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>

drivers/net/wireless/rt2x00/Kconfig

@@ -88,6 +88,9 @@ config RT2X00_LIB_USB
 config RT2X00_LIB
 	tristate
 
+config RT2X00_LIB_HT
+	boolean
+
 config RT2X00_LIB_FIRMWARE
 	boolean
 	select FW_LOADER

drivers/net/wireless/rt2x00/Makefile

@@ -8,6 +8,7 @@ rt2x00lib-$(CONFIG_RT2X00_LIB_CRYPTO)	+= rt2x00crypto.o
 rt2x00lib-$(CONFIG_RT2X00_LIB_RFKILL)	+= rt2x00rfkill.o
 rt2x00lib-$(CONFIG_RT2X00_LIB_FIRMWARE)	+= rt2x00firmware.o
 rt2x00lib-$(CONFIG_RT2X00_LIB_LEDS)	+= rt2x00leds.o
+rt2x00lib-$(CONFIG_RT2X00_LIB_HT)	+= rt2x00ht.o
 
 obj-$(CONFIG_RT2X00_LIB)		+= rt2x00lib.o
 obj-$(CONFIG_RT2X00_LIB_PCI)		+= rt2x00pci.o

drivers/net/wireless/rt2x00/rt2x00.h

@@ -366,6 +366,7 @@ static inline struct rt2x00_intf* vif_to_intf(struct ieee80211_vif *vif)
  *	for @tx_power_a, @tx_power_bg and @channels.
  * @channels: Device/chipset specific channel values (See &struct rf_channel).
  * @channels_info: Additional information for channels (See &struct channel_info).
+ * @ht: Driver HT Capabilities (See &ieee80211_sta_ht_cap).
  */
 struct hw_mode_spec {
 	unsigned int supported_bands;
@@ -379,6 +380,8 @@ struct hw_mode_spec {
 	unsigned int num_channels;
 	const struct rf_channel *channels;
 	const struct channel_info *channels_info;
+
+	struct ieee80211_sta_ht_cap ht;
 };
 
 /*
@@ -616,6 +619,7 @@ enum rt2x00_flags {
 	CONFIG_EXTERNAL_LNA_BG,
 	CONFIG_DOUBLE_ANTENNA,
 	CONFIG_DISABLE_LINK_TUNING,
+	CONFIG_CHANNEL_HT40,
 };
 
 /*
@@ -787,6 +791,13 @@ struct rt2x00_dev {
 	 */
 	u8 freq_offset;
 
+	/*
+	 * Calibration information (for rt2800usb & rt2800pci).
+	 * [0] -> BW20
+	 * [1] -> BW40
+	 */
+	u8 calibration[2];
+
 	/*
 	 * Low level statistics which will have
 	 * to be kept up to date while device is running.

drivers/net/wireless/rt2x00/rt2x00config.c

@@ -173,6 +173,11 @@ void rt2x00lib_config(struct rt2x00_dev *rt2x00dev,
 	libconf.conf = conf;
 
 	if (ieee80211_flags & IEEE80211_CONF_CHANGE_CHANNEL) {
+		if (conf_is_ht40(conf))
+			__set_bit(CONFIG_CHANNEL_HT40, &rt2x00dev->flags);
+		else
+			__clear_bit(CONFIG_CHANNEL_HT40, &rt2x00dev->flags);
+
 		memcpy(&libconf.rf,
 		       &rt2x00dev->spec.channels[conf->channel->hw_value],
 		       sizeof(libconf.rf));

drivers/net/wireless/rt2x00/rt2x00dev.c

@@ -323,19 +323,54 @@ void rt2x00lib_txdone(struct queue_entry *entry,
 }
 EXPORT_SYMBOL_GPL(rt2x00lib_txdone);
 
