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v3.15
 
  1/*
  2 * Net1080 based USB host-to-host cables
  3 * Copyright (C) 2000-2005 by David Brownell
  4 *
  5 * This program is free software; you can redistribute it and/or modify
  6 * it under the terms of the GNU General Public License as published by
  7 * the Free Software Foundation; either version 2 of the License, or
  8 * (at your option) any later version.
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 *
 15 * You should have received a copy of the GNU General Public License
 16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 17 */
 18
 19// #define	DEBUG			// error path messages, extra info
 20// #define	VERBOSE			// more; success messages
 21
 22#include <linux/module.h>
 23#include <linux/netdevice.h>
 24#include <linux/etherdevice.h>
 25#include <linux/ethtool.h>
 26#include <linux/workqueue.h>
 27#include <linux/mii.h>
 28#include <linux/usb.h>
 29#include <linux/usb/usbnet.h>
 30#include <linux/slab.h>
 31
 32#include <asm/unaligned.h>
 33
 34
 35/*
 36 * Netchip 1080 driver ... http://www.netchip.com
 37 * (Sept 2004:  End-of-life announcement has been sent.)
 38 * Used in (some) LapLink cables
 39 */
 40
 41#define frame_errors	data[1]
 42
 43/*
 44 * NetChip framing of ethernet packets, supporting additional error
 45 * checks for links that may drop bulk packets from inside messages.
 46 * Odd USB length == always short read for last usb packet.
 47 *	- nc_header
 48 *	- Ethernet header (14 bytes)
 49 *	- payload
 50 *	- (optional padding byte, if needed so length becomes odd)
 51 *	- nc_trailer
 52 *
 53 * This framing is to be avoided for non-NetChip devices.
 54 */
 55
 56struct nc_header {		// packed:
 57	__le16	hdr_len;		// sizeof nc_header (LE, all)
 58	__le16	packet_len;		// payload size (including ethhdr)
 59	__le16	packet_id;		// detects dropped packets
 60#define MIN_HEADER	6
 61
 62	// all else is optional, and must start with:
 63	// __le16	vendorId;	// from usb-if
 64	// __le16	productId;
 65} __packed;
 66
 67#define	PAD_BYTE	((unsigned char)0xAC)
 68
 69struct nc_trailer {
 70	__le16	packet_id;
 71} __packed;
 72
 73// packets may use FLAG_FRAMING_NC and optional pad
 74#define FRAMED_SIZE(mtu) (sizeof (struct nc_header) \
 75				+ sizeof (struct ethhdr) \
 76				+ (mtu) \
 77				+ 1 \
 78				+ sizeof (struct nc_trailer))
 79
 80#define MIN_FRAMED	FRAMED_SIZE(0)
 81
 82/* packets _could_ be up to 64KB... */
 83#define NC_MAX_PACKET	32767
 84
 85
 86/*
 87 * Zero means no timeout; else, how long a 64 byte bulk packet may be queued
 88 * before the hardware drops it.  If that's done, the driver will need to
 89 * frame network packets to guard against the dropped USB packets.  The win32
 90 * driver sets this for both sides of the link.
 91 */
 92#define	NC_READ_TTL_MS	((u8)255)	// ms
 93
 94/*
 95 * We ignore most registers and EEPROM contents.
 96 */
 97#define	REG_USBCTL	((u8)0x04)
 98#define REG_TTL		((u8)0x10)
 99#define REG_STATUS	((u8)0x11)
100
101/*
102 * Vendor specific requests to read/write data
103 */
104#define	REQUEST_REGISTER	((u8)0x10)
105#define	REQUEST_EEPROM		((u8)0x11)
106
107static int
108nc_vendor_read(struct usbnet *dev, u8 req, u8 regnum, u16 *retval_ptr)
109{
110	int status = usbnet_read_cmd(dev, req,
111				     USB_DIR_IN | USB_TYPE_VENDOR |
112				     USB_RECIP_DEVICE,
113				     0, regnum, retval_ptr,
114				     sizeof *retval_ptr);
115	if (status > 0)
116		status = 0;
117	if (!status)
118		le16_to_cpus(retval_ptr);
119	return status;
120}
121
122static inline int
123nc_register_read(struct usbnet *dev, u8 regnum, u16 *retval_ptr)
124{
125	return nc_vendor_read(dev, REQUEST_REGISTER, regnum, retval_ptr);
126}
127
128// no retval ... can become async, usable in_interrupt()
129static void
130nc_vendor_write(struct usbnet *dev, u8 req, u8 regnum, u16 value)
131{
132	usbnet_write_cmd(dev, req,
133			 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
134			 value, regnum, NULL, 0);
135}
136
137static inline void
138nc_register_write(struct usbnet *dev, u8 regnum, u16 value)
