1 /* CAN driver for Geschwister Schneider USB/CAN devices
2 * and bytewerk.org candleLight USB CAN interfaces.
3 *
4 * Copyright (C) 2013-2016 Geschwister Schneider Technologie-,
5 * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
6 * Copyright (C) 2016 Hubert Denkmair
7 *
8 * Many thanks to all socketcan devs!
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published
12 * by the Free Software Foundation; version 2 of the License.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 */
19
20 #include <linux/init.h>
21 #include <linux/signal.h>
22 #include <linux/module.h>
23 #include <linux/netdevice.h>
24 #include <linux/usb.h>
25
26 #include <linux/can.h>
27 #include <linux/can/dev.h>
28 #include <linux/can/error.h>
29
30 /* Device specific constants */
31 #define USB_GSUSB_1_VENDOR_ID 0x1d50
32 #define USB_GSUSB_1_PRODUCT_ID 0x606f
33
34 #define USB_CANDLELIGHT_VENDOR_ID 0x1209
35 #define USB_CANDLELIGHT_PRODUCT_ID 0x2323
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 };
51
52 enum gs_can_mode {
53 /* reset a channel. turns it off */
54 GS_CAN_MODE_RESET = 0,
55 /* starts a channel */
56 GS_CAN_MODE_START
57 };
58
59 enum gs_can_state {
60 GS_CAN_STATE_ERROR_ACTIVE = 0,
61 GS_CAN_STATE_ERROR_WARNING,
62 GS_CAN_STATE_ERROR_PASSIVE,
63 GS_CAN_STATE_BUS_OFF,
64 GS_CAN_STATE_STOPPED,
65 GS_CAN_STATE_SLEEPING
66 };
67
68 enum gs_can_identify_mode {
69 GS_CAN_IDENTIFY_OFF = 0,
70 GS_CAN_IDENTIFY_ON
71 };
72
73 /* data types passed between host and device */
74 struct gs_host_config {
75 u32 byte_order;
76 } __packed;
77 /* All data exchanged between host and device is exchanged in host byte order,
78 * thanks to the struct gs_host_config byte_order member, which is sent first
79 * to indicate the desired byte order.
80 */
81
82 struct gs_device_config {
83 u8 reserved1;
84 u8 reserved2;
85 u8 reserved3;
86 u8 icount;
87 u32 sw_version;
88 u32 hw_version;
89 } __packed;
90
91 #define GS_CAN_MODE_NORMAL 0
92 #define GS_CAN_MODE_LISTEN_ONLY BIT(0)
93 #define GS_CAN_MODE_LOOP_BACK BIT(1)
94 #define GS_CAN_MODE_TRIPLE_SAMPLE BIT(2)
95 #define GS_CAN_MODE_ONE_SHOT BIT(3)
96
97 struct gs_device_mode {
98 u32 mode;
99 u32 flags;
100 } __packed;
101
102 struct gs_device_state {
103 u32 state;
104 u32 rxerr;
105 u32 txerr;
106 } __packed;
107
108 struct gs_device_bittiming {
109 u32 prop_seg;
110 u32 phase_seg1;
111 u32 phase_seg2;
112 u32 sjw;
113 u32 brp;
114 } __packed;
115
116 struct gs_identify_mode {
117 u32 mode;
118 } __packed;
119
120 #define GS_CAN_FEATURE_LISTEN_ONLY BIT(0)
121 #define GS_CAN_FEATURE_LOOP_BACK BIT(1)
122 #define GS_CAN_FEATURE_TRIPLE_SAMPLE BIT(2)
123 #define GS_CAN_FEATURE_ONE_SHOT BIT(3)
124 #define GS_CAN_FEATURE_HW_TIMESTAMP BIT(4)
125 #define GS_CAN_FEATURE_IDENTIFY BIT(5)
126
127 struct gs_device_bt_const {
128 u32 feature;
129 u32 fclk_can;
130 u32 tseg1_min;
131 u32 tseg1_max;
132 u32 tseg2_min;
133 u32 tseg2_max;
134 u32 sjw_max;
135 u32 brp_min;
136 u32 brp_max;
137 u32 brp_inc;
138 } __packed;
139
140 #define GS_CAN_FLAG_OVERFLOW 1
141
142 struct gs_host_frame {
143 u32 echo_id;
144 u32 can_id;
145
146 u8 can_dlc;
147 u8 channel;
148 u8 flags;
149 u8 reserved;
150
151 u8 data[8];
152 } __packed;
153 /* The GS USB devices make use of the same flags and masks as in
154 * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
155 */
156
157 /* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
158 #define GS_MAX_TX_URBS 10
159 /* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
160 #define GS_MAX_RX_URBS 30
161 /* Maximum number of interfaces the driver supports per device.
