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1/*
2 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7
3 *
4 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche
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/signal.h>
20#include <linux/slab.h>
21#include <linux/module.h>
22#include <linux/netdevice.h>
23#include <linux/usb.h>
24
25#include <linux/can.h>
26#include <linux/can/dev.h>
27#include <linux/can/error.h>
28
29MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
30MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
31MODULE_LICENSE("GPL v2");
32
33/* Control-Values for CPC_Control() Command Subject Selection */
34#define CONTR_CAN_MESSAGE 0x04
35#define CONTR_CAN_STATE 0x0C
36#define CONTR_BUS_ERROR 0x1C
37
38/* Control Command Actions */
39#define CONTR_CONT_OFF 0
40#define CONTR_CONT_ON 1
41#define CONTR_ONCE 2
42
43/* Messages from CPC to PC */
44#define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */
45#define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */
46#define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */
47#define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */
48#define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */
49#define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */
50#define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */
51#define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */
52#define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */
53#define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
54#define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */
55
56/* Messages from the PC to the CPC interface */
57#define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */
58#define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */
59#define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */
60#define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */
61#define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */
62#define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */
63#define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */
64#define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */
65
66#define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
67#define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */
68#define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
69
70#define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
71
72#define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
73
74/* Overrun types */
75#define CPC_OVR_EVENT_CAN 0x01
76#define CPC_OVR_EVENT_CANSTATE 0x02
77#define CPC_OVR_EVENT_BUSERROR 0x04
78
79/*
80 * If the CAN controller lost a message we indicate it with the highest bit
81 * set in the count field.
82 */
83#define CPC_OVR_HW 0x80
84
85/* Size of the "struct ems_cpc_msg" without the union */
86#define CPC_MSG_HEADER_LEN 11
87#define CPC_CAN_MSG_MIN_SIZE 5
88
89/* Define these values to match your devices */
90#define USB_CPCUSB_VENDOR_ID 0x12D6
91
92#define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
93
94/* Mode register NXP LPC2119/SJA1000 CAN Controller */
95#define SJA1000_MOD_NORMAL 0x00
96#define SJA1000_MOD_RM 0x01
97
98/* ECC register NXP LPC2119/SJA1000 CAN Controller */
99#define SJA1000_ECC_SEG 0x1F
100#define SJA1000_ECC_DIR 0x20
101#define SJA1000_ECC_ERR 0x06
102#define SJA1000_ECC_BIT 0x00
103#define SJA1000_ECC_FORM 0x40
104#define SJA1000_ECC_STUFF 0x80
105#define SJA1000_ECC_MASK 0xc0
106
107/* Status register content */
108#define SJA1000_SR_BS 0x80
109#define SJA1000_SR_ES 0x40
110
111#define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
112
113/*
114 * The device actually uses a 16MHz clock to generate the CAN clock
115 * but it expects SJA1000 bit settings based on 8MHz (is internally
116 * converted).
117 */
118#define EMS_USB_ARM7_CLOCK 8000000
119
120#define CPC_TX_QUEUE_TRIGGER_LOW 25
121#define CPC_TX_QUEUE_TRIGGER_HIGH 35
122
123/*
124 * CAN-Message representation in a CPC_MSG. Message object type is
125 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
126 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
127 */
128struct cpc_can_msg {
129 __le32 id;
130 u8 length;
131 u8 msg[8];
132};
133
134/* Representation of the CAN parameters for the SJA1000 controller */
135struct cpc_sja1000_params {
136 u8 mode;
137 u8 acc_code0;
138 u8 acc_code1;
139 u8 acc_code2;
140 u8 acc_code3;
141 u8 acc_mask0;
142 u8 acc_mask1;
143 u8 acc_mask2;
144 u8 acc_mask3;
145 u8 btr0;
146 u8 btr1;
147 u8 outp_contr;
148};
149
150/* CAN params message representation */
151struct cpc_can_params {
152 u8 cc_type;
153
154 /* Will support M16C CAN controller in the future */
155 union {
156 struct cpc_sja1000_params sja1000;
157 } cc_params;
158};
159
160/* Structure for confirmed message handling */
161struct cpc_confirm {
162 u8 error; /* error code */
163};
164
165/* Structure for overrun conditions */
166struct cpc_overrun {
167 u8 event;
168 u8 count;
169};
170
171/* SJA1000 CAN errors (compatible to NXP LPC2119) */
172struct cpc_sja1000_can_error {
173 u8 ecc;
174 u8 rxerr;
175 u8 txerr;
176};
177
178/* structure for CAN error conditions */
179struct cpc_can_error {
180 u8 ecode;
181
182 struct {
183 u8 cc_type;
184
185 /* Other controllers may also provide error code capture regs */
186 union {
187 struct cpc_sja1000_can_error sja1000;
188 } regs;
189 } cc;
190};
191
192/*
193 * Structure containing RX/TX error counter. This structure is used to request
194 * the values of the CAN controllers TX and RX error counter.
195 */
196struct cpc_can_err_counter {
197 u8 rx;
198 u8 tx;
199};
200
201/* Main message type used between library and application */
202struct __packed ems_cpc_msg {
203 u8 type; /* type of message */
204 u8 length; /* length of data within union 'msg' */
205 u8 msgid; /* confirmation handle */
206 __le32 ts_sec; /* timestamp in seconds */
207 __le32 ts_nsec; /* timestamp in nano seconds */
208
209 union {
210 u8 generic[64];
211 struct cpc_can_msg can_msg;
212 struct cpc_can_params can_params;
213 struct cpc_confirm confirmation;
214 struct cpc_overrun overrun;
215 struct cpc_can_error error;
216 struct cpc_can_err_counter err_counter;
217 u8 can_state;
218 } msg;
219};
220
221/*
222 * Table of devices that work with this driver
223 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
224 */
225static struct usb_device_id ems_usb_table[] = {
226 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
227 {} /* Terminating entry */
228};
229
230MODULE_DEVICE_TABLE(usb, ems_usb_table);
231
232#define RX_BUFFER_SIZE 64
233#define CPC_HEADER_SIZE 4
234#define INTR_IN_BUFFER_SIZE 4
235
236#define MAX_RX_URBS 10
237#define MAX_TX_URBS 10
238
239struct ems_usb;
240
241struct ems_tx_urb_context {
242 struct ems_usb *dev;
243
244 u32 echo_index;
245 u8 dlc;
246};
247
248struct ems_usb {
249 struct can_priv can; /* must be the first member */
250
251 struct sk_buff *echo_skb[MAX_TX_URBS];
252
253 struct usb_device *udev;
254 struct net_device *netdev;
255
256 atomic_t active_tx_urbs;
257 struct usb_anchor tx_submitted;
258 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
259
260 struct usb_anchor rx_submitted;
261
262 struct urb *intr_urb;
263
264 u8 *tx_msg_buffer;
265
266 u8 *intr_in_buffer;
267 unsigned int free_slots; /* remember number of available slots */
268
269 struct ems_cpc_msg active_params; /* active controller parameters */
270};
271
272static void ems_usb_read_interrupt_callback(struct urb *urb)
273{
274 struct ems_usb *dev = urb->context;
275 struct net_device *netdev = dev->netdev;
