1 /*
2 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7
3 *
4 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published
8 * by the Free Software Foundation; version 2 of the License.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19 #include <linux/signal.h>
20 #include <linux/slab.h>
21 #include <linux/module.h>
22 #include <linux/netdevice.h>
23 #include <linux/usb.h>
24
25 #include <linux/can.h>
26 #include <linux/can/dev.h>
27 #include <linux/can/error.h>
28
29 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
30 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
31 MODULE_LICENSE("GPL v2");
32
33 /* Control-Values for CPC_Control() Command Subject Selection */
34 #define CONTR_CAN_MESSAGE 0x04
35 #define CONTR_CAN_STATE 0x0C
36 #define CONTR_BUS_ERROR 0x1C
37
38 /* Control Command Actions */
39 #define CONTR_CONT_OFF 0
40 #define CONTR_CONT_ON 1
41 #define CONTR_ONCE 2
42
43 /* Messages from CPC to PC */
44 #define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */
45 #define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */
46 #define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */
47 #define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */
48 #define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */
49 #define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */
50 #define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */
51 #define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */
52 #define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */
53 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
54 #define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */
55
56 /* Messages from the PC to the CPC interface */
57 #define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */
58 #define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */
59 #define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */
60 #define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */
61 #define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */
62 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */
63 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */
64 #define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */
65
66 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
67 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */
68 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
69
70 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
71
72 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
73
74 /* Overrun types */
75 #define CPC_OVR_EVENT_CAN 0x01
76 #define CPC_OVR_EVENT_CANSTATE 0x02
77 #define CPC_OVR_EVENT_BUSERROR 0x04
78
79 /*
80 * If the CAN controller lost a message we indicate it with the highest bit
81 * set in the count field.
82 */
83 #define CPC_OVR_HW 0x80
84
85 /* Size of the "struct ems_cpc_msg" without the union */
86 #define CPC_MSG_HEADER_LEN 11
87 #define CPC_CAN_MSG_MIN_SIZE 5
88
89 /* Define these values to match your devices */
90 #define USB_CPCUSB_VENDOR_ID 0x12D6
91
92 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
93
94 /* Mode register NXP LPC2119/SJA1000 CAN Controller */
95 #define SJA1000_MOD_NORMAL 0x00
96 #define SJA1000_MOD_RM 0x01
97
98 /* ECC register NXP LPC2119/SJA1000 CAN Controller */
99 #define SJA1000_ECC_SEG 0x1F
100 #define SJA1000_ECC_DIR 0x20
101 #define SJA1000_ECC_ERR 0x06
102 #define SJA1000_ECC_BIT 0x00
103 #define SJA1000_ECC_FORM 0x40
104 #define SJA1000_ECC_STUFF 0x80
105 #define SJA1000_ECC_MASK 0xc0
106
107 /* Status register content */
108 #define SJA1000_SR_BS 0x80
109 #define SJA1000_SR_ES 0x40
110
111 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
112
113 /*
114 * The device actually uses a 16MHz clock to generate the CAN clock
115 * but it expects SJA1000 bit settings based on 8MHz (is internally
116 * converted).
117 */
118 #define EMS_USB_ARM7_CLOCK 8000000
119
120 #define CPC_TX_QUEUE_TRIGGER_LOW 25
121 #define CPC_TX_QUEUE_TRIGGER_HIGH 35
122
123 /*
124 * CAN-Message representation in a CPC_MSG. Message object type is
125 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
126 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
127 */
128 struct cpc_can_msg {
129 __le32 id;
130 u8 length;
131 u8 msg[8];
132 };
133
134 /* Representation of the CAN parameters for the SJA1000 controller */
135 struct cpc_sja1000_params {
136 u8 mode;
137 u8 acc_code0;
138 u8 acc_code1;
139 u8 acc_code2;
140 u8 acc_code3;
141 u8 acc_mask0;
142 u8 acc_mask1;
143 u8 acc_mask2;
144 u8 acc_mask3;
145 u8 btr0;
146 u8 btr1;
147 u8 outp_contr;
148 };
149
150 /* CAN params message representation */
151 struct cpc_can_params {
152 u8 cc_type;
153
154 /* Will support M16C CAN controller in the future */
155 union {
156 struct cpc_sja1000_params sja1000;
157 } cc_params;
158 };
159
160 /* Structure for confirmed message handling */
161 struct cpc_confirm {
162 u8 error; /* error code */
163 };
164
165 /* Structure for overrun conditions */
166 struct cpc_overrun {
167 u8 event;
168 u8 count;
169 };
170
171 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
172 struct cpc_sja1000_can_error {
173 u8 ecc;
174 u8 rxerr;
175 u8 txerr;
176 };
177
178 /* structure for CAN error conditions */
179 struct cpc_can_error {
180 u8 ecode;
181
182 struct {
183 u8 cc_type;
184
185 /* Other controllers may also provide error code capture regs */
186 union {
187 struct cpc_sja1000_can_error sja1000;
188 } regs;
189 } cc;
190 };
191
192 /*
193 * Structure containing RX/TX error counter. This structure is used to request
194 * the values of the CAN controllers TX and RX error counter.
