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 void *rxbuf[GS_MAX_RX_URBS];
188 dma_addr_t rxbuf_dma[GS_MAX_RX_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 struct usb_device *udev;
196 u8 active_channels;
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_can *gsdev)246 static int gs_cmd_reset(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 device_detach;
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 = le32_to_cpu(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 (le32_to_cpu(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 stats->rx_over_errors++;
385 stats->rx_errors++;
386
387 skb = alloc_can_err_skb(netdev, &cf);
388 if (!skb)
389 goto resubmit_urb;
390
391 cf->can_id |= CAN_ERR_CRTL;
392 cf->can_dlc = CAN_ERR_DLC;
393 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
394 netif_rx(skb);
395 }
396
397 resubmit_urb:
398 usb_fill_bulk_urb(urb,
399 usbcan->udev,
400 usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
401 hf,
402 sizeof(struct gs_host_frame),
403 gs_usb_receive_bulk_callback,
404 usbcan
405 );
406
407 rc = usb_submit_urb(urb, GFP_ATOMIC);
408
409 /* USB failure take down all interfaces */
410 if (rc == -ENODEV) {
411 device_detach:
412 for (rc = 0; rc < GS_MAX_INTF; rc++) {
413 if (usbcan->canch[rc])
414 netif_device_detach(usbcan->canch[rc]->netdev);
415 }
416 }
417 }
418
gs_usb_set_bittiming(struct net_device *netdev)419 static int gs_usb_set_bittiming(struct net_device *netdev)
420 {
421 struct gs_can *dev = netdev_priv(netdev);
422 struct can_bittiming *bt = &dev->can.bittiming;
423 struct usb_interface *intf = dev->iface;
424 int rc;
425 struct gs_device_bittiming *dbt;
426
427 dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
428 if (!dbt)
429 return -ENOMEM;
430
431 dbt->prop_seg = cpu_to_le32(bt->prop_seg);
432 dbt->phase_seg1 = cpu_to_le32(bt->phase_seg1);
433 dbt->phase_seg2 = cpu_to_le32(bt->phase_seg2);
434 dbt->sjw = cpu_to_le32(bt->sjw);
435 dbt->brp = cpu_to_le32(bt->brp);
436
437 /* request bit timings */
438 rc = usb_control_msg(interface_to_usbdev(intf),
439 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
440 GS_USB_BREQ_BITTIMING,
441 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
442 dev->channel,
443 0,
444 dbt,
445 sizeof(*dbt),
446 1000);
447
448 kfree(dbt);
449
450 if (rc < 0)
451 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
452 rc);
453
454 return (rc > 0) ? 0 : rc;
455 }
456
gs_usb_xmit_callback(struct urb *urb)457 static void gs_usb_xmit_callback(struct urb *urb)
458 {
459 struct gs_tx_context *txc = urb->context;
460 struct gs_can *dev = txc->dev;
461 struct net_device *netdev = dev->netdev;
462
463 if (urb->status)
464 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
465
466 usb_free_coherent(urb->dev,
467 urb->transfer_buffer_length,
468 urb->transfer_buffer,
469 urb->transfer_dma);
470 }
471
gs_can_start_xmit(struct sk_buff *skb, struct net_device *netdev)472 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
473 struct net_device *netdev)
474 {
475 struct gs_can *dev = netdev_priv(netdev);
476 struct net_device_stats *stats = &dev->netdev->stats;
477 struct urb *urb;
478 struct gs_host_frame *hf;
479 struct can_frame *cf;
480 int rc;
481 unsigned int idx;
482 struct gs_tx_context *txc;
483
484 if (can_dropped_invalid_skb(netdev, skb))
485 return NETDEV_TX_OK;
486
487 /* find an empty context to keep track of transmission */
488 txc = gs_alloc_tx_context(dev);
489 if (!txc)
490 return NETDEV_TX_BUSY;
491
492 /* create a URB, and a buffer for it */
493 urb = usb_alloc_urb(0, GFP_ATOMIC);
494 if (!urb)
495 goto nomem_urb;
496
497 hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
498 &urb->transfer_dma);
499 if (!hf) {
500 netdev_err(netdev, "No memory left for USB buffer\n");
501 goto nomem_hf;
502 }
503
504 idx = txc->echo_id;
