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esd_usb2.c
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1 /*
2  * CAN driver for esd CAN-USB/2
3  *
4  * Copyright (C) 2010 Matthias Fuchs <[email protected]>, esd gmbh
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; if not, write to the Free Software Foundation, Inc.,
17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18  */
19 #include <linux/init.h>
20 #include <linux/signal.h>
21 #include <linux/slab.h>
22 #include <linux/module.h>
23 #include <linux/netdevice.h>
24 #include <linux/usb.h>
25 
26 #include <linux/can.h>
27 #include <linux/can/dev.h>
28 #include <linux/can/error.h>
29 
30 MODULE_AUTHOR("Matthias Fuchs <[email protected]>");
31 MODULE_DESCRIPTION("CAN driver for esd CAN-USB/2 interfaces");
32 MODULE_LICENSE("GPL v2");
33 
34 /* Define these values to match your devices */
35 #define USB_ESDGMBH_VENDOR_ID 0x0ab4
36 #define USB_CANUSB2_PRODUCT_ID 0x0010
37 
38 #define ESD_USB2_CAN_CLOCK 60000000
39 #define ESD_USB2_MAX_NETS 2
40 
41 /* USB2 commands */
42 #define CMD_VERSION 1 /* also used for VERSION_REPLY */
43 #define CMD_CAN_RX 2 /* device to host only */
44 #define CMD_CAN_TX 3 /* also used for TX_DONE */
45 #define CMD_SETBAUD 4 /* also used for SETBAUD_REPLY */
46 #define CMD_TS 5 /* also used for TS_REPLY */
47 #define CMD_IDADD 6 /* also used for IDADD_REPLY */
48 
49 /* esd CAN message flags - dlc field */
50 #define ESD_RTR 0x10
51 
52 /* esd CAN message flags - id field */
53 #define ESD_EXTID 0x20000000
54 #define ESD_EVENT 0x40000000
55 #define ESD_IDMASK 0x1fffffff
56 
57 /* esd CAN event ids used by this driver */
58 #define ESD_EV_CAN_ERROR_EXT 2
59 
60 /* baudrate message flags */
61 #define ESD_USB2_UBR 0x80000000
62 #define ESD_USB2_LOM 0x40000000
63 #define ESD_USB2_NO_BAUDRATE 0x7fffffff
64 #define ESD_USB2_TSEG1_MIN 1
65 #define ESD_USB2_TSEG1_MAX 16
66 #define ESD_USB2_TSEG1_SHIFT 16
67 #define ESD_USB2_TSEG2_MIN 1
68 #define ESD_USB2_TSEG2_MAX 8
69 #define ESD_USB2_TSEG2_SHIFT 20
70 #define ESD_USB2_SJW_MAX 4
71 #define ESD_USB2_SJW_SHIFT 14
72 #define ESD_USB2_BRP_MIN 1
73 #define ESD_USB2_BRP_MAX 1024
74 #define ESD_USB2_BRP_INC 1
75 #define ESD_USB2_3_SAMPLES 0x00800000
76 
77 /* esd IDADD message */
78 #define ESD_ID_ENABLE 0x80
79 #define ESD_MAX_ID_SEGMENT 64
80 
81 /* SJA1000 ECC register (emulated by usb2 firmware) */
82 #define SJA1000_ECC_SEG 0x1F
83 #define SJA1000_ECC_DIR 0x20
84 #define SJA1000_ECC_ERR 0x06
85 #define SJA1000_ECC_BIT 0x00
86 #define SJA1000_ECC_FORM 0x40
87 #define SJA1000_ECC_STUFF 0x80
88 #define SJA1000_ECC_MASK 0xc0
89 
90 /* esd bus state event codes */
91 #define ESD_BUSSTATE_MASK 0xc0
92 #define ESD_BUSSTATE_WARN 0x40
93 #define ESD_BUSSTATE_ERRPASSIVE 0x80
94 #define ESD_BUSSTATE_BUSOFF 0xc0
95 
96 #define RX_BUFFER_SIZE 1024
97 #define MAX_RX_URBS 4
98 #define MAX_TX_URBS 16 /* must be power of 2 */
99 
100 struct header_msg {
101  u8 len; /* len is always the total message length in 32bit words */
103  u8 rsvd[2];
104 };
105 
106 struct version_msg {
112 };
113 