195 */
196 struct cpc_can_err_counter {
197 u8 rx;
198 u8 tx;
199 };
200
201 /* Main message type used between library and application */
202 struct __packed ems_cpc_msg {
203 u8 type; /* type of message */
204 u8 length; /* length of data within union 'msg' */
205 u8 msgid; /* confirmation handle */
206 __le32 ts_sec; /* timestamp in seconds */
207 __le32 ts_nsec; /* timestamp in nano seconds */
208
209 union {
210 u8 generic[64];
211 struct cpc_can_msg can_msg;
212 struct cpc_can_params can_params;
213 struct cpc_confirm confirmation;
214 struct cpc_overrun overrun;
215 struct cpc_can_error error;
216 struct cpc_can_err_counter err_counter;
217 u8 can_state;
218 } msg;
219 };
220
221 /*
222 * Table of devices that work with this driver
223 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
224 */
225 static struct usb_device_id ems_usb_table[] = {
226 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
227 {} /* Terminating entry */
228 };
229
230 MODULE_DEVICE_TABLE(usb, ems_usb_table);
231
232 #define RX_BUFFER_SIZE 64
233 #define CPC_HEADER_SIZE 4
234 #define INTR_IN_BUFFER_SIZE 4
235
236 #define MAX_RX_URBS 10
237 #define MAX_TX_URBS 10
238
239 struct ems_usb;
240
241 struct ems_tx_urb_context {
242 struct ems_usb *dev;
243
244 u32 echo_index;
245 u8 dlc;
246 };
247
248 struct ems_usb {
249 struct can_priv can; /* must be the first member */
250
251 struct sk_buff *echo_skb[MAX_TX_URBS];
252
253 struct usb_device *udev;
254 struct net_device *netdev;
255
256 atomic_t active_tx_urbs;
257 struct usb_anchor tx_submitted;
258 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
259
260 struct usb_anchor rx_submitted;
261
262 struct urb *intr_urb;
263
264 u8 *tx_msg_buffer;
265
266 u8 *intr_in_buffer;
267 unsigned int free_slots; /* remember number of available slots */
268
269 struct ems_cpc_msg active_params; /* active controller parameters */
270 };
271
ems_usb_read_interrupt_callback(struct urb * urb)272 static void ems_usb_read_interrupt_callback(struct urb *urb)
273 {
274 struct ems_usb *dev = urb->context;
275 struct net_device *netdev = dev->netdev;
276 int err;
277
278 if (!netif_device_present(netdev))
279 return;
280
281 switch (urb->status) {
282 case 0:
283 dev->free_slots = dev->intr_in_buffer[1];
284 if(dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH){
285 if (netif_queue_stopped(netdev)){
286 netif_wake_queue(netdev);
287 }
288 }
289 break;
290
291 case -ECONNRESET: /* unlink */
292 case -ENOENT:
293 case -ESHUTDOWN:
294 return;
295
296 default:
297 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
298 break;
299 }
300
301 err = usb_submit_urb(urb, GFP_ATOMIC);
302
303 if (err == -ENODEV)
304 netif_device_detach(netdev);
305 else if (err)
306 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
307 }
308
ems_usb_rx_can_msg(struct ems_usb * dev,struct ems_cpc_msg * msg)309 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
310 {
311 struct can_frame *cf;
312 struct sk_buff *skb;
313 int i;
314 struct net_device_stats *stats = &dev->netdev->stats;
315
316 skb = alloc_can_skb(dev->netdev, &cf);
317 if (skb == NULL)
318 return;
319
320 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
321 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
322
323 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
324 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
325 cf->can_id |= CAN_EFF_FLAG;
326
327 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
328 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
329 cf->can_id |= CAN_RTR_FLAG;
330 } else {
331 for (i = 0; i < cf->can_dlc; i++)
