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 */
47 enum 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 */
64 enum 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 */
117 static const struct usb_device_id usb_8dev_table[] = {
118 { USB_DEVICE(USB_8DEV_VENDOR_ID, USB_8DEV_PRODUCT_ID) },
119 { } /* Terminating entry */
120 };
121
122 MODULE_DEVICE_TABLE(usb, usb_8dev_table);
123
124 struct 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 */
132 struct 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 void *rxbuf[MAX_RX_URBS];
152 dma_addr_t rxbuf_dma[MAX_RX_URBS];
153 };
154
155 /* tx frame */
156 struct __packed usb_8dev_tx_msg {
157 u8 begin;
158 u8 flags; /* RTR and EXT_ID flag */
159 __be32 id; /* upper 3 bits not used */
160 u8 dlc; /* data length code 0-8 bytes */
161 u8 data[8]; /* 64-bit data */
162 u8 end;
163 };
164
165 /* rx frame */
166 struct __packed usb_8dev_rx_msg {
167 u8 begin;
168 u8 type; /* frame type */
169 u8 flags; /* RTR and EXT_ID flag */
170 __be32 id; /* upper 3 bits not used */
171 u8 dlc; /* data length code 0-8 bytes */
172 u8 data[8]; /* 64-bit data */
173 __be32 timestamp; /* 32-bit timestamp */
174 u8 end;
175 };
176
177 /* command frame */
178 struct __packed usb_8dev_cmd_msg {
179 u8 begin;
180 u8 channel; /* unkown - always 0 */
181 u8 command; /* command to execute */
182 u8 opt1; /* optional parameter / return value */
183 u8 opt2; /* optional parameter 2 */
184 u8 data[10]; /* optional parameter and data */
185 u8 end;
186 };
187
usb_8dev_send_cmd_msg(struct usb_8dev_priv * priv,u8 * msg,int size)188 static int usb_8dev_send_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size)
189 {
190 int actual_length;
191
192 return usb_bulk_msg(priv->udev,
193 usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_TX),
194 msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT);
195 }
196
usb_8dev_wait_cmd_msg(struct usb_8dev_priv * priv,u8 * msg,int size,int * actual_length)197 static int usb_8dev_wait_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size,
198 int *actual_length)
199 {
200 return usb_bulk_msg(priv->udev,
201 usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_RX),
202 msg, size, actual_length, USB_8DEV_CMD_TIMEOUT);
203 }
204
205 /* Send command to device and receive result.
206 * Command was successful when opt1 = 0.
207 */
usb_8dev_send_cmd(struct usb_8dev_priv * priv,struct usb_8dev_cmd_msg * out,struct usb_8dev_cmd_msg * in)208 static int usb_8dev_send_cmd(struct usb_8dev_priv *priv,
209 struct usb_8dev_cmd_msg *out,
210 struct usb_8dev_cmd_msg *in)
211 {
212 int err;
213 int num_bytes_read;
214 struct net_device *netdev;
215
216 netdev = priv->netdev;
217
218 out->begin = USB_8DEV_CMD_START;
219 out->end = USB_8DEV_CMD_END;
220
221 mutex_lock(&priv->usb_8dev_cmd_lock);
222
223 memcpy(priv->cmd_msg_buffer, out,
224 sizeof(struct usb_8dev_cmd_msg));
225
226 err = usb_8dev_send_cmd_msg(priv, priv->cmd_msg_buffer,
227 sizeof(struct usb_8dev_cmd_msg));
228 if (err < 0) {
229 netdev_err(netdev, "sending command message failed\n");
230 goto failed;
231 }
232
233 err = usb_8dev_wait_cmd_msg(priv, priv->cmd_msg_buffer,
234 sizeof(struct usb_8dev_cmd_msg),
235 &num_bytes_read);
236 if (err < 0) {
237 netdev_err(netdev, "no command message answer\n");
238 goto failed;
239 }
240
241 memcpy(in, priv->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg));
242
243 if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END ||
244 num_bytes_read != 16 || in->opt1 != 0)
245 err = -EPROTO;
246
247 failed:
248 mutex_unlock(&priv->usb_8dev_cmd_lock);
249 return err;
250 }
251
252 /* Send open command to device */
