mac80211-ops.c

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/*-
 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
 * Copyright (c) 2004-2005 Atheros Communications, Inc.
 * Copyright (c) 2006 Devicescape Software, Inc.
 * Copyright (c) 2007 Jiri Slaby <[email protected]>
 * Copyright (c) 2007 Luis R. Rodriguez <[email protected]>
 * Copyright (c) 2010 Bruno Randolf <[email protected]>
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
 *    redistribution must be conditioned upon including a substantially
 *    similar Disclaimer requirement for further binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGES.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <net/mac80211.h>
#include <asm/unaligned.h>

#include "ath5k.h"
#include "base.h"
#include "reg.h"

/********************\
* Mac80211 functions *
\********************/

static void
ath5k_tx(struct ieee80211_hw *hw, struct ieee80211_tx_control *control,
     struct sk_buff *skb)
{
    struct ath5k_hw *ah = hw->priv;
    u16 qnum = skb_get_queue_mapping(skb);

    if (WARN_ON(qnum >= ah->ah_capabilities.cap_queues.q_tx_num)) {
        dev_kfree_skb_any(skb);
        return;
    }

    ath5k_tx_queue(hw, skb, &ah->txqs[qnum]);
}


static int
ath5k_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
{
    struct ath5k_hw *ah = hw->priv;
    int ret;
    struct ath5k_vif *avf = (void *)vif->drv_priv;

    mutex_lock(&ah->lock);

    if ((vif->type == NL80211_IFTYPE_AP ||
         vif->type == NL80211_IFTYPE_ADHOC)
        && (ah->num_ap_vifs + ah->num_adhoc_vifs) >= ATH_BCBUF) {
        ret = -ELNRNG;
        goto end;
    }

    /* Don't allow other interfaces if one ad-hoc is configured.
     * TODO: Fix the problems with ad-hoc and multiple other interfaces.
     * We would need to operate the HW in ad-hoc mode to allow TSF updates
     * for the IBSS, but this breaks with additional AP or STA interfaces
     * at the moment. */
    if (ah->num_adhoc_vifs ||
        (ah->nvifs && vif->type == NL80211_IFTYPE_ADHOC)) {
        ATH5K_ERR(ah, "Only one single ad-hoc interface is allowed.\n");
        ret = -ELNRNG;
        goto end;
    }

    switch (vif->type) {
    case NL80211_IFTYPE_AP:
    case NL80211_IFTYPE_STATION:
    case NL80211_IFTYPE_ADHOC:
    case NL80211_IFTYPE_MESH_POINT:
        avf->opmode = vif->type;
        break;
    default:
        ret = -EOPNOTSUPP;
        goto end;
    }

    ah->nvifs++;
    ATH5K_DBG(ah, ATH5K_DEBUG_MODE, "add interface mode %d\n", avf->opmode);

    /* Assign the vap/adhoc to a beacon xmit slot. */
    if ((avf->opmode == NL80211_IFTYPE_AP) ||
        (avf->opmode == NL80211_IFTYPE_ADHOC) ||
        (avf->opmode == NL80211_IFTYPE_MESH_POINT)) {
        int slot;

        WARN_ON(list_empty(&ah->bcbuf));
        avf->bbuf = list_first_entry(&ah->bcbuf, struct ath5k_buf,
                         list);
        list_del(&avf->bbuf->list);

        avf->bslot = 0;
        for (slot = 0; slot < ATH_BCBUF; slot++) {
            if (!ah->bslot[slot]) {
                avf->bslot = slot;
                break;
            }
        }
        BUG_ON(ah->bslot[avf->bslot] != NULL);
        ah->bslot[avf->bslot] = vif;
        if (avf->opmode == NL80211_IFTYPE_AP)
            ah->num_ap_vifs++;
        else if (avf->opmode == NL80211_IFTYPE_ADHOC)
            ah->num_adhoc_vifs++;
        else if (avf->opmode == NL80211_IFTYPE_MESH_POINT)
            ah->num_mesh_vifs++;
    }

