ath9k_hw: calibrate PA input for PA predistortion

Re-train if the calibrated PA linearization curve is out of bounds
(affects AR933x and AR9485).

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 111 insertions, 1 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_paprd.c b/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
index 2173bd75dd21..0ed3846f9cbb 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
@@ -786,6 +786,102 @@ int ar9003_paprd_setup_gain_table(struct ath_hw *ah, int chain)
 }
 EXPORT_SYMBOL(ar9003_paprd_setup_gain_table);
 
+static bool ar9003_paprd_retrain_pa_in(struct ath_hw *ah,
+                                       struct ath9k_hw_cal_data *caldata,
+                                       int chain)
+{
+        u32 *pa_in = caldata->pa_table[chain];
+        int capdiv_offset, quick_drop_offset;
+        int capdiv2g, quick_drop;
+        int count = 0;
+        int i;
+
+        if (!AR_SREV_9485(ah) && !AR_SREV_9330(ah))
+                return false;
+
+        capdiv2g = REG_READ_FIELD(ah, AR_PHY_65NM_CH0_TXRF3,
+                                  AR_PHY_65NM_CH0_TXRF3_CAPDIV2G);
+
+        quick_drop = REG_READ_FIELD(ah, AR_PHY_PAPRD_TRAINER_CNTL3,
+                                    AR_PHY_PAPRD_TRAINER_CNTL3_CF_PAPRD_QUICK_DROP);
+
+        if (quick_drop)
+                quick_drop -= 0x40;
+
+        for (i = 0; i < NUM_BIN + 1; i++) {
+                if (pa_in[i] == 1400)
+                        count++;
+        }
+
+        if (AR_SREV_9485(ah)) {
+                if (pa_in[23] < 800) {
+                        capdiv_offset = (int)((1000 - pa_in[23] + 75) / 150);
+                        capdiv2g += capdiv_offset;
+                        if (capdiv2g > 7) {
+                                capdiv2g = 7;
+                                if (pa_in[23] < 600) {
+                                        quick_drop++;
+                                        if (quick_drop > 0)
+                                                quick_drop = 0;
+                                }
+                        }
+                } else if (pa_in[23] == 1400) {
+                        quick_drop_offset = min_t(int, count / 3, 2);
+                        quick_drop += quick_drop_offset;
+                        capdiv2g += quick_drop_offset / 2;
+
+                        if (capdiv2g > 7)
+                                capdiv2g = 7;
+
+                        if (quick_drop > 0) {
+                                quick_drop = 0;
+                                capdiv2g -= quick_drop_offset;
+                                if (capdiv2g < 0)
+                                        capdiv2g = 0;
+                        }
+                } else {
+                        return false;
+                }
+        } else if (AR_SREV_9330(ah)) {
+                if (pa_in[23] < 1000) {
+                        capdiv_offset = (1000 - pa_in[23]) / 100;
+                        capdiv2g += capdiv_offset;
+                        if (capdiv_offset > 3) {
+                                capdiv_offset = 1;
+                                quick_drop--;
+                        }
+
+                        capdiv2g += capdiv_offset;
+                        if (capdiv2g > 6)
+                                capdiv2g = 6;
+                        if (quick_drop < -4)
+                                quick_drop = -4;
+                } else if (pa_in[23] == 1400) {
+                        if (count > 3) {
+                                quick_drop++;
+                                capdiv2g -= count / 4;
+                                if (quick_drop > -2)
+                                        quick_drop = -2;
+                        } else {
+                                capdiv2g--;
+                        }
+
+                        if (capdiv2g < 0)
+                                capdiv2g = 0;
+                } else {
+                        return false;
+                }
+        }
+
+        REG_RMW_FIELD(ah, AR_PHY_65NM_CH0_TXRF3,
+                      AR_PHY_65NM_CH0_TXRF3_CAPDIV2G, capdiv2g);
+        REG_RMW_FIELD(ah, AR_PHY_PAPRD_TRAINER_CNTL3,
+                      AR_PHY_PAPRD_TRAINER_CNTL3_CF_PAPRD_QUICK_DROP,
+                      quick_drop);
+
+        return true;
+}
+
 int ar9003_paprd_create_curve(struct ath_hw *ah,
                               struct ath9k_hw_cal_data *caldata, int chain)
 {
@@ -821,6 +917,9 @@ int ar9003_paprd_create_curve(struct ath_hw *ah,
         if (!create_pa_curve(data_L, data_U, pa_table, small_signal_gain))
                 status = -2;
 
+        if (ar9003_paprd_retrain_pa_in(ah, caldata, chain))
+                status = -EINPROGRESS;
+
         REG_CLR_BIT(ah, AR_PHY_PAPRD_TRAINER_STAT1,
                     AR_PHY_PAPRD_TRAINER_STAT1_PAPRD_TRAIN_DONE);
 
diff --git a/drivers/net/wireless/ath/ath9k/ar9003_phy.h b/drivers/net/wireless/ath/ath9k/ar9003_phy.h
index 7bfbaf065a43..84d3d4956861 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_phy.h
+++ b/drivers/net/wireless/ath/ath9k/ar9003_phy.h
@@ -625,6 +625,10 @@
 #define AR_PHY_AIC_CTRL_4_B0    (AR_SM_BASE + 0x4c0)
 #define AR_PHY_AIC_STAT_2_B0    (AR_SM_BASE + 0x4cc)
 
+#define AR_PHY_65NM_CH0_TXRF3       0x16048
+#define AR_PHY_65NM_CH0_TXRF3_CAPDIV2G          0x0000001e
+#define AR_PHY_65NM_CH0_TXRF3_CAPDIV2G_S        1
+
 #define AR_PHY_65NM_CH0_SYNTH4      0x1608c
 #define AR_PHY_SYNTH4_LONG_SHIFT_SELECT   (AR_SREV_9462(ah) ? 0x00000001 : 0x00000002)
 #define AR_PHY_SYNTH4_LONG_SHIFT_SELECT_S (AR_SREV_9462(ah) ? 0 : 1)
diff --git a/drivers/net/wireless/ath/ath9k/link.c b/drivers/net/wireless/ath/ath9k/link.c
index d4549e9aac5c..1c241921f95e 100644
--- a/drivers/net/wireless/ath/ath9k/link.c
+++ b/drivers/net/wireless/ath/ath9k/link.c
@@ -254,6 +254,7 @@ void ath_paprd_calibrate(struct work_struct *work)
         int chain_ok = 0;
         int chain;
         int len = 1800;
+        int ret;
 
         if (!caldata)
                 return;
@@ -302,7 +303,13 @@ void ath_paprd_calibrate(struct work_struct *work)
                         break;
                 }
 
-                if (ar9003_paprd_create_curve(ah, caldata, chain)) {
+                ret = ar9003_paprd_create_curve(ah, caldata, chain);
+                if (ret == -EINPROGRESS) {
+                        ath_dbg(common, CALIBRATE,
+                                "PAPRD curve on chain %d needs to be re-trained\n",
+                                chain);
+                        break;
+                } else if (ret) {
                         ath_dbg(common, CALIBRATE,
                                 "PAPRD create curve failed on chain %d\n",
                                 chain);