1/*
2 * Ultra Wide Band
3 * Life cycle of radio controllers
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 * FIXME: docs
24 *
25 * A UWB radio controller is also a UWB device, so it embeds one...
26 *
27 * List of RCs comes from the 'struct class uwb_rc_class'.
28 */
29
30#include <linux/kernel.h>
31#include <linux/string.h>
32#include <linux/device.h>
33#include <linux/err.h>
34#include <linux/random.h>
35#include <linux/kdev_t.h>
36#include <linux/etherdevice.h>
37#include <linux/usb.h>
38#include <linux/slab.h>
39#include <linux/export.h>
40
41#include "uwb-internal.h"
42
43static int uwb_rc_index_match(struct device *dev, const void *data)
44{
45	const int *index = data;
46	struct uwb_rc *rc = dev_get_drvdata(dev);
47
48	if (rc->index == *index)
49		return 1;
50	return 0;
51}
52
53static struct uwb_rc *uwb_rc_find_by_index(int index)
54{
55	struct device *dev;
56	struct uwb_rc *rc = NULL;
57
58	dev = class_find_device(&uwb_rc_class, NULL, &index, uwb_rc_index_match);
59	if (dev)
60		rc = dev_get_drvdata(dev);
61	return rc;
62}
63
64static int uwb_rc_new_index(void)
65{
66	int index = 0;
67
68	for (;;) {
69		if (!uwb_rc_find_by_index(index))
70			return index;
71		if (++index < 0)
72			index = 0;
73	}
74}
75
76/**
77 * Release the backing device of a uwb_rc that has been dynamically allocated.
78 */
79static void uwb_rc_sys_release(struct device *dev)
80{
81	struct uwb_dev *uwb_dev = container_of(dev, struct uwb_dev, dev);
82	struct uwb_rc *rc = container_of(uwb_dev, struct uwb_rc, uwb_dev);
83
84	uwb_rc_ie_release(rc);
85	kfree(rc);
86}
87
88
89void uwb_rc_init(struct uwb_rc *rc)
90{
91	struct uwb_dev *uwb_dev = &rc->uwb_dev;
92
93	uwb_dev_init(uwb_dev);
94	rc->uwb_dev.dev.class = &uwb_rc_class;
95	rc->uwb_dev.dev.release = uwb_rc_sys_release;
96	uwb_rc_neh_create(rc);
97	rc->beaconing = -1;
98	rc->scan_type = UWB_SCAN_DISABLED;
99	INIT_LIST_HEAD(&rc->notifs_chain.list);
100	mutex_init(&rc->notifs_chain.mutex);
101	INIT_LIST_HEAD(&rc->uwb_beca.list);
102	mutex_init(&rc->uwb_beca.mutex);
103	uwb_drp_avail_init(rc);
104	uwb_rc_ie_init(rc);
105	uwb_rsv_init(rc);
106	uwb_rc_pal_init(rc);
107}
108EXPORT_SYMBOL_GPL(uwb_rc_init);
109
110
111struct uwb_rc *uwb_rc_alloc(void)
112{
113	struct uwb_rc *rc;
114	rc = kzalloc(sizeof(*rc), GFP_KERNEL);
115	if (rc == NULL)
116		return NULL;
117	uwb_rc_init(rc);
118	return rc;
119}
120EXPORT_SYMBOL_GPL(uwb_rc_alloc);
121
122/*
123 * Show the ASIE that is broadcast in the UWB beacon by this uwb_rc device.
124 */
125static ssize_t ASIE_show(struct device *dev,
126				struct device_attribute *attr, char *buf)
127{
128	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
129	struct uwb_rc *rc = uwb_dev->rc;
130	struct uwb_ie_hdr *ie;
131	void *ptr;
132	size_t len;
133	int result = 0;
134
135	/* init empty buffer. */
136	result = scnprintf(buf, PAGE_SIZE, "\n");
137	mutex_lock(&rc->ies_mutex);
138	/* walk IEData looking for an ASIE. */
139	ptr = rc->ies->IEData;
140	len = le16_to_cpu(rc->ies->wIELength);
141	for (;;) {
142		ie = uwb_ie_next(&ptr, &len);
143		if (!ie)
144			break;
145		if (ie->element_id == UWB_APP_SPEC_IE) {
146			result = uwb_ie_dump_hex(ie,
147					ie->length + sizeof(struct uwb_ie_hdr),
148					buf, PAGE_SIZE);
149			break;
150		}
151	}
152	mutex_unlock(&rc->ies_mutex);
153
154	return result;
155}
156
157/*
158 * Update the ASIE that is broadcast in the UWB beacon by this uwb_rc device.
