cfg80211: export cfg80211_chandef_dfs_required

It will be used later by the IBSS CSA implementation of mac80211.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index cb71091..45f6bf5 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -437,6 +437,15 @@
 			     u32 prohibited_flags);
 
 /**
+ * cfg80211_chandef_dfs_required - checks if radar detection is required
+ * @wiphy: the wiphy to validate against
+ * @chandef: the channel definition to check
+ * Return: 1 if radar detection is required, 0 if it is not, < 0 on error
+ */
+int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
+				  const struct cfg80211_chan_def *chandef);
+
+/**
  * ieee80211_chandef_rate_flags - returns rate flags for a channel
  *
  * In some channel types, not all rates may be used - for example CCK