/*
 * 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 "reg.h"
#include "ps.h"
#include "io.h"
#include "tx.h"
#include "debug.h"

#define WL1271_WAKEUP_TIMEOUT 500

void wl1271_elp_work(struct work_struct *work)
{
        struct delayed_work *dwork;
        struct wl1271 *wl;
        struct wl12xx_vif *wlvif;

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

        wl1271_debug(DEBUG_PSM, "elp work");

        mutex_lock(&wl->mutex);

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

        /* our work might have been already cancelled */
        if (unlikely(!test_bit(WL1271_FLAG_ELP_REQUESTED, &wl->flags)))
                goto out;

        if (test_bit(WL1271_FLAG_IN_ELP, &wl->flags))
                goto out;

        wl12xx_for_each_wlvif(wl, wlvif) {
                if (wlvif->bss_type == BSS_TYPE_AP_BSS)
                        goto out;

                if (!test_bit(WLVIF_FLAG_PSM, &wlvif->flags) &&
                    test_bit(WLVIF_FLAG_IN_USE, &wlvif->flags))
                        goto out;
        }

        wl1271_debug(DEBUG_PSM, "chip to elp");
        wl1271_raw_write32(wl, HW_ACCESS_ELP_CTRL_REG_ADDR, ELPCTRL_SLEEP);
        set_bit(WL1271_FLAG_IN_ELP, &wl->flags);

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

#define ELP_ENTRY_DELAY  5

/* Routines to toggle sleep mode while in ELP */
void wl1271_ps_elp_sleep(struct wl1271 *wl)
{
        struct wl12xx_vif *wlvif;

        /* we shouldn't get consecutive sleep requests */
        if (WARN_ON(test_and_set_bit(WL1271_FLAG_ELP_REQUESTED, &wl->flags)))
                return;

        wl12xx_for_each_wlvif(wl, wlvif) {
                if (wlvif->bss_type == BSS_TYPE_AP_BSS)
                        return;

                if (!test_bit(WLVIF_FLAG_PSM, &wlvif->flags) &&
                    test_bit(WLVIF_FLAG_IN_USE, &wlvif->flags))
                        return;
        }

        ieee80211_queue_delayed_work(wl->hw, &wl->elp_work,
                                     msecs_to_jiffies(ELP_ENTRY_DELAY));
}

int wl1271_ps_elp_wakeup(struct wl1271 *wl)
{
        DECLARE_COMPLETION_ONSTACK(compl);
        unsigned long flags;
        int ret;
        u32 start_time = jiffies;
        bool pending = false;

        /*
         * we might try to wake up even if we didn't go to sleep
         * before (e.g. on boot)
         */
        if (!test_and_clear_bit(WL1271_FLAG_ELP_REQUESTED, &wl->flags))
                return 0;

        /* don't cancel_sync as it might contend for a mutex and deadlock */
        cancel_delayed_work(&wl->elp_work);

        if (!test_bit(WL1271_FLAG_IN_ELP, &wl->flags))
                return 0;

        wl1271_debug(DEBUG_PSM, "waking up chip from elp");

        /*
         * The spinlock is required here to synchronize both the work and
         * the completion variable in one entity.
         */
        spin_lock_irqsave(&wl->wl_lock, flags);
        if (test_bit(WL1271_FLAG_IRQ_RUNNING, &wl->flags))
                pending = true;
        else
                wl->elp_compl = &compl;
        spin_unlock_irqrestore(&wl->wl_lock, flags);

        wl1271_raw_write32(wl, HW_ACCESS_ELP_CTRL_REG_ADDR, ELPCTRL_WAKE_UP);

        if (!pending) {
                ret = wait_for_completion_timeout(
                        &compl, msecs_to_jiffies(WL1271_WAKEUP_TIMEOUT));
                if (ret == 0) {
                        wl1271_error("ELP wakeup timeout!");
                        wl12xx_queue_recovery_work(wl);
                        ret = -ETIMEDOUT;
                        goto err;
                } else if (ret < 0) {
                        wl1271_error("ELP wakeup completion error.");
                        goto err;
                }
        }

        clear_bit(WL1271_FLAG_IN_ELP, &wl->flags);

        wl1271_debug(DEBUG_PSM, "wakeup time: %u ms",
                     jiffies_to_msecs(jiffies - start_time));
        goto out;

err:
        spin_lock_irqsave(&wl->wl_lock, flags);
        wl->elp_compl = NULL;
        spin_unlock_irqrestore(&wl->wl_lock, flags);
        return ret;