162 * Current hardware only supports 2 interfaces. The future may vary.
163 */
164 #define GS_MAX_INTF 2
165
166 struct gs_tx_context {
167 struct gs_can *dev;
168 unsigned int echo_id;
169 };
170
171 struct gs_can {
172 struct can_priv can; /* must be the first member */
173
174 struct gs_usb *parent;
175
176 struct net_device *netdev;
177 struct usb_device *udev;
178 struct usb_interface *iface;
179
180 struct can_bittiming_const bt_const;
181 unsigned int channel; /* channel number */
182
183 /* This lock prevents a race condition between xmit and receive. */
184 spinlock_t tx_ctx_lock;
185 struct gs_tx_context tx_context[GS_MAX_TX_URBS];
186
187 struct usb_anchor tx_submitted;
188 atomic_t active_tx_urbs;
189 };
190
191 /* usb interface struct */
192 struct gs_usb {
193 struct gs_can *canch[GS_MAX_INTF];
194 struct usb_anchor rx_submitted;
195 atomic_t active_channels;
196 struct usb_device *udev;
197 };
198
199 /* 'allocate' a tx context.
200 * returns a valid tx context or NULL if there is no space.
201 */
gs_alloc_tx_context(struct gs_can * dev)202 static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
203 {
204 int i = 0;
205 unsigned long flags;
206
207 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
208
209 for (; i < GS_MAX_TX_URBS; i++) {
210 if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
211 dev->tx_context[i].echo_id = i;
212 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
213 return &dev->tx_context[i];
214 }
215 }
216
217 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
218 return NULL;
219 }
220
221 /* releases a tx context
222 */
gs_free_tx_context(struct gs_tx_context * txc)223 static void gs_free_tx_context(struct gs_tx_context *txc)
224 {
225 txc->echo_id = GS_MAX_TX_URBS;
226 }
227
228 /* Get a tx context by id.
229 */
gs_get_tx_context(struct gs_can * dev,unsigned int id)230 static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
231 unsigned int id)
232 {
233 unsigned long flags;
234
235 if (id < GS_MAX_TX_URBS) {
236 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
237 if (dev->tx_context[id].echo_id == id) {
238 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
239 return &dev->tx_context[id];
240 }
241 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
242 }
243 return NULL;
244 }
245
gs_cmd_reset(struct gs_usb * gsusb,struct gs_can * gsdev)246 static int gs_cmd_reset(struct gs_usb *gsusb, struct gs_can *gsdev)
247 {
248 struct gs_device_mode *dm;
249 struct usb_interface *intf = gsdev->iface;
250 int rc;
251
252 dm = kzalloc(sizeof(*dm), GFP_KERNEL);
253 if (!dm)
254 return -ENOMEM;
255
256 dm->mode = GS_CAN_MODE_RESET;
257
258 rc = usb_control_msg(interface_to_usbdev(intf),
259 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
260 GS_USB_BREQ_MODE,
261 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
262 gsdev->channel,
263 0,
264 dm,
265 sizeof(*dm),
266 1000);
267
268 kfree(dm);
269
270 return rc;
271 }
272
gs_update_state(struct gs_can * dev,struct can_frame * cf)273 static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
274 {
275 struct can_device_stats *can_stats = &dev->can.can_stats;
276
277 if (cf->can_id & CAN_ERR_RESTARTED) {
278 dev->can.state = CAN_STATE_ERROR_ACTIVE;
279 can_stats->restarts++;
280 } else if (cf->can_id & CAN_ERR_BUSOFF) {
281 dev->can.state = CAN_STATE_BUS_OFF;
282 can_stats->bus_off++;
283 } else if (cf->can_id & CAN_ERR_CRTL) {
284 if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
285 (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
286 dev->can.state = CAN_STATE_ERROR_WARNING;
287 can_stats->error_warning++;
288 } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
289 (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