139{
140	nc_vendor_write(dev, REQUEST_REGISTER, regnum, value);
141}
142
143
144#if 0
145static void nc_dump_registers(struct usbnet *dev)
146{
147	u8	reg;
148	u16	*vp = kmalloc(sizeof (u16));
149
150	if (!vp)
151		return;
152
153	netdev_dbg(dev->net, "registers:\n");
154	for (reg = 0; reg < 0x20; reg++) {
155		int retval;
156
157		// reading some registers is trouble
158		if (reg >= 0x08 && reg <= 0xf)
159			continue;
160		if (reg >= 0x12 && reg <= 0x1e)
161			continue;
162
163		retval = nc_register_read(dev, reg, vp);
164		if (retval < 0)
165			netdev_dbg(dev->net, "reg [0x%x] ==> error %d\n",
166				   reg, retval);
167		else
168			netdev_dbg(dev->net, "reg [0x%x] = 0x%x\n", reg, *vp);
169	}
170	kfree(vp);
171}
172#endif
173
174
175/*-------------------------------------------------------------------------*/
176
177/*
178 * Control register
179 */
180
181#define	USBCTL_WRITABLE_MASK	0x1f0f
182// bits 15-13 reserved, r/o
183#define	USBCTL_ENABLE_LANG	(1 << 12)
184#define	USBCTL_ENABLE_MFGR	(1 << 11)
185#define	USBCTL_ENABLE_PROD	(1 << 10)
186#define	USBCTL_ENABLE_SERIAL	(1 << 9)
187#define	USBCTL_ENABLE_DEFAULTS	(1 << 8)
188// bits 7-4 reserved, r/o
189#define	USBCTL_FLUSH_OTHER	(1 << 3)
190#define	USBCTL_FLUSH_THIS	(1 << 2)
191#define	USBCTL_DISCONN_OTHER	(1 << 1)
192#define	USBCTL_DISCONN_THIS	(1 << 0)
193
194static inline void nc_dump_usbctl(struct usbnet *dev, u16 usbctl)
195{
196	netif_dbg(dev, link, dev->net,
197		  "net1080 %s-%s usbctl 0x%x:%s%s%s%s%s; this%s%s; other%s%s; r/o 0x%x\n",
198		  dev->udev->bus->bus_name, dev->udev->devpath,
199		  usbctl,
200		  (usbctl & USBCTL_ENABLE_LANG) ? " lang" : "",
201		  (usbctl & USBCTL_ENABLE_MFGR) ? " mfgr" : "",
202		  (usbctl & USBCTL_ENABLE_PROD) ? " prod" : "",
203		  (usbctl & USBCTL_ENABLE_SERIAL) ? " serial" : "",
204		  (usbctl & USBCTL_ENABLE_DEFAULTS) ? " defaults" : "",
205
206		  (usbctl & USBCTL_FLUSH_THIS) ? " FLUSH" : "",
207		  (usbctl & USBCTL_DISCONN_THIS) ? " DIS" : "",
208
209		  (usbctl & USBCTL_FLUSH_OTHER) ? " FLUSH" : "",
210		  (usbctl & USBCTL_DISCONN_OTHER) ? " DIS" : "",
211
212		  usbctl & ~USBCTL_WRITABLE_MASK);
213}
214
215/*-------------------------------------------------------------------------*/
216
217/*
218 * Status register
219 */
220
221#define	STATUS_PORT_A		(1 << 15)
222
223#define	STATUS_CONN_OTHER	(1 << 14)
224#define	STATUS_SUSPEND_OTHER	(1 << 13)
225#define	STATUS_MAILBOX_OTHER	(1 << 12)
226#define	STATUS_PACKETS_OTHER(n)	(((n) >> 8) & 0x03)
227
228#define	STATUS_CONN_THIS	(1 << 6)
229#define	STATUS_SUSPEND_THIS	(1 << 5)
230#define	STATUS_MAILBOX_THIS	(1 << 4)
231#define	STATUS_PACKETS_THIS(n)	(((n) >> 0) & 0x03)
232
233#define	STATUS_UNSPEC_MASK	0x0c8c
234#define	STATUS_NOISE_MASK 	((u16)~(0x0303|STATUS_UNSPEC_MASK))
235
236
237static inline void nc_dump_status(struct usbnet *dev, u16 status)
238{
239	netif_dbg(dev, link, dev->net,
240		  "net1080 %s-%s status 0x%x: this (%c) PKT=%d%s%s%s; other PKT=%d%s%s%s; unspec 0x%x\n",
241		  dev->udev->bus->bus_name, dev->udev->devpath,
242		  status,
243
244		  // XXX the packet counts don't seem right
245		  // (1 at reset, not 0); maybe UNSPEC too
246
247		  (status & STATUS_PORT_A) ? 'A' : 'B',
248		  STATUS_PACKETS_THIS(status),
249		  (status & STATUS_CONN_THIS) ? " CON" : "",
250		  (status & STATUS_SUSPEND_THIS) ? " SUS" : "",
251		  (status & STATUS_MAILBOX_THIS) ? " MBOX" : "",
252
253		  STATUS_PACKETS_OTHER(status),
254		  (status & STATUS_CONN_OTHER) ? " CON" : "",
255		  (status & STATUS_SUSPEND_OTHER) ? " SUS" : "",
256		  (status & STATUS_MAILBOX_OTHER) ? " MBOX" : "",
257
258		  status & STATUS_UNSPEC_MASK);
259}
260
261/*-------------------------------------------------------------------------*/
262
263/*
264 * TTL register
265 */
266
267#define	TTL_THIS(ttl)	(0x00ff & ttl)
268#define	TTL_OTHER(ttl)	(0x00ff & (ttl >> 8))
269#define MK_TTL(this,other)	((u16)(((other)<<8)|(0x00ff&(this))))
270
271static inline void nc_dump_ttl(struct usbnet *dev, u16 ttl)
272{
273	netif_dbg(dev, link, dev->net, "net1080 %s-%s ttl 0x%x this = %d, other = %d\n",
