esd_usb2.c revision aabdfd6adb804d0aaba0188ade0f1afe42a52e31
1/*
2 * CAN driver for esd CAN-USB/2
3 *
4 * Copyright (C) 2010 Matthias Fuchs <matthias.fuchs@esd.eu>, esd gmbh
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published
8 * by the Free Software Foundation; version 2 of the License.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19#include <linux/init.h>
20#include <linux/signal.h>
21#include <linux/slab.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
30MODULE_AUTHOR("Matthias Fuchs <matthias.fuchs@esd.eu>");
31MODULE_DESCRIPTION("CAN driver for esd CAN-USB/2 interfaces");
32MODULE_LICENSE("GPL v2");
33
34/* Define these values to match your devices */
35#define USB_ESDGMBH_VENDOR_ID	0x0ab4
36#define USB_CANUSB2_PRODUCT_ID	0x0010
37
38#define ESD_USB2_CAN_CLOCK	60000000
39#define ESD_USB2_MAX_NETS	2
40
41/* USB2 commands */
42#define CMD_VERSION		1 /* also used for VERSION_REPLY */
43#define CMD_CAN_RX		2 /* device to host only */
44#define CMD_CAN_TX		3 /* also used for TX_DONE */
45#define CMD_SETBAUD		4 /* also used for SETBAUD_REPLY */
46#define CMD_TS			5 /* also used for TS_REPLY */
47#define CMD_IDADD		6 /* also used for IDADD_REPLY */
48
49/* esd CAN message flags - dlc field */
50#define ESD_RTR			0x10
51
52/* esd CAN message flags - id field */
53#define ESD_EXTID		0x20000000
54#define ESD_EVENT		0x40000000
55#define ESD_IDMASK		0x1fffffff
56
57/* esd CAN event ids used by this driver */
58#define ESD_EV_CAN_ERROR_EXT	2
59
60/* baudrate message flags */
61#define ESD_USB2_UBR		0x80000000
62#define ESD_USB2_LOM		0x40000000
63#define ESD_USB2_NO_BAUDRATE	0x7fffffff
64#define ESD_USB2_TSEG1_MIN	1
65#define ESD_USB2_TSEG1_MAX	16
66#define ESD_USB2_TSEG1_SHIFT	16
67#define ESD_USB2_TSEG2_MIN	1
68#define ESD_USB2_TSEG2_MAX	8
69#define ESD_USB2_TSEG2_SHIFT	20
70#define ESD_USB2_SJW_MAX	4
71#define ESD_USB2_SJW_SHIFT	14
72#define ESD_USB2_BRP_MIN	1
73#define ESD_USB2_BRP_MAX	1024
74#define ESD_USB2_BRP_INC	1
75#define ESD_USB2_3_SAMPLES	0x00800000
76
77/* esd IDADD message */
78#define ESD_ID_ENABLE		0x80
79#define ESD_MAX_ID_SEGMENT	64
80
81/* SJA1000 ECC register (emulated by usb2 firmware) */
82#define SJA1000_ECC_SEG		0x1F
83#define SJA1000_ECC_DIR		0x20
84#define SJA1000_ECC_ERR		0x06
85#define SJA1000_ECC_BIT		0x00
86#define SJA1000_ECC_FORM	0x40
87#define SJA1000_ECC_STUFF	0x80
88#define SJA1000_ECC_MASK	0xc0
89
90/* esd bus state event codes */
91#define ESD_BUSSTATE_MASK	0xc0
92#define ESD_BUSSTATE_WARN	0x40
93#define ESD_BUSSTATE_ERRPASSIVE	0x80
94#define ESD_BUSSTATE_BUSOFF	0xc0
95
96#define RX_BUFFER_SIZE		1024
97#define MAX_RX_URBS		4
98#define MAX_TX_URBS		16 /* must be power of 2 */
99
100struct header_msg {
101	u8 len; /* len is always the total message length in 32bit words */
102	u8 cmd;
103	u8 rsvd[2];
104};
105
106struct version_msg {
107	u8 len;
108	u8 cmd;
109	u8 rsvd;
110	u8 flags;
111	__le32 drv_version;
112};
113
114struct version_reply_msg {
115	u8 len;
116	u8 cmd;
117	u8 nets;
118	u8 features;
119	__le32 version;
120	u8 name[16];
121	__le32 rsvd;
122	__le32 ts;
123};
124
125struct rx_msg {
126	u8 len;
127	u8 cmd;
128	u8 net;
129	u8 dlc;
130	__le32 ts;
131	__le32 id; /* upper 3 bits contain flags */
132	u8 data[8];
133};
134
135struct tx_msg {
136	u8 len;
137	u8 cmd;
138	u8 net;
139	u8 dlc;
140	__le32 hnd;
141	__le32 id; /* upper 3 bits contain flags */
142	u8 data[8];
143};
144
145struct tx_done_msg {
146	u8 len;
147	u8 cmd;
148	u8 net;
149	u8 status;
150	__le32 hnd;
151	__le32 ts;
152};
153
154struct id_filter_msg {
155	u8 len;
156	u8 cmd;
