xref: /openbmc/linux/drivers/net/can/usb/gs_usb.c (revision bbb774d9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* CAN driver for Geschwister Schneider USB/CAN devices
3  * and bytewerk.org candleLight USB CAN interfaces.
4  *
5  * Copyright (C) 2013-2016 Geschwister Schneider Technologie-,
6  * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
7  * Copyright (C) 2016 Hubert Denkmair
8  *
9  * Many thanks to all socketcan devs!
10  */
11 
12 #include <linux/bitfield.h>
13 #include <linux/ethtool.h>
14 #include <linux/init.h>
15 #include <linux/module.h>
16 #include <linux/netdevice.h>
17 #include <linux/signal.h>
18 #include <linux/usb.h>
19 
20 #include <linux/can.h>
21 #include <linux/can/dev.h>
22 #include <linux/can/error.h>
23 
24 /* Device specific constants */
25 #define USB_GSUSB_1_VENDOR_ID 0x1d50
26 #define USB_GSUSB_1_PRODUCT_ID 0x606f
27 
28 #define USB_CANDLELIGHT_VENDOR_ID 0x1209
29 #define USB_CANDLELIGHT_PRODUCT_ID 0x2323
30 
31 #define USB_CES_CANEXT_FD_VENDOR_ID 0x1cd2
32 #define USB_CES_CANEXT_FD_PRODUCT_ID 0x606f
33 
34 #define USB_ABE_CANDEBUGGER_FD_VENDOR_ID 0x16d0
35 #define USB_ABE_CANDEBUGGER_FD_PRODUCT_ID 0x10b8
36 
37 #define GSUSB_ENDPOINT_IN 1
38 #define GSUSB_ENDPOINT_OUT 2
39 
40 /* Device specific constants */
41 enum gs_usb_breq {
42 	GS_USB_BREQ_HOST_FORMAT = 0,
43 	GS_USB_BREQ_BITTIMING,
44 	GS_USB_BREQ_MODE,
45 	GS_USB_BREQ_BERR,
46 	GS_USB_BREQ_BT_CONST,
47 	GS_USB_BREQ_DEVICE_CONFIG,
48 	GS_USB_BREQ_TIMESTAMP,
49 	GS_USB_BREQ_IDENTIFY,
50 	GS_USB_BREQ_GET_USER_ID,
51 	GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING = GS_USB_BREQ_GET_USER_ID,
52 	GS_USB_BREQ_SET_USER_ID,
53 	GS_USB_BREQ_DATA_BITTIMING,
54 	GS_USB_BREQ_BT_CONST_EXT,
55 };
56 
57 enum gs_can_mode {
58 	/* reset a channel. turns it off */
59 	GS_CAN_MODE_RESET = 0,
60 	/* starts a channel */
61 	GS_CAN_MODE_START
62 };
63 
64 enum gs_can_state {
65 	GS_CAN_STATE_ERROR_ACTIVE = 0,
66 	GS_CAN_STATE_ERROR_WARNING,
67 	GS_CAN_STATE_ERROR_PASSIVE,
68 	GS_CAN_STATE_BUS_OFF,
69 	GS_CAN_STATE_STOPPED,
70 	GS_CAN_STATE_SLEEPING
71 };
72 
73 enum gs_can_identify_mode {
74 	GS_CAN_IDENTIFY_OFF = 0,
75 	GS_CAN_IDENTIFY_ON
76 };
77 
78 /* data types passed between host and device */
79 
80 /* The firmware on the original USB2CAN by Geschwister Schneider
81  * Technologie Entwicklungs- und Vertriebs UG exchanges all data
82  * between the host and the device in host byte order. This is done
83  * with the struct gs_host_config::byte_order member, which is sent
84  * first to indicate the desired byte order.
85  *
86  * The widely used open source firmware candleLight doesn't support
87  * this feature and exchanges the data in little endian byte order.
88  */
89 struct gs_host_config {
90 	__le32 byte_order;
91 } __packed;
92 
93 struct gs_device_config {
94 	u8 reserved1;
95 	u8 reserved2;
96 	u8 reserved3;
97 	u8 icount;
98 	__le32 sw_version;
99 	__le32 hw_version;
100 } __packed;
101 
102 #define GS_CAN_MODE_NORMAL 0
103 #define GS_CAN_MODE_LISTEN_ONLY BIT(0)
104 #define GS_CAN_MODE_LOOP_BACK BIT(1)
105 #define GS_CAN_MODE_TRIPLE_SAMPLE BIT(2)
106 #define GS_CAN_MODE_ONE_SHOT BIT(3)
107 #define GS_CAN_MODE_HW_TIMESTAMP BIT(4)
108 /* GS_CAN_FEATURE_IDENTIFY BIT(5) */
109 /* GS_CAN_FEATURE_USER_ID BIT(6) */
110 #define GS_CAN_MODE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
111 #define GS_CAN_MODE_FD BIT(8)
112 /* GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9) */
113 /* GS_CAN_FEATURE_BT_CONST_EXT BIT(10) */
114 
115 struct gs_device_mode {
116 	__le32 mode;
117 	__le32 flags;
118 } __packed;
119 
120 struct gs_device_state {
121 	__le32 state;
122 	__le32 rxerr;
123 	__le32 txerr;
124 } __packed;
125 
126 struct gs_device_bittiming {
127 	__le32 prop_seg;
128 	__le32 phase_seg1;
129 	__le32 phase_seg2;
130 	__le32 sjw;
131 	__le32 brp;
132 } __packed;
133 
134 struct gs_identify_mode {
135 	__le32 mode;
136 } __packed;
137 
138 #define GS_CAN_FEATURE_LISTEN_ONLY BIT(0)
139 #define GS_CAN_FEATURE_LOOP_BACK BIT(1)
140 #define GS_CAN_FEATURE_TRIPLE_SAMPLE BIT(2)
141 #define GS_CAN_FEATURE_ONE_SHOT BIT(3)
142 #define GS_CAN_FEATURE_HW_TIMESTAMP BIT(4)
143 #define GS_CAN_FEATURE_IDENTIFY BIT(5)
144 #define GS_CAN_FEATURE_USER_ID BIT(6)
145 #define GS_CAN_FEATURE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
146 #define GS_CAN_FEATURE_FD BIT(8)