+static int rt2x00lib_rxdone_read_signal(struct rt2x00_dev *rt2x00dev,
+					struct rxdone_entry_desc *rxdesc)
+{
+	struct ieee80211_supported_band *sband;
+	const struct rt2x00_rate *rate;
+	unsigned int i;
+	int signal;
+	int type;
+
+	/*
+	 * For non-HT rates the MCS value needs to contain the
+	 * actually used rate modulation (CCK or OFDM).
+	 */
+	if (rxdesc->dev_flags & RXDONE_SIGNAL_MCS)
+		signal = RATE_MCS(rxdesc->rate_mode, rxdesc->signal);
+	else
+		signal = rxdesc->signal;
+
+	type = (rxdesc->dev_flags & RXDONE_SIGNAL_MASK);
+
+	sband = &rt2x00dev->bands[rt2x00dev->curr_band];
+	for (i = 0; i < sband->n_bitrates; i++) {
+		rate = rt2x00_get_rate(sband->bitrates[i].hw_value);
+
+		if (((type == RXDONE_SIGNAL_PLCP) &&
+		     (rate->plcp == signal)) ||
+		    ((type == RXDONE_SIGNAL_BITRATE) &&
+		      (rate->bitrate == signal)) ||
+		    ((type == RXDONE_SIGNAL_MCS) &&
+		      (rate->mcs == signal))) {
+			return i;
+		}
+	}
+
+	WARNING(rt2x00dev, "Frame received with unrecognized signal, "
+		"signal=0x%.4x, type=%d.\n", signal, type);
+	return 0;
+}
+
 void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev,
 		      struct queue_entry *entry)
 {
 	struct rxdone_entry_desc rxdesc;
 	struct sk_buff *skb;
 	struct ieee80211_rx_status *rx_status = &rt2x00dev->rx_status;
-	struct ieee80211_supported_band *sband;
-	const struct rt2x00_rate *rate;
 	unsigned int header_length;
 	bool l2pad;
-	unsigned int i;
-	int idx = -1;
-
+	int rate_idx;
 	/*
 	 * Allocate a new sk_buffer. If no new buffer available, drop the
 	 * received frame and reuse the existing buffer.
@@ -379,26 +414,17 @@ void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev,
 		rt2x00queue_payload_align(entry->skb, l2pad, header_length);
 
 	/*
-	 * Update RX statistics.
+	 * Check if the frame was received using HT. In that case,
+	 * the rate is the MCS index and should be passed to mac80211
+	 * directly. Otherwise we need to translate the signal to
+	 * the correct bitrate index.
 	 */
-	sband = &rt2x00dev->bands[rt2x00dev->curr_band];
-	for (i = 0; i < sband->n_bitrates; i++) {
-		rate = rt2x00_get_rate(sband->bitrates[i].hw_value);
-
-		if (((rxdesc.dev_flags & RXDONE_SIGNAL_PLCP) &&
-		     (rate->plcp == rxdesc.signal)) ||
-		    ((rxdesc.dev_flags & RXDONE_SIGNAL_BITRATE) &&
-		      (rate->bitrate == rxdesc.signal))) {
-			idx = i;
-			break;
-		}
-	}
-
-	if (idx < 0) {
-		WARNING(rt2x00dev, "Frame received with unrecognized signal,"
-			"signal=0x%.2x, type=%d.\n", rxdesc.signal,
-			(rxdesc.dev_flags & RXDONE_SIGNAL_MASK));
-		idx = 0;
+	if (rxdesc.rate_mode == RATE_MODE_CCK ||
+	    rxdesc.rate_mode == RATE_MODE_OFDM) {
+		rate_idx = rt2x00lib_rxdone_read_signal(rt2x00dev, &rxdesc);
+	} else {
+		rxdesc.flags |= RX_FLAG_HT;
+		rate_idx = rxdesc.signal;
 	}
 
 	/*
@@ -408,7 +434,7 @@ void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev,
 	rt2x00debug_update_crypto(rt2x00dev, &rxdesc);
 
