xref: /openbmc/linux/drivers/net/can/usb/gs_usb.c (revision 88021836)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* CAN driver for Geschwister Schneider USB/CAN devices
3  * and bytewerk.org candleLight USB CAN interfaces.
4  *
5  * Copyright (C) 2013-2016 Geschwister Schneider Technologie-,
6  * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
7  * Copyright (C) 2016 Hubert Denkmair
8  *
9  * Many thanks to all socketcan devs!
10  */
11 
12 #include <linux/bitfield.h>
13 #include <linux/clocksource.h>
14 #include <linux/ethtool.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/netdevice.h>
18 #include <linux/signal.h>
19 #include <linux/timecounter.h>
20 #include <linux/units.h>
21 #include <linux/usb.h>
22 #include <linux/workqueue.h>
23 
24 #include <linux/can.h>
25 #include <linux/can/dev.h>
26 #include <linux/can/error.h>
27 
28 /* Device specific constants */
29 #define USB_GS_USB_1_VENDOR_ID 0x1d50
30 #define USB_GS_USB_1_PRODUCT_ID 0x606f
31 
32 #define USB_CANDLELIGHT_VENDOR_ID 0x1209
33 #define USB_CANDLELIGHT_PRODUCT_ID 0x2323
34 
35 #define USB_CES_CANEXT_FD_VENDOR_ID 0x1cd2
36 #define USB_CES_CANEXT_FD_PRODUCT_ID 0x606f
37 
38 #define USB_ABE_CANDEBUGGER_FD_VENDOR_ID 0x16d0
39 #define USB_ABE_CANDEBUGGER_FD_PRODUCT_ID 0x10b8
40 
41 #define GS_USB_ENDPOINT_IN 1
42 #define GS_USB_ENDPOINT_OUT 2
43 
44 /* Timestamp 32 bit timer runs at 1 MHz (1 µs tick). Worker accounts
45  * for timer overflow (will be after ~71 minutes)
46  */
47 #define GS_USB_TIMESTAMP_TIMER_HZ (1 * HZ_PER_MHZ)
48 #define GS_USB_TIMESTAMP_WORK_DELAY_SEC 1800
49 static_assert(GS_USB_TIMESTAMP_WORK_DELAY_SEC <
50 	      CYCLECOUNTER_MASK(32) / GS_USB_TIMESTAMP_TIMER_HZ / 2);
51 
52 /* Device specific constants */
53 enum gs_usb_breq {
54 	GS_USB_BREQ_HOST_FORMAT = 0,
55 	GS_USB_BREQ_BITTIMING,
56 	GS_USB_BREQ_MODE,
57 	GS_USB_BREQ_BERR,
58 	GS_USB_BREQ_BT_CONST,
59 	GS_USB_BREQ_DEVICE_CONFIG,
60 	GS_USB_BREQ_TIMESTAMP,
61 	GS_USB_BREQ_IDENTIFY,
62 	GS_USB_BREQ_GET_USER_ID,
63 	GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING = GS_USB_BREQ_GET_USER_ID,
64 	GS_USB_BREQ_SET_USER_ID,
65 	GS_USB_BREQ_DATA_BITTIMING,
66 	GS_USB_BREQ_BT_CONST_EXT,
67 	GS_USB_BREQ_SET_TERMINATION,
68 	GS_USB_BREQ_GET_TERMINATION,
69 	GS_USB_BREQ_GET_STATE,
70 };
71 
72 enum gs_can_mode {
73 	/* reset a channel. turns it off */
74 	GS_CAN_MODE_RESET = 0,
75 	/* starts a channel */
76 	GS_CAN_MODE_START
77 };
78 
79 enum gs_can_state {
80 	GS_CAN_STATE_ERROR_ACTIVE = 0,
81 	GS_CAN_STATE_ERROR_WARNING,
82 	GS_CAN_STATE_ERROR_PASSIVE,
83 	GS_CAN_STATE_BUS_OFF,
84 	GS_CAN_STATE_STOPPED,
85 	GS_CAN_STATE_SLEEPING
86 };
87 
88 enum gs_can_identify_mode {
89 	GS_CAN_IDENTIFY_OFF = 0,
90 	GS_CAN_IDENTIFY_ON
91 };
92 
93 enum gs_can_termination_state {
94 	GS_CAN_TERMINATION_STATE_OFF = 0,
95 	GS_CAN_TERMINATION_STATE_ON
96 };
97 
98 #define GS_USB_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
99 #define GS_USB_TERMINATION_ENABLED 120
100 
101 /* data types passed between host and device */
102 
103 /* The firmware on the original USB2CAN by Geschwister Schneider
104  * Technologie Entwicklungs- und Vertriebs UG exchanges all data
105  * between the host and the device in host byte order. This is done
106  * with the struct gs_host_config::byte_order member, which is sent
107  * first to indicate the desired byte order.
108  *
109  * The widely used open source firmware candleLight doesn't support
110  * this feature and exchanges the data in little endian byte order.
111  */
112 struct gs_host_config {
113 	__le32 byte_order;
114 } __packed;
115 
116 struct gs_device_config {
117 	u8 reserved1;
118 	u8 reserved2;
119 	u8 reserved3;
120 	u8 icount;
121 	__le32 sw_version;
122 	__le32 hw_version;
123 } __packed;
124 
125 #define GS_CAN_MODE_NORMAL 0
126 #define GS_CAN_MODE_LISTEN_ONLY BIT(0)
127 #define GS_CAN_MODE_LOOP_BACK BIT(1)
128 #define GS_CAN_MODE_TRIPLE_SAMPLE BIT(2)
129 #define GS_CAN_MODE_ONE_SHOT BIT(3)
130 #define GS_CAN_MODE_HW_TIMESTAMP BIT(4)
131 /* GS_CAN_FEATURE_IDENTIFY BIT(5) */
132 /* GS_CAN_FEATURE_USER_ID BIT(6) */
133 #define GS_CAN_MODE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
134 #define GS_CAN_MODE_FD BIT(8)
135 /* GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9) */
136 /* GS_CAN_FEATURE_BT_CONST_EXT BIT(10) */
137 /* GS_CAN_FEATURE_TERMINATION BIT(11) */
138 #define GS_CAN_MODE_BERR_REPORTING BIT(12)
139 /* GS_CAN_FEATURE_GET_STATE BIT(13) */
140 
141 struct gs_device_mode {
142 	__le32 mode;
143 	__le32 flags;
144 } __packed;
145 
146 struct gs_device_state {
147 	__le32 state;
148 	__le32 rxerr;
149 	__le32 txerr;
150 } __packed;
151 
152 struct gs_device_bittiming {
153 	__le32 prop_seg;
154 	__le32 phase_seg1;
155 	__le32 phase_seg2;
156 	__le32 sjw;
157 	__le32 brp;
158 } __packed;
159 
160 struct gs_identify_mode {
161 	__le32 mode;
162 } __packed;
163 
164 struct gs_device_termination_state {
165 	__le32 state;
166 } __packed;
167 
168 #define GS_CAN_FEATURE_LISTEN_ONLY BIT(0)
169 #define GS_CAN_FEATURE_LOOP_BACK BIT(1)
170 #define GS_CAN_FEATURE_TRIPLE_SAMPLE BIT(2)
171 #define GS_CAN_FEATURE_ONE_SHOT BIT(3)
