1/*
2 * Wireless USB - Cable Based Association
3 *
4 *
5 * Copyright (C) 2006 Intel Corporation
6 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
7 * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License version
11 * 2 as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 * 02110-1301, USA.
22 *
23 *
24 * WUSB devices have to be paired (associated in WUSB lingo) so
25 * that they can connect to the system.
26 *
27 * One way of pairing is using CBA-Cable Based Association. First
28 * time you plug the device with a cable, association is done between
29 * host and device and subsequent times, you can connect wirelessly
30 * without having to associate again. That's the idea.
31 *
32 * This driver does nothing Earth shattering. It just provides an
33 * interface to chat with the wire-connected device so we can get a
34 * CDID (device ID) that might have been previously associated to a
35 * CHID (host ID) and to set up a new <CHID,CDID,CK> triplet
36 * (connection context), with the CK being the secret, or connection
37 * key. This is the pairing data.
38 *
39 * When a device with the CBA capability connects, the probe routine
40 * just creates a bunch of sysfs files that a user space enumeration
41 * manager uses to allow it to connect wirelessly to the system or not.
42 *
43 * The process goes like this:
44 *
45 * 1. Device plugs, cbaf is loaded, notifications happen.
46 *
47 * 2. The connection manager (CM) sees a device with CBAF capability
48 *    (the wusb_chid etc. files in /sys/devices/blah/OURDEVICE).
49 *
50 * 3. The CM writes the host name, supported band groups, and the CHID
51 *    (host ID) into the wusb_host_name, wusb_host_band_groups and
52 *    wusb_chid files. These get sent to the device and the CDID (if
53 *    any) for this host is requested.
54 *
55 * 4. The CM can verify that the device's supported band groups
56 *    (wusb_device_band_groups) are compatible with the host.
57 *
58 * 5. The CM reads the wusb_cdid file.
59 *
60 * 6. The CM looks up its database
61 *
62 * 6.1 If it has a matching CHID,CDID entry, the device has been
63 *     authorized before (paired) and nothing further needs to be
64 *     done.
65 *
66 * 6.2 If the CDID is zero (or the CM doesn't find a matching CDID in
67 *     its database), the device is assumed to be not known.  The CM
68 *     may associate the host with device by: writing a randomly
69 *     generated CDID to wusb_cdid and then a random CK to wusb_ck
70 *     (this uploads the new CC to the device).
71 *
72 *     CMD may choose to prompt the user before associating with a new
73 *     device.
74 *
75 * 7. Device is unplugged.
76 *
77 * When the device tries to connect wirelessly, it will present its
78 * CDID to the WUSB host controller.  The CM will query the
79 * database. If the CHID/CDID pair found, it will (with a 4-way
80 * handshake) challenge the device to demonstrate it has the CK secret
81 * key (from our database) without actually exchanging it. Once
82 * satisfied, crypto keys are derived from the CK, the device is
83 * connected and all communication is encrypted.
84 *
85 * References:
86 *   [WUSB-AM] Association Models Supplement to the Certified Wireless
87 *             Universal Serial Bus Specification, version 1.0.
88 */
89#include <linux/module.h>
90#include <linux/ctype.h>
91#include <linux/usb.h>
92#include <linux/interrupt.h>
93#include <linux/delay.h>
94#include <linux/random.h>
95#include <linux/slab.h>
96#include <linux/mutex.h>
97#include <linux/uwb.h>
98#include <linux/usb/wusb.h>
99#include <linux/usb/association.h>
100
101#define CBA_NAME_LEN 0x40 /* [WUSB-AM] table 4-7 */
102
103/* An instance of a Cable-Based-Association-Framework device */
104struct cbaf {
105	struct usb_device *usb_dev;
106	struct usb_interface *usb_iface;
107	void *buffer;
108	size_t buffer_size;
109
110	struct wusb_ckhdid chid;
111	char host_name[CBA_NAME_LEN];
112	u16 host_band_groups;
113
114	struct wusb_ckhdid cdid;
115	char device_name[CBA_NAME_LEN];
116	u16 device_band_groups;
117
118	struct wusb_ckhdid ck;
119};
120
121/*
122 * Verify that a CBAF USB-interface has what we need
123 *
124 * According to [WUSB-AM], CBA devices should provide at least two
125 * interfaces:
126 *  - RETRIEVE_HOST_INFO
127 *  - ASSOCIATE
128 *
129 * If the device doesn't provide these interfaces, we do not know how
130 * to deal with it.
