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
17 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
18 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
19 MODULE_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 */
116 struct 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 */
123 struct 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 */
139 struct 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 */
149 struct cpc_confirm {
150 u8 error; /* error code */
151 };
152
153 /* Structure for overrun conditions */
154 struct cpc_overrun {
155 u8 event;
156 u8 count;
157 };
158
159 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
160 struct cpc_sja1000_can_error {
161 u8 ecc;
162 u8 rxerr;
163 u8 txerr;
164 };
165
166 /* structure for CAN error conditions */
167 struct 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 */
184 struct cpc_can_err_counter {
185 u8 rx;
186 u8 tx;
187 };
188
189 /* Main message type used between library and application */
190 struct __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 */
213 static struct usb_device_id ems_usb_table[] = {
214 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
215 {} /* Terminating entry */
216 };
217
218 MODULE_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
227 struct ems_usb;
228
229 struct ems_tx_urb_context {
230 struct ems_usb *dev;
231
232 u32 echo_index;
233 u8 dlc;
234 };
235
236 struct ems_usb {
237 struct can_priv can; /* must be the first member */
238
239 struct sk_buff *echo_skb[MAX_TX_URBS];
240
241 struct usb_device *udev;
242 struct net_device *netdev;
243
244 atomic_t active_tx_urbs;
245 struct usb_anchor tx_submitted;
246 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
247
248 struct usb_anchor rx_submitted;
249
250 struct urb *intr_urb;
251
252 u8 *tx_msg_buffer;
253
254 u8 *intr_in_buffer;
255 unsigned int free_slots; /* remember number of available slots */
256
257 struct ems_cpc_msg active_params; /* active controller parameters */
258 void *rxbuf[MAX_RX_URBS];
259 dma_addr_t rxbuf_dma[MAX_RX_URBS];
260 };
261
ems_usb_read_interrupt_callback(struct urb * urb)262 static void ems_usb_read_interrupt_callback(struct urb *urb)
263 {
264 struct ems_usb *dev = urb->context;
265 struct net_device *netdev = dev->netdev;
266 int err;
267
268 if (!netif_device_present(netdev))
269 return;
270
271 switch (urb->status) {
272 case 0:
273 dev->free_slots = dev->intr_in_buffer[1];
274 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH &&
275 netif_queue_stopped(netdev))
276 netif_wake_queue(netdev);
277 break;
278
279 case -ECONNRESET: /* unlink */
280 case -ENOENT:
281 case -EPIPE:
282 case -EPROTO:
283 case -ESHUTDOWN:
284 return;
285
286 default:
287 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
288 break;
289 }
290
291 err = usb_submit_urb(urb, GFP_ATOMIC);
292
293 if (err == -ENODEV)
294 netif_device_detach(netdev);
295 else if (err)
296 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
297 }
298
ems_usb_rx_can_msg(struct ems_usb * dev,struct ems_cpc_msg * msg)299 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
300 {
301 struct can_frame *cf;
302 struct sk_buff *skb;
303 int i;
304 struct net_device_stats *stats = &dev->netdev->stats;
305
306 skb = alloc_can_skb(dev->netdev, &cf);
307 if (skb == NULL)
308 return;
309
310 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
311 cf->len = can_cc_dlc2len(msg->msg.can_msg.length & 0xF);
312
313 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
314 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
315 cf->can_id |= CAN_EFF_FLAG;
316
317 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