172 #define GS_CAN_FEATURE_HW_TIMESTAMP BIT(4)
173 #define GS_CAN_FEATURE_IDENTIFY BIT(5)
174 #define GS_CAN_FEATURE_USER_ID BIT(6)
175 #define GS_CAN_FEATURE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
176 #define GS_CAN_FEATURE_FD BIT(8)
177 #define GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9)
178 #define GS_CAN_FEATURE_BT_CONST_EXT BIT(10)
179 #define GS_CAN_FEATURE_TERMINATION BIT(11)
180 #define GS_CAN_FEATURE_BERR_REPORTING BIT(12)
181 #define GS_CAN_FEATURE_GET_STATE BIT(13)
182 #define GS_CAN_FEATURE_MASK GENMASK(13, 0)
183 
184 /* internal quirks - keep in GS_CAN_FEATURE space for now */
185 
186 /* CANtact Pro original firmware:
187  * BREQ DATA_BITTIMING overlaps with GET_USER_ID
188  */
189 #define GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO BIT(31)
190 
191 struct gs_device_bt_const {
192 	__le32 feature;
193 	__le32 fclk_can;
194 	__le32 tseg1_min;
195 	__le32 tseg1_max;
196 	__le32 tseg2_min;
197 	__le32 tseg2_max;
198 	__le32 sjw_max;
199 	__le32 brp_min;
200 	__le32 brp_max;
201 	__le32 brp_inc;
202 } __packed;
203 
204 struct gs_device_bt_const_extended {
205 	__le32 feature;
206 	__le32 fclk_can;
207 	__le32 tseg1_min;
208 	__le32 tseg1_max;
209 	__le32 tseg2_min;
210 	__le32 tseg2_max;
211 	__le32 sjw_max;
212 	__le32 brp_min;
213 	__le32 brp_max;
214 	__le32 brp_inc;
215 
216 	__le32 dtseg1_min;
217 	__le32 dtseg1_max;
218 	__le32 dtseg2_min;
219 	__le32 dtseg2_max;
220 	__le32 dsjw_max;
221 	__le32 dbrp_min;
222 	__le32 dbrp_max;
223 	__le32 dbrp_inc;
224 } __packed;
225 
226 #define GS_CAN_FLAG_OVERFLOW BIT(0)
227 #define GS_CAN_FLAG_FD BIT(1)
228 #define GS_CAN_FLAG_BRS BIT(2)
229 #define GS_CAN_FLAG_ESI BIT(3)
230 
231 struct classic_can {
232 	u8 data[8];
233 } __packed;
234 
235 struct classic_can_ts {
236 	u8 data[8];
237 	__le32 timestamp_us;
238 } __packed;
239 
240 struct classic_can_quirk {
241 	u8 data[8];
242 	u8 quirk;
243 } __packed;
244 
245 struct canfd {
246 	u8 data[64];
247 } __packed;
248 
249 struct canfd_ts {
250 	u8 data[64];
251 	__le32 timestamp_us;
252 } __packed;
253 
254 struct canfd_quirk {
255 	u8 data[64];
256 	u8 quirk;
257 } __packed;
258 
259 struct gs_host_frame {
260 	u32 echo_id;
261 	__le32 can_id;
262 
263 	u8 can_dlc;
264 	u8 channel;
265 	u8 flags;
266 	u8 reserved;
267 
268 	union {
269 		DECLARE_FLEX_ARRAY(struct classic_can, classic_can);
270 		DECLARE_FLEX_ARRAY(struct classic_can_ts, classic_can_ts);
271 		DECLARE_FLEX_ARRAY(struct classic_can_quirk, classic_can_quirk);
272 		DECLARE_FLEX_ARRAY(struct canfd, canfd);
273 		DECLARE_FLEX_ARRAY(struct canfd_ts, canfd_ts);
274 		DECLARE_FLEX_ARRAY(struct canfd_quirk, canfd_quirk);
275 	};
276 } __packed;
277 /* The GS USB devices make use of the same flags and masks as in
278  * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
279  */
280 
281 /* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
282 #define GS_MAX_TX_URBS 10
283 /* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
284 #define GS_MAX_RX_URBS 30
285 /* Maximum number of interfaces the driver supports per device.
286  * Current hardware only supports 3 interfaces. The future may vary.
287  */
288 #define GS_MAX_INTF 3
289 
290 struct gs_tx_context {
291 	struct gs_can *dev;
292 	unsigned int echo_id;
293 };
294 
295 struct gs_can {
296 	struct can_priv can; /* must be the first member */
297 
298 	struct gs_usb *parent;
299 
300 	struct net_device *netdev;
301 	struct usb_device *udev;
302 
303 	struct can_bittiming_const bt_const, data_bt_const;
304 	unsigned int channel;	/* channel number */
305 
306 	u32 feature;
307 	unsigned int hf_size_tx;
308 
309 	/* This lock prevents a race condition between xmit and receive. */
310 	spinlock_t tx_ctx_lock;
311 	struct gs_tx_context tx_context[GS_MAX_TX_URBS];
312 
313 	struct usb_anchor tx_submitted;
314 	atomic_t active_tx_urbs;
315 };
316 
317 /* usb interface struct */
318 struct gs_usb {
319 	struct gs_can *canch[GS_MAX_INTF];
320 	struct usb_anchor rx_submitted;
321 	struct usb_device *udev;
322 
323 	/* time counter for hardware timestamps */
324 	struct cyclecounter cc;
325 	struct timecounter tc;
326 	spinlock_t tc_lock; /* spinlock to guard access tc->cycle_last */
327 	struct delayed_work timestamp;
328 
329 	unsigned int hf_size_rx;
330 	u8 active_channels;
331 };
332 
333 /* 'allocate' a tx context.
334  * returns a valid tx context or NULL if there is no space.
335  */
336 static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
337 {
338 	int i = 0;
339 	unsigned long flags;
340 
341 	spin_lock_irqsave(&dev->tx_ctx_lock, flags);
342 
343 	for (; i < GS_MAX_TX_URBS; i++) {
344 		if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
345 			dev->tx_context[i].echo_id = i;
346 			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
347 			return &dev->tx_context[i];
348 		}
349 	}
350 
351 	spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
352 	return NULL;
353 }
354 
355 /* releases a tx context
356  */
357 static void gs_free_tx_context(struct gs_tx_context *txc)
358 {
359 	txc->echo_id = GS_MAX_TX_URBS;
360 }
361 
362 /* Get a tx context by id.
