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 stats->rx_packets++;
336 stats->rx_bytes += cf->can_dlc;
337 netif_rx(skb);
338 }
339
ems_usb_rx_err(struct ems_usb * dev,struct ems_cpc_msg * msg)340 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
341 {
342 struct can_frame *cf;
343 struct sk_buff *skb;
344 struct net_device_stats *stats = &dev->netdev->stats;
345
346 skb = alloc_can_err_skb(dev->netdev, &cf);
347 if (skb == NULL)
348 return;
349
350 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
351 u8 state = msg->msg.can_state;
352
353 if (state & SJA1000_SR_BS) {
354 dev->can.state = CAN_STATE_BUS_OFF;
355 cf->can_id |= CAN_ERR_BUSOFF;
356
357 dev->can.can_stats.bus_off++;
358 can_bus_off(dev->netdev);
359 } else if (state & SJA1000_SR_ES) {
360 dev->can.state = CAN_STATE_ERROR_WARNING;
361 dev->can.can_stats.error_warning++;
362 } else {
363 dev->can.state = CAN_STATE_ERROR_ACTIVE;
364 dev->can.can_stats.error_passive++;
365 }
366 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
367 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
368 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
369 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
370
371 /* bus error interrupt */
372 dev->can.can_stats.bus_error++;
373 stats->rx_errors++;
374
375 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
376
377 switch (ecc & SJA1000_ECC_MASK) {
378 case SJA1000_ECC_BIT:
379 cf->data[2] |= CAN_ERR_PROT_BIT;
380 break;
381 case SJA1000_ECC_FORM:
382 cf->data[2] |= CAN_ERR_PROT_FORM;
383 break;
384 case SJA1000_ECC_STUFF:
385 cf->data[2] |= CAN_ERR_PROT_STUFF;
386 break;
387 default:
388 cf->data[3] = ecc & SJA1000_ECC_SEG;
389 break;
390 }
391
392 /* Error occurred during transmission? */
393 if ((ecc & SJA1000_ECC_DIR) == 0)
394 cf->data[2] |= CAN_ERR_PROT_TX;
395
396 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
397 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
398 cf->data[1] = (txerr > rxerr) ?
399 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
400 }
401 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
402 cf->can_id |= CAN_ERR_CRTL;
403 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
404
405 stats->rx_over_errors++;
406 stats->rx_errors++;
407 }
408
409 stats->rx_packets++;
410 stats->rx_bytes += cf->can_dlc;
411 netif_rx(skb);
412 }
413
414 /*
415 * callback for bulk IN urb
416 */
ems_usb_read_bulk_callback(struct urb * urb)417 static void ems_usb_read_bulk_callback(struct urb *urb)
418 {
419 struct ems_usb *dev = urb->context;
420 struct net_device *netdev;
421 int retval;
422
423 netdev = dev->netdev;
424
425 if (!netif_device_present(netdev))
426 return;
427
428 switch (urb->status) {
429 case 0: /* success */
430 break;
431
432 case -ENOENT:
433 return;
434
435 default:
436 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
437 goto resubmit_urb;
438 }
439
440 if (urb->actual_length > CPC_HEADER_SIZE) {
441 struct ems_cpc_msg *msg;
442 u8 *ibuf = urb->transfer_buffer;
443 u8 msg_count, start;
444
445 msg_count = 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 netdev_err(netdev, "format error\n");
481 break;
482 }
483 }
484 }
485
486 resubmit_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 netdev_err(netdev,
497 "failed resubmitting read bulk urb: %d\n", retval);
498 }
499
500 /*
501 * callback for bulk IN urb
502 */
ems_usb_write_bulk_callback(struct urb * urb)503 static 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 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
525
526 netdev->trans_start = jiffies;
527
528 /* transmission complete interrupt */
529 netdev->stats.tx_packets++;
530 netdev->stats.tx_bytes += context->dlc;
531
532 can_get_echo_skb(netdev, context->echo_index);
533
534 /* Release context */
535 context->echo_index = MAX_TX_URBS;
536
537 }
538
539 /*
540 * Send the given CPC command synchronously
541 */
ems_usb_command_msg(struct ems_usb * dev,struct ems_cpc_msg * msg)542 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
543 {
544 int actual_length;
545
546 /* Copy payload */
547 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
548 msg->length + CPC_MSG_HEADER_LEN);
549
550 /* Clear header */
551 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
552
553 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
554 &dev->tx_msg_buffer[0],
555 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
556 &actual_length, 1000);
557 }
558
559 /*
560 * Change CAN controllers' mode register
561 */
ems_usb_write_mode(struct ems_usb * dev,u8 mode)562 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
563 {
564 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
565
566 return ems_usb_command_msg(dev, &dev->active_params);
567 }
568
569 /*
570 * Send a CPC_Control command to change behaviour when interface receives a CAN
571 * message, bus error or CAN state changed notifications.
