/*
   * Copyright (c) 2013 Qualcomm Atheros, 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 "ath9k.h"
  
  static void ath9k_tx99_stop(struct ath_softc *sc)
  {
  	struct ath_hw *ah = sc->sc_ah;
  	struct ath_common *common = ath9k_hw_common(ah);
  
  	ath_drain_all_txq(sc);
  	ath_startrecv(sc);
  
  	ath9k_hw_set_interrupts(ah);
  	ath9k_hw_enable_interrupts(ah);
  
  	ieee80211_wake_queues(sc->hw);
  
  	kfree_skb(sc->tx99_skb);
  	sc->tx99_skb = NULL;
  	sc->tx99_state = false;
  
  	ath9k_hw_tx99_stop(sc->sc_ah);
  	ath_dbg(common, XMIT, "TX99 stopped
  ");
  }
  
  static struct sk_buff *ath9k_build_tx99_skb(struct ath_softc *sc)
  {
  	static u8 PN9Data[] = {0xff, 0x87, 0xb8, 0x59, 0xb7, 0xa1, 0xcc, 0x24,
  			       0x57, 0x5e, 0x4b, 0x9c, 0x0e, 0xe9, 0xea, 0x50,
  			       0x2a, 0xbe, 0xb4, 0x1b, 0xb6, 0xb0, 0x5d, 0xf1,
  			       0xe6, 0x9a, 0xe3, 0x45, 0xfd, 0x2c, 0x53, 0x18,
  			       0x0c, 0xca, 0xc9, 0xfb, 0x49, 0x37, 0xe5, 0xa8,
  			       0x51, 0x3b, 0x2f, 0x61, 0xaa, 0x72, 0x18, 0x84,
  			       0x02, 0x23, 0x23, 0xab, 0x63, 0x89, 0x51, 0xb3,
  			       0xe7, 0x8b, 0x72, 0x90, 0x4c, 0xe8, 0xfb, 0xc0};
  	u32 len = 1200;
  	struct ieee80211_tx_rate *rate;
  	struct ieee80211_hw *hw = sc->hw;
  	struct ath_hw *ah = sc->sc_ah;
  	struct ieee80211_hdr *hdr;
  	struct ieee80211_tx_info *tx_info;
  	struct sk_buff *skb;
  	struct ath_vif *avp;
  
  	if (!sc->tx99_vif)
  		return NULL;
  
  	avp = (struct ath_vif *)sc->tx99_vif->drv_priv;
  
  	skb = alloc_skb(len, GFP_KERNEL);
  	if (!skb)
  		return NULL;
  
  	skb_put(skb, len);
  
  	memset(skb->data, 0, len);
  
  	hdr = (struct ieee80211_hdr *)skb->data;
  	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA);
  	hdr->duration_id = 0;
  
  	memcpy(hdr->addr1, hw->wiphy->perm_addr, ETH_ALEN);
  	memcpy(hdr->addr2, hw->wiphy->perm_addr, ETH_ALEN);
  	memcpy(hdr->addr3, hw->wiphy->perm_addr, ETH_ALEN);
  
  	hdr->seq_ctrl |= cpu_to_le16(avp->seq_no);
  
  	tx_info = IEEE80211_SKB_CB(skb);
  	memset(tx_info, 0, sizeof(*tx_info));
  	rate = &tx_info->control.rates[0];
  	tx_info->band = sc->cur_chan->chandef.chan->band;
  	tx_info->flags = IEEE80211_TX_CTL_NO_ACK;
  	tx_info->control.vif = sc->tx99_vif;
  	rate->count = 1;
  	if (ah->curchan && IS_CHAN_HT(ah->curchan)) {
  		rate->flags |= IEEE80211_TX_RC_MCS;
  		if (IS_CHAN_HT40(ah->curchan))
  			rate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
  	}
  
  	memcpy(skb->data + sizeof(*hdr), PN9Data, sizeof(PN9Data));
  
  	return skb;
  }
  
  static void ath9k_tx99_deinit(struct ath_softc *sc)
  {
  	ath_reset(sc, NULL);
  
  	ath9k_ps_wakeup(sc);
  	ath9k_tx99_stop(sc);
  	ath9k_ps_restore(sc);
  }
  
  static int ath9k_tx99_init(struct ath_softc *sc)
  {
  	struct ieee80211_hw *hw = sc->hw;
  	struct ath_hw *ah = sc->sc_ah;
  	struct ath_common *common = ath9k_hw_common(ah);
  	struct ath_tx_control txctl;
  	int r;
  
  	if (test_bit(ATH_OP_INVALID, &common->op_flags)) {
  		ath_err(common,
  			"driver is in invalid state unable to use TX99");
  		return -EINVAL;
  	}
  
  	sc->tx99_skb = ath9k_build_tx99_skb(sc);
  	if (!sc->tx99_skb)
  		return -ENOMEM;
  
