xref: /openbmc/linux/drivers/net/usb/cdc_ether.c (revision 22246614)
1 /*
2  * CDC Ethernet based networking peripherals
3  * Copyright (C) 2003-2005 by David Brownell
4  * Copyright (C) 2006 by Ole Andre Vadla Ravnas (ActiveSync)
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20 
21 // #define	DEBUG			// error path messages, extra info
22 // #define	VERBOSE			// more; success messages
23 
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/netdevice.h>
27 #include <linux/etherdevice.h>
28 #include <linux/ctype.h>
29 #include <linux/ethtool.h>
30 #include <linux/workqueue.h>
31 #include <linux/mii.h>
32 #include <linux/usb.h>
33 #include <linux/usb/cdc.h>
34 #include <linux/usb/usbnet.h>
35 
36 
37 #if defined(CONFIG_USB_NET_RNDIS_HOST) || defined(CONFIG_USB_NET_RNDIS_HOST_MODULE)
38 
39 static int is_rndis(struct usb_interface_descriptor *desc)
40 {
41 	return desc->bInterfaceClass == USB_CLASS_COMM
42 		&& desc->bInterfaceSubClass == 2
43 		&& desc->bInterfaceProtocol == 0xff;
44 }
45 
46 static int is_activesync(struct usb_interface_descriptor *desc)
47 {
48 	return desc->bInterfaceClass == USB_CLASS_MISC
49 		&& desc->bInterfaceSubClass == 1
50 		&& desc->bInterfaceProtocol == 1;
51 }
52 
53 #else
54 
55 #define is_rndis(desc)		0
56 #define is_activesync(desc)	0
57 
58 #endif
59 
60 /*
61  * probes control interface, claims data interface, collects the bulk
62  * endpoints, activates data interface (if needed), maybe sets MTU.
63  * all pure cdc, except for certain firmware workarounds, and knowing
64  * that rndis uses one different rule.
65  */
66 int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
67 {
68 	u8				*buf = intf->cur_altsetting->extra;
69 	int				len = intf->cur_altsetting->extralen;
70 	struct usb_interface_descriptor	*d;
71 	struct cdc_state		*info = (void *) &dev->data;
72 	int				status;
73 	int				rndis;
74 	struct usb_driver		*driver = driver_of(intf);
75 
76 	if (sizeof dev->data < sizeof *info)
77 		return -EDOM;
78 
79 	/* expect strict spec conformance for the descriptors, but
80 	 * cope with firmware which stores them in the wrong place
81 	 */
82 	if (len == 0 && dev->udev->actconfig->extralen) {
83 		/* Motorola SB4100 (and others: Brad Hards says it's
84 		 * from a Broadcom design) put CDC descriptors here
85 		 */
86 		buf = dev->udev->actconfig->extra;
87 		len = dev->udev->actconfig->extralen;
88 		if (len)
89 			dev_dbg(&intf->dev,
90 				"CDC descriptors on config\n");
91 	}
92 
93 	/* Maybe CDC descriptors are after the endpoint?  This bug has
94 	 * been seen on some 2Wire Inc RNDIS-ish products.
95 	 */
96 	if (len == 0) {
97 		struct usb_host_endpoint	*hep;
98 
99 		hep = intf->cur_altsetting->endpoint;
100 		if (hep) {
101 			buf = hep->extra;
102 			len = hep->extralen;
103 		}
104 		if (len)
105 			dev_dbg(&intf->dev,
106 				"CDC descriptors on endpoint\n");
107 	}
108 
109 	/* this assumes that if there's a non-RNDIS vendor variant
110 	 * of cdc-acm, it'll fail RNDIS requests cleanly.
111 	 */
112 	rndis = is_rndis(&intf->cur_altsetting->desc)
113 		|| is_activesync(&intf->cur_altsetting->desc);
114 
115 	memset(info, 0, sizeof *info);
116 	info->control = intf;
117 	while (len > 3) {
118 		if (buf [1] != USB_DT_CS_INTERFACE)
119 			goto next_desc;
120 
121 		/* use bDescriptorSubType to identify the CDC descriptors.
122 		 * We expect devices with CDC header and union descriptors.
123 		 * For CDC Ethernet we need the ethernet descriptor.
124 		 * For RNDIS, ignore two (pointless) CDC modem descriptors
125 		 * in favor of a complicated OID-based RPC scheme doing what
126 		 * CDC Ethernet achieves with a simple descriptor.
