ar9170: implement frequency calibration for one-stage/openfw

This patch ports some code from the vendor driver, which is
supposed to upload the right calibration values for the
chosen frequency.

In theory, this should give a better range and throughput
for all users with the open, or one-stage firmware.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 122 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ar9170/phy.c b/drivers/net/wireless/ath/ar9170/phy.c
index 3ace58ab40c8..108ebfe21fcf 100644
--- a/drivers/net/wireless/ath/ar9170/phy.c
+++ b/drivers/net/wireless/ath/ar9170/phy.c
@@ -1120,6 +1120,124 @@ static u8 ar9170_interpolate_u8(u8 x, u8 x1, u8 y1, u8 x2, u8 y2)
 #undef SHIFT
 }
 
+static u8 ar9170_interpolate_val(u8 x, u8 *x_array, u8 *y_array)
+{
+        int i;
+
+        for (i = 0; i < 3; i++)
+                if (x <= x_array[i + 1])
+                        break;
+
+        return ar9170_interpolate_u8(x,
+                                     x_array[i],
+                                     y_array[i],
+                                     x_array[i + 1],
+                                     y_array[i + 1]);
+}
+
+static int ar9170_set_freq_cal_data(struct ar9170 *ar,
+                                    struct ieee80211_channel *channel)
+{
+        u8 *cal_freq_pier;
+        u8 vpds[2][AR5416_PD_GAIN_ICEPTS];
+        u8 pwrs[2][AR5416_PD_GAIN_ICEPTS];
+        int chain, idx, i;
+        u8 f;
+
+        switch (channel->band) {
+        case IEEE80211_BAND_2GHZ:
+                f = channel->center_freq - 2300;
+                cal_freq_pier = ar->eeprom.cal_freq_pier_2G;
+                i = AR5416_NUM_2G_CAL_PIERS - 1;
+                break;
+
+        case IEEE80211_BAND_5GHZ:
+                f = (channel->center_freq - 4800) / 5;
+                cal_freq_pier = ar->eeprom.cal_freq_pier_5G;
+                i = AR5416_NUM_5G_CAL_PIERS - 1;
+                break;
+
+        default:
+                return -EINVAL;
+                break;
+        }
+
+        for (; i >= 0; i--) {
+                if (cal_freq_pier[i] != 0xff)
+                        break;
+        }
+        if (i < 0)
+                return -EINVAL;
+
+        idx = ar9170_find_freq_idx(i, cal_freq_pier, f);
+
+        ar9170_regwrite_begin(ar);
+
+        for (chain = 0; chain < AR5416_MAX_CHAINS; chain++) {
+                for (i = 0; i < AR5416_PD_GAIN_ICEPTS; i++) {
+                        struct ar9170_calibration_data_per_freq *cal_pier_data;
+                        int j;
+
+                        switch (channel->band) {
+                        case IEEE80211_BAND_2GHZ:
+                                cal_pier_data = &ar->eeprom.
+                                        cal_pier_data_2G[chain][idx];
+                                break;
+
+                        case IEEE80211_BAND_5GHZ:
+                                cal_pier_data = &ar->eeprom.
+                                        cal_pier_data_5G[chain][idx];
+                                break;
+
+                        default:
+                                return -EINVAL;
+                        }
+
+                        for (j = 0; j < 2; j++) {
+                                vpds[j][i] = ar9170_interpolate_u8(f,
+                                        cal_freq_pier[idx],
+                                        cal_pier_data->vpd_pdg[j][i],
+                                        cal_freq_pier[idx + 1],
+                                        cal_pier_data[1].vpd_pdg[j][i]);
+
+                                pwrs[j][i] = ar9170_interpolate_u8(f,
+                                        cal_freq_pier[idx],
+                                        cal_pier_data->pwr_pdg[j][i],
+                                        cal_freq_pier[idx + 1],
+                                        cal_pier_data[1].pwr_pdg[j][i]) / 2;
+                        }
+                }
+
+                for (i = 0; i < 76; i++) {
+                        u32 phy_data;
+                        u8 tmp;
+
+                        if (i < 25) {
+                                tmp = ar9170_interpolate_val(i, &pwrs[0][0],
+                                                             &vpds[0][0]);
+                        } else {
+                                tmp = ar9170_interpolate_val(i - 12,
+                                                             &pwrs[1][0],
+                                                             &vpds[1][0]);
+                        }
+
+                        phy_data |= tmp << ((i & 3) << 3);
+                        if ((i & 3) == 3) {
+                                ar9170_regwrite(0x1c6280 + chain * 0x1000 +
+                                                (i & ~3), phy_data);
+                                phy_data = 0;
+                        }
+                }
+
+                for (i = 19; i < 32; i++)
+                        ar9170_regwrite(0x1c6280 + chain * 0x1000 + (i << 2),
+                                        0x0);
+        }
+
+        ar9170_regwrite_finish();
+        return ar9170_regwrite_result();
+}
+
 static int ar9170_set_power_cal(struct ar9170 *ar, u32 freq, enum ar9170_bw bw)
 {
         struct ar9170_calibration_target_power_legacy *ctpl;
@@ -1340,6 +1458,10 @@ int ar9170_set_channel(struct ar9170 *ar, struct ieee80211_channel *channel,
         if (err)
                 return err;
 
+        err = ar9170_set_freq_cal_data(ar, channel);
+        if (err)
+                return err;
+
         err = ar9170_set_power_cal(ar, channel->center_freq, bw);
         if (err)
                 return err;