/*
 * 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"

#define WL1271_WAKEUP_TIMEOUT 500

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

        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;

        if (test_bit(WL1271_FLAG_IN_ELP, &wl->flags) ||
            (!test_bit(WL1271_FLAG_PSM, &wl->flags) &&
             !test_bit(WL1271_FLAG_IDLE, &wl->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)
{
        if (test_bit(WL1271_FLAG_PSM, &wl->flags) ||
            test_bit(WL1271_FLAG_IDLE, &wl->flags)) {
                cancel_delayed_work(&wl->elp_work);
                ieee80211_queue_delayed_work(wl->hw, &wl->elp_work,
                                             msecs_to_jiffies(ELP_ENTRY_DELAY));
        }
}

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

        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 (work_pending(&wl->irq_work) || chip_awake)
                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!");
                        ieee80211_queue_work(wl->hw, &wl->recovery_work);
                        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, 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);
                if (ret < 0) {
                        wl1271_error("couldn't set wake up conditions");
                        return ret;
                }

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

                set_bit(WL1271_FLAG_PSM, &wl->flags);
                break;
        case STATION_ACTIVE_MODE:
        default:
                wl1271_debug(DEBUG_PSM, "leaving psm");
                ret = wl1271_ps_elp_wakeup(wl, false);
                if (ret < 0)
                        return ret;

                /* disable beacon early termination */
                ret = wl1271_acx_bet_enable(wl, false);
                if (ret < 0)
                        return ret;

                /* disable beacon filtering */
                ret = wl1271_acx_beacon_filter_opt(wl, false);
                if (ret < 0)
                        return ret;

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

                clear_bit(WL1271_FLAG_PSM, &wl->flags);
                break;
        }

        return ret;
}