127 		 */
128 		switch (buf [2]) {
129 		case USB_CDC_HEADER_TYPE:
130 			if (info->header) {
131 				dev_dbg(&intf->dev, "extra CDC header\n");
132 				goto bad_desc;
133 			}
134 			info->header = (void *) buf;
135 			if (info->header->bLength != sizeof *info->header) {
136 				dev_dbg(&intf->dev, "CDC header len %u\n",
137 					info->header->bLength);
138 				goto bad_desc;
139 			}
140 			break;
141 		case USB_CDC_ACM_TYPE:
142 			/* paranoia:  disambiguate a "real" vendor-specific
143 			 * modem interface from an RNDIS non-modem.
144 			 */
145 			if (rndis) {
146 				struct usb_cdc_acm_descriptor *acm;
147 
148 				acm = (void *) buf;
149 				if (acm->bmCapabilities) {
150 					dev_dbg(&intf->dev,
151 						"ACM capabilities %02x, "
152 						"not really RNDIS?\n",
153 						acm->bmCapabilities);
154 					goto bad_desc;
155 				}
156 			}
157 			break;
158 		case USB_CDC_UNION_TYPE:
159 			if (info->u) {
160 				dev_dbg(&intf->dev, "extra CDC union\n");
161 				goto bad_desc;
162 			}
163 			info->u = (void *) buf;
164 			if (info->u->bLength != sizeof *info->u) {
165 				dev_dbg(&intf->dev, "CDC union len %u\n",
166 					info->u->bLength);
167 				goto bad_desc;
168 			}
169 
170 			/* we need a master/control interface (what we're
171 			 * probed with) and a slave/data interface; union
172 			 * descriptors sort this all out.
173 			 */
174 			info->control = usb_ifnum_to_if(dev->udev,
175 						info->u->bMasterInterface0);
176 			info->data = usb_ifnum_to_if(dev->udev,
177 						info->u->bSlaveInterface0);
178 			if (!info->control || !info->data) {
179 				dev_dbg(&intf->dev,
180 					"master #%u/%p slave #%u/%p\n",
181 					info->u->bMasterInterface0,
182 					info->control,
183 					info->u->bSlaveInterface0,
184 					info->data);
185 				goto bad_desc;
186 			}
187 			if (info->control != intf) {
188 				dev_dbg(&intf->dev, "bogus CDC Union\n");
189 				/* Ambit USB Cable Modem (and maybe others)
190 				 * interchanges master and slave interface.
191 				 */
192 				if (info->data == intf) {
193 					info->data = info->control;
194 					info->control = intf;
195 				} else
196 					goto bad_desc;
197 			}
198 
199 			/* a data interface altsetting does the real i/o */
200 			d = &info->data->cur_altsetting->desc;
201 			if (d->bInterfaceClass != USB_CLASS_CDC_DATA) {
202 				dev_dbg(&intf->dev, "slave class %u\n",
203 					d->bInterfaceClass);
204 				goto bad_desc;
205 			}
206 			break;
207 		case USB_CDC_ETHERNET_TYPE:
208 			if (info->ether) {
209 				dev_dbg(&intf->dev, "extra CDC ether\n");
210 				goto bad_desc;
211 			}
212 			info->ether = (void *) buf;
213 			if (info->ether->bLength != sizeof *info->ether) {
214 				dev_dbg(&intf->dev, "CDC ether len %u\n",
215 					info->ether->bLength);
216 				goto bad_desc;
217 			}
218 			dev->hard_mtu = le16_to_cpu(
219 						info->ether->wMaxSegmentSize);
220 			/* because of Zaurus, we may be ignoring the host
221 			 * side link address we were given.
222 			 */
223 			break;
224 		}
225 next_desc:
226 		len -= buf [0];	/* bLength */
227 		buf += buf [0];
228 	}
229 
230 	/* Microsoft ActiveSync based and some regular RNDIS devices lack the
231 	 * CDC descriptors, so we'll hard-wire the interfaces and not check
232 	 * for descriptors.
233 	 */
234 	if (rndis && !info->u) {
235 		info->control = usb_ifnum_to_if(dev->udev, 0);
236 		info->data = usb_ifnum_to_if(dev->udev, 1);
237 		if (!info->control || !info->data) {
238 			dev_dbg(&intf->dev,
239 				"rndis: master #0/%p slave #1/%p\n",
240 				info->control,
241 				info->data);
242 			goto bad_desc;
243 		}
244 
245 	} else if (!info->header || !info->u || (!rndis && !info->ether)) {
246 		dev_dbg(&intf->dev, "missing cdc %s%s%sdescriptor\n",
247 			info->header ? "" : "header ",
248 			info->u ? "" : "union ",
249 			info->ether ? "" : "ether ");
250 		goto bad_desc;
251 	}
252 
253 	/* claim data interface and set it up ... with side effects.
