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ath9k: add spectral scan feature
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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>
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Simon Wunderlich authored and John W. Linville committed Jan 9, 2013
1 parent 1a26cda commit e93d083
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Showing 10 changed files with 653 additions and 1 deletion.
64 changes: 64 additions & 0 deletions drivers/net/wireless/ath/ath9k/ar9002_phy.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -555,6 +555,67 @@ static void ar9002_hw_antdiv_comb_conf_set(struct ath_hw *ah,
REG_WRITE(ah, AR_PHY_MULTICHAIN_GAIN_CTL, regval);
}

void ar9002_hw_spectral_scan_config(struct ath_hw *ah,
struct ath_spec_scan *param)
{
u8 count;

if (!param->enabled) {
REG_CLR_BIT(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_ENABLE);
return;
}
REG_SET_BIT(ah, AR_PHY_RADAR_0, AR_PHY_RADAR_0_FFT_ENA);
REG_SET_BIT(ah, AR_PHY_SPECTRAL_SCAN, AR_PHY_SPECTRAL_SCAN_ENABLE);

if (param->short_repeat)
REG_SET_BIT(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_SHORT_REPEAT);
else
REG_CLR_BIT(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_SHORT_REPEAT);

/* on AR92xx, the highest bit of count will make the the chip send
* spectral samples endlessly. Check if this really was intended,
* and fix otherwise.
*/
count = param->count;
if (param->endless)
count = 0;
else if (count & 0x80)
count = 0x7f;

REG_RMW_FIELD(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_COUNT, count);
REG_RMW_FIELD(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_PERIOD, param->period);
REG_RMW_FIELD(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_FFT_PERIOD, param->fft_period);

return;
}

static void ar9002_hw_spectral_scan_trigger(struct ath_hw *ah)
{
REG_SET_BIT(ah, AR_PHY_SPECTRAL_SCAN, AR_PHY_SPECTRAL_SCAN_ENABLE);
/* Activate spectral scan */
REG_SET_BIT(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_ACTIVE);
}

static void ar9002_hw_spectral_scan_wait(struct ath_hw *ah)
{
struct ath_common *common = ath9k_hw_common(ah);

/* Poll for spectral scan complete */
if (!ath9k_hw_wait(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_ACTIVE,
0, AH_WAIT_TIMEOUT)) {
ath_err(common, "spectral scan wait failed\n");
return;
}
}

void ar9002_hw_attach_phy_ops(struct ath_hw *ah)
{
struct ath_hw_private_ops *priv_ops = ath9k_hw_private_ops(ah);
Expand All @@ -569,6 +630,9 @@ void ar9002_hw_attach_phy_ops(struct ath_hw *ah)

ops->antdiv_comb_conf_get = ar9002_hw_antdiv_comb_conf_get;
ops->antdiv_comb_conf_set = ar9002_hw_antdiv_comb_conf_set;
ops->spectral_scan_config = ar9002_hw_spectral_scan_config;
ops->spectral_scan_trigger = ar9002_hw_spectral_scan_trigger;
ops->spectral_scan_wait = ar9002_hw_spectral_scan_wait;

ar9002_hw_set_nf_limits(ah);
}
64 changes: 64 additions & 0 deletions drivers/net/wireless/ath/ath9k/ar9003_phy.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1453,6 +1453,67 @@ static int ar9003_hw_fast_chan_change(struct ath_hw *ah,
return 0;
}

static void ar9003_hw_spectral_scan_config(struct ath_hw *ah,
struct ath_spec_scan *param)
{
u8 count;

if (!param->enabled) {
REG_CLR_BIT(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_ENABLE);
return;
}

REG_SET_BIT(ah, AR_PHY_RADAR_0, AR_PHY_RADAR_0_FFT_ENA);
REG_SET_BIT(ah, AR_PHY_SPECTRAL_SCAN, AR_PHY_SPECTRAL_SCAN_ENABLE);

/* on AR93xx and newer, count = 0 will make the the chip send
* spectral samples endlessly. Check if this really was intended,
* and fix otherwise.
*/
count = param->count;
if (param->endless)
count = 0;
else if (param->count == 0)
count = 1;

if (param->short_repeat)
REG_SET_BIT(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_SHORT_REPEAT);
else
REG_CLR_BIT(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_SHORT_REPEAT);

REG_RMW_FIELD(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_COUNT, count);
REG_RMW_FIELD(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_PERIOD, param->period);
REG_RMW_FIELD(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_FFT_PERIOD, param->fft_period);

return;
}

static void ar9003_hw_spectral_scan_trigger(struct ath_hw *ah)
{
/* Activate spectral scan */
REG_SET_BIT(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_ACTIVE);
}

static void ar9003_hw_spectral_scan_wait(struct ath_hw *ah)
{
struct ath_common *common = ath9k_hw_common(ah);

/* Poll for spectral scan complete */
if (!ath9k_hw_wait(ah, AR_PHY_SPECTRAL_SCAN,
AR_PHY_SPECTRAL_SCAN_ACTIVE,
0, AH_WAIT_TIMEOUT)) {
ath_err(common, "spectral scan wait failed\n");
return;
}
}

void ar9003_hw_attach_phy_ops(struct ath_hw *ah)
{
struct ath_hw_private_ops *priv_ops = ath9k_hw_private_ops(ah);
Expand Down Expand Up @@ -1486,6 +1547,9 @@ void ar9003_hw_attach_phy_ops(struct ath_hw *ah)
ops->antdiv_comb_conf_get = ar9003_hw_antdiv_comb_conf_get;
ops->antdiv_comb_conf_set = ar9003_hw_antdiv_comb_conf_set;
ops->antctrl_shared_chain_lnadiv = ar9003_hw_antctrl_shared_chain_lnadiv;
ops->spectral_scan_config = ar9003_hw_spectral_scan_config;
ops->spectral_scan_trigger = ar9003_hw_spectral_scan_trigger;
ops->spectral_scan_wait = ar9003_hw_spectral_scan_wait;

ar9003_hw_set_nf_limits(ah);
ar9003_hw_set_radar_conf(ah);
Expand Down
152 changes: 152 additions & 0 deletions drivers/net/wireless/ath/ath9k/ath9k.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -670,6 +670,23 @@ struct ath9k_vif_iter_data {
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;
Expand Down Expand Up @@ -738,6 +755,10 @@ struct ath_softc {
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;
Expand All @@ -746,6 +767,133 @@ struct ath_softc {
#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 *);

Expand All @@ -768,6 +916,10 @@ void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw);
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);
Expand Down
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