/*
 * This file is part of wl18xx
 *
 * Copyright (C) 2011 Texas Instruments Inc.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include "../wlcore/wlcore.h"
#include "../wlcore/cmd.h"
#include "../wlcore/debug.h"
#include "../wlcore/acx.h"
#include "../wlcore/tx.h"

#include "wl18xx.h"
#include "tx.h"

static
void wl18xx_get_last_tx_rate(struct wl1271 *wl, struct ieee80211_vif *vif,
                             u8 band, struct ieee80211_tx_rate *rate, u8 hlid)
{
        u8 fw_rate = wl->links[hlid].fw_rate_idx;

        if (fw_rate > CONF_HW_RATE_INDEX_MAX) {
                wl1271_error("last Tx rate invalid: %d", fw_rate);
                rate->idx = 0;
                rate->flags = 0;
                return;
        }

        if (fw_rate <= CONF_HW_RATE_INDEX_54MBPS) {
                rate->idx = fw_rate;
                if (band == NL80211_BAND_5GHZ)
                        rate->idx -= CONF_HW_RATE_INDEX_6MBPS;
                rate->flags = 0;
        } else {
                rate->flags = IEEE80211_TX_RC_MCS;
                rate->idx = fw_rate - CONF_HW_RATE_INDEX_MCS0;

                /* SGI modifier is counted as a separate rate */
                if (fw_rate >= CONF_HW_RATE_INDEX_MCS7_SGI)
                        (rate->idx)--;
                if (fw_rate == CONF_HW_RATE_INDEX_MCS15_SGI)
                        (rate->idx)--;

                /* this also covers the 40Mhz SGI case (= MCS15) */
                if (fw_rate == CONF_HW_RATE_INDEX_MCS7_SGI ||
                    fw_rate == CONF_HW_RATE_INDEX_MCS15_SGI)
                        rate->flags |= IEEE80211_TX_RC_SHORT_GI;

                if (fw_rate > CONF_HW_RATE_INDEX_MCS7_SGI && vif) {
                        struct wl12xx_vif *wlvif = wl12xx_vif_to_data(vif);
                        if (wlvif->channel_type == NL80211_CHAN_HT40MINUS ||
                            wlvif->channel_type == NL80211_CHAN_HT40PLUS) {
                                /* adjustment needed for range 0-7 */
                                rate->idx -= 8;
                                rate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
                        }
                }
        }
}

static void wl18xx_tx_complete_packet(struct wl1271 *wl, u8 tx_stat_byte)
{
        struct ieee80211_tx_info *info;
        struct sk_buff *skb;
        int id = tx_stat_byte & WL18XX_TX_STATUS_DESC_ID_MASK;
        bool tx_success;
        struct wl1271_tx_hw_descr *tx_desc;

        /* check for id legality */
        if (unlikely(id >= wl->num_tx_desc || wl->tx_frames[id] == NULL)) {
                wl1271_warning("illegal id in tx completion: %d", id);
                return;
        }

        /* a zero bit indicates Tx success */
        tx_success = !(tx_stat_byte & BIT(WL18XX_TX_STATUS_STAT_BIT_IDX));

        skb = wl->tx_frames[id];
        info = IEEE80211_SKB_CB(skb);
        tx_desc = (struct wl1271_tx_hw_descr *)skb->data;

        if (wl12xx_is_dummy_packet(wl, skb)) {
                wl1271_free_tx_id(wl, id);
                return;
        }

        /* update the TX status info */
        if (tx_success && !(info->flags & IEEE80211_TX_CTL_NO_ACK))
                info->flags |= IEEE80211_TX_STAT_ACK;
        /*
         * first pass info->control.vif while it's valid, and then fill out
         * the info->status structures
         */
        wl18xx_get_last_tx_rate(wl, info->control.vif,
                                info->band,
                                &info->status.rates[0],
                                tx_desc->hlid);

        info->status.rates[0].count = 1; /* no data about retries */
        info->status.ack_signal = -1;

        if (!tx_success)
                wl->stats.retry_count++;

        /*
         * TODO: update sequence number for encryption? seems to be
         * unsupported for now. needed for recovery with encryption.
         */

        /* remove private header from packet */
        skb_pull(skb, sizeof(struct wl1271_tx_hw_descr));

        /* remove TKIP header space if present */
        if ((wl->quirks & WLCORE_QUIRK_TKIP_HEADER_SPACE) &&
            info->control.hw_key &&
            info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
                int hdrlen = ieee80211_get_hdrlen_from_skb(skb);
                memmove(skb->data + WL1271_EXTRA_SPACE_TKIP, skb->data, hdrlen);
                skb_pull(skb, WL1271_EXTRA_SPACE_TKIP);
        }

        wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p success %d",
                     id, skb, tx_success);

        /* return the packet to the stack */
        skb_queue_tail(&wl->deferred_tx_queue, skb);
        queue_work(wl->freezable_wq, &wl->netstack_work);
        wl1271_free_tx_id(wl, id);
}

void wl18xx_tx_immediate_complete(struct wl1271 *wl)
{
        struct wl18xx_fw_status_priv *status_priv =
                (struct wl18xx_fw_status_priv *)wl->fw_status->priv;
        struct wl18xx_priv *priv = wl->priv;
        u8 i, hlid;

        /* nothing to do here */
        if (priv->last_fw_rls_idx == status_priv->fw_release_idx)
                return;

        /* update rates per link */
        hlid = wl->fw_status->counters.hlid;

        if (hlid < WLCORE_MAX_LINKS) {
                wl->links[hlid].fw_rate_idx =
                                wl->fw_status->counters.tx_last_rate;
                wl->links[hlid].fw_rate_mbps =
                                wl->fw_status->counters.tx_last_rate_mbps;
        }

        /* freed Tx descriptors */
        wl1271_debug(DEBUG_TX, "last released desc = %d, current idx = %d",
                     priv->last_fw_rls_idx, status_priv->fw_release_idx);

        if (status_priv->fw_release_idx >= WL18XX_FW_MAX_TX_STATUS_DESC) {
                wl1271_error("invalid desc release index %d",
                             status_priv->fw_release_idx);
                WARN_ON(1);
                return;
        }

        for (i = priv->last_fw_rls_idx;
             i != status_priv->fw_release_idx;
             i = (i + 1) % WL18XX_FW_MAX_TX_STATUS_DESC) {
                wl18xx_tx_complete_packet(wl,
                        status_priv->released_tx_desc[i]);

                wl->tx_results_count++;
        }

        priv->last_fw_rls_idx = status_priv->fw_release_idx;
}