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1/*
2 * WUSB Host Wire Adapter: Radio Control Interface (WUSB[8.6])
3 * Radio Control command/event transport
4 *
5 * Copyright (C) 2005-2006 Intel Corporation
6 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License version
10 * 2 as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
20 * 02110-1301, USA.
21 *
22 *
23 * Initialize the Radio Control interface Driver.
24 *
25 * For each device probed, creates an 'struct hwarc' which contains
26 * just the representation of the UWB Radio Controller, and the logic
27 * for reading notifications and passing them to the UWB Core.
28 *
29 * So we initialize all of those, register the UWB Radio Controller
30 * and setup the notification/event handle to pipe the notifications
31 * to the UWB management Daemon.
32 *
33 * Command and event filtering.
34 *
35 * This is the driver for the Radio Control Interface described in WUSB
36 * 1.0. The core UWB module assumes that all drivers are compliant to the
37 * WHCI 0.95 specification. We thus create a filter that parses all
38 * incoming messages from the (WUSB 1.0) device and manipulate them to
39 * conform to the WHCI 0.95 specification. Similarly, outgoing messages
40 * are parsed and manipulated to conform to the WUSB 1.0 compliant messages
41 * that the device expects. Only a few messages are affected:
42 * Affected events:
43 *    UWB_RC_EVT_BEACON
44 *    UWB_RC_EVT_BP_SLOT_CHANGE
45 *    UWB_RC_EVT_DRP_AVAIL
46 *    UWB_RC_EVT_DRP
47 * Affected commands:
48 *    UWB_RC_CMD_SCAN
49 *    UWB_RC_CMD_SET_DRP_IE
50 *
51 *
52 *
53 */
54#include <linux/init.h>
55#include <linux/module.h>
56#include <linux/slab.h>
57#include <linux/usb.h>
58#include <linux/usb/wusb.h>
59#include <linux/usb/wusb-wa.h>
60#include <linux/uwb.h>
61
62#include "uwb-internal.h"
63
64/* The device uses commands and events from the WHCI specification, although
65 * reporting itself as WUSB compliant. */
66#define WUSB_QUIRK_WHCI_CMD_EVT		0x01
67
68/**
69 * Descriptor for an instance of the UWB Radio Control Driver that
70 * attaches to the RCI interface of the Host Wired Adapter.
71 *
72 * Unless there is a lock specific to the 'data members', all access
73 * is protected by uwb_rc->mutex.
74 *
75 * The NEEP (Notification/Event EndPoint) URB (@neep_urb) writes to
76 * @rd_buffer. Note there is no locking because it is perfectly (heh!)
77 * serialized--probe() submits an URB, callback is called, processes
78 * the data (synchronously), submits another URB, and so on. There is
79 * no concurrent access to the buffer.
80 */
81struct hwarc {
82	struct usb_device *usb_dev;
83	struct usb_interface *usb_iface;
84	struct uwb_rc *uwb_rc;		/* UWB host controller */
85	struct urb *neep_urb;		/* Notification endpoint handling */
86	struct edc neep_edc;
87	void *rd_buffer;		/* NEEP read buffer */
88};
89
90
91/* Beacon received notification (WUSB 1.0 [8.6.3.2]) */
92struct uwb_rc_evt_beacon_WUSB_0100 {
93	struct uwb_rceb rceb;
94	u8	bChannelNumber;
95	__le16	wBPSTOffset;
96	u8	bLQI;
97	u8	bRSSI;
98	__le16	wBeaconInfoLength;
99	u8	BeaconInfo[];
100} __attribute__((packed));
101
102/**
103 * Filter WUSB 1.0 BEACON RCV notification to be WHCI 0.95
104 *
105 * @header: the incoming event
106 * @buf_size: size of buffer containing incoming event
107 * @new_size: size of event after filtering completed
108 *
109 * The WHCI 0.95 spec has a "Beacon Type" field. This value is unknown at
110 * the time we receive the beacon from WUSB so we just set it to
111 * UWB_RC_BEACON_TYPE_NEIGHBOR as a default.
112 * The solution below allocates memory upon receipt of every beacon from a
113 * WUSB device. This will deteriorate performance. What is the right way to
114 * do this?