290 dev->can.state = CAN_STATE_ERROR_PASSIVE;
291 can_stats->error_passive++;
292 } else {
293 dev->can.state = CAN_STATE_ERROR_ACTIVE;
294 }
295 }
296 }
297
gs_usb_receive_bulk_callback(struct urb * urb)298 static void gs_usb_receive_bulk_callback(struct urb *urb)
299 {
300 struct gs_usb *usbcan = urb->context;
301 struct gs_can *dev;
302 struct net_device *netdev;
303 int rc;
304 struct net_device_stats *stats;
305 struct gs_host_frame *hf = urb->transfer_buffer;
306 struct gs_tx_context *txc;
307 struct can_frame *cf;
308 struct sk_buff *skb;
309
310 BUG_ON(!usbcan);
311
312 switch (urb->status) {
313 case 0: /* success */
314 break;
315 case -ENOENT:
316 case -ESHUTDOWN:
317 return;
318 default:
319 /* do not resubmit aborted urbs. eg: when device goes down */
320 return;
321 }
322
323 /* device reports out of range channel id */
324 if (hf->channel >= GS_MAX_INTF)
325 goto resubmit_urb;
326
327 dev = usbcan->canch[hf->channel];
328
329 netdev = dev->netdev;
330 stats = &netdev->stats;
331
332 if (!netif_device_present(netdev))
333 return;
334
335 if (hf->echo_id == -1) { /* normal rx */
336 skb = alloc_can_skb(dev->netdev, &cf);
337 if (!skb)
338 return;
339
340 cf->can_id = hf->can_id;
341
342 cf->can_dlc = get_can_dlc(hf->can_dlc);
343 memcpy(cf->data, hf->data, 8);
344
345 /* ERROR frames tell us information about the controller */
346 if (hf->can_id & CAN_ERR_FLAG)
347 gs_update_state(dev, cf);
348
349 netdev->stats.rx_packets++;
350 netdev->stats.rx_bytes += hf->can_dlc;
351
352 netif_rx(skb);
353 } else { /* echo_id == hf->echo_id */
354 if (hf->echo_id >= GS_MAX_TX_URBS) {
355 netdev_err(netdev,
356 "Unexpected out of range echo id %d\n",
357 hf->echo_id);
358 goto resubmit_urb;
359 }
360
361 netdev->stats.tx_packets++;
362 netdev->stats.tx_bytes += hf->can_dlc;
363
364 txc = gs_get_tx_context(dev, hf->echo_id);
365
366 /* bad devices send bad echo_ids. */
367 if (!txc) {
368 netdev_err(netdev,
369 "Unexpected unused echo id %d\n",
370 hf->echo_id);
371 goto resubmit_urb;
372 }
373
374 can_get_echo_skb(netdev, hf->echo_id);
375
376 gs_free_tx_context(txc);
377
378 atomic_dec(&dev->active_tx_urbs);
379
380 netif_wake_queue(netdev);
381 }
382
383 if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
384 skb = alloc_can_err_skb(netdev, &cf);
385 if (!skb)
386 goto resubmit_urb;
387
388 cf->can_id |= CAN_ERR_CRTL;
389 cf->can_dlc = CAN_ERR_DLC;
390 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
391 stats->rx_over_errors++;
392 stats->rx_errors++;
393 netif_rx(skb);
394 }
395
396 resubmit_urb:
397 usb_fill_bulk_urb(urb,
398 usbcan->udev,
399 usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
400 hf,
401 sizeof(struct gs_host_frame),
402 gs_usb_receive_bulk_callback,
403 usbcan
404 );
405
406 rc = usb_submit_urb(urb, GFP_ATOMIC);
407
408 /* USB failure take down all interfaces */
409 if (rc == -ENODEV) {
410 for (rc = 0; rc < GS_MAX_INTF; rc++) {
411 if (usbcan->canch[rc])
412 netif_device_detach(usbcan->canch[rc]->netdev);
413 }
414 }
415 }
416
gs_usb_set_bittiming(struct net_device * netdev)417 static int gs_usb_set_bittiming(struct net_device *netdev)
418 {
419 struct gs_can *dev = netdev_priv(netdev);
420 struct can_bittiming *bt = &dev->can.bittiming;
421 struct usb_interface *intf = dev->iface;
422 int rc;
423 struct gs_device_bittiming *dbt;
424
425 dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
426 if (!dbt)
427 return -ENOMEM;
428
429 dbt->prop_seg = bt->prop_seg;
430 dbt->phase_seg1 = bt->phase_seg1;
431 dbt->phase_seg2 = bt->phase_seg2;
432 dbt->sjw = bt->sjw;
433 dbt->brp = bt->brp;
434
435 /* request bit timings */
436 rc = usb_control_msg(interface_to_usbdev(intf),
437 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