    /* Any MAC address is fine, all others are included through the
     * filter.
     */
    ath5k_hw_set_lladdr(ah, vif->addr);

    ath5k_update_bssid_mask_and_opmode(ah, vif);
    ret = 0;
end:
    mutex_unlock(&ah->lock);
    return ret;
}


static void
ath5k_remove_interface(struct ieee80211_hw *hw,
               struct ieee80211_vif *vif)
{
    struct ath5k_hw *ah = hw->priv;
    struct ath5k_vif *avf = (void *)vif->drv_priv;
    unsigned int i;

    mutex_lock(&ah->lock);
    ah->nvifs--;

    if (avf->bbuf) {
        ath5k_txbuf_free_skb(ah, avf->bbuf);
        list_add_tail(&avf->bbuf->list, &ah->bcbuf);
        for (i = 0; i < ATH_BCBUF; i++) {
            if (ah->bslot[i] == vif) {
                ah->bslot[i] = NULL;
                break;
            }
        }
        avf->bbuf = NULL;
    }
    if (avf->opmode == NL80211_IFTYPE_AP)
        ah->num_ap_vifs--;
    else if (avf->opmode == NL80211_IFTYPE_ADHOC)
        ah->num_adhoc_vifs--;
    else if (avf->opmode == NL80211_IFTYPE_MESH_POINT)
        ah->num_mesh_vifs--;

    ath5k_update_bssid_mask_and_opmode(ah, NULL);
    mutex_unlock(&ah->lock);
}


/*
 * TODO: Phy disable/diversity etc
 */
static int
ath5k_config(struct ieee80211_hw *hw, u32 changed)
{
    struct ath5k_hw *ah = hw->priv;
    struct ieee80211_conf *conf = &hw->conf;
    int ret = 0;
    int i;

    mutex_lock(&ah->lock);

    if (changed & IEEE80211_CONF_CHANGE_CHANNEL) {
        ret = ath5k_chan_set(ah, conf->channel);
        if (ret < 0)
            goto unlock;
    }

    if ((changed & IEEE80211_CONF_CHANGE_POWER) &&
    (ah->ah_txpower.txp_requested != conf->power_level)) {
        ah->ah_txpower.txp_requested = conf->power_level;

        /* Half dB steps */
        ath5k_hw_set_txpower_limit(ah, (conf->power_level * 2));
    }

    if (changed & IEEE80211_CONF_CHANGE_RETRY_LIMITS) {
        ah->ah_retry_long = conf->long_frame_max_tx_count;
        ah->ah_retry_short = conf->short_frame_max_tx_count;

        for (i = 0; i < ah->ah_capabilities.cap_queues.q_tx_num; i++)
            ath5k_hw_set_tx_retry_limits(ah, i);
    }

    /* TODO:
     * 1) Move this on config_interface and handle each case
     * separately eg. when we have only one STA vif, use
     * AR5K_ANTMODE_SINGLE_AP
     *
     * 2) Allow the user to change antenna mode eg. when only
     * one antenna is present
     *
     * 3) Allow the user to set default/tx antenna when possible
     *
     * 4) Default mode should handle 90% of the cases, together
     * with fixed a/b and single AP modes we should be able to
     * handle 99%. Sectored modes are extreme cases and i still
     * haven't found a usage for them. If we decide to support them,
     * then we must allow the user to set how many tx antennas we
     * have available
     */
    ath5k_hw_set_antenna_mode(ah, ah->ah_ant_mode);

unlock:
    mutex_unlock(&ah->lock);
    return ret;
}


static void
ath5k_bss_info_changed(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
               struct ieee80211_bss_conf *bss_conf, u32 changes)
{
    struct ath5k_vif *avf = (void *)vif->drv_priv;
    struct ath5k_hw *ah = hw->priv;
    struct ath_common *common = ath5k_hw_common(ah);

    mutex_lock(&ah->lock);

    if (changes & BSS_CHANGED_BSSID) {
        /* Cache for later use during resets */
        memcpy(common->curbssid, bss_conf->bssid, ETH_ALEN);
        common->curaid = 0;
        ath5k_hw_set_bssid(ah);
        mmiowb();
    }

    if (changes & BSS_CHANGED_BEACON_INT)
        ah->bintval = bss_conf->beacon_int;

