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 void *rxbuf[MAX_RX_URBS];
271 dma_addr_t rxbuf_dma[MAX_RX_URBS];
272 };
273
ems_usb_read_interrupt_callback(struct urb * urb)274 static void ems_usb_read_interrupt_callback(struct urb *urb)
275 {
276 struct ems_usb *dev = urb->context;
277 struct net_device *netdev = dev->netdev;
278 int err;
279
280 if (!netif_device_present(netdev))
281 return;
282
283 switch (urb->status) {
284 case 0:
285 dev->free_slots = dev->intr_in_buffer[1];
286 if(dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH){
287 if (netif_queue_stopped(netdev)){
288 netif_wake_queue(netdev);
289 }
290 }
291 break;
292
293 case -ECONNRESET: /* unlink */
294 case -ENOENT:
295 case -EPIPE:
296 case -EPROTO:
297 case -ESHUTDOWN:
298 return;
299
300 default:
301 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
302 break;
303 }
304
305 err = usb_submit_urb(urb, GFP_ATOMIC);
306
307 if (err == -ENODEV)
308 netif_device_detach(netdev);
309 else if (err)
310 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
311 }
312
ems_usb_rx_can_msg(struct ems_usb * dev,struct ems_cpc_msg * msg)313 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
314 {
315 struct can_frame *cf;
316 struct sk_buff *skb;
317 int i;
318 struct net_device_stats *stats = &dev->netdev->stats;
319
320 skb = alloc_can_skb(dev->netdev, &cf);
321 if (skb == NULL)
322 return;
323
324 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
325 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
326
327 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
328 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
329 cf->can_id |= CAN_EFF_FLAG;
330
331 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
332 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
333 cf->can_id |= CAN_RTR_FLAG;
334 } else {
335 for (i = 0; i < cf->can_dlc; i++)
336 cf->data[i] = msg->msg.can_msg.msg[i];
337 }
338
339 stats->rx_packets++;
340 stats->rx_bytes += cf->can_dlc;
341 netif_rx(skb);
342 }
343
ems_usb_rx_err(struct ems_usb * dev,struct ems_cpc_msg * msg)344 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
345 {
346 struct can_frame *cf;
347 struct sk_buff *skb;
348 struct net_device_stats *stats = &dev->netdev->stats;
349
350 skb = alloc_can_err_skb(dev->netdev, &cf);
351 if (skb == NULL)
352 return;
353
354 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
355 u8 state = msg->msg.can_state;
356
357 if (state & SJA1000_SR_BS) {
358 dev->can.state = CAN_STATE_BUS_OFF;
359 cf->can_id |= CAN_ERR_BUSOFF;
360
361 dev->can.can_stats.bus_off++;
362 can_bus_off(dev->netdev);
363 } else if (state & SJA1000_SR_ES) {
364 dev->can.state = CAN_STATE_ERROR_WARNING;
365 dev->can.can_stats.error_warning++;
366 } else {
367 dev->can.state = CAN_STATE_ERROR_ACTIVE;
368 dev->can.can_stats.error_passive++;
369 }
370 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
371 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
372 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
373 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
374
375 /* bus error interrupt */
376 dev->can.can_stats.bus_error++;
377 stats->rx_errors++;
378
379 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
380
381 switch (ecc & SJA1000_ECC_MASK) {
382 case SJA1000_ECC_BIT:
383 cf->data[2] |= CAN_ERR_PROT_BIT;
384 break;
385 case SJA1000_ECC_FORM:
386 cf->data[2] |= CAN_ERR_PROT_FORM;
387 break;
388 case SJA1000_ECC_STUFF:
389 cf->data[2] |= CAN_ERR_PROT_STUFF;
390 break;
391 default:
392 cf->data[3] = ecc & SJA1000_ECC_SEG;
393 break;
394 }
395
396 /* Error occurred during transmission? */
397 if ((ecc & SJA1000_ECC_DIR) == 0)
398 cf->data[2] |= CAN_ERR_PROT_TX;
399
400 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
401 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
402 cf->data[1] = (txerr > rxerr) ?
