/*
 * Copyright (c) 2010-2011 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.
 */

#include "htc.h"

#define FUDGE 2

void ath9k_htc_beaconq_config(struct ath9k_htc_priv *priv)
{
        struct ath_hw *ah = priv->ah;
        struct ath9k_tx_queue_info qi, qi_be;

        memset(&qi, 0, sizeof(struct ath9k_tx_queue_info));
        memset(&qi_be, 0, sizeof(struct ath9k_tx_queue_info));

        ath9k_hw_get_txq_props(ah, priv->beacon.beaconq, &qi);

        if (priv->ah->opmode == NL80211_IFTYPE_AP ||
            priv->ah->opmode == NL80211_IFTYPE_MESH_POINT) {
                qi.tqi_aifs = 1;
                qi.tqi_cwmin = 0;
                qi.tqi_cwmax = 0;
        } else if (priv->ah->opmode == NL80211_IFTYPE_ADHOC) {
                int qnum = priv->hwq_map[IEEE80211_AC_BE];

                ath9k_hw_get_txq_props(ah, qnum, &qi_be);

                qi.tqi_aifs = qi_be.tqi_aifs;

                /*
                 * For WIFI Beacon Distribution
                 * Long slot time  : 2x cwmin
                 * Short slot time : 4x cwmin
                 */
                if (ah->slottime == 20)
                        qi.tqi_cwmin = 2*qi_be.tqi_cwmin;
                else
                        qi.tqi_cwmin = 4*qi_be.tqi_cwmin;

                qi.tqi_cwmax = qi_be.tqi_cwmax;

        }

        if (!ath9k_hw_set_txq_props(ah, priv->beacon.beaconq, &qi)) {
                ath_err(ath9k_hw_common(ah),
                        "Unable to update beacon queue %u!\n", priv->beacon.beaconq);
        } else {
                ath9k_hw_resettxqueue(ah, priv->beacon.beaconq);
        }
}

/*
 * Both nexttbtt and intval have to be in usecs.
 */
static void ath9k_htc_beacon_init(struct ath9k_htc_priv *priv,
                                  struct ath_beacon_config *conf,
                                  bool reset_tsf)
{
        struct ath_hw *ah = priv->ah;
        int ret __attribute__ ((unused));
        __be32 htc_imask = 0;
        u8 cmd_rsp;

        if (conf->intval >= TU_TO_USEC(DEFAULT_SWBA_RESPONSE))
                ah->config.sw_beacon_response_time = DEFAULT_SWBA_RESPONSE;
        else
                ah->config.sw_beacon_response_time = MIN_SWBA_RESPONSE;

        WMI_CMD(WMI_DISABLE_INTR_CMDID);
        if (reset_tsf)
                ath9k_hw_reset_tsf(ah);
        ath9k_htc_beaconq_config(priv);
        ath9k_hw_beaconinit(ah, conf->nexttbtt, conf->intval);
        priv->beacon.bmisscnt = 0;
        htc_imask = cpu_to_be32(ah->imask);
        WMI_CMD_BUF(WMI_ENABLE_INTR_CMDID, &htc_imask);
}

static void ath9k_htc_beacon_config_sta(struct ath9k_htc_priv *priv,
                                        struct ath_beacon_config *bss_conf)
{
        struct ath9k_beacon_state bs;
        enum ath9k_int imask = 0;
        __be32 htc_imask = 0;
        int ret __attribute__ ((unused));
        u8 cmd_rsp;

        if (ath9k_cmn_beacon_config_sta(priv->ah, bss_conf, &bs) == -EPERM)
                return;

        WMI_CMD(WMI_DISABLE_INTR_CMDID);
        ath9k_hw_set_sta_beacon_timers(priv->ah, &bs);
        imask |= ATH9K_INT_BMISS;
        htc_imask = cpu_to_be32(imask);
        WMI_CMD_BUF(WMI_ENABLE_INTR_CMDID, &htc_imask);
}

static void ath9k_htc_beacon_config_ap(struct ath9k_htc_priv *priv,
                                       struct ath_beacon_config *conf)
{
        struct ath_hw *ah = priv->ah;
        ah->imask = 0;

        ath9k_cmn_beacon_config_ap(ah, conf, ATH9K_HTC_MAX_BCN_VIF);
        ath9k_htc_beacon_init(priv, conf, false);
}

static void ath9k_htc_beacon_config_adhoc(struct ath9k_htc_priv *priv,
                                          struct ath_beacon_config *conf)
{
        struct ath_hw *ah = priv->ah;
        ah->imask = 0;

        ath9k_cmn_beacon_config_adhoc(ah, conf);
        ath9k_htc_beacon_init(priv, conf, conf->ibss_creator);
}

