/*
 * 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\n");
}

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;

        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);

        if (sc->tx99_vif) {
                avp = (struct ath_vif *) sc->tx99_vif->drv_priv;
                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);
        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\n");
                return r;
        }

        ath_dbg(common, XMIT, "TX99 xmit started using %d ( %ddBm)\n",
                sc->tx99_power,
                sc->tx99_power / 2);

        /* We leave the hardware 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\n", 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);
        bool start;
        ssize_t ret;
        int r;

        if (count < 1)
                return -EINVAL;

        if (sc->cur_chan->nvifs > 1)
                return -EOPNOTSUPP;

        ret = kstrtobool_from_user(user_buf, count, &start);
        if (ret)
                return ret;

        mutex_lock(&sc->mutex);

        if (start == sc->tx99_state) {
                if (!start)
                        goto out;
                ath_dbg(common, XMIT, "Resetting TX99\n");
                ath9k_tx99_deinit(sc);
        }

        if (!start) {
                ath9k_tx99_deinit(sc);
                goto out;
        }

        r = ath9k_tx99_init(sc);
        if (r) {
                mutex_unlock(&sc->mutex);
                return r;
        }
out:
        mutex_unlock(&sc->mutex);
        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)\n",
                      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_9280_20_OR_LATER(sc->sc_ah))
                return;

        debugfs_create_file("tx99", 0600,
                            sc->debug.debugfs_phy, sc,
                            &fops_tx99);
        debugfs_create_file("tx99_power", 0600,
                            sc->debug.debugfs_phy, sc,
                            &fops_tx99_power);
}