xref: /linux/drivers/net/can/usb/gs_usb.c (revision 2697b79a469b68e3ad3640f55284359c1396278d)
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  * Copyright (c) 2023 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
9  *
10  * Many thanks to all socketcan devs!
11  */
12 
13 #include <linux/bitfield.h>
14 #include <linux/clocksource.h>
15 #include <linux/ethtool.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/netdevice.h>
19 #include <linux/signal.h>
20 #include <linux/timecounter.h>
21 #include <linux/units.h>
22 #include <linux/usb.h>
23 #include <linux/workqueue.h>
24 
25 #include <linux/can.h>
26 #include <linux/can/dev.h>
27 #include <linux/can/error.h>
28 #include <linux/can/rx-offload.h>
29 
30 /* Device specific constants */
31 #define USB_GS_USB_1_VENDOR_ID 0x1d50
32 #define USB_GS_USB_1_PRODUCT_ID 0x606f
33 
34 #define USB_CANDLELIGHT_VENDOR_ID 0x1209
35 #define USB_CANDLELIGHT_PRODUCT_ID 0x2323
36 
37 #define USB_CES_CANEXT_FD_VENDOR_ID 0x1cd2
38 #define USB_CES_CANEXT_FD_PRODUCT_ID 0x606f
39 
40 #define USB_ABE_CANDEBUGGER_FD_VENDOR_ID 0x16d0
41 #define USB_ABE_CANDEBUGGER_FD_PRODUCT_ID 0x10b8
42 
43 #define GS_USB_ENDPOINT_IN 1
44 #define GS_USB_ENDPOINT_OUT 2
45 
46 /* Timestamp 32 bit timer runs at 1 MHz (1 µs tick). Worker accounts
47  * for timer overflow (will be after ~71 minutes)
48  */
49 #define GS_USB_TIMESTAMP_TIMER_HZ (1 * HZ_PER_MHZ)
50 #define GS_USB_TIMESTAMP_WORK_DELAY_SEC 1800
51 static_assert(GS_USB_TIMESTAMP_WORK_DELAY_SEC <
52 	      CYCLECOUNTER_MASK(32) / GS_USB_TIMESTAMP_TIMER_HZ / 2);
53 
54 /* Device specific constants */
55 enum gs_usb_breq {
56 	GS_USB_BREQ_HOST_FORMAT = 0,
57 	GS_USB_BREQ_BITTIMING,
58 	GS_USB_BREQ_MODE,
59 	GS_USB_BREQ_BERR,
60 	GS_USB_BREQ_BT_CONST,
61 	GS_USB_BREQ_DEVICE_CONFIG,
62 	GS_USB_BREQ_TIMESTAMP,
63 	GS_USB_BREQ_IDENTIFY,
64 	GS_USB_BREQ_GET_USER_ID,
65 	GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING = GS_USB_BREQ_GET_USER_ID,
66 	GS_USB_BREQ_SET_USER_ID,
67 	GS_USB_BREQ_DATA_BITTIMING,
68 	GS_USB_BREQ_BT_CONST_EXT,
69 	GS_USB_BREQ_SET_TERMINATION,
70 	GS_USB_BREQ_GET_TERMINATION,
71 	GS_USB_BREQ_GET_STATE,
72 };
73 
74 enum gs_can_mode {
75 	/* reset a channel. turns it off */
76 	GS_CAN_MODE_RESET = 0,
77 	/* starts a channel */
78 	GS_CAN_MODE_START
79 };
80 
81 enum gs_can_state {
82 	GS_CAN_STATE_ERROR_ACTIVE = 0,
83 	GS_CAN_STATE_ERROR_WARNING,
84 	GS_CAN_STATE_ERROR_PASSIVE,
85 	GS_CAN_STATE_BUS_OFF,
86 	GS_CAN_STATE_STOPPED,
87 	GS_CAN_STATE_SLEEPING
88 };
89 
90 enum gs_can_identify_mode {
91 	GS_CAN_IDENTIFY_OFF = 0,
92 	GS_CAN_IDENTIFY_ON
93 };
94 
95 enum gs_can_termination_state {
96 	GS_CAN_TERMINATION_STATE_OFF = 0,
97 	GS_CAN_TERMINATION_STATE_ON
98 };
99 
100 #define GS_USB_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
101 #define GS_USB_TERMINATION_ENABLED 120
102 
103 /* data types passed between host and device */
104 
105 /* The firmware on the original USB2CAN by Geschwister Schneider
106  * Technologie Entwicklungs- und Vertriebs UG exchanges all data
107  * between the host and the device in host byte order. This is done
108  * with the struct gs_host_config::byte_order member, which is sent
109  * first to indicate the desired byte order.
110  *
111  * The widely used open source firmware candleLight doesn't support
112  * this feature and exchanges the data in little endian byte order.
113  */
114 struct gs_host_config {
115 	__le32 byte_order;
116 } __packed;
117 
118 struct gs_device_config {
119 	u8 reserved1;
120 	u8 reserved2;
121 	u8 reserved3;
122 	u8 icount;
123 	__le32 sw_version;
124 	__le32 hw_version;
125 } __packed;
126 
127 #define GS_CAN_MODE_NORMAL 0
128 #define GS_CAN_MODE_LISTEN_ONLY BIT(0)
129 #define GS_CAN_MODE_LOOP_BACK BIT(1)
130 #define GS_CAN_MODE_TRIPLE_SAMPLE BIT(2)
131 #define GS_CAN_MODE_ONE_SHOT BIT(3)
132 #define GS_CAN_MODE_HW_TIMESTAMP BIT(4)
133 /* GS_CAN_FEATURE_IDENTIFY BIT(5) */
134 /* GS_CAN_FEATURE_USER_ID BIT(6) */
135 #define GS_CAN_MODE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
136 #define GS_CAN_MODE_FD BIT(8)
137 /* GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9) */
138 /* GS_CAN_FEATURE_BT_CONST_EXT BIT(10) */
139 /* GS_CAN_FEATURE_TERMINATION BIT(11) */
140 #define GS_CAN_MODE_BERR_REPORTING BIT(12)
141 /* GS_CAN_FEATURE_GET_STATE BIT(13) */
142 
143 struct gs_device_mode {
144 	__le32 mode;
145 	__le32 flags;
146 } __packed;
147 
148 struct gs_device_state {
149 	__le32 state;
150 	__le32 rxerr;
151 	__le32 txerr;
152 } __packed;
153 
154 struct gs_device_bittiming {
155 	__le32 prop_seg;
156 	__le32 phase_seg1;
157 	__le32 phase_seg2;
158 	__le32 sjw;
159 	__le32 brp;
160 } __packed;
161 
162 struct gs_identify_mode {
163 	__le32 mode;
164 } __packed;
165 
166 struct gs_device_termination_state {
167 	__le32 state;
168 } __packed;
169 
170 #define GS_CAN_FEATURE_LISTEN_ONLY BIT(0)
171 #define GS_CAN_FEATURE_LOOP_BACK BIT(1)
172 #define GS_CAN_FEATURE_TRIPLE_SAMPLE BIT(2)
173 #define GS_CAN_FEATURE_ONE_SHOT BIT(3)
174 #define GS_CAN_FEATURE_HW_TIMESTAMP BIT(4)
175 #define GS_CAN_FEATURE_IDENTIFY BIT(5)