276 int err;
277
278 if (!netif_device_present(netdev))
279 return;
280
281 switch (urb->status) {
282 case 0:
283 dev->free_slots = dev->intr_in_buffer[1];
284 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH &&
285 netif_queue_stopped(netdev))
286 netif_wake_queue(netdev);
287 break;
288
289 case -ECONNRESET: /* unlink */
290 case -ENOENT:
291 case -EPIPE:
292 case -EPROTO:
293 case -ESHUTDOWN:
294 return;
295
296 default:
297 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
298 break;
299 }
300
301 err = usb_submit_urb(urb, GFP_ATOMIC);
302
303 if (err == -ENODEV)
304 netif_device_detach(netdev);
305 else if (err)
306 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
307}
308
309static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
310{
311 struct can_frame *cf;
312 struct sk_buff *skb;
313 int i;
314 struct net_device_stats *stats = &dev->netdev->stats;
315
316 skb = alloc_can_skb(dev->netdev, &cf);
317 if (skb == NULL)
318 return;
319
320 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
321 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
322
323 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
324 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
325 cf->can_id |= CAN_EFF_FLAG;
326
327 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
328 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
329 cf->can_id |= CAN_RTR_FLAG;
330 } else {
331 for (i = 0; i < cf->can_dlc; i++)
332 cf->data[i] = msg->msg.can_msg.msg[i];
333 }
334
335 stats->rx_packets++;
336 stats->rx_bytes += cf->can_dlc;
337 netif_rx(skb);
338}
339
340static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
341{
342 struct can_frame *cf;
343 struct sk_buff *skb;
344 struct net_device_stats *stats = &dev->netdev->stats;
345
346 skb = alloc_can_err_skb(dev->netdev, &cf);
347 if (skb == NULL)
348 return;
349
350 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
351 u8 state = msg->msg.can_state;
352
353 if (state & SJA1000_SR_BS) {
354 dev->can.state = CAN_STATE_BUS_OFF;
355 cf->can_id |= CAN_ERR_BUSOFF;
356
357 dev->can.can_stats.bus_off++;
358 can_bus_off(dev->netdev);
359 } else if (state & SJA1000_SR_ES) {
360 dev->can.state = CAN_STATE_ERROR_WARNING;
361 dev->can.can_stats.error_warning++;
362 } else {
363 dev->can.state = CAN_STATE_ERROR_ACTIVE;
364 dev->can.can_stats.error_passive++;
365 }
366 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
367 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
368 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
369 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
370
371 /* bus error interrupt */
372 dev->can.can_stats.bus_error++;
373 stats->rx_errors++;
374
375 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
376
377 switch (ecc & SJA1000_ECC_MASK) {
378 case SJA1000_ECC_BIT:
379 cf->data[2] |= CAN_ERR_PROT_BIT;
380 break;
381 case SJA1000_ECC_FORM:
382 cf->data[2] |= CAN_ERR_PROT_FORM;
383 break;
384 case SJA1000_ECC_STUFF:
385 cf->data[2] |= CAN_ERR_PROT_STUFF;
386 break;
387 default:
388 cf->data[3] = ecc & SJA1000_ECC_SEG;
389 break;
390 }
391
392 /* Error occurred during transmission? */
393 if ((ecc & SJA1000_ECC_DIR) == 0)
394 cf->data[2] |= CAN_ERR_PROT_TX;
395
396 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
397 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
398 cf->can_id |= CAN_ERR_CRTL;
399 cf->data[1] = (txerr > rxerr) ?
400 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
401 }
402 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
403 cf->can_id |= CAN_ERR_CRTL;
404 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
405
406 stats->rx_over_errors++;
407 stats->rx_errors++;
408 }
409
410 stats->rx_packets++;
411 stats->rx_bytes += cf->can_dlc;
412 netif_rx(skb);
413}
414
415/*
416 * callback for bulk IN urb
417 */
418static void ems_usb_read_bulk_callback(struct urb *urb)
419{
420 struct ems_usb *dev = urb->context;
421 struct net_device *netdev;
422 int retval;
423
424 netdev = dev->netdev;
425
426 if (!netif_device_present(netdev))
427 return;
428
429 switch (urb->status) {
430 case 0: /* success */
431 break;
432
433 case -ENOENT:
434 return;
435
436 default:
437 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
438 goto resubmit_urb;
439 }
440
441 if (urb->actual_length > CPC_HEADER_SIZE) {
442 struct ems_cpc_msg *msg;
443 u8 *ibuf = urb->transfer_buffer;
444 u8 msg_count, start;
445
446 msg_count = ibuf[0] & ~0x80;
447
448 start = CPC_HEADER_SIZE;
449
450 while (msg_count) {
451 msg = (struct ems_cpc_msg *)&ibuf[start];
452
453 switch (msg->type) {
454 case CPC_MSG_TYPE_CAN_STATE:
455 /* Process CAN state changes */
456 ems_usb_rx_err(dev, msg);
457 break;
458
459 case CPC_MSG_TYPE_CAN_FRAME:
460 case CPC_MSG_TYPE_EXT_CAN_FRAME:
461 case CPC_MSG_TYPE_RTR_FRAME:
462 case CPC_MSG_TYPE_EXT_RTR_FRAME:
463 ems_usb_rx_can_msg(dev, msg);
464 break;
465
466 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
467 /* Process errorframe */
468 ems_usb_rx_err(dev, msg);
469 break;
470
471 case CPC_MSG_TYPE_OVERRUN:
472 /* Message lost while receiving */
473 ems_usb_rx_err(dev, msg);
474 break;
475 }
476
477 start += CPC_MSG_HEADER_LEN + msg->length;
478 msg_count--;
479
480 if (start > urb->transfer_buffer_length) {
481 netdev_err(netdev, "format error\n");
482 break;
483 }
484 }
485 }
486
487resubmit_urb:
488 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
489 urb->transfer_buffer, RX_BUFFER_SIZE,
490 ems_usb_read_bulk_callback, dev);
491
492 retval = usb_submit_urb(urb, GFP_ATOMIC);
493
494 if (retval == -ENODEV)
495 netif_device_detach(netdev);
496 else if (retval)
497 netdev_err(netdev,
498 "failed resubmitting read bulk urb: %d\n", retval);
499}
500
501/*
502 * callback for bulk IN urb
503 */
504static void ems_usb_write_bulk_callback(struct urb *urb)
505{
506 struct ems_tx_urb_context *context = urb->context;
507 struct ems_usb *dev;
508 struct net_device *netdev;
509
510 BUG_ON(!context);
511
512 dev = context->dev;
513 netdev = dev->netdev;
514
515 /* free up our allocated buffer */
516 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
517 urb->transfer_buffer, urb->transfer_dma);
518
519 atomic_dec(&dev->active_tx_urbs);
520
521 if (!netif_device_present(netdev))
522 return;
523
524 if (urb->status)
525 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
526
527 netif_trans_update(netdev);
528
529 /* transmission complete interrupt */
530 netdev->stats.tx_packets++;
531 netdev->stats.tx_bytes += context->dlc;
532
533 can_get_echo_skb(netdev, context->echo_index);
534
535 /* Release context */
536 context->echo_index = MAX_TX_URBS;
537
538}
539
540/*
541 * Send the given CPC command synchronously
542 */
543static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
544{
545 int actual_length;
546
547 /* Copy payload */
548 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
549 msg->length + CPC_MSG_HEADER_LEN);
550
551 /* Clear header */
552 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
553
554 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
555 &dev->tx_msg_buffer[0],
556 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
557 &actual_length, 1000);
558}
559
560/*
561 * Change CAN controllers' mode register
562 */
563static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
564{
565 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
566
567 return ems_usb_command_msg(dev, &dev->active_params);
568}
569
570/*
571 * Send a CPC_Control command to change behaviour when interface receives a CAN
572 * message, bus error or CAN state changed notifications.