    if (changes & BSS_CHANGED_ERP_SLOT) {
        int slot_time;

        ah->ah_short_slot = bss_conf->use_short_slot;
        slot_time = ath5k_hw_get_default_slottime(ah) +
                3 * ah->ah_coverage_class;
        ath5k_hw_set_ifs_intervals(ah, slot_time);
    }

    if (changes & BSS_CHANGED_ASSOC) {
        avf->assoc = bss_conf->assoc;
        if (bss_conf->assoc)
            ah->assoc = bss_conf->assoc;
        else
            ah->assoc = ath5k_any_vif_assoc(ah);

        if (ah->opmode == NL80211_IFTYPE_STATION)
            ath5k_set_beacon_filter(hw, ah->assoc);
        ath5k_hw_set_ledstate(ah, ah->assoc ?
            AR5K_LED_ASSOC : AR5K_LED_INIT);
        if (bss_conf->assoc) {
            ATH5K_DBG(ah, ATH5K_DEBUG_ANY,
                  "Bss Info ASSOC %d, bssid: %pM\n",
                  bss_conf->aid, common->curbssid);
            common->curaid = bss_conf->aid;
            ath5k_hw_set_bssid(ah);
            /* Once ANI is available you would start it here */
        }
    }

    if (changes & BSS_CHANGED_BEACON) {
        spin_lock_bh(&ah->block);
        ath5k_beacon_update(hw, vif);
        spin_unlock_bh(&ah->block);
    }

    if (changes & BSS_CHANGED_BEACON_ENABLED)
        ah->enable_beacon = bss_conf->enable_beacon;

    if (changes & (BSS_CHANGED_BEACON | BSS_CHANGED_BEACON_ENABLED |
               BSS_CHANGED_BEACON_INT))
        ath5k_beacon_config(ah);

    mutex_unlock(&ah->lock);
}


static u64
ath5k_prepare_multicast(struct ieee80211_hw *hw,
            struct netdev_hw_addr_list *mc_list)
{
    u32 mfilt[2], val;
    u8 pos;
    struct netdev_hw_addr *ha;

    mfilt[0] = 0;
    mfilt[1] = 1;

    netdev_hw_addr_list_for_each(ha, mc_list) {
        /* calculate XOR of eight 6-bit values */
        val = get_unaligned_le32(ha->addr + 0);
        pos = (val >> 18) ^ (val >> 12) ^ (val >> 6) ^ val;
        val = get_unaligned_le32(ha->addr + 3);
        pos ^= (val >> 18) ^ (val >> 12) ^ (val >> 6) ^ val;
        pos &= 0x3f;
        mfilt[pos / 32] |= (1 << (pos % 32));
        /* XXX: we might be able to just do this instead,
        * but not sure, needs testing, if we do use this we'd
        * need to inform below not to reset the mcast */
        /* ath5k_hw_set_mcast_filterindex(ah,
         *      ha->addr[5]); */
    }

    return ((u64)(mfilt[1]) << 32) | mfilt[0];
}


/*
 * o always accept unicast, broadcast, and multicast traffic
 * o multicast traffic for all BSSIDs will be enabled if mac80211
 *   says it should be
 * o maintain current state of phy ofdm or phy cck error reception.
 *   If the hardware detects any of these type of errors then
 *   ath5k_hw_get_rx_filter() will pass to us the respective
 *   hardware filters to be able to receive these type of frames.
 * o probe request frames are accepted only when operating in
 *   hostap, adhoc, or monitor modes
 * o enable promiscuous mode according to the interface state
 * o accept beacons:
 *   - when operating in adhoc mode so the 802.11 layer creates
 *     node table entries for peers,
 *   - when operating in station mode for collecting rssi data when
 *     the station is otherwise quiet, or
 *   - when scanning
 */
static void
ath5k_configure_filter(struct ieee80211_hw *hw, unsigned int changed_flags,
               unsigned int *new_flags, u64 multicast)
{
#define SUPPORTED_FIF_FLAGS \
    (FIF_PROMISC_IN_BSS |  FIF_ALLMULTI | FIF_FCSFAIL | \
    FIF_PLCPFAIL | FIF_CONTROL | FIF_OTHER_BSS | \
    FIF_BCN_PRBRESP_PROMISC)

    struct ath5k_hw *ah = hw->priv;
    u32 mfilt[2], rfilt;
    struct ath5k_vif_iter_data iter_data; /* to count STA interfaces */

    mutex_lock(&ah->lock);

    mfilt[0] = multicast;
    mfilt[1] = multicast >> 32;

