linux/drivers/net/wireless/ath/ath9k/dfs.c

/*
 * Copyright (c) 2008-2011 Atheros Communications Inc.
 * Copyright (c) 2011 Neratec Solutions AG
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "hw.h"
#include "hw-ops.h"
#include "ath9k.h"
#include "dfs.h"
#include "dfs_debug.h"

/* internal struct to pass radar data */
struct ath_radar_data { … };

/**** begin: CHIRP ************************************************************/

/* min and max gradients for defined FCC chirping pulses, given by
 * - 20MHz chirp width over a pulse width of  50us
 * -  5MHz chirp width over a pulse width of 100us
 */
static const int BIN_DELTA_MIN		= …;
static const int BIN_DELTA_MAX		= …;

/* we need at least 3 deltas / 4 samples for a reliable chirp detection */
#define NUM_DIFFS …
#define FFT_NUM_SAMPLES …

/* Threshold for difference of delta peaks */
static const int MAX_DIFF		= …;

/* width range to be checked for chirping */
static const int MIN_CHIRP_PULSE_WIDTH	= …;
static const int MAX_CHIRP_PULSE_WIDTH	= …;

struct ath9k_dfs_fft_20 { … } __packed;
struct ath9k_dfs_fft_40 { … } __packed;

static inline int fft_max_index(u8 *bins)
{ … }
static inline int fft_max_magnitude(u8 *bins)
{ … }
static inline u8 fft_bitmap_weight(u8 *bins)
{ … }

static int ath9k_get_max_index_ht40(struct ath9k_dfs_fft_40 *fft,
				    bool is_ctl, bool is_ext)
{ … }
static bool ath9k_check_chirping(struct ath_softc *sc, u8 *data,
				 int datalen, bool is_ctl, bool is_ext)
{ … }
/**** end: CHIRP **************************************************************/

/* convert pulse duration to usecs, considering clock mode */
static u32 dur_to_usecs(struct ath_hw *ah, u32 dur)
{ … }

#define PRI_CH_RADAR_FOUND …
#define EXT_CH_RADAR_FOUND …
static bool
ath9k_postprocess_radar_event(struct ath_softc *sc,
			      struct ath_radar_data *ard,
			      struct pulse_event *pe)
{ … }

static void
ath9k_dfs_process_radar_pulse(struct ath_softc *sc, struct pulse_event *pe)
{ … }

/*
 * DFS: check PHY-error for radar pulse and feed the detector
 */
void ath9k_dfs_process_phyerr(struct ath_softc *sc, void *data,
			      struct ath_rx_status *rs, u64 mactime)
{ … }
#undef PRI_CH_RADAR_FOUND
#undef EXT_CH_RADAR_FOUND