147 #define GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9)
148 #define GS_CAN_FEATURE_BT_CONST_EXT BIT(10)
149 #define GS_CAN_FEATURE_MASK GENMASK(10, 0)
150 
151 /* internal quirks - keep in GS_CAN_FEATURE space for now */
152 
153 /* CANtact Pro original firmware:
154  * BREQ DATA_BITTIMING overlaps with GET_USER_ID
155  */
156 #define GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO BIT(31)
157 
158 struct gs_device_bt_const {
159 	__le32 feature;
160 	__le32 fclk_can;
161 	__le32 tseg1_min;
162 	__le32 tseg1_max;
163 	__le32 tseg2_min;
164 	__le32 tseg2_max;
165 	__le32 sjw_max;
166 	__le32 brp_min;
167 	__le32 brp_max;
168 	__le32 brp_inc;
169 } __packed;
170 
171 struct gs_device_bt_const_extended {
172 	__le32 feature;
173 	__le32 fclk_can;
174 	__le32 tseg1_min;
175 	__le32 tseg1_max;
176 	__le32 tseg2_min;
177 	__le32 tseg2_max;
178 	__le32 sjw_max;
179 	__le32 brp_min;
180 	__le32 brp_max;
181 	__le32 brp_inc;
182 
183 	__le32 dtseg1_min;
184 	__le32 dtseg1_max;
185 	__le32 dtseg2_min;
186 	__le32 dtseg2_max;
187 	__le32 dsjw_max;
188 	__le32 dbrp_min;
189 	__le32 dbrp_max;
190 	__le32 dbrp_inc;
191 } __packed;
192 
193 #define GS_CAN_FLAG_OVERFLOW BIT(0)
194 #define GS_CAN_FLAG_FD BIT(1)
195 #define GS_CAN_FLAG_BRS BIT(2)
196 #define GS_CAN_FLAG_ESI BIT(3)
197 
198 struct classic_can {
199 	u8 data[8];
200 } __packed;
201 
202 struct classic_can_quirk {
203 	u8 data[8];
204 	u8 quirk;
205 } __packed;
206 
207 struct canfd {
208 	u8 data[64];
209 } __packed;
210 
211 struct canfd_quirk {
212 	u8 data[64];
213 	u8 quirk;
214 } __packed;
215 
216 struct gs_host_frame {
217 	u32 echo_id;
218 	__le32 can_id;
219 
220 	u8 can_dlc;
221 	u8 channel;
222 	u8 flags;
223 	u8 reserved;
224 
225 	union {
226 		DECLARE_FLEX_ARRAY(struct classic_can, classic_can);
227 		DECLARE_FLEX_ARRAY(struct classic_can_quirk, classic_can_quirk);
228 		DECLARE_FLEX_ARRAY(struct canfd, canfd);
229 		DECLARE_FLEX_ARRAY(struct canfd_quirk, canfd_quirk);
230 	};
231 } __packed;
232 /* The GS USB devices make use of the same flags and masks as in
233  * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
234  */
235 
236 /* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
237 #define GS_MAX_TX_URBS 10
238 /* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
239 #define GS_MAX_RX_URBS 30
240 /* Maximum number of interfaces the driver supports per device.
241  * Current hardware only supports 3 interfaces. The future may vary.
242  */
243 #define GS_MAX_INTF 3
244 
245 struct gs_tx_context {
246 	struct gs_can *dev;
247 	unsigned int echo_id;
248 };
249 
250 struct gs_can {
251 	struct can_priv can; /* must be the first member */
252 
253 	struct gs_usb *parent;
254 
255 	struct net_device *netdev;
256 	struct usb_device *udev;
257 	struct usb_interface *iface;
258 
259 	struct can_bittiming_const bt_const, data_bt_const;
260 	unsigned int channel;	/* channel number */
261 
262 	u32 feature;
263 	unsigned int hf_size_tx;
264 
265 	/* This lock prevents a race condition between xmit and receive. */
266 	spinlock_t tx_ctx_lock;
267 	struct gs_tx_context tx_context[GS_MAX_TX_URBS];
268 
269 	struct usb_anchor tx_submitted;
270 	atomic_t active_tx_urbs;
271 	void *rxbuf[GS_MAX_RX_URBS];
272 	dma_addr_t rxbuf_dma[GS_MAX_RX_URBS];
273 };
274 
275 /* usb interface struct */
276 struct gs_usb {
277 	struct gs_can *canch[GS_MAX_INTF];
278 	struct usb_anchor rx_submitted;
279 	struct usb_device *udev;
280 	unsigned int hf_size_rx;
281 	u8 active_channels;
282 };
283 
284 /* 'allocate' a tx context.
285  * returns a valid tx context or NULL if there is no space.
286  */
287 static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
288 {
289 	int i = 0;
290 	unsigned long flags;
291 
292 	spin_lock_irqsave(&dev->tx_ctx_lock, flags);
293 
294 	for (; i < GS_MAX_TX_URBS; i++) {
295 		if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
296 			dev->tx_context[i].echo_id = i;
297 			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
298 			return &dev->tx_context[i];
299 		}
300 	}
301 
302 	spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
303 	return NULL;
304 }
305 
306 /* releases a tx context
307  */
308 static void gs_free_tx_context(struct gs_tx_context *txc)
309 {
310 	txc->echo_id = GS_MAX_TX_URBS;
311 }
312 
313 /* Get a tx context by id.