176 #define GS_CAN_FEATURE_USER_ID BIT(6)
177 #define GS_CAN_FEATURE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
178 #define GS_CAN_FEATURE_FD BIT(8)
179 #define GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9)
180 #define GS_CAN_FEATURE_BT_CONST_EXT BIT(10)
181 #define GS_CAN_FEATURE_TERMINATION BIT(11)
182 #define GS_CAN_FEATURE_BERR_REPORTING BIT(12)
183 #define GS_CAN_FEATURE_GET_STATE BIT(13)
184 #define GS_CAN_FEATURE_MASK GENMASK(13, 0)
185 
186 /* internal quirks - keep in GS_CAN_FEATURE space for now */
187 
188 /* CANtact Pro original firmware:
189  * BREQ DATA_BITTIMING overlaps with GET_USER_ID
190  */
191 #define GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO BIT(31)
192 
193 struct gs_device_bt_const {
194 	__le32 feature;
195 	__le32 fclk_can;
196 	__le32 tseg1_min;
197 	__le32 tseg1_max;
198 	__le32 tseg2_min;
199 	__le32 tseg2_max;
200 	__le32 sjw_max;
201 	__le32 brp_min;
202 	__le32 brp_max;
203 	__le32 brp_inc;
204 } __packed;
205 
206 struct gs_device_bt_const_extended {
207 	__le32 feature;
208 	__le32 fclk_can;
209 	__le32 tseg1_min;
210 	__le32 tseg1_max;
211 	__le32 tseg2_min;
212 	__le32 tseg2_max;
213 	__le32 sjw_max;
214 	__le32 brp_min;
215 	__le32 brp_max;
216 	__le32 brp_inc;
217 
218 	__le32 dtseg1_min;
219 	__le32 dtseg1_max;
220 	__le32 dtseg2_min;
221 	__le32 dtseg2_max;
222 	__le32 dsjw_max;
223 	__le32 dbrp_min;
224 	__le32 dbrp_max;
225 	__le32 dbrp_inc;
226 } __packed;
227 
228 #define GS_CAN_FLAG_OVERFLOW BIT(0)
229 #define GS_CAN_FLAG_FD BIT(1)
230 #define GS_CAN_FLAG_BRS BIT(2)
231 #define GS_CAN_FLAG_ESI BIT(3)
232 
233 struct classic_can {
234 	u8 data[8];
235 } __packed;
236 
237 struct classic_can_ts {
238 	u8 data[8];
239 	__le32 timestamp_us;
240 } __packed;
241 
242 struct classic_can_quirk {
243 	u8 data[8];
244 	u8 quirk;
245 } __packed;
246 
247 struct canfd {
248 	u8 data[64];
249 } __packed;
250 
251 struct canfd_ts {
252 	u8 data[64];
253 	__le32 timestamp_us;
254 } __packed;
255 
256 struct canfd_quirk {
257 	u8 data[64];
258 	u8 quirk;
259 } __packed;
260 
261 struct gs_host_frame {
262 	u32 echo_id;
263 	__le32 can_id;
264 
265 	u8 can_dlc;
266 	u8 channel;
267 	u8 flags;
268 	u8 reserved;
269 
270 	union {
271 		DECLARE_FLEX_ARRAY(struct classic_can, classic_can);
272 		DECLARE_FLEX_ARRAY(struct classic_can_ts, classic_can_ts);
273 		DECLARE_FLEX_ARRAY(struct classic_can_quirk, classic_can_quirk);
274 		DECLARE_FLEX_ARRAY(struct canfd, canfd);
275 		DECLARE_FLEX_ARRAY(struct canfd_ts, canfd_ts);
276 		DECLARE_FLEX_ARRAY(struct canfd_quirk, canfd_quirk);
277 	};
278 } __packed;
279 /* The GS USB devices make use of the same flags and masks as in
280  * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
281  */
282 
283 /* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
284 #define GS_MAX_TX_URBS 10
285 /* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
286 #define GS_MAX_RX_URBS 30
287 #define GS_NAPI_WEIGHT 32
288 
289 /* Maximum number of interfaces the driver supports per device.
290  * Current hardware only supports 3 interfaces. The future may vary.
291  */
292 #define GS_MAX_INTF 3
293 
294 struct gs_tx_context {
295 	struct gs_can *dev;
296 	unsigned int echo_id;
297 };
298 
299 struct gs_can {
300 	struct can_priv can; /* must be the first member */
301 
302 	struct can_rx_offload offload;
303 	struct gs_usb *parent;
304 
305 	struct net_device *netdev;
306 	struct usb_device *udev;
307 
308 	struct can_bittiming_const bt_const, data_bt_const;
309 	unsigned int channel;	/* channel number */
310 
311 	u32 feature;
312 	unsigned int hf_size_tx;
313 
314 	/* This lock prevents a race condition between xmit and receive. */
315 	spinlock_t tx_ctx_lock;
316 	struct gs_tx_context tx_context[GS_MAX_TX_URBS];
317 
318 	struct usb_anchor tx_submitted;
319 	atomic_t active_tx_urbs;
320 };
321 
322 /* usb interface struct */
323 struct gs_usb {
324 	struct gs_can *canch[GS_MAX_INTF];
325 	struct usb_anchor rx_submitted;
326 	struct usb_device *udev;
327 
328 	/* time counter for hardware timestamps */
329 	struct cyclecounter cc;
330 	struct timecounter tc;
331 	spinlock_t tc_lock; /* spinlock to guard access tc->cycle_last */
332 	struct delayed_work timestamp;
333 
334 	unsigned int hf_size_rx;
335 	u8 active_channels;
336 };
337 
338 /* 'allocate' a tx context.
339  * returns a valid tx context or NULL if there is no space.
340  */
341 static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
342 {
343 	int i = 0;
344 	unsigned long flags;
345 
346 	spin_lock_irqsave(&dev->tx_ctx_lock, flags);
347 
348 	for (; i < GS_MAX_TX_URBS; i++) {
349 		if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
350 			dev->tx_context[i].echo_id = i;
351 			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
352 			return &dev->tx_context[i];
353 		}
354 	}
355 
356 	spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
357 	return NULL;
358 }
359 
360 /* releases a tx context
361  */
362 static void gs_free_tx_context(struct gs_tx_context *txc)
363 {
364 	txc->echo_id = GS_MAX_TX_URBS;
365 }
366 
367 /* Get a tx context by id.
