drivers/net/wireless/ath/ath5k/base.c

/*-
 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
 * Copyright (c) 2004-2005 Atheros Communications, Inc.
 * Copyright (c) 2006 Devicescape Software, Inc.
 * Copyright (c) 2007 Jiri Slaby <jirislaby@gmail.com>
 * Copyright (c) 2007 Luis R. Rodriguez <mcgrof@winlab.rutgers.edu>
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
 *    redistribution must be conditioned upon including a substantially
 *    similar Disclaimer requirement for further binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGES.
 *
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/hardirq.h>
#include <linux/if.h>
#include <linux/io.h>
#include <linux/netdevice.h>
#include <linux/cache.h>
#include <linux/pci.h>
#include <linux/pci-aspm.h>
#include <linux/ethtool.h>
#include <linux/uaccess.h>
#include <linux/slab.h>

#include <net/ieee80211_radiotap.h>

#include <asm/unaligned.h>

#include "base.h"
#include "reg.h"
#include "debug.h"
#include "ani.h"

static int modparam_nohwcrypt;
module_param_named(nohwcrypt, modparam_nohwcrypt, bool, S_IRUGO);
MODULE_PARM_DESC(nohwcrypt, "Disable hardware encryption.");

static int modparam_all_channels;
module_param_named(all_channels, modparam_all_channels, bool, S_IRUGO);
MODULE_PARM_DESC(all_channels, "Expose all channels the device can use.");

/* Module info */
MODULE_AUTHOR("Jiri Slaby");
MODULE_AUTHOR("Nick Kossifidis");
MODULE_DESCRIPTION("Support for 5xxx series of Atheros 802.11 wireless LAN cards.");
MODULE_SUPPORTED_DEVICE("Atheros 5xxx WLAN cards");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_VERSION("0.6.0 (EXPERIMENTAL)");

static int ath5k_reset(struct ath5k_softc *sc, struct ieee80211_channel *chan);
static int ath5k_beacon_update(struct ieee80211_hw *hw,
		struct ieee80211_vif *vif);
static void ath5k_beacon_update_timers(struct ath5k_softc *sc, u64 bc_tsf);

/* Known PCI ids */
static DEFINE_PCI_DEVICE_TABLE(ath5k_pci_id_table) = {
	{ PCI_VDEVICE(ATHEROS, 0x0207) }, /* 5210 early */
	{ PCI_VDEVICE(ATHEROS, 0x0007) }, /* 5210 */
	{ PCI_VDEVICE(ATHEROS, 0x0011) }, /* 5311 - this is on AHB bus !*/
	{ PCI_VDEVICE(ATHEROS, 0x0012) }, /* 5211 */
	{ PCI_VDEVICE(ATHEROS, 0x0013) }, /* 5212 */
	{ PCI_VDEVICE(3COM_2,  0x0013) }, /* 3com 5212 */
	{ PCI_VDEVICE(3COM,    0x0013) }, /* 3com 3CRDAG675 5212 */
	{ PCI_VDEVICE(ATHEROS, 0x1014) }, /* IBM minipci 5212 */
	{ PCI_VDEVICE(ATHEROS, 0x0014) }, /* 5212 combatible */
	{ PCI_VDEVICE(ATHEROS, 0x0015) }, /* 5212 combatible */
	{ PCI_VDEVICE(ATHEROS, 0x0016) }, /* 5212 combatible */
	{ PCI_VDEVICE(ATHEROS, 0x0017) }, /* 5212 combatible */
	{ PCI_VDEVICE(ATHEROS, 0x0018) }, /* 5212 combatible */
	{ PCI_VDEVICE(ATHEROS, 0x0019) }, /* 5212 combatible */
	{ PCI_VDEVICE(ATHEROS, 0x001a) }, /* 2413 Griffin-lite */
	{ PCI_VDEVICE(ATHEROS, 0x001b) }, /* 5413 Eagle */
	{ PCI_VDEVICE(ATHEROS, 0x001c) }, /* PCI-E cards */
	{ PCI_VDEVICE(ATHEROS, 0x001d) }, /* 2417 Nala */
	{ 0 }
};
MODULE_DEVICE_TABLE(pci, ath5k_pci_id_table);

/* Known SREVs */
static const struct ath5k_srev_name srev_names[] = {
	{ "5210",	AR5K_VERSION_MAC,	AR5K_SREV_AR5210 },
	{ "5311",	AR5K_VERSION_MAC,	AR5K_SREV_AR5311 },
	{ "5311A",	AR5K_VERSION_MAC,	AR5K_SREV_AR5311A },
	{ "5311B",	AR5K_VERSION_MAC,	AR5K_SREV_AR5311B },
	{ "5211",	AR5K_VERSION_MAC,	AR5K_SREV_AR5211 },
	{ "5212",	AR5K_VERSION_MAC,	AR5K_SREV_AR5212 },
	{ "5213",	AR5K_VERSION_MAC,	AR5K_SREV_AR5213 },
	{ "5213A",	AR5K_VERSION_MAC,	AR5K_SREV_AR5213A },
	{ "2413",	AR5K_VERSION_MAC,	AR5K_SREV_AR2413 },
	{ "2414",	AR5K_VERSION_MAC,	AR5K_SREV_AR2414 },
	{ "5424",	AR5K_VERSION_MAC,	AR5K_SREV_AR5424 },
	{ "5413",	AR5K_VERSION_MAC,	AR5K_SREV_AR5413 },
	{ "5414",	AR5K_VERSION_MAC,	AR5K_SREV_AR5414 },
	{ "2415",	AR5K_VERSION_MAC,	AR5K_SREV_AR2415 },
	{ "5416",	AR5K_VERSION_MAC,	AR5K_SREV_AR5416 },
	{ "5418",	AR5K_VERSION_MAC,	AR5K_SREV_AR5418 },
	{ "2425",	AR5K_VERSION_MAC,	AR5K_SREV_AR2425 },
	{ "2417",	AR5K_VERSION_MAC,	AR5K_SREV_AR2417 },
	{ "xxxxx",	AR5K_VERSION_MAC,	AR5K_SREV_UNKNOWN },
	{ "5110",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_5110 },
	{ "5111",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_5111 },
	{ "5111A",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_5111A },
	{ "2111",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_2111 },
	{ "5112",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_5112 },
	{ "5112A",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_5112A },
	{ "5112B",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_5112B },
	{ "2112",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_2112 },
	{ "2112A",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_2112A },
	{ "2112B",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_2112B },
	{ "2413",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_2413 },
	{ "5413",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_5413 },
	{ "2316",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_2316 },
	{ "2317",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_2317 },
	{ "5424",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_5424 },
	{ "5133",	AR5K_VERSION_RAD,	AR5K_SREV_RAD_5133 },
	{ "xxxxx",	AR5K_VERSION_RAD,	AR5K_SREV_UNKNOWN },
};

static const struct ieee80211_rate ath5k_rates[] = {
	{ .bitrate = 10,
	  .hw_value = ATH5K_RATE_CODE_1M, },
	{ .bitrate = 20,
	  .hw_value = ATH5K_RATE_CODE_2M,
	  .hw_value_short = ATH5K_RATE_CODE_2M | AR5K_SET_SHORT_PREAMBLE,
	  .flags = IEEE80211_RATE_SHORT_PREAMBLE },
	{ .bitrate = 55,
	  .hw_value = ATH5K_RATE_CODE_5_5M,
	  .hw_value_short = ATH5K_RATE_CODE_5_5M | AR5K_SET_SHORT_PREAMBLE,
	  .flags = IEEE80211_RATE_SHORT_PREAMBLE },
	{ .bitrate = 110,
	  .hw_value = ATH5K_RATE_CODE_11M,
	  .hw_value_short = ATH5K_RATE_CODE_11M | AR5K_SET_SHORT_PREAMBLE,
	  .flags = IEEE80211_RATE_SHORT_PREAMBLE },
	{ .bitrate = 60,
	  .hw_value = ATH5K_RATE_CODE_6M,
	  .flags = 0 },
	{ .bitrate = 90,
	  .hw_value = ATH5K_RATE_CODE_9M,
	  .flags = 0 },
	{ .bitrate = 120,
	  .hw_value = ATH5K_RATE_CODE_12M,
	  .flags = 0 },
	{ .bitrate = 180,
	  .hw_value = ATH5K_RATE_CODE_18M,
	  .flags = 0 },
	{ .bitrate = 240,
	  .hw_value = ATH5K_RATE_CODE_24M,
	  .flags = 0 },
	{ .bitrate = 360,
	  .hw_value = ATH5K_RATE_CODE_36M,
	  .flags = 0 },
	{ .bitrate = 480,
	  .hw_value = ATH5K_RATE_CODE_48M,
	  .flags = 0 },
	{ .bitrate = 540,
	  .hw_value = ATH5K_RATE_CODE_54M,
	  .flags = 0 },
	/* XR missing */
};

static inline void ath5k_txbuf_free_skb(struct ath5k_softc *sc,
				struct ath5k_buf *bf)
{
	BUG_ON(!bf);
	if (!bf->skb)
		return;
	pci_unmap_single(sc->pdev, bf->skbaddr, bf->skb->len,
			PCI_DMA_TODEVICE);
	dev_kfree_skb_any(bf->skb);
	bf->skb = NULL;
	bf->skbaddr = 0;
	bf->desc->ds_data = 0;
}

static inline void ath5k_rxbuf_free_skb(struct ath5k_softc *sc,
				struct ath5k_buf *bf)
{
	struct ath5k_hw *ah = sc->ah;
	struct ath_common *common = ath5k_hw_common(ah);

	BUG_ON(!bf);
	if (!bf->skb)
		return;
	pci_unmap_single(sc->pdev, bf->skbaddr, common->rx_bufsize,
			PCI_DMA_FROMDEVICE);
	dev_kfree_skb_any(bf->skb);
	bf->skb = NULL;
	bf->skbaddr = 0;
	bf->desc->ds_data = 0;
}


static inline u64 ath5k_extend_tsf(struct ath5k_hw *ah, u32 rstamp)
{
	u64 tsf = ath5k_hw_get_tsf64(ah);

	if ((tsf & 0x7fff) < rstamp)
		tsf -= 0x8000;

	return (tsf & ~0x7fff) | rstamp;
}

static const char *
ath5k_chip_name(enum ath5k_srev_type type, u_int16_t val)
{
	const char *name = "xxxxx";
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(srev_names); i++) {
		if (srev_names[i].sr_type != type)
			continue;

		if ((val & 0xf0) == srev_names[i].sr_val)
			name = srev_names[i].sr_name;

		if ((val & 0xff) == srev_names[i].sr_val) {
			name = srev_names[i].sr_name;
			break;
		}
	}

	return name;
}
static unsigned int ath5k_ioread32(void *hw_priv, u32 reg_offset)
{
	struct ath5k_hw *ah = (struct ath5k_hw *) hw_priv;
	return ath5k_hw_reg_read(ah, reg_offset);
}

static void ath5k_iowrite32(void *hw_priv, u32 val, u32 reg_offset)
{
	struct ath5k_hw *ah = (struct ath5k_hw *) hw_priv;
	ath5k_hw_reg_write(ah, val, reg_offset);
}

static const struct ath_ops ath5k_common_ops = {
	.read = ath5k_ioread32,
	.write = ath5k_iowrite32,
};

/***********************\
* Driver Initialization *
\***********************/

static int ath5k_reg_notifier(struct wiphy *wiphy, struct regulatory_request *request)
{
	struct ieee80211_hw *hw = wiphy_to_ieee80211_hw(wiphy);
	struct ath5k_softc *sc = hw->priv;
	struct ath_regulatory *regulatory = ath5k_hw_regulatory(sc->ah);

	return ath_reg_notifier_apply(wiphy, request, regulatory);
}

/********************\
* Channel/mode setup *
\********************/

/*
 * Convert IEEE channel number to MHz frequency.
 */
static inline short
ath5k_ieee2mhz(short chan)
{
	if (chan <= 14 || chan >= 27)
		return ieee80211chan2mhz(chan);
	else
		return 2212 + chan * 20;
}

/*
 * Returns true for the channel numbers used without all_channels modparam.
 */
static bool ath5k_is_standard_channel(short chan)
{
	return ((chan <= 14) ||
		/* UNII 1,2 */
		((chan & 3) == 0 && chan >= 36 && chan <= 64) ||
		/* midband */
		((chan & 3) == 0 && chan >= 100 && chan <= 140) ||
		/* UNII-3 */
		((chan & 3) == 1 && chan >= 149 && chan <= 165));
}

static unsigned int
ath5k_copy_channels(struct ath5k_hw *ah,
		struct ieee80211_channel *channels,
		unsigned int mode,
		unsigned int max)
{
	unsigned int i, count, size, chfreq, freq, ch;

	if (!test_bit(mode, ah->ah_modes))
		return 0;

	switch (mode) {
	case AR5K_MODE_11A:
	case AR5K_MODE_11A_TURBO:
		/* 1..220, but 2GHz frequencies are filtered by check_channel */
		size = 220 ;
		chfreq = CHANNEL_5GHZ;
		break;
	case AR5K_MODE_11B:
	case AR5K_MODE_11G:
	case AR5K_MODE_11G_TURBO:
		size = 26;
		chfreq = CHANNEL_2GHZ;
		break;
	default:
		ATH5K_WARN(ah->ah_sc, "bad mode, not copying channels\n");
		return 0;
	}

	for (i = 0, count = 0; i < size && max > 0; i++) {
		ch = i + 1 ;
		freq = ath5k_ieee2mhz(ch);

		/* Check if channel is supported by the chipset */
		if (!ath5k_channel_ok(ah, freq, chfreq))
			continue;

		if (!modparam_all_channels && !ath5k_is_standard_channel(ch))
			continue;

		/* Write channel info and increment counter */
		channels[count].center_freq = freq;
		channels[count].band = (chfreq == CHANNEL_2GHZ) ?
			IEEE80211_BAND_2GHZ : IEEE80211_BAND_5GHZ;
		switch (mode) {
		case AR5K_MODE_11A:
		case AR5K_MODE_11G:
			channels[count].hw_value = chfreq | CHANNEL_OFDM;
			break;
		case AR5K_MODE_11A_TURBO:
		case AR5K_MODE_11G_TURBO:
			channels[count].hw_value = chfreq |
				CHANNEL_OFDM | CHANNEL_TURBO;
			break;
		case AR5K_MODE_11B:
			channels[count].hw_value = CHANNEL_B;
		}

		count++;
		max--;
	}

	return count;
}

static void
ath5k_setup_rate_idx(struct ath5k_softc *sc, struct ieee80211_supported_band *b)
{
	u8 i;

	for (i = 0; i < AR5K_MAX_RATES; i++)
		sc->rate_idx[b->band][i] = -1;

	for (i = 0; i < b->n_bitrates; i++) {
		sc->rate_idx[b->band][b->bitrates[i].hw_value] = i;
		if (b->bitrates[i].hw_value_short)
			sc->rate_idx[b->band][b->bitrates[i].hw_value_short] = i;
	}
}

static int
ath5k_setup_bands(struct ieee80211_hw *hw)
{
	struct ath5k_softc *sc = hw->priv;
	struct ath5k_hw *ah = sc->ah;
	struct ieee80211_supported_band *sband;
	int max_c, count_c = 0;
	int i;

	BUILD_BUG_ON(ARRAY_SIZE(sc->sbands) < IEEE80211_NUM_BANDS);
	max_c = ARRAY_SIZE(sc->channels);

