1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7
4 *
5 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche
6 */
7 #include <linux/ethtool.h>
8 #include <linux/signal.h>
9 #include <linux/slab.h>
10 #include <linux/module.h>
11 #include <linux/netdevice.h>
12 #include <linux/usb.h>
13
14 #include <linux/can.h>
15 #include <linux/can/dev.h>
16 #include <linux/can/error.h>
17
18 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
19 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
20 MODULE_LICENSE("GPL v2");
21
22 /* Control-Values for CPC_Control() Command Subject Selection */
23 #define CONTR_CAN_MESSAGE 0x04
24 #define CONTR_CAN_STATE 0x0C
25 #define CONTR_BUS_ERROR 0x1C
26
27 /* Control Command Actions */
28 #define CONTR_CONT_OFF 0
29 #define CONTR_CONT_ON 1
30 #define CONTR_ONCE 2
31
32 /* Messages from CPC to PC */
33 #define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */
34 #define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */
35 #define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */
36 #define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */
37 #define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */
38 #define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */
39 #define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */
40 #define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */
41 #define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */
42 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
43 #define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */
44
45 /* Messages from the PC to the CPC interface */
46 #define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */
47 #define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */
48 #define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */
49 #define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */
50 #define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */
51 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */
52 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */
53 #define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */
54
55 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
56 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */
57 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
58
59 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
60
61 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
62
63 /* Overrun types */
64 #define CPC_OVR_EVENT_CAN 0x01
65 #define CPC_OVR_EVENT_CANSTATE 0x02
66 #define CPC_OVR_EVENT_BUSERROR 0x04
67
68 /*
69 * If the CAN controller lost a message we indicate it with the highest bit
70 * set in the count field.
71 */
72 #define CPC_OVR_HW 0x80
73
74 /* Size of the "struct ems_cpc_msg" without the union */
75 #define CPC_MSG_HEADER_LEN 11
76 #define CPC_CAN_MSG_MIN_SIZE 5
77
78 /* Define these values to match your devices */
79 #define USB_CPCUSB_VENDOR_ID 0x12D6
80
81 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
82
83 /* Mode register NXP LPC2119/SJA1000 CAN Controller */
84 #define SJA1000_MOD_NORMAL 0x00
85 #define SJA1000_MOD_RM 0x01
86
87 /* ECC register NXP LPC2119/SJA1000 CAN Controller */
88 #define SJA1000_ECC_SEG 0x1F
89 #define SJA1000_ECC_DIR 0x20
90 #define SJA1000_ECC_ERR 0x06
91 #define SJA1000_ECC_BIT 0x00
92 #define SJA1000_ECC_FORM 0x40
93 #define SJA1000_ECC_STUFF 0x80
94 #define SJA1000_ECC_MASK 0xc0
95
96 /* Status register content */
97 #define SJA1000_SR_BS 0x80
98 #define SJA1000_SR_ES 0x40
99
100 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
101
102 /*
103 * The device actually uses a 16MHz clock to generate the CAN clock
104 * but it expects SJA1000 bit settings based on 8MHz (is internally
105 * converted).
106 */
107 #define EMS_USB_ARM7_CLOCK 8000000
108
109 #define CPC_TX_QUEUE_TRIGGER_LOW 25
110 #define CPC_TX_QUEUE_TRIGGER_HIGH 35
111
112 /*
113 * CAN-Message representation in a CPC_MSG. Message object type is
114 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
115 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
116 */
117 struct cpc_can_msg {
118 __le32 id;
119 u8 length;
120 u8 msg[8];
121 };
122
123 /* Representation of the CAN parameters for the SJA1000 controller */
124 struct cpc_sja1000_params {
125 u8 mode;
126 u8 acc_code0;
127 u8 acc_code1;
128 u8 acc_code2;
129 u8 acc_code3;
130 u8 acc_mask0;
131 u8 acc_mask1;
132 u8 acc_mask2;
133 u8 acc_mask3;
134 u8 btr0;
135 u8 btr1;
136 u8 outp_contr;
137 };
138
139 /* CAN params message representation */
140 struct cpc_can_params {
141 u8 cc_type;
142
143 /* Will support M16C CAN controller in the future */
144 union {
145 struct cpc_sja1000_params sja1000;
146 } cc_params;
147 };
148
149 /* Structure for confirmed message handling */
150 struct cpc_confirm {
151 u8 error; /* error code */
152 };
153
154 /* Structure for overrun conditions */
155 struct cpc_overrun {
156 u8 event;
157 u8 count;
158 };
159
160 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
161 struct cpc_sja1000_can_error {
162 u8 ecc;
163 u8 rxerr;
164 u8 txerr;
165 };
166
167 /* structure for CAN error conditions */
168 struct cpc_can_error {
169 u8 ecode;
170
171 struct {
172 u8 cc_type;
173
174 /* Other controllers may also provide error code capture regs */
175 union {
176 struct cpc_sja1000_can_error sja1000;
177 } regs;
178 } cc;
179 };
180
181 /*
182 * Structure containing RX/TX error counter. This structure is used to request
183 * the values of the CAN controllers TX and RX error counter.