403 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
404 }
405 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
406 cf->can_id |= CAN_ERR_CRTL;
407 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
408
409 stats->rx_over_errors++;
410 stats->rx_errors++;
411 }
412
413 stats->rx_packets++;
414 stats->rx_bytes += cf->can_dlc;
415 netif_rx(skb);
416 }
417
418 /*
419 * callback for bulk IN urb
420 */
ems_usb_read_bulk_callback(struct urb * urb)421 static void ems_usb_read_bulk_callback(struct urb *urb)
422 {
423 struct ems_usb *dev = urb->context;
424 struct net_device *netdev;
425 int retval;
426
427 netdev = dev->netdev;
428
429 if (!netif_device_present(netdev))
430 return;
431
432 switch (urb->status) {
433 case 0: /* success */
434 break;
435
436 case -ENOENT:
437 return;
438
439 default:
440 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
441 goto resubmit_urb;
442 }
443
444 if (urb->actual_length > CPC_HEADER_SIZE) {
445 struct ems_cpc_msg *msg;
446 u8 *ibuf = urb->transfer_buffer;
447 u8 msg_count, start;
448
449 msg_count = ibuf[0] & ~0x80;
450
451 start = CPC_HEADER_SIZE;
452
453 while (msg_count) {
454 msg = (struct ems_cpc_msg *)&ibuf[start];
455
456 switch (msg->type) {
457 case CPC_MSG_TYPE_CAN_STATE:
458 /* Process CAN state changes */
459 ems_usb_rx_err(dev, msg);
460 break;
461
462 case CPC_MSG_TYPE_CAN_FRAME:
463 case CPC_MSG_TYPE_EXT_CAN_FRAME:
464 case CPC_MSG_TYPE_RTR_FRAME:
465 case CPC_MSG_TYPE_EXT_RTR_FRAME:
466 ems_usb_rx_can_msg(dev, msg);
467 break;
468
469 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
470 /* Process errorframe */
471 ems_usb_rx_err(dev, msg);
472 break;
473
474 case CPC_MSG_TYPE_OVERRUN:
475 /* Message lost while receiving */
476 ems_usb_rx_err(dev, msg);
477 break;
478 }
479
480 start += CPC_MSG_HEADER_LEN + msg->length;
481 msg_count--;
482
483 if (start > urb->transfer_buffer_length) {
484 netdev_err(netdev, "format error\n");
485 break;
486 }
487 }
488 }
489
490 resubmit_urb:
491 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
492 urb->transfer_buffer, RX_BUFFER_SIZE,
493 ems_usb_read_bulk_callback, dev);
494
495 retval = usb_submit_urb(urb, GFP_ATOMIC);
496
497 if (retval == -ENODEV)
498 netif_device_detach(netdev);
499 else if (retval)
500 netdev_err(netdev,
501 "failed resubmitting read bulk urb: %d\n", retval);
502 }
503
504 /*
505 * callback for bulk IN urb
506 */
ems_usb_write_bulk_callback(struct urb * urb)507 static void ems_usb_write_bulk_callback(struct urb *urb)
508 {
509 struct ems_tx_urb_context *context = urb->context;
510 struct ems_usb *dev;
511 struct net_device *netdev;
512
513 BUG_ON(!context);
514
515 dev = context->dev;
516 netdev = dev->netdev;
517
518 /* free up our allocated buffer */
519 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
520 urb->transfer_buffer, urb->transfer_dma);
521
522 atomic_dec(&dev->active_tx_urbs);
523
524 if (!netif_device_present(netdev))
525 return;
526
527 if (urb->status)
528 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
529
530 netdev->trans_start = jiffies;
531
532 /* transmission complete interrupt */
533 netdev->stats.tx_packets++;
534 netdev->stats.tx_bytes += context->dlc;
535
536 can_get_echo_skb(netdev, context->echo_index);
537
538 /* Release context */
539 context->echo_index = MAX_TX_URBS;
540
541 }
542
543 /*
544 * Send the given CPC command synchronously
545 */
ems_usb_command_msg(struct ems_usb * dev,struct ems_cpc_msg * msg)546 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
547 {
548 int actual_length;
549
550 /* Copy payload */
551 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
552 msg->length + CPC_MSG_HEADER_LEN);
553
554 /* Clear header */
555 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
556
557 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
558 &dev->tx_msg_buffer[0],
559 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
560 &actual_length, 1000);
561 }
562
563 /*
564 * Change CAN controllers' mode register
565 */
ems_usb_write_mode(struct ems_usb * dev,u8 mode)566 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
567 {
568 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
569
570 return ems_usb_command_msg(dev, &dev->active_params);
571 }
572
573 /*
574 * Send a CPC_Control command to change behaviour when interface receives a CAN
575 * message, bus error or CAN state changed notifications.