318 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
319 cf->can_id |= CAN_RTR_FLAG;
320 } else {
321 for (i = 0; i < cf->len; i++)
322 cf->data[i] = msg->msg.can_msg.msg[i];
323 }
324
325 stats->rx_packets++;
326 stats->rx_bytes += cf->len;
327 netif_rx(skb);
328 }
329
ems_usb_rx_err(struct ems_usb * dev,struct ems_cpc_msg * msg)330 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
331 {
332 struct can_frame *cf;
333 struct sk_buff *skb;
334 struct net_device_stats *stats = &dev->netdev->stats;
335
336 skb = alloc_can_err_skb(dev->netdev, &cf);
337 if (skb == NULL)
338 return;
339
340 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
341 u8 state = msg->msg.can_state;
342
343 if (state & SJA1000_SR_BS) {
344 dev->can.state = CAN_STATE_BUS_OFF;
345 cf->can_id |= CAN_ERR_BUSOFF;
346
347 dev->can.can_stats.bus_off++;
348 can_bus_off(dev->netdev);
349 } else if (state & SJA1000_SR_ES) {
350 dev->can.state = CAN_STATE_ERROR_WARNING;
351 dev->can.can_stats.error_warning++;
352 } else {
353 dev->can.state = CAN_STATE_ERROR_ACTIVE;
354 dev->can.can_stats.error_passive++;
355 }
356 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
357 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
358 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
359 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
360
361 /* bus error interrupt */
362 dev->can.can_stats.bus_error++;
363 stats->rx_errors++;
364
365 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
366
367 switch (ecc & SJA1000_ECC_MASK) {
368 case SJA1000_ECC_BIT:
369 cf->data[2] |= CAN_ERR_PROT_BIT;
370 break;
371 case SJA1000_ECC_FORM:
372 cf->data[2] |= CAN_ERR_PROT_FORM;
373 break;
374 case SJA1000_ECC_STUFF:
375 cf->data[2] |= CAN_ERR_PROT_STUFF;
376 break;
377 default:
378 cf->data[3] = ecc & SJA1000_ECC_SEG;
379 break;
380 }
381
382 /* Error occurred during transmission? */
383 if ((ecc & SJA1000_ECC_DIR) == 0)
384 cf->data[2] |= CAN_ERR_PROT_TX;
385
386 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
387 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
388 cf->can_id |= CAN_ERR_CRTL;
389 cf->data[1] = (txerr > rxerr) ?
390 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
391 }
392 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
393 cf->can_id |= CAN_ERR_CRTL;
394 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
395
396 stats->rx_over_errors++;
397 stats->rx_errors++;
398 }
399
400 stats->rx_packets++;
401 stats->rx_bytes += cf->len;
402 netif_rx(skb);
403 }
404
405 /*
406 * callback for bulk IN urb
407 */
ems_usb_read_bulk_callback(struct urb * urb)408 static void ems_usb_read_bulk_callback(struct urb *urb)
409 {
410 struct ems_usb *dev = urb->context;
411 struct net_device *netdev;
412 int retval;
413
414 netdev = dev->netdev;
415
416 if (!netif_device_present(netdev))
417 return;
418
419 switch (urb->status) {
420 case 0: /* success */
421 break;
422
423 case -ENOENT:
424 return;
425
426 default:
427 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
428 goto resubmit_urb;
429 }
430
431 if (urb->actual_length > CPC_HEADER_SIZE) {
432 struct ems_cpc_msg *msg;
433 u8 *ibuf = urb->transfer_buffer;
434 u8 msg_count, start;
435
436 msg_count = ibuf[0] & ~0x80;
437
438 start = CPC_HEADER_SIZE;
439
440 while (msg_count) {
441 msg = (struct ems_cpc_msg *)&ibuf[start];
442
443 switch (msg->type) {
444 case CPC_MSG_TYPE_CAN_STATE:
445 /* Process CAN state changes */
446 ems_usb_rx_err(dev, msg);
447 break;
448
449 case CPC_MSG_TYPE_CAN_FRAME:
450 case CPC_MSG_TYPE_EXT_CAN_FRAME:
451 case CPC_MSG_TYPE_RTR_FRAME:
452 case CPC_MSG_TYPE_EXT_RTR_FRAME:
453 ems_usb_rx_can_msg(dev, msg);
454 break;
455
456 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
