xref: /linux/drivers/net/can/usb/gs_usb.c (revision 57885276cc16a2e2b76282c808a4e84cbecb3aae)
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 USB_XYLANTA_SAINT3_VENDOR_ID 0x16d0
44 #define USB_XYLANTA_SAINT3_PRODUCT_ID 0x0f30
45 
46 #define USB_CANNECTIVITY_VENDOR_ID 0x1209
47 #define USB_CANNECTIVITY_PRODUCT_ID 0xca01
48 
49 /* Timestamp 32 bit timer runs at 1 MHz (1 µs tick). Worker accounts
50  * for timer overflow (will be after ~71 minutes)
51  */
52 #define GS_USB_TIMESTAMP_TIMER_HZ (1 * HZ_PER_MHZ)
53 #define GS_USB_TIMESTAMP_WORK_DELAY_SEC 1800
54 static_assert(GS_USB_TIMESTAMP_WORK_DELAY_SEC <
55 	      CYCLECOUNTER_MASK(32) / GS_USB_TIMESTAMP_TIMER_HZ / 2);
56 
57 /* Device specific constants */
58 enum gs_usb_breq {
59 	GS_USB_BREQ_HOST_FORMAT = 0,
60 	GS_USB_BREQ_BITTIMING,
61 	GS_USB_BREQ_MODE,
62 	GS_USB_BREQ_BERR,
63 	GS_USB_BREQ_BT_CONST,
64 	GS_USB_BREQ_DEVICE_CONFIG,
65 	GS_USB_BREQ_TIMESTAMP,
66 	GS_USB_BREQ_IDENTIFY,
67 	GS_USB_BREQ_GET_USER_ID,
68 	GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING = GS_USB_BREQ_GET_USER_ID,
69 	GS_USB_BREQ_SET_USER_ID,
70 	GS_USB_BREQ_DATA_BITTIMING,
71 	GS_USB_BREQ_BT_CONST_EXT,
72 	GS_USB_BREQ_SET_TERMINATION,
73 	GS_USB_BREQ_GET_TERMINATION,
74 	GS_USB_BREQ_GET_STATE,
75 };
76 
77 enum gs_can_mode {
78 	/* reset a channel. turns it off */
79 	GS_CAN_MODE_RESET = 0,
80 	/* starts a channel */
81 	GS_CAN_MODE_START
82 };
83 
84 enum gs_can_state {
85 	GS_CAN_STATE_ERROR_ACTIVE = 0,
86 	GS_CAN_STATE_ERROR_WARNING,
87 	GS_CAN_STATE_ERROR_PASSIVE,
88 	GS_CAN_STATE_BUS_OFF,
89 	GS_CAN_STATE_STOPPED,
90 	GS_CAN_STATE_SLEEPING
91 };
92 
93 enum gs_can_identify_mode {
94 	GS_CAN_IDENTIFY_OFF = 0,
95 	GS_CAN_IDENTIFY_ON
96 };
97 
98 enum gs_can_termination_state {
99 	GS_CAN_TERMINATION_STATE_OFF = 0,
100 	GS_CAN_TERMINATION_STATE_ON
101 };
102 
103 #define GS_USB_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
104 #define GS_USB_TERMINATION_ENABLED 120
105 
106 /* data types passed between host and device */
107 
108 /* The firmware on the original USB2CAN by Geschwister Schneider
109  * Technologie Entwicklungs- und Vertriebs UG exchanges all data
110  * between the host and the device in host byte order. This is done
111  * with the struct gs_host_config::byte_order member, which is sent
112  * first to indicate the desired byte order.
113  *
114  * The widely used open source firmware candleLight doesn't support
115  * this feature and exchanges the data in little endian byte order.
116  */
117 struct gs_host_config {
118 	__le32 byte_order;
119 } __packed;
120 
121 struct gs_device_config {
122 	u8 reserved1;
123 	u8 reserved2;
124 	u8 reserved3;
125 	u8 icount;
126 	__le32 sw_version;
127 	__le32 hw_version;
128 } __packed;
129 
130 #define GS_CAN_MODE_NORMAL 0
131 #define GS_CAN_MODE_LISTEN_ONLY BIT(0)
132 #define GS_CAN_MODE_LOOP_BACK BIT(1)
133 #define GS_CAN_MODE_TRIPLE_SAMPLE BIT(2)
134 #define GS_CAN_MODE_ONE_SHOT BIT(3)
135 #define GS_CAN_MODE_HW_TIMESTAMP BIT(4)
136 /* GS_CAN_FEATURE_IDENTIFY BIT(5) */
137 /* GS_CAN_FEATURE_USER_ID BIT(6) */
138 #define GS_CAN_MODE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
139 #define GS_CAN_MODE_FD BIT(8)
140 /* GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9) */
141 /* GS_CAN_FEATURE_BT_CONST_EXT BIT(10) */
142 /* GS_CAN_FEATURE_TERMINATION BIT(11) */
143 #define GS_CAN_MODE_BERR_REPORTING BIT(12)
144 /* GS_CAN_FEATURE_GET_STATE BIT(13) */
145 
146 struct gs_device_mode {
147 	__le32 mode;
148 	__le32 flags;
149 } __packed;
150 
151 struct gs_device_state {
152 	__le32 state;
153 	__le32 rxerr;
154 	__le32 txerr;
155 } __packed;
156 
157 struct gs_device_bittiming {
158 	__le32 prop_seg;
159 	__le32 phase_seg1;
160 	__le32 phase_seg2;
161 	__le32 sjw;
162 	__le32 brp;
163 } __packed;
164 
165 struct gs_identify_mode {
166 	__le32 mode;
167 } __packed;
168 
169 struct gs_device_termination_state {
170 	__le32 state;
171 } __packed;
172 
173 #define GS_CAN_FEATURE_LISTEN_ONLY BIT(0)
174 #define GS_CAN_FEATURE_LOOP_BACK BIT(1)
175 #define GS_CAN_FEATURE_TRIPLE_SAMPLE BIT(2)
176 #define GS_CAN_FEATURE_ONE_SHOT BIT(3)
177 #define GS_CAN_FEATURE_HW_TIMESTAMP BIT(4)
178 #define GS_CAN_FEATURE_IDENTIFY BIT(5)
179 #define GS_CAN_FEATURE_USER_ID BIT(6)
180 #define GS_CAN_FEATURE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
181 #define GS_CAN_FEATURE_FD BIT(8)
182 #define GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9)
183 #define GS_CAN_FEATURE_BT_CONST_EXT BIT(10)
184 #define GS_CAN_FEATURE_TERMINATION BIT(11)
185 #define GS_CAN_FEATURE_BERR_REPORTING BIT(12)
186 #define GS_CAN_FEATURE_GET_STATE BIT(13)
187 #define GS_CAN_FEATURE_MASK GENMASK(13, 0)
188 
189 /* internal quirks - keep in GS_CAN_FEATURE space for now */
190 
191 /* CANtact Pro original firmware:
192  * BREQ DATA_BITTIMING overlaps with GET_USER_ID
193  */
194 #define GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO BIT(31)
195 
196 struct gs_device_bt_const {
197 	__le32 feature;
198 	__le32 fclk_can;
199 	__le32 tseg1_min;
200 	__le32 tseg1_max;
201 	__le32 tseg2_min;
202 	__le32 tseg2_max;
203 	__le32 sjw_max;
204 	__le32 brp_min;
205 	__le32 brp_max;
206 	__le32 brp_inc;
207 } __packed;
208 
209 struct gs_device_bt_const_extended {
210 	__le32 feature;
211 	__le32 fclk_can;
212 	__le32 tseg1_min;
213 	__le32 tseg1_max;
214 	__le32 tseg2_min;
215 	__le32 tseg2_max;
216 	__le32 sjw_max;
217 	__le32 brp_min;
218 	__le32 brp_max;
219 	__le32 brp_inc;
220 
221 	__le32 dtseg1_min;
222 	__le32 dtseg1_max;
223 	__le32 dtseg2_min;
224 	__le32 dtseg2_max;
225 	__le32 dsjw_max;
226 	__le32 dbrp_min;
227 	__le32 dbrp_max;
228 	__le32 dbrp_inc;
229 } __packed;
230 
231 #define GS_CAN_FLAG_OVERFLOW BIT(0)
232 #define GS_CAN_FLAG_FD BIT(1)
233 #define GS_CAN_FLAG_BRS BIT(2)
234 #define GS_CAN_FLAG_ESI BIT(3)
235 
236 struct classic_can {
237 	u8 data[8];
238 } __packed;
239 
240 struct classic_can_ts {
241 	u8 data[8];
242 	__le32 timestamp_us;
243 } __packed;
244 
245 struct classic_can_quirk {
246 	u8 data[8];
247 	u8 quirk;
248 } __packed;
249 
250 struct canfd {
251 	u8 data[64];
252 } __packed;
253 
254 struct canfd_ts {
255 	u8 data[64];
256 	__le32 timestamp_us;
257 } __packed;
258 
259 struct canfd_quirk {
260 	u8 data[64];
261 	u8 quirk;
262 } __packed;
263 
264 /* struct gs_host_frame::echo_id == GS_HOST_FRAME_ECHO_ID_RX indicates