    /* Only deal with supported flags */
    changed_flags &= SUPPORTED_FIF_FLAGS;
    *new_flags &= SUPPORTED_FIF_FLAGS;

    /* If HW detects any phy or radar errors, leave those filters on.
     * Also, always enable Unicast, Broadcasts and Multicast
     * XXX: move unicast, bssid broadcasts and multicast to mac80211 */
    rfilt = (ath5k_hw_get_rx_filter(ah) & (AR5K_RX_FILTER_PHYERR)) |
        (AR5K_RX_FILTER_UCAST | AR5K_RX_FILTER_BCAST |
        AR5K_RX_FILTER_MCAST);

    if (changed_flags & (FIF_PROMISC_IN_BSS | FIF_OTHER_BSS)) {
        if (*new_flags & FIF_PROMISC_IN_BSS)
            __set_bit(ATH_STAT_PROMISC, ah->status);
        else
            __clear_bit(ATH_STAT_PROMISC, ah->status);
    }

    if (test_bit(ATH_STAT_PROMISC, ah->status))
        rfilt |= AR5K_RX_FILTER_PROM;

    /* Note, AR5K_RX_FILTER_MCAST is already enabled */
    if (*new_flags & FIF_ALLMULTI) {
        mfilt[0] =  ~0;
        mfilt[1] =  ~0;
    }

    /* This is the best we can do */
    if (*new_flags & (FIF_FCSFAIL | FIF_PLCPFAIL))
        rfilt |= AR5K_RX_FILTER_PHYERR;

    /* FIF_BCN_PRBRESP_PROMISC really means to enable beacons
    * and probes for any BSSID */
    if ((*new_flags & FIF_BCN_PRBRESP_PROMISC) || (ah->nvifs > 1))
        rfilt |= AR5K_RX_FILTER_BEACON;

    /* FIF_CONTROL doc says that if FIF_PROMISC_IN_BSS is not
     * set we should only pass on control frames for this
     * station. This needs testing. I believe right now this
     * enables *all* control frames, which is OK.. but
     * but we should see if we can improve on granularity */
    if (*new_flags & FIF_CONTROL)
        rfilt |= AR5K_RX_FILTER_CONTROL;

    /* Additional settings per mode -- this is per ath5k */

    /* XXX move these to mac80211, and add a beacon IFF flag to mac80211 */

    switch (ah->opmode) {
    case NL80211_IFTYPE_MESH_POINT:
        rfilt |= AR5K_RX_FILTER_CONTROL |
             AR5K_RX_FILTER_BEACON |
             AR5K_RX_FILTER_PROBEREQ |
             AR5K_RX_FILTER_PROM;
        break;
    case NL80211_IFTYPE_AP:
    case NL80211_IFTYPE_ADHOC:
        rfilt |= AR5K_RX_FILTER_PROBEREQ |
             AR5K_RX_FILTER_BEACON;
        break;
    case NL80211_IFTYPE_STATION:
        if (ah->assoc)
            rfilt |= AR5K_RX_FILTER_BEACON;
    default:
        break;
    }

    iter_data.hw_macaddr = NULL;
    iter_data.n_stas = 0;
    iter_data.need_set_hw_addr = false;
    ieee80211_iterate_active_interfaces_atomic(ah->hw, ath5k_vif_iter,
                           &iter_data);

    /* Set up RX Filter */
    if (iter_data.n_stas > 1) {
        /* If you have multiple STA interfaces connected to
         * different APs, ARPs are not received (most of the time?)
         * Enabling PROMISC appears to fix that problem.
         */
        rfilt |= AR5K_RX_FILTER_PROM;
    }

    /* Set filters */
    ath5k_hw_set_rx_filter(ah, rfilt);

