main.c

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/*
 * mac80211 glue code for mac80211 Prism54 drivers
 *
 * Copyright (c) 2006, Michael Wu <[email protected]>
 * Copyright (c) 2007-2009, Christian Lamparter <[email protected]>
 * Copyright 2008, Johannes Berg <[email protected]>
 *
 * Based on:
 * - the islsm (softmac prism54) driver, which is:
 *   Copyright 2004-2006 Jean-Baptiste Note <[email protected]>, et al.
 * - stlc45xx driver
 *   Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies).
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/firmware.h>
#include <linux/etherdevice.h>
#include <linux/module.h>

#include <net/mac80211.h>

#include "p54.h"
#include "lmac.h"

static bool modparam_nohwcrypt;
module_param_named(nohwcrypt, modparam_nohwcrypt, bool, S_IRUGO);
MODULE_PARM_DESC(nohwcrypt, "Disable hardware encryption.");
MODULE_AUTHOR("Michael Wu <[email protected]>");
MODULE_DESCRIPTION("Softmac Prism54 common code");
MODULE_LICENSE("GPL");
MODULE_ALIAS("prism54common");

static int p54_sta_add_remove(struct ieee80211_hw *hw,
                  struct ieee80211_vif *vif,
                  struct ieee80211_sta *sta)
{
    struct p54_common *priv = hw->priv;

    /*
     * Notify the firmware that we don't want or we don't
     * need to buffer frames for this station anymore.
     */

    p54_sta_unlock(priv, sta->addr);

    return 0;
}

static void p54_sta_notify(struct ieee80211_hw *dev, struct ieee80211_vif *vif,
                  enum sta_notify_cmd notify_cmd,
                  struct ieee80211_sta *sta)
{
    struct p54_common *priv = dev->priv;

    switch (notify_cmd) {
    case STA_NOTIFY_AWAKE:
        /* update the firmware's filter table */
        p54_sta_unlock(priv, sta->addr);
        break;
    default:
        break;
    }
}

static int p54_set_tim(struct ieee80211_hw *dev, struct ieee80211_sta *sta,
            bool set)
{
    struct p54_common *priv = dev->priv;

    return p54_update_beacon_tim(priv, sta->aid, set);
}

u8 *p54_find_ie(struct sk_buff *skb, u8 ie)
{
    struct ieee80211_mgmt *mgmt = (void *)skb->data;
    u8 *pos, *end;

    if (skb->len <= sizeof(mgmt))
        return NULL;

    pos = (u8 *)mgmt->u.beacon.variable;
    end = skb->data + skb->len;
    while (pos < end) {
        if (pos + 2 + pos[1] > end)
            return NULL;

        if (pos[0] == ie)
            return pos;

        pos += 2 + pos[1];
    }
    return NULL;
}

static int p54_beacon_format_ie_tim(struct sk_buff *skb)
{
    /*
     * the good excuse for this mess is ... the firmware.
     * The dummy TIM MUST be at the end of the beacon frame,
     * because it'll be overwritten!
     */
    u8 *tim;
    u8 dtim_len;
    u8 dtim_period;
    u8 *next;

    tim = p54_find_ie(skb, WLAN_EID_TIM);
    if (!tim)
        return 0;

    dtim_len = tim[1];
    dtim_period = tim[3];
    next = tim + 2 + dtim_len;

    if (dtim_len < 3)
        return -EINVAL;

    memmove(tim, next, skb_tail_pointer(skb) - next);
    tim = skb_tail_pointer(skb) - (dtim_len + 2);

    /* add the dummy at the end */
    tim[0] = WLAN_EID_TIM;
    tim[1] = 3;
    tim[2] = 0;
    tim[3] = dtim_period;
    tim[4] = 0;

    if (dtim_len > 3)
        skb_trim(skb, skb->len - (dtim_len - 3));

    return 0;
}

static int p54_beacon_update(struct p54_common *priv,
            struct ieee80211_vif *vif)
{
    struct ieee80211_tx_control control = { };
    struct sk_buff *beacon;
    int ret;

    beacon = ieee80211_beacon_get(priv->hw, vif);
    if (!beacon)
        return -ENOMEM;
    ret = p54_beacon_format_ie_tim(beacon);
    if (ret)
        return ret;

