1 // SPDX-License-Identifier: GPL-2.0-only
2 /* SocketCAN driver for Microchip CAN BUS Analyzer Tool
3 *
4 * Copyright (C) 2017 Mobica Limited
5 *
6 * This driver is inspired by the 4.6.2 version of net/can/usb/usb_8dev.c
7 */
8
9 #include <linux/unaligned.h>
10 #include <linux/can.h>
11 #include <linux/can/dev.h>
12 #include <linux/can/error.h>
13 #include <linux/ethtool.h>
14 #include <linux/module.h>
15 #include <linux/netdevice.h>
16 #include <linux/signal.h>
17 #include <linux/slab.h>
18 #include <linux/usb.h>
19
20 /* vendor and product id */
21 #define MCBA_MODULE_NAME "mcba_usb"
22 #define MCBA_VENDOR_ID 0x04d8
23 #define MCBA_PRODUCT_ID 0x0a30
24
25 /* driver constants */
26 #define MCBA_MAX_RX_URBS 20
27 #define MCBA_MAX_TX_URBS 20
28 #define MCBA_CTX_FREE MCBA_MAX_TX_URBS
29
30 /* RX buffer must be bigger than msg size since at the
31 * beginning USB messages are stacked.
32 */
33 #define MCBA_USB_RX_BUFF_SIZE 64
34 #define MCBA_USB_TX_BUFF_SIZE (sizeof(struct mcba_usb_msg))
35
36 /* Microchip command id */
37 #define MBCA_CMD_RECEIVE_MESSAGE 0xE3
38 #define MBCA_CMD_I_AM_ALIVE_FROM_CAN 0xF5
39 #define MBCA_CMD_I_AM_ALIVE_FROM_USB 0xF7
40 #define MBCA_CMD_CHANGE_BIT_RATE 0xA1
41 #define MBCA_CMD_TRANSMIT_MESSAGE_EV 0xA3
42 #define MBCA_CMD_SETUP_TERMINATION_RESISTANCE 0xA8
43 #define MBCA_CMD_READ_FW_VERSION 0xA9
44 #define MBCA_CMD_NOTHING_TO_SEND 0xFF
45 #define MBCA_CMD_TRANSMIT_MESSAGE_RSP 0xE2
46
47 #define MCBA_VER_REQ_USB 1
48 #define MCBA_VER_REQ_CAN 2
49
50 /* Drive the CAN_RES signal LOW "0" to activate R24 and R25 */
51 #define MCBA_VER_TERMINATION_ON 0
52 #define MCBA_VER_TERMINATION_OFF 1
53
54 #define MCBA_SIDL_EXID_MASK 0x8
55 #define MCBA_DLC_MASK 0xf
56 #define MCBA_DLC_RTR_MASK 0x40
57
58 #define MCBA_CAN_STATE_WRN_TH 95
59 #define MCBA_CAN_STATE_ERR_PSV_TH 127
60
61 #define MCBA_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
62 #define MCBA_TERMINATION_ENABLED 120
63
64 struct mcba_usb_ctx {
65 struct mcba_priv *priv;
66 u32 ndx;
67 bool can;
68 };
69
70 /* Structure to hold all of our device specific stuff */
71 struct mcba_priv {
72 struct can_priv can; /* must be the first member */
73 struct sk_buff *echo_skb[MCBA_MAX_TX_URBS];
74 struct mcba_usb_ctx tx_context[MCBA_MAX_TX_URBS];
75 struct usb_device *udev;
76 struct net_device *netdev;
77 struct usb_anchor tx_submitted;
78 struct usb_anchor rx_submitted;
79 struct can_berr_counter bec;
80 bool usb_ka_first_pass;
81 bool can_ka_first_pass;
82 bool can_speed_check;
83 atomic_t free_ctx_cnt;
84 void *rxbuf[MCBA_MAX_RX_URBS];
85 dma_addr_t rxbuf_dma[MCBA_MAX_RX_URBS];
86 int rx_pipe;
87 int tx_pipe;
88 };
89
90 /* CAN frame */
91 struct __packed mcba_usb_msg_can {
92 u8 cmd_id;
93 __be16 eid;