131 */
132static int cbaf_check(struct cbaf *cbaf)
133{
134	int result;
135	struct device *dev = &cbaf->usb_iface->dev;
136	struct wusb_cbaf_assoc_info *assoc_info;
137	struct wusb_cbaf_assoc_request *assoc_request;
138	size_t assoc_size;
139	void *itr, *top;
140	int ar_rhi = 0, ar_assoc = 0;
141
142	result = usb_control_msg(
143		cbaf->usb_dev, usb_rcvctrlpipe(cbaf->usb_dev, 0),
144		CBAF_REQ_GET_ASSOCIATION_INFORMATION,
145		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
146		0, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
147		cbaf->buffer, cbaf->buffer_size, USB_CTRL_GET_TIMEOUT);
148	if (result < 0) {
149		dev_err(dev, "Cannot get available association types: %d\n",
150			result);
151		return result;
152	}
153
154	assoc_info = cbaf->buffer;
155	if (result < sizeof(*assoc_info)) {
156		dev_err(dev, "Not enough data to decode association info "
157			"header (%zu vs %zu bytes required)\n",
158			(size_t)result, sizeof(*assoc_info));
159		return result;
160	}
161
162	assoc_size = le16_to_cpu(assoc_info->Length);
163	if (result < assoc_size) {
164		dev_err(dev, "Not enough data to decode association info "
165			"(%zu vs %zu bytes required)\n",
166			(size_t)assoc_size, sizeof(*assoc_info));
167		return result;
168	}
169	/*
170	 * From now on, we just verify, but won't error out unless we
171	 * don't find the AR_TYPE_WUSB_{RETRIEVE_HOST_INFO,ASSOCIATE}
172	 * types.
173	 */
174	itr = cbaf->buffer + sizeof(*assoc_info);
175	top = cbaf->buffer + assoc_size;
176	dev_dbg(dev, "Found %u association requests (%zu bytes)\n",
177		 assoc_info->NumAssociationRequests, assoc_size);
178
179	while (itr < top) {
180		u16 ar_type, ar_subtype;
181		u32 ar_size;
182		const char *ar_name;
183
184		assoc_request = itr;
185
186		if (top - itr < sizeof(*assoc_request)) {
187			dev_err(dev, "Not enough data to decode association "
188				"request (%zu vs %zu bytes needed)\n",
189				top - itr, sizeof(*assoc_request));
190			break;
191		}
192
193		ar_type = le16_to_cpu(assoc_request->AssociationTypeId);
194		ar_subtype = le16_to_cpu(assoc_request->AssociationSubTypeId);
195		ar_size = le32_to_cpu(assoc_request->AssociationTypeInfoSize);
196		ar_name = "unknown";
197
198		switch (ar_type) {
199		case AR_TYPE_WUSB:
200			/* Verify we have what is mandated by [WUSB-AM]. */
201			switch (ar_subtype) {
202			case AR_TYPE_WUSB_RETRIEVE_HOST_INFO:
203				ar_name = "RETRIEVE_HOST_INFO";
204				ar_rhi = 1;
205				break;
206			case AR_TYPE_WUSB_ASSOCIATE:
207				/* send assoc data */
208				ar_name = "ASSOCIATE";
209				ar_assoc = 1;
210				break;
211			}
212			break;
213		}
214
215		dev_dbg(dev, "Association request #%02u: 0x%04x/%04x "
216			 "(%zu bytes): %s\n",
217			 assoc_request->AssociationDataIndex, ar_type,
218			 ar_subtype, (size_t)ar_size, ar_name);
219
220		itr += sizeof(*assoc_request);
221	}
222
223	if (!ar_rhi) {
224		dev_err(dev, "Missing RETRIEVE_HOST_INFO association "
225			"request\n");
226		return -EINVAL;
227	}
228	if (!ar_assoc) {
229		dev_err(dev, "Missing ASSOCIATE association request\n");
230		return -EINVAL;
231	}
232
233	return 0;
234}
235
236static const struct wusb_cbaf_host_info cbaf_host_info_defaults = {
237	.AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
238	.AssociationTypeId	  = cpu_to_le16(AR_TYPE_WUSB),
239	.AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
240	.AssociationSubTypeId = cpu_to_le16(AR_TYPE_WUSB_RETRIEVE_HOST_INFO),
