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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/ethtool.h>
8#include <linux/signal.h>
9#include <linux/slab.h>
10#include <linux/module.h>
11#include <linux/netdevice.h>
12#include <linux/usb.h>
13
14#include <linux/can.h>
15#include <linux/can/dev.h>
16#include <linux/can/error.h>
17
18MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
19MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
20MODULE_LICENSE("GPL v2");
21
22/* Control-Values for CPC_Control() Command Subject Selection */
23#define CONTR_CAN_MESSAGE 0x04
24#define CONTR_CAN_STATE 0x0C
25#define CONTR_BUS_ERROR 0x1C
26
27/* Control Command Actions */
28#define CONTR_CONT_OFF 0
29#define CONTR_CONT_ON 1
30#define CONTR_ONCE 2
31
32/* Messages from CPC to PC */
33#define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */
34#define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */
35#define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */
36#define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */
37#define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */
38#define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */
39#define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */
40#define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */
41#define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */
42#define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
43#define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */
44
45/* Messages from the PC to the CPC interface */
46#define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */
47#define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */
48#define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */
49#define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */
50#define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */
51#define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */
52#define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */
53#define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */
54
55#define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
56#define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */
57#define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
58
59#define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
60
61#define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
62
63/* Overrun types */
64#define CPC_OVR_EVENT_CAN 0x01
65#define CPC_OVR_EVENT_CANSTATE 0x02
66#define CPC_OVR_EVENT_BUSERROR 0x04
67
68/*
69 * If the CAN controller lost a message we indicate it with the highest bit
70 * set in the count field.
71 */
72#define CPC_OVR_HW 0x80
73
74/* Size of the "struct ems_cpc_msg" without the union */
75#define CPC_MSG_HEADER_LEN 11
76#define CPC_CAN_MSG_MIN_SIZE 5
77
78/* Define these values to match your devices */
79#define USB_CPCUSB_VENDOR_ID 0x12D6
80
81#define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
82
83/* Mode register NXP LPC2119/SJA1000 CAN Controller */
84#define SJA1000_MOD_NORMAL 0x00
85#define SJA1000_MOD_RM 0x01
86
87/* ECC register NXP LPC2119/SJA1000 CAN Controller */
88#define SJA1000_ECC_SEG 0x1F
89#define SJA1000_ECC_DIR 0x20
90#define SJA1000_ECC_ERR 0x06
91#define SJA1000_ECC_BIT 0x00
92#define SJA1000_ECC_FORM 0x40
93#define SJA1000_ECC_STUFF 0x80
94#define SJA1000_ECC_MASK 0xc0
95
96/* Status register content */
97#define SJA1000_SR_BS 0x80
98#define SJA1000_SR_ES 0x40
99
100#define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
101
102/*
103 * The device actually uses a 16MHz clock to generate the CAN clock
104 * but it expects SJA1000 bit settings based on 8MHz (is internally
105 * converted).
106 */
107#define EMS_USB_ARM7_CLOCK 8000000
108
109#define CPC_TX_QUEUE_TRIGGER_LOW 25
110#define CPC_TX_QUEUE_TRIGGER_HIGH 35
111
112/*
113 * CAN-Message representation in a CPC_MSG. Message object type is
114 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
115 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
116 */
117struct cpc_can_msg {
118 __le32 id;
119 u8 length;
120 u8 msg[8];
121};
122
123/* Representation of the CAN parameters for the SJA1000 controller */
124struct cpc_sja1000_params {
125 u8 mode;
126 u8 acc_code0;
127 u8 acc_code1;
128 u8 acc_code2;
129 u8 acc_code3;
130 u8 acc_mask0;
131 u8 acc_mask1;
132 u8 acc_mask2;
133 u8 acc_mask3;
134 u8 btr0;
135 u8 btr1;
136 u8 outp_contr;
137};
138
139/* CAN params message representation */
140struct cpc_can_params {
141 u8 cc_type;
142
143 /* Will support M16C CAN controller in the future */
144 union {
145 struct cpc_sja1000_params sja1000;
146 } cc_params;
147};
148
149/* Structure for confirmed message handling */
150struct cpc_confirm {
151 u8 error; /* error code */
152};
153
154/* Structure for overrun conditions */
155struct cpc_overrun {
156 u8 event;
157 u8 count;
158};
159
160/* SJA1000 CAN errors (compatible to NXP LPC2119) */
161struct cpc_sja1000_can_error {
162 u8 ecc;
163 u8 rxerr;
164 u8 txerr;
165};
166
167/* structure for CAN error conditions */
168struct cpc_can_error {
169 u8 ecode;
170
171 struct {
172 u8 cc_type;
173
174 /* Other controllers may also provide error code capture regs */
175 union {
176 struct cpc_sja1000_can_error sja1000;
177 } regs;
178 } cc;
179};
180
181/*
182 * Structure containing RX/TX error counter. This structure is used to request
183 * the values of the CAN controllers TX and RX error counter.