120  u8 name[16];
123 };
124 
125 struct rx_msg {
131  __le32 id; /* upper 3 bits contain flags */
132  u8 data[8];
133 };
134 
135 struct tx_msg {
141  __le32 id; /* upper 3 bits contain flags */
142  u8 data[8];
143 };
144 
145 struct tx_done_msg {
152 };
153 
160 };
161 
168 };
169 
170 /* Main message type used between library and application */
171 struct __attribute__ ((packed)) esd_usb2_msg {
172  union {
173  struct header_msg hdr;
174  struct version_msg version;
175  struct version_reply_msg version_reply;
176  struct rx_msg rx;
177  struct tx_msg tx;
178  struct tx_done_msg txdone;
179  struct set_baudrate_msg setbaud;
180  struct id_filter_msg filter;
181  } msg;
182 };
183 
184 static struct usb_device_id esd_usb2_table[] = {
186  {}
187 };
188 MODULE_DEVICE_TABLE(usb, esd_usb2_table);
189 
190 struct esd_usb2_net_priv;
191 
195  int dlc;
196 };
197 
198 struct esd_usb2 {
199  struct usb_device *udev;
201 
202  struct usb_anchor rx_submitted;
203 
207 };
208 
210  struct can_priv can; /* must be the first member */
211 
213  struct usb_anchor tx_submitted;
215 
217  struct esd_usb2 *usb2;
219  int index;
222 };
223 
224 static void esd_usb2_rx_event(struct esd_usb2_net_priv *priv,
225  struct esd_usb2_msg *msg)
226 {
227  struct net_device_stats *stats = &priv->netdev->stats;
228  struct can_frame *cf;
229  struct sk_buff *skb;
230  u32 id = le32_to_cpu(msg->msg.rx.id) & ESD_IDMASK;
231 
232  if (id == ESD_EV_CAN_ERROR_EXT) {
233  u8 state = msg->msg.rx.data[0];
234  u8 ecc = msg->msg.rx.data[1];
235  u8 txerr = msg->msg.rx.data[2];
236  u8 rxerr = msg->msg.rx.data[3];
237 
238  skb = alloc_can_err_skb(priv->netdev, &cf);
239  if (skb == NULL) {
240  stats->rx_dropped++;
241  return;
242  }
243 
244  if (state != priv->old_state) {
245  priv->old_state = state;
246 
247  switch (state & ESD_BUSSTATE_MASK) {
248  case ESD_BUSSTATE_BUSOFF:
249  priv->can.state = CAN_STATE_BUS_OFF;
250  cf->can_id |= CAN_ERR_BUSOFF;
251  can_bus_off(priv->netdev);
252  break;
253  case ESD_BUSSTATE_WARN:
254  priv->can.state = CAN_STATE_ERROR_WARNING;
255  priv->can.can_stats.error_warning++;
256  break;
258  priv->can.state = CAN_STATE_ERROR_PASSIVE;
259  priv->can.can_stats.error_passive++;
260  break;
261  default:
262  priv->can.state = CAN_STATE_ERROR_ACTIVE;
263  break;
264  }
265  } else {
266  priv->can.can_stats.bus_error++;
267  stats->rx_errors++;
268 
270 
271  switch (ecc & SJA1000_ECC_MASK) {
272  case SJA1000_ECC_BIT:
273  cf->data[2] |= CAN_ERR_PROT_BIT;
274  break;
275  case SJA1000_ECC_FORM:
276  cf->data[2] |= CAN_ERR_PROT_FORM;
277  break;
278  case SJA1000_ECC_STUFF:
279  cf->data[2] |= CAN_ERR_PROT_STUFF;
280  break;
281  default:
282  cf->data[2] |= CAN_ERR_PROT_UNSPEC;
283  cf->data[3] = ecc & SJA1000_ECC_SEG;
284  break;
285  }
286 
287  /* Error occurred during transmission? */
288  if (!(ecc & SJA1000_ECC_DIR))
289  cf->data[2] |= CAN_ERR_PROT_TX;
290 
291  if (priv->can.state == CAN_STATE_ERROR_WARNING ||
292  priv->can.state == CAN_STATE_ERROR_PASSIVE) {
293  cf->data[1] = (txerr > rxerr) ?