274		  dev->udev->bus->bus_name, dev->udev->devpath,
275		  ttl, TTL_THIS(ttl), TTL_OTHER(ttl));
276}
277
278/*-------------------------------------------------------------------------*/
279
280static int net1080_reset(struct usbnet *dev)
281{
282	u16		usbctl, status, ttl;
283	u16		vp;
284	int		retval;
285
286	// nc_dump_registers(dev);
287
288	if ((retval = nc_register_read(dev, REG_STATUS, &vp)) < 0) {
289		netdev_dbg(dev->net, "can't read %s-%s status: %d\n",
290			   dev->udev->bus->bus_name, dev->udev->devpath, retval);
291		goto done;
292	}
293	status = vp;
294	nc_dump_status(dev, status);
295
296	if ((retval = nc_register_read(dev, REG_USBCTL, &vp)) < 0) {
297		netdev_dbg(dev->net, "can't read USBCTL, %d\n", retval);
298		goto done;
299	}
300	usbctl = vp;
301	nc_dump_usbctl(dev, usbctl);
302
303	nc_register_write(dev, REG_USBCTL,
304			USBCTL_FLUSH_THIS | USBCTL_FLUSH_OTHER);
305
306	if ((retval = nc_register_read(dev, REG_TTL, &vp)) < 0) {
307		netdev_dbg(dev->net, "can't read TTL, %d\n", retval);
308		goto done;
309	}
310	ttl = vp;
311	// nc_dump_ttl(dev, ttl);
312
313	nc_register_write(dev, REG_TTL,
314			MK_TTL(NC_READ_TTL_MS, TTL_OTHER(ttl)) );
315	netdev_dbg(dev->net, "assigned TTL, %d ms\n", NC_READ_TTL_MS);
316
317	netif_info(dev, link, dev->net, "port %c, peer %sconnected\n",
318		   (status & STATUS_PORT_A) ? 'A' : 'B',
319		   (status & STATUS_CONN_OTHER) ? "" : "dis");
320	retval = 0;
321
322done:
323	return retval;
324}
325
326static int net1080_check_connect(struct usbnet *dev)
327{
328	int			retval;
329	u16			status;
330	u16			vp;
331
332	retval = nc_register_read(dev, REG_STATUS, &vp);
333	status = vp;
334	if (retval != 0) {
335		netdev_dbg(dev->net, "net1080_check_conn read - %d\n", retval);
336		return retval;
337	}
338	if ((status & STATUS_CONN_OTHER) != STATUS_CONN_OTHER)
339		return -ENOLINK;
340	return 0;
341}
342
343static void nc_ensure_sync(struct usbnet *dev)
344{
345	if (++dev->frame_errors <= 5)
346		return;
347
348	if (usbnet_write_cmd_async(dev, REQUEST_REGISTER,
349					USB_DIR_OUT | USB_TYPE_VENDOR |
350					USB_RECIP_DEVICE,
351					USBCTL_FLUSH_THIS |
352					USBCTL_FLUSH_OTHER,
353					REG_USBCTL, NULL, 0))
354		return;
355
356	netif_dbg(dev, rx_err, dev->net,
357		  "flush net1080; too many framing errors\n");
358	dev->frame_errors = 0;
359}
360
361static int net1080_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
362{
363	struct nc_header	*header;
364	struct nc_trailer	*trailer;
365	u16			hdr_len, packet_len;
366
367	/* This check is no longer done by usbnet */
368	if (skb->len < dev->net->hard_header_len)
369		return 0;
370
371	if (!(skb->len & 0x01)) {
372		netdev_dbg(dev->net, "rx framesize %d range %d..%d mtu %d\n",
373			   skb->len, dev->net->hard_header_len, dev->hard_mtu,
374			   dev->net->mtu);
375		dev->net->stats.rx_frame_errors++;
376		nc_ensure_sync(dev);
377		return 0;
378	}
379
380	header = (struct nc_header *) skb->data;
381	hdr_len = le16_to_cpup(&header->hdr_len);
382	packet_len = le16_to_cpup(&header->packet_len);
383	if (FRAMED_SIZE(packet_len) > NC_MAX_PACKET) {
384		dev->net->stats.rx_frame_errors++;
385		netdev_dbg(dev->net, "packet too big, %d\n", packet_len);
386		nc_ensure_sync(dev);
387		return 0;
388	} else if (hdr_len < MIN_HEADER) {
389		dev->net->stats.rx_frame_errors++;
390		netdev_dbg(dev->net, "header too short, %d\n", hdr_len);
391		nc_ensure_sync(dev);
392		return 0;
393	} else if (hdr_len > MIN_HEADER) {
394		// out of band data for us?
395		netdev_dbg(dev->net, "header OOB, %d bytes\n", hdr_len - MIN_HEADER);
396		nc_ensure_sync(dev);
397		// switch (vendor/product ids) { ... }
398	}
399	skb_pull(skb, hdr_len);
400
401	trailer = (struct nc_trailer *)
402		(skb->data + skb->len - sizeof *trailer);
403	skb_trim(skb, skb->len - sizeof *trailer);
404
405	if ((packet_len & 0x01) == 0) {
406		if (skb->data [packet_len] != PAD_BYTE) {
407			dev->net->stats.rx_frame_errors++;
408			netdev_dbg(dev->net, "bad pad\n");
409			return 0;
410		}
411		skb_trim(skb, skb->len - 1);
412	}
413	if (skb->len != packet_len) {
414		dev->net->stats.rx_frame_errors++;