505
506 if (idx >= GS_MAX_TX_URBS) {
507 netdev_err(netdev, "Invalid tx context %d\n", idx);
508 goto badidx;
509 }
510
511 hf->echo_id = idx;
512 hf->channel = dev->channel;
513 hf->flags = 0;
514 hf->reserved = 0;
515
516 cf = (struct can_frame *)skb->data;
517
518 hf->can_id = cpu_to_le32(cf->can_id);
519 hf->can_dlc = cf->can_dlc;
520 memcpy(hf->data, cf->data, cf->can_dlc);
521
522 usb_fill_bulk_urb(urb, dev->udev,
523 usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
524 hf,
525 sizeof(*hf),
526 gs_usb_xmit_callback,
527 txc);
528
529 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
530 usb_anchor_urb(urb, &dev->tx_submitted);
531
532 can_put_echo_skb(skb, netdev, idx);
533
534 atomic_inc(&dev->active_tx_urbs);
535
536 rc = usb_submit_urb(urb, GFP_ATOMIC);
537 if (unlikely(rc)) { /* usb send failed */
538 atomic_dec(&dev->active_tx_urbs);
539
540 can_free_echo_skb(netdev, idx);
541 gs_free_tx_context(txc);
542
543 usb_unanchor_urb(urb);
544 usb_free_coherent(dev->udev,
545 sizeof(*hf),
546 hf,
547 urb->transfer_dma);
548
549 if (rc == -ENODEV) {
550 netif_device_detach(netdev);
551 } else {
552 netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
553 stats->tx_dropped++;
554 }
555 } else {
556 /* Slow down tx path */
557 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
558 netif_stop_queue(netdev);
559 }
560
561 /* let usb core take care of this urb */
562 usb_free_urb(urb);
563
564 return NETDEV_TX_OK;
565
566 badidx:
567 usb_free_coherent(dev->udev,
568 sizeof(*hf),
569 hf,
570 urb->transfer_dma);
571 nomem_hf:
572 usb_free_urb(urb);
573
574 nomem_urb:
575 gs_free_tx_context(txc);
576 dev_kfree_skb(skb);
577 stats->tx_dropped++;
578 return NETDEV_TX_OK;
579 }
580
gs_can_open(struct net_device *netdev)581 static int gs_can_open(struct net_device *netdev)
582 {
583 struct gs_can *dev = netdev_priv(netdev);
584 struct gs_usb *parent = dev->parent;
585 int rc, i;
586 struct gs_device_mode *dm;
587 u32 ctrlmode;
588 u32 flags = 0;
589
590 rc = open_candev(netdev);
591 if (rc)
592 return rc;
593
594 if (!parent->active_channels) {
595 for (i = 0; i < GS_MAX_RX_URBS; i++) {
596 struct urb *urb;
597 u8 *buf;
598 dma_addr_t buf_dma;
599
600 /* alloc rx urb */
601 urb = usb_alloc_urb(0, GFP_KERNEL);
602 if (!urb)
603 return -ENOMEM;
604
605 /* alloc rx buffer */
606 buf = usb_alloc_coherent(dev->udev,
607 sizeof(struct gs_host_frame),
608 GFP_KERNEL,
609 &buf_dma);
610 if (!buf) {
611 netdev_err(netdev,
612 "No memory left for USB buffer\n");
613 usb_free_urb(urb);
614 return -ENOMEM;
615 }
616
617 urb->transfer_dma = buf_dma;
618
619 /* fill, anchor, and submit rx urb */
620 usb_fill_bulk_urb(urb,
621 dev->udev,
622 usb_rcvbulkpipe(dev->udev,
623 GSUSB_ENDPOINT_IN),
624 buf,
625 sizeof(struct gs_host_frame),
626 gs_usb_receive_bulk_callback,
627 parent);
628 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
629
630 usb_anchor_urb(urb, &parent->rx_submitted);
631
632 rc = usb_submit_urb(urb, GFP_KERNEL);
633 if (rc) {
634 if (rc == -ENODEV)
635 netif_device_detach(dev->netdev);
636
637 netdev_err(netdev,
638 "usb_submit failed (err=%d)\n",
639 rc);
640
641 usb_unanchor_urb(urb);
642 usb_free_coherent(dev->udev,
643 sizeof(struct gs_host_frame),
644 buf,
645 buf_dma);
646 usb_free_urb(urb);
647 break;
648 }
649
650 dev->rxbuf[i] = buf;
651 dev->rxbuf_dma[i] = buf_dma;
652
653 /* Drop reference,
654 * USB core will take care of freeing it
655 */
656 usb_free_urb(urb);
657 }
658 }
659
660 dm = kmalloc(sizeof(*dm), GFP_KERNEL);
661 if (!dm)
662 return -ENOMEM;
663
664 /* flags */
665 ctrlmode = dev->can.ctrlmode;
666
667 if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
668 flags |= GS_CAN_MODE_LOOP_BACK;
669 else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
670 flags |= GS_CAN_MODE_LISTEN_ONLY;
671