184 */
185 struct cpc_can_err_counter {
186 u8 rx;
187 u8 tx;
188 };
189
190 /* Main message type used between library and application */
191 struct __packed ems_cpc_msg {
192 u8 type; /* type of message */
193 u8 length; /* length of data within union 'msg' */
194 u8 msgid; /* confirmation handle */
195 __le32 ts_sec; /* timestamp in seconds */
196 __le32 ts_nsec; /* timestamp in nano seconds */
197
198 union __packed {
199 u8 generic[64];
200 struct cpc_can_msg can_msg;
201 struct cpc_can_params can_params;
202 struct cpc_confirm confirmation;
203 struct cpc_overrun overrun;
204 struct cpc_can_error error;
205 struct cpc_can_err_counter err_counter;
206 u8 can_state;
207 } msg;
208 };
209
210 /*
211 * Table of devices that work with this driver
212 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
213 */
214 static struct usb_device_id ems_usb_table[] = {
215 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
216 {} /* Terminating entry */
217 };
218
219 MODULE_DEVICE_TABLE(usb, ems_usb_table);
220
221 #define RX_BUFFER_SIZE 64
222 #define CPC_HEADER_SIZE 4
223 #define INTR_IN_BUFFER_SIZE 4
224
225 #define MAX_RX_URBS 10
226 #define MAX_TX_URBS 10
227
228 struct ems_usb;
229
230 struct ems_tx_urb_context {
231 struct ems_usb *dev;
232
233 u32 echo_index;
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 stats->rx_bytes += cf->len;
325 }
326 stats->rx_packets++;
327
328 netif_rx(skb);
329 }
330
ems_usb_rx_err(struct ems_usb * dev,struct ems_cpc_msg * msg)331 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
332 {
333 struct can_frame *cf;
334 struct sk_buff *skb;
335 struct net_device_stats *stats = &dev->netdev->stats;
336
337 skb = alloc_can_err_skb(dev->netdev, &cf);
338
339 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
340 u8 state = msg->msg.can_state;
341
342 if (state & SJA1000_SR_BS) {
343 dev->can.state = CAN_STATE_BUS_OFF;
344 if (skb)
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
364 if (skb) {
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
383 /* Error occurred during transmission? */
384 if ((ecc & SJA1000_ECC_DIR) == 0) {
385 stats->tx_errors++;
386 if (skb)
387 cf->data[2] |= CAN_ERR_PROT_TX;
388 } else {
389 stats->rx_errors++;
390 }
391
392 if (skb && (dev->can.state == CAN_STATE_ERROR_WARNING ||
393 dev->can.state == CAN_STATE_ERROR_PASSIVE)) {
394 cf->can_id |= CAN_ERR_CRTL;
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 if (skb) {
400 cf->can_id |= CAN_ERR_CRTL;
401 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
402 }
403
404 stats->rx_over_errors++;
405 stats->rx_errors++;
406 }
407
408 if (skb)
409 netif_rx(skb);
410 }
411
ems_usb_rx_msg_len_valid(struct ems_cpc_msg * msg)412 static bool ems_usb_rx_msg_len_valid(struct ems_cpc_msg *msg)
413 {
414 size_t len = msg->length;
415 size_t can_len;
416
417 switch (msg->type) {
418 case CPC_MSG_TYPE_CAN_STATE:
419 return len >= sizeof(msg->msg.can_state);
420
421 case CPC_MSG_TYPE_CAN_FRAME:
422 case CPC_MSG_TYPE_EXT_CAN_FRAME:
423 case CPC_MSG_TYPE_RTR_FRAME:
424 case CPC_MSG_TYPE_EXT_RTR_FRAME:
425 if (len < CPC_CAN_MSG_MIN_SIZE)
426 return false;
427
428 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
429 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
430 return true;
431
432 can_len = can_cc_dlc2len(msg->msg.can_msg.length & 0xf);
433 return len >= CPC_CAN_MSG_MIN_SIZE + can_len;
434
435 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
436 return len >= sizeof(msg->msg.error);
437
438 case CPC_MSG_TYPE_OVERRUN:
