1/*
2 * CAN driver for esd CAN-USB/2 and CAN-USB/Micro
3 *
4 * Copyright (C) 2010-2012 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/signal.h>
20#include <linux/slab.h>
21#include <linux/module.h>
22#include <linux/netdevice.h>
23#include <linux/usb.h>
24
25#include <linux/can.h>
26#include <linux/can/dev.h>
27#include <linux/can/error.h>
28
29MODULE_AUTHOR("Matthias Fuchs <matthias.fuchs@esd.eu>");
30MODULE_DESCRIPTION("CAN driver for esd CAN-USB/2 and CAN-USB/Micro interfaces");
31MODULE_LICENSE("GPL v2");
32
33/* Define these values to match your devices */
34#define USB_ESDGMBH_VENDOR_ID	0x0ab4
35#define USB_CANUSB2_PRODUCT_ID	0x0010
36#define USB_CANUSBM_PRODUCT_ID	0x0011
37
38#define ESD_USB2_CAN_CLOCK	60000000
39#define ESD_USBM_CAN_CLOCK	36000000
40#define ESD_USB2_MAX_NETS	2
41
42/* USB2 commands */
43#define CMD_VERSION		1 /* also used for VERSION_REPLY */
44#define CMD_CAN_RX		2 /* device to host only */
45#define CMD_CAN_TX		3 /* also used for TX_DONE */
46#define CMD_SETBAUD		4 /* also used for SETBAUD_REPLY */
47#define CMD_TS			5 /* also used for TS_REPLY */
48#define CMD_IDADD		6 /* also used for IDADD_REPLY */
49
50/* esd CAN message flags - dlc field */
51#define ESD_RTR			0x10
52
53/* esd CAN message flags - id field */
54#define ESD_EXTID		0x20000000
55#define ESD_EVENT		0x40000000
56#define ESD_IDMASK		0x1fffffff
57
58/* esd CAN event ids used by this driver */
59#define ESD_EV_CAN_ERROR_EXT	2
60
61/* baudrate message flags */
62#define ESD_USB2_UBR		0x80000000
63#define ESD_USB2_LOM		0x40000000
64#define ESD_USB2_NO_BAUDRATE	0x7fffffff
65#define ESD_USB2_TSEG1_MIN	1
66#define ESD_USB2_TSEG1_MAX	16
67#define ESD_USB2_TSEG1_SHIFT	16
68#define ESD_USB2_TSEG2_MIN	1
69#define ESD_USB2_TSEG2_MAX	8
70#define ESD_USB2_TSEG2_SHIFT	20
71#define ESD_USB2_SJW_MAX	4
72#define ESD_USB2_SJW_SHIFT	14
73#define ESD_USBM_SJW_SHIFT	24
74#define ESD_USB2_BRP_MIN	1
75#define ESD_USB2_BRP_MAX	1024
76#define ESD_USB2_BRP_INC	1
77#define ESD_USB2_3_SAMPLES	0x00800000
78
79/* esd IDADD message */
80#define ESD_ID_ENABLE		0x80
81#define ESD_MAX_ID_SEGMENT	64
82
83/* SJA1000 ECC register (emulated by usb2 firmware) */
84#define SJA1000_ECC_SEG		0x1F
85#define SJA1000_ECC_DIR		0x20
86#define SJA1000_ECC_ERR		0x06
87#define SJA1000_ECC_BIT		0x00
88#define SJA1000_ECC_FORM	0x40
89#define SJA1000_ECC_STUFF	0x80
90#define SJA1000_ECC_MASK	0xc0
91
92/* esd bus state event codes */
93#define ESD_BUSSTATE_MASK	0xc0
94#define ESD_BUSSTATE_WARN	0x40
95#define ESD_BUSSTATE_ERRPASSIVE	0x80
96#define ESD_BUSSTATE_BUSOFF	0xc0
97
98#define RX_BUFFER_SIZE		1024
99#define MAX_RX_URBS		4
100#define MAX_TX_URBS		16 /* must be power of 2 */
101
102struct header_msg {
103	u8 len; /* len is always the total message length in 32bit words */
104	u8 cmd;
105	u8 rsvd[2];
106};
107
108struct version_msg {
109	u8 len;
110	u8 cmd;
111	u8 rsvd;
112	u8 flags;
113	__le32 drv_version;
114};
115
116struct version_reply_msg {
117	u8 len;
118	u8 cmd;
119	u8 nets;
120	u8 features;
121	__le32 version;
122	u8 name[16];
123	__le32 rsvd;
124	__le32 ts;
125};
126
127struct rx_msg {
128	u8 len;
129	u8 cmd;
130	u8 net;
131	u8 dlc;
132	__le32 ts;
133	__le32 id; /* upper 3 bits contain flags */
134	u8 data[8];
135};
136
137struct tx_msg {
138	u8 len;
139	u8 cmd;
140	u8 net;
141	u8 dlc;
142	__le32 hnd;
143	__le32 id; /* upper 3 bits contain flags */
144	u8 data[8];
145};
146
147struct tx_done_msg {
148	u8 len;
149	u8 cmd;
150	u8 net;
151	u8 status;
152	__le32 hnd;
153	__le32 ts;
154};
155
156struct id_filter_msg {
157	u8 len;
158	u8 cmd;
159	u8 net;
160	u8 option;
