iwlwifi: legacy tx_cmd_protection function

Legacy (4965 and 3945) devices has different tx_cmd_protection routine.
Move to iwl-legacy.c

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-legacy.c b/drivers/net/wireless/iwlwifi/iwl-legacy.c
index f49e500..10d9c42 100644
--- a/drivers/net/wireless/iwlwifi/iwl-legacy.c
+++ b/drivers/net/wireless/iwlwifi/iwl-legacy.c
@@ -620,3 +620,37 @@
 	return IRQ_NONE;
 }
 EXPORT_SYMBOL(iwl_isr_legacy);
+
+/*
+ *  iwl_legacy_tx_cmd_protection: Set rts/cts. 3945 and 4965 only share this
+ *  function.
+ */
+void iwl_legacy_tx_cmd_protection(struct iwl_priv *priv,
+			       struct ieee80211_tx_info *info,
+			       __le16 fc, __le32 *tx_flags)
+{
+	if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) {
+		*tx_flags |= TX_CMD_FLG_RTS_MSK;
+		*tx_flags &= ~TX_CMD_FLG_CTS_MSK;
+		*tx_flags |= TX_CMD_FLG_FULL_TXOP_PROT_MSK;
+
+		if (!ieee80211_is_mgmt(fc))
+			return;
+
+		switch (fc & cpu_to_le16(IEEE80211_FCTL_STYPE)) {
+		case cpu_to_le16(IEEE80211_STYPE_AUTH):
+		case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
+		case cpu_to_le16(IEEE80211_STYPE_ASSOC_REQ):
+		case cpu_to_le16(IEEE80211_STYPE_REASSOC_REQ):
+			*tx_flags &= ~TX_CMD_FLG_RTS_MSK;
+			*tx_flags |= TX_CMD_FLG_CTS_MSK;
+			break;
+		}
+	} else if (info->control.rates[0].flags &
+		   IEEE80211_TX_RC_USE_CTS_PROTECT) {
+		*tx_flags &= ~TX_CMD_FLG_RTS_MSK;
+		*tx_flags |= TX_CMD_FLG_CTS_MSK;
+		*tx_flags |= TX_CMD_FLG_FULL_TXOP_PROT_MSK;
+	}
+}
+EXPORT_SYMBOL(iwl_legacy_tx_cmd_protection);