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
412 /*
413 * callback for bulk IN urb
414 */
ems_usb_read_bulk_callback(struct urb * urb)415 static void ems_usb_read_bulk_callback(struct urb *urb)
416 {
417 struct ems_usb *dev = urb->context;
418 struct net_device *netdev;
419 int retval;
420
421 netdev = dev->netdev;
422
423 if (!netif_device_present(netdev))
424 return;
425
426 switch (urb->status) {
427 case 0: /* success */
428 break;
429
430 case -ENOENT:
431 return;
432
433 default:
434 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
435 goto resubmit_urb;
436 }
437
438 if (urb->actual_length > CPC_HEADER_SIZE) {
439 struct ems_cpc_msg *msg;
440 u8 *ibuf = urb->transfer_buffer;
441 u8 msg_count, start;
442
443 msg_count = ibuf[0] & ~0x80;
444
445 start = CPC_HEADER_SIZE;
446
447 while (msg_count) {
448 msg = (struct ems_cpc_msg *)&ibuf[start];
449
450 switch (msg->type) {
451 case CPC_MSG_TYPE_CAN_STATE:
452 /* Process CAN state changes */
453 ems_usb_rx_err(dev, msg);
454 break;
455
456 case CPC_MSG_TYPE_CAN_FRAME:
457 case CPC_MSG_TYPE_EXT_CAN_FRAME:
458 case CPC_MSG_TYPE_RTR_FRAME:
459 case CPC_MSG_TYPE_EXT_RTR_FRAME:
460 ems_usb_rx_can_msg(dev, msg);
461 break;
462
463 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
464 /* Process errorframe */
465 ems_usb_rx_err(dev, msg);
466 break;
467
468 case CPC_MSG_TYPE_OVERRUN:
469 /* Message lost while receiving */
470 ems_usb_rx_err(dev, msg);
471 break;
472 }
473
474 start += CPC_MSG_HEADER_LEN + msg->length;
475 msg_count--;
476
477 if (start > urb->transfer_buffer_length) {
478 netdev_err(netdev, "format error\n");
479 break;
480 }
481 }
482 }
483
484 resubmit_urb:
485 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
486 urb->transfer_buffer, RX_BUFFER_SIZE,
487 ems_usb_read_bulk_callback, dev);
488
489 retval = usb_submit_urb(urb, GFP_ATOMIC);
490
491 if (retval == -ENODEV)
492 netif_device_detach(netdev);
493 else if (retval)
494 netdev_err(netdev,
495 "failed resubmitting read bulk urb: %d\n", retval);
496 }
497
498 /*
499 * callback for bulk IN urb
500 */
ems_usb_write_bulk_callback(struct urb * urb)501 static void ems_usb_write_bulk_callback(struct urb *urb)
502 {
503 struct ems_tx_urb_context *context = urb->context;
504 struct ems_usb *dev;
505 struct net_device *netdev;
506
507 BUG_ON(!context);
508
509 dev = context->dev;
510 netdev = dev->netdev;
511
512 /* free up our allocated buffer */
513 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
514 urb->transfer_buffer, urb->transfer_dma);
515
516 atomic_dec(&dev->active_tx_urbs);
517
518 if (!netif_device_present(netdev))
519 return;
520
521 if (urb->status)
522 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
523
524 netif_trans_update(netdev);
525
526 /* transmission complete interrupt */
527 netdev->stats.tx_packets++;
528 netdev->stats.tx_bytes += can_get_echo_skb(netdev, context->echo_index,
529 NULL);
530
531 /* Release context */
532 context->echo_index = MAX_TX_URBS;
533
534 }
535
536 /*
537 * Send the given CPC command synchronously
538 */
ems_usb_command_msg(struct ems_usb * dev,struct ems_cpc_msg * msg)539 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
540 {
541 int actual_length;
542
543 /* Copy payload */
544 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
545 msg->length + CPC_MSG_HEADER_LEN);
546
547 /* Clear header */
548 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
549
550 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
551 &dev->tx_msg_buffer[0],
552 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
553 &actual_length, 1000);
554 }
555
556 /*
557 * Change CAN controllers' mode register
558 */
ems_usb_write_mode(struct ems_usb * dev,u8 mode)559 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
560 {
561 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
562
563 return ems_usb_command_msg(dev, &dev->active_params);
564 }
565
566 /*
567 * Send a CPC_Control command to change behaviour when interface receives a CAN
568 * message, bus error or CAN state changed notifications.
