mac80211: Read the TSF via debugfs

This patch adds an low-level driver independent entry to read the TSF value into the debugfs of mac80211. This makes debugging the IBSS handling of wifi drivers easier.

Signed-off-by: Alina Friedrichsen <x-alina@gmx.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c
index 18541bb..717d548 100644
--- a/net/mac80211/debugfs.c
+++ b/net/mac80211/debugfs.c
@@ -61,6 +61,8 @@
 		      local->wep_iv & 0xffffff);
 DEBUGFS_READONLY_FILE(rate_ctrl_alg, 100, "%s",
 		      local->rate_ctrl ? local->rate_ctrl->ops->name : "<unset>");
+DEBUGFS_READONLY_FILE(tsf, 20, "%#018llx",
+                      (unsigned long long) (local->ops->get_tsf ? local->ops->get_tsf(local_to_hw(local)) : 0));
 
 /* statistics stuff */
 
@@ -202,6 +204,7 @@
 	DEBUGFS_ADD(long_retry_limit);
 	DEBUGFS_ADD(total_ps_buffered);
 	DEBUGFS_ADD(wep_iv);
+	DEBUGFS_ADD(tsf);
 
 	statsd = debugfs_create_dir("statistics", phyd);
 	local->debugfs.statistics = statsd;
@@ -255,6 +258,7 @@
 	DEBUGFS_DEL(long_retry_limit);
 	DEBUGFS_DEL(total_ps_buffered);
 	DEBUGFS_DEL(wep_iv);
+	DEBUGFS_DEL(tsf);
 
 	DEBUGFS_STATS_DEL(transmitted_fragment_count);
 	DEBUGFS_STATS_DEL(multicast_transmitted_frame_count);