161	__le32 mask[ESD_MAX_ID_SEGMENT + 1];
162};
163
164struct set_baudrate_msg {
165	u8 len;
166	u8 cmd;
167	u8 net;
168	u8 rsvd;
169	__le32 baud;
170};
171
172/* Main message type used between library and application */
173struct __attribute__ ((packed)) esd_usb2_msg {
174	union {
175		struct header_msg hdr;
176		struct version_msg version;
177		struct version_reply_msg version_reply;
178		struct rx_msg rx;
179		struct tx_msg tx;
180		struct tx_done_msg txdone;
181		struct set_baudrate_msg setbaud;
182		struct id_filter_msg filter;
183	} msg;
184};
185
186static struct usb_device_id esd_usb2_table[] = {
187	{USB_DEVICE(USB_ESDGMBH_VENDOR_ID, USB_CANUSB2_PRODUCT_ID)},
188	{USB_DEVICE(USB_ESDGMBH_VENDOR_ID, USB_CANUSBM_PRODUCT_ID)},
189	{}
190};
191MODULE_DEVICE_TABLE(usb, esd_usb2_table);
192
193struct esd_usb2_net_priv;
194
195struct esd_tx_urb_context {
196	struct esd_usb2_net_priv *priv;
197	u32 echo_index;
198	int dlc;
199};
200
201struct esd_usb2 {
202	struct usb_device *udev;
203	struct esd_usb2_net_priv *nets[ESD_USB2_MAX_NETS];
204
205	struct usb_anchor rx_submitted;
206
207	int net_count;
208	u32 version;
209	int rxinitdone;
210};
211
212struct esd_usb2_net_priv {
213	struct can_priv can; /* must be the first member */
214
215	atomic_t active_tx_jobs;
216	struct usb_anchor tx_submitted;
217	struct esd_tx_urb_context tx_contexts[MAX_TX_URBS];
218
219	struct esd_usb2 *usb2;
220	struct net_device *netdev;
221	int index;
222	u8 old_state;
223	struct can_berr_counter bec;
224};
225
226static void esd_usb2_rx_event(struct esd_usb2_net_priv *priv,
227			      struct esd_usb2_msg *msg)
228{
229	struct net_device_stats *stats = &priv->netdev->stats;
230	struct can_frame *cf;
231	struct sk_buff *skb;
232	u32 id = le32_to_cpu(msg->msg.rx.id) & ESD_IDMASK;
233
234	if (id == ESD_EV_CAN_ERROR_EXT) {
235		u8 state = msg->msg.rx.data[0];
236		u8 ecc = msg->msg.rx.data[1];
237		u8 txerr = msg->msg.rx.data[2];
238		u8 rxerr = msg->msg.rx.data[3];
239
240		skb = alloc_can_err_skb(priv->netdev, &cf);
241		if (skb == NULL) {
242			stats->rx_dropped++;
243			return;
244		}
245
246		if (state != priv->old_state) {
247			priv->old_state = state;
248
249			switch (state & ESD_BUSSTATE_MASK) {
250			case ESD_BUSSTATE_BUSOFF:
251				priv->can.state = CAN_STATE_BUS_OFF;
252				cf->can_id |= CAN_ERR_BUSOFF;
253				can_bus_off(priv->netdev);
254				break;
255			case ESD_BUSSTATE_WARN:
256				priv->can.state = CAN_STATE_ERROR_WARNING;
257				priv->can.can_stats.error_warning++;
258				break;
259			case ESD_BUSSTATE_ERRPASSIVE:
260				priv->can.state = CAN_STATE_ERROR_PASSIVE;
261				priv->can.can_stats.error_passive++;
262				break;
263			default:
264				priv->can.state = CAN_STATE_ERROR_ACTIVE;
265				break;
266			}
267		} else {
268			priv->can.can_stats.bus_error++;
269			stats->rx_errors++;
270
271			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
272
273			switch (ecc & SJA1000_ECC_MASK) {
274			case SJA1000_ECC_BIT:
275				cf->data[2] |= CAN_ERR_PROT_BIT;
276				break;
277			case SJA1000_ECC_FORM:
278				cf->data[2] |= CAN_ERR_PROT_FORM;
279				break;
280			case SJA1000_ECC_STUFF:
281				cf->data[2] |= CAN_ERR_PROT_STUFF;
282				break;
283			default:
284				cf->data[2] |= CAN_ERR_PROT_UNSPEC;
285				cf->data[3] = ecc & SJA1000_ECC_SEG;
286				break;
287			}
288
289			/* Error occurred during transmission? */
290			if (!(ecc & SJA1000_ECC_DIR))
291				cf->data[2] |= CAN_ERR_PROT_TX;
292
293			if (priv->can.state == CAN_STATE_ERROR_WARNING ||
294			    priv->can.state == CAN_STATE_ERROR_PASSIVE) {
295				cf->data[1] = (txerr > rxerr) ?