241	.CHID_hdr                 = WUSB_AR_CHID,
242	.LangID_hdr               = WUSB_AR_LangID,
243	.HostFriendlyName_hdr     = WUSB_AR_HostFriendlyName,
244};
245
246/* Send WUSB host information (CHID and name) to a CBAF device */
247static int cbaf_send_host_info(struct cbaf *cbaf)
248{
249	struct wusb_cbaf_host_info *hi;
250	size_t name_len;
251	size_t hi_size;
252
253	hi = cbaf->buffer;
254	memset(hi, 0, sizeof(*hi));
255	*hi = cbaf_host_info_defaults;
256	hi->CHID = cbaf->chid;
257	hi->LangID = 0;	/* FIXME: I guess... */
258	strlcpy(hi->HostFriendlyName, cbaf->host_name, CBA_NAME_LEN);
259	name_len = strlen(cbaf->host_name);
260	hi->HostFriendlyName_hdr.len = cpu_to_le16(name_len);
261	hi_size = sizeof(*hi) + name_len;
262
263	return usb_control_msg(cbaf->usb_dev,
264			usb_sndctrlpipe(cbaf->usb_dev, 0),
265			CBAF_REQ_SET_ASSOCIATION_RESPONSE,
266			USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
267			0x0101,
268			cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
269			hi, hi_size, USB_CTRL_SET_TIMEOUT);
270}
271
272/*
273 * Get device's information (CDID) associated to CHID
274 *
275 * The device will return it's information (CDID, name, bandgroups)
276 * associated to the CHID we have set before, or 0 CDID and default
277 * name and bandgroup if no CHID set or unknown.
278 */
279static int cbaf_cdid_get(struct cbaf *cbaf)
280{
281	int result;
282	struct device *dev = &cbaf->usb_iface->dev;
283	struct wusb_cbaf_device_info *di;
284	size_t needed;
285
286	di = cbaf->buffer;
287	result = usb_control_msg(
288		cbaf->usb_dev, usb_rcvctrlpipe(cbaf->usb_dev, 0),
289		CBAF_REQ_GET_ASSOCIATION_REQUEST,
290		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
291		0x0200, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
292		di, cbaf->buffer_size, USB_CTRL_GET_TIMEOUT);
293	if (result < 0) {
294		dev_err(dev, "Cannot request device information: %d\n",
295			result);
296		return result;
297	}
298
299	needed = result < sizeof(*di) ? sizeof(*di) : le32_to_cpu(di->Length);
300	if (result < needed) {
301		dev_err(dev, "Not enough data in DEVICE_INFO reply (%zu vs "
302			"%zu bytes needed)\n", (size_t)result, needed);
303		return -ENOENT;
304	}
305
306	strlcpy(cbaf->device_name, di->DeviceFriendlyName, CBA_NAME_LEN);
307	cbaf->cdid = di->CDID;
308	cbaf->device_band_groups = le16_to_cpu(di->BandGroups);
309
310	return 0;
311}
312
313static ssize_t cbaf_wusb_chid_show(struct device *dev,
314					struct device_attribute *attr,
315					char *buf)
316{
317	struct usb_interface *iface = to_usb_interface(dev);
318	struct cbaf *cbaf = usb_get_intfdata(iface);
319	char pr_chid[WUSB_CKHDID_STRSIZE];
320
321	ckhdid_printf(pr_chid, sizeof(pr_chid), &cbaf->chid);
322	return scnprintf(buf, PAGE_SIZE, "%s\n", pr_chid);
323}
324
325static ssize_t cbaf_wusb_chid_store(struct device *dev,
326					 struct device_attribute *attr,
327					 const char *buf, size_t size)
328{
329	ssize_t result;
330	struct usb_interface *iface = to_usb_interface(dev);
331	struct cbaf *cbaf = usb_get_intfdata(iface);
332
333	result = sscanf(buf,
334			"%02hhx %02hhx %02hhx %02hhx "
335			"%02hhx %02hhx %02hhx %02hhx "
336			"%02hhx %02hhx %02hhx %02hhx "
337			"%02hhx %02hhx %02hhx %02hhx",
338			&cbaf->chid.data[0] , &cbaf->chid.data[1],
339			&cbaf->chid.data[2] , &cbaf->chid.data[3],
340			&cbaf->chid.data[4] , &cbaf->chid.data[5],
341			&cbaf->chid.data[6] , &cbaf->chid.data[7],
342			&cbaf->chid.data[8] , &cbaf->chid.data[9],