159 */
160static ssize_t ASIE_store(struct device *dev,
161				 struct device_attribute *attr,
162				 const char *buf, size_t size)
163{
164	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
165	struct uwb_rc *rc = uwb_dev->rc;
166	char ie_buf[255];
167	int result, ie_len = 0;
168	const char *cur_ptr = buf;
169	struct uwb_ie_hdr *ie;
170
171	/* empty string means clear the ASIE. */
172	if (strlen(buf) <= 1) {
173		uwb_rc_ie_rm(rc, UWB_APP_SPEC_IE);
174		return size;
175	}
176
177	/* if non-empty string, convert string of hex chars to binary. */
178	while (ie_len < sizeof(ie_buf)) {
179		int char_count;
180
181		if (sscanf(cur_ptr, " %02hhX %n",
182				&(ie_buf[ie_len]), &char_count) > 0) {
183			++ie_len;
184			/* skip chars read from cur_ptr. */
185			cur_ptr += char_count;
186		} else {
187			break;
188		}
189	}
190
191	/* validate IE length and type. */
192	if (ie_len < sizeof(struct uwb_ie_hdr)) {
193		dev_err(dev, "%s: Invalid ASIE size %d.\n", __func__, ie_len);
194		return -EINVAL;
195	}
196
197	ie = (struct uwb_ie_hdr *)ie_buf;
198	if (ie->element_id != UWB_APP_SPEC_IE) {
199		dev_err(dev, "%s: Invalid IE element type size = 0x%02X.\n",
200				__func__, ie->element_id);
201		return -EINVAL;
202	}
203
204	/* bounds check length field from user. */
205	if (ie->length > (ie_len - sizeof(struct uwb_ie_hdr)))
206		ie->length = ie_len - sizeof(struct uwb_ie_hdr);
207
208	/*
209	 * Valid ASIE received. Remove current ASIE then add the new one using
210	 * uwb_rc_ie_add.
211	 */
212	uwb_rc_ie_rm(rc, UWB_APP_SPEC_IE);
213
214	result = uwb_rc_ie_add(rc, ie, ie->length + sizeof(struct uwb_ie_hdr));
215
216	return result >= 0 ? size : result;
217}
218static DEVICE_ATTR_RW(ASIE);
219
220static struct attribute *rc_attrs[] = {
221		&dev_attr_mac_address.attr,
222		&dev_attr_scan.attr,
223		&dev_attr_beacon.attr,
224		&dev_attr_ASIE.attr,
225		NULL,
226};
227
228static struct attribute_group rc_attr_group = {
229	.attrs = rc_attrs,
230};
231
232/*
233 * Registration of sysfs specific stuff
234 */
235static int uwb_rc_sys_add(struct uwb_rc *rc)
236{
237	return sysfs_create_group(&rc->uwb_dev.dev.kobj, &rc_attr_group);
238}
239
240
241static void __uwb_rc_sys_rm(struct uwb_rc *rc)
242{
243	sysfs_remove_group(&rc->uwb_dev.dev.kobj, &rc_attr_group);
244}
245
246/**
247 * uwb_rc_mac_addr_setup - get an RC's EUI-48 address or set it
248 * @rc:  the radio controller.
249 *
250 * If the EUI-48 address is 00:00:00:00:00:00 or FF:FF:FF:FF:FF:FF
251 * then a random locally administered EUI-48 is generated and set on
252 * the device.  The probability of address collisions is sufficiently
253 * unlikely (1/2^40 = 9.1e-13) that they're not checked for.
254 */
255static
256int uwb_rc_mac_addr_setup(struct uwb_rc *rc)
257{
258	int result;
259	struct device *dev = &rc->uwb_dev.dev;
260	struct uwb_dev *uwb_dev = &rc->uwb_dev;
261	char devname[UWB_ADDR_STRSIZE];
262	struct uwb_mac_addr addr;
263
264	result = uwb_rc_mac_addr_get(rc, &addr);
265	if (result < 0) {
266		dev_err(dev, "cannot retrieve UWB EUI-48 address: %d\n", result);
267		return result;
268	}
269
270	if (uwb_mac_addr_unset(&addr) || uwb_mac_addr_bcast(&addr)) {
271		addr.data[0] = 0x02; /* locally administered and unicast */
272		get_random_bytes(&addr.data[1], sizeof(addr.data)-1);
273
274		result = uwb_rc_mac_addr_set(rc, &addr);
275		if (result < 0) {
276			uwb_mac_addr_print(devname, sizeof(devname), &addr);
277			dev_err(dev, "cannot set EUI-48 address %s: %d\n",
278				devname, result);
279			return result;
280		}
281	}
282	uwb_dev->mac_addr = addr;
283	return 0;
284}
285
286
287
288static int uwb_rc_setup(struct uwb_rc *rc)
289{
290	int result;
291	struct device *dev = &rc->uwb_dev.dev;
292
293	result = uwb_radio_setup(rc);
294	if (result < 0) {
295		dev_err(dev, "cannot setup UWB radio: %d\n", result);
296		goto error;
297	}
298	result = uwb_rc_mac_addr_setup(rc);
299	if (result < 0) {
300		dev_err(dev, "cannot setup UWB MAC address: %d\n", result);
301		goto error;
302	}
303	result = uwb_rc_dev_addr_assign(rc);
304	if (result < 0) {
305		dev_err(dev, "cannot assign UWB DevAddr: %d\n", result);
306		goto error;
307	}
308	result = uwb_rc_ie_setup(rc);
309	if (result < 0) {
310		dev_err(dev, "cannot setup IE subsystem: %d\n", result);
311		goto error_ie_setup;
312	}
313	result = uwb_rsv_setup(rc);
314	if (result < 0) {
315		dev_err(dev, "cannot setup reservation subsystem: %d\n", result);
316		goto error_rsv_setup;
317	}
318	uwb_dbg_add_rc(rc);
319	return 0;
320
321error_rsv_setup:
322	uwb_rc_ie_release(rc);
323error_ie_setup:
324error:
325	return result;
326}
327
328
329/**
330 * Register a new UWB radio controller
331 *
332 * Did you call uwb_rc_init() on your rc?