115 */
116static
117int hwarc_filter_evt_beacon_WUSB_0100(struct uwb_rc *rc,
118				      struct uwb_rceb **header,
119				      const size_t buf_size,
120				      size_t *new_size)
121{
122	struct uwb_rc_evt_beacon_WUSB_0100 *be;
123	struct uwb_rc_evt_beacon *newbe;
124	size_t bytes_left, ielength;
125	struct device *dev = &rc->uwb_dev.dev;
126
127	be = container_of(*header, struct uwb_rc_evt_beacon_WUSB_0100, rceb);
128	bytes_left = buf_size;
129	if (bytes_left < sizeof(*be)) {
130		dev_err(dev, "Beacon Received Notification: Not enough data "
131			"to decode for filtering (%zu vs %zu bytes needed)\n",
132			bytes_left, sizeof(*be));
133		return -EINVAL;
134	}
135	bytes_left -= sizeof(*be);
136	ielength = le16_to_cpu(be->wBeaconInfoLength);
137	if (bytes_left < ielength) {
138		dev_err(dev, "Beacon Received Notification: Not enough data "
139			"to decode IEs (%zu vs %zu bytes needed)\n",
140			bytes_left, ielength);
141		return -EINVAL;
142	}
143	newbe = kzalloc(sizeof(*newbe) + ielength, GFP_ATOMIC);
144	if (newbe == NULL)
145		return -ENOMEM;
146	newbe->rceb = be->rceb;
147	newbe->bChannelNumber = be->bChannelNumber;
148	newbe->bBeaconType = UWB_RC_BEACON_TYPE_NEIGHBOR;
149	newbe->wBPSTOffset = be->wBPSTOffset;
150	newbe->bLQI = be->bLQI;
151	newbe->bRSSI = be->bRSSI;
152	newbe->wBeaconInfoLength = be->wBeaconInfoLength;
153	memcpy(newbe->BeaconInfo, be->BeaconInfo, ielength);
154	*header = &newbe->rceb;
155	*new_size = sizeof(*newbe) + ielength;
156	return 1;  /* calling function will free memory */
157}
158
159
160/* DRP Availability change notification (WUSB 1.0 [8.6.3.8]) */
161struct uwb_rc_evt_drp_avail_WUSB_0100 {
162	struct uwb_rceb rceb;
163	__le16 wIELength;
164	u8 IEData[];
165} __attribute__((packed));
166
167/**
168 * Filter WUSB 1.0 DRP AVAILABILITY CHANGE notification to be WHCI 0.95
169 *
170 * @header: the incoming event
171 * @buf_size: size of buffer containing incoming event
172 * @new_size: size of event after filtering completed
173 */
174static
175int hwarc_filter_evt_drp_avail_WUSB_0100(struct uwb_rc *rc,
176					 struct uwb_rceb **header,
177					 const size_t buf_size,
178					 size_t *new_size)
179{
180	struct uwb_rc_evt_drp_avail_WUSB_0100 *da;
181	struct uwb_rc_evt_drp_avail *newda;
182	struct uwb_ie_hdr *ie_hdr;
183	size_t bytes_left, ielength;
184	struct device *dev = &rc->uwb_dev.dev;
185
186
187	da = container_of(*header, struct uwb_rc_evt_drp_avail_WUSB_0100, rceb);
188	bytes_left = buf_size;
189	if (bytes_left < sizeof(*da)) {
190		dev_err(dev, "Not enough data to decode DRP Avail "
191			"Notification for filtering. Expected %zu, "
192			"received %zu.\n", (size_t)sizeof(*da), bytes_left);
193		return -EINVAL;
194	}
195	bytes_left -= sizeof(*da);
196	ielength = le16_to_cpu(da->wIELength);
197	if (bytes_left < ielength) {
198		dev_err(dev, "DRP Avail Notification filter: IE length "
199			"[%zu bytes] does not match actual length "
200			"[%zu bytes].\n", ielength, bytes_left);
201		return -EINVAL;
202	}
203	if (ielength < sizeof(*ie_hdr)) {
204		dev_err(dev, "DRP Avail Notification filter: Not enough "
205			"data to decode IE [%zu bytes, %zu needed]\n",
206			ielength, sizeof(*ie_hdr));
207		return -EINVAL;
208	}
209	ie_hdr = (void *) da->IEData;
210	if (ie_hdr->length > 32) {
211		dev_err(dev, "DRP Availability Change event has unexpected "
212			"length for filtering. Expected < 32 bytes, "
213			"got %zu bytes.\n", (size_t)ie_hdr->length);
214		return -EINVAL;
215	}
216	newda = kzalloc(sizeof(*newda), GFP_ATOMIC);
217	if (newda == NULL)
218		return -ENOMEM;
219	newda->rceb = da->rceb;
220	memcpy(newda->bmp, (u8 *) ie_hdr + sizeof(*ie_hdr), ie_hdr->length);
221	*header = &newda->rceb;
222	*new_size = sizeof(*newda);
223	return 1; /* calling function will free memory */
224}
225
226
227/* DRP notification (WUSB 1.0 [8.6.3.9]) */
228struct uwb_rc_evt_drp_WUSB_0100 {
229	struct uwb_rceb rceb;
230	struct uwb_dev_addr wSrcAddr;
231	u8 bExplicit;
232	__le16 wIELength;
233	u8 IEData[];
234} __attribute__((packed));
235
236/**
237 * Filter WUSB 1.0 DRP Notification to be WHCI 0.95
238 *
239 * @header: the incoming event
240 * @buf_size: size of buffer containing incoming event
241 * @new_size: size of event after filtering completed
242 *
243 * It is hard to manage DRP reservations without having a Reason code.