343			&cbaf->chid.data[10], &cbaf->chid.data[11],
344			&cbaf->chid.data[12], &cbaf->chid.data[13],
345			&cbaf->chid.data[14], &cbaf->chid.data[15]);
346
347	if (result != 16)
348		return -EINVAL;
349
350	result = cbaf_send_host_info(cbaf);
351	if (result < 0)
352		return result;
353	result = cbaf_cdid_get(cbaf);
354	if (result < 0)
355		return result;
356	return size;
357}
358static DEVICE_ATTR(wusb_chid, 0600, cbaf_wusb_chid_show, cbaf_wusb_chid_store);
359
360static ssize_t cbaf_wusb_host_name_show(struct device *dev,
361					struct device_attribute *attr,
362					char *buf)
363{
364	struct usb_interface *iface = to_usb_interface(dev);
365	struct cbaf *cbaf = usb_get_intfdata(iface);
366
367	return scnprintf(buf, PAGE_SIZE, "%s\n", cbaf->host_name);
368}
369
370static ssize_t cbaf_wusb_host_name_store(struct device *dev,
371					 struct device_attribute *attr,
372					 const char *buf, size_t size)
373{
374	ssize_t result;
375	struct usb_interface *iface = to_usb_interface(dev);
376	struct cbaf *cbaf = usb_get_intfdata(iface);
377
378	result = sscanf(buf, "%63s", cbaf->host_name);
379	if (result != 1)
380		return -EINVAL;
381
382	return size;
383}
384static DEVICE_ATTR(wusb_host_name, 0600, cbaf_wusb_host_name_show,
385					 cbaf_wusb_host_name_store);
386
387static ssize_t cbaf_wusb_host_band_groups_show(struct device *dev,
388					       struct device_attribute *attr,
389					       char *buf)
390{
391	struct usb_interface *iface = to_usb_interface(dev);
392	struct cbaf *cbaf = usb_get_intfdata(iface);
393
394	return scnprintf(buf, PAGE_SIZE, "0x%04x\n", cbaf->host_band_groups);
395}
396
397static ssize_t cbaf_wusb_host_band_groups_store(struct device *dev,
398						struct device_attribute *attr,
399						const char *buf, size_t size)
400{
401	ssize_t result;
402	struct usb_interface *iface = to_usb_interface(dev);
403	struct cbaf *cbaf = usb_get_intfdata(iface);
404	u16 band_groups = 0;
405
406	result = sscanf(buf, "%04hx", &band_groups);
407	if (result != 1)
408		return -EINVAL;
409
410	cbaf->host_band_groups = band_groups;
411
412	return size;
413}
414
415static DEVICE_ATTR(wusb_host_band_groups, 0600,
416		   cbaf_wusb_host_band_groups_show,
417		   cbaf_wusb_host_band_groups_store);
418
419static const struct wusb_cbaf_device_info cbaf_device_info_defaults = {
420	.Length_hdr               = WUSB_AR_Length,
421	.CDID_hdr                 = WUSB_AR_CDID,
422	.BandGroups_hdr           = WUSB_AR_BandGroups,
423	.LangID_hdr               = WUSB_AR_LangID,
424	.DeviceFriendlyName_hdr   = WUSB_AR_DeviceFriendlyName,
425};
426
427static ssize_t cbaf_wusb_cdid_show(struct device *dev,
428				   struct device_attribute *attr, char *buf)
429{
430	struct usb_interface *iface = to_usb_interface(dev);
431	struct cbaf *cbaf = usb_get_intfdata(iface);
432	char pr_cdid[WUSB_CKHDID_STRSIZE];
433
434	ckhdid_printf(pr_cdid, sizeof(pr_cdid), &cbaf->cdid);
435	return scnprintf(buf, PAGE_SIZE, "%s\n", pr_cdid);
436}
437
438static ssize_t cbaf_wusb_cdid_store(struct device *dev,
439				struct device_attribute *attr,
440				const char *buf, size_t size)
441{
442	ssize_t result;
443	struct usb_interface *iface = to_usb_interface(dev);
444	struct cbaf *cbaf = usb_get_intfdata(iface);
445	struct wusb_ckhdid cdid;
446
447	result = sscanf(buf,
448			"%02hhx %02hhx %02hhx %02hhx "
449			"%02hhx %02hhx %02hhx %02hhx "
450			"%02hhx %02hhx %02hhx %02hhx "
451			"%02hhx %02hhx %02hhx %02hhx",