333 *
334 * We assume that this is being called with a > 0 refcount on
335 * it [through ops->{get|put}_device(). We'll take our own, though.
336 *
337 * @parent_dev is our real device, the one that provides the actual UWB device
338 */
339int uwb_rc_add(struct uwb_rc *rc, struct device *parent_dev, void *priv)
340{
341	int result;
342	struct device *dev;
343	char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
344
345	rc->index = uwb_rc_new_index();
346
347	dev = &rc->uwb_dev.dev;
348	dev_set_name(dev, "uwb%d", rc->index);
349
350	rc->priv = priv;
351
352	init_waitqueue_head(&rc->uwbd.wq);
353	INIT_LIST_HEAD(&rc->uwbd.event_list);
354	spin_lock_init(&rc->uwbd.event_list_lock);
355
356	uwbd_start(rc);
357
358	result = rc->start(rc);
359	if (result < 0)
360		goto error_rc_start;
361
362	result = uwb_rc_setup(rc);
363	if (result < 0) {
364		dev_err(dev, "cannot setup UWB radio controller: %d\n", result);
365		goto error_rc_setup;
366	}
367
368	result = uwb_dev_add(&rc->uwb_dev, parent_dev, rc);
369	if (result < 0 && result != -EADDRNOTAVAIL)
370		goto error_dev_add;
371
372	result = uwb_rc_sys_add(rc);
373	if (result < 0) {
374		dev_err(parent_dev, "cannot register UWB radio controller "
375			"dev attributes: %d\n", result);
376		goto error_sys_add;
377	}
378
379	uwb_mac_addr_print(macbuf, sizeof(macbuf), &rc->uwb_dev.mac_addr);
380	uwb_dev_addr_print(devbuf, sizeof(devbuf), &rc->uwb_dev.dev_addr);
381	dev_info(dev,
382		 "new uwb radio controller (mac %s dev %s) on %s %s\n",
383		 macbuf, devbuf, parent_dev->bus->name, dev_name(parent_dev));
384	rc->ready = 1;
385	return 0;
386
387error_sys_add:
388	uwb_dev_rm(&rc->uwb_dev);
389error_dev_add:
390error_rc_setup:
391	rc->stop(rc);
392error_rc_start:
393	uwbd_stop(rc);
394	return result;
395}
396EXPORT_SYMBOL_GPL(uwb_rc_add);
397
398
399static int uwb_dev_offair_helper(struct device *dev, void *priv)
400{
401	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
402
403	return __uwb_dev_offair(uwb_dev, uwb_dev->rc);
404}
405
406/*
407 * Remove a Radio Controller; stop beaconing/scanning, disconnect all children
408 */
409void uwb_rc_rm(struct uwb_rc *rc)
410{
411	rc->ready = 0;
412
413	uwb_dbg_del_rc(rc);
414	uwb_rsv_remove_all(rc);
415	uwb_radio_shutdown(rc);
416
417	rc->stop(rc);
418
419	uwbd_stop(rc);
420	uwb_rc_neh_destroy(rc);
421
422	uwb_dev_lock(&rc->uwb_dev);
423	rc->priv = NULL;
424	rc->cmd = NULL;
425	uwb_dev_unlock(&rc->uwb_dev);
426	mutex_lock(&rc->uwb_beca.mutex);
427	uwb_dev_for_each(rc, uwb_dev_offair_helper, NULL);
428	__uwb_rc_sys_rm(rc);
429	mutex_unlock(&rc->uwb_beca.mutex);
430	uwb_rsv_cleanup(rc);
431 	uwb_beca_release(rc);
432	uwb_dev_rm(&rc->uwb_dev);
433}
434EXPORT_SYMBOL_GPL(uwb_rc_rm);
435
436static int find_rc_try_get(struct device *dev, const void *data)
437{
438	const struct uwb_rc *target_rc = data;
439	struct uwb_rc *rc = dev_get_drvdata(dev);
440
441	if (rc == NULL) {
442		WARN_ON(1);
443		return 0;
444	}
445	if (rc == target_rc) {
446		if (rc->ready == 0)
447			return 0;
448		else
449			return 1;
450	}
451	return 0;
452}
453
454/**
455 * Given a radio controller descriptor, validate and refcount it
456 *
457 * @returns NULL if the rc does not exist or is quiescing; the ptr to
458 *               it otherwise.