332 cf->data[i] = msg->msg.can_msg.msg[i];
333 }
334
335 netif_rx(skb);
336
337 stats->rx_packets++;
338 stats->rx_bytes += cf->can_dlc;
339 }
340
ems_usb_rx_err(struct ems_usb * dev,struct ems_cpc_msg * msg)341 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
342 {
343 struct can_frame *cf;
344 struct sk_buff *skb;
345 struct net_device_stats *stats = &dev->netdev->stats;
346
347 skb = alloc_can_err_skb(dev->netdev, &cf);
348 if (skb == NULL)
349 return;
350
351 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
352 u8 state = msg->msg.can_state;
353
354 if (state & SJA1000_SR_BS) {
355 dev->can.state = CAN_STATE_BUS_OFF;
356 cf->can_id |= CAN_ERR_BUSOFF;
357
358 dev->can.can_stats.bus_off++;
359 can_bus_off(dev->netdev);
360 } else if (state & SJA1000_SR_ES) {
361 dev->can.state = CAN_STATE_ERROR_WARNING;
362 dev->can.can_stats.error_warning++;
363 } else {
364 dev->can.state = CAN_STATE_ERROR_ACTIVE;
365 dev->can.can_stats.error_passive++;
366 }
367 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
368 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
369 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
370 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
371
372 /* bus error interrupt */
373 dev->can.can_stats.bus_error++;
374 stats->rx_errors++;
375
376 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
377
378 switch (ecc & SJA1000_ECC_MASK) {
379 case SJA1000_ECC_BIT:
380 cf->data[2] |= CAN_ERR_PROT_BIT;
381 break;
382 case SJA1000_ECC_FORM:
383 cf->data[2] |= CAN_ERR_PROT_FORM;
384 break;
385 case SJA1000_ECC_STUFF:
386 cf->data[2] |= CAN_ERR_PROT_STUFF;
387 break;
388 default:
389 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
390 cf->data[3] = ecc & SJA1000_ECC_SEG;
391 break;
392 }
393
394 /* Error occurred during transmission? */
395 if ((ecc & SJA1000_ECC_DIR) == 0)
396 cf->data[2] |= CAN_ERR_PROT_TX;
397
398 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
399 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
400 cf->data[1] = (txerr > rxerr) ?
401 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
402 }
403 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
404 cf->can_id |= CAN_ERR_CRTL;
405 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
406
407 stats->rx_over_errors++;
408 stats->rx_errors++;
409 }
410
411 netif_rx(skb);
412
413 stats->rx_packets++;
414 stats->rx_bytes += cf->can_dlc;
415 }
416
417 /*
418 * callback for bulk IN urb
419 */
ems_usb_read_bulk_callback(struct urb * urb)420 static void ems_usb_read_bulk_callback(struct urb *urb)
421 {
422 struct ems_usb *dev = urb->context;
423 struct net_device *netdev;
424 int retval;
425
426 netdev = dev->netdev;
427
428 if (!netif_device_present(netdev))
429 return;
430
431 switch (urb->status) {
432 case 0: /* success */
433 break;
434
435 case -ENOENT:
436 return;
437
438 default:
439 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
440 goto resubmit_urb;
441 }
442
443 if (urb->actual_length > CPC_HEADER_SIZE) {
444 struct ems_cpc_msg *msg;
445 u8 *ibuf = urb->transfer_buffer;
446 u8 msg_count, start;
447
448 msg_count = ibuf[0] & ~0x80;
449
450 start = CPC_HEADER_SIZE;
451
452 while (msg_count) {
453 msg = (struct ems_cpc_msg *)&ibuf[start];
454
455 switch (msg->type) {
456 case CPC_MSG_TYPE_CAN_STATE:
457 /* Process CAN state changes */
458 ems_usb_rx_err(dev, msg);
459 break;
460
461 case CPC_MSG_TYPE_CAN_FRAME:
462 case CPC_MSG_TYPE_EXT_CAN_FRAME:
463 case CPC_MSG_TYPE_RTR_FRAME:
464 case CPC_MSG_TYPE_EXT_RTR_FRAME:
465 ems_usb_rx_can_msg(dev, msg);
466 break;
467
468 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