265  * a regular RX'ed CAN frame
266  */
267 #define GS_HOST_FRAME_ECHO_ID_RX 0xffffffff
268 
269 struct gs_host_frame {
270 	struct_group(header,
271 		u32 echo_id;
272 		__le32 can_id;
273 
274 		u8 can_dlc;
275 		u8 channel;
276 		u8 flags;
277 		u8 reserved;
278 	);
279 
280 	union {
281 		DECLARE_FLEX_ARRAY(struct classic_can, classic_can);
282 		DECLARE_FLEX_ARRAY(struct classic_can_ts, classic_can_ts);
283 		DECLARE_FLEX_ARRAY(struct classic_can_quirk, classic_can_quirk);
284 		DECLARE_FLEX_ARRAY(struct canfd, canfd);
285 		DECLARE_FLEX_ARRAY(struct canfd_ts, canfd_ts);
286 		DECLARE_FLEX_ARRAY(struct canfd_quirk, canfd_quirk);
287 	};
288 } __packed;
289 /* The GS USB devices make use of the same flags and masks as in
290  * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
291  */
292 
293 /* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
294 #define GS_MAX_TX_URBS 10
295 /* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
296 #define GS_MAX_RX_URBS 30
297 #define GS_NAPI_WEIGHT 32
298 
299 struct gs_tx_context {
300 	struct gs_can *dev;
301 	unsigned int echo_id;
302 };
303 
304 struct gs_can {
305 	struct can_priv can; /* must be the first member */
306 
307 	struct can_rx_offload offload;
308 	struct gs_usb *parent;
309 
310 	struct net_device *netdev;
311 	struct usb_device *udev;
312 
313 	struct can_bittiming_const bt_const, data_bt_const;
314 	unsigned int channel;	/* channel number */
315 
316 	u32 feature;
317 	unsigned int hf_size_tx;
318 
319 	/* This lock prevents a race condition between xmit and receive. */
320 	spinlock_t tx_ctx_lock;
321 	struct gs_tx_context tx_context[GS_MAX_TX_URBS];
322 
323 	struct usb_anchor tx_submitted;
324 	atomic_t active_tx_urbs;
325 };
326 
327 /* usb interface struct */
328 struct gs_usb {
329 	struct usb_anchor rx_submitted;
330 	struct usb_device *udev;
331 
332 	/* time counter for hardware timestamps */
333 	struct cyclecounter cc;
334 	struct timecounter tc;
335 	spinlock_t tc_lock; /* spinlock to guard access tc->cycle_last */
336 	struct delayed_work timestamp;
337 
338 	unsigned int hf_size_rx;
339 	u8 active_channels;
340 	u8 channel_cnt;
341 
342 	unsigned int pipe_in;
343 	unsigned int pipe_out;
344 	struct gs_can *canch[] __counted_by(channel_cnt);
345 };
346 
347 /* 'allocate' a tx context.
348  * returns a valid tx context or NULL if there is no space.
349  */
350 static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
351 {
352 	int i = 0;
353 	unsigned long flags;
354 
355 	spin_lock_irqsave(&dev->tx_ctx_lock, flags);
356 
357 	for (; i < GS_MAX_TX_URBS; i++) {
358 		if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
359 			dev->tx_context[i].echo_id = i;
360 			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
361 			return &dev->tx_context[i];
362 		}
363 	}
364 
365 	spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
366 	return NULL;
367 }
368 
369 /* releases a tx context
370  */
371 static void gs_free_tx_context(struct gs_tx_context *txc)
372 {
373 	txc->echo_id = GS_MAX_TX_URBS;
374 }
375 
376 /* Get a tx context by id.
377  */
378 static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
379 					       unsigned int id)
380 {
381 	unsigned long flags;
382 
383 	if (id < GS_MAX_TX_URBS) {
384 		spin_lock_irqsave(&dev->tx_ctx_lock, flags);
385 		if (dev->tx_context[id].echo_id == id) {
386 			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
387 			return &dev->tx_context[id];
388 		}
389 		spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
390 	}
391 	return NULL;
392 }
393 
394 static int gs_cmd_reset(struct gs_can *dev)
395 {
396 	struct gs_device_mode dm = {
397 		.mode = cpu_to_le32(GS_CAN_MODE_RESET),
398 	};
399 
400 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_MODE,
401 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
402 				    dev->channel, 0, &dm, sizeof(dm), 1000,
403 				    GFP_KERNEL);
404 }
405 
406 static inline int gs_usb_get_timestamp(const struct gs_usb *parent,
407 				       u32 *timestamp_p)
408 {
409 	__le32 timestamp;
410 	int rc;
411 
412 	rc = usb_control_msg_recv(parent->udev, 0, GS_USB_BREQ_TIMESTAMP,
413 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
414 				  0, 0,
415 				  &timestamp, sizeof(timestamp),
416 				  USB_CTRL_GET_TIMEOUT,
417 				  GFP_KERNEL);
418 	if (rc)
419 		return rc;
420 
421 	*timestamp_p = le32_to_cpu(timestamp);
422 
423 	return 0;
424 }
425 
426 static u64 gs_usb_timestamp_read(struct cyclecounter *cc) __must_hold(&dev->tc_lock)
427 {
428 	struct gs_usb *parent = container_of(cc, struct gs_usb, cc);
429 	u32 timestamp = 0;
430 	int err;
431 
432 	lockdep_assert_held(&parent->tc_lock);
433 
434 	/* drop lock for synchronous USB transfer */
435 	spin_unlock_bh(&parent->tc_lock);
436 	err = gs_usb_get_timestamp(parent, &timestamp);
437 	spin_lock_bh(&parent->tc_lock);
438 	if (err)
439 		dev_err(&parent->udev->dev,
440 			"Error %d while reading timestamp. HW timestamps may be inaccurate.",
441 			err);
442 
443 	return timestamp;
444 }
445 
446 static void gs_usb_timestamp_work(struct work_struct *work)
447 {
448 	struct delayed_work *delayed_work = to_delayed_work(work);
449 	struct gs_usb *parent;
450 
451 	parent = container_of(delayed_work, struct gs_usb, timestamp);
452 	spin_lock_bh(&parent->tc_lock);
453 	timecounter_read(&parent->tc);
454 	spin_unlock_bh(&parent->tc_lock);
455 
456 	schedule_delayed_work(&parent->timestamp,
457 			      GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
458 }
459 
460 static void gs_usb_skb_set_timestamp(struct gs_can *dev,
461 				     struct sk_buff *skb, u32 timestamp)
462 {
463 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
464 	struct gs_usb *parent = dev->parent;
465 	u64 ns;
466 
467 	spin_lock_bh(&parent->tc_lock);
468 	ns = timecounter_cyc2time(&parent->tc, timestamp);
469 	spin_unlock_bh(&parent->tc_lock);
470 
471 	hwtstamps->hwtstamp = ns_to_ktime(ns);
472 }
473 
474 static void gs_usb_timestamp_init(struct gs_usb *parent)
475 {
476 	struct cyclecounter *cc = &parent->cc;
477 
478 	cc->read = gs_usb_timestamp_read;
479 	cc->mask = CYCLECOUNTER_MASK(32);
480 	cc->shift = 32 - bits_per(NSEC_PER_SEC / GS_USB_TIMESTAMP_TIMER_HZ);
481 	cc->mult = clocksource_hz2mult(GS_USB_TIMESTAMP_TIMER_HZ, cc->shift);
482 
483 	spin_lock_init(&parent->tc_lock);
484 	spin_lock_bh(&parent->tc_lock);
