ath5k: Add Spur filter support on newer chips

* Add spur filter support for RF5413 and later chips

 Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
 Signed-off-by: Bob Copeland <me@bobcopeland.com>

Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 251 insertions, 4 deletions

diff --git a/drivers/net/wireless/ath/ath5k/phy.c b/drivers/net/wireless/ath/ath5k/phy.c
index fd93c4e20214..6737ba0a4de3 100644
--- a/drivers/net/wireless/ath/ath5k/phy.c
+++ b/drivers/net/wireless/ath/ath5k/phy.c
@@ -1353,6 +1353,257 @@ int ath5k_hw_phy_calibrate(struct ath5k_hw *ah,
 	return ret;
 }
 
+/***************************\
+* Spur mitigation functions *
+\***************************/
+
+bool ath5k_hw_chan_has_spur_noise(struct ath5k_hw *ah,
+				struct ieee80211_channel *channel)
+{
+	u8 refclk_freq;
+
+	if ((ah->ah_radio == AR5K_RF5112) ||
+	(ah->ah_radio == AR5K_RF5413) ||
+	(ah->ah_mac_version == (AR5K_SREV_AR2417 >> 4)))
+		refclk_freq = 40;
+	else
+		refclk_freq = 32;
+
+	if ((channel->center_freq % refclk_freq != 0) &&
+	((channel->center_freq % refclk_freq < 10) ||
+	(channel->center_freq % refclk_freq > 22)))
+		return true;
+	else
+		return false;
+}
+
+void
+ath5k_hw_set_spur_mitigation_filter(struct ath5k_hw *ah,
+				struct ieee80211_channel *channel)
+{
+	struct ath5k_eeprom_info *ee = &ah->ah_capabilities.cap_eeprom;
+	u32 mag_mask[4] = {0, 0, 0, 0};
+	u32 pilot_mask[2] = {0, 0};
+	/* Note: fbin values are scaled up by 2 */
+	u16 spur_chan_fbin, chan_fbin, symbol_width, spur_detection_window;
+	s32 spur_delta_phase, spur_freq_sigma_delta;
+	s32 spur_offset, num_symbols_x16;
+	u8 num_symbol_offsets, i, freq_band;
+
+	/* Convert current frequency to fbin value (the same way channels
+	 * are stored on EEPROM, check out ath5k_eeprom_bin2freq) and scale
+	 * up by 2 so we can compare it later */
+	if (channel->hw_value & CHANNEL_2GHZ) {
+		chan_fbin = (channel->center_freq - 2300) * 10;
+		freq_band = AR5K_EEPROM_BAND_2GHZ;
+	} else {
+		chan_fbin = (channel->center_freq - 4900) * 10;
+		freq_band = AR5K_EEPROM_BAND_5GHZ;
+	}
+
+	/* Check if any spur_chan_fbin from EEPROM is
+	 * within our current channel's spur detection range */
+	spur_chan_fbin = AR5K_EEPROM_NO_SPUR;
+	spur_detection_window = AR5K_SPUR_CHAN_WIDTH;
+	/* XXX: Half/Quarter channels ?*/
+	if (channel->hw_value & CHANNEL_TURBO)
+		spur_detection_window *= 2;
+
+	for (i = 0; i < AR5K_EEPROM_N_SPUR_CHANS; i++) {
+		spur_chan_fbin = ee->ee_spur_chans[i][freq_band];
+
+		/* Note: mask cleans AR5K_EEPROM_NO_SPUR flag
+		 * so it's zero if we got nothing from EEPROM */
+		if (spur_chan_fbin == AR5K_EEPROM_NO_SPUR) {
+			spur_chan_fbin &= AR5K_EEPROM_SPUR_CHAN_MASK;
+			break;
+		}
+
+		if ((chan_fbin - spur_detection_window <=
+		(spur_chan_fbin & AR5K_EEPROM_SPUR_CHAN_MASK)) &&
+		(chan_fbin + spur_detection_window >=
+		(spur_chan_fbin & AR5K_EEPROM_SPUR_CHAN_MASK))) {
+			spur_chan_fbin &= AR5K_EEPROM_SPUR_CHAN_MASK;
+			break;
+		}
+	}
+
+	/* We need to enable spur filter for this channel */
+	if (spur_chan_fbin) {
+		spur_offset = spur_chan_fbin - chan_fbin;