usb_8dev_cmd_open(struct usb_8dev_priv * priv)253 static int usb_8dev_cmd_open(struct usb_8dev_priv *priv)
254 {
255 struct can_bittiming *bt = &priv->can.bittiming;
256 struct usb_8dev_cmd_msg outmsg;
257 struct usb_8dev_cmd_msg inmsg;
258 u32 ctrlmode = priv->can.ctrlmode;
259 u32 flags = USB_8DEV_STATUS_FRAME;
260 __be32 beflags;
261 __be16 bebrp;
262
263 memset(&outmsg, 0, sizeof(outmsg));
264 outmsg.command = USB_8DEV_OPEN;
265 outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
266 outmsg.data[0] = bt->prop_seg + bt->phase_seg1;
267 outmsg.data[1] = bt->phase_seg2;
268 outmsg.data[2] = bt->sjw;
269
270 /* BRP */
271 bebrp = cpu_to_be16((u16)bt->brp);
272 memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp));
273
274 /* flags */
275 if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
276 flags |= USB_8DEV_LOOPBACK;
277 if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
278 flags |= USB_8DEV_SILENT;
279 if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
280 flags |= USB_8DEV_DISABLE_AUTO_RESTRANS;
281
282 beflags = cpu_to_be32(flags);
283 memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
284
285 return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
286 }
287
288 /* Send close command to device */
usb_8dev_cmd_close(struct usb_8dev_priv * priv)289 static int usb_8dev_cmd_close(struct usb_8dev_priv *priv)
290 {
291 struct usb_8dev_cmd_msg inmsg;
292 struct usb_8dev_cmd_msg outmsg = {
293 .channel = 0,
294 .command = USB_8DEV_CLOSE,
295 .opt1 = 0,
296 .opt2 = 0
297 };
298
299 return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
300 }
301
302 /* Get firmware and hardware version */
usb_8dev_cmd_version(struct usb_8dev_priv * priv,u32 * res)303 static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, u32 *res)
304 {
305 struct usb_8dev_cmd_msg inmsg;
306 struct usb_8dev_cmd_msg outmsg = {
307 .channel = 0,
308 .command = USB_8DEV_GET_SOFTW_HARDW_VER,
309 .opt1 = 0,
310 .opt2 = 0
311 };
312
313 int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg);
314 if (err)
315 return err;
316
317 *res = be32_to_cpup((__be32 *)inmsg.data);
318
319 return err;
320 }
321
322 /* Set network device mode
323 *
324 * Maybe we should leave this function empty, because the device
325 * set mode variable with open command.
326 */
usb_8dev_set_mode(struct net_device * netdev,enum can_mode mode)327 static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode)
328 {
329 struct usb_8dev_priv *priv = netdev_priv(netdev);
330 int err = 0;
331
332 switch (mode) {
333 case CAN_MODE_START:
334 err = usb_8dev_cmd_open(priv);
335 if (err)
336 netdev_warn(netdev, "couldn't start device");
337 break;
338
339 default:
340 return -EOPNOTSUPP;
341 }
342
343 return err;
344 }
345
346 /* Read error/status frames */
usb_8dev_rx_err_msg(struct usb_8dev_priv * priv,struct usb_8dev_rx_msg * msg)347 static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
348 struct usb_8dev_rx_msg *msg)
349 {
350 struct can_frame *cf;
351 struct sk_buff *skb;
352 struct net_device_stats *stats = &priv->netdev->stats;
353
354 /* Error message:
355 * byte 0: Status
356 * byte 1: bit 7: Receive Passive
357 * byte 1: bit 0-6: Receive Error Counter
358 * byte 2: Transmit Error Counter
359 * byte 3: Always 0 (maybe reserved for future use)
360 */
361
362 u8 state = msg->data[0];
363 u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
364 u8 txerr = msg->data[2];
365 int rx_errors = 0;
366 int tx_errors = 0;
367
368 skb = alloc_can_err_skb(priv->netdev, &cf);
369 if (!skb)
370 return;
371
372 switch (state) {
373 case USB_8DEV_STATUSMSG_OK:
374 priv->can.state = CAN_STATE_ERROR_ACTIVE;