573 */
574static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
575{
576 struct ems_cpc_msg cmd;
577
578 cmd.type = CPC_CMD_TYPE_CONTROL;
579 cmd.length = CPC_MSG_HEADER_LEN + 1;
580
581 cmd.msgid = 0;
582
583 cmd.msg.generic[0] = val;
584
585 return ems_usb_command_msg(dev, &cmd);
586}
587
588/*
589 * Start interface
590 */
591static int ems_usb_start(struct ems_usb *dev)
592{
593 struct net_device *netdev = dev->netdev;
594 int err, i;
595
596 dev->intr_in_buffer[0] = 0;
597 dev->free_slots = 50; /* initial size */
598
599 for (i = 0; i < MAX_RX_URBS; i++) {
600 struct urb *urb = NULL;
601 u8 *buf = NULL;
602
603 /* create a URB, and a buffer for it */
604 urb = usb_alloc_urb(0, GFP_KERNEL);
605 if (!urb) {
606 err = -ENOMEM;
607 break;
608 }
609
610 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
611 &urb->transfer_dma);
612 if (!buf) {
613 netdev_err(netdev, "No memory left for USB buffer\n");
614 usb_free_urb(urb);
615 err = -ENOMEM;
616 break;
617 }
618
619 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
620 buf, RX_BUFFER_SIZE,
621 ems_usb_read_bulk_callback, dev);
622 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
623 usb_anchor_urb(urb, &dev->rx_submitted);
624
625 err = usb_submit_urb(urb, GFP_KERNEL);
626 if (err) {
627 usb_unanchor_urb(urb);
628 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
629 urb->transfer_dma);
630 usb_free_urb(urb);
631 break;
632 }
633
634 /* Drop reference, USB core will take care of freeing it */
635 usb_free_urb(urb);
636 }
637
638 /* Did we submit any URBs */
639 if (i == 0) {
640 netdev_warn(netdev, "couldn't setup read URBs\n");
641 return err;
642 }
643
644 /* Warn if we've couldn't transmit all the URBs */
645 if (i < MAX_RX_URBS)
646 netdev_warn(netdev, "rx performance may be slow\n");
647
648 /* Setup and start interrupt URB */
649 usb_fill_int_urb(dev->intr_urb, dev->udev,
650 usb_rcvintpipe(dev->udev, 1),
651 dev->intr_in_buffer,
652 INTR_IN_BUFFER_SIZE,
653 ems_usb_read_interrupt_callback, dev, 1);
654
655 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
656 if (err) {
657 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
658
659 return err;
660 }
661
662 /* CPC-USB will transfer received message to host */
663 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
664 if (err)
665 goto failed;
666
667 /* CPC-USB will transfer CAN state changes to host */
668 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
669 if (err)
670 goto failed;
671
672 /* CPC-USB will transfer bus errors to host */
673 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
674 if (err)
675 goto failed;
676
677 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
678 if (err)
679 goto failed;
680
681 dev->can.state = CAN_STATE_ERROR_ACTIVE;
682
683 return 0;
684
685failed:
686 netdev_warn(netdev, "couldn't submit control: %d\n", err);
687
688 return err;
689}
690
691static void unlink_all_urbs(struct ems_usb *dev)
692{
693 int i;
694
695 usb_unlink_urb(dev->intr_urb);
696
697 usb_kill_anchored_urbs(&dev->rx_submitted);
698
699 usb_kill_anchored_urbs(&dev->tx_submitted);
700 atomic_set(&dev->active_tx_urbs, 0);
701
702 for (i = 0; i < MAX_TX_URBS; i++)
703 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
704}
705
706static int ems_usb_open(struct net_device *netdev)
707{
708 struct ems_usb *dev = netdev_priv(netdev);
709 int err;
710
711 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
712 if (err)
713 return err;
714
715 /* common open */
716 err = open_candev(netdev);
717 if (err)
718 return err;
719
720 /* finally start device */
721 err = ems_usb_start(dev);
722 if (err) {
723 if (err == -ENODEV)
724 netif_device_detach(dev->netdev);
725
726 netdev_warn(netdev, "couldn't start device: %d\n", err);
727
728 close_candev(netdev);
729
730 return err;
731 }
732
733
734 netif_start_queue(netdev);
735
736 return 0;
737}
738
739static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
740{
741 struct ems_usb *dev = netdev_priv(netdev);
742 struct ems_tx_urb_context *context = NULL;
743 struct net_device_stats *stats = &netdev->stats;
744 struct can_frame *cf = (struct can_frame *)skb->data;
745 struct ems_cpc_msg *msg;
746 struct urb *urb;
747 u8 *buf;
748 int i, err;
749 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
750 + sizeof(struct cpc_can_msg);
751
752 if (can_dropped_invalid_skb(netdev, skb))
753 return NETDEV_TX_OK;
754
755 /* create a URB, and a buffer for it, and copy the data to the URB */
756 urb = usb_alloc_urb(0, GFP_ATOMIC);
757 if (!urb)
758 goto nomem;
759
760 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
761 if (!buf) {
762 netdev_err(netdev, "No memory left for USB buffer\n");
763 usb_free_urb(urb);
764 goto nomem;
765 }
766
767 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
768
769 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
770 msg->msg.can_msg.length = cf->can_dlc;
771
772 if (cf->can_id & CAN_RTR_FLAG) {
773 msg->type = cf->can_id & CAN_EFF_FLAG ?
774 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
775
776 msg->length = CPC_CAN_MSG_MIN_SIZE;
777 } else {
778 msg->type = cf->can_id & CAN_EFF_FLAG ?
779 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
780
781 for (i = 0; i < cf->can_dlc; i++)
782 msg->msg.can_msg.msg[i] = cf->data[i];
783
784 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
785 }
786
787 for (i = 0; i < MAX_TX_URBS; i++) {
788 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
789 context = &dev->tx_contexts[i];
790 break;
791 }
792 }
793
794 /*
795 * May never happen! When this happens we'd more URBs in flight as
796 * allowed (MAX_TX_URBS).
797 */
798 if (!context) {
799 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
800 usb_free_urb(urb);
801
802 netdev_warn(netdev, "couldn't find free context\n");
803
804 return NETDEV_TX_BUSY;
805 }
806
807 context->dev = dev;
808 context->echo_index = i;
809 context->dlc = cf->can_dlc;
810
811 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
812 size, ems_usb_write_bulk_callback, context);
813 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
814 usb_anchor_urb(urb, &dev->tx_submitted);
815
816 can_put_echo_skb(skb, netdev, context->echo_index);
817
818 atomic_inc(&dev->active_tx_urbs);
819
820 err = usb_submit_urb(urb, GFP_ATOMIC);
821 if (unlikely(err)) {
822 can_free_echo_skb(netdev, context->echo_index);
823
824 usb_unanchor_urb(urb);
825 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
826 dev_kfree_skb(skb);
827
828 atomic_dec(&dev->active_tx_urbs);
829
830 if (err == -ENODEV) {
831 netif_device_detach(netdev);
832 } else {
833 netdev_warn(netdev, "failed tx_urb %d\n", err);
834
835 stats->tx_dropped++;
836 }
837 } else {
838 netif_trans_update(netdev);
839
840 /* Slow down tx path */
841 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
842 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
843 netif_stop_queue(netdev);
844 }
845 }
846
847 /*
848 * Release our reference to this URB, the USB core will eventually free
849 * it entirely.