94 __be16 sid;
95 u8 dlc;
96 u8 data[8];
97 u8 timestamp[4];
98 u8 checksum;
99 };
100
101 /* command frame */
102 struct __packed mcba_usb_msg {
103 u8 cmd_id;
104 u8 unused[18];
105 };
106
107 struct __packed mcba_usb_msg_ka_usb {
108 u8 cmd_id;
109 u8 termination_state;
110 u8 soft_ver_major;
111 u8 soft_ver_minor;
112 u8 unused[15];
113 };
114
115 struct __packed mcba_usb_msg_ka_can {
116 u8 cmd_id;
117 u8 tx_err_cnt;
118 u8 rx_err_cnt;
119 u8 rx_buff_ovfl;
120 u8 tx_bus_off;
121 __be16 can_bitrate;
122 __le16 rx_lost;
123 u8 can_stat;
124 u8 soft_ver_major;
125 u8 soft_ver_minor;
126 u8 debug_mode;
127 u8 test_complete;
128 u8 test_result;
129 u8 unused[4];
130 };
131
132 struct __packed mcba_usb_msg_change_bitrate {
133 u8 cmd_id;
134 __be16 bitrate;
135 u8 unused[16];
136 };
137
138 struct __packed mcba_usb_msg_termination {
139 u8 cmd_id;
140 u8 termination;
141 u8 unused[17];
142 };
143
144 struct __packed mcba_usb_msg_fw_ver {
145 u8 cmd_id;
146 u8 pic;
147 u8 unused[17];
148 };
149
150 static const struct usb_device_id mcba_usb_table[] = {
151 { USB_DEVICE(MCBA_VENDOR_ID, MCBA_PRODUCT_ID) },
152 {} /* Terminating entry */
153 };
154
155 MODULE_DEVICE_TABLE(usb, mcba_usb_table);
156
157 static const u16 mcba_termination[] = { MCBA_TERMINATION_DISABLED,
158 MCBA_TERMINATION_ENABLED };
159
160 static const u32 mcba_bitrate[] = { 20000, 33333, 50000, 80000, 83333,
161 100000, 125000, 150000, 175000, 200000,
162 225000, 250000, 275000, 300000, 500000,
163 625000, 800000, 1000000 };
164
mcba_init_ctx(struct mcba_priv * priv)165 static inline void mcba_init_ctx(struct mcba_priv *priv)
166 {
167 int i = 0;
168
169 for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
170 priv->tx_context[i].ndx = MCBA_CTX_FREE;
171 priv->tx_context[i].priv = priv;
172 }
173
174 atomic_set(&priv->free_ctx_cnt, ARRAY_SIZE(priv->tx_context));
175 }
176
mcba_usb_get_free_ctx(struct mcba_priv * priv,struct can_frame * cf)177 static inline struct mcba_usb_ctx *mcba_usb_get_free_ctx(struct mcba_priv *priv,
178 struct can_frame *cf)
179 {
180 int i = 0;
181 struct mcba_usb_ctx *ctx = NULL;
182
183 for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
184 if (priv->tx_context[i].ndx == MCBA_CTX_FREE) {
185 ctx = &priv->tx_context[i];
186 ctx->ndx = i;
187
188 if (cf)
189 ctx->can = true;
190 else
191 ctx->can = false;
192
193 atomic_dec(&priv->free_ctx_cnt);
194 break;
195 }
196 }
197
198 if (!atomic_read(&priv->free_ctx_cnt))
199 /* That was the last free ctx. Slow down tx path */
200 netif_stop_queue(priv->netdev);
201
202 return ctx;
203 }
204
205 /* mcba_usb_free_ctx and mcba_usb_get_free_ctx are executed by different
206 * threads. The order of execution in below function is important.