    /*
     * During operation, the firmware takes care of beaconing.
     * The driver only needs to upload a new beacon template, once
     * the template was changed by the stack or userspace.
     *
     * LMAC API 3.2.2 also specifies that the driver does not need
     * to cancel the old beacon template by hand, instead the firmware
     * will release the previous one through the feedback mechanism.
     */
    p54_tx_80211(priv->hw, &control, beacon);
    priv->tsf_high32 = 0;
    priv->tsf_low32 = 0;

    return 0;
}

static int p54_start(struct ieee80211_hw *dev)
{
    struct p54_common *priv = dev->priv;
    int err;

    mutex_lock(&priv->conf_mutex);
    err = priv->open(dev);
    if (err)
        goto out;
    P54_SET_QUEUE(priv->qos_params[0], 0x0002, 0x0003, 0x0007, 47);
    P54_SET_QUEUE(priv->qos_params[1], 0x0002, 0x0007, 0x000f, 94);
    P54_SET_QUEUE(priv->qos_params[2], 0x0003, 0x000f, 0x03ff, 0);
    P54_SET_QUEUE(priv->qos_params[3], 0x0007, 0x000f, 0x03ff, 0);
    err = p54_set_edcf(priv);
    if (err)
        goto out;

    memset(priv->bssid, ~0, ETH_ALEN);
    priv->mode = NL80211_IFTYPE_MONITOR;
    err = p54_setup_mac(priv);
    if (err) {
        priv->mode = NL80211_IFTYPE_UNSPECIFIED;
        goto out;
    }

    ieee80211_queue_delayed_work(dev, &priv->work, 0);

    priv->softled_state = 0;
    err = p54_set_leds(priv);

out:
    mutex_unlock(&priv->conf_mutex);
    return err;
}

static void p54_stop(struct ieee80211_hw *dev)
{
    struct p54_common *priv = dev->priv;
    int i;

    priv->mode = NL80211_IFTYPE_UNSPECIFIED;
    priv->softled_state = 0;
    cancel_delayed_work_sync(&priv->work);
    mutex_lock(&priv->conf_mutex);
    p54_set_leds(priv);
    priv->stop(dev);
    skb_queue_purge(&priv->tx_pending);
    skb_queue_purge(&priv->tx_queue);
    for (i = 0; i < P54_QUEUE_NUM; i++) {
        priv->tx_stats[i].count = 0;
        priv->tx_stats[i].len = 0;
    }

    priv->beacon_req_id = cpu_to_le32(0);
    priv->tsf_high32 = priv->tsf_low32 = 0;
    mutex_unlock(&priv->conf_mutex);
}

static int p54_add_interface(struct ieee80211_hw *dev,
                 struct ieee80211_vif *vif)
{
    struct p54_common *priv = dev->priv;
    int err;

    vif->driver_flags |= IEEE80211_VIF_BEACON_FILTER;

    mutex_lock(&priv->conf_mutex);
    if (priv->mode != NL80211_IFTYPE_MONITOR) {
        mutex_unlock(&priv->conf_mutex);
        return -EOPNOTSUPP;
    }

    priv->vif = vif;

    switch (vif->type) {
    case NL80211_IFTYPE_STATION:
    case NL80211_IFTYPE_ADHOC:
    case NL80211_IFTYPE_AP:
    case NL80211_IFTYPE_MESH_POINT:
        priv->mode = vif->type;
        break;
    default:
        mutex_unlock(&priv->conf_mutex);
        return -EOPNOTSUPP;
    }

    memcpy(priv->mac_addr, vif->addr, ETH_ALEN);
    err = p54_setup_mac(priv);
    mutex_unlock(&priv->conf_mutex);
    return err;
}

static void p54_remove_interface(struct ieee80211_hw *dev,
                 struct ieee80211_vif *vif)
{
    struct p54_common *priv = dev->priv;

    mutex_lock(&priv->conf_mutex);
    priv->vif = NULL;