452			&cdid.data[0] , &cdid.data[1],
453			&cdid.data[2] , &cdid.data[3],
454			&cdid.data[4] , &cdid.data[5],
455			&cdid.data[6] , &cdid.data[7],
456			&cdid.data[8] , &cdid.data[9],
457			&cdid.data[10], &cdid.data[11],
458			&cdid.data[12], &cdid.data[13],
459			&cdid.data[14], &cdid.data[15]);
460	if (result != 16)
461		return -EINVAL;
462
463	cbaf->cdid = cdid;
464
465	return size;
466}
467static DEVICE_ATTR(wusb_cdid, 0600, cbaf_wusb_cdid_show, cbaf_wusb_cdid_store);
468
469static ssize_t cbaf_wusb_device_band_groups_show(struct device *dev,
470						 struct device_attribute *attr,
471						 char *buf)
472{
473	struct usb_interface *iface = to_usb_interface(dev);
474	struct cbaf *cbaf = usb_get_intfdata(iface);
475
476	return scnprintf(buf, PAGE_SIZE, "0x%04x\n", cbaf->device_band_groups);
477}
478
479static DEVICE_ATTR(wusb_device_band_groups, 0600,
480		   cbaf_wusb_device_band_groups_show,
481		   NULL);
482
483static ssize_t cbaf_wusb_device_name_show(struct device *dev,
484					struct device_attribute *attr,
485					char *buf)
486{
487	struct usb_interface *iface = to_usb_interface(dev);
488	struct cbaf *cbaf = usb_get_intfdata(iface);
489
490	return scnprintf(buf, PAGE_SIZE, "%s\n", cbaf->device_name);
491}
492static DEVICE_ATTR(wusb_device_name, 0600, cbaf_wusb_device_name_show, NULL);
493
494static const struct wusb_cbaf_cc_data cbaf_cc_data_defaults = {
495	.AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
496	.AssociationTypeId	  = cpu_to_le16(AR_TYPE_WUSB),
497	.AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
498	.AssociationSubTypeId     = cpu_to_le16(AR_TYPE_WUSB_ASSOCIATE),
499	.Length_hdr               = WUSB_AR_Length,
500	.Length		= cpu_to_le32(sizeof(struct wusb_cbaf_cc_data)),
501	.ConnectionContext_hdr    = WUSB_AR_ConnectionContext,
502	.BandGroups_hdr           = WUSB_AR_BandGroups,
503};
504
505static const struct wusb_cbaf_cc_data_fail cbaf_cc_data_fail_defaults = {
506	.AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
507	.AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
508	.Length_hdr               = WUSB_AR_Length,
509	.AssociationStatus_hdr    = WUSB_AR_AssociationStatus,
510};
511
512/*
513 * Send a new CC to the device.
514 */
515static int cbaf_cc_upload(struct cbaf *cbaf)
516{
517	int result;
518	struct device *dev = &cbaf->usb_iface->dev;
519	struct wusb_cbaf_cc_data *ccd;
520	char pr_cdid[WUSB_CKHDID_STRSIZE];
521
522	ccd =  cbaf->buffer;
523	*ccd = cbaf_cc_data_defaults;
524	ccd->CHID = cbaf->chid;
525	ccd->CDID = cbaf->cdid;
526	ccd->CK = cbaf->ck;
527	ccd->BandGroups = cpu_to_le16(cbaf->host_band_groups);
528
529	dev_dbg(dev, "Trying to upload CC:\n");
530	ckhdid_printf(pr_cdid, sizeof(pr_cdid), &ccd->CHID);
531	dev_dbg(dev, "  CHID       %s\n", pr_cdid);
532	ckhdid_printf(pr_cdid, sizeof(pr_cdid), &ccd->CDID);
533	dev_dbg(dev, "  CDID       %s\n", pr_cdid);
534	dev_dbg(dev, "  Bandgroups 0x%04x\n", cbaf->host_band_groups);
535
536	result = usb_control_msg(
537		cbaf->usb_dev, usb_sndctrlpipe(cbaf->usb_dev, 0),
538		CBAF_REQ_SET_ASSOCIATION_RESPONSE,
539		USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
540		0x0201, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
541		ccd, sizeof(*ccd), USB_CTRL_SET_TIMEOUT);
542
543	return result;
544}
545
546static ssize_t cbaf_wusb_ck_store(struct device *dev,
547				  struct device_attribute *attr,
548				  const char *buf, size_t size)
549{