572 */
ems_usb_control_cmd(struct ems_usb * dev,u8 val)573 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
574 {
575 struct ems_cpc_msg cmd;
576
577 cmd.type = CPC_CMD_TYPE_CONTROL;
578 cmd.length = CPC_MSG_HEADER_LEN + 1;
579
580 cmd.msgid = 0;
581
582 cmd.msg.generic[0] = val;
583
584 return ems_usb_command_msg(dev, &cmd);
585 }
586
587 /*
588 * Start interface
589 */
ems_usb_start(struct ems_usb * dev)590 static int ems_usb_start(struct ems_usb *dev)
591 {
592 struct net_device *netdev = dev->netdev;
593 int err, i;
594
595 dev->intr_in_buffer[0] = 0;
596 dev->free_slots = 50; /* initial size */
597
598 for (i = 0; i < MAX_RX_URBS; i++) {
599 struct urb *urb = NULL;
600 u8 *buf = NULL;
601
602 /* create a URB, and a buffer for it */
603 urb = usb_alloc_urb(0, GFP_KERNEL);
604 if (!urb) {
605 netdev_err(netdev, "No memory left for URBs\n");
606 err = -ENOMEM;
607 break;
608 }
609
610 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
611 &urb->transfer_dma);
612 if (!buf) {
613 netdev_err(netdev, "No memory left for USB buffer\n");
614 usb_free_urb(urb);
615 err = -ENOMEM;
616 break;
617 }
618
619 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
620 buf, RX_BUFFER_SIZE,
621 ems_usb_read_bulk_callback, dev);
622 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
623 usb_anchor_urb(urb, &dev->rx_submitted);
624
625 err = usb_submit_urb(urb, GFP_KERNEL);
626 if (err) {
627 usb_unanchor_urb(urb);
628 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
629 urb->transfer_dma);
630 usb_free_urb(urb);
631 break;
632 }
633
634 /* Drop reference, USB core will take care of freeing it */
635 usb_free_urb(urb);
636 }
637
638 /* Did we submit any URBs */
639 if (i == 0) {
640 netdev_warn(netdev, "couldn't setup read URBs\n");
641 return err;
642 }
643
644 /* Warn if we've couldn't transmit all the URBs */
645 if (i < MAX_RX_URBS)
646 netdev_warn(netdev, "rx performance may be slow\n");
647
648 /* Setup and start interrupt URB */
649 usb_fill_int_urb(dev->intr_urb, dev->udev,
650 usb_rcvintpipe(dev->udev, 1),
651 dev->intr_in_buffer,
652 INTR_IN_BUFFER_SIZE,
653 ems_usb_read_interrupt_callback, dev, 1);
654
655 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
656 if (err) {
657 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
658
659 return err;
660 }
661
662 /* CPC-USB will transfer received message to host */
663 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
664 if (err)
665 goto failed;
666
667 /* CPC-USB will transfer CAN state changes to host */
668 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
669 if (err)
670 goto failed;
671
672 /* CPC-USB will transfer bus errors to host */
673 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
674 if (err)
675 goto failed;
676
677 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
678 if (err)
679 goto failed;
680
681 dev->can.state = CAN_STATE_ERROR_ACTIVE;
682
683 return 0;
684
685 failed:
686 netdev_warn(netdev, "couldn't submit control: %d\n", err);