296  }
297  cf->data[6] = txerr;
298  cf->data[7] = rxerr;
299  }
300 
301  netif_rx(skb);
302 
303  priv->bec.txerr = txerr;
304  priv->bec.rxerr = rxerr;
305 
306  stats->rx_packets++;
307  stats->rx_bytes += cf->can_dlc;
308  }
309 }
310 
311 static void esd_usb2_rx_can_msg(struct esd_usb2_net_priv *priv,
312  struct esd_usb2_msg *msg)
313 {
314  struct net_device_stats *stats = &priv->netdev->stats;
315  struct can_frame *cf;
316  struct sk_buff *skb;
317  int i;
318  u32 id;
319 
320  if (!netif_device_present(priv->netdev))
321  return;
322 
323  id = le32_to_cpu(msg->msg.rx.id);
324 
325  if (id & ESD_EVENT) {
326  esd_usb2_rx_event(priv, msg);
327  } else {
328  skb = alloc_can_skb(priv->netdev, &cf);
329  if (skb == NULL) {
330  stats->rx_dropped++;
331  return;
332  }
333 
334  cf->can_id = id & ESD_IDMASK;
335  cf->can_dlc = get_can_dlc(msg->msg.rx.dlc);
336 
337  if (id & ESD_EXTID)
338  cf->can_id |= CAN_EFF_FLAG;
339 
340  if (msg->msg.rx.dlc & ESD_RTR) {
341  cf->can_id |= CAN_RTR_FLAG;
342  } else {
343  for (i = 0; i < cf->can_dlc; i++)
344  cf->data[i] = msg->msg.rx.data[i];
345  }
346 
347  netif_rx(skb);
348 
349  stats->rx_packets++;
350  stats->rx_bytes += cf->can_dlc;
351  }
352 
353  return;
354 }
355 
356 static void esd_usb2_tx_done_msg(struct esd_usb2_net_priv *priv,
357  struct esd_usb2_msg *msg)
358 {
359  struct net_device_stats *stats = &priv->netdev->stats;
360  struct net_device *netdev = priv->netdev;
361  struct esd_tx_urb_context *context;
362 
363  if (!netif_device_present(netdev))
364  return;
365 
366  context = &priv->tx_contexts[msg->msg.txdone.hnd & (MAX_TX_URBS - 1)];
367 
368  if (!msg->msg.txdone.status) {
369  stats->tx_packets++;
370  stats->tx_bytes += context->dlc;
371  can_get_echo_skb(netdev, context->echo_index);
372  } else {
373  stats->tx_errors++;
374  can_free_echo_skb(netdev, context->echo_index);
375  }
376 
377  /* Release context */
378  context->echo_index = MAX_TX_URBS;
379  atomic_dec(&priv->active_tx_jobs);
380 
381  netif_wake_queue(netdev);
382 }
383 
384 static void esd_usb2_read_bulk_callback(struct urb *urb)
385 {
386  struct esd_usb2 *dev = urb->context;
387  int retval;
388  int pos = 0;
389  int i;
390 
391  switch (urb->status) {
392  case 0: /* success */
393  break;
394 
395  case -ENOENT:
396  case -ESHUTDOWN:
397  return;
398 
399  default:
400  dev_info(dev->udev->dev.parent,
401  "Rx URB aborted (%d)\n", urb->status);
402  goto resubmit_urb;
403  }
404 
405  while (pos < urb->actual_length) {
406  struct esd_usb2_msg *msg;
407 
408  msg = (struct esd_usb2_msg *)(urb->transfer_buffer + pos);
409 
410  switch (msg->msg.hdr.cmd) {
411  case CMD_CAN_RX:
412  esd_usb2_rx_can_msg(dev->nets[msg->msg.rx.net], msg);
413  break;
414 
415  case CMD_CAN_TX:
416  esd_usb2_tx_done_msg(dev->nets[msg->msg.txdone.net],
417  msg);
418  break;
419  }
420 
421  pos += msg->msg.hdr.len << 2;
422 
423  if (pos > urb->actual_length) {
424  dev_err(dev->udev->dev.parent, "format error\n");
425  break;
426  }
427  }
428 
429 resubmit_urb:
430  usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
431  urb->transfer_buffer, RX_BUFFER_SIZE,
432  esd_usb2_read_bulk_callback, dev);
433 
434  retval = usb_submit_urb(urb, GFP_ATOMIC);
435  if (retval == -ENODEV) {
436  for (i = 0; i < dev->net_count; i++) {
437  if (dev->nets[i])
438  netif_device_detach(dev->nets[i]->netdev);
439  }
440  } else if (retval) {
441  dev_err(dev->udev->dev.parent,
442  "failed resubmitting read bulk urb: %d\n", retval);
443  }
444 
445  return;
446 }
447 
448 /*
449  * callback for bulk IN urb
450  */
451 static void esd_usb2_write_bulk_callback(struct urb *urb)
452 {
453  struct esd_tx_urb_context *context = urb->context;
454  struct esd_usb2_net_priv *priv;
455  struct esd_usb2 *dev;
456  struct net_device *netdev;
457  size_t size = sizeof(struct esd_usb2_msg);
458 
459  WARN_ON(!context);
460 
461  priv = context->priv;