850 */
851 usb_free_urb(urb);
852
853 return NETDEV_TX_OK;
854
855nomem:
856 dev_kfree_skb(skb);
857 stats->tx_dropped++;
858
859 return NETDEV_TX_OK;
860}
861
862static int ems_usb_close(struct net_device *netdev)
863{
864 struct ems_usb *dev = netdev_priv(netdev);
865
866 /* Stop polling */
867 unlink_all_urbs(dev);
868
869 netif_stop_queue(netdev);
870
871 /* Set CAN controller to reset mode */
872 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
873 netdev_warn(netdev, "couldn't stop device");
874
875 close_candev(netdev);
876
877 return 0;
878}
879
880static const struct net_device_ops ems_usb_netdev_ops = {
881 .ndo_open = ems_usb_open,
882 .ndo_stop = ems_usb_close,
883 .ndo_start_xmit = ems_usb_start_xmit,
884 .ndo_change_mtu = can_change_mtu,
885};
886
887static const struct can_bittiming_const ems_usb_bittiming_const = {
888 .name = "ems_usb",
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 = 64,
896 .brp_inc = 1,
897};
898
899static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
900{
901 struct ems_usb *dev = netdev_priv(netdev);
902
903 switch (mode) {
904 case CAN_MODE_START:
905 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
906 netdev_warn(netdev, "couldn't start device");
907
908 if (netif_queue_stopped(netdev))
909 netif_wake_queue(netdev);
910 break;
911
912 default:
913 return -EOPNOTSUPP;
914 }
915
916 return 0;
917}
918
919static int ems_usb_set_bittiming(struct net_device *netdev)
920{
921 struct ems_usb *dev = netdev_priv(netdev);
922 struct can_bittiming *bt = &dev->can.bittiming;
923 u8 btr0, btr1;
924
925 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
926 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
927 (((bt->phase_seg2 - 1) & 0x7) << 4);
928 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
929 btr1 |= 0x80;
930
931 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
932
933 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
934 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
935
936 return ems_usb_command_msg(dev, &dev->active_params);
937}
938
939static void init_params_sja1000(struct ems_cpc_msg *msg)
940{
941 struct cpc_sja1000_params *sja1000 =
942 &msg->msg.can_params.cc_params.sja1000;
943
944 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
945 msg->length = sizeof(struct cpc_can_params);
946 msg->msgid = 0;
947
948 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
949
950 /* Acceptance filter open */
951 sja1000->acc_code0 = 0x00;
952 sja1000->acc_code1 = 0x00;
953 sja1000->acc_code2 = 0x00;
954 sja1000->acc_code3 = 0x00;
955
956 /* Acceptance filter open */
957 sja1000->acc_mask0 = 0xFF;
958 sja1000->acc_mask1 = 0xFF;
959 sja1000->acc_mask2 = 0xFF;
960 sja1000->acc_mask3 = 0xFF;
961
962 sja1000->btr0 = 0;
963 sja1000->btr1 = 0;
964
965 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
966 sja1000->mode = SJA1000_MOD_RM;
967}
968
969/*
970 * probe function for new CPC-USB devices
971 */
972static int ems_usb_probe(struct usb_interface *intf,
973 const struct usb_device_id *id)
974{
975 struct net_device *netdev;
976 struct ems_usb *dev;
977 int i, err = -ENOMEM;
978
979 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
980 if (!netdev) {
981 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
982 return -ENOMEM;
983 }
984
985 dev = netdev_priv(netdev);
986
987 dev->udev = interface_to_usbdev(intf);
988 dev->netdev = netdev;
989
990 dev->can.state = CAN_STATE_STOPPED;
991 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
992 dev->can.bittiming_const = &ems_usb_bittiming_const;
993 dev->can.do_set_bittiming = ems_usb_set_bittiming;
994 dev->can.do_set_mode = ems_usb_set_mode;
995 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
996
997 netdev->netdev_ops = &ems_usb_netdev_ops;
998
999 netdev->flags |= IFF_ECHO; /* we support local echo */
1000
1001 init_usb_anchor(&dev->rx_submitted);
1002
1003 init_usb_anchor(&dev->tx_submitted);
1004 atomic_set(&dev->active_tx_urbs, 0);
1005
1006 for (i = 0; i < MAX_TX_URBS; i++)
1007 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1008
1009 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1010 if (!dev->intr_urb)
1011 goto cleanup_candev;
1012
1013 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1014 if (!dev->intr_in_buffer)
1015 goto cleanup_intr_urb;
1016
1017 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1018 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1019 if (!dev->tx_msg_buffer)
1020 goto cleanup_intr_in_buffer;
1021
1022 usb_set_intfdata(intf, dev);
1023
1024 SET_NETDEV_DEV(netdev, &intf->dev);
1025
1026 init_params_sja1000(&dev->active_params);
1027
1028 err = ems_usb_command_msg(dev, &dev->active_params);
1029 if (err) {
1030 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1031 goto cleanup_tx_msg_buffer;
1032 }
1033
1034 err = register_candev(netdev);
1035 if (err) {
1036 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1037 goto cleanup_tx_msg_buffer;
1038 }
1039
1040 return 0;
1041
1042cleanup_tx_msg_buffer:
1043 kfree(dev->tx_msg_buffer);
1044
1045cleanup_intr_in_buffer:
1046 kfree(dev->intr_in_buffer);
1047
1048cleanup_intr_urb:
1049 usb_free_urb(dev->intr_urb);
1050
1051cleanup_candev:
1052 free_candev(netdev);
1053
1054 return err;
1055}
1056
1057/*
1058 * called by the usb core when the device is removed from the system
1059 */
1060static void ems_usb_disconnect(struct usb_interface *intf)
1061{
1062 struct ems_usb *dev = usb_get_intfdata(intf);
1063
1064 usb_set_intfdata(intf, NULL);
1065
1066 if (dev) {
1067 unregister_netdev(dev->netdev);
1068 free_candev(dev->netdev);
1069
1070 unlink_all_urbs(dev);
1071
1072 usb_free_urb(dev->intr_urb);
1073
1074 kfree(dev->intr_in_buffer);
1075 }
1076}
1077
1078/* usb specific object needed to register this driver with the usb subsystem */
1079static struct usb_driver ems_usb_driver = {
1080 .name = "ems_usb",
1081 .probe = ems_usb_probe,
1082 .disconnect = ems_usb_disconnect,
1083 .id_table = ems_usb_table,
1084};
1085
1086module_usb_driver(ems_usb_driver);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7
4 *
5 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche
6 */
7#include <linux/signal.h>
8#include <linux/slab.h>
9#include <linux/module.h>
10#include <linux/netdevice.h>
11#include <linux/usb.h>
12
13#include <linux/can.h>
14#include <linux/can/dev.h>
15#include <linux/can/error.h>
16
17MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
18MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
19MODULE_LICENSE("GPL v2");
20
21/* Control-Values for CPC_Control() Command Subject Selection */
22#define CONTR_CAN_MESSAGE 0x04
23#define CONTR_CAN_STATE 0x0C
24#define CONTR_BUS_ERROR 0x1C
25
26/* Control Command Actions */
27#define CONTR_CONT_OFF 0
28#define CONTR_CONT_ON 1
29#define CONTR_ONCE 2
30
31/* Messages from CPC to PC */
32#define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */
33#define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */
34#define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */
35#define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */
36#define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */
37#define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */
38#define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */
39#define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */
40#define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */
41#define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
42#define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */
43
44/* Messages from the PC to the CPC interface */
45#define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */
46#define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */
47#define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */
48#define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */
49#define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */
50#define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */
51#define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */
52#define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */
53
54#define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
55#define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */
56#define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
57
58#define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
59
60#define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
61
62/* Overrun types */
63#define CPC_OVR_EVENT_CAN 0x01
64#define CPC_OVR_EVENT_CANSTATE 0x02
65#define CPC_OVR_EVENT_BUSERROR 0x04
66
67/*
68 * If the CAN controller lost a message we indicate it with the highest bit
69 * set in the count field.