244 * Unfortunately there is none in the WUSB spec. We just set the default to
245 * DRP IE RECEIVED.
246 * We do not currently use the bBeaconSlotNumber value, so we set this to
247 * zero for now.
248 */
249static
250int hwarc_filter_evt_drp_WUSB_0100(struct uwb_rc *rc,
251				   struct uwb_rceb **header,
252				   const size_t buf_size,
253				   size_t *new_size)
254{
255	struct uwb_rc_evt_drp_WUSB_0100 *drpev;
256	struct uwb_rc_evt_drp *newdrpev;
257	size_t bytes_left, ielength;
258	struct device *dev = &rc->uwb_dev.dev;
259
260	drpev = container_of(*header, struct uwb_rc_evt_drp_WUSB_0100, rceb);
261	bytes_left = buf_size;
262	if (bytes_left < sizeof(*drpev)) {
263		dev_err(dev, "Not enough data to decode DRP Notification "
264			"for filtering. Expected %zu, received %zu.\n",
265			(size_t)sizeof(*drpev), bytes_left);
266		return -EINVAL;
267	}
268	ielength = le16_to_cpu(drpev->wIELength);
269	bytes_left -= sizeof(*drpev);
270	if (bytes_left < ielength) {
271		dev_err(dev, "DRP Notification filter: header length [%zu "
272			"bytes] does not match actual length [%zu "
273			"bytes].\n", ielength, bytes_left);
274		return -EINVAL;
275	}
276	newdrpev = kzalloc(sizeof(*newdrpev) + ielength, GFP_ATOMIC);
277	if (newdrpev == NULL)
278		return -ENOMEM;
279	newdrpev->rceb = drpev->rceb;
280	newdrpev->src_addr = drpev->wSrcAddr;
281	newdrpev->reason = UWB_DRP_NOTIF_DRP_IE_RCVD;
282	newdrpev->beacon_slot_number = 0;
283	newdrpev->ie_length = drpev->wIELength;
284	memcpy(newdrpev->ie_data, drpev->IEData, ielength);
285	*header = &newdrpev->rceb;
286	*new_size = sizeof(*newdrpev) + ielength;
287	return 1; /* calling function will free memory */
288}
289
290
291/* Scan Command (WUSB 1.0 [8.6.2.5]) */
292struct uwb_rc_cmd_scan_WUSB_0100 {
293	struct uwb_rccb rccb;
294	u8 bChannelNumber;
295	u8 bScanState;
296} __attribute__((packed));
297
298/**
299 * Filter WHCI 0.95 SCAN command to be WUSB 1.0 SCAN command
300 *
301 * @header:   command sent to device (compliant to WHCI 0.95)
302 * @size:     size of command sent to device
303 *
304 * We only reduce the size by two bytes because the WUSB 1.0 scan command
305 * does not have the last field (wStarttime). Also, make sure we don't send
306 * the device an unexpected scan type.
307 */
308static
309int hwarc_filter_cmd_scan_WUSB_0100(struct uwb_rc *rc,
310				    struct uwb_rccb **header,
311				    size_t *size)
312{
313	struct uwb_rc_cmd_scan *sc;
314
315	sc = container_of(*header, struct uwb_rc_cmd_scan, rccb);
316
317	if (sc->bScanState == UWB_SCAN_ONLY_STARTTIME)
318		sc->bScanState = UWB_SCAN_ONLY;
319	/* Don't send the last two bytes. */
320	*size -= 2;
321	return 0;
322}
323
324
325/* SET DRP IE command (WUSB 1.0 [8.6.2.7]) */
326struct uwb_rc_cmd_set_drp_ie_WUSB_0100 {
327	struct uwb_rccb rccb;
328	u8 bExplicit;
329	__le16 wIELength;
330	struct uwb_ie_drp IEData[];
331} __attribute__((packed));
332
333/**
334 * Filter WHCI 0.95 SET DRP IE command to be WUSB 1.0 SET DRP IE command
335 *
336 * @header:   command sent to device (compliant to WHCI 0.95)
337 * @size:     size of command sent to device
338 *
339 * WUSB has an extra bExplicit field - we assume always explicit
340 * negotiation so this field is set. The command expected by the device is
341 * thus larger than the one prepared by the driver so we need to
342 * reallocate memory to accommodate this.
343 * We trust the driver to send us the correct data so no checking is done
344 * on incoming data - evn though it is variable length.