569 */
ems_usb_control_cmd(struct ems_usb * dev,u8 val)570 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
571 {
572 struct ems_cpc_msg cmd;
573
574 cmd.type = CPC_CMD_TYPE_CONTROL;
575 cmd.length = CPC_MSG_HEADER_LEN + 1;
576
577 cmd.msgid = 0;
578
579 cmd.msg.generic[0] = val;
580
581 return ems_usb_command_msg(dev, &cmd);
582 }
583
584 /*
585 * Start interface
586 */
ems_usb_start(struct ems_usb * dev)587 static int ems_usb_start(struct ems_usb *dev)
588 {
589 struct net_device *netdev = dev->netdev;
590 int err, i;
591
592 dev->intr_in_buffer[0] = 0;
593 dev->free_slots = 50; /* initial size */
594
595 for (i = 0; i < MAX_RX_URBS; i++) {
596 struct urb *urb = NULL;
597 u8 *buf = NULL;
598 dma_addr_t buf_dma;
599
600 /* create a URB, and a buffer for it */
601 urb = usb_alloc_urb(0, GFP_KERNEL);
602 if (!urb) {
603 err = -ENOMEM;
604 break;
605 }
606
607 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
608 &buf_dma);
609 if (!buf) {
610 netdev_err(netdev, "No memory left for USB buffer\n");
611 usb_free_urb(urb);
612 err = -ENOMEM;
613 break;
614 }
615
616 urb->transfer_dma = buf_dma;
617
618 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
619 buf, RX_BUFFER_SIZE,
620 ems_usb_read_bulk_callback, dev);
621 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
622 usb_anchor_urb(urb, &dev->rx_submitted);
623
624 err = usb_submit_urb(urb, GFP_KERNEL);
625 if (err) {
626 usb_unanchor_urb(urb);
627 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
628 urb->transfer_dma);
629 usb_free_urb(urb);
630 break;
631 }
632
633 dev->rxbuf[i] = buf;
634 dev->rxbuf_dma[i] = buf_dma;
635
636 /* Drop reference, USB core will take care of freeing it */
637 usb_free_urb(urb);
638 }
639
640 /* Did we submit any URBs */
641 if (i == 0) {
642 netdev_warn(netdev, "couldn't setup read URBs\n");
643 return err;
644 }
645
646 /* Warn if we've couldn't transmit all the URBs */
647 if (i < MAX_RX_URBS)
648 netdev_warn(netdev, "rx performance may be slow\n");
649
650 /* Setup and start interrupt URB */
651 usb_fill_int_urb(dev->intr_urb, dev->udev,
652 usb_rcvintpipe(dev->udev, 1),
653 dev->intr_in_buffer,
654 INTR_IN_BUFFER_SIZE,
655 ems_usb_read_interrupt_callback, dev, 1);
656
657 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
658 if (err) {
659 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
660
661 return err;
662 }
663
664 /* CPC-USB will transfer received message to host */
665 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
666 if (err)
667 goto failed;
668
669 /* CPC-USB will transfer CAN state changes to host */
670 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
671 if (err)
672 goto failed;
673
674 /* CPC-USB will transfer bus errors to host */
675 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
676 if (err)
677 goto failed;
678
679 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
680 if (err)
681 goto failed;
682
683 dev->can.state = CAN_STATE_ERROR_ACTIVE;
684
685 return 0;
686
687 failed:
688 netdev_warn(netdev, "couldn't submit control: %d\n", err);
689
690 return err;
691 }
692
unlink_all_urbs(struct ems_usb * dev)693 static void unlink_all_urbs(struct ems_usb *dev)
694 {
695 int i;
696
697 usb_unlink_urb(dev->intr_urb);
698
699 usb_kill_anchored_urbs(&dev->rx_submitted);
700
701 for (i = 0; i < MAX_RX_URBS; ++i)
702 usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
703 dev->rxbuf[i], dev->rxbuf_dma[i]);
704
705 usb_kill_anchored_urbs(&dev->tx_submitted);
706 atomic_set(&dev->active_tx_urbs, 0);
707
708 for (i = 0; i < MAX_TX_URBS; i++)