368  */
369 static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
370 					       unsigned int id)
371 {
372 	unsigned long flags;
373 
374 	if (id < GS_MAX_TX_URBS) {
375 		spin_lock_irqsave(&dev->tx_ctx_lock, flags);
376 		if (dev->tx_context[id].echo_id == id) {
377 			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
378 			return &dev->tx_context[id];
379 		}
380 		spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
381 	}
382 	return NULL;
383 }
384 
385 static int gs_cmd_reset(struct gs_can *dev)
386 {
387 	struct gs_device_mode dm = {
388 		.mode = cpu_to_le32(GS_CAN_MODE_RESET),
389 	};
390 
391 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_MODE,
392 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
393 				    dev->channel, 0, &dm, sizeof(dm), 1000,
394 				    GFP_KERNEL);
395 }
396 
397 static inline int gs_usb_get_timestamp(const struct gs_usb *parent,
398 				       u32 *timestamp_p)
399 {
400 	__le32 timestamp;
401 	int rc;
402 
403 	rc = usb_control_msg_recv(parent->udev, 0, GS_USB_BREQ_TIMESTAMP,
404 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
405 				  0, 0,
406 				  &timestamp, sizeof(timestamp),
407 				  USB_CTRL_GET_TIMEOUT,
408 				  GFP_KERNEL);
409 	if (rc)
410 		return rc;
411 
412 	*timestamp_p = le32_to_cpu(timestamp);
413 
414 	return 0;
415 }
416 
417 static u64 gs_usb_timestamp_read(const struct cyclecounter *cc) __must_hold(&dev->tc_lock)
418 {
419 	struct gs_usb *parent = container_of(cc, struct gs_usb, cc);
420 	u32 timestamp = 0;
421 	int err;
422 
423 	lockdep_assert_held(&parent->tc_lock);
424 
425 	/* drop lock for synchronous USB transfer */
426 	spin_unlock_bh(&parent->tc_lock);
427 	err = gs_usb_get_timestamp(parent, &timestamp);
428 	spin_lock_bh(&parent->tc_lock);
429 	if (err)
430 		dev_err(&parent->udev->dev,
431 			"Error %d while reading timestamp. HW timestamps may be inaccurate.",
432 			err);
433 
434 	return timestamp;
435 }
436 
437 static void gs_usb_timestamp_work(struct work_struct *work)
438 {
439 	struct delayed_work *delayed_work = to_delayed_work(work);
440 	struct gs_usb *parent;
441 
442 	parent = container_of(delayed_work, struct gs_usb, timestamp);
443 	spin_lock_bh(&parent->tc_lock);
444 	timecounter_read(&parent->tc);
445 	spin_unlock_bh(&parent->tc_lock);
446 
447 	schedule_delayed_work(&parent->timestamp,
448 			      GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
449 }
450 
451 static void gs_usb_skb_set_timestamp(struct gs_can *dev,
452 				     struct sk_buff *skb, u32 timestamp)
453 {
454 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
455 	struct gs_usb *parent = dev->parent;
456 	u64 ns;
457 
458 	spin_lock_bh(&parent->tc_lock);
459 	ns = timecounter_cyc2time(&parent->tc, timestamp);
460 	spin_unlock_bh(&parent->tc_lock);
461 
462 	hwtstamps->hwtstamp = ns_to_ktime(ns);
463 }
464 
465 static void gs_usb_timestamp_init(struct gs_usb *parent)
466 {
467 	struct cyclecounter *cc = &parent->cc;
468 
469 	cc->read = gs_usb_timestamp_read;
470 	cc->mask = CYCLECOUNTER_MASK(32);
471 	cc->shift = 32 - bits_per(NSEC_PER_SEC / GS_USB_TIMESTAMP_TIMER_HZ);
472 	cc->mult = clocksource_hz2mult(GS_USB_TIMESTAMP_TIMER_HZ, cc->shift);
473 
474 	spin_lock_init(&parent->tc_lock);
475 	spin_lock_bh(&parent->tc_lock);
476 	timecounter_init(&parent->tc, &parent->cc, ktime_get_real_ns());
477 	spin_unlock_bh(&parent->tc_lock);
478 
479 	INIT_DELAYED_WORK(&parent->timestamp, gs_usb_timestamp_work);
480 	schedule_delayed_work(&parent->timestamp,
481 			      GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
482 }
483 
484 static void gs_usb_timestamp_stop(struct gs_usb *parent)
485 {
486 	cancel_delayed_work_sync(&parent->timestamp);
487 }
488 
489 static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
490 {
491 	struct can_device_stats *can_stats = &dev->can.can_stats;
492 
493 	if (cf->can_id & CAN_ERR_RESTARTED) {
494 		dev->can.state = CAN_STATE_ERROR_ACTIVE;
495 		can_stats->restarts++;
496 	} else if (cf->can_id & CAN_ERR_BUSOFF) {
497 		dev->can.state = CAN_STATE_BUS_OFF;
498 		can_stats->bus_off++;
499 	} else if (cf->can_id & CAN_ERR_CRTL) {
500 		if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
501 		    (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
502 			dev->can.state = CAN_STATE_ERROR_WARNING;
503 			can_stats->error_warning++;
504 		} else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
505 			   (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
506 			dev->can.state = CAN_STATE_ERROR_PASSIVE;
507 			can_stats->error_passive++;
508 		} else {
509 			dev->can.state = CAN_STATE_ERROR_ACTIVE;
510 		}
511 	}
512 }
513 
514 static u32 gs_usb_set_timestamp(struct gs_can *dev, struct sk_buff *skb,
515 				const struct gs_host_frame *hf)
516 {
517 	u32 timestamp;
518 
519 	if (hf->flags & GS_CAN_FLAG_FD)
520 		timestamp = le32_to_cpu(hf->canfd_ts->timestamp_us);
521 	else
522 		timestamp = le32_to_cpu(hf->classic_can_ts->timestamp_us);
523 
524 	if (skb)
525 		gs_usb_skb_set_timestamp(dev, skb, timestamp);
526 
527 	return timestamp;
528 }
529 
530 static void gs_usb_rx_offload(struct gs_can *dev, struct sk_buff *skb,
531 			      const struct gs_host_frame *hf)
532 {
533 	struct can_rx_offload *offload = &dev->offload;
534 	int rc;
535 
536 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) {
537 		const u32 ts = gs_usb_set_timestamp(dev, skb, hf);
538 
539 		rc = can_rx_offload_queue_timestamp(offload, skb, ts);
540 	} else {
541 		rc = can_rx_offload_queue_tail(offload, skb);
542 	}
543 
544 	if (rc)
545 		dev->netdev->stats.rx_fifo_errors++;
546 }
547 
548 static unsigned int
549 gs_usb_get_echo_skb(struct gs_can *dev, struct sk_buff *skb,
550 		    const struct gs_host_frame *hf)
551 {
552 	struct can_rx_offload *offload = &dev->offload;
553 	const u32 echo_id = hf->echo_id;
554 	unsigned int len;
555 
556 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) {
557 		const u32 ts = gs_usb_set_timestamp(dev, skb, hf);
558 
559 		len = can_rx_offload_get_echo_skb_queue_timestamp(offload, echo_id,
560 								  ts, NULL);
561 	} else {
562 		len = can_rx_offload_get_echo_skb_queue_tail(offload, echo_id,
563 							     NULL);
564 	}
565 
566 	return len;
567 }
568 