	/* 2GHz band */
	sband = &sc->sbands[IEEE80211_BAND_2GHZ];
	sband->band = IEEE80211_BAND_2GHZ;
	sband->bitrates = &sc->rates[IEEE80211_BAND_2GHZ][0];

	if (test_bit(AR5K_MODE_11G, sc->ah->ah_capabilities.cap_mode)) {
		/* G mode */
		memcpy(sband->bitrates, &ath5k_rates[0],
		       sizeof(struct ieee80211_rate) * 12);
		sband->n_bitrates = 12;

		sband->channels = sc->channels;
		sband->n_channels = ath5k_copy_channels(ah, sband->channels,
					AR5K_MODE_11G, max_c);

		hw->wiphy->bands[IEEE80211_BAND_2GHZ] = sband;
		count_c = sband->n_channels;
		max_c -= count_c;
	} else if (test_bit(AR5K_MODE_11B, sc->ah->ah_capabilities.cap_mode)) {
		/* B mode */
		memcpy(sband->bitrates, &ath5k_rates[0],
		       sizeof(struct ieee80211_rate) * 4);
		sband->n_bitrates = 4;

		/* 5211 only supports B rates and uses 4bit rate codes
		 * (e.g normally we have 0x1B for 1M, but on 5211 we have 0x0B)
		 * fix them up here:
		 */
		if (ah->ah_version == AR5K_AR5211) {
			for (i = 0; i < 4; i++) {
				sband->bitrates[i].hw_value =
					sband->bitrates[i].hw_value & 0xF;
				sband->bitrates[i].hw_value_short =
					sband->bitrates[i].hw_value_short & 0xF;
			}
		}

		sband->channels = sc->channels;
		sband->n_channels = ath5k_copy_channels(ah, sband->channels,
					AR5K_MODE_11B, max_c);

		hw->wiphy->bands[IEEE80211_BAND_2GHZ] = sband;
		count_c = sband->n_channels;
		max_c -= count_c;
	}
	ath5k_setup_rate_idx(sc, sband);

	/* 5GHz band, A mode */
	if (test_bit(AR5K_MODE_11A, sc->ah->ah_capabilities.cap_mode)) {
		sband = &sc->sbands[IEEE80211_BAND_5GHZ];
		sband->band = IEEE80211_BAND_5GHZ;
		sband->bitrates = &sc->rates[IEEE80211_BAND_5GHZ][0];

		memcpy(sband->bitrates, &ath5k_rates[4],
		       sizeof(struct ieee80211_rate) * 8);
		sband->n_bitrates = 8;

		sband->channels = &sc->channels[count_c];
		sband->n_channels = ath5k_copy_channels(ah, sband->channels,
					AR5K_MODE_11A, max_c);

		hw->wiphy->bands[IEEE80211_BAND_5GHZ] = sband;
	}
	ath5k_setup_rate_idx(sc, sband);

	ath5k_debug_dump_bands(sc);

	return 0;
}

/*
 * Set/change channels. We always reset the chip.
 * To accomplish this we must first cleanup any pending DMA,
 * then restart stuff after a la  ath5k_init.
 *
 * Called with sc->lock.
 */
static int
ath5k_chan_set(struct ath5k_softc *sc, struct ieee80211_channel *chan)
{
	ATH5K_DBG(sc, ATH5K_DEBUG_RESET,
		  "channel set, resetting (%u -> %u MHz)\n",
		  sc->curchan->center_freq, chan->center_freq);

	/*
	 * To switch channels clear any pending DMA operations;
	 * wait long enough for the RX fifo to drain, reset the
	 * hardware at the new frequency, and then re-enable
	 * the relevant bits of the h/w.
	 */
	return ath5k_reset(sc, chan);
}

static void
ath5k_setcurmode(struct ath5k_softc *sc, unsigned int mode)
{
	sc->curmode = mode;

	if (mode == AR5K_MODE_11A) {
		sc->curband = &sc->sbands[IEEE80211_BAND_5GHZ];
	} else {
		sc->curband = &sc->sbands[IEEE80211_BAND_2GHZ];
	}
}

static void
ath5k_mode_setup(struct ath5k_softc *sc)
{
	struct ath5k_hw *ah = sc->ah;
	u32 rfilt;

	/* configure rx filter */
	rfilt = sc->filter_flags;
	ath5k_hw_set_rx_filter(ah, rfilt);

	if (ath5k_hw_hasbssidmask(ah))
		ath5k_hw_set_bssid_mask(ah, sc->bssidmask);

	/* configure operational mode */
	ath5k_hw_set_opmode(ah, sc->opmode);

	ATH5K_DBG(sc, ATH5K_DEBUG_MODE, "mode setup opmode %d\n", sc->opmode);
	ATH5K_DBG(sc, ATH5K_DEBUG_MODE, "RX filter 0x%x\n", rfilt);
}

static inline int
ath5k_hw_to_driver_rix(struct ath5k_softc *sc, int hw_rix)
{
	int rix;

	/* return base rate on errors */
	if (WARN(hw_rix < 0 || hw_rix >= AR5K_MAX_RATES,
			"hw_rix out of bounds: %x\n", hw_rix))
		return 0;

	rix = sc->rate_idx[sc->curband->band][hw_rix];
	if (WARN(rix < 0, "invalid hw_rix: %x\n", hw_rix))
		rix = 0;

	return rix;
}

/***************\
* Buffers setup *
\***************/

static
struct sk_buff *ath5k_rx_skb_alloc(struct ath5k_softc *sc, dma_addr_t *skb_addr)
{
	struct ath_common *common = ath5k_hw_common(sc->ah);
	struct sk_buff *skb;

	/*
	 * Allocate buffer with headroom_needed space for the
	 * fake physical layer header at the start.
	 */
	skb = ath_rxbuf_alloc(common,
			      common->rx_bufsize,
			      GFP_ATOMIC);

	if (!skb) {
		ATH5K_ERR(sc, "can't alloc skbuff of size %u\n",
				common->rx_bufsize);
		return NULL;
	}

	*skb_addr = pci_map_single(sc->pdev,
				   skb->data, common->rx_bufsize,
				   PCI_DMA_FROMDEVICE);
	if (unlikely(pci_dma_mapping_error(sc->pdev, *skb_addr))) {
		ATH5K_ERR(sc, "%s: DMA mapping failed\n", __func__);
		dev_kfree_skb(skb);
		return NULL;
	}
	return skb;
}

static int
ath5k_rxbuf_setup(struct ath5k_softc *sc, struct ath5k_buf *bf)
{
	struct ath5k_hw *ah = sc->ah;
	struct sk_buff *skb = bf->skb;
	struct ath5k_desc *ds;
	int ret;

	if (!skb) {
		skb = ath5k_rx_skb_alloc(sc, &bf->skbaddr);
		if (!skb)
			return -ENOMEM;
		bf->skb = skb;
	}

	/*
	 * Setup descriptors.  For receive we always terminate
	 * the descriptor list with a self-linked entry so we'll
	 * not get overrun under high load (as can happen with a
	 * 5212 when ANI processing enables PHY error frames).
	 *
	 * To ensure the last descriptor is self-linked we create
	 * each descriptor as self-linked and add it to the end.  As
	 * each additional descriptor is added the previous self-linked
	 * entry is "fixed" naturally.  This should be safe even
	 * if DMA is happening.  When processing RX interrupts we
	 * never remove/process the last, self-linked, entry on the
	 * descriptor list.  This ensures the hardware always has
	 * someplace to write a new frame.
	 */
	ds = bf->desc;
	ds->ds_link = bf->daddr;	/* link to self */
	ds->ds_data = bf->skbaddr;
	ret = ath5k_hw_setup_rx_desc(ah, ds, ah->common.rx_bufsize, 0);
	if (ret) {
		ATH5K_ERR(sc, "%s: could not setup RX desc\n", __func__);
		return ret;
	}

	if (sc->rxlink != NULL)
		*sc->rxlink = bf->daddr;
	sc->rxlink = &ds->ds_link;
	return 0;
}

static enum ath5k_pkt_type get_hw_packet_type(struct sk_buff *skb)
{
	struct ieee80211_hdr *hdr;
	enum ath5k_pkt_type htype;
	__le16 fc;

	hdr = (struct ieee80211_hdr *)skb->data;
	fc = hdr->frame_control;

	if (ieee80211_is_beacon(fc))
		htype = AR5K_PKT_TYPE_BEACON;
	else if (ieee80211_is_probe_resp(fc))
		htype = AR5K_PKT_TYPE_PROBE_RESP;
	else if (ieee80211_is_atim(fc))
		htype = AR5K_PKT_TYPE_ATIM;
	else if (ieee80211_is_pspoll(fc))
		htype = AR5K_PKT_TYPE_PSPOLL;
	else
		htype = AR5K_PKT_TYPE_NORMAL;

	return htype;
}

static int
ath5k_txbuf_setup(struct ath5k_softc *sc, struct ath5k_buf *bf,
		  struct ath5k_txq *txq, int padsize)
{
	struct ath5k_hw *ah = sc->ah;
	struct ath5k_desc *ds = bf->desc;
	struct sk_buff *skb = bf->skb;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	unsigned int pktlen, flags, keyidx = AR5K_TXKEYIX_INVALID;
	struct ieee80211_rate *rate;
	unsigned int mrr_rate[3], mrr_tries[3];
	int i, ret;
	u16 hw_rate;
	u16 cts_rate = 0;
	u16 duration = 0;
	u8 rc_flags;

	flags = AR5K_TXDESC_INTREQ | AR5K_TXDESC_CLRDMASK;

	/* XXX endianness */
	bf->skbaddr = pci_map_single(sc->pdev, skb->data, skb->len,
			PCI_DMA_TODEVICE);

	rate = ieee80211_get_tx_rate(sc->hw, info);

	if (info->flags & IEEE80211_TX_CTL_NO_ACK)
		flags |= AR5K_TXDESC_NOACK;

	rc_flags = info->control.rates[0].flags;
	hw_rate = (rc_flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE) ?
		rate->hw_value_short : rate->hw_value;

	pktlen = skb->len;

	/* FIXME: If we are in g mode and rate is a CCK rate
	 * subtract ah->ah_txpower.txp_cck_ofdm_pwr_delta
	 * from tx power (value is in dB units already) */
	if (info->control.hw_key) {
		keyidx = info->control.hw_key->hw_key_idx;
		pktlen += info->control.hw_key->icv_len;
	}
	if (rc_flags & IEEE80211_TX_RC_USE_RTS_CTS) {
		flags |= AR5K_TXDESC_RTSENA;
		cts_rate = ieee80211_get_rts_cts_rate(sc->hw, info)->hw_value;
		duration = le16_to_cpu(ieee80211_rts_duration(sc->hw,
			sc->vif, pktlen, info));
	}
	if (rc_flags & IEEE80211_TX_RC_USE_CTS_PROTECT) {
		flags |= AR5K_TXDESC_CTSENA;
		cts_rate = ieee80211_get_rts_cts_rate(sc->hw, info)->hw_value;
		duration = le16_to_cpu(ieee80211_ctstoself_duration(sc->hw,
			sc->vif, pktlen, info));
	}
	ret = ah->ah_setup_tx_desc(ah, ds, pktlen,
		ieee80211_get_hdrlen_from_skb(skb), padsize,
		get_hw_packet_type(skb),
		(sc->power_level * 2),
		hw_rate,
		info->control.rates[0].count, keyidx, ah->ah_tx_ant, flags,
		cts_rate, duration);
	if (ret)
		goto err_unmap;

	memset(mrr_rate, 0, sizeof(mrr_rate));
	memset(mrr_tries, 0, sizeof(mrr_tries));
	for (i = 0; i < 3; i++) {
		rate = ieee80211_get_alt_retry_rate(sc->hw, info, i);
		if (!rate)
			break;

		mrr_rate[i] = rate->hw_value;
		mrr_tries[i] = info->control.rates[i + 1].count;
	}

	ath5k_hw_setup_mrr_tx_desc(ah, ds,
		mrr_rate[0], mrr_tries[0],
		mrr_rate[1], mrr_tries[1],
		mrr_rate[2], mrr_tries[2]);

	ds->ds_link = 0;
	ds->ds_data = bf->skbaddr;

	spin_lock_bh(&txq->lock);
	list_add_tail(&bf->list, &txq->q);
	txq->txq_len++;
	if (txq->link == NULL) /* is this first packet? */
		ath5k_hw_set_txdp(ah, txq->qnum, bf->daddr);
	else /* no, so only link it */
		*txq->link = bf->daddr;

	txq->link = &ds->ds_link;
	ath5k_hw_start_tx_dma(ah, txq->qnum);
	mmiowb();
	spin_unlock_bh(&txq->lock);

	return 0;
err_unmap:
	pci_unmap_single(sc->pdev, bf->skbaddr, skb->len, PCI_DMA_TODEVICE);
	return ret;
}

/*******************\
* Descriptors setup *
\*******************/

static int
ath5k_desc_alloc(struct ath5k_softc *sc, struct pci_dev *pdev)
{
	struct ath5k_desc *ds;
	struct ath5k_buf *bf;
	dma_addr_t da;
	unsigned int i;
	int ret;

	/* allocate descriptors */
	sc->desc_len = sizeof(struct ath5k_desc) *
			(ATH_TXBUF + ATH_RXBUF + ATH_BCBUF + 1);
	sc->desc = pci_alloc_consistent(pdev, sc->desc_len, &sc->desc_daddr);
	if (sc->desc == NULL) {
		ATH5K_ERR(sc, "can't allocate descriptors\n");
		ret = -ENOMEM;
		goto err;
	}
	ds = sc->desc;
	da = sc->desc_daddr;
	ATH5K_DBG(sc, ATH5K_DEBUG_ANY, "DMA map: %p (%zu) -> %llx\n",
		ds, sc->desc_len, (unsigned long long)sc->desc_daddr);

	bf = kcalloc(1 + ATH_TXBUF + ATH_RXBUF + ATH_BCBUF,
			sizeof(struct ath5k_buf), GFP_KERNEL);
	if (bf == NULL) {
		ATH5K_ERR(sc, "can't allocate bufptr\n");
		ret = -ENOMEM;
		goto err_free;
	}
	sc->bufptr = bf;

	INIT_LIST_HEAD(&sc->rxbuf);
	for (i = 0; i < ATH_RXBUF; i++, bf++, ds++, da += sizeof(*ds)) {
		bf->desc = ds;
		bf->daddr = da;
		list_add_tail(&bf->list, &sc->rxbuf);
	}

	INIT_LIST_HEAD(&sc->txbuf);
	sc->txbuf_len = ATH_TXBUF;
	for (i = 0; i < ATH_TXBUF; i++, bf++, ds++,
			da += sizeof(*ds)) {
		bf->desc = ds;
		bf->daddr = da;
		list_add_tail(&bf->list, &sc->txbuf);
	}

	/* beacon buffer */
	bf->desc = ds;
	bf->daddr = da;
	sc->bbuf = bf;

	return 0;
err_free:
	pci_free_consistent(pdev, sc->desc_len, sc->desc, sc->desc_daddr);
err:
	sc->desc = NULL;
	return ret;
}

static void
ath5k_desc_free(struct ath5k_softc *sc, struct pci_dev *pdev)
{
	struct ath5k_buf *bf;

	ath5k_txbuf_free_skb(sc, sc->bbuf);
	list_for_each_entry(bf, &sc->txbuf, list)
		ath5k_txbuf_free_skb(sc, bf);
	list_for_each_entry(bf, &sc->rxbuf, list)
		ath5k_rxbuf_free_skb(sc, bf);