    /*
     * LMAC API 3.2.2 states that any active beacon template must be
     * canceled by the driver before attempting a mode transition.
     */
    if (le32_to_cpu(priv->beacon_req_id) != 0) {
        p54_tx_cancel(priv, priv->beacon_req_id);
        wait_for_completion_interruptible_timeout(&priv->beacon_comp, HZ);
    }
    priv->mode = NL80211_IFTYPE_MONITOR;
    memset(priv->mac_addr, 0, ETH_ALEN);
    memset(priv->bssid, 0, ETH_ALEN);
    p54_setup_mac(priv);
    mutex_unlock(&priv->conf_mutex);
}

static int p54_wait_for_stats(struct ieee80211_hw *dev)
{
    struct p54_common *priv = dev->priv;
    int ret;

    priv->update_stats = true;
    ret = p54_fetch_statistics(priv);
    if (ret)
        return ret;

    ret = wait_for_completion_interruptible_timeout(&priv->stat_comp, HZ);
    if (ret == 0)
        return -ETIMEDOUT;

    return 0;
}

static void p54_reset_stats(struct p54_common *priv)
{
    struct ieee80211_channel *chan = priv->curchan;

    if (chan) {
        struct survey_info *info = &priv->survey[chan->hw_value];

        /* only reset channel statistics, don't touch .filled, etc. */
        info->channel_time = 0;
        info->channel_time_busy = 0;
        info->channel_time_tx = 0;
    }

    priv->update_stats = true;
    priv->survey_raw.active = 0;
    priv->survey_raw.cca = 0;
    priv->survey_raw.tx = 0;
}

static int p54_config(struct ieee80211_hw *dev, u32 changed)
{
    int ret = 0;
    struct p54_common *priv = dev->priv;
    struct ieee80211_conf *conf = &dev->conf;

    mutex_lock(&priv->conf_mutex);
    if (changed & IEEE80211_CONF_CHANGE_POWER)
        priv->output_power = conf->power_level << 2;
    if (changed & IEEE80211_CONF_CHANGE_CHANNEL) {
        struct ieee80211_channel *oldchan;
        WARN_ON(p54_wait_for_stats(dev));
        oldchan = priv->curchan;
        priv->curchan = NULL;
        ret = p54_scan(priv, P54_SCAN_EXIT, 0);
        if (ret) {
            priv->curchan = oldchan;
            goto out;
        }
        /*
         * TODO: Use the LM_SCAN_TRAP to determine the current
         * operating channel.
         */
        priv->curchan = priv->hw->conf.channel;
        p54_reset_stats(priv);
        WARN_ON(p54_fetch_statistics(priv));
    }
    if (changed & IEEE80211_CONF_CHANGE_PS) {
        WARN_ON(p54_wait_for_stats(dev));
        ret = p54_set_ps(priv);
        if (ret)
            goto out;
        WARN_ON(p54_wait_for_stats(dev));
    }
    if (changed & IEEE80211_CONF_CHANGE_IDLE) {
        WARN_ON(p54_wait_for_stats(dev));
        ret = p54_setup_mac(priv);
        if (ret)
            goto out;
        WARN_ON(p54_wait_for_stats(dev));
    }

out:
    mutex_unlock(&priv->conf_mutex);
    return ret;
}

static u64 p54_prepare_multicast(struct ieee80211_hw *dev,
                 struct netdev_hw_addr_list *mc_list)
{
    struct p54_common *priv = dev->priv;
    struct netdev_hw_addr *ha;
    int i;

    BUILD_BUG_ON(ARRAY_SIZE(priv->mc_maclist) !=
        ARRAY_SIZE(((struct p54_group_address_table *)NULL)->mac_list));
    /*
     * The first entry is reserved for the global broadcast MAC.
     * Otherwise the firmware will drop it and ARP will no longer work.
     */
    i = 1;
    priv->mc_maclist_num = netdev_hw_addr_list_count(mc_list) + i;
    netdev_hw_addr_list_for_each(ha, mc_list) {
        memcpy(&priv->mc_maclist[i], ha->addr, ETH_ALEN);
        i++;
        if (i >= ARRAY_SIZE(priv->mc_maclist))
            break;
    }

    return 1; /* update */
}

static void p54_configure_filter(struct ieee80211_hw *dev,
                 unsigned int changed_flags,
                 unsigned int *total_flags,
                 u64 multicast)
{
    struct p54_common *priv = dev->priv;

