/*
 * Copyright (c) 2013 Qualcomm Atheros, Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "ath9k.h"

static const struct wiphy_wowlan_support ath9k_wowlan_support = {
        .flags = WIPHY_WOWLAN_MAGIC_PKT | WIPHY_WOWLAN_DISCONNECT,
        .n_patterns = MAX_NUM_USER_PATTERN,
        .pattern_min_len = 1,
        .pattern_max_len = MAX_PATTERN_SIZE,
};

static void ath9k_wow_map_triggers(struct ath_softc *sc,
                                   struct cfg80211_wowlan *wowlan,
                                   u32 *wow_triggers)
{
        if (wowlan->disconnect)
                *wow_triggers |= AH_WOW_LINK_CHANGE |
                                 AH_WOW_BEACON_MISS;
        if (wowlan->magic_pkt)
                *wow_triggers |= AH_WOW_MAGIC_PATTERN_EN;

        if (wowlan->n_patterns)
                *wow_triggers |= AH_WOW_USER_PATTERN_EN;

        sc->wow_enabled = *wow_triggers;

}

static void ath9k_wow_add_disassoc_deauth_pattern(struct ath_softc *sc)
{
        struct ath_hw *ah = sc->sc_ah;
        struct ath_common *common = ath9k_hw_common(ah);
        int pattern_count = 0;
        int i, byte_cnt;
        u8 dis_deauth_pattern[MAX_PATTERN_SIZE];
        u8 dis_deauth_mask[MAX_PATTERN_SIZE];

        memset(dis_deauth_pattern, 0, MAX_PATTERN_SIZE);
        memset(dis_deauth_mask, 0, MAX_PATTERN_SIZE);

        /*
         * Create Dissassociate / Deauthenticate packet filter
         *
         *     2 bytes        2 byte    6 bytes   6 bytes  6 bytes
         *  +--------------+----------+---------+--------+--------+----
         *  + Frame Control+ Duration +   DA    +  SA    +  BSSID +
         *  +--------------+----------+---------+--------+--------+----
         *
         * The above is the management frame format for disassociate/
         * deauthenticate pattern, from this we need to match the first byte
         * of 'Frame Control' and DA, SA, and BSSID fields
         * (skipping 2nd byte of FC and Duration feild.
         *
         * Disassociate pattern
         * --------------------
         * Frame control = 00 00 1010
         * DA, SA, BSSID = x:x:x:x:x:x
         * Pattern will be A0000000 | x:x:x:x:x:x | x:x:x:x:x:x
         *                          | x:x:x:x:x:x  -- 22 bytes
         *
         * Deauthenticate pattern
         * ----------------------
         * Frame control = 00 00 1100
         * DA, SA, BSSID = x:x:x:x:x:x
         * Pattern will be C0000000 | x:x:x:x:x:x | x:x:x:x:x:x
         *                          | x:x:x:x:x:x  -- 22 bytes
         */

        /* Create Disassociate Pattern first */

        byte_cnt = 0;

        /* Fill out the mask with all FF's */

        for (i = 0; i < MAX_PATTERN_MASK_SIZE; i++)
                dis_deauth_mask[i] = 0xff;

        /* copy the first byte of frame control field */
        dis_deauth_pattern[byte_cnt] = 0xa0;
        byte_cnt++;

        /* skip 2nd byte of frame control and Duration field */
        byte_cnt += 3;

        /*
         * need not match the destination mac address, it can be a broadcast
         * mac address or an unicast to this station
         */
        byte_cnt += 6;

        /* copy the source mac address */
        memcpy((dis_deauth_pattern + byte_cnt), common->curbssid, ETH_ALEN);

        byte_cnt += 6;

        /* copy the bssid, its same as the source mac address */

        memcpy((dis_deauth_pattern + byte_cnt), common->curbssid, ETH_ALEN);