457 /* Process errorframe */
458 ems_usb_rx_err(dev, msg);
459 break;
460
461 case CPC_MSG_TYPE_OVERRUN:
462 /* Message lost while receiving */
463 ems_usb_rx_err(dev, msg);
464 break;
465 }
466
467 start += CPC_MSG_HEADER_LEN + msg->length;
468 msg_count--;
469
470 if (start > urb->transfer_buffer_length) {
471 netdev_err(netdev, "format error\n");
472 break;
473 }
474 }
475 }
476
477 resubmit_urb:
478 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
479 urb->transfer_buffer, RX_BUFFER_SIZE,
480 ems_usb_read_bulk_callback, dev);
481
482 retval = usb_submit_urb(urb, GFP_ATOMIC);
483
484 if (retval == -ENODEV)
485 netif_device_detach(netdev);
486 else if (retval)
487 netdev_err(netdev,
488 "failed resubmitting read bulk urb: %d\n", retval);
489 }
490
491 /*
492 * callback for bulk IN urb
493 */
ems_usb_write_bulk_callback(struct urb * urb)494 static void ems_usb_write_bulk_callback(struct urb *urb)
495 {
496 struct ems_tx_urb_context *context = urb->context;
497 struct ems_usb *dev;
498 struct net_device *netdev;
499
500 BUG_ON(!context);
501
502 dev = context->dev;
503 netdev = dev->netdev;
504
505 /* free up our allocated buffer */
506 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
507 urb->transfer_buffer, urb->transfer_dma);
508
509 atomic_dec(&dev->active_tx_urbs);
510
511 if (!netif_device_present(netdev))
512 return;
513
514 if (urb->status)
515 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
516
517 netif_trans_update(netdev);
518
519 /* transmission complete interrupt */
520 netdev->stats.tx_packets++;
521 netdev->stats.tx_bytes += context->dlc;
522
523 can_get_echo_skb(netdev, context->echo_index, NULL);
524
525 /* Release context */
526 context->echo_index = MAX_TX_URBS;
527
528 }
529
530 /*
531 * Send the given CPC command synchronously
532 */
ems_usb_command_msg(struct ems_usb * dev,struct ems_cpc_msg * msg)533 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
534 {
535 int actual_length;
536
537 /* Copy payload */
538 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
539 msg->length + CPC_MSG_HEADER_LEN);
540
541 /* Clear header */
542 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
543
544 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
545 &dev->tx_msg_buffer[0],
546 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
547 &actual_length, 1000);
548 }
549
550 /*
551 * Change CAN controllers' mode register
552 */
ems_usb_write_mode(struct ems_usb * dev,u8 mode)553 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
554 {
555 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
556
557 return ems_usb_command_msg(dev, &dev->active_params);
558 }
559
560 /*
561 * Send a CPC_Control command to change behaviour when interface receives a CAN
562 * message, bus error or CAN state changed notifications.
563 */
ems_usb_control_cmd(struct ems_usb * dev,u8 val)564 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
565 {
566 struct ems_cpc_msg cmd;
567
568 cmd.type = CPC_CMD_TYPE_CONTROL;
569 cmd.length = CPC_MSG_HEADER_LEN + 1;
570
571 cmd.msgid = 0;
572
573 cmd.msg.generic[0] = val;
574
575 return ems_usb_command_msg(dev, &cmd);
576 }
577
578 /*
579 * Start interface
580 */
ems_usb_start(struct ems_usb * dev)581 static int ems_usb_start(struct ems_usb *dev)
582 {
583 struct net_device *netdev = dev->netdev;
584 int err, i;
585
586 dev->intr_in_buffer[0] = 0;
587 dev->free_slots = 50; /* initial size */
588
589 for (i = 0; i < MAX_RX_URBS; i++) {
590 struct urb *urb = NULL;
591 u8 *buf = NULL;
592 dma_addr_t buf_dma;
593
594 /* create a URB, and a buffer for it */
595 urb = usb_alloc_urb(0, GFP_KERNEL);
596 if (!urb) {
597 err = -ENOMEM;
598 break;
599 }
600
