xref: /openbmc/linux/drivers/net/usb/net1080.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  */
19 
20 // #define	DEBUG			// error path messages, extra info
21 // #define	VERBOSE			// more; success messages
22 
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/netdevice.h>
26 #include <linux/etherdevice.h>
27 #include <linux/ethtool.h>
28 #include <linux/workqueue.h>
29 #include <linux/mii.h>
30 #include <linux/usb.h>
31 
32 #include <asm/unaligned.h>
33 
34 #include "usbnet.h"
35 
36 
37 /*
38  * Netchip 1080 driver ... http://www.netchip.com
39  * (Sept 2004:  End-of-life announcement has been sent.)
40  * Used in (some) LapLink cables
41  */
42 
43 #define frame_errors	data[1]
44 
45 /*
46  * NetChip framing of ethernet packets, supporting additional error
47  * checks for links that may drop bulk packets from inside messages.
48  * Odd USB length == always short read for last usb packet.
49  *	- nc_header
50  *	- Ethernet header (14 bytes)
51  *	- payload
52  *	- (optional padding byte, if needed so length becomes odd)
53  *	- nc_trailer
54  *
55  * This framing is to be avoided for non-NetChip devices.
56  */
57 
58 struct nc_header {		// packed:
59 	__le16	hdr_len;		// sizeof nc_header (LE, all)
60 	__le16	packet_len;		// payload size (including ethhdr)
61 	__le16	packet_id;		// detects dropped packets
62 #define MIN_HEADER	6
63 
64 	// all else is optional, and must start with:
65 	// __le16	vendorId;	// from usb-if
66 	// __le16	productId;
67 } __attribute__((__packed__));
68 
69 #define	PAD_BYTE	((unsigned char)0xAC)
70 
71 struct nc_trailer {
72 	__le16	packet_id;
73 } __attribute__((__packed__));
74 
75 // packets may use FLAG_FRAMING_NC and optional pad
76 #define FRAMED_SIZE(mtu) (sizeof (struct nc_header) \
77 				+ sizeof (struct ethhdr) \
78 				+ (mtu) \
79 				+ 1 \
80 				+ sizeof (struct nc_trailer))
81 
82 #define MIN_FRAMED	FRAMED_SIZE(0)
83 
84 /* packets _could_ be up to 64KB... */
85 #define NC_MAX_PACKET	32767
86 
87 
88 /*
89  * Zero means no timeout; else, how long a 64 byte bulk packet may be queued
90  * before the hardware drops it.  If that's done, the driver will need to
91  * frame network packets to guard against the dropped USB packets.  The win32
92  * driver sets this for both sides of the link.
93  */
94 #define	NC_READ_TTL_MS	((u8)255)	// ms
95 
96 /*
97  * We ignore most registers and EEPROM contents.