569 static void gs_usb_receive_bulk_callback(struct urb *urb)
570 {
571 	struct gs_usb *parent = urb->context;
572 	struct gs_can *dev;
573 	struct net_device *netdev;
574 	int rc;
575 	struct net_device_stats *stats;
576 	struct gs_host_frame *hf = urb->transfer_buffer;
577 	struct gs_tx_context *txc;
578 	struct can_frame *cf;
579 	struct canfd_frame *cfd;
580 	struct sk_buff *skb;
581 
582 	BUG_ON(!parent);
583 
584 	switch (urb->status) {
585 	case 0: /* success */
586 		break;
587 	case -ENOENT:
588 	case -ESHUTDOWN:
589 		return;
590 	default:
591 		/* do not resubmit aborted urbs. eg: when device goes down */
592 		return;
593 	}
594 
595 	/* device reports out of range channel id */
596 	if (hf->channel >= GS_MAX_INTF)
597 		goto device_detach;
598 
599 	dev = parent->canch[hf->channel];
600 
601 	netdev = dev->netdev;
602 	stats = &netdev->stats;
603 
604 	if (!netif_device_present(netdev))
605 		return;
606 
607 	if (!netif_running(netdev))
608 		goto resubmit_urb;
609 
610 	if (hf->echo_id == -1) { /* normal rx */
611 		if (hf->flags & GS_CAN_FLAG_FD) {
612 			skb = alloc_canfd_skb(netdev, &cfd);
613 			if (!skb)
614 				return;
615 
616 			cfd->can_id = le32_to_cpu(hf->can_id);
617 			cfd->len = can_fd_dlc2len(hf->can_dlc);
618 			if (hf->flags & GS_CAN_FLAG_BRS)
619 				cfd->flags |= CANFD_BRS;
620 			if (hf->flags & GS_CAN_FLAG_ESI)
621 				cfd->flags |= CANFD_ESI;
622 
623 			memcpy(cfd->data, hf->canfd->data, cfd->len);
624 		} else {
625 			skb = alloc_can_skb(netdev, &cf);
626 			if (!skb)
627 				return;
628 
629 			cf->can_id = le32_to_cpu(hf->can_id);
630 			can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);
631 
632 			memcpy(cf->data, hf->classic_can->data, 8);
633 
634 			/* ERROR frames tell us information about the controller */
635 			if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)
636 				gs_update_state(dev, cf);
637 		}
638 
639 		gs_usb_rx_offload(dev, skb, hf);
640 	} else { /* echo_id == hf->echo_id */
641 		if (hf->echo_id >= GS_MAX_TX_URBS) {
642 			netdev_err(netdev,
643 				   "Unexpected out of range echo id %u\n",
644 				   hf->echo_id);
645 			goto resubmit_urb;
646 		}
647 
648 		txc = gs_get_tx_context(dev, hf->echo_id);
649 
650 		/* bad devices send bad echo_ids. */
651 		if (!txc) {
652 			netdev_err(netdev,
653 				   "Unexpected unused echo id %u\n",
654 				   hf->echo_id);
655 			goto resubmit_urb;
656 		}
657 
658 		skb = dev->can.echo_skb[hf->echo_id];
659 		stats->tx_packets++;
660 		stats->tx_bytes += gs_usb_get_echo_skb(dev, skb, hf);
661 		gs_free_tx_context(txc);
662 
663 		atomic_dec(&dev->active_tx_urbs);
664 
665 		netif_wake_queue(netdev);
666 	}
667 
668 	if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
669 		stats->rx_over_errors++;
670 		stats->rx_errors++;
671 
672 		skb = alloc_can_err_skb(netdev, &cf);
673 		if (!skb)
674 			goto resubmit_urb;
675 
676 		cf->can_id |= CAN_ERR_CRTL;
677 		cf->len = CAN_ERR_DLC;
678 		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
679 
680 		gs_usb_rx_offload(dev, skb, hf);
681 	}
682 
683 	can_rx_offload_irq_finish(&dev->offload);
684 
685 resubmit_urb:
686 	usb_fill_bulk_urb(urb, parent->udev,
687 			  usb_rcvbulkpipe(parent->udev, GS_USB_ENDPOINT_IN),
688 			  hf, dev->parent->hf_size_rx,
689 			  gs_usb_receive_bulk_callback, parent);
690 
691 	rc = usb_submit_urb(urb, GFP_ATOMIC);
692 
693 	/* USB failure take down all interfaces */
694 	if (rc == -ENODEV) {
695 device_detach:
696 		for (rc = 0; rc < GS_MAX_INTF; rc++) {
697 			if (parent->canch[rc])
698 				netif_device_detach(parent->canch[rc]->netdev);
699 		}
700 	}
701 }
702 
703 static int gs_usb_set_bittiming(struct net_device *netdev)
704 {
705 	struct gs_can *dev = netdev_priv(netdev);
706 	struct can_bittiming *bt = &dev->can.bittiming;
707 	struct gs_device_bittiming dbt = {
708 		.prop_seg = cpu_to_le32(bt->prop_seg),
709 		.phase_seg1 = cpu_to_le32(bt->phase_seg1),
710 		.phase_seg2 = cpu_to_le32(bt->phase_seg2),
711 		.sjw = cpu_to_le32(bt->sjw),
712 		.brp = cpu_to_le32(bt->brp),
713 	};
714 
715 	/* request bit timings */
716 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_BITTIMING,
717 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
718 				    dev->channel, 0, &dbt, sizeof(dbt), 1000,
719 				    GFP_KERNEL);
720 }
721 
722 static int gs_usb_set_data_bittiming(struct net_device *netdev)
723 {
724 	struct gs_can *dev = netdev_priv(netdev);
725 	struct can_bittiming *bt = &dev->can.data_bittiming;
726 	struct gs_device_bittiming dbt = {
727 		.prop_seg = cpu_to_le32(bt->prop_seg),
728 		.phase_seg1 = cpu_to_le32(bt->phase_seg1),
729 		.phase_seg2 = cpu_to_le32(bt->phase_seg2),
730 		.sjw = cpu_to_le32(bt->sjw),
731 		.brp = cpu_to_le32(bt->brp),
732 	};
733 	u8 request = GS_USB_BREQ_DATA_BITTIMING;
734 
735 	if (dev->feature & GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO)
736 		request = GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING;
737 
738 	/* request data bit timings */
739 	return usb_control_msg_send(dev->udev, 0, request,
740 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
741 				    dev->channel, 0, &dbt, sizeof(dbt), 1000,
742 				    GFP_KERNEL);
743 }
744 
745 static void gs_usb_xmit_callback(struct urb *urb)
746 {
747 	struct gs_tx_context *txc = urb->context;
748 	struct gs_can *dev = txc->dev;
749 	struct net_device *netdev = dev->netdev;
750 
751 	if (urb->status)
752 		netdev_info(netdev, "usb xmit fail %u\n", txc->echo_id);
753 }
754 
755 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
756 				     struct net_device *netdev)
757 {
758 	struct gs_can *dev = netdev_priv(netdev);
759 	struct net_device_stats *stats = &dev->netdev->stats;
760 	struct urb *urb;
761 	struct gs_host_frame *hf;
762 	struct can_frame *cf;
763 	struct canfd_frame *cfd;
764 	int rc;
765 	unsigned int idx;
766 	struct gs_tx_context *txc;
767 
768 	if (can_dev_dropped_skb(netdev, skb))
769 		return NETDEV_TX_OK;
770 
771 	/* find an empty context to keep track of transmission */
772 	txc = gs_alloc_tx_context(dev);
773 	if (!txc)
774 		return NETDEV_TX_BUSY;
775 
776 	/* create a URB, and a buffer for it */
777 	urb = usb_alloc_urb(0, GFP_ATOMIC);
778 	if (!urb)
779 		goto nomem_urb;
780 
781 	hf = kmalloc(dev->hf_size_tx, GFP_ATOMIC);