375 cf->can_id |= CAN_ERR_PROT;
376 cf->data[2] = CAN_ERR_PROT_ACTIVE;
377 break;
378 case USB_8DEV_STATUSMSG_BUSOFF:
379 priv->can.state = CAN_STATE_BUS_OFF;
380 cf->can_id |= CAN_ERR_BUSOFF;
381 priv->can.can_stats.bus_off++;
382 can_bus_off(priv->netdev);
383 break;
384 case USB_8DEV_STATUSMSG_OVERRUN:
385 case USB_8DEV_STATUSMSG_BUSLIGHT:
386 case USB_8DEV_STATUSMSG_BUSHEAVY:
387 cf->can_id |= CAN_ERR_CRTL;
388 break;
389 default:
390 priv->can.state = CAN_STATE_ERROR_WARNING;
391 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
392 priv->can.can_stats.bus_error++;
393 break;
394 }
395
396 switch (state) {
397 case USB_8DEV_STATUSMSG_OK:
398 case USB_8DEV_STATUSMSG_BUSOFF:
399 break;
400 case USB_8DEV_STATUSMSG_ACK:
401 cf->can_id |= CAN_ERR_ACK;
402 tx_errors = 1;
403 break;
404 case USB_8DEV_STATUSMSG_CRC:
405 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
406 rx_errors = 1;
407 break;
408 case USB_8DEV_STATUSMSG_BIT0:
409 cf->data[2] |= CAN_ERR_PROT_BIT0;
410 tx_errors = 1;
411 break;
412 case USB_8DEV_STATUSMSG_BIT1:
413 cf->data[2] |= CAN_ERR_PROT_BIT1;
414 tx_errors = 1;
415 break;
416 case USB_8DEV_STATUSMSG_FORM:
417 cf->data[2] |= CAN_ERR_PROT_FORM;
418 rx_errors = 1;
419 break;
420 case USB_8DEV_STATUSMSG_STUFF:
421 cf->data[2] |= CAN_ERR_PROT_STUFF;
422 rx_errors = 1;
423 break;
424 case USB_8DEV_STATUSMSG_OVERRUN:
425 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
426 stats->rx_over_errors++;
427 rx_errors = 1;
428 break;
429 case USB_8DEV_STATUSMSG_BUSLIGHT:
430 priv->can.state = CAN_STATE_ERROR_WARNING;
431 cf->data[1] = (txerr > rxerr) ?
432 CAN_ERR_CRTL_TX_WARNING :
433 CAN_ERR_CRTL_RX_WARNING;
434 priv->can.can_stats.error_warning++;
435 break;
436 case USB_8DEV_STATUSMSG_BUSHEAVY:
437 priv->can.state = CAN_STATE_ERROR_PASSIVE;
438 cf->data[1] = (txerr > rxerr) ?
439 CAN_ERR_CRTL_TX_PASSIVE :
440 CAN_ERR_CRTL_RX_PASSIVE;
441 priv->can.can_stats.error_passive++;
442 break;
443 default:
444 netdev_warn(priv->netdev,
445 "Unknown status/error message (%d)\n", state);
446 break;
447 }
448
449 if (tx_errors) {
450 cf->data[2] |= CAN_ERR_PROT_TX;
451 stats->tx_errors++;
452 }
453
454 if (rx_errors)
455 stats->rx_errors++;
456
457 cf->data[6] = txerr;
458 cf->data[7] = rxerr;
459
460 priv->bec.txerr = txerr;
461 priv->bec.rxerr = rxerr;
462
463 stats->rx_packets++;
464 stats->rx_bytes += cf->can_dlc;
465 netif_rx(skb);
466 }
467
468 /* Read data and status frames */
usb_8dev_rx_can_msg(struct usb_8dev_priv * priv,struct usb_8dev_rx_msg * msg)469 static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
470 struct usb_8dev_rx_msg *msg)
471 {
472 struct can_frame *cf;
473 struct sk_buff *skb;
474 struct net_device_stats *stats = &priv->netdev->stats;
475
476 if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
477 msg->flags == USB_8DEV_ERR_FLAG) {
478 usb_8dev_rx_err_msg(priv, msg);
479 } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
480 skb = alloc_can_skb(priv->netdev, &cf);
481 if (!skb)
482 return;
483
484 cf->can_id = be32_to_cpu(msg->id);
485 cf->can_dlc = get_can_dlc(msg->dlc & 0xF);
486
487 if (msg->flags & USB_8DEV_EXTID)
488 cf->can_id |= CAN_EFF_FLAG;
489
490 if (msg->flags & USB_8DEV_RTR)
491 cf->can_id |= CAN_RTR_FLAG;
492 else
493 memcpy(cf->data, msg->data, cf->can_dlc);
494
495 stats->rx_packets++;
496 stats->rx_bytes += cf->can_dlc;
497 netif_rx(skb);
498
499 can_led_event(priv->netdev, CAN_LED_EVENT_RX);
500 } else {
501 netdev_warn(priv->netdev, "frame type %d unknown",
502 msg->type);
503 }
504
505 }
506
507 /* Callback for reading data from device
508 *
509 * Check urb status, call read function and resubmit urb read operation.