469 /* Process errorframe */
470 ems_usb_rx_err(dev, msg);
471 break;
472
473 case CPC_MSG_TYPE_OVERRUN:
474 /* Message lost while receiving */
475 ems_usb_rx_err(dev, msg);
476 break;
477 }
478
479 start += CPC_MSG_HEADER_LEN + msg->length;
480 msg_count--;
481
482 if (start > urb->transfer_buffer_length) {
483 netdev_err(netdev, "format error\n");
484 break;
485 }
486 }
487 }
488
489 resubmit_urb:
490 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
491 urb->transfer_buffer, RX_BUFFER_SIZE,
492 ems_usb_read_bulk_callback, dev);
493
494 retval = usb_submit_urb(urb, GFP_ATOMIC);
495
496 if (retval == -ENODEV)
497 netif_device_detach(netdev);
498 else if (retval)
499 netdev_err(netdev,
500 "failed resubmitting read bulk urb: %d\n", retval);
501 }
502
503 /*
504 * callback for bulk IN urb
505 */
ems_usb_write_bulk_callback(struct urb * urb)506 static void ems_usb_write_bulk_callback(struct urb *urb)
507 {
508 struct ems_tx_urb_context *context = urb->context;
509 struct ems_usb *dev;
510 struct net_device *netdev;
511
512 BUG_ON(!context);
513
514 dev = context->dev;
515 netdev = dev->netdev;
516
517 /* free up our allocated buffer */
518 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
519 urb->transfer_buffer, urb->transfer_dma);
520
521 atomic_dec(&dev->active_tx_urbs);
522
523 if (!netif_device_present(netdev))
524 return;
525
526 if (urb->status)
527 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
528
529 netdev->trans_start = jiffies;
530
531 /* transmission complete interrupt */
532 netdev->stats.tx_packets++;
533 netdev->stats.tx_bytes += context->dlc;
534
535 can_get_echo_skb(netdev, context->echo_index);
536
537 /* Release context */
538 context->echo_index = MAX_TX_URBS;
539
540 }
541
542 /*
543 * Send the given CPC command synchronously
544 */
ems_usb_command_msg(struct ems_usb * dev,struct ems_cpc_msg * msg)545 static 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 */
ems_usb_write_mode(struct ems_usb * dev,u8 mode)565 static 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 */
ems_usb_control_cmd(struct ems_usb * dev,u8 val)576 static 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 */
ems_usb_start(struct ems_usb * dev)593 static 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 = 50; /* 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 netdev_err(netdev, "No memory left for URBs\n");
609 err = -ENOMEM;
610 break;
611 }
612
613 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
614 &urb->transfer_dma);
615 if (!buf) {
616 netdev_err(netdev, "No memory left for USB buffer\n");
617 usb_free_urb(urb);
618 err = -ENOMEM;
619 break;
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 usb_unanchor_urb(urb);
631 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
632 urb->transfer_dma);
633 usb_free_urb(urb);
634 break;
635 }
636
637 /* Drop reference, USB core will take care of freeing it */
638 usb_free_urb(urb);
639 }
640
641 /* Did we submit any URBs */
642 if (i == 0) {
643 netdev_warn(netdev, "couldn't setup read URBs\n");
644 return err;
645 }
646
647 /* Warn if we've couldn't transmit all the URBs */
648 if (i < MAX_RX_URBS)
649 netdev_warn(netdev, "rx performance may be slow\n");
650
651 /* Setup and start interrupt URB */
652 usb_fill_int_urb(dev->intr_urb, dev->udev,
653 usb_rcvintpipe(dev->udev, 1),
654 dev->intr_in_buffer,
655 INTR_IN_BUFFER_SIZE,
656 ems_usb_read_interrupt_callback, dev, 1);
657
658 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
659 if (err) {
660 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
661
662 return err;
663 }
664
665 /* CPC-USB will transfer received message to host */
