[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / net / wireless / ath / ath9k / dfs_pattern_detector.c

/*
 * Copyright (c) 2012 Neratec Solutions AG
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <linux/slab.h>
#include <linux/export.h>

#include "dfs_pattern_detector.h"
#include "dfs_pri_detector.h"

/*
 * tolerated deviation of radar time stamp in usecs on both sides
 * TODO: this might need to be HW-dependent
 */
#define PRI_TOLERANCE	16

/**
 * struct radar_types - contains array of patterns defined for one DFS domain
 * @domain: DFS regulatory domain
 * @num_radar_types: number of radar types to follow
 * @radar_types: radar types array
 */
struct radar_types {
	enum nl80211_dfs_regions region;
	u32 num_radar_types;
	const struct radar_detector_specs *radar_types;
};

/* percentage on ppb threshold to trigger detection */
#define MIN_PPB_THRESH	50
#define PPB_THRESH(PPB) ((PPB * MIN_PPB_THRESH + 50) / 100)
#define PRF2PRI(PRF) ((1000000 + PRF / 2) / PRF)
/* percentage of pulse width tolerance */
#define WIDTH_TOLERANCE 5
#define WIDTH_LOWER(X) ((X*(100-WIDTH_TOLERANCE)+50)/100)
#define WIDTH_UPPER(X) ((X*(100+WIDTH_TOLERANCE)+50)/100)

#define ETSI_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB)	\
{								\
	ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX),		\
	(PRF2PRI(PMAX) - PRI_TOLERANCE),			\
	(PRF2PRI(PMIN) * PRF + PRI_TOLERANCE), PRF, PPB * PRF,	\
	PPB_THRESH(PPB), PRI_TOLERANCE,				\
}

/* radar types as defined by ETSI EN-301-893 v1.5.1 */
static const struct radar_detector_specs etsi_radar_ref_types_v15[] = {
	ETSI_PATTERN(0,  0,  1,  700,  700, 1, 18),
	ETSI_PATTERN(1,  0,  5,  200, 1000, 1, 10),
	ETSI_PATTERN(2,  0, 15,  200, 1600, 1, 15),
	ETSI_PATTERN(3,  0, 15, 2300, 4000, 1, 25),
	ETSI_PATTERN(4, 20, 30, 2000, 4000, 1, 20),
	ETSI_PATTERN(5,  0,  2,  300,  400, 3, 10),
	ETSI_PATTERN(6,  0,  2,  400, 1200, 3, 15),
};

static const struct radar_types etsi_radar_types_v15 = {
	.region			= NL80211_DFS_ETSI,
	.num_radar_types	= ARRAY_SIZE(etsi_radar_ref_types_v15),
	.radar_types		= etsi_radar_ref_types_v15,
};

/* for now, we support ETSI radar types, FCC and JP are TODO */
static const struct radar_types *dfs_domains[] = {
	&etsi_radar_types_v15,
};

/**
 * get_dfs_domain_radar_types() - get radar types for a given DFS domain
 * @param domain DFS domain
 * @return radar_types ptr on success, NULL if DFS domain is not supported
 */
static const struct radar_types *
get_dfs_domain_radar_types(enum nl80211_dfs_regions region)
{
	u32 i;
	for (i = 0; i < ARRAY_SIZE(dfs_domains); i++) {
		if (dfs_domains[i]->region == region)
			return dfs_domains[i];
	}
	return NULL;
}

/**
 * struct channel_detector - detector elements for a DFS channel
 * @head: list_head
 * @freq: frequency for this channel detector in MHz
 * @detectors: array of dynamically created detector elements for this freq
 *
 * Channel detectors are required to provide multi-channel DFS detection, e.g.
 * to support off-channel scanning. A pattern detector has a list of channels
 * radar pulses have been reported for in the past.
 */
struct channel_detector {
	struct list_head head;
	u16 freq;
	struct pri_detector **detectors;
};

/* channel_detector_reset() - reset detector lines for a given channel */
static void channel_detector_reset(struct dfs_pattern_detector *dpd,
				   struct channel_detector *cd)
{
	u32 i;
	if (cd == NULL)
		return;
	for (i = 0; i < dpd->num_radar_types; i++)
		cd->detectors[i]->reset(cd->detectors[i], dpd->last_pulse_ts);
}

