/*
   * 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 == ATH9K_SLOT_TIME_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!
  ", 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
  ");
  			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
  ");
  		} 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);
  	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
  ");
  		}
  		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
  ",
  		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 (swba->beacon_pending != 0) {
  		priv->beacon.bmisscnt++;
  		if (priv->beacon.bmisscnt > BSTUCK_THRESHOLD) {
  			ath_dbg(common, BSTUCK, "Beacon stuck, HW reset
  ");
  			ieee80211_queue_work(priv->hw,
  					     &priv->fatal_work);
  		}
  		return;
  	}
  
  	if (priv->beacon.bmisscnt) {
  		ath_dbg(common, BSTUCK,
  			"Resuming beacon xmit after %u misses
  ",
  			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
  ",
  		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
  ",
  		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
  ",
  		(unsigned long long)tsfadjust, avp->bslot);
  }
  
  static void ath9k_htc_beacon_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
  {
  	bool *beacon_configured = (bool *)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 !
  ");
  		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
  ");
  		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
  ");
  			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
  ");
  		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
  ");
  		return;
  	}
  }
  
  bool ath9k_htc_csa_is_finished(struct ath9k_htc_priv *priv)
  {
  	struct ieee80211_vif *vif;
  
  	vif = priv->csa_vif;
  	if (!vif || !vif->csa_active)
  		return false;
  
  	if (!ieee80211_csa_is_complete(vif))
  		return false;
  
  	ieee80211_csa_finish(vif);
  
  	priv->csa_vif = NULL;
  	return true;
  }