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/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
64struct 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 */
71struct 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 */
91struct __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 */
102struct __packed mcba_usb_msg {
103	u8 cmd_id;
104	u8 unused[18];
105};
106
107struct __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
115struct __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
132struct __packed mcba_usb_msg_change_bitrate {
133	u8 cmd_id;
134	__be16 bitrate;
135	u8 unused[16];
136};
137
138struct __packed mcba_usb_msg_termination {
139	u8 cmd_id;
140	u8 termination;
141	u8 unused[17];
142};
143
144struct __packed mcba_usb_msg_fw_ver {
145	u8 cmd_id;
146	u8 pic;
147	u8 unused[17];
148};
149
150static const struct usb_device_id mcba_usb_table[] = {
151	{ USB_DEVICE(MCBA_VENDOR_ID, MCBA_PRODUCT_ID) },
152	{} /* Terminating entry */
153};
154
155MODULE_DEVICE_TABLE(usb, mcba_usb_table);
156
157static const u16 mcba_termination[] = { MCBA_TERMINATION_DISABLED,
158					MCBA_TERMINATION_ENABLED };
159
160static 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
165static 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
177static 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 */
208static 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
219static 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 */
249static 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
288failed:
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
298nomembuf:
299	usb_free_urb(urb);
300
301	return err;
302}
303
304/* Send data to device */
305static 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
362xmit_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 */
371static 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
392static 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
403static 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
413static 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
460static 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
476static 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
486static 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
523static 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 */
562static 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
604resubmit_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 */
621static 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 */
691static 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
709static 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 */
723static 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 */
744static int mcba_net_set_mode(struct net_device *netdev, enum can_mode mode)
745{
746	return 0;
747}
748
749static 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
760static 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};
765
766static const struct ethtool_ops mcba_ethtool_ops = {
767	.get_ts_info = ethtool_op_get_ts_info,
768};
769
770/* Microchip CANBUS has hardcoded bittiming values by default.
771 * This function sends request via USB to change the speed and align bittiming
772 * values for presentation purposes only
773 */
774static int mcba_net_set_bittiming(struct net_device *netdev)
775{
776	struct mcba_priv *priv = netdev_priv(netdev);
777	const u16 bitrate_kbps = priv->can.bittiming.bitrate / 1000;
778
779	mcba_usb_xmit_change_bitrate(priv, bitrate_kbps);
780
781	return 0;
782}
783
784static int mcba_set_termination(struct net_device *netdev, u16 term)
785{
786	struct mcba_priv *priv = netdev_priv(netdev);
787	struct mcba_usb_msg_termination usb_msg = {
788		.cmd_id = MBCA_CMD_SETUP_TERMINATION_RESISTANCE
789	};
790
791	if (term == MCBA_TERMINATION_ENABLED)
792		usb_msg.termination = MCBA_VER_TERMINATION_ON;
793	else
794		usb_msg.termination = MCBA_VER_TERMINATION_OFF;
795
796	mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
797
798	return 0;
799}
800
801static int mcba_usb_probe(struct usb_interface *intf,
802			  const struct usb_device_id *id)
803{
804	struct net_device *netdev;
805	struct mcba_priv *priv;
806	int err;
807	struct usb_device *usbdev = interface_to_usbdev(intf);
808	struct usb_endpoint_descriptor *in, *out;
809
810	err = usb_find_common_endpoints(intf->cur_altsetting, &in, &out, NULL, NULL);
811	if (err) {
812		dev_err(&intf->dev, "Can't find endpoints\n");
813		return err;
814	}
815
816	netdev = alloc_candev(sizeof(struct mcba_priv), MCBA_MAX_TX_URBS);
817	if (!netdev) {
818		dev_err(&intf->dev, "Couldn't alloc candev\n");
819		return -ENOMEM;
820	}
821
822	priv = netdev_priv(netdev);
823
824	priv->udev = usbdev;
825	priv->netdev = netdev;
826	priv->usb_ka_first_pass = true;
827	priv->can_ka_first_pass = true;
828	priv->can_speed_check = false;
829
830	init_usb_anchor(&priv->rx_submitted);
831	init_usb_anchor(&priv->tx_submitted);
832
833	usb_set_intfdata(intf, priv);
834
835	/* Init CAN device */
836	priv->can.state = CAN_STATE_STOPPED;
837	priv->can.termination_const = mcba_termination;
838	priv->can.termination_const_cnt = ARRAY_SIZE(mcba_termination);
839	priv->can.bitrate_const = mcba_bitrate;
840	priv->can.bitrate_const_cnt = ARRAY_SIZE(mcba_bitrate);
841
842	priv->can.do_set_termination = mcba_set_termination;
843	priv->can.do_set_mode = mcba_net_set_mode;
844	priv->can.do_get_berr_counter = mcba_net_get_berr_counter;
845	priv->can.do_set_bittiming = mcba_net_set_bittiming;
846
847	netdev->netdev_ops = &mcba_netdev_ops;
848	netdev->ethtool_ops = &mcba_ethtool_ops;
849
850	netdev->flags |= IFF_ECHO; /* we support local echo */
851
852	SET_NETDEV_DEV(netdev, &intf->dev);
853
854	err = register_candev(netdev);
855	if (err) {
856		netdev_err(netdev, "couldn't register CAN device: %d\n", err);
857
858		goto cleanup_free_candev;
859	}
860
861	priv->rx_pipe = usb_rcvbulkpipe(priv->udev, in->bEndpointAddress);
862	priv->tx_pipe = usb_sndbulkpipe(priv->udev, out->bEndpointAddress);
863
864	/* Start USB dev only if we have successfully registered CAN device */
865	err = mcba_usb_start(priv);
866	if (err) {
867		if (err == -ENODEV)
868			netif_device_detach(priv->netdev);
869
870		netdev_warn(netdev, "couldn't start device: %d\n", err);
871
872		goto cleanup_unregister_candev;
873	}
874
875	dev_info(&intf->dev, "Microchip CAN BUS Analyzer connected\n");
876
877	return 0;
878
879cleanup_unregister_candev:
880	unregister_candev(priv->netdev);
881
882cleanup_free_candev:
883	free_candev(netdev);
884
885	return err;
886}
887
888/* Called by the usb core when driver is unloaded or device is removed */
889static void mcba_usb_disconnect(struct usb_interface *intf)
890{
891	struct mcba_priv *priv = usb_get_intfdata(intf);
892
893	usb_set_intfdata(intf, NULL);
894
895	netdev_info(priv->netdev, "device disconnected\n");
896
897	unregister_candev(priv->netdev);
898	mcba_urb_unlink(priv);
899	free_candev(priv->netdev);
900}
901
902static struct usb_driver mcba_usb_driver = {
903	.name = MCBA_MODULE_NAME,
904	.probe = mcba_usb_probe,
905	.disconnect = mcba_usb_disconnect,
906	.id_table = mcba_usb_table,
907};
908
909module_usb_driver(mcba_usb_driver);
910
911MODULE_AUTHOR("Remigiusz Ko������taj <remigiusz.kollataj@mobica.com>");
912MODULE_DESCRIPTION("SocketCAN driver for Microchip CAN BUS Analyzer Tool");
913MODULE_LICENSE("GPL v2");
914