| /* |
| * 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_KERNEL); |
| 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_KERNEL); |
| 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); |