ath9k: add debugfs based DFS radar simulation

This helps testing DFS without radar generating
equipment and is required for certification.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Zefir Kurtisi <zefir.kurtisi@neratec.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/dfs_debug.c b/drivers/net/wireless/ath/ath9k/dfs_debug.c
index 55d2807..b7611b7 100644
--- a/drivers/net/wireless/ath/ath9k/dfs_debug.c
+++ b/drivers/net/wireless/ath/ath9k/dfs_debug.c
@@ -105,6 +105,24 @@
 	return count;
 }
 
+static ssize_t write_file_simulate_radar(struct file *file,
+					 const char __user *user_buf,
+					 size_t count, loff_t *ppos)
+{
+	struct ath_softc *sc = file->private_data;
+
+	ieee80211_radar_detected(sc->hw);
+
+	return count;
+}
+
+static const struct file_operations fops_simulate_radar = {
+	.write = write_file_simulate_radar,
+	.open = simple_open,
+	.owner = THIS_MODULE,
+	.llseek = default_llseek,
+};
+
 static const struct file_operations fops_dfs_stats = {
 	.read = read_file_dfs,
 	.write = write_file_dfs,
@@ -117,4 +135,6 @@
 {
 	debugfs_create_file("dfs_stats", S_IRUSR,
 			    sc->debug.debugfs_phy, sc, &fops_dfs_stats);
+	debugfs_create_file("dfs_simulate_radar", S_IWUSR,
+			    sc->debug.debugfs_phy, sc, &fops_simulate_radar);
 }