    /* Set multicast bits */
    ath5k_hw_set_mcast_filter(ah, mfilt[0], mfilt[1]);
    /* Set the cached hw filter flags, this will later actually
     * be set in HW */
    ah->filter_flags = rfilt;

    mutex_unlock(&ah->lock);
}


static int
ath5k_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
          struct ieee80211_vif *vif, struct ieee80211_sta *sta,
          struct ieee80211_key_conf *key)
{
    struct ath5k_hw *ah = hw->priv;
    struct ath_common *common = ath5k_hw_common(ah);
    int ret = 0;

    if (ath5k_modparam_nohwcrypt)
        return -EOPNOTSUPP;

    if (key->flags & IEEE80211_KEY_FLAG_RX_MGMT)
        return -EOPNOTSUPP;

    if (vif->type == NL80211_IFTYPE_ADHOC &&
        (key->cipher == WLAN_CIPHER_SUITE_TKIP ||
         key->cipher == WLAN_CIPHER_SUITE_CCMP) &&
        !(key->flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
        /* don't program group keys when using IBSS_RSN */
        return -EOPNOTSUPP;
    }

    switch (key->cipher) {
    case WLAN_CIPHER_SUITE_WEP40:
    case WLAN_CIPHER_SUITE_WEP104:
    case WLAN_CIPHER_SUITE_TKIP:
        break;
    case WLAN_CIPHER_SUITE_CCMP:
        if (common->crypt_caps & ATH_CRYPT_CAP_CIPHER_AESCCM)
            break;
        return -EOPNOTSUPP;
    default:
        WARN_ON(1);
        return -EINVAL;
    }

    mutex_lock(&ah->lock);

    switch (cmd) {
    case SET_KEY:
        ret = ath_key_config(common, vif, sta, key);
        if (ret >= 0) {
            key->hw_key_idx = ret;
            /* push IV and Michael MIC generation to stack */
            key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
            if (key->cipher == WLAN_CIPHER_SUITE_TKIP)
                key->flags |= IEEE80211_KEY_FLAG_GENERATE_MMIC;
            if (key->cipher == WLAN_CIPHER_SUITE_CCMP)
                key->flags |= IEEE80211_KEY_FLAG_SW_MGMT_TX;
            ret = 0;
        }
        break;
    case DISABLE_KEY:
        ath_key_delete(common, key);
        break;
    default:
        ret = -EINVAL;
    }

    mmiowb();
    mutex_unlock(&ah->lock);
    return ret;
}


static void
ath5k_sw_scan_start(struct ieee80211_hw *hw)
{
    struct ath5k_hw *ah = hw->priv;
    if (!ah->assoc)
        ath5k_hw_set_ledstate(ah, AR5K_LED_SCAN);
}


static void
ath5k_sw_scan_complete(struct ieee80211_hw *hw)
{
    struct ath5k_hw *ah = hw->priv;
    ath5k_hw_set_ledstate(ah, ah->assoc ?
        AR5K_LED_ASSOC : AR5K_LED_INIT);
}


static int
ath5k_get_stats(struct ieee80211_hw *hw,
        struct ieee80211_low_level_stats *stats)
{
    struct ath5k_hw *ah = hw->priv;

    /* Force update */
    ath5k_hw_update_mib_counters(ah);

    stats->dot11ACKFailureCount = ah->stats.ack_fail;
    stats->dot11RTSFailureCount = ah->stats.rts_fail;
    stats->dot11RTSSuccessCount = ah->stats.rts_ok;
    stats->dot11FCSErrorCount = ah->stats.fcs_error;

    return 0;
}


static int
ath5k_conf_tx(struct ieee80211_hw *hw, struct ieee80211_vif *vif, u16 queue,
          const struct ieee80211_tx_queue_params *params)
{
    struct ath5k_hw *ah = hw->priv;
    struct ath5k_txq_info qi;
    int ret = 0;

    if (queue >= ah->ah_capabilities.cap_queues.q_tx_num)
        return 0;

    mutex_lock(&ah->lock);

    ath5k_hw_get_tx_queueprops(ah, queue, &qi);

    qi.tqi_aifs = params->aifs;
    qi.tqi_cw_min = params->cw_min;
    qi.tqi_cw_max = params->cw_max;
    qi.tqi_burst_time = params->txop * 32;