184 */
185struct cpc_can_err_counter {
186 u8 rx;
187 u8 tx;
188};
189
190/* Main message type used between library and application */
191struct __packed ems_cpc_msg {
192 u8 type; /* type of message */
193 u8 length; /* length of data within union 'msg' */
194 u8 msgid; /* confirmation handle */
195 __le32 ts_sec; /* timestamp in seconds */
196 __le32 ts_nsec; /* timestamp in nano seconds */
197
198 union __packed {
199 u8 generic[64];
200 struct cpc_can_msg can_msg;
201 struct cpc_can_params can_params;
202 struct cpc_confirm confirmation;
203 struct cpc_overrun overrun;
204 struct cpc_can_error error;
205 struct cpc_can_err_counter err_counter;
206 u8 can_state;
207 } msg;
208};
209
210/*
211 * Table of devices that work with this driver
212 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
213 */
214static struct usb_device_id ems_usb_table[] = {
215 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
216 {} /* Terminating entry */
217};
218
219MODULE_DEVICE_TABLE(usb, ems_usb_table);
220
221#define RX_BUFFER_SIZE 64
222#define CPC_HEADER_SIZE 4
223#define INTR_IN_BUFFER_SIZE 4
224
225#define MAX_RX_URBS 10
226#define MAX_TX_URBS 10
227
228struct ems_usb;
229
230struct ems_tx_urb_context {
231 struct ems_usb *dev;
232
233 u32 echo_index;
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 void *rxbuf[MAX_RX_URBS];
259 dma_addr_t rxbuf_dma[MAX_RX_URBS];
260};
261
262static void ems_usb_read_interrupt_callback(struct urb *urb)
263{
264 struct ems_usb *dev = urb->context;
265 struct net_device *netdev = dev->netdev;
266 int err;
267
268 if (!netif_device_present(netdev))
269 return;
270
271 switch (urb->status) {
272 case 0:
273 dev->free_slots = dev->intr_in_buffer[1];
274 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH &&
275 netif_queue_stopped(netdev))
276 netif_wake_queue(netdev);
277 break;
278
279 case -ECONNRESET: /* unlink */
280 case -ENOENT:
281 case -EPIPE:
282 case -EPROTO:
283 case -ESHUTDOWN:
284 return;
285
286 default:
287 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
288 break;
289 }
290
291 err = usb_submit_urb(urb, GFP_ATOMIC);
292
293 if (err == -ENODEV)
294 netif_device_detach(netdev);
295 else if (err)
296 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
297}
298
299static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
300{
301 struct can_frame *cf;
302 struct sk_buff *skb;
303 int i;
304 struct net_device_stats *stats = &dev->netdev->stats;
305
306 skb = alloc_can_skb(dev->netdev, &cf);
307 if (skb == NULL)
308 return;
309
310 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
311 cf->len = can_cc_dlc2len(msg->msg.can_msg.length & 0xF);
312
313 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
314 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
315 cf->can_id |= CAN_EFF_FLAG;
316
317 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
318 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
319 cf->can_id |= CAN_RTR_FLAG;
320 } else {
321 for (i = 0; i < cf->len; i++)
322 cf->data[i] = msg->msg.can_msg.msg[i];
323
324 stats->rx_bytes += cf->len;
325 }
326 stats->rx_packets++;
327
328 netif_rx(skb);
329}
330
331static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
332{
333 struct can_frame *cf;
334 struct sk_buff *skb;
335 struct net_device_stats *stats = &dev->netdev->stats;
336
337 skb = alloc_can_err_skb(dev->netdev, &cf);
338 if (skb == NULL)
339 return;
340
341 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
342 u8 state = msg->msg.can_state;
343
344 if (state & SJA1000_SR_BS) {
345 dev->can.state = CAN_STATE_BUS_OFF;
346 cf->can_id |= CAN_ERR_BUSOFF;
347
348 dev->can.can_stats.bus_off++;