363  */
364 static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
365 					       unsigned int id)
366 {
367 	unsigned long flags;
368 
369 	if (id < GS_MAX_TX_URBS) {
370 		spin_lock_irqsave(&dev->tx_ctx_lock, flags);
371 		if (dev->tx_context[id].echo_id == id) {
372 			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
373 			return &dev->tx_context[id];
374 		}
375 		spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
376 	}
377 	return NULL;
378 }
379 
380 static int gs_cmd_reset(struct gs_can *dev)
381 {
382 	struct gs_device_mode dm = {
383 		.mode = GS_CAN_MODE_RESET,
384 	};
385 
386 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_MODE,
387 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
388 				    dev->channel, 0, &dm, sizeof(dm), 1000,
389 				    GFP_KERNEL);
390 }
391 
392 static inline int gs_usb_get_timestamp(const struct gs_usb *parent,
393 				       u32 *timestamp_p)
394 {
395 	__le32 timestamp;
396 	int rc;
397 
398 	rc = usb_control_msg_recv(parent->udev, 0, GS_USB_BREQ_TIMESTAMP,
399 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
400 				  0, 0,
401 				  &timestamp, sizeof(timestamp),
402 				  USB_CTRL_GET_TIMEOUT,
403 				  GFP_KERNEL);
404 	if (rc)
405 		return rc;
406 
407 	*timestamp_p = le32_to_cpu(timestamp);
408 
409 	return 0;
410 }
411 
412 static u64 gs_usb_timestamp_read(const struct cyclecounter *cc) __must_hold(&dev->tc_lock)
413 {
414 	struct gs_usb *parent = container_of(cc, struct gs_usb, cc);
415 	u32 timestamp = 0;
416 	int err;
417 
418 	lockdep_assert_held(&parent->tc_lock);
419 
420 	/* drop lock for synchronous USB transfer */
421 	spin_unlock_bh(&parent->tc_lock);
422 	err = gs_usb_get_timestamp(parent, &timestamp);
423 	spin_lock_bh(&parent->tc_lock);
424 	if (err)
425 		dev_err(&parent->udev->dev,
426 			"Error %d while reading timestamp. HW timestamps may be inaccurate.",
427 			err);
428 
429 	return timestamp;
430 }
431 
432 static void gs_usb_timestamp_work(struct work_struct *work)
433 {
434 	struct delayed_work *delayed_work = to_delayed_work(work);
435 	struct gs_usb *parent;
436 
437 	parent = container_of(delayed_work, struct gs_usb, timestamp);
438 	spin_lock_bh(&parent->tc_lock);
439 	timecounter_read(&parent->tc);
440 	spin_unlock_bh(&parent->tc_lock);
441 
442 	schedule_delayed_work(&parent->timestamp,
443 			      GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
444 }
445 
446 static void gs_usb_skb_set_timestamp(struct gs_can *dev,
447 				     struct sk_buff *skb, u32 timestamp)
448 {
449 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
450 	struct gs_usb *parent = dev->parent;
451 	u64 ns;
452 
453 	spin_lock_bh(&parent->tc_lock);
454 	ns = timecounter_cyc2time(&parent->tc, timestamp);
455 	spin_unlock_bh(&parent->tc_lock);
456 
457 	hwtstamps->hwtstamp = ns_to_ktime(ns);
458 }
459 
460 static void gs_usb_timestamp_init(struct gs_usb *parent)
461 {
462 	struct cyclecounter *cc = &parent->cc;
463 
464 	cc->read = gs_usb_timestamp_read;
465 	cc->mask = CYCLECOUNTER_MASK(32);
466 	cc->shift = 32 - bits_per(NSEC_PER_SEC / GS_USB_TIMESTAMP_TIMER_HZ);
467 	cc->mult = clocksource_hz2mult(GS_USB_TIMESTAMP_TIMER_HZ, cc->shift);
468 
469 	spin_lock_init(&parent->tc_lock);
470 	spin_lock_bh(&parent->tc_lock);
471 	timecounter_init(&parent->tc, &parent->cc, ktime_get_real_ns());
472 	spin_unlock_bh(&parent->tc_lock);
473 
474 	INIT_DELAYED_WORK(&parent->timestamp, gs_usb_timestamp_work);
475 	schedule_delayed_work(&parent->timestamp,
476 			      GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
477 }
478 
479 static void gs_usb_timestamp_stop(struct gs_usb *parent)
480 {
481 	cancel_delayed_work_sync(&parent->timestamp);
482 }
483 
484 static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
485 {
486 	struct can_device_stats *can_stats = &dev->can.can_stats;
487 
488 	if (cf->can_id & CAN_ERR_RESTARTED) {
489 		dev->can.state = CAN_STATE_ERROR_ACTIVE;
490 		can_stats->restarts++;
491 	} else if (cf->can_id & CAN_ERR_BUSOFF) {
492 		dev->can.state = CAN_STATE_BUS_OFF;
493 		can_stats->bus_off++;
494 	} else if (cf->can_id & CAN_ERR_CRTL) {
495 		if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
496 		    (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
497 			dev->can.state = CAN_STATE_ERROR_WARNING;
498 			can_stats->error_warning++;
499 		} else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
500 			   (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
501 			dev->can.state = CAN_STATE_ERROR_PASSIVE;
502 			can_stats->error_passive++;
503 		} else {
504 			dev->can.state = CAN_STATE_ERROR_ACTIVE;
505 		}
506 	}
507 }
508 
509 static void gs_usb_set_timestamp(struct gs_can *dev, struct sk_buff *skb,
510 				 const struct gs_host_frame *hf)
511 {
512 	u32 timestamp;
513 
514 	if (!(dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP))
515 		return;
516 
517 	if (hf->flags & GS_CAN_FLAG_FD)
518 		timestamp = le32_to_cpu(hf->canfd_ts->timestamp_us);
519 	else
520 		timestamp = le32_to_cpu(hf->classic_can_ts->timestamp_us);
521 
522 	gs_usb_skb_set_timestamp(dev, skb, timestamp);
523 
524 	return;
525 }
526 
527 static void gs_usb_receive_bulk_callback(struct urb *urb)
528 {
529 	struct gs_usb *usbcan = urb->context;
530 	struct gs_can *dev;
531 	struct net_device *netdev;
532 	int rc;
533 	struct net_device_stats *stats;
534 	struct gs_host_frame *hf = urb->transfer_buffer;
535 	struct gs_tx_context *txc;
536 	struct can_frame *cf;
537 	struct canfd_frame *cfd;
538 	struct sk_buff *skb;
539 
540 	BUG_ON(!usbcan);
541 
542 	switch (urb->status) {
543 	case 0: /* success */
544 		break;
545 	case -ENOENT:
546 	case -ESHUTDOWN:
547 		return;
548 	default:
549 		/* do not resubmit aborted urbs. eg: when device goes down */
550 		return;
551 	}
552 
553 	/* device reports out of range channel id */
554 	if (hf->channel >= GS_MAX_INTF)
555 		goto device_detach;
556 
557 	dev = usbcan->canch[hf->channel];
558 
559 	netdev = dev->netdev;
560 	stats = &netdev->stats;
561 
562 	if (!netif_device_present(netdev))
563 		return;
564 