439 return len >= sizeof(msg->msg.overrun);
440
441 default:
442 return true;
443 }
444 }
445
446 /*
447 * callback for bulk IN urb
448 */
ems_usb_read_bulk_callback(struct urb * urb)449 static void ems_usb_read_bulk_callback(struct urb *urb)
450 {
451 struct ems_usb *dev = urb->context;
452 struct net_device *netdev;
453 int retval;
454
455 netdev = dev->netdev;
456
457 if (!netif_device_present(netdev))
458 return;
459
460 switch (urb->status) {
461 case 0: /* success */
462 break;
463
464 case -ENOENT:
465 return;
466
467 default:
468 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
469 goto resubmit_urb;
470 }
471
472 if (urb->actual_length > CPC_HEADER_SIZE) {
473 struct ems_cpc_msg *msg;
474 u8 *ibuf = urb->transfer_buffer;
475 u8 msg_count, start;
476
477 msg_count = ibuf[0] & ~0x80;
478
479 start = CPC_HEADER_SIZE;
480
481 while (msg_count) {
482 if (start + CPC_MSG_HEADER_LEN > urb->actual_length) {
483 netdev_err(netdev, "format error\n");
484 break;
485 }
486
487 msg = (struct ems_cpc_msg *)&ibuf[start];
488 if (msg->length >
489 urb->actual_length - start - CPC_MSG_HEADER_LEN) {
490 netdev_err(netdev, "format error\n");
491 break;
492 }
493 if (!ems_usb_rx_msg_len_valid(msg)) {
494 netdev_err(netdev, "format error\n");
495 break;
496 }
497
498 switch (msg->type) {
499 case CPC_MSG_TYPE_CAN_STATE:
500 /* Process CAN state changes */
501 ems_usb_rx_err(dev, msg);
502 break;
503
504 case CPC_MSG_TYPE_CAN_FRAME:
505 case CPC_MSG_TYPE_EXT_CAN_FRAME:
506 case CPC_MSG_TYPE_RTR_FRAME:
507 case CPC_MSG_TYPE_EXT_RTR_FRAME:
508 ems_usb_rx_can_msg(dev, msg);
509 break;
510
511 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
512 /* Process errorframe */
513 ems_usb_rx_err(dev, msg);
514 break;
515
516 case CPC_MSG_TYPE_OVERRUN:
517 /* Message lost while receiving */
518 ems_usb_rx_err(dev, msg);
519 break;
520 }
521
522 start += CPC_MSG_HEADER_LEN + msg->length;
523 msg_count--;
524
525 if (start > urb->actual_length) {
526 netdev_err(netdev, "format error\n");
527 break;
528 }
529 }
530 }
531
532 resubmit_urb:
533 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
534 urb->transfer_buffer, RX_BUFFER_SIZE,
535 ems_usb_read_bulk_callback, dev);
536
537 usb_anchor_urb(urb, &dev->rx_submitted);
538
539 retval = usb_submit_urb(urb, GFP_ATOMIC);
540 if (!retval)
541 return;
542
543 usb_unanchor_urb(urb);
544
545 if (retval == -ENODEV)
546 netif_device_detach(netdev);
547 else
548 netdev_err(netdev,
549 "failed resubmitting read bulk urb: %d\n", retval);
550 }
551
552 /*
553 * callback for bulk IN urb
554 */
ems_usb_write_bulk_callback(struct urb * urb)555 static void ems_usb_write_bulk_callback(struct urb *urb)
556 {
557 struct ems_tx_urb_context *context = urb->context;
558 struct ems_usb *dev;
559 struct net_device *netdev;
560
561 BUG_ON(!context);
562
563 dev = context->dev;
564 netdev = dev->netdev;
565
566 /* free up our allocated buffer */
567 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
568 urb->transfer_buffer, urb->transfer_dma);
569
570 atomic_dec(&dev->active_tx_urbs);
571
572 if (!netif_device_present(netdev))
573 return;
574
575 if (urb->status)
576 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
577
578 netif_trans_update(netdev);
579
580 /* transmission complete interrupt */
581 netdev->stats.tx_packets++;
582 netdev->stats.tx_bytes += can_get_echo_skb(netdev, context->echo_index,
583 NULL);
584
585 /* Release context */
586 context->echo_index = MAX_TX_URBS;
587
588 }
589
590 /*
591 * Send the given CPC command synchronously
592 */
