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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/init.h>
20#include <linux/signal.h>
21#include <linux/slab.h>
22#include <linux/module.h>
23#include <linux/netdevice.h>
24#include <linux/usb.h>
25
26#include <linux/can.h>
27#include <linux/can/dev.h>
28#include <linux/can/error.h>
29
30MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
31MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
32MODULE_LICENSE("GPL v2");
33
34/* Control-Values for CPC_Control() Command Subject Selection */
35#define CONTR_CAN_MESSAGE 0x04
36#define CONTR_CAN_STATE 0x0C
37#define CONTR_BUS_ERROR 0x1C
38
39/* Control Command Actions */
40#define CONTR_CONT_OFF 0
41#define CONTR_CONT_ON 1
42#define CONTR_ONCE 2
43
44/* Messages from CPC to PC */
45#define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */
46#define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */
47#define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */
48#define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */
49#define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */
50#define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */
51#define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */
52#define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */
53#define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */
54#define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
55#define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */
56
57/* Messages from the PC to the CPC interface */
58#define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */
59#define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */
60#define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */
61#define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */
62#define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */
63#define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */
64#define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */
65#define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */
66
67#define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
68#define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */
69#define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
70
71#define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
72
73#define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
74
75/* Overrun types */
76#define CPC_OVR_EVENT_CAN 0x01
77#define CPC_OVR_EVENT_CANSTATE 0x02
78#define CPC_OVR_EVENT_BUSERROR 0x04
79
80/*
81 * If the CAN controller lost a message we indicate it with the highest bit
82 * set in the count field.
83 */
84#define CPC_OVR_HW 0x80
85
86/* Size of the "struct ems_cpc_msg" without the union */
87#define CPC_MSG_HEADER_LEN 11
88#define CPC_CAN_MSG_MIN_SIZE 5
89
90/* Define these values to match your devices */
91#define USB_CPCUSB_VENDOR_ID 0x12D6
92
93#define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
94
95/* Mode register NXP LPC2119/SJA1000 CAN Controller */
96#define SJA1000_MOD_NORMAL 0x00
97#define SJA1000_MOD_RM 0x01
98
99/* ECC register NXP LPC2119/SJA1000 CAN Controller */
100#define SJA1000_ECC_SEG 0x1F
101#define SJA1000_ECC_DIR 0x20
102#define SJA1000_ECC_ERR 0x06
103#define SJA1000_ECC_BIT 0x00
104#define SJA1000_ECC_FORM 0x40
105#define SJA1000_ECC_STUFF 0x80
106#define SJA1000_ECC_MASK 0xc0
107
108/* Status register content */
109#define SJA1000_SR_BS 0x80
110#define SJA1000_SR_ES 0x40
111
112#define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
113
114/*
115 * The device actually uses a 16MHz clock to generate the CAN clock
116 * but it expects SJA1000 bit settings based on 8MHz (is internally
117 * converted).
118 */
119#define EMS_USB_ARM7_CLOCK 8000000
120
121/*
122 * CAN-Message representation in a CPC_MSG. Message object type is
123 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
124 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
125 */
126struct cpc_can_msg {
127 u32 id;
128 u8 length;
129 u8 msg[8];
130};
131
132/* Representation of the CAN parameters for the SJA1000 controller */
133struct cpc_sja1000_params {
134 u8 mode;
135 u8 acc_code0;
136 u8 acc_code1;
137 u8 acc_code2;
138 u8 acc_code3;
139 u8 acc_mask0;
140 u8 acc_mask1;
141 u8 acc_mask2;
142 u8 acc_mask3;
143 u8 btr0;
144 u8 btr1;
145 u8 outp_contr;
146};
147
148/* CAN params message representation */
149struct cpc_can_params {
150 u8 cc_type;
151
152 /* Will support M16C CAN controller in the future */
153 union {
154 struct cpc_sja1000_params sja1000;
155 } cc_params;
156};
157
158/* Structure for confirmed message handling */
159struct cpc_confirm {
160 u8 error; /* error code */
161};
162
163/* Structure for overrun conditions */
164struct cpc_overrun {
165 u8 event;
166 u8 count;
167};
168
169/* SJA1000 CAN errors (compatible to NXP LPC2119) */
170struct cpc_sja1000_can_error {
171 u8 ecc;
172 u8 rxerr;
173 u8 txerr;
174};
175
176/* structure for CAN error conditions */
177struct cpc_can_error {
178 u8 ecode;
179
180 struct {
181 u8 cc_type;
182
183 /* Other controllers may also provide error code capture regs */
184 union {
185 struct cpc_sja1000_can_error sja1000;
186 } regs;
187 } cc;
188};
189
190/*
191 * Structure containing RX/TX error counter. This structure is used to request
192 * the values of the CAN controllers TX and RX error counter.