    *total_flags &= FIF_PROMISC_IN_BSS |
            FIF_ALLMULTI |
            FIF_OTHER_BSS;

    priv->filter_flags = *total_flags;

    if (changed_flags & (FIF_PROMISC_IN_BSS | FIF_OTHER_BSS))
        p54_setup_mac(priv);

    if (changed_flags & FIF_ALLMULTI || multicast)
        p54_set_groupfilter(priv);
}

static int p54_conf_tx(struct ieee80211_hw *dev,
               struct ieee80211_vif *vif, u16 queue,
               const struct ieee80211_tx_queue_params *params)
{
    struct p54_common *priv = dev->priv;
    int ret;

    mutex_lock(&priv->conf_mutex);
    if (queue < dev->queues) {
        P54_SET_QUEUE(priv->qos_params[queue], params->aifs,
            params->cw_min, params->cw_max, params->txop);
        ret = p54_set_edcf(priv);
    } else
        ret = -EINVAL;
    mutex_unlock(&priv->conf_mutex);
    return ret;
}

static void p54_work(struct work_struct *work)
{
    struct p54_common *priv = container_of(work, struct p54_common,
                           work.work);

    if (unlikely(priv->mode == NL80211_IFTYPE_UNSPECIFIED))
        return ;

    /*
     * TODO: walk through tx_queue and do the following tasks
     *  1. initiate bursts.
     *      2. cancel stuck frames / reset the device if necessary.
     */

    mutex_lock(&priv->conf_mutex);
    WARN_ON_ONCE(p54_fetch_statistics(priv));
    mutex_unlock(&priv->conf_mutex);
}

static int p54_get_stats(struct ieee80211_hw *dev,
             struct ieee80211_low_level_stats *stats)
{
    struct p54_common *priv = dev->priv;

    memcpy(stats, &priv->stats, sizeof(*stats));
    return 0;
}

static void p54_bss_info_changed(struct ieee80211_hw *dev,
                 struct ieee80211_vif *vif,
                 struct ieee80211_bss_conf *info,
                 u32 changed)
{
    struct p54_common *priv = dev->priv;

    mutex_lock(&priv->conf_mutex);
    if (changed & BSS_CHANGED_BSSID) {
        memcpy(priv->bssid, info->bssid, ETH_ALEN);
        p54_setup_mac(priv);
    }

    if (changed & BSS_CHANGED_BEACON) {
        p54_scan(priv, P54_SCAN_EXIT, 0);
        p54_setup_mac(priv);
        p54_beacon_update(priv, vif);
        p54_set_edcf(priv);
    }

    if (changed & (BSS_CHANGED_ERP_SLOT | BSS_CHANGED_BEACON)) {
        priv->use_short_slot = info->use_short_slot;
        p54_set_edcf(priv);
    }
    if (changed & BSS_CHANGED_BASIC_RATES) {
        if (dev->conf.channel->band == IEEE80211_BAND_5GHZ)
            priv->basic_rate_mask = (info->basic_rates << 4);
        else
            priv->basic_rate_mask = info->basic_rates;
        p54_setup_mac(priv);
        if (priv->fw_var >= 0x500)
            p54_scan(priv, P54_SCAN_EXIT, 0);
    }
    if (changed & BSS_CHANGED_ASSOC) {
        if (info->assoc) {
            priv->aid = info->aid;
            priv->wakeup_timer = info->beacon_int *
                         info->dtim_period * 5;
            p54_setup_mac(priv);
        } else {
            priv->wakeup_timer = 500;
            priv->aid = 0;
        }
    }

    mutex_unlock(&priv->conf_mutex);
}

static int p54_set_key(struct ieee80211_hw *dev, enum set_key_cmd cmd,
               struct ieee80211_vif *vif, struct ieee80211_sta *sta,
               struct ieee80211_key_conf *key)
{
    struct p54_common *priv = dev->priv;
    int slot, ret = 0;
    u8 algo = 0;
    u8 *addr = NULL;

