ath9k_hw: Fix RTT calibration

This patch fixes multiple issues with the current RTT
implementation in ath9k.

* The data that is obtained from the RTT interface registers
  are stored in 31:5 - mask out the extra bits when reading them.

* A history buffer is maintained which is not needed at all.
  Remove this array and just store the baseband data for each
  chain (or bank).

* A 'num_readings' variable was being used to handle the
  last entry. But it was being used in an improper manner, with
  the result that the RTT values were never being written
  to the RTT Interface registers. Fix this by using a simple
  flag.

* Stop baseband operations before programming the calibration values
  to the HW.

* Do not restore RX gain settings as part of RTT.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 69 insertions, 15 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_rtt.c b/drivers/net/wireless/ath/ath9k/ar9003_rtt.c
index 458bedf0b0ae..74de3539c2c8 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_rtt.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_rtt.c
@@ -15,6 +15,7 @@
  */
 
 #include "hw.h"
+#include "hw-ops.h"
 #include "ar9003_phy.h"
 #include "ar9003_rtt.h"
 
@@ -69,7 +70,7 @@ bool ar9003_hw_rtt_force_restore(struct ath_hw *ah)
 }
 
 static void ar9003_hw_rtt_load_hist_entry(struct ath_hw *ah, u8 chain,
-		u32 index, u32 data28)
+					  u32 index, u32 data28)
 {
 	u32 val;
 
@@ -100,12 +101,21 @@ static void ar9003_hw_rtt_load_hist_entry(struct ath_hw *ah, u8 chain,
 		      RTT_ACCESS_TIMEOUT);
 }
 
-void ar9003_hw_rtt_load_hist(struct ath_hw *ah, u8 chain, u32 *table)
+void ar9003_hw_rtt_load_hist(struct ath_hw *ah)
 {
-	int i;
+	int chain, i;
 
-	for (i = 0; i < MAX_RTT_TABLE_ENTRY; i++)
-		ar9003_hw_rtt_load_hist_entry(ah, chain, i, table[i]);
+	for (chain = 0; chain < AR9300_MAX_CHAINS; chain++) {
+		if (!(ah->rxchainmask & (1 << chain)))
+			continue;
+		for (i = 0; i < MAX_RTT_TABLE_ENTRY; i++) {
+			ar9003_hw_rtt_load_hist_entry(ah, chain, i,
+					      ah->caldata->rtt_table[chain][i]);
+			ath_dbg(ath9k_hw_common(ah), CALIBRATE,
+				"Load RTT value at idx %d, chain %d: 0x%x\n",
+				i, chain, ah->caldata->rtt_table[chain][i]);
+		}
+	}
 }
 
 static int ar9003_hw_rtt_fill_hist_entry(struct ath_hw *ah, u8 chain, u32 index)
@@ -128,27 +138,71 @@ static int ar9003_hw_rtt_fill_hist_entry(struct ath_hw *ah, u8 chain, u32 index)
 			   RTT_ACCESS_TIMEOUT))
 		return RTT_BAD_VALUE;
 
-	val = REG_READ(ah, AR_PHY_RTT_TABLE_SW_INTF_1_B(chain));
+	val = MS(REG_READ(ah, AR_PHY_RTT_TABLE_SW_INTF_1_B(chain)),
+		 AR_PHY_RTT_SW_RTT_TABLE_DATA);
+
 
 	return val;
 }
 
-void ar9003_hw_rtt_fill_hist(struct ath_hw *ah, u8 chain, u32 *table)
+void ar9003_hw_rtt_fill_hist(struct ath_hw *ah)
 {
-	int i;
+	int chain, i;
+
+	for (chain = 0; chain < AR9300_MAX_CHAINS; chain++) {
+		if (!(ah->rxchainmask & (1 << chain)))
+			continue;
+		for (i = 0; i < MAX_RTT_TABLE_ENTRY; i++) {
+			ah->caldata->rtt_table[chain][i] =
+				ar9003_hw_rtt_fill_hist_entry(ah, chain, i);
+			ath_dbg(ath9k_hw_common(ah), CALIBRATE,
+				"RTT value at idx %d, chain %d is: 0x%x\n",
+				i, chain, ah->caldata->rtt_table[chain][i]);
+		}
+	}
 
-	for (i = 0; i < MAX_RTT_TABLE_ENTRY; i++)
-		table[i] = ar9003_hw_rtt_fill_hist_entry(ah, chain, i);
+	ah->caldata->rtt_done = true;
 }
 
 void ar9003_hw_rtt_clear_hist(struct ath_hw *ah)
 {
-	int i, j;
+	int chain, i;
 
-	for (i = 0; i < AR9300_MAX_CHAINS; i++) {
-		if (!(ah->rxchainmask & (1 << i)))
+	for (chain = 0; chain < AR9300_MAX_CHAINS; chain++) {
+		if (!(ah->rxchainmask & (1 << chain)))
 			continue;
-		for (j = 0; j < MAX_RTT_TABLE_ENTRY; j++)
-			ar9003_hw_rtt_load_hist_entry(ah, i, j, 0);
+		for (i = 0; i < MAX_RTT_TABLE_ENTRY; i++)
+			ar9003_hw_rtt_load_hist_entry(ah, chain, i, 0);
 	}
+
+	if (ah->caldata)
+		ah->caldata->rtt_done = false;
+}
+
+bool ar9003_hw_rtt_restore(struct ath_hw *ah, struct ath9k_channel *chan)
+{
+	bool restore;
+
+	if (!ah->caldata)
+		return false;
+
+	if (!ah->caldata->rtt_done)
+		return false;
+
+	ar9003_hw_rtt_enable(ah);
+	ar9003_hw_rtt_set_mask(ah, 0x10);
+
+	if (!ath9k_hw_rfbus_req(ah)) {
+		ath_err(ath9k_hw_common(ah), "Could not stop baseband\n");
+		restore = false;
+		goto fail;
+	}
+
+	ar9003_hw_rtt_load_hist(ah);
+	restore = ar9003_hw_rtt_force_restore(ah);
+
+fail:
+	ath9k_hw_rfbus_done(ah);
+	ar9003_hw_rtt_disable(ah);
+	return restore;
 }