out:
        return 0;
}

int wl1271_ps_set_mode(struct wl1271 *wl, struct wl12xx_vif *wlvif,
                       enum wl1271_cmd_ps_mode mode, u32 rates, bool send)
{
        int ret;

        switch (mode) {
        case STATION_POWER_SAVE_MODE:
                wl1271_debug(DEBUG_PSM, "entering psm");

                ret = wl1271_acx_wake_up_conditions(wl, wlvif);
                if (ret < 0) {
                        wl1271_error("couldn't set wake up conditions");
                        return ret;
                }

                ret = wl1271_cmd_ps_mode(wl, wlvif, STATION_POWER_SAVE_MODE);
                if (ret < 0)
                        return ret;

                set_bit(WLVIF_FLAG_PSM, &wlvif->flags);
                break;
        case STATION_ACTIVE_MODE:
        default:
                wl1271_debug(DEBUG_PSM, "leaving psm");

                /* disable beacon early termination */
                if (wlvif->band == IEEE80211_BAND_2GHZ) {
                        ret = wl1271_acx_bet_enable(wl, wlvif, false);
                        if (ret < 0)
                                return ret;
                }

                ret = wl1271_cmd_ps_mode(wl, wlvif, STATION_ACTIVE_MODE);
                if (ret < 0)
                        return ret;

                clear_bit(WLVIF_FLAG_PSM, &wlvif->flags);
                break;
        }

        return ret;
}

static void wl1271_ps_filter_frames(struct wl1271 *wl, u8 hlid)
{
        int i;
        struct sk_buff *skb;
        struct ieee80211_tx_info *info;
        unsigned long flags;
        int filtered[NUM_TX_QUEUES];

        /* filter all frames currently in the low level queues for this hlid */
        for (i = 0; i < NUM_TX_QUEUES; i++) {
                filtered[i] = 0;
                while ((skb = skb_dequeue(&wl->links[hlid].tx_queue[i]))) {
                        filtered[i]++;

                        if (WARN_ON(wl12xx_is_dummy_packet(wl, skb)))
                                continue;

                        info = IEEE80211_SKB_CB(skb);
                        info->flags |= IEEE80211_TX_STAT_TX_FILTERED;
                        info->status.rates[0].idx = -1;
                        ieee80211_tx_status_ni(wl->hw, skb);
                }
        }

        spin_lock_irqsave(&wl->wl_lock, flags);
        for (i = 0; i < NUM_TX_QUEUES; i++)
                wl->tx_queue_count[i] -= filtered[i];
        spin_unlock_irqrestore(&wl->wl_lock, flags);

        wl1271_handle_tx_low_watermark(wl);
}

void wl12xx_ps_link_start(struct wl1271 *wl, struct wl12xx_vif *wlvif,
                          u8 hlid, bool clean_queues)
{
        struct ieee80211_sta *sta;
        struct ieee80211_vif *vif = wl12xx_wlvif_to_vif(wlvif);

        if (test_bit(hlid, &wl->ap_ps_map))
                return;

        wl1271_debug(DEBUG_PSM, "start mac80211 PSM on hlid %d pkts %d "
                     "clean_queues %d", hlid, wl->links[hlid].allocated_pkts,
                     clean_queues);

        rcu_read_lock();
        sta = ieee80211_find_sta(vif, wl->links[hlid].addr);
        if (!sta) {
                wl1271_error("could not find sta %pM for starting ps",
                             wl->links[hlid].addr);
                rcu_read_unlock();
                return;
        }

        ieee80211_sta_ps_transition_ni(sta, true);
        rcu_read_unlock();

        /* do we want to filter all frames from this link's queues? */
        if (clean_queues)
                wl1271_ps_filter_frames(wl, hlid);

        __set_bit(hlid, &wl->ap_ps_map);
}

void wl12xx_ps_link_end(struct wl1271 *wl, struct wl12xx_vif *wlvif, u8 hlid)
{
        struct ieee80211_sta *sta;
        struct ieee80211_vif *vif = wl12xx_wlvif_to_vif(wlvif);

        if (!test_bit(hlid, &wl->ap_ps_map))
                return;

        wl1271_debug(DEBUG_PSM, "end mac80211 PSM on hlid %d", hlid);

        __clear_bit(hlid, &wl->ap_ps_map);

        rcu_read_lock();
        sta = ieee80211_find_sta(vif, wl->links[hlid].addr);
        if (!sta) {
                wl1271_error("could not find sta %pM for ending ps",
                             wl->links[hlid].addr);
                goto end;
        }

        ieee80211_sta_ps_transition_ni(sta, false);
end:
        rcu_read_unlock();
}