    if (modparam_nohwcrypt)
        return -EOPNOTSUPP;

    if (key->flags & IEEE80211_KEY_FLAG_RX_MGMT) {
        /*
         * Unfortunately most/all firmwares are trying to decrypt
         * incoming management frames if a suitable key can be found.
         * However, in doing so the data in these frames gets
         * corrupted. So, we can't have firmware supported crypto
         * offload in this case.
         */
        return -EOPNOTSUPP;
    }

    mutex_lock(&priv->conf_mutex);
    if (cmd == SET_KEY) {
        switch (key->cipher) {
        case WLAN_CIPHER_SUITE_TKIP:
            if (!(priv->privacy_caps & (BR_DESC_PRIV_CAP_MICHAEL |
                  BR_DESC_PRIV_CAP_TKIP))) {
                ret = -EOPNOTSUPP;
                goto out_unlock;
            }
            key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
            algo = P54_CRYPTO_TKIPMICHAEL;
            break;
        case WLAN_CIPHER_SUITE_WEP40:
        case WLAN_CIPHER_SUITE_WEP104:
            if (!(priv->privacy_caps & BR_DESC_PRIV_CAP_WEP)) {
                ret = -EOPNOTSUPP;
                goto out_unlock;
            }
            key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
            algo = P54_CRYPTO_WEP;
            break;
        case WLAN_CIPHER_SUITE_CCMP:
            if (!(priv->privacy_caps & BR_DESC_PRIV_CAP_AESCCMP)) {
                ret = -EOPNOTSUPP;
                goto out_unlock;
            }
            key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
            algo = P54_CRYPTO_AESCCMP;
            break;
        default:
            ret = -EOPNOTSUPP;
            goto out_unlock;
        }
        slot = bitmap_find_free_region(priv->used_rxkeys,
                           priv->rx_keycache_size, 0);

        if (slot < 0) {
            /*
             * The device supports the chosen algorithm, but the
             * firmware does not provide enough key slots to store
             * all of them.
             * But encryption offload for outgoing frames is always
             * possible, so we just pretend that the upload was
             * successful and do the decryption in software.
             */

            /* mark the key as invalid. */
            key->hw_key_idx = 0xff;
            goto out_unlock;
        }
    } else {
        slot = key->hw_key_idx;

        if (slot == 0xff) {
            /* This key was not uploaded into the rx key cache. */

            goto out_unlock;
        }

        bitmap_release_region(priv->used_rxkeys, slot, 0);
        algo = 0;
    }

    if (sta)
        addr = sta->addr;

    ret = p54_upload_key(priv, algo, slot, key->keyidx,
                 key->keylen, addr, key->key);
    if (ret) {
        bitmap_release_region(priv->used_rxkeys, slot, 0);
        ret = -EOPNOTSUPP;
        goto out_unlock;
    }

    key->hw_key_idx = slot;

out_unlock:
    mutex_unlock(&priv->conf_mutex);
    return ret;
}

static int p54_get_survey(struct ieee80211_hw *dev, int idx,
                struct survey_info *survey)
{
    struct p54_common *priv = dev->priv;
    struct ieee80211_channel *chan;
    int err, tries;
    bool in_use = false;

    if (idx >= priv->chan_num)
        return -ENOENT;

#define MAX_TRIES 1
    for (tries = 0; tries < MAX_TRIES; tries++) {
        chan = priv->curchan;
        if (chan && chan->hw_value == idx) {
            mutex_lock(&priv->conf_mutex);
            err = p54_wait_for_stats(dev);
            mutex_unlock(&priv->conf_mutex);
            if (err)
                return err;

            in_use = true;
        }

        memcpy(survey, &priv->survey[idx], sizeof(*survey));

        if (in_use) {
            /* test if the reported statistics are valid. */
            if  (survey->channel_time != 0) {
                survey->filled |= SURVEY_INFO_IN_USE;
            } else {
                /*
                 * hw/fw has not accumulated enough sample sets.
                 * Wait for 100ms, this ought to be enough to
                 * to get at least one non-null set of channel
                 * usage statistics.
                 */
                msleep(100);
                continue;
            }
        }
        return 0;
    }
    return -ETIMEDOUT;
#undef MAX_TRIES
}

static unsigned int p54_flush_count(struct p54_common *priv)
{
    unsigned int total = 0, i;