349 can_bus_off(dev->netdev);
350 } else if (state & SJA1000_SR_ES) {
351 dev->can.state = CAN_STATE_ERROR_WARNING;
352 dev->can.can_stats.error_warning++;
353 } else {
354 dev->can.state = CAN_STATE_ERROR_ACTIVE;
355 dev->can.can_stats.error_passive++;
356 }
357 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
358 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
359 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
360 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
361
362 /* bus error interrupt */
363 dev->can.can_stats.bus_error++;
364 stats->rx_errors++;
365
366 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
367
368 switch (ecc & SJA1000_ECC_MASK) {
369 case SJA1000_ECC_BIT:
370 cf->data[2] |= CAN_ERR_PROT_BIT;
371 break;
372 case SJA1000_ECC_FORM:
373 cf->data[2] |= CAN_ERR_PROT_FORM;
374 break;
375 case SJA1000_ECC_STUFF:
376 cf->data[2] |= CAN_ERR_PROT_STUFF;
377 break;
378 default:
379 cf->data[3] = ecc & SJA1000_ECC_SEG;
380 break;
381 }
382
383 /* Error occurred during transmission? */
384 if ((ecc & SJA1000_ECC_DIR) == 0)
385 cf->data[2] |= CAN_ERR_PROT_TX;
386
387 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
388 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
389 cf->can_id |= CAN_ERR_CRTL;
390 cf->data[1] = (txerr > rxerr) ?
391 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
392 }
393 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
394 cf->can_id |= CAN_ERR_CRTL;
395 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
396
397 stats->rx_over_errors++;
398 stats->rx_errors++;
399 }
400
401 netif_rx(skb);
402}
403
404/*
405 * callback for bulk IN urb
406 */
407static void ems_usb_read_bulk_callback(struct urb *urb)
408{
409 struct ems_usb *dev = urb->context;
410 struct net_device *netdev;
411 int retval;
412
413 netdev = dev->netdev;
414
415 if (!netif_device_present(netdev))
416 return;
417
418 switch (urb->status) {
419 case 0: /* success */
420 break;
421
422 case -ENOENT:
423 return;
424
425 default:
426 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
427 goto resubmit_urb;
428 }
429
430 if (urb->actual_length > CPC_HEADER_SIZE) {
431 struct ems_cpc_msg *msg;
432 u8 *ibuf = urb->transfer_buffer;
433 u8 msg_count, start;
434
435 msg_count = ibuf[0] & ~0x80;
436
437 start = CPC_HEADER_SIZE;
438
439 while (msg_count) {
440 msg = (struct ems_cpc_msg *)&ibuf[start];
441
442 switch (msg->type) {
443 case CPC_MSG_TYPE_CAN_STATE:
444 /* Process CAN state changes */
445 ems_usb_rx_err(dev, msg);
446 break;
447
448 case CPC_MSG_TYPE_CAN_FRAME:
449 case CPC_MSG_TYPE_EXT_CAN_FRAME:
450 case CPC_MSG_TYPE_RTR_FRAME:
451 case CPC_MSG_TYPE_EXT_RTR_FRAME:
452 ems_usb_rx_can_msg(dev, msg);
453 break;
454
455 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
456 /* Process errorframe */
457 ems_usb_rx_err(dev, msg);
458 break;
459
460 case CPC_MSG_TYPE_OVERRUN:
461 /* Message lost while receiving */
462 ems_usb_rx_err(dev, msg);
463 break;
464 }
465
466 start += CPC_MSG_HEADER_LEN + msg->length;
467 msg_count--;
468
469 if (start > urb->transfer_buffer_length) {
470 netdev_err(netdev, "format error\n");
471 break;
472 }
473 }
474 }
475
476resubmit_urb:
477 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
478 urb->transfer_buffer, RX_BUFFER_SIZE,
479 ems_usb_read_bulk_callback, dev);
480
481 retval = usb_submit_urb(urb, GFP_ATOMIC);
482
483 if (retval == -ENODEV)
484 netif_device_detach(netdev);
485 else if (retval)
486 netdev_err(netdev,
487 "failed resubmitting read bulk urb: %d\n", retval);
488}
489
490/*
491 * callback for bulk IN urb
492 */
493static void ems_usb_write_bulk_callback(struct urb *urb)
494{
495 struct ems_tx_urb_context *context = urb->context;