485 	timecounter_init(&parent->tc, &parent->cc, ktime_get_real_ns());
486 	spin_unlock_bh(&parent->tc_lock);
487 
488 	INIT_DELAYED_WORK(&parent->timestamp, gs_usb_timestamp_work);
489 	schedule_delayed_work(&parent->timestamp,
490 			      GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
491 }
492 
493 static void gs_usb_timestamp_stop(struct gs_usb *parent)
494 {
495 	cancel_delayed_work_sync(&parent->timestamp);
496 }
497 
498 static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
499 {
500 	struct can_device_stats *can_stats = &dev->can.can_stats;
501 
502 	if (cf->can_id & CAN_ERR_RESTARTED) {
503 		dev->can.state = CAN_STATE_ERROR_ACTIVE;
504 		can_stats->restarts++;
505 	} else if (cf->can_id & CAN_ERR_BUSOFF) {
506 		dev->can.state = CAN_STATE_BUS_OFF;
507 		can_stats->bus_off++;
508 	} else if (cf->can_id & CAN_ERR_CRTL) {
509 		if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
510 		    (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
511 			dev->can.state = CAN_STATE_ERROR_WARNING;
512 			can_stats->error_warning++;
513 		} else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
514 			   (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
515 			dev->can.state = CAN_STATE_ERROR_PASSIVE;
516 			can_stats->error_passive++;
517 		} else {
518 			dev->can.state = CAN_STATE_ERROR_ACTIVE;
519 		}
520 	}
521 }
522 
523 static u32 gs_usb_set_timestamp(struct gs_can *dev, struct sk_buff *skb,
524 				const struct gs_host_frame *hf)
525 {
526 	u32 timestamp;
527 
528 	if (hf->flags & GS_CAN_FLAG_FD)
529 		timestamp = le32_to_cpu(hf->canfd_ts->timestamp_us);
530 	else
531 		timestamp = le32_to_cpu(hf->classic_can_ts->timestamp_us);
532 
533 	if (skb)
534 		gs_usb_skb_set_timestamp(dev, skb, timestamp);
535 
536 	return timestamp;
537 }
538 
539 static void gs_usb_rx_offload(struct gs_can *dev, struct sk_buff *skb,
540 			      const struct gs_host_frame *hf)
541 {
542 	struct can_rx_offload *offload = &dev->offload;
543 	int rc;
544 
545 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) {
546 		const u32 ts = gs_usb_set_timestamp(dev, skb, hf);
547 
548 		rc = can_rx_offload_queue_timestamp(offload, skb, ts);
549 	} else {
550 		rc = can_rx_offload_queue_tail(offload, skb);
551 	}
552 
553 	if (rc)
554 		dev->netdev->stats.rx_fifo_errors++;
555 }
556 
557 static unsigned int
558 gs_usb_get_echo_skb(struct gs_can *dev, struct sk_buff *skb,
559 		    const struct gs_host_frame *hf)
560 {
561 	struct can_rx_offload *offload = &dev->offload;
562 	const u32 echo_id = hf->echo_id;
563 	unsigned int len;
564 
565 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) {
566 		const u32 ts = gs_usb_set_timestamp(dev, skb, hf);
567 
568 		len = can_rx_offload_get_echo_skb_queue_timestamp(offload, echo_id,
569 								  ts, NULL);
570 	} else {
571 		len = can_rx_offload_get_echo_skb_queue_tail(offload, echo_id,
572 							     NULL);
573 	}
574 
575 	return len;
576 }
577 
578 static unsigned int
579 gs_usb_get_minimum_rx_length(const struct gs_can *dev, const struct gs_host_frame *hf,
580 			     unsigned int *data_length_p)
581 {
582 	unsigned int minimum_length, data_length = 0;
583 
584 	if (hf->flags & GS_CAN_FLAG_FD) {
585 		if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX)
586 			data_length = can_fd_dlc2len(hf->can_dlc);
587 
588 		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
589 			/* timestamp follows data field of max size */
590 			minimum_length = struct_size(hf, canfd_ts, 1);
591 		else
592 			minimum_length = sizeof(hf->header) + data_length;
593 	} else {
594 		if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX &&
595 		    !(hf->can_id & cpu_to_le32(CAN_RTR_FLAG)))
596 			data_length = can_cc_dlc2len(hf->can_dlc);
597 
598 		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
599 			/* timestamp follows data field of max size */
600 			minimum_length = struct_size(hf, classic_can_ts, 1);
601 		else
602 			minimum_length = sizeof(hf->header) + data_length;
603 	}
604 
605 	*data_length_p = data_length;
606 	return minimum_length;
607 }
608 
609 static void gs_usb_receive_bulk_callback(struct urb *urb)
610 {
611 	struct gs_usb *parent = urb->context;
612 	struct gs_can *dev;
613 	struct net_device *netdev = NULL;
614 	int rc;
615 	struct net_device_stats *stats;
616 	struct gs_host_frame *hf = urb->transfer_buffer;
617 	unsigned int minimum_length, data_length;
618 	struct gs_tx_context *txc;
619 	struct can_frame *cf;
620 	struct canfd_frame *cfd;
621 	struct sk_buff *skb;
622 
623 	BUG_ON(!parent);
624 
625 	switch (urb->status) {
626 	case 0: /* success */
627 		break;
628 	case -ENOENT:
629 	case -ESHUTDOWN:
630 		return;
631 	default:
632 		/* do not resubmit aborted urbs. eg: when device goes down */
633 		return;
634 	}
635 
636 	minimum_length = sizeof(hf->header);
637 	if (urb->actual_length < minimum_length) {
638 		dev_err_ratelimited(&parent->udev->dev,
639 				    "short read (actual_length=%u, minimum_length=%u)\n",
640 				    urb->actual_length, minimum_length);
641 
642 		goto resubmit_urb;
643 	}
644 
645 	/* device reports out of range channel id */
646 	if (hf->channel >= parent->channel_cnt)
647 		goto device_detach;
648 
649 	dev = parent->canch[hf->channel];
650 
651 	netdev = dev->netdev;
652 	stats = &netdev->stats;
653 
654 	if (!netif_device_present(netdev))
655 		return;
656 
657 	if (!netif_running(netdev))
658 		goto resubmit_urb;
659 
660 	minimum_length = gs_usb_get_minimum_rx_length(dev, hf, &data_length);
661 	if (urb->actual_length < minimum_length) {
662 		stats->rx_errors++;
663 		stats->rx_length_errors++;
664 
665 		if (net_ratelimit())
666 			netdev_err(netdev,
667 				   "short read (actual_length=%u, minimum_length=%u)\n",
668 				   urb->actual_length, minimum_length);
669 
670 		goto resubmit_urb;
671 	}
672 
673 	if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX) { /* normal rx */
674 		if (hf->flags & GS_CAN_FLAG_FD) {
675 			skb = alloc_canfd_skb(netdev, &cfd);
676 			if (!skb)
677 				return;
678 
679 			cfd->can_id = le32_to_cpu(hf->can_id);
680 			cfd->len = data_length;
681 			if (hf->flags & GS_CAN_FLAG_BRS)
682 				cfd->flags |= CANFD_BRS;
683 			if (hf->flags & GS_CAN_FLAG_ESI)
684 				cfd->flags |= CANFD_ESI;
685 
686 			memcpy(cfd->data, hf->canfd->data, data_length);
687 		} else {
688 			skb = alloc_can_skb(netdev, &cf);