314  */
315 static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
316 					       unsigned int id)
317 {
318 	unsigned long flags;
319 
320 	if (id < GS_MAX_TX_URBS) {
321 		spin_lock_irqsave(&dev->tx_ctx_lock, flags);
322 		if (dev->tx_context[id].echo_id == id) {
323 			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
324 			return &dev->tx_context[id];
325 		}
326 		spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
327 	}
328 	return NULL;
329 }
330 
331 static int gs_cmd_reset(struct gs_can *gsdev)
332 {
333 	struct gs_device_mode *dm;
334 	struct usb_interface *intf = gsdev->iface;
335 	int rc;
336 
337 	dm = kzalloc(sizeof(*dm), GFP_KERNEL);
338 	if (!dm)
339 		return -ENOMEM;
340 
341 	dm->mode = GS_CAN_MODE_RESET;
342 
343 	rc = usb_control_msg(interface_to_usbdev(intf),
344 			     usb_sndctrlpipe(interface_to_usbdev(intf), 0),
345 			     GS_USB_BREQ_MODE,
346 			     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
347 			     gsdev->channel, 0, dm, sizeof(*dm), 1000);
348 
349 	kfree(dm);
350 
351 	return rc;
352 }
353 
354 static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
355 {
356 	struct can_device_stats *can_stats = &dev->can.can_stats;
357 
358 	if (cf->can_id & CAN_ERR_RESTARTED) {
359 		dev->can.state = CAN_STATE_ERROR_ACTIVE;
360 		can_stats->restarts++;
361 	} else if (cf->can_id & CAN_ERR_BUSOFF) {
362 		dev->can.state = CAN_STATE_BUS_OFF;
363 		can_stats->bus_off++;
364 	} else if (cf->can_id & CAN_ERR_CRTL) {
365 		if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
366 		    (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
367 			dev->can.state = CAN_STATE_ERROR_WARNING;
368 			can_stats->error_warning++;
369 		} else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
370 			   (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
371 			dev->can.state = CAN_STATE_ERROR_PASSIVE;
372 			can_stats->error_passive++;
373 		} else {
374 			dev->can.state = CAN_STATE_ERROR_ACTIVE;
375 		}
376 	}
377 }
378 
379 static void gs_usb_receive_bulk_callback(struct urb *urb)
380 {
381 	struct gs_usb *usbcan = urb->context;
382 	struct gs_can *dev;
383 	struct net_device *netdev;
384 	int rc;
385 	struct net_device_stats *stats;
386 	struct gs_host_frame *hf = urb->transfer_buffer;
387 	struct gs_tx_context *txc;
388 	struct can_frame *cf;
389 	struct canfd_frame *cfd;
390 	struct sk_buff *skb;
391 
392 	BUG_ON(!usbcan);
393 
394 	switch (urb->status) {
395 	case 0: /* success */
396 		break;
397 	case -ENOENT:
398 	case -ESHUTDOWN:
399 		return;
400 	default:
401 		/* do not resubmit aborted urbs. eg: when device goes down */
402 		return;
403 	}
404 
405 	/* device reports out of range channel id */
406 	if (hf->channel >= GS_MAX_INTF)
407 		goto device_detach;
408 
409 	dev = usbcan->canch[hf->channel];
410 
411 	netdev = dev->netdev;
412 	stats = &netdev->stats;
413 
414 	if (!netif_device_present(netdev))
415 		return;
416 
417 	if (hf->echo_id == -1) { /* normal rx */
418 		if (hf->flags & GS_CAN_FLAG_FD) {
419 			skb = alloc_canfd_skb(dev->netdev, &cfd);
420 			if (!skb)
421 				return;
422 
423 			cfd->can_id = le32_to_cpu(hf->can_id);
424 			cfd->len = can_fd_dlc2len(hf->can_dlc);
425 			if (hf->flags & GS_CAN_FLAG_BRS)
426 				cfd->flags |= CANFD_BRS;
427 			if (hf->flags & GS_CAN_FLAG_ESI)
428 				cfd->flags |= CANFD_ESI;
429 
430 			memcpy(cfd->data, hf->canfd->data, cfd->len);
431 		} else {
432 			skb = alloc_can_skb(dev->netdev, &cf);
433 			if (!skb)
434 				return;
435 
436 			cf->can_id = le32_to_cpu(hf->can_id);
437 			can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);
438 
439 			memcpy(cf->data, hf->classic_can->data, 8);
440 
441 			/* ERROR frames tell us information about the controller */
442 			if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)
443 				gs_update_state(dev, cf);
444 		}
445 
446 		netdev->stats.rx_packets++;
447 		netdev->stats.rx_bytes += hf->can_dlc;
448 
449 		netif_rx(skb);
450 	} else { /* echo_id == hf->echo_id */
451 		if (hf->echo_id >= GS_MAX_TX_URBS) {
452 			netdev_err(netdev,
453 				   "Unexpected out of range echo id %u\n",
454 				   hf->echo_id);
455 			goto resubmit_urb;
456 		}
457 
458 		txc = gs_get_tx_context(dev, hf->echo_id);
459 
460 		/* bad devices send bad echo_ids. */
461 		if (!txc) {
462 			netdev_err(netdev,
463 				   "Unexpected unused echo id %u\n",
464 				   hf->echo_id);
465 			goto resubmit_urb;
466 		}
467 
468 		netdev->stats.tx_packets++;
469 		netdev->stats.tx_bytes += can_get_echo_skb(netdev, hf->echo_id,
470 							   NULL);
471 
472 		gs_free_tx_context(txc);
473 
474 		atomic_dec(&dev->active_tx_urbs);
475 
476 		netif_wake_queue(netdev);
477 	}
478 
479 	if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
480 		skb = alloc_can_err_skb(netdev, &cf);
481 		if (!skb)
482 			goto resubmit_urb;
483 
484 		cf->can_id |= CAN_ERR_CRTL;
485 		cf->len = CAN_ERR_DLC;
486 		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
487 		stats->rx_over_errors++;
488 		stats->rx_errors++;
489 		netif_rx(skb);
490 	}
491 
492  resubmit_urb:
493 	usb_fill_bulk_urb(urb, usbcan->udev,
494 			  usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
495 			  hf, dev->parent->hf_size_rx,
496 			  gs_usb_receive_bulk_callback, usbcan);
497 
498 	rc = usb_submit_urb(urb, GFP_ATOMIC);
499 
500 	/* USB failure take down all interfaces */
501 	if (rc == -ENODEV) {
502  device_detach:
503 		for (rc = 0; rc < GS_MAX_INTF; rc++) {