462  netdev = priv->netdev;
463  dev = priv->usb2;
464 
465  /* free up our allocated buffer */
466  usb_free_coherent(urb->dev, size,
467  urb->transfer_buffer, urb->transfer_dma);
468 
469  if (!netif_device_present(netdev))
470  return;
471 
472  if (urb->status)
473  netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
474 
475  netdev->trans_start = jiffies;
476 }
477 
478 static ssize_t show_firmware(struct device *d,
479  struct device_attribute *attr, char *buf)
480 {
481  struct usb_interface *intf = to_usb_interface(d);
482  struct esd_usb2 *dev = usb_get_intfdata(intf);
483 
484  return sprintf(buf, "%d.%d.%d\n",
485  (dev->version >> 12) & 0xf,
486  (dev->version >> 8) & 0xf,
487  dev->version & 0xff);
488 }
489 static DEVICE_ATTR(firmware, S_IRUGO, show_firmware, NULL);
490 
491 static ssize_t show_hardware(struct device *d,
492  struct device_attribute *attr, char *buf)
493 {
494  struct usb_interface *intf = to_usb_interface(d);
495  struct esd_usb2 *dev = usb_get_intfdata(intf);
496 
497  return sprintf(buf, "%d.%d.%d\n",
498  (dev->version >> 28) & 0xf,
499  (dev->version >> 24) & 0xf,
500  (dev->version >> 16) & 0xff);
501 }
502 static DEVICE_ATTR(hardware, S_IRUGO, show_hardware, NULL);
503 
504 static ssize_t show_nets(struct device *d,
505  struct device_attribute *attr, char *buf)
506 {
507  struct usb_interface *intf = to_usb_interface(d);
508  struct esd_usb2 *dev = usb_get_intfdata(intf);
509 
510  return sprintf(buf, "%d", dev->net_count);
511 }
512 static DEVICE_ATTR(nets, S_IRUGO, show_nets, NULL);
513 
514 static int esd_usb2_send_msg(struct esd_usb2 *dev, struct esd_usb2_msg *msg)
515 {
516  int actual_length;
517 
518  return usb_bulk_msg(dev->udev,
519  usb_sndbulkpipe(dev->udev, 2),
520  msg,
521  msg->msg.hdr.len << 2,
522  &actual_length,
523  1000);
524 }
525 
526 static int esd_usb2_wait_msg(struct esd_usb2 *dev,
527  struct esd_usb2_msg *msg)
528 {
529  int actual_length;
530 
531  return usb_bulk_msg(dev->udev,
532  usb_rcvbulkpipe(dev->udev, 1),
533  msg,
534  sizeof(*msg),
535  &actual_length,
536  1000);
537 }
538 
539 static int esd_usb2_setup_rx_urbs(struct esd_usb2 *dev)
540 {
541  int i, err = 0;
542 
543  if (dev->rxinitdone)
544  return 0;
545 
546  for (i = 0; i < MAX_RX_URBS; i++) {
547  struct urb *urb = NULL;
548  u8 *buf = NULL;
549 
550  /* create a URB, and a buffer for it */
551  urb = usb_alloc_urb(0, GFP_KERNEL);
552  if (!urb) {
553  dev_warn(dev->udev->dev.parent,
554  "No memory left for URBs\n");
555  err = -ENOMEM;
556  break;
557  }
558 
560  &urb->transfer_dma);
561  if (!buf) {
562  dev_warn(dev->udev->dev.parent,
563  "No memory left for USB buffer\n");
564  err = -ENOMEM;
565  goto freeurb;
566  }
567 
568  usb_fill_bulk_urb(urb, dev->udev,
569  usb_rcvbulkpipe(dev->udev, 1),
570  buf, RX_BUFFER_SIZE,
571  esd_usb2_read_bulk_callback, dev);
572  urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
573  usb_anchor_urb(urb, &dev->rx_submitted);
574 
575  err = usb_submit_urb(urb, GFP_KERNEL);
576  if (err) {
577  usb_unanchor_urb(urb);
579  urb->transfer_dma);
580  }
581 
582 freeurb:
583  /* Drop reference, USB core will take care of freeing it */
584  usb_free_urb(urb);
585  if (err)
586  break;
587  }
588 
589  /* Did we submit any URBs */
590  if (i == 0) {
591  dev_err(dev->udev->dev.parent, "couldn't setup read URBs\n");
592  return err;
593  }
594 
595  /* Warn if we've couldn't transmit all the URBs */
596  if (i < MAX_RX_URBS) {
597  dev_warn(dev->udev->dev.parent,
598  "rx performance may be slow\n");
599  }
600 
601  dev->rxinitdone = 1;
602  return 0;
603 }
604 
605 /*
606  * Start interface
607  */
608 static int esd_usb2_start(struct esd_usb2_net_priv *priv)
609 {
610  struct esd_usb2 *dev = priv->usb2;
611  struct net_device *netdev = priv->netdev;
612  struct esd_usb2_msg msg;
613  int err, i;
614 
615  /*
616  * Enable all IDs
617  * The IDADD message takes up to 64 32 bit bitmasks (2048 bits).