        /* Create Disassociate pattern mask */

        dis_deauth_mask[0] = 0xfe;
        dis_deauth_mask[1] = 0x03;
        dis_deauth_mask[2] = 0xc0;

        ath_dbg(common, WOW, "Adding disassoc/deauth patterns for WoW\n");

        ath9k_hw_wow_apply_pattern(ah, dis_deauth_pattern, dis_deauth_mask,
                                   pattern_count, byte_cnt);

        pattern_count++;
        /*
         * for de-authenticate pattern, only the first byte of the frame
         * control field gets changed from 0xA0 to 0xC0
         */
        dis_deauth_pattern[0] = 0xC0;

        ath9k_hw_wow_apply_pattern(ah, dis_deauth_pattern, dis_deauth_mask,
                                   pattern_count, byte_cnt);

}

static void ath9k_wow_add_pattern(struct ath_softc *sc,
                                  struct cfg80211_wowlan *wowlan)
{
        struct ath_hw *ah = sc->sc_ah;
        struct ath9k_wow_pattern *wow_pattern = NULL;
        struct cfg80211_pkt_pattern *patterns = wowlan->patterns;
        int mask_len;
        s8 i = 0;

        if (!wowlan->n_patterns)
                return;

        /*
         * Add the new user configured patterns
         */
        for (i = 0; i < wowlan->n_patterns; i++) {

                wow_pattern = kzalloc(sizeof(*wow_pattern), GFP_KERNEL);

                if (!wow_pattern)
                        return;

                /*
                 * TODO: convert the generic user space pattern to
                 * appropriate chip specific/802.11 pattern.
                 */

                mask_len = DIV_ROUND_UP(wowlan->patterns[i].pattern_len, 8);
                memset(wow_pattern->pattern_bytes, 0, MAX_PATTERN_SIZE);
                memset(wow_pattern->mask_bytes, 0, MAX_PATTERN_SIZE);
                memcpy(wow_pattern->pattern_bytes, patterns[i].pattern,
                       patterns[i].pattern_len);
                memcpy(wow_pattern->mask_bytes, patterns[i].mask, mask_len);
                wow_pattern->pattern_len = patterns[i].pattern_len;

                /*
                 * just need to take care of deauth and disssoc pattern,
                 * make sure we don't overwrite them.
                 */

                ath9k_hw_wow_apply_pattern(ah, wow_pattern->pattern_bytes,
                                           wow_pattern->mask_bytes,
                                           i + 2,
                                           wow_pattern->pattern_len);
                kfree(wow_pattern);

        }

}

int ath9k_suspend(struct ieee80211_hw *hw,
                  struct cfg80211_wowlan *wowlan)
{
        struct ath_softc *sc = hw->priv;
        struct ath_hw *ah = sc->sc_ah;
        struct ath_common *common = ath9k_hw_common(ah);
        u32 wow_triggers_enabled = 0;
        int ret = 0;

        mutex_lock(&sc->mutex);

        ath_cancel_work(sc);
        ath_stop_ani(sc);

        if (test_bit(ATH_OP_INVALID, &common->op_flags)) {
                ath_dbg(common, ANY, "Device not present\n");
                ret = -EINVAL;
                goto fail_wow;
        }

        if (WARN_ON(!wowlan)) {
                ath_dbg(common, WOW, "None of the WoW triggers enabled\n");
                ret = -EINVAL;
                goto fail_wow;
        }

        if (!device_can_wakeup(sc->dev)) {
                ath_dbg(common, WOW, "device_can_wakeup failed, WoW is not enabled\n");
                ret = 1;
                goto fail_wow;
        }

        /*
         * none of the sta vifs are associated
         * and we are not currently handling multivif
         * cases, for instance we have to seperately
         * configure 'keep alive frame' for each
         * STA.
         */

        if (!test_bit(ATH_OP_PRIM_STA_VIF, &common->op_flags)) {
                ath_dbg(common, WOW, "None of the STA vifs are associated\n");
                ret = 1;
                goto fail_wow;
        }

        if (sc->nvifs > 1) {
                ath_dbg(common, WOW, "WoW for multivif is not yet supported\n");
                ret = 1;
                goto fail_wow;
        }

        ath9k_wow_map_triggers(sc, wowlan, &wow_triggers_enabled);

        ath_dbg(common, WOW, "WoW triggers enabled 0x%x\n",
                wow_triggers_enabled);

        ath9k_ps_wakeup(sc);

        ath9k_stop_btcoex(sc);