550	ssize_t result;
551	struct usb_interface *iface = to_usb_interface(dev);
552	struct cbaf *cbaf = usb_get_intfdata(iface);
553
554	result = sscanf(buf,
555			"%02hhx %02hhx %02hhx %02hhx "
556			"%02hhx %02hhx %02hhx %02hhx "
557			"%02hhx %02hhx %02hhx %02hhx "
558			"%02hhx %02hhx %02hhx %02hhx",
559			&cbaf->ck.data[0] , &cbaf->ck.data[1],
560			&cbaf->ck.data[2] , &cbaf->ck.data[3],
561			&cbaf->ck.data[4] , &cbaf->ck.data[5],
562			&cbaf->ck.data[6] , &cbaf->ck.data[7],
563			&cbaf->ck.data[8] , &cbaf->ck.data[9],
564			&cbaf->ck.data[10], &cbaf->ck.data[11],
565			&cbaf->ck.data[12], &cbaf->ck.data[13],
566			&cbaf->ck.data[14], &cbaf->ck.data[15]);
567	if (result != 16)
568		return -EINVAL;
569
570	result = cbaf_cc_upload(cbaf);
571	if (result < 0)
572		return result;
573
574	return size;
575}
576static DEVICE_ATTR(wusb_ck, 0600, NULL, cbaf_wusb_ck_store);
577
578static struct attribute *cbaf_dev_attrs[] = {
579	&dev_attr_wusb_host_name.attr,
580	&dev_attr_wusb_host_band_groups.attr,
581	&dev_attr_wusb_chid.attr,
582	&dev_attr_wusb_cdid.attr,
583	&dev_attr_wusb_device_name.attr,
584	&dev_attr_wusb_device_band_groups.attr,
585	&dev_attr_wusb_ck.attr,
586	NULL,
587};
588
589static struct attribute_group cbaf_dev_attr_group = {
590	.name = NULL,	/* we want them in the same directory */
591	.attrs = cbaf_dev_attrs,
592};
593
594static int cbaf_probe(struct usb_interface *iface,
595		      const struct usb_device_id *id)
596{
597	struct cbaf *cbaf;
598	struct device *dev = &iface->dev;
599	int result = -ENOMEM;
600
601	cbaf = kzalloc(sizeof(*cbaf), GFP_KERNEL);
602	if (cbaf == NULL)
603		goto error_kzalloc;
604	cbaf->buffer = kmalloc(512, GFP_KERNEL);
605	if (cbaf->buffer == NULL)
606		goto error_kmalloc_buffer;
607
608	cbaf->buffer_size = 512;
609	cbaf->usb_dev = usb_get_dev(interface_to_usbdev(iface));
610	cbaf->usb_iface = usb_get_intf(iface);
611	result = cbaf_check(cbaf);
612	if (result < 0) {
613		dev_err(dev, "This device is not WUSB-CBAF compliant"
614			"and is not supported yet.\n");
615		goto error_check;
616	}
617
618	result = sysfs_create_group(&dev->kobj, &cbaf_dev_attr_group);
619	if (result < 0) {
620		dev_err(dev, "Can't register sysfs attr group: %d\n", result);
621		goto error_create_group;
622	}
623	usb_set_intfdata(iface, cbaf);
624	return 0;
625
626error_create_group:
627error_check:
628	usb_put_intf(iface);
629	usb_put_dev(cbaf->usb_dev);
630	kfree(cbaf->buffer);
631error_kmalloc_buffer:
632	kfree(cbaf);
633error_kzalloc:
634	return result;
635}
636
637static void cbaf_disconnect(struct usb_interface *iface)
638{
639	struct cbaf *cbaf = usb_get_intfdata(iface);
640	struct device *dev = &iface->dev;
641	sysfs_remove_group(&dev->kobj, &cbaf_dev_attr_group);
642	usb_set_intfdata(iface, NULL);
643	usb_put_intf(iface);
644	usb_put_dev(cbaf->usb_dev);
645	kfree(cbaf->buffer);
646	/* paranoia: clean up crypto keys */
647	kzfree(cbaf);
648}
649
650static const struct usb_device_id cbaf_id_table[] = {
651	{ USB_INTERFACE_INFO(0xef, 0x03, 0x01), },
652	{ },
653};
654MODULE_DEVICE_TABLE(usb, cbaf_id_table);
655
656static struct usb_driver cbaf_driver = {
657	.name =		"wusb-cbaf",
658	.id_table =	cbaf_id_table,
659	.probe =	cbaf_probe,
660	.disconnect =	cbaf_disconnect,
661};
662
663module_usb_driver(cbaf_driver);
664
665MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
666MODULE_DESCRIPTION("Wireless USB Cable Based Association");
667MODULE_LICENSE("GPL");
668