709 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
710 }
711
ems_usb_open(struct net_device * netdev)712 static int ems_usb_open(struct net_device *netdev)
713 {
714 struct ems_usb *dev = netdev_priv(netdev);
715 int err;
716
717 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
718 if (err)
719 return err;
720
721 /* common open */
722 err = open_candev(netdev);
723 if (err)
724 return err;
725
726 /* finally start device */
727 err = ems_usb_start(dev);
728 if (err) {
729 if (err == -ENODEV)
730 netif_device_detach(dev->netdev);
731
732 netdev_warn(netdev, "couldn't start device: %d\n", err);
733
734 close_candev(netdev);
735
736 return err;
737 }
738
739
740 netif_start_queue(netdev);
741
742 return 0;
743 }
744
ems_usb_start_xmit(struct sk_buff * skb,struct net_device * netdev)745 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
746 {
747 struct ems_usb *dev = netdev_priv(netdev);
748 struct ems_tx_urb_context *context = NULL;
749 struct net_device_stats *stats = &netdev->stats;
750 struct can_frame *cf = (struct can_frame *)skb->data;
751 struct ems_cpc_msg *msg;
752 struct urb *urb;
753 u8 *buf;
754 int i, err;
755 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
756 + sizeof(struct cpc_can_msg);
757
758 if (can_dev_dropped_skb(netdev, skb))
759 return NETDEV_TX_OK;
760
761 /* create a URB, and a buffer for it, and copy the data to the URB */
762 urb = usb_alloc_urb(0, GFP_ATOMIC);
763 if (!urb)
764 goto nomem;
765
766 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
767 if (!buf) {
768 netdev_err(netdev, "No memory left for USB buffer\n");
769 usb_free_urb(urb);
770 goto nomem;
771 }
772
773 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
774
775 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
776 msg->msg.can_msg.length = cf->len;
777
778 if (cf->can_id & CAN_RTR_FLAG) {
779 msg->type = cf->can_id & CAN_EFF_FLAG ?
780 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
781
782 msg->length = CPC_CAN_MSG_MIN_SIZE;
783 } else {
784 msg->type = cf->can_id & CAN_EFF_FLAG ?
785 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
786
787 for (i = 0; i < cf->len; i++)
788 msg->msg.can_msg.msg[i] = cf->data[i];
789
790 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len;
791 }
792
793 for (i = 0; i < MAX_TX_URBS; i++) {
794 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
795 context = &dev->tx_contexts[i];
796 break;
797 }
798 }
799
800 /*
801 * May never happen! When this happens we'd more URBs in flight as
802 * allowed (MAX_TX_URBS).
803 */
804 if (!context) {
805 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
806 usb_free_urb(urb);
807
808 netdev_warn(netdev, "couldn't find free context\n");
809
810 return NETDEV_TX_BUSY;
811 }
812
813 context->dev = dev;
814 context->echo_index = i;
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, 0);
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, NULL);
828
829 usb_unanchor_urb(urb);
830 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
831
832 atomic_dec(&dev->active_tx_urbs);
833
834 if (err == -ENODEV) {
835 netif_device_detach(netdev);
836 } else {
837 netdev_warn(netdev, "failed tx_urb %d\n", err);
838
839 stats->tx_dropped++;
840 }
841 } else {
842 netif_trans_update(netdev);
843
844 /* Slow down tx path */
845 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
846 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
847 netif_stop_queue(netdev);
848 }
849 }
850
851 /*
852 * Release our reference to this URB, the USB core will eventually free
853 * it entirely.