98  */
99 #define	REG_USBCTL	((u8)0x04)
100 #define REG_TTL		((u8)0x10)
101 #define REG_STATUS	((u8)0x11)
102 
103 /*
104  * Vendor specific requests to read/write data
105  */
106 #define	REQUEST_REGISTER	((u8)0x10)
107 #define	REQUEST_EEPROM		((u8)0x11)
108 
109 static int
110 nc_vendor_read(struct usbnet *dev, u8 req, u8 regnum, u16 *retval_ptr)
111 {
112 	int status = usb_control_msg(dev->udev,
113 		usb_rcvctrlpipe(dev->udev, 0),
114 		req,
115 		USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
116 		0, regnum,
117 		retval_ptr, sizeof *retval_ptr,
118 		USB_CTRL_GET_TIMEOUT);
119 	if (status > 0)
120 		status = 0;
121 	if (!status)
122 		le16_to_cpus(retval_ptr);
123 	return status;
124 }
125 
126 static inline int
127 nc_register_read(struct usbnet *dev, u8 regnum, u16 *retval_ptr)
128 {
129 	return nc_vendor_read(dev, REQUEST_REGISTER, regnum, retval_ptr);
130 }
131 
132 // no retval ... can become async, usable in_interrupt()
133 static void
134 nc_vendor_write(struct usbnet *dev, u8 req, u8 regnum, u16 value)
135 {
136 	usb_control_msg(dev->udev,
137 		usb_sndctrlpipe(dev->udev, 0),
138 		req,
139 		USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
140 		value, regnum,
141 		NULL, 0,			// data is in setup packet
142 		USB_CTRL_SET_TIMEOUT);
143 }
144 
145 static inline void
146 nc_register_write(struct usbnet *dev, u8 regnum, u16 value)
147 {
148 	nc_vendor_write(dev, REQUEST_REGISTER, regnum, value);
149 }
150 
151 
152 #if 0
153 static void nc_dump_registers(struct usbnet *dev)
154 {
155 	u8	reg;
156 	u16	*vp = kmalloc(sizeof (u16));
157 
158 	if (!vp) {
159 		dbg("no memory?");
160 		return;
161 	}
162 
163 	dbg("%s registers:", dev->net->name);
164 	for (reg = 0; reg < 0x20; reg++) {
165 		int retval;
166 
167 		// reading some registers is trouble
168 		if (reg >= 0x08 && reg <= 0xf)
169 			continue;
170 		if (reg >= 0x12 && reg <= 0x1e)
171 			continue;
172 
173 		retval = nc_register_read(dev, reg, vp);
174 		if (retval < 0)
175 			dbg("%s reg [0x%x] ==> error %d",
176 				dev->net->name, reg, retval);
177 		else
178 			dbg("%s reg [0x%x] = 0x%x",
179 				dev->net->name, reg, *vp);
180 	}
181 	kfree(vp);
182 }
183 #endif
184 
185 
186 /*-------------------------------------------------------------------------*/
187 
188 /*
189  * Control register
190  */
191 
192 #define	USBCTL_WRITABLE_MASK	0x1f0f
193 // bits 15-13 reserved, r/o
194 #define	USBCTL_ENABLE_LANG	(1 << 12)
195 #define	USBCTL_ENABLE_MFGR	(1 << 11)
196 #define	USBCTL_ENABLE_PROD	(1 << 10)
197 #define	USBCTL_ENABLE_SERIAL	(1 << 9)
198 #define	USBCTL_ENABLE_DEFAULTS	(1 << 8)
199 // bits 7-4 reserved, r/o
200 #define	USBCTL_FLUSH_OTHER	(1 << 3)
201 #define	USBCTL_FLUSH_THIS	(1 << 2)
202 #define	USBCTL_DISCONN_OTHER	(1 << 1)
203 #define	USBCTL_DISCONN_THIS	(1 << 0)
204 
205 static inline void nc_dump_usbctl(struct usbnet *dev, u16 usbctl)
206 {