ems_usb_command_msg(struct ems_usb * dev,struct ems_cpc_msg * msg)593 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
594 {
595 int actual_length;
596
597 /* Copy payload */
598 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
599 msg->length + CPC_MSG_HEADER_LEN);
600
601 /* Clear header */
602 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
603
604 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
605 &dev->tx_msg_buffer[0],
606 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
607 &actual_length, 1000);
608 }
609
610 /*
611 * Change CAN controllers' mode register
612 */
ems_usb_write_mode(struct ems_usb * dev,u8 mode)613 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
614 {
615 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
616
617 return ems_usb_command_msg(dev, &dev->active_params);
618 }
619
620 /*
621 * Send a CPC_Control command to change behaviour when interface receives a CAN
622 * message, bus error or CAN state changed notifications.
623 */
ems_usb_control_cmd(struct ems_usb * dev,u8 val)624 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
625 {
626 struct ems_cpc_msg cmd;
627
628 cmd.type = CPC_CMD_TYPE_CONTROL;
629 cmd.length = CPC_MSG_HEADER_LEN + 1;
630
631 cmd.msgid = 0;
632
633 cmd.msg.generic[0] = val;
634
635 return ems_usb_command_msg(dev, &cmd);
636 }
637
638 /*
639 * Start interface
640 */
ems_usb_start(struct ems_usb * dev)641 static int ems_usb_start(struct ems_usb *dev)
642 {
643 struct net_device *netdev = dev->netdev;
644 int err, i;
645
646 dev->intr_in_buffer[0] = 0;
647 dev->free_slots = 50; /* initial size */
648
649 for (i = 0; i < MAX_RX_URBS; i++) {
650 struct urb *urb = NULL;
651 u8 *buf = NULL;
652 dma_addr_t buf_dma;
653
654 /* create a URB, and a buffer for it */
655 urb = usb_alloc_urb(0, GFP_KERNEL);
656 if (!urb) {
657 err = -ENOMEM;
658 break;
659 }
660
661 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
662 &buf_dma);
663 if (!buf) {
664 netdev_err(netdev, "No memory left for USB buffer\n");
665 usb_free_urb(urb);
666 err = -ENOMEM;
667 break;
668 }
669
670 urb->transfer_dma = buf_dma;
671
672 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
673 buf, RX_BUFFER_SIZE,
674 ems_usb_read_bulk_callback, dev);
675 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
676 usb_anchor_urb(urb, &dev->rx_submitted);
677
678 err = usb_submit_urb(urb, GFP_KERNEL);
679 if (err) {
680 usb_unanchor_urb(urb);
681 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
682 urb->transfer_dma);
683 usb_free_urb(urb);
684 break;
685 }
686
687 dev->rxbuf[i] = buf;
688 dev->rxbuf_dma[i] = buf_dma;
689
690 /* Drop reference, USB core will take care of freeing it */
691 usb_free_urb(urb);
692 }
693
694 /* Did we submit any URBs */
695 if (i == 0) {
696 netdev_warn(netdev, "couldn't setup read URBs\n");
697 return err;
698 }
699
700 /* Warn if we've couldn't transmit all the URBs */
701 if (i < MAX_RX_URBS)
702 netdev_warn(netdev, "rx performance may be slow\n");
703
704 /* Setup and start interrupt URB */
705 usb_fill_int_urb(dev->intr_urb, dev->udev,
706 usb_rcvintpipe(dev->udev, 1),
707 dev->intr_in_buffer,
708 INTR_IN_BUFFER_SIZE,
709 ems_usb_read_interrupt_callback, dev, 1);
710
711 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
712 if (err) {
713 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
714
715 return err;
716 }
717
718 /* CPC-USB will transfer received message to host */
719 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
720 if (err)
721 goto failed;
722
723 /* CPC-USB will transfer CAN state changes to host */