496 struct ems_usb *dev;
497 struct net_device *netdev;
498
499 BUG_ON(!context);
500
501 dev = context->dev;
502 netdev = dev->netdev;
503
504 /* free up our allocated buffer */
505 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
506 urb->transfer_buffer, urb->transfer_dma);
507
508 atomic_dec(&dev->active_tx_urbs);
509
510 if (!netif_device_present(netdev))
511 return;
512
513 if (urb->status)
514 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
515
516 netif_trans_update(netdev);
517
518 /* transmission complete interrupt */
519 netdev->stats.tx_packets++;
520 netdev->stats.tx_bytes += can_get_echo_skb(netdev, context->echo_index,
521 NULL);
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 dma_addr_t buf_dma;
591
592 /* create a URB, and a buffer for it */
593 urb = usb_alloc_urb(0, GFP_KERNEL);
594 if (!urb) {
595 err = -ENOMEM;
596 break;
597 }
598
599 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
600 &buf_dma);
601 if (!buf) {
602 netdev_err(netdev, "No memory left for USB buffer\n");
603 usb_free_urb(urb);
604 err = -ENOMEM;
605 break;
606 }
607
608 urb->transfer_dma = buf_dma;
609
610 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
611 buf, RX_BUFFER_SIZE,
612 ems_usb_read_bulk_callback, dev);
613 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
614 usb_anchor_urb(urb, &dev->rx_submitted);
615
616 err = usb_submit_urb(urb, GFP_KERNEL);
617 if (err) {
618 usb_unanchor_urb(urb);
619 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
620 urb->transfer_dma);
621 usb_free_urb(urb);
622 break;
623 }
624
625 dev->rxbuf[i] = buf;
626 dev->rxbuf_dma[i] = buf_dma;
627
628 /* Drop reference, USB core will take care of freeing it */
629 usb_free_urb(urb);
630 }
631
632 /* Did we submit any URBs */
633 if (i == 0) {
634 netdev_warn(netdev, "couldn't setup read URBs\n");
635 return err;
636 }
637
638 /* Warn if we've couldn't transmit all the URBs */
639 if (i < MAX_RX_URBS)
640 netdev_warn(netdev, "rx performance may be slow\n");
641
642 /* Setup and start interrupt URB */
643 usb_fill_int_urb(dev->intr_urb, dev->udev,
644 usb_rcvintpipe(dev->udev, 1),
645 dev->intr_in_buffer,
646 INTR_IN_BUFFER_SIZE,
647 ems_usb_read_interrupt_callback, dev, 1);
648
649 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
650 if (err) {
651 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
652
653 return err;
654 }
655
656 /* CPC-USB will transfer received message to host */
657 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
658 if (err)
659 goto failed;
660
661 /* CPC-USB will transfer CAN state changes to host */
662 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
663 if (err)
664 goto failed;
665
666 /* CPC-USB will transfer bus errors to host */
667 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
668 if (err)
669 goto failed;
670
671 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
672 if (err)
673 goto failed;
674
675 dev->can.state = CAN_STATE_ERROR_ACTIVE;
676
677 return 0;
678
679failed:
680 netdev_warn(netdev, "couldn't submit control: %d\n", err);
681
682 return err;
683}
684
685static void unlink_all_urbs(struct ems_usb *dev)
686{
687 int i;
688
689 usb_unlink_urb(dev->intr_urb);
690
691 usb_kill_anchored_urbs(&dev->rx_submitted);
692
693 for (i = 0; i < MAX_RX_URBS; ++i)
694 usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
695 dev->rxbuf[i], dev->rxbuf_dma[i]);
696
697 usb_kill_anchored_urbs(&dev->tx_submitted);
698 atomic_set(&dev->active_tx_urbs, 0);
699
700 for (i = 0; i < MAX_TX_URBS; i++)
701 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
702}
703
704static int ems_usb_open(struct net_device *netdev)
