ath9k: allow disabling bands via platform data

Some devices have multiple bands enables in the EEPROM data, even though
they are only calibrated for one. Allow platform data to disable
unsupported bands.

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

drivers/net/wireless/ath/ath9k/hw.c

@@ -2344,17 +2344,25 @@ int ath9k_hw_fill_cap_info(struct ath_hw *ah)
 	}
 
 	eeval = ah->eep_ops->get_eeprom(ah, EEP_OP_MODE);
-	if ((eeval & (AR5416_OPFLAGS_11G | AR5416_OPFLAGS_11A)) == 0) {
-		ath_err(common,
-			"no band has been marked as supported in EEPROM\n");
-		return -EINVAL;
+
+	if (eeval & AR5416_OPFLAGS_11A) {
+		if (ah->disable_5ghz)
+			ath_warn(common, "disabling 5GHz band\n");
+		else
+			pCap->hw_caps |= ATH9K_HW_CAP_5GHZ;
 	}
 
-	if (eeval & AR5416_OPFLAGS_11A)
-		pCap->hw_caps |= ATH9K_HW_CAP_5GHZ;
+	if (eeval & AR5416_OPFLAGS_11G) {
+		if (ah->disable_2ghz)
+			ath_warn(common, "disabling 2GHz band\n");
+		else
+			pCap->hw_caps |= ATH9K_HW_CAP_2GHZ;
+	}
 
-	if (eeval & AR5416_OPFLAGS_11G)
-		pCap->hw_caps |= ATH9K_HW_CAP_2GHZ;
+	if ((pCap->hw_caps & (ATH9K_HW_CAP_2GHZ | ATH9K_HW_CAP_5GHZ)) == 0) {
+		ath_err(common, "both bands are disabled\n");
+		return -EINVAL;
+	}
 
 	if (AR_SREV_9485(ah) ||
 	    AR_SREV_9285(ah) ||