207 	if (!netif_msg_link(dev))
208 		return;
209 	devdbg(dev, "net1080 %s-%s usbctl 0x%x:%s%s%s%s%s;"
210 			" this%s%s;"
211 			" other%s%s; r/o 0x%x",
212 		dev->udev->bus->bus_name, dev->udev->devpath,
213 		usbctl,
214 		(usbctl & USBCTL_ENABLE_LANG) ? " lang" : "",
215 		(usbctl & USBCTL_ENABLE_MFGR) ? " mfgr" : "",
216 		(usbctl & USBCTL_ENABLE_PROD) ? " prod" : "",
217 		(usbctl & USBCTL_ENABLE_SERIAL) ? " serial" : "",
218 		(usbctl & USBCTL_ENABLE_DEFAULTS) ? " defaults" : "",
219 
220 		(usbctl & USBCTL_FLUSH_OTHER) ? " FLUSH" : "",
221 		(usbctl & USBCTL_DISCONN_OTHER) ? " DIS" : "",
222 		(usbctl & USBCTL_FLUSH_THIS) ? " FLUSH" : "",
223 		(usbctl & USBCTL_DISCONN_THIS) ? " DIS" : "",
224 		usbctl & ~USBCTL_WRITABLE_MASK
225 		);
226 }
227 
228 /*-------------------------------------------------------------------------*/
229 
230 /*
231  * Status register
232  */
233 
234 #define	STATUS_PORT_A		(1 << 15)
235 
236 #define	STATUS_CONN_OTHER	(1 << 14)
237 #define	STATUS_SUSPEND_OTHER	(1 << 13)
238 #define	STATUS_MAILBOX_OTHER	(1 << 12)
239 #define	STATUS_PACKETS_OTHER(n)	(((n) >> 8) & 0x03)
240 
241 #define	STATUS_CONN_THIS	(1 << 6)
242 #define	STATUS_SUSPEND_THIS	(1 << 5)
243 #define	STATUS_MAILBOX_THIS	(1 << 4)
244 #define	STATUS_PACKETS_THIS(n)	(((n) >> 0) & 0x03)
245 
246 #define	STATUS_UNSPEC_MASK	0x0c8c
247 #define	STATUS_NOISE_MASK 	((u16)~(0x0303|STATUS_UNSPEC_MASK))
248 
249 
250 static inline void nc_dump_status(struct usbnet *dev, u16 status)
251 {
252 	if (!netif_msg_link(dev))
253 		return;
254 	devdbg(dev, "net1080 %s-%s status 0x%x:"
255 			" this (%c) PKT=%d%s%s%s;"
256 			" other PKT=%d%s%s%s; unspec 0x%x",
257 		dev->udev->bus->bus_name, dev->udev->devpath,
258 		status,
259 
260 		// XXX the packet counts don't seem right
261 		// (1 at reset, not 0); maybe UNSPEC too
262 
263 		(status & STATUS_PORT_A) ? 'A' : 'B',
264 		STATUS_PACKETS_THIS(status),
265 		(status & STATUS_CONN_THIS) ? " CON" : "",
266 		(status & STATUS_SUSPEND_THIS) ? " SUS" : "",
267 		(status & STATUS_MAILBOX_THIS) ? " MBOX" : "",
268 
269 		STATUS_PACKETS_OTHER(status),
270 		(status & STATUS_CONN_OTHER) ? " CON" : "",
271 		(status & STATUS_SUSPEND_OTHER) ? " SUS" : "",
272 		(status & STATUS_MAILBOX_OTHER) ? " MBOX" : "",
273 
274 		status & STATUS_UNSPEC_MASK
275 		);
276 }
277 
278 /*-------------------------------------------------------------------------*/
279 
280 /*
281  * TTL register
282  */
283 
284 #define	TTL_THIS(ttl)	(0x00ff & ttl)
285 #define	TTL_OTHER(ttl)	(0x00ff & (ttl >> 8))
286 #define MK_TTL(this,other)	((u16)(((other)<<8)|(0x00ff&(this))))
287 
288 static inline void nc_dump_ttl(struct usbnet *dev, u16 ttl)
289 {
290 	if (netif_msg_link(dev))
291 		devdbg(dev, "net1080 %s-%s ttl 0x%x this = %d, other = %d",
292 			dev->udev->bus->bus_name, dev->udev->devpath,
293 			ttl, TTL_THIS(ttl), TTL_OTHER(ttl));
294 }
295 