705{
706 struct ems_usb *dev = netdev_priv(netdev);
707 int err;
708
709 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
710 if (err)
711 return err;
712
713 /* common open */
714 err = open_candev(netdev);
715 if (err)
716 return err;
717
718 /* finally start device */
719 err = ems_usb_start(dev);
720 if (err) {
721 if (err == -ENODEV)
722 netif_device_detach(dev->netdev);
723
724 netdev_warn(netdev, "couldn't start device: %d\n", err);
725
726 close_candev(netdev);
727
728 return err;
729 }
730
731
732 netif_start_queue(netdev);
733
734 return 0;
735}
736
737static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
738{
739 struct ems_usb *dev = netdev_priv(netdev);
740 struct ems_tx_urb_context *context = NULL;
741 struct net_device_stats *stats = &netdev->stats;
742 struct can_frame *cf = (struct can_frame *)skb->data;
743 struct ems_cpc_msg *msg;
744 struct urb *urb;
745 u8 *buf;
746 int i, err;
747 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
748 + sizeof(struct cpc_can_msg);
749
750 if (can_dev_dropped_skb(netdev, skb))
751 return NETDEV_TX_OK;
752
753 /* create a URB, and a buffer for it, and copy the data to the URB */
754 urb = usb_alloc_urb(0, GFP_ATOMIC);
755 if (!urb)
756 goto nomem;
757
758 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
759 if (!buf) {
760 netdev_err(netdev, "No memory left for USB buffer\n");
761 usb_free_urb(urb);
762 goto nomem;
763 }
764
765 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
766
767 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
768 msg->msg.can_msg.length = cf->len;
769
770 if (cf->can_id & CAN_RTR_FLAG) {
771 msg->type = cf->can_id & CAN_EFF_FLAG ?
772 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
773
774 msg->length = CPC_CAN_MSG_MIN_SIZE;
775 } else {
776 msg->type = cf->can_id & CAN_EFF_FLAG ?
777 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
778
779 for (i = 0; i < cf->len; i++)
780 msg->msg.can_msg.msg[i] = cf->data[i];
781
782 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len;
783 }
784
785 for (i = 0; i < MAX_TX_URBS; i++) {
786 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
787 context = &dev->tx_contexts[i];
788 break;
789 }
790 }
791
792 /*
793 * May never happen! When this happens we'd more URBs in flight as
794 * allowed (MAX_TX_URBS).
795 */
796 if (!context) {
797 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
798 usb_free_urb(urb);
799
800 netdev_warn(netdev, "couldn't find free context\n");
801
802 return NETDEV_TX_BUSY;
803 }
804
805 context->dev = dev;
806 context->echo_index = i;
807
808 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
809 size, ems_usb_write_bulk_callback, context);
810 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
811 usb_anchor_urb(urb, &dev->tx_submitted);
812
813 can_put_echo_skb(skb, netdev, context->echo_index, 0);
814
815 atomic_inc(&dev->active_tx_urbs);
816
817 err = usb_submit_urb(urb, GFP_ATOMIC);
818 if (unlikely(err)) {
819 can_free_echo_skb(netdev, context->echo_index, NULL);
820
821 usb_unanchor_urb(urb);
822 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
823
824 atomic_dec(&dev->active_tx_urbs);
825
826 if (err == -ENODEV) {
827 netif_device_detach(netdev);
828 } else {
829 netdev_warn(netdev, "failed tx_urb %d\n", err);
830
831 stats->tx_dropped++;
832 }
833 } else {
834 netif_trans_update(netdev);
835
836 /* Slow down tx path */
837 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
838 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
839 netif_stop_queue(netdev);
840 }
841 }
842
843 /*
844 * Release our reference to this URB, the USB core will eventually free
845 * it entirely.