510 */
usb_8dev_read_bulk_callback(struct urb * urb)511 static void usb_8dev_read_bulk_callback(struct urb *urb)
512 {
513 struct usb_8dev_priv *priv = urb->context;
514 struct net_device *netdev;
515 int retval;
516 int pos = 0;
517
518 netdev = priv->netdev;
519
520 if (!netif_device_present(netdev))
521 return;
522
523 switch (urb->status) {
524 case 0: /* success */
525 break;
526
527 case -ENOENT:
528 case -EPIPE:
529 case -EPROTO:
530 case -ESHUTDOWN:
531 return;
532
533 default:
534 netdev_info(netdev, "Rx URB aborted (%d)\n",
535 urb->status);
536 goto resubmit_urb;
537 }
538
539 while (pos < urb->actual_length) {
540 struct usb_8dev_rx_msg *msg;
541
542 if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
543 netdev_err(priv->netdev, "format error\n");
544 break;
545 }
546
547 msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
548 usb_8dev_rx_can_msg(priv, msg);
549
550 pos += sizeof(struct usb_8dev_rx_msg);
551 }
552
553 resubmit_urb:
554 usb_fill_bulk_urb(urb, priv->udev,
555 usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
556 urb->transfer_buffer, RX_BUFFER_SIZE,
557 usb_8dev_read_bulk_callback, priv);
558
559 retval = usb_submit_urb(urb, GFP_ATOMIC);
560
561 if (retval == -ENODEV)
562 netif_device_detach(netdev);
563 else if (retval)
564 netdev_err(netdev,
565 "failed resubmitting read bulk urb: %d\n", retval);
566 }
567
568 /* Callback handler for write operations
569 *
570 * Free allocated buffers, check transmit status and
571 * calculate statistic.
572 */
usb_8dev_write_bulk_callback(struct urb * urb)573 static void usb_8dev_write_bulk_callback(struct urb *urb)
574 {
575 struct usb_8dev_tx_urb_context *context = urb->context;
576 struct usb_8dev_priv *priv;
577 struct net_device *netdev;
578
579 BUG_ON(!context);
580
581 priv = context->priv;
582 netdev = priv->netdev;
583
584 /* free up our allocated buffer */
585 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
586 urb->transfer_buffer, urb->transfer_dma);
587
588 atomic_dec(&priv->active_tx_urbs);
589
590 if (!netif_device_present(netdev))
591 return;
592
593 if (urb->status)
594 netdev_info(netdev, "Tx URB aborted (%d)\n",
595 urb->status);
596
597 netdev->stats.tx_packets++;
598 netdev->stats.tx_bytes += context->dlc;
599
600 can_get_echo_skb(netdev, context->echo_index);
601
602 can_led_event(netdev, CAN_LED_EVENT_TX);
603
604 /* Release context */
605 context->echo_index = MAX_TX_URBS;
606
607 netif_wake_queue(netdev);
608 }
609
610 /* Send data to device */
usb_8dev_start_xmit(struct sk_buff * skb,struct net_device * netdev)611 static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
612 struct net_device *netdev)
613 {
614 struct usb_8dev_priv *priv = netdev_priv(netdev);
615 struct net_device_stats *stats = &netdev->stats;
616 struct can_frame *cf = (struct can_frame *) skb->data;
617 struct usb_8dev_tx_msg *msg;
618 struct urb *urb;
619 struct usb_8dev_tx_urb_context *context = NULL;
620 u8 *buf;
621 int i, err;
622 size_t size = sizeof(struct usb_8dev_tx_msg);
623
624 if (can_dropped_invalid_skb(netdev, skb))
625 return NETDEV_TX_OK;
626
627 /* create a URB, and a buffer for it, and copy the data to the URB */
628 urb = usb_alloc_urb(0, GFP_ATOMIC);
629 if (!urb) {
630 netdev_err(netdev, "No memory left for URBs\n");
631 goto nomem;
632 }
633
634 buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
635 &urb->transfer_dma);
636 if (!buf) {
637 netdev_err(netdev, "No memory left for USB buffer\n");
638 goto nomembuf;
639 }
640
641 memset(buf, 0, size);
642
643 msg = (struct usb_8dev_tx_msg *)buf;
644 msg->begin = USB_8DEV_DATA_START;
645 msg->flags = 0x00;
646
647 if (cf->can_id & CAN_RTR_FLAG)
648 msg->flags |= USB_8DEV_RTR;
649
650 if (cf->can_id & CAN_EFF_FLAG)
651 msg->flags |= USB_8DEV_EXTID;
652
653 msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
654 msg->dlc = cf->can_dlc;
655 memcpy(msg->data, cf->data, cf->can_dlc);
656 msg->end = USB_8DEV_DATA_END;
657
658 for (i = 0; i < MAX_TX_URBS; i++) {
659 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
660 context = &priv->tx_contexts[i];
661 break;
662 }
663 }
664
665 /* May never happen! When this happens we'd more URBs in flight as
666 * allowed (MAX_TX_URBS).