296 /*-------------------------------------------------------------------------*/
297 
298 static int net1080_reset(struct usbnet *dev)
299 {
300 	u16		usbctl, status, ttl;
301 	u16		*vp = kmalloc(sizeof (u16), GFP_KERNEL);
302 	int		retval;
303 
304 	if (!vp)
305 		return -ENOMEM;
306 
307 	// nc_dump_registers(dev);
308 
309 	if ((retval = nc_register_read(dev, REG_STATUS, vp)) < 0) {
310 		dbg("can't read %s-%s status: %d",
311 			dev->udev->bus->bus_name, dev->udev->devpath, retval);
312 		goto done;
313 	}
314 	status = *vp;
315 	nc_dump_status(dev, status);
316 
317 	if ((retval = nc_register_read(dev, REG_USBCTL, vp)) < 0) {
318 		dbg("can't read USBCTL, %d", retval);
319 		goto done;
320 	}
321 	usbctl = *vp;
322 	nc_dump_usbctl(dev, usbctl);
323 
324 	nc_register_write(dev, REG_USBCTL,
325 			USBCTL_FLUSH_THIS | USBCTL_FLUSH_OTHER);
326 
327 	if ((retval = nc_register_read(dev, REG_TTL, vp)) < 0) {
328 		dbg("can't read TTL, %d", retval);
329 		goto done;
330 	}
331 	ttl = *vp;
332 	// nc_dump_ttl(dev, ttl);
333 
334 	nc_register_write(dev, REG_TTL,
335 			MK_TTL(NC_READ_TTL_MS, TTL_OTHER(ttl)) );
336 	dbg("%s: assigned TTL, %d ms", dev->net->name, NC_READ_TTL_MS);
337 
338 	if (netif_msg_link(dev))
339 		devinfo(dev, "port %c, peer %sconnected",
340 			(status & STATUS_PORT_A) ? 'A' : 'B',
341 			(status & STATUS_CONN_OTHER) ? "" : "dis"
342 			);
343 	retval = 0;
344 
345 done:
346 	kfree(vp);
347 	return retval;
348 }
349 
350 static int net1080_check_connect(struct usbnet *dev)
351 {
352 	int			retval;
353 	u16			status;
354 	u16			*vp = kmalloc(sizeof (u16), GFP_KERNEL);
355 
356 	if (!vp)
357 		return -ENOMEM;
358 	retval = nc_register_read(dev, REG_STATUS, vp);
359 	status = *vp;
360 	kfree(vp);
361 	if (retval != 0) {
362 		dbg("%s net1080_check_conn read - %d", dev->net->name, retval);
363 		return retval;
364 	}
365 	if ((status & STATUS_CONN_OTHER) != STATUS_CONN_OTHER)
366 		return -ENOLINK;
367 	return 0;
368 }
369 
370 static void nc_flush_complete(struct urb *urb)
371 {
372 	kfree(urb->context);
373 	usb_free_urb(urb);
374 }
375 
376 static void nc_ensure_sync(struct usbnet *dev)
377 {
378 	dev->frame_errors++;
379 	if (dev->frame_errors > 5) {
380 		struct urb		*urb;
381 		struct usb_ctrlrequest	*req;
382 		int			status;
383 
384 		/* Send a flush */
385 		urb = usb_alloc_urb(0, GFP_ATOMIC);
386 		if (!urb)
387 			return;
388 
389 		req = kmalloc(sizeof *req, GFP_ATOMIC);
390 		if (!req) {
391 			usb_free_urb(urb);
392 			return;
393 		}
394 
395 		req->bRequestType = USB_DIR_OUT
396 			| USB_TYPE_VENDOR
397 			| USB_RECIP_DEVICE;
398 		req->bRequest = REQUEST_REGISTER;
399 		req->wValue = cpu_to_le16(USBCTL_FLUSH_THIS
400 				| USBCTL_FLUSH_OTHER);
401 		req->wIndex = cpu_to_le16(REG_USBCTL);
402 		req->wLength = cpu_to_le16(0);
403 
404 		/* queue an async control request, we don't need
405 		 * to do anything when it finishes except clean up.