687
688 return err;
689 }
690
unlink_all_urbs(struct ems_usb * dev)691 static void unlink_all_urbs(struct ems_usb *dev)
692 {
693 int i;
694
695 usb_unlink_urb(dev->intr_urb);
696
697 usb_kill_anchored_urbs(&dev->rx_submitted);
698
699 usb_kill_anchored_urbs(&dev->tx_submitted);
700 atomic_set(&dev->active_tx_urbs, 0);
701
702 for (i = 0; i < MAX_TX_URBS; i++)
703 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
704 }
705
ems_usb_open(struct net_device * netdev)706 static int ems_usb_open(struct net_device *netdev)
707 {
708 struct ems_usb *dev = netdev_priv(netdev);
709 int err;
710
711 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
712 if (err)
713 return err;
714
715 /* common open */
716 err = open_candev(netdev);
717 if (err)
718 return err;
719
720 /* finally start device */
721 err = ems_usb_start(dev);
722 if (err) {
723 if (err == -ENODEV)
724 netif_device_detach(dev->netdev);
725
726 netdev_warn(netdev, "couldn't start device: %d\n", err);
727
728 close_candev(netdev);
729
730 return err;
731 }
732
733
734 netif_start_queue(netdev);
735
736 return 0;
737 }
738
ems_usb_start_xmit(struct sk_buff * skb,struct net_device * netdev)739 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
740 {
741 struct ems_usb *dev = netdev_priv(netdev);
742 struct ems_tx_urb_context *context = NULL;
743 struct net_device_stats *stats = &netdev->stats;
744 struct can_frame *cf = (struct can_frame *)skb->data;
745 struct ems_cpc_msg *msg;
746 struct urb *urb;
747 u8 *buf;
748 int i, err;
749 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
750 + sizeof(struct cpc_can_msg);
751
752 if (can_dropped_invalid_skb(netdev, skb))
753 return NETDEV_TX_OK;
754
755 /* create a URB, and a buffer for it, and copy the data to the URB */
756 urb = usb_alloc_urb(0, GFP_ATOMIC);
757 if (!urb) {
758 netdev_err(netdev, "No memory left for URBs\n");
759 goto nomem;
760 }
761
762 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
763 if (!buf) {
764 netdev_err(netdev, "No memory left for USB buffer\n");
765 usb_free_urb(urb);
766 goto nomem;
767 }
768
769 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
770
771 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
772 msg->msg.can_msg.length = cf->can_dlc;
773
774 if (cf->can_id & CAN_RTR_FLAG) {
775 msg->type = cf->can_id & CAN_EFF_FLAG ?
776 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
777
778 msg->length = CPC_CAN_MSG_MIN_SIZE;
779 } else {
780 msg->type = cf->can_id & CAN_EFF_FLAG ?
781 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
782
783 for (i = 0; i < cf->can_dlc; i++)
784 msg->msg.can_msg.msg[i] = cf->data[i];
785
786 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
787 }
788
789 for (i = 0; i < MAX_TX_URBS; i++) {
790 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
791 context = &dev->tx_contexts[i];
792 break;
793 }
794 }
795
796 /*
797 * May never happen! When this happens we'd more URBs in flight as
798 * allowed (MAX_TX_URBS).
