[PATCH ath-next] wifi: ath9k: improve stability on AR9330/AR9340

[Rosen Penev <rosenp@gmail.com>]

Setting a couple of registers on these platforms improves stability.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/net/wireless/ath/ath9k/hw.c  | 25 +++++++++++++++++++++++++
 drivers/net/wireless/ath/ath9k/phy.h |  3 +++
 2 files changed, 28 insertions(+)

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 05c95e67a853..5168c02bb73c 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -248,6 +248,19 @@ void ath9k_hw_get_channel_centers(struct ath_hw *ah,
 		centers->synth_center + (extoff * HT40_CHANNEL_CENTER_SHIFT);
 }
 
+static inline void ath9k_hw_disable_pll_lock_detect(struct ath_hw *ah)
+{
+	/* On AR9330 and AR9340 devices, some PHY registers must be
+	 * tuned to gain better stability/performance. These registers
+	 * might be changed while doing wlan reset so the registers must
+	 * be reprogrammed after each reset.
+	 */
+	REG_CLR_BIT(ah, AR_PHY_USB_CTRL1, BIT(20));
+	REG_RMW(ah, AR_PHY_USB_CTRL2,
+		(1 << 21) | (0xf << 22),
+		(1 << 21) | (0x3 << 22));
+}
+
 /******************/
 /* Chip Revisions */
 /******************/
@@ -1438,6 +1451,9 @@ static bool ath9k_hw_set_reset(struct ath_hw *ah, int type)
 	if (AR_SREV_9100(ah))
 		udelay(50);
 
+	if (AR_SREV_9330(ah) || AR_SREV_9340(ah))
+		ath9k_hw_disable_pll_lock_detect(ah);
+
 	return true;
 }
 
@@ -1537,6 +1553,9 @@ static bool ath9k_hw_chip_reset(struct ath_hw *ah,
 		ar9003_hw_internal_regulator_apply(ah);
 	ath9k_hw_init_pll(ah, chan);
 
+	if (AR_SREV_9330(ah) || AR_SREV_9340(ah))
+		ath9k_hw_disable_pll_lock_detect(ah);
+
 	return true;
 }
 
@@ -1843,6 +1862,9 @@ static int ath9k_hw_do_fastcc(struct ath_hw *ah, struct ath9k_channel *chan)
 	if (AR_SREV_9271(ah))
 		ar9002_hw_load_ani_reg(ah, chan);
 
+	if (AR_SREV_9330(ah) || AR_SREV_9340(ah))
+		ath9k_hw_disable_pll_lock_detect(ah);
+
 	return 0;
 fail:
 	return -EINVAL;
@@ -2074,6 +2096,9 @@ int ath9k_hw_reset(struct ath_hw *ah, struct ath9k_channel *chan,
 		ath9k_hw_set_radar_params(ah);
 	}
 
+	if (AR_SREV_9330(ah) || AR_SREV_9340(ah))
+		ath9k_hw_disable_pll_lock_detect(ah);
+
 	return 0;
 }
 EXPORT_SYMBOL(ath9k_hw_reset);
diff --git a/drivers/net/wireless/ath/ath9k/phy.h b/drivers/net/wireless/ath/ath9k/phy.h
index 4a1b99238ec2..af667a3629b1 100644
--- a/drivers/net/wireless/ath/ath9k/phy.h
+++ b/drivers/net/wireless/ath/ath9k/phy.h
@@ -48,6 +48,9 @@
 #define AR_PHY_PLL_CONTROL 0x16180
 #define AR_PHY_PLL_MODE 0x16184
 
+#define AR_PHY_USB_CTRL1	0x16c84
+#define AR_PHY_USB_CTRL2	0x16c88
+
 enum ath9k_ant_div_comb_lna_conf {
 	ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2,
 	ATH_ANT_DIV_COMB_LNA2,
-- 
2.54.0