345 */
346static
347int hwarc_filter_cmd_set_drp_ie_WUSB_0100(struct uwb_rc *rc,
348					  struct uwb_rccb **header,
349					  size_t *size)
350{
351	struct uwb_rc_cmd_set_drp_ie *orgcmd;
352	struct uwb_rc_cmd_set_drp_ie_WUSB_0100 *cmd;
353	size_t ielength;
354
355	orgcmd = container_of(*header, struct uwb_rc_cmd_set_drp_ie, rccb);
356	ielength = le16_to_cpu(orgcmd->wIELength);
357	cmd = kzalloc(sizeof(*cmd) + ielength, GFP_KERNEL);
358	if (cmd == NULL)
359		return -ENOMEM;
360	cmd->rccb = orgcmd->rccb;
361	cmd->bExplicit = 0;
362	cmd->wIELength = orgcmd->wIELength;
363	memcpy(cmd->IEData, orgcmd->IEData, ielength);
364	*header = &cmd->rccb;
365	*size = sizeof(*cmd) + ielength;
366	return 1; /* calling function will free memory */
367}
368
369
370/**
371 * Filter data from WHCI driver to WUSB device
372 *
373 * @header: WHCI 0.95 compliant command from driver
374 * @size:   length of command
375 *
376 * The routine managing commands to the device (uwb_rc_cmd()) will call the
377 * filtering function pointer (if it exists) before it passes any data to
378 * the device. At this time the command has been formatted according to
379 * WHCI 0.95 and is ready to be sent to the device.
380 *
381 * The filter function will be provided with the current command and its
382 * length. The function will manipulate the command if necessary and
383 * potentially reallocate memory for a command that needed more memory that
384 * the given command. If new memory was created the function will return 1
385 * to indicate to the calling function that the memory need to be freed
386 * when not needed any more. The size will contain the new length of the
387 * command.
388 * If memory has not been allocated we rely on the original mechanisms to
389 * free the memory of the command - even when we reduce the value of size.
390 */
391static
392int hwarc_filter_cmd_WUSB_0100(struct uwb_rc *rc, struct uwb_rccb **header,
393			       size_t *size)
394{
395	int result;
396	struct uwb_rccb *rccb = *header;
397	int cmd = le16_to_cpu(rccb->wCommand);
398	switch (cmd) {
399	case UWB_RC_CMD_SCAN:
400		result = hwarc_filter_cmd_scan_WUSB_0100(rc, header, size);
401		break;
402	case UWB_RC_CMD_SET_DRP_IE:
403		result = hwarc_filter_cmd_set_drp_ie_WUSB_0100(rc, header, size);
404		break;
405	default:
406		result = -ENOANO;
407		break;
408	}
409	return result;
410}
411
412
413/**
414 * Filter data from WHCI driver to WUSB device
415 *
416 * @header: WHCI 0.95 compliant command from driver
417 * @size:   length of command
418 *
419 * Filter commands based on which protocol the device supports. The WUSB
420 * errata should be the same as WHCI 0.95 so we do not filter that here -
421 * only WUSB 1.0.
422 */
423static
424int hwarc_filter_cmd(struct uwb_rc *rc, struct uwb_rccb **header,
425		     size_t *size)
426{
427	int result = -ENOANO;
428	if (rc->version == 0x0100)
429		result = hwarc_filter_cmd_WUSB_0100(rc, header, size);
430	return result;
431}
432
433
434/**
435 * Compute return value as sum of incoming value and value at given offset
436 *
437 * @rceb:      event for which we compute the size, it contains a variable
438 *	       length field.
439 * @core_size: size of the "non variable" part of the event
440 * @offset:    place in event where the length of the variable part is stored
441 * @buf_size: total length of buffer in which event arrived - we need to make
442 *	       sure we read the offset in memory that is still part of the event
443 */
444static
445ssize_t hwarc_get_event_size(struct uwb_rc *rc, const struct uwb_rceb *rceb,
446			     size_t core_size, size_t offset,
447			     const size_t buf_size)
448{
449	ssize_t size = -ENOSPC;
450	const void *ptr = rceb;
451	size_t type_size = sizeof(__le16);
452	struct device *dev = &rc->uwb_dev.dev;
453
454	if (offset + type_size >= buf_size) {
455		dev_err(dev, "Not enough data to read extra size of event "
456			"0x%02x/%04x/%02x, only got %zu bytes.\n",
457			rceb->bEventType, le16_to_cpu(rceb->wEvent),
458			rceb->bEventContext, buf_size);
459		goto out;
460	}
461	ptr += offset;
462	size = core_size + le16_to_cpu(*(__le16 *)ptr);
463out:
464	return size;
465}
466
467
468/* Beacon slot change notification (WUSB 1.0 [8.6.3.5]) */
469struct uwb_rc_evt_bp_slot_change_WUSB_0100 {
470	struct uwb_rceb rceb;
471	u8 bSlotNumber;
472} __attribute__((packed));
473
474
475/**
476 * Filter data from WUSB device to WHCI driver
477 *
478 * @header:	 incoming event
479 * @buf_size:	 size of buffer in which event arrived
480 * @_event_size: actual size of event in the buffer
481 * @new_size:	 size of event after filtered
482 *
483 * We don't know how the buffer is constructed - there may be more than one
484 * event in it so buffer length does not determine event length. We first
485 * determine the expected size of the incoming event. This value is passed
486 * back only if the actual filtering succeeded (so we know the computed
487 * expected size is correct). This value will be zero if
488 * the event did not need any filtering.
