/*
 * Copyright (c) 2014 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"

/* Set/change channels.  If the channel is really being changed, it's done
 * by reseting the chip.  To accomplish this we must first cleanup any pending
 * DMA, then restart stuff.
 */
static int ath_set_channel(struct ath_softc *sc)
{
	struct ath_hw *ah = sc->sc_ah;
	struct ath_common *common = ath9k_hw_common(ah);
	struct ieee80211_hw *hw = sc->hw;
	struct ath9k_channel *hchan;
	struct cfg80211_chan_def *chandef = &sc->cur_chan->chandef;
	struct ieee80211_channel *chan = chandef->chan;
	int pos = chan->hw_value;
	int old_pos = -1;
	int r;

	if (test_bit(ATH_OP_INVALID, &common->op_flags))
		return -EIO;

	if (ah->curchan)
		old_pos = ah->curchan - &ah->channels[0];

	ath_dbg(common, CONFIG, "Set channel: %d MHz width: %d\n",
		chan->center_freq, chandef->width);

	/* update survey stats for the old channel before switching */
	spin_lock_bh(&common->cc_lock);
	ath_update_survey_stats(sc);
	spin_unlock_bh(&common->cc_lock);

	ath9k_cmn_get_channel(hw, ah, chandef);

	/* If the operating channel changes, change the survey in-use flags
	 * along with it.
	 * Reset the survey data for the new channel, unless we're switching
	 * back to the operating channel from an off-channel operation.
	 */
	if (!sc->cur_chan->offchannel && sc->cur_survey != &sc->survey[pos]) {
		if (sc->cur_survey)
			sc->cur_survey->filled &= ~SURVEY_INFO_IN_USE;

		sc->cur_survey = &sc->survey[pos];

		memset(sc->cur_survey, 0, sizeof(struct survey_info));
		sc->cur_survey->filled |= SURVEY_INFO_IN_USE;
	} else if (!(sc->survey[pos].filled & SURVEY_INFO_IN_USE)) {
		memset(&sc->survey[pos], 0, sizeof(struct survey_info));
	}

	hchan = &sc->sc_ah->channels[pos];
	r = ath_reset_internal(sc, hchan);
	if (r)
		return r;

	/* The most recent snapshot of channel->noisefloor for the old
	 * channel is only available after the hardware reset. Copy it to
	 * the survey stats now.
	 */
	if (old_pos >= 0)
		ath_update_survey_nf(sc, old_pos);

	/* Enable radar pulse detection if on a DFS channel. Spectral
	 * scanning and radar detection can not be used concurrently.
	 */
	if (hw->conf.radar_enabled) {
		u32 rxfilter;

		/* set HW specific DFS configuration */
		ath9k_hw_set_radar_params(ah);
		rxfilter = ath9k_hw_getrxfilter(ah);
		rxfilter |= ATH9K_RX_FILTER_PHYRADAR |
				ATH9K_RX_FILTER_PHYERR;
		ath9k_hw_setrxfilter(ah, rxfilter);
		ath_dbg(common, DFS, "DFS enabled at freq %d\n",
			chan->center_freq);
	} else {
		/* perform spectral scan if requested. */
		if (test_bit(ATH_OP_SCANNING, &common->op_flags) &&
			sc->spectral_mode == SPECTRAL_CHANSCAN)
			ath9k_spectral_scan_trigger(hw);
	}

	return 0;
}

void ath_chanctx_init(struct ath_softc *sc)
{
	struct ath_chanctx *ctx;
	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
	struct ieee80211_supported_band *sband;
	struct ieee80211_channel *chan;
	int i;

	sband = &common->sbands[IEEE80211_BAND_2GHZ];
	if (!sband->n_channels)
		sband = &common->sbands[IEEE80211_BAND_5GHZ];

	chan = &sband->channels[0];
	for (i = 0; i < ATH9K_NUM_CHANCTX; i++) {
		ctx = &sc->chanctx[i];
		cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
		INIT_LIST_HEAD(&ctx->vifs);
	}
	sc->cur_chan = &sc->chanctx[0];
}

int ath_chanctx_set_channel(struct ath_softc *sc, struct ath_chanctx *ctx,
			      struct cfg80211_chan_def *chandef)
{
	memcpy(&ctx->chandef, chandef, sizeof(ctx->chandef));
	if (ctx != sc->cur_chan)
		return 0;

	return ath_set_channel(sc);
}