296					CAN_ERR_CRTL_TX_PASSIVE :
297					CAN_ERR_CRTL_RX_PASSIVE;
298			}
299			cf->data[6] = txerr;
300			cf->data[7] = rxerr;
301		}
302
303		netif_rx(skb);
304
305		priv->bec.txerr = txerr;
306		priv->bec.rxerr = rxerr;
307
308		stats->rx_packets++;
309		stats->rx_bytes += cf->can_dlc;
310	}
311}
312
313static void esd_usb2_rx_can_msg(struct esd_usb2_net_priv *priv,
314				struct esd_usb2_msg *msg)
315{
316	struct net_device_stats *stats = &priv->netdev->stats;
317	struct can_frame *cf;
318	struct sk_buff *skb;
319	int i;
320	u32 id;
321
322	if (!netif_device_present(priv->netdev))
323		return;
324
325	id = le32_to_cpu(msg->msg.rx.id);
326
327	if (id & ESD_EVENT) {
328		esd_usb2_rx_event(priv, msg);
329	} else {
330		skb = alloc_can_skb(priv->netdev, &cf);
331		if (skb == NULL) {
332			stats->rx_dropped++;
333			return;
334		}
335
336		cf->can_id = id & ESD_IDMASK;
337		cf->can_dlc = get_can_dlc(msg->msg.rx.dlc);
338
339		if (id & ESD_EXTID)
340			cf->can_id |= CAN_EFF_FLAG;
341
342		if (msg->msg.rx.dlc & ESD_RTR) {
343			cf->can_id |= CAN_RTR_FLAG;
344		} else {
345			for (i = 0; i < cf->can_dlc; i++)
346				cf->data[i] = msg->msg.rx.data[i];
347		}
348
349		netif_rx(skb);
350
351		stats->rx_packets++;
352		stats->rx_bytes += cf->can_dlc;
353	}
354
355	return;
356}
357
358static void esd_usb2_tx_done_msg(struct esd_usb2_net_priv *priv,
359				 struct esd_usb2_msg *msg)
360{
361	struct net_device_stats *stats = &priv->netdev->stats;
362	struct net_device *netdev = priv->netdev;
363	struct esd_tx_urb_context *context;
364
365	if (!netif_device_present(netdev))
366		return;
367
368	context = &priv->tx_contexts[msg->msg.txdone.hnd & (MAX_TX_URBS - 1)];
369
370	if (!msg->msg.txdone.status) {
371		stats->tx_packets++;
372		stats->tx_bytes += context->dlc;
373		can_get_echo_skb(netdev, context->echo_index);
374	} else {
375		stats->tx_errors++;
376		can_free_echo_skb(netdev, context->echo_index);
377	}
378
379	/* Release context */
380	context->echo_index = MAX_TX_URBS;
381	atomic_dec(&priv->active_tx_jobs);
382
383	netif_wake_queue(netdev);
384}
385
386static void esd_usb2_read_bulk_callback(struct urb *urb)
387{
388	struct esd_usb2 *dev = urb->context;
389	int retval;
390	int pos = 0;
391	int i;
392
393	switch (urb->status) {
394	case 0: /* success */
395		break;
396
397	case -ENOENT:
398	case -ESHUTDOWN:
399		return;
400
401	default:
402		dev_info(dev->udev->dev.parent,
403			 "Rx URB aborted (%d)\n", urb->status);
404		goto resubmit_urb;
405	}
406
407	while (pos < urb->actual_length) {
408		struct esd_usb2_msg *msg;
409
410		msg = (struct esd_usb2_msg *)(urb->transfer_buffer + pos);
411
412		switch (msg->msg.hdr.cmd) {
413		case CMD_CAN_RX:
414			if (msg->msg.rx.net >= dev->net_count) {
415				dev_err(dev->udev->dev.parent, "format error\n");
416				break;
417			}
418
419			esd_usb2_rx_can_msg(dev->nets[msg->msg.rx.net], msg);
420			break;
421
422		case CMD_CAN_TX:
423			if (msg->msg.txdone.net >= dev->net_count) {
424				dev_err(dev->udev->dev.parent, "format error\n");
425				break;
426			}
427
428			esd_usb2_tx_done_msg(dev->nets[msg->msg.txdone.net],
429					     msg);
430			break;
431		}
432
433		pos += msg->msg.hdr.len << 2;
434
435		if (pos > urb->actual_length) {
436			dev_err(dev->udev->dev.parent, "format error\n");
437			break;
438		}
439	}
440
441resubmit_urb:
442	usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
443			  urb->transfer_buffer, RX_BUFFER_SIZE,
444			  esd_usb2_read_bulk_callback, dev);
445
446	retval = usb_submit_urb(urb, GFP_ATOMIC);
447	if (retval == -ENODEV) {
448		for (i = 0; i < dev->net_count; i++) {
449			if (dev->nets[i])
450				netif_device_detach(dev->nets[i]->netdev);
451		}
452	} else if (retval) {
453		dev_err(dev->udev->dev.parent,
454			"failed resubmitting read bulk urb: %d\n", retval);
455	}
456
457	return;
458}
459
460/*
461 * callback for bulk IN urb
462 */
463static void esd_usb2_write_bulk_callback(struct urb *urb)
464{
465	struct esd_tx_urb_context *context = urb->context;
466	struct esd_usb2_net_priv *priv;
467	struct net_device *netdev;
468	size_t size = sizeof(struct esd_usb2_msg);
469
470	WARN_ON(!context);
471
472	priv = context->priv;
473	netdev = priv->netdev;