438 GS_USB_BREQ_BITTIMING,
439 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
440 dev->channel,
441 0,
442 dbt,
443 sizeof(*dbt),
444 1000);
445
446 kfree(dbt);
447
448 if (rc < 0)
449 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
450 rc);
451
452 return (rc > 0) ? 0 : rc;
453 }
454
gs_usb_xmit_callback(struct urb * urb)455 static void gs_usb_xmit_callback(struct urb *urb)
456 {
457 struct gs_tx_context *txc = urb->context;
458 struct gs_can *dev = txc->dev;
459 struct net_device *netdev = dev->netdev;
460
461 if (urb->status)
462 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
463
464 usb_free_coherent(urb->dev,
465 urb->transfer_buffer_length,
466 urb->transfer_buffer,
467 urb->transfer_dma);
468 }
469
gs_can_start_xmit(struct sk_buff * skb,struct net_device * netdev)470 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
471 struct net_device *netdev)
472 {
473 struct gs_can *dev = netdev_priv(netdev);
474 struct net_device_stats *stats = &dev->netdev->stats;
475 struct urb *urb;
476 struct gs_host_frame *hf;
477 struct can_frame *cf;
478 int rc;
479 unsigned int idx;
480 struct gs_tx_context *txc;
481
482 if (can_dropped_invalid_skb(netdev, skb))
483 return NETDEV_TX_OK;
484
485 /* find an empty context to keep track of transmission */
486 txc = gs_alloc_tx_context(dev);
487 if (!txc)
488 return NETDEV_TX_BUSY;
489
490 /* create a URB, and a buffer for it */
491 urb = usb_alloc_urb(0, GFP_ATOMIC);
492 if (!urb)
493 goto nomem_urb;
494
495 hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
496 &urb->transfer_dma);
497 if (!hf) {
498 netdev_err(netdev, "No memory left for USB buffer\n");
499 goto nomem_hf;
500 }
501
502 idx = txc->echo_id;
503
504 if (idx >= GS_MAX_TX_URBS) {
505 netdev_err(netdev, "Invalid tx context %d\n", idx);
506 goto badidx;
507 }
508
509 hf->echo_id = idx;
510 hf->channel = dev->channel;
511
512 cf = (struct can_frame *)skb->data;
513
514 hf->can_id = cf->can_id;
515 hf->can_dlc = cf->can_dlc;
516 memcpy(hf->data, cf->data, cf->can_dlc);
517
518 usb_fill_bulk_urb(urb, dev->udev,
519 usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
520 hf,
521 sizeof(*hf),
522 gs_usb_xmit_callback,
523 txc);
524
525 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
526 usb_anchor_urb(urb, &dev->tx_submitted);
527
528 can_put_echo_skb(skb, netdev, idx);
529
530 atomic_inc(&dev->active_tx_urbs);
531
532 rc = usb_submit_urb(urb, GFP_ATOMIC);
533 if (unlikely(rc)) { /* usb send failed */
534 atomic_dec(&dev->active_tx_urbs);
535
536 can_free_echo_skb(netdev, idx);
537 gs_free_tx_context(txc);
538
539 usb_unanchor_urb(urb);
540 usb_free_coherent(dev->udev,
541 sizeof(*hf),
542 hf,
543 urb->transfer_dma);
544
545 if (rc == -ENODEV) {
546 netif_device_detach(netdev);
547 } else {
548 netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
549 stats->tx_dropped++;
550 }
551 } else {
552 /* Slow down tx path */
553 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
554 netif_stop_queue(netdev);
555 }
556
557 /* let usb core take care of this urb */
558 usb_free_urb(urb);
559
560 return NETDEV_TX_OK;
561
562 badidx:
563 usb_free_coherent(dev->udev,
564 sizeof(*hf),
565 hf,
566 urb->transfer_dma);
567 nomem_hf:
568 usb_free_urb(urb);
569
570 nomem_urb:
571 gs_free_tx_context(txc);
572 dev_kfree_skb(skb);
573 stats->tx_dropped++;
574 return NETDEV_TX_OK;
575 }
576
gs_can_open(struct net_device * netdev)577 static int gs_can_open(struct net_device *netdev)
578 {
579 struct gs_can *dev = netdev_priv(netdev);
580 struct gs_usb *parent = dev->parent;
581 int rc, i;
582 struct gs_device_mode *dm;
583 u32 ctrlmode;
584
585 rc = open_candev(netdev);
586 if (rc)
587 return rc;
588