489 *
490 * WHCI interprets the BP Slot Change event's data differently than
491 * WUSB. The event sizes are exactly the same. The data field
492 * indicates the new beacon slot in which a RC is transmitting its
493 * beacon. The maximum value of this is 96 (wMacBPLength ECMA-368
494 * 17.16 (Table 117)). We thus know that the WUSB value will not set
495 * the bit bNoSlot, so we don't really do anything (placeholder).
496 */
497static
498int hwarc_filter_event_WUSB_0100(struct uwb_rc *rc, struct uwb_rceb **header,
499				 const size_t buf_size, size_t *_real_size,
500				 size_t *_new_size)
501{
502	int result = -ENOANO;
503	struct uwb_rceb *rceb = *header;
504	int event = le16_to_cpu(rceb->wEvent);
505	ssize_t event_size;
506	size_t core_size, offset;
507
508	if (rceb->bEventType != UWB_RC_CET_GENERAL)
509		goto out;
510	switch (event) {
511	case UWB_RC_EVT_BEACON:
512		core_size = sizeof(struct uwb_rc_evt_beacon_WUSB_0100);
513		offset = offsetof(struct uwb_rc_evt_beacon_WUSB_0100,
514				  wBeaconInfoLength);
515		event_size = hwarc_get_event_size(rc, rceb, core_size,
516						  offset, buf_size);
517		if (event_size < 0)
518			goto out;
519		*_real_size = event_size;
520		result = hwarc_filter_evt_beacon_WUSB_0100(rc, header,
521							   buf_size, _new_size);
522		break;
523	case UWB_RC_EVT_BP_SLOT_CHANGE:
524		*_new_size = *_real_size =
525			sizeof(struct uwb_rc_evt_bp_slot_change_WUSB_0100);
526		result = 0;
527		break;
528
529	case UWB_RC_EVT_DRP_AVAIL:
530		core_size = sizeof(struct uwb_rc_evt_drp_avail_WUSB_0100);
531		offset = offsetof(struct uwb_rc_evt_drp_avail_WUSB_0100,
532				  wIELength);
533		event_size = hwarc_get_event_size(rc, rceb, core_size,
534						  offset, buf_size);
535		if (event_size < 0)
536			goto out;
537		*_real_size = event_size;
538		result = hwarc_filter_evt_drp_avail_WUSB_0100(
539			rc, header, buf_size, _new_size);
540		break;
541
542	case UWB_RC_EVT_DRP:
543		core_size = sizeof(struct uwb_rc_evt_drp_WUSB_0100);
544		offset = offsetof(struct uwb_rc_evt_drp_WUSB_0100, wIELength);
545		event_size = hwarc_get_event_size(rc, rceb, core_size,
546						  offset, buf_size);
547		if (event_size < 0)
548			goto out;
549		*_real_size = event_size;
550		result = hwarc_filter_evt_drp_WUSB_0100(rc, header,
551							buf_size, _new_size);
552		break;
553
554	default:
555		break;
556	}
557out:
558	return result;
559}
560
561/**
562 * Filter data from WUSB device to WHCI driver
563 *
564 * @header:	 incoming event
565 * @buf_size:	 size of buffer in which event arrived
566 * @_event_size: actual size of event in the buffer
567 * @_new_size:	 size of event after filtered
568 *
569 * Filter events based on which protocol the device supports. The WUSB
570 * errata should be the same as WHCI 0.95 so we do not filter that here -
571 * only WUSB 1.0.
572 *
573 * If we don't handle it, we return -ENOANO (why the weird error code?
574 * well, so if I get it, I can pinpoint in the code that raised
575 * it...after all, not too many places use the higher error codes).
576 */
577static
578int hwarc_filter_event(struct uwb_rc *rc, struct uwb_rceb **header,
579		       const size_t buf_size, size_t *_real_size,
580		       size_t *_new_size)
581{
582	int result = -ENOANO;
583	if (rc->version == 0x0100)
584		result =  hwarc_filter_event_WUSB_0100(
585			rc, header, buf_size, _real_size, _new_size);
586	return result;
587}
588
589
590/**
591 * Execute an UWB RC command on HWA
592 *
593 * @rc:	      Instance of a Radio Controller that is a HWA
594 * @cmd:      Buffer containing the RCCB and payload to execute
595 * @cmd_size: Size of the command buffer.