565 	if (!netif_running(netdev))
566 		goto resubmit_urb;
567 
568 	if (hf->echo_id == -1) { /* normal rx */
569 		if (hf->flags & GS_CAN_FLAG_FD) {
570 			skb = alloc_canfd_skb(dev->netdev, &cfd);
571 			if (!skb)
572 				return;
573 
574 			cfd->can_id = le32_to_cpu(hf->can_id);
575 			cfd->len = can_fd_dlc2len(hf->can_dlc);
576 			if (hf->flags & GS_CAN_FLAG_BRS)
577 				cfd->flags |= CANFD_BRS;
578 			if (hf->flags & GS_CAN_FLAG_ESI)
579 				cfd->flags |= CANFD_ESI;
580 
581 			memcpy(cfd->data, hf->canfd->data, cfd->len);
582 		} else {
583 			skb = alloc_can_skb(dev->netdev, &cf);
584 			if (!skb)
585 				return;
586 
587 			cf->can_id = le32_to_cpu(hf->can_id);
588 			can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);
589 
590 			memcpy(cf->data, hf->classic_can->data, 8);
591 
592 			/* ERROR frames tell us information about the controller */
593 			if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)
594 				gs_update_state(dev, cf);
595 		}
596 
597 		gs_usb_set_timestamp(dev, skb, hf);
598 
599 		netdev->stats.rx_packets++;
600 		netdev->stats.rx_bytes += hf->can_dlc;
601 
602 		netif_rx(skb);
603 	} else { /* echo_id == hf->echo_id */
604 		if (hf->echo_id >= GS_MAX_TX_URBS) {
605 			netdev_err(netdev,
606 				   "Unexpected out of range echo id %u\n",
607 				   hf->echo_id);
608 			goto resubmit_urb;
609 		}
610 
611 		txc = gs_get_tx_context(dev, hf->echo_id);
612 
613 		/* bad devices send bad echo_ids. */
614 		if (!txc) {
615 			netdev_err(netdev,
616 				   "Unexpected unused echo id %u\n",
617 				   hf->echo_id);
618 			goto resubmit_urb;
619 		}
620 
621 		skb = dev->can.echo_skb[hf->echo_id];
622 		gs_usb_set_timestamp(dev, skb, hf);
623 
624 		netdev->stats.tx_packets++;
625 		netdev->stats.tx_bytes += can_get_echo_skb(netdev, hf->echo_id,
626 							   NULL);
627 
628 		gs_free_tx_context(txc);
629 
630 		atomic_dec(&dev->active_tx_urbs);
631 
632 		netif_wake_queue(netdev);
633 	}
634 
635 	if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
636 		skb = alloc_can_err_skb(netdev, &cf);
637 		if (!skb)
638 			goto resubmit_urb;
639 
640 		cf->can_id |= CAN_ERR_CRTL;
641 		cf->len = CAN_ERR_DLC;
642 		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
643 		stats->rx_over_errors++;
644 		stats->rx_errors++;
645 		netif_rx(skb);
646 	}
647 
648  resubmit_urb:
649 	usb_fill_bulk_urb(urb, usbcan->udev,
650 			  usb_rcvbulkpipe(usbcan->udev, GS_USB_ENDPOINT_IN),
651 			  hf, dev->parent->hf_size_rx,
652 			  gs_usb_receive_bulk_callback, usbcan);
653 
654 	rc = usb_submit_urb(urb, GFP_ATOMIC);
655 
656 	/* USB failure take down all interfaces */
657 	if (rc == -ENODEV) {
658  device_detach:
659 		for (rc = 0; rc < GS_MAX_INTF; rc++) {
660 			if (usbcan->canch[rc])
661 				netif_device_detach(usbcan->canch[rc]->netdev);
662 		}
663 	}
664 }
665 
666 static int gs_usb_set_bittiming(struct net_device *netdev)
667 {
668 	struct gs_can *dev = netdev_priv(netdev);
669 	struct can_bittiming *bt = &dev->can.bittiming;
670 	struct gs_device_bittiming dbt = {
671 		.prop_seg = cpu_to_le32(bt->prop_seg),
672 		.phase_seg1 = cpu_to_le32(bt->phase_seg1),
673 		.phase_seg2 = cpu_to_le32(bt->phase_seg2),
674 		.sjw = cpu_to_le32(bt->sjw),
675 		.brp = cpu_to_le32(bt->brp),
676 	};
677 
678 	/* request bit timings */
679 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_BITTIMING,
680 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
681 				    dev->channel, 0, &dbt, sizeof(dbt), 1000,
682 				    GFP_KERNEL);
683 }
684 
685 static int gs_usb_set_data_bittiming(struct net_device *netdev)
686 {
687 	struct gs_can *dev = netdev_priv(netdev);
688 	struct can_bittiming *bt = &dev->can.data_bittiming;
689 	struct gs_device_bittiming dbt = {
690 		.prop_seg = cpu_to_le32(bt->prop_seg),
691 		.phase_seg1 = cpu_to_le32(bt->phase_seg1),
692 		.phase_seg2 = cpu_to_le32(bt->phase_seg2),
693 		.sjw = cpu_to_le32(bt->sjw),
694 		.brp = cpu_to_le32(bt->brp),
695 	};
696 	u8 request = GS_USB_BREQ_DATA_BITTIMING;
697 
698 	if (dev->feature & GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO)
699 		request = GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING;
700 
701 	/* request data bit timings */
702 	return usb_control_msg_send(dev->udev, 0, request,
703 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
704 				    dev->channel, 0, &dbt, sizeof(dbt), 1000,
705 				    GFP_KERNEL);
706 }
707 
708 static void gs_usb_xmit_callback(struct urb *urb)
709 {
710 	struct gs_tx_context *txc = urb->context;
711 	struct gs_can *dev = txc->dev;
712 	struct net_device *netdev = dev->netdev;
713 
714 	if (urb->status)
715 		netdev_info(netdev, "usb xmit fail %u\n", txc->echo_id);
716 }
717 
718 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
719 				     struct net_device *netdev)
720 {
721 	struct gs_can *dev = netdev_priv(netdev);
722 	struct net_device_stats *stats = &dev->netdev->stats;
723 	struct urb *urb;
724 	struct gs_host_frame *hf;
725 	struct can_frame *cf;
726 	struct canfd_frame *cfd;
727 	int rc;
728 	unsigned int idx;
729 	struct gs_tx_context *txc;
730 
731 	if (can_dev_dropped_skb(netdev, skb))
732 		return NETDEV_TX_OK;
733 
734 	/* find an empty context to keep track of transmission */
735 	txc = gs_alloc_tx_context(dev);
736 	if (!txc)
737 		return NETDEV_TX_BUSY;
738 
739 	/* create a URB, and a buffer for it */
740 	urb = usb_alloc_urb(0, GFP_ATOMIC);
741 	if (!urb)
742 		goto nomem_urb;
743 
744 	hf = kmalloc(dev->hf_size_tx, GFP_ATOMIC);
745 	if (!hf) {
746 		netdev_err(netdev, "No memory left for USB buffer\n");
747 		goto nomem_hf;
748 	}
749 
750 	idx = txc->echo_id;
751 
752 	if (idx >= GS_MAX_TX_URBS) {
753 		netdev_err(netdev, "Invalid tx context %u\n", idx);
754 		goto badidx;
755 	}
756 
757 	hf->echo_id = idx;
758 	hf->channel = dev->channel;
759 	hf->flags = 0;
760 	hf->reserved = 0;
761 
762 	if (can_is_canfd_skb(skb)) {
763 		cfd = (struct canfd_frame *)skb->data;
764 
765 		hf->can_id = cpu_to_le32(cfd->can_id);
766 		hf->can_dlc = can_fd_len2dlc(cfd->len);
767 		hf->flags |= GS_CAN_FLAG_FD;
