ath9k_hw: Improve fast channel change for AR9003 chips

In order to reduce the overall scan time, fast channel change
should be implemented properly. This patch adds fast channel
change support across band switch or channel mode switch
instead of doing full chip reset. During the fastcc, tx iqcal
measurements are preserved and will be reloaded after successful
the channel change.

This patch also addressed fast channel issue where the STA can not
see APs in higher than operating channel on 5GHz band after
the association.

Cc: Paul Stewart <pstew@google.com>
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 67 insertions, 5 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_calib.c b/drivers/net/wireless/ath/ath9k/ar9003_calib.c
index e4b1a83..026aa5b 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_calib.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_calib.c
@@ -18,7 +18,7 @@
 #include "hw-ops.h"
 #include "ar9003_phy.h"
 
-#define MAX_MEASUREMENT	8
+#define MAX_MEASUREMENT	MAX_IQCAL_MEASUREMENT
 #define MAX_MAG_DELTA	11
 #define MAX_PHS_DELTA	10
 
@@ -663,6 +663,7 @@ static void ar9003_hw_tx_iqcal_load_avg_2_passes(struct ath_hw *ah,
 {
 	int i, im, nmeasurement;
 	u32 tx_corr_coeff[MAX_MEASUREMENT][AR9300_MAX_CHAINS];
+	struct ath9k_hw_cal_data *caldata = ah->caldata;
 
 	memset(tx_corr_coeff, 0, sizeof(tx_corr_coeff));
 	for (i = 0; i < MAX_MEASUREMENT / 2; i++) {
@@ -712,13 +713,21 @@ static void ar9003_hw_tx_iqcal_load_avg_2_passes(struct ath_hw *ah,
 				REG_RMW_FIELD(ah, tx_corr_coeff[im][i],
 					AR_PHY_TX_IQCAL_CORR_COEFF_01_COEFF_TABLE,
 					coeff->iqc_coeff[0]);
+
+			if (caldata)
+				caldata->tx_corr_coeff[im][i] =
+					coeff->iqc_coeff[0];
 		}
+		if (caldata)
+			caldata->num_measures[i] = nmeasurement;
 	}
 
 	REG_RMW_FIELD(ah, AR_PHY_TX_IQCAL_CONTROL_3,
 		      AR_PHY_TX_IQCAL_CONTROL_3_IQCORR_EN, 0x1);
 	REG_RMW_FIELD(ah, AR_PHY_RX_IQCAL_CORR_B0,
 		      AR_PHY_RX_IQCAL_CORR_B0_LOOPBACK_IQCORR_EN, 0x1);
+	if (caldata)
+		caldata->done_txiqcal_once = true;
 
 	return;
 
@@ -845,10 +854,55 @@ tx_iqcal_fail:
 	ath_dbg(common, ATH_DBG_CALIBRATE, "Tx IQ Cal failed\n");
 	return;
 }
+
+static void ar9003_hw_tx_iq_cal_reload(struct ath_hw *ah)
+{
+	struct ath9k_hw_cal_data *caldata = ah->caldata;
+	u32 tx_corr_coeff[MAX_MEASUREMENT][AR9300_MAX_CHAINS];
+	int i, im;
+
+	memset(tx_corr_coeff, 0, sizeof(tx_corr_coeff));
+	for (i = 0; i < MAX_MEASUREMENT / 2; i++) {
+		tx_corr_coeff[i * 2][0] = tx_corr_coeff[(i * 2) + 1][0] =
+					AR_PHY_TX_IQCAL_CORR_COEFF_B0(i);
+		if (!AR_SREV_9485(ah)) {
+			tx_corr_coeff[i * 2][1] =
+			tx_corr_coeff[(i * 2) + 1][1] =
+					AR_PHY_TX_IQCAL_CORR_COEFF_B1(i);
+
+			tx_corr_coeff[i * 2][2] =
+			tx_corr_coeff[(i * 2) + 1][2] =
+					AR_PHY_TX_IQCAL_CORR_COEFF_B2(i);
+		}
+	}
+
+	for (i = 0; i < AR9300_MAX_CHAINS; i++) {
+		if (!(ah->txchainmask & (1 << i)))
+			continue;
+
+		for (im = 0; im < caldata->num_measures[i]; im++) {
+			if ((im % 2) == 0)
+				REG_RMW_FIELD(ah, tx_corr_coeff[im][i],
+				     AR_PHY_TX_IQCAL_CORR_COEFF_00_COEFF_TABLE,
+				     caldata->tx_corr_coeff[im][i]);
+			else
+				REG_RMW_FIELD(ah, tx_corr_coeff[im][i],
+				     AR_PHY_TX_IQCAL_CORR_COEFF_01_COEFF_TABLE,
+				     caldata->tx_corr_coeff[im][i]);
+		}
+	}
+
+	REG_RMW_FIELD(ah, AR_PHY_TX_IQCAL_CONTROL_3,
+		      AR_PHY_TX_IQCAL_CONTROL_3_IQCORR_EN, 0x1);
+	REG_RMW_FIELD(ah, AR_PHY_RX_IQCAL_CORR_B0,
+		      AR_PHY_RX_IQCAL_CORR_B0_LOOPBACK_IQCORR_EN, 0x1);
+}
+
 static bool ar9003_hw_init_cal(struct ath_hw *ah,
 			       struct ath9k_channel *chan)
 {
 	struct ath_common *common = ath9k_hw_common(ah);
+	struct ath9k_hw_cal_data *caldata = ah->caldata;
 	bool txiqcal_done = false;
 
 	/* Do Tx IQ Calibration */
@@ -860,9 +914,15 @@ static bool ar9003_hw_init_cal(struct ath_hw *ah,
 	 * For AR9485 or later chips, TxIQ cal runs as part of
 	 * AGC calibration
 	 */
-	if (AR_SREV_9485_OR_LATER(ah))
+	if (AR_SREV_9485_OR_LATER(ah) && !AR_SREV_9340(ah)) {
+		if (caldata && !caldata->done_txiqcal_once)
+			REG_SET_BIT(ah, AR_PHY_TX_IQCAL_CONTROL_0,
+				    AR_PHY_TX_IQCAL_CONTROL_0_ENABLE_TXIQ_CAL);
+		else
+			REG_CLR_BIT(ah, AR_PHY_TX_IQCAL_CONTROL_0,
+				    AR_PHY_TX_IQCAL_CONTROL_0_ENABLE_TXIQ_CAL);
 		txiqcal_done = true;
-	else {
+	} else {
 		txiqcal_done = ar9003_hw_tx_iq_cal_run(ah);
 		REG_WRITE(ah, AR_PHY_ACTIVE, AR_PHY_ACTIVE_DIS);
 		udelay(5);
@@ -884,6 +944,8 @@ static bool ar9003_hw_init_cal(struct ath_hw *ah,
 
 	if (txiqcal_done)
 		ar9003_hw_tx_iq_cal_post_proc(ah);
+	else if (caldata && caldata->done_txiqcal_once)
+		ar9003_hw_tx_iq_cal_reload(ah);
 
 	ath9k_hw_loadnf(ah, chan);
 	ath9k_hw_start_nfcal(ah, true);
@@ -912,8 +974,8 @@ static bool ar9003_hw_init_cal(struct ath_hw *ah,
 	if (ah->cal_list_curr)
 		ath9k_hw_reset_calibration(ah, ah->cal_list_curr);
 
-	if (ah->caldata)
-		ah->caldata->CalValid = 0;
+	if (caldata)
+		caldata->CalValid = 0;
 
 	return true;
 }