782 	if (!hf)
783 		goto nomem_hf;
784 
785 	idx = txc->echo_id;
786 
787 	if (idx >= GS_MAX_TX_URBS) {
788 		netdev_err(netdev, "Invalid tx context %u\n", idx);
789 		goto badidx;
790 	}
791 
792 	hf->echo_id = idx;
793 	hf->channel = dev->channel;
794 	hf->flags = 0;
795 	hf->reserved = 0;
796 
797 	if (can_is_canfd_skb(skb)) {
798 		cfd = (struct canfd_frame *)skb->data;
799 
800 		hf->can_id = cpu_to_le32(cfd->can_id);
801 		hf->can_dlc = can_fd_len2dlc(cfd->len);
802 		hf->flags |= GS_CAN_FLAG_FD;
803 		if (cfd->flags & CANFD_BRS)
804 			hf->flags |= GS_CAN_FLAG_BRS;
805 		if (cfd->flags & CANFD_ESI)
806 			hf->flags |= GS_CAN_FLAG_ESI;
807 
808 		memcpy(hf->canfd->data, cfd->data, cfd->len);
809 	} else {
810 		cf = (struct can_frame *)skb->data;
811 
812 		hf->can_id = cpu_to_le32(cf->can_id);
813 		hf->can_dlc = can_get_cc_dlc(cf, dev->can.ctrlmode);
814 
815 		memcpy(hf->classic_can->data, cf->data, cf->len);
816 	}
817 
818 	usb_fill_bulk_urb(urb, dev->udev,
819 			  usb_sndbulkpipe(dev->udev, GS_USB_ENDPOINT_OUT),
820 			  hf, dev->hf_size_tx,
821 			  gs_usb_xmit_callback, txc);
822 
823 	urb->transfer_flags |= URB_FREE_BUFFER;
824 	usb_anchor_urb(urb, &dev->tx_submitted);
825 
826 	can_put_echo_skb(skb, netdev, idx, 0);
827 
828 	atomic_inc(&dev->active_tx_urbs);
829 
830 	rc = usb_submit_urb(urb, GFP_ATOMIC);
831 	if (unlikely(rc)) {			/* usb send failed */
832 		atomic_dec(&dev->active_tx_urbs);
833 
834 		can_free_echo_skb(netdev, idx, NULL);
835 		gs_free_tx_context(txc);
836 
837 		usb_unanchor_urb(urb);
838 
839 		if (rc == -ENODEV) {
840 			netif_device_detach(netdev);
841 		} else {
842 			netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
843 			stats->tx_dropped++;
844 		}
845 	} else {
846 		/* Slow down tx path */
847 		if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
848 			netif_stop_queue(netdev);
849 	}
850 
851 	/* let usb core take care of this urb */
852 	usb_free_urb(urb);
853 
854 	return NETDEV_TX_OK;
855 
856 badidx:
857 	kfree(hf);
858 nomem_hf:
859 	usb_free_urb(urb);
860 
861 nomem_urb:
862 	gs_free_tx_context(txc);
863 	dev_kfree_skb(skb);
864 	stats->tx_dropped++;
865 	return NETDEV_TX_OK;
866 }
867 
868 static int gs_can_open(struct net_device *netdev)
869 {
870 	struct gs_can *dev = netdev_priv(netdev);
871 	struct gs_usb *parent = dev->parent;
872 	struct gs_device_mode dm = {
873 		.mode = cpu_to_le32(GS_CAN_MODE_START),
874 	};
875 	struct gs_host_frame *hf;
876 	struct urb *urb = NULL;
877 	u32 ctrlmode;
878 	u32 flags = 0;
879 	int rc, i;
880 
881 	rc = open_candev(netdev);
882 	if (rc)
883 		return rc;
884 
885 	ctrlmode = dev->can.ctrlmode;
886 	if (ctrlmode & CAN_CTRLMODE_FD) {
887 		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
888 			dev->hf_size_tx = struct_size(hf, canfd_quirk, 1);
889 		else
890 			dev->hf_size_tx = struct_size(hf, canfd, 1);
891 	} else {
892 		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
893 			dev->hf_size_tx = struct_size(hf, classic_can_quirk, 1);
894 		else
895 			dev->hf_size_tx = struct_size(hf, classic_can, 1);
896 	}
897 
898 	can_rx_offload_enable(&dev->offload);
899 
900 	if (!parent->active_channels) {
901 		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
902 			gs_usb_timestamp_init(parent);
903 
904 		for (i = 0; i < GS_MAX_RX_URBS; i++) {
905 			u8 *buf;
906 
907 			/* alloc rx urb */
908 			urb = usb_alloc_urb(0, GFP_KERNEL);
909 			if (!urb) {
910 				rc = -ENOMEM;
911 				goto out_usb_kill_anchored_urbs;
912 			}
913 
914 			/* alloc rx buffer */
915 			buf = kmalloc(dev->parent->hf_size_rx,
916 				      GFP_KERNEL);
917 			if (!buf) {
918 				rc = -ENOMEM;
919 				goto out_usb_free_urb;
920 			}
921 
922 			/* fill, anchor, and submit rx urb */
923 			usb_fill_bulk_urb(urb,
924 					  dev->udev,
925 					  usb_rcvbulkpipe(dev->udev,
926 							  GS_USB_ENDPOINT_IN),
927 					  buf,
928 					  dev->parent->hf_size_rx,
929 					  gs_usb_receive_bulk_callback, parent);
930 			urb->transfer_flags |= URB_FREE_BUFFER;
931 
932 			usb_anchor_urb(urb, &parent->rx_submitted);
933 
934 			rc = usb_submit_urb(urb, GFP_KERNEL);
935 			if (rc) {
936 				if (rc == -ENODEV)
937 					netif_device_detach(dev->netdev);
938 
939 				netdev_err(netdev,
940 					   "usb_submit_urb() failed, error %pe\n",
941 					   ERR_PTR(rc));
942 
943 				goto out_usb_unanchor_urb;
944 			}
945 
946 			/* Drop reference,
947 			 * USB core will take care of freeing it
948 			 */
949 			usb_free_urb(urb);
950 		}
951 	}
952 
953 	/* flags */
954 	if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
955 		flags |= GS_CAN_MODE_LOOP_BACK;
956 
957 	if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
958 		flags |= GS_CAN_MODE_LISTEN_ONLY;
959 
960 	if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
961 		flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
962 
963 	if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
964 		flags |= GS_CAN_MODE_ONE_SHOT;
965 
966 	if (ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
967 		flags |= GS_CAN_MODE_BERR_REPORTING;
968 
969 	if (ctrlmode & CAN_CTRLMODE_FD)
970 		flags |= GS_CAN_MODE_FD;
971 
972 	/* if hardware supports timestamps, enable it */
973 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
974 		flags |= GS_CAN_MODE_HW_TIMESTAMP;
975 
976 	/* finally start device */
977 	dev->can.state = CAN_STATE_ERROR_ACTIVE;
978 	dm.flags = cpu_to_le32(flags);
979 	rc = usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_MODE,
980 				  USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
981 				  dev->channel, 0, &dm, sizeof(dm), 1000,
982 				  GFP_KERNEL);
983 	if (rc) {
984 		netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
985 		dev->can.state = CAN_STATE_STOPPED;
986 
987 		goto out_usb_kill_anchored_urbs;
988 	}
989 
990 	parent->active_channels++;
991 	if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
992 		netif_start_queue(netdev);
993 
994 	return 0;
995 
996 out_usb_unanchor_urb:
997 	usb_unanchor_urb(urb);
998 out_usb_free_urb:
999 	usb_free_urb(urb);
1000 out_usb_kill_anchored_urbs:
1001 	if (!parent->active_channels) {
1002 		usb_kill_anchored_urbs(&dev->tx_submitted);
1003 