void ath9k_htc_beaconep(void *drv_priv, struct sk_buff *skb,
                        enum htc_endpoint_id ep_id, bool txok)
{
        dev_kfree_skb_any(skb);
}

static void ath9k_htc_send_buffered(struct ath9k_htc_priv *priv,
                                    int slot)
{
        struct ath_common *common = ath9k_hw_common(priv->ah);
        struct ieee80211_vif *vif;
        struct sk_buff *skb;
        struct ieee80211_hdr *hdr;
        int padpos, padsize, ret, tx_slot;

        spin_lock_bh(&priv->beacon_lock);

        vif = priv->beacon.bslot[slot];

        skb = ieee80211_get_buffered_bc(priv->hw, vif);

        while(skb) {
                hdr = (struct ieee80211_hdr *) skb->data;

                padpos = ieee80211_hdrlen(hdr->frame_control);
                padsize = padpos & 3;
                if (padsize && skb->len > padpos) {
                        if (skb_headroom(skb) < padsize) {
                                dev_kfree_skb_any(skb);
                                goto next;
                        }
                        skb_push(skb, padsize);
                        memmove(skb->data, skb->data + padsize, padpos);
                }

                tx_slot = ath9k_htc_tx_get_slot(priv);
                if (tx_slot < 0) {
                        ath_dbg(common, XMIT, "No free CAB slot\n");
                        dev_kfree_skb_any(skb);
                        goto next;
                }

                ret = ath9k_htc_tx_start(priv, NULL, skb, tx_slot, true);
                if (ret != 0) {
                        ath9k_htc_tx_clear_slot(priv, tx_slot);
                        dev_kfree_skb_any(skb);

                        ath_dbg(common, XMIT, "Failed to send CAB frame\n");
                } else {
                        spin_lock_bh(&priv->tx.tx_lock);
                        priv->tx.queued_cnt++;
                        spin_unlock_bh(&priv->tx.tx_lock);
                }
        next:
                skb = ieee80211_get_buffered_bc(priv->hw, vif);
        }

        spin_unlock_bh(&priv->beacon_lock);
}

static void ath9k_htc_send_beacon(struct ath9k_htc_priv *priv,
                                  int slot)
{
        struct ath_common *common = ath9k_hw_common(priv->ah);
        struct ieee80211_vif *vif;
        struct ath9k_htc_vif *avp;
        struct tx_beacon_header beacon_hdr;
        struct ath9k_htc_tx_ctl *tx_ctl;
        struct ieee80211_tx_info *info;
        struct ieee80211_mgmt *mgmt;
        struct sk_buff *beacon;
        u8 *tx_fhdr;
        int ret;

        memset(&beacon_hdr, 0, sizeof(struct tx_beacon_header));

        spin_lock_bh(&priv->beacon_lock);

        vif = priv->beacon.bslot[slot];
        avp = (struct ath9k_htc_vif *)vif->drv_priv;

        if (unlikely(test_bit(ATH_OP_SCANNING, &common->op_flags))) {
                spin_unlock_bh(&priv->beacon_lock);
                return;
        }

        /* Get a new beacon */
        beacon = ieee80211_beacon_get(priv->hw, vif, 0);
        if (!beacon) {
                spin_unlock_bh(&priv->beacon_lock);
                return;
        }

        /*
         * Update the TSF adjust value here, the HW will
         * add this value for every beacon.
         */
        mgmt = (struct ieee80211_mgmt *)beacon->data;
        mgmt->u.beacon.timestamp = avp->tsfadjust;

        info = IEEE80211_SKB_CB(beacon);
        if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
                struct ieee80211_hdr *hdr =
                        (struct ieee80211_hdr *) beacon->data;
                avp->seq_no += 0x10;
                hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
                hdr->seq_ctrl |= cpu_to_le16(avp->seq_no);
        }

        tx_ctl = HTC_SKB_CB(beacon);
        memset(tx_ctl, 0, sizeof(*tx_ctl));

        tx_ctl->type = ATH9K_HTC_BEACON;
        tx_ctl->epid = priv->beacon_ep;

        beacon_hdr.vif_index = avp->index;
        tx_fhdr = skb_push(beacon, sizeof(beacon_hdr));
        memcpy(tx_fhdr, (u8 *) &beacon_hdr, sizeof(beacon_hdr));

        ret = htc_send(priv->htc, beacon);
        if (ret != 0) {
                if (ret == -ENOMEM) {
                        ath_dbg(common, BSTUCK,
                                "Failed to send beacon, no free TX buffer\n");
                }
                dev_kfree_skb_any(beacon);
        }

        spin_unlock_bh(&priv->beacon_lock);

        ath9k_htc_csa_is_finished(priv);
}

static int ath9k_htc_choose_bslot(struct ath9k_htc_priv *priv,
                                  struct wmi_event_swba *swba)
{
        struct ath_common *common = ath9k_hw_common(priv->ah);
        u64 tsf;
        u32 tsftu;
        u16 intval;
        int slot;