854 */
855 usb_free_urb(urb);
856
857 return NETDEV_TX_OK;
858
859 nomem:
860 dev_kfree_skb(skb);
861 stats->tx_dropped++;
862
863 return NETDEV_TX_OK;
864 }
865
ems_usb_close(struct net_device * netdev)866 static int ems_usb_close(struct net_device *netdev)
867 {
868 struct ems_usb *dev = netdev_priv(netdev);
869
870 /* Stop polling */
871 unlink_all_urbs(dev);
872
873 netif_stop_queue(netdev);
874
875 /* Set CAN controller to reset mode */
876 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
877 netdev_warn(netdev, "couldn't stop device");
878
879 close_candev(netdev);
880
881 return 0;
882 }
883
884 static const struct net_device_ops ems_usb_netdev_ops = {
885 .ndo_open = ems_usb_open,
886 .ndo_stop = ems_usb_close,
887 .ndo_start_xmit = ems_usb_start_xmit,
888 .ndo_change_mtu = can_change_mtu,
889 };
890
891 static const struct ethtool_ops ems_usb_ethtool_ops = {
892 .get_ts_info = ethtool_op_get_ts_info,
893 };
894
895 static const struct can_bittiming_const ems_usb_bittiming_const = {
896 .name = KBUILD_MODNAME,
897 .tseg1_min = 1,
898 .tseg1_max = 16,
899 .tseg2_min = 1,
900 .tseg2_max = 8,
901 .sjw_max = 4,
902 .brp_min = 1,
903 .brp_max = 64,
904 .brp_inc = 1,
905 };
906
ems_usb_set_mode(struct net_device * netdev,enum can_mode mode)907 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
908 {
909 struct ems_usb *dev = netdev_priv(netdev);
910
911 switch (mode) {
912 case CAN_MODE_START:
913 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
914 netdev_warn(netdev, "couldn't start device");
915
916 if (netif_queue_stopped(netdev))
917 netif_wake_queue(netdev);
918 break;
919
920 default:
921 return -EOPNOTSUPP;
922 }
923
924 return 0;
925 }
926
ems_usb_set_bittiming(struct net_device * netdev)927 static int ems_usb_set_bittiming(struct net_device *netdev)
928 {
929 struct ems_usb *dev = netdev_priv(netdev);
930 struct can_bittiming *bt = &dev->can.bittiming;
931 u8 btr0, btr1;
932
933 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
934 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
935 (((bt->phase_seg2 - 1) & 0x7) << 4);
936 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
937 btr1 |= 0x80;
938
939 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
940
941 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
942 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
943
944 return ems_usb_command_msg(dev, &dev->active_params);
945 }
946
init_params_sja1000(struct ems_cpc_msg * msg)947 static void init_params_sja1000(struct ems_cpc_msg *msg)
948 {
949 struct cpc_sja1000_params *sja1000 =
950 &msg->msg.can_params.cc_params.sja1000;
951
952 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
953 msg->length = sizeof(struct cpc_can_params);
954 msg->msgid = 0;
955
956 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
957
958 /* Acceptance filter open */
959 sja1000->acc_code0 = 0x00;
960 sja1000->acc_code1 = 0x00;
961 sja1000->acc_code2 = 0x00;
962 sja1000->acc_code3 = 0x00;
963
964 /* Acceptance filter open */
965 sja1000->acc_mask0 = 0xFF;
966 sja1000->acc_mask1 = 0xFF;
967 sja1000->acc_mask2 = 0xFF;
968 sja1000->acc_mask3 = 0xFF;
969
970 sja1000->btr0 = 0;
971 sja1000->btr1 = 0;
972
973 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
974 sja1000->mode = SJA1000_MOD_RM;
975 }
976
977 /*
978 * probe function for new CPC-USB devices