207 */
mcba_usb_free_ctx(struct mcba_usb_ctx * ctx)208 static inline void mcba_usb_free_ctx(struct mcba_usb_ctx *ctx)
209 {
210 /* Increase number of free ctxs before freeing ctx */
211 atomic_inc(&ctx->priv->free_ctx_cnt);
212
213 ctx->ndx = MCBA_CTX_FREE;
214
215 /* Wake up the queue once ctx is marked free */
216 netif_wake_queue(ctx->priv->netdev);
217 }
218
mcba_usb_write_bulk_callback(struct urb * urb)219 static void mcba_usb_write_bulk_callback(struct urb *urb)
220 {
221 struct mcba_usb_ctx *ctx = urb->context;
222 struct net_device *netdev;
223
224 WARN_ON(!ctx);
225
226 netdev = ctx->priv->netdev;
227
228 /* free up our allocated buffer */
229 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
230 urb->transfer_buffer, urb->transfer_dma);
231
232 if (ctx->can) {
233 if (!netif_device_present(netdev))
234 return;
235
236 netdev->stats.tx_packets++;
237 netdev->stats.tx_bytes += can_get_echo_skb(netdev, ctx->ndx,
238 NULL);
239 }
240
241 if (urb->status)
242 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
243
244 /* Release the context */
245 mcba_usb_free_ctx(ctx);
246 }
247
248 /* Send data to device */
mcba_usb_xmit(struct mcba_priv * priv,struct mcba_usb_msg * usb_msg,struct mcba_usb_ctx * ctx)249 static netdev_tx_t mcba_usb_xmit(struct mcba_priv *priv,
250 struct mcba_usb_msg *usb_msg,
251 struct mcba_usb_ctx *ctx)
252 {
253 struct urb *urb;
254 u8 *buf;
255 int err;
256
257 /* create a URB, and a buffer for it, and copy the data to the URB */
258 urb = usb_alloc_urb(0, GFP_ATOMIC);
259 if (!urb)
260 return -ENOMEM;
261
262 buf = usb_alloc_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, GFP_ATOMIC,
263 &urb->transfer_dma);
264 if (!buf) {
265 err = -ENOMEM;
266 goto nomembuf;
267 }
268
269 memcpy(buf, usb_msg, MCBA_USB_TX_BUFF_SIZE);
270
271 usb_fill_bulk_urb(urb, priv->udev, priv->tx_pipe, buf, MCBA_USB_TX_BUFF_SIZE,
272 mcba_usb_write_bulk_callback, ctx);
273
274 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
275 usb_anchor_urb(urb, &priv->tx_submitted);
276
277 err = usb_submit_urb(urb, GFP_ATOMIC);
278 if (unlikely(err))
279 goto failed;
280
281 /* Release our reference to this URB, the USB core will eventually free
282 * it entirely.
283 */
284 usb_free_urb(urb);
285
286 return 0;
287
288 failed:
289 usb_unanchor_urb(urb);
290 usb_free_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, buf,
291 urb->transfer_dma);
292
293 if (err == -ENODEV)
294 netif_device_detach(priv->netdev);
295 else
296 netdev_warn(priv->netdev, "failed tx_urb %d\n", err);
297
298 nomembuf:
299 usb_free_urb(urb);
300
301 return err;
302 }
303
304 /* Send data to device */
mcba_usb_start_xmit(struct sk_buff * skb,struct net_device * netdev)305 static netdev_tx_t mcba_usb_start_xmit(struct sk_buff *skb,
306 struct net_device *netdev)
307 {
308 struct mcba_priv *priv = netdev_priv(netdev);
309 struct can_frame *cf = (struct can_frame *)skb->data;
310 struct mcba_usb_ctx *ctx = NULL;
311 struct net_device_stats *stats = &priv->netdev->stats;
312 u16 sid;
313 int err;
314 struct mcba_usb_msg_can usb_msg = {
315 .cmd_id = MBCA_CMD_TRANSMIT_MESSAGE_EV
316 };
317
318 if (can_dev_dropped_skb(netdev, skb))
319 return NETDEV_TX_OK;
320
321 ctx = mcba_usb_get_free_ctx(priv, cf);