667 */
668 if (!context)
669 goto nofreecontext;
670
671 context->priv = priv;
672 context->echo_index = i;
673 context->dlc = cf->can_dlc;
674
675 usb_fill_bulk_urb(urb, priv->udev,
676 usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
677 buf, size, usb_8dev_write_bulk_callback, context);
678 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
679 usb_anchor_urb(urb, &priv->tx_submitted);
680
681 can_put_echo_skb(skb, netdev, context->echo_index);
682
683 atomic_inc(&priv->active_tx_urbs);
684
685 err = usb_submit_urb(urb, GFP_ATOMIC);
686 if (unlikely(err))
687 goto failed;
688 else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
689 /* Slow down tx path */
690 netif_stop_queue(netdev);
691
692 /* Release our reference to this URB, the USB core will eventually free
693 * it entirely.
694 */
695 usb_free_urb(urb);
696
697 return NETDEV_TX_OK;
698
699 nofreecontext:
700 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
701 usb_free_urb(urb);
702
703 netdev_warn(netdev, "couldn't find free context");
704
705 return NETDEV_TX_BUSY;
706
707 failed:
708 can_free_echo_skb(netdev, context->echo_index);
709
710 usb_unanchor_urb(urb);
711 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
712
713 atomic_dec(&priv->active_tx_urbs);
714
715 if (err == -ENODEV)
716 netif_device_detach(netdev);
717 else
718 netdev_warn(netdev, "failed tx_urb %d\n", err);
719
720 nomembuf:
721 usb_free_urb(urb);
722
723 nomem:
724 dev_kfree_skb(skb);
725 stats->tx_dropped++;
726
727 return NETDEV_TX_OK;
728 }
729
usb_8dev_get_berr_counter(const struct net_device * netdev,struct can_berr_counter * bec)730 static int usb_8dev_get_berr_counter(const struct net_device *netdev,
731 struct can_berr_counter *bec)
732 {
733 struct usb_8dev_priv *priv = netdev_priv(netdev);
734
735 bec->txerr = priv->bec.txerr;
736 bec->rxerr = priv->bec.rxerr;
737
738 return 0;
739 }
740
741 /* Start USB device */
usb_8dev_start(struct usb_8dev_priv * priv)742 static int usb_8dev_start(struct usb_8dev_priv *priv)
743 {
744 struct net_device *netdev = priv->netdev;
745 int err, i;
746
747 for (i = 0; i < MAX_RX_URBS; i++) {
748 struct urb *urb = NULL;
749 u8 *buf;
750 dma_addr_t buf_dma;
751
752 /* create a URB, and a buffer for it */
753 urb = usb_alloc_urb(0, GFP_KERNEL);
754 if (!urb) {
755 netdev_err(netdev, "No memory left for URBs\n");
756 err = -ENOMEM;
757 break;
758 }
759
760 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
761 &buf_dma);
762 if (!buf) {
763 netdev_err(netdev, "No memory left for USB buffer\n");
764 usb_free_urb(urb);
765 err = -ENOMEM;
766 break;
767 }
768
769 urb->transfer_dma = buf_dma;
770
771 usb_fill_bulk_urb(urb, priv->udev,
772 usb_rcvbulkpipe(priv->udev,
773 USB_8DEV_ENDP_DATA_RX),
774 buf, RX_BUFFER_SIZE,
775 usb_8dev_read_bulk_callback, priv);
776 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
777 usb_anchor_urb(urb, &priv->rx_submitted);
778
779 err = usb_submit_urb(urb, GFP_KERNEL);
780 if (err) {
781 usb_unanchor_urb(urb);
782 usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
783 urb->transfer_dma);
784 usb_free_urb(urb);