601 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
602 &buf_dma);
603 if (!buf) {
604 netdev_err(netdev, "No memory left for USB buffer\n");
605 usb_free_urb(urb);
606 err = -ENOMEM;
607 break;
608 }
609
610 urb->transfer_dma = buf_dma;
611
612 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
613 buf, RX_BUFFER_SIZE,
614 ems_usb_read_bulk_callback, dev);
615 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
616 usb_anchor_urb(urb, &dev->rx_submitted);
617
618 err = usb_submit_urb(urb, GFP_KERNEL);
619 if (err) {
620 usb_unanchor_urb(urb);
621 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
622 urb->transfer_dma);
623 usb_free_urb(urb);
624 break;
625 }
626
627 dev->rxbuf[i] = buf;
628 dev->rxbuf_dma[i] = buf_dma;
629
630 /* Drop reference, USB core will take care of freeing it */
631 usb_free_urb(urb);
632 }
633
634 /* Did we submit any URBs */
635 if (i == 0) {
636 netdev_warn(netdev, "couldn't setup read URBs\n");
637 return err;
638 }
639
640 /* Warn if we've couldn't transmit all the URBs */
641 if (i < MAX_RX_URBS)
642 netdev_warn(netdev, "rx performance may be slow\n");
643
644 /* Setup and start interrupt URB */
645 usb_fill_int_urb(dev->intr_urb, dev->udev,
646 usb_rcvintpipe(dev->udev, 1),
647 dev->intr_in_buffer,
648 INTR_IN_BUFFER_SIZE,
649 ems_usb_read_interrupt_callback, dev, 1);
650
651 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
652 if (err) {
653 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
654
655 return err;
656 }
657
658 /* CPC-USB will transfer received message to host */
659 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
660 if (err)
661 goto failed;
662
663 /* CPC-USB will transfer CAN state changes to host */
664 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
665 if (err)
666 goto failed;
667
668 /* CPC-USB will transfer bus errors to host */
669 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
670 if (err)
671 goto failed;
672
673 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
674 if (err)
675 goto failed;
676
677 dev->can.state = CAN_STATE_ERROR_ACTIVE;
678
679 return 0;
680
681 failed:
682 netdev_warn(netdev, "couldn't submit control: %d\n", err);
683
684 return err;
685 }
686
unlink_all_urbs(struct ems_usb * dev)687 static void unlink_all_urbs(struct ems_usb *dev)
688 {
689 int i;
690
691 usb_unlink_urb(dev->intr_urb);
692
693 usb_kill_anchored_urbs(&dev->rx_submitted);
694
695 for (i = 0; i < MAX_RX_URBS; ++i)
696 usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
697 dev->rxbuf[i], dev->rxbuf_dma[i]);
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 goto nomem;
759
760 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
761 if (!buf) {
762 netdev_err(netdev, "No memory left for USB buffer\n");
763 usb_free_urb(urb);
764 goto nomem;
765 }
766
767 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
768
769 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
770 msg->msg.can_msg.length = cf->len;
771
772 if (cf->can_id & CAN_RTR_FLAG) {
773 msg->type = cf->can_id & CAN_EFF_FLAG ?
774 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
775
776 msg->length = CPC_CAN_MSG_MIN_SIZE;
777 } else {
778 msg->type = cf->can_id & CAN_EFF_FLAG ?
779 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
780
781 for (i = 0; i < cf->len; i++)
782 msg->msg.can_msg.msg[i] = cf->data[i];
783
784 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len;
785 }
786
787 for (i = 0; i < MAX_TX_URBS; i++) {
788 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
789 context = &dev->tx_contexts[i];
790 break;
791 }
792 }
793
794 /*
795 * May never happen! When this happens we'd more URBs in flight as
796 * allowed (MAX_TX_URBS).