322 if (!ctx)
323 return NETDEV_TX_BUSY;
324
325 if (cf->can_id & CAN_EFF_FLAG) {
326 /* SIDH | SIDL | EIDH | EIDL
327 * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0
328 */
329 sid = MCBA_SIDL_EXID_MASK;
330 /* store 28-18 bits */
331 sid |= (cf->can_id & 0x1ffc0000) >> 13;
332 /* store 17-16 bits */
333 sid |= (cf->can_id & 0x30000) >> 16;
334 put_unaligned_be16(sid, &usb_msg.sid);
335
336 /* store 15-0 bits */
337 put_unaligned_be16(cf->can_id & 0xffff, &usb_msg.eid);
338 } else {
339 /* SIDH | SIDL
340 * 10 - 3 | 2 1 0 x x x x x
341 */
342 put_unaligned_be16((cf->can_id & CAN_SFF_MASK) << 5,
343 &usb_msg.sid);
344 usb_msg.eid = 0;
345 }
346
347 usb_msg.dlc = cf->len;
348
349 memcpy(usb_msg.data, cf->data, usb_msg.dlc);
350
351 if (cf->can_id & CAN_RTR_FLAG)
352 usb_msg.dlc |= MCBA_DLC_RTR_MASK;
353
354 can_put_echo_skb(skb, priv->netdev, ctx->ndx, 0);
355
356 err = mcba_usb_xmit(priv, (struct mcba_usb_msg *)&usb_msg, ctx);
357 if (err)
358 goto xmit_failed;
359
360 return NETDEV_TX_OK;
361
362 xmit_failed:
363 can_free_echo_skb(priv->netdev, ctx->ndx, NULL);
364 mcba_usb_free_ctx(ctx);
365 stats->tx_dropped++;
366
367 return NETDEV_TX_OK;
368 }
369
370 /* Send cmd to device */
mcba_usb_xmit_cmd(struct mcba_priv * priv,struct mcba_usb_msg * usb_msg)371 static void mcba_usb_xmit_cmd(struct mcba_priv *priv,
372 struct mcba_usb_msg *usb_msg)
373 {
374 struct mcba_usb_ctx *ctx = NULL;
375 int err;
376
377 ctx = mcba_usb_get_free_ctx(priv, NULL);
378 if (!ctx) {
379 netdev_err(priv->netdev,
380 "Lack of free ctx. Sending (%d) cmd aborted",
381 usb_msg->cmd_id);
382
383 return;
384 }
385
386 err = mcba_usb_xmit(priv, usb_msg, ctx);
387 if (err)
388 netdev_err(priv->netdev, "Failed to send cmd (%d)",
389 usb_msg->cmd_id);
390 }
391
mcba_usb_xmit_change_bitrate(struct mcba_priv * priv,u16 bitrate)392 static void mcba_usb_xmit_change_bitrate(struct mcba_priv *priv, u16 bitrate)
393 {
394 struct mcba_usb_msg_change_bitrate usb_msg = {
395 .cmd_id = MBCA_CMD_CHANGE_BIT_RATE
396 };
397
398 put_unaligned_be16(bitrate, &usb_msg.bitrate);
399
400 mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
401 }
402
mcba_usb_xmit_read_fw_ver(struct mcba_priv * priv,u8 pic)403 static void mcba_usb_xmit_read_fw_ver(struct mcba_priv *priv, u8 pic)
404 {
405 struct mcba_usb_msg_fw_ver usb_msg = {
406 .cmd_id = MBCA_CMD_READ_FW_VERSION,
407 .pic = pic
408 };
409
410 mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
411 }
412
mcba_usb_process_can(struct mcba_priv * priv,struct mcba_usb_msg_can * msg)413 static void mcba_usb_process_can(struct mcba_priv *priv,
414 struct mcba_usb_msg_can *msg)
415 {
416 struct can_frame *cf;
417 struct sk_buff *skb;
418 struct net_device_stats *stats = &priv->netdev->stats;
419 u16 sid;
420
421 skb = alloc_can_skb(priv->netdev, &cf);
422 if (!skb)
423 return;
424
425 sid = get_unaligned_be16(&msg->sid);
426
427 if (sid & MCBA_SIDL_EXID_MASK) {
428 /* SIDH | SIDL | EIDH | EIDL
429 * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0
430 */
431 cf->can_id = CAN_EFF_FLAG;
432
433 /* store 28-18 bits */
434 cf->can_id |= (sid & 0xffe0) << 13;
435 /* store 17-16 bits */
436 cf->can_id |= (sid & 3) << 16;
437 /* store 15-0 bits */