+		/*
+		 * Calculate deltas:
+		 * spur_freq_sigma_delta -> spur_offset / sample_freq << 21
+		 * spur_delta_phase -> spur_offset / chip_freq << 11
+		 * Note: Both values have 100KHz resolution
+		 */
+		/* XXX: Half/Quarter rate channels ? */
+		switch (channel->hw_value) {
+		case CHANNEL_A:
+			/* Both sample_freq and chip_freq are 40MHz */
+			spur_delta_phase = (spur_offset << 17) / 25;
+			spur_freq_sigma_delta = (spur_delta_phase >> 10);
+			symbol_width = AR5K_SPUR_SYMBOL_WIDTH_BASE_100Hz;
+			break;
+		case CHANNEL_G:
+			/* sample_freq -> 40MHz chip_freq -> 44MHz
+			 * (for b compatibility) */
+			spur_freq_sigma_delta = (spur_offset << 8) / 55;
+			spur_delta_phase = (spur_offset << 17) / 25;
+			symbol_width = AR5K_SPUR_SYMBOL_WIDTH_BASE_100Hz;
+			break;
+		case CHANNEL_T:
+		case CHANNEL_TG:
+			/* Both sample_freq and chip_freq are 80MHz */
+			spur_delta_phase = (spur_offset << 16) / 25;
+			spur_freq_sigma_delta = (spur_delta_phase >> 10);
+			symbol_width = AR5K_SPUR_SYMBOL_WIDTH_TURBO_100Hz;
+			break;
+		default:
+			return;
+		}
+
+		/* Calculate pilot and magnitude masks */
+
+		/* Scale up spur_offset by 1000 to switch to 100HZ resolution
+		 * and divide by symbol_width to find how many symbols we have
+		 * Note: number of symbols is scaled up by 16 */
+		num_symbols_x16 = ((spur_offset * 1000) << 4) / symbol_width;
+
+		/* Spur is on a symbol if num_symbols_x16 % 16 is zero */
+		if (!(num_symbols_x16 & 0xF))
+			/* _X_ */
+			num_symbol_offsets = 3;
+		else
+			/* _xx_ */
+			num_symbol_offsets = 4;
+
+		for (i = 0; i < num_symbol_offsets; i++) {
+
+			/* Calculate pilot mask */
+			s32 curr_sym_off =
+				(num_symbols_x16 / 16) + i + 25;
+
+			/* Pilot magnitude mask seems to be a way to
+			 * declare the boundaries for our detection
+			 * window or something, it's 2 for the middle
+			 * value(s) where the symbol is expected to be
+			 * and 1 on the boundary values */
+			u8 plt_mag_map =
+				(i == 0 || i == (num_symbol_offsets - 1))
+								? 1 : 2;
+
+			if (curr_sym_off >= 0 && curr_sym_off <= 32) {
+				if (curr_sym_off <= 25)
+					pilot_mask[0] |= 1 << curr_sym_off;
+				else if (curr_sym_off >= 27)
+					pilot_mask[0] |= 1 << (curr_sym_off - 1);
+			} else if (curr_sym_off >= 33 && curr_sym_off <= 52)
+				pilot_mask[1] |= 1 << (curr_sym_off - 33);
+
+			/* Calculate magnitude mask (for viterbi decoder) */
+			if (curr_sym_off >= -1 && curr_sym_off <= 14)
+				mag_mask[0] |=
+					plt_mag_map << (curr_sym_off + 1) * 2;
+			else if (curr_sym_off >= 15 && curr_sym_off <= 30)
+				mag_mask[1] |=
+					plt_mag_map << (curr_sym_off - 15) * 2;
+			else if (curr_sym_off >= 31 && curr_sym_off <= 46)
+				mag_mask[2] |=
+					plt_mag_map << (curr_sym_off - 31) * 2;
+			else if (curr_sym_off >= 46 && curr_sym_off <= 53)
+				mag_mask[3] |=
+					plt_mag_map << (curr_sym_off - 47) * 2;
+
+		}
+
+		/* Write settings on hw to enable spur filter */
+		AR5K_REG_WRITE_BITS(ah, AR5K_PHY_BIN_MASK_CTL,
+					AR5K_PHY_BIN_MASK_CTL_RATE, 0xff);
+		/* XXX: Self correlator also ? */