459 */
460struct uwb_rc *__uwb_rc_try_get(struct uwb_rc *target_rc)
461{
462	struct device *dev;
463	struct uwb_rc *rc = NULL;
464
465	dev = class_find_device(&uwb_rc_class, NULL, target_rc,
466				find_rc_try_get);
467	if (dev) {
468		rc = dev_get_drvdata(dev);
469		__uwb_rc_get(rc);
470	}
471	return rc;
472}
473EXPORT_SYMBOL_GPL(__uwb_rc_try_get);
474
475/*
476 * RC get for external refcount acquirers...
477 *
478 * Increments the refcount of the device and it's backend modules
479 */
480static inline struct uwb_rc *uwb_rc_get(struct uwb_rc *rc)
481{
482	if (rc->ready == 0)
483		return NULL;
484	uwb_dev_get(&rc->uwb_dev);
485	return rc;
486}
487
488static int find_rc_grandpa(struct device *dev, const void *data)
489{
490	const struct device *grandpa_dev = data;
491	struct uwb_rc *rc = dev_get_drvdata(dev);
492
493	if (rc->uwb_dev.dev.parent->parent == grandpa_dev) {
494		rc = uwb_rc_get(rc);
495		return 1;
496	}
497	return 0;
498}
499
500/**
501 * Locate and refcount a radio controller given a common grand-parent
502 *
503 * @grandpa_dev  Pointer to the 'grandparent' device structure.
504 * @returns NULL If the rc does not exist or is quiescing; the ptr to
505 *               it otherwise, properly referenced.
506 *
507 * The Radio Control interface (or the UWB Radio Controller) is always
508 * an interface of a device. The parent is the interface, the
509 * grandparent is the device that encapsulates the interface.
510 *
511 * There is no need to lock around as the "grandpa" would be
512 * refcounted by the target, and to remove the referemes, the
513 * uwb_rc_class->sem would have to be taken--we hold it, ergo we
514 * should be safe.
515 */
516struct uwb_rc *uwb_rc_get_by_grandpa(const struct device *grandpa_dev)
517{
518	struct device *dev;
519	struct uwb_rc *rc = NULL;
520
521	dev = class_find_device(&uwb_rc_class, NULL, grandpa_dev,
522				find_rc_grandpa);
523	if (dev)
524		rc = dev_get_drvdata(dev);
525	return rc;
526}
527EXPORT_SYMBOL_GPL(uwb_rc_get_by_grandpa);
528
529/**
530 * Find a radio controller by device address
531 *
532 * @returns the pointer to the radio controller, properly referenced
533 */
534static int find_rc_dev(struct device *dev, const void *data)
535{
536	const struct uwb_dev_addr *addr = data;
537	struct uwb_rc *rc = dev_get_drvdata(dev);
538
539	if (rc == NULL) {
540		WARN_ON(1);
541		return 0;
542	}
543	if (!uwb_dev_addr_cmp(&rc->uwb_dev.dev_addr, addr)) {
544		rc = uwb_rc_get(rc);
545		return 1;
546	}
547	return 0;
548}
549
550struct uwb_rc *uwb_rc_get_by_dev(const struct uwb_dev_addr *addr)
551{
552	struct device *dev;
553	struct uwb_rc *rc = NULL;
554
555	dev = class_find_device(&uwb_rc_class, NULL, addr, find_rc_dev);
556	if (dev)
557		rc = dev_get_drvdata(dev);
558
559	return rc;
560}
561EXPORT_SYMBOL_GPL(uwb_rc_get_by_dev);
562
563/**
564 * Drop a reference on a radio controller
565 *
566 * This is the version that should be done by entities external to the
567 * UWB Radio Control stack (ie: clients of the API).
568 */
569void uwb_rc_put(struct uwb_rc *rc)
570{
571	__uwb_rc_put(rc);
572}
573EXPORT_SYMBOL_GPL(uwb_rc_put);
574