504 			if (usbcan->canch[rc])
505 				netif_device_detach(usbcan->canch[rc]->netdev);
506 		}
507 	}
508 }
509 
510 static int gs_usb_set_bittiming(struct net_device *netdev)
511 {
512 	struct gs_can *dev = netdev_priv(netdev);
513 	struct can_bittiming *bt = &dev->can.bittiming;
514 	struct usb_interface *intf = dev->iface;
515 	int rc;
516 	struct gs_device_bittiming *dbt;
517 
518 	dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
519 	if (!dbt)
520 		return -ENOMEM;
521 
522 	dbt->prop_seg = cpu_to_le32(bt->prop_seg);
523 	dbt->phase_seg1 = cpu_to_le32(bt->phase_seg1);
524 	dbt->phase_seg2 = cpu_to_le32(bt->phase_seg2);
525 	dbt->sjw = cpu_to_le32(bt->sjw);
526 	dbt->brp = cpu_to_le32(bt->brp);
527 
528 	/* request bit timings */
529 	rc = usb_control_msg(interface_to_usbdev(intf),
530 			     usb_sndctrlpipe(interface_to_usbdev(intf), 0),
531 			     GS_USB_BREQ_BITTIMING,
532 			     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
533 			     dev->channel, 0, dbt, sizeof(*dbt), 1000);
534 
535 	kfree(dbt);
536 
537 	if (rc < 0)
538 		dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
539 			rc);
540 
541 	return (rc > 0) ? 0 : rc;
542 }
543 
544 static int gs_usb_set_data_bittiming(struct net_device *netdev)
545 {
546 	struct gs_can *dev = netdev_priv(netdev);
547 	struct can_bittiming *bt = &dev->can.data_bittiming;
548 	struct usb_interface *intf = dev->iface;
549 	struct gs_device_bittiming *dbt;
550 	u8 request = GS_USB_BREQ_DATA_BITTIMING;
551 	int rc;
552 
553 	dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
554 	if (!dbt)
555 		return -ENOMEM;
556 
557 	dbt->prop_seg = cpu_to_le32(bt->prop_seg);
558 	dbt->phase_seg1 = cpu_to_le32(bt->phase_seg1);
559 	dbt->phase_seg2 = cpu_to_le32(bt->phase_seg2);
560 	dbt->sjw = cpu_to_le32(bt->sjw);
561 	dbt->brp = cpu_to_le32(bt->brp);
562 
563 	if (dev->feature & GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO)
564 		request = GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING;
565 
566 	/* request bit timings */
567 	rc = usb_control_msg(interface_to_usbdev(intf),
568 			     usb_sndctrlpipe(interface_to_usbdev(intf), 0),
569 			     request,
570 			     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
571 			     dev->channel, 0, dbt, sizeof(*dbt), 1000);
572 
573 	kfree(dbt);
574 
575 	if (rc < 0)
576 		dev_err(netdev->dev.parent,
577 			"Couldn't set data bittimings (err=%d)", rc);
578 
579 	return (rc > 0) ? 0 : rc;
580 }
581 
582 static void gs_usb_xmit_callback(struct urb *urb)
583 {
584 	struct gs_tx_context *txc = urb->context;
585 	struct gs_can *dev = txc->dev;
586 	struct net_device *netdev = dev->netdev;
587 
588 	if (urb->status)
589 		netdev_info(netdev, "usb xmit fail %u\n", txc->echo_id);
590 
591 	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
592 			  urb->transfer_buffer, urb->transfer_dma);
593 }
594 
595 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
596 				     struct net_device *netdev)
597 {
598 	struct gs_can *dev = netdev_priv(netdev);
599 	struct net_device_stats *stats = &dev->netdev->stats;
600 	struct urb *urb;
601 	struct gs_host_frame *hf;
602 	struct can_frame *cf;
603 	struct canfd_frame *cfd;
604 	int rc;
605 	unsigned int idx;
606 	struct gs_tx_context *txc;
607 
608 	if (can_dropped_invalid_skb(netdev, skb))
609 		return NETDEV_TX_OK;
610 
611 	/* find an empty context to keep track of transmission */
612 	txc = gs_alloc_tx_context(dev);
613 	if (!txc)
614 		return NETDEV_TX_BUSY;
615 
616 	/* create a URB, and a buffer for it */
617 	urb = usb_alloc_urb(0, GFP_ATOMIC);
618 	if (!urb)
619 		goto nomem_urb;
620 
621 	hf = usb_alloc_coherent(dev->udev, dev->hf_size_tx, GFP_ATOMIC,
622 				&urb->transfer_dma);
623 	if (!hf) {
624 		netdev_err(netdev, "No memory left for USB buffer\n");
625 		goto nomem_hf;
626 	}
627 
628 	idx = txc->echo_id;
629 
630 	if (idx >= GS_MAX_TX_URBS) {
631 		netdev_err(netdev, "Invalid tx context %u\n", idx);
632 		goto badidx;
633 	}
634 
635 	hf->echo_id = idx;
636 	hf->channel = dev->channel;
637 	hf->flags = 0;
638 	hf->reserved = 0;
639 
640 	if (can_is_canfd_skb(skb)) {
641 		cfd = (struct canfd_frame *)skb->data;
642 
643 		hf->can_id = cpu_to_le32(cfd->can_id);
644 		hf->can_dlc = can_fd_len2dlc(cfd->len);
645 		hf->flags |= GS_CAN_FLAG_FD;
646 		if (cfd->flags & CANFD_BRS)
647 			hf->flags |= GS_CAN_FLAG_BRS;
648 		if (cfd->flags & CANFD_ESI)
649 			hf->flags |= GS_CAN_FLAG_ESI;
650 
651 		memcpy(hf->canfd->data, cfd->data, cfd->len);
652 	} else {
653 		cf = (struct can_frame *)skb->data;
654 
655 		hf->can_id = cpu_to_le32(cf->can_id);
656 		hf->can_dlc = can_get_cc_dlc(cf, dev->can.ctrlmode);
657 
658 		memcpy(hf->classic_can->data, cf->data, cf->len);
659 	}
660 
661 	usb_fill_bulk_urb(urb, dev->udev,
662 			  usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
663 			  hf, dev->hf_size_tx,
664 			  gs_usb_xmit_callback, txc);
665 
666 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
667 	usb_anchor_urb(urb, &dev->tx_submitted);
668 
669 	can_put_echo_skb(skb, netdev, idx, 0);
670 
671 	atomic_inc(&dev->active_tx_urbs);
672 
673 	rc = usb_submit_urb(urb, GFP_ATOMIC);
674 	if (unlikely(rc)) {			/* usb send failed */
675 		atomic_dec(&dev->active_tx_urbs);
676 
677 		can_free_echo_skb(netdev, idx, NULL);
678 		gs_free_tx_context(txc);
679 
680 		usb_unanchor_urb(urb);
681 		usb_free_coherent(dev->udev, urb->transfer_buffer_length,
682 				  urb->transfer_buffer, urb->transfer_dma);