+		AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_IQ,
+					AR5K_PHY_IQ_PILOT_MASK_EN |
+					AR5K_PHY_IQ_CHAN_MASK_EN |
+					AR5K_PHY_IQ_SPUR_FILT_EN);
+
+		/* Set delta phase and freq sigma delta */
+		ath5k_hw_reg_write(ah,
+				AR5K_REG_SM(spur_delta_phase,
+					AR5K_PHY_TIMING_11_SPUR_DELTA_PHASE) |
+				AR5K_REG_SM(spur_freq_sigma_delta,
+				AR5K_PHY_TIMING_11_SPUR_FREQ_SD) |
+				AR5K_PHY_TIMING_11_USE_SPUR_IN_AGC,
+				AR5K_PHY_TIMING_11);
+
+		/* Write pilot masks */
+		ath5k_hw_reg_write(ah, pilot_mask[0], AR5K_PHY_TIMING_7);
+		AR5K_REG_WRITE_BITS(ah, AR5K_PHY_TIMING_8,
+					AR5K_PHY_TIMING_8_PILOT_MASK_2,
+					pilot_mask[1]);
+
+		ath5k_hw_reg_write(ah, pilot_mask[0], AR5K_PHY_TIMING_9);
+		AR5K_REG_WRITE_BITS(ah, AR5K_PHY_TIMING_10,
+					AR5K_PHY_TIMING_10_PILOT_MASK_2,
+					pilot_mask[1]);
+
+		/* Write magnitude masks */
+		ath5k_hw_reg_write(ah, mag_mask[0], AR5K_PHY_BIN_MASK_1);
+		ath5k_hw_reg_write(ah, mag_mask[1], AR5K_PHY_BIN_MASK_2);
+		ath5k_hw_reg_write(ah, mag_mask[2], AR5K_PHY_BIN_MASK_3);
+		AR5K_REG_WRITE_BITS(ah, AR5K_PHY_BIN_MASK_CTL,
+					AR5K_PHY_BIN_MASK_CTL_MASK_4,
+					mag_mask[3]);
+
+		ath5k_hw_reg_write(ah, mag_mask[0], AR5K_PHY_BIN_MASK2_1);
+		ath5k_hw_reg_write(ah, mag_mask[1], AR5K_PHY_BIN_MASK2_2);
+		ath5k_hw_reg_write(ah, mag_mask[2], AR5K_PHY_BIN_MASK2_3);
+		AR5K_REG_WRITE_BITS(ah, AR5K_PHY_BIN_MASK2_4,
+					AR5K_PHY_BIN_MASK2_4_MASK_4,
+					mag_mask[3]);
+
+	} else if (ath5k_hw_reg_read(ah, AR5K_PHY_IQ) &
+	AR5K_PHY_IQ_SPUR_FILT_EN) {
+		/* Clean up spur mitigation settings and disable fliter */
+		AR5K_REG_WRITE_BITS(ah, AR5K_PHY_BIN_MASK_CTL,
+					AR5K_PHY_BIN_MASK_CTL_RATE, 0);
+		AR5K_REG_DISABLE_BITS(ah, AR5K_PHY_IQ,
+					AR5K_PHY_IQ_PILOT_MASK_EN |
+					AR5K_PHY_IQ_CHAN_MASK_EN |
+					AR5K_PHY_IQ_SPUR_FILT_EN);
+		ath5k_hw_reg_write(ah, 0, AR5K_PHY_TIMING_11);
+
+		/* Clear pilot masks */
+		ath5k_hw_reg_write(ah, 0, AR5K_PHY_TIMING_7);
+		AR5K_REG_WRITE_BITS(ah, AR5K_PHY_TIMING_8,
+					AR5K_PHY_TIMING_8_PILOT_MASK_2,
+					0);
+
+		ath5k_hw_reg_write(ah, 0, AR5K_PHY_TIMING_9);
+		AR5K_REG_WRITE_BITS(ah, AR5K_PHY_TIMING_10,
+					AR5K_PHY_TIMING_10_PILOT_MASK_2,
+					0);
+
+		/* Clear magnitude masks */
+		ath5k_hw_reg_write(ah, 0, AR5K_PHY_BIN_MASK_1);
+		ath5k_hw_reg_write(ah, 0, AR5K_PHY_BIN_MASK_2);
+		ath5k_hw_reg_write(ah, 0, AR5K_PHY_BIN_MASK_3);
+		AR5K_REG_WRITE_BITS(ah, AR5K_PHY_BIN_MASK_CTL,
+					AR5K_PHY_BIN_MASK_CTL_MASK_4,
+					0);
+
+		ath5k_hw_reg_write(ah, 0, AR5K_PHY_BIN_MASK2_1);
+		ath5k_hw_reg_write(ah, 0, AR5K_PHY_BIN_MASK2_2);
+		ath5k_hw_reg_write(ah, 0, AR5K_PHY_BIN_MASK2_3);
+		AR5K_REG_WRITE_BITS(ah, AR5K_PHY_BIN_MASK2_4,
+					AR5K_PHY_BIN_MASK2_4_MASK_4,
+					0);
+	}
+}
+
+/********************\
+  Misc PHY functions
+\********************/
+
 int ath5k_hw_phy_disable(struct ath5k_hw *ah)
 {
 	ATH5K_TRACE(ah->ah_sc);
@@ -1362,10 +1613,6 @@ int ath5k_hw_phy_disable(struct ath5k_hw *ah)
 	return 0;
 }
 
-/********************\
-  Misc PHY functions
-\********************/
-
 /*
  * Get the PHY Chip revision
  */