254 	 * network traffic can't flow until an altsetting is enabled.
255 	 */
256 	status = usb_driver_claim_interface(driver, info->data, dev);
257 	if (status < 0)
258 		return status;
259 	status = usbnet_get_endpoints(dev, info->data);
260 	if (status < 0) {
261 		/* ensure immediate exit from usbnet_disconnect */
262 		usb_set_intfdata(info->data, NULL);
263 		usb_driver_release_interface(driver, info->data);
264 		return status;
265 	}
266 
267 	/* status endpoint: optional for CDC Ethernet, not RNDIS (or ACM) */
268 	dev->status = NULL;
269 	if (info->control->cur_altsetting->desc.bNumEndpoints == 1) {
270 		struct usb_endpoint_descriptor	*desc;
271 
272 		dev->status = &info->control->cur_altsetting->endpoint [0];
273 		desc = &dev->status->desc;
274 		if (!usb_endpoint_is_int_in(desc)
275 				|| (le16_to_cpu(desc->wMaxPacketSize)
276 					< sizeof(struct usb_cdc_notification))
277 				|| !desc->bInterval) {
278 			dev_dbg(&intf->dev, "bad notification endpoint\n");
279 			dev->status = NULL;
280 		}
281 	}
282 	if (rndis && !dev->status) {
283 		dev_dbg(&intf->dev, "missing RNDIS status endpoint\n");
284 		usb_set_intfdata(info->data, NULL);
285 		usb_driver_release_interface(driver, info->data);
286 		return -ENODEV;
287 	}
288 	return 0;
289 
290 bad_desc:
291 	dev_info(&dev->udev->dev, "bad CDC descriptors\n");
292 	return -ENODEV;
293 }
294 EXPORT_SYMBOL_GPL(usbnet_generic_cdc_bind);
295 
296 void usbnet_cdc_unbind(struct usbnet *dev, struct usb_interface *intf)
297 {
298 	struct cdc_state		*info = (void *) &dev->data;
299 	struct usb_driver		*driver = driver_of(intf);
300 
301 	/* disconnect master --> disconnect slave */
302 	if (intf == info->control && info->data) {
303 		/* ensure immediate exit from usbnet_disconnect */
304 		usb_set_intfdata(info->data, NULL);
305 		usb_driver_release_interface(driver, info->data);
306 		info->data = NULL;
307 	}
308 
309 	/* and vice versa (just in case) */
310 	else if (intf == info->data && info->control) {
311 		/* ensure immediate exit from usbnet_disconnect */
312 		usb_set_intfdata(info->control, NULL);
313 		usb_driver_release_interface(driver, info->control);
314 		info->control = NULL;
315 	}
316 }
317 EXPORT_SYMBOL_GPL(usbnet_cdc_unbind);
318 
319 /*-------------------------------------------------------------------------
320  *
321  * Communications Device Class, Ethernet Control model
322  *
323  * Takes two interfaces.  The DATA interface is inactive till an altsetting
324  * is selected.  Configuration data includes class descriptors.  There's
325  * an optional status endpoint on the control interface.
326  *
327  * This should interop with whatever the 2.4 "CDCEther.c" driver
328  * (by Brad Hards) talked with, with more functionality.
329  *
330  *-------------------------------------------------------------------------*/
331 
332 static void dumpspeed(struct usbnet *dev, __le32 *speeds)
333 {
334 	if (netif_msg_timer(dev))
335 		devinfo(dev, "link speeds: %u kbps up, %u kbps down",
336 			__le32_to_cpu(speeds[0]) / 1000,
337 		__le32_to_cpu(speeds[1]) / 1000);
338 }
339 
340 static void cdc_status(struct usbnet *dev, struct urb *urb)
341 {
342 	struct usb_cdc_notification	*event;
343 
344 	if (urb->actual_length < sizeof *event)
345 		return;
346 
347 	/* SPEED_CHANGE can get split into two 8-byte packets */
348 	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
349 		dumpspeed(dev, (__le32 *) urb->transfer_buffer);
350 		return;
351 	}
352 
353 	event = urb->transfer_buffer;
354 	switch (event->bNotificationType) {
355 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
356 		if (netif_msg_timer(dev))
357 			devdbg(dev, "CDC: carrier %s",
358 					event->wValue ? "on" : "off");
359 		if (event->wValue)
360 			netif_carrier_on(dev->net);
361 		else
362 			netif_carrier_off(dev->net);
363 		break;
364 	case USB_CDC_NOTIFY_SPEED_CHANGE:	/* tx/rx rates */
365 		if (netif_msg_timer(dev))
366 			devdbg(dev, "CDC: speed change (len %d)",
367 					urb->actual_length);
368 		if (urb->actual_length != (sizeof *event + 8))
369 			set_bit(EVENT_STS_SPLIT, &dev->flags);
370 		else
371 			dumpspeed(dev, (__le32 *) &event[1]);
372 		break;
373 	/* USB_CDC_NOTIFY_RESPONSE_AVAILABLE can happen too (e.g. RNDIS),
374 	 * but there are no standard formats for the response data.