768 		if (cfd->flags & CANFD_BRS)
769 			hf->flags |= GS_CAN_FLAG_BRS;
770 		if (cfd->flags & CANFD_ESI)
771 			hf->flags |= GS_CAN_FLAG_ESI;
772 
773 		memcpy(hf->canfd->data, cfd->data, cfd->len);
774 	} else {
775 		cf = (struct can_frame *)skb->data;
776 
777 		hf->can_id = cpu_to_le32(cf->can_id);
778 		hf->can_dlc = can_get_cc_dlc(cf, dev->can.ctrlmode);
779 
780 		memcpy(hf->classic_can->data, cf->data, cf->len);
781 	}
782 
783 	usb_fill_bulk_urb(urb, dev->udev,
784 			  usb_sndbulkpipe(dev->udev, GS_USB_ENDPOINT_OUT),
785 			  hf, dev->hf_size_tx,
786 			  gs_usb_xmit_callback, txc);
787 
788 	urb->transfer_flags |= URB_FREE_BUFFER;
789 	usb_anchor_urb(urb, &dev->tx_submitted);
790 
791 	can_put_echo_skb(skb, netdev, idx, 0);
792 
793 	atomic_inc(&dev->active_tx_urbs);
794 
795 	rc = usb_submit_urb(urb, GFP_ATOMIC);
796 	if (unlikely(rc)) {			/* usb send failed */
797 		atomic_dec(&dev->active_tx_urbs);
798 
799 		can_free_echo_skb(netdev, idx, NULL);
800 		gs_free_tx_context(txc);
801 
802 		usb_unanchor_urb(urb);
803 
804 		if (rc == -ENODEV) {
805 			netif_device_detach(netdev);
806 		} else {
807 			netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
808 			stats->tx_dropped++;
809 		}
810 	} else {
811 		/* Slow down tx path */
812 		if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
813 			netif_stop_queue(netdev);
814 	}
815 
816 	/* let usb core take care of this urb */
817 	usb_free_urb(urb);
818 
819 	return NETDEV_TX_OK;
820 
821  badidx:
822 	kfree(hf);
823  nomem_hf:
824 	usb_free_urb(urb);
825 
826  nomem_urb:
827 	gs_free_tx_context(txc);
828 	dev_kfree_skb(skb);
829 	stats->tx_dropped++;
830 	return NETDEV_TX_OK;
831 }
832 
833 static int gs_can_open(struct net_device *netdev)
834 {
835 	struct gs_can *dev = netdev_priv(netdev);
836 	struct gs_usb *parent = dev->parent;
837 	struct gs_device_mode dm = {
838 		.mode = cpu_to_le32(GS_CAN_MODE_START),
839 	};
840 	struct gs_host_frame *hf;
841 	struct urb *urb = NULL;
842 	u32 ctrlmode;
843 	u32 flags = 0;
844 	int rc, i;
845 
846 	rc = open_candev(netdev);
847 	if (rc)
848 		return rc;
849 
850 	ctrlmode = dev->can.ctrlmode;
851 	if (ctrlmode & CAN_CTRLMODE_FD) {
852 		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
853 			dev->hf_size_tx = struct_size(hf, canfd_quirk, 1);
854 		else
855 			dev->hf_size_tx = struct_size(hf, canfd, 1);
856 	} else {
857 		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
858 			dev->hf_size_tx = struct_size(hf, classic_can_quirk, 1);
859 		else
860 			dev->hf_size_tx = struct_size(hf, classic_can, 1);
861 	}
862 
863 	if (!parent->active_channels) {
864 		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
865 			gs_usb_timestamp_init(parent);
866 
867 		for (i = 0; i < GS_MAX_RX_URBS; i++) {
868 			u8 *buf;
869 
870 			/* alloc rx urb */
871 			urb = usb_alloc_urb(0, GFP_KERNEL);
872 			if (!urb) {
873 				rc = -ENOMEM;
874 				goto out_usb_kill_anchored_urbs;
875 			}
876 
877 			/* alloc rx buffer */
878 			buf = kmalloc(dev->parent->hf_size_rx,
879 				      GFP_KERNEL);
880 			if (!buf) {
881 				netdev_err(netdev,
882 					   "No memory left for USB buffer\n");
883 				rc = -ENOMEM;
884 				goto out_usb_free_urb;
885 			}
886 
887 			/* fill, anchor, and submit rx urb */
888 			usb_fill_bulk_urb(urb,
889 					  dev->udev,
890 					  usb_rcvbulkpipe(dev->udev,
891 							  GS_USB_ENDPOINT_IN),
892 					  buf,
893 					  dev->parent->hf_size_rx,
894 					  gs_usb_receive_bulk_callback, parent);
895 			urb->transfer_flags |= URB_FREE_BUFFER;
896 
897 			usb_anchor_urb(urb, &parent->rx_submitted);
898 
899 			rc = usb_submit_urb(urb, GFP_KERNEL);
900 			if (rc) {
901 				if (rc == -ENODEV)
902 					netif_device_detach(dev->netdev);
903 
904 				netdev_err(netdev,
905 					   "usb_submit failed (err=%d)\n", rc);
906 
907 				goto out_usb_unanchor_urb;
908 			}
909 
910 			/* Drop reference,
911 			 * USB core will take care of freeing it
912 			 */
913 			usb_free_urb(urb);
914 		}
915 	}
916 
917 	/* flags */
918 	if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
919 		flags |= GS_CAN_MODE_LOOP_BACK;
920 
921 	if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
922 		flags |= GS_CAN_MODE_LISTEN_ONLY;
923 
924 	if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
925 		flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
926 
927 	if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
928 		flags |= GS_CAN_MODE_ONE_SHOT;
929 
930 	if (ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
931 		flags |= GS_CAN_MODE_BERR_REPORTING;
932 
933 	if (ctrlmode & CAN_CTRLMODE_FD)
934 		flags |= GS_CAN_MODE_FD;
935 
936 	/* if hardware supports timestamps, enable it */
937 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
938 		flags |= GS_CAN_MODE_HW_TIMESTAMP;
939 
940 	/* finally start device */
941 	dev->can.state = CAN_STATE_ERROR_ACTIVE;
942 	dm.flags = cpu_to_le32(flags);
943 	rc = usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_MODE,
944 				  USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
945 				  dev->channel, 0, &dm, sizeof(dm), 1000,
946 				  GFP_KERNEL);
947 	if (rc) {
948 		netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
949 		dev->can.state = CAN_STATE_STOPPED;
950 
951 		goto out_usb_kill_anchored_urbs;
952 	}
953 
954 	parent->active_channels++;
955 	if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
956 		netif_start_queue(netdev);
957 
958 	return 0;
959 
960 out_usb_unanchor_urb:
961 	usb_unanchor_urb(urb);
962 out_usb_free_urb:
963 	usb_free_urb(urb);
964 out_usb_kill_anchored_urbs:
965 	if (!parent->active_channels) {
966 		usb_kill_anchored_urbs(&dev->tx_submitted);
967 
968 		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
969 			gs_usb_timestamp_stop(parent);
970 	}
971 
972 	close_candev(netdev);
973 
974 	return rc;
975 }
976 
977 static int gs_usb_get_state(const struct net_device *netdev,
978 			    struct can_berr_counter *bec,
979 			    enum can_state *state)
980 {
981 	struct gs_can *dev = netdev_priv(netdev);