415		netdev_dbg(dev->net, "bad packet len %d (expected %d)\n",
416			   skb->len, packet_len);
417		nc_ensure_sync(dev);
418		return 0;
419	}
420	if (header->packet_id != get_unaligned(&trailer->packet_id)) {
421		dev->net->stats.rx_fifo_errors++;
422		netdev_dbg(dev->net, "(2+ dropped) rx packet_id mismatch 0x%x 0x%x\n",
423			   le16_to_cpu(header->packet_id),
424			   le16_to_cpu(trailer->packet_id));
425		return 0;
426	}
427#if 0
428	netdev_dbg(dev->net, "frame <rx h %d p %d id %d\n", header->hdr_len,
429		   header->packet_len, header->packet_id);
430#endif
431	dev->frame_errors = 0;
432	return 1;
433}
434
435static struct sk_buff *
436net1080_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
437{
438	struct sk_buff		*skb2;
439	struct nc_header	*header = NULL;
440	struct nc_trailer	*trailer = NULL;
441	int			padlen = sizeof (struct nc_trailer);
442	int			len = skb->len;
443
444	if (!((len + padlen + sizeof (struct nc_header)) & 0x01))
445		padlen++;
446	if (!skb_cloned(skb)) {
447		int	headroom = skb_headroom(skb);
448		int	tailroom = skb_tailroom(skb);
449
450		if (padlen <= tailroom &&
451		    sizeof(struct nc_header) <= headroom)
452			/* There's enough head and tail room */
453			goto encapsulate;
454
455		if ((sizeof (struct nc_header) + padlen) <
456				(headroom + tailroom)) {
457			/* There's enough total room, so just readjust */
458			skb->data = memmove(skb->head
459						+ sizeof (struct nc_header),
460					    skb->data, skb->len);
461			skb_set_tail_pointer(skb, len);
462			goto encapsulate;
463		}
464	}
465
466	/* Create a new skb to use with the correct size */
467	skb2 = skb_copy_expand(skb,
468				sizeof (struct nc_header),
469				padlen,
470				flags);
471	dev_kfree_skb_any(skb);
472	if (!skb2)
473		return skb2;
474	skb = skb2;
475
476encapsulate:
477	/* header first */
478	header = (struct nc_header *) skb_push(skb, sizeof *header);
479	header->hdr_len = cpu_to_le16(sizeof (*header));
480	header->packet_len = cpu_to_le16(len);
481	header->packet_id = cpu_to_le16((u16)dev->xid++);
482
483	/* maybe pad; then trailer */
484	if (!((skb->len + sizeof *trailer) & 0x01))
485		*skb_put(skb, 1) = PAD_BYTE;
486	trailer = (struct nc_trailer *) skb_put(skb, sizeof *trailer);
487	put_unaligned(header->packet_id, &trailer->packet_id);
488#if 0
489	netdev_dbg(dev->net, "frame >tx h %d p %d id %d\n",
490		   header->hdr_len, header->packet_len,
491		   header->packet_id);
492#endif
493	return skb;
494}
495
496static int net1080_bind(struct usbnet *dev, struct usb_interface *intf)
497{
498	unsigned	extra = sizeof (struct nc_header)
499				+ 1
500				+ sizeof (struct nc_trailer);
501
502	dev->net->hard_header_len += extra;
503	dev->rx_urb_size = dev->net->hard_header_len + dev->net->mtu;
504	dev->hard_mtu = NC_MAX_PACKET;
505	return usbnet_get_endpoints (dev, intf);
506}
507
508static const struct driver_info	net1080_info = {
509	.description =	"NetChip TurboCONNECT",
510	.flags =	FLAG_POINTTOPOINT | FLAG_FRAMING_NC,
511	.bind =		net1080_bind,
512	.reset =	net1080_reset,
513	.check_connect = net1080_check_connect,
514	.rx_fixup =	net1080_rx_fixup,
515	.tx_fixup =	net1080_tx_fixup,
516};
517
518static const struct usb_device_id	products [] = {
519{
520	USB_DEVICE(0x0525, 0x1080),	// NetChip ref design
521	.driver_info =	(unsigned long) &net1080_info,
522}, {
523	USB_DEVICE(0x06D0, 0x0622),	// Laplink Gold
524	.driver_info =	(unsigned long) &net1080_info,
525},
526	{ },		// END
527};
528MODULE_DEVICE_TABLE(usb, products);
529
530static struct usb_driver net1080_driver = {
531	.name =		"net1080",
532	.id_table =	products,
533	.probe =	usbnet_probe,
534	.disconnect =	usbnet_disconnect,
535	.suspend =	usbnet_suspend,
536	.resume =	usbnet_resume,
537	.disable_hub_initiated_lpm = 1,
538};
539
540module_usb_driver(net1080_driver);
541
542MODULE_AUTHOR("David Brownell");
543MODULE_DESCRIPTION("NetChip 1080 based USB Host-to-Host Links");
544MODULE_LICENSE("GPL");
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Net1080 based USB host-to-host cables
  4 * Copyright (C) 2000-2005 by David Brownell
 
