mode = usb_8dev_set_mode;
933 priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
934 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
935 CAN_CTRLMODE_LISTENONLY |
936 CAN_CTRLMODE_ONE_SHOT |
937 CAN_CTRLMODE_CC_LEN8_DLC;
938
939 netdev->netdev_ops = &usb_8dev_netdev_ops;
940 netdev->ethtool_ops = &usb_8dev_ethtool_ops;
941
942 netdev->flags |= IFF_ECHO; /* we support local echo */
943
944 init_usb_anchor(&priv->rx_submitted);
945
946 init_usb_anchor(&priv->tx_submitted);
947 atomic_set(&priv->active_tx_urbs, 0);
948
949 for (i = 0; i < MAX_TX_URBS; i++)
950 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
951
952 priv->cmd_msg_buffer = devm_kzalloc(&intf->dev, sizeof(struct usb_8dev_cmd_msg),
953 GFP_KERNEL);
954 if (!priv->cmd_msg_buffer)
955 goto cleanup_candev;
956
957 usb_set_intfdata(intf, priv);
958
959 SET_NETDEV_DEV(netdev, &intf->dev);
960
961 mutex_init(&priv->usb_8dev_cmd_lock);
962
963 err = register_candev(netdev);
964 if (err) {
965 netdev_err(netdev,
966 "couldn't register CAN device: %d\n", err);
967 goto cleanup_candev;
968 }
969
970 err = usb_8dev_cmd_version(priv, &version);
971 if (err) {
972 netdev_err(netdev, "can't get firmware version\n");
973 goto cleanup_unregister_candev;
974 } else {
975 netdev_info(netdev,
976 "firmware: %d.%d, hardware: %d.%d\n",
977 (version>>24) & 0xff, (version>>16) & 0xff,
978 (version>>8) & 0xff, version & 0xff);
979 }
980
981 return 0;
982
983cleanup_unregister_candev:
984 unregister_netdev(priv->netdev);
985
986cleanup_candev:
987 free_candev(netdev);
988
989 return err;
990
991}
992
993/* Called by the usb core when driver is unloaded or device is removed */
994static void usb_8dev_disconnect(struct usb_interface *intf)
995{
996 struct usb_8dev_priv *priv = usb_get_intfdata(intf);
997
998 usb_set_intfdata(intf, NULL);
999
1000 if (priv) {
1001 netdev_info(priv->netdev, "device disconnected\n");
1002
1003 unregister_netdev(priv->netdev);
1004 unlink_all_urbs(priv);
1005 free_candev(priv->netdev);
1006 }
1007
1008}
1009
1010static struct usb_driver usb_8dev_driver = {
1011 .name = KBUILD_MODNAME,
1012 .probe = usb_8dev_probe,
1013 .disconnect = usb_8dev_disconnect,
1014 .id_table = usb_8dev_table,
1015};
1016
1017module_usb_driver(usb_8dev_driver);
1018
1019MODULE_AUTHOR("Bernd Krumboeck <[email protected]>");
1020MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
1021MODULE_LICENSE("GPL v2");