438 cf->can_id |= get_unaligned_be16(&msg->eid);
439 } else {
440 /* SIDH | SIDL
441 * 10 - 3 | 2 1 0 x x x x x
442 */
443 cf->can_id = (sid & 0xffe0) >> 5;
444 }
445
446 cf->len = can_cc_dlc2len(msg->dlc & MCBA_DLC_MASK);
447
448 if (msg->dlc & MCBA_DLC_RTR_MASK) {
449 cf->can_id |= CAN_RTR_FLAG;
450 } else {
451 memcpy(cf->data, msg->data, cf->len);
452
453 stats->rx_bytes += cf->len;
454 }
455 stats->rx_packets++;
456
457 netif_rx(skb);
458 }
459
mcba_usb_process_ka_usb(struct mcba_priv * priv,struct mcba_usb_msg_ka_usb * msg)460 static void mcba_usb_process_ka_usb(struct mcba_priv *priv,
461 struct mcba_usb_msg_ka_usb *msg)
462 {
463 if (unlikely(priv->usb_ka_first_pass)) {
464 netdev_info(priv->netdev, "PIC USB version %u.%u\n",
465 msg->soft_ver_major, msg->soft_ver_minor);
466
467 priv->usb_ka_first_pass = false;
468 }
469
470 if (msg->termination_state == MCBA_VER_TERMINATION_ON)
471 priv->can.termination = MCBA_TERMINATION_ENABLED;
472 else
473 priv->can.termination = MCBA_TERMINATION_DISABLED;
474 }
475
convert_can2host_bitrate(struct mcba_usb_msg_ka_can * msg)476 static u32 convert_can2host_bitrate(struct mcba_usb_msg_ka_can *msg)
477 {
478 const u32 bitrate = get_unaligned_be16(&msg->can_bitrate);
479
480 if ((bitrate == 33) || (bitrate == 83))
481 return bitrate * 1000 + 333;
482 else
483 return bitrate * 1000;
484 }
485
mcba_usb_process_ka_can(struct mcba_priv * priv,struct mcba_usb_msg_ka_can * msg)486 static void mcba_usb_process_ka_can(struct mcba_priv *priv,
487 struct mcba_usb_msg_ka_can *msg)
488 {
489 if (unlikely(priv->can_ka_first_pass)) {
490 netdev_info(priv->netdev, "PIC CAN version %u.%u\n",
491 msg->soft_ver_major, msg->soft_ver_minor);
492
493 priv->can_ka_first_pass = false;
494 }
495
496 if (unlikely(priv->can_speed_check)) {
497 const u32 bitrate = convert_can2host_bitrate(msg);
498
499 priv->can_speed_check = false;
500
501 if (bitrate != priv->can.bittiming.bitrate)
502 netdev_err(
503 priv->netdev,
504 "Wrong bitrate reported by the device (%u). Expected %u",
505 bitrate, priv->can.bittiming.bitrate);
506 }
507
508 priv->bec.txerr = msg->tx_err_cnt;
509 priv->bec.rxerr = msg->rx_err_cnt;
510
511 if (msg->tx_bus_off)
512 priv->can.state = CAN_STATE_BUS_OFF;
513
514 else if ((priv->bec.txerr > MCBA_CAN_STATE_ERR_PSV_TH) ||
515 (priv->bec.rxerr > MCBA_CAN_STATE_ERR_PSV_TH))
516 priv->can.state = CAN_STATE_ERROR_PASSIVE;
517
518 else if ((priv->bec.txerr > MCBA_CAN_STATE_WRN_TH) ||
519 (priv->bec.rxerr > MCBA_CAN_STATE_WRN_TH))
520 priv->can.state = CAN_STATE_ERROR_WARNING;
521 }
522
mcba_usb_process_rx(struct mcba_priv * priv,struct mcba_usb_msg * msg)523 static void mcba_usb_process_rx(struct mcba_priv *priv,
524 struct mcba_usb_msg *msg)
525 {
526 switch (msg->cmd_id) {
527 case MBCA_CMD_I_AM_ALIVE_FROM_CAN:
528 mcba_usb_process_ka_can(priv,
529 (struct mcba_usb_msg_ka_can *)msg);
530 break;
531
532 case MBCA_CMD_I_AM_ALIVE_FROM_USB:
533 mcba_usb_process_ka_usb(priv,
534 (struct mcba_usb_msg_ka_usb *)msg);
535 break;
536
537 case MBCA_CMD_RECEIVE_MESSAGE:
538 mcba_usb_process_can(priv, (struct mcba_usb_msg_can *)msg);
539 break;
540
541 case MBCA_CMD_NOTHING_TO_SEND:
542 /* Side effect of communication between PIC_USB and PIC_CAN.