 	rx_status->mactime = rxdesc.timestamp;
-	rx_status->rate_idx = idx;
+	rx_status->rate_idx = rate_idx;
 	rx_status->qual = rt2x00link_calculate_signal(rt2x00dev, rxdesc.rssi);
 	rx_status->signal = rxdesc.rssi;
 	rx_status->noise = rxdesc.noise;
@@ -443,72 +469,84 @@ const struct rt2x00_rate rt2x00_supported_rates[12] = {
 		.bitrate = 10,
 		.ratemask = BIT(0),
 		.plcp = 0x00,
+		.mcs = RATE_MCS(RATE_MODE_CCK, 0),
 	},
 	{
 		.flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
 		.bitrate = 20,
 		.ratemask = BIT(1),
 		.plcp = 0x01,
+		.mcs = RATE_MCS(RATE_MODE_CCK, 1),
 	},
 	{
 		.flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
 		.bitrate = 55,
 		.ratemask = BIT(2),
 		.plcp = 0x02,
+		.mcs = RATE_MCS(RATE_MODE_CCK, 2),
 	},
 	{
 		.flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
 		.bitrate = 110,
 		.ratemask = BIT(3),
 		.plcp = 0x03,
+		.mcs = RATE_MCS(RATE_MODE_CCK, 3),
 	},
 	{
 		.flags = DEV_RATE_OFDM,
 		.bitrate = 60,
 		.ratemask = BIT(4),
 		.plcp = 0x0b,
+		.mcs = RATE_MCS(RATE_MODE_OFDM, 0),
 	},
 	{
 		.flags = DEV_RATE_OFDM,
 		.bitrate = 90,
 		.ratemask = BIT(5),
 		.plcp = 0x0f,
+		.mcs = RATE_MCS(RATE_MODE_OFDM, 1),
 	},
 	{
 		.flags = DEV_RATE_OFDM,
 		.bitrate = 120,
 		.ratemask = BIT(6),
 		.plcp = 0x0a,
+		.mcs = RATE_MCS(RATE_MODE_OFDM, 2),
 	},
 	{
 		.flags = DEV_RATE_OFDM,
 		.bitrate = 180,
 		.ratemask = BIT(7),
 		.plcp = 0x0e,
+		.mcs = RATE_MCS(RATE_MODE_OFDM, 3),
 	},
 	{
 		.flags = DEV_RATE_OFDM,
 		.bitrate = 240,
 		.ratemask = BIT(8),
 		.plcp = 0x09,
+		.mcs = RATE_MCS(RATE_MODE_OFDM, 4),
 	},
 	{
 		.flags = DEV_RATE_OFDM,
 		.bitrate = 360,
 		.ratemask = BIT(9),
 		.plcp = 0x0d,
+		.mcs = RATE_MCS(RATE_MODE_OFDM, 5),
 	},
 	{
 		.flags = DEV_RATE_OFDM,
 		.bitrate = 480,
 		.ratemask = BIT(10),
 		.plcp = 0x08,
+		.mcs = RATE_MCS(RATE_MODE_OFDM, 6),
 	},
 	{
 		.flags = DEV_RATE_OFDM,
 		.bitrate = 540,
 		.ratemask = BIT(11),
 		.plcp = 0x0c,
+		.mcs = RATE_MCS(RATE_MODE_OFDM, 7),
 	},
 };
 
@@ -584,6 +622,8 @@ static int rt2x00lib_probe_hw_modes(struct rt2x00_dev *rt2x00dev,
 		rt2x00dev->bands[IEEE80211_BAND_2GHZ].bitrates = rates;
 		hw->wiphy->bands[IEEE80211_BAND_2GHZ] =
 		    &rt2x00dev->bands[IEEE80211_BAND_2GHZ];
+		memcpy(&rt2x00dev->bands[IEEE80211_BAND_2GHZ].ht_cap,
+		       &spec->ht, sizeof(spec->ht));
 	}
 
 	/*
@@ -600,6 +640,8 @@ static int rt2x00lib_probe_hw_modes(struct rt2x00_dev *rt2x00dev,
 		rt2x00dev->bands[IEEE80211_BAND_5GHZ].bitrates = &rates[4];
 		hw->wiphy->bands[IEEE80211_BAND_5GHZ] =
 		    &rt2x00dev->bands[IEEE80211_BAND_5GHZ];
+		memcpy(&rt2x00dev->bands[IEEE80211_BAND_5GHZ].ht_cap,
+		       &spec->ht, sizeof(spec->ht));
 	}
 
 	return 0;

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);
+}

drivers/net/wireless/rt2x00/rt2x00lib.h

@@ -48,6 +48,7 @@ struct rt2x00_rate {
 	unsigned short ratemask;
 
 	unsigned short plcp;
+	unsigned short mcs;
 };
 
 extern const struct rt2x00_rate rt2x00_supported_rates[12];
@@ -57,6 +58,14 @@ static inline const struct rt2x00_rate *rt2x00_get_rate(const u16 hw_value)
 	return &rt2x00_supported_rates[hw_value & 0xff];
 }
 
+#define RATE_MCS(__mode, __mcs) \
+	( (((__mode) & 0x00ff) << 8) | ((__mcs) & 0x00ff) )
+
+static inline int rt2x00_get_rate_mcs(const u16 mcs_value)
+{
+	return (mcs_value & 0x00ff);
+}
+
 /*
  * Radio control handlers.
  */
@@ -359,6 +368,21 @@ static inline void rt2x00crypto_rx_insert_iv(struct sk_buff *skb, bool l2pad,
 }
 #endif /* CONFIG_RT2X00_LIB_CRYPTO */
 
+/*
+ * HT handlers.
+ */
+#ifdef CONFIG_RT2X00_LIB_HT
+void rt2x00ht_create_tx_descriptor(struct queue_entry *entry,
+				   struct txentry_desc *txdesc,
+				   const struct rt2x00_rate *hwrate);
+#else
+static inline void rt2x00ht_create_tx_descriptor(struct queue_entry *entry,
+						 struct txentry_desc *txdesc,
+						 const struct rt2x00_rate *hwrate)
+{
+}
+#endif /* CONFIG_RT2X00_LIB_HT */
+
 /*
  * RFkill handlers.
  */