/*
 * This file is part of wl1271
 *
 * Copyright (C) 2008-2009 Nokia Corporation
 *
 * Contact: Luciano Coelho <luciano.coelho@nokia.com>
 *
 * 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 "wl12xx.h"
#include "reg.h"
#include "io.h"
#include "event.h"
#include "ps.h"
#include "scan.h"
#include "wl12xx_80211.h"

void wl1271_pspoll_work(struct work_struct *work)
{
        struct delayed_work *dwork;
        struct wl1271 *wl;
        int ret;

        dwork = container_of(work, struct delayed_work, work);
        wl = container_of(dwork, struct wl1271, pspoll_work);

        wl1271_debug(DEBUG_EVENT, "pspoll work");

        mutex_lock(&wl->mutex);

        if (unlikely(wl->state == WL1271_STATE_OFF))
                goto out;

        if (!test_and_clear_bit(WL1271_FLAG_PSPOLL_FAILURE, &wl->flags))
                goto out;

        if (!test_bit(WL1271_FLAG_STA_ASSOCIATED, &wl->flags))
                goto out;

        /*
         * if we end up here, then we were in powersave when the pspoll
         * delivery failure occurred, and no-one changed state since, so
         * we should go back to powersave.
         */
        ret = wl1271_ps_elp_wakeup(wl);
        if (ret < 0)
                goto out;

        wl1271_ps_set_mode(wl, STATION_POWER_SAVE_MODE, wl->basic_rate, true);

        wl1271_ps_elp_sleep(wl);
out:
        mutex_unlock(&wl->mutex);
};

static void wl1271_event_pspoll_delivery_fail(struct wl1271 *wl)
{
        int delay = wl->conf.conn.ps_poll_recovery_period;
        int ret;

        wl->ps_poll_failures++;
        if (wl->ps_poll_failures == 1)
                wl1271_info("AP with dysfunctional ps-poll, "
                            "trying to work around it.");

        /* force active mode receive data from the AP */
        if (test_bit(WL1271_FLAG_PSM, &wl->flags)) {
                ret = wl1271_ps_set_mode(wl, STATION_ACTIVE_MODE,
                                         wl->basic_rate, true);
                if (ret < 0)
                        return;
                set_bit(WL1271_FLAG_PSPOLL_FAILURE, &wl->flags);
                ieee80211_queue_delayed_work(wl->hw, &wl->pspoll_work,
                                             msecs_to_jiffies(delay));
        }

        /*
         * If already in active mode, lets we should be getting data from
         * the AP right away. If we enter PSM too fast after this, and data
         * remains on the AP, we will get another event like this, and we'll
         * go into active once more.
         */
}

static int wl1271_event_ps_report(struct wl1271 *wl,
                                  struct event_mailbox *mbox,
                                  bool *beacon_loss)
{
        int ret = 0;
        u32 total_retries = wl->conf.conn.psm_entry_retries;

        wl1271_debug(DEBUG_EVENT, "ps_status: 0x%x", mbox->ps_status);

        switch (mbox->ps_status) {
        case EVENT_ENTER_POWER_SAVE_FAIL:
                wl1271_debug(DEBUG_PSM, "PSM entry failed");

                if (!test_bit(WL1271_FLAG_PSM, &wl->flags)) {
                        /* remain in active mode */
                        wl->psm_entry_retry = 0;
                        break;
                }

                if (wl->psm_entry_retry < total_retries) {
                        wl->psm_entry_retry++;
                        ret = wl1271_ps_set_mode(wl, STATION_POWER_SAVE_MODE,
                                                 wl->basic_rate, true);
                } else {
                        wl1271_info("No ack to nullfunc from AP.");
                        wl->psm_entry_retry = 0;
                        *beacon_loss = true;
                }
                break;
        case EVENT_ENTER_POWER_SAVE_SUCCESS:
                wl->psm_entry_retry = 0;

                /* enable beacon filtering */
                ret = wl1271_acx_beacon_filter_opt(wl, true);
                if (ret < 0)
                        break;

                /*
                 * BET has only a minor effect in 5GHz and masks
                 * channel switch IEs, so we only enable BET on 2.4GHz
                */
                if (wl->band == IEEE80211_BAND_2GHZ)
                        /* enable beacon early termination */
                        ret = wl1271_acx_bet_enable(wl, true);

                if (wl->ps_compl) {
                        complete(wl->ps_compl);
                        wl->ps_compl = NULL;
                }
                break;
        default:
                break;
        }

        return ret;
}

static void wl1271_event_rssi_trigger(struct wl1271 *wl,
                                      struct event_mailbox *mbox)
{
        enum nl80211_cqm_rssi_threshold_event event;
        s8 metric = mbox->rssi_snr_trigger_metric[0];

        wl1271_debug(DEBUG_EVENT, "RSSI trigger metric: %d", metric);