1004 		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1005 			gs_usb_timestamp_stop(parent);
1006 	}
1007 
1008 	can_rx_offload_disable(&dev->offload);
1009 	close_candev(netdev);
1010 
1011 	return rc;
1012 }
1013 
1014 static int gs_usb_get_state(const struct net_device *netdev,
1015 			    struct can_berr_counter *bec,
1016 			    enum can_state *state)
1017 {
1018 	struct gs_can *dev = netdev_priv(netdev);
1019 	struct gs_device_state ds;
1020 	int rc;
1021 
1022 	rc = usb_control_msg_recv(dev->udev, 0, GS_USB_BREQ_GET_STATE,
1023 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1024 				  dev->channel, 0,
1025 				  &ds, sizeof(ds),
1026 				  USB_CTRL_GET_TIMEOUT,
1027 				  GFP_KERNEL);
1028 	if (rc)
1029 		return rc;
1030 
1031 	if (le32_to_cpu(ds.state) >= CAN_STATE_MAX)
1032 		return -EOPNOTSUPP;
1033 
1034 	*state = le32_to_cpu(ds.state);
1035 	bec->txerr = le32_to_cpu(ds.txerr);
1036 	bec->rxerr = le32_to_cpu(ds.rxerr);
1037 
1038 	return 0;
1039 }
1040 
1041 static int gs_usb_can_get_berr_counter(const struct net_device *netdev,
1042 				       struct can_berr_counter *bec)
1043 {
1044 	enum can_state state;
1045 
1046 	return gs_usb_get_state(netdev, bec, &state);
1047 }
1048 
1049 static int gs_can_close(struct net_device *netdev)
1050 {
1051 	int rc;
1052 	struct gs_can *dev = netdev_priv(netdev);
1053 	struct gs_usb *parent = dev->parent;
1054 
1055 	netif_stop_queue(netdev);
1056 
1057 	/* Stop polling */
1058 	parent->active_channels--;
1059 	if (!parent->active_channels) {
1060 		usb_kill_anchored_urbs(&parent->rx_submitted);
1061 
1062 		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1063 			gs_usb_timestamp_stop(parent);
1064 	}
1065 
1066 	/* Stop sending URBs */
1067 	usb_kill_anchored_urbs(&dev->tx_submitted);
1068 	atomic_set(&dev->active_tx_urbs, 0);
1069 
1070 	dev->can.state = CAN_STATE_STOPPED;
1071 
1072 	/* reset the device */
1073 	gs_cmd_reset(dev);
1074 
1075 	/* reset tx contexts */
1076 	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
1077 		dev->tx_context[rc].dev = dev;
1078 		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
1079 	}
1080 
1081 	can_rx_offload_disable(&dev->offload);
1082 
1083 	/* close the netdev */
1084 	close_candev(netdev);
1085 
1086 	return 0;
1087 }
1088 
1089 static int gs_can_eth_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
1090 {
1091 	const struct gs_can *dev = netdev_priv(netdev);
1092 
1093 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1094 		return can_eth_ioctl_hwts(netdev, ifr, cmd);
1095 
1096 	return -EOPNOTSUPP;
1097 }
1098 
1099 static const struct net_device_ops gs_usb_netdev_ops = {
1100 	.ndo_open = gs_can_open,
1101 	.ndo_stop = gs_can_close,
1102 	.ndo_start_xmit = gs_can_start_xmit,
1103 	.ndo_change_mtu = can_change_mtu,
1104 	.ndo_eth_ioctl = gs_can_eth_ioctl,
1105 };
1106 
1107 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
1108 {
1109 	struct gs_can *dev = netdev_priv(netdev);
1110 	struct gs_identify_mode imode;
1111 
1112 	if (do_identify)
1113 		imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
1114 	else
1115 		imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
1116 
1117 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_IDENTIFY,
1118 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1119 				    dev->channel, 0, &imode, sizeof(imode), 100,
1120 				    GFP_KERNEL);
1121 }
1122 
1123 /* blink LED's for finding the this interface */
1124 static int gs_usb_set_phys_id(struct net_device *netdev,
1125 			      enum ethtool_phys_id_state state)
1126 {
1127 	const struct gs_can *dev = netdev_priv(netdev);
1128 	int rc = 0;
1129 
1130 	if (!(dev->feature & GS_CAN_FEATURE_IDENTIFY))
1131 		return -EOPNOTSUPP;
1132 
1133 	switch (state) {
1134 	case ETHTOOL_ID_ACTIVE:
1135 		rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_ON);
1136 		break;
1137 	case ETHTOOL_ID_INACTIVE:
1138 		rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_OFF);
1139 		break;
1140 	default:
1141 		break;
1142 	}
1143 
1144 	return rc;
1145 }
1146 
1147 static int gs_usb_get_ts_info(struct net_device *netdev,
1148 			      struct ethtool_ts_info *info)
1149 {
1150 	struct gs_can *dev = netdev_priv(netdev);
1151 
1152 	/* report if device supports HW timestamps */
1153 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1154 		return can_ethtool_op_get_ts_info_hwts(netdev, info);
1155 
1156 	return ethtool_op_get_ts_info(netdev, info);
1157 }
1158 
1159 static const struct ethtool_ops gs_usb_ethtool_ops = {
1160 	.set_phys_id = gs_usb_set_phys_id,
1161 	.get_ts_info = gs_usb_get_ts_info,
1162 };
1163 
1164 static int gs_usb_get_termination(struct net_device *netdev, u16 *term)
1165 {
1166 	struct gs_can *dev = netdev_priv(netdev);
1167 	struct gs_device_termination_state term_state;
1168 	int rc;
1169 
1170 	rc = usb_control_msg_recv(dev->udev, 0, GS_USB_BREQ_GET_TERMINATION,
1171 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1172 				  dev->channel, 0,
1173 				  &term_state, sizeof(term_state), 1000,
1174 				  GFP_KERNEL);
1175 	if (rc)
1176 		return rc;
1177 
1178 	if (term_state.state == cpu_to_le32(GS_CAN_TERMINATION_STATE_ON))
1179 		*term = GS_USB_TERMINATION_ENABLED;
1180 	else
1181 		*term = GS_USB_TERMINATION_DISABLED;
1182 
1183 	return 0;
1184 }
1185 
1186 static int gs_usb_set_termination(struct net_device *netdev, u16 term)
1187 {
1188 	struct gs_can *dev = netdev_priv(netdev);
1189 	struct gs_device_termination_state term_state;
1190 
1191 	if (term == GS_USB_TERMINATION_ENABLED)
1192 		term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_ON);
1193 	else
1194 		term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_OFF);
1195 
1196 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_SET_TERMINATION,
1197 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1198 				    dev->channel, 0,
1199 				    &term_state, sizeof(term_state), 1000,
1200 				    GFP_KERNEL);
1201 }
1202 
1203 static const u16 gs_usb_termination_const[] = {
1204 	GS_USB_TERMINATION_DISABLED,
1205 	GS_USB_TERMINATION_ENABLED
1206 };
1207 
1208 static struct gs_can *gs_make_candev(unsigned int channel,
1209 				     struct usb_interface *intf,
1210 				     struct gs_device_config *dconf)
1211 {
1212 	struct gs_can *dev;
1213 	struct net_device *netdev;