689 			if (!skb)
690 				return;
691 
692 			cf->can_id = le32_to_cpu(hf->can_id);
693 			can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);
694 
695 			memcpy(cf->data, hf->classic_can->data, data_length);
696 
697 			/* ERROR frames tell us information about the controller */
698 			if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)
699 				gs_update_state(dev, cf);
700 		}
701 
702 		gs_usb_rx_offload(dev, skb, hf);
703 	} else { /* echo_id == hf->echo_id */
704 		if (hf->echo_id >= GS_MAX_TX_URBS) {
705 			netdev_err(netdev,
706 				   "Unexpected out of range echo id %u\n",
707 				   hf->echo_id);
708 			goto resubmit_urb;
709 		}
710 
711 		txc = gs_get_tx_context(dev, hf->echo_id);
712 
713 		/* bad devices send bad echo_ids. */
714 		if (!txc) {
715 			netdev_err(netdev,
716 				   "Unexpected unused echo id %u\n",
717 				   hf->echo_id);
718 			goto resubmit_urb;
719 		}
720 
721 		skb = dev->can.echo_skb[hf->echo_id];
722 		stats->tx_packets++;
723 		stats->tx_bytes += gs_usb_get_echo_skb(dev, skb, hf);
724 		gs_free_tx_context(txc);
725 
726 		atomic_dec(&dev->active_tx_urbs);
727 
728 		netif_wake_queue(netdev);
729 	}
730 
731 	if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
732 		stats->rx_over_errors++;
733 		stats->rx_errors++;
734 
735 		skb = alloc_can_err_skb(netdev, &cf);
736 		if (!skb)
737 			goto resubmit_urb;
738 
739 		cf->can_id |= CAN_ERR_CRTL;
740 		cf->len = CAN_ERR_DLC;
741 		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
742 
743 		gs_usb_rx_offload(dev, skb, hf);
744 	}
745 
746 	can_rx_offload_irq_finish(&dev->offload);
747 
748 resubmit_urb:
749 	usb_fill_bulk_urb(urb, parent->udev,
750 			  parent->pipe_in,
751 			  hf, parent->hf_size_rx,
752 			  gs_usb_receive_bulk_callback, parent);
753 
754 	usb_anchor_urb(urb, &parent->rx_submitted);
755 
756 	rc = usb_submit_urb(urb, GFP_ATOMIC);
757 	if (!rc)
758 		return;
759 
760 	usb_unanchor_urb(urb);
761 
762 	/* USB failure take down all interfaces */
763 	if (rc == -ENODEV) {
764 device_detach:
765 		for (rc = 0; rc < parent->channel_cnt; rc++) {
766 			if (parent->canch[rc])
767 				netif_device_detach(parent->canch[rc]->netdev);
768 		}
769 	} else if (rc != -ESHUTDOWN && net_ratelimit()) {
770 		netdev_info(netdev, "failed to re-submit IN URB: %pe\n",
771 			    ERR_PTR(rc));
772 	}
773 }
774 
775 static int gs_usb_set_bittiming(struct gs_can *dev)
776 {
777 	struct can_bittiming *bt = &dev->can.bittiming;
778 	struct gs_device_bittiming dbt = {
779 		.prop_seg = cpu_to_le32(bt->prop_seg),
780 		.phase_seg1 = cpu_to_le32(bt->phase_seg1),
781 		.phase_seg2 = cpu_to_le32(bt->phase_seg2),
782 		.sjw = cpu_to_le32(bt->sjw),
783 		.brp = cpu_to_le32(bt->brp),
784 	};
785 
786 	/* request bit timings */
787 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_BITTIMING,
788 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
789 				    dev->channel, 0, &dbt, sizeof(dbt), 1000,
790 				    GFP_KERNEL);
791 }
792 
793 static int gs_usb_set_data_bittiming(struct gs_can *dev)
794 {
795 	struct can_bittiming *bt = &dev->can.fd.data_bittiming;
796 	struct gs_device_bittiming dbt = {
797 		.prop_seg = cpu_to_le32(bt->prop_seg),
798 		.phase_seg1 = cpu_to_le32(bt->phase_seg1),
799 		.phase_seg2 = cpu_to_le32(bt->phase_seg2),
800 		.sjw = cpu_to_le32(bt->sjw),
801 		.brp = cpu_to_le32(bt->brp),
802 	};
803 	u8 request = GS_USB_BREQ_DATA_BITTIMING;
804 
805 	if (dev->feature & GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO)
806 		request = GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING;
807 
808 	/* request data bit timings */
809 	return usb_control_msg_send(dev->udev, 0, request,
810 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
811 				    dev->channel, 0, &dbt, sizeof(dbt), 1000,
812 				    GFP_KERNEL);
813 }
814 
815 static void gs_usb_xmit_callback(struct urb *urb)
816 {
817 	struct gs_tx_context *txc = urb->context;
818 	struct gs_can *dev = txc->dev;
819 	struct net_device *netdev = dev->netdev;
820 
821 	if (!urb->status)
822 		return;
823 
824 	if (urb->status != -ESHUTDOWN && net_ratelimit())
825 		netdev_info(netdev, "failed to xmit URB %u: %pe\n",
826 			    txc->echo_id, ERR_PTR(urb->status));
827 
828 	netdev->stats.tx_dropped++;
829 	netdev->stats.tx_errors++;
830 
831 	can_free_echo_skb(netdev, txc->echo_id, NULL);
832 	gs_free_tx_context(txc);
833 	atomic_dec(&dev->active_tx_urbs);
834 
835 	netif_wake_queue(netdev);
836 }
837 
838 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
839 				     struct net_device *netdev)
840 {
841 	struct gs_can *dev = netdev_priv(netdev);
842 	struct net_device_stats *stats = &dev->netdev->stats;
843 	struct urb *urb;
844 	struct gs_host_frame *hf;
845 	struct can_frame *cf;
846 	struct canfd_frame *cfd;
847 	int rc;
848 	unsigned int idx;
849 	struct gs_tx_context *txc;
850 
851 	if (can_dev_dropped_skb(netdev, skb))
852 		return NETDEV_TX_OK;
853 
854 	/* find an empty context to keep track of transmission */
855 	txc = gs_alloc_tx_context(dev);
856 	if (!txc)
857 		return NETDEV_TX_BUSY;
858 
859 	/* create a URB, and a buffer for it */
860 	urb = usb_alloc_urb(0, GFP_ATOMIC);
861 	if (!urb)
862 		goto nomem_urb;
863 
864 	hf = kmalloc(dev->hf_size_tx, GFP_ATOMIC);
865 	if (!hf)
866 		goto nomem_hf;
867 
868 	idx = txc->echo_id;
869 
870 	if (idx >= GS_MAX_TX_URBS) {
871 		netdev_err(netdev, "Invalid tx context %u\n", idx);
872 		goto badidx;
873 	}
874 
875 	hf->echo_id = idx;
876 	hf->channel = dev->channel;
877 	hf->flags = 0;
878 	hf->reserved = 0;
879 
880 	if (can_is_canfd_skb(skb)) {
881 		cfd = (struct canfd_frame *)skb->data;
882 
883 		hf->can_id = cpu_to_le32(cfd->can_id);
884 		hf->can_dlc = can_fd_len2dlc(cfd->len);
885 		hf->flags |= GS_CAN_FLAG_FD;
886 		if (cfd->flags & CANFD_BRS)
887 			hf->flags |= GS_CAN_FLAG_BRS;
888 		if (cfd->flags & CANFD_ESI)
889 			hf->flags |= GS_CAN_FLAG_ESI;
890 
891 		memcpy(hf->canfd->data, cfd->data, cfd->len);
892 	} else {
893 		cf = (struct can_frame *)skb->data;
894 
895 		hf->can_id = cpu_to_le32(cf->can_id);
896 		hf->can_dlc = can_get_cc_dlc(cf, dev->can.ctrlmode);
897 
898 		memcpy(hf->classic_can->data, cf->data, cf->len);
899 	}
900 
901 	usb_fill_bulk_urb(urb, dev->udev,
902 			  dev->parent->pipe_out,
903 			  hf, dev->hf_size_tx,
904 			  gs_usb_xmit_callback, txc);
905 
906 	urb->transfer_flags |= URB_FREE_BUFFER;
