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