/*
 * This file is part of wl1251
 *
 * Copyright (C) 2008 Nokia Corporation
 *
 * 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 "cmd.h"
#include "io.h"

/* in ms */
#define WL1251_WAKEUP_TIMEOUT 100

void wl1251_elp_work(struct work_struct *work)
{
        struct delayed_work *dwork;
        struct wl1251 *wl;

        dwork = container_of(work, struct delayed_work, work);
        wl = container_of(dwork, struct wl1251, elp_work);

        wl1251_debug(DEBUG_PSM, "elp work");

        mutex_lock(&wl->mutex);

        if (wl->elp || !wl->psm)
                goto out;

        wl1251_debug(DEBUG_PSM, "chip to elp");
        wl1251_write_elp(wl, HW_ACCESS_ELP_CTRL_REG_ADDR, ELPCTRL_SLEEP);
        wl->elp = true;

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

#define ELP_ENTRY_DELAY  5

/* Routines to toggle sleep mode while in ELP */
void wl1251_ps_elp_sleep(struct wl1251 *wl)
{
        unsigned long delay;

        if (wl->psm) {
                cancel_delayed_work(&wl->elp_work);
                delay = msecs_to_jiffies(ELP_ENTRY_DELAY);
                ieee80211_queue_delayed_work(wl->hw, &wl->elp_work, delay);
        }
}

int wl1251_ps_elp_wakeup(struct wl1251 *wl)
{
        unsigned long timeout, start;
        u32 elp_reg;

        if (!wl->elp)
                return 0;

        wl1251_debug(DEBUG_PSM, "waking up chip from elp");

        start = jiffies;
        timeout = jiffies + msecs_to_jiffies(WL1251_WAKEUP_TIMEOUT);

        wl1251_write_elp(wl, HW_ACCESS_ELP_CTRL_REG_ADDR, ELPCTRL_WAKE_UP);

        elp_reg = wl1251_read_elp(wl, HW_ACCESS_ELP_CTRL_REG_ADDR);

        /*
         * FIXME: we should wait for irq from chip but, as a temporary
         * solution to simplify locking, let's poll instead
         */
        while (!(elp_reg & ELPCTRL_WLAN_READY)) {
                if (time_after(jiffies, timeout)) {
                        wl1251_error("elp wakeup timeout");
                        return -ETIMEDOUT;
                }
                msleep(1);
                elp_reg = wl1251_read_elp(wl, HW_ACCESS_ELP_CTRL_REG_ADDR);
        }

        wl1251_debug(DEBUG_PSM, "wakeup time: %u ms",
                     jiffies_to_msecs(jiffies - start));

        wl->elp = false;

        return 0;
}

static int wl1251_ps_set_elp(struct wl1251 *wl, bool enable)
{
        int ret;

        if (enable) {
                wl1251_debug(DEBUG_PSM, "sleep auth psm/elp");

                ret = wl1251_acx_sleep_auth(wl, WL1251_PSM_ELP);
                if (ret < 0)
                        return ret;

                wl1251_ps_elp_sleep(wl);
        } else {
                wl1251_debug(DEBUG_PSM, "sleep auth cam");

                /*
                 * When the target is in ELP, we can only
                 * access the ELP control register. Thus,
                 * we have to wake the target up before
                 * changing the power authorization.
                 */

                wl1251_ps_elp_wakeup(wl);

                ret = wl1251_acx_sleep_auth(wl, WL1251_PSM_CAM);
                if (ret < 0)
                        return ret;
        }

        return 0;
}

int wl1251_ps_set_mode(struct wl1251 *wl, enum wl1251_cmd_ps_mode mode)
{
        int ret;

        switch (mode) {
        case STATION_POWER_SAVE_MODE:
                wl1251_debug(DEBUG_PSM, "entering psm");

                /* enable beacon filtering */
                ret = wl1251_acx_beacon_filter_opt(wl, true);
                if (ret < 0)
                        return ret;

                ret = wl1251_acx_wake_up_conditions(wl,
                                                    WAKE_UP_EVENT_DTIM_BITMAP,
                                                    wl->listen_int);
                if (ret < 0)
                        return ret;

                ret = wl1251_cmd_ps_mode(wl, STATION_POWER_SAVE_MODE);
                if (ret < 0)
                        return ret;

                ret = wl1251_ps_set_elp(wl, true);
                if (ret < 0)
                        return ret;

                wl->psm = 1;
                break;
        case STATION_ACTIVE_MODE:
        default:
                wl1251_debug(DEBUG_PSM, "leaving psm");
                ret = wl1251_ps_set_elp(wl, false);
                if (ret < 0)
                        return ret;

                /* disable beacon filtering */
                ret = wl1251_acx_beacon_filter_opt(wl, false);
                if (ret < 0)
                        return ret;

                ret = wl1251_acx_wake_up_conditions(wl,
                                                    WAKE_UP_EVENT_DTIM_BITMAP,
                                                    wl->listen_int);
                if (ret < 0)
                        return ret;

                ret = wl1251_cmd_ps_mode(wl, STATION_ACTIVE_MODE);
                if (ret < 0)
                        return ret;

                wl->psm = 0;
                break;
        }

        return ret;
}