	/* Free memory associated with all descriptors */
	pci_free_consistent(pdev, sc->desc_len, sc->desc, sc->desc_daddr);
	sc->desc = NULL;
	sc->desc_daddr = 0;

	kfree(sc->bufptr);
	sc->bufptr = NULL;
	sc->bbuf = NULL;
}


/**************\
* Queues setup *
\**************/

static struct ath5k_txq *
ath5k_txq_setup(struct ath5k_softc *sc,
		int qtype, int subtype)
{
	struct ath5k_hw *ah = sc->ah;
	struct ath5k_txq *txq;
	struct ath5k_txq_info qi = {
		.tqi_subtype = subtype,
		.tqi_aifs = AR5K_TXQ_USEDEFAULT,
		.tqi_cw_min = AR5K_TXQ_USEDEFAULT,
		.tqi_cw_max = AR5K_TXQ_USEDEFAULT
	};
	int qnum;

	/*
	 * Enable interrupts only for EOL and DESC conditions.
	 * We mark tx descriptors to receive a DESC interrupt
	 * when a tx queue gets deep; otherwise we wait for the
	 * EOL to reap descriptors.  Note that this is done to
	 * reduce interrupt load and this only defers reaping
	 * descriptors, never transmitting frames.  Aside from
	 * reducing interrupts this also permits more concurrency.
	 * The only potential downside is if the tx queue backs
	 * up in which case the top half of the kernel may backup
	 * due to a lack of tx descriptors.
	 */
	qi.tqi_flags = AR5K_TXQ_FLAG_TXEOLINT_ENABLE |
				AR5K_TXQ_FLAG_TXDESCINT_ENABLE;
	qnum = ath5k_hw_setup_tx_queue(ah, qtype, &qi);
	if (qnum < 0) {
		/*
		 * NB: don't print a message, this happens
		 * normally on parts with too few tx queues
		 */
		return ERR_PTR(qnum);
	}
	if (qnum >= ARRAY_SIZE(sc->txqs)) {
		ATH5K_ERR(sc, "hw qnum %u out of range, max %tu!\n",
			qnum, ARRAY_SIZE(sc->txqs));
		ath5k_hw_release_tx_queue(ah, qnum);
		return ERR_PTR(-EINVAL);
	}
	txq = &sc->txqs[qnum];
	if (!txq->setup) {
		txq->qnum = qnum;
		txq->link = NULL;
		INIT_LIST_HEAD(&txq->q);
		spin_lock_init(&txq->lock);
		txq->setup = true;
		txq->txq_len = 0;
	}
	return &sc->txqs[qnum];
}

static int
ath5k_beaconq_setup(struct ath5k_hw *ah)
{
	struct ath5k_txq_info qi = {
		.tqi_aifs = AR5K_TXQ_USEDEFAULT,
		.tqi_cw_min = AR5K_TXQ_USEDEFAULT,
		.tqi_cw_max = AR5K_TXQ_USEDEFAULT,
		/* NB: for dynamic turbo, don't enable any other interrupts */
		.tqi_flags = AR5K_TXQ_FLAG_TXDESCINT_ENABLE
	};

	return ath5k_hw_setup_tx_queue(ah, AR5K_TX_QUEUE_BEACON, &qi);
}

static int
ath5k_beaconq_config(struct ath5k_softc *sc)
{
	struct ath5k_hw *ah = sc->ah;
	struct ath5k_txq_info qi;
	int ret;

	ret = ath5k_hw_get_tx_queueprops(ah, sc->bhalq, &qi);
	if (ret)
		goto err;

	if (sc->opmode == NL80211_IFTYPE_AP ||
		sc->opmode == NL80211_IFTYPE_MESH_POINT) {
		/*
		 * Always burst out beacon and CAB traffic
		 * (aifs = cwmin = cwmax = 0)
		 */
		qi.tqi_aifs = 0;
		qi.tqi_cw_min = 0;
		qi.tqi_cw_max = 0;
	} else if (sc->opmode == NL80211_IFTYPE_ADHOC) {
		/*
		 * Adhoc mode; backoff between 0 and (2 * cw_min).
		 */
		qi.tqi_aifs = 0;
		qi.tqi_cw_min = 0;
		qi.tqi_cw_max = 2 * ah->ah_cw_min;
	}

	ATH5K_DBG(sc, ATH5K_DEBUG_BEACON,
		"beacon queueprops tqi_aifs:%d tqi_cw_min:%d tqi_cw_max:%d\n",
		qi.tqi_aifs, qi.tqi_cw_min, qi.tqi_cw_max);

	ret = ath5k_hw_set_tx_queueprops(ah, sc->bhalq, &qi);
	if (ret) {
		ATH5K_ERR(sc, "%s: unable to update parameters for beacon "
			"hardware queue!\n", __func__);
		goto err;
	}
	ret = ath5k_hw_reset_tx_queue(ah, sc->bhalq); /* push to h/w */
	if (ret)
		goto err;

	/* reconfigure cabq with ready time to 80% of beacon_interval */
	ret = ath5k_hw_get_tx_queueprops(ah, AR5K_TX_QUEUE_ID_CAB, &qi);
	if (ret)
		goto err;

	qi.tqi_ready_time = (sc->bintval * 80) / 100;
	ret = ath5k_hw_set_tx_queueprops(ah, AR5K_TX_QUEUE_ID_CAB, &qi);
	if (ret)
		goto err;

	ret = ath5k_hw_reset_tx_queue(ah, AR5K_TX_QUEUE_ID_CAB);
err:
	return ret;
}

static void
ath5k_txq_drainq(struct ath5k_softc *sc, struct ath5k_txq *txq)
{
	struct ath5k_buf *bf, *bf0;

	/*
	 * NB: this assumes output has been stopped and
	 *     we do not need to block ath5k_tx_tasklet
	 */
	spin_lock_bh(&txq->lock);
	list_for_each_entry_safe(bf, bf0, &txq->q, list) {
		ath5k_debug_printtxbuf(sc, bf);

		ath5k_txbuf_free_skb(sc, bf);

		spin_lock_bh(&sc->txbuflock);
		list_move_tail(&bf->list, &sc->txbuf);
		sc->txbuf_len++;
		txq->txq_len--;
		spin_unlock_bh(&sc->txbuflock);
	}
	txq->link = NULL;
	spin_unlock_bh(&txq->lock);
}

/*
 * Drain the transmit queues and reclaim resources.
 */
static void
ath5k_txq_cleanup(struct ath5k_softc *sc)
{
	struct ath5k_hw *ah = sc->ah;
	unsigned int i;

	/* XXX return value */
	if (likely(!test_bit(ATH_STAT_INVALID, sc->status))) {
		/* don't touch the hardware if marked invalid */
		ath5k_hw_stop_tx_dma(ah, sc->bhalq);
		ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "beacon queue %x\n",
			ath5k_hw_get_txdp(ah, sc->bhalq));
		for (i = 0; i < ARRAY_SIZE(sc->txqs); i++)
			if (sc->txqs[i].setup) {
				ath5k_hw_stop_tx_dma(ah, sc->txqs[i].qnum);
				ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "txq [%u] %x, "
					"link %p\n",
					sc->txqs[i].qnum,
					ath5k_hw_get_txdp(ah,
							sc->txqs[i].qnum),
					sc->txqs[i].link);
			}
	}

	for (i = 0; i < ARRAY_SIZE(sc->txqs); i++)
		if (sc->txqs[i].setup)
			ath5k_txq_drainq(sc, &sc->txqs[i]);
}

static void
ath5k_txq_release(struct ath5k_softc *sc)
{
	struct ath5k_txq *txq = sc->txqs;
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(sc->txqs); i++, txq++)
		if (txq->setup) {
			ath5k_hw_release_tx_queue(sc->ah, txq->qnum);
			txq->setup = false;
		}
}


/*************\
* RX Handling *
\*************/

/*
 * Enable the receive h/w following a reset.
 */
static int
ath5k_rx_start(struct ath5k_softc *sc)
{
	struct ath5k_hw *ah = sc->ah;
	struct ath_common *common = ath5k_hw_common(ah);
	struct ath5k_buf *bf;
	int ret;

	common->rx_bufsize = roundup(IEEE80211_MAX_FRAME_LEN, common->cachelsz);

	ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "cachelsz %u rx_bufsize %u\n",
		  common->cachelsz, common->rx_bufsize);

	spin_lock_bh(&sc->rxbuflock);
	sc->rxlink = NULL;
	list_for_each_entry(bf, &sc->rxbuf, list) {
		ret = ath5k_rxbuf_setup(sc, bf);
		if (ret != 0) {
			spin_unlock_bh(&sc->rxbuflock);
			goto err;
		}
	}
	bf = list_first_entry(&sc->rxbuf, struct ath5k_buf, list);
	ath5k_hw_set_rxdp(ah, bf->daddr);
	spin_unlock_bh(&sc->rxbuflock);

	ath5k_hw_start_rx_dma(ah);	/* enable recv descriptors */
	ath5k_mode_setup(sc);		/* set filters, etc. */
	ath5k_hw_start_rx_pcu(ah);	/* re-enable PCU/DMA engine */

	return 0;
err:
	return ret;
}

/*
 * Disable the receive h/w in preparation for a reset.
 */
static void
ath5k_rx_stop(struct ath5k_softc *sc)
{
	struct ath5k_hw *ah = sc->ah;

	ath5k_hw_stop_rx_pcu(ah);	/* disable PCU */
	ath5k_hw_set_rx_filter(ah, 0);	/* clear recv filter */
	ath5k_hw_stop_rx_dma(ah);	/* disable DMA engine */

	ath5k_debug_printrxbuffs(sc, ah);
}

static unsigned int
ath5k_rx_decrypted(struct ath5k_softc *sc, struct sk_buff *skb,
		   struct ath5k_rx_status *rs)
{
	struct ath5k_hw *ah = sc->ah;
	struct ath_common *common = ath5k_hw_common(ah);
	struct ieee80211_hdr *hdr = (void *)skb->data;
	unsigned int keyix, hlen;

	if (!(rs->rs_status & AR5K_RXERR_DECRYPT) &&
			rs->rs_keyix != AR5K_RXKEYIX_INVALID)
		return RX_FLAG_DECRYPTED;

	/* Apparently when a default key is used to decrypt the packet
	   the hw does not set the index used to decrypt.  In such cases
	   get the index from the packet. */
	hlen = ieee80211_hdrlen(hdr->frame_control);
	if (ieee80211_has_protected(hdr->frame_control) &&
	    !(rs->rs_status & AR5K_RXERR_DECRYPT) &&
	    skb->len >= hlen + 4) {
		keyix = skb->data[hlen + 3] >> 6;

		if (test_bit(keyix, common->keymap))
			return RX_FLAG_DECRYPTED;
	}

	return 0;
}


static void
ath5k_check_ibss_tsf(struct ath5k_softc *sc, struct sk_buff *skb,
		     struct ieee80211_rx_status *rxs)
{
	struct ath_common *common = ath5k_hw_common(sc->ah);
	u64 tsf, bc_tstamp;
	u32 hw_tu;
	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)skb->data;

	if (ieee80211_is_beacon(mgmt->frame_control) &&
	    le16_to_cpu(mgmt->u.beacon.capab_info) & WLAN_CAPABILITY_IBSS &&
	    memcmp(mgmt->bssid, common->curbssid, ETH_ALEN) == 0) {
		/*
		 * Received an IBSS beacon with the same BSSID. Hardware *must*
		 * have updated the local TSF. We have to work around various
		 * hardware bugs, though...
		 */
		tsf = ath5k_hw_get_tsf64(sc->ah);
		bc_tstamp = le64_to_cpu(mgmt->u.beacon.timestamp);
		hw_tu = TSF_TO_TU(tsf);

		ATH5K_DBG_UNLIMIT(sc, ATH5K_DEBUG_BEACON,
			"beacon %llx mactime %llx (diff %lld) tsf now %llx\n",
			(unsigned long long)bc_tstamp,
			(unsigned long long)rxs->mactime,
			(unsigned long long)(rxs->mactime - bc_tstamp),
			(unsigned long long)tsf);

		/*
		 * Sometimes the HW will give us a wrong tstamp in the rx
		 * status, causing the timestamp extension to go wrong.
		 * (This seems to happen especially with beacon frames bigger
		 * than 78 byte (incl. FCS))
		 * But we know that the receive timestamp must be later than the
		 * timestamp of the beacon since HW must have synced to that.
		 *
		 * NOTE: here we assume mactime to be after the frame was
		 * received, not like mac80211 which defines it at the start.
		 */
		if (bc_tstamp > rxs->mactime) {
			ATH5K_DBG_UNLIMIT(sc, ATH5K_DEBUG_BEACON,
				"fixing mactime from %llx to %llx\n",
				(unsigned long long)rxs->mactime,
				(unsigned long long)tsf);
			rxs->mactime = tsf;
		}

		/*
		 * Local TSF might have moved higher than our beacon timers,
		 * in that case we have to update them to continue sending
		 * beacons. This also takes care of synchronizing beacon sending
		 * times with other stations.
		 */
		if (hw_tu >= sc->nexttbtt)
			ath5k_beacon_update_timers(sc, bc_tstamp);
	}
}

static void
ath5k_update_beacon_rssi(struct ath5k_softc *sc, struct sk_buff *skb, int rssi)
{
	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)skb->data;
	struct ath5k_hw *ah = sc->ah;
	struct ath_common *common = ath5k_hw_common(ah);

	/* only beacons from our BSSID */
	if (!ieee80211_is_beacon(mgmt->frame_control) ||
	    memcmp(mgmt->bssid, common->curbssid, ETH_ALEN) != 0)
		return;

	ah->ah_beacon_rssi_avg = ath5k_moving_average(ah->ah_beacon_rssi_avg,
						      rssi);

	/* in IBSS mode we should keep RSSI statistics per neighbour */
	/* le16_to_cpu(mgmt->u.beacon.capab_info) & WLAN_CAPABILITY_IBSS */
}

/*
 * Compute padding position. skb must contain an IEEE 802.11 frame
 */
static int ath5k_common_padpos(struct sk_buff *skb)
{
	struct ieee80211_hdr * hdr = (struct ieee80211_hdr *)skb->data;
	__le16 frame_control = hdr->frame_control;
	int padpos = 24;

	if (ieee80211_has_a4(frame_control)) {
		padpos += ETH_ALEN;
	}
	if (ieee80211_is_data_qos(frame_control)) {
		padpos += IEEE80211_QOS_CTL_LEN;
	}

	return padpos;
}

/*
 * This function expects an 802.11 frame and returns the number of
 * bytes added, or -1 if we don't have enough header room.
 */
static int ath5k_add_padding(struct sk_buff *skb)
{
	int padpos = ath5k_common_padpos(skb);
	int padsize = padpos & 3;

	if (padsize && skb->len>padpos) {

		if (skb_headroom(skb) < padsize)
			return -1;

		skb_push(skb, padsize);
		memmove(skb->data, skb->data+padsize, padpos);
		return padsize;
	}

	return 0;
}

/*
 * The MAC header is padded to have 32-bit boundary if the
 * packet payload is non-zero. The general calculation for
 * padsize would take into account odd header lengths:
 * padsize = 4 - (hdrlen & 3); however, since only
 * even-length headers are used, padding can only be 0 or 2
 * bytes and we can optimize this a bit.  We must not try to
 * remove padding from short control frames that do not have a
 * payload.
 *
 * This function expects an 802.11 frame and returns the number of
 * bytes removed.
 */
static int ath5k_remove_padding(struct sk_buff *skb)
{
	int padpos = ath5k_common_padpos(skb);
	int padsize = padpos & 3;

	if (padsize && skb->len>=padpos+padsize) {
		memmove(skb->data + padsize, skb->data, padpos);
		skb_pull(skb, padsize);
		return padsize;
	}

	return 0;
}

static void
ath5k_receive_frame(struct ath5k_softc *sc, struct sk_buff *skb,
		    struct ath5k_rx_status *rs)
{
	struct ieee80211_rx_status *rxs;

	ath5k_remove_padding(skb);

	rxs = IEEE80211_SKB_RXCB(skb);

	rxs->flag = 0;
	if (unlikely(rs->rs_status & AR5K_RXERR_MIC))
		rxs->flag |= RX_FLAG_MMIC_ERROR;

