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

/*
 * Copyright (c) 2009-2011 Atheros Communications Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * Module for common driver code between ath9k and ath9k_htc
 */

#include <linux/kernel.h>
#include <linux/module.h>

#include "common.h"

MODULE_AUTHOR("Atheros Communications");
MODULE_DESCRIPTION("Shared library for Atheros wireless 802.11n LAN cards.");
MODULE_LICENSE("Dual BSD/GPL");

int ath9k_cmn_process_rate(struct ath_common *common,
			   struct ieee80211_hw *hw,
			   struct ath_rx_status *rx_stats,
			   struct ieee80211_rx_status *rxs)
{
	struct ieee80211_supported_band *sband;
	enum ieee80211_band band;
	unsigned int i = 0;
	struct ath_hw *ah = common->ah;

	band = ah->curchan->chan->band;
	sband = hw->wiphy->bands[band];

	if (IS_CHAN_QUARTER_RATE(ah->curchan))
		rxs->flag |= RX_FLAG_5MHZ;
	else if (IS_CHAN_HALF_RATE(ah->curchan))
		rxs->flag |= RX_FLAG_10MHZ;

	if (rx_stats->rs_rate & 0x80) {
		/* HT rate */
		rxs->flag |= RX_FLAG_HT;
		rxs->flag |= rx_stats->flag;
		rxs->rate_idx = rx_stats->rs_rate & 0x7f;
		return 0;
	}

	for (i = 0; i < sband->n_bitrates; i++) {
		if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
			rxs->rate_idx = i;
			return 0;
		}
		if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
			rxs->flag |= RX_FLAG_SHORTPRE;
			rxs->rate_idx = i;
			return 0;
		}
	}

	return -EINVAL;
}
EXPORT_SYMBOL(ath9k_cmn_process_rate);

void ath9k_cmn_process_rssi(struct ath_common *common,
			    struct ieee80211_hw *hw,
			    struct ath_rx_status *rx_stats,
			    struct ieee80211_rx_status *rxs)
{
	struct ath_hw *ah = common->ah;
	int last_rssi;
	int rssi = rx_stats->rs_rssi;
	int i, j;

	/*
	 * RSSI is not available for subframes in an A-MPDU.
	 */
	if (rx_stats->rs_moreaggr) {
		rxs->flag |= RX_FLAG_NO_SIGNAL_VAL;
		return;
	}

	/*
	 * Check if the RSSI for the last subframe in an A-MPDU
	 * or an unaggregated frame is valid.
	 */
	if (rx_stats->rs_rssi == ATH9K_RSSI_BAD) {
		rxs->flag |= RX_FLAG_NO_SIGNAL_VAL;
		return;
	}

	for (i = 0, j = 0; i < ARRAY_SIZE(rx_stats->rs_rssi_ctl); i++) {
		s8 rssi;

		if (!(ah->rxchainmask & BIT(i)))
			continue;

		rssi = rx_stats->rs_rssi_ctl[i];
		if (rssi != ATH9K_RSSI_BAD) {
		    rxs->chains |= BIT(j);
		    rxs->chain_signal[j] = ah->noise + rssi;
		}
		j++;
	}

	/*
	 * Update Beacon RSSI, this is used by ANI.
	 */
	if (rx_stats->is_mybeacon &&
	    ((ah->opmode == NL80211_IFTYPE_STATION) ||
	     (ah->opmode == NL80211_IFTYPE_ADHOC))) {
		ATH_RSSI_LPF(common->last_rssi, rx_stats->rs_rssi);
		last_rssi = common->last_rssi;

		if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
			rssi = ATH_EP_RND(last_rssi, ATH_RSSI_EP_MULTIPLIER);
		if (rssi < 0)
			rssi = 0;

		ah->stats.avgbrssi = rssi;
	}

	rxs->signal = ah->noise + rx_stats->rs_rssi;
}
EXPORT_SYMBOL(ath9k_cmn_process_rssi);

int ath9k_cmn_get_hw_crypto_keytype(struct sk_buff *skb)
{
	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);

	if (tx_info->control.hw_key) {
		switch (tx_info->control.hw_key->cipher) {
		case WLAN_CIPHER_SUITE_WEP40:
		case WLAN_CIPHER_SUITE_WEP104:
			return ATH9K_KEY_TYPE_WEP;
		case WLAN_CIPHER_SUITE_TKIP:
			return ATH9K_KEY_TYPE_TKIP;
		case WLAN_CIPHER_SUITE_CCMP:
			return ATH9K_KEY_TYPE_AES;
		default:
			break;
		}
	}

	return ATH9K_KEY_TYPE_CLEAR;
}
EXPORT_SYMBOL(ath9k_cmn_get_hw_crypto_keytype);