846 */
847 usb_free_urb(urb);
848
849 return NETDEV_TX_OK;
850
851nomem:
852 dev_kfree_skb(skb);
853 stats->tx_dropped++;
854
855 return NETDEV_TX_OK;
856}
857
858static int ems_usb_close(struct net_device *netdev)
859{
860 struct ems_usb *dev = netdev_priv(netdev);
861
862 /* Stop polling */
863 unlink_all_urbs(dev);
864
865 netif_stop_queue(netdev);
866
867 /* Set CAN controller to reset mode */
868 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
869 netdev_warn(netdev, "couldn't stop device");
870
871 close_candev(netdev);
872
873 return 0;
874}
875
876static const struct net_device_ops ems_usb_netdev_ops = {
877 .ndo_open = ems_usb_open,
878 .ndo_stop = ems_usb_close,
879 .ndo_start_xmit = ems_usb_start_xmit,
880 .ndo_change_mtu = can_change_mtu,
881};
882
883static const struct ethtool_ops ems_usb_ethtool_ops = {
884 .get_ts_info = ethtool_op_get_ts_info,
885};
886
887static const struct can_bittiming_const ems_usb_bittiming_const = {
888 .name = KBUILD_MODNAME,
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 netdev->ethtool_ops = &ems_usb_ethtool_ops;
999
1000 netdev->flags |= IFF_ECHO; /* we support local echo */
1001
1002 init_usb_anchor(&dev->rx_submitted);
1003
1004 init_usb_anchor(&dev->tx_submitted);
1005 atomic_set(&dev->active_tx_urbs, 0);
1006
1007 for (i = 0; i < MAX_TX_URBS; i++)
1008 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1009
1010 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1011 if (!dev->intr_urb)
1012 goto cleanup_candev;
1013
1014 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1015 if (!dev->intr_in_buffer)
1016 goto cleanup_intr_urb;
1017
1018 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1019 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1020 if (!dev->tx_msg_buffer)
1021 goto cleanup_intr_in_buffer;
1022
1023 usb_set_intfdata(intf, dev);
1024
1025 SET_NETDEV_DEV(netdev, &intf->dev);
1026
1027 init_params_sja1000(&dev->active_params);
1028
1029 err = ems_usb_command_msg(dev, &dev->active_params);
1030 if (err) {
1031 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1032 goto cleanup_tx_msg_buffer;
1033 }
1034
1035 err = register_candev(netdev);
1036 if (err) {
1037 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1038 goto cleanup_tx_msg_buffer;
1039 }
1040
1041 return 0;
1042
1043cleanup_tx_msg_buffer:
1044 kfree(dev->tx_msg_buffer);
1045
1046cleanup_intr_in_buffer:
1047 kfree(dev->intr_in_buffer);
1048
1049cleanup_intr_urb:
1050 usb_free_urb(dev->intr_urb);
1051
1052cleanup_candev:
1053 free_candev(netdev);
1054
1055 return err;
1056}
1057
1058/*
1059 * called by the usb core when the device is removed from the system
1060 */
1061static void ems_usb_disconnect(struct usb_interface *intf)
1062{
1063 struct ems_usb *dev = usb_get_intfdata(intf);
1064
1065 usb_set_intfdata(intf, NULL);
1066
1067 if (dev) {
1068 unregister_netdev(dev->netdev);
1069
1070 unlink_all_urbs(dev);
1071
1072 usb_free_urb(dev->intr_urb);
1073
1074 kfree(dev->intr_in_buffer);
1075 kfree(dev->tx_msg_buffer);
1076
1077 free_candev(dev->netdev);
1078 }
1079}
1080
1081/* usb specific object needed to register this driver with the usb subsystem */
1082static struct usb_driver ems_usb_driver = {
1083 .name = KBUILD_MODNAME,
1084 .probe = ems_usb_probe,
1085 .disconnect = ems_usb_disconnect,
1086 .id_table = ems_usb_table,
1087};
1088
1089module_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);