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