589 if (atomic_add_return(1, &parent->active_channels) == 1) {
590 for (i = 0; i < GS_MAX_RX_URBS; i++) {
591 struct urb *urb;
592 u8 *buf;
593
594 /* alloc rx urb */
595 urb = usb_alloc_urb(0, GFP_KERNEL);
596 if (!urb)
597 return -ENOMEM;
598
599 /* alloc rx buffer */
600 buf = usb_alloc_coherent(dev->udev,
601 sizeof(struct gs_host_frame),
602 GFP_KERNEL,
603 &urb->transfer_dma);
604 if (!buf) {
605 netdev_err(netdev,
606 "No memory left for USB buffer\n");
607 usb_free_urb(urb);
608 return -ENOMEM;
609 }
610
611 /* fill, anchor, and submit rx urb */
612 usb_fill_bulk_urb(urb,
613 dev->udev,
614 usb_rcvbulkpipe(dev->udev,
615 GSUSB_ENDPOINT_IN),
616 buf,
617 sizeof(struct gs_host_frame),
618 gs_usb_receive_bulk_callback,
619 parent);
620 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
621
622 usb_anchor_urb(urb, &parent->rx_submitted);
623
624 rc = usb_submit_urb(urb, GFP_KERNEL);
625 if (rc) {
626 if (rc == -ENODEV)
627 netif_device_detach(dev->netdev);
628
629 netdev_err(netdev,
630 "usb_submit failed (err=%d)\n",
631 rc);
632
633 usb_unanchor_urb(urb);
634 usb_free_urb(urb);
635 break;
636 }
637
638 /* Drop reference,
639 * USB core will take care of freeing it
640 */
641 usb_free_urb(urb);
642 }
643 }
644
645 dm = kmalloc(sizeof(*dm), GFP_KERNEL);
646 if (!dm)
647 return -ENOMEM;
648
649 /* flags */
650 ctrlmode = dev->can.ctrlmode;
651 dm->flags = 0;
652
653 if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
654 dm->flags |= GS_CAN_MODE_LOOP_BACK;
655 else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
656 dm->flags |= GS_CAN_MODE_LISTEN_ONLY;
657
658 /* Controller is not allowed to retry TX
659 * this mode is unavailable on atmels uc3c hardware
660 */
661 if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
662 dm->flags |= GS_CAN_MODE_ONE_SHOT;
663
664 if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
665 dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
666
667 /* finally start device */
668 dm->mode = GS_CAN_MODE_START;
669 rc = usb_control_msg(interface_to_usbdev(dev->iface),
670 usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
671 GS_USB_BREQ_MODE,
672 USB_DIR_OUT | USB_TYPE_VENDOR |
673 USB_RECIP_INTERFACE,
674 dev->channel,
675 0,
676 dm,
677 sizeof(*dm),
678 1000);
679
680 if (rc < 0) {
681 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
682 kfree(dm);
683 return rc;
684 }
685
686 kfree(dm);
687
688 dev->can.state = CAN_STATE_ERROR_ACTIVE;
689
690 if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
691 netif_start_queue(netdev);
692
693 return 0;
694 }
695
gs_can_close(struct net_device * netdev)696 static int gs_can_close(struct net_device *netdev)
697 {
698 int rc;
699 struct gs_can *dev = netdev_priv(netdev);
700 struct gs_usb *parent = dev->parent;
701
702 netif_stop_queue(netdev);
703
704 /* Stop polling */
705 if (atomic_dec_and_test(&parent->active_channels))
706 usb_kill_anchored_urbs(&parent->rx_submitted);
707
708 /* Stop sending URBs */
709 usb_kill_anchored_urbs(&dev->tx_submitted);
710 atomic_set(&dev->active_tx_urbs, 0);
711
712 /* reset the device */
713 rc = gs_cmd_reset(parent, dev);
714 if (rc < 0)
715 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
716
717 /* reset tx contexts */
718 for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
719 dev->tx_context[rc].dev = dev;
720 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
721 }
722
723 /* close the netdev */
724 close_candev(netdev);
725
726 return 0;
727 }
728
729 static const struct net_device_ops gs_usb_netdev_ops = {
730 .ndo_open = gs_can_open,
731 .ndo_stop = gs_can_close,
732 .ndo_start_xmit = gs_can_start_xmit,
733 .ndo_change_mtu = can_change_mtu,
734 };
735