596 *
597 * NOTE: rc's mutex has to be locked
598 */
599static
600int hwarc_cmd(struct uwb_rc *uwb_rc, const struct uwb_rccb *cmd, size_t cmd_size)
601{
602	struct hwarc *hwarc = uwb_rc->priv;
603	return usb_control_msg(
604		hwarc->usb_dev, usb_sndctrlpipe(hwarc->usb_dev, 0),
605		WA_EXEC_RC_CMD, USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
606		0, hwarc->usb_iface->cur_altsetting->desc.bInterfaceNumber,
607		(void *) cmd, cmd_size, 100 /* FIXME: this is totally arbitrary */);
608}
609
610static
611int hwarc_reset(struct uwb_rc *uwb_rc)
612{
613	struct hwarc *hwarc = uwb_rc->priv;
614	int result;
615
616	/* device lock must be held when calling usb_reset_device. */
617	result = usb_lock_device_for_reset(hwarc->usb_dev, NULL);
618	if (result >= 0) {
619		result = usb_reset_device(hwarc->usb_dev);
620		usb_unlock_device(hwarc->usb_dev);
621	}
622
623	return result;
624}
625
626/**
627 * Callback for the notification and event endpoint
628 *
629 * Check's that everything is fine and then passes the read data to
630 * the notification/event handling mechanism (neh).
631 */
632static
633void hwarc_neep_cb(struct urb *urb)
634{
635	struct hwarc *hwarc = urb->context;
636	struct usb_interface *usb_iface = hwarc->usb_iface;
637	struct device *dev = &usb_iface->dev;
638	int result;
639
640	switch (result = urb->status) {
641	case 0:
642		uwb_rc_neh_grok(hwarc->uwb_rc, urb->transfer_buffer,
643				urb->actual_length);
644		break;
645	case -ECONNRESET:	/* Not an error, but a controlled situation; */
646	case -ENOENT:		/* (we killed the URB)...so, no broadcast */
647		goto out;
648	case -ESHUTDOWN:	/* going away! */
649		goto out;
650	default:		/* On general errors, retry unless it gets ugly */
651		if (edc_inc(&hwarc->neep_edc, EDC_MAX_ERRORS,
652			    EDC_ERROR_TIMEFRAME))
653			goto error_exceeded;
654		dev_err(dev, "NEEP: URB error %d\n", urb->status);
655	}
656	result = usb_submit_urb(urb, GFP_ATOMIC);
657	if (result < 0 && result != -ENODEV && result != -EPERM) {
658		/* ignoring unrecoverable errors */
659		dev_err(dev, "NEEP: Can't resubmit URB (%d) resetting device\n",
660			result);
661		goto error;
662	}
663out:
664	return;
665
666error_exceeded:
667	dev_err(dev, "NEEP: URB max acceptable errors "
668		"exceeded, resetting device\n");
669error:
670	uwb_rc_neh_error(hwarc->uwb_rc, result);
671	uwb_rc_reset_all(hwarc->uwb_rc);
672	return;
673}
674
675static void hwarc_init(struct hwarc *hwarc)
676{
677	edc_init(&hwarc->neep_edc);
678}
679
680/**
681 * Initialize the notification/event endpoint stuff
682 *
683 * Note this is effectively a parallel thread; it knows that
684 * hwarc->uwb_rc always exists because the existence of a 'hwarc'
685 * means that there is a reverence on the hwarc->uwb_rc (see
686 * _probe()), and thus _neep_cb() can execute safely.
687 */
688static int hwarc_neep_init(struct uwb_rc *rc)
689{
690	struct hwarc *hwarc = rc->priv;
691	struct usb_interface *iface = hwarc->usb_iface;
692	struct usb_device *usb_dev = interface_to_usbdev(iface);
693	struct device *dev = &iface->dev;
694	int result;
695	struct usb_endpoint_descriptor *epd;
696
697	epd = &iface->cur_altsetting->endpoint[0].desc;
698	hwarc->rd_buffer = (void *) __get_free_page(GFP_KERNEL);
699	if (hwarc->rd_buffer == NULL) {
700		dev_err(dev, "Unable to allocate notification's read buffer\n");
701		goto error_rd_buffer;
702	}
703	hwarc->neep_urb = usb_alloc_urb(0, GFP_KERNEL);
704	if (hwarc->neep_urb == NULL) {
705		dev_err(dev, "Unable to allocate notification URB\n");
706		goto error_urb_alloc;
707	}
708	usb_fill_int_urb(hwarc->neep_urb, usb_dev,
709			 usb_rcvintpipe(usb_dev, epd->bEndpointAddress),
710			 hwarc->rd_buffer, PAGE_SIZE,
711			 hwarc_neep_cb, hwarc, epd->bInterval);
712	result = usb_submit_urb(hwarc->neep_urb, GFP_ATOMIC);
713	if (result < 0) {
714		dev_err(dev, "Cannot submit notification URB: %d\n", result);
715		goto error_neep_submit;
716	}
717	return 0;
718
719error_neep_submit:
720	usb_free_urb(hwarc->neep_urb);
721	hwarc->neep_urb = NULL;
722error_urb_alloc:
723	free_page((unsigned long)hwarc->rd_buffer);
724	hwarc->rd_buffer = NULL;
725error_rd_buffer:
726	return -ENOMEM;
727}
728
729
730/** Clean up all the notification endpoint resources */
731static void hwarc_neep_release(struct uwb_rc *rc)
732{
733	struct hwarc *hwarc = rc->priv;
734
735	usb_kill_urb(hwarc->neep_urb);
736	usb_free_urb(hwarc->neep_urb);
737	hwarc->neep_urb = NULL;
738
739	free_page((unsigned long)hwarc->rd_buffer);
740	hwarc->rd_buffer = NULL;
741}
742
743/**
744 * Get the version from class-specific descriptor
745 *
746 * NOTE: this descriptor comes with the big bundled configuration
747 *	 descriptor that includes the interfaces' and endpoints', so
748 *	 we just look for it in the cached copy kept by the USB stack.