618  * Each bit represents one 11 bit CAN identifier. A set bit
619  * enables reception of the corresponding CAN identifier. A cleared
620  * bit disabled this identifier. An additional bitmask value
621  * following the CAN 2.0A bits is used to enable reception of
622  * extended CAN frames. Only the LSB of this final mask is checked
623  * for the complete 29 bit ID range. The IDADD message also allows
624  * filter configuration for an ID subset. In this case you can add
625  * the number of the starting bitmask (0..64) to the filter.option
626  * field followed by only some bitmasks.
627  */
628  msg.msg.hdr.cmd = CMD_IDADD;
629  msg.msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
630  msg.msg.filter.net = priv->index;
631  msg.msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
632  for (i = 0; i < ESD_MAX_ID_SEGMENT; i++)
633  msg.msg.filter.mask[i] = cpu_to_le32(0xffffffff);
634  /* enable 29bit extended IDs */
635  msg.msg.filter.mask[ESD_MAX_ID_SEGMENT] = cpu_to_le32(0x00000001);
636 
637  err = esd_usb2_send_msg(dev, &msg);
638  if (err)
639  goto failed;
640 
641  err = esd_usb2_setup_rx_urbs(dev);
642  if (err)
643  goto failed;
644 
645  priv->can.state = CAN_STATE_ERROR_ACTIVE;
646 
647  return 0;
648 
649 failed:
650  if (err == -ENODEV)
651  netif_device_detach(netdev);
652 
653  netdev_err(netdev, "couldn't start device: %d\n", err);
654 
655  return err;
656 }
657 
658 static void unlink_all_urbs(struct esd_usb2 *dev)
659 {
660  struct esd_usb2_net_priv *priv;
661  int i, j;
662 
664  for (i = 0; i < dev->net_count; i++) {
665  priv = dev->nets[i];
666  if (priv) {
668  atomic_set(&priv->active_tx_jobs, 0);
669 
670  for (j = 0; j < MAX_TX_URBS; j++)
671  priv->tx_contexts[j].echo_index = MAX_TX_URBS;
672  }
673  }
674 }
675 
676 static int esd_usb2_open(struct net_device *netdev)
677 {
678  struct esd_usb2_net_priv *priv = netdev_priv(netdev);
679  int err;
680 
681  /* common open */
682  err = open_candev(netdev);
683  if (err)
684  return err;
685 
686  /* finally start device */
687  err = esd_usb2_start(priv);
688  if (err) {
689  netdev_warn(netdev, "couldn't start device: %d\n", err);
690  close_candev(netdev);
691  return err;
692  }
693 
694  priv->open_time = jiffies;
695 
696  netif_start_queue(netdev);
697 
698  return 0;
699 }
700 
701 static netdev_tx_t esd_usb2_start_xmit(struct sk_buff *skb,
702  struct net_device *netdev)
703 {
704  struct esd_usb2_net_priv *priv = netdev_priv(netdev);
705  struct esd_usb2 *dev = priv->usb2;
706  struct esd_tx_urb_context *context = NULL;
707  struct net_device_stats *stats = &netdev->stats;
708  struct can_frame *cf = (struct can_frame *)skb->data;
709  struct esd_usb2_msg *msg;
710  struct urb *urb;
711  u8 *buf;
712  int i, err;
713  int ret = NETDEV_TX_OK;
714  size_t size = sizeof(struct esd_usb2_msg);
715 
716  if (can_dropped_invalid_skb(netdev, skb))
717  return NETDEV_TX_OK;
718 
719  /* create a URB, and a buffer for it, and copy the data to the URB */
720  urb = usb_alloc_urb(0, GFP_ATOMIC);
721  if (!urb) {
722  netdev_err(netdev, "No memory left for URBs\n");
723  stats->tx_dropped++;
724  dev_kfree_skb(skb);
725  goto nourbmem;
726  }
727 
728  buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC,
729  &urb->transfer_dma);
730  if (!buf) {
731  netdev_err(netdev, "No memory left for USB buffer\n");
732  stats->tx_dropped++;
733  dev_kfree_skb(skb);
734  goto nobufmem;
735  }
