2 * Copyright (c) 2012 Neratec Solutions AG
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.
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.
17 #include <linux/slab.h>
18 #include <linux/export.h>
20 #include "dfs_pattern_detector.h"
21 #include "dfs_pri_detector.h"
24 * tolerated deviation of radar time stamp in usecs on both sides
25 * TODO: this might need to be HW-dependent
27 #define PRI_TOLERANCE 16
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
36 enum nl80211_dfs_regions region;
38 const struct radar_detector_specs *radar_types;
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)
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)
50 #define ETSI_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB) \
52 ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \
53 (PRF2PRI(PMAX) - PRI_TOLERANCE), \
54 (PRF2PRI(PMIN) * PRF + PRI_TOLERANCE), PRF, PPB * PRF, \
55 PPB_THRESH(PPB), PRI_TOLERANCE, \
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),
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,
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,
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
85 static const struct radar_types *
86 get_dfs_domain_radar_types(enum nl80211_dfs_regions region)
89 for (i = 0; i < ARRAY_SIZE(dfs_domains); i++) {
90 if (dfs_domains[i]->region == region)
91 return dfs_domains[i];
97 * struct channel_detector - detector elements for a DFS channel
99 * @freq: frequency for this channel detector in MHz
100 * @detectors: array of dynamically created detector elements for this freq
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.
106 struct channel_detector {
107 struct list_head head;
109 struct pri_detector **detectors;
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)
119 for (i = 0; i < dpd->num_radar_types; i++)
120 cd->detectors[i]->reset(cd->detectors[i], dpd->last_pulse_ts);
123 /* channel_detector_exit() - destructor */
124 static void channel_detector_exit(struct dfs_pattern_detector *dpd,
125 struct channel_detector *cd)
131 for (i = 0; i < dpd->num_radar_types; i++) {
132 struct pri_detector *de = cd->detectors[i];
136 kfree(cd->detectors);
140 static struct channel_detector *
141 channel_detector_create(struct dfs_pattern_detector *dpd, u16 freq)
144 struct channel_detector *cd;
146 cd = kmalloc(sizeof(*cd), GFP_ATOMIC);
150 INIT_LIST_HEAD(&cd->head);
152 sz = sizeof(cd->detectors) * dpd->num_radar_types;
153 cd->detectors = kzalloc(sz, GFP_ATOMIC);
154 if (cd->detectors == NULL)
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);
162 cd->detectors[i] = de;
164 list_add(&cd->head, &dpd->channel_detectors);
168 pr_err("failed to allocate channel_detector for freq=%d\n", freq);
169 channel_detector_exit(dpd, cd);
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
179 * Return existing channel detector for the given frequency or return a
182 static struct channel_detector *
183 channel_detector_get(struct dfs_pattern_detector *dpd, u16 freq)
185 struct channel_detector *cd;
186 list_for_each_entry(cd, &dpd->channel_detectors, head) {
187 if (cd->freq == freq)
190 return channel_detector_create(dpd, freq);
194 * DFS Pattern Detector
197 /* dpd_reset(): reset all channel detectors */
198 static void dpd_reset(struct dfs_pattern_detector *dpd)
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);
206 static void dpd_exit(struct dfs_pattern_detector *dpd)
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);
216 dpd_add_pulse(struct dfs_pattern_detector *dpd, struct pulse_event *event)
220 struct channel_detector *cd;
222 if (dpd->region == NL80211_DFS_UNSET) {
224 * pulses received for a non-supported or un-initialized
225 * domain are treated as detected radars
230 cd = channel_detector_get(dpd, event->freq);
234 ts_wraparound = (event->ts < dpd->last_pulse_ts);
235 dpd->last_pulse_ts = event->ts;
238 * reset detector on time stamp wraparound
239 * with monotonic time stamps, this should never happen
241 pr_warn("DFS: time stamp wraparound detected, resetting\n");
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);
254 static bool dpd_set_domain(struct dfs_pattern_detector *dpd,
255 enum nl80211_dfs_regions region)
257 const struct radar_types *rt;
258 struct channel_detector *cd, *cd0;
260 if (dpd->region == region)
263 dpd->region = NL80211_DFS_UNSET;
265 rt = get_dfs_domain_radar_types(region);
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;
276 dpd->region = region;
280 static struct dfs_pattern_detector default_dpd = {
282 .set_dfs_domain = dpd_set_domain,
283 .add_pulse = dpd_add_pulse,
284 .region = NL80211_DFS_UNSET,
287 struct dfs_pattern_detector *
288 dfs_pattern_detector_init(enum nl80211_dfs_regions region)
290 struct dfs_pattern_detector *dpd;
292 dpd = kmalloc(sizeof(*dpd), GFP_KERNEL);
297 INIT_LIST_HEAD(&dpd->channel_detectors);
299 if (dpd->set_dfs_domain(dpd, region))
302 pr_err("Could not set DFS domain to %d. ", region);
306 EXPORT_SYMBOL(dfs_pattern_detector_init);