724 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
725 if (err)
726 goto failed;
727
728 /* CPC-USB will transfer bus errors to host */
729 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
730 if (err)
731 goto failed;
732
733 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
734 if (err)
735 goto failed;
736
737 dev->can.state = CAN_STATE_ERROR_ACTIVE;
738
739 return 0;
740
741 failed:
742 netdev_warn(netdev, "couldn't submit control: %d\n", err);
743
744 return err;
745 }
746
unlink_all_urbs(struct ems_usb * dev)747 static void unlink_all_urbs(struct ems_usb *dev)
748 {
749 int i;
750
751 usb_unlink_urb(dev->intr_urb);
752
753 usb_kill_anchored_urbs(&dev->rx_submitted);
754
755 for (i = 0; i < MAX_RX_URBS; ++i)
756 usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
757 dev->rxbuf[i], dev->rxbuf_dma[i]);
758
759 usb_kill_anchored_urbs(&dev->tx_submitted);
760 atomic_set(&dev->active_tx_urbs, 0);
761
762 for (i = 0; i < MAX_TX_URBS; i++)
763 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
764 }
765
ems_usb_open(struct net_device * netdev)766 static int ems_usb_open(struct net_device *netdev)
767 {
768 struct ems_usb *dev = netdev_priv(netdev);
769 int err;
770
771 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
772 if (err)
773 return err;
774
775 /* common open */
776 err = open_candev(netdev);
777 if (err)
778 return err;
779
780 /* finally start device */
781 err = ems_usb_start(dev);
782 if (err) {
783 if (err == -ENODEV)
784 netif_device_detach(dev->netdev);
785
786 netdev_warn(netdev, "couldn't start device: %d\n", err);
787
788 close_candev(netdev);
789
790 return err;
791 }
792
793
794 netif_start_queue(netdev);
795
796 return 0;
797 }
798
ems_usb_start_xmit(struct sk_buff * skb,struct net_device * netdev)799 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
800 {
801 struct ems_usb *dev = netdev_priv(netdev);
802 struct ems_tx_urb_context *context = NULL;
803 struct net_device_stats *stats = &netdev->stats;
804 struct can_frame *cf = (struct can_frame *)skb->data;
805 struct ems_cpc_msg *msg;
806 struct urb *urb;
807 u8 *buf;
808 int i, err;
809 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
810 + sizeof(struct cpc_can_msg);
811
812 if (can_dev_dropped_skb(netdev, skb))
813 return NETDEV_TX_OK;
814
815 /* create a URB, and a buffer for it, and copy the data to the URB */
816 urb = usb_alloc_urb(0, GFP_ATOMIC);
817 if (!urb)
818 goto nomem;
819
820 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
821 if (!buf) {
822 netdev_err(netdev, "No memory left for USB buffer\n");
823 usb_free_urb(urb);
824 goto nomem;
825 }
826
827 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
828
829 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
830 msg->msg.can_msg.length = cf->len;
831
832 if (cf->can_id & CAN_RTR_FLAG) {
833 msg->type = cf->can_id & CAN_EFF_FLAG ?
834 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
835
836 msg->length = CPC_CAN_MSG_MIN_SIZE;
837 } else {
838 msg->type = cf->can_id & CAN_EFF_FLAG ?
839 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
840
841 for (i = 0; i < cf->len; i++)
842 msg->msg.can_msg.msg[i] = cf->data[i];
843
844 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len;
845 }
846
847 for (i = 0; i < MAX_TX_URBS; i++) {
848 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
849 context = &dev->tx_contexts[i];
850 break;
851 }
852 }
853
854 /*
855 * May never happen! When this happens we'd more URBs in flight as
856 * allowed (MAX_TX_URBS).