        /*
         * Enable wake up on recieving disassoc/deauth
         * frame by default.
         */
        ath9k_wow_add_disassoc_deauth_pattern(sc);

        if (wow_triggers_enabled & AH_WOW_USER_PATTERN_EN)
                ath9k_wow_add_pattern(sc, wowlan);

        spin_lock_bh(&sc->sc_pcu_lock);
        /*
         * To avoid false wake, we enable beacon miss interrupt only
         * when we go to sleep. We save the current interrupt mask
         * so we can restore it after the system wakes up
         */
        sc->wow_intr_before_sleep = ah->imask;
        ah->imask &= ~ATH9K_INT_GLOBAL;
        ath9k_hw_disable_interrupts(ah);
        ah->imask = ATH9K_INT_BMISS | ATH9K_INT_GLOBAL;
        ath9k_hw_set_interrupts(ah);
        ath9k_hw_enable_interrupts(ah);

        spin_unlock_bh(&sc->sc_pcu_lock);

        /*
         * we can now sync irq and kill any running tasklets, since we already
         * disabled interrupts and not holding a spin lock
         */
        synchronize_irq(sc->irq);
        tasklet_kill(&sc->intr_tq);

        ath9k_hw_wow_enable(ah, wow_triggers_enabled);

        ath9k_ps_restore(sc);
        ath_dbg(common, ANY, "WoW enabled in ath9k\n");
        atomic_inc(&sc->wow_sleep_proc_intr);

fail_wow:
        mutex_unlock(&sc->mutex);
        return ret;
}

int ath9k_resume(struct ieee80211_hw *hw)
{
        struct ath_softc *sc = hw->priv;
        struct ath_hw *ah = sc->sc_ah;
        struct ath_common *common = ath9k_hw_common(ah);
        u32 wow_status;

        mutex_lock(&sc->mutex);

        ath9k_ps_wakeup(sc);

        spin_lock_bh(&sc->sc_pcu_lock);

        ath9k_hw_disable_interrupts(ah);
        ah->imask = sc->wow_intr_before_sleep;
        ath9k_hw_set_interrupts(ah);
        ath9k_hw_enable_interrupts(ah);

        spin_unlock_bh(&sc->sc_pcu_lock);

        wow_status = ath9k_hw_wow_wakeup(ah);

        if (atomic_read(&sc->wow_got_bmiss_intr) == 0) {
                /*
                 * some devices may not pick beacon miss
                 * as the reason they woke up so we add
                 * that here for that shortcoming.
                 */
                wow_status |= AH_WOW_BEACON_MISS;
                atomic_dec(&sc->wow_got_bmiss_intr);
                ath_dbg(common, ANY, "Beacon miss interrupt picked up during WoW sleep\n");
        }

        atomic_dec(&sc->wow_sleep_proc_intr);

        if (wow_status) {
                ath_dbg(common, ANY, "Waking up due to WoW triggers %s with WoW status = %x\n",
                        ath9k_hw_wow_event_to_string(wow_status), wow_status);
        }

        ath_restart_work(sc);
        ath9k_start_btcoex(sc);

        ath9k_ps_restore(sc);
        mutex_unlock(&sc->mutex);

        return 0;
}

void ath9k_set_wakeup(struct ieee80211_hw *hw, bool enabled)
{
        struct ath_softc *sc = hw->priv;

        mutex_lock(&sc->mutex);
        device_init_wakeup(sc->dev, 1);
        device_set_wakeup_enable(sc->dev, enabled);
        mutex_unlock(&sc->mutex);
}

void ath9k_init_wow(struct ieee80211_hw *hw)
{
        struct ath_softc *sc = hw->priv;

        if ((sc->sc_ah->caps.hw_caps & ATH9K_HW_WOW_DEVICE_CAPABLE) &&
            (sc->driver_data & ATH9K_PCI_WOW) &&
            device_can_wakeup(sc->dev))
                hw->wiphy->wowlan = &ath9k_wowlan_support;

        atomic_set(&sc->wow_sleep_proc_intr, -1);
        atomic_set(&sc->wow_got_bmiss_intr, -1);
}