907 	usb_anchor_urb(urb, &dev->tx_submitted);
908 
909 	can_put_echo_skb(skb, netdev, idx, 0);
910 
911 	atomic_inc(&dev->active_tx_urbs);
912 
913 	rc = usb_submit_urb(urb, GFP_ATOMIC);
914 	if (unlikely(rc)) {			/* usb send failed */
915 		atomic_dec(&dev->active_tx_urbs);
916 
917 		can_free_echo_skb(netdev, idx, NULL);
918 		gs_free_tx_context(txc);
919 
920 		usb_unanchor_urb(urb);
921 
922 		if (rc == -ENODEV) {
923 			netif_device_detach(netdev);
924 		} else {
925 			netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
926 			stats->tx_dropped++;
927 		}
928 	} else {
929 		/* Slow down tx path */
930 		if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
931 			netif_stop_queue(netdev);
932 	}
933 
934 	/* let usb core take care of this urb */
935 	usb_free_urb(urb);
936 
937 	return NETDEV_TX_OK;
938 
939 badidx:
940 	kfree(hf);
941 nomem_hf:
942 	usb_free_urb(urb);
943 
944 nomem_urb:
945 	gs_free_tx_context(txc);
946 	dev_kfree_skb(skb);
947 	stats->tx_dropped++;
948 	return NETDEV_TX_OK;
949 }
950 
951 static int gs_can_open(struct net_device *netdev)
952 {
953 	struct gs_can *dev = netdev_priv(netdev);
954 	struct gs_usb *parent = dev->parent;
955 	struct gs_device_mode dm = {
956 		.mode = cpu_to_le32(GS_CAN_MODE_START),
957 	};
958 	struct gs_host_frame *hf;
959 	struct urb *urb = NULL;
960 	u32 ctrlmode;
961 	u32 flags = 0;
962 	int rc, i;
963 
964 	rc = open_candev(netdev);
965 	if (rc)
966 		return rc;
967 
968 	ctrlmode = dev->can.ctrlmode;
969 	if (ctrlmode & CAN_CTRLMODE_FD) {
970 		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
971 			dev->hf_size_tx = struct_size(hf, canfd_quirk, 1);
972 		else
973 			dev->hf_size_tx = struct_size(hf, canfd, 1);
974 	} else {
975 		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
976 			dev->hf_size_tx = struct_size(hf, classic_can_quirk, 1);
977 		else
978 			dev->hf_size_tx = struct_size(hf, classic_can, 1);
979 	}
980 
981 	can_rx_offload_enable(&dev->offload);
982 
983 	if (!parent->active_channels) {
984 		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
985 			gs_usb_timestamp_init(parent);
986 
987 		for (i = 0; i < GS_MAX_RX_URBS; i++) {
988 			u8 *buf;
989 
990 			/* alloc rx urb */
991 			urb = usb_alloc_urb(0, GFP_KERNEL);
992 			if (!urb) {
993 				rc = -ENOMEM;
994 				goto out_usb_kill_anchored_urbs;
995 			}
996 
997 			/* alloc rx buffer */
998 			buf = kmalloc(dev->parent->hf_size_rx,
999 				      GFP_KERNEL);
1000 			if (!buf) {
1001 				rc = -ENOMEM;
1002 				goto out_usb_free_urb;
1003 			}
1004 
1005 			/* fill, anchor, and submit rx urb */
1006 			usb_fill_bulk_urb(urb,
1007 					  dev->udev,
1008 					  dev->parent->pipe_in,
1009 					  buf,
1010 					  dev->parent->hf_size_rx,
1011 					  gs_usb_receive_bulk_callback, parent);
1012 			urb->transfer_flags |= URB_FREE_BUFFER;
1013 
1014 			usb_anchor_urb(urb, &parent->rx_submitted);
1015 
1016 			rc = usb_submit_urb(urb, GFP_KERNEL);
1017 			if (rc) {
1018 				if (rc == -ENODEV)
1019 					netif_device_detach(dev->netdev);
1020 
1021 				netdev_err(netdev,
1022 					   "usb_submit_urb() failed, error %pe\n",
1023 					   ERR_PTR(rc));
1024 
1025 				goto out_usb_unanchor_urb;
1026 			}
1027 
1028 			/* Drop reference,
1029 			 * USB core will take care of freeing it
1030 			 */
1031 			usb_free_urb(urb);
1032 		}
1033 	}
1034 
1035 	/* flags */
1036 	if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
1037 		flags |= GS_CAN_MODE_LOOP_BACK;
1038 
1039 	if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
1040 		flags |= GS_CAN_MODE_LISTEN_ONLY;
1041 
1042 	if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
1043 		flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
1044 
1045 	if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
1046 		flags |= GS_CAN_MODE_ONE_SHOT;
1047 
1048 	if (ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
1049 		flags |= GS_CAN_MODE_BERR_REPORTING;
1050 
1051 	if (ctrlmode & CAN_CTRLMODE_FD)
1052 		flags |= GS_CAN_MODE_FD;
1053 
1054 	/* if hardware supports timestamps, enable it */
1055 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1056 		flags |= GS_CAN_MODE_HW_TIMESTAMP;
1057 
1058 	rc = gs_usb_set_bittiming(dev);
1059 	if (rc) {
1060 		netdev_err(netdev, "failed to set bittiming: %pe\n", ERR_PTR(rc));
1061 		goto out_usb_kill_anchored_urbs;
1062 	}
1063 
1064 	if (ctrlmode & CAN_CTRLMODE_FD) {
1065 		rc = gs_usb_set_data_bittiming(dev);
1066 		if (rc) {
1067 			netdev_err(netdev, "failed to set data bittiming: %pe\n", ERR_PTR(rc));
1068 			goto out_usb_kill_anchored_urbs;
1069 		}
1070 	}
1071 
1072 	/* finally start device */
1073 	dev->can.state = CAN_STATE_ERROR_ACTIVE;
1074 	dm.flags = cpu_to_le32(flags);
1075 	rc = usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_MODE,
1076 				  USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1077 				  dev->channel, 0, &dm, sizeof(dm), 1000,
1078 				  GFP_KERNEL);
1079 	if (rc) {
1080 		netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
1081 		dev->can.state = CAN_STATE_STOPPED;
1082 
1083 		goto out_usb_kill_anchored_urbs;
1084 	}
1085 
1086 	parent->active_channels++;
1087 	if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
1088 		netif_start_queue(netdev);
1089 
1090 	return 0;
1091 
1092 out_usb_unanchor_urb:
1093 	usb_unanchor_urb(urb);
1094 out_usb_free_urb:
1095 	usb_free_urb(urb);
1096 out_usb_kill_anchored_urbs:
1097 	if (!parent->active_channels) {
1098 		usb_kill_anchored_urbs(&parent->rx_submitted);
1099 
1100 		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1101 			gs_usb_timestamp_stop(parent);
1102 	}
1103 
1104 	can_rx_offload_disable(&dev->offload);
1105 	close_candev(netdev);
1106 
1107 	return rc;
1108 }
1109 
1110 static int gs_usb_get_state(const struct net_device *netdev,
1111 			    struct can_berr_counter *bec,
1112 			    enum can_state *state)
1113 {
1114 	struct gs_can *dev = netdev_priv(netdev);
1115 	struct gs_device_state ds;
1116 	int rc;
1117 
1118 	rc = usb_control_msg_recv(dev->udev, 0, GS_USB_BREQ_GET_STATE,
1119 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1120 				  dev->channel, 0,
1121 				  &ds, sizeof(ds),
1122 				  USB_CTRL_GET_TIMEOUT,
1123 				  GFP_KERNEL);
1124 	if (rc)
1125 		return rc;
1126 
1127 	if (le32_to_cpu(ds.state) >= CAN_STATE_MAX)
1128 		return -EOPNOTSUPP;
1129 