/* channel_detector_exit() - destructor */
static void channel_detector_exit(struct dfs_pattern_detector *dpd,
				  struct channel_detector *cd)
{
	u32 i;
	if (cd == NULL)
		return;
	list_del(&cd->head);
	for (i = 0; i < dpd->num_radar_types; i++) {
		struct pri_detector *de = cd->detectors[i];
		if (de != NULL)
			de->exit(de);
	}
	kfree(cd->detectors);
	kfree(cd);
}

static struct channel_detector *
channel_detector_create(struct dfs_pattern_detector *dpd, u16 freq)
{
	u32 sz, i;
	struct channel_detector *cd;

	cd = kmalloc(sizeof(*cd), GFP_ATOMIC);
	if (cd == NULL)
		goto fail;

	INIT_LIST_HEAD(&cd->head);
	cd->freq = freq;
	sz = sizeof(cd->detectors) * dpd->num_radar_types;
	cd->detectors = kzalloc(sz, GFP_ATOMIC);
	if (cd->detectors == NULL)
		goto fail;

	for (i = 0; i < dpd->num_radar_types; i++) {
		const struct radar_detector_specs *rs = &dpd->radar_spec[i];
		struct pri_detector *de = pri_detector_init(rs);
		if (de == NULL)
			goto fail;
		cd->detectors[i] = de;
	}
	list_add(&cd->head, &dpd->channel_detectors);
	return cd;

fail:
	pr_err("failed to allocate channel_detector for freq=%d\n", freq);
	channel_detector_exit(dpd, cd);
	return NULL;
}

/**
 * channel_detector_get() - get channel detector for given frequency
 * @param dpd instance pointer
 * @param freq frequency in MHz
 * @return pointer to channel detector on success, NULL otherwise
 *
 * Return existing channel detector for the given frequency or return a
 * newly create one.
 */
static struct channel_detector *
channel_detector_get(struct dfs_pattern_detector *dpd, u16 freq)
{
	struct channel_detector *cd;
	list_for_each_entry(cd, &dpd->channel_detectors, head) {
		if (cd->freq == freq)
			return cd;
	}
	return channel_detector_create(dpd, freq);
}

/*
 * DFS Pattern Detector
 */

/* dpd_reset(): reset all channel detectors */
static void dpd_reset(struct dfs_pattern_detector *dpd)
{
	struct channel_detector *cd;
	if (!list_empty(&dpd->channel_detectors))
		list_for_each_entry(cd, &dpd->channel_detectors, head)
			channel_detector_reset(dpd, cd);

}
static void dpd_exit(struct dfs_pattern_detector *dpd)
{
	struct channel_detector *cd, *cd0;
	if (!list_empty(&dpd->channel_detectors))
		list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
			channel_detector_exit(dpd, cd);
	kfree(dpd);
}

static bool
dpd_add_pulse(struct dfs_pattern_detector *dpd, struct pulse_event *event)
{
	u32 i;
	bool ts_wraparound;
	struct channel_detector *cd;

	if (dpd->region == NL80211_DFS_UNSET) {
		/*
		 * pulses received for a non-supported or un-initialized
		 * domain are treated as detected radars
		 */
		return true;
	}

	cd = channel_detector_get(dpd, event->freq);
	if (cd == NULL)
		return false;

	ts_wraparound = (event->ts < dpd->last_pulse_ts);
	dpd->last_pulse_ts = event->ts;
	if (ts_wraparound) {
		/*
		 * reset detector on time stamp wraparound
		 * with monotonic time stamps, this should never happen
		 */
		pr_warn("DFS: time stamp wraparound detected, resetting\n");
		dpd_reset(dpd);
	}
	/* do type individual pattern matching */
	for (i = 0; i < dpd->num_radar_types; i++) {
		if (cd->detectors[i]->add_pulse(cd->detectors[i], event) != 0) {
			channel_detector_reset(dpd, cd);
			return true;
		}
	}
	return false;
}

static bool dpd_set_domain(struct dfs_pattern_detector *dpd,
			   enum nl80211_dfs_regions region)
{
	const struct radar_types *rt;
	struct channel_detector *cd, *cd0;

	if (dpd->region == region)
		return true;

	dpd->region = NL80211_DFS_UNSET;

	rt = get_dfs_domain_radar_types(region);
	if (rt == NULL)
		return false;