1214 	int rc;
1215 	struct gs_device_bt_const_extended bt_const_extended;
1216 	struct gs_device_bt_const bt_const;
1217 	u32 feature;
1218 
1219 	/* fetch bit timing constants */
1220 	rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
1221 				  GS_USB_BREQ_BT_CONST,
1222 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1223 				  channel, 0, &bt_const, sizeof(bt_const), 1000,
1224 				  GFP_KERNEL);
1225 
1226 	if (rc) {
1227 		dev_err(&intf->dev,
1228 			"Couldn't get bit timing const for channel %d (%pe)\n",
1229 			channel, ERR_PTR(rc));
1230 		return ERR_PTR(rc);
1231 	}
1232 
1233 	/* create netdev */
1234 	netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
1235 	if (!netdev) {
1236 		dev_err(&intf->dev, "Couldn't allocate candev\n");
1237 		return ERR_PTR(-ENOMEM);
1238 	}
1239 
1240 	dev = netdev_priv(netdev);
1241 
1242 	netdev->netdev_ops = &gs_usb_netdev_ops;
1243 	netdev->ethtool_ops = &gs_usb_ethtool_ops;
1244 
1245 	netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
1246 	netdev->dev_id = channel;
1247 
1248 	/* dev setup */
1249 	strcpy(dev->bt_const.name, KBUILD_MODNAME);
1250 	dev->bt_const.tseg1_min = le32_to_cpu(bt_const.tseg1_min);
1251 	dev->bt_const.tseg1_max = le32_to_cpu(bt_const.tseg1_max);
1252 	dev->bt_const.tseg2_min = le32_to_cpu(bt_const.tseg2_min);
1253 	dev->bt_const.tseg2_max = le32_to_cpu(bt_const.tseg2_max);
1254 	dev->bt_const.sjw_max = le32_to_cpu(bt_const.sjw_max);
1255 	dev->bt_const.brp_min = le32_to_cpu(bt_const.brp_min);
1256 	dev->bt_const.brp_max = le32_to_cpu(bt_const.brp_max);
1257 	dev->bt_const.brp_inc = le32_to_cpu(bt_const.brp_inc);
1258 
1259 	dev->udev = interface_to_usbdev(intf);
1260 	dev->netdev = netdev;
1261 	dev->channel = channel;
1262 
1263 	init_usb_anchor(&dev->tx_submitted);
1264 	atomic_set(&dev->active_tx_urbs, 0);
1265 	spin_lock_init(&dev->tx_ctx_lock);
1266 	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
1267 		dev->tx_context[rc].dev = dev;
1268 		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
1269 	}
1270 
1271 	/* can setup */
1272 	dev->can.state = CAN_STATE_STOPPED;
1273 	dev->can.clock.freq = le32_to_cpu(bt_const.fclk_can);
1274 	dev->can.bittiming_const = &dev->bt_const;
1275 	dev->can.do_set_bittiming = gs_usb_set_bittiming;
1276 
1277 	dev->can.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC;
1278 
1279 	feature = le32_to_cpu(bt_const.feature);
1280 	dev->feature = FIELD_GET(GS_CAN_FEATURE_MASK, feature);
1281 	if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
1282 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
1283 
1284 	if (feature & GS_CAN_FEATURE_LOOP_BACK)
1285 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
1286 
1287 	if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
1288 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1289 
1290 	if (feature & GS_CAN_FEATURE_ONE_SHOT)
1291 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
1292 
1293 	if (feature & GS_CAN_FEATURE_FD) {
1294 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
1295 		/* The data bit timing will be overwritten, if
1296 		 * GS_CAN_FEATURE_BT_CONST_EXT is set.
1297 		 */
1298 		dev->can.data_bittiming_const = &dev->bt_const;
1299 		dev->can.do_set_data_bittiming = gs_usb_set_data_bittiming;
1300 	}
1301 
1302 	if (feature & GS_CAN_FEATURE_TERMINATION) {
1303 		rc = gs_usb_get_termination(netdev, &dev->can.termination);
1304 		if (rc) {
1305 			dev->feature &= ~GS_CAN_FEATURE_TERMINATION;
1306 
1307 			dev_info(&intf->dev,
1308 				 "Disabling termination support for channel %d (%pe)\n",
1309 				 channel, ERR_PTR(rc));
1310 		} else {
1311 			dev->can.termination_const = gs_usb_termination_const;
1312 			dev->can.termination_const_cnt = ARRAY_SIZE(gs_usb_termination_const);
1313 			dev->can.do_set_termination = gs_usb_set_termination;
1314 		}
1315 	}
1316 
1317 	if (feature & GS_CAN_FEATURE_BERR_REPORTING)
1318 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_BERR_REPORTING;
1319 
1320 	if (feature & GS_CAN_FEATURE_GET_STATE)
1321 		dev->can.do_get_berr_counter = gs_usb_can_get_berr_counter;
1322 
1323 	/* The CANtact Pro from LinkLayer Labs is based on the
1324 	 * LPC54616 µC, which is affected by the NXP LPC USB transfer
1325 	 * erratum. However, the current firmware (version 2) doesn't
1326 	 * set the GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX bit. Set the
1327 	 * feature GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX to workaround
1328 	 * this issue.
1329 	 *
1330 	 * For the GS_USB_BREQ_DATA_BITTIMING USB control message the
1331 	 * CANtact Pro firmware uses a request value, which is already
1332 	 * used by the candleLight firmware for a different purpose
1333 	 * (GS_USB_BREQ_GET_USER_ID). Set the feature
1334 	 * GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO to workaround this
1335 	 * issue.
1336 	 */
1337 	if (dev->udev->descriptor.idVendor == cpu_to_le16(USB_GS_USB_1_VENDOR_ID) &&
1338 	    dev->udev->descriptor.idProduct == cpu_to_le16(USB_GS_USB_1_PRODUCT_ID) &&
1339 	    dev->udev->manufacturer && dev->udev->product &&
1340 	    !strcmp(dev->udev->manufacturer, "LinkLayer Labs") &&
1341 	    !strcmp(dev->udev->product, "CANtact Pro") &&
1342 	    (le32_to_cpu(dconf->sw_version) <= 2))
1343 		dev->feature |= GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX |
1344 			GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO;
1345 
1346 	/* GS_CAN_FEATURE_IDENTIFY is only supported for sw_version > 1 */
1347 	if (!(le32_to_cpu(dconf->sw_version) > 1 &&
1348 	      feature & GS_CAN_FEATURE_IDENTIFY))
1349 		dev->feature &= ~GS_CAN_FEATURE_IDENTIFY;
1350 
1351 	/* fetch extended bit timing constants if device has feature
1352 	 * GS_CAN_FEATURE_FD and GS_CAN_FEATURE_BT_CONST_EXT
1353 	 */
1354 	if (feature & GS_CAN_FEATURE_FD &&
1355 	    feature & GS_CAN_FEATURE_BT_CONST_EXT) {
1356 		rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
1357 					  GS_USB_BREQ_BT_CONST_EXT,
1358 					  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1359 					  channel, 0, &bt_const_extended,
1360 					  sizeof(bt_const_extended),
1361 					  1000, GFP_KERNEL);
1362 		if (rc) {
1363 			dev_err(&intf->dev,
1364 				"Couldn't get extended bit timing const for channel %d (%pe)\n",