474
475	/* free up our allocated buffer */
476	usb_free_coherent(urb->dev, size,
477			  urb->transfer_buffer, urb->transfer_dma);
478
479	if (!netif_device_present(netdev))
480		return;
481
482	if (urb->status)
483		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
484
485	netdev->trans_start = jiffies;
486}
487
488static ssize_t show_firmware(struct device *d,
489			     struct device_attribute *attr, char *buf)
490{
491	struct usb_interface *intf = to_usb_interface(d);
492	struct esd_usb2 *dev = usb_get_intfdata(intf);
493
494	return sprintf(buf, "%d.%d.%d\n",
495		       (dev->version >> 12) & 0xf,
496		       (dev->version >> 8) & 0xf,
497		       dev->version & 0xff);
498}
499static DEVICE_ATTR(firmware, S_IRUGO, show_firmware, NULL);
500
501static ssize_t show_hardware(struct device *d,
502			     struct device_attribute *attr, char *buf)
503{
504	struct usb_interface *intf = to_usb_interface(d);
505	struct esd_usb2 *dev = usb_get_intfdata(intf);
506
507	return sprintf(buf, "%d.%d.%d\n",
508		       (dev->version >> 28) & 0xf,
509		       (dev->version >> 24) & 0xf,
510		       (dev->version >> 16) & 0xff);
511}
512static DEVICE_ATTR(hardware, S_IRUGO, show_hardware, NULL);
513
514static ssize_t show_nets(struct device *d,
515			 struct device_attribute *attr, char *buf)
516{
517	struct usb_interface *intf = to_usb_interface(d);
518	struct esd_usb2 *dev = usb_get_intfdata(intf);
519
520	return sprintf(buf, "%d", dev->net_count);
521}
522static DEVICE_ATTR(nets, S_IRUGO, show_nets, NULL);
523
524static int esd_usb2_send_msg(struct esd_usb2 *dev, struct esd_usb2_msg *msg)
525{
526	int actual_length;
527
528	return usb_bulk_msg(dev->udev,
529			    usb_sndbulkpipe(dev->udev, 2),
530			    msg,
531			    msg->msg.hdr.len << 2,
532			    &actual_length,
533			    1000);
534}
535
536static int esd_usb2_wait_msg(struct esd_usb2 *dev,
537			     struct esd_usb2_msg *msg)
538{
539	int actual_length;
540
541	return usb_bulk_msg(dev->udev,
542			    usb_rcvbulkpipe(dev->udev, 1),
543			    msg,
544			    sizeof(*msg),
545			    &actual_length,
546			    1000);
547}
548
549static int esd_usb2_setup_rx_urbs(struct esd_usb2 *dev)
550{
551	int i, err = 0;
552
553	if (dev->rxinitdone)
554		return 0;
555
556	for (i = 0; i < MAX_RX_URBS; i++) {
557		struct urb *urb = NULL;
558		u8 *buf = NULL;
559
560		/* create a URB, and a buffer for it */
561		urb = usb_alloc_urb(0, GFP_KERNEL);
562		if (!urb) {
563			dev_warn(dev->udev->dev.parent,
564				 "No memory left for URBs\n");
565			err = -ENOMEM;
566			break;
567		}
568
569		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
570					 &urb->transfer_dma);
571		if (!buf) {
572			dev_warn(dev->udev->dev.parent,
573				 "No memory left for USB buffer\n");
574			err = -ENOMEM;
575			goto freeurb;
576		}
577
578		usb_fill_bulk_urb(urb, dev->udev,
579				  usb_rcvbulkpipe(dev->udev, 1),
580				  buf, RX_BUFFER_SIZE,
581				  esd_usb2_read_bulk_callback, dev);
582		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
583		usb_anchor_urb(urb, &dev->rx_submitted);
584
585		err = usb_submit_urb(urb, GFP_KERNEL);
586		if (err) {
587			usb_unanchor_urb(urb);
588			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
589					  urb->transfer_dma);
590		}
591
592freeurb:
593		/* Drop reference, USB core will take care of freeing it */
594		usb_free_urb(urb);
595		if (err)
596			break;
597	}
598
599	/* Did we submit any URBs */
600	if (i == 0) {
601		dev_err(dev->udev->dev.parent, "couldn't setup read URBs\n");
602		return err;
603	}
604
605	/* Warn if we've couldn't transmit all the URBs */
606	if (i < MAX_RX_URBS) {
607		dev_warn(dev->udev->dev.parent,
608			 "rx performance may be slow\n");
609	}
610
611	dev->rxinitdone = 1;
612	return 0;
613}
614
615/*
616 * Start interface
617 */
618static int esd_usb2_start(struct esd_usb2_net_priv *priv)
619{
620	struct esd_usb2 *dev = priv->usb2;
621	struct net_device *netdev = priv->netdev;
622	struct esd_usb2_msg *msg;
623	int err, i;
624
625	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
626	if (!msg) {
627		err = -ENOMEM;
628		goto out;
629	}
630
631	/*
632	 * Enable all IDs
633	 * The IDADD message takes up to 64 32 bit bitmasks (2048 bits).
