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