1365 				channel, ERR_PTR(rc));
1366 			goto out_free_candev;
1367 		}
1368 
1369 		strcpy(dev->data_bt_const.name, KBUILD_MODNAME);
1370 		dev->data_bt_const.tseg1_min = le32_to_cpu(bt_const_extended.dtseg1_min);
1371 		dev->data_bt_const.tseg1_max = le32_to_cpu(bt_const_extended.dtseg1_max);
1372 		dev->data_bt_const.tseg2_min = le32_to_cpu(bt_const_extended.dtseg2_min);
1373 		dev->data_bt_const.tseg2_max = le32_to_cpu(bt_const_extended.dtseg2_max);
1374 		dev->data_bt_const.sjw_max = le32_to_cpu(bt_const_extended.dsjw_max);
1375 		dev->data_bt_const.brp_min = le32_to_cpu(bt_const_extended.dbrp_min);
1376 		dev->data_bt_const.brp_max = le32_to_cpu(bt_const_extended.dbrp_max);
1377 		dev->data_bt_const.brp_inc = le32_to_cpu(bt_const_extended.dbrp_inc);
1378 
1379 		dev->can.data_bittiming_const = &dev->data_bt_const;
1380 	}
1381 
1382 	can_rx_offload_add_manual(netdev, &dev->offload, GS_NAPI_WEIGHT);
1383 	SET_NETDEV_DEV(netdev, &intf->dev);
1384 
1385 	rc = register_candev(dev->netdev);
1386 	if (rc) {
1387 		dev_err(&intf->dev,
1388 			"Couldn't register candev for channel %d (%pe)\n",
1389 			channel, ERR_PTR(rc));
1390 		goto out_can_rx_offload_del;
1391 	}
1392 
1393 	return dev;
1394 
1395 out_can_rx_offload_del:
1396 	can_rx_offload_del(&dev->offload);
1397 out_free_candev:
1398 	free_candev(dev->netdev);
1399 	return ERR_PTR(rc);
1400 }
1401 
1402 static void gs_destroy_candev(struct gs_can *dev)
1403 {
1404 	unregister_candev(dev->netdev);
1405 	can_rx_offload_del(&dev->offload);
1406 	free_candev(dev->netdev);
1407 }
1408 
1409 static int gs_usb_probe(struct usb_interface *intf,
1410 			const struct usb_device_id *id)
1411 {
1412 	struct usb_device *udev = interface_to_usbdev(intf);
1413 	struct gs_host_frame *hf;
1414 	struct gs_usb *parent;
1415 	struct gs_host_config hconf = {
1416 		.byte_order = cpu_to_le32(0x0000beef),
1417 	};
1418 	struct gs_device_config dconf;
1419 	unsigned int icount, i;
1420 	int rc;
1421 
1422 	/* send host config */
1423 	rc = usb_control_msg_send(udev, 0,
1424 				  GS_USB_BREQ_HOST_FORMAT,
1425 				  USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1426 				  1, intf->cur_altsetting->desc.bInterfaceNumber,
1427 				  &hconf, sizeof(hconf), 1000,
1428 				  GFP_KERNEL);
1429 	if (rc) {
1430 		dev_err(&intf->dev, "Couldn't send data format (err=%d)\n", rc);
1431 		return rc;
1432 	}
1433 
1434 	/* read device config */
1435 	rc = usb_control_msg_recv(udev, 0,
1436 				  GS_USB_BREQ_DEVICE_CONFIG,
1437 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1438 				  1, intf->cur_altsetting->desc.bInterfaceNumber,
1439 				  &dconf, sizeof(dconf), 1000,
1440 				  GFP_KERNEL);
1441 	if (rc) {
1442 		dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
1443 			rc);
1444 		return rc;
1445 	}
1446 
1447 	icount = dconf.icount + 1;
1448 	dev_info(&intf->dev, "Configuring for %u interfaces\n", icount);
1449 
1450 	if (icount > GS_MAX_INTF) {
1451 		dev_err(&intf->dev,
1452 			"Driver cannot handle more that %u CAN interfaces\n",
1453 			GS_MAX_INTF);
1454 		return -EINVAL;
1455 	}
1456 
1457 	parent = kzalloc(sizeof(*parent), GFP_KERNEL);
1458 	if (!parent)
1459 		return -ENOMEM;
1460 
1461 	init_usb_anchor(&parent->rx_submitted);
1462 
1463 	usb_set_intfdata(intf, parent);
1464 	parent->udev = udev;
1465 
1466 	for (i = 0; i < icount; i++) {
1467 		unsigned int hf_size_rx = 0;
1468 
1469 		parent->canch[i] = gs_make_candev(i, intf, &dconf);
1470 		if (IS_ERR_OR_NULL(parent->canch[i])) {
1471 			/* save error code to return later */
1472 			rc = PTR_ERR(parent->canch[i]);
1473 
1474 			/* on failure destroy previously created candevs */
1475 			icount = i;
1476 			for (i = 0; i < icount; i++)
1477 				gs_destroy_candev(parent->canch[i]);
1478 
1479 			usb_kill_anchored_urbs(&parent->rx_submitted);
1480 			kfree(parent);
1481 			return rc;
1482 		}
1483 		parent->canch[i]->parent = parent;
1484 
1485 		/* set RX packet size based on FD and if hardware
1486 		 * timestamps are supported.
1487 		 */
1488 		if (parent->canch[i]->can.ctrlmode_supported & CAN_CTRLMODE_FD) {
1489 			if (parent->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1490 				hf_size_rx = struct_size(hf, canfd_ts, 1);
1491 			else
1492 				hf_size_rx = struct_size(hf, canfd, 1);
1493 		} else {
1494 			if (parent->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1495 				hf_size_rx = struct_size(hf, classic_can_ts, 1);
1496 			else
1497 				hf_size_rx = struct_size(hf, classic_can, 1);
1498 		}
1499 		parent->hf_size_rx = max(parent->hf_size_rx, hf_size_rx);
1500 	}
1501 
1502 	return 0;
1503 }
1504 
1505 static void gs_usb_disconnect(struct usb_interface *intf)
1506 {
1507 	struct gs_usb *parent = usb_get_intfdata(intf);
1508 	unsigned int i;
1509 
1510 	usb_set_intfdata(intf, NULL);
1511 
1512 	if (!parent) {
1513 		dev_err(&intf->dev, "Disconnect (nodata)\n");
1514 		return;
1515 	}
1516 
1517 	for (i = 0; i < GS_MAX_INTF; i++)
1518 		if (parent->canch[i])
1519 			gs_destroy_candev(parent->canch[i]);
1520 
1521 	kfree(parent);
1522 }
1523 
1524 static const struct usb_device_id gs_usb_table[] = {
1525 	{ USB_DEVICE_INTERFACE_NUMBER(USB_GS_USB_1_VENDOR_ID,
1526 				      USB_GS_USB_1_PRODUCT_ID, 0) },
1527 	{ USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1528 				      USB_CANDLELIGHT_PRODUCT_ID, 0) },
1529 	{ USB_DEVICE_INTERFACE_NUMBER(USB_CES_CANEXT_FD_VENDOR_ID,
1530 				      USB_CES_CANEXT_FD_PRODUCT_ID, 0) },
1531 	{ USB_DEVICE_INTERFACE_NUMBER(USB_ABE_CANDEBUGGER_FD_VENDOR_ID,
1532 				      USB_ABE_CANDEBUGGER_FD_PRODUCT_ID, 0) },
1533 	{} /* Terminating entry */
1534 };
1535 
1536 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1537 
1538 static struct usb_driver gs_usb_driver = {
1539 	.name = KBUILD_MODNAME,
1540 	.probe = gs_usb_probe,
1541 	.disconnect = gs_usb_disconnect,
1542 	.id_table = gs_usb_table,
1543 };
1544 
1545 module_usb_driver(gs_usb_driver);
1546 
1547 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1548 MODULE_DESCRIPTION(
1549 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1550 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1551 "and bytewerk.org candleLight USB CAN interfaces.");
1552 MODULE_LICENSE("GPL v2");
1553