1 files changed, 320 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/dfs_pattern_detector.c b/drivers/net/wireless/ath/dfs_pattern_detector.c
new file mode 100644
index 000000000000..a1a69c5db409
--- /dev/null
+++ b/drivers/net/wireless/ath/dfs_pattern_detector.c
@@ -0,0 +1,320 @@
+/*
+ * 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"
+#include "ath.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:
+	ath_dbg(dpd->common, DFS,
+		"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;
+	struct channel_detector *cd;
+
+	/*
+	 * pulses received for a non-supported or un-initialized
+	 * domain are treated as detected radars for fail-safety
+	 */
+	if (dpd->region == NL80211_DFS_UNSET)
+		return true;
+
+	cd = channel_detector_get(dpd, event->freq);
+	if (cd == NULL)
+		return false;
+
+	dpd->last_pulse_ts = event->ts;
+	/* reset detector on time stamp wraparound, caused by TSF reset */
+	if (event->ts < dpd->last_pulse_ts)
+		dpd_reset(dpd);
+
+	/* do type individual pattern matching */
+	for (i = 0; i < dpd->num_radar_types; i++) {
+		struct pri_detector *pd = cd->detectors[i];
+		struct pri_sequence *ps = pd->add_pulse(pd, event);
+		if (ps != NULL) {
+			ath_dbg(dpd->common, DFS,
+				"DFS: radar found on freq=%d: id=%d, pri=%d, "
+				"count=%d, count_false=%d\n",
+				event->freq, pd->rs->type_id,
+				ps->pri, ps->count, ps->count_falses);
+			channel_detector_reset(dpd, cd);
+			return true;
+		}
+	}
+	return false;
+}
+
+static struct ath_dfs_pool_stats
+dpd_get_stats(struct dfs_pattern_detector *dpd)
+{
+	return global_dfs_pool_stats;
+}
+
+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,
+	.get_stats	= dpd_get_stats,
+	.region		= NL80211_DFS_UNSET,
+};
+
+struct dfs_pattern_detector *
+dfs_pattern_detector_init(struct ath_common *common,
+			  enum nl80211_dfs_regions region)
+{
+	struct dfs_pattern_detector *dpd;
+
+	if (!config_enabled(CONFIG_CFG80211_CERTIFICATION_ONUS))
+		return NULL;
+
+	dpd = kmalloc(sizeof(*dpd), GFP_KERNEL);
+	if (dpd == NULL)
+		return NULL;
+
+	*dpd = default_dpd;
+	INIT_LIST_HEAD(&dpd->channel_detectors);
+
+	dpd->common = common;
+	if (dpd->set_dfs_domain(dpd, region))
+		return dpd;
+
+	ath_dbg(common, DFS,"Could not set DFS domain to %d", region);
+	kfree(dpd);
+	return NULL;
+}
+EXPORT_SYMBOL(dfs_pattern_detector_init);