683 
684 		if (rc == -ENODEV) {
685 			netif_device_detach(netdev);
686 		} else {
687 			netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
688 			stats->tx_dropped++;
689 		}
690 	} else {
691 		/* Slow down tx path */
692 		if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
693 			netif_stop_queue(netdev);
694 	}
695 
696 	/* let usb core take care of this urb */
697 	usb_free_urb(urb);
698 
699 	return NETDEV_TX_OK;
700 
701  badidx:
702 	usb_free_coherent(dev->udev, urb->transfer_buffer_length,
703 			  urb->transfer_buffer, urb->transfer_dma);
704  nomem_hf:
705 	usb_free_urb(urb);
706 
707  nomem_urb:
708 	gs_free_tx_context(txc);
709 	dev_kfree_skb(skb);
710 	stats->tx_dropped++;
711 	return NETDEV_TX_OK;
712 }
713 
714 static int gs_can_open(struct net_device *netdev)
715 {
716 	struct gs_can *dev = netdev_priv(netdev);
717 	struct gs_usb *parent = dev->parent;
718 	int rc, i;
719 	struct gs_device_mode *dm;
720 	struct gs_host_frame *hf;
721 	u32 ctrlmode;
722 	u32 flags = 0;
723 
724 	rc = open_candev(netdev);
725 	if (rc)
726 		return rc;
727 
728 	ctrlmode = dev->can.ctrlmode;
729 	if (ctrlmode & CAN_CTRLMODE_FD) {
730 		flags |= GS_CAN_MODE_FD;
731 
732 		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
733 			dev->hf_size_tx = struct_size(hf, canfd_quirk, 1);
734 		else
735 			dev->hf_size_tx = struct_size(hf, canfd, 1);
736 	} else {
737 		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
738 			dev->hf_size_tx = struct_size(hf, classic_can_quirk, 1);
739 		else
740 			dev->hf_size_tx = struct_size(hf, classic_can, 1);
741 	}
742 
743 	if (!parent->active_channels) {
744 		for (i = 0; i < GS_MAX_RX_URBS; i++) {
745 			struct urb *urb;
746 			u8 *buf;
747 			dma_addr_t buf_dma;
748 
749 			/* alloc rx urb */
750 			urb = usb_alloc_urb(0, GFP_KERNEL);
751 			if (!urb)
752 				return -ENOMEM;
753 
754 			/* alloc rx buffer */
755 			buf = usb_alloc_coherent(dev->udev,
756 						 dev->parent->hf_size_rx,
757 						 GFP_KERNEL,
758 						 &buf_dma);
759 			if (!buf) {
760 				netdev_err(netdev,
761 					   "No memory left for USB buffer\n");
762 				usb_free_urb(urb);
763 				return -ENOMEM;
764 			}
765 
766 			urb->transfer_dma = buf_dma;
767 
768 			/* fill, anchor, and submit rx urb */
769 			usb_fill_bulk_urb(urb,
770 					  dev->udev,
771 					  usb_rcvbulkpipe(dev->udev,
772 							  GSUSB_ENDPOINT_IN),
773 					  buf,
774 					  dev->parent->hf_size_rx,
775 					  gs_usb_receive_bulk_callback, parent);
776 			urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
777 
778 			usb_anchor_urb(urb, &parent->rx_submitted);
779 
780 			rc = usb_submit_urb(urb, GFP_KERNEL);
781 			if (rc) {
782 				if (rc == -ENODEV)
783 					netif_device_detach(dev->netdev);
784 
785 				netdev_err(netdev,
786 					   "usb_submit failed (err=%d)\n", rc);
787 
788 				usb_unanchor_urb(urb);
789 				usb_free_coherent(dev->udev,
790 						  sizeof(struct gs_host_frame),
791 						  buf,
792 						  buf_dma);
793 				usb_free_urb(urb);
794 				break;
795 			}
796 
797 			dev->rxbuf[i] = buf;
798 			dev->rxbuf_dma[i] = buf_dma;
799 
800 			/* Drop reference,
801 			 * USB core will take care of freeing it
802 			 */
803 			usb_free_urb(urb);
804 		}
805 	}
806 
807 	dm = kmalloc(sizeof(*dm), GFP_KERNEL);
808 	if (!dm)
809 		return -ENOMEM;
810 
811 	/* flags */
812 	if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
813 		flags |= GS_CAN_MODE_LOOP_BACK;
814 	else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
815 		flags |= GS_CAN_MODE_LISTEN_ONLY;
816 
817 	/* Controller is not allowed to retry TX
818 	 * this mode is unavailable on atmels uc3c hardware
819 	 */
820 	if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
821 		flags |= GS_CAN_MODE_ONE_SHOT;
822 
823 	if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
824 		flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
825 
826 	/* finally start device */
827 	dm->mode = cpu_to_le32(GS_CAN_MODE_START);
828 	dm->flags = cpu_to_le32(flags);
829 	rc = usb_control_msg(interface_to_usbdev(dev->iface),
830 			     usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
831 			     GS_USB_BREQ_MODE,
832 			     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
833 			     dev->channel, 0, dm, sizeof(*dm), 1000);
834 
835 	if (rc < 0) {
836 		netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
837 		kfree(dm);
838 		return rc;
839 	}
840 
841 	kfree(dm);
842 
843 	dev->can.state = CAN_STATE_ERROR_ACTIVE;
844 
845 	parent->active_channels++;
846 	if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
847 		netif_start_queue(netdev);
848 
849 	return 0;
850 }
851 
852 static int gs_can_close(struct net_device *netdev)
853 {
854 	int rc;
855 	struct gs_can *dev = netdev_priv(netdev);
856 	struct gs_usb *parent = dev->parent;
857 	unsigned int i;
858 
859 	netif_stop_queue(netdev);
860 
861 	/* Stop polling */
862 	parent->active_channels--;
863 	if (!parent->active_channels) {
864 		usb_kill_anchored_urbs(&parent->rx_submitted);
865 		for (i = 0; i < GS_MAX_RX_URBS; i++)
866 			usb_free_coherent(dev->udev,
867 					  sizeof(struct gs_host_frame),
868 					  dev->rxbuf[i],
869 					  dev->rxbuf_dma[i]);
870 	}
871 
872 	/* Stop sending URBs */
873 	usb_kill_anchored_urbs(&dev->tx_submitted);
874 	atomic_set(&dev->active_tx_urbs, 0);
875 
876 	/* reset the device */
877 	rc = gs_cmd_reset(dev);
878 	if (rc < 0)
879 		netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