/*
 * Update internal channel flags.
 */
static void ath9k_cmn_update_ichannel(struct ath9k_channel *ichan,
				      struct cfg80211_chan_def *chandef)
{
	struct ieee80211_channel *chan = chandef->chan;
	u16 flags = 0;

	ichan->channel = chan->center_freq;
	ichan->chan = chan;

	if (chan->band == IEEE80211_BAND_5GHZ)
		flags |= CHANNEL_5GHZ;

	switch (chandef->width) {
	case NL80211_CHAN_WIDTH_5:
		flags |= CHANNEL_QUARTER;
		break;
	case NL80211_CHAN_WIDTH_10:
		flags |= CHANNEL_HALF;
		break;
	case NL80211_CHAN_WIDTH_20_NOHT:
		break;
	case NL80211_CHAN_WIDTH_20:
		flags |= CHANNEL_HT;
		break;
	case NL80211_CHAN_WIDTH_40:
		if (chandef->center_freq1 > chandef->chan->center_freq)
			flags |= CHANNEL_HT40PLUS | CHANNEL_HT;
		else
			flags |= CHANNEL_HT40MINUS | CHANNEL_HT;
		break;
	default:
		WARN_ON(1);
	}

	ichan->channelFlags = flags;
}

/*
 * Get the internal channel reference.
 */
struct ath9k_channel *ath9k_cmn_get_channel(struct ieee80211_hw *hw,
					    struct ath_hw *ah,
					    struct cfg80211_chan_def *chandef)
{
	struct ieee80211_channel *curchan = chandef->chan;
	struct ath9k_channel *channel;

	channel = &ah->channels[curchan->hw_value];
	ath9k_cmn_update_ichannel(channel, chandef);

	return channel;
}
EXPORT_SYMBOL(ath9k_cmn_get_channel);

int ath9k_cmn_count_streams(unsigned int chainmask, int max)
{
	int streams = 0;

	do {
		if (++streams == max)
			break;
	} while ((chainmask = chainmask & (chainmask - 1)));

	return streams;
}
EXPORT_SYMBOL(ath9k_cmn_count_streams);

void ath9k_cmn_update_txpow(struct ath_hw *ah, u16 cur_txpow,
			    u16 new_txpow, u16 *txpower)
{
	struct ath_regulatory *reg = ath9k_hw_regulatory(ah);

	if (reg->power_limit != new_txpow) {
		ath9k_hw_set_txpowerlimit(ah, new_txpow, false);
		/* read back in case value is clamped */
		*txpower = reg->max_power_level;
	}
}
EXPORT_SYMBOL(ath9k_cmn_update_txpow);

void ath9k_cmn_init_crypto(struct ath_hw *ah)
{
	struct ath_common *common = ath9k_hw_common(ah);
	int i = 0;

	/* Get the hardware key cache size. */
	common->keymax = AR_KEYTABLE_SIZE;

	/*
	 * Check whether the separate key cache entries
	 * are required to handle both tx+rx MIC keys.
	 * With split mic keys the number of stations is limited
	 * to 27 otherwise 59.
	 */
	if (ah->misc_mode & AR_PCU_MIC_NEW_LOC_ENA)
		common->crypt_caps |= ATH_CRYPT_CAP_MIC_COMBINED;

	/*
	 * Reset the key cache since some parts do not
	 * reset the contents on initial power up.
	 */
	for (i = 0; i < common->keymax; i++)
		ath_hw_keyreset(common, (u16) i);
}
EXPORT_SYMBOL(ath9k_cmn_init_crypto);

static int __init ath9k_cmn_init(void)
{
	return 0;
}
module_init(ath9k_cmn_init);

static void __exit ath9k_cmn_exit(void)
{
	return;
}
module_exit(ath9k_cmn_exit);