576 */
ems_usb_control_cmd(struct ems_usb * dev,u8 val)577 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
578 {
579 struct ems_cpc_msg cmd;
580
581 cmd.type = CPC_CMD_TYPE_CONTROL;
582 cmd.length = CPC_MSG_HEADER_LEN + 1;
583
584 cmd.msgid = 0;
585
586 cmd.msg.generic[0] = val;
587
588 return ems_usb_command_msg(dev, &cmd);
589 }
590
591 /*
592 * Start interface
593 */
ems_usb_start(struct ems_usb * dev)594 static int ems_usb_start(struct ems_usb *dev)
595 {
596 struct net_device *netdev = dev->netdev;
597 int err, i;
598
599 dev->intr_in_buffer[0] = 0;
600 dev->free_slots = 50; /* initial size */
601
602 for (i = 0; i < MAX_RX_URBS; i++) {
603 struct urb *urb = NULL;
604 u8 *buf = NULL;
605 dma_addr_t buf_dma;
606
607 /* create a URB, and a buffer for it */
608 urb = usb_alloc_urb(0, GFP_KERNEL);
609 if (!urb) {
610 netdev_err(netdev, "No memory left for URBs\n");
611 err = -ENOMEM;
612 break;
613 }
614
615 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
616 &buf_dma);
617 if (!buf) {
618 netdev_err(netdev, "No memory left for USB buffer\n");
619 usb_free_urb(urb);
620 err = -ENOMEM;
621 break;
622 }
623
624 urb->transfer_dma = buf_dma;
625
626 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
627 buf, RX_BUFFER_SIZE,
628 ems_usb_read_bulk_callback, dev);
629 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
630 usb_anchor_urb(urb, &dev->rx_submitted);
631
632 err = usb_submit_urb(urb, GFP_KERNEL);
633 if (err) {
634 usb_unanchor_urb(urb);
635 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
636 urb->transfer_dma);
637 usb_free_urb(urb);
638 break;
639 }
640
641 dev->rxbuf[i] = buf;
642 dev->rxbuf_dma[i] = buf_dma;
643
644 /* Drop reference, USB core will take care of freeing it */
645 usb_free_urb(urb);
646 }
647
648 /* Did we submit any URBs */
649 if (i == 0) {
650 netdev_warn(netdev, "couldn't setup read URBs\n");
651 return err;
652 }
653
654 /* Warn if we've couldn't transmit all the URBs */
655 if (i < MAX_RX_URBS)
656 netdev_warn(netdev, "rx performance may be slow\n");
657
658 /* Setup and start interrupt URB */
659 usb_fill_int_urb(dev->intr_urb, dev->udev,
660 usb_rcvintpipe(dev->udev, 1),
661 dev->intr_in_buffer,
662 INTR_IN_BUFFER_SIZE,
663 ems_usb_read_interrupt_callback, dev, 1);
664
665 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
666 if (err) {
667 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
668
669 return err;
670 }
671
672 /* CPC-USB will transfer received message to host */
673 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
674 if (err)
675 goto failed;
676
677 /* CPC-USB will transfer CAN state changes to host */
678 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
679 if (err)
680 goto failed;
681
682 /* CPC-USB will transfer bus errors to host */
683 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
684 if (err)
685 goto failed;
686
687 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
688 if (err)
689 goto failed;
690
691 dev->can.state = CAN_STATE_ERROR_ACTIVE;
692
693 return 0;
694
695 failed:
696 netdev_warn(netdev, "couldn't submit control: %d\n", err);