736 
737  msg = (struct esd_usb2_msg *)buf;
738 
739  msg->msg.hdr.len = 3; /* minimal length */
740  msg->msg.hdr.cmd = CMD_CAN_TX;
741  msg->msg.tx.net = priv->index;
742  msg->msg.tx.dlc = cf->can_dlc;
743  msg->msg.tx.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
744 
745  if (cf->can_id & CAN_RTR_FLAG)
746  msg->msg.tx.dlc |= ESD_RTR;
747 
748  if (cf->can_id & CAN_EFF_FLAG)
749  msg->msg.tx.id |= cpu_to_le32(ESD_EXTID);
750 
751  for (i = 0; i < cf->can_dlc; i++)
752  msg->msg.tx.data[i] = cf->data[i];
753 
754  msg->msg.hdr.len += (cf->can_dlc + 3) >> 2;
755 
756  for (i = 0; i < MAX_TX_URBS; i++) {
757  if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
758  context = &priv->tx_contexts[i];
759  break;
760  }
761  }
762 
763  /*
764  * This may never happen.
765  */
766  if (!context) {
767  netdev_warn(netdev, "couldn't find free context\n");
769  goto releasebuf;
770  }
771 
772  context->priv = priv;
773  context->echo_index = i;
774  context->dlc = cf->can_dlc;
775 
776  /* hnd must not be 0 - MSB is stripped in txdone handling */
777  msg->msg.tx.hnd = 0x80000000 | i; /* returned in TX done message */
778 
779  usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
780  msg->msg.hdr.len << 2,
781  esd_usb2_write_bulk_callback, context);
782 
783  urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
784 
785  usb_anchor_urb(urb, &priv->tx_submitted);
786 
787  can_put_echo_skb(skb, netdev, context->echo_index);
788 
789  atomic_inc(&priv->active_tx_jobs);
790 
791  /* Slow down tx path */
792  if (atomic_read(&priv->active_tx_jobs) >= MAX_TX_URBS)
793  netif_stop_queue(netdev);
794 
795  err = usb_submit_urb(urb, GFP_ATOMIC);
796  if (err) {
797  can_free_echo_skb(netdev, context->echo_index);
798 
799  atomic_dec(&priv->active_tx_jobs);
800  usb_unanchor_urb(urb);
801 
802  stats->tx_dropped++;
803 
804  if (err == -ENODEV)
805  netif_device_detach(netdev);
806  else
807  netdev_warn(netdev, "failed tx_urb %d\n", err);
808 
809  goto releasebuf;
810  }
811 
812  netdev->trans_start = jiffies;
813 
814  /*
815  * Release our reference to this URB, the USB core will eventually free
816  * it entirely.
817  */
818  usb_free_urb(urb);
819 
820  return NETDEV_TX_OK;
821 
822 releasebuf:
823  usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
824 
825 nobufmem:
826  usb_free_urb(urb);
827 
828 nourbmem:
829  return ret;
830 }
831 
832 static int esd_usb2_close(struct net_device *netdev)
833 {
834  struct esd_usb2_net_priv *priv = netdev_priv(netdev);
835  struct esd_usb2_msg msg;
836  int i;
837 
838  /* Disable all IDs (see esd_usb2_start()) */
839  msg.msg.hdr.cmd = CMD_IDADD;
840  msg.msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
841  msg.msg.filter.net = priv->index;
842  msg.msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
843  for (i = 0; i <= ESD_MAX_ID_SEGMENT; i++)
844  msg.msg.filter.mask[i] = 0;
845  if (esd_usb2_send_msg(priv->usb2, &msg) < 0)
846  netdev_err(netdev, "sending idadd message failed\n");
847 
848  /* set CAN controller to reset mode */
849  msg.msg.hdr.len = 2;
850  msg.msg.hdr.cmd = CMD_SETBAUD;
851  msg.msg.setbaud.net = priv->index;
852  msg.msg.setbaud.rsvd = 0;
853  msg.msg.setbaud.baud = cpu_to_le32(ESD_USB2_NO_BAUDRATE);
854  if (esd_usb2_send_msg(priv->usb2, &msg) < 0)
855  netdev_err(netdev, "sending setbaud message failed\n");
856 
857  priv->can.state = CAN_STATE_STOPPED;
858 
859  netif_stop_queue(netdev);
