mac80211: add driver RSSI threshold events

mac80211 maintains a running average of the RSSI when a STA
is associated to an AP. Report threshold events to any driver
that has registered callbacks for getting RSSI measurements.

Implement callbacks in mac80211 so that driver can set thresholds.
Add callbacks in mac80211 which is invoked when an RSSI threshold
event occurs.

mac80211: add tracing to rssi_reports api and remove extraneous fn argument
mac80211: scale up rssi thresholds from driver by 16 before storing

Signed-off-by: Meenakshi Venkataraman <meenakshi.venkataraman@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 652e5695225..190132063c9 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1450,3 +1450,43 @@ size_t ieee80211_ie_split_vendor(const u8 *ies, size_t ielen, size_t offset)
 
 	return pos;
 }
+
+static void _ieee80211_enable_rssi_reports(struct ieee80211_sub_if_data *sdata,
+					    int rssi_min_thold,
+					    int rssi_max_thold)
+{
+	trace_api_enable_rssi_reports(sdata, rssi_min_thold, rssi_max_thold);
+
+	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION))
+		return;
+
+	/*
+	 * Scale up threshold values before storing it, as the RSSI averaging
+	 * algorithm uses a scaled up value as well. Change this scaling
+	 * factor if the RSSI averaging algorithm changes.
+	 */
+	sdata->u.mgd.rssi_min_thold = rssi_min_thold*16;
+	sdata->u.mgd.rssi_max_thold = rssi_max_thold*16;
+}
+
+void ieee80211_enable_rssi_reports(struct ieee80211_vif *vif,
+				    int rssi_min_thold,
+				    int rssi_max_thold)
+{
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+	WARN_ON(rssi_min_thold == rssi_max_thold ||
+		rssi_min_thold > rssi_max_thold);
+
+	_ieee80211_enable_rssi_reports(sdata, rssi_min_thold,
+				       rssi_max_thold);
+}
+EXPORT_SYMBOL(ieee80211_enable_rssi_reports);
+
+void ieee80211_disable_rssi_reports(struct ieee80211_vif *vif)
+{
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+	_ieee80211_enable_rssi_reports(sdata, 0, 0);
+}
+EXPORT_SYMBOL(ieee80211_disable_rssi_reports);