193 */
194struct cpc_can_err_counter {
195 u8 rx;
196 u8 tx;
197};
198
199/* Main message type used between library and application */
200struct __packed ems_cpc_msg {
201 u8 type; /* type of message */
202 u8 length; /* length of data within union 'msg' */
203 u8 msgid; /* confirmation handle */
204 u32 ts_sec; /* timestamp in seconds */
205 u32 ts_nsec; /* timestamp in nano seconds */
206
207 union {
208 u8 generic[64];
209 struct cpc_can_msg can_msg;
210 struct cpc_can_params can_params;
211 struct cpc_confirm confirmation;
212 struct cpc_overrun overrun;
213 struct cpc_can_error error;
214 struct cpc_can_err_counter err_counter;
215 u8 can_state;
216 } msg;
217};
218
219/*
220 * Table of devices that work with this driver
221 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
222 */
223static struct usb_device_id ems_usb_table[] = {
224 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
225 {} /* Terminating entry */
226};
227
228MODULE_DEVICE_TABLE(usb, ems_usb_table);
229
230#define RX_BUFFER_SIZE 64
231#define CPC_HEADER_SIZE 4
232#define INTR_IN_BUFFER_SIZE 4
233
234#define MAX_RX_URBS 10
235#define MAX_TX_URBS 10
236
237struct ems_usb;
238
239struct ems_tx_urb_context {
240 struct ems_usb *dev;
241
242 u32 echo_index;
243 u8 dlc;
244};
245
246struct ems_usb {
247 struct can_priv can; /* must be the first member */
248 int open_time;
249
250 struct sk_buff *echo_skb[MAX_TX_URBS];
251
252 struct usb_device *udev;
253 struct net_device *netdev;
254
255 atomic_t active_tx_urbs;
256 struct usb_anchor tx_submitted;
257 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
258
259 struct usb_anchor rx_submitted;
260
261 struct urb *intr_urb;
262
263 u8 *tx_msg_buffer;
264
265 u8 *intr_in_buffer;
266 unsigned int free_slots; /* remember number of available slots */
267
268 struct ems_cpc_msg active_params; /* active controller parameters */
269};
270
271static void ems_usb_read_interrupt_callback(struct urb *urb)
272{
273 struct ems_usb *dev = urb->context;
274 struct net_device *netdev = dev->netdev;
275 int err;
276
277 if (!netif_device_present(netdev))
278 return;
279
280 switch (urb->status) {
281 case 0:
282 dev->free_slots = dev->intr_in_buffer[1];
283 break;
284
285 case -ECONNRESET: /* unlink */
286 case -ENOENT:
287 case -ESHUTDOWN:
288 return;
289
290 default:
291 dev_info(netdev->dev.parent, "Rx interrupt aborted %d\n",
292 urb->status);
293 break;
294 }
295
296 err = usb_submit_urb(urb, GFP_ATOMIC);
297
298 if (err == -ENODEV)
299 netif_device_detach(netdev);
300 else if (err)
301 dev_err(netdev->dev.parent,
302 "failed resubmitting intr urb: %d\n", err);
303}
304
305static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
306{
307 struct can_frame *cf;
308 struct sk_buff *skb;
309 int i;
310 struct net_device_stats *stats = &dev->netdev->stats;
311
312 skb = alloc_can_skb(dev->netdev, &cf);
313 if (skb == NULL)
314 return;
315
316 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
317 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
318
319 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
320 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