    ATH5K_DBG(ah, ATH5K_DEBUG_ANY,
          "Configure tx [queue %d],  "
          "aifs: %d, cw_min: %d, cw_max: %d, txop: %d\n",
          queue, params->aifs, params->cw_min,
          params->cw_max, params->txop);

    if (ath5k_hw_set_tx_queueprops(ah, queue, &qi)) {
        ATH5K_ERR(ah,
              "Unable to update hardware queue %u!\n", queue);
        ret = -EIO;
    } else
        ath5k_hw_reset_tx_queue(ah, queue);

    mutex_unlock(&ah->lock);

    return ret;
}


static u64
ath5k_get_tsf(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
{
    struct ath5k_hw *ah = hw->priv;

    return ath5k_hw_get_tsf64(ah);
}


static void
ath5k_set_tsf(struct ieee80211_hw *hw, struct ieee80211_vif *vif, u64 tsf)
{
    struct ath5k_hw *ah = hw->priv;

    ath5k_hw_set_tsf64(ah, tsf);
}


static void
ath5k_reset_tsf(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
{
    struct ath5k_hw *ah = hw->priv;

    /*
     * in IBSS mode we need to update the beacon timers too.
     * this will also reset the TSF if we call it with 0
     */
    if (ah->opmode == NL80211_IFTYPE_ADHOC)
        ath5k_beacon_update_timers(ah, 0);
    else
        ath5k_hw_reset_tsf(ah);
}


static int
ath5k_get_survey(struct ieee80211_hw *hw, int idx, struct survey_info *survey)
{
    struct ath5k_hw *ah = hw->priv;
    struct ieee80211_conf *conf = &hw->conf;
    struct ath_common *common = ath5k_hw_common(ah);
    struct ath_cycle_counters *cc = &common->cc_survey;
    unsigned int div = common->clockrate * 1000;

    if (idx != 0)
        return -ENOENT;

    spin_lock_bh(&common->cc_lock);
    ath_hw_cycle_counters_update(common);
    if (cc->cycles > 0) {
        ah->survey.channel_time += cc->cycles / div;
        ah->survey.channel_time_busy += cc->rx_busy / div;
        ah->survey.channel_time_rx += cc->rx_frame / div;
        ah->survey.channel_time_tx += cc->tx_frame / div;
    }
    memset(cc, 0, sizeof(*cc));
    spin_unlock_bh(&common->cc_lock);

    memcpy(survey, &ah->survey, sizeof(*survey));

    survey->channel = conf->channel;
    survey->noise = ah->ah_noise_floor;
    survey->filled = SURVEY_INFO_NOISE_DBM |
            SURVEY_INFO_CHANNEL_TIME |
            SURVEY_INFO_CHANNEL_TIME_BUSY |
            SURVEY_INFO_CHANNEL_TIME_RX |
            SURVEY_INFO_CHANNEL_TIME_TX;

    return 0;
}


static void
ath5k_set_coverage_class(struct ieee80211_hw *hw, u8 coverage_class)
{
    struct ath5k_hw *ah = hw->priv;

    mutex_lock(&ah->lock);
    ath5k_hw_set_coverage_class(ah, coverage_class);
    mutex_unlock(&ah->lock);
}


static int
ath5k_set_antenna(struct ieee80211_hw *hw, u32 tx_ant, u32 rx_ant)
{
    struct ath5k_hw *ah = hw->priv;

    if (tx_ant == 1 && rx_ant == 1)
        ath5k_hw_set_antenna_mode(ah, AR5K_ANTMODE_FIXED_A);
    else if (tx_ant == 2 && rx_ant == 2)
        ath5k_hw_set_antenna_mode(ah, AR5K_ANTMODE_FIXED_B);
    else if ((tx_ant & 3) == 3 && (rx_ant & 3) == 3)
        ath5k_hw_set_antenna_mode(ah, AR5K_ANTMODE_DEFAULT);
    else
        return -EINVAL;
    return 0;
}