672 /* Controller is not allowed to retry TX
673 * this mode is unavailable on atmels uc3c hardware
674 */
675 if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
676 flags |= GS_CAN_MODE_ONE_SHOT;
677
678 if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
679 flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
680
681 /* finally start device */
682 dev->can.state = CAN_STATE_ERROR_ACTIVE;
683 dm->mode = cpu_to_le32(GS_CAN_MODE_START);
684 dm->flags = cpu_to_le32(flags);
685 rc = usb_control_msg(interface_to_usbdev(dev->iface),
686 usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
687 GS_USB_BREQ_MODE,
688 USB_DIR_OUT | USB_TYPE_VENDOR |
689 USB_RECIP_INTERFACE,
690 dev->channel,
691 0,
692 dm,
693 sizeof(*dm),
694 1000);
695
696 if (rc < 0) {
697 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
698 kfree(dm);
699 dev->can.state = CAN_STATE_STOPPED;
700 return rc;
701 }
702
703 kfree(dm);
704
705 parent->active_channels++;
706 if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
707 netif_start_queue(netdev);
708
709 return 0;
710 }
711
gs_can_close(struct net_device *netdev)712 static int gs_can_close(struct net_device *netdev)
713 {
714 int rc;
715 struct gs_can *dev = netdev_priv(netdev);
716 struct gs_usb *parent = dev->parent;
717 unsigned int i;
718
719 netif_stop_queue(netdev);
720
721 /* Stop polling */
722 parent->active_channels--;
723 if (!parent->active_channels) {
724 usb_kill_anchored_urbs(&parent->rx_submitted);
725 for (i = 0; i < GS_MAX_RX_URBS; i++)
726 usb_free_coherent(dev->udev,
727 sizeof(struct gs_host_frame),
728 dev->rxbuf[i],
729 dev->rxbuf_dma[i]);
730 }
731
732 /* Stop sending URBs */
733 usb_kill_anchored_urbs(&dev->tx_submitted);
734 atomic_set(&dev->active_tx_urbs, 0);
735
736 dev->can.state = CAN_STATE_STOPPED;
737
738 /* reset the device */
739 rc = gs_cmd_reset(dev);
740 if (rc < 0)
741 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
742
743 /* reset tx contexts */
744 for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
745 dev->tx_context[rc].dev = dev;
746 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
747 }
748
749 /* close the netdev */
750 close_candev(netdev);
751
752 return 0;
753 }
754
755 static const struct net_device_ops gs_usb_netdev_ops = {
756 .ndo_open = gs_can_open,
757 .ndo_stop = gs_can_close,
758 .ndo_start_xmit = gs_can_start_xmit,
759 .ndo_change_mtu = can_change_mtu,
760 };
761
gs_usb_set_identify(struct net_device *netdev, bool do_identify)762 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
763 {
764 struct gs_can *dev = netdev_priv(netdev);
765 struct gs_identify_mode *imode;
766 int rc;
767
768 imode = kmalloc(sizeof(*imode), GFP_KERNEL);
769
770 if (!imode)
771 return -ENOMEM;
772
773 if (do_identify)
774 imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
775 else
776 imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
777
778 rc = usb_control_msg(interface_to_usbdev(dev->iface),
779 usb_sndctrlpipe(interface_to_usbdev(dev->iface),
780 0),
781 GS_USB_BREQ_IDENTIFY,
782 USB_DIR_OUT | USB_TYPE_VENDOR |
783 USB_RECIP_INTERFACE,
784 dev->channel,
785 0,
786 imode,
787 sizeof(*imode),
788 100);
789
790 kfree(imode);
791
792 return (rc > 0) ? 0 : rc;
793 }
794
795 /* blink LED's for finding the this interface */
gs_usb_set_phys_id(struct net_device *dev, enum ethtool_phys_id_state state)796 static int gs_usb_set_phys_id(struct net_device *dev,
797 enum ethtool_phys_id_state state)
798 {
799 int rc = 0;
800
801 switch (state) {
802 case ETHTOOL_ID_ACTIVE:
803 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
804 break;
805 case ETHTOOL_ID_INACTIVE:
806 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
807 break;
808 default:
809 break;
810 }
811
812 return rc;
813 }
814
815 static const struct ethtool_ops gs_usb_ethtool_ops = {
816 .set_phys_id = gs_usb_set_phys_id,