1130 	*state = le32_to_cpu(ds.state);
1131 	bec->txerr = le32_to_cpu(ds.txerr);
1132 	bec->rxerr = le32_to_cpu(ds.rxerr);
1133 
1134 	return 0;
1135 }
1136 
1137 static int gs_usb_can_get_berr_counter(const struct net_device *netdev,
1138 				       struct can_berr_counter *bec)
1139 {
1140 	enum can_state state;
1141 
1142 	return gs_usb_get_state(netdev, bec, &state);
1143 }
1144 
1145 static int gs_can_close(struct net_device *netdev)
1146 {
1147 	int rc;
1148 	struct gs_can *dev = netdev_priv(netdev);
1149 	struct gs_usb *parent = dev->parent;
1150 
1151 	netif_stop_queue(netdev);
1152 
1153 	/* Stop polling */
1154 	parent->active_channels--;
1155 	if (!parent->active_channels) {
1156 		usb_kill_anchored_urbs(&parent->rx_submitted);
1157 
1158 		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1159 			gs_usb_timestamp_stop(parent);
1160 	}
1161 
1162 	/* Stop sending URBs */
1163 	usb_kill_anchored_urbs(&dev->tx_submitted);
1164 	atomic_set(&dev->active_tx_urbs, 0);
1165 
1166 	dev->can.state = CAN_STATE_STOPPED;
1167 
1168 	/* reset the device */
1169 	gs_cmd_reset(dev);
1170 
1171 	/* reset tx contexts */
1172 	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
1173 		dev->tx_context[rc].dev = dev;
1174 		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
1175 	}
1176 
1177 	can_rx_offload_disable(&dev->offload);
1178 
1179 	/* close the netdev */
1180 	close_candev(netdev);
1181 
1182 	return 0;
1183 }
1184 
1185 static int gs_can_hwtstamp_get(struct net_device *netdev,
1186 			       struct kernel_hwtstamp_config *cfg)
1187 {
1188 	const struct gs_can *dev = netdev_priv(netdev);
1189 
1190 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1191 		return can_hwtstamp_get(netdev, cfg);
1192 
1193 	return -EOPNOTSUPP;
1194 }
1195 
1196 static int gs_can_hwtstamp_set(struct net_device *netdev,
1197 			       struct kernel_hwtstamp_config *cfg,
1198 			       struct netlink_ext_ack *extack)
1199 {
1200 	const struct gs_can *dev = netdev_priv(netdev);
1201 
1202 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1203 		return can_hwtstamp_set(netdev, cfg, extack);
1204 
1205 	return -EOPNOTSUPP;
1206 }
1207 
1208 static const struct net_device_ops gs_usb_netdev_ops = {
1209 	.ndo_open = gs_can_open,
1210 	.ndo_stop = gs_can_close,
1211 	.ndo_start_xmit = gs_can_start_xmit,
1212 	.ndo_hwtstamp_get = gs_can_hwtstamp_get,
1213 	.ndo_hwtstamp_set = gs_can_hwtstamp_set,
1214 };
1215 
1216 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
1217 {
1218 	struct gs_can *dev = netdev_priv(netdev);
1219 	struct gs_identify_mode imode;
1220 
1221 	if (do_identify)
1222 		imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
1223 	else
1224 		imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
1225 
1226 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_IDENTIFY,
1227 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1228 				    dev->channel, 0, &imode, sizeof(imode), 100,
1229 				    GFP_KERNEL);
1230 }
1231 
1232 /* blink LED's for finding the this interface */
1233 static int gs_usb_set_phys_id(struct net_device *netdev,
1234 			      enum ethtool_phys_id_state state)
1235 {
1236 	const struct gs_can *dev = netdev_priv(netdev);
1237 	int rc = 0;
1238 
1239 	if (!(dev->feature & GS_CAN_FEATURE_IDENTIFY))
1240 		return -EOPNOTSUPP;
1241 
1242 	switch (state) {
1243 	case ETHTOOL_ID_ACTIVE:
1244 		rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_ON);
1245 		break;
1246 	case ETHTOOL_ID_INACTIVE:
1247 		rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_OFF);
1248 		break;
1249 	default:
1250 		break;
1251 	}
1252 
1253 	return rc;
1254 }
1255 
1256 static int gs_usb_get_ts_info(struct net_device *netdev,
1257 			      struct kernel_ethtool_ts_info *info)
1258 {
1259 	struct gs_can *dev = netdev_priv(netdev);
1260 
1261 	/* report if device supports HW timestamps */
1262 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1263 		return can_ethtool_op_get_ts_info_hwts(netdev, info);
1264 
1265 	return ethtool_op_get_ts_info(netdev, info);
1266 }
1267 
1268 static const struct ethtool_ops gs_usb_ethtool_ops = {
1269 	.set_phys_id = gs_usb_set_phys_id,
1270 	.get_ts_info = gs_usb_get_ts_info,
1271 };
1272 
1273 static int gs_usb_get_termination(struct net_device *netdev, u16 *term)
1274 {
1275 	struct gs_can *dev = netdev_priv(netdev);
1276 	struct gs_device_termination_state term_state;
1277 	int rc;
1278 
1279 	rc = usb_control_msg_recv(dev->udev, 0, GS_USB_BREQ_GET_TERMINATION,
1280 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1281 				  dev->channel, 0,
1282 				  &term_state, sizeof(term_state), 1000,
1283 				  GFP_KERNEL);
1284 	if (rc)
1285 		return rc;
1286 
1287 	if (term_state.state == cpu_to_le32(GS_CAN_TERMINATION_STATE_ON))
1288 		*term = GS_USB_TERMINATION_ENABLED;
1289 	else
1290 		*term = GS_USB_TERMINATION_DISABLED;
1291 
1292 	return 0;
1293 }
1294 
1295 static int gs_usb_set_termination(struct net_device *netdev, u16 term)
1296 {
1297 	struct gs_can *dev = netdev_priv(netdev);
1298 	struct gs_device_termination_state term_state;
1299 
1300 	if (term == GS_USB_TERMINATION_ENABLED)
1301 		term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_ON);
1302 	else
1303 		term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_OFF);
1304 
1305 	return usb_control_msg_send(dev->udev, 0, GS_USB_BREQ_SET_TERMINATION,
1306 				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1307 				    dev->channel, 0,
1308 				    &term_state, sizeof(term_state), 1000,
1309 				    GFP_KERNEL);
1310 }
1311 
1312 static const u16 gs_usb_termination_const[] = {
1313 	GS_USB_TERMINATION_DISABLED,
1314 	GS_USB_TERMINATION_ENABLED
1315 };
1316 
1317 static struct gs_can *gs_make_candev(unsigned int channel,
1318 				     struct usb_interface *intf,
1319 				     struct gs_device_config *dconf)
1320 {
1321 	struct gs_can *dev;
1322 	struct net_device *netdev;
1323 	int rc;
1324 	struct gs_device_bt_const_extended bt_const_extended;
1325 	struct gs_device_bt_const bt_const;
1326 	u32 feature;
1327 
1328 	/* fetch bit timing constants */
1329 	rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
1330 				  GS_USB_BREQ_BT_CONST,
1331 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1332 				  channel, 0, &bt_const, sizeof(bt_const), 1000,
1333 				  GFP_KERNEL);
1334 
1335 	if (rc) {
1336 		dev_err(&intf->dev,