634	 * Each bit represents one 11 bit CAN identifier. A set bit
635	 * enables reception of the corresponding CAN identifier. A cleared
636	 * bit disabled this identifier. An additional bitmask value
637	 * following the CAN 2.0A bits is used to enable reception of
638	 * extended CAN frames. Only the LSB of this final mask is checked
639	 * for the complete 29 bit ID range. The IDADD message also allows
640	 * filter configuration for an ID subset. In this case you can add
641	 * the number of the starting bitmask (0..64) to the filter.option
642	 * field followed by only some bitmasks.
643	 */
644	msg->msg.hdr.cmd = CMD_IDADD;
645	msg->msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
646	msg->msg.filter.net = priv->index;
647	msg->msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
648	for (i = 0; i < ESD_MAX_ID_SEGMENT; i++)
649		msg->msg.filter.mask[i] = cpu_to_le32(0xffffffff);
650	/* enable 29bit extended IDs */
651	msg->msg.filter.mask[ESD_MAX_ID_SEGMENT] = cpu_to_le32(0x00000001);
652
653	err = esd_usb2_send_msg(dev, msg);
654	if (err)
655		goto out;
656
657	err = esd_usb2_setup_rx_urbs(dev);
658	if (err)
659		goto out;
660
661	priv->can.state = CAN_STATE_ERROR_ACTIVE;
662
663out:
664	if (err == -ENODEV)
665		netif_device_detach(netdev);
666	if (err)
667		netdev_err(netdev, "couldn't start device: %d\n", err);
668
669	kfree(msg);
670	return err;
671}
672
673static void unlink_all_urbs(struct esd_usb2 *dev)
674{
675	struct esd_usb2_net_priv *priv;
676	int i, j;
677
678	usb_kill_anchored_urbs(&dev->rx_submitted);
679	for (i = 0; i < dev->net_count; i++) {
680		priv = dev->nets[i];
681		if (priv) {
682			usb_kill_anchored_urbs(&priv->tx_submitted);
683			atomic_set(&priv->active_tx_jobs, 0);
684
685			for (j = 0; j < MAX_TX_URBS; j++)
686				priv->tx_contexts[j].echo_index = MAX_TX_URBS;
687		}
688	}
689}
690
691static int esd_usb2_open(struct net_device *netdev)
692{
693	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
694	int err;
695
696	/* common open */
697	err = open_candev(netdev);
698	if (err)
699		return err;
700
701	/* finally start device */
702	err = esd_usb2_start(priv);
703	if (err) {
704		netdev_warn(netdev, "couldn't start device: %d\n", err);
705		close_candev(netdev);
706		return err;
707	}
708
709	netif_start_queue(netdev);
710
711	return 0;
712}
713
714static netdev_tx_t esd_usb2_start_xmit(struct sk_buff *skb,
715				      struct net_device *netdev)
716{
717	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
718	struct esd_usb2 *dev = priv->usb2;
719	struct esd_tx_urb_context *context = NULL;
720	struct net_device_stats *stats = &netdev->stats;
721	struct can_frame *cf = (struct can_frame *)skb->data;
722	struct esd_usb2_msg *msg;
723	struct urb *urb;
724	u8 *buf;
725	int i, err;
726	int ret = NETDEV_TX_OK;
727	size_t size = sizeof(struct esd_usb2_msg);
728
729	if (can_dropped_invalid_skb(netdev, skb))
730		return NETDEV_TX_OK;
731
732	/* create a URB, and a buffer for it, and copy the data to the URB */
733	urb = usb_alloc_urb(0, GFP_ATOMIC);
734	if (!urb) {
735		netdev_err(netdev, "No memory left for URBs\n");
736		stats->tx_dropped++;
737		dev_kfree_skb(skb);
738		goto nourbmem;
739	}
740
741	buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC,
742				 &urb->transfer_dma);
743	if (!buf) {
744		netdev_err(netdev, "No memory left for USB buffer\n");
745		stats->tx_dropped++;
746		dev_kfree_skb(skb);
747		goto nobufmem;
748	}
749
750	msg = (struct esd_usb2_msg *)buf;
751
752	msg->msg.hdr.len = 3; /* minimal length */
753	msg->msg.hdr.cmd = CMD_CAN_TX;
754	msg->msg.tx.net = priv->index;
755	msg->msg.tx.dlc = cf->can_dlc;