gs_usb_set_identify(struct net_device * netdev,bool do_identify)736 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
737 {
738 struct gs_can *dev = netdev_priv(netdev);
739 struct gs_identify_mode *imode;
740 int rc;
741
742 imode = kmalloc(sizeof(*imode), GFP_KERNEL);
743
744 if (!imode)
745 return -ENOMEM;
746
747 if (do_identify)
748 imode->mode = GS_CAN_IDENTIFY_ON;
749 else
750 imode->mode = GS_CAN_IDENTIFY_OFF;
751
752 rc = usb_control_msg(interface_to_usbdev(dev->iface),
753 usb_sndctrlpipe(interface_to_usbdev(dev->iface),
754 0),
755 GS_USB_BREQ_IDENTIFY,
756 USB_DIR_OUT | USB_TYPE_VENDOR |
757 USB_RECIP_INTERFACE,
758 dev->channel,
759 0,
760 imode,
761 sizeof(*imode),
762 100);
763
764 kfree(imode);
765
766 return (rc > 0) ? 0 : rc;
767 }
768
769 /* blink LED's for finding the this interface */
gs_usb_set_phys_id(struct net_device * dev,enum ethtool_phys_id_state state)770 static int gs_usb_set_phys_id(struct net_device *dev,
771 enum ethtool_phys_id_state state)
772 {
773 int rc = 0;
774
775 switch (state) {
776 case ETHTOOL_ID_ACTIVE:
777 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
778 break;
779 case ETHTOOL_ID_INACTIVE:
780 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
781 break;
782 default:
783 break;
784 }
785
786 return rc;
787 }
788
789 static const struct ethtool_ops gs_usb_ethtool_ops = {
790 .set_phys_id = gs_usb_set_phys_id,
791 };
792
gs_make_candev(unsigned int channel,struct usb_interface * intf,struct gs_device_config * dconf)793 static struct gs_can *gs_make_candev(unsigned int channel,
794 struct usb_interface *intf,
795 struct gs_device_config *dconf)
796 {
797 struct gs_can *dev;
798 struct net_device *netdev;
799 int rc;
800 struct gs_device_bt_const *bt_const;
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 settup */
840 strcpy(dev->bt_const.name, "gs_usb");
841 dev->bt_const.tseg1_min = bt_const->tseg1_min;
842 dev->bt_const.tseg1_max = bt_const->tseg1_max;
843 dev->bt_const.tseg2_min = bt_const->tseg2_min;
844 dev->bt_const.tseg2_max = bt_const->tseg2_max;
845 dev->bt_const.sjw_max = bt_const->sjw_max;
846 dev->bt_const.brp_min = bt_const->brp_min;
847 dev->bt_const.brp_max = bt_const->brp_max;
848 dev->bt_const.brp_inc = 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 settup */
864 dev->can.state = CAN_STATE_STOPPED;
865 dev->can.clock.freq = 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 if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
872 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
873
874 if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
875 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
876
877 if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
878 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
879
880 if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
881 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
882
883 SET_NETDEV_DEV(netdev, &intf->dev);
884
885 if (dconf->sw_version > 1)
886 if (bt_const->feature & GS_CAN_FEATURE_IDENTIFY)
887 netdev->ethtool_ops = &gs_usb_ethtool_ops;
888
889 kfree(bt_const);
890
891 rc = register_candev(dev->netdev);
892 if (rc) {
893 free_candev(dev->netdev);
894 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
895 return ERR_PTR(rc);
896 }
897
898 return dev;
899 }
900
gs_destroy_candev(struct gs_can * dev)901 static void gs_destroy_candev(struct gs_can *dev)
902 {
903 unregister_candev(dev->netdev);
904 usb_kill_anchored_urbs(&dev->tx_submitted);
905 free_candev(dev->netdev);
906 }
907
gs_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)908 static int gs_usb_probe(struct usb_interface *intf,
909 const struct usb_device_id *id)
910 {
911 struct gs_usb *dev;
912 int rc = -ENOMEM;
913 unsigned int icount, i;