157	u8 net;
158	u8 option;
159	__le32 mask[ESD_MAX_ID_SEGMENT + 1];
160};
161
162struct set_baudrate_msg {
163	u8 len;
164	u8 cmd;
165	u8 net;
166	u8 rsvd;
167	__le32 baud;
168};
169
170/* Main message type used between library and application */
171struct __attribute__ ((packed)) esd_usb2_msg {
172	union {
173		struct header_msg hdr;
174		struct version_msg version;
175		struct version_reply_msg version_reply;
176		struct rx_msg rx;
177		struct tx_msg tx;
178		struct tx_done_msg txdone;
179		struct set_baudrate_msg setbaud;
180		struct id_filter_msg filter;
181	} msg;
182};
183
184static struct usb_device_id esd_usb2_table[] = {
185	{USB_DEVICE(USB_ESDGMBH_VENDOR_ID, USB_CANUSB2_PRODUCT_ID)},
186	{}
187};
188MODULE_DEVICE_TABLE(usb, esd_usb2_table);
189
190struct esd_usb2_net_priv;
191
192struct esd_tx_urb_context {
193	struct esd_usb2_net_priv *priv;
194	u32 echo_index;
195	int dlc;
196};
197
198struct esd_usb2 {
199	struct usb_device *udev;
200	struct esd_usb2_net_priv *nets[ESD_USB2_MAX_NETS];
201
202	struct usb_anchor rx_submitted;
203
204	int net_count;
205	u32 version;
206	int rxinitdone;
207};
208
209struct esd_usb2_net_priv {
210	struct can_priv can; /* must be the first member */
211
212	atomic_t active_tx_jobs;
213	struct usb_anchor tx_submitted;
214	struct esd_tx_urb_context tx_contexts[MAX_TX_URBS];
215
216	int open_time;
217	struct esd_usb2 *usb2;
218	struct net_device *netdev;
219	int index;
220	u8 old_state;
221	struct can_berr_counter bec;
222};
223
224static void esd_usb2_rx_event(struct esd_usb2_net_priv *priv,
225			      struct esd_usb2_msg *msg)
226{
227	struct net_device_stats *stats = &priv->netdev->stats;
228	struct can_frame *cf;
229	struct sk_buff *skb;
230	u32 id = le32_to_cpu(msg->msg.rx.id) & ESD_IDMASK;
231
232	if (id == ESD_EV_CAN_ERROR_EXT) {
233		u8 state = msg->msg.rx.data[0];
234		u8 ecc = msg->msg.rx.data[1];
235		u8 txerr = msg->msg.rx.data[2];
236		u8 rxerr = msg->msg.rx.data[3];
237
238		skb = alloc_can_err_skb(priv->netdev, &cf);
239		if (skb == NULL) {
240			stats->rx_dropped++;
241			return;
242		}
243
244		if (state != priv->old_state) {
245			priv->old_state = state;
246
247			switch (state & ESD_BUSSTATE_MASK) {
248			case ESD_BUSSTATE_BUSOFF:
249				priv->can.state = CAN_STATE_BUS_OFF;
250				cf->can_id |= CAN_ERR_BUSOFF;
251				can_bus_off(priv->netdev);
252				break;
253			case ESD_BUSSTATE_WARN:
254				priv->can.state = CAN_STATE_ERROR_WARNING;
255				priv->can.can_stats.error_warning++;
256				break;
257			case ESD_BUSSTATE_ERRPASSIVE:
258				priv->can.state = CAN_STATE_ERROR_PASSIVE;
259				priv->can.can_stats.error_passive++;
260				break;
261			default:
262				priv->can.state = CAN_STATE_ERROR_ACTIVE;
263				break;
264			}
265		} else {
266			priv->can.can_stats.bus_error++;
267			stats->rx_errors++;
268
269			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
270
271			switch (ecc & SJA1000_ECC_MASK) {
272			case SJA1000_ECC_BIT:
273				cf->data[2] |= CAN_ERR_PROT_BIT;
274				break;
275			case SJA1000_ECC_FORM:
276				cf->data[2] |= CAN_ERR_PROT_FORM;
277				break;
278			case SJA1000_ECC_STUFF:
279				cf->data[2] |= CAN_ERR_PROT_STUFF;
280				break;
281			default:
282				cf->data[2] |= CAN_ERR_PROT_UNSPEC;
283				cf->data[3] = ecc & SJA1000_ECC_SEG;
284				break;
285			}
286
287			/* Error occurred during transmission? */
288			if (!(ecc & SJA1000_ECC_DIR))
289				cf->data[2] |= CAN_ERR_PROT_TX;
290
291			if (priv->can.state == CAN_STATE_ERROR_WARNING ||
292			    priv->can.state == CAN_STATE_ERROR_PASSIVE) {
293				cf->data[1] = (txerr > rxerr) ?