666 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
667 if (err)
668 goto failed;
669
670 /* CPC-USB will transfer CAN state changes to host */
671 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
672 if (err)
673 goto failed;
674
675 /* CPC-USB will transfer bus errors to host */
676 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
677 if (err)
678 goto failed;
679
680 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
681 if (err)
682 goto failed;
683
684 dev->can.state = CAN_STATE_ERROR_ACTIVE;
685
686 return 0;
687
688 failed:
689 netdev_warn(netdev, "couldn't submit control: %d\n", err);
690
691 return err;
692 }
693
unlink_all_urbs(struct ems_usb * dev)694 static void unlink_all_urbs(struct ems_usb *dev)
695 {
696 int i;
697
698 usb_unlink_urb(dev->intr_urb);
699
700 usb_kill_anchored_urbs(&dev->rx_submitted);
701
702 usb_kill_anchored_urbs(&dev->tx_submitted);
703 atomic_set(&dev->active_tx_urbs, 0);
704
705 for (i = 0; i < MAX_TX_URBS; i++)
706 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
707 }
708
ems_usb_open(struct net_device * netdev)709 static int ems_usb_open(struct net_device *netdev)
710 {
711 struct ems_usb *dev = netdev_priv(netdev);
712 int err;
713
714 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
715 if (err)
716 return err;
717
718 /* common open */
719 err = open_candev(netdev);
720 if (err)
721 return err;
722
723 /* finally start device */
724 err = ems_usb_start(dev);
725 if (err) {
726 if (err == -ENODEV)
727 netif_device_detach(dev->netdev);
728
729 netdev_warn(netdev, "couldn't start device: %d\n", err);
730
731 close_candev(netdev);
732
733 return err;
734 }
735
736
737 netif_start_queue(netdev);
738
739 return 0;
740 }
741
ems_usb_start_xmit(struct sk_buff * skb,struct net_device * netdev)742 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
743 {
744 struct ems_usb *dev = netdev_priv(netdev);
745 struct ems_tx_urb_context *context = NULL;
746 struct net_device_stats *stats = &netdev->stats;
747 struct can_frame *cf = (struct can_frame *)skb->data;
748 struct ems_cpc_msg *msg;
749 struct urb *urb;
750 u8 *buf;
751 int i, err;
752 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
753 + sizeof(struct cpc_can_msg);
754
755 if (can_dropped_invalid_skb(netdev, skb))
756 return NETDEV_TX_OK;
757
758 /* create a URB, and a buffer for it, and copy the data to the URB */
759 urb = usb_alloc_urb(0, GFP_ATOMIC);
760 if (!urb) {
761 netdev_err(netdev, "No memory left for URBs\n");
762 goto nomem;
763 }
764
765 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
766 if (!buf) {
767 netdev_err(netdev, "No memory left for USB buffer\n");
768 usb_free_urb(urb);
769 goto nomem;
770 }
771
772 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
773
774 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
775 msg->msg.can_msg.length = cf->can_dlc;
776
777 if (cf->can_id & CAN_RTR_FLAG) {
778 msg->type = cf->can_id & CAN_EFF_FLAG ?
779 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
780
781 msg->length = CPC_CAN_MSG_MIN_SIZE;
782 } else {
783 msg->type = cf->can_id & CAN_EFF_FLAG ?
784 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
785
786 for (i = 0; i < cf->can_dlc; i++)
787 msg->msg.can_msg.msg[i] = cf->data[i];
788
789 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
790 }
791
792 for (i = 0; i < MAX_TX_URBS; i++) {
793 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
794 context = &dev->tx_contexts[i];
795 break;
796 }
797 }
798
799 /*
800 * May never happen! When this happens we'd more URBs in flight as
801 * allowed (MAX_TX_URBS).