749 *
750 * NOTE2: We convert LE fields to CPU order.
751 */
752static int hwarc_get_version(struct uwb_rc *rc)
753{
754	int result;
755
756	struct hwarc *hwarc = rc->priv;
757	struct uwb_rc_control_intf_class_desc *descr;
758	struct device *dev = &rc->uwb_dev.dev;
759	struct usb_device *usb_dev = hwarc->usb_dev;
760	char *itr;
761	struct usb_descriptor_header *hdr;
762	size_t itr_size, actconfig_idx;
763	u16 version;
764
765	actconfig_idx = (usb_dev->actconfig - usb_dev->config) /
766		sizeof(usb_dev->config[0]);
767	itr = usb_dev->rawdescriptors[actconfig_idx];
768	itr_size = le16_to_cpu(usb_dev->actconfig->desc.wTotalLength);
769	while (itr_size >= sizeof(*hdr)) {
770		hdr = (struct usb_descriptor_header *) itr;
771		dev_dbg(dev, "Extra device descriptor: "
772			"type %02x/%u bytes @ %zu (%zu left)\n",
773			hdr->bDescriptorType, hdr->bLength,
774			(itr - usb_dev->rawdescriptors[actconfig_idx]),
775			itr_size);
776		if (hdr->bDescriptorType == USB_DT_CS_RADIO_CONTROL)
777			goto found;
778		itr += hdr->bLength;
779		itr_size -= hdr->bLength;
780	}
781	dev_err(dev, "cannot find Radio Control Interface Class descriptor\n");
782	return -ENODEV;
783
784found:
785	result = -EINVAL;
786	if (hdr->bLength > itr_size) {	/* is it available? */
787		dev_err(dev, "incomplete Radio Control Interface Class "
788			"descriptor (%zu bytes left, %u needed)\n",
789			itr_size, hdr->bLength);
790		goto error;
791	}
792	if (hdr->bLength < sizeof(*descr)) {
793		dev_err(dev, "short Radio Control Interface Class "
794			"descriptor\n");
795		goto error;
796	}
797	descr = (struct uwb_rc_control_intf_class_desc *) hdr;
798	/* Make LE fields CPU order */
799	version = __le16_to_cpu(descr->bcdRCIVersion);
800	if (version != 0x0100) {
801		dev_err(dev, "Device reports protocol version 0x%04x. We "
802			"do not support that. \n", version);
803		result = -EINVAL;
804		goto error;
805	}
806	rc->version = version;
807	dev_dbg(dev, "Device supports WUSB protocol version 0x%04x \n",	rc->version);
808	result = 0;
809error:
810	return result;
811}
812
813/*
814 * By creating a 'uwb_rc', we have a reference on it -- that reference
815 * is the one we drop when we disconnect.
816 *
817 * No need to switch altsettings; according to WUSB1.0[8.6.1.1], there
818 * is only one altsetting allowed.