294					CAN_ERR_CRTL_TX_PASSIVE :
295					CAN_ERR_CRTL_RX_PASSIVE;
296			}
297			cf->data[6] = txerr;
298			cf->data[7] = rxerr;
299		}
300
301		netif_rx(skb);
302
303		priv->bec.txerr = txerr;
304		priv->bec.rxerr = rxerr;
305
306		stats->rx_packets++;
307		stats->rx_bytes += cf->can_dlc;
308	}
309}
310
311static void esd_usb2_rx_can_msg(struct esd_usb2_net_priv *priv,
312				struct esd_usb2_msg *msg)
313{
314	struct net_device_stats *stats = &priv->netdev->stats;
315	struct can_frame *cf;
316	struct sk_buff *skb;
317	int i;
318	u32 id;
319
320	if (!netif_device_present(priv->netdev))
321		return;
322
323	id = le32_to_cpu(msg->msg.rx.id);
324
325	if (id & ESD_EVENT) {
326		esd_usb2_rx_event(priv, msg);
327	} else {
328		skb = alloc_can_skb(priv->netdev, &cf);
329		if (skb == NULL) {
330			stats->rx_dropped++;
331			return;
332		}
333
334		cf->can_id = id & ESD_IDMASK;
335		cf->can_dlc = get_can_dlc(msg->msg.rx.dlc);
336
337		if (id & ESD_EXTID)
338			cf->can_id |= CAN_EFF_FLAG;
339
340		if (msg->msg.rx.dlc & ESD_RTR) {
341			cf->can_id |= CAN_RTR_FLAG;
342		} else {
343			for (i = 0; i < cf->can_dlc; i++)
344				cf->data[i] = msg->msg.rx.data[i];
345		}
346
347		netif_rx(skb);
348
349		stats->rx_packets++;
350		stats->rx_bytes += cf->can_dlc;
351	}
352
353	return;
354}
355
356static void esd_usb2_tx_done_msg(struct esd_usb2_net_priv *priv,
357				 struct esd_usb2_msg *msg)
358{
359	struct net_device_stats *stats = &priv->netdev->stats;
360	struct net_device *netdev = priv->netdev;
361	struct esd_tx_urb_context *context;
362
363	if (!netif_device_present(netdev))
364		return;
365
366	context = &priv->tx_contexts[msg->msg.txdone.hnd & (MAX_TX_URBS - 1)];
367
368	if (!msg->msg.txdone.status) {
369		stats->tx_packets++;
370		stats->tx_bytes += context->dlc;
371		can_get_echo_skb(netdev, context->echo_index);
372	} else {
373		stats->tx_errors++;
374		can_free_echo_skb(netdev, context->echo_index);
375	}
376
377	/* Release context */
378	context->echo_index = MAX_TX_URBS;
379	atomic_dec(&priv->active_tx_jobs);
380
381	netif_wake_queue(netdev);
382}
383
384static void esd_usb2_read_bulk_callback(struct urb *urb)
385{
386	struct esd_usb2 *dev = urb->context;
387	int retval;
388	int pos = 0;
389	int i;
390
391	switch (urb->status) {
392	case 0: /* success */
393		break;
394
395	case -ENOENT:
396	case -ESHUTDOWN:
397		return;
398
399	default:
400		dev_info(dev->udev->dev.parent,
401			 "Rx URB aborted (%d)\n", urb->status);
402		goto resubmit_urb;
403	}
404
405	while (pos < urb->actual_length) {
406		struct esd_usb2_msg *msg;
407
408		msg = (struct esd_usb2_msg *)(urb->transfer_buffer + pos);
409
410		switch (msg->msg.hdr.cmd) {
411		case CMD_CAN_RX:
412			esd_usb2_rx_can_msg(dev->nets[msg->msg.rx.net], msg);
413			break;
414
415		case CMD_CAN_TX:
416			esd_usb2_tx_done_msg(dev->nets[msg->msg.txdone.net],
417					     msg);
418			break;
419		}
420
421		pos += msg->msg.hdr.len << 2;
422
423		if (pos > urb->actual_length) {
424			dev_err(dev->udev->dev.parent, "format error\n");
425			break;
426		}
427	}
428
429resubmit_urb:
430	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
431			  urb->transfer_buffer, RX_BUFFER_SIZE,
432			  esd_usb2_read_bulk_callback, dev);
433
434	retval = usb_submit_urb(urb, GFP_ATOMIC);
435	if (retval == -ENODEV) {
436		for (i = 0; i < dev->net_count; i++) {
437			if (dev->nets[i])
438				netif_device_detach(dev->nets[i]->netdev);
439		}