880 
881 	/* reset tx contexts */
882 	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
883 		dev->tx_context[rc].dev = dev;
884 		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
885 	}
886 
887 	/* close the netdev */
888 	close_candev(netdev);
889 
890 	return 0;
891 }
892 
893 static const struct net_device_ops gs_usb_netdev_ops = {
894 	.ndo_open = gs_can_open,
895 	.ndo_stop = gs_can_close,
896 	.ndo_start_xmit = gs_can_start_xmit,
897 	.ndo_change_mtu = can_change_mtu,
898 };
899 
900 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
901 {
902 	struct gs_can *dev = netdev_priv(netdev);
903 	struct gs_identify_mode *imode;
904 	int rc;
905 
906 	imode = kmalloc(sizeof(*imode), GFP_KERNEL);
907 
908 	if (!imode)
909 		return -ENOMEM;
910 
911 	if (do_identify)
912 		imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
913 	else
914 		imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
915 
916 	rc = usb_control_msg(interface_to_usbdev(dev->iface),
917 			     usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
918 			     GS_USB_BREQ_IDENTIFY,
919 			     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
920 			     dev->channel, 0, imode, sizeof(*imode), 100);
921 
922 	kfree(imode);
923 
924 	return (rc > 0) ? 0 : rc;
925 }
926 
927 /* blink LED's for finding the this interface */
928 static int gs_usb_set_phys_id(struct net_device *dev,
929 			      enum ethtool_phys_id_state state)
930 {
931 	int rc = 0;
932 
933 	switch (state) {
934 	case ETHTOOL_ID_ACTIVE:
935 		rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
936 		break;
937 	case ETHTOOL_ID_INACTIVE:
938 		rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
939 		break;
940 	default:
941 		break;
942 	}
943 
944 	return rc;
945 }
946 
947 static const struct ethtool_ops gs_usb_ethtool_ops = {
948 	.set_phys_id = gs_usb_set_phys_id,
949 	.get_ts_info = ethtool_op_get_ts_info,
950 };
951 
952 static struct gs_can *gs_make_candev(unsigned int channel,
953 				     struct usb_interface *intf,
954 				     struct gs_device_config *dconf)
955 {
956 	struct gs_can *dev;
957 	struct net_device *netdev;
958 	int rc;
959 	struct gs_device_bt_const *bt_const;
960 	struct gs_device_bt_const_extended *bt_const_extended;
961 	u32 feature;
962 
963 	bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
964 	if (!bt_const)
965 		return ERR_PTR(-ENOMEM);
966 
967 	/* fetch bit timing constants */
968 	rc = usb_control_msg(interface_to_usbdev(intf),
969 			     usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
970 			     GS_USB_BREQ_BT_CONST,
971 			     USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
972 			     channel, 0, bt_const, sizeof(*bt_const), 1000);
973 
974 	if (rc < 0) {
975 		dev_err(&intf->dev,
976 			"Couldn't get bit timing const for channel (err=%d)\n",
977 			rc);
978 		kfree(bt_const);
979 		return ERR_PTR(rc);
980 	}
981 
982 	/* create netdev */
983 	netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
984 	if (!netdev) {
985 		dev_err(&intf->dev, "Couldn't allocate candev\n");
986 		kfree(bt_const);
987 		return ERR_PTR(-ENOMEM);
988 	}
989 
990 	dev = netdev_priv(netdev);
991 
992 	netdev->netdev_ops = &gs_usb_netdev_ops;
993 	netdev->ethtool_ops = &gs_usb_ethtool_ops;
994 
995 	netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
996 
997 	/* dev setup */
998 	strcpy(dev->bt_const.name, KBUILD_MODNAME);
999 	dev->bt_const.tseg1_min = le32_to_cpu(bt_const->tseg1_min);
1000 	dev->bt_const.tseg1_max = le32_to_cpu(bt_const->tseg1_max);
1001 	dev->bt_const.tseg2_min = le32_to_cpu(bt_const->tseg2_min);
1002 	dev->bt_const.tseg2_max = le32_to_cpu(bt_const->tseg2_max);
1003 	dev->bt_const.sjw_max = le32_to_cpu(bt_const->sjw_max);
1004 	dev->bt_const.brp_min = le32_to_cpu(bt_const->brp_min);
1005 	dev->bt_const.brp_max = le32_to_cpu(bt_const->brp_max);
1006 	dev->bt_const.brp_inc = le32_to_cpu(bt_const->brp_inc);
1007 
1008 	dev->udev = interface_to_usbdev(intf);
1009 	dev->iface = intf;
1010 	dev->netdev = netdev;
1011 	dev->channel = channel;
1012 
1013 	init_usb_anchor(&dev->tx_submitted);
1014 	atomic_set(&dev->active_tx_urbs, 0);
1015 	spin_lock_init(&dev->tx_ctx_lock);
1016 	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
1017 		dev->tx_context[rc].dev = dev;
1018 		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
1019 	}
1020 
1021 	/* can setup */
1022 	dev->can.state = CAN_STATE_STOPPED;
1023 	dev->can.clock.freq = le32_to_cpu(bt_const->fclk_can);
1024 	dev->can.bittiming_const = &dev->bt_const;
1025 	dev->can.do_set_bittiming = gs_usb_set_bittiming;
1026 
1027 	dev->can.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC;
1028 
1029 	feature = le32_to_cpu(bt_const->feature);
1030 	dev->feature = FIELD_GET(GS_CAN_FEATURE_MASK, feature);
1031 	if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
1032 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
1033 
1034 	if (feature & GS_CAN_FEATURE_LOOP_BACK)
1035 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
1036 
1037 	if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
1038 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1039 
1040 	if (feature & GS_CAN_FEATURE_ONE_SHOT)
1041 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
1042 
1043 	if (feature & GS_CAN_FEATURE_FD) {
1044 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
1045 		/* The data bit timing will be overwritten, if
1046 		 * GS_CAN_FEATURE_BT_CONST_EXT is set.