	/*
	 * always extend the mac timestamp, since this information is
	 * also needed for proper IBSS merging.
	 *
	 * XXX: it might be too late to do it here, since rs_tstamp is
	 * 15bit only. that means TSF extension has to be done within
	 * 32768usec (about 32ms). it might be necessary to move this to
	 * the interrupt handler, like it is done in madwifi.
	 *
	 * Unfortunately we don't know when the hardware takes the rx
	 * timestamp (beginning of phy frame, data frame, end of rx?).
	 * The only thing we know is that it is hardware specific...
	 * On AR5213 it seems the rx timestamp is at the end of the
	 * frame, but i'm not sure.
	 *
	 * NOTE: mac80211 defines mactime at the beginning of the first
	 * data symbol. Since we don't have any time references it's
	 * impossible to comply to that. This affects IBSS merge only
	 * right now, so it's not too bad...
	 */
	rxs->mactime = ath5k_extend_tsf(sc->ah, rs->rs_tstamp);
	rxs->flag |= RX_FLAG_TSFT;

	rxs->freq = sc->curchan->center_freq;
	rxs->band = sc->curband->band;

	rxs->signal = sc->ah->ah_noise_floor + rs->rs_rssi;

	rxs->antenna = rs->rs_antenna;

	if (rs->rs_antenna > 0 && rs->rs_antenna < 5)
		sc->stats.antenna_rx[rs->rs_antenna]++;
	else
		sc->stats.antenna_rx[0]++; /* invalid */

	rxs->rate_idx = ath5k_hw_to_driver_rix(sc, rs->rs_rate);
	rxs->flag |= ath5k_rx_decrypted(sc, skb, rs);

	if (rxs->rate_idx >= 0 && rs->rs_rate ==
	    sc->curband->bitrates[rxs->rate_idx].hw_value_short)
		rxs->flag |= RX_FLAG_SHORTPRE;

	ath5k_debug_dump_skb(sc, skb, "RX  ", 0);

	ath5k_update_beacon_rssi(sc, skb, rs->rs_rssi);

	/* check beacons in IBSS mode */
	if (sc->opmode == NL80211_IFTYPE_ADHOC)
		ath5k_check_ibss_tsf(sc, skb, rxs);

	ieee80211_rx(sc->hw, skb);
}

/** ath5k_frame_receive_ok() - Do we want to receive this frame or not?
 *
 * Check if we want to further process this frame or not. Also update
 * statistics. Return true if we want this frame, false if not.
 */
static bool
ath5k_receive_frame_ok(struct ath5k_softc *sc, struct ath5k_rx_status *rs)
{
	sc->stats.rx_all_count++;

	if (unlikely(rs->rs_status)) {
		if (rs->rs_status & AR5K_RXERR_CRC)
			sc->stats.rxerr_crc++;
		if (rs->rs_status & AR5K_RXERR_FIFO)
			sc->stats.rxerr_fifo++;
		if (rs->rs_status & AR5K_RXERR_PHY) {
			sc->stats.rxerr_phy++;
			if (rs->rs_phyerr > 0 && rs->rs_phyerr < 32)
				sc->stats.rxerr_phy_code[rs->rs_phyerr]++;
			return false;
		}
		if (rs->rs_status & AR5K_RXERR_DECRYPT) {
			/*
			 * Decrypt error.  If the error occurred
			 * because there was no hardware key, then
			 * let the frame through so the upper layers
			 * can process it.  This is necessary for 5210
			 * parts which have no way to setup a ``clear''
			 * key cache entry.
			 *
			 * XXX do key cache faulting
			 */
			sc->stats.rxerr_decrypt++;
			if (rs->rs_keyix == AR5K_RXKEYIX_INVALID &&
			    !(rs->rs_status & AR5K_RXERR_CRC))
				return true;
		}
		if (rs->rs_status & AR5K_RXERR_MIC) {
			sc->stats.rxerr_mic++;
			return true;
		}

		/* reject any frames with non-crypto errors */
		if (rs->rs_status & ~(AR5K_RXERR_DECRYPT))
			return false;
	}

	if (unlikely(rs->rs_more)) {
		sc->stats.rxerr_jumbo++;
		return false;
	}
	return true;
}

static void
ath5k_tasklet_rx(unsigned long data)
{
	struct ath5k_rx_status rs = {};
	struct sk_buff *skb, *next_skb;
	dma_addr_t next_skb_addr;
	struct ath5k_softc *sc = (void *)data;
	struct ath5k_hw *ah = sc->ah;
	struct ath_common *common = ath5k_hw_common(ah);
	struct ath5k_buf *bf;
	struct ath5k_desc *ds;
	int ret;

	spin_lock(&sc->rxbuflock);
	if (list_empty(&sc->rxbuf)) {
		ATH5K_WARN(sc, "empty rx buf pool\n");
		goto unlock;
	}
	do {
		bf = list_first_entry(&sc->rxbuf, struct ath5k_buf, list);
		BUG_ON(bf->skb == NULL);
		skb = bf->skb;
		ds = bf->desc;

		/* bail if HW is still using self-linked descriptor */
		if (ath5k_hw_get_rxdp(sc->ah) == bf->daddr)
			break;

		ret = sc->ah->ah_proc_rx_desc(sc->ah, ds, &rs);
		if (unlikely(ret == -EINPROGRESS))
			break;
		else if (unlikely(ret)) {
			ATH5K_ERR(sc, "error in processing rx descriptor\n");
			sc->stats.rxerr_proc++;
			break;
		}

		if (ath5k_receive_frame_ok(sc, &rs)) {
			next_skb = ath5k_rx_skb_alloc(sc, &next_skb_addr);

			/*
			 * If we can't replace bf->skb with a new skb under
			 * memory pressure, just skip this packet
			 */
			if (!next_skb)
				goto next;

			pci_unmap_single(sc->pdev, bf->skbaddr,
					 common->rx_bufsize,
					 PCI_DMA_FROMDEVICE);

			skb_put(skb, rs.rs_datalen);

			ath5k_receive_frame(sc, skb, &rs);

			bf->skb = next_skb;
			bf->skbaddr = next_skb_addr;
		}
next:
		list_move_tail(&bf->list, &sc->rxbuf);
	} while (ath5k_rxbuf_setup(sc, bf) == 0);
unlock:
	spin_unlock(&sc->rxbuflock);
}


/*************\
* TX Handling *
\*************/

static int ath5k_tx_queue(struct ieee80211_hw *hw, struct sk_buff *skb,
			  struct ath5k_txq *txq)
{
	struct ath5k_softc *sc = hw->priv;
	struct ath5k_buf *bf;
	unsigned long flags;
	int padsize;

	ath5k_debug_dump_skb(sc, skb, "TX  ", 1);

	/*
	 * The hardware expects the header padded to 4 byte boundaries.
	 * If this is not the case, we add the padding after the header.
	 */
	padsize = ath5k_add_padding(skb);
	if (padsize < 0) {
		ATH5K_ERR(sc, "tx hdrlen not %%4: not enough"
			  " headroom to pad");
		goto drop_packet;
	}

	if (txq->txq_len >= ATH5K_TXQ_LEN_MAX)
		ieee80211_stop_queue(hw, txq->qnum);

	spin_lock_irqsave(&sc->txbuflock, flags);
	if (list_empty(&sc->txbuf)) {
		ATH5K_ERR(sc, "no further txbuf available, dropping packet\n");
		spin_unlock_irqrestore(&sc->txbuflock, flags);
		ieee80211_stop_queues(hw);
		goto drop_packet;
	}
	bf = list_first_entry(&sc->txbuf, struct ath5k_buf, list);
	list_del(&bf->list);
	sc->txbuf_len--;
	if (list_empty(&sc->txbuf))
		ieee80211_stop_queues(hw);
	spin_unlock_irqrestore(&sc->txbuflock, flags);

	bf->skb = skb;

	if (ath5k_txbuf_setup(sc, bf, txq, padsize)) {
		bf->skb = NULL;
		spin_lock_irqsave(&sc->txbuflock, flags);
		list_add_tail(&bf->list, &sc->txbuf);
		sc->txbuf_len++;
		spin_unlock_irqrestore(&sc->txbuflock, flags);
		goto drop_packet;
	}
	return NETDEV_TX_OK;

drop_packet:
	dev_kfree_skb_any(skb);
	return NETDEV_TX_OK;
}


static void
ath5k_tx_processq(struct ath5k_softc *sc, struct ath5k_txq *txq)
{
	struct ath5k_tx_status ts = {};
	struct ath5k_buf *bf, *bf0;
	struct ath5k_desc *ds;
	struct sk_buff *skb;
	struct ieee80211_tx_info *info;
	int i, ret;

	spin_lock(&txq->lock);
	list_for_each_entry_safe(bf, bf0, &txq->q, list) {
		ds = bf->desc;

		/*
		 * It's possible that the hardware can say the buffer is
		 * completed when it hasn't yet loaded the ds_link from
		 * host memory and moved on.  If there are more TX
		 * descriptors in the queue, wait for TXDP to change
		 * before processing this one.
		 */
		if (ath5k_hw_get_txdp(sc->ah, txq->qnum) == bf->daddr &&
		    !list_is_last(&bf->list, &txq->q))
			break;

		ret = sc->ah->ah_proc_tx_desc(sc->ah, ds, &ts);
		if (unlikely(ret == -EINPROGRESS))
			break;
		else if (unlikely(ret)) {
			ATH5K_ERR(sc, "error %d while processing queue %u\n",
				ret, txq->qnum);
			break;
		}

		sc->stats.tx_all_count++;
		skb = bf->skb;
		info = IEEE80211_SKB_CB(skb);
		bf->skb = NULL;

		pci_unmap_single(sc->pdev, bf->skbaddr, skb->len,
				PCI_DMA_TODEVICE);

		ieee80211_tx_info_clear_status(info);
		for (i = 0; i < 4; i++) {
			struct ieee80211_tx_rate *r =
				&info->status.rates[i];

			if (ts.ts_rate[i]) {
				r->idx = ath5k_hw_to_driver_rix(sc, ts.ts_rate[i]);
				r->count = ts.ts_retry[i];
			} else {
				r->idx = -1;
				r->count = 0;
			}
		}

		/* count the successful attempt as well */
		info->status.rates[ts.ts_final_idx].count++;

		if (unlikely(ts.ts_status)) {
			sc->stats.ack_fail++;
			if (ts.ts_status & AR5K_TXERR_FILT) {
				info->flags |= IEEE80211_TX_STAT_TX_FILTERED;
				sc->stats.txerr_filt++;
			}
			if (ts.ts_status & AR5K_TXERR_XRETRY)
				sc->stats.txerr_retry++;
			if (ts.ts_status & AR5K_TXERR_FIFO)
				sc->stats.txerr_fifo++;
		} else {
			info->flags |= IEEE80211_TX_STAT_ACK;
			info->status.ack_signal = ts.ts_rssi;
		}

		/*
		 * Remove MAC header padding before giving the frame
		 * back to mac80211.
		 */
		ath5k_remove_padding(skb);

		if (ts.ts_antenna > 0 && ts.ts_antenna < 5)
			sc->stats.antenna_tx[ts.ts_antenna]++;
		else
			sc->stats.antenna_tx[0]++; /* invalid */

		ieee80211_tx_status(sc->hw, skb);

		spin_lock(&sc->txbuflock);
		list_move_tail(&bf->list, &sc->txbuf);
		sc->txbuf_len++;
		txq->txq_len--;
		spin_unlock(&sc->txbuflock);
	}
	if (likely(list_empty(&txq->q)))
		txq->link = NULL;
	spin_unlock(&txq->lock);
	if (txq->txq_len < ATH5K_TXQ_LEN_LOW)
		ieee80211_wake_queue(sc->hw, txq->qnum);
}

static void
ath5k_tasklet_tx(unsigned long data)
{
	int i;
	struct ath5k_softc *sc = (void *)data;

	for (i=0; i < AR5K_NUM_TX_QUEUES; i++)
		if (sc->txqs[i].setup && (sc->ah->ah_txq_isr & BIT(i)))
			ath5k_tx_processq(sc, &sc->txqs[i]);
}


/*****************\
* Beacon handling *
\*****************/

/*
 * Setup the beacon frame for transmit.
 */
static int
ath5k_beacon_setup(struct ath5k_softc *sc, struct ath5k_buf *bf)
{
	struct sk_buff *skb = bf->skb;
	struct	ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ath5k_hw *ah = sc->ah;
	struct ath5k_desc *ds;
	int ret = 0;
	u8 antenna;
	u32 flags;
	const int padsize = 0;

	bf->skbaddr = pci_map_single(sc->pdev, skb->data, skb->len,
			PCI_DMA_TODEVICE);
	ATH5K_DBG(sc, ATH5K_DEBUG_BEACON, "skb %p [data %p len %u] "
			"skbaddr %llx\n", skb, skb->data, skb->len,
			(unsigned long long)bf->skbaddr);
	if (pci_dma_mapping_error(sc->pdev, bf->skbaddr)) {
		ATH5K_ERR(sc, "beacon DMA mapping failed\n");
		return -EIO;
	}

	ds = bf->desc;
	antenna = ah->ah_tx_ant;

	flags = AR5K_TXDESC_NOACK;
	if (sc->opmode == NL80211_IFTYPE_ADHOC && ath5k_hw_hasveol(ah)) {
		ds->ds_link = bf->daddr;	/* self-linked */
		flags |= AR5K_TXDESC_VEOL;
	} else
		ds->ds_link = 0;

	/*
	 * If we use multiple antennas on AP and use
	 * the Sectored AP scenario, switch antenna every
	 * 4 beacons to make sure everybody hears our AP.
	 * When a client tries to associate, hw will keep
	 * track of the tx antenna to be used for this client
	 * automaticaly, based on ACKed packets.
	 *
	 * Note: AP still listens and transmits RTS on the
	 * default antenna which is supposed to be an omni.
	 *
	 * Note2: On sectored scenarios it's possible to have
	 * multiple antennas (1 omni -- the default -- and 14
	 * sectors), so if we choose to actually support this
	 * mode, we need to allow the user to set how many antennas
	 * we have and tweak the code below to send beacons
	 * on all of them.
	 */
	if (ah->ah_ant_mode == AR5K_ANTMODE_SECTOR_AP)
		antenna = sc->bsent & 4 ? 2 : 1;