440	} else if (retval) {
441		dev_err(dev->udev->dev.parent,
442			"failed resubmitting read bulk urb: %d\n", retval);
443	}
444
445	return;
446}
447
448/*
449 * callback for bulk IN urb
450 */
451static void esd_usb2_write_bulk_callback(struct urb *urb)
452{
453	struct esd_tx_urb_context *context = urb->context;
454	struct esd_usb2_net_priv *priv;
455	struct esd_usb2 *dev;
456	struct net_device *netdev;
457	size_t size = sizeof(struct esd_usb2_msg);
458
459	WARN_ON(!context);
460
461	priv = context->priv;
462	netdev = priv->netdev;
463	dev = priv->usb2;
464
465	/* free up our allocated buffer */
466	usb_free_coherent(urb->dev, size,
467			  urb->transfer_buffer, urb->transfer_dma);
468
469	if (!netif_device_present(netdev))
470		return;
471
472	if (urb->status)
473		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
474
475	netdev->trans_start = jiffies;
476}
477
478static ssize_t show_firmware(struct device *d,
479			     struct device_attribute *attr, char *buf)
480{
481	struct usb_interface *intf = to_usb_interface(d);
482	struct esd_usb2 *dev = usb_get_intfdata(intf);
483
484	return sprintf(buf, "%d.%d.%d\n",
485		       (dev->version >> 12) & 0xf,
486		       (dev->version >> 8) & 0xf,
487		       dev->version & 0xff);
488}
489static DEVICE_ATTR(firmware, S_IRUGO, show_firmware, NULL);
490
491static ssize_t show_hardware(struct device *d,
492			     struct device_attribute *attr, char *buf)
493{
494	struct usb_interface *intf = to_usb_interface(d);
495	struct esd_usb2 *dev = usb_get_intfdata(intf);
496
497	return sprintf(buf, "%d.%d.%d\n",
498		       (dev->version >> 28) & 0xf,
499		       (dev->version >> 24) & 0xf,
500		       (dev->version >> 16) & 0xff);
501}
502static DEVICE_ATTR(hardware, S_IRUGO, show_hardware, NULL);
503
504static ssize_t show_nets(struct device *d,
505			 struct device_attribute *attr, char *buf)
506{
507	struct usb_interface *intf = to_usb_interface(d);
508	struct esd_usb2 *dev = usb_get_intfdata(intf);
509
510	return sprintf(buf, "%d", dev->net_count);
511}
512static DEVICE_ATTR(nets, S_IRUGO, show_nets, NULL);
513
514static int esd_usb2_send_msg(struct esd_usb2 *dev, struct esd_usb2_msg *msg)
515{
516	int actual_length;
517
518	return usb_bulk_msg(dev->udev,
519			    usb_sndbulkpipe(dev->udev, 2),
520			    msg,
521			    msg->msg.hdr.len << 2,
522			    &actual_length,
523			    1000);
524}
525
526static int esd_usb2_wait_msg(struct esd_usb2 *dev,
527			     struct esd_usb2_msg *msg)
528{
529	int actual_length;
530
531	return usb_bulk_msg(dev->udev,
532			    usb_rcvbulkpipe(dev->udev, 1),
533			    msg,
534			    sizeof(*msg),
535			    &actual_length,
536			    1000);
537}
538
539static int esd_usb2_setup_rx_urbs(struct esd_usb2 *dev)
540{
541	int i, err = 0;
542
543	if (dev->rxinitdone)
544		return 0;
545
546	for (i = 0; i < MAX_RX_URBS; i++) {
547		struct urb *urb = NULL;
548		u8 *buf = NULL;
549
550		/* create a URB, and a buffer for it */
551		urb = usb_alloc_urb(0, GFP_KERNEL);
552		if (!urb) {
553			dev_warn(dev->udev->dev.parent,
554				 "No memory left for URBs\n");
555			err = -ENOMEM;
556			break;
557		}
558
559		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
560					 &urb->transfer_dma);
561		if (!buf) {
562			dev_warn(dev->udev->dev.parent,
563				 "No memory left for USB buffer\n");
564			err = -ENOMEM;
565			goto freeurb;
566		}
567
568		usb_fill_bulk_urb(urb, dev->udev,
569				  usb_rcvbulkpipe(dev->udev, 1),