 
 
 
 
 
 
 
 
 
 
 
 
  5 */
  6
  7// #define	DEBUG			// error path messages, extra info
  8// #define	VERBOSE			// more; success messages
  9
 10#include <linux/module.h>
 11#include <linux/netdevice.h>
 12#include <linux/etherdevice.h>
 13#include <linux/ethtool.h>
 14#include <linux/workqueue.h>
 15#include <linux/mii.h>
 16#include <linux/usb.h>
 17#include <linux/usb/usbnet.h>
 18#include <linux/slab.h>
 19
 20#include <linux/unaligned.h>
 21
 22
 23/*
 24 * Netchip 1080 driver ... http://www.netchip.com
 25 * (Sept 2004:  End-of-life announcement has been sent.)
 26 * Used in (some) LapLink cables
 27 */
 28
 29#define frame_errors	data[1]
 30
 31/*
 32 * NetChip framing of ethernet packets, supporting additional error
 33 * checks for links that may drop bulk packets from inside messages.
 34 * Odd USB length == always short read for last usb packet.
 35 *	- nc_header
 36 *	- Ethernet header (14 bytes)
 37 *	- payload
 38 *	- (optional padding byte, if needed so length becomes odd)
 39 *	- nc_trailer
 40 *
 41 * This framing is to be avoided for non-NetChip devices.
 42 */
 43
 44struct nc_header {		// packed:
 45	__le16	hdr_len;		// sizeof nc_header (LE, all)
 46	__le16	packet_len;		// payload size (including ethhdr)
 47	__le16	packet_id;		// detects dropped packets
 48#define MIN_HEADER	6
 49
 50	// all else is optional, and must start with:
 51	// __le16	vendorId;	// from usb-if
 52	// __le16	productId;
 53} __packed;
 54
 55#define	PAD_BYTE	((unsigned char)0xAC)
 56
 57struct nc_trailer {
 58	__le16	packet_id;
 59} __packed;
 60
 61// packets may use FLAG_FRAMING_NC and optional pad
 62#define FRAMED_SIZE(mtu) (sizeof (struct nc_header) \
 63				+ sizeof (struct ethhdr) \
 64				+ (mtu) \
 65				+ 1 \
 66				+ sizeof (struct nc_trailer))
 67
 68#define MIN_FRAMED	FRAMED_SIZE(0)
 69
 70/* packets _could_ be up to 64KB... */
 71#define NC_MAX_PACKET	32767
 72
 73
 74/*
 75 * Zero means no timeout; else, how long a 64 byte bulk packet may be queued
 76 * before the hardware drops it.  If that's done, the driver will need to
 77 * frame network packets to guard against the dropped USB packets.  The win32
 78 * driver sets this for both sides of the link.
 79 */
 80#define	NC_READ_TTL_MS	((u8)255)	// ms
 81
 82/*
 83 * We ignore most registers and EEPROM contents.
 84 */
 85#define	REG_USBCTL	((u8)0x04)
 86#define REG_TTL		((u8)0x10)
 87#define REG_STATUS	((u8)0x11)
 88
 89/*
 90 * Vendor specific requests to read/write data
 91 */
 92#define	REQUEST_REGISTER	((u8)0x10)
 93#define	REQUEST_EEPROM		((u8)0x11)
 94
 95static int
 96nc_vendor_read(struct usbnet *dev, u8 req, u8 regnum, u16 *retval_ptr)
 97{
 98	int status = usbnet_read_cmd(dev, req,
 99				     USB_DIR_IN | USB_TYPE_VENDOR |
100				     USB_RECIP_DEVICE,
101				     0, regnum, retval_ptr,
102				     sizeof *retval_ptr);
103	if (status > 0)
104		status = 0;
105	if (!status)
106		le16_to_cpus(retval_ptr);
107	return status;
108}
109
110static inline int
111nc_register_read(struct usbnet *dev, u8 regnum, u16 *retval_ptr)
112{
113	return nc_vendor_read(dev, REQUEST_REGISTER, regnum, retval_ptr);
114}
115
 