982 	struct gs_device_state ds;
983 	int rc;
984 
985 	rc = usb_control_msg_recv(dev->udev, 0, GS_USB_BREQ_GET_STATE,
986 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
987 				  dev->channel, 0,
988 				  &ds, sizeof(ds),
989 				  USB_CTRL_GET_TIMEOUT,
990 				  GFP_KERNEL);
991 	if (rc)
992 		return rc;
993 
994 	if (le32_to_cpu(ds.state) >= CAN_STATE_MAX)
995 		return -EOPNOTSUPP;
996 
997 	*state = le32_to_cpu(ds.state);
998 	bec->txerr = le32_to_cpu(ds.txerr);
999 	bec->rxerr = le32_to_cpu(ds.rxerr);
1000 
1001 	return 0;
1002 }
1003 
1004 static int gs_usb_can_get_berr_counter(const struct net_device *netdev,
1005 				       struct can_berr_counter *bec)
1006 {
1007 	enum can_state state;
1008 
1009 	return gs_usb_get_state(netdev, bec, &state);
1010 }
1011 
1012 static int gs_can_close(struct net_device *netdev)
1013 {
1014 	int rc;
1015 	struct gs_can *dev = netdev_priv(netdev);
1016 	struct gs_usb *parent = dev->parent;
1017 
1018 	netif_stop_queue(netdev);
1019 
1020 	/* Stop polling */
1021 	parent->active_channels--;
1022 	if (!parent->active_channels) {
1023 		usb_kill_anchored_urbs(&parent->rx_submitted);
1024 
1025 		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1026 			gs_usb_timestamp_stop(parent);
1027 	}
1028 
1029 	/* Stop sending URBs */
1030 	usb_kill_anchored_urbs(&dev->tx_submitted);
1031 	atomic_set(&dev->active_tx_urbs, 0);
1032 
1033 	/* reset the device */
1034 	rc = gs_cmd_reset(dev);
1035 	if (rc < 0)
1036 		netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
1037 
1038 	/* reset tx contexts */
1039 	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
1040 		dev->tx_context[rc].dev = dev;
1041 		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
1042 	}
1043 
1044 	/* close the netdev */
1045 	close_candev(netdev);
1046 
1047 	return 0;
1048 }
1049 
1050 static int gs_can_eth_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
1051 {
1052 	const struct gs_can *dev = netdev_priv(netdev);
1053 
1054 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1055 		return can_eth_ioctl_hwts(netdev, ifr, cmd);
1056 
1057 	return -EOPNOTSUPP;
1058 }
1059 
1060 static const struct net_device_ops gs_usb_netdev_ops = {
1061 	.ndo_open = gs_can_open,
1062 	.ndo_stop = gs_can_close,
1063 	.ndo_start_xmit = gs_can_start_xmit,
1064 	.ndo_change_mtu = can_change_mtu,
1065 	.ndo_eth_ioctl = gs_can_eth_ioctl,
1066 };
1067 
1068 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
1069 {
1070 	struct gs_can *dev = netdev_priv(netdev);
1071 	struct gs_identify_mode imode;
1072 
1073 	if (do_identify)
1074 		imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
1075 	else
1076 		imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
1077 
1078 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_IDENTIFY,
1079 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1080 				    dev->channel, 0, &imode, sizeof(imode), 100,
1081 				    GFP_KERNEL);
1082 }
1083 
1084 /* blink LED's for finding the this interface */
1085 static int gs_usb_set_phys_id(struct net_device *netdev,
1086 			      enum ethtool_phys_id_state state)
1087 {
1088 	const struct gs_can *dev = netdev_priv(netdev);
1089 	int rc = 0;
1090 
1091 	if (!(dev->feature & GS_CAN_FEATURE_IDENTIFY))
1092 		return -EOPNOTSUPP;
1093 
1094 	switch (state) {
1095 	case ETHTOOL_ID_ACTIVE:
1096 		rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_ON);
1097 		break;
1098 	case ETHTOOL_ID_INACTIVE:
1099 		rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_OFF);
1100 		break;
1101 	default:
1102 		break;
1103 	}
1104 
1105 	return rc;
1106 }
1107 
1108 static int gs_usb_get_ts_info(struct net_device *netdev,
1109 			      struct ethtool_ts_info *info)
1110 {
1111 	struct gs_can *dev = netdev_priv(netdev);
1112 
1113 	/* report if device supports HW timestamps */
1114 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1115 		return can_ethtool_op_get_ts_info_hwts(netdev, info);
1116 
1117 	return ethtool_op_get_ts_info(netdev, info);
1118 }
1119 
1120 static const struct ethtool_ops gs_usb_ethtool_ops = {
1121 	.set_phys_id = gs_usb_set_phys_id,
1122 	.get_ts_info = gs_usb_get_ts_info,
1123 };
1124 
1125 static int gs_usb_get_termination(struct net_device *netdev, u16 *term)
1126 {
1127 	struct gs_can *dev = netdev_priv(netdev);
1128 	struct gs_device_termination_state term_state;
1129 	int rc;
1130 
1131 	rc = usb_control_msg_recv(dev->udev, 0, GS_USB_BREQ_GET_TERMINATION,
1132 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1133 				  dev->channel, 0,
1134 				  &term_state, sizeof(term_state), 1000,
1135 				  GFP_KERNEL);
1136 	if (rc)
1137 		return rc;
1138 
1139 	if (term_state.state == cpu_to_le32(GS_CAN_TERMINATION_STATE_ON))
1140 		*term = GS_USB_TERMINATION_ENABLED;
1141 	else
1142 		*term = GS_USB_TERMINATION_DISABLED;
1143 
1144 	return 0;
1145 }
1146 
1147 static int gs_usb_set_termination(struct net_device *netdev, u16 term)
1148 {
1149 	struct gs_can *dev = netdev_priv(netdev);
1150 	struct gs_device_termination_state term_state;
1151 
1152 	if (term == GS_USB_TERMINATION_ENABLED)
1153 		term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_ON);
1154 	else
1155 		term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_OFF);
1156 
1157 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_SET_TERMINATION,
1158 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1159 				    dev->channel, 0,
1160 				    &term_state, sizeof(term_state), 1000,
1161 				    GFP_KERNEL);
1162 }
1163 
1164 static const u16 gs_usb_termination_const[] = {
1165 	GS_USB_TERMINATION_DISABLED,
1166 	GS_USB_TERMINATION_ENABLED
1167 };
1168 
1169 static struct gs_can *gs_make_candev(unsigned int channel,
1170 				     struct usb_interface *intf,
1171 				     struct gs_device_config *dconf)
1172 {
1173 	struct gs_can *dev;
1174 	struct net_device *netdev;
1175 	int rc;
1176 	struct gs_device_bt_const_extended bt_const_extended;
1177 	struct gs_device_bt_const bt_const;
1178 	u32 feature;
1179 
1180 	/* fetch bit timing constants */
1181 	rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