785 break;
786 }
787
788 priv->rxbuf[i] = buf;
789 priv->rxbuf_dma[i] = buf_dma;
790
791 /* Drop reference, USB core will take care of freeing it */
792 usb_free_urb(urb);
793 }
794
795 /* Did we submit any URBs */
796 if (i == 0) {
797 netdev_warn(netdev, "couldn't setup read URBs\n");
798 return err;
799 }
800
801 /* Warn if we've couldn't transmit all the URBs */
802 if (i < MAX_RX_URBS)
803 netdev_warn(netdev, "rx performance may be slow\n");
804
805 err = usb_8dev_cmd_open(priv);
806 if (err)
807 goto failed;
808
809 priv->can.state = CAN_STATE_ERROR_ACTIVE;
810
811 return 0;
812
813 failed:
814 if (err == -ENODEV)
815 netif_device_detach(priv->netdev);
816
817 netdev_warn(netdev, "couldn't submit control: %d\n", err);
818
819 return err;
820 }
821
822 /* Open USB device */
usb_8dev_open(struct net_device * netdev)823 static int usb_8dev_open(struct net_device *netdev)
824 {
825 struct usb_8dev_priv *priv = netdev_priv(netdev);
826 int err;
827
828 /* common open */
829 err = open_candev(netdev);
830 if (err)
831 return err;
832
833 can_led_event(netdev, CAN_LED_EVENT_OPEN);
834
835 /* finally start device */
836 err = usb_8dev_start(priv);
837 if (err) {
838 if (err == -ENODEV)
839 netif_device_detach(priv->netdev);
840
841 netdev_warn(netdev, "couldn't start device: %d\n",
842 err);
843
844 close_candev(netdev);
845
846 return err;
847 }
848
849 netif_start_queue(netdev);
850
851 return 0;
852 }
853
unlink_all_urbs(struct usb_8dev_priv * priv)854 static void unlink_all_urbs(struct usb_8dev_priv *priv)
855 {
856 int i;
857
858 usb_kill_anchored_urbs(&priv->rx_submitted);
859
860 for (i = 0; i < MAX_RX_URBS; ++i)
861 usb_free_coherent(priv->udev, RX_BUFFER_SIZE,
862 priv->rxbuf[i], priv->rxbuf_dma[i]);
863
864 usb_kill_anchored_urbs(&priv->tx_submitted);
865 atomic_set(&priv->active_tx_urbs, 0);
866
867 for (i = 0; i < MAX_TX_URBS; i++)
868 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
869 }
870
871 /* Close USB device */
usb_8dev_close(struct net_device * netdev)872 static int usb_8dev_close(struct net_device *netdev)
873 {
874 struct usb_8dev_priv *priv = netdev_priv(netdev);
875 int err = 0;
876
877 /* Send CLOSE command to CAN controller */
878 err = usb_8dev_cmd_close(priv);
879 if (err)
880 netdev_warn(netdev, "couldn't stop device");
881
882 priv->can.state = CAN_STATE_STOPPED;
883
884 netif_stop_queue(netdev);
885
886 /* Stop polling */
887 unlink_all_urbs(priv);
888
889 close_candev(netdev);
890
891 can_led_event(netdev, CAN_LED_EVENT_STOP);
892
893 return err;
894 }
895
896 static const struct net_device_ops usb_8dev_netdev_ops = {
897 .ndo_open = usb_8dev_open,
898 .ndo_stop = usb_8dev_close,
899 .ndo_start_xmit = usb_8dev_start_xmit,
900 .ndo_change_mtu = can_change_mtu,
901 };
902
903 static const struct can_bittiming_const usb_8dev_bittiming_const = {
904 .name = "usb_8dev",
905 .tseg1_min = 1,
906 .tseg1_max = 16,
907 .tseg2_min = 1,
908 .tseg2_max = 8,
909 .sjw_max = 4,
910 .brp_min = 1,
911 .brp_max = 1024,
912 .brp_inc = 1,
913 };
914
915 /* Probe USB device
916 *
917 * Check device and firmware.