	/* FIXME: If we are in g mode and rate is a CCK rate
	 * subtract ah->ah_txpower.txp_cck_ofdm_pwr_delta
	 * from tx power (value is in dB units already) */
	ds->ds_data = bf->skbaddr;
	ret = ah->ah_setup_tx_desc(ah, ds, skb->len,
			ieee80211_get_hdrlen_from_skb(skb), padsize,
			AR5K_PKT_TYPE_BEACON, (sc->power_level * 2),
			ieee80211_get_tx_rate(sc->hw, info)->hw_value,
			1, AR5K_TXKEYIX_INVALID,
			antenna, flags, 0, 0);
	if (ret)
		goto err_unmap;

	return 0;
err_unmap:
	pci_unmap_single(sc->pdev, bf->skbaddr, skb->len, PCI_DMA_TODEVICE);
	return ret;
}

/*
 * Updates the beacon that is sent by ath5k_beacon_send.  For adhoc,
 * this is called only once at config_bss time, for AP we do it every
 * SWBA interrupt so that the TIM will reflect buffered frames.
 *
 * Called with the beacon lock.
 */
static int
ath5k_beacon_update(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
{
	int ret;
	struct ath5k_softc *sc = hw->priv;
	struct sk_buff *skb;

	if (WARN_ON(!vif)) {
		ret = -EINVAL;
		goto out;
	}

	skb = ieee80211_beacon_get(hw, vif);

	if (!skb) {
		ret = -ENOMEM;
		goto out;
	}

	ath5k_debug_dump_skb(sc, skb, "BC  ", 1);

	ath5k_txbuf_free_skb(sc, sc->bbuf);
	sc->bbuf->skb = skb;
	ret = ath5k_beacon_setup(sc, sc->bbuf);
	if (ret)
		sc->bbuf->skb = NULL;
out:
	return ret;
}

/*
 * Transmit a beacon frame at SWBA.  Dynamic updates to the
 * frame contents are done as needed and the slot time is
 * also adjusted based on current state.
 *
 * This is called from software irq context (beacontq tasklets)
 * or user context from ath5k_beacon_config.
 */
static void
ath5k_beacon_send(struct ath5k_softc *sc)
{
	struct ath5k_buf *bf = sc->bbuf;
	struct ath5k_hw *ah = sc->ah;
	struct sk_buff *skb;

	ATH5K_DBG_UNLIMIT(sc, ATH5K_DEBUG_BEACON, "in beacon_send\n");

	if (unlikely(bf->skb == NULL || sc->opmode == NL80211_IFTYPE_STATION)) {
		ATH5K_WARN(sc, "bf=%p bf_skb=%p\n", bf, bf ? bf->skb : NULL);
		return;
	}
	/*
	 * Check if the previous beacon has gone out.  If
	 * not, don't don't try to post another: skip this
	 * period and wait for the next.  Missed beacons
	 * indicate a problem and should not occur.  If we
	 * miss too many consecutive beacons reset the device.
	 */
	if (unlikely(ath5k_hw_num_tx_pending(ah, sc->bhalq) != 0)) {
		sc->bmisscount++;
		ATH5K_DBG(sc, ATH5K_DEBUG_BEACON,
			"missed %u consecutive beacons\n", sc->bmisscount);
		if (sc->bmisscount > 10) {	/* NB: 10 is a guess */
			ATH5K_DBG(sc, ATH5K_DEBUG_BEACON,
				"stuck beacon time (%u missed)\n",
				sc->bmisscount);
			ATH5K_DBG(sc, ATH5K_DEBUG_RESET,
				  "stuck beacon, resetting\n");
			ieee80211_queue_work(sc->hw, &sc->reset_work);
		}
		return;
	}
	if (unlikely(sc->bmisscount != 0)) {
		ATH5K_DBG(sc, ATH5K_DEBUG_BEACON,
			"resume beacon xmit after %u misses\n",
			sc->bmisscount);
		sc->bmisscount = 0;
	}

	/*
	 * Stop any current dma and put the new frame on the queue.
	 * This should never fail since we check above that no frames
	 * are still pending on the queue.
	 */
	if (unlikely(ath5k_hw_stop_tx_dma(ah, sc->bhalq))) {
		ATH5K_WARN(sc, "beacon queue %u didn't start/stop ?\n", sc->bhalq);
		/* NB: hw still stops DMA, so proceed */
	}

	/* refresh the beacon for AP mode */
	if (sc->opmode == NL80211_IFTYPE_AP)
		ath5k_beacon_update(sc->hw, sc->vif);

	ath5k_hw_set_txdp(ah, sc->bhalq, bf->daddr);
	ath5k_hw_start_tx_dma(ah, sc->bhalq);
	ATH5K_DBG(sc, ATH5K_DEBUG_BEACON, "TXDP[%u] = %llx (%p)\n",
		sc->bhalq, (unsigned long long)bf->daddr, bf->desc);

	skb = ieee80211_get_buffered_bc(sc->hw, sc->vif);
	while (skb) {
		ath5k_tx_queue(sc->hw, skb, sc->cabq);
		skb = ieee80211_get_buffered_bc(sc->hw, sc->vif);
	}

	sc->bsent++;
}

/**
 * ath5k_beacon_update_timers - update beacon timers
 *
 * @sc: struct ath5k_softc pointer we are operating on
 * @bc_tsf: the timestamp of the beacon. 0 to reset the TSF. -1 to perform a
 *          beacon timer update based on the current HW TSF.
 *
 * Calculate the next target beacon transmit time (TBTT) based on the timestamp
 * of a received beacon or the current local hardware TSF and write it to the
 * beacon timer registers.
 *
 * This is called in a variety of situations, e.g. when a beacon is received,
 * when a TSF update has been detected, but also when an new IBSS is created or
 * when we otherwise know we have to update the timers, but we keep it in this
 * function to have it all together in one place.
 */
static void
ath5k_beacon_update_timers(struct ath5k_softc *sc, u64 bc_tsf)
{
	struct ath5k_hw *ah = sc->ah;
	u32 nexttbtt, intval, hw_tu, bc_tu;
	u64 hw_tsf;

	intval = sc->bintval & AR5K_BEACON_PERIOD;
	if (WARN_ON(!intval))
		return;

	/* beacon TSF converted to TU */
	bc_tu = TSF_TO_TU(bc_tsf);

	/* current TSF converted to TU */
	hw_tsf = ath5k_hw_get_tsf64(ah);
	hw_tu = TSF_TO_TU(hw_tsf);

#define FUDGE 3
	/* we use FUDGE to make sure the next TBTT is ahead of the current TU */
	if (bc_tsf == -1) {
		/*
		 * no beacons received, called internally.
		 * just need to refresh timers based on HW TSF.
		 */
		nexttbtt = roundup(hw_tu + FUDGE, intval);
	} else if (bc_tsf == 0) {
		/*
		 * no beacon received, probably called by ath5k_reset_tsf().
		 * reset TSF to start with 0.
		 */
		nexttbtt = intval;
		intval |= AR5K_BEACON_RESET_TSF;
	} else if (bc_tsf > hw_tsf) {
		/*
		 * beacon received, SW merge happend but HW TSF not yet updated.
		 * not possible to reconfigure timers yet, but next time we
		 * receive a beacon with the same BSSID, the hardware will
		 * automatically update the TSF and then we need to reconfigure
		 * the timers.
		 */
		ATH5K_DBG_UNLIMIT(sc, ATH5K_DEBUG_BEACON,
			"need to wait for HW TSF sync\n");
		return;
	} else {
		/*
		 * most important case for beacon synchronization between STA.
		 *
		 * beacon received and HW TSF has been already updated by HW.
		 * update next TBTT based on the TSF of the beacon, but make
		 * sure it is ahead of our local TSF timer.
		 */
		nexttbtt = bc_tu + roundup(hw_tu + FUDGE - bc_tu, intval);
	}
#undef FUDGE

	sc->nexttbtt = nexttbtt;

	intval |= AR5K_BEACON_ENA;
	ath5k_hw_init_beacon(ah, nexttbtt, intval);

	/*
	 * debugging output last in order to preserve the time critical aspect
	 * of this function
	 */
	if (bc_tsf == -1)
		ATH5K_DBG_UNLIMIT(sc, ATH5K_DEBUG_BEACON,
			"reconfigured timers based on HW TSF\n");
	else if (bc_tsf == 0)
		ATH5K_DBG_UNLIMIT(sc, ATH5K_DEBUG_BEACON,
			"reset HW TSF and timers\n");
	else
		ATH5K_DBG_UNLIMIT(sc, ATH5K_DEBUG_BEACON,
			"updated timers based on beacon TSF\n");

	ATH5K_DBG_UNLIMIT(sc, ATH5K_DEBUG_BEACON,
			  "bc_tsf %llx hw_tsf %llx bc_tu %u hw_tu %u nexttbtt %u\n",
			  (unsigned long long) bc_tsf,
			  (unsigned long long) hw_tsf, bc_tu, hw_tu, nexttbtt);
	ATH5K_DBG_UNLIMIT(sc, ATH5K_DEBUG_BEACON, "intval %u %s %s\n",
		intval & AR5K_BEACON_PERIOD,
		intval & AR5K_BEACON_ENA ? "AR5K_BEACON_ENA" : "",
		intval & AR5K_BEACON_RESET_TSF ? "AR5K_BEACON_RESET_TSF" : "");
}

/**
 * ath5k_beacon_config - Configure the beacon queues and interrupts
 *
 * @sc: struct ath5k_softc pointer we are operating on
 *
 * In IBSS mode we use a self-linked tx descriptor if possible. We enable SWBA
 * interrupts to detect TSF updates only.
 */
static void
ath5k_beacon_config(struct ath5k_softc *sc)
{
	struct ath5k_hw *ah = sc->ah;
	unsigned long flags;

	spin_lock_irqsave(&sc->block, flags);
	sc->bmisscount = 0;
	sc->imask &= ~(AR5K_INT_BMISS | AR5K_INT_SWBA);

	if (sc->enable_beacon) {
		/*
		 * In IBSS mode we use a self-linked tx descriptor and let the
		 * hardware send the beacons automatically. We have to load it
		 * only once here.
		 * We use the SWBA interrupt only to keep track of the beacon
		 * timers in order to detect automatic TSF updates.
		 */
		ath5k_beaconq_config(sc);

		sc->imask |= AR5K_INT_SWBA;

		if (sc->opmode == NL80211_IFTYPE_ADHOC) {
			if (ath5k_hw_hasveol(ah))
				ath5k_beacon_send(sc);
		} else
			ath5k_beacon_update_timers(sc, -1);
	} else {
		ath5k_hw_stop_tx_dma(sc->ah, sc->bhalq);
	}

	ath5k_hw_set_imr(ah, sc->imask);
	mmiowb();
	spin_unlock_irqrestore(&sc->block, flags);
}

static void ath5k_tasklet_beacon(unsigned long data)
{
	struct ath5k_softc *sc = (struct ath5k_softc *) data;

	/*
	 * Software beacon alert--time to send a beacon.
	 *
	 * In IBSS mode we use this interrupt just to
	 * keep track of the next TBTT (target beacon
	 * transmission time) in order to detect wether
	 * automatic TSF updates happened.
	 */
	if (sc->opmode == NL80211_IFTYPE_ADHOC) {
		/* XXX: only if VEOL suppported */
		u64 tsf = ath5k_hw_get_tsf64(sc->ah);
		sc->nexttbtt += sc->bintval;
		ATH5K_DBG(sc, ATH5K_DEBUG_BEACON,
				"SWBA nexttbtt: %x hw_tu: %x "
				"TSF: %llx\n",
				sc->nexttbtt,
				TSF_TO_TU(tsf),
				(unsigned long long) tsf);
	} else {
		spin_lock(&sc->block);
		ath5k_beacon_send(sc);
		spin_unlock(&sc->block);
	}
}


/********************\
* Interrupt handling *
\********************/

static void
ath5k_intr_calibration_poll(struct ath5k_hw *ah)
{
	if (time_is_before_eq_jiffies(ah->ah_cal_next_ani) &&
	    !(ah->ah_cal_mask & AR5K_CALIBRATION_FULL)) {
		/* run ANI only when full calibration is not active */
		ah->ah_cal_next_ani = jiffies +
			msecs_to_jiffies(ATH5K_TUNE_CALIBRATION_INTERVAL_ANI);
		tasklet_schedule(&ah->ah_sc->ani_tasklet);

	} else if (time_is_before_eq_jiffies(ah->ah_cal_next_full)) {
		ah->ah_cal_next_full = jiffies +
			msecs_to_jiffies(ATH5K_TUNE_CALIBRATION_INTERVAL_FULL);
		tasklet_schedule(&ah->ah_sc->calib);
	}
	/* we could use SWI to generate enough interrupts to meet our
	 * calibration interval requirements, if necessary:
	 * AR5K_REG_ENABLE_BITS(ah, AR5K_CR, AR5K_CR_SWI); */
}

static irqreturn_t
ath5k_intr(int irq, void *dev_id)
{
	struct ath5k_softc *sc = dev_id;
	struct ath5k_hw *ah = sc->ah;
	enum ath5k_int status;
	unsigned int counter = 1000;

	if (unlikely(test_bit(ATH_STAT_INVALID, sc->status) ||
				!ath5k_hw_is_intr_pending(ah)))
		return IRQ_NONE;

	do {
		ath5k_hw_get_isr(ah, &status);		/* NB: clears IRQ too */
		ATH5K_DBG(sc, ATH5K_DEBUG_INTR, "status 0x%x/0x%x\n",
				status, sc->imask);
		if (unlikely(status & AR5K_INT_FATAL)) {
			/*
			 * Fatal errors are unrecoverable.
			 * Typically these are caused by DMA errors.
			 */
			ATH5K_DBG(sc, ATH5K_DEBUG_RESET,
				  "fatal int, resetting\n");
			ieee80211_queue_work(sc->hw, &sc->reset_work);
		} else if (unlikely(status & AR5K_INT_RXORN)) {
			/*
			 * Receive buffers are full. Either the bus is busy or
			 * the CPU is not fast enough to process all received
			 * frames.
			 * Older chipsets need a reset to come out of this
			 * condition, but we treat it as RX for newer chips.
			 * We don't know exactly which versions need a reset -
			 * this guess is copied from the HAL.
			 */
			sc->stats.rxorn_intr++;
			if (ah->ah_mac_srev < AR5K_SREV_AR5212) {
				ATH5K_DBG(sc, ATH5K_DEBUG_RESET,
					  "rx overrun, resetting\n");
				ieee80211_queue_work(sc->hw, &sc->reset_work);
			}
			else
				tasklet_schedule(&sc->rxtq);
		} else {
			if (status & AR5K_INT_SWBA) {
				tasklet_hi_schedule(&sc->beacontq);
			}
			if (status & AR5K_INT_RXEOL) {
				/*
				* NB: the hardware should re-read the link when
				*     RXE bit is written, but it doesn't work at
				*     least on older hardware revs.
				*/
				sc->stats.rxeol_intr++;
			}
			if (status & AR5K_INT_TXURN) {
				/* bump tx trigger level */
				ath5k_hw_update_tx_triglevel(ah, true);
			}
			if (status & (AR5K_INT_RXOK | AR5K_INT_RXERR))
				tasklet_schedule(&sc->rxtq);
			if (status & (AR5K_INT_TXOK | AR5K_INT_TXDESC
					| AR5K_INT_TXERR | AR5K_INT_TXEOL))
				tasklet_schedule(&sc->txtq);
			if (status & AR5K_INT_BMISS) {
				/* TODO */
			}
			if (status & AR5K_INT_MIB) {
				sc->stats.mib_intr++;
				ath5k_hw_update_mib_counters(ah);
				ath5k_ani_mib_intr(ah);
			}
			if (status & AR5K_INT_GPIO)
				tasklet_schedule(&sc->rf_kill.toggleq);

