rt2x00: Implement support for 802.11n

Extend rt2x00lib capabilities to support 802.11n,
it still lacks aggregation support, but that can
be added in the future.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00ht.c b/drivers/net/wireless/rt2x00/rt2x00ht.c
new file mode 100644
index 0000000..e3cec83
--- /dev/null
+++ b/drivers/net/wireless/rt2x00/rt2x00ht.c
@@ -0,0 +1,69 @@
+/*
+	Copyright (C) 2004 - 2009 rt2x00 SourceForge Project
+	<http://rt2x00.serialmonkey.com>
+
+	This program is free software; you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation; either version 2 of the License, or
+	(at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to the
+	Free Software Foundation, Inc.,
+	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+/*
+	Module: rt2x00lib
+	Abstract: rt2x00 HT specific routines.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "rt2x00.h"
+#include "rt2x00lib.h"
+
+void rt2x00ht_create_tx_descriptor(struct queue_entry *entry,
+				   struct txentry_desc *txdesc,
+				   const struct rt2x00_rate *hwrate)
+{
+	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
+	struct ieee80211_tx_rate *txrate = &tx_info->control.rates[0];
+
+	if (tx_info->control.sta)
+		txdesc->mpdu_density =
+		    tx_info->control.sta->ht_cap.ampdu_density;
+	else
+		txdesc->mpdu_density = 0;
+
+	txdesc->ba_size = 7;	/* FIXME: What value is needed? */
+	txdesc->stbc = 0;	/* FIXME: What value is needed? */
+
+	txdesc->mcs = rt2x00_get_rate_mcs(hwrate->mcs);
+	if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
+		txdesc->mcs |= 0x08;
+
+	/*
+	 * Convert flags
+	 */
+	if (tx_info->flags & IEEE80211_TX_CTL_AMPDU)
+		__set_bit(ENTRY_TXD_HT_AMPDU, &txdesc->flags);
+
+	/*
+	 * Determine HT Mix/Greenfield rate mode
+	 */
+	if (txrate->flags & IEEE80211_TX_RC_MCS)
+		txdesc->rate_mode = RATE_MODE_HT_MIX;
+	if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
+		txdesc->rate_mode = RATE_MODE_HT_GREENFIELD;
+	if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
+		__set_bit(ENTRY_TXD_HT_BW_40, &txdesc->flags);
+	if (txrate->flags & IEEE80211_TX_RC_SHORT_GI)
+		__set_bit(ENTRY_TXD_HT_SHORT_GI, &txdesc->flags);
+}