799 */
800 if (!context) {
801 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
802 usb_free_urb(urb);
803
804 netdev_warn(netdev, "couldn't find free context\n");
805
806 return NETDEV_TX_BUSY;
807 }
808
809 context->dev = dev;
810 context->echo_index = i;
811 context->dlc = cf->can_dlc;
812
813 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
814 size, ems_usb_write_bulk_callback, context);
815 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
816 usb_anchor_urb(urb, &dev->tx_submitted);
817
818 can_put_echo_skb(skb, netdev, context->echo_index);
819
820 atomic_inc(&dev->active_tx_urbs);
821
822 err = usb_submit_urb(urb, GFP_ATOMIC);
823 if (unlikely(err)) {
824 can_free_echo_skb(netdev, context->echo_index);
825
826 usb_unanchor_urb(urb);
827 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
828 dev_kfree_skb(skb);
829
830 atomic_dec(&dev->active_tx_urbs);
831
832 if (err == -ENODEV) {
833 netif_device_detach(netdev);
834 } else {
835 netdev_warn(netdev, "failed tx_urb %d\n", err);
836
837 stats->tx_dropped++;
838 }
839 } else {
840 netdev->trans_start = jiffies;
841
842 /* Slow down tx path */
843 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
844 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
845 netif_stop_queue(netdev);
846 }
847 }
848
849 /*
850 * Release our reference to this URB, the USB core will eventually free
851 * it entirely.
852 */
853 usb_free_urb(urb);
854
855 return NETDEV_TX_OK;
856
857 nomem:
858 dev_kfree_skb(skb);
859 stats->tx_dropped++;
860
861 return NETDEV_TX_OK;
862 }
863
ems_usb_close(struct net_device * netdev)864 static int ems_usb_close(struct net_device *netdev)
865 {
866 struct ems_usb *dev = netdev_priv(netdev);
867
868 /* Stop polling */
869 unlink_all_urbs(dev);
870
871 netif_stop_queue(netdev);
872
873 /* Set CAN controller to reset mode */
874 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
875 netdev_warn(netdev, "couldn't stop device");
876
877 close_candev(netdev);
878
879 return 0;
880 }
881
882 static const struct net_device_ops ems_usb_netdev_ops = {
883 .ndo_open = ems_usb_open,
884 .ndo_stop = ems_usb_close,
885 .ndo_start_xmit = ems_usb_start_xmit,
886 .ndo_change_mtu = can_change_mtu,
887 };
888
889 static const struct can_bittiming_const ems_usb_bittiming_const = {
890 .name = "ems_usb",
891 .tseg1_min = 1,
892 .tseg1_max = 16,
893 .tseg2_min = 1,
894 .tseg2_max = 8,
895 .sjw_max = 4,
896 .brp_min = 1,
897 .brp_max = 64,
898 .brp_inc = 1,
899 };
900
ems_usb_set_mode(struct net_device * netdev,enum can_mode mode)901 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
902 {
903 struct ems_usb *dev = netdev_priv(netdev);
904
905 switch (mode) {
906 case CAN_MODE_START:
907 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
908 netdev_warn(netdev, "couldn't start device");
909
910 if (netif_queue_stopped(netdev))
911 netif_wake_queue(netdev);
912 break;
913
914 default:
915 return -EOPNOTSUPP;
916 }
917
918 return 0;
919 }
920
ems_usb_set_bittiming(struct net_device * netdev)921 static int ems_usb_set_bittiming(struct net_device *netdev)
922 {
923 struct ems_usb *dev = netdev_priv(netdev);
924 struct can_bittiming *bt = &dev->can.bittiming;
925 u8 btr0, btr1;
926
927 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
928 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
929 (((bt->phase_seg2 - 1) & 0x7) << 4);
930 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
931 btr1 |= 0x80;
932
933 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
934
935 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
936 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
937
938 return ems_usb_command_msg(dev, &dev->active_params);
939 }
940
init_params_sja1000(struct ems_cpc_msg * msg)941 static void init_params_sja1000(struct ems_cpc_msg *msg)
942 {
943 struct cpc_sja1000_params *sja1000 =
944 &msg->msg.can_params.cc_params.sja1000;
945
946 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