860 
861  close_candev(netdev);
862 
863  priv->open_time = 0;
864 
865  return 0;
866 }
867 
868 static const struct net_device_ops esd_usb2_netdev_ops = {
869  .ndo_open = esd_usb2_open,
870  .ndo_stop = esd_usb2_close,
871  .ndo_start_xmit = esd_usb2_start_xmit,
872 };
873 
874 static const struct can_bittiming_const esd_usb2_bittiming_const = {
875  .name = "esd_usb2",
876  .tseg1_min = ESD_USB2_TSEG1_MIN,
877  .tseg1_max = ESD_USB2_TSEG1_MAX,
878  .tseg2_min = ESD_USB2_TSEG2_MIN,
879  .tseg2_max = ESD_USB2_TSEG2_MAX,
880  .sjw_max = ESD_USB2_SJW_MAX,
881  .brp_min = ESD_USB2_BRP_MIN,
882  .brp_max = ESD_USB2_BRP_MAX,
883  .brp_inc = ESD_USB2_BRP_INC,
884 };
885 
886 static int esd_usb2_set_bittiming(struct net_device *netdev)
887 {
888  struct esd_usb2_net_priv *priv = netdev_priv(netdev);
889  struct can_bittiming *bt = &priv->can.bittiming;
890  struct esd_usb2_msg msg;
891  u32 canbtr;
892 
893  canbtr = ESD_USB2_UBR;
894  canbtr |= (bt->brp - 1) & (ESD_USB2_BRP_MAX - 1);
895  canbtr |= ((bt->sjw - 1) & (ESD_USB2_SJW_MAX - 1))
897  canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
898  & (ESD_USB2_TSEG1_MAX - 1))
900  canbtr |= ((bt->phase_seg2 - 1) & (ESD_USB2_TSEG2_MAX - 1))
902  if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
903  canbtr |= ESD_USB2_3_SAMPLES;
904 
905  msg.msg.hdr.len = 2;
906  msg.msg.hdr.cmd = CMD_SETBAUD;
907  msg.msg.setbaud.net = priv->index;
908  msg.msg.setbaud.rsvd = 0;
909  msg.msg.setbaud.baud = cpu_to_le32(canbtr);
910 
911  netdev_info(netdev, "setting BTR=%#x\n", canbtr);
912 
913  return esd_usb2_send_msg(priv->usb2, &msg);
914 }
915 
916 static int esd_usb2_get_berr_counter(const struct net_device *netdev,
917  struct can_berr_counter *bec)
918 {
919  struct esd_usb2_net_priv *priv = netdev_priv(netdev);
920 
921  bec->txerr = priv->bec.txerr;
922  bec->rxerr = priv->bec.rxerr;
923 
924  return 0;
925 }
926 
927 static int esd_usb2_set_mode(struct net_device *netdev, enum can_mode mode)
928 {
929  struct esd_usb2_net_priv *priv = netdev_priv(netdev);
930 
931  if (!priv->open_time)
932  return -EINVAL;
933 
934  switch (mode) {
935  case CAN_MODE_START:
936  netif_wake_queue(netdev);
937  break;
938 
939  default:
940  return -EOPNOTSUPP;
941  }
942 
943  return 0;
944 }
945 
946 static int esd_usb2_probe_one_net(struct usb_interface *intf, int index)
947 {
948  struct esd_usb2 *dev = usb_get_intfdata(intf);
949  struct net_device *netdev;
950  struct esd_usb2_net_priv *priv;
951  int err = 0;
952  int i;
953 
954  netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
955  if (!netdev) {
956  dev_err(&intf->dev, "couldn't alloc candev\n");
957  err = -ENOMEM;
958  goto done;
959  }
960 
961  priv = netdev_priv(netdev);
962 
963  init_usb_anchor(&priv->tx_submitted);
964  atomic_set(&priv->active_tx_jobs, 0);
965 
966  for (i = 0; i < MAX_TX_URBS; i++)
967  priv->tx_contexts[i].echo_index = MAX_TX_URBS;
968 
969  priv->usb2 = dev;
970  priv->netdev = netdev;
971  priv->index = index;
972 
973  priv->can.state = CAN_STATE_STOPPED;
974  priv->can.clock.freq = ESD_USB2_CAN_CLOCK;
975  priv->can.bittiming_const = &esd_usb2_bittiming_const;
976  priv->can.do_set_bittiming = esd_usb2_set_bittiming;
977  priv->can.do_set_mode = esd_usb2_set_mode;
978  priv->can.do_get_berr_counter = esd_usb2_get_berr_counter;
979  priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
980 
981  netdev->flags |= IFF_ECHO; /* we support local echo */
