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Commit e93d083f authored by Simon Wunderlich's avatar Simon Wunderlich Committed by John W. Linville
Browse files

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: default avatarSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: default avatarMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 1a26cda8

drivers/net/wireless/ath/ath9k/ar9002_phy.c

+64 −0
Original line number Diff line number Diff line
@@ -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);
@@ -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);

}

drivers/net/wireless/ath/ath9k/ar9003_phy.c

+64 −0
Original line number Diff line number Diff line
@@ -1453,6 +1453,67 @@ set_rfmode: 
	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);
@@ -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);

drivers/net/wireless/ath/ath9k/ath9k.h

+152 −0
Original line number Diff line number Diff line
@@ -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;
@@ -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;
@@ -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 *);
@@ -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);

drivers/net/wireless/ath/ath9k/debug.c

+115 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/slab.h>

#include <linux/vmalloc.h>

#include <linux/export.h>

#include <linux/relay.h>

#include <asm/unaligned.h>



#include "ath9k.h"
@@ -966,6 +967,112 @@ static const struct file_operations fops_recv = { 
	.llseek = default_llseek,

};



static ssize_t read_file_spec_scan_ctl(struct file *file, char __user *user_buf,

				       size_t count, loff_t *ppos)

{

	struct ath_softc *sc = file->private_data;

	char *mode = "";

	unsigned int len;



	switch (sc->spectral_mode) {

	case SPECTRAL_DISABLED:

		mode = "disable";

		break;

	case SPECTRAL_BACKGROUND:

		mode = "background";

		break;

	case SPECTRAL_CHANSCAN:

		mode = "chanscan";

		break;

	case SPECTRAL_MANUAL:

		mode = "manual";

		break;

	}

	len = strlen(mode);

	return simple_read_from_buffer(user_buf, count, ppos, mode, len);

}



static ssize_t write_file_spec_scan_ctl(struct file *file,

					const char __user *user_buf,

					size_t count, loff_t *ppos)

{

	struct ath_softc *sc = file->private_data;

	struct ath_common *common = ath9k_hw_common(sc->sc_ah);

	char buf[32];

	ssize_t len;



	len = min(count, sizeof(buf) - 1);

	if (copy_from_user(buf, user_buf, len))

		return -EFAULT;



	buf[len] = '\0';



	if (strncmp("trigger", buf, 7) == 0) {

		ath9k_spectral_scan_trigger(sc->hw);

	} else if (strncmp("background", buf, 9) == 0) {

		ath9k_spectral_scan_config(sc->hw, SPECTRAL_BACKGROUND);

		ath_dbg(common, CONFIG, "spectral scan: background mode enabled\n");

	} else if (strncmp("chanscan", buf, 8) == 0) {

		ath9k_spectral_scan_config(sc->hw, SPECTRAL_CHANSCAN);

		ath_dbg(common, CONFIG, "spectral scan: channel scan mode enabled\n");

	} else if (strncmp("manual", buf, 6) == 0) {

		ath9k_spectral_scan_config(sc->hw, SPECTRAL_MANUAL);

		ath_dbg(common, CONFIG, "spectral scan: manual mode enabled\n");

	} else if (strncmp("disable", buf, 7) == 0) {

		ath9k_spectral_scan_config(sc->hw, SPECTRAL_DISABLED);

		ath_dbg(common, CONFIG, "spectral scan: disabled\n");

	} else {

		return -EINVAL;

	}



	return count;

}



static const struct file_operations fops_spec_scan_ctl = {

	.read = read_file_spec_scan_ctl,

	.write = write_file_spec_scan_ctl,

	.open = simple_open,

	.owner = THIS_MODULE,

	.llseek = default_llseek,

};



static struct dentry *create_buf_file_handler(const char *filename,

					      struct dentry *parent,

					      umode_t mode,

					      struct rchan_buf *buf,

					      int *is_global)

{

	struct dentry *buf_file;



	buf_file = debugfs_create_file(filename, mode, parent, buf,

				       &relay_file_operations);

	*is_global = 1;

	return buf_file;

}



static int remove_buf_file_handler(struct dentry *dentry)

{

	debugfs_remove(dentry);



	return 0;

}



void ath_debug_send_fft_sample(struct ath_softc *sc,

			       struct fft_sample_tlv *fft_sample_tlv)

{

	if (!sc->rfs_chan_spec_scan)

		return;



	relay_write(sc->rfs_chan_spec_scan, fft_sample_tlv,

		    fft_sample_tlv->length + sizeof(*fft_sample_tlv));

}



static struct rchan_callbacks rfs_spec_scan_cb = {

	.create_buf_file = create_buf_file_handler,

	.remove_buf_file = remove_buf_file_handler,

};





static ssize_t read_file_regidx(struct file *file, char __user *user_buf,

                                size_t count, loff_t *ppos)

{
@@ -1780,6 +1887,14 @@ int ath9k_init_debug(struct ath_hw *ah) 
			    &fops_base_eeprom);

	debugfs_create_file("modal_eeprom", S_IRUSR, sc->debug.debugfs_phy, sc,

			    &fops_modal_eeprom);

	sc->rfs_chan_spec_scan = relay_open("spectral_scan",

					    sc->debug.debugfs_phy,

					    262144, 4, &rfs_spec_scan_cb,

					    NULL);

	debugfs_create_file("spectral_scan_ctl", S_IRUSR | S_IWUSR,

			    sc->debug.debugfs_phy, sc,

			    &fops_spec_scan_ctl);



#ifdef CONFIG_ATH9K_MAC_DEBUG

	debugfs_create_file("samples", S_IRUSR, sc->debug.debugfs_phy, sc,

			    &fops_samps);

drivers/net/wireless/ath/ath9k/debug.h

+5 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 


struct ath_txq;

struct ath_buf;

struct fft_sample_tlv;



#ifdef CONFIG_ATH9K_DEBUGFS

#define TX_STAT_INC(q, c) sc->debug.stats.txstats[q].c++
@@ -323,6 +324,10 @@ void ath9k_sta_remove_debugfs(struct ieee80211_hw *hw, 
			      struct ieee80211_vif *vif,

			      struct ieee80211_sta *sta,

			      struct dentry *dir);



void ath_debug_send_fft_sample(struct ath_softc *sc,

			       struct fft_sample_tlv *fft_sample);



#else



#define RX_STAT_INC(c) /* NOP */