697
698 return err;
699 }
700
unlink_all_urbs(struct ems_usb * dev)701 static void unlink_all_urbs(struct ems_usb *dev)
702 {
703 int i;
704
705 usb_unlink_urb(dev->intr_urb);
706
707 usb_kill_anchored_urbs(&dev->rx_submitted);
708
709 for (i = 0; i < MAX_RX_URBS; ++i)
710 usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
711 dev->rxbuf[i], dev->rxbuf_dma[i]);
712
713 usb_kill_anchored_urbs(&dev->tx_submitted);
714 atomic_set(&dev->active_tx_urbs, 0);
715
716 for (i = 0; i < MAX_TX_URBS; i++)
717 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
718 }
719
ems_usb_open(struct net_device * netdev)720 static int ems_usb_open(struct net_device *netdev)
721 {
722 struct ems_usb *dev = netdev_priv(netdev);
723 int err;
724
725 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
726 if (err)
727 return err;
728
729 /* common open */
730 err = open_candev(netdev);
731 if (err)
732 return err;
733
734 /* finally start device */
735 err = ems_usb_start(dev);
736 if (err) {
737 if (err == -ENODEV)
738 netif_device_detach(dev->netdev);
739
740 netdev_warn(netdev, "couldn't start device: %d\n", err);
741
742 close_candev(netdev);
743
744 return err;
745 }
746
747
748 netif_start_queue(netdev);
749
750 return 0;
751 }
752
ems_usb_start_xmit(struct sk_buff * skb,struct net_device * netdev)753 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
754 {
755 struct ems_usb *dev = netdev_priv(netdev);
756 struct ems_tx_urb_context *context = NULL;
757 struct net_device_stats *stats = &netdev->stats;
758 struct can_frame *cf = (struct can_frame *)skb->data;
759 struct ems_cpc_msg *msg;
760 struct urb *urb;
761 u8 *buf;
762 int i, err;
763 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
764 + sizeof(struct cpc_can_msg);
765
766 if (can_dropped_invalid_skb(netdev, skb))
767 return NETDEV_TX_OK;
768
769 /* create a URB, and a buffer for it, and copy the data to the URB */
770 urb = usb_alloc_urb(0, GFP_ATOMIC);
771 if (!urb) {
772 netdev_err(netdev, "No memory left for URBs\n");
773 goto nomem;
774 }
775
776 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
777 if (!buf) {
778 netdev_err(netdev, "No memory left for USB buffer\n");
779 usb_free_urb(urb);
780 goto nomem;
781 }
782
783 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
784
785 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
786 msg->msg.can_msg.length = cf->can_dlc;
787
788 if (cf->can_id & CAN_RTR_FLAG) {
789 msg->type = cf->can_id & CAN_EFF_FLAG ?
790 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
791
792 msg->length = CPC_CAN_MSG_MIN_SIZE;
793 } else {
794 msg->type = cf->can_id & CAN_EFF_FLAG ?
795 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
796
797 for (i = 0; i < cf->can_dlc; i++)
798 msg->msg.can_msg.msg[i] = cf->data[i];
799
800 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
801 }
802
803 for (i = 0; i < MAX_TX_URBS; i++) {
804 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
805 context = &dev->tx_contexts[i];
806 break;
807 }
808 }
809
810 /*
811 * May never happen! When this happens we'd more URBs in flight as
812 * allowed (MAX_TX_URBS).