570				  buf, RX_BUFFER_SIZE,
571				  esd_usb2_read_bulk_callback, dev);
572		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
573		usb_anchor_urb(urb, &dev->rx_submitted);
574
575		err = usb_submit_urb(urb, GFP_KERNEL);
576		if (err) {
577			usb_unanchor_urb(urb);
578			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
579					  urb->transfer_dma);
580		}
581
582freeurb:
583		/* Drop reference, USB core will take care of freeing it */
584		usb_free_urb(urb);
585		if (err)
586			break;
587	}
588
589	/* Did we submit any URBs */
590	if (i == 0) {
591		dev_err(dev->udev->dev.parent, "couldn't setup read URBs\n");
592		return err;
593	}
594
595	/* Warn if we've couldn't transmit all the URBs */
596	if (i < MAX_RX_URBS) {
597		dev_warn(dev->udev->dev.parent,
598			 "rx performance may be slow\n");
599	}
600
601	dev->rxinitdone = 1;
602	return 0;
603}
604
605/*
606 * Start interface
607 */
608static int esd_usb2_start(struct esd_usb2_net_priv *priv)
609{
610	struct esd_usb2 *dev = priv->usb2;
611	struct net_device *netdev = priv->netdev;
612	struct esd_usb2_msg msg;
613	int err, i;
614
615	/*
616	 * Enable all IDs
617	 * The IDADD message takes up to 64 32 bit bitmasks (2048 bits).
618	 * Each bit represents one 11 bit CAN identifier. A set bit
619	 * enables reception of the corresponding CAN identifier. A cleared
620	 * bit disabled this identifier. An additional bitmask value
621	 * following the CAN 2.0A bits is used to enable reception of
622	 * extended CAN frames. Only the LSB of this final mask is checked
623	 * for the complete 29 bit ID range. The IDADD message also allows
624	 * filter configuration for an ID subset. In this case you can add
625	 * the number of the starting bitmask (0..64) to the filter.option
626	 * field followed by only some bitmasks.
627	 */
628	msg.msg.hdr.cmd = CMD_IDADD;
629	msg.msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
630	msg.msg.filter.net = priv->index;
631	msg.msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
632	for (i = 0; i < ESD_MAX_ID_SEGMENT; i++)
633		msg.msg.filter.mask[i] = cpu_to_le32(0xffffffff);
634	/* enable 29bit extended IDs */
635	msg.msg.filter.mask[ESD_MAX_ID_SEGMENT] = cpu_to_le32(0x00000001);
636
637	err = esd_usb2_send_msg(dev, &msg);
638	if (err)
639		goto failed;
640
641	err = esd_usb2_setup_rx_urbs(dev);
642	if (err)
643		goto failed;
644
645	priv->can.state = CAN_STATE_ERROR_ACTIVE;
646
647	return 0;
648
649failed:
650	if (err == -ENODEV)
651		netif_device_detach(netdev);
652
653	netdev_err(netdev, "couldn't start device: %d\n", err);
654
655	return err;
656}
657
658static void unlink_all_urbs(struct esd_usb2 *dev)
659{
660	struct esd_usb2_net_priv *priv;
661	int i, j;
662
663	usb_kill_anchored_urbs(&dev->rx_submitted);
664	for (i = 0; i < dev->net_count; i++) {
665		priv = dev->nets[i];
666		if (priv) {
667			usb_kill_anchored_urbs(&priv->tx_submitted);
668			atomic_set(&priv->active_tx_jobs, 0);
669
670			for (j = 0; j < MAX_TX_URBS; j++)
671				priv->tx_contexts[j].echo_index = MAX_TX_URBS;
672		}
673	}
674}
675
676static int esd_usb2_open(struct net_device *netdev)
677{
678	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
679	int err;
680
681	/* common open */
682	err = open_candev(netdev);
683	if (err)
684		return err;
685
686	/* finally start device */
687	err = esd_usb2_start(priv);
688	if (err) {
689		netdev_warn(netdev, "couldn't start device: %d\n", err);