979 */
ems_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)980 static int ems_usb_probe(struct usb_interface *intf,
981 const struct usb_device_id *id)
982 {
983 struct net_device *netdev;
984 struct ems_usb *dev;
985 int i, err = -ENOMEM;
986
987 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
988 if (!netdev) {
989 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
990 return -ENOMEM;
991 }
992
993 dev = netdev_priv(netdev);
994
995 dev->udev = interface_to_usbdev(intf);
996 dev->netdev = netdev;
997
998 dev->can.state = CAN_STATE_STOPPED;
999 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1000 dev->can.bittiming_const = &ems_usb_bittiming_const;
1001 dev->can.do_set_bittiming = ems_usb_set_bittiming;
1002 dev->can.do_set_mode = ems_usb_set_mode;
1003 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
1004
1005 netdev->netdev_ops = &ems_usb_netdev_ops;
1006 netdev->ethtool_ops = &ems_usb_ethtool_ops;
1007
1008 netdev->flags |= IFF_ECHO; /* we support local echo */
1009
1010 init_usb_anchor(&dev->rx_submitted);
1011
1012 init_usb_anchor(&dev->tx_submitted);
1013 atomic_set(&dev->active_tx_urbs, 0);
1014
1015 for (i = 0; i < MAX_TX_URBS; i++)
1016 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1017
1018 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1019 if (!dev->intr_urb)
1020 goto cleanup_candev;
1021
1022 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1023 if (!dev->intr_in_buffer)
1024 goto cleanup_intr_urb;
1025
1026 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1027 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1028 if (!dev->tx_msg_buffer)
1029 goto cleanup_intr_in_buffer;
1030
1031 usb_set_intfdata(intf, dev);
1032
1033 SET_NETDEV_DEV(netdev, &intf->dev);
1034
1035 init_params_sja1000(&dev->active_params);
1036
1037 err = ems_usb_command_msg(dev, &dev->active_params);
1038 if (err) {
1039 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1040 goto cleanup_tx_msg_buffer;
1041 }
1042
1043 err = register_candev(netdev);
1044 if (err) {
1045 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1046 goto cleanup_tx_msg_buffer;
1047 }
1048
1049 return 0;
1050
1051 cleanup_tx_msg_buffer:
1052 kfree(dev->tx_msg_buffer);
1053
1054 cleanup_intr_in_buffer:
1055 kfree(dev->intr_in_buffer);
1056
1057 cleanup_intr_urb:
1058 usb_free_urb(dev->intr_urb);
1059
1060 cleanup_candev:
1061 free_candev(netdev);
1062
1063 return err;
1064 }
1065
1066 /*
1067 * called by the usb core when the device is removed from the system
1068 */
ems_usb_disconnect(struct usb_interface * intf)1069 static void ems_usb_disconnect(struct usb_interface *intf)
1070 {
1071 struct ems_usb *dev = usb_get_intfdata(intf);
1072
1073 usb_set_intfdata(intf, NULL);
1074
1075 if (dev) {
1076 unregister_netdev(dev->netdev);
1077
1078 unlink_all_urbs(dev);
1079
1080 usb_free_urb(dev->intr_urb);
1081
1082 kfree(dev->intr_in_buffer);
1083 kfree(dev->tx_msg_buffer);
1084
1085 free_candev(dev->netdev);
1086 }
1087 }
1088
1089 /* usb specific object needed to register this driver with the usb subsystem */
1090 static struct usb_driver ems_usb_driver = {
1091 .name = KBUILD_MODNAME,
1092 .probe = ems_usb_probe,
1093 .disconnect = ems_usb_disconnect,
1094 .id_table = ems_usb_table,
1095 };
1096
1097 module_usb_driver(ems_usb_driver);
1098