1047 		 */
1048 		dev->can.data_bittiming_const = &dev->bt_const;
1049 		dev->can.do_set_data_bittiming = gs_usb_set_data_bittiming;
1050 	}
1051 
1052 	/* The CANtact Pro from LinkLayer Labs is based on the
1053 	 * LPC54616 µC, which is affected by the NXP LPC USB transfer
1054 	 * erratum. However, the current firmware (version 2) doesn't
1055 	 * set the GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX bit. Set the
1056 	 * feature GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX to workaround
1057 	 * this issue.
1058 	 *
1059 	 * For the GS_USB_BREQ_DATA_BITTIMING USB control message the
1060 	 * CANtact Pro firmware uses a request value, which is already
1061 	 * used by the candleLight firmware for a different purpose
1062 	 * (GS_USB_BREQ_GET_USER_ID). Set the feature
1063 	 * GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO to workaround this
1064 	 * issue.
1065 	 */
1066 	if (dev->udev->descriptor.idVendor == cpu_to_le16(USB_GSUSB_1_VENDOR_ID) &&
1067 	    dev->udev->descriptor.idProduct == cpu_to_le16(USB_GSUSB_1_PRODUCT_ID) &&
1068 	    dev->udev->manufacturer && dev->udev->product &&
1069 	    !strcmp(dev->udev->manufacturer, "LinkLayer Labs") &&
1070 	    !strcmp(dev->udev->product, "CANtact Pro") &&
1071 	    (le32_to_cpu(dconf->sw_version) <= 2))
1072 		dev->feature |= GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX |
1073 			GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO;
1074 
1075 	if (le32_to_cpu(dconf->sw_version) > 1)
1076 		if (feature & GS_CAN_FEATURE_IDENTIFY)
1077 			netdev->ethtool_ops = &gs_usb_ethtool_ops;
1078 
1079 	kfree(bt_const);
1080 
1081 	/* fetch extended bit timing constants if device has feature
1082 	 * GS_CAN_FEATURE_FD and GS_CAN_FEATURE_BT_CONST_EXT
1083 	 */
1084 	if (feature & GS_CAN_FEATURE_FD &&
1085 	    feature & GS_CAN_FEATURE_BT_CONST_EXT) {
1086 		bt_const_extended = kmalloc(sizeof(*bt_const_extended), GFP_KERNEL);
1087 		if (!bt_const_extended)
1088 			return ERR_PTR(-ENOMEM);
1089 
1090 		rc = usb_control_msg(interface_to_usbdev(intf),
1091 				     usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
1092 				     GS_USB_BREQ_BT_CONST_EXT,
1093 				     USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1094 				     channel, 0, bt_const_extended,
1095 				     sizeof(*bt_const_extended),
1096 				     1000);
1097 		if (rc < 0) {
1098 			dev_err(&intf->dev,
1099 				"Couldn't get extended bit timing const for channel (err=%d)\n",
1100 				rc);
1101 			kfree(bt_const_extended);
1102 			return ERR_PTR(rc);
1103 		}
1104 
1105 		strcpy(dev->data_bt_const.name, KBUILD_MODNAME);
1106 		dev->data_bt_const.tseg1_min = le32_to_cpu(bt_const_extended->dtseg1_min);
1107 		dev->data_bt_const.tseg1_max = le32_to_cpu(bt_const_extended->dtseg1_max);
1108 		dev->data_bt_const.tseg2_min = le32_to_cpu(bt_const_extended->dtseg2_min);
1109 		dev->data_bt_const.tseg2_max = le32_to_cpu(bt_const_extended->dtseg2_max);
1110 		dev->data_bt_const.sjw_max = le32_to_cpu(bt_const_extended->dsjw_max);
1111 		dev->data_bt_const.brp_min = le32_to_cpu(bt_const_extended->dbrp_min);
1112 		dev->data_bt_const.brp_max = le32_to_cpu(bt_const_extended->dbrp_max);
1113 		dev->data_bt_const.brp_inc = le32_to_cpu(bt_const_extended->dbrp_inc);
1114 
1115 		dev->can.data_bittiming_const = &dev->data_bt_const;
1116 
1117 		kfree(bt_const_extended);
1118 	}
1119 
1120 	SET_NETDEV_DEV(netdev, &intf->dev);
1121 
1122 	rc = register_candev(dev->netdev);
1123 	if (rc) {
1124 		free_candev(dev->netdev);
1125 		dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
1126 		return ERR_PTR(rc);
1127 	}
1128 
1129 	return dev;
1130 }
1131 
1132 static void gs_destroy_candev(struct gs_can *dev)
1133 {
1134 	unregister_candev(dev->netdev);
1135 	usb_kill_anchored_urbs(&dev->tx_submitted);
1136 	free_candev(dev->netdev);
1137 }
1138 
1139 static int gs_usb_probe(struct usb_interface *intf,
1140 			const struct usb_device_id *id)
1141 {
1142 	struct usb_device *udev = interface_to_usbdev(intf);
1143 	struct gs_host_frame *hf;
1144 	struct gs_usb *dev;
1145 	int rc = -ENOMEM;
1146 	unsigned int icount, i;
1147 	struct gs_host_config *hconf;
1148 	struct gs_device_config *dconf;
1149 
1150 	hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