70 */
71#define CPC_OVR_HW 0x80
72
73/* Size of the "struct ems_cpc_msg" without the union */
74#define CPC_MSG_HEADER_LEN 11
75#define CPC_CAN_MSG_MIN_SIZE 5
76
77/* Define these values to match your devices */
78#define USB_CPCUSB_VENDOR_ID 0x12D6
79
80#define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
81
82/* Mode register NXP LPC2119/SJA1000 CAN Controller */
83#define SJA1000_MOD_NORMAL 0x00
84#define SJA1000_MOD_RM 0x01
85
86/* ECC register NXP LPC2119/SJA1000 CAN Controller */
87#define SJA1000_ECC_SEG 0x1F
88#define SJA1000_ECC_DIR 0x20
89#define SJA1000_ECC_ERR 0x06
90#define SJA1000_ECC_BIT 0x00
91#define SJA1000_ECC_FORM 0x40
92#define SJA1000_ECC_STUFF 0x80
93#define SJA1000_ECC_MASK 0xc0
94
95/* Status register content */
96#define SJA1000_SR_BS 0x80
97#define SJA1000_SR_ES 0x40
98
99#define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
100
101/*
102 * The device actually uses a 16MHz clock to generate the CAN clock
103 * but it expects SJA1000 bit settings based on 8MHz (is internally
104 * converted).
105 */
106#define EMS_USB_ARM7_CLOCK 8000000
107
108#define CPC_TX_QUEUE_TRIGGER_LOW 25
109#define CPC_TX_QUEUE_TRIGGER_HIGH 35
110
111/*
112 * CAN-Message representation in a CPC_MSG. Message object type is
113 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
114 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
115 */
116struct cpc_can_msg {
117 __le32 id;
118 u8 length;
119 u8 msg[8];
120};
121
122/* Representation of the CAN parameters for the SJA1000 controller */
123struct cpc_sja1000_params {
124 u8 mode;
125 u8 acc_code0;
126 u8 acc_code1;
127 u8 acc_code2;
128 u8 acc_code3;
129 u8 acc_mask0;
130 u8 acc_mask1;
131 u8 acc_mask2;
132 u8 acc_mask3;
133 u8 btr0;
134 u8 btr1;
135 u8 outp_contr;
136};
137
138/* CAN params message representation */
139struct cpc_can_params {
140 u8 cc_type;
141
142 /* Will support M16C CAN controller in the future */
143 union {
144 struct cpc_sja1000_params sja1000;
145 } cc_params;
146};
147
148/* Structure for confirmed message handling */
149struct cpc_confirm {
150 u8 error; /* error code */
151};
152
153/* Structure for overrun conditions */
154struct cpc_overrun {
155 u8 event;
156 u8 count;
157};
158
159/* SJA1000 CAN errors (compatible to NXP LPC2119) */
160struct cpc_sja1000_can_error {
161 u8 ecc;
162 u8 rxerr;
163 u8 txerr;
164};
165
166/* structure for CAN error conditions */
167struct cpc_can_error {
168 u8 ecode;
169
170 struct {
171 u8 cc_type;
172
173 /* Other controllers may also provide error code capture regs */
174 union {
175 struct cpc_sja1000_can_error sja1000;
176 } regs;
177 } cc;
178};
179
180/*
181 * Structure containing RX/TX error counter. This structure is used to request
182 * the values of the CAN controllers TX and RX error counter.
183 */
184struct cpc_can_err_counter {
185 u8 rx;
186 u8 tx;
187};
188
189/* Main message type used between library and application */
190struct __packed ems_cpc_msg {
191 u8 type; /* type of message */
192 u8 length; /* length of data within union 'msg' */
193 u8 msgid; /* confirmation handle */
194 __le32 ts_sec; /* timestamp in seconds */
195 __le32 ts_nsec; /* timestamp in nano seconds */
196
197 union {
198 u8 generic[64];
199 struct cpc_can_msg can_msg;
200 struct cpc_can_params can_params;
201 struct cpc_confirm confirmation;
202 struct cpc_overrun overrun;
203 struct cpc_can_error error;
204 struct cpc_can_err_counter err_counter;
205 u8 can_state;
206 } msg;
207};
208
209/*
210 * Table of devices that work with this driver
211 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
212 */
213static struct usb_device_id ems_usb_table[] = {
214 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
215 {} /* Terminating entry */
216};
217
218MODULE_DEVICE_TABLE(usb, ems_usb_table);
219
220#define RX_BUFFER_SIZE 64
221#define CPC_HEADER_SIZE 4
222#define INTR_IN_BUFFER_SIZE 4
223
224#define MAX_RX_URBS 10
225#define MAX_TX_URBS 10
226
227struct ems_usb;
228
229struct ems_tx_urb_context {
230 struct ems_usb *dev;
231
232 u32 echo_index;
233 u8 dlc;
234};
235
236struct ems_usb {
237 struct can_priv can; /* must be the first member */
238
239 struct sk_buff *echo_skb[MAX_TX_URBS];
240
241 struct usb_device *udev;
242 struct net_device *netdev;
243
244 atomic_t active_tx_urbs;
245 struct usb_anchor tx_submitted;
246 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
247
248 struct usb_anchor rx_submitted;
249
250 struct urb *intr_urb;
251
252 u8 *tx_msg_buffer;
253
254 u8 *intr_in_buffer;
255 unsigned int free_slots; /* remember number of available slots */
256
257 struct ems_cpc_msg active_params; /* active controller parameters */
258};
259
260static void ems_usb_read_interrupt_callback(struct urb *urb)
261{
262 struct ems_usb *dev = urb->context;
263 struct net_device *netdev = dev->netdev;
264 int err;
265
266 if (!netif_device_present(netdev))
267 return;
268
269 switch (urb->status) {
270 case 0:
271 dev->free_slots = dev->intr_in_buffer[1];
272 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH &&
273 netif_queue_stopped(netdev))
274 netif_wake_queue(netdev);
275 break;
276
277 case -ECONNRESET: /* unlink */
278 case -ENOENT:
279 case -EPIPE:
280 case -EPROTO:
281 case -ESHUTDOWN:
282 return;
283
284 default:
285 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
286 break;
287 }
288
289 err = usb_submit_urb(urb, GFP_ATOMIC);
290
291 if (err == -ENODEV)
292 netif_device_detach(netdev);
293 else if (err)
294 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
295}
296
297static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
298{
299 struct can_frame *cf;
300 struct sk_buff *skb;
301 int i;
302 struct net_device_stats *stats = &dev->netdev->stats;
303
304 skb = alloc_can_skb(dev->netdev, &cf);
305 if (skb == NULL)
306 return;
307
308 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
309 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
310
311 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
312 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
313 cf->can_id |= CAN_EFF_FLAG;
314
315 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
316 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