982 
983  netdev->netdev_ops = &esd_usb2_netdev_ops;
984 
985  SET_NETDEV_DEV(netdev, &intf->dev);
986 
987  err = register_candev(netdev);
988  if (err) {
989  dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
990  free_candev(netdev);
991  err = -ENOMEM;
992  goto done;
993  }
994 
995  dev->nets[index] = priv;
996  netdev_info(netdev, "device %s registered\n", netdev->name);
997 
998 done:
999  return err;
1000 }
1001 
1002 /*
1003  * probe function for new USB2 devices
1004  *
1005  * check version information and number of available
1006  * CAN interfaces
1007  */
1008 static int esd_usb2_probe(struct usb_interface *intf,
1009  const struct usb_device_id *id)
1010 {
1011  struct esd_usb2 *dev;
1012  struct esd_usb2_msg msg;
1013  int i, err;
1014 
1015  dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1016  if (!dev) {
1017  err = -ENOMEM;
1018  goto done;
1019  }
1020 
1021  dev->udev = interface_to_usbdev(intf);
1022 
1023  init_usb_anchor(&dev->rx_submitted);
1024 
1025  usb_set_intfdata(intf, dev);
1026 
1027  /* query number of CAN interfaces (nets) */
1028  msg.msg.hdr.cmd = CMD_VERSION;
1029  msg.msg.hdr.len = 2;
1030  msg.msg.version.rsvd = 0;
1031  msg.msg.version.flags = 0;
1032  msg.msg.version.drv_version = 0;
1033 
1034  err = esd_usb2_send_msg(dev, &msg);
1035  if (err < 0) {
1036  dev_err(&intf->dev, "sending version message failed\n");
1037  goto free_dev;
1038  }
1039 
1040  err = esd_usb2_wait_msg(dev, &msg);
1041  if (err < 0) {
1042  dev_err(&intf->dev, "no version message answer\n");
1043  goto free_dev;
1044  }
1045 
1046  dev->net_count = (int)msg.msg.version_reply.nets;
1047  dev->version = le32_to_cpu(msg.msg.version_reply.version);
1048 
1049  if (device_create_file(&intf->dev, &dev_attr_firmware))
1050  dev_err(&intf->dev,
1051  "Couldn't create device file for firmware\n");
1052 
1053  if (device_create_file(&intf->dev, &dev_attr_hardware))
1054  dev_err(&intf->dev,
1055  "Couldn't create device file for hardware\n");
1056 
1057  if (device_create_file(&intf->dev, &dev_attr_nets))
1058  dev_err(&intf->dev,
1059  "Couldn't create device file for nets\n");
1060 
1061  /* do per device probing */
1062  for (i = 0; i < dev->net_count; i++)
1063  esd_usb2_probe_one_net(intf, i);
1064 
1065  return 0;
1066 
1067 free_dev:
1068  kfree(dev);
1069 done:
1070  return err;
1071 }
1072 
1073 /*
1074  * called by the usb core when the device is removed from the system
1075  */
1076 static void esd_usb2_disconnect(struct usb_interface *intf)
1077 {
1078  struct esd_usb2 *dev = usb_get_intfdata(intf);
1079  struct net_device *netdev;
1080  int i;
1081 
1082  device_remove_file(&intf->dev, &dev_attr_firmware);
1083  device_remove_file(&intf->dev, &dev_attr_hardware);
1084  device_remove_file(&intf->dev, &dev_attr_nets);
1085 
1086  usb_set_intfdata(intf, NULL);
1087 
1088  if (dev) {
1089  for (i = 0; i < dev->net_count; i++) {
1090  if (dev->nets[i]) {
1091  netdev = dev->nets[i]->netdev;
1092  unregister_netdev(netdev);
1093  free_candev(netdev);
1094  }
1095  }
1096  unlink_all_urbs(dev);
1097  }
1098 }
1099 
1100 /* usb specific object needed to register this driver with the usb subsystem */
1101 static struct usb_driver esd_usb2_driver = {
1102  .name = "esd_usb2",
1103  .probe = esd_usb2_probe,
1104  .disconnect = esd_usb2_disconnect,
1105  .id_table = esd_usb2_table,
1106 };
1107 
1108 module_usb_driver(esd_usb2_driver);