ath9k: add spectral scan feature
Adds the spectral scan feature for ath9k. AR92xx and AR93xx chips
are supported for now. The spectral scan is triggered by configuring
a mode through a debugfs control file. Samples can be gathered via
another relay debugfs file.
Essentially, to try it out:
echo chanscan > /sys/kernel/debug/ieee80211/phy0/ath9k/spectral_scan_ctl
iw dev wlan0 scan
cat /sys/kernel/debug/ieee80211/phy0/ath9k/spectral_scan0 > samples
echo disable > /sys/kernel/debug/ieee80211/phy0/ath9k/spectral_scan_ctl
This feature is still experimental.
The special "chanscan" mode is used to perform spectral scan while
mac80211 is scanning for channels. To allow this,
sw_scan_start/complete() ops have been added.
The patch contains code snippets and information from Zefir Kurtisi and
information provided by Adrian Chadd and Felix Fietkau.
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index e1fa705..32417fd 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1075,6 +1075,86 @@
ath_dbg(common, PS, "PowerSave disabled\n");
}
+void ath9k_spectral_scan_trigger(struct ieee80211_hw *hw)
+{
+ struct ath_softc *sc = hw->priv;
+ struct ath_hw *ah = sc->sc_ah;
+ struct ath_common *common = ath9k_hw_common(ah);
+ u32 rxfilter;
+
+ if (!ath9k_hw_ops(ah)->spectral_scan_trigger) {
+ ath_err(common, "spectrum analyzer not implemented on this hardware\n");
+ return;
+ }
+
+ ath9k_ps_wakeup(sc);
+ rxfilter = ath9k_hw_getrxfilter(ah);
+ ath9k_hw_setrxfilter(ah, rxfilter |
+ ATH9K_RX_FILTER_PHYRADAR |
+ ATH9K_RX_FILTER_PHYERR);
+
+ /* TODO: usually this should not be neccesary, but for some reason
+ * (or in some mode?) the trigger must be called after the
+ * configuration, otherwise the register will have its values reset
+ * (on my ar9220 to value 0x01002310)
+ */
+ ath9k_spectral_scan_config(hw, sc->spectral_mode);
+ ath9k_hw_ops(ah)->spectral_scan_trigger(ah);
+ ath9k_ps_restore(sc);
+}
+
+int ath9k_spectral_scan_config(struct ieee80211_hw *hw,
+ enum spectral_mode spectral_mode)
+{
+ struct ath_softc *sc = hw->priv;
+ struct ath_hw *ah = sc->sc_ah;
+ struct ath_common *common = ath9k_hw_common(ah);
+ struct ath_spec_scan param;
+
+ if (!ath9k_hw_ops(ah)->spectral_scan_trigger) {
+ ath_err(common, "spectrum analyzer not implemented on this hardware\n");
+ return -1;
+ }
+
+ /* NOTE: this will generate a few samples ...
+ *
+ * TODO: review default parameters, and/or define an interface to set
+ * them.
+ */
+ param.enabled = 1;
+ param.short_repeat = true;
+ param.count = 8;
+ param.endless = false;
+ param.period = 0xFF;
+ param.fft_period = 0xF;
+
+ switch (spectral_mode) {
+ case SPECTRAL_DISABLED:
+ param.enabled = 0;
+ break;
+ case SPECTRAL_BACKGROUND:
+ /* send endless samples.
+ * TODO: is this really useful for "background"?
+ */
+ param.endless = 1;
+ break;
+ case SPECTRAL_CHANSCAN:
+ break;
+ case SPECTRAL_MANUAL:
+ break;
+ default:
+ return -1;
+ }
+
+ ath9k_ps_wakeup(sc);
+ ath9k_hw_ops(ah)->spectral_scan_config(ah, ¶m);
+ ath9k_ps_restore(sc);
+
+ sc->spectral_mode = spectral_mode;
+
+ return 0;
+}
+
static int ath9k_config(struct ieee80211_hw *hw, u32 changed)
{
struct ath_softc *sc = hw->priv;
@@ -1188,6 +1268,11 @@
*/
if (old_pos >= 0)
ath_update_survey_nf(sc, old_pos);
+
+ /* perform spectral scan if requested. */
+ if (sc->scanning && sc->spectral_mode == SPECTRAL_CHANSCAN)
+ ath9k_spectral_scan_trigger(hw);
+
}
if (changed & IEEE80211_CONF_CHANGE_POWER) {
@@ -2240,6 +2325,19 @@
}
#endif
+static void ath9k_sw_scan_start(struct ieee80211_hw *hw)
+{
+ struct ath_softc *sc = hw->priv;
+
+ sc->scanning = 1;
+}
+
+static void ath9k_sw_scan_complete(struct ieee80211_hw *hw)
+{
+ struct ath_softc *sc = hw->priv;
+
+ sc->scanning = 0;
+}
struct ieee80211_ops ath9k_ops = {
.tx = ath9k_tx,
@@ -2286,4 +2384,6 @@
.sta_add_debugfs = ath9k_sta_add_debugfs,
.sta_remove_debugfs = ath9k_sta_remove_debugfs,
#endif
+ .sw_scan_start = ath9k_sw_scan_start,
+ .sw_scan_complete = ath9k_sw_scan_complete,
};