813 */
814 if (!context) {
815 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
816 usb_free_urb(urb);
817
818 netdev_warn(netdev, "couldn't find free context\n");
819
820 return NETDEV_TX_BUSY;
821 }
822
823 context->dev = dev;
824 context->echo_index = i;
825 context->dlc = cf->can_dlc;
826
827 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
828 size, ems_usb_write_bulk_callback, context);
829 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
830 usb_anchor_urb(urb, &dev->tx_submitted);
831
832 can_put_echo_skb(skb, netdev, context->echo_index);
833
834 atomic_inc(&dev->active_tx_urbs);
835
836 err = usb_submit_urb(urb, GFP_ATOMIC);
837 if (unlikely(err)) {
838 can_free_echo_skb(netdev, context->echo_index);
839
840 usb_unanchor_urb(urb);
841 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
842 dev_kfree_skb(skb);
843
844 atomic_dec(&dev->active_tx_urbs);
845
846 if (err == -ENODEV) {
847 netif_device_detach(netdev);
848 } else {
849 netdev_warn(netdev, "failed tx_urb %d\n", err);
850
851 stats->tx_dropped++;
852 }
853 } else {
854 netdev->trans_start = jiffies;
855
856 /* Slow down tx path */
857 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
858 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
859 netif_stop_queue(netdev);
860 }
861 }
862
863 /*
864 * Release our reference to this URB, the USB core will eventually free
865 * it entirely.
866 */
867 usb_free_urb(urb);
868
869 return NETDEV_TX_OK;
870
871 nomem:
872 dev_kfree_skb(skb);
873 stats->tx_dropped++;
874
875 return NETDEV_TX_OK;
876 }
877
ems_usb_close(struct net_device * netdev)878 static int ems_usb_close(struct net_device *netdev)
879 {
880 struct ems_usb *dev = netdev_priv(netdev);
881
882 /* Stop polling */
883 unlink_all_urbs(dev);
884
885 netif_stop_queue(netdev);
886
887 /* Set CAN controller to reset mode */
888 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
889 netdev_warn(netdev, "couldn't stop device");
890
891 close_candev(netdev);
892
893 return 0;
894 }
895
896 static const struct net_device_ops ems_usb_netdev_ops = {
897 .ndo_open = ems_usb_open,
898 .ndo_stop = ems_usb_close,
899 .ndo_start_xmit = ems_usb_start_xmit,
900 .ndo_change_mtu = can_change_mtu,
901 };
902
903 static const struct can_bittiming_const ems_usb_bittiming_const = {
904 .name = "ems_usb",
905 .tseg1_min = 1,
906 .tseg1_max = 16,
907 .tseg2_min = 1,
908 .tseg2_max = 8,
909 .sjw_max = 4,
910 .brp_min = 1,
911 .brp_max = 64,
912 .brp_inc = 1,
913 };
914
ems_usb_set_mode(struct net_device * netdev,enum can_mode mode)915 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
916 {
917 struct ems_usb *dev = netdev_priv(netdev);
918
919 switch (mode) {
920 case CAN_MODE_START:
921 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
922 netdev_warn(netdev, "couldn't start device");
923
924 if (netif_queue_stopped(netdev))
925 netif_wake_queue(netdev);
926 break;
927
928 default:
929 return -EOPNOTSUPP;
930 }
931
932 return 0;
933 }
934
ems_usb_set_bittiming(struct net_device * netdev)935 static int ems_usb_set_bittiming(struct net_device *netdev)
936 {
937 struct ems_usb *dev = netdev_priv(netdev);
938 struct can_bittiming *bt = &dev->can.bittiming;
939 u8 btr0, btr1;
940
941 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
942 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
943 (((bt->phase_seg2 - 1) & 0x7) << 4);
944 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
945 btr1 |= 0x80;
946
947 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
948
949 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
950 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
951
952 return ems_usb_command_msg(dev, &dev->active_params);
953 }
954
init_params_sja1000(struct ems_cpc_msg * msg)955 static void init_params_sja1000(struct ems_cpc_msg *msg)
956 {
957 struct cpc_sja1000_params *sja1000 =
958 &msg->msg.can_params.cc_params.sja1000;
959
960 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