756	msg->msg.tx.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
757
758	if (cf->can_id & CAN_RTR_FLAG)
759		msg->msg.tx.dlc |= ESD_RTR;
760
761	if (cf->can_id & CAN_EFF_FLAG)
762		msg->msg.tx.id |= cpu_to_le32(ESD_EXTID);
763
764	for (i = 0; i < cf->can_dlc; i++)
765		msg->msg.tx.data[i] = cf->data[i];
766
767	msg->msg.hdr.len += (cf->can_dlc + 3) >> 2;
768
769	for (i = 0; i < MAX_TX_URBS; i++) {
770		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
771			context = &priv->tx_contexts[i];
772			break;
773		}
774	}
775
776	/*
777	 * This may never happen.
778	 */
779	if (!context) {
780		netdev_warn(netdev, "couldn't find free context\n");
781		ret = NETDEV_TX_BUSY;
782		goto releasebuf;
783	}
784
785	context->priv = priv;
786	context->echo_index = i;
787	context->dlc = cf->can_dlc;
788
789	/* hnd must not be 0 - MSB is stripped in txdone handling */
790	msg->msg.tx.hnd = 0x80000000 | i; /* returned in TX done message */
791
792	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
793			  msg->msg.hdr.len << 2,
794			  esd_usb2_write_bulk_callback, context);
795
796	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
797
798	usb_anchor_urb(urb, &priv->tx_submitted);
799
800	can_put_echo_skb(skb, netdev, context->echo_index);
801
802	atomic_inc(&priv->active_tx_jobs);
803
804	/* Slow down tx path */
805	if (atomic_read(&priv->active_tx_jobs) >= MAX_TX_URBS)
806		netif_stop_queue(netdev);
807
808	err = usb_submit_urb(urb, GFP_ATOMIC);
809	if (err) {
810		can_free_echo_skb(netdev, context->echo_index);
811
812		atomic_dec(&priv->active_tx_jobs);
813		usb_unanchor_urb(urb);
814
815		stats->tx_dropped++;
816
817		if (err == -ENODEV)
818			netif_device_detach(netdev);
819		else
820			netdev_warn(netdev, "failed tx_urb %d\n", err);
821
822		goto releasebuf;
823	}
824
825	netdev->trans_start = jiffies;
826
827	/*
828	 * Release our reference to this URB, the USB core will eventually free
829	 * it entirely.
830	 */
831	usb_free_urb(urb);
832
833	return NETDEV_TX_OK;
834
835releasebuf:
836	usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
837
838nobufmem:
839	usb_free_urb(urb);
840
841nourbmem:
842	return ret;
843}
844
845static int esd_usb2_close(struct net_device *netdev)
846{
847	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
848	struct esd_usb2_msg *msg;
849	int i;
850
851	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
852	if (!msg)
853		return -ENOMEM;
854
855	/* Disable all IDs (see esd_usb2_start()) */
856	msg->msg.hdr.cmd = CMD_IDADD;
857	msg->msg.hdr.len = 2 + ESD_MAX_ID_SEGMENT;
858	msg->msg.filter.net = priv->index;
859	msg->msg.filter.option = ESD_ID_ENABLE; /* start with segment 0 */
860	for (i = 0; i <= ESD_MAX_ID_SEGMENT; i++)
861		msg->msg.filter.mask[i] = 0;
862	if (esd_usb2_send_msg(priv->usb2, msg) < 0)
863		netdev_err(netdev, "sending idadd message failed\n");
864
865	/* set CAN controller to reset mode */
866	msg->msg.hdr.len = 2;
867	msg->msg.hdr.cmd = CMD_SETBAUD;
868	msg->msg.setbaud.net = priv->index;
869	msg->msg.setbaud.rsvd = 0;
870	msg->msg.setbaud.baud = cpu_to_le32(ESD_USB2_NO_BAUDRATE);
871	if (esd_usb2_send_msg(priv->usb2, msg) < 0)
872		netdev_err(netdev, "sending setbaud message failed\n");
873
874	priv->can.state = CAN_STATE_STOPPED;
875
876	netif_stop_queue(netdev);
877
878	close_candev(netdev);
879
880	kfree(msg);
881
882	return 0;
883}
884
885static const struct net_device_ops esd_usb2_netdev_ops = {
886	.ndo_open = esd_usb2_open,
887	.ndo_stop = esd_usb2_close,
888	.ndo_start_xmit = esd_usb2_start_xmit,
889	.ndo_change_mtu = can_change_mtu,
890};
891
892static const struct can_bittiming_const esd_usb2_bittiming_const = {