		}
	} while (ath5k_hw_is_intr_pending(ah) && --counter > 0);

	if (unlikely(!counter))
		ATH5K_WARN(sc, "too many interrupts, giving up for now\n");

	ath5k_intr_calibration_poll(ah);

	return IRQ_HANDLED;
}

/*
 * Periodically recalibrate the PHY to account
 * for temperature/environment changes.
 */
static void
ath5k_tasklet_calibrate(unsigned long data)
{
	struct ath5k_softc *sc = (void *)data;
	struct ath5k_hw *ah = sc->ah;

	/* Only full calibration for now */
	ah->ah_cal_mask |= AR5K_CALIBRATION_FULL;

	ATH5K_DBG(sc, ATH5K_DEBUG_CALIBRATE, "channel %u/%x\n",
		ieee80211_frequency_to_channel(sc->curchan->center_freq),
		sc->curchan->hw_value);

	if (ath5k_hw_gainf_calibrate(ah) == AR5K_RFGAIN_NEED_CHANGE) {
		/*
		 * Rfgain is out of bounds, reset the chip
		 * to load new gain values.
		 */
		ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "calibration, resetting\n");
		ieee80211_queue_work(sc->hw, &sc->reset_work);
	}
	if (ath5k_hw_phy_calibrate(ah, sc->curchan))
		ATH5K_ERR(sc, "calibration of channel %u failed\n",
			ieee80211_frequency_to_channel(
				sc->curchan->center_freq));

	/* Noise floor calibration interrupts rx/tx path while I/Q calibration
	 * doesn't.
	 * TODO: We should stop TX here, so that it doesn't interfere.
	 * Note that stopping the queues is not enough to stop TX! */
	if (time_is_before_eq_jiffies(ah->ah_cal_next_nf)) {
		ah->ah_cal_next_nf = jiffies +
			msecs_to_jiffies(ATH5K_TUNE_CALIBRATION_INTERVAL_NF);
		ath5k_hw_update_noise_floor(ah);
	}

	ah->ah_cal_mask &= ~AR5K_CALIBRATION_FULL;
}


static void
ath5k_tasklet_ani(unsigned long data)
{
	struct ath5k_softc *sc = (void *)data;
	struct ath5k_hw *ah = sc->ah;

	ah->ah_cal_mask |= AR5K_CALIBRATION_ANI;
	ath5k_ani_calibration(ah);
	ah->ah_cal_mask &= ~AR5K_CALIBRATION_ANI;
}


/*************************\
* Initialization routines *
\*************************/

static int
ath5k_stop_locked(struct ath5k_softc *sc)
{
	struct ath5k_hw *ah = sc->ah;

	ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "invalid %u\n",
			test_bit(ATH_STAT_INVALID, sc->status));

	/*
	 * Shutdown the hardware and driver:
	 *    stop output from above
	 *    disable interrupts
	 *    turn off timers
	 *    turn off the radio
	 *    clear transmit machinery
	 *    clear receive machinery
	 *    drain and release tx queues
	 *    reclaim beacon resources
	 *    power down hardware
	 *
	 * Note that some of this work is not possible if the
	 * hardware is gone (invalid).
	 */
	ieee80211_stop_queues(sc->hw);

	if (!test_bit(ATH_STAT_INVALID, sc->status)) {
		ath5k_led_off(sc);
		ath5k_hw_set_imr(ah, 0);
		synchronize_irq(sc->pdev->irq);
	}
	ath5k_txq_cleanup(sc);
	if (!test_bit(ATH_STAT_INVALID, sc->status)) {
		ath5k_rx_stop(sc);
		ath5k_hw_phy_disable(ah);
	}

	return 0;
}

static int
ath5k_init(struct ath5k_softc *sc)
{
	struct ath5k_hw *ah = sc->ah;
	struct ath_common *common = ath5k_hw_common(ah);
	int ret, i;

	mutex_lock(&sc->lock);

	ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "mode %d\n", sc->opmode);

	/*
	 * Stop anything previously setup.  This is safe
	 * no matter this is the first time through or not.
	 */
	ath5k_stop_locked(sc);

	/*
	 * The basic interface to setting the hardware in a good
	 * state is ``reset''.  On return the hardware is known to
	 * be powered up and with interrupts disabled.  This must
	 * be followed by initialization of the appropriate bits
	 * and then setup of the interrupt mask.
	 */
	sc->curchan = sc->hw->conf.channel;
	sc->curband = &sc->sbands[sc->curchan->band];
	sc->imask = AR5K_INT_RXOK | AR5K_INT_RXERR | AR5K_INT_RXEOL |
		AR5K_INT_RXORN | AR5K_INT_TXDESC | AR5K_INT_TXEOL |
		AR5K_INT_FATAL | AR5K_INT_GLOBAL | AR5K_INT_MIB;

	ret = ath5k_reset(sc, NULL);
	if (ret)
		goto done;

	ath5k_rfkill_hw_start(ah);

	/*
	 * Reset the key cache since some parts do not reset the
	 * contents on initial power up or resume from suspend.
	 */
	for (i = 0; i < common->keymax; i++)
		ath_hw_keyreset(common, (u16) i);

	ath5k_hw_set_ack_bitrate_high(ah, true);
	ret = 0;
done:
	mmiowb();
	mutex_unlock(&sc->lock);
	return ret;
}

static void stop_tasklets(struct ath5k_softc *sc)
{
	tasklet_kill(&sc->rxtq);
	tasklet_kill(&sc->txtq);
	tasklet_kill(&sc->calib);
	tasklet_kill(&sc->beacontq);
	tasklet_kill(&sc->ani_tasklet);
}

/*
 * Stop the device, grabbing the top-level lock to protect
 * against concurrent entry through ath5k_init (which can happen
 * if another thread does a system call and the thread doing the
 * stop is preempted).
 */
static int
ath5k_stop_hw(struct ath5k_softc *sc)
{
	int ret;

	mutex_lock(&sc->lock);
	ret = ath5k_stop_locked(sc);
	if (ret == 0 && !test_bit(ATH_STAT_INVALID, sc->status)) {
		/*
		 * Don't set the card in full sleep mode!
		 *
		 * a) When the device is in this state it must be carefully
		 * woken up or references to registers in the PCI clock
		 * domain may freeze the bus (and system).  This varies
		 * by chip and is mostly an issue with newer parts
		 * (madwifi sources mentioned srev >= 0x78) that go to
		 * sleep more quickly.
		 *
		 * b) On older chips full sleep results a weird behaviour
		 * during wakeup. I tested various cards with srev < 0x78
		 * and they don't wake up after module reload, a second
		 * module reload is needed to bring the card up again.
		 *
		 * Until we figure out what's going on don't enable
		 * full chip reset on any chip (this is what Legacy HAL
		 * and Sam's HAL do anyway). Instead Perform a full reset
		 * on the device (same as initial state after attach) and
		 * leave it idle (keep MAC/BB on warm reset) */
		ret = ath5k_hw_on_hold(sc->ah);

		ATH5K_DBG(sc, ATH5K_DEBUG_RESET,
				"putting device to sleep\n");
	}
	ath5k_txbuf_free_skb(sc, sc->bbuf);

	mmiowb();
	mutex_unlock(&sc->lock);

	stop_tasklets(sc);

	ath5k_rfkill_hw_stop(sc->ah);

	return ret;
}

/*
 * Reset the hardware.  If chan is not NULL, then also pause rx/tx
 * and change to the given channel.
 *
 * This should be called with sc->lock.
 */
static int
ath5k_reset(struct ath5k_softc *sc, struct ieee80211_channel *chan)
{
	struct ath5k_hw *ah = sc->ah;
	int ret;

	ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "resetting\n");

	ath5k_hw_set_imr(ah, 0);
	synchronize_irq(sc->pdev->irq);
	stop_tasklets(sc);

	if (chan) {
		ath5k_txq_cleanup(sc);
		ath5k_rx_stop(sc);

		sc->curchan = chan;
		sc->curband = &sc->sbands[chan->band];
	}
	ret = ath5k_hw_reset(ah, sc->opmode, sc->curchan, chan != NULL);
	if (ret) {
		ATH5K_ERR(sc, "can't reset hardware (%d)\n", ret);
		goto err;
	}

	ret = ath5k_rx_start(sc);
	if (ret) {
		ATH5K_ERR(sc, "can't start recv logic\n");
		goto err;
	}

	ath5k_ani_init(ah, ah->ah_sc->ani_state.ani_mode);

	ah->ah_cal_next_full = jiffies;
	ah->ah_cal_next_ani = jiffies;
	ah->ah_cal_next_nf = jiffies;

	/*
	 * Change channels and update the h/w rate map if we're switching;
	 * e.g. 11a to 11b/g.
	 *
	 * We may be doing a reset in response to an ioctl that changes the
	 * channel so update any state that might change as a result.
	 *
	 * XXX needed?
	 */
/*	ath5k_chan_change(sc, c); */

	ath5k_beacon_config(sc);
	/* intrs are enabled by ath5k_beacon_config */

	ieee80211_wake_queues(sc->hw);

	return 0;
err:
	return ret;
}

static void ath5k_reset_work(struct work_struct *work)
{
	struct ath5k_softc *sc = container_of(work, struct ath5k_softc,
		reset_work);

	mutex_lock(&sc->lock);
	ath5k_reset(sc, sc->curchan);
	mutex_unlock(&sc->lock);
}

static int
ath5k_attach(struct pci_dev *pdev, struct ieee80211_hw *hw)
{
	struct ath5k_softc *sc = hw->priv;
	struct ath5k_hw *ah = sc->ah;
	struct ath_regulatory *regulatory = ath5k_hw_regulatory(ah);
	struct ath5k_txq *txq;
	u8 mac[ETH_ALEN] = {};
	int ret;

	ATH5K_DBG(sc, ATH5K_DEBUG_ANY, "devid 0x%x\n", pdev->device);

	/*
	 * Check if the MAC has multi-rate retry support.
	 * We do this by trying to setup a fake extended
	 * descriptor.  MACs that don't have support will
	 * return false w/o doing anything.  MACs that do
	 * support it will return true w/o doing anything.
	 */
	ret = ath5k_hw_setup_mrr_tx_desc(ah, NULL, 0, 0, 0, 0, 0, 0);

	if (ret < 0)
		goto err;
	if (ret > 0)
		__set_bit(ATH_STAT_MRRETRY, sc->status);

	/*
	 * Collect the channel list.  The 802.11 layer
	 * is resposible for filtering this list based
	 * on settings like the phy mode and regulatory
	 * domain restrictions.
	 */
	ret = ath5k_setup_bands(hw);
	if (ret) {
		ATH5K_ERR(sc, "can't get channels\n");
		goto err;
	}

	/* NB: setup here so ath5k_rate_update is happy */
	if (test_bit(AR5K_MODE_11A, ah->ah_modes))
		ath5k_setcurmode(sc, AR5K_MODE_11A);
	else
		ath5k_setcurmode(sc, AR5K_MODE_11B);

	/*
	 * Allocate tx+rx descriptors and populate the lists.
	 */
	ret = ath5k_desc_alloc(sc, pdev);
	if (ret) {
		ATH5K_ERR(sc, "can't allocate descriptors\n");
		goto err;
	}

	/*
	 * Allocate hardware transmit queues: one queue for
	 * beacon frames and one data queue for each QoS
	 * priority.  Note that hw functions handle resetting
	 * these queues at the needed time.
	 */
	ret = ath5k_beaconq_setup(ah);
	if (ret < 0) {
		ATH5K_ERR(sc, "can't setup a beacon xmit queue\n");
		goto err_desc;
	}
	sc->bhalq = ret;
	sc->cabq = ath5k_txq_setup(sc, AR5K_TX_QUEUE_CAB, 0);
	if (IS_ERR(sc->cabq)) {
		ATH5K_ERR(sc, "can't setup cab queue\n");
		ret = PTR_ERR(sc->cabq);
		goto err_bhal;
	}

	/* This order matches mac80211's queue priority, so we can
	 * directly use the mac80211 queue number without any mapping */
	txq = ath5k_txq_setup(sc, AR5K_TX_QUEUE_DATA, AR5K_WME_AC_VO);
	if (IS_ERR(txq)) {
		ATH5K_ERR(sc, "can't setup xmit queue\n");
		ret = PTR_ERR(txq);
		goto err_queues;
	}
	txq = ath5k_txq_setup(sc, AR5K_TX_QUEUE_DATA, AR5K_WME_AC_VI);
	if (IS_ERR(txq)) {
		ATH5K_ERR(sc, "can't setup xmit queue\n");
		ret = PTR_ERR(txq);
		goto err_queues;
	}
	txq = ath5k_txq_setup(sc, AR5K_TX_QUEUE_DATA, AR5K_WME_AC_BE);
	if (IS_ERR(txq)) {
		ATH5K_ERR(sc, "can't setup xmit queue\n");
		ret = PTR_ERR(txq);
		goto err_queues;
	}
	txq = ath5k_txq_setup(sc, AR5K_TX_QUEUE_DATA, AR5K_WME_AC_BK);
	if (IS_ERR(txq)) {
		ATH5K_ERR(sc, "can't setup xmit queue\n");
		ret = PTR_ERR(txq);
		goto err_queues;
	}
	hw->queues = 4;

	tasklet_init(&sc->rxtq, ath5k_tasklet_rx, (unsigned long)sc);
	tasklet_init(&sc->txtq, ath5k_tasklet_tx, (unsigned long)sc);
	tasklet_init(&sc->calib, ath5k_tasklet_calibrate, (unsigned long)sc);
	tasklet_init(&sc->beacontq, ath5k_tasklet_beacon, (unsigned long)sc);
	tasklet_init(&sc->ani_tasklet, ath5k_tasklet_ani, (unsigned long)sc);

	INIT_WORK(&sc->reset_work, ath5k_reset_work);

	ret = ath5k_eeprom_read_mac(ah, mac);
	if (ret) {
		ATH5K_ERR(sc, "unable to read address from EEPROM: 0x%04x\n",
			sc->pdev->device);
		goto err_queues;
	}

	SET_IEEE80211_PERM_ADDR(hw, mac);
	/* All MAC address bits matter for ACKs */
	memcpy(sc->bssidmask, ath_bcast_mac, ETH_ALEN);
	ath5k_hw_set_bssid_mask(sc->ah, sc->bssidmask);

	regulatory->current_rd = ah->ah_capabilities.cap_eeprom.ee_regdomain;
	ret = ath_regd_init(regulatory, hw->wiphy, ath5k_reg_notifier);
	if (ret) {
		ATH5K_ERR(sc, "can't initialize regulatory system\n");
		goto err_queues;
	}

	ret = ieee80211_register_hw(hw);
	if (ret) {
		ATH5K_ERR(sc, "can't register ieee80211 hw\n");
		goto err_queues;
	}

	if (!ath_is_world_regd(regulatory))
		regulatory_hint(hw->wiphy, regulatory->alpha2);

	ath5k_init_leds(sc);

	ath5k_sysfs_register(sc);

	return 0;
err_queues:
	ath5k_txq_release(sc);
err_bhal:
	ath5k_hw_release_tx_queue(ah, sc->bhalq);
err_desc:
	ath5k_desc_free(sc, pdev);
err:
	return ret;
}

static void
ath5k_detach(struct pci_dev *pdev, struct ieee80211_hw *hw)
{
	struct ath5k_softc *sc = hw->priv;