321 cf->can_id |= CAN_EFF_FLAG;
322
323 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
324 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
325 cf->can_id |= CAN_RTR_FLAG;
326 } else {
327 for (i = 0; i < cf->can_dlc; i++)
328 cf->data[i] = msg->msg.can_msg.msg[i];
329 }
330
331 netif_rx(skb);
332
333 stats->rx_packets++;
334 stats->rx_bytes += cf->can_dlc;
335}
336
337static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
338{
339 struct can_frame *cf;
340 struct sk_buff *skb;
341 struct net_device_stats *stats = &dev->netdev->stats;
342
343 skb = alloc_can_err_skb(dev->netdev, &cf);
344 if (skb == NULL)
345 return;
346
347 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
348 u8 state = msg->msg.can_state;
349
350 if (state & SJA1000_SR_BS) {
351 dev->can.state = CAN_STATE_BUS_OFF;
352 cf->can_id |= CAN_ERR_BUSOFF;
353
354 can_bus_off(dev->netdev);
355 } else if (state & SJA1000_SR_ES) {
356 dev->can.state = CAN_STATE_ERROR_WARNING;
357 dev->can.can_stats.error_warning++;
358 } else {
359 dev->can.state = CAN_STATE_ERROR_ACTIVE;
360 dev->can.can_stats.error_passive++;
361 }
362 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
363 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
364 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
365 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
366
367 /* bus error interrupt */
368 dev->can.can_stats.bus_error++;
369 stats->rx_errors++;
370
371 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
372
373 switch (ecc & SJA1000_ECC_MASK) {
374 case SJA1000_ECC_BIT:
375 cf->data[2] |= CAN_ERR_PROT_BIT;
376 break;
377 case SJA1000_ECC_FORM:
378 cf->data[2] |= CAN_ERR_PROT_FORM;
379 break;
380 case SJA1000_ECC_STUFF:
381 cf->data[2] |= CAN_ERR_PROT_STUFF;
382 break;
383 default:
384 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
385 cf->data[3] = ecc & SJA1000_ECC_SEG;
386 break;
387 }
388
389 /* Error occurred during transmission? */
390 if ((ecc & SJA1000_ECC_DIR) == 0)
391 cf->data[2] |= CAN_ERR_PROT_TX;
392
393 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
394 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
395 cf->data[1] = (txerr > rxerr) ?
396 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
397 }
398 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
399 cf->can_id |= CAN_ERR_CRTL;
400 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
401
402 stats->rx_over_errors++;
403 stats->rx_errors++;
404 }
405
406 netif_rx(skb);
407
408 stats->rx_packets++;
409 stats->rx_bytes += cf->can_dlc;
410}
411
412/*
413 * callback for bulk IN urb
414 */
415static void ems_usb_read_bulk_callback(struct urb *urb)
416{
417 struct ems_usb *dev = urb->context;
418 struct net_device *netdev;
419 int retval;
420
421 netdev = dev->netdev;
422
423 if (!netif_device_present(netdev))
424 return;
425
426 switch (urb->status) {
427 case 0: /* success */
428 break;
429
430 case -ENOENT:
431 return;
432
433 default:
434 dev_info(netdev->dev.parent, "Rx URB aborted (%d)\n",
435 urb->status);
436 goto resubmit_urb;
437 }
438
439 if (urb->actual_length > CPC_HEADER_SIZE) {
440 struct ems_cpc_msg *msg;
441 u8 *ibuf = urb->transfer_buffer;