690		close_candev(netdev);
691		return err;
692	}
693
694	priv->open_time = jiffies;
695
696	netif_start_queue(netdev);
697
698	return 0;
699}
700
701static netdev_tx_t esd_usb2_start_xmit(struct sk_buff *skb,
702				      struct net_device *netdev)
703{
704	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
705	struct esd_usb2 *dev = priv->usb2;
706	struct esd_tx_urb_context *context = NULL;
707	struct net_device_stats *stats = &netdev->stats;
708	struct can_frame *cf = (struct can_frame *)skb->data;
709	struct esd_usb2_msg *msg;
710	struct urb *urb;
711	u8 *buf;
712	int i, err;
713	int ret = NETDEV_TX_OK;
714	size_t size = sizeof(struct esd_usb2_msg);
715
716	if (can_dropped_invalid_skb(netdev, skb))
717		return NETDEV_TX_OK;
718
719	/* create a URB, and a buffer for it, and copy the data to the URB */
720	urb = usb_alloc_urb(0, GFP_ATOMIC);
721	if (!urb) {
722		netdev_err(netdev, "No memory left for URBs\n");
723		stats->tx_dropped++;
724		dev_kfree_skb(skb);
725		goto nourbmem;
726	}
727
728	buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC,
729				 &urb->transfer_dma);
730	if (!buf) {
731		netdev_err(netdev, "No memory left for USB buffer\n");
732		stats->tx_dropped++;
733		dev_kfree_skb(skb);
734		goto nobufmem;
735	}
736
737	msg = (struct esd_usb2_msg *)buf;
738
739	msg->msg.hdr.len = 3; /* minimal length */
740	msg->msg.hdr.cmd = CMD_CAN_TX;
741	msg->msg.tx.net = priv->index;
742	msg->msg.tx.dlc = cf->can_dlc;
743	msg->msg.tx.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
744
745	if (cf->can_id & CAN_RTR_FLAG)
746		msg->msg.tx.dlc |= ESD_RTR;
747
748	if (cf->can_id & CAN_EFF_FLAG)
749		msg->msg.tx.id |= cpu_to_le32(ESD_EXTID);
750
751	for (i = 0; i < cf->can_dlc; i++)
752		msg->msg.tx.data[i] = cf->data[i];
753
754	msg->msg.hdr.len += (cf->can_dlc + 3) >> 2;
755
756	for (i = 0; i < MAX_TX_URBS; i++) {
757		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
758			context = &priv->tx_contexts[i];
759			break;
760		}
761	}
762
763	/*
764	 * This may never happen.
765	 */
766	if (!context) {
767		netdev_warn(netdev, "couldn't find free context\n");
768		ret = NETDEV_TX_BUSY;
769		goto releasebuf;
770	}
771
772	context->priv = priv;
773	context->echo_index = i;
774	context->dlc = cf->can_dlc;
775
776	/* hnd must not be 0 - MSB is stripped in txdone handling */
777	msg->msg.tx.hnd = 0x80000000 | i; /* returned in TX done message */
778
779	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
780			  msg->msg.hdr.len << 2,
781			  esd_usb2_write_bulk_callback, context);
782
783	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
784
785	usb_anchor_urb(urb, &priv->tx_submitted);
786
787	can_put_echo_skb(skb, netdev, context->echo_index);
788
789	atomic_inc(&priv->active_tx_jobs);
790
791	/* Slow down tx path */
792	if (atomic_read(&priv->active_tx_jobs) >= MAX_TX_URBS)
793		netif_stop_queue(netdev);
794
795	err = usb_submit_urb(urb, GFP_ATOMIC);
796	if (err) {
797		can_free_echo_skb(netdev, context->echo_index);
798
799		atomic_dec(&priv->active_tx_jobs);
800		usb_unanchor_urb(urb);
801
802		stats->tx_dropped++;
803
804		if (err == -ENODEV)
805			netif_device_detach(netdev);
806		else
807			netdev_warn(netdev, "failed tx_urb %d\n", err);
808
809		goto releasebuf;
810	}
811
812	netdev->trans_start = jiffies;
813
814	/*
815	 * Release our reference to this URB, the USB core will eventually free
816	 * it entirely.