857 */
858 if (!context) {
859 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
860 usb_free_urb(urb);
861
862 netdev_warn(netdev, "couldn't find free context\n");
863
864 return NETDEV_TX_BUSY;
865 }
866
867 context->dev = dev;
868 context->echo_index = i;
869
870 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
871 size, ems_usb_write_bulk_callback, context);
872 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
873 usb_anchor_urb(urb, &dev->tx_submitted);
874
875 can_put_echo_skb(skb, netdev, context->echo_index, 0);
876
877 atomic_inc(&dev->active_tx_urbs);
878
879 err = usb_submit_urb(urb, GFP_ATOMIC);
880 if (unlikely(err)) {
881 can_free_echo_skb(netdev, context->echo_index, NULL);
882
883 usb_unanchor_urb(urb);
884 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
885
886 atomic_dec(&dev->active_tx_urbs);
887
888 if (err == -ENODEV) {
889 netif_device_detach(netdev);
890 } else {
891 netdev_warn(netdev, "failed tx_urb %d\n", err);
892
893 stats->tx_dropped++;
894 }
895 } else {
896 netif_trans_update(netdev);
897
898 /* Slow down tx path */
899 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
900 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
901 netif_stop_queue(netdev);
902 }
903 }
904
905 /*
906 * Release our reference to this URB, the USB core will eventually free
907 * it entirely.
908 */
909 usb_free_urb(urb);
910
911 return NETDEV_TX_OK;
912
913 nomem:
914 dev_kfree_skb(skb);
915 stats->tx_dropped++;
916
917 return NETDEV_TX_OK;
918 }
919
ems_usb_close(struct net_device * netdev)920 static int ems_usb_close(struct net_device *netdev)
921 {
922 struct ems_usb *dev = netdev_priv(netdev);
923
924 /* Stop polling */
925 unlink_all_urbs(dev);
926
927 netif_stop_queue(netdev);
928
929 /* Set CAN controller to reset mode */
930 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
931 netdev_warn(netdev, "couldn't stop device");
932
933 close_candev(netdev);
934
935 return 0;
936 }
937
938 static const struct net_device_ops ems_usb_netdev_ops = {
939 .ndo_open = ems_usb_open,
940 .ndo_stop = ems_usb_close,
941 .ndo_start_xmit = ems_usb_start_xmit,
942 };
943
944 static const struct ethtool_ops ems_usb_ethtool_ops = {
945 .get_ts_info = ethtool_op_get_ts_info,
946 };
947
948 static const struct can_bittiming_const ems_usb_bittiming_const = {
949 .name = KBUILD_MODNAME,
950 .tseg1_min = 1,
951 .tseg1_max = 16,
952 .tseg2_min = 1,
953 .tseg2_max = 8,
954 .sjw_max = 4,
955 .brp_min = 1,
956 .brp_max = 64,
957 .brp_inc = 1,
958 };
959
ems_usb_set_mode(struct net_device * netdev,enum can_mode mode)960 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
961 {
962 struct ems_usb *dev = netdev_priv(netdev);
963
964 switch (mode) {
965 case CAN_MODE_START:
966 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
967 netdev_warn(netdev, "couldn't start device");
968
969 if (netif_queue_stopped(netdev))
970 netif_wake_queue(netdev);
971 break;
972
973 default:
974 return -EOPNOTSUPP;
975 }
976
977 return 0;
978 }
979
ems_usb_set_bittiming(struct net_device * netdev)980 static int ems_usb_set_bittiming(struct net_device *netdev)
981 {
982 struct ems_usb *dev = netdev_priv(netdev);
983 struct can_bittiming *bt = &dev->can.bittiming;
984 u8 btr0, btr1;
985
986 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
987 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
988 (((bt->phase_seg2 - 1) & 0x7) << 4);
989 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
990 btr1 |= 0x80;
991
992 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
993
994 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
995 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
996
997 return ems_usb_command_msg(dev, &dev->active_params);
998 }
999
init_params_sja1000(struct ems_cpc_msg * msg)1000 static void init_params_sja1000(struct ems_cpc_msg *msg)
1001 {
1002 struct cpc_sja1000_params *sja1000 =
1003 &msg->msg.can_params.cc_params.sja1000;
1004
1005 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