    BUILD_BUG_ON(P54_QUEUE_NUM > ARRAY_SIZE(priv->tx_stats));

    /*
     * Because the firmware has the sole control over any frames
     * in the P54_QUEUE_BEACON or P54_QUEUE_SCAN queues, they
     * don't really count as pending or active.
     */
    for (i = P54_QUEUE_MGMT; i < P54_QUEUE_NUM; i++)
        total += priv->tx_stats[i].len;
    return total;
}

static void p54_flush(struct ieee80211_hw *dev, bool drop)
{
    struct p54_common *priv = dev->priv;
    unsigned int total, i;

    /*
     * Currently, it wouldn't really matter if we wait for one second
     * or 15 minutes. But once someone gets around and completes the
     * TODOs [ancel stuck frames / reset device] in p54_work, it will
     * suddenly make sense to wait that long.
     */
    i = P54_STATISTICS_UPDATE * 2 / 20;

    /*
     * In this case no locking is required because as we speak the
     * queues have already been stopped and no new frames can sneak
     * up from behind.
     */
    while ((total = p54_flush_count(priv) && i--)) {
        /* waste time */
        msleep(20);
    }

    WARN(total, "tx flush timeout, unresponsive firmware");
}

static void p54_set_coverage_class(struct ieee80211_hw *dev, u8 coverage_class)
{
    struct p54_common *priv = dev->priv;

    mutex_lock(&priv->conf_mutex);
    /* support all coverage class values as in 802.11-2007 Table 7-27 */
    priv->coverage_class = clamp_t(u8, coverage_class, 0, 31);
    p54_set_edcf(priv);
    mutex_unlock(&priv->conf_mutex);
}

static const struct ieee80211_ops p54_ops = {
    .tx         = p54_tx_80211,
    .start          = p54_start,
    .stop           = p54_stop,
    .add_interface      = p54_add_interface,
    .remove_interface   = p54_remove_interface,
    .set_tim        = p54_set_tim,
    .sta_notify     = p54_sta_notify,
    .sta_add        = p54_sta_add_remove,
    .sta_remove     = p54_sta_add_remove,
    .set_key        = p54_set_key,
    .config         = p54_config,
    .flush          = p54_flush,
    .bss_info_changed   = p54_bss_info_changed,
    .prepare_multicast  = p54_prepare_multicast,
    .configure_filter   = p54_configure_filter,
    .conf_tx        = p54_conf_tx,
    .get_stats      = p54_get_stats,
    .get_survey     = p54_get_survey,
    .set_coverage_class = p54_set_coverage_class,
};

struct ieee80211_hw *p54_init_common(size_t priv_data_len)
{
    struct ieee80211_hw *dev;
    struct p54_common *priv;

    dev = ieee80211_alloc_hw(priv_data_len, &p54_ops);
    if (!dev)
        return NULL;

    priv = dev->priv;
    priv->hw = dev;
    priv->mode = NL80211_IFTYPE_UNSPECIFIED;
    priv->basic_rate_mask = 0x15f;
    spin_lock_init(&priv->tx_stats_lock);
    skb_queue_head_init(&priv->tx_queue);
    skb_queue_head_init(&priv->tx_pending);
    dev->flags = IEEE80211_HW_RX_INCLUDES_FCS |
             IEEE80211_HW_SIGNAL_DBM |
             IEEE80211_HW_SUPPORTS_PS |
             IEEE80211_HW_PS_NULLFUNC_STACK |
             IEEE80211_HW_MFP_CAPABLE |
             IEEE80211_HW_REPORTS_TX_ACK_STATUS;