442 u8 msg_count, again, start;
443
444 msg_count = ibuf[0] & ~0x80;
445 again = ibuf[0] & 0x80;
446
447 start = CPC_HEADER_SIZE;
448
449 while (msg_count) {
450 msg = (struct ems_cpc_msg *)&ibuf[start];
451
452 switch (msg->type) {
453 case CPC_MSG_TYPE_CAN_STATE:
454 /* Process CAN state changes */
455 ems_usb_rx_err(dev, msg);
456 break;
457
458 case CPC_MSG_TYPE_CAN_FRAME:
459 case CPC_MSG_TYPE_EXT_CAN_FRAME:
460 case CPC_MSG_TYPE_RTR_FRAME:
461 case CPC_MSG_TYPE_EXT_RTR_FRAME:
462 ems_usb_rx_can_msg(dev, msg);
463 break;
464
465 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
466 /* Process errorframe */
467 ems_usb_rx_err(dev, msg);
468 break;
469
470 case CPC_MSG_TYPE_OVERRUN:
471 /* Message lost while receiving */
472 ems_usb_rx_err(dev, msg);
473 break;
474 }
475
476 start += CPC_MSG_HEADER_LEN + msg->length;
477 msg_count--;
478
479 if (start > urb->transfer_buffer_length) {
480 dev_err(netdev->dev.parent, "format error\n");
481 break;
482 }
483 }
484 }
485
486resubmit_urb:
487 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
488 urb->transfer_buffer, RX_BUFFER_SIZE,
489 ems_usb_read_bulk_callback, dev);
490
491 retval = usb_submit_urb(urb, GFP_ATOMIC);
492
493 if (retval == -ENODEV)
494 netif_device_detach(netdev);
495 else if (retval)
496 dev_err(netdev->dev.parent,
497 "failed resubmitting read bulk urb: %d\n", retval);
498}
499
500/*
501 * callback for bulk IN urb
502 */
503static void ems_usb_write_bulk_callback(struct urb *urb)
504{
505 struct ems_tx_urb_context *context = urb->context;
506 struct ems_usb *dev;
507 struct net_device *netdev;
508
509 BUG_ON(!context);
510
511 dev = context->dev;
512 netdev = dev->netdev;
513
514 /* free up our allocated buffer */
515 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
516 urb->transfer_buffer, urb->transfer_dma);
517
518 atomic_dec(&dev->active_tx_urbs);
519
520 if (!netif_device_present(netdev))
521 return;
522
523 if (urb->status)
524 dev_info(netdev->dev.parent, "Tx URB aborted (%d)\n",
525 urb->status);
526
527 netdev->trans_start = jiffies;
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 if (netif_queue_stopped(netdev))
539 netif_wake_queue(netdev);
540}
541
542/*
543 * Send the given CPC command synchronously
544 */
545static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
546{
547 int actual_length;
548
549 /* Copy payload */
550 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
551 msg->length + CPC_MSG_HEADER_LEN);
552
553 /* Clear header */
554 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
555
556 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
557 &dev->tx_msg_buffer[0],
558 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
559 &actual_length, 1000);
560}
561
562/*
563 * Change CAN controllers' mode register
564 */
565static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
566{
567 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
568
569 return ems_usb_command_msg(dev, &dev->active_params);
570}
571
572/*
573 * Send a CPC_Control command to change behaviour when interface receives a CAN
574 * message, bus error or CAN state changed notifications.