817 };
818
gs_make_candev(unsigned int channel, struct usb_interface *intf, struct gs_device_config *dconf)819 static struct gs_can *gs_make_candev(unsigned int channel,
820 struct usb_interface *intf,
821 struct gs_device_config *dconf)
822 {
823 struct gs_can *dev;
824 struct net_device *netdev;
825 int rc;
826 struct gs_device_bt_const *bt_const;
827 u32 feature;
828
829 bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
830 if (!bt_const)
831 return ERR_PTR(-ENOMEM);
832
833 /* fetch bit timing constants */
834 rc = usb_control_msg(interface_to_usbdev(intf),
835 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
836 GS_USB_BREQ_BT_CONST,
837 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
838 channel,
839 0,
840 bt_const,
841 sizeof(*bt_const),
842 1000);
843
844 if (rc < 0) {
845 dev_err(&intf->dev,
846 "Couldn't get bit timing const for channel (err=%d)\n",
847 rc);
848 kfree(bt_const);
849 return ERR_PTR(rc);
850 }
851
852 /* create netdev */
853 netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
854 if (!netdev) {
855 dev_err(&intf->dev, "Couldn't allocate candev\n");
856 kfree(bt_const);
857 return ERR_PTR(-ENOMEM);
858 }
859
860 dev = netdev_priv(netdev);
861
862 netdev->netdev_ops = &gs_usb_netdev_ops;
863
864 netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
865
866 /* dev setup */
867 strcpy(dev->bt_const.name, "gs_usb");
868 dev->bt_const.tseg1_min = le32_to_cpu(bt_const->tseg1_min);
869 dev->bt_const.tseg1_max = le32_to_cpu(bt_const->tseg1_max);
870 dev->bt_const.tseg2_min = le32_to_cpu(bt_const->tseg2_min);
871 dev->bt_const.tseg2_max = le32_to_cpu(bt_const->tseg2_max);
872 dev->bt_const.sjw_max = le32_to_cpu(bt_const->sjw_max);
873 dev->bt_const.brp_min = le32_to_cpu(bt_const->brp_min);
874 dev->bt_const.brp_max = le32_to_cpu(bt_const->brp_max);
875 dev->bt_const.brp_inc = le32_to_cpu(bt_const->brp_inc);
876
877 dev->udev = interface_to_usbdev(intf);
878 dev->iface = intf;
879 dev->netdev = netdev;
880 dev->channel = channel;
881
882 init_usb_anchor(&dev->tx_submitted);
883 atomic_set(&dev->active_tx_urbs, 0);
884 spin_lock_init(&dev->tx_ctx_lock);
885 for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
886 dev->tx_context[rc].dev = dev;
887 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
888 }
889
890 /* can setup */
891 dev->can.state = CAN_STATE_STOPPED;
892 dev->can.clock.freq = le32_to_cpu(bt_const->fclk_can);
893 dev->can.bittiming_const = &dev->bt_const;
894 dev->can.do_set_bittiming = gs_usb_set_bittiming;
895
896 dev->can.ctrlmode_supported = 0;
897
898 feature = le32_to_cpu(bt_const->feature);
899 if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
900 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
901
902 if (feature & GS_CAN_FEATURE_LOOP_BACK)
903 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
904
905 if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
906 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
907
908 if (feature & GS_CAN_FEATURE_ONE_SHOT)
909 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
910
911 SET_NETDEV_DEV(netdev, &intf->dev);
912
913 if (le32_to_cpu(dconf->sw_version) > 1)
914 if (feature & GS_CAN_FEATURE_IDENTIFY)
915 netdev->ethtool_ops = &gs_usb_ethtool_ops;
916
917 kfree(bt_const);
918
919 rc = register_candev(dev->netdev);
920 if (rc) {
921 free_candev(dev->netdev);
922 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
923 return ERR_PTR(rc);
924 }
925
926 return dev;
927 }
928
gs_destroy_candev(struct gs_can *dev)929 static void gs_destroy_candev(struct gs_can *dev)
930 {
931 unregister_candev(dev->netdev);
932 usb_kill_anchored_urbs(&dev->tx_submitted);
933 free_candev(dev->netdev);
934 }
935
gs_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)936 static int gs_usb_probe(struct usb_interface *intf,