	/*
	 * NB: the order of these is important:
	 * o call the 802.11 layer before detaching ath5k_hw to
	 *   ensure callbacks into the driver to delete global
	 *   key cache entries can be handled
	 * o reclaim the tx queue data structures after calling
	 *   the 802.11 layer as we'll get called back to reclaim
	 *   node state and potentially want to use them
	 * o to cleanup the tx queues the hal is called, so detach
	 *   it last
	 * XXX: ??? detach ath5k_hw ???
	 * Other than that, it's straightforward...
	 */
	ieee80211_unregister_hw(hw);
	ath5k_desc_free(sc, pdev);
	ath5k_txq_release(sc);
	ath5k_hw_release_tx_queue(sc->ah, sc->bhalq);
	ath5k_unregister_leds(sc);

	ath5k_sysfs_unregister(sc);
	/*
	 * NB: can't reclaim these until after ieee80211_ifdetach
	 * returns because we'll get called back to reclaim node
	 * state and potentially want to use them.
	 */
}

/********************\
* Mac80211 functions *
\********************/

static int
ath5k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
{
	struct ath5k_softc *sc = hw->priv;
	u16 qnum = skb_get_queue_mapping(skb);

	if (WARN_ON(qnum >= sc->ah->ah_capabilities.cap_queues.q_tx_num)) {
		dev_kfree_skb_any(skb);
		return 0;
	}

	return ath5k_tx_queue(hw, skb, &sc->txqs[qnum]);
}

static int ath5k_start(struct ieee80211_hw *hw)
{
	return ath5k_init(hw->priv);
}

static void ath5k_stop(struct ieee80211_hw *hw)
{
	ath5k_stop_hw(hw->priv);
}

static int ath5k_add_interface(struct ieee80211_hw *hw,
		struct ieee80211_vif *vif)
{
	struct ath5k_softc *sc = hw->priv;
	int ret;

	mutex_lock(&sc->lock);
	if (sc->vif) {
		ret = 0;
		goto end;
	}

	sc->vif = vif;

	switch (vif->type) {
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_ADHOC:
	case NL80211_IFTYPE_MESH_POINT:
		sc->opmode = vif->type;
		break;
	default:
		ret = -EOPNOTSUPP;
		goto end;
	}

	ATH5K_DBG(sc, ATH5K_DEBUG_MODE, "add interface mode %d\n", sc->opmode);

	ath5k_hw_set_lladdr(sc->ah, vif->addr);
	ath5k_mode_setup(sc);

	ret = 0;
end:
	mutex_unlock(&sc->lock);
	return ret;
}

static void
ath5k_remove_interface(struct ieee80211_hw *hw,
			struct ieee80211_vif *vif)
{
	struct ath5k_softc *sc = hw->priv;
	u8 mac[ETH_ALEN] = {};

	mutex_lock(&sc->lock);
	if (sc->vif != vif)
		goto end;

	ath5k_hw_set_lladdr(sc->ah, mac);
	sc->vif = NULL;
end:
	mutex_unlock(&sc->lock);
}

/*
 * TODO: Phy disable/diversity etc
 */
static int
ath5k_config(struct ieee80211_hw *hw, u32 changed)
{
	struct ath5k_softc *sc = hw->priv;
	struct ath5k_hw *ah = sc->ah;
	struct ieee80211_conf *conf = &hw->conf;
	int ret = 0;

	mutex_lock(&sc->lock);

	if (changed & IEEE80211_CONF_CHANGE_CHANNEL) {
		ret = ath5k_chan_set(sc, conf->channel);
		if (ret < 0)
			goto unlock;
	}

	if ((changed & IEEE80211_CONF_CHANGE_POWER) &&
	(sc->power_level != conf->power_level)) {
		sc->power_level = conf->power_level;

		/* Half dB steps */
		ath5k_hw_set_txpower_limit(ah, (conf->power_level * 2));
	}

	/* TODO:
	 * 1) Move this on config_interface and handle each case
	 * separately eg. when we have only one STA vif, use
	 * AR5K_ANTMODE_SINGLE_AP
	 *
	 * 2) Allow the user to change antenna mode eg. when only
	 * one antenna is present
	 *
	 * 3) Allow the user to set default/tx antenna when possible
	 *
	 * 4) Default mode should handle 90% of the cases, together
	 * with fixed a/b and single AP modes we should be able to
	 * handle 99%. Sectored modes are extreme cases and i still
	 * haven't found a usage for them. If we decide to support them,
	 * then we must allow the user to set how many tx antennas we
	 * have available
	 */
	ath5k_hw_set_antenna_mode(ah, ah->ah_ant_mode);

unlock:
	mutex_unlock(&sc->lock);
	return ret;
}

static u64 ath5k_prepare_multicast(struct ieee80211_hw *hw,
				   struct netdev_hw_addr_list *mc_list)
{
	u32 mfilt[2], val;
	u8 pos;
	struct netdev_hw_addr *ha;

	mfilt[0] = 0;
	mfilt[1] = 1;

	netdev_hw_addr_list_for_each(ha, mc_list) {
		/* calculate XOR of eight 6-bit values */
		val = get_unaligned_le32(ha->addr + 0);
		pos = (val >> 18) ^ (val >> 12) ^ (val >> 6) ^ val;
		val = get_unaligned_le32(ha->addr + 3);
		pos ^= (val >> 18) ^ (val >> 12) ^ (val >> 6) ^ val;
		pos &= 0x3f;
		mfilt[pos / 32] |= (1 << (pos % 32));
		/* XXX: we might be able to just do this instead,
		* but not sure, needs testing, if we do use this we'd
		* neet to inform below to not reset the mcast */
		/* ath5k_hw_set_mcast_filterindex(ah,
		 *      ha->addr[5]); */
	}

	return ((u64)(mfilt[1]) << 32) | mfilt[0];
}

#define SUPPORTED_FIF_FLAGS \
	FIF_PROMISC_IN_BSS |  FIF_ALLMULTI | FIF_FCSFAIL | \
	FIF_PLCPFAIL | FIF_CONTROL | FIF_OTHER_BSS | \
	FIF_BCN_PRBRESP_PROMISC
/*
 * o always accept unicast, broadcast, and multicast traffic
 * o multicast traffic for all BSSIDs will be enabled if mac80211
 *   says it should be
 * o maintain current state of phy ofdm or phy cck error reception.
 *   If the hardware detects any of these type of errors then
 *   ath5k_hw_get_rx_filter() will pass to us the respective
 *   hardware filters to be able to receive these type of frames.
 * o probe request frames are accepted only when operating in
 *   hostap, adhoc, or monitor modes
 * o enable promiscuous mode according to the interface state
 * o accept beacons:
 *   - when operating in adhoc mode so the 802.11 layer creates
 *     node table entries for peers,
 *   - when operating in station mode for collecting rssi data when
 *     the station is otherwise quiet, or
 *   - when scanning
 */
static void ath5k_configure_filter(struct ieee80211_hw *hw,
		unsigned int changed_flags,
		unsigned int *new_flags,
		u64 multicast)
{
	struct ath5k_softc *sc = hw->priv;
	struct ath5k_hw *ah = sc->ah;
	u32 mfilt[2], rfilt;

	mutex_lock(&sc->lock);

	mfilt[0] = multicast;
	mfilt[1] = multicast >> 32;

	/* Only deal with supported flags */
	changed_flags &= SUPPORTED_FIF_FLAGS;
	*new_flags &= SUPPORTED_FIF_FLAGS;

	/* If HW detects any phy or radar errors, leave those filters on.
	 * Also, always enable Unicast, Broadcasts and Multicast
	 * XXX: move unicast, bssid broadcasts and multicast to mac80211 */
	rfilt = (ath5k_hw_get_rx_filter(ah) & (AR5K_RX_FILTER_PHYERR)) |
		(AR5K_RX_FILTER_UCAST | AR5K_RX_FILTER_BCAST |
		AR5K_RX_FILTER_MCAST);

	if (changed_flags & (FIF_PROMISC_IN_BSS | FIF_OTHER_BSS)) {
		if (*new_flags & FIF_PROMISC_IN_BSS) {
			__set_bit(ATH_STAT_PROMISC, sc->status);
		} else {
			__clear_bit(ATH_STAT_PROMISC, sc->status);
		}
	}

	if (test_bit(ATH_STAT_PROMISC, sc->status))
		rfilt |= AR5K_RX_FILTER_PROM;

	/* Note, AR5K_RX_FILTER_MCAST is already enabled */
	if (*new_flags & FIF_ALLMULTI) {
		mfilt[0] =  ~0;
		mfilt[1] =  ~0;
	}

	/* This is the best we can do */
	if (*new_flags & (FIF_FCSFAIL | FIF_PLCPFAIL))
		rfilt |= AR5K_RX_FILTER_PHYERR;

	/* FIF_BCN_PRBRESP_PROMISC really means to enable beacons
	* and probes for any BSSID */
	if (*new_flags & FIF_BCN_PRBRESP_PROMISC)
		rfilt |= AR5K_RX_FILTER_BEACON;

	/* FIF_CONTROL doc says that if FIF_PROMISC_IN_BSS is not
	 * set we should only pass on control frames for this
	 * station. This needs testing. I believe right now this
	 * enables *all* control frames, which is OK.. but
	 * but we should see if we can improve on granularity */
	if (*new_flags & FIF_CONTROL)
		rfilt |= AR5K_RX_FILTER_CONTROL;

	/* Additional settings per mode -- this is per ath5k */

	/* XXX move these to mac80211, and add a beacon IFF flag to mac80211 */

	switch (sc->opmode) {
	case NL80211_IFTYPE_MESH_POINT:
		rfilt |= AR5K_RX_FILTER_CONTROL |
			 AR5K_RX_FILTER_BEACON |
			 AR5K_RX_FILTER_PROBEREQ |
			 AR5K_RX_FILTER_PROM;
		break;
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_ADHOC:
		rfilt |= AR5K_RX_FILTER_PROBEREQ |
			 AR5K_RX_FILTER_BEACON;
		break;
	case NL80211_IFTYPE_STATION:
		if (sc->assoc)
			rfilt |= AR5K_RX_FILTER_BEACON;
	default:
		break;
	}

	/* Set filters */
	ath5k_hw_set_rx_filter(ah, rfilt);

	/* Set multicast bits */
	ath5k_hw_set_mcast_filter(ah, mfilt[0], mfilt[1]);
	/* Set the cached hw filter flags, this will later actually
	 * be set in HW */
	sc->filter_flags = rfilt;

	mutex_unlock(&sc->lock);
}

static int
ath5k_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
	      struct ieee80211_vif *vif, struct ieee80211_sta *sta,
	      struct ieee80211_key_conf *key)
{
	struct ath5k_softc *sc = hw->priv;
	struct ath5k_hw *ah = sc->ah;
	struct ath_common *common = ath5k_hw_common(ah);
	int ret = 0;

	if (modparam_nohwcrypt)
		return -EOPNOTSUPP;

	switch (key->cipher) {
	case WLAN_CIPHER_SUITE_WEP40:
	case WLAN_CIPHER_SUITE_WEP104:
	case WLAN_CIPHER_SUITE_TKIP:
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		if (common->crypt_caps & ATH_CRYPT_CAP_CIPHER_AESCCM)
			break;
		return -EOPNOTSUPP;
	default:
		WARN_ON(1);
		return -EINVAL;
	}

	mutex_lock(&sc->lock);

	switch (cmd) {
	case SET_KEY:
		ret = ath_key_config(common, vif, sta, key);
		if (ret >= 0) {
			key->hw_key_idx = ret;
			/* push IV and Michael MIC generation to stack */
			key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
			if (key->cipher == WLAN_CIPHER_SUITE_TKIP)
				key->flags |= IEEE80211_KEY_FLAG_GENERATE_MMIC;
			if (key->cipher == WLAN_CIPHER_SUITE_CCMP)
				key->flags |= IEEE80211_KEY_FLAG_SW_MGMT;
			ret = 0;
		}
		break;
	case DISABLE_KEY:
		ath_key_delete(common, key);
		break;
	default:
		ret = -EINVAL;
	}

	mmiowb();
	mutex_unlock(&sc->lock);
	return ret;
}

static int
ath5k_get_stats(struct ieee80211_hw *hw,
		struct ieee80211_low_level_stats *stats)
{
	struct ath5k_softc *sc = hw->priv;

	/* Force update */
	ath5k_hw_update_mib_counters(sc->ah);

	stats->dot11ACKFailureCount = sc->stats.ack_fail;
	stats->dot11RTSFailureCount = sc->stats.rts_fail;
	stats->dot11RTSSuccessCount = sc->stats.rts_ok;
	stats->dot11FCSErrorCount = sc->stats.fcs_error;

	return 0;
}

static int ath5k_get_survey(struct ieee80211_hw *hw, int idx,
		struct survey_info *survey)
{
	struct ath5k_softc *sc = hw->priv;
	struct ieee80211_conf *conf = &hw->conf;

	 if (idx != 0)
		return -ENOENT;

	survey->channel = conf->channel;
	survey->filled = SURVEY_INFO_NOISE_DBM;
	survey->noise = sc->ah->ah_noise_floor;

	return 0;
}

static u64
ath5k_get_tsf(struct ieee80211_hw *hw)
{
	struct ath5k_softc *sc = hw->priv;

	return ath5k_hw_get_tsf64(sc->ah);
}

static void
ath5k_set_tsf(struct ieee80211_hw *hw, u64 tsf)
{
	struct ath5k_softc *sc = hw->priv;

	ath5k_hw_set_tsf64(sc->ah, tsf);
}

static void
ath5k_reset_tsf(struct ieee80211_hw *hw)
{
	struct ath5k_softc *sc = hw->priv;