	/* delete all channel detectors for previous DFS domain */
	if (!list_empty(&dpd->channel_detectors))
		list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
			channel_detector_exit(dpd, cd);
	dpd->radar_spec = rt->radar_types;
	dpd->num_radar_types = rt->num_radar_types;

	dpd->region = region;
	return true;
}

static struct dfs_pattern_detector default_dpd = {
	.exit		= dpd_exit,
	.set_dfs_domain	= dpd_set_domain,
	.add_pulse	= dpd_add_pulse,
	.region		= NL80211_DFS_UNSET,
};

struct dfs_pattern_detector *
dfs_pattern_detector_init(enum nl80211_dfs_regions region)
{
	struct dfs_pattern_detector *dpd;

	dpd = kmalloc(sizeof(*dpd), GFP_KERNEL);
	if (dpd == NULL)
		return NULL;

	*dpd = default_dpd;
	INIT_LIST_HEAD(&dpd->channel_detectors);

	if (dpd->set_dfs_domain(dpd, region))
		return dpd;

	pr_err("Could not set DFS domain to %d. ", region);
	kfree(dpd);
	return NULL;
}
EXPORT_SYMBOL(dfs_pattern_detector_init);
Commit	Line	Data
6ee159e2 ZK	1	/*
	2	* Copyright (c) 2012 Neratec Solutions AG
	3	*
	4	* Permission to use, copy, modify, and/or distribute this software for any
	5	* purpose with or without fee is hereby granted, provided that the above
	6	* copyright notice and this permission notice appear in all copies.
	7	*
	8	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	9	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	10	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	11	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	12	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	13	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	14	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	15	*/
	16
	17	#include <linux/slab.h>
	18	#include <linux/export.h>
	19
	20	#include "dfs_pattern_detector.h"
	21	#include "dfs_pri_detector.h"
	22
	23	/*
	24	* tolerated deviation of radar time stamp in usecs on both sides
	25	* TODO: this might need to be HW-dependent
	26	*/
	27	#define PRI_TOLERANCE 16
	28
	29	/**
	30	* struct radar_types - contains array of patterns defined for one DFS domain
	31	* @domain: DFS regulatory domain
	32	* @num_radar_types: number of radar types to follow
	33	* @radar_types: radar types array
	34	*/
	35	struct radar_types {
	36	enum nl80211_dfs_regions region;
	37	u32 num_radar_types;
	38	const struct radar_detector_specs *radar_types;
	39	};
	40
	41	/* percentage on ppb threshold to trigger detection */
	42	#define MIN_PPB_THRESH 50
	43	#define PPB_THRESH(PPB) ((PPB * MIN_PPB_THRESH + 50) / 100)
	44	#define PRF2PRI(PRF) ((1000000 + PRF / 2) / PRF)
a6952287 ZK	45	/* percentage of pulse width tolerance */
	46	#define WIDTH_TOLERANCE 5
	47	#define WIDTH_LOWER(X) ((X*(100-WIDTH_TOLERANCE)+50)/100)
	48	#define WIDTH_UPPER(X) ((X*(100+WIDTH_TOLERANCE)+50)/100)
6ee159e2 ZK	49
	50	#define ETSI_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB) \
	51	{ \
a6952287 ZK	52	ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \
a6952287 ZK	53	(PRF2PRI(PMAX) - PRI_TOLERANCE), \
6ee159e2 ZK	54	(PRF2PRI(PMIN) * PRF + PRI_TOLERANCE), PRF, PPB * PRF, \
	55	PPB_THRESH(PPB), PRI_TOLERANCE, \
	56	}
	57
	58	/* radar types as defined by ETSI EN-301-893 v1.5.1 */
	59	static const struct radar_detector_specs etsi_radar_ref_types_v15[] = {
	60	ETSI_PATTERN(0, 0, 1, 700, 700, 1, 18),
	61	ETSI_PATTERN(1, 0, 5, 200, 1000, 1, 10),
	62	ETSI_PATTERN(2, 0, 15, 200, 1600, 1, 15),
	63	ETSI_PATTERN(3, 0, 15, 2300, 4000, 1, 25),
	64	ETSI_PATTERN(4, 20, 30, 2000, 4000, 1, 20),
	65	ETSI_PATTERN(5, 0, 2, 300, 400, 3, 10),
	66	ETSI_PATTERN(6, 0, 2, 400, 1200, 3, 15),