819 */
820static int hwarc_probe(struct usb_interface *iface,
821		       const struct usb_device_id *id)
822{
823	int result;
824	struct uwb_rc *uwb_rc;
825	struct hwarc *hwarc;
826	struct device *dev = &iface->dev;
827
828	result = -ENOMEM;
829	uwb_rc = uwb_rc_alloc();
830	if (uwb_rc == NULL) {
831		dev_err(dev, "unable to allocate RC instance\n");
832		goto error_rc_alloc;
833	}
834	hwarc = kzalloc(sizeof(*hwarc), GFP_KERNEL);
835	if (hwarc == NULL) {
836		dev_err(dev, "unable to allocate HWA RC instance\n");
837		goto error_alloc;
838	}
839	hwarc_init(hwarc);
840	hwarc->usb_dev = usb_get_dev(interface_to_usbdev(iface));
841	hwarc->usb_iface = usb_get_intf(iface);
842	hwarc->uwb_rc = uwb_rc;
843
844	uwb_rc->owner = THIS_MODULE;
845	uwb_rc->start = hwarc_neep_init;
846	uwb_rc->stop  = hwarc_neep_release;
847	uwb_rc->cmd   = hwarc_cmd;
848	uwb_rc->reset = hwarc_reset;
849	if (id->driver_info & WUSB_QUIRK_WHCI_CMD_EVT) {
850		uwb_rc->filter_cmd   = NULL;
851		uwb_rc->filter_event = NULL;
852	} else {
853		uwb_rc->filter_cmd   = hwarc_filter_cmd;
854		uwb_rc->filter_event = hwarc_filter_event;
855	}
856
857	result = uwb_rc_add(uwb_rc, dev, hwarc);
858	if (result < 0)
859		goto error_rc_add;
860	result = hwarc_get_version(uwb_rc);
861	if (result < 0) {
862		dev_err(dev, "cannot retrieve version of RC \n");
863		goto error_get_version;
864	}
865	usb_set_intfdata(iface, hwarc);
866	return 0;
867
868error_get_version:
869	uwb_rc_rm(uwb_rc);
870error_rc_add:
871	usb_put_intf(iface);
872	usb_put_dev(hwarc->usb_dev);
873error_alloc:
874	uwb_rc_put(uwb_rc);
875error_rc_alloc:
876	return result;
877}
878
879static void hwarc_disconnect(struct usb_interface *iface)
880{
881	struct hwarc *hwarc = usb_get_intfdata(iface);
882	struct uwb_rc *uwb_rc = hwarc->uwb_rc;
883
884	usb_set_intfdata(hwarc->usb_iface, NULL);
885	uwb_rc_rm(uwb_rc);
886	usb_put_intf(hwarc->usb_iface);
887	usb_put_dev(hwarc->usb_dev);
888	kfree(hwarc);
889	uwb_rc_put(uwb_rc);	/* when creating the device, refcount = 1 */
890}
891
892static int hwarc_pre_reset(struct usb_interface *iface)
893{
894	struct hwarc *hwarc = usb_get_intfdata(iface);
895	struct uwb_rc *uwb_rc = hwarc->uwb_rc;
896
897	uwb_rc_pre_reset(uwb_rc);
898	return 0;
899}
900
901static int hwarc_post_reset(struct usb_interface *iface)
902{
903	struct hwarc *hwarc = usb_get_intfdata(iface);
904	struct uwb_rc *uwb_rc = hwarc->uwb_rc;
905
906	return uwb_rc_post_reset(uwb_rc);
907}
908
909/** USB device ID's that we handle */
910static const struct usb_device_id hwarc_id_table[] = {
911	/* D-Link DUB-1210 */
912	{ USB_DEVICE_AND_INTERFACE_INFO(0x07d1, 0x3d02, 0xe0, 0x01, 0x02),
913	  .driver_info = WUSB_QUIRK_WHCI_CMD_EVT },
914	/* Intel i1480 (using firmware 1.3PA2-20070828) */
915	{ USB_DEVICE_AND_INTERFACE_INFO(0x8086, 0x0c3b, 0xe0, 0x01, 0x02),
916	  .driver_info = WUSB_QUIRK_WHCI_CMD_EVT },
917	/* Alereon 5310 */
918	{ USB_DEVICE_AND_INTERFACE_INFO(0x13dc, 0x5310, 0xe0, 0x01, 0x02),
919	  .driver_info = WUSB_QUIRK_WHCI_CMD_EVT },
920	/* Alereon 5611 */
921	{ USB_DEVICE_AND_INTERFACE_INFO(0x13dc, 0x5611, 0xe0, 0x01, 0x02),
922	  .driver_info = WUSB_QUIRK_WHCI_CMD_EVT },
923	/* Generic match for the Radio Control interface */
924	{ USB_INTERFACE_INFO(0xe0, 0x01, 0x02), },
925	{ },
926};
927MODULE_DEVICE_TABLE(usb, hwarc_id_table);
928
929static struct usb_driver hwarc_driver = {
930	.name =		"hwa-rc",
931	.id_table =	hwarc_id_table,
932	.probe =	hwarc_probe,
933	.disconnect =	hwarc_disconnect,
934	.pre_reset =    hwarc_pre_reset,
935	.post_reset =   hwarc_post_reset,
936};
937
938module_usb_driver(hwarc_driver);
939
940MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
941MODULE_DESCRIPTION("Host Wireless Adapter Radio Control Driver");
942MODULE_LICENSE("GPL");
943