        intval = priv->cur_beacon_conf.beacon_interval;

        tsf = be64_to_cpu(swba->tsf);
        tsftu = TSF_TO_TU(tsf >> 32, tsf);
        slot = ((tsftu % intval) * ATH9K_HTC_MAX_BCN_VIF) / intval;
        slot = ATH9K_HTC_MAX_BCN_VIF - slot - 1;

        ath_dbg(common, BEACON,
                "Choose slot: %d, tsf: %llu, tsftu: %u, intval: %u\n",
                slot, tsf, tsftu, intval);

        return slot;
}

void ath9k_htc_swba(struct ath9k_htc_priv *priv,
                    struct wmi_event_swba *swba)
{
        struct ath_common *common = ath9k_hw_common(priv->ah);
        int slot;

        if (!priv->cur_beacon_conf.enable_beacon)
                return;

        if (swba->beacon_pending != 0) {
                priv->beacon.bmisscnt++;
                if (priv->beacon.bmisscnt > BSTUCK_THRESHOLD) {
                        ath_dbg(common, BSTUCK, "Beacon stuck, HW reset\n");
                        ieee80211_queue_work(priv->hw,
                                             &priv->fatal_work);
                }
                return;
        }

        if (priv->beacon.bmisscnt) {
                ath_dbg(common, BSTUCK,
                        "Resuming beacon xmit after %u misses\n",
                        priv->beacon.bmisscnt);
                priv->beacon.bmisscnt = 0;
        }

        slot = ath9k_htc_choose_bslot(priv, swba);
        spin_lock_bh(&priv->beacon_lock);
        if (priv->beacon.bslot[slot] == NULL) {
                spin_unlock_bh(&priv->beacon_lock);
                return;
        }
        spin_unlock_bh(&priv->beacon_lock);

        ath9k_htc_send_buffered(priv, slot);
        ath9k_htc_send_beacon(priv, slot);
}

void ath9k_htc_assign_bslot(struct ath9k_htc_priv *priv,
                            struct ieee80211_vif *vif)
{
        struct ath_common *common = ath9k_hw_common(priv->ah);
        struct ath9k_htc_vif *avp = (struct ath9k_htc_vif *)vif->drv_priv;
        int i = 0;

        spin_lock_bh(&priv->beacon_lock);
        for (i = 0; i < ATH9K_HTC_MAX_BCN_VIF; i++) {
                if (priv->beacon.bslot[i] == NULL) {
                        avp->bslot = i;
                        break;
                }
        }

        priv->beacon.bslot[avp->bslot] = vif;
        spin_unlock_bh(&priv->beacon_lock);

        ath_dbg(common, CONFIG, "Added interface at beacon slot: %d\n",
                avp->bslot);
}

void ath9k_htc_remove_bslot(struct ath9k_htc_priv *priv,
                            struct ieee80211_vif *vif)
{
        struct ath_common *common = ath9k_hw_common(priv->ah);
        struct ath9k_htc_vif *avp = (struct ath9k_htc_vif *)vif->drv_priv;

        spin_lock_bh(&priv->beacon_lock);
        priv->beacon.bslot[avp->bslot] = NULL;
        spin_unlock_bh(&priv->beacon_lock);

        ath_dbg(common, CONFIG, "Removed interface at beacon slot: %d\n",
                avp->bslot);
}

/*
 * Calculate the TSF adjustment value for all slots
 * other than zero.
 */
void ath9k_htc_set_tsfadjust(struct ath9k_htc_priv *priv,
                             struct ieee80211_vif *vif)
{
        struct ath_common *common = ath9k_hw_common(priv->ah);
        struct ath9k_htc_vif *avp = (struct ath9k_htc_vif *)vif->drv_priv;
        struct ath_beacon_config *cur_conf = &priv->cur_beacon_conf;
        u64 tsfadjust;

        if (avp->bslot == 0)
                return;

        /*
         * The beacon interval cannot be different for multi-AP mode,
         * and we reach here only for VIF slots greater than zero,
         * so beacon_interval is guaranteed to be set in cur_conf.
         */
        tsfadjust = cur_conf->beacon_interval * avp->bslot / ATH9K_HTC_MAX_BCN_VIF;
        avp->tsfadjust = cpu_to_le64(TU_TO_USEC(tsfadjust));

        ath_dbg(common, CONFIG, "tsfadjust is: %llu for bslot: %d\n",
                (unsigned long long)tsfadjust, avp->bslot);
}

static void ath9k_htc_beacon_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
{
        bool *beacon_configured = data;
        struct ath9k_htc_vif *avp = (struct ath9k_htc_vif *) vif->drv_priv;

        if (vif->type == NL80211_IFTYPE_STATION &&
            avp->beacon_configured)
                *beacon_configured = true;
}

static bool ath9k_htc_check_beacon_config(struct ath9k_htc_priv *priv,
                                          struct ieee80211_vif *vif)
{
        struct ath_common *common = ath9k_hw_common(priv->ah);
        struct ath_beacon_config *cur_conf = &priv->cur_beacon_conf;
        struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
        bool beacon_configured;