375 	 */
376 	default:
377 		deverr(dev, "CDC: unexpected notification %02x!",
378 				 event->bNotificationType);
379 		break;
380 	}
381 }
382 
383 static u8 nibble(unsigned char c)
384 {
385 	if (likely(isdigit(c)))
386 		return c - '0';
387 	c = toupper(c);
388 	if (likely(isxdigit(c)))
389 		return 10 + c - 'A';
390 	return 0;
391 }
392 
393 static inline int
394 get_ethernet_addr(struct usbnet *dev, struct usb_cdc_ether_desc *e)
395 {
396 	int 		tmp, i;
397 	unsigned char	buf [13];
398 
399 	tmp = usb_string(dev->udev, e->iMACAddress, buf, sizeof buf);
400 	if (tmp != 12) {
401 		dev_dbg(&dev->udev->dev,
402 			"bad MAC string %d fetch, %d\n", e->iMACAddress, tmp);
403 		if (tmp >= 0)
404 			tmp = -EINVAL;
405 		return tmp;
406 	}
407 	for (i = tmp = 0; i < 6; i++, tmp += 2)
408 		dev->net->dev_addr [i] =
409 			(nibble(buf [tmp]) << 4) + nibble(buf [tmp + 1]);
410 	return 0;
411 }
412 
413 static int cdc_bind(struct usbnet *dev, struct usb_interface *intf)
414 {
415 	int				status;
416 	struct cdc_state		*info = (void *) &dev->data;
417 
418 	status = usbnet_generic_cdc_bind(dev, intf);
419 	if (status < 0)
420 		return status;
421 
422 	status = get_ethernet_addr(dev, info->ether);
423 	if (status < 0) {
424 		usb_set_intfdata(info->data, NULL);
425 		usb_driver_release_interface(driver_of(intf), info->data);
426 		return status;
427 	}
428 
429 	/* FIXME cdc-ether has some multicast code too, though it complains
430 	 * in routine cases.  info->ether describes the multicast support.
431 	 * Implement that here, manipulating the cdc filter as needed.
432 	 */
433 	return 0;
434 }
435 
436 static const struct driver_info	cdc_info = {
437 	.description =	"CDC Ethernet Device",
438 	.flags =	FLAG_ETHER,
439 	// .check_connect = cdc_check_connect,
440 	.bind =		cdc_bind,
441 	.unbind =	usbnet_cdc_unbind,
442 	.status =	cdc_status,
443 };
444 
445 /*-------------------------------------------------------------------------*/
446 
447 
448 static const struct usb_device_id	products [] = {
449 /*
450  * BLACKLIST !!
451  *
452  * First blacklist any products that are egregiously nonconformant
453  * with the CDC Ethernet specs.  Minor braindamage we cope with; when
454  * they're not even trying, needing a separate driver is only the first
455  * of the differences to show up.
456  */
457 
458 #define	ZAURUS_MASTER_INTERFACE \
459 	.bInterfaceClass	= USB_CLASS_COMM, \
460 	.bInterfaceSubClass	= USB_CDC_SUBCLASS_ETHERNET, \
461 	.bInterfaceProtocol	= USB_CDC_PROTO_NONE
462 
463 /* SA-1100 based Sharp Zaurus ("collie"), or compatible;
464  * wire-incompatible with true CDC Ethernet implementations.
465  * (And, it seems, needlessly so...)