116static void
117nc_vendor_write(struct usbnet *dev, u8 req, u8 regnum, u16 value)
118{
119	usbnet_write_cmd(dev, req,
120			 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
121			 value, regnum, NULL, 0);
122}
123
124static inline void
125nc_register_write(struct usbnet *dev, u8 regnum, u16 value)
126{
127	nc_vendor_write(dev, REQUEST_REGISTER, regnum, value);
128}
129
130
131#if 0
132static void nc_dump_registers(struct usbnet *dev)
133{
134	u8	reg;
135	u16	*vp = kmalloc(sizeof (u16));
136
137	if (!vp)
138		return;
139
140	netdev_dbg(dev->net, "registers:\n");
141	for (reg = 0; reg < 0x20; reg++) {
142		int retval;
143
144		// reading some registers is trouble
145		if (reg >= 0x08 && reg <= 0xf)
146			continue;
147		if (reg >= 0x12 && reg <= 0x1e)
148			continue;
149
150		retval = nc_register_read(dev, reg, vp);
151		if (retval < 0)
152			netdev_dbg(dev->net, "reg [0x%x] ==> error %d\n",
153				   reg, retval);
154		else
155			netdev_dbg(dev->net, "reg [0x%x] = 0x%x\n", reg, *vp);
156	}
157	kfree(vp);
158}
159#endif
160
161
162/*-------------------------------------------------------------------------*/
163
164/*
165 * Control register
166 */
167
168#define	USBCTL_WRITABLE_MASK	0x1f0f
169// bits 15-13 reserved, r/o
170#define	USBCTL_ENABLE_LANG	(1 << 12)
171#define	USBCTL_ENABLE_MFGR	(1 << 11)
172#define	USBCTL_ENABLE_PROD	(1 << 10)
173#define	USBCTL_ENABLE_SERIAL	(1 << 9)
174#define	USBCTL_ENABLE_DEFAULTS	(1 << 8)
175// bits 7-4 reserved, r/o
176#define	USBCTL_FLUSH_OTHER	(1 << 3)
177#define	USBCTL_FLUSH_THIS	(1 << 2)
178#define	USBCTL_DISCONN_OTHER	(1 << 1)
179#define	USBCTL_DISCONN_THIS	(1 << 0)
180
181static inline void nc_dump_usbctl(struct usbnet *dev, u16 usbctl)
182{
183	netif_dbg(dev, link, dev->net,
184		  "net1080 %s-%s usbctl 0x%x:%s%s%s%s%s; this%s%s; other%s%s; r/o 0x%x\n",
185		  dev->udev->bus->bus_name, dev->udev->devpath,
186		  usbctl,
187		  (usbctl & USBCTL_ENABLE_LANG) ? " lang" : "",
188		  (usbctl & USBCTL_ENABLE_MFGR) ? " mfgr" : "",
189		  (usbctl & USBCTL_ENABLE_PROD) ? " prod" : "",
190		  (usbctl & USBCTL_ENABLE_SERIAL) ? " serial" : "",
191		  (usbctl & USBCTL_ENABLE_DEFAULTS) ? " defaults" : "",
192
193		  (usbctl & USBCTL_FLUSH_THIS) ? " FLUSH" : "",
194		  (usbctl & USBCTL_DISCONN_THIS) ? " DIS" : "",
195
196		  (usbctl & USBCTL_FLUSH_OTHER) ? " FLUSH" : "",
197		  (usbctl & USBCTL_DISCONN_OTHER) ? " DIS" : "",
198
199		  usbctl & ~USBCTL_WRITABLE_MASK);
200}
201
202/*-------------------------------------------------------------------------*/
203
204/*
205 * Status register
206 */
207
208#define	STATUS_PORT_A		(1 << 15)
209
210#define	STATUS_CONN_OTHER	(1 << 14)
211#define	STATUS_SUSPEND_OTHER	(1 << 13)
212#define	STATUS_MAILBOX_OTHER	(1 << 12)
213#define	STATUS_PACKETS_OTHER(n)	(((n) >> 8) & 0x03)
214
215#define	STATUS_CONN_THIS	(1 << 6)
216#define	STATUS_SUSPEND_THIS	(1 << 5)
217#define	STATUS_MAILBOX_THIS	(1 << 4)
218#define	STATUS_PACKETS_THIS(n)	(((n) >> 0) & 0x03)
219
220#define	STATUS_UNSPEC_MASK	0x0c8c
221#define	STATUS_NOISE_MASK 	((u16)~(0x0303|STATUS_UNSPEC_MASK))
222
223
224static inline void nc_dump_status(struct usbnet *dev, u16 status)
225{
226	netif_dbg(dev, link, dev->net,
227		  "net1080 %s-%s status 0x%x: this (%c) PKT=%d%s%s%s; other PKT=%d%s%s%s; unspec 0x%x\n",
228		  dev->udev->bus->bus_name, dev->udev->devpath,
229		  status,
230
231		  // XXX the packet counts don't seem right
232		  // (1 at reset, not 0); maybe UNSPEC too
233
234		  (status & STATUS_PORT_A) ? 'A' : 'B',
235		  STATUS_PACKETS_THIS(status),
236		  (status & STATUS_CONN_THIS) ? " CON" : "",
237		  (status & STATUS_SUSPEND_THIS) ? " SUS" : "",
238		  (status & STATUS_MAILBOX_THIS) ? " MBOX" : "",
239
240		  STATUS_PACKETS_OTHER(status),
241		  (status & STATUS_CONN_OTHER) ? " CON" : "",
242		  (status & STATUS_SUSPEND_OTHER) ? " SUS" : "",
243		  (status & STATUS_MAILBOX_OTHER) ? " MBOX" : "",
244
245		  status & STATUS_UNSPEC_MASK);
246}
247
248/*-------------------------------------------------------------------------*/
249
250/*
251 * TTL register
252 */
253
 