317 cf->can_id |= CAN_RTR_FLAG;
318 } else {
319 for (i = 0; i < cf->can_dlc; i++)
320 cf->data[i] = msg->msg.can_msg.msg[i];
321 }
322
323 stats->rx_packets++;
324 stats->rx_bytes += cf->can_dlc;
325 netif_rx(skb);
326}
327
328static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
329{
330 struct can_frame *cf;
331 struct sk_buff *skb;
332 struct net_device_stats *stats = &dev->netdev->stats;
333
334 skb = alloc_can_err_skb(dev->netdev, &cf);
335 if (skb == NULL)
336 return;
337
338 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
339 u8 state = msg->msg.can_state;
340
341 if (state & SJA1000_SR_BS) {
342 dev->can.state = CAN_STATE_BUS_OFF;
343 cf->can_id |= CAN_ERR_BUSOFF;
344
345 dev->can.can_stats.bus_off++;
346 can_bus_off(dev->netdev);
347 } else if (state & SJA1000_SR_ES) {
348 dev->can.state = CAN_STATE_ERROR_WARNING;
349 dev->can.can_stats.error_warning++;
350 } else {
351 dev->can.state = CAN_STATE_ERROR_ACTIVE;
352 dev->can.can_stats.error_passive++;
353 }
354 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
355 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
356 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
357 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
358
359 /* bus error interrupt */
360 dev->can.can_stats.bus_error++;
361 stats->rx_errors++;
362
363 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
364
365 switch (ecc & SJA1000_ECC_MASK) {
366 case SJA1000_ECC_BIT:
367 cf->data[2] |= CAN_ERR_PROT_BIT;
368 break;
369 case SJA1000_ECC_FORM:
370 cf->data[2] |= CAN_ERR_PROT_FORM;
371 break;
372 case SJA1000_ECC_STUFF:
373 cf->data[2] |= CAN_ERR_PROT_STUFF;
374 break;
375 default:
376 cf->data[3] = ecc & SJA1000_ECC_SEG;
377 break;
378 }
379
380 /* Error occurred during transmission? */
381 if ((ecc & SJA1000_ECC_DIR) == 0)
382 cf->data[2] |= CAN_ERR_PROT_TX;
383
384 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
385 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
386 cf->can_id |= CAN_ERR_CRTL;
387 cf->data[1] = (txerr > rxerr) ?
388 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
389 }
390 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
391 cf->can_id |= CAN_ERR_CRTL;
392 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
393
394 stats->rx_over_errors++;
395 stats->rx_errors++;
396 }
397
398 stats->rx_packets++;
399 stats->rx_bytes += cf->can_dlc;
400 netif_rx(skb);
401}
402
403/*
404 * callback for bulk IN urb
405 */
406static void ems_usb_read_bulk_callback(struct urb *urb)
407{
408 struct ems_usb *dev = urb->context;
409 struct net_device *netdev;
410 int retval;
411
412 netdev = dev->netdev;
413
414 if (!netif_device_present(netdev))
415 return;
416
417 switch (urb->status) {
418 case 0: /* success */
419 break;
420
421 case -ENOENT:
422 return;
423
424 default:
425 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
426 goto resubmit_urb;
427 }
428
429 if (urb->actual_length > CPC_HEADER_SIZE) {
430 struct ems_cpc_msg *msg;
431 u8 *ibuf = urb->transfer_buffer;
432 u8 msg_count, start;
433
434 msg_count = ibuf[0] & ~0x80;
435
436 start = CPC_HEADER_SIZE;
437
438 while (msg_count) {
439 msg = (struct ems_cpc_msg *)&ibuf[start];
440
441 switch (msg->type) {
442 case CPC_MSG_TYPE_CAN_STATE:
443 /* Process CAN state changes */
444 ems_usb_rx_err(dev, msg);
445 break;
446
447 case CPC_MSG_TYPE_CAN_FRAME:
448 case CPC_MSG_TYPE_EXT_CAN_FRAME:
449 case CPC_MSG_TYPE_RTR_FRAME:
450 case CPC_MSG_TYPE_EXT_RTR_FRAME:
451 ems_usb_rx_can_msg(dev, msg);
452 break;
453
454 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
455 /* Process errorframe */
456 ems_usb_rx_err(dev, msg);
457 break;
458
459 case CPC_MSG_TYPE_OVERRUN:
460 /* Message lost while receiving */
461 ems_usb_rx_err(dev, msg);
462 break;
463 }
464
465 start += CPC_MSG_HEADER_LEN + msg->length;
466 msg_count--;
467
468 if (start > urb->transfer_buffer_length) {
469 netdev_err(netdev, "format error\n");
470 break;
471 }
472 }
473 }
474
475resubmit_urb:
476 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
477 urb->transfer_buffer, RX_BUFFER_SIZE,
478 ems_usb_read_bulk_callback, dev);
479
480 retval = usb_submit_urb(urb, GFP_ATOMIC);
481
482 if (retval == -ENODEV)
483 netif_device_detach(netdev);
484 else if (retval)
485 netdev_err(netdev,
486 "failed resubmitting read bulk urb: %d\n", retval);
487}
488
489/*
490 * callback for bulk IN urb
491 */
492static void ems_usb_write_bulk_callback(struct urb *urb)
493{
494 struct ems_tx_urb_context *context = urb->context;
495 struct ems_usb *dev;
496 struct net_device *netdev;
497
498 BUG_ON(!context);
499
500 dev = context->dev;
501 netdev = dev->netdev;
502
503 /* free up our allocated buffer */
504 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
505 urb->transfer_buffer, urb->transfer_dma);
506
507 atomic_dec(&dev->active_tx_urbs);
508
509 if (!netif_device_present(netdev))
510 return;
511
512 if (urb->status)
513 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
514
515 netif_trans_update(netdev);
516
517 /* transmission complete interrupt */
518 netdev->stats.tx_packets++;
519 netdev->stats.tx_bytes += context->dlc;
520
521 can_get_echo_skb(netdev, context->echo_index);
522
523 /* Release context */
524 context->echo_index = MAX_TX_URBS;
525
526}
527
528/*
529 * Send the given CPC command synchronously
530 */
531static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
532{
533 int actual_length;
534
535 /* Copy payload */
536 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
537 msg->length + CPC_MSG_HEADER_LEN);
538
539 /* Clear header */
540 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
541
542 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
543 &dev->tx_msg_buffer[0],
544 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
545 &actual_length, 1000);
546}
547
548/*
549 * Change CAN controllers' mode register
550 */
551static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
552{
553 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
554
555 return ems_usb_command_msg(dev, &dev->active_params);
556}
557
558/*
559 * Send a CPC_Control command to change behaviour when interface receives a CAN
560 * message, bus error or CAN state changed notifications.