575 */
576static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
577{
578 struct ems_cpc_msg cmd;
579
580 cmd.type = CPC_CMD_TYPE_CONTROL;
581 cmd.length = CPC_MSG_HEADER_LEN + 1;
582
583 cmd.msgid = 0;
584
585 cmd.msg.generic[0] = val;
586
587 return ems_usb_command_msg(dev, &cmd);
588}
589
590/*
591 * Start interface
592 */
593static int ems_usb_start(struct ems_usb *dev)
594{
595 struct net_device *netdev = dev->netdev;
596 int err, i;
597
598 dev->intr_in_buffer[0] = 0;
599 dev->free_slots = 15; /* initial size */
600
601 for (i = 0; i < MAX_RX_URBS; i++) {
602 struct urb *urb = NULL;
603 u8 *buf = NULL;
604
605 /* create a URB, and a buffer for it */
606 urb = usb_alloc_urb(0, GFP_KERNEL);
607 if (!urb) {
608 dev_err(netdev->dev.parent,
609 "No memory left for URBs\n");
610 return -ENOMEM;
611 }
612
613 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
614 &urb->transfer_dma);
615 if (!buf) {
616 dev_err(netdev->dev.parent,
617 "No memory left for USB buffer\n");
618 usb_free_urb(urb);
619 return -ENOMEM;
620 }
621
622 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
623 buf, RX_BUFFER_SIZE,
624 ems_usb_read_bulk_callback, dev);
625 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
626 usb_anchor_urb(urb, &dev->rx_submitted);
627
628 err = usb_submit_urb(urb, GFP_KERNEL);
629 if (err) {
630 if (err == -ENODEV)
631 netif_device_detach(dev->netdev);
632
633 usb_unanchor_urb(urb);
634 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
635 urb->transfer_dma);
636 break;
637 }
638
639 /* Drop reference, USB core will take care of freeing it */
640 usb_free_urb(urb);
641 }
642
643 /* Did we submit any URBs */
644 if (i == 0) {
645 dev_warn(netdev->dev.parent, "couldn't setup read URBs\n");
646 return err;
647 }
648
649 /* Warn if we've couldn't transmit all the URBs */
650 if (i < MAX_RX_URBS)
651 dev_warn(netdev->dev.parent, "rx performance may be slow\n");
652
653 /* Setup and start interrupt URB */
654 usb_fill_int_urb(dev->intr_urb, dev->udev,
655 usb_rcvintpipe(dev->udev, 1),
656 dev->intr_in_buffer,
657 INTR_IN_BUFFER_SIZE,
658 ems_usb_read_interrupt_callback, dev, 1);
659
660 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
661 if (err) {
662 if (err == -ENODEV)
663 netif_device_detach(dev->netdev);
664
665 dev_warn(netdev->dev.parent, "intr URB submit failed: %d\n",
666 err);
667
668 return err;
669 }
670
671 /* CPC-USB will transfer received message to host */
672 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
673 if (err)
674 goto failed;
675
676 /* CPC-USB will transfer CAN state changes to host */
677 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
678 if (err)
679 goto failed;
680
681 /* CPC-USB will transfer bus errors to host */
682 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
683 if (err)
684 goto failed;
685
686 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
687 if (err)
688 goto failed;
689
690 dev->can.state = CAN_STATE_ERROR_ACTIVE;
691
692 return 0;
693
694failed:
695 if (err == -ENODEV)
696 netif_device_detach(dev->netdev);
697
698 dev_warn(netdev->dev.parent, "couldn't submit control: %d\n", err);
699
700 return err;
701}
702
703static void unlink_all_urbs(struct ems_usb *dev)
704{
705 int i;
706
707 usb_unlink_urb(dev->intr_urb);
708
709 usb_kill_anchored_urbs(&dev->rx_submitted);
710
711 usb_kill_anchored_urbs(&dev->tx_submitted);
712 atomic_set(&dev->active_tx_urbs, 0);
713
714 for (i = 0; i < MAX_TX_URBS; i++)
715 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
716}
717
718static int ems_usb_open(struct net_device *netdev)
719{
720 struct ems_usb *dev = netdev_priv(netdev);
721 int err;
722
723 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
724 if (err)
725 return err;
726
727 /* common open */