817	 */
818	usb_free_urb(urb);
819
820	return NETDEV_TX_OK;
821
822releasebuf:
823	usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
824
825nobufmem:
826	usb_free_urb(urb);
827
828nourbmem:
829	return ret;
830}
831
832static int esd_usb2_close(struct net_device *netdev)
833{
834	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
835	struct esd_usb2_msg msg;
836	int i;
837
838	/* Disable all IDs (see esd_usb2_start()) */
839	msg.msg.hdr.cmd = CMD_IDADD;
840	msg.msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
841	msg.msg.filter.net = priv->index;
842	msg.msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
843	for (i = 0; i <= ESD_MAX_ID_SEGMENT; i++)
844		msg.msg.filter.mask[i] = 0;
845	if (esd_usb2_send_msg(priv->usb2, &msg) < 0)
846		netdev_err(netdev, "sending idadd message failed\n");
847
848	/* set CAN controller to reset mode */
849	msg.msg.hdr.len = 2;
850	msg.msg.hdr.cmd = CMD_SETBAUD;
851	msg.msg.setbaud.net = priv->index;
852	msg.msg.setbaud.rsvd = 0;
853	msg.msg.setbaud.baud = cpu_to_le32(ESD_USB2_NO_BAUDRATE);
854	if (esd_usb2_send_msg(priv->usb2, &msg) < 0)
855		netdev_err(netdev, "sending setbaud message failed\n");
856
857	priv->can.state = CAN_STATE_STOPPED;
858
859	netif_stop_queue(netdev);
860
861	close_candev(netdev);
862
863	priv->open_time = 0;
864
865	return 0;
866}
867
868static const struct net_device_ops esd_usb2_netdev_ops = {
869	.ndo_open = esd_usb2_open,
870	.ndo_stop = esd_usb2_close,
871	.ndo_start_xmit = esd_usb2_start_xmit,
872};
873
874static struct can_bittiming_const esd_usb2_bittiming_const = {
875	.name = "esd_usb2",
876	.tseg1_min = ESD_USB2_TSEG1_MIN,
877	.tseg1_max = ESD_USB2_TSEG1_MAX,
878	.tseg2_min = ESD_USB2_TSEG2_MIN,
879	.tseg2_max = ESD_USB2_TSEG2_MAX,
880	.sjw_max = ESD_USB2_SJW_MAX,
881	.brp_min = ESD_USB2_BRP_MIN,
882	.brp_max = ESD_USB2_BRP_MAX,
883	.brp_inc = ESD_USB2_BRP_INC,
884};
885
886static int esd_usb2_set_bittiming(struct net_device *netdev)
887{
888	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
889	struct can_bittiming *bt = &priv->can.bittiming;
890	struct esd_usb2_msg msg;
891	u32 canbtr;
892
893	canbtr = ESD_USB2_UBR;
894	canbtr |= (bt->brp - 1) & (ESD_USB2_BRP_MAX - 1);
895	canbtr |= ((bt->sjw - 1) & (ESD_USB2_SJW_MAX - 1))
896		<< ESD_USB2_SJW_SHIFT;
897	canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
898		   & (ESD_USB2_TSEG1_MAX - 1))
899		<< ESD_USB2_TSEG1_SHIFT;
900	canbtr |= ((bt->phase_seg2 - 1) & (ESD_USB2_TSEG2_MAX - 1))
901		<< ESD_USB2_TSEG2_SHIFT;
902	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
903		canbtr |= ESD_USB2_3_SAMPLES;
904
905	msg.msg.hdr.len = 2;
906	msg.msg.hdr.cmd = CMD_SETBAUD;
907	msg.msg.setbaud.net = priv->index;
908	msg.msg.setbaud.rsvd = 0;
909	msg.msg.setbaud.baud = cpu_to_le32(canbtr);
910
911	netdev_info(netdev, "setting BTR=%#x\n", canbtr);
912
913	return esd_usb2_send_msg(priv->usb2, &msg);
914}
915
916static int esd_usb2_get_berr_counter(const struct net_device *netdev,
917				     struct can_berr_counter *bec)
918{
919	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
920
921	bec->txerr = priv->bec.txerr;
922	bec->rxerr = priv->bec.rxerr;
923
924	return 0;
925}
926
927static int esd_usb2_set_mode(struct net_device *netdev, enum can_mode mode)
928{
929	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
930
931	if (!priv->open_time)
932		return -EINVAL;
933
934	switch (mode) {
935	case CAN_MODE_START:
936		netif_wake_queue(netdev);
937		break;
938
939	default:
940		return -EOPNOTSUPP;
941	}
942
943	return 0;
944}
945
946static int esd_usb2_probe_one_net(struct usb_interface *intf, int index)
947{
948	struct esd_usb2 *dev = usb_get_intfdata(intf);
949	struct net_device *netdev;
950	struct esd_usb2_net_priv *priv;
951	int err = 0;
952	int i;
953
954	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
955	if (!netdev) {
956		dev_err(&intf->dev, "couldn't alloc candev\n");
957		err = -ENOMEM;
958		goto done;
959	}
960
961	priv = netdev_priv(netdev);
962
963	init_usb_anchor(&priv->tx_submitted);