	/*
	 * in IBSS mode we need to update the beacon timers too.
	 * this will also reset the TSF if we call it with 0
	 */
	if (sc->opmode == NL80211_IFTYPE_ADHOC)
		ath5k_beacon_update_timers(sc, 0);
	else
		ath5k_hw_reset_tsf(sc->ah);
}

static void
set_beacon_filter(struct ieee80211_hw *hw, bool enable)
{
	struct ath5k_softc *sc = hw->priv;
	struct ath5k_hw *ah = sc->ah;
	u32 rfilt;
	rfilt = ath5k_hw_get_rx_filter(ah);
	if (enable)
		rfilt |= AR5K_RX_FILTER_BEACON;
	else
		rfilt &= ~AR5K_RX_FILTER_BEACON;
	ath5k_hw_set_rx_filter(ah, rfilt);
	sc->filter_flags = rfilt;
}

static void ath5k_bss_info_changed(struct ieee80211_hw *hw,
				    struct ieee80211_vif *vif,
				    struct ieee80211_bss_conf *bss_conf,
				    u32 changes)
{
	struct ath5k_softc *sc = hw->priv;
	struct ath5k_hw *ah = sc->ah;
	struct ath_common *common = ath5k_hw_common(ah);
	unsigned long flags;

	mutex_lock(&sc->lock);
	if (WARN_ON(sc->vif != vif))
		goto unlock;

	if (changes & BSS_CHANGED_BSSID) {
		/* Cache for later use during resets */
		memcpy(common->curbssid, bss_conf->bssid, ETH_ALEN);
		common->curaid = 0;
		ath5k_hw_set_bssid(ah);
		mmiowb();
	}

	if (changes & BSS_CHANGED_BEACON_INT)
		sc->bintval = bss_conf->beacon_int;

	if (changes & BSS_CHANGED_ASSOC) {
		sc->assoc = bss_conf->assoc;
		if (sc->opmode == NL80211_IFTYPE_STATION)
			set_beacon_filter(hw, sc->assoc);
		ath5k_hw_set_ledstate(sc->ah, sc->assoc ?
			AR5K_LED_ASSOC : AR5K_LED_INIT);
		if (bss_conf->assoc) {
			ATH5K_DBG(sc, ATH5K_DEBUG_ANY,
				  "Bss Info ASSOC %d, bssid: %pM\n",
				  bss_conf->aid, common->curbssid);
			common->curaid = bss_conf->aid;
			ath5k_hw_set_bssid(ah);
			/* Once ANI is available you would start it here */
		}
	}

	if (changes & BSS_CHANGED_BEACON) {
		spin_lock_irqsave(&sc->block, flags);
		ath5k_beacon_update(hw, vif);
		spin_unlock_irqrestore(&sc->block, flags);
	}

	if (changes & BSS_CHANGED_BEACON_ENABLED)
		sc->enable_beacon = bss_conf->enable_beacon;

	if (changes & (BSS_CHANGED_BEACON | BSS_CHANGED_BEACON_ENABLED |
		       BSS_CHANGED_BEACON_INT))
		ath5k_beacon_config(sc);

 unlock:
	mutex_unlock(&sc->lock);
}

static void ath5k_sw_scan_start(struct ieee80211_hw *hw)
{
	struct ath5k_softc *sc = hw->priv;
	if (!sc->assoc)
		ath5k_hw_set_ledstate(sc->ah, AR5K_LED_SCAN);
}

static void ath5k_sw_scan_complete(struct ieee80211_hw *hw)
{
	struct ath5k_softc *sc = hw->priv;
	ath5k_hw_set_ledstate(sc->ah, sc->assoc ?
		AR5K_LED_ASSOC : AR5K_LED_INIT);
}

/**
 * ath5k_set_coverage_class - Set IEEE 802.11 coverage class
 *
 * @hw: struct ieee80211_hw pointer
 * @coverage_class: IEEE 802.11 coverage class number
 *
 * Mac80211 callback. Sets slot time, ACK timeout and CTS timeout for given
 * coverage class. The values are persistent, they are restored after device
 * reset.
 */
static void ath5k_set_coverage_class(struct ieee80211_hw *hw, u8 coverage_class)
{
	struct ath5k_softc *sc = hw->priv;

	mutex_lock(&sc->lock);
	ath5k_hw_set_coverage_class(sc->ah, coverage_class);
	mutex_unlock(&sc->lock);
}

static const struct ieee80211_ops ath5k_hw_ops = {
	.tx 		= ath5k_tx,
	.start 		= ath5k_start,
	.stop 		= ath5k_stop,
	.add_interface 	= ath5k_add_interface,
	.remove_interface = ath5k_remove_interface,
	.config 	= ath5k_config,
	.prepare_multicast = ath5k_prepare_multicast,
	.configure_filter = ath5k_configure_filter,
	.set_key 	= ath5k_set_key,
	.get_stats 	= ath5k_get_stats,
	.get_survey	= ath5k_get_survey,
	.conf_tx 	= NULL,
	.get_tsf 	= ath5k_get_tsf,
	.set_tsf 	= ath5k_set_tsf,
	.reset_tsf 	= ath5k_reset_tsf,
	.bss_info_changed = ath5k_bss_info_changed,
	.sw_scan_start	= ath5k_sw_scan_start,
	.sw_scan_complete = ath5k_sw_scan_complete,
	.set_coverage_class = ath5k_set_coverage_class,
};

/********************\
* PCI Initialization *
\********************/

static int __devinit
ath5k_pci_probe(struct pci_dev *pdev,
		const struct pci_device_id *id)
{
	void __iomem *mem;
	struct ath5k_softc *sc;
	struct ath_common *common;
	struct ieee80211_hw *hw;
	int ret;
	u8 csz;

	/*
	 * L0s needs to be disabled on all ath5k cards.
	 *
	 * For distributions shipping with CONFIG_PCIEASPM (this will be enabled
	 * by default in the future in 2.6.36) this will also mean both L1 and
	 * L0s will be disabled when a pre 1.1 PCIe device is detected. We do
	 * know L1 works correctly even for all ath5k pre 1.1 PCIe devices
	 * though but cannot currently undue the effect of a blacklist, for
	 * details you can read pcie_aspm_sanity_check() and see how it adjusts
	 * the device link capability.
	 *
	 * It may be possible in the future to implement some PCI API to allow
	 * drivers to override blacklists for pre 1.1 PCIe but for now it is
	 * best to accept that both L0s and L1 will be disabled completely for
	 * distributions shipping with CONFIG_PCIEASPM rather than having this
	 * issue present. Motivation for adding this new API will be to help
	 * with power consumption for some of these devices.
	 */
	pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S);

	ret = pci_enable_device(pdev);
	if (ret) {
		dev_err(&pdev->dev, "can't enable device\n");
		goto err;
	}

	/* XXX 32-bit addressing only */
	ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
	if (ret) {
		dev_err(&pdev->dev, "32-bit DMA not available\n");
		goto err_dis;
	}

	/*
	 * Cache line size is used to size and align various
	 * structures used to communicate with the hardware.
	 */
	pci_read_config_byte(pdev, PCI_CACHE_LINE_SIZE, &csz);
	if (csz == 0) {
		/*
		 * Linux 2.4.18 (at least) writes the cache line size
		 * register as a 16-bit wide register which is wrong.
		 * We must have this setup properly for rx buffer
		 * DMA to work so force a reasonable value here if it
		 * comes up zero.
		 */
		csz = L1_CACHE_BYTES >> 2;
		pci_write_config_byte(pdev, PCI_CACHE_LINE_SIZE, csz);
	}
	/*
	 * The default setting of latency timer yields poor results,
	 * set it to the value used by other systems.  It may be worth
	 * tweaking this setting more.
	 */
	pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0xa8);

	/* Enable bus mastering */
	pci_set_master(pdev);

	/*
	 * Disable the RETRY_TIMEOUT register (0x41) to keep
	 * PCI Tx retries from interfering with C3 CPU state.
	 */
	pci_write_config_byte(pdev, 0x41, 0);

	ret = pci_request_region(pdev, 0, "ath5k");
	if (ret) {
		dev_err(&pdev->dev, "cannot reserve PCI memory region\n");
		goto err_dis;
	}

	mem = pci_iomap(pdev, 0, 0);
	if (!mem) {
		dev_err(&pdev->dev, "cannot remap PCI memory region\n") ;
		ret = -EIO;
		goto err_reg;
	}

	/*
	 * Allocate hw (mac80211 main struct)
	 * and hw->priv (driver private data)
	 */
	hw = ieee80211_alloc_hw(sizeof(*sc), &ath5k_hw_ops);
	if (hw == NULL) {
		dev_err(&pdev->dev, "cannot allocate ieee80211_hw\n");
		ret = -ENOMEM;
		goto err_map;
	}

	dev_info(&pdev->dev, "registered as '%s'\n", wiphy_name(hw->wiphy));

	/* Initialize driver private data */
	SET_IEEE80211_DEV(hw, &pdev->dev);
	hw->flags = IEEE80211_HW_RX_INCLUDES_FCS |
		    IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING |
		    IEEE80211_HW_SIGNAL_DBM;

	hw->wiphy->interface_modes =
		BIT(NL80211_IFTYPE_AP) |
		BIT(NL80211_IFTYPE_STATION) |
		BIT(NL80211_IFTYPE_ADHOC) |
		BIT(NL80211_IFTYPE_MESH_POINT);

	hw->extra_tx_headroom = 2;
	hw->channel_change_time = 5000;
	sc = hw->priv;
	sc->hw = hw;
	sc->pdev = pdev;

	ath5k_debug_init_device(sc);

	/*
	 * Mark the device as detached to avoid processing
	 * interrupts until setup is complete.
	 */
	__set_bit(ATH_STAT_INVALID, sc->status);

	sc->iobase = mem; /* So we can unmap it on detach */
	sc->opmode = NL80211_IFTYPE_STATION;
	sc->bintval = 1000;
	mutex_init(&sc->lock);
	spin_lock_init(&sc->rxbuflock);
	spin_lock_init(&sc->txbuflock);
	spin_lock_init(&sc->block);

	/* Set private data */
	pci_set_drvdata(pdev, sc);

	/* Setup interrupt handler */
	ret = request_irq(pdev->irq, ath5k_intr, IRQF_SHARED, "ath", sc);
	if (ret) {
		ATH5K_ERR(sc, "request_irq failed\n");
		goto err_free;
	}

	/* If we passed the test, malloc an ath5k_hw struct */
	sc->ah = kzalloc(sizeof(struct ath5k_hw), GFP_KERNEL);
	if (!sc->ah) {
		ret = -ENOMEM;
		ATH5K_ERR(sc, "out of memory\n");
		goto err_irq;
	}

	sc->ah->ah_sc = sc;
	sc->ah->ah_iobase = sc->iobase;
	common = ath5k_hw_common(sc->ah);
	common->ops = &ath5k_common_ops;
	common->ah = sc->ah;
	common->hw = hw;
	common->cachelsz = csz << 2; /* convert to bytes */

	/* Initialize device */
	ret = ath5k_hw_attach(sc);
	if (ret) {
		goto err_free_ah;
	}

	/* set up multi-rate retry capabilities */
	if (sc->ah->ah_version == AR5K_AR5212) {
		hw->max_rates = 4;
		hw->max_rate_tries = 11;
	}

	/* Finish private driver data initialization */
	ret = ath5k_attach(pdev, hw);
	if (ret)
		goto err_ah;

	ATH5K_INFO(sc, "Atheros AR%s chip found (MAC: 0x%x, PHY: 0x%x)\n",
			ath5k_chip_name(AR5K_VERSION_MAC, sc->ah->ah_mac_srev),
					sc->ah->ah_mac_srev,
					sc->ah->ah_phy_revision);

	if (!sc->ah->ah_single_chip) {
		/* Single chip radio (!RF5111) */
		if (sc->ah->ah_radio_5ghz_revision &&
			!sc->ah->ah_radio_2ghz_revision) {
			/* No 5GHz support -> report 2GHz radio */
			if (!test_bit(AR5K_MODE_11A,
				sc->ah->ah_capabilities.cap_mode)) {
				ATH5K_INFO(sc, "RF%s 2GHz radio found (0x%x)\n",
					ath5k_chip_name(AR5K_VERSION_RAD,
						sc->ah->ah_radio_5ghz_revision),
						sc->ah->ah_radio_5ghz_revision);
			/* No 2GHz support (5110 and some
			 * 5Ghz only cards) -> report 5Ghz radio */
			} else if (!test_bit(AR5K_MODE_11B,
				sc->ah->ah_capabilities.cap_mode)) {
				ATH5K_INFO(sc, "RF%s 5GHz radio found (0x%x)\n",
					ath5k_chip_name(AR5K_VERSION_RAD,
						sc->ah->ah_radio_5ghz_revision),
						sc->ah->ah_radio_5ghz_revision);
			/* Multiband radio */
			} else {
				ATH5K_INFO(sc, "RF%s multiband radio found"
					" (0x%x)\n",
					ath5k_chip_name(AR5K_VERSION_RAD,
						sc->ah->ah_radio_5ghz_revision),
						sc->ah->ah_radio_5ghz_revision);
			}
		}
		/* Multi chip radio (RF5111 - RF2111) ->
		 * report both 2GHz/5GHz radios */
		else if (sc->ah->ah_radio_5ghz_revision &&
				sc->ah->ah_radio_2ghz_revision){
			ATH5K_INFO(sc, "RF%s 5GHz radio found (0x%x)\n",
				ath5k_chip_name(AR5K_VERSION_RAD,
					sc->ah->ah_radio_5ghz_revision),
					sc->ah->ah_radio_5ghz_revision);
			ATH5K_INFO(sc, "RF%s 2GHz radio found (0x%x)\n",
				ath5k_chip_name(AR5K_VERSION_RAD,
					sc->ah->ah_radio_2ghz_revision),
					sc->ah->ah_radio_2ghz_revision);
		}
	}


	/* ready to process interrupts */
	__clear_bit(ATH_STAT_INVALID, sc->status);

	return 0;
err_ah:
	ath5k_hw_detach(sc->ah);
err_free_ah:
	kfree(sc->ah);
err_irq:
	free_irq(pdev->irq, sc);
err_free:
	ieee80211_free_hw(hw);
err_map:
	pci_iounmap(pdev, mem);
err_reg:
	pci_release_region(pdev, 0);
err_dis:
	pci_disable_device(pdev);
err:
	return ret;
}

static void __devexit
ath5k_pci_remove(struct pci_dev *pdev)
{
	struct ath5k_softc *sc = pci_get_drvdata(pdev);

	ath5k_debug_finish_device(sc);
	ath5k_detach(pdev, sc->hw);
	ath5k_hw_detach(sc->ah);
	kfree(sc->ah);
	free_irq(pdev->irq, sc);
	pci_iounmap(pdev, sc->iobase);
	pci_release_region(pdev, 0);
	pci_disable_device(pdev);
	ieee80211_free_hw(sc->hw);
}

#ifdef CONFIG_PM_SLEEP
static int ath5k_pci_suspend(struct device *dev)
{
	struct ath5k_softc *sc = pci_get_drvdata(to_pci_dev(dev));

	ath5k_led_off(sc);
	return 0;
}

static int ath5k_pci_resume(struct device *dev)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	struct ath5k_softc *sc = pci_get_drvdata(pdev);

	/*
	 * Suspend/Resume resets the PCI configuration space, so we have to
	 * re-disable the RETRY_TIMEOUT register (0x41) to keep
	 * PCI Tx retries from interfering with C3 CPU state
	 */
	pci_write_config_byte(pdev, 0x41, 0);

	ath5k_led_enable(sc);
	return 0;
}

static SIMPLE_DEV_PM_OPS(ath5k_pm_ops, ath5k_pci_suspend, ath5k_pci_resume);
#define ATH5K_PM_OPS	(&ath5k_pm_ops)
#else
#define ATH5K_PM_OPS	NULL
#endif /* CONFIG_PM_SLEEP */

static struct pci_driver ath5k_pci_driver = {
	.name		= KBUILD_MODNAME,
	.id_table	= ath5k_pci_id_table,
	.probe		= ath5k_pci_probe,
	.remove		= __devexit_p(ath5k_pci_remove),
	.driver.pm	= ATH5K_PM_OPS,
};

/*
 * Module init/exit functions
 */
static int __init
init_ath5k_pci(void)
{
	int ret;

	ath5k_debug_init();

	ret = pci_register_driver(&ath5k_pci_driver);
	if (ret) {
		printk(KERN_ERR "ath5k_pci: can't register pci driver\n");
		return ret;
	}

	return 0;
}

static void __exit
exit_ath5k_pci(void)
{
	pci_unregister_driver(&ath5k_pci_driver);

	ath5k_debug_finish();
}

module_init(init_ath5k_pci);
module_exit(exit_ath5k_pci);