561 */
562static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
563{
564 struct ems_cpc_msg cmd;
565
566 cmd.type = CPC_CMD_TYPE_CONTROL;
567 cmd.length = CPC_MSG_HEADER_LEN + 1;
568
569 cmd.msgid = 0;
570
571 cmd.msg.generic[0] = val;
572
573 return ems_usb_command_msg(dev, &cmd);
574}
575
576/*
577 * Start interface
578 */
579static int ems_usb_start(struct ems_usb *dev)
580{
581 struct net_device *netdev = dev->netdev;
582 int err, i;
583
584 dev->intr_in_buffer[0] = 0;
585 dev->free_slots = 50; /* initial size */
586
587 for (i = 0; i < MAX_RX_URBS; i++) {
588 struct urb *urb = NULL;
589 u8 *buf = NULL;
590
591 /* create a URB, and a buffer for it */
592 urb = usb_alloc_urb(0, GFP_KERNEL);
593 if (!urb) {
594 err = -ENOMEM;
595 break;
596 }
597
598 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
599 &urb->transfer_dma);
600 if (!buf) {
601 netdev_err(netdev, "No memory left for USB buffer\n");
602 usb_free_urb(urb);
603 err = -ENOMEM;
604 break;
605 }
606
607 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
608 buf, RX_BUFFER_SIZE,
609 ems_usb_read_bulk_callback, dev);
610 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
611 usb_anchor_urb(urb, &dev->rx_submitted);
612
613 err = usb_submit_urb(urb, GFP_KERNEL);
614 if (err) {
615 usb_unanchor_urb(urb);
616 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
617 urb->transfer_dma);
618 usb_free_urb(urb);
619 break;
620 }
621
622 /* Drop reference, USB core will take care of freeing it */
623 usb_free_urb(urb);
624 }
625
626 /* Did we submit any URBs */
627 if (i == 0) {
628 netdev_warn(netdev, "couldn't setup read URBs\n");
629 return err;
630 }
631
632 /* Warn if we've couldn't transmit all the URBs */
633 if (i < MAX_RX_URBS)
634 netdev_warn(netdev, "rx performance may be slow\n");
635
636 /* Setup and start interrupt URB */
637 usb_fill_int_urb(dev->intr_urb, dev->udev,
638 usb_rcvintpipe(dev->udev, 1),
639 dev->intr_in_buffer,
640 INTR_IN_BUFFER_SIZE,
641 ems_usb_read_interrupt_callback, dev, 1);
642
643 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
644 if (err) {
645 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
646
647 return err;
648 }
649
650 /* CPC-USB will transfer received message to host */
651 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
652 if (err)
653 goto failed;
654
655 /* CPC-USB will transfer CAN state changes to host */
656 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
657 if (err)
658 goto failed;
659
660 /* CPC-USB will transfer bus errors to host */
661 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
662 if (err)
663 goto failed;
664
665 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
666 if (err)
667 goto failed;
668
669 dev->can.state = CAN_STATE_ERROR_ACTIVE;
670
671 return 0;
672
673failed:
674 netdev_warn(netdev, "couldn't submit control: %d\n", err);
675
676 return err;
677}
678
679static void unlink_all_urbs(struct ems_usb *dev)
680{
681 int i;
682
683 usb_unlink_urb(dev->intr_urb);
684
685 usb_kill_anchored_urbs(&dev->rx_submitted);
686
687 usb_kill_anchored_urbs(&dev->tx_submitted);
688 atomic_set(&dev->active_tx_urbs, 0);
689
690 for (i = 0; i < MAX_TX_URBS; i++)
691 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
692}
693
694static int ems_usb_open(struct net_device *netdev)
695{
696 struct ems_usb *dev = netdev_priv(netdev);
697 int err;
698
699 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
700 if (err)
701 return err;
702
703 /* common open */
704 err = open_candev(netdev);
705 if (err)
706 return err;
707
708 /* finally start device */
709 err = ems_usb_start(dev);
710 if (err) {
711 if (err == -ENODEV)
712 netif_device_detach(dev->netdev);
713
714 netdev_warn(netdev, "couldn't start device: %d\n", err);
715
716 close_candev(netdev);
717
718 return err;
719 }
720
721
722 netif_start_queue(netdev);
723
724 return 0;
725}
726
727static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
728{
729 struct ems_usb *dev = netdev_priv(netdev);
730 struct ems_tx_urb_context *context = NULL;
731 struct net_device_stats *stats = &netdev->stats;
732 struct can_frame *cf = (struct can_frame *)skb->data;
733 struct ems_cpc_msg *msg;
734 struct urb *urb;
735 u8 *buf;
736 int i, err;
737 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
738 + sizeof(struct cpc_can_msg);
739
740 if (can_dropped_invalid_skb(netdev, skb))
741 return NETDEV_TX_OK;
742
743 /* create a URB, and a buffer for it, and copy the data to the URB */
744 urb = usb_alloc_urb(0, GFP_ATOMIC);
745 if (!urb)
746 goto nomem;
747
748 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
749 if (!buf) {
750 netdev_err(netdev, "No memory left for USB buffer\n");
751 usb_free_urb(urb);
752 goto nomem;
753 }
754
755 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
756
757 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
758 msg->msg.can_msg.length = cf->can_dlc;
759
760 if (cf->can_id & CAN_RTR_FLAG) {
761 msg->type = cf->can_id & CAN_EFF_FLAG ?
762 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
763
764 msg->length = CPC_CAN_MSG_MIN_SIZE;
765 } else {
766 msg->type = cf->can_id & CAN_EFF_FLAG ?
767 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
768
769 for (i = 0; i < cf->can_dlc; i++)
770 msg->msg.can_msg.msg[i] = cf->data[i];
771
772 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
773 }
774
775 for (i = 0; i < MAX_TX_URBS; i++) {
776 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
777 context = &dev->tx_contexts[i];
778 break;
779 }
780 }
781
782 /*
783 * May never happen! When this happens we'd more URBs in flight as
784 * allowed (MAX_TX_URBS).
785 */
786 if (!context) {
787 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
788 usb_free_urb(urb);
789
790 netdev_warn(netdev, "couldn't find free context\n");
791
792 return NETDEV_TX_BUSY;
793 }
794
795 context->dev = dev;
796 context->echo_index = i;
797 context->dlc = cf->can_dlc;
798
799 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
800 size, ems_usb_write_bulk_callback, context);
801 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
802 usb_anchor_urb(urb, &dev->tx_submitted);
803
804 can_put_echo_skb(skb, netdev, context->echo_index);
805
806 atomic_inc(&dev->active_tx_urbs);
807
808 err = usb_submit_urb(urb, GFP_ATOMIC);
809 if (unlikely(err)) {
810 can_free_echo_skb(netdev, context->echo_index);
811
812 usb_unanchor_urb(urb);
813 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
814 dev_kfree_skb(skb);
815
816 atomic_dec(&dev->active_tx_urbs);
817
818 if (err == -ENODEV) {
819 netif_device_detach(netdev);
820 } else {
821 netdev_warn(netdev, "failed tx_urb %d\n", err);
822
823 stats->tx_dropped++;
824 }
825 } else {
826 netif_trans_update(netdev);
827
828 /* Slow down tx path */
829 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
830 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
831 netif_stop_queue(netdev);
832 }
833 }
834
835 /*
836 * Release our reference to this URB, the USB core will eventually free
837 * it entirely.