1151 	if (!hconf)
1152 		return -ENOMEM;
1153 
1154 	hconf->byte_order = cpu_to_le32(0x0000beef);
1155 
1156 	/* send host config */
1157 	rc = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1158 			     GS_USB_BREQ_HOST_FORMAT,
1159 			     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1160 			     1, intf->cur_altsetting->desc.bInterfaceNumber,
1161 			     hconf, sizeof(*hconf), 1000);
1162 
1163 	kfree(hconf);
1164 
1165 	if (rc < 0) {
1166 		dev_err(&intf->dev, "Couldn't send data format (err=%d)\n", rc);
1167 		return rc;
1168 	}
1169 
1170 	dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
1171 	if (!dconf)
1172 		return -ENOMEM;
1173 
1174 	/* read device config */
1175 	rc = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
1176 			     GS_USB_BREQ_DEVICE_CONFIG,
1177 			     USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
1178 			     1, intf->cur_altsetting->desc.bInterfaceNumber,
1179 			     dconf, sizeof(*dconf), 1000);
1180 	if (rc < 0) {
1181 		dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
1182 			rc);
1183 		kfree(dconf);
1184 		return rc;
1185 	}
1186 
1187 	icount = dconf->icount + 1;
1188 	dev_info(&intf->dev, "Configuring for %u interfaces\n", icount);
1189 
1190 	if (icount > GS_MAX_INTF) {
1191 		dev_err(&intf->dev,
1192 			"Driver cannot handle more that %u CAN interfaces\n",
1193 			GS_MAX_INTF);
1194 		kfree(dconf);
1195 		return -EINVAL;
1196 	}
1197 
1198 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1199 	if (!dev) {
1200 		kfree(dconf);
1201 		return -ENOMEM;
1202 	}
1203 
1204 	init_usb_anchor(&dev->rx_submitted);
1205 	/* default to classic CAN, switch to CAN-FD if at least one of
1206 	 * our channels support CAN-FD.
1207 	 */
1208 	dev->hf_size_rx = struct_size(hf, classic_can, 1);
1209 
1210 	usb_set_intfdata(intf, dev);
1211 	dev->udev = udev;
1212 
1213 	for (i = 0; i < icount; i++) {
1214 		dev->canch[i] = gs_make_candev(i, intf, dconf);
1215 		if (IS_ERR_OR_NULL(dev->canch[i])) {
1216 			/* save error code to return later */
1217 			rc = PTR_ERR(dev->canch[i]);
1218 
1219 			/* on failure destroy previously created candevs */
1220 			icount = i;
1221 			for (i = 0; i < icount; i++)
1222 				gs_destroy_candev(dev->canch[i]);
1223 
1224 			usb_kill_anchored_urbs(&dev->rx_submitted);
1225 			kfree(dconf);
1226 			kfree(dev);
1227 			return rc;
1228 		}
1229 		dev->canch[i]->parent = dev;
1230 
1231 		if (dev->canch[i]->can.ctrlmode_supported & CAN_CTRLMODE_FD)
1232 			dev->hf_size_rx = struct_size(hf, canfd, 1);
1233 	}
1234 
1235 	kfree(dconf);
1236 
1237 	return 0;
1238 }
1239 
1240 static void gs_usb_disconnect(struct usb_interface *intf)
1241 {
1242 	struct gs_usb *dev = usb_get_intfdata(intf);
1243 	unsigned int i;
1244 
1245 	usb_set_intfdata(intf, NULL);
1246 
1247 	if (!dev) {
1248 		dev_err(&intf->dev, "Disconnect (nodata)\n");
1249 		return;
1250 	}
1251 
1252 	for (i = 0; i < GS_MAX_INTF; i++)
1253 		if (dev->canch[i])
1254 			gs_destroy_candev(dev->canch[i]);
1255 
1256 	usb_kill_anchored_urbs(&dev->rx_submitted);
1257 	kfree(dev);
1258 }
1259 
1260 static const struct usb_device_id gs_usb_table[] = {
1261 	{ USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1262 				      USB_GSUSB_1_PRODUCT_ID, 0) },
1263 	{ USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1264 				      USB_CANDLELIGHT_PRODUCT_ID, 0) },
1265 	{ USB_DEVICE_INTERFACE_NUMBER(USB_CES_CANEXT_FD_VENDOR_ID,
1266 				      USB_CES_CANEXT_FD_PRODUCT_ID, 0) },
1267 	{ USB_DEVICE_INTERFACE_NUMBER(USB_ABE_CANDEBUGGER_FD_VENDOR_ID,
1268 				      USB_ABE_CANDEBUGGER_FD_PRODUCT_ID, 0) },
1269 	{} /* Terminating entry */
1270 };
1271 
1272 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1273 
1274 static struct usb_driver gs_usb_driver = {
1275 	.name = KBUILD_MODNAME,
1276 	.probe = gs_usb_probe,
1277 	.disconnect = gs_usb_disconnect,
1278 	.id_table = gs_usb_table,
1279 };
1280 
1281 module_usb_driver(gs_usb_driver);
1282 
1283 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1284 MODULE_DESCRIPTION(
1285 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1286 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1287 "and bytewerk.org candleLight USB CAN interfaces.");
1288 MODULE_LICENSE("GPL v2");
1289