964	atomic_set(&priv->active_tx_jobs, 0);
965
966	for (i = 0; i < MAX_TX_URBS; i++)
967		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
968
969	priv->usb2 = dev;
970	priv->netdev = netdev;
971	priv->index = index;
972
973	priv->can.state = CAN_STATE_STOPPED;
974	priv->can.clock.freq = ESD_USB2_CAN_CLOCK;
975	priv->can.bittiming_const = &esd_usb2_bittiming_const;
976	priv->can.do_set_bittiming = esd_usb2_set_bittiming;
977	priv->can.do_set_mode = esd_usb2_set_mode;
978	priv->can.do_get_berr_counter = esd_usb2_get_berr_counter;
979	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
980
981	netdev->flags |= IFF_ECHO; /* we support local echo */
982
983	netdev->netdev_ops = &esd_usb2_netdev_ops;
984
985	SET_NETDEV_DEV(netdev, &intf->dev);
986
987	err = register_candev(netdev);
988	if (err) {
989		dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
990		free_candev(netdev);
991		err = -ENOMEM;
992		goto done;
993	}
994
995	dev->nets[index] = priv;
996	netdev_info(netdev, "device %s registered\n", netdev->name);
997
998done:
999	return err;
1000}
1001
1002/*
1003 * probe function for new USB2 devices
1004 *
1005 * check version information and number of available
1006 * CAN interfaces
1007 */
1008static int esd_usb2_probe(struct usb_interface *intf,
1009			 const struct usb_device_id *id)
1010{
1011	struct esd_usb2 *dev;
1012	struct esd_usb2_msg msg;
1013	int i, err;
1014
1015	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1016	if (!dev) {
1017		err = -ENOMEM;
1018		goto done;
1019	}
1020
1021	dev->udev = interface_to_usbdev(intf);
1022
1023	init_usb_anchor(&dev->rx_submitted);
1024
1025	usb_set_intfdata(intf, dev);
1026
1027	/* query number of CAN interfaces (nets) */
1028	msg.msg.hdr.cmd = CMD_VERSION;
1029	msg.msg.hdr.len = 2;
1030	msg.msg.version.rsvd = 0;
1031	msg.msg.version.flags = 0;
1032	msg.msg.version.drv_version = 0;
1033
1034	err = esd_usb2_send_msg(dev, &msg);
1035	if (err < 0) {
1036		dev_err(&intf->dev, "sending version message failed\n");
1037		goto free_dev;
1038	}
1039
1040	err = esd_usb2_wait_msg(dev, &msg);
1041	if (err < 0) {
1042		dev_err(&intf->dev, "no version message answer\n");
1043		goto free_dev;
1044	}
1045
1046	dev->net_count = (int)msg.msg.version_reply.nets;
1047	dev->version = le32_to_cpu(msg.msg.version_reply.version);
1048
1049	if (device_create_file(&intf->dev, &dev_attr_firmware))
1050		dev_err(&intf->dev,
1051			"Couldn't create device file for firmware\n");
1052
1053	if (device_create_file(&intf->dev, &dev_attr_hardware))
1054		dev_err(&intf->dev,
1055			"Couldn't create device file for hardware\n");
1056
1057	if (device_create_file(&intf->dev, &dev_attr_nets))
1058		dev_err(&intf->dev,
1059			"Couldn't create device file for nets\n");
1060
1061	/* do per device probing */
1062	for (i = 0; i < dev->net_count; i++)
1063		esd_usb2_probe_one_net(intf, i);
1064
1065	return 0;
1066
1067free_dev:
1068	kfree(dev);
1069done:
1070	return err;
1071}
1072
1073/*
1074 * called by the usb core when the device is removed from the system
1075 */
1076static void esd_usb2_disconnect(struct usb_interface *intf)
1077{
1078	struct esd_usb2 *dev = usb_get_intfdata(intf);
1079	struct net_device *netdev;
1080	int i;
1081
1082	device_remove_file(&intf->dev, &dev_attr_firmware);
1083	device_remove_file(&intf->dev, &dev_attr_hardware);
1084	device_remove_file(&intf->dev, &dev_attr_nets);
1085
1086	usb_set_intfdata(intf, NULL);
1087
1088	if (dev) {
1089		for (i = 0; i < dev->net_count; i++) {
1090			if (dev->nets[i]) {
1091				netdev = dev->nets[i]->netdev;
1092				unregister_netdev(netdev);
1093				free_candev(netdev);
1094			}
1095		}
1096		unlink_all_urbs(dev);
1097	}
1098}
1099
1100/* usb specific object needed to register this driver with the usb subsystem */
1101static struct usb_driver esd_usb2_driver = {
1102	.name = "esd_usb2",
1103	.probe = esd_usb2_probe,
1104	.disconnect = esd_usb2_disconnect,
1105	.id_table = esd_usb2_table,
1106};
1107
1108module_usb_driver(esd_usb2_driver);
1109