1006 msg->length = sizeof(struct cpc_can_params);
1007 msg->msgid = 0;
1008
1009 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
1010
1011 /* Acceptance filter open */
1012 sja1000->acc_code0 = 0x00;
1013 sja1000->acc_code1 = 0x00;
1014 sja1000->acc_code2 = 0x00;
1015 sja1000->acc_code3 = 0x00;
1016
1017 /* Acceptance filter open */
1018 sja1000->acc_mask0 = 0xFF;
1019 sja1000->acc_mask1 = 0xFF;
1020 sja1000->acc_mask2 = 0xFF;
1021 sja1000->acc_mask3 = 0xFF;
1022
1023 sja1000->btr0 = 0;
1024 sja1000->btr1 = 0;
1025
1026 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
1027 sja1000->mode = SJA1000_MOD_RM;
1028 }
1029
1030 /*
1031 * probe function for new CPC-USB devices
1032 */
ems_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)1033 static int ems_usb_probe(struct usb_interface *intf,
1034 const struct usb_device_id *id)
1035 {
1036 struct net_device *netdev;
1037 struct ems_usb *dev;
1038 int i, err = -ENOMEM;
1039
1040 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
1041 if (!netdev) {
1042 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
1043 return -ENOMEM;
1044 }
1045
1046 dev = netdev_priv(netdev);
1047
1048 dev->udev = interface_to_usbdev(intf);
1049 dev->netdev = netdev;
1050
1051 dev->can.state = CAN_STATE_STOPPED;
1052 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1053 dev->can.bittiming_const = &ems_usb_bittiming_const;
1054 dev->can.do_set_bittiming = ems_usb_set_bittiming;
1055 dev->can.do_set_mode = ems_usb_set_mode;
1056 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
1057
1058 netdev->netdev_ops = &ems_usb_netdev_ops;
1059 netdev->ethtool_ops = &ems_usb_ethtool_ops;
1060
1061 netdev->flags |= IFF_ECHO; /* we support local echo */
1062
1063 init_usb_anchor(&dev->rx_submitted);
1064
1065 init_usb_anchor(&dev->tx_submitted);
1066 atomic_set(&dev->active_tx_urbs, 0);
1067
1068 for (i = 0; i < MAX_TX_URBS; i++)
1069 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1070
1071 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1072 if (!dev->intr_urb)
1073 goto cleanup_candev;
1074
1075 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1076 if (!dev->intr_in_buffer)
1077 goto cleanup_intr_urb;
1078
1079 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1080 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1081 if (!dev->tx_msg_buffer)
1082 goto cleanup_intr_in_buffer;
1083
1084 usb_set_intfdata(intf, dev);
1085
1086 SET_NETDEV_DEV(netdev, &intf->dev);
1087
1088 init_params_sja1000(&dev->active_params);
1089
1090 err = ems_usb_command_msg(dev, &dev->active_params);
1091 if (err) {
1092 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1093 goto cleanup_tx_msg_buffer;
1094 }
1095
1096 err = register_candev(netdev);
1097 if (err) {
1098 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1099 goto cleanup_tx_msg_buffer;
1100 }
1101
1102 return 0;
1103
1104 cleanup_tx_msg_buffer:
1105 kfree(dev->tx_msg_buffer);
1106
1107 cleanup_intr_in_buffer:
1108 kfree(dev->intr_in_buffer);
1109
1110 cleanup_intr_urb:
1111 usb_free_urb(dev->intr_urb);
1112
1113 cleanup_candev:
1114 free_candev(netdev);
1115
1116 return err;
1117 }
1118
1119 /*
1120 * called by the usb core when the device is removed from the system
1121 */
ems_usb_disconnect(struct usb_interface * intf)1122 static void ems_usb_disconnect(struct usb_interface *intf)
1123 {
1124 struct ems_usb *dev = usb_get_intfdata(intf);
1125
1126 usb_set_intfdata(intf, NULL);
1127
1128 if (dev) {
1129 unregister_netdev(dev->netdev);
1130
1131 unlink_all_urbs(dev);
1132
1133 usb_free_urb(dev->intr_urb);
1134
1135 kfree(dev->intr_in_buffer);
1136 kfree(dev->tx_msg_buffer);
1137
1138 free_candev(dev->netdev);
1139 }
1140 }
1141
1142 /* usb specific object needed to register this driver with the usb subsystem */
1143 static struct usb_driver ems_usb_driver = {
1144 .name = KBUILD_MODNAME,
1145 .probe = ems_usb_probe,
1146 .disconnect = ems_usb_disconnect,
1147 .id_table = ems_usb_table,
1148 };
1149
1150 module_usb_driver(ems_usb_driver);
1151