	67	};
	68
	69	static const struct radar_types etsi_radar_types_v15 = {
	70	.region = NL80211_DFS_ETSI,
	71	.num_radar_types = ARRAY_SIZE(etsi_radar_ref_types_v15),
	72	.radar_types = etsi_radar_ref_types_v15,
	73	};
	74
	75	/* for now, we support ETSI radar types, FCC and JP are TODO */
	76	static const struct radar_types *dfs_domains[] = {
	77	&etsi_radar_types_v15,
	78	};
	79
	80	/**
	81	* get_dfs_domain_radar_types() - get radar types for a given DFS domain
	82	* @param domain DFS domain
	83	* @return radar_types ptr on success, NULL if DFS domain is not supported
	84	*/
	85	static const struct radar_types *
	86	get_dfs_domain_radar_types(enum nl80211_dfs_regions region)
	87	{
	88	u32 i;
	89	for (i = 0; i < ARRAY_SIZE(dfs_domains); i++) {
	90	if (dfs_domains[i]->region == region)
	91	return dfs_domains[i];
	92	}
	93	return NULL;
	94	}
	95
	96	/**
	97	* struct channel_detector - detector elements for a DFS channel
	98	* @head: list_head
	99	* @freq: frequency for this channel detector in MHz
	100	* @detectors: array of dynamically created detector elements for this freq
	101	*
	102	* Channel detectors are required to provide multi-channel DFS detection, e.g.
	103	* to support off-channel scanning. A pattern detector has a list of channels
	104	* radar pulses have been reported for in the past.
	105	*/
	106	struct channel_detector {
	107	struct list_head head;
	108	u16 freq;
	109	struct pri_detector **detectors;
	110	};
	111
	112	/* channel_detector_reset() - reset detector lines for a given channel */
	113	static void channel_detector_reset(struct dfs_pattern_detector *dpd,
	114	struct channel_detector *cd)
	115	{
	116	u32 i;
	117	if (cd == NULL)
118	return;
119	for (i = 0; i < dpd->num_radar_types; i++)
120	cd->detectors[i]->reset(cd->detectors[i], dpd->last_pulse_ts);
121	}
122
123	/* channel_detector_exit() - destructor */
124	static void channel_detector_exit(struct dfs_pattern_detector *dpd,
125	struct channel_detector *cd)
126	{
127	u32 i;
128	if (cd == NULL)
129	return;
130	list_del(&cd->head);
131	for (i = 0; i < dpd->num_radar_types; i++) {
132	struct pri_detector *de = cd->detectors[i];
133	if (de != NULL)
134	de->exit(de);
135	}
136	kfree(cd->detectors);
137	kfree(cd);
138	}
139
140	static struct channel_detector *
141	channel_detector_create(struct dfs_pattern_detector *dpd, u16 freq)
142	{
143	u32 sz, i;
144	struct channel_detector *cd;
145
5d8cd3b1	146	cd = kmalloc(sizeof(*cd), GFP_ATOMIC);
6ee159e2 ZK	147	if (cd == NULL)
	148	goto fail;
	149
	150	INIT_LIST_HEAD(&cd->head);
	151	cd->freq = freq;
	152	sz = sizeof(cd->detectors) * dpd->num_radar_types;
5d8cd3b1	153	cd->detectors = kzalloc(sz, GFP_ATOMIC);
6ee159e2 ZK	154	if (cd->detectors == NULL)
	155	goto fail;
	156
	157	for (i = 0; i < dpd->num_radar_types; i++) {
	158	const struct radar_detector_specs *rs = &dpd->radar_spec[i];
	159	struct pri_detector *de = pri_detector_init(rs);
	160	if (de == NULL)
	161	goto fail;
	162	cd->detectors[i] = de;
	163	}
	164	list_add(&cd->head, &dpd->channel_detectors);
	165	return cd;
	166
	167	fail:
	168	pr_err("failed to allocate channel_detector for freq=%d\n", freq);
	169	channel_detector_exit(dpd, cd);
	170	return NULL;
	171	}
	172
	173	/**
	174	* channel_detector_get() - get channel detector for given frequency
	175	* @param dpd instance pointer
	176	* @param freq frequency in MHz
	177	* @return pointer to channel detector on success, NULL otherwise
	178	*
	179	* Return existing channel detector for the given frequency or return a
	180	* newly create one.
	181	*/