947 msg->length = sizeof(struct cpc_can_params);
948 msg->msgid = 0;
949
950 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
951
952 /* Acceptance filter open */
953 sja1000->acc_code0 = 0x00;
954 sja1000->acc_code1 = 0x00;
955 sja1000->acc_code2 = 0x00;
956 sja1000->acc_code3 = 0x00;
957
958 /* Acceptance filter open */
959 sja1000->acc_mask0 = 0xFF;
960 sja1000->acc_mask1 = 0xFF;
961 sja1000->acc_mask2 = 0xFF;
962 sja1000->acc_mask3 = 0xFF;
963
964 sja1000->btr0 = 0;
965 sja1000->btr1 = 0;
966
967 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
968 sja1000->mode = SJA1000_MOD_RM;
969 }
970
971 /*
972 * probe function for new CPC-USB devices
973 */
ems_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)974 static int ems_usb_probe(struct usb_interface *intf,
975 const struct usb_device_id *id)
976 {
977 struct net_device *netdev;
978 struct ems_usb *dev;
979 int i, err = -ENOMEM;
980
981 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
982 if (!netdev) {
983 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
984 return -ENOMEM;
985 }
986
987 dev = netdev_priv(netdev);
988
989 dev->udev = interface_to_usbdev(intf);
990 dev->netdev = netdev;
991
992 dev->can.state = CAN_STATE_STOPPED;
993 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
994 dev->can.bittiming_const = &ems_usb_bittiming_const;
995 dev->can.do_set_bittiming = ems_usb_set_bittiming;
996 dev->can.do_set_mode = ems_usb_set_mode;
997 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
998
999 netdev->netdev_ops = &ems_usb_netdev_ops;
1000
1001 netdev->flags |= IFF_ECHO; /* we support local echo */
1002
1003 init_usb_anchor(&dev->rx_submitted);
1004
1005 init_usb_anchor(&dev->tx_submitted);
1006 atomic_set(&dev->active_tx_urbs, 0);
1007
1008 for (i = 0; i < MAX_TX_URBS; i++)
1009 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1010
1011 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1012 if (!dev->intr_urb) {
1013 dev_err(&intf->dev, "Couldn't alloc intr URB\n");
1014 goto cleanup_candev;
1015 }
1016
1017 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1018 if (!dev->intr_in_buffer)
1019 goto cleanup_intr_urb;
1020
1021 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1022 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1023 if (!dev->tx_msg_buffer)
1024 goto cleanup_intr_in_buffer;
1025
1026 usb_set_intfdata(intf, dev);
1027
1028 SET_NETDEV_DEV(netdev, &intf->dev);
1029
1030 init_params_sja1000(&dev->active_params);
1031
1032 err = ems_usb_command_msg(dev, &dev->active_params);
1033 if (err) {
1034 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1035 goto cleanup_tx_msg_buffer;
1036 }
1037
1038 err = register_candev(netdev);
1039 if (err) {
1040 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1041 goto cleanup_tx_msg_buffer;
1042 }
1043
1044 return 0;
1045
1046 cleanup_tx_msg_buffer:
1047 kfree(dev->tx_msg_buffer);
1048
1049 cleanup_intr_in_buffer:
1050 kfree(dev->intr_in_buffer);
1051
1052 cleanup_intr_urb:
1053 usb_free_urb(dev->intr_urb);
1054
1055 cleanup_candev:
1056 free_candev(netdev);
1057
1058 return err;
1059 }
1060
1061 /*
1062 * called by the usb core when the device is removed from the system
1063 */
ems_usb_disconnect(struct usb_interface * intf)1064 static void ems_usb_disconnect(struct usb_interface *intf)
1065 {
1066 struct ems_usb *dev = usb_get_intfdata(intf);
1067
1068 usb_set_intfdata(intf, NULL);
1069
1070 if (dev) {
1071 unregister_netdev(dev->netdev);
1072 free_candev(dev->netdev);
1073
1074 unlink_all_urbs(dev);
1075
1076 usb_free_urb(dev->intr_urb);
1077
1078 kfree(dev->intr_in_buffer);
1079 }
1080 }
1081
1082 /* usb specific object needed to register this driver with the usb subsystem */
1083 static struct usb_driver ems_usb_driver = {
1084 .name = "ems_usb",
1085 .probe = ems_usb_probe,
1086 .disconnect = ems_usb_disconnect,
1087 .id_table = ems_usb_table,
1088 };
1089
1090 module_usb_driver(ems_usb_driver);
1091