1182 				  GS_USB_BREQ_BT_CONST,
1183 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1184 				  channel, 0, &bt_const, sizeof(bt_const), 1000,
1185 				  GFP_KERNEL);
1186 
1187 	if (rc) {
1188 		dev_err(&intf->dev,
1189 			"Couldn't get bit timing const for channel %d (%pe)\n",
1190 			channel, ERR_PTR(rc));
1191 		return ERR_PTR(rc);
1192 	}
1193 
1194 	/* create netdev */
1195 	netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
1196 	if (!netdev) {
1197 		dev_err(&intf->dev, "Couldn't allocate candev\n");
1198 		return ERR_PTR(-ENOMEM);
1199 	}
1200 
1201 	dev = netdev_priv(netdev);
1202 
1203 	netdev->netdev_ops = &gs_usb_netdev_ops;
1204 	netdev->ethtool_ops = &gs_usb_ethtool_ops;
1205 
1206 	netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
1207 	netdev->dev_id = channel;
1208 
1209 	/* dev setup */
1210 	strcpy(dev->bt_const.name, KBUILD_MODNAME);
1211 	dev->bt_const.tseg1_min = le32_to_cpu(bt_const.tseg1_min);
1212 	dev->bt_const.tseg1_max = le32_to_cpu(bt_const.tseg1_max);
1213 	dev->bt_const.tseg2_min = le32_to_cpu(bt_const.tseg2_min);
1214 	dev->bt_const.tseg2_max = le32_to_cpu(bt_const.tseg2_max);
1215 	dev->bt_const.sjw_max = le32_to_cpu(bt_const.sjw_max);
1216 	dev->bt_const.brp_min = le32_to_cpu(bt_const.brp_min);
1217 	dev->bt_const.brp_max = le32_to_cpu(bt_const.brp_max);
1218 	dev->bt_const.brp_inc = le32_to_cpu(bt_const.brp_inc);
1219 
1220 	dev->udev = interface_to_usbdev(intf);
1221 	dev->netdev = netdev;
1222 	dev->channel = channel;
1223 
1224 	init_usb_anchor(&dev->tx_submitted);
1225 	atomic_set(&dev->active_tx_urbs, 0);
1226 	spin_lock_init(&dev->tx_ctx_lock);
1227 	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
1228 		dev->tx_context[rc].dev = dev;
1229 		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
1230 	}
1231 
1232 	/* can setup */
1233 	dev->can.state = CAN_STATE_STOPPED;
1234 	dev->can.clock.freq = le32_to_cpu(bt_const.fclk_can);
1235 	dev->can.bittiming_const = &dev->bt_const;
1236 	dev->can.do_set_bittiming = gs_usb_set_bittiming;
1237 
1238 	dev->can.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC;
1239 
1240 	feature = le32_to_cpu(bt_const.feature);
1241 	dev->feature = FIELD_GET(GS_CAN_FEATURE_MASK, feature);
1242 	if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
1243 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
1244 
1245 	if (feature & GS_CAN_FEATURE_LOOP_BACK)
1246 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
1247 
1248 	if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
1249 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1250 
1251 	if (feature & GS_CAN_FEATURE_ONE_SHOT)
1252 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
1253 
1254 	if (feature & GS_CAN_FEATURE_FD) {
1255 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
1256 		/* The data bit timing will be overwritten, if
1257 		 * GS_CAN_FEATURE_BT_CONST_EXT is set.
1258 		 */
1259 		dev->can.data_bittiming_const = &dev->bt_const;
1260 		dev->can.do_set_data_bittiming = gs_usb_set_data_bittiming;
1261 	}
1262 
1263 	if (feature & GS_CAN_FEATURE_TERMINATION) {
1264 		rc = gs_usb_get_termination(netdev, &dev->can.termination);
1265 		if (rc) {
1266 			dev->feature &= ~GS_CAN_FEATURE_TERMINATION;
1267 
1268 			dev_info(&intf->dev,
1269 				 "Disabling termination support for channel %d (%pe)\n",
1270 				 channel, ERR_PTR(rc));
1271 		} else {
1272 			dev->can.termination_const = gs_usb_termination_const;
1273 			dev->can.termination_const_cnt = ARRAY_SIZE(gs_usb_termination_const);
1274 			dev->can.do_set_termination = gs_usb_set_termination;
1275 		}
1276 	}
1277 
1278 	if (feature & GS_CAN_FEATURE_BERR_REPORTING)
1279 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_BERR_REPORTING;
1280 
1281 	if (feature & GS_CAN_FEATURE_GET_STATE)
1282 		dev->can.do_get_berr_counter = gs_usb_can_get_berr_counter;
1283 
1284 	/* The CANtact Pro from LinkLayer Labs is based on the
1285 	 * LPC54616 µC, which is affected by the NXP LPC USB transfer
1286 	 * erratum. However, the current firmware (version 2) doesn't
1287 	 * set the GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX bit. Set the
1288 	 * feature GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX to workaround
1289 	 * this issue.
1290 	 *
1291 	 * For the GS_USB_BREQ_DATA_BITTIMING USB control message the
1292 	 * CANtact Pro firmware uses a request value, which is already
1293 	 * used by the candleLight firmware for a different purpose
1294 	 * (GS_USB_BREQ_GET_USER_ID). Set the feature
1295 	 * GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO to workaround this
1296 	 * issue.
1297 	 */
1298 	if (dev->udev->descriptor.idVendor == cpu_to_le16(USB_GS_USB_1_VENDOR_ID) &&
1299 	    dev->udev->descriptor.idProduct == cpu_to_le16(USB_GS_USB_1_PRODUCT_ID) &&
1300 	    dev->udev->manufacturer && dev->udev->product &&
1301 	    !strcmp(dev->udev->manufacturer, "LinkLayer Labs") &&
1302 	    !strcmp(dev->udev->product, "CANtact Pro") &&
1303 	    (le32_to_cpu(dconf->sw_version) <= 2))
1304 		dev->feature |= GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX |
1305 			GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO;
1306 
1307 	/* GS_CAN_FEATURE_IDENTIFY is only supported for sw_version > 1 */
1308 	if (!(le32_to_cpu(dconf->sw_version) > 1 &&
1309 	      feature & GS_CAN_FEATURE_IDENTIFY))
1310 		dev->feature &= ~GS_CAN_FEATURE_IDENTIFY;
1311 
1312 	/* fetch extended bit timing constants if device has feature
1313 	 * GS_CAN_FEATURE_FD and GS_CAN_FEATURE_BT_CONST_EXT
1314 	 */
1315 	if (feature & GS_CAN_FEATURE_FD &&
1316 	    feature & GS_CAN_FEATURE_BT_CONST_EXT) {
1317 		rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
1318 					  GS_USB_BREQ_BT_CONST_EXT,
1319 					  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1320 					  channel, 0, &bt_const_extended,
1321 					  sizeof(bt_const_extended),
1322 					  1000, GFP_KERNEL);
1323 		if (rc) {
1324 			dev_err(&intf->dev,
1325 				"Couldn't get extended bit timing const for channel %d (%pe)\n",