838 */
839 usb_free_urb(urb);
840
841 return NETDEV_TX_OK;
842
843nomem:
844 dev_kfree_skb(skb);
845 stats->tx_dropped++;
846
847 return NETDEV_TX_OK;
848}
849
850static int ems_usb_close(struct net_device *netdev)
851{
852 struct ems_usb *dev = netdev_priv(netdev);
853
854 /* Stop polling */
855 unlink_all_urbs(dev);
856
857 netif_stop_queue(netdev);
858
859 /* Set CAN controller to reset mode */
860 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
861 netdev_warn(netdev, "couldn't stop device");
862
863 close_candev(netdev);
864
865 return 0;
866}
867
868static const struct net_device_ops ems_usb_netdev_ops = {
869 .ndo_open = ems_usb_open,
870 .ndo_stop = ems_usb_close,
871 .ndo_start_xmit = ems_usb_start_xmit,
872 .ndo_change_mtu = can_change_mtu,
873};
874
875static const struct can_bittiming_const ems_usb_bittiming_const = {
876 .name = "ems_usb",
877 .tseg1_min = 1,
878 .tseg1_max = 16,
879 .tseg2_min = 1,
880 .tseg2_max = 8,
881 .sjw_max = 4,
882 .brp_min = 1,
883 .brp_max = 64,
884 .brp_inc = 1,
885};
886
887static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
888{
889 struct ems_usb *dev = netdev_priv(netdev);
890
891 switch (mode) {
892 case CAN_MODE_START:
893 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
894 netdev_warn(netdev, "couldn't start device");
895
896 if (netif_queue_stopped(netdev))
897 netif_wake_queue(netdev);
898 break;
899
900 default:
901 return -EOPNOTSUPP;
902 }
903
904 return 0;
905}
906
907static int ems_usb_set_bittiming(struct net_device *netdev)
908{
909 struct ems_usb *dev = netdev_priv(netdev);
910 struct can_bittiming *bt = &dev->can.bittiming;
911 u8 btr0, btr1;
912
913 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
914 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
915 (((bt->phase_seg2 - 1) & 0x7) << 4);
916 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
917 btr1 |= 0x80;
918
919 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
920
921 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
922 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
923
924 return ems_usb_command_msg(dev, &dev->active_params);
925}
926
927static void init_params_sja1000(struct ems_cpc_msg *msg)
928{
929 struct cpc_sja1000_params *sja1000 =
930 &msg->msg.can_params.cc_params.sja1000;
931
932 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
933 msg->length = sizeof(struct cpc_can_params);
934 msg->msgid = 0;
935
936 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
937
938 /* Acceptance filter open */
939 sja1000->acc_code0 = 0x00;
940 sja1000->acc_code1 = 0x00;
941 sja1000->acc_code2 = 0x00;
942 sja1000->acc_code3 = 0x00;
943
944 /* Acceptance filter open */
945 sja1000->acc_mask0 = 0xFF;
946 sja1000->acc_mask1 = 0xFF;
947 sja1000->acc_mask2 = 0xFF;
948 sja1000->acc_mask3 = 0xFF;
949
950 sja1000->btr0 = 0;
951 sja1000->btr1 = 0;
952
953 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
954 sja1000->mode = SJA1000_MOD_RM;
955}
956
957/*
958 * probe function for new CPC-USB devices
959 */
960static int ems_usb_probe(struct usb_interface *intf,
961 const struct usb_device_id *id)
962{
963 struct net_device *netdev;
964 struct ems_usb *dev;
965 int i, err = -ENOMEM;
966
967 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
968 if (!netdev) {
969 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
970 return -ENOMEM;
971 }
972
973 dev = netdev_priv(netdev);
974
975 dev->udev = interface_to_usbdev(intf);
976 dev->netdev = netdev;
977
978 dev->can.state = CAN_STATE_STOPPED;
979 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
980 dev->can.bittiming_const = &ems_usb_bittiming_const;
981 dev->can.do_set_bittiming = ems_usb_set_bittiming;
982 dev->can.do_set_mode = ems_usb_set_mode;
983 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
984
985 netdev->netdev_ops = &ems_usb_netdev_ops;
986
987 netdev->flags |= IFF_ECHO; /* we support local echo */
988
989 init_usb_anchor(&dev->rx_submitted);
990
991 init_usb_anchor(&dev->tx_submitted);
992 atomic_set(&dev->active_tx_urbs, 0);
993
994 for (i = 0; i < MAX_TX_URBS; i++)
995 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
996
997 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
998 if (!dev->intr_urb)
999 goto cleanup_candev;
1000
1001 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1002 if (!dev->intr_in_buffer)
1003 goto cleanup_intr_urb;
1004
1005 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1006 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1007 if (!dev->tx_msg_buffer)
1008 goto cleanup_intr_in_buffer;
1009
1010 usb_set_intfdata(intf, dev);
1011
1012 SET_NETDEV_DEV(netdev, &intf->dev);
1013
1014 init_params_sja1000(&dev->active_params);
1015
1016 err = ems_usb_command_msg(dev, &dev->active_params);
1017 if (err) {
1018 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1019 goto cleanup_tx_msg_buffer;
1020 }
1021
1022 err = register_candev(netdev);
1023 if (err) {
1024 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1025 goto cleanup_tx_msg_buffer;
1026 }
1027
1028 return 0;
1029
1030cleanup_tx_msg_buffer:
1031 kfree(dev->tx_msg_buffer);
1032
1033cleanup_intr_in_buffer:
1034 kfree(dev->intr_in_buffer);
1035
1036cleanup_intr_urb:
1037 usb_free_urb(dev->intr_urb);
1038
1039cleanup_candev:
1040 free_candev(netdev);
1041
1042 return err;
1043}
1044
1045/*
1046 * called by the usb core when the device is removed from the system
1047 */
1048static void ems_usb_disconnect(struct usb_interface *intf)
1049{
1050 struct ems_usb *dev = usb_get_intfdata(intf);
1051
1052 usb_set_intfdata(intf, NULL);
1053
1054 if (dev) {
1055 unregister_netdev(dev->netdev);
1056 free_candev(dev->netdev);
1057
1058 unlink_all_urbs(dev);
1059
1060 usb_free_urb(dev->intr_urb);
1061
1062 kfree(dev->intr_in_buffer);
1063 kfree(dev->tx_msg_buffer);
1064 }
1065}
1066
1067/* usb specific object needed to register this driver with the usb subsystem */
1068static struct usb_driver ems_usb_driver = {
1069 .name = "ems_usb",
1070 .probe = ems_usb_probe,
1071 .disconnect = ems_usb_disconnect,
1072 .id_table = ems_usb_table,
1073};
1074
1075module_usb_driver(ems_usb_driver);