        /*
         * Changing the beacon interval when multiple AP interfaces
         * are configured will affect beacon transmission of all
         * of them.
         */
        if ((priv->ah->opmode == NL80211_IFTYPE_AP) &&
            (priv->num_ap_vif > 1) &&
            (vif->type == NL80211_IFTYPE_AP) &&
            (cur_conf->beacon_interval != bss_conf->beacon_int)) {
                ath_dbg(common, CONFIG,
                        "Changing beacon interval of multiple AP interfaces !\n");
                return false;
        }

        /*
         * If the HW is operating in AP mode, any new station interfaces that
         * are added cannot change the beacon parameters.
         */
        if (priv->num_ap_vif &&
            (vif->type != NL80211_IFTYPE_AP)) {
                ath_dbg(common, CONFIG,
                        "HW in AP mode, cannot set STA beacon parameters\n");
                return false;
        }

        /*
         * The beacon parameters are configured only for the first
         * station interface.
         */
        if ((priv->ah->opmode == NL80211_IFTYPE_STATION) &&
            (priv->num_sta_vif > 1) &&
            (vif->type == NL80211_IFTYPE_STATION)) {
                beacon_configured = false;
                ieee80211_iterate_active_interfaces_atomic(
                        priv->hw, IEEE80211_IFACE_ITER_RESUME_ALL,
                        ath9k_htc_beacon_iter, &beacon_configured);

                if (beacon_configured) {
                        ath_dbg(common, CONFIG,
                                "Beacon already configured for a station interface\n");
                        return false;
                }
        }

        return true;
}

void ath9k_htc_beacon_config(struct ath9k_htc_priv *priv,
                             struct ieee80211_vif *vif)
{
        struct ath_common *common = ath9k_hw_common(priv->ah);
        struct ath_beacon_config *cur_conf = &priv->cur_beacon_conf;
        struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
        struct ath9k_htc_vif *avp = (struct ath9k_htc_vif *) vif->drv_priv;

        if (!ath9k_htc_check_beacon_config(priv, vif))
                return;

        cur_conf->beacon_interval = bss_conf->beacon_int;
        if (cur_conf->beacon_interval == 0)
                cur_conf->beacon_interval = 100;

        cur_conf->dtim_period = bss_conf->dtim_period;
        cur_conf->bmiss_timeout =
                ATH_DEFAULT_BMISS_LIMIT * cur_conf->beacon_interval;

        switch (vif->type) {
        case NL80211_IFTYPE_STATION:
                ath9k_htc_beacon_config_sta(priv, cur_conf);
                avp->beacon_configured = true;
                break;
        case NL80211_IFTYPE_ADHOC:
                ath9k_htc_beacon_config_adhoc(priv, cur_conf);
                break;
        case NL80211_IFTYPE_MESH_POINT:
        case NL80211_IFTYPE_AP:
                ath9k_htc_beacon_config_ap(priv, cur_conf);
                break;
        default:
                ath_dbg(common, CONFIG, "Unsupported beaconing mode\n");
                return;
        }
}

void ath9k_htc_beacon_reconfig(struct ath9k_htc_priv *priv)
{
        struct ath_common *common = ath9k_hw_common(priv->ah);
        struct ath_beacon_config *cur_conf = &priv->cur_beacon_conf;

        switch (priv->ah->opmode) {
        case NL80211_IFTYPE_STATION:
                ath9k_htc_beacon_config_sta(priv, cur_conf);
                break;
        case NL80211_IFTYPE_ADHOC:
                ath9k_htc_beacon_config_adhoc(priv, cur_conf);
                break;
        case NL80211_IFTYPE_MESH_POINT:
        case NL80211_IFTYPE_AP:
                ath9k_htc_beacon_config_ap(priv, cur_conf);
                break;
        default:
                ath_dbg(common, CONFIG, "Unsupported beaconing mode\n");
                return;
        }
}

bool ath9k_htc_csa_is_finished(struct ath9k_htc_priv *priv)
{
        struct ieee80211_vif *vif;

        vif = priv->csa_vif;
        if (!vif || !vif->bss_conf.csa_active)
                return false;

        if (!ieee80211_beacon_cntdwn_is_complete(vif, 0))
                return false;

        ieee80211_csa_finish(vif, 0);

        priv->csa_vif = NULL;
        return true;
}