static int
ath5k_get_antenna(struct ieee80211_hw *hw, u32 *tx_ant, u32 *rx_ant)
{
    struct ath5k_hw *ah = hw->priv;

    switch (ah->ah_ant_mode) {
    case AR5K_ANTMODE_FIXED_A:
        *tx_ant = 1; *rx_ant = 1; break;
    case AR5K_ANTMODE_FIXED_B:
        *tx_ant = 2; *rx_ant = 2; break;
    case AR5K_ANTMODE_DEFAULT:
        *tx_ant = 3; *rx_ant = 3; break;
    }
    return 0;
}


static void ath5k_get_ringparam(struct ieee80211_hw *hw,
                u32 *tx, u32 *tx_max, u32 *rx, u32 *rx_max)
{
    struct ath5k_hw *ah = hw->priv;

    *tx = ah->txqs[AR5K_TX_QUEUE_ID_DATA_MIN].txq_max;

    *tx_max = ATH5K_TXQ_LEN_MAX;
    *rx = *rx_max = ATH_RXBUF;
}


static int ath5k_set_ringparam(struct ieee80211_hw *hw, u32 tx, u32 rx)
{
    struct ath5k_hw *ah = hw->priv;
    u16 qnum;

    /* only support setting tx ring size for now */
    if (rx != ATH_RXBUF)
        return -EINVAL;

    /* restrict tx ring size min/max */
    if (!tx || tx > ATH5K_TXQ_LEN_MAX)
        return -EINVAL;

    for (qnum = 0; qnum < ARRAY_SIZE(ah->txqs); qnum++) {
        if (!ah->txqs[qnum].setup)
            continue;
        if (ah->txqs[qnum].qnum < AR5K_TX_QUEUE_ID_DATA_MIN ||
            ah->txqs[qnum].qnum > AR5K_TX_QUEUE_ID_DATA_MAX)
            continue;

        ah->txqs[qnum].txq_max = tx;
        if (ah->txqs[qnum].txq_len >= ah->txqs[qnum].txq_max)
            ieee80211_stop_queue(hw, ah->txqs[qnum].qnum);
    }

    return 0;
}


const struct ieee80211_ops ath5k_hw_ops = {
    .tx         = ath5k_tx,
    .start          = ath5k_start,
    .stop           = ath5k_stop,
    .add_interface      = ath5k_add_interface,
    /* .change_interface    = not implemented */
    .remove_interface   = ath5k_remove_interface,
    .config         = ath5k_config,
    .bss_info_changed   = ath5k_bss_info_changed,
    .prepare_multicast  = ath5k_prepare_multicast,
    .configure_filter   = ath5k_configure_filter,
    /* .set_tim     = not implemented */
    .set_key        = ath5k_set_key,
    /* .update_tkip_key = not implemented */
    /* .hw_scan     = not implemented */
    .sw_scan_start      = ath5k_sw_scan_start,
    .sw_scan_complete   = ath5k_sw_scan_complete,
    .get_stats      = ath5k_get_stats,
    /* .get_tkip_seq    = not implemented */
    /* .set_frag_threshold  = not implemented */
    /* .set_rts_threshold   = not implemented */
    /* .sta_add     = not implemented */
    /* .sta_remove      = not implemented */
    /* .sta_notify      = not implemented */
    .conf_tx        = ath5k_conf_tx,
    .get_tsf        = ath5k_get_tsf,
    .set_tsf        = ath5k_set_tsf,
    .reset_tsf      = ath5k_reset_tsf,
    /* .tx_last_beacon  = not implemented */
    /* .ampdu_action    = not needed */
    .get_survey     = ath5k_get_survey,
    .set_coverage_class = ath5k_set_coverage_class,
    /* .rfkill_poll     = not implemented */
    /* .flush       = not implemented */
    /* .channel_switch  = not implemented */
    /* .napi_poll       = not implemented */
    .set_antenna        = ath5k_set_antenna,
    .get_antenna        = ath5k_get_antenna,
    .set_ringparam      = ath5k_set_ringparam,
    .get_ringparam      = ath5k_get_ringparam,
};