1337 			"Couldn't get bit timing const for channel %d (%pe)\n",
1338 			channel, ERR_PTR(rc));
1339 		return ERR_PTR(rc);
1340 	}
1341 
1342 	/* create netdev */
1343 	netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
1344 	if (!netdev) {
1345 		dev_err(&intf->dev, "Couldn't allocate candev\n");
1346 		return ERR_PTR(-ENOMEM);
1347 	}
1348 
1349 	dev = netdev_priv(netdev);
1350 
1351 	netdev->netdev_ops = &gs_usb_netdev_ops;
1352 	netdev->ethtool_ops = &gs_usb_ethtool_ops;
1353 
1354 	netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
1355 	netdev->dev_id = channel;
1356 	netdev->dev_port = channel;
1357 
1358 	/* dev setup */
1359 	strcpy(dev->bt_const.name, KBUILD_MODNAME);
1360 	dev->bt_const.tseg1_min = le32_to_cpu(bt_const.tseg1_min);
1361 	dev->bt_const.tseg1_max = le32_to_cpu(bt_const.tseg1_max);
1362 	dev->bt_const.tseg2_min = le32_to_cpu(bt_const.tseg2_min);
1363 	dev->bt_const.tseg2_max = le32_to_cpu(bt_const.tseg2_max);
1364 	dev->bt_const.sjw_max = le32_to_cpu(bt_const.sjw_max);
1365 	dev->bt_const.brp_min = le32_to_cpu(bt_const.brp_min);
1366 	dev->bt_const.brp_max = le32_to_cpu(bt_const.brp_max);
1367 	dev->bt_const.brp_inc = le32_to_cpu(bt_const.brp_inc);
1368 
1369 	dev->udev = interface_to_usbdev(intf);
1370 	dev->netdev = netdev;
1371 	dev->channel = channel;
1372 
1373 	init_usb_anchor(&dev->tx_submitted);
1374 	atomic_set(&dev->active_tx_urbs, 0);
1375 	spin_lock_init(&dev->tx_ctx_lock);
1376 	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
1377 		dev->tx_context[rc].dev = dev;
1378 		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
1379 	}
1380 
1381 	/* can setup */
1382 	dev->can.state = CAN_STATE_STOPPED;
1383 	dev->can.clock.freq = le32_to_cpu(bt_const.fclk_can);
1384 	dev->can.bittiming_const = &dev->bt_const;
1385 
1386 	dev->can.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC;
1387 
1388 	feature = le32_to_cpu(bt_const.feature);
1389 	dev->feature = FIELD_GET(GS_CAN_FEATURE_MASK, feature);
1390 	if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
1391 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
1392 
1393 	if (feature & GS_CAN_FEATURE_LOOP_BACK)
1394 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
1395 
1396 	if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
1397 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1398 
1399 	if (feature & GS_CAN_FEATURE_ONE_SHOT)
1400 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
1401 
1402 	if (feature & GS_CAN_FEATURE_FD) {
1403 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
1404 		/* The data bit timing will be overwritten, if
1405 		 * GS_CAN_FEATURE_BT_CONST_EXT is set.
1406 		 */
1407 		dev->can.fd.data_bittiming_const = &dev->bt_const;
1408 	}
1409 
1410 	if (feature & GS_CAN_FEATURE_TERMINATION) {
1411 		rc = gs_usb_get_termination(netdev, &dev->can.termination);
1412 		if (rc) {
1413 			dev->feature &= ~GS_CAN_FEATURE_TERMINATION;
1414 
1415 			dev_info(&intf->dev,
1416 				 "Disabling termination support for channel %d (%pe)\n",
1417 				 channel, ERR_PTR(rc));
1418 		} else {
1419 			dev->can.termination_const = gs_usb_termination_const;
1420 			dev->can.termination_const_cnt = ARRAY_SIZE(gs_usb_termination_const);
1421 			dev->can.do_set_termination = gs_usb_set_termination;
1422 		}
1423 	}
1424 
1425 	if (feature & GS_CAN_FEATURE_BERR_REPORTING)
1426 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_BERR_REPORTING;
1427 
1428 	if (feature & GS_CAN_FEATURE_GET_STATE)
1429 		dev->can.do_get_berr_counter = gs_usb_can_get_berr_counter;
1430 
1431 	/* The CANtact Pro from LinkLayer Labs is based on the
1432 	 * LPC54616 µC, which is affected by the NXP LPC USB transfer
1433 	 * erratum. However, the current firmware (version 2) doesn't
1434 	 * set the GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX bit. Set the
1435 	 * feature GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX to workaround
1436 	 * this issue.
1437 	 *
1438 	 * For the GS_USB_BREQ_DATA_BITTIMING USB control message the
1439 	 * CANtact Pro firmware uses a request value, which is already
1440 	 * used by the candleLight firmware for a different purpose
1441 	 * (GS_USB_BREQ_GET_USER_ID). Set the feature
1442 	 * GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO to workaround this
1443 	 * issue.
1444 	 */
1445 	if (dev->udev->descriptor.idVendor == cpu_to_le16(USB_GS_USB_1_VENDOR_ID) &&
1446 	    dev->udev->descriptor.idProduct == cpu_to_le16(USB_GS_USB_1_PRODUCT_ID) &&
1447 	    dev->udev->manufacturer && dev->udev->product &&
1448 	    !strcmp(dev->udev->manufacturer, "LinkLayer Labs") &&
1449 	    !strcmp(dev->udev->product, "CANtact Pro") &&
1450 	    (le32_to_cpu(dconf->sw_version) <= 2))
1451 		dev->feature |= GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX |
1452 			GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO;
1453 
1454 	/* GS_CAN_FEATURE_IDENTIFY is only supported for sw_version > 1 */
1455 	if (!(le32_to_cpu(dconf->sw_version) > 1 &&
1456 	      feature & GS_CAN_FEATURE_IDENTIFY))
1457 		dev->feature &= ~GS_CAN_FEATURE_IDENTIFY;
1458 
1459 	/* fetch extended bit timing constants if device has feature
1460 	 * GS_CAN_FEATURE_FD and GS_CAN_FEATURE_BT_CONST_EXT
1461 	 */
1462 	if (feature & GS_CAN_FEATURE_FD &&
1463 	    feature & GS_CAN_FEATURE_BT_CONST_EXT) {
1464 		rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
1465 					  GS_USB_BREQ_BT_CONST_EXT,
1466 					  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1467 					  channel, 0, &bt_const_extended,
1468 					  sizeof(bt_const_extended),
1469 					  1000, GFP_KERNEL);
1470 		if (rc) {
1471 			dev_err(&intf->dev,
1472 				"Couldn't get extended bit timing const for channel %d (%pe)\n",
1473 				channel, ERR_PTR(rc));
1474 			goto out_free_candev;
1475 		}
1476 
1477 		strcpy(dev->data_bt_const.name, KBUILD_MODNAME);
1478 		dev->data_bt_const.tseg1_min = le32_to_cpu(bt_const_extended.dtseg1_min);
1479 		dev->data_bt_const.tseg1_max = le32_to_cpu(bt_const_extended.dtseg1_max);
1480 		dev->data_bt_const.tseg2_min = le32_to_cpu(bt_const_extended.dtseg2_min);
1481 		dev->data_bt_const.tseg2_max = le32_to_cpu(bt_const_extended.dtseg2_max);
1482 		dev->data_bt_const.sjw_max = le32_to_cpu(bt_const_extended.dsjw_max);
1483 		dev->data_bt_const.brp_min = le32_to_cpu(bt_const_extended.dbrp_min);
1484 		dev->data_bt_const.brp_max = le32_to_cpu(bt_const_extended.dbrp_max);