937 const struct usb_device_id *id)
938 {
939 struct gs_usb *dev;
940 int rc = -ENOMEM;
941 unsigned int icount, i;
942 struct gs_host_config *hconf;
943 struct gs_device_config *dconf;
944
945 hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
946 if (!hconf)
947 return -ENOMEM;
948
949 hconf->byte_order = cpu_to_le32(0x0000beef);
950
951 /* send host config */
952 rc = usb_control_msg(interface_to_usbdev(intf),
953 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
954 GS_USB_BREQ_HOST_FORMAT,
955 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
956 1,
957 intf->cur_altsetting->desc.bInterfaceNumber,
958 hconf,
959 sizeof(*hconf),
960 1000);
961
962 kfree(hconf);
963
964 if (rc < 0) {
965 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
966 rc);
967 return rc;
968 }
969
970 dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
971 if (!dconf)
972 return -ENOMEM;
973
974 /* read device config */
975 rc = usb_control_msg(interface_to_usbdev(intf),
976 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
977 GS_USB_BREQ_DEVICE_CONFIG,
978 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
979 1,
980 intf->cur_altsetting->desc.bInterfaceNumber,
981 dconf,
982 sizeof(*dconf),
983 1000);
984 if (rc < 0) {
985 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
986 rc);
987 kfree(dconf);
988 return rc;
989 }
990
991 icount = dconf->icount + 1;
992 dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
993
994 if (icount > GS_MAX_INTF) {
995 dev_err(&intf->dev,
996 "Driver cannot handle more that %d CAN interfaces\n",
997 GS_MAX_INTF);
998 kfree(dconf);
999 return -EINVAL;
1000 }
1001
1002 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1003 if (!dev) {
1004 kfree(dconf);
1005 return -ENOMEM;
1006 }
1007
1008 init_usb_anchor(&dev->rx_submitted);
1009
1010 usb_set_intfdata(intf, dev);
1011 dev->udev = interface_to_usbdev(intf);
1012
1013 for (i = 0; i < icount; i++) {
1014 dev->canch[i] = gs_make_candev(i, intf, dconf);
1015 if (IS_ERR_OR_NULL(dev->canch[i])) {
1016 /* save error code to return later */
1017 rc = PTR_ERR(dev->canch[i]);
1018
1019 /* on failure destroy previously created candevs */
1020 icount = i;
1021 for (i = 0; i < icount; i++)
1022 gs_destroy_candev(dev->canch[i]);
1023
1024 usb_kill_anchored_urbs(&dev->rx_submitted);
1025 kfree(dconf);
1026 kfree(dev);
1027 return rc;
1028 }
1029 dev->canch[i]->parent = dev;
1030 }
1031
1032 kfree(dconf);
1033
1034 return 0;
1035 }
1036
gs_usb_disconnect(struct usb_interface *intf)1037 static void gs_usb_disconnect(struct usb_interface *intf)
1038 {
1039 unsigned i;
1040 struct gs_usb *dev = usb_get_intfdata(intf);
1041 usb_set_intfdata(intf, NULL);
1042
1043 if (!dev) {
1044 dev_err(&intf->dev, "Disconnect (nodata)\n");
1045 return;
1046 }
1047
1048 for (i = 0; i < GS_MAX_INTF; i++)
1049 if (dev->canch[i])
1050 gs_destroy_candev(dev->canch[i]);
1051
1052 usb_kill_anchored_urbs(&dev->rx_submitted);
1053 kfree(dev);
1054 }
1055
1056 static const struct usb_device_id gs_usb_table[] = {
1057 { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1058 USB_GSUSB_1_PRODUCT_ID, 0) },
1059 { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1060 USB_CANDLELIGHT_PRODUCT_ID, 0) },
1061 {} /* Terminating entry */
1062 };
1063
1064 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1065
1066 static struct usb_driver gs_usb_driver = {
1067 .name = "gs_usb",
1068 .probe = gs_usb_probe,
1069 .disconnect = gs_usb_disconnect,
1070 .id_table = gs_usb_table,
1071 };
1072
1073 module_usb_driver(gs_usb_driver);
1074
1075 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1076 MODULE_DESCRIPTION(
1077 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1078 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1079 "and bytewerk.org candleLight USB CAN interfaces.");
1080 MODULE_LICENSE("GPL v2");
1081