543 * PIC_CAN is telling us that it has nothing to send
544 */
545 break;
546
547 case MBCA_CMD_TRANSMIT_MESSAGE_RSP:
548 /* Transmission response from the device containing timestamp */
549 break;
550
551 default:
552 netdev_warn(priv->netdev, "Unsupported msg (0x%X)",
553 msg->cmd_id);
554 break;
555 }
556 }
557
558 /* Callback for reading data from device
559 *
560 * Check urb status, call read function and resubmit urb read operation.
561 */
mcba_usb_read_bulk_callback(struct urb * urb)562 static void mcba_usb_read_bulk_callback(struct urb *urb)
563 {
564 struct mcba_priv *priv = urb->context;
565 struct net_device *netdev;
566 int retval;
567 int pos = 0;
568
569 netdev = priv->netdev;
570
571 if (!netif_device_present(netdev))
572 return;
573
574 switch (urb->status) {
575 case 0: /* success */
576 break;
577
578 case -ENOENT:
579 case -EPIPE:
580 case -EPROTO:
581 case -ESHUTDOWN:
582 return;
583
584 default:
585 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
586
587 goto resubmit_urb;
588 }
589
590 while (pos < urb->actual_length) {
591 struct mcba_usb_msg *msg;
592
593 if (pos + sizeof(struct mcba_usb_msg) > urb->actual_length) {
594 netdev_err(priv->netdev, "format error\n");
595 break;
596 }
597
598 msg = (struct mcba_usb_msg *)(urb->transfer_buffer + pos);
599 mcba_usb_process_rx(priv, msg);
600
601 pos += sizeof(struct mcba_usb_msg);
602 }
603
604 resubmit_urb:
605
606 usb_fill_bulk_urb(urb, priv->udev,
607 priv->rx_pipe,
608 urb->transfer_buffer, MCBA_USB_RX_BUFF_SIZE,
609 mcba_usb_read_bulk_callback, priv);
610
611 retval = usb_submit_urb(urb, GFP_ATOMIC);
612
613 if (retval == -ENODEV)
614 netif_device_detach(netdev);
615 else if (retval)
616 netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
617 retval);
618 }
619
620 /* Start USB device */
mcba_usb_start(struct mcba_priv * priv)621 static int mcba_usb_start(struct mcba_priv *priv)
622 {
623 struct net_device *netdev = priv->netdev;
624 int err, i;
625
626 mcba_init_ctx(priv);
627
628 for (i = 0; i < MCBA_MAX_RX_URBS; i++) {
629 struct urb *urb = NULL;
630 u8 *buf;
631 dma_addr_t buf_dma;
632
633 /* create a URB, and a buffer for it */
634 urb = usb_alloc_urb(0, GFP_KERNEL);
635 if (!urb) {
636 err = -ENOMEM;
637 break;
638 }
639
640 buf = usb_alloc_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
641 GFP_KERNEL, &buf_dma);
642 if (!buf) {
643 netdev_err(netdev, "No memory left for USB buffer\n");
644 usb_free_urb(urb);
645 err = -ENOMEM;
646 break;
647 }
648
649 urb->transfer_dma = buf_dma;
650
651 usb_fill_bulk_urb(urb, priv->udev,
652 priv->rx_pipe,
653 buf, MCBA_USB_RX_BUFF_SIZE,
654 mcba_usb_read_bulk_callback, priv);
655 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
656 usb_anchor_urb(urb, &priv->rx_submitted);
657
658 err = usb_submit_urb(urb, GFP_KERNEL);
659 if (err) {
660 usb_unanchor_urb(urb);
661 usb_free_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