728 err = open_candev(netdev);
729 if (err)
730 return err;
731
732 /* finally start device */
733 err = ems_usb_start(dev);
734 if (err) {
735 if (err == -ENODEV)
736 netif_device_detach(dev->netdev);
737
738 dev_warn(netdev->dev.parent, "couldn't start device: %d\n",
739 err);
740
741 close_candev(netdev);
742
743 return err;
744 }
745
746 dev->open_time = jiffies;
747
748 netif_start_queue(netdev);
749
750 return 0;
751}
752
753static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
754{
755 struct ems_usb *dev = netdev_priv(netdev);
756 struct ems_tx_urb_context *context = NULL;
757 struct net_device_stats *stats = &netdev->stats;
758 struct can_frame *cf = (struct can_frame *)skb->data;
759 struct ems_cpc_msg *msg;
760 struct urb *urb;
761 u8 *buf;
762 int i, err;
763 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
764 + sizeof(struct cpc_can_msg);
765
766 if (can_dropped_invalid_skb(netdev, skb))
767 return NETDEV_TX_OK;
768
769 /* create a URB, and a buffer for it, and copy the data to the URB */
770 urb = usb_alloc_urb(0, GFP_ATOMIC);
771 if (!urb) {
772 dev_err(netdev->dev.parent, "No memory left for URBs\n");
773 goto nomem;
774 }
775
776 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
777 if (!buf) {
778 dev_err(netdev->dev.parent, "No memory left for USB buffer\n");
779 usb_free_urb(urb);
780 goto nomem;
781 }
782
783 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
784
785 msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK;
786 msg->msg.can_msg.length = cf->can_dlc;
787
788 if (cf->can_id & CAN_RTR_FLAG) {
789 msg->type = cf->can_id & CAN_EFF_FLAG ?
790 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
791
792 msg->length = CPC_CAN_MSG_MIN_SIZE;
793 } else {
794 msg->type = cf->can_id & CAN_EFF_FLAG ?
795 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
796
797 for (i = 0; i < cf->can_dlc; i++)
798 msg->msg.can_msg.msg[i] = cf->data[i];
799
800 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
801 }
802
803 /* Respect byte order */
804 msg->msg.can_msg.id = cpu_to_le32(msg->msg.can_msg.id);
805
806 for (i = 0; i < MAX_TX_URBS; i++) {
807 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
808 context = &dev->tx_contexts[i];
809 break;
810 }
811 }
812
813 /*
814 * May never happen! When this happens we'd more URBs in flight as
815 * allowed (MAX_TX_URBS).
816 */
817 if (!context) {
818 usb_unanchor_urb(urb);
819 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
820
821 dev_warn(netdev->dev.parent, "couldn't find free context\n");
822
823 return NETDEV_TX_BUSY;
824 }
825
826 context->dev = dev;
827 context->echo_index = i;
828 context->dlc = cf->can_dlc;
829
830 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
831 size, ems_usb_write_bulk_callback, context);
832 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
833 usb_anchor_urb(urb, &dev->tx_submitted);
834
835 can_put_echo_skb(skb, netdev, context->echo_index);
836
837 atomic_inc(&dev->active_tx_urbs);
838
839 err = usb_submit_urb(urb, GFP_ATOMIC);
840 if (unlikely(err)) {
841 can_free_echo_skb(netdev, context->echo_index);
842
843 usb_unanchor_urb(urb);
844 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
845 dev_kfree_skb(skb);
846
847 atomic_dec(&dev->active_tx_urbs);
848
849 if (err == -ENODEV) {
850 netif_device_detach(netdev);
851 } else {
852 dev_warn(netdev->dev.parent, "failed tx_urb %d\n", err);
853
854 stats->tx_dropped++;
855 }
856 } else {
857 netdev->trans_start = jiffies;
858
859 /* Slow down tx path */
860 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
861 dev->free_slots < 5) {
862 netif_stop_queue(netdev);
863 }
864 }
865
866 /*
867 * Release our reference to this URB, the USB core will eventually free
868 * it entirely.