254#define	TTL_OTHER(ttl)	(0x00ff & (ttl >> 8))
255#define MK_TTL(this,other)	((u16)(((other)<<8)|(0x00ff&(this))))
256
 
 
 
 
 
 
 
257/*-------------------------------------------------------------------------*/
258
259static int net1080_reset(struct usbnet *dev)
260{
261	u16		usbctl, status, ttl;
262	u16		vp;
263	int		retval;
264
265	// nc_dump_registers(dev);
266
267	if ((retval = nc_register_read(dev, REG_STATUS, &vp)) < 0) {
268		netdev_dbg(dev->net, "can't read %s-%s status: %d\n",
269			   dev->udev->bus->bus_name, dev->udev->devpath, retval);
270		goto done;
271	}
272	status = vp;
273	nc_dump_status(dev, status);
274
275	if ((retval = nc_register_read(dev, REG_USBCTL, &vp)) < 0) {
276		netdev_dbg(dev->net, "can't read USBCTL, %d\n", retval);
277		goto done;
278	}
279	usbctl = vp;
280	nc_dump_usbctl(dev, usbctl);
281
282	nc_register_write(dev, REG_USBCTL,
283			USBCTL_FLUSH_THIS | USBCTL_FLUSH_OTHER);
284
285	if ((retval = nc_register_read(dev, REG_TTL, &vp)) < 0) {
286		netdev_dbg(dev->net, "can't read TTL, %d\n", retval);
287		goto done;
288	}
289	ttl = vp;
 