797 */
798 if (!context) {
799 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
800 usb_free_urb(urb);
801
802 netdev_warn(netdev, "couldn't find free context\n");
803
804 return NETDEV_TX_BUSY;
805 }
806
807 context->dev = dev;
808 context->echo_index = i;
809 context->dlc = cf->len;
810
811 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
812 size, ems_usb_write_bulk_callback, context);
813 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
814 usb_anchor_urb(urb, &dev->tx_submitted);
815
816 can_put_echo_skb(skb, netdev, context->echo_index, 0);
817
818 atomic_inc(&dev->active_tx_urbs);
819
820 err = usb_submit_urb(urb, GFP_ATOMIC);
821 if (unlikely(err)) {
822 can_free_echo_skb(netdev, context->echo_index, NULL);
823
824 usb_unanchor_urb(urb);
825 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
826 dev_kfree_skb(skb);
827
828 atomic_dec(&dev->active_tx_urbs);
829
830 if (err == -ENODEV) {
831 netif_device_detach(netdev);
832 } else {
833 netdev_warn(netdev, "failed tx_urb %d\n", err);
834
835 stats->tx_dropped++;
836 }
837 } else {
838 netif_trans_update(netdev);
839
840 /* Slow down tx path */
841 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
842 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
843 netif_stop_queue(netdev);
844 }
845 }
846
847 /*
848 * Release our reference to this URB, the USB core will eventually free
849 * it entirely.
850 */
851 usb_free_urb(urb);
852
853 return NETDEV_TX_OK;
854
855 nomem:
856 dev_kfree_skb(skb);
857 stats->tx_dropped++;
858
859 return NETDEV_TX_OK;
860 }
861
ems_usb_close(struct net_device * netdev)862 static int ems_usb_close(struct net_device *netdev)
863 {
864 struct ems_usb *dev = netdev_priv(netdev);
865
866 /* Stop polling */
867 unlink_all_urbs(dev);
868
869 netif_stop_queue(netdev);
870
871 /* Set CAN controller to reset mode */
872 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
873 netdev_warn(netdev, "couldn't stop device");
874
875 close_candev(netdev);
876
877 return 0;
878 }
879
880 static const struct net_device_ops ems_usb_netdev_ops = {
881 .ndo_open = ems_usb_open,
882 .ndo_stop = ems_usb_close,
883 .ndo_start_xmit = ems_usb_start_xmit,
884 .ndo_change_mtu = can_change_mtu,
885 };
886
887 static const struct can_bittiming_const ems_usb_bittiming_const = {
888 .name = "ems_usb",
889 .tseg1_min = 1,
890 .tseg1_max = 16,
891 .tseg2_min = 1,
892 .tseg2_max = 8,
893 .sjw_max = 4,
894 .brp_min = 1,
895 .brp_max = 64,
896 .brp_inc = 1,
897 };
898
ems_usb_set_mode(struct net_device * netdev,enum can_mode mode)899 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
900 {
901 struct ems_usb *dev = netdev_priv(netdev);
902
903 switch (mode) {
904 case CAN_MODE_START:
905 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
906 netdev_warn(netdev, "couldn't start device");
907
908 if (netif_queue_stopped(netdev))
909 netif_wake_queue(netdev);
910 break;
911
912 default:
913 return -EOPNOTSUPP;
914 }
915
916 return 0;
917 }
918
ems_usb_set_bittiming(struct net_device * netdev)919 static int ems_usb_set_bittiming(struct net_device *netdev)
920 {
921 struct ems_usb *dev = netdev_priv(netdev);
922 struct can_bittiming *bt = &dev->can.bittiming;
923 u8 btr0, btr1;
924
925 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
926 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
927 (((bt->phase_seg2 - 1) & 0x7) << 4);
928 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
929 btr1 |= 0x80;
930
931 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
932
933 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
934 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
935
936 return ems_usb_command_msg(dev, &dev->active_params);
937 }
938
init_params_sja1000(struct ems_cpc_msg * msg)939 static void init_params_sja1000(struct ems_cpc_msg *msg)
940 {
941 struct cpc_sja1000_params *sja1000 =
942 &msg->msg.can_params.cc_params.sja1000;
943
944 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