893	.name = "esd_usb2",
894	.tseg1_min = ESD_USB2_TSEG1_MIN,
895	.tseg1_max = ESD_USB2_TSEG1_MAX,
896	.tseg2_min = ESD_USB2_TSEG2_MIN,
897	.tseg2_max = ESD_USB2_TSEG2_MAX,
898	.sjw_max = ESD_USB2_SJW_MAX,
899	.brp_min = ESD_USB2_BRP_MIN,
900	.brp_max = ESD_USB2_BRP_MAX,
901	.brp_inc = ESD_USB2_BRP_INC,
902};
903
904static int esd_usb2_set_bittiming(struct net_device *netdev)
905{
906	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
907	struct can_bittiming *bt = &priv->can.bittiming;
908	struct esd_usb2_msg *msg;
909	int err;
910	u32 canbtr;
911	int sjw_shift;
912
913	canbtr = ESD_USB2_UBR;
914	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
915		canbtr |= ESD_USB2_LOM;
916
917	canbtr |= (bt->brp - 1) & (ESD_USB2_BRP_MAX - 1);
918
919	if (le16_to_cpu(priv->usb2->udev->descriptor.idProduct) ==
920	    USB_CANUSBM_PRODUCT_ID)
921		sjw_shift = ESD_USBM_SJW_SHIFT;
922	else
923		sjw_shift = ESD_USB2_SJW_SHIFT;
924
925	canbtr |= ((bt->sjw - 1) & (ESD_USB2_SJW_MAX - 1))
926		<< sjw_shift;
927	canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
928		   & (ESD_USB2_TSEG1_MAX - 1))
929		<< ESD_USB2_TSEG1_SHIFT;
930	canbtr |= ((bt->phase_seg2 - 1) & (ESD_USB2_TSEG2_MAX - 1))
931		<< ESD_USB2_TSEG2_SHIFT;
932	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
933		canbtr |= ESD_USB2_3_SAMPLES;
934
935	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
936	if (!msg)
937		return -ENOMEM;
938
939	msg->msg.hdr.len = 2;
940	msg->msg.hdr.cmd = CMD_SETBAUD;
941	msg->msg.setbaud.net = priv->index;
942	msg->msg.setbaud.rsvd = 0;
943	msg->msg.setbaud.baud = cpu_to_le32(canbtr);
944
945	netdev_info(netdev, "setting BTR=%#x\n", canbtr);
946
947	err = esd_usb2_send_msg(priv->usb2, msg);
948
949	kfree(msg);
950	return err;
951}
952
953static int esd_usb2_get_berr_counter(const struct net_device *netdev,
954				     struct can_berr_counter *bec)
955{
956	struct esd_usb2_net_priv *priv = netdev_priv(netdev);
957
958	bec->txerr = priv->bec.txerr;
959	bec->rxerr = priv->bec.rxerr;
960
961	return 0;
962}
963
964static int esd_usb2_set_mode(struct net_device *netdev, enum can_mode mode)
965{
966	switch (mode) {
967	case CAN_MODE_START:
968		netif_wake_queue(netdev);
969		break;
970
971	default:
972		return -EOPNOTSUPP;
973	}
974
975	return 0;
976}
977
978static int esd_usb2_probe_one_net(struct usb_interface *intf, int index)
979{
980	struct esd_usb2 *dev = usb_get_intfdata(intf);
981	struct net_device *netdev;
982	struct esd_usb2_net_priv *priv;
983	int err = 0;
984	int i;
985
986	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
987	if (!netdev) {
988		dev_err(&intf->dev, "couldn't alloc candev\n");
989		err = -ENOMEM;
990		goto done;
991	}
992
993	priv = netdev_priv(netdev);
994
995	init_usb_anchor(&priv->tx_submitted);
996	atomic_set(&priv->active_tx_jobs, 0);
997
998	for (i = 0; i < MAX_TX_URBS; i++)
999		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
1000
1001	priv->usb2 = dev;
1002	priv->netdev = netdev;
1003	priv->index = index;
1004
1005	priv->can.state = CAN_STATE_STOPPED;
1006	priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY;
1007
1008	if (le16_to_cpu(dev->udev->descriptor.idProduct) ==
1009	    USB_CANUSBM_PRODUCT_ID)
1010		priv->can.clock.freq = ESD_USBM_CAN_CLOCK;
1011	else {
1012		priv->can.clock.freq = ESD_USB2_CAN_CLOCK;
1013		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1014	}
1015
1016	priv->can.bittiming_const = &esd_usb2_bittiming_const;
1017	priv->can.do_set_bittiming = esd_usb2_set_bittiming;
1018	priv->can.do_set_mode = esd_usb2_set_mode;
1019	priv->can.do_get_berr_counter = esd_usb2_get_berr_counter;