        if (metric <= wl->rssi_thold)
                event = NL80211_CQM_RSSI_THRESHOLD_EVENT_LOW;
        else
                event = NL80211_CQM_RSSI_THRESHOLD_EVENT_HIGH;

        if (event != wl->last_rssi_event)
                ieee80211_cqm_rssi_notify(wl->vif, event, GFP_KERNEL);
        wl->last_rssi_event = event;
}

static void wl1271_stop_ba_event(struct wl1271 *wl)
{
        if (wl->bss_type != BSS_TYPE_AP_BSS) {
                if (!wl->ba_rx_bitmap)
                        return;
                ieee80211_stop_rx_ba_session(wl->vif, wl->ba_rx_bitmap,
                                             wl->bssid);
        } else {
                int i;
                struct wl1271_link *lnk;
                for (i = WL1271_AP_STA_HLID_START; i < AP_MAX_LINKS; i++) {
                        lnk = &wl->links[i];
                        if (!wl1271_is_active_sta(wl, i) || !lnk->ba_bitmap)
                                continue;

                        ieee80211_stop_rx_ba_session(wl->vif,
                                                     lnk->ba_bitmap,
                                                     lnk->addr);
                }
        }
}

static void wl12xx_event_soft_gemini_sense(struct wl1271 *wl,
                                               u8 enable)
{
        if (enable) {
                /* disable dynamic PS when requested by the firmware */
                ieee80211_disable_dyn_ps(wl->vif);
                set_bit(WL1271_FLAG_SOFT_GEMINI, &wl->flags);
        } else {
                ieee80211_enable_dyn_ps(wl->vif);
                clear_bit(WL1271_FLAG_SOFT_GEMINI, &wl->flags);
                wl1271_recalc_rx_streaming(wl);
        }

}

static void wl1271_event_mbox_dump(struct event_mailbox *mbox)
{
        wl1271_debug(DEBUG_EVENT, "MBOX DUMP:");
        wl1271_debug(DEBUG_EVENT, "\tvector: 0x%x", mbox->events_vector);
        wl1271_debug(DEBUG_EVENT, "\tmask: 0x%x", mbox->events_mask);
}

static int wl1271_event_process(struct wl1271 *wl, struct event_mailbox *mbox)
{
        int ret;
        u32 vector;
        bool beacon_loss = false;
        bool is_ap = (wl->bss_type == BSS_TYPE_AP_BSS);
        bool disconnect_sta = false;
        unsigned long sta_bitmap = 0;

        wl1271_event_mbox_dump(mbox);

        vector = le32_to_cpu(mbox->events_vector);
        vector &= ~(le32_to_cpu(mbox->events_mask));
        wl1271_debug(DEBUG_EVENT, "vector: 0x%x", vector);

        if (vector & SCAN_COMPLETE_EVENT_ID) {
                wl1271_debug(DEBUG_EVENT, "status: 0x%x",
                             mbox->scheduled_scan_status);

                wl1271_scan_stm(wl);
        }

        if (vector & PERIODIC_SCAN_REPORT_EVENT_ID) {
                wl1271_debug(DEBUG_EVENT, "PERIODIC_SCAN_REPORT_EVENT "
                             "(status 0x%0x)", mbox->scheduled_scan_status);

                wl1271_scan_sched_scan_results(wl);
        }

        if (vector & PERIODIC_SCAN_COMPLETE_EVENT_ID) {
                wl1271_debug(DEBUG_EVENT, "PERIODIC_SCAN_COMPLETE_EVENT "
                             "(status 0x%0x)", mbox->scheduled_scan_status);
                if (wl->sched_scanning) {
                        wl1271_scan_sched_scan_stop(wl);
                        ieee80211_sched_scan_stopped(wl->hw);
                }
        }

        if (vector & SOFT_GEMINI_SENSE_EVENT_ID &&
            wl->bss_type == BSS_TYPE_STA_BSS)
                wl12xx_event_soft_gemini_sense(wl,
                                               mbox->soft_gemini_sense_info);

        /*
         * The BSS_LOSE_EVENT_ID is only needed while psm (and hence beacon
         * filtering) is enabled. Without PSM, the stack will receive all
         * beacons and can detect beacon loss by itself.
         *
         * As there's possibility that the driver disables PSM before receiving
         * BSS_LOSE_EVENT, beacon loss has to be reported to the stack.
         *
         */
        if ((vector & BSS_LOSE_EVENT_ID) && !is_ap) {
                wl1271_info("Beacon loss detected.");