945 msg->length = sizeof(struct cpc_can_params);
946 msg->msgid = 0;
947
948 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
949
950 /* Acceptance filter open */
951 sja1000->acc_code0 = 0x00;
952 sja1000->acc_code1 = 0x00;
953 sja1000->acc_code2 = 0x00;
954 sja1000->acc_code3 = 0x00;
955
956 /* Acceptance filter open */
957 sja1000->acc_mask0 = 0xFF;
958 sja1000->acc_mask1 = 0xFF;
959 sja1000->acc_mask2 = 0xFF;
960 sja1000->acc_mask3 = 0xFF;
961
962 sja1000->btr0 = 0;
963 sja1000->btr1 = 0;
964
965 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
966 sja1000->mode = SJA1000_MOD_RM;
967 }
968
969 /*
970 * probe function for new CPC-USB devices
971 */
ems_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)972 static int ems_usb_probe(struct usb_interface *intf,
973 const struct usb_device_id *id)
974 {
975 struct net_device *netdev;
976 struct ems_usb *dev;
977 int i, err = -ENOMEM;
978
979 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
980 if (!netdev) {
981 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
982 return -ENOMEM;
983 }
984
985 dev = netdev_priv(netdev);
986
987 dev->udev = interface_to_usbdev(intf);
988 dev->netdev = netdev;
989
990 dev->can.state = CAN_STATE_STOPPED;
991 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
992 dev->can.bittiming_const = &ems_usb_bittiming_const;
993 dev->can.do_set_bittiming = ems_usb_set_bittiming;
994 dev->can.do_set_mode = ems_usb_set_mode;
995 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
996
997 netdev->netdev_ops = &ems_usb_netdev_ops;
998
999 netdev->flags |= IFF_ECHO; /* we support local echo */
1000
1001 init_usb_anchor(&dev->rx_submitted);
1002
1003 init_usb_anchor(&dev->tx_submitted);
1004 atomic_set(&dev->active_tx_urbs, 0);
1005
1006 for (i = 0; i < MAX_TX_URBS; i++)
1007 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1008
1009 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1010 if (!dev->intr_urb)
1011 goto cleanup_candev;
1012
1013 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1014 if (!dev->intr_in_buffer)
1015 goto cleanup_intr_urb;
1016
1017 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1018 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1019 if (!dev->tx_msg_buffer)
1020 goto cleanup_intr_in_buffer;
1021
1022 usb_set_intfdata(intf, dev);
1023
1024 SET_NETDEV_DEV(netdev, &intf->dev);
1025
1026 init_params_sja1000(&dev->active_params);
1027
1028 err = ems_usb_command_msg(dev, &dev->active_params);
1029 if (err) {
1030 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1031 goto cleanup_tx_msg_buffer;
1032 }
1033
1034 err = register_candev(netdev);
1035 if (err) {
1036 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1037 goto cleanup_tx_msg_buffer;
1038 }
1039
1040 return 0;
1041
1042 cleanup_tx_msg_buffer:
1043 kfree(dev->tx_msg_buffer);
1044
1045 cleanup_intr_in_buffer:
1046 kfree(dev->intr_in_buffer);
1047
1048 cleanup_intr_urb:
1049 usb_free_urb(dev->intr_urb);
1050
1051 cleanup_candev:
1052 free_candev(netdev);
1053
1054 return err;
1055 }
1056
1057 /*
1058 * called by the usb core when the device is removed from the system
1059 */
ems_usb_disconnect(struct usb_interface * intf)1060 static void ems_usb_disconnect(struct usb_interface *intf)
1061 {
1062 struct ems_usb *dev = usb_get_intfdata(intf);
1063
1064 usb_set_intfdata(intf, NULL);
1065
1066 if (dev) {
1067 unregister_netdev(dev->netdev);
1068
1069 unlink_all_urbs(dev);
1070
1071 usb_free_urb(dev->intr_urb);
1072
1073 kfree(dev->intr_in_buffer);
1074 kfree(dev->tx_msg_buffer);
1075
1076 free_candev(dev->netdev);
1077 }
1078 }
1079
1080 /* usb specific object needed to register this driver with the usb subsystem */
1081 static struct usb_driver ems_usb_driver = {
1082 .name = "ems_usb",
1083 .probe = ems_usb_probe,
1084 .disconnect = ems_usb_disconnect,
1085 .id_table = ems_usb_table,
1086 };
1087
1088 module_usb_driver(ems_usb_driver);
1089