  	memset(&txctl, 0, sizeof(txctl));
  	txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO];
  
  	ath_reset(sc, NULL);
  
  	ath9k_ps_wakeup(sc);
  
  	ath9k_hw_disable_interrupts(ah);
  	atomic_set(&ah->intr_ref_cnt, -1);
  	ath_drain_all_txq(sc);
  	ath_stoprecv(sc);
  
  	sc->tx99_state = true;
  
  	ieee80211_stop_queues(hw);
  
  	if (sc->tx99_power == MAX_RATE_POWER + 1)
  		sc->tx99_power = MAX_RATE_POWER;
  
  	ath9k_hw_tx99_set_txpower(ah, sc->tx99_power);
  	r = ath9k_tx99_send(sc, sc->tx99_skb, &txctl);
  	if (r) {
  		ath_dbg(common, XMIT, "Failed to xmit TX99 skb
  ");
  		return r;
  	}
  
  	ath_dbg(common, XMIT, "TX99 xmit started using %d ( %ddBm)
  ",
  		sc->tx99_power,
  		sc->tx99_power / 2);
  
  	/* We leave the harware awake as it will be chugging on */
  
  	return 0;
  }
  
  static ssize_t read_file_tx99(struct file *file, char __user *user_buf,
  			      size_t count, loff_t *ppos)
  {
  	struct ath_softc *sc = file->private_data;
  	char buf[3];
  	unsigned int len;
  
  	len = sprintf(buf, "%d
  ", sc->tx99_state);
  	return simple_read_from_buffer(user_buf, count, ppos, buf, len);
  }
  
  static ssize_t write_file_tx99(struct file *file, const char __user *user_buf,
  			       size_t count, loff_t *ppos)
  {
  	struct ath_softc *sc = file->private_data;
  	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
  	char buf[32];
  	bool start;
  	ssize_t len;
  	int r;
  
  	if (sc->cur_chan->nvifs > 1)
  		return -EOPNOTSUPP;
  
  	len = min(count, sizeof(buf) - 1);
  	if (copy_from_user(buf, user_buf, len))
  		return -EFAULT;
  
  	if (strtobool(buf, &start))
  		return -EINVAL;
  
  	if (start == sc->tx99_state) {
  		if (!start)
  			return count;
  		ath_dbg(common, XMIT, "Resetting TX99
  ");
  		ath9k_tx99_deinit(sc);
  	}
  
  	if (!start) {
  		ath9k_tx99_deinit(sc);
  		return count;
  	}
  
  	r = ath9k_tx99_init(sc);
  	if (r)
  		return r;
  
  	return count;
  }
  
  static const struct file_operations fops_tx99 = {
  	.read = read_file_tx99,
  	.write = write_file_tx99,
  	.open = simple_open,
  	.owner = THIS_MODULE,
  	.llseek = default_llseek,
  };
  
  static ssize_t read_file_tx99_power(struct file *file,
  				    char __user *user_buf,
  				    size_t count, loff_t *ppos)
  {
  	struct ath_softc *sc = file->private_data;
  	char buf[32];
  	unsigned int len;
  
  	len = sprintf(buf, "%d (%d dBm)
  ",
  		      sc->tx99_power,
  		      sc->tx99_power / 2);
  
  	return simple_read_from_buffer(user_buf, count, ppos, buf, len);
  }
  
  static ssize_t write_file_tx99_power(struct file *file,
  				     const char __user *user_buf,
  				     size_t count, loff_t *ppos)
  {
  	struct ath_softc *sc = file->private_data;
  	int r;
  	u8 tx_power;
  
  	r = kstrtou8_from_user(user_buf, count, 0, &tx_power);
  	if (r)
  		return r;
  
  	if (tx_power > MAX_RATE_POWER)
  		return -EINVAL;
  
  	sc->tx99_power = tx_power;
  
  	ath9k_ps_wakeup(sc);
  	ath9k_hw_tx99_set_txpower(sc->sc_ah, sc->tx99_power);
  	ath9k_ps_restore(sc);
  
  	return count;
  }
  
  static const struct file_operations fops_tx99_power = {
  	.read = read_file_tx99_power,
  	.write = write_file_tx99_power,
  	.open = simple_open,
  	.owner = THIS_MODULE,
  	.llseek = default_llseek,
  };
  
  void ath9k_tx99_init_debug(struct ath_softc *sc)
  {
  	if (!AR_SREV_9300_20_OR_LATER(sc->sc_ah))
  		return;
  
  	debugfs_create_file("tx99", S_IRUSR | S_IWUSR,
  			    sc->debug.debugfs_phy, sc,
  			    &fops_tx99);
  	debugfs_create_file("tx99_power", S_IRUSR | S_IWUSR,
  			    sc->debug.debugfs_phy, sc,
  			    &fops_tx99_power);
  }