406 		 */
407 		usb_fill_control_urb(urb, dev->udev,
408 			usb_sndctrlpipe(dev->udev, 0),
409 			(unsigned char *) req,
410 			NULL, 0,
411 			nc_flush_complete, req);
412 		status = usb_submit_urb(urb, GFP_ATOMIC);
413 		if (status) {
414 			kfree(req);
415 			usb_free_urb(urb);
416 			return;
417 		}
418 
419 		if (netif_msg_rx_err(dev))
420 			devdbg(dev, "flush net1080; too many framing errors");
421 		dev->frame_errors = 0;
422 	}
423 }
424 
425 static int net1080_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
426 {
427 	struct nc_header	*header;
428 	struct nc_trailer	*trailer;
429 	u16			hdr_len, packet_len;
430 
431 	if (!(skb->len & 0x01)) {
432 #ifdef DEBUG
433 		struct net_device	*net = dev->net;
434 		dbg("rx framesize %d range %d..%d mtu %d", skb->len,
435 			net->hard_header_len, dev->hard_mtu, net->mtu);
436 #endif
437 		dev->stats.rx_frame_errors++;
438 		nc_ensure_sync(dev);
439 		return 0;
440 	}
441 
442 	header = (struct nc_header *) skb->data;
443 	hdr_len = le16_to_cpup(&header->hdr_len);
444 	packet_len = le16_to_cpup(&header->packet_len);
445 	if (FRAMED_SIZE(packet_len) > NC_MAX_PACKET) {
446 		dev->stats.rx_frame_errors++;
447 		dbg("packet too big, %d", packet_len);
448 		nc_ensure_sync(dev);
449 		return 0;
450 	} else if (hdr_len < MIN_HEADER) {
451 		dev->stats.rx_frame_errors++;
452 		dbg("header too short, %d", hdr_len);
453 		nc_ensure_sync(dev);
454 		return 0;
455 	} else if (hdr_len > MIN_HEADER) {
456 		// out of band data for us?
457 		dbg("header OOB, %d bytes", hdr_len - MIN_HEADER);
458 		nc_ensure_sync(dev);
459 		// switch (vendor/product ids) { ... }
460 	}
461 	skb_pull(skb, hdr_len);
462 
463 	trailer = (struct nc_trailer *)
464 		(skb->data + skb->len - sizeof *trailer);
465 	skb_trim(skb, skb->len - sizeof *trailer);
466 
467 	if ((packet_len & 0x01) == 0) {
468 		if (skb->data [packet_len] != PAD_BYTE) {
469 			dev->stats.rx_frame_errors++;
470 			dbg("bad pad");
471 			return 0;
472 		}
473 		skb_trim(skb, skb->len - 1);
474 	}
475 	if (skb->len != packet_len) {
476 		dev->stats.rx_frame_errors++;
477 		dbg("bad packet len %d (expected %d)",
478 			skb->len, packet_len);
479 		nc_ensure_sync(dev);
480 		return 0;
481 	}
482 	if (header->packet_id != get_unaligned(&trailer->packet_id)) {
483 		dev->stats.rx_fifo_errors++;
484 		dbg("(2+ dropped) rx packet_id mismatch 0x%x 0x%x",
485 			le16_to_cpu(header->packet_id),
486 			le16_to_cpu(trailer->packet_id));
487 		return 0;
488 	}
489 #if 0
490 	devdbg(dev, "frame <rx h %d p %d id %d", header->hdr_len,
491 		header->packet_len, header->packet_id);
492 #endif
493 	dev->frame_errors = 0;
494 	return 1;
495 }
496 
497 static struct sk_buff *
498 net1080_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
499 {
500 	struct sk_buff		*skb2;
501 	struct nc_header	*header = NULL;
502 	struct nc_trailer	*trailer = NULL;
503 	int			padlen = sizeof (struct nc_trailer);
504 	int			len = skb->len;
505 
506 	if (!((len + padlen + sizeof (struct nc_header)) & 0x01))
507 		padlen++;
508 	if (!skb_cloned(skb)) {
509 		int	headroom = skb_headroom(skb);
510 		int	tailroom = skb_tailroom(skb);