290
291	nc_register_write(dev, REG_TTL,
292			MK_TTL(NC_READ_TTL_MS, TTL_OTHER(ttl)) );
293	netdev_dbg(dev->net, "assigned TTL, %d ms\n", NC_READ_TTL_MS);
294
295	netif_info(dev, link, dev->net, "port %c, peer %sconnected\n",
296		   (status & STATUS_PORT_A) ? 'A' : 'B',
297		   (status & STATUS_CONN_OTHER) ? "" : "dis");
298	retval = 0;
299
300done:
301	return retval;
302}
303
304static int net1080_check_connect(struct usbnet *dev)
305{
306	int			retval;
307	u16			status;
308	u16			vp;
309
310	retval = nc_register_read(dev, REG_STATUS, &vp);
311	status = vp;
312	if (retval != 0) {
313		netdev_dbg(dev->net, "net1080_check_conn read - %d\n", retval);
314		return retval;
315	}
316	if ((status & STATUS_CONN_OTHER) != STATUS_CONN_OTHER)
317		return -ENOLINK;
318	return 0;
319}
320
321static void nc_ensure_sync(struct usbnet *dev)
322{
323	if (++dev->frame_errors <= 5)
324		return;
325
326	if (usbnet_write_cmd_async(dev, REQUEST_REGISTER,
327					USB_DIR_OUT | USB_TYPE_VENDOR |
328					USB_RECIP_DEVICE,
329					USBCTL_FLUSH_THIS |
330					USBCTL_FLUSH_OTHER,
331					REG_USBCTL, NULL, 0))
332		return;
333
334	netif_dbg(dev, rx_err, dev->net,
335		  "flush net1080; too many framing errors\n");
336	dev->frame_errors = 0;
337}
338
339static int net1080_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
340{
341	struct nc_header	*header;
342	struct nc_trailer	*trailer;
343	u16			hdr_len, packet_len;
344
345	/* This check is no longer done by usbnet */
346	if (skb->len < dev->net->hard_header_len)
347		return 0;
348
349	if (!(skb->len & 0x01)) {
350		netdev_dbg(dev->net, "rx framesize %d range %d..%d mtu %d\n",
351			   skb->len, dev->net->hard_header_len, dev->hard_mtu,
352			   dev->net->mtu);
353		dev->net->stats.rx_frame_errors++;
354		nc_ensure_sync(dev);
355		return 0;
356	}
357
358	header = (struct nc_header *) skb->data;
359	hdr_len = le16_to_cpup(&header->hdr_len);
360	packet_len = le16_to_cpup(&header->packet_len);
361	if (FRAMED_SIZE(packet_len) > NC_MAX_PACKET) {
362		dev->net->stats.rx_frame_errors++;
363		netdev_dbg(dev->net, "packet too big, %d\n", packet_len);
364		nc_ensure_sync(dev);
365		return 0;
366	} else if (hdr_len < MIN_HEADER) {
367		dev->net->stats.rx_frame_errors++;
368		netdev_dbg(dev->net, "header too short, %d\n", hdr_len);
369		nc_ensure_sync(dev);
370		return 0;
371	} else if (hdr_len > MIN_HEADER) {
372		// out of band data for us?
373		netdev_dbg(dev->net, "header OOB, %d bytes\n", hdr_len - MIN_HEADER);
374		nc_ensure_sync(dev);
375		// switch (vendor/product ids) { ... }
376	}
377	skb_pull(skb, hdr_len);
378
379	trailer = (struct nc_trailer *)
380		(skb->data + skb->len - sizeof *trailer);
381	skb_trim(skb, skb->len - sizeof *trailer);
382
383	if ((packet_len & 0x01) == 0) {
384		if (skb->data [packet_len] != PAD_BYTE) {
385			dev->net->stats.rx_frame_errors++;
386			netdev_dbg(dev->net, "bad pad\n");
387			return 0;
388		}
389		skb_trim(skb, skb->len - 1);
390	}
391	if (skb->len != packet_len) {
392		dev->net->stats.rx_frame_errors++;
393		netdev_dbg(dev->net, "bad packet len %d (expected %d)\n",
394			   skb->len, packet_len);
395		nc_ensure_sync(dev);
396		return 0;
397	}
398	if (header->packet_id != get_unaligned(&trailer->packet_id)) {
399		dev->net->stats.rx_fifo_errors++;
400		netdev_dbg(dev->net, "(2+ dropped) rx packet_id mismatch 0x%x 0x%x\n",
401			   le16_to_cpu(header->packet_id),
402			   le16_to_cpu(trailer->packet_id));
403		return 0;
404	}
405#if 0
406	netdev_dbg(dev->net, "frame <rx h %d p %d id %d\n", header->hdr_len,
407		   header->packet_len, header->packet_id);
408#endif
409	dev->frame_errors = 0;
410	return 1;
411}
412
413static struct sk_buff *
414net1080_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
415{
416	struct sk_buff		*skb2;
417	struct nc_header	*header = NULL;
418	struct nc_trailer	*trailer = NULL;
419	int			padlen = sizeof (struct nc_trailer);
420	int			len = skb->len;
421
422	if (!((len + padlen + sizeof (struct nc_header)) & 0x01))
423		padlen++;
424	if (!skb_cloned(skb)) {
425		int	headroom = skb_headroom(skb);
426		int	tailroom = skb_tailroom(skb);
427
428		if (padlen <= tailroom &&
429		    sizeof(struct nc_header) <= headroom)
430			/* There's enough head and tail room */
431			goto encapsulate;
432
433		if ((sizeof (struct nc_header) + padlen) <
434				(headroom + tailroom)) {
435			/* There's enough total room, so just readjust */
436			skb->data = memmove(skb->head
437						+ sizeof (struct nc_header),
438					    skb->data, skb->len);
439			skb_set_tail_pointer(skb, len);
440			goto encapsulate;
441		}
442	}
443
444	/* Create a new skb to use with the correct size */
445	skb2 = skb_copy_expand(skb,
446				sizeof (struct nc_header),
447				padlen,
448				flags);
449	dev_kfree_skb_any(skb);
450	if (!skb2)
451		return skb2;
452	skb = skb2;
453
454encapsulate:
455	/* header first */
456	header = skb_push(skb, sizeof *header);
457	header->hdr_len = cpu_to_le16(sizeof (*header));
458	header->packet_len = cpu_to_le16(len);
459	header->packet_id = cpu_to_le16((u16)dev->xid++);
460
461	/* maybe pad; then trailer */
462	if (!((skb->len + sizeof *trailer) & 0x01))
463		skb_put_u8(skb, PAD_BYTE);
464	trailer = skb_put(skb, sizeof *trailer);
465	put_unaligned(header->packet_id, &trailer->packet_id);
466#if 0
467	netdev_dbg(dev->net, "frame >tx h %d p %d id %d\n",
468		   header->hdr_len, header->packet_len,
469		   header->packet_id);
470#endif
471	return skb;
472}
473
474static int net1080_bind(struct usbnet *dev, struct usb_interface *intf)
475{
476	unsigned	extra = sizeof (struct nc_header)
477				+ 1
478				+ sizeof (struct nc_trailer);
479
480	dev->net->hard_header_len += extra;
481	dev->rx_urb_size = dev->net->hard_header_len + dev->net->mtu;
482	dev->hard_mtu = NC_MAX_PACKET;
483	return usbnet_get_endpoints (dev, intf);
484}
485
486static const struct driver_info	net1080_info = {
487	.description =	"NetChip TurboCONNECT",
488	.flags =	FLAG_POINTTOPOINT | FLAG_FRAMING_NC,
489	.bind =		net1080_bind,
490	.reset =	net1080_reset,
491	.check_connect = net1080_check_connect,
492	.rx_fixup =	net1080_rx_fixup,
493	.tx_fixup =	net1080_tx_fixup,
494};
495
496static const struct usb_device_id	products [] = {
497{
498	USB_DEVICE(0x0525, 0x1080),	// NetChip ref design
499	.driver_info =	(unsigned long) &net1080_info,
500}, {
501	USB_DEVICE(0x06D0, 0x0622),	// Laplink Gold
502	.driver_info =	(unsigned long) &net1080_info,
503},
504	{ },		// END
505};
506MODULE_DEVICE_TABLE(usb, products);
507
508static struct usb_driver net1080_driver = {
509	.name =		"net1080",
510	.id_table =	products,
511	.probe =	usbnet_probe,
512	.disconnect =	usbnet_disconnect,
513	.suspend =	usbnet_suspend,
514	.resume =	usbnet_resume,
515	.disable_hub_initiated_lpm = 1,
516};
517
518module_usb_driver(net1080_driver);
519
520MODULE_AUTHOR("David Brownell");
521MODULE_DESCRIPTION("NetChip 1080 based USB Host-to-Host Links");
522MODULE_LICENSE("GPL");