961 msg->length = sizeof(struct cpc_can_params);
962 msg->msgid = 0;
963
964 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
965
966 /* Acceptance filter open */
967 sja1000->acc_code0 = 0x00;
968 sja1000->acc_code1 = 0x00;
969 sja1000->acc_code2 = 0x00;
970 sja1000->acc_code3 = 0x00;
971
972 /* Acceptance filter open */
973 sja1000->acc_mask0 = 0xFF;
974 sja1000->acc_mask1 = 0xFF;
975 sja1000->acc_mask2 = 0xFF;
976 sja1000->acc_mask3 = 0xFF;
977
978 sja1000->btr0 = 0;
979 sja1000->btr1 = 0;
980
981 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
982 sja1000->mode = SJA1000_MOD_RM;
983 }
984
985 /*
986 * probe function for new CPC-USB devices
987 */
ems_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)988 static int ems_usb_probe(struct usb_interface *intf,
989 const struct usb_device_id *id)
990 {
991 struct net_device *netdev;
992 struct ems_usb *dev;
993 int i, err = -ENOMEM;
994
995 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
996 if (!netdev) {
997 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
998 return -ENOMEM;
999 }
1000
1001 dev = netdev_priv(netdev);
1002
1003 dev->udev = interface_to_usbdev(intf);
1004 dev->netdev = netdev;
1005
1006 dev->can.state = CAN_STATE_STOPPED;
1007 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1008 dev->can.bittiming_const = &ems_usb_bittiming_const;
1009 dev->can.do_set_bittiming = ems_usb_set_bittiming;
1010 dev->can.do_set_mode = ems_usb_set_mode;
1011 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
1012
1013 netdev->netdev_ops = &ems_usb_netdev_ops;
1014
1015 netdev->flags |= IFF_ECHO; /* we support local echo */
1016
1017 init_usb_anchor(&dev->rx_submitted);
1018
1019 init_usb_anchor(&dev->tx_submitted);
1020 atomic_set(&dev->active_tx_urbs, 0);
1021
1022 for (i = 0; i < MAX_TX_URBS; i++)
1023 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1024
1025 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1026 if (!dev->intr_urb) {
1027 dev_err(&intf->dev, "Couldn't alloc intr URB\n");
1028 goto cleanup_candev;
1029 }
1030
1031 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1032 if (!dev->intr_in_buffer)
1033 goto cleanup_intr_urb;
1034
1035 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1036 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1037 if (!dev->tx_msg_buffer)
1038 goto cleanup_intr_in_buffer;
1039
1040 usb_set_intfdata(intf, dev);
1041
1042 SET_NETDEV_DEV(netdev, &intf->dev);
1043
1044 init_params_sja1000(&dev->active_params);
1045
1046 err = ems_usb_command_msg(dev, &dev->active_params);
1047 if (err) {
1048 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1049 goto cleanup_tx_msg_buffer;
1050 }
1051
1052 err = register_candev(netdev);
1053 if (err) {
1054 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1055 goto cleanup_tx_msg_buffer;
1056 }
1057
1058 return 0;
1059
1060 cleanup_tx_msg_buffer:
1061 kfree(dev->tx_msg_buffer);
1062
1063 cleanup_intr_in_buffer:
1064 kfree(dev->intr_in_buffer);
1065
1066 cleanup_intr_urb:
1067 usb_free_urb(dev->intr_urb);
1068
1069 cleanup_candev:
1070 free_candev(netdev);
1071
1072 return err;
1073 }
1074
1075 /*
1076 * called by the usb core when the device is removed from the system
1077 */
ems_usb_disconnect(struct usb_interface * intf)1078 static void ems_usb_disconnect(struct usb_interface *intf)
1079 {
1080 struct ems_usb *dev = usb_get_intfdata(intf);
1081
1082 usb_set_intfdata(intf, NULL);
1083
1084 if (dev) {
1085 unregister_netdev(dev->netdev);
1086
1087 unlink_all_urbs(dev);
1088
1089 usb_free_urb(dev->intr_urb);
1090
1091 kfree(dev->intr_in_buffer);
1092 kfree(dev->tx_msg_buffer);
1093
1094 free_candev(dev->netdev);
1095 }
1096 }
1097
1098 /* usb specific object needed to register this driver with the usb subsystem */
1099 static struct usb_driver ems_usb_driver = {
1100 .name = "ems_usb",
1101 .probe = ems_usb_probe,
1102 .disconnect = ems_usb_disconnect,
1103 .id_table = ems_usb_table,
1104 };
1105
1106 module_usb_driver(ems_usb_driver);
1107