	182	static struct channel_detector *
	183	channel_detector_get(struct dfs_pattern_detector *dpd, u16 freq)
	184	{
	185	struct channel_detector *cd;
	186	list_for_each_entry(cd, &dpd->channel_detectors, head) {
	187	if (cd->freq == freq)
	188	return cd;
	189	}
	190	return channel_detector_create(dpd, freq);
	191	}
	192
	193	/*
	194	* DFS Pattern Detector
	195	*/
	196
	197	/* dpd_reset(): reset all channel detectors */
	198	static void dpd_reset(struct dfs_pattern_detector *dpd)
	199	{
	200	struct channel_detector *cd;
	201	if (!list_empty(&dpd->channel_detectors))
	202	list_for_each_entry(cd, &dpd->channel_detectors, head)
	203	channel_detector_reset(dpd, cd);
	204
	205	}
	206	static void dpd_exit(struct dfs_pattern_detector *dpd)
	207	{
	208	struct channel_detector cd, cd0;
	209	if (!list_empty(&dpd->channel_detectors))
	210	list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
	211	channel_detector_exit(dpd, cd);
	212	kfree(dpd);
	213	}
	214
	215	static bool
	216	dpd_add_pulse(struct dfs_pattern_detector dpd, struct pulse_event event)
	217	{
218	u32 i;
219	bool ts_wraparound;
220	struct channel_detector *cd;
221
222	if (dpd->region == NL80211_DFS_UNSET) {
223	/*
224	* pulses received for a non-supported or un-initialized
225	* domain are treated as detected radars
226	*/
227	return true;
228	}
229
230	cd = channel_detector_get(dpd, event->freq);
231	if (cd == NULL)
232	return false;
233
234	ts_wraparound = (event->ts < dpd->last_pulse_ts);
235	dpd->last_pulse_ts = event->ts;
236	if (ts_wraparound) {
237	/*
238	* reset detector on time stamp wraparound
239	* with monotonic time stamps, this should never happen
240	*/
241	pr_warn("DFS: time stamp wraparound detected, resetting\n");
242	dpd_reset(dpd);
243	}
244	/* do type individual pattern matching */
245	for (i = 0; i < dpd->num_radar_types; i++) {
246	if (cd->detectors[i]->add_pulse(cd->detectors[i], event) != 0) {
247	channel_detector_reset(dpd, cd);
248	return true;
249	}
250	}
251	return false;
252	}
253
254	static bool dpd_set_domain(struct dfs_pattern_detector *dpd,
255	enum nl80211_dfs_regions region)
256	{
257	const struct radar_types *rt;
258	struct channel_detector cd, cd0;
259
260	if (dpd->region == region)
261	return true;
262
263	dpd->region = NL80211_DFS_UNSET;
264
265	rt = get_dfs_domain_radar_types(region);
266	if (rt == NULL)
267	return false;
268
269	/* delete all channel detectors for previous DFS domain */
270	if (!list_empty(&dpd->channel_detectors))
271	list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
272	channel_detector_exit(dpd, cd);
273	dpd->radar_spec = rt->radar_types;
274	dpd->num_radar_types = rt->num_radar_types;
275
276	dpd->region = region;
277	return true;
278	}
279
280	static struct dfs_pattern_detector default_dpd = {
281	.exit = dpd_exit,
259bcf87	282	.set_dfs_domain = dpd_set_domain,
6ee159e2 ZK	283	.add_pulse = dpd_add_pulse,
	284	.region = NL80211_DFS_UNSET,
	285	};
	286
	287	struct dfs_pattern_detector *
	288	dfs_pattern_detector_init(enum nl80211_dfs_regions region)
	289	{
	290	struct dfs_pattern_detector *dpd;
0d2e7a5c	291
6ee159e2	292	dpd = kmalloc(sizeof(*dpd), GFP_KERNEL);
0d2e7a5c	293	if (dpd == NULL)
6ee159e2	294	return NULL;
0d2e7a5c	295
6ee159e2 ZK	296	*dpd = default_dpd;
	297	INIT_LIST_HEAD(&dpd->channel_detectors);
	298
259bcf87	299	if (dpd->set_dfs_domain(dpd, region))
6ee159e2 ZK	300	return dpd;
	301
	302	pr_err("Could not set DFS domain to %d. ", region);
70bf870b	303	kfree(dpd);
6ee159e2 ZK	304	return NULL;
	305	}
	306	EXPORT_SYMBOL(dfs_pattern_detector_init);