1020
1021	netdev->flags |= IFF_ECHO; /* we support local echo */
1022
1023	netdev->netdev_ops = &esd_usb2_netdev_ops;
1024
1025	SET_NETDEV_DEV(netdev, &intf->dev);
1026	netdev->dev_id = index;
1027
1028	err = register_candev(netdev);
1029	if (err) {
1030		dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
1031		free_candev(netdev);
1032		err = -ENOMEM;
1033		goto done;
1034	}
1035
1036	dev->nets[index] = priv;
1037	netdev_info(netdev, "device %s registered\n", netdev->name);
1038
1039done:
1040	return err;
1041}
1042
1043/*
1044 * probe function for new USB2 devices
1045 *
1046 * check version information and number of available
1047 * CAN interfaces
1048 */
1049static int esd_usb2_probe(struct usb_interface *intf,
1050			 const struct usb_device_id *id)
1051{
1052	struct esd_usb2 *dev;
1053	struct esd_usb2_msg *msg;
1054	int i, err;
1055
1056	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1057	if (!dev) {
1058		err = -ENOMEM;
1059		goto done;
1060	}
1061
1062	dev->udev = interface_to_usbdev(intf);
1063
1064	init_usb_anchor(&dev->rx_submitted);
1065
1066	usb_set_intfdata(intf, dev);
1067
1068	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
1069	if (!msg) {
1070		err = -ENOMEM;
1071		goto free_msg;
1072	}
1073
1074	/* query number of CAN interfaces (nets) */
1075	msg->msg.hdr.cmd = CMD_VERSION;
1076	msg->msg.hdr.len = 2;
1077	msg->msg.version.rsvd = 0;
1078	msg->msg.version.flags = 0;
1079	msg->msg.version.drv_version = 0;
1080
1081	err = esd_usb2_send_msg(dev, msg);
1082	if (err < 0) {
1083		dev_err(&intf->dev, "sending version message failed\n");
1084		goto free_msg;
1085	}
1086
1087	err = esd_usb2_wait_msg(dev, msg);
1088	if (err < 0) {
1089		dev_err(&intf->dev, "no version message answer\n");
1090		goto free_msg;
1091	}
1092
1093	dev->net_count = (int)msg->msg.version_reply.nets;
1094	dev->version = le32_to_cpu(msg->msg.version_reply.version);
1095
1096	if (device_create_file(&intf->dev, &dev_attr_firmware))
1097		dev_err(&intf->dev,
1098			"Couldn't create device file for firmware\n");
1099
1100	if (device_create_file(&intf->dev, &dev_attr_hardware))
1101		dev_err(&intf->dev,
1102			"Couldn't create device file for hardware\n");
1103
1104	if (device_create_file(&intf->dev, &dev_attr_nets))
1105		dev_err(&intf->dev,
1106			"Couldn't create device file for nets\n");
1107
1108	/* do per device probing */
1109	for (i = 0; i < dev->net_count; i++)
1110		esd_usb2_probe_one_net(intf, i);
1111
1112free_msg:
1113	kfree(msg);
1114	if (err)
1115		kfree(dev);
1116done:
1117	return err;
1118}
1119
1120/*
1121 * called by the usb core when the device is removed from the system
1122 */
1123static void esd_usb2_disconnect(struct usb_interface *intf)
1124{
1125	struct esd_usb2 *dev = usb_get_intfdata(intf);
1126	struct net_device *netdev;
1127	int i;
1128
1129	device_remove_file(&intf->dev, &dev_attr_firmware);
1130	device_remove_file(&intf->dev, &dev_attr_hardware);
1131	device_remove_file(&intf->dev, &dev_attr_nets);
1132
1133	usb_set_intfdata(intf, NULL);
1134
1135	if (dev) {
1136		for (i = 0; i < dev->net_count; i++) {
1137			if (dev->nets[i]) {
1138				netdev = dev->nets[i]->netdev;
1139				unregister_netdev(netdev);
1140				free_candev(netdev);
1141			}
1142		}
1143		unlink_all_urbs(dev);
1144		kfree(dev);
1145	}
1146}
1147
1148/* usb specific object needed to register this driver with the usb subsystem */
1149static struct usb_driver esd_usb2_driver = {
1150	.name = "esd_usb2",
1151	.probe = esd_usb2_probe,
1152	.disconnect = esd_usb2_disconnect,
1153	.id_table = esd_usb2_table,
1154};
1155
1156module_usb_driver(esd_usb2_driver);
1157