918 * Set supported modes and bittiming constants.
919 * Allocate some memory.
920 */
usb_8dev_probe(struct usb_interface * intf,const struct usb_device_id * id)921 static int usb_8dev_probe(struct usb_interface *intf,
922 const struct usb_device_id *id)
923 {
924 struct net_device *netdev;
925 struct usb_8dev_priv *priv;
926 int i, err = -ENOMEM;
927 u32 version;
928 char buf[18];
929 struct usb_device *usbdev = interface_to_usbdev(intf);
930
931 /* product id looks strange, better we also check iProduct string */
932 if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
933 sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
934 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
935 return -ENODEV;
936 }
937
938 netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
939 if (!netdev) {
940 dev_err(&intf->dev, "Couldn't alloc candev\n");
941 return -ENOMEM;
942 }
943
944 priv = netdev_priv(netdev);
945
946 priv->udev = usbdev;
947 priv->netdev = netdev;
948
949 priv->can.state = CAN_STATE_STOPPED;
950 priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
951 priv->can.bittiming_const = &usb_8dev_bittiming_const;
952 priv->can.do_set_mode = usb_8dev_set_mode;
953 priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
954 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
955 CAN_CTRLMODE_LISTENONLY |
956 CAN_CTRLMODE_ONE_SHOT;
957
958 netdev->netdev_ops = &usb_8dev_netdev_ops;
959
960 netdev->flags |= IFF_ECHO; /* we support local echo */
961
962 init_usb_anchor(&priv->rx_submitted);
963
964 init_usb_anchor(&priv->tx_submitted);
965 atomic_set(&priv->active_tx_urbs, 0);
966
967 for (i = 0; i < MAX_TX_URBS; i++)
968 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
969
970 priv->cmd_msg_buffer = devm_kzalloc(&intf->dev, sizeof(struct usb_8dev_cmd_msg),
971 GFP_KERNEL);
972 if (!priv->cmd_msg_buffer)
973 goto cleanup_candev;
974
975 usb_set_intfdata(intf, priv);
976
977 SET_NETDEV_DEV(netdev, &intf->dev);
978
979 mutex_init(&priv->usb_8dev_cmd_lock);
980
981 err = register_candev(netdev);
982 if (err) {
983 netdev_err(netdev,
984 "couldn't register CAN device: %d\n", err);
985 goto cleanup_candev;
986 }
987
988 err = usb_8dev_cmd_version(priv, &version);
989 if (err) {
990 netdev_err(netdev, "can't get firmware version\n");
991 goto cleanup_unregister_candev;
992 } else {
993 netdev_info(netdev,
994 "firmware: %d.%d, hardware: %d.%d\n",
995 (version>>24) & 0xff, (version>>16) & 0xff,
996 (version>>8) & 0xff, version & 0xff);
997 }
998
999 devm_can_led_init(netdev);
1000
1001 return 0;
1002
1003 cleanup_unregister_candev:
1004 unregister_netdev(priv->netdev);
1005
1006 cleanup_candev:
1007 free_candev(netdev);
1008
1009 return err;
1010
1011 }
1012
1013 /* Called by the usb core when driver is unloaded or device is removed */
usb_8dev_disconnect(struct usb_interface * intf)1014 static void usb_8dev_disconnect(struct usb_interface *intf)
1015 {
1016 struct usb_8dev_priv *priv = usb_get_intfdata(intf);
1017
1018 usb_set_intfdata(intf, NULL);
1019
1020 if (priv) {
1021 netdev_info(priv->netdev, "device disconnected\n");
1022
1023 unregister_netdev(priv->netdev);
1024 unlink_all_urbs(priv);
1025 free_candev(priv->netdev);
1026 }
1027
1028 }
1029
1030 static struct usb_driver usb_8dev_driver = {
1031 .name = "usb_8dev",
1032 .probe = usb_8dev_probe,
1033 .disconnect = usb_8dev_disconnect,
1034 .id_table = usb_8dev_table,
1035 };
1036
1037 module_usb_driver(usb_8dev_driver);
1038
1039 MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>");
1040 MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
1041 MODULE_LICENSE("GPL v2");
1042