1485 		dev->data_bt_const.brp_inc = le32_to_cpu(bt_const_extended.dbrp_inc);
1486 
1487 		dev->can.fd.data_bittiming_const = &dev->data_bt_const;
1488 	}
1489 
1490 	can_rx_offload_add_manual(netdev, &dev->offload, GS_NAPI_WEIGHT);
1491 	SET_NETDEV_DEV(netdev, &intf->dev);
1492 
1493 	rc = register_candev(dev->netdev);
1494 	if (rc) {
1495 		dev_err(&intf->dev,
1496 			"Couldn't register candev for channel %d (%pe)\n",
1497 			channel, ERR_PTR(rc));
1498 		goto out_can_rx_offload_del;
1499 	}
1500 
1501 	return dev;
1502 
1503 out_can_rx_offload_del:
1504 	can_rx_offload_del(&dev->offload);
1505 out_free_candev:
1506 	free_candev(dev->netdev);
1507 	return ERR_PTR(rc);
1508 }
1509 
1510 static void gs_destroy_candev(struct gs_can *dev)
1511 {
1512 	unregister_candev(dev->netdev);
1513 	can_rx_offload_del(&dev->offload);
1514 	free_candev(dev->netdev);
1515 }
1516 
1517 static int gs_usb_probe(struct usb_interface *intf,
1518 			const struct usb_device_id *id)
1519 {
1520 	struct usb_device *udev = interface_to_usbdev(intf);
1521 	struct usb_endpoint_descriptor *ep_in, *ep_out;
1522 	struct gs_host_frame *hf;
1523 	struct gs_usb *parent;
1524 	struct gs_host_config hconf = {
1525 		.byte_order = cpu_to_le32(0x0000beef),
1526 	};
1527 	struct gs_device_config dconf;
1528 	unsigned int icount, i;
1529 	int rc;
1530 
1531 	rc = usb_find_common_endpoints(intf->cur_altsetting,
1532 				       &ep_in, &ep_out, NULL, NULL);
1533 	if (rc) {
1534 		dev_err(&intf->dev, "Required endpoints not found\n");
1535 		return rc;
1536 	}
1537 
1538 	/* send host config */
1539 	rc = usb_control_msg_send(udev, 0,
1540 				  GS_USB_BREQ_HOST_FORMAT,
1541 				  USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1542 				  1, intf->cur_altsetting->desc.bInterfaceNumber,
1543 				  &hconf, sizeof(hconf), 1000,
1544 				  GFP_KERNEL);
1545 	if (rc) {
1546 		dev_err(&intf->dev, "Couldn't send data format (err=%d)\n", rc);
1547 		return rc;
1548 	}
1549 
1550 	/* read device config */
1551 	rc = usb_control_msg_recv(udev, 0,
1552 				  GS_USB_BREQ_DEVICE_CONFIG,
1553 				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1554 				  1, intf->cur_altsetting->desc.bInterfaceNumber,
1555 				  &dconf, sizeof(dconf), 1000,
1556 				  GFP_KERNEL);
1557 	if (rc) {
1558 		dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
1559 			rc);
1560 		return rc;
1561 	}
1562 
1563 	icount = dconf.icount + 1;
1564 	dev_info(&intf->dev, "Configuring for %u interfaces\n", icount);
1565 
1566 	if (icount > type_max(parent->channel_cnt)) {
1567 		dev_err(&intf->dev,
1568 			"Driver cannot handle more that %u CAN interfaces\n",
1569 			type_max(parent->channel_cnt));
1570 		return -EINVAL;
1571 	}
1572 
1573 	parent = kzalloc_flex(*parent, canch, icount);
1574 	if (!parent)
1575 		return -ENOMEM;
1576 
1577 	parent->channel_cnt = icount;
1578 
1579 	init_usb_anchor(&parent->rx_submitted);
1580 
1581 	usb_set_intfdata(intf, parent);
1582 	parent->udev = udev;
1583 
1584 	/* store the detected endpoints */
1585 	parent->pipe_in = usb_rcvbulkpipe(parent->udev, ep_in->bEndpointAddress);
1586 	parent->pipe_out = usb_sndbulkpipe(parent->udev, ep_out->bEndpointAddress);
1587 
1588 	for (i = 0; i < icount; i++) {
1589 		unsigned int hf_size_rx = 0;
1590 
1591 		parent->canch[i] = gs_make_candev(i, intf, &dconf);
1592 		if (IS_ERR_OR_NULL(parent->canch[i])) {
1593 			/* save error code to return later */
1594 			rc = PTR_ERR(parent->canch[i]);
1595 
1596 			/* on failure destroy previously created candevs */
1597 			icount = i;
1598 			for (i = 0; i < icount; i++)
1599 				gs_destroy_candev(parent->canch[i]);
1600 
1601 			usb_kill_anchored_urbs(&parent->rx_submitted);
1602 			kfree(parent);
1603 			return rc;
1604 		}
1605 		parent->canch[i]->parent = parent;
1606 
1607 		/* set RX packet size based on FD and if hardware
1608 		 * timestamps are supported.
1609 		 */
1610 		if (parent->canch[i]->can.ctrlmode_supported & CAN_CTRLMODE_FD) {
1611 			if (parent->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1612 				hf_size_rx = struct_size(hf, canfd_ts, 1);
1613 			else
1614 				hf_size_rx = struct_size(hf, canfd, 1);
1615 		} else {
1616 			if (parent->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
1617 				hf_size_rx = struct_size(hf, classic_can_ts, 1);
1618 			else
1619 				hf_size_rx = struct_size(hf, classic_can, 1);
1620 		}
1621 		parent->hf_size_rx = max(parent->hf_size_rx, hf_size_rx);
1622 	}
1623 
1624 	return 0;
1625 }
1626 
1627 static void gs_usb_disconnect(struct usb_interface *intf)
1628 {
1629 	struct gs_usb *parent = usb_get_intfdata(intf);
1630 	unsigned int i;
1631 
1632 	usb_set_intfdata(intf, NULL);
1633 
1634 	if (!parent) {
1635 		dev_err(&intf->dev, "Disconnect (nodata)\n");
1636 		return;
1637 	}
1638 
1639 	for (i = 0; i < parent->channel_cnt; i++)
1640 		if (parent->canch[i])
1641 			gs_destroy_candev(parent->canch[i]);
1642 
1643 	kfree(parent);
1644 }
1645 
1646 static const struct usb_device_id gs_usb_table[] = {
1647 	{ USB_DEVICE_INTERFACE_NUMBER(USB_GS_USB_1_VENDOR_ID,
1648 				      USB_GS_USB_1_PRODUCT_ID, 0) },
1649 	{ USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1650 				      USB_CANDLELIGHT_PRODUCT_ID, 0) },
1651 	{ USB_DEVICE_INTERFACE_NUMBER(USB_CES_CANEXT_FD_VENDOR_ID,
1652 				      USB_CES_CANEXT_FD_PRODUCT_ID, 0) },
1653 	{ USB_DEVICE_INTERFACE_NUMBER(USB_ABE_CANDEBUGGER_FD_VENDOR_ID,
1654 				      USB_ABE_CANDEBUGGER_FD_PRODUCT_ID, 0) },
1655 	{ USB_DEVICE_INTERFACE_NUMBER(USB_XYLANTA_SAINT3_VENDOR_ID,
1656 				      USB_XYLANTA_SAINT3_PRODUCT_ID, 0) },
1657 	{ USB_DEVICE_INTERFACE_NUMBER(USB_CANNECTIVITY_VENDOR_ID,
1658 				      USB_CANNECTIVITY_PRODUCT_ID, 0) },
1659 	{} /* Terminating entry */
1660 };
1661 
1662 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1663 
1664 static struct usb_driver gs_usb_driver = {
1665 	.name = KBUILD_MODNAME,
1666 	.probe = gs_usb_probe,
1667 	.disconnect = gs_usb_disconnect,
1668 	.id_table = gs_usb_table,
1669 };
1670 
1671 module_usb_driver(gs_usb_driver);
1672 
1673 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1674 MODULE_DESCRIPTION(
1675 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1676 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1677 "and bytewerk.org candleLight USB CAN interfaces.");
1678 MODULE_LICENSE("GPL v2");
1679