914 struct gs_host_config *hconf;
915 struct gs_device_config *dconf;
916
917 hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
918 if (!hconf)
919 return -ENOMEM;
920
921 hconf->byte_order = 0x0000beef;
922
923 /* send host config */
924 rc = usb_control_msg(interface_to_usbdev(intf),
925 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
926 GS_USB_BREQ_HOST_FORMAT,
927 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
928 1,
929 intf->cur_altsetting->desc.bInterfaceNumber,
930 hconf,
931 sizeof(*hconf),
932 1000);
933
934 kfree(hconf);
935
936 if (rc < 0) {
937 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
938 rc);
939 return rc;
940 }
941
942 dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
943 if (!dconf)
944 return -ENOMEM;
945
946 /* read device config */
947 rc = usb_control_msg(interface_to_usbdev(intf),
948 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
949 GS_USB_BREQ_DEVICE_CONFIG,
950 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
951 1,
952 intf->cur_altsetting->desc.bInterfaceNumber,
953 dconf,
954 sizeof(*dconf),
955 1000);
956 if (rc < 0) {
957 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
958 rc);
959 kfree(dconf);
960 return rc;
961 }
962
963 icount = dconf->icount + 1;
964 dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
965
966 if (icount > GS_MAX_INTF) {
967 dev_err(&intf->dev,
968 "Driver cannot handle more that %d CAN interfaces\n",
969 GS_MAX_INTF);
970 kfree(dconf);
971 return -EINVAL;
972 }
973
974 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
975 if (!dev) {
976 kfree(dconf);
977 return -ENOMEM;
978 }
979
980 init_usb_anchor(&dev->rx_submitted);
981
982 atomic_set(&dev->active_channels, 0);
983
984 usb_set_intfdata(intf, dev);
985 dev->udev = interface_to_usbdev(intf);
986
987 for (i = 0; i < icount; i++) {
988 dev->canch[i] = gs_make_candev(i, intf, dconf);
989 if (IS_ERR_OR_NULL(dev->canch[i])) {
990 /* save error code to return later */
991 rc = PTR_ERR(dev->canch[i]);
992
993 /* on failure destroy previously created candevs */
994 icount = i;
995 for (i = 0; i < icount; i++)
996 gs_destroy_candev(dev->canch[i]);
997
998 usb_kill_anchored_urbs(&dev->rx_submitted);
999 kfree(dconf);
1000 kfree(dev);
1001 return rc;
1002 }
1003 dev->canch[i]->parent = dev;
1004 }
1005
1006 kfree(dconf);
1007
1008 return 0;
1009 }
1010
gs_usb_disconnect(struct usb_interface * intf)1011 static void gs_usb_disconnect(struct usb_interface *intf)
1012 {
1013 unsigned i;
1014 struct gs_usb *dev = usb_get_intfdata(intf);
1015 usb_set_intfdata(intf, NULL);
1016
1017 if (!dev) {
1018 dev_err(&intf->dev, "Disconnect (nodata)\n");
1019 return;
1020 }
1021
1022 for (i = 0; i < GS_MAX_INTF; i++)
1023 if (dev->canch[i])
1024 gs_destroy_candev(dev->canch[i]);
1025
1026 usb_kill_anchored_urbs(&dev->rx_submitted);
1027 kfree(dev);
1028 }
1029
1030 static const struct usb_device_id gs_usb_table[] = {
1031 { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1032 USB_GSUSB_1_PRODUCT_ID, 0) },
1033 { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1034 USB_CANDLELIGHT_PRODUCT_ID, 0) },
1035 {} /* Terminating entry */
1036 };
1037
1038 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1039
1040 static struct usb_driver gs_usb_driver = {
1041 .name = "gs_usb",
1042 .probe = gs_usb_probe,
1043 .disconnect = gs_usb_disconnect,
1044 .id_table = gs_usb_table,
1045 };
1046
1047 module_usb_driver(gs_usb_driver);
1048
1049 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1050 MODULE_DESCRIPTION(
1051 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1052 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1053 "and bytewerk.org candleLight USB CAN interfaces.");
1054 MODULE_LICENSE("GPL v2");
1055