/*
 * 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);
}