1326 				channel, ERR_PTR(rc));
1327 			goto out_free_candev;
1328 		}
1329 
1330 		strcpy(dev->data_bt_const.name, KBUILD_MODNAME);
1331 		dev->data_bt_const.tseg1_min = le32_to_cpu(bt_const_extended.dtseg1_min);
1332 		dev->data_bt_const.tseg1_max = le32_to_cpu(bt_const_extended.dtseg1_max);
1333 		dev->data_bt_const.tseg2_min = le32_to_cpu(bt_const_extended.dtseg2_min);
1334 		dev->data_bt_const.tseg2_max = le32_to_cpu(bt_const_extended.dtseg2_max);
1335 		dev->data_bt_const.sjw_max = le32_to_cpu(bt_const_extended.dsjw_max);
1336 		dev->data_bt_const.brp_min = le32_to_cpu(bt_const_extended.dbrp_min);
1337 		dev->data_bt_const.brp_max = le32_to_cpu(bt_const_extended.dbrp_max);
1338 		dev->data_bt_const.brp_inc = le32_to_cpu(bt_const_extended.dbrp_inc);
1339 
1340 		dev->can.data_bittiming_const = &dev->data_bt_const;
1341 	}
1342 
1343 	SET_NETDEV_DEV(netdev, &intf->dev);
1344 
1345 	rc = register_candev(dev->netdev);
1346 	if (rc) {
1347 		dev_err(&intf->dev,
1348 			"Couldn't register candev for channel %d (%pe)\n",
1349 			channel, ERR_PTR(rc));
1350 		goto out_free_candev;
1351 	}
1352 
1353 	return dev;
1354 
1355  out_free_candev:
1356 	free_candev(dev->netdev);
1357 	return ERR_PTR(rc);
1358 }
1359 
1360 static void gs_destroy_candev(struct gs_can *dev)
1361 {
1362 	unregister_candev(dev->netdev);
1363 	usb_kill_anchored_urbs(&dev->tx_submitted);
1364 	free_candev(dev->netdev);
1365 }
1366 
1367 static int gs_usb_probe(struct usb_interface *intf,
1368 			const struct usb_device_id *id)
1369 {
1370 	struct usb_device *udev = interface_to_usbdev(intf);
1371 	struct gs_host_frame *hf;
1372 	struct gs_usb *dev;
1373 	struct gs_host_config hconf = {
1374 		.byte_order = cpu_to_le32(0x0000beef),
1375 	};
1376 	struct gs_device_config dconf;
1377 	unsigned int icount, i;
1378 	int rc;
1379 
1380 	/* send host config */
1381 	rc = usb_control_msg_send(udev, 0,
1382 				  GS_USB_BREQ_HOST_FORMAT,
1383 				  USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1384 				  1, intf->cur_altsetting->desc.bInterfaceNumber,
1385 				  &hconf, sizeof(hconf), 1000,
1386 				  GFP_KERNEL);
1387 	if (rc) {
1388 		dev_err(&intf->dev, "Couldn't send data format (err=%d)\n", rc);
1389 		return rc;
1390 	}
1391 
1392 	/* read device config */
1393 	rc = usb_control_msg_recv(udev, 0,
1394 				  GS_USB_BREQ_DEVICE_CONFIG,
1395 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1396 				  1, intf->cur_altsetting->desc.bInterfaceNumber,
1397 				  &dconf, sizeof(dconf), 1000,
1398 				  GFP_KERNEL);
1399 	if (rc) {
1400 		dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
1401 			rc);
1402 		return rc;
1403 	}
1404 
1405 	icount = dconf.icount + 1;
1406 	dev_info(&intf->dev, "Configuring for %u interfaces\n", icount);
1407 
1408 	if (icount > GS_MAX_INTF) {
1409 		dev_err(&intf->dev,
1410 			"Driver cannot handle more that %u CAN interfaces\n",
1411 			GS_MAX_INTF);
1412 		return -EINVAL;
1413 	}
1414 
1415 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1416 	if (!dev)
1417 		return -ENOMEM;
1418 
1419 	init_usb_anchor(&dev->rx_submitted);
1420 
1421 	usb_set_intfdata(intf, dev);
1422 	dev->udev = udev;
1423 
1424 	for (i = 0; i < icount; i++) {
1425 		unsigned int hf_size_rx = 0;
1426 
1427 		dev->canch[i] = gs_make_candev(i, intf, &dconf);
1428 		if (IS_ERR_OR_NULL(dev->canch[i])) {
1429 			/* save error code to return later */
1430 			rc = PTR_ERR(dev->canch[i]);
1431 
1432 			/* on failure destroy previously created candevs */
1433 			icount = i;
1434 			for (i = 0; i < icount; i++)
1435 				gs_destroy_candev(dev->canch[i]);
1436 
1437 			usb_kill_anchored_urbs(&dev->rx_submitted);
1438 			kfree(dev);
1439 			return rc;
1440 		}
1441 		dev->canch[i]->parent = dev;
1442 
1443 		/* set RX packet size based on FD and if hardware
1444                 * timestamps are supported.
1445 		*/
1446 		if (dev->canch[i]->can.ctrlmode_supported & CAN_CTRLMODE_FD) {
1447 			if (dev->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1448 				hf_size_rx = struct_size(hf, canfd_ts, 1);
1449 			else
1450 				hf_size_rx = struct_size(hf, canfd, 1);
1451 		} else {
1452 			if (dev->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1453 				hf_size_rx = struct_size(hf, classic_can_ts, 1);
1454 			else
1455 				hf_size_rx = struct_size(hf, classic_can, 1);
1456 		}
1457 		dev->hf_size_rx = max(dev->hf_size_rx, hf_size_rx);
1458 	}
1459 
1460 	return 0;
1461 }
1462 
1463 static void gs_usb_disconnect(struct usb_interface *intf)
1464 {
1465 	struct gs_usb *dev = usb_get_intfdata(intf);
1466 	unsigned int i;
1467 
1468 	usb_set_intfdata(intf, NULL);
1469 
1470 	if (!dev) {
1471 		dev_err(&intf->dev, "Disconnect (nodata)\n");
1472 		return;
1473 	}
1474 
1475 	for (i = 0; i < GS_MAX_INTF; i++)
1476 		if (dev->canch[i])
1477 			gs_destroy_candev(dev->canch[i]);
1478 
1479 	usb_kill_anchored_urbs(&dev->rx_submitted);
1480 	kfree(dev);
1481 }
1482 
1483 static const struct usb_device_id gs_usb_table[] = {
1484 	{ USB_DEVICE_INTERFACE_NUMBER(USB_GS_USB_1_VENDOR_ID,
1485 				      USB_GS_USB_1_PRODUCT_ID, 0) },
1486 	{ USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1487 				      USB_CANDLELIGHT_PRODUCT_ID, 0) },
1488 	{ USB_DEVICE_INTERFACE_NUMBER(USB_CES_CANEXT_FD_VENDOR_ID,
1489 				      USB_CES_CANEXT_FD_PRODUCT_ID, 0) },
1490 	{ USB_DEVICE_INTERFACE_NUMBER(USB_ABE_CANDEBUGGER_FD_VENDOR_ID,
1491 				      USB_ABE_CANDEBUGGER_FD_PRODUCT_ID, 0) },
1492 	{} /* Terminating entry */
1493 };
1494 
1495 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1496 
1497 static struct usb_driver gs_usb_driver = {
1498 	.name = KBUILD_MODNAME,
1499 	.probe = gs_usb_probe,
1500 	.disconnect = gs_usb_disconnect,
1501 	.id_table = gs_usb_table,
1502 };
1503 
1504 module_usb_driver(gs_usb_driver);
1505 
1506 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1507 MODULE_DESCRIPTION(
1508 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1509 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1510 "and bytewerk.org candleLight USB CAN interfaces.");
1511 MODULE_LICENSE("GPL v2");
1512