802 */
803 if (!context) {
804 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
805 usb_free_urb(urb);
806
807 netdev_warn(netdev, "couldn't find free context\n");
808
809 return NETDEV_TX_BUSY;
810 }
811
812 context->dev = dev;
813 context->echo_index = i;
814 context->dlc = cf->can_dlc;
815
816 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
817 size, ems_usb_write_bulk_callback, context);
818 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
819 usb_anchor_urb(urb, &dev->tx_submitted);
820
821 can_put_echo_skb(skb, netdev, context->echo_index);
822
823 atomic_inc(&dev->active_tx_urbs);
824
825 err = usb_submit_urb(urb, GFP_ATOMIC);
826 if (unlikely(err)) {
827 can_free_echo_skb(netdev, context->echo_index);
828
829 usb_unanchor_urb(urb);
830 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
831 dev_kfree_skb(skb);
832
833 atomic_dec(&dev->active_tx_urbs);
834
835 if (err == -ENODEV) {
836 netif_device_detach(netdev);
837 } else {
838 netdev_warn(netdev, "failed tx_urb %d\n", err);
839
840 stats->tx_dropped++;
841 }
842 } else {
843 netdev->trans_start = jiffies;
844
845 /* Slow down tx path */
846 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
847 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
848 netif_stop_queue(netdev);
849 }
850 }
851
852 /*
853 * Release our reference to this URB, the USB core will eventually free
854 * it entirely.
855 */
856 usb_free_urb(urb);
857
858 return NETDEV_TX_OK;
859
860 nomem:
861 dev_kfree_skb(skb);
862 stats->tx_dropped++;
863
864 return NETDEV_TX_OK;
865 }
866
ems_usb_close(struct net_device * netdev)867 static int ems_usb_close(struct net_device *netdev)
868 {
869 struct ems_usb *dev = netdev_priv(netdev);
870
871 /* Stop polling */
872 unlink_all_urbs(dev);
873
874 netif_stop_queue(netdev);
875
876 /* Set CAN controller to reset mode */
877 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
878 netdev_warn(netdev, "couldn't stop device");
879
880 close_candev(netdev);
881
882 return 0;
883 }
884
885 static const struct net_device_ops ems_usb_netdev_ops = {
886 .ndo_open = ems_usb_open,
887 .ndo_stop = ems_usb_close,
888 .ndo_start_xmit = ems_usb_start_xmit,
889 .ndo_change_mtu = can_change_mtu,
890 };
891
892 static const struct can_bittiming_const ems_usb_bittiming_const = {
893 .name = "ems_usb",
894 .tseg1_min = 1,
895 .tseg1_max = 16,
896 .tseg2_min = 1,
897 .tseg2_max = 8,
898 .sjw_max = 4,
899 .brp_min = 1,
900 .brp_max = 64,
901 .brp_inc = 1,
902 };
903
ems_usb_set_mode(struct net_device * netdev,enum can_mode mode)904 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
905 {
906 struct ems_usb *dev = netdev_priv(netdev);
907
908 switch (mode) {
909 case CAN_MODE_START:
910 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
911 netdev_warn(netdev, "couldn't start device");
912
913 if (netif_queue_stopped(netdev))
914 netif_wake_queue(netdev);
915 break;
916
917 default:
918 return -EOPNOTSUPP;
919 }
920
921 return 0;
922 }
923
ems_usb_set_bittiming(struct net_device * netdev)924 static int ems_usb_set_bittiming(struct net_device *netdev)
925 {
926 struct ems_usb *dev = netdev_priv(netdev);
927 struct can_bittiming *bt = &dev->can.bittiming;
928 u8 btr0, btr1;
929
930 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
931 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
932 (((bt->phase_seg2 - 1) & 0x7) << 4);
933 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
934 btr1 |= 0x80;
935
936 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
937
938 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
939 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
940
941 return ems_usb_command_msg(dev, &dev->active_params);
942 }
943
init_params_sja1000(struct ems_cpc_msg * msg)944 static void init_params_sja1000(struct ems_cpc_msg *msg)
945 {
946 struct cpc_sja1000_params *sja1000 =
947 &msg->msg.can_params.cc_params.sja1000;
948
949 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