869 */
870 usb_free_urb(urb);
871
872 return NETDEV_TX_OK;
873
874nomem:
875 dev_kfree_skb(skb);
876 stats->tx_dropped++;
877
878 return NETDEV_TX_OK;
879}
880
881static int ems_usb_close(struct net_device *netdev)
882{
883 struct ems_usb *dev = netdev_priv(netdev);
884
885 /* Stop polling */
886 unlink_all_urbs(dev);
887
888 netif_stop_queue(netdev);
889
890 /* Set CAN controller to reset mode */
891 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
892 dev_warn(netdev->dev.parent, "couldn't stop device");
893
894 close_candev(netdev);
895
896 dev->open_time = 0;
897
898 return 0;
899}
900
901static const struct net_device_ops ems_usb_netdev_ops = {
902 .ndo_open = ems_usb_open,
903 .ndo_stop = ems_usb_close,
904 .ndo_start_xmit = ems_usb_start_xmit,
905};
906
907static struct can_bittiming_const ems_usb_bittiming_const = {
908 .name = "ems_usb",
909 .tseg1_min = 1,
910 .tseg1_max = 16,
911 .tseg2_min = 1,
912 .tseg2_max = 8,
913 .sjw_max = 4,
914 .brp_min = 1,
915 .brp_max = 64,
916 .brp_inc = 1,
917};
918
919static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
920{
921 struct ems_usb *dev = netdev_priv(netdev);
922
923 if (!dev->open_time)
924 return -EINVAL;
925
926 switch (mode) {
927 case CAN_MODE_START:
928 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
929 dev_warn(netdev->dev.parent, "couldn't start device");
930
931 if (netif_queue_stopped(netdev))
932 netif_wake_queue(netdev);
933 break;
934
935 default:
936 return -EOPNOTSUPP;
937 }
938
939 return 0;
940}
941
942static int ems_usb_set_bittiming(struct net_device *netdev)
943{
944 struct ems_usb *dev = netdev_priv(netdev);
945 struct can_bittiming *bt = &dev->can.bittiming;
946 u8 btr0, btr1;
947
948 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
949 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
950 (((bt->phase_seg2 - 1) & 0x7) << 4);
951 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
952 btr1 |= 0x80;
953
954 dev_info(netdev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n",
955 btr0, btr1);
956
957 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
958 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
959
960 return ems_usb_command_msg(dev, &dev->active_params);
961}
962
963static void init_params_sja1000(struct ems_cpc_msg *msg)
964{
965 struct cpc_sja1000_params *sja1000 =
966 &msg->msg.can_params.cc_params.sja1000;
967
968 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
969 msg->length = sizeof(struct cpc_can_params);
970 msg->msgid = 0;
971
972 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
973
974 /* Acceptance filter open */
975 sja1000->acc_code0 = 0x00;
976 sja1000->acc_code1 = 0x00;
977 sja1000->acc_code2 = 0x00;
978 sja1000->acc_code3 = 0x00;
979
980 /* Acceptance filter open */
981 sja1000->acc_mask0 = 0xFF;
982 sja1000->acc_mask1 = 0xFF;
983 sja1000->acc_mask2 = 0xFF;
984 sja1000->acc_mask3 = 0xFF;
985
986 sja1000->btr0 = 0;
987 sja1000->btr1 = 0;
988
989 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
990 sja1000->mode = SJA1000_MOD_RM;
991}
992
993/*
994 * probe function for new CPC-USB devices
995 */
996static int ems_usb_probe(struct usb_interface *intf,
997 const struct usb_device_id *id)
998{
999 struct net_device *netdev;
1000 struct ems_usb *dev;
1001 int i, err = -ENOMEM;
1002
1003 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
1004 if (!netdev) {
1005 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
1006 return -ENOMEM;
1007 }
1008
1009 dev = netdev_priv(netdev);
1010