                /* indicate to the stack, that beacons have been lost */
                beacon_loss = true;
        }

        if ((vector & PS_REPORT_EVENT_ID) && !is_ap) {
                wl1271_debug(DEBUG_EVENT, "PS_REPORT_EVENT");
                ret = wl1271_event_ps_report(wl, mbox, &beacon_loss);
                if (ret < 0)
                        return ret;
        }

        if ((vector & PSPOLL_DELIVERY_FAILURE_EVENT_ID) && !is_ap)
                wl1271_event_pspoll_delivery_fail(wl);

        if (vector & RSSI_SNR_TRIGGER_0_EVENT_ID) {
                wl1271_debug(DEBUG_EVENT, "RSSI_SNR_TRIGGER_0_EVENT");
                if (wl->vif)
                        wl1271_event_rssi_trigger(wl, mbox);
        }

        if ((vector & BA_SESSION_RX_CONSTRAINT_EVENT_ID)) {
                wl1271_debug(DEBUG_EVENT, "BA_SESSION_RX_CONSTRAINT_EVENT_ID. "
                             "ba_allowed = 0x%x", mbox->rx_ba_allowed);

                wl->ba_allowed = !!mbox->rx_ba_allowed;

                if (wl->vif && !wl->ba_allowed)
                        wl1271_stop_ba_event(wl);
        }

        if ((vector & CHANNEL_SWITCH_COMPLETE_EVENT_ID) && !is_ap) {
                wl1271_debug(DEBUG_EVENT, "CHANNEL_SWITCH_COMPLETE_EVENT_ID. "
                                          "status = 0x%x",
                                          mbox->channel_switch_status);
                /*
                 * That event uses for two cases:
                 * 1) channel switch complete with status=0
                 * 2) channel switch failed status=1
                 */
                if (test_and_clear_bit(WL1271_FLAG_CS_PROGRESS, &wl->flags) &&
                    (wl->vif))
                        ieee80211_chswitch_done(wl->vif,
                                mbox->channel_switch_status ? false : true);
        }

        if ((vector & DUMMY_PACKET_EVENT_ID)) {
                wl1271_debug(DEBUG_EVENT, "DUMMY_PACKET_ID_EVENT_ID");
                if (wl->vif)
                        wl1271_tx_dummy_packet(wl);
        }

        /*
         * "TX retries exceeded" has a different meaning according to mode.
         * In AP mode the offending station is disconnected.
         */
        if ((vector & MAX_TX_RETRY_EVENT_ID) && is_ap) {
                wl1271_debug(DEBUG_EVENT, "MAX_TX_RETRY_EVENT_ID");
                sta_bitmap |= le16_to_cpu(mbox->sta_tx_retry_exceeded);
                disconnect_sta = true;
        }

        if ((vector & INACTIVE_STA_EVENT_ID) && is_ap) {
                wl1271_debug(DEBUG_EVENT, "INACTIVE_STA_EVENT_ID");
                sta_bitmap |= le16_to_cpu(mbox->sta_aging_status);
                disconnect_sta = true;
        }

        if (is_ap && disconnect_sta) {
                u32 num_packets = wl->conf.tx.max_tx_retries;
                struct ieee80211_sta *sta;
                const u8 *addr;
                int h;

                for (h = find_first_bit(&sta_bitmap, AP_MAX_LINKS);
                     h < AP_MAX_LINKS;
                     h = find_next_bit(&sta_bitmap, AP_MAX_LINKS, h+1)) {
                        if (!wl1271_is_active_sta(wl, h))
                                continue;

                        addr = wl->links[h].addr;

                        rcu_read_lock();
                        sta = ieee80211_find_sta(wl->vif, addr);
                        if (sta) {
                                wl1271_debug(DEBUG_EVENT, "remove sta %d", h);
                                ieee80211_report_low_ack(sta, num_packets);
                        }
                        rcu_read_unlock();
                }
        }

        if (wl->vif && beacon_loss)
                ieee80211_connection_loss(wl->vif);

        return 0;
}

int wl1271_event_unmask(struct wl1271 *wl)
{
        int ret;

        ret = wl1271_acx_event_mbox_mask(wl, ~(wl->event_mask));
        if (ret < 0)
                return ret;

        return 0;
}

void wl1271_event_mbox_config(struct wl1271 *wl)
{
        wl->mbox_ptr[0] = wl1271_read32(wl, REG_EVENT_MAILBOX_PTR);
        wl->mbox_ptr[1] = wl->mbox_ptr[0] + sizeof(struct event_mailbox);

        wl1271_debug(DEBUG_EVENT, "MBOX ptrs: 0x%x 0x%x",
                     wl->mbox_ptr[0], wl->mbox_ptr[1]);
}

int wl1271_event_handle(struct wl1271 *wl, u8 mbox_num)
{
        struct event_mailbox mbox;
        int ret;

        wl1271_debug(DEBUG_EVENT, "EVENT on mbox %d", mbox_num);

        if (mbox_num > 1)
                return -EINVAL;

        /* first we read the mbox descriptor */
        wl1271_read(wl, wl->mbox_ptr[mbox_num], &mbox,
                    sizeof(struct event_mailbox), false);

        /* process the descriptor */
        ret = wl1271_event_process(wl, &mbox);
        if (ret < 0)
                return ret;

        /* then we let the firmware know it can go on...*/
        wl1271_write32(wl, ACX_REG_INTERRUPT_TRIG, INTR_TRIG_EVENT_ACK);

        return 0;
}