950 msg->length = sizeof(struct cpc_can_params);
951 msg->msgid = 0;
952
953 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
954
955 /* Acceptance filter open */
956 sja1000->acc_code0 = 0x00;
957 sja1000->acc_code1 = 0x00;
958 sja1000->acc_code2 = 0x00;
959 sja1000->acc_code3 = 0x00;
960
961 /* Acceptance filter open */
962 sja1000->acc_mask0 = 0xFF;
963 sja1000->acc_mask1 = 0xFF;
964 sja1000->acc_mask2 = 0xFF;
965 sja1000->acc_mask3 = 0xFF;
966
967 sja1000->btr0 = 0;
968 sja1000->btr1 = 0;
969
970 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
971 sja1000->mode = SJA1000_MOD_RM;
972 }
973
974 /*
975 * probe function for new CPC-USB devices
976 */
ems_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)977 static int ems_usb_probe(struct usb_interface *intf,
978 const struct usb_device_id *id)
979 {
980 struct net_device *netdev;
981 struct ems_usb *dev;
982 int i, err = -ENOMEM;
983
984 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
985 if (!netdev) {
986 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
987 return -ENOMEM;
988 }
989
990 dev = netdev_priv(netdev);
991
992 dev->udev = interface_to_usbdev(intf);
993 dev->netdev = netdev;
994
995 dev->can.state = CAN_STATE_STOPPED;
996 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
997 dev->can.bittiming_const = &ems_usb_bittiming_const;
998 dev->can.do_set_bittiming = ems_usb_set_bittiming;
999 dev->can.do_set_mode = ems_usb_set_mode;
1000 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
1001
1002 netdev->netdev_ops = &ems_usb_netdev_ops;
1003
1004 netdev->flags |= IFF_ECHO; /* we support local echo */
1005
1006 init_usb_anchor(&dev->rx_submitted);
1007
1008 init_usb_anchor(&dev->tx_submitted);
1009 atomic_set(&dev->active_tx_urbs, 0);
1010
1011 for (i = 0; i < MAX_TX_URBS; i++)
1012 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1013
1014 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1015 if (!dev->intr_urb) {
1016 dev_err(&intf->dev, "Couldn't alloc intr URB\n");
1017 goto cleanup_candev;
1018 }
1019
1020 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1021 if (!dev->intr_in_buffer)
1022 goto cleanup_intr_urb;
1023
1024 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1025 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1026 if (!dev->tx_msg_buffer)
1027 goto cleanup_intr_in_buffer;
1028
1029 usb_set_intfdata(intf, dev);
1030
1031 SET_NETDEV_DEV(netdev, &intf->dev);
1032
1033 init_params_sja1000(&dev->active_params);
1034
1035 err = ems_usb_command_msg(dev, &dev->active_params);
1036 if (err) {
1037 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1038 goto cleanup_tx_msg_buffer;
1039 }
1040
1041 err = register_candev(netdev);
1042 if (err) {
1043 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1044 goto cleanup_tx_msg_buffer;
1045 }
1046
1047 return 0;
1048
1049 cleanup_tx_msg_buffer:
1050 kfree(dev->tx_msg_buffer);
1051
1052 cleanup_intr_in_buffer:
1053 kfree(dev->intr_in_buffer);
1054
1055 cleanup_intr_urb:
1056 usb_free_urb(dev->intr_urb);
1057
1058 cleanup_candev:
1059 free_candev(netdev);
1060
1061 return err;
1062 }
1063
1064 /*
1065 * called by the usb core when the device is removed from the system
1066 */
ems_usb_disconnect(struct usb_interface * intf)1067 static void ems_usb_disconnect(struct usb_interface *intf)
1068 {
1069 struct ems_usb *dev = usb_get_intfdata(intf);
1070
1071 usb_set_intfdata(intf, NULL);
1072
1073 if (dev) {
1074 unregister_netdev(dev->netdev);
1075 free_candev(dev->netdev);
1076
1077 unlink_all_urbs(dev);
1078
1079 usb_free_urb(dev->intr_urb);
1080
1081 kfree(dev->intr_in_buffer);
1082 }
1083 }
1084
1085 /* usb specific object needed to register this driver with the usb subsystem */
1086 static struct usb_driver ems_usb_driver = {
1087 .name = "ems_usb",
1088 .probe = ems_usb_probe,
1089 .disconnect = ems_usb_disconnect,
1090 .id_table = ems_usb_table,
1091 };
1092
1093 module_usb_driver(ems_usb_driver);
1094