511 
512 		if (padlen <= tailroom &&
513 		    sizeof(struct nc_header) <= headroom)
514 			/* There's enough head and tail room */
515 			goto encapsulate;
516 
517 		if ((sizeof (struct nc_header) + padlen) <
518 				(headroom + tailroom)) {
519 			/* There's enough total room, so just readjust */
520 			skb->data = memmove(skb->head
521 						+ sizeof (struct nc_header),
522 					    skb->data, skb->len);
523 			skb_set_tail_pointer(skb, len);
524 			goto encapsulate;
525 		}
526 	}
527 
528 	/* Create a new skb to use with the correct size */
529 	skb2 = skb_copy_expand(skb,
530 				sizeof (struct nc_header),
531 				padlen,
532 				flags);
533 	dev_kfree_skb_any(skb);
534 	if (!skb2)
535 		return skb2;
536 	skb = skb2;
537 
538 encapsulate:
539 	/* header first */
540 	header = (struct nc_header *) skb_push(skb, sizeof *header);
541 	header->hdr_len = cpu_to_le16(sizeof (*header));
542 	header->packet_len = cpu_to_le16(len);
543 	header->packet_id = cpu_to_le16((u16)dev->xid++);
544 
545 	/* maybe pad; then trailer */
546 	if (!((skb->len + sizeof *trailer) & 0x01))
547 		*skb_put(skb, 1) = PAD_BYTE;
548 	trailer = (struct nc_trailer *) skb_put(skb, sizeof *trailer);
549 	put_unaligned(header->packet_id, &trailer->packet_id);
550 #if 0
551 	devdbg(dev, "frame >tx h %d p %d id %d",
552 		header->hdr_len, header->packet_len,
553 		header->packet_id);
554 #endif
555 	return skb;
556 }
557 
558 static int net1080_bind(struct usbnet *dev, struct usb_interface *intf)
559 {
560 	unsigned	extra = sizeof (struct nc_header)
561 				+ 1
562 				+ sizeof (struct nc_trailer);
563 
564 	dev->net->hard_header_len += extra;
565 	dev->rx_urb_size = dev->net->hard_header_len + dev->net->mtu;
566 	dev->hard_mtu = NC_MAX_PACKET;
567 	return usbnet_get_endpoints (dev, intf);
568 }
569 
570 static const struct driver_info	net1080_info = {
571 	.description =	"NetChip TurboCONNECT",
572 	.flags =	FLAG_FRAMING_NC,
573 	.bind =		net1080_bind,
574 	.reset =	net1080_reset,
575 	.check_connect = net1080_check_connect,
576 	.rx_fixup =	net1080_rx_fixup,
577 	.tx_fixup =	net1080_tx_fixup,
578 };
579 
580 static const struct usb_device_id	products [] = {
581 {
582 	USB_DEVICE(0x0525, 0x1080),	// NetChip ref design
583 	.driver_info =	(unsigned long) &net1080_info,
584 }, {
585 	USB_DEVICE(0x06D0, 0x0622),	// Laplink Gold
586 	.driver_info =	(unsigned long) &net1080_info,
587 },
588 	{ },		// END
589 };
590 MODULE_DEVICE_TABLE(usb, products);
591 
592 static struct usb_driver net1080_driver = {
593 	.name =		"net1080",
594 	.id_table =	products,
595 	.probe =	usbnet_probe,
596 	.disconnect =	usbnet_disconnect,
597 	.suspend =	usbnet_suspend,
598 	.resume =	usbnet_resume,
599 };
600 
601 static int __init net1080_init(void)
602 {
603  	return usb_register(&net1080_driver);
604 }
605 module_init(net1080_init);
606 
607 static void __exit net1080_exit(void)
608 {
609  	usb_deregister(&net1080_driver);
610 }
611 module_exit(net1080_exit);
612 
613 MODULE_AUTHOR("David Brownell");
614 MODULE_DESCRIPTION("NetChip 1080 based USB Host-to-Host Links");
615 MODULE_LICENSE("GPL");
616