662 buf, buf_dma);
663 usb_free_urb(urb);
664 break;
665 }
666
667 priv->rxbuf[i] = buf;
668 priv->rxbuf_dma[i] = buf_dma;
669
670 /* Drop reference, USB core will take care of freeing it */
671 usb_free_urb(urb);
672 }
673
674 /* Did we submit any URBs */
675 if (i == 0) {
676 netdev_warn(netdev, "couldn't setup read URBs\n");
677 return err;
678 }
679
680 /* Warn if we've couldn't transmit all the URBs */
681 if (i < MCBA_MAX_RX_URBS)
682 netdev_warn(netdev, "rx performance may be slow\n");
683
684 mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_USB);
685 mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_CAN);
686
687 return err;
688 }
689
690 /* Open USB device */
mcba_usb_open(struct net_device * netdev)691 static int mcba_usb_open(struct net_device *netdev)
692 {
693 struct mcba_priv *priv = netdev_priv(netdev);
694 int err;
695
696 /* common open */
697 err = open_candev(netdev);
698 if (err)
699 return err;
700
701 priv->can_speed_check = true;
702 priv->can.state = CAN_STATE_ERROR_ACTIVE;
703
704 netif_start_queue(netdev);
705
706 return 0;
707 }
708
mcba_urb_unlink(struct mcba_priv * priv)709 static void mcba_urb_unlink(struct mcba_priv *priv)
710 {
711 int i;
712
713 usb_kill_anchored_urbs(&priv->rx_submitted);
714
715 for (i = 0; i < MCBA_MAX_RX_URBS; ++i)
716 usb_free_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
717 priv->rxbuf[i], priv->rxbuf_dma[i]);
718
719 usb_kill_anchored_urbs(&priv->tx_submitted);
720 }
721
722 /* Close USB device */
mcba_usb_close(struct net_device * netdev)723 static int mcba_usb_close(struct net_device *netdev)
724 {
725 struct mcba_priv *priv = netdev_priv(netdev);
726
727 priv->can.state = CAN_STATE_STOPPED;
728
729 netif_stop_queue(netdev);
730
731 /* Stop polling */
732 mcba_urb_unlink(priv);
733
734 close_candev(netdev);
735
736 return 0;
737 }
738
739 /* Set network device mode
740 *
741 * Maybe we should leave this function empty, because the device
742 * set mode variable with open command.
743 */
mcba_net_set_mode(struct net_device * netdev,enum can_mode mode)744 static int mcba_net_set_mode(struct net_device *netdev, enum can_mode mode)
745 {
746 return 0;
747 }
748
mcba_net_get_berr_counter(const struct net_device * netdev,struct can_berr_counter * bec)749 static int mcba_net_get_berr_counter(const struct net_device *netdev,
750 struct can_berr_counter *bec)
751 {
752 struct mcba_priv *priv = netdev_priv(netdev);
753
754 bec->txerr = priv->bec.txerr;
755 bec->rxerr = priv->bec.rxerr;
756
757 return 0;
758 }
759
760 static const struct net_device_ops mcba_netdev_ops = {
761 .ndo_open = mcba_usb_open,
762 .ndo_stop = mcba_usb_close,
763 .ndo_start_xmit = mcba_usb_start_xmit,
764 .ndo_change_mtu = can_change_mtu,
765 };
766
767 static const struct ethtool_ops mcba_ethtool_ops = {
768 .get_ts_info = ethtool_op_get_ts_info,
769 };
770
771 /* Microchip CANBUS has hardcoded bittiming values by default.