1011 dev->udev = interface_to_usbdev(intf);
1012 dev->netdev = netdev;
1013
1014 dev->can.state = CAN_STATE_STOPPED;
1015 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1016 dev->can.bittiming_const = &ems_usb_bittiming_const;
1017 dev->can.do_set_bittiming = ems_usb_set_bittiming;
1018 dev->can.do_set_mode = ems_usb_set_mode;
1019 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
1020
1021 netdev->netdev_ops = &ems_usb_netdev_ops;
1022
1023 netdev->flags |= IFF_ECHO; /* we support local echo */
1024
1025 init_usb_anchor(&dev->rx_submitted);
1026
1027 init_usb_anchor(&dev->tx_submitted);
1028 atomic_set(&dev->active_tx_urbs, 0);
1029
1030 for (i = 0; i < MAX_TX_URBS; i++)
1031 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1032
1033 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1034 if (!dev->intr_urb) {
1035 dev_err(&intf->dev, "Couldn't alloc intr URB\n");
1036 goto cleanup_candev;
1037 }
1038
1039 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1040 if (!dev->intr_in_buffer) {
1041 dev_err(&intf->dev, "Couldn't alloc Intr buffer\n");
1042 goto cleanup_intr_urb;
1043 }
1044
1045 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1046 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1047 if (!dev->tx_msg_buffer) {
1048 dev_err(&intf->dev, "Couldn't alloc Tx buffer\n");
1049 goto cleanup_intr_in_buffer;
1050 }
1051
1052 usb_set_intfdata(intf, dev);
1053
1054 SET_NETDEV_DEV(netdev, &intf->dev);
1055
1056 init_params_sja1000(&dev->active_params);
1057
1058 err = ems_usb_command_msg(dev, &dev->active_params);
1059 if (err) {
1060 dev_err(netdev->dev.parent,
1061 "couldn't initialize controller: %d\n", err);
1062 goto cleanup_tx_msg_buffer;
1063 }
1064
1065 err = register_candev(netdev);
1066 if (err) {
1067 dev_err(netdev->dev.parent,
1068 "couldn't register CAN device: %d\n", err);
1069 goto cleanup_tx_msg_buffer;
1070 }
1071
1072 return 0;
1073
1074cleanup_tx_msg_buffer:
1075 kfree(dev->tx_msg_buffer);
1076
1077cleanup_intr_in_buffer:
1078 kfree(dev->intr_in_buffer);
1079
1080cleanup_intr_urb:
1081 usb_free_urb(dev->intr_urb);
1082
1083cleanup_candev:
1084 free_candev(netdev);
1085
1086 return err;
1087}
1088
1089/*
1090 * called by the usb core when the device is removed from the system
1091 */
1092static void ems_usb_disconnect(struct usb_interface *intf)
1093{
1094 struct ems_usb *dev = usb_get_intfdata(intf);
1095
1096 usb_set_intfdata(intf, NULL);
1097
1098 if (dev) {
1099 unregister_netdev(dev->netdev);
1100 free_candev(dev->netdev);
1101
1102 unlink_all_urbs(dev);
1103
1104 usb_free_urb(dev->intr_urb);
1105
1106 kfree(dev->intr_in_buffer);
1107 }
1108}
1109
1110/* usb specific object needed to register this driver with the usb subsystem */
1111static struct usb_driver ems_usb_driver = {
1112 .name = "ems_usb",
1113 .probe = ems_usb_probe,
1114 .disconnect = ems_usb_disconnect,
1115 .id_table = ems_usb_table,
1116};
1117
1118static int __init ems_usb_init(void)
1119{
1120 int err;
1121
1122 printk(KERN_INFO "CPC-USB kernel driver loaded\n");
1123
1124 /* register this driver with the USB subsystem */
1125 err = usb_register(&ems_usb_driver);
1126
1127 if (err) {
1128 err("usb_register failed. Error number %d\n", err);
1129 return err;
1130 }
1131
1132 return 0;
1133}
1134
1135static void __exit ems_usb_exit(void)
1136{
1137 /* deregister this driver with the USB subsystem */
1138 usb_deregister(&ems_usb_driver);
1139}
1140
1141module_init(ems_usb_init);
1142module_exit(ems_usb_exit);
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);