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/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 7250107..094a9322 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -670,6 +670,23 @@
int nadhocs; /* number of adhoc vifs */
};
+/* enum spectral_mode:
+ *
+ * @SPECTRAL_DISABLED: spectral mode is disabled
+ * @SPECTRAL_BACKGROUND: hardware sends samples when it is not busy with
+ * something else.
+ * @SPECTRAL_MANUAL: spectral scan is enabled, triggering for samples
+ * is performed manually.
+ * @SPECTRAL_CHANSCAN: Like manual, but also triggered when changing channels
+ * during a channel scan.
+ */
+enum spectral_mode {
+ SPECTRAL_DISABLED = 0,
+ SPECTRAL_BACKGROUND,
+ SPECTRAL_MANUAL,
+ SPECTRAL_CHANSCAN,
+};
+
struct ath_softc {
struct ieee80211_hw *hw;
struct device *dev;
@@ -738,6 +755,10 @@
u8 ant_tx, ant_rx;
struct dfs_pattern_detector *dfs_detector;
u32 wow_enabled;
+ /* relay(fs) channel for spectral scan */
+ struct rchan *rfs_chan_spec_scan;
+ enum spectral_mode spectral_mode;
+ int scanning;
#ifdef CONFIG_PM_SLEEP
atomic_t wow_got_bmiss_intr;
@@ -746,6 +767,133 @@
#endif
};
+#define SPECTRAL_SCAN_BITMASK 0x10
+/* Radar info packet format, used for DFS and spectral formats. */
+struct ath_radar_info {
+ u8 pulse_length_pri;
+ u8 pulse_length_ext;
+ u8 pulse_bw_info;
+} __packed;
+
+/* The HT20 spectral data has 4 bytes of additional information at it's end.
+ *
+ * [7:0]: all bins {max_magnitude[1:0], bitmap_weight[5:0]}
+ * [7:0]: all bins max_magnitude[9:2]
+ * [7:0]: all bins {max_index[5:0], max_magnitude[11:10]}
+ * [3:0]: max_exp (shift amount to size max bin to 8-bit unsigned)
+ */
+struct ath_ht20_mag_info {
+ u8 all_bins[3];
+ u8 max_exp;
+} __packed;
+
+#define SPECTRAL_HT20_NUM_BINS 56
+
+/* WARNING: don't actually use this struct! MAC may vary the amount of
+ * data by -1/+2. This struct is for reference only.
+ */
+struct ath_ht20_fft_packet {
+ u8 data[SPECTRAL_HT20_NUM_BINS];
+ struct ath_ht20_mag_info mag_info;
+ struct ath_radar_info radar_info;
+} __packed;
+
+#define SPECTRAL_HT20_TOTAL_DATA_LEN (sizeof(struct ath_ht20_fft_packet))
+
+/* Dynamic 20/40 mode:
+ *
+ * [7:0]: lower bins {max_magnitude[1:0], bitmap_weight[5:0]}
+ * [7:0]: lower bins max_magnitude[9:2]
+ * [7:0]: lower bins {max_index[5:0], max_magnitude[11:10]}
+ * [7:0]: upper bins {max_magnitude[1:0], bitmap_weight[5:0]}
+ * [7:0]: upper bins max_magnitude[9:2]
+ * [7:0]: upper bins {max_index[5:0], max_magnitude[11:10]}
+ * [3:0]: max_exp (shift amount to size max bin to 8-bit unsigned)
+ */
+struct ath_ht20_40_mag_info {
+ u8 lower_bins[3];
+ u8 upper_bins[3];
+ u8 max_exp;
+} __packed;
+
+#define SPECTRAL_HT20_40_NUM_BINS 128
+
+/* WARNING: don't actually use this struct! MAC may vary the amount of
+ * data. This struct is for reference only.
+ */
+struct ath_ht20_40_fft_packet {
+ u8 data[SPECTRAL_HT20_40_NUM_BINS];
+ struct ath_ht20_40_mag_info mag_info;
+ struct ath_radar_info radar_info;
+} __packed;
+
+
+#define SPECTRAL_HT20_40_TOTAL_DATA_LEN (sizeof(struct ath_ht20_40_fft_packet))
+
+/* grabs the max magnitude from the all/upper/lower bins */
+static inline u16 spectral_max_magnitude(u8 *bins)
+{
+ return (bins[0] & 0xc0) >> 6 |
+ (bins[1] & 0xff) << 2 |
+ (bins[2] & 0x03) << 10;
+}
+
+/* return the max magnitude from the all/upper/lower bins */
+static inline u8 spectral_max_index(u8 *bins)
+{
+ s8 m = (bins[2] & 0xfc) >> 2;
+
+ /* TODO: this still doesn't always report the right values ... */
+ if (m > 32)
+ m |= 0xe0;
+ else
+ m &= ~0xe0;
+
+ return m + 29;
+}
+
+/* return the bitmap weight from the all/upper/lower bins */
+static inline u8 spectral_bitmap_weight(u8 *bins)
+{
+ return bins[0] & 0x3f;
+}
+
+/* FFT sample format given to userspace via debugfs.
+ *
+ * Please keep the type/length at the front position and change
+ * other fields after adding another sample type
+ *
+ * TODO: this might need rework when switching to nl80211-based
+ * interface.
+ */
+enum ath_fft_sample_type {
+ ATH_FFT_SAMPLE_HT20 = 0,
+};
+
+struct fft_sample_tlv {
+ u8 type; /* see ath_fft_sample */
+ u16 length;
+ /* type dependent data follows */
+} __packed;
+
+struct fft_sample_ht20 {
+ struct fft_sample_tlv tlv;
+
+ u8 __alignment;
+
+ u16 freq;
+ s8 rssi;
+ s8 noise;
+
+ u16 max_magnitude;
+ u8 max_index;
+ u8 bitmap_weight;
+
+ u64 tsf;
+
+ u16 data[SPECTRAL_HT20_NUM_BINS];
+} __packed;
+
void ath9k_tasklet(unsigned long data);
int ath_cabq_update(struct ath_softc *);
@@ -768,6 +916,10 @@
void ath9k_reload_chainmask_settings(struct ath_softc *sc);
bool ath9k_uses_beacons(int type);
+void ath9k_spectral_scan_trigger(struct ieee80211_hw *hw);
+int ath9k_spectral_scan_config(struct ieee80211_hw *hw,
+ enum spectral_mode spectral_mode);
+
#ifdef CONFIG_ATH9K_PCI
int ath_pci_init(void);