ath9k: Use a separate TX gain table for WZR-HP-G450H

The Buffalo device WZR-HP-G450H uses the index 3 for TX gain,
which is set to the high_power table currently. Later variants
of the router use the same index, but instead refer to the
low_ob_db gain table. This is not handled in the driver since
there is no way to distinguish board revisions and the high_power
table is used (incorrectly) for the newer variants.

By default, devices based on AR9300 using the TX gain index 3 have
to use the high_power table. To make sure that WZR-HP-G450H is not
broken when the high_power table is updated, use a separate array
based on information obtained from the platform data.

The current situation where only the original variant of WZR-HP-G450H
works properly stays unchanged.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 5a0b7e82..609b7e1 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -554,7 +554,7 @@
 	sc->spec_config.fft_period = 0xF;
 }
 
-static void ath9k_init_platform(struct ath_softc *sc)
+static void ath9k_init_pcoem_platform(struct ath_softc *sc)
 {
 	struct ath_hw *ah = sc->sc_ah;
 	struct ath9k_hw_capabilities *pCap = &ah->caps;
@@ -664,6 +664,27 @@
 	release_firmware(sc->sc_ah->eeprom_blob);
 }
 
+static int ath9k_init_soc_platform(struct ath_softc *sc)
+{
+	struct ath9k_platform_data *pdata = sc->dev->platform_data;
+	struct ath_hw *ah = sc->sc_ah;
+	int ret = 0;
+
+	if (!pdata)
+		return 0;
+
+	if (pdata->eeprom_name) {
+		ret = ath9k_eeprom_request(sc, pdata->eeprom_name);
+		if (ret)
+			return ret;
+	}
+
+	if (pdata->tx_gain_buffalo)
+		ah->config.tx_gain_buffalo = true;
+
+	return ret;
+}
+
 static int ath9k_init_softc(u16 devid, struct ath_softc *sc,
 			    const struct ath_bus_ops *bus_ops)
 {
@@ -717,7 +738,11 @@
 	/*
 	 * Platform quirks.
 	 */
-	ath9k_init_platform(sc);
+	ath9k_init_pcoem_platform(sc);
+
+	ret = ath9k_init_soc_platform(sc);
+	if (ret)
+		return ret;
 
 	/*
 	 * Enable WLAN/BT RX Antenna diversity only when:
@@ -731,7 +756,6 @@
 		common->bt_ant_diversity = 1;
 
 	spin_lock_init(&common->cc_lock);
-
 	spin_lock_init(&sc->sc_serial_rw);
 	spin_lock_init(&sc->sc_pm_lock);
 	mutex_init(&sc->mutex);
@@ -753,12 +777,6 @@
 	ath_read_cachesize(common, &csz);
 	common->cachelsz = csz << 2; /* convert to bytes */
 
-	if (pdata && pdata->eeprom_name) {
-		ret = ath9k_eeprom_request(sc, pdata->eeprom_name);
-		if (ret)
-			return ret;
-	}
-
 	/* Initializes the hardware for all supported chipsets */
 	ret = ath9k_hw_init(ah);
 	if (ret)