    dev->wiphy->interface_modes = BIT(NL80211_IFTYPE_STATION) |
                      BIT(NL80211_IFTYPE_ADHOC) |
                      BIT(NL80211_IFTYPE_AP) |
                      BIT(NL80211_IFTYPE_MESH_POINT);

    dev->channel_change_time = 1000;    /* TODO: find actual value */
    priv->beacon_req_id = cpu_to_le32(0);
    priv->tx_stats[P54_QUEUE_BEACON].limit = 1;
    priv->tx_stats[P54_QUEUE_FWSCAN].limit = 1;
    priv->tx_stats[P54_QUEUE_MGMT].limit = 3;
    priv->tx_stats[P54_QUEUE_CAB].limit = 3;
    priv->tx_stats[P54_QUEUE_DATA].limit = 5;
    dev->queues = 1;
    priv->noise = -94;
    /*
     * We support at most 8 tries no matter which rate they're at,
     * we cannot support max_rates * max_rate_tries as we set it
     * here, but setting it correctly to 4/2 or so would limit us
     * artificially if the RC algorithm wants just two rates, so
     * let's say 4/7, we'll redistribute it at TX time, see the
     * comments there.
     */
    dev->max_rates = 4;
    dev->max_rate_tries = 7;
    dev->extra_tx_headroom = sizeof(struct p54_hdr) + 4 +
                 sizeof(struct p54_tx_data);

    /*
     * For now, disable PS by default because it affects
     * link stability significantly.
     */
    dev->wiphy->flags &= ~WIPHY_FLAG_PS_ON_BY_DEFAULT;

    mutex_init(&priv->conf_mutex);
    mutex_init(&priv->eeprom_mutex);
    init_completion(&priv->stat_comp);
    init_completion(&priv->eeprom_comp);
    init_completion(&priv->beacon_comp);
    INIT_DELAYED_WORK(&priv->work, p54_work);

    memset(&priv->mc_maclist[0], ~0, ETH_ALEN);
    priv->curchan = NULL;
    p54_reset_stats(priv);
    return dev;
}
EXPORT_SYMBOL_GPL(p54_init_common);

int p54_register_common(struct ieee80211_hw *dev, struct device *pdev)
{
    struct p54_common __maybe_unused *priv = dev->priv;
    int err;

    err = ieee80211_register_hw(dev);
    if (err) {
        dev_err(pdev, "Cannot register device (%d).\n", err);
        return err;
    }
    priv->registered = true;

#ifdef CONFIG_P54_LEDS
    err = p54_init_leds(priv);
    if (err) {
        p54_unregister_common(dev);
        return err;
    }
#endif /* CONFIG_P54_LEDS */

    dev_info(pdev, "is registered as '%s'\n", wiphy_name(dev->wiphy));
    return 0;
}
EXPORT_SYMBOL_GPL(p54_register_common);

void p54_free_common(struct ieee80211_hw *dev)
{
    struct p54_common *priv = dev->priv;
    unsigned int i;

    for (i = 0; i < IEEE80211_NUM_BANDS; i++)
        kfree(priv->band_table[i]);

    kfree(priv->iq_autocal);
    kfree(priv->output_limit);
    kfree(priv->curve_data);
    kfree(priv->rssi_db);
    kfree(priv->used_rxkeys);
    kfree(priv->survey);
    priv->iq_autocal = NULL;
    priv->output_limit = NULL;
    priv->curve_data = NULL;
    priv->rssi_db = NULL;
    priv->used_rxkeys = NULL;
    priv->survey = NULL;
    ieee80211_free_hw(dev);
}
EXPORT_SYMBOL_GPL(p54_free_common);

void p54_unregister_common(struct ieee80211_hw *dev)
{
    struct p54_common *priv = dev->priv;

#ifdef CONFIG_P54_LEDS
    p54_unregister_leds(priv);
#endif /* CONFIG_P54_LEDS */

    if (priv->registered) {
        priv->registered = false;
        ieee80211_unregister_hw(dev);
    }

    mutex_destroy(&priv->conf_mutex);
    mutex_destroy(&priv->eeprom_mutex);
}
EXPORT_SYMBOL_GPL(p54_unregister_common);