466  */
467 {
468 	.match_flags	=   USB_DEVICE_ID_MATCH_INT_INFO
469 			  | USB_DEVICE_ID_MATCH_DEVICE,
470 	.idVendor		= 0x04DD,
471 	.idProduct		= 0x8004,
472 	ZAURUS_MASTER_INTERFACE,
473 	.driver_info		= 0,
474 },
475 
476 /* PXA-25x based Sharp Zaurii.  Note that it seems some of these
477  * (later models especially) may have shipped only with firmware
478  * advertising false "CDC MDLM" compatibility ... but we're not
479  * clear which models did that, so for now let's assume the worst.
480  */
481 {
482 	.match_flags	=   USB_DEVICE_ID_MATCH_INT_INFO
483 			  | USB_DEVICE_ID_MATCH_DEVICE,
484 	.idVendor		= 0x04DD,
485 	.idProduct		= 0x8005,	/* A-300 */
486 	ZAURUS_MASTER_INTERFACE,
487 	.driver_info		= 0,
488 }, {
489 	.match_flags	=   USB_DEVICE_ID_MATCH_INT_INFO
490 			  | USB_DEVICE_ID_MATCH_DEVICE,
491 	.idVendor		= 0x04DD,
492 	.idProduct		= 0x8006,	/* B-500/SL-5600 */
493 	ZAURUS_MASTER_INTERFACE,
494 	.driver_info		= 0,
495 }, {
496 	.match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
497 	          | USB_DEVICE_ID_MATCH_DEVICE,
498 	.idVendor		= 0x04DD,
499 	.idProduct		= 0x8007,	/* C-700 */
500 	ZAURUS_MASTER_INTERFACE,
501 	.driver_info		= 0,
502 }, {
503 	.match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
504 		 | USB_DEVICE_ID_MATCH_DEVICE,
505 	.idVendor               = 0x04DD,
506 	.idProduct              = 0x9031,	/* C-750 C-760 */
507 	ZAURUS_MASTER_INTERFACE,
508 	.driver_info		= 0,
509 }, {
510 	.match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
511 		 | USB_DEVICE_ID_MATCH_DEVICE,
512 	.idVendor               = 0x04DD,
513 	.idProduct              = 0x9032,	/* SL-6000 */
514 	ZAURUS_MASTER_INTERFACE,
515 	.driver_info		= 0,
516 }, {
517 	.match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
518 		 | USB_DEVICE_ID_MATCH_DEVICE,
519 	.idVendor               = 0x04DD,
520 	/* reported with some C860 units */
521 	.idProduct              = 0x9050,	/* C-860 */
522 	ZAURUS_MASTER_INTERFACE,
523 	.driver_info		= 0,
524 },
525 
526 /* Olympus has some models with a Zaurus-compatible option.
527  * R-1000 uses a FreeScale i.MXL cpu (ARMv4T)
528  */
529 {
530 	.match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
531 		 | USB_DEVICE_ID_MATCH_DEVICE,
532 	.idVendor               = 0x07B4,
533 	.idProduct              = 0x0F02,	/* R-1000 */
534 	ZAURUS_MASTER_INTERFACE,
535 	.driver_info		= 0,
536 },
537 
538 /*
539  * WHITELIST!!!
540  *
541  * CDC Ether uses two interfaces, not necessarily consecutive.
542  * We match the main interface, ignoring the optional device
543  * class so we could handle devices that aren't exclusively
544  * CDC ether.
545  *
546  * NOTE:  this match must come AFTER entries blacklisting devices
547  * because of bugs/quirks in a given product (like Zaurus, above).
548  */
549 {
550 	USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ETHERNET,
551 			USB_CDC_PROTO_NONE),
552 	.driver_info = (unsigned long) &cdc_info,
553 },
554 	{ },		// END
555 };
556 MODULE_DEVICE_TABLE(usb, products);
557 
558 static struct usb_driver cdc_driver = {
559 	.name =		"cdc_ether",
560 	.id_table =	products,
561 	.probe =	usbnet_probe,
562 	.disconnect =	usbnet_disconnect,
563 	.suspend =	usbnet_suspend,
564 	.resume =	usbnet_resume,
565 };
566 
567 
568 static int __init cdc_init(void)
569 {
570 	BUILD_BUG_ON((sizeof(((struct usbnet *)0)->data)
571 			< sizeof(struct cdc_state)));
572 
573  	return usb_register(&cdc_driver);
574 }
575 module_init(cdc_init);
576 
577 static void __exit cdc_exit(void)
578 {
579  	usb_deregister(&cdc_driver);
580 }
581 module_exit(cdc_exit);
582 
583 MODULE_AUTHOR("David Brownell");
584 MODULE_DESCRIPTION("USB CDC Ethernet devices");
585 MODULE_LICENSE("GPL");
586