772 * This function sends request via USB to change the speed and align bittiming
773 * values for presentation purposes only
774 */
mcba_net_set_bittiming(struct net_device * netdev)775 static int mcba_net_set_bittiming(struct net_device *netdev)
776 {
777 struct mcba_priv *priv = netdev_priv(netdev);
778 const u16 bitrate_kbps = priv->can.bittiming.bitrate / 1000;
779
780 mcba_usb_xmit_change_bitrate(priv, bitrate_kbps);
781
782 return 0;
783 }
784
mcba_set_termination(struct net_device * netdev,u16 term)785 static int mcba_set_termination(struct net_device *netdev, u16 term)
786 {
787 struct mcba_priv *priv = netdev_priv(netdev);
788 struct mcba_usb_msg_termination usb_msg = {
789 .cmd_id = MBCA_CMD_SETUP_TERMINATION_RESISTANCE
790 };
791
792 if (term == MCBA_TERMINATION_ENABLED)
793 usb_msg.termination = MCBA_VER_TERMINATION_ON;
794 else
795 usb_msg.termination = MCBA_VER_TERMINATION_OFF;
796
797 mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
798
799 return 0;
800 }
801
mcba_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)802 static int mcba_usb_probe(struct usb_interface *intf,
803 const struct usb_device_id *id)
804 {
805 struct net_device *netdev;
806 struct mcba_priv *priv;
807 int err;
808 struct usb_device *usbdev = interface_to_usbdev(intf);
809 struct usb_endpoint_descriptor *in, *out;
810
811 err = usb_find_common_endpoints(intf->cur_altsetting, &in, &out, NULL, NULL);
812 if (err) {
813 dev_err(&intf->dev, "Can't find endpoints\n");
814 return err;
815 }
816
817 netdev = alloc_candev(sizeof(struct mcba_priv), MCBA_MAX_TX_URBS);
818 if (!netdev) {
819 dev_err(&intf->dev, "Couldn't alloc candev\n");
820 return -ENOMEM;
821 }
822
823 priv = netdev_priv(netdev);
824
825 priv->udev = usbdev;
826 priv->netdev = netdev;
827 priv->usb_ka_first_pass = true;
828 priv->can_ka_first_pass = true;
829 priv->can_speed_check = false;
830
831 init_usb_anchor(&priv->rx_submitted);
832 init_usb_anchor(&priv->tx_submitted);
833
834 usb_set_intfdata(intf, priv);
835
836 /* Init CAN device */
837 priv->can.state = CAN_STATE_STOPPED;
838 priv->can.termination_const = mcba_termination;
839 priv->can.termination_const_cnt = ARRAY_SIZE(mcba_termination);
840 priv->can.bitrate_const = mcba_bitrate;
841 priv->can.bitrate_const_cnt = ARRAY_SIZE(mcba_bitrate);
842
843 priv->can.do_set_termination = mcba_set_termination;
844 priv->can.do_set_mode = mcba_net_set_mode;
845 priv->can.do_get_berr_counter = mcba_net_get_berr_counter;
846 priv->can.do_set_bittiming = mcba_net_set_bittiming;
847
848 netdev->netdev_ops = &mcba_netdev_ops;
849 netdev->ethtool_ops = &mcba_ethtool_ops;
850
851 netdev->flags |= IFF_ECHO; /* we support local echo */
852
853 SET_NETDEV_DEV(netdev, &intf->dev);
854
855 err = register_candev(netdev);
856 if (err) {
857 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
858
859 goto cleanup_free_candev;
860 }
861
862 priv->rx_pipe = usb_rcvbulkpipe(priv->udev, in->bEndpointAddress);
863 priv->tx_pipe = usb_sndbulkpipe(priv->udev, out->bEndpointAddress);
864
865 /* Start USB dev only if we have successfully registered CAN device */
866 err = mcba_usb_start(priv);
867 if (err) {
868 if (err == -ENODEV)
869 netif_device_detach(priv->netdev);
870
871 netdev_warn(netdev, "couldn't start device: %d\n", err);
872
873 goto cleanup_unregister_candev;
874 }
875
876 dev_info(&intf->dev, "Microchip CAN BUS Analyzer connected\n");
877
878 return 0;
879
880 cleanup_unregister_candev:
881 unregister_candev(priv->netdev);
882
883 cleanup_free_candev:
884 free_candev(netdev);
885
886 return err;
887 }
888
889 /* Called by the usb core when driver is unloaded or device is removed */
mcba_usb_disconnect(struct usb_interface * intf)890 static void mcba_usb_disconnect(struct usb_interface *intf)
891 {
892 struct mcba_priv *priv = usb_get_intfdata(intf);
893
894 usb_set_intfdata(intf, NULL);
895
896 netdev_info(priv->netdev, "device disconnected\n");
897
898 unregister_candev(priv->netdev);
899 mcba_urb_unlink(priv);
900 free_candev(priv->netdev);
901 }
902
903 static struct usb_driver mcba_usb_driver = {
904 .name = MCBA_MODULE_NAME,
905 .probe = mcba_usb_probe,
906 .disconnect = mcba_usb_disconnect,
907 .id_table = mcba_usb_table,
908 };
909
910 module_usb_driver(mcba_usb_driver);
911
912 MODULE_AUTHOR("Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>");
913 MODULE_DESCRIPTION("SocketCAN driver for Microchip CAN BUS Analyzer Tool");
914 MODULE_LICENSE("GPL v2");
915