ath5k: fix locking in ath5k_config

[linux-2.6/mini2440.git] / drivers / net / wireless / 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/ethtool.h>
#include <linux/uaccess.h>

#include <net/ieee80211_radiotap.h>

#include <asm/unaligned.h>

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

static int ath5k_calinterval = 10; /* Calibrate PHY every 10 secs (TODO: Fixme) */
static int modparam_nohwcrypt;
module_param_named(nohwcrypt, modparam_nohwcrypt, int, 0444);
MODULE_PARM_DESC(nohwcrypt, "Disable hardware encryption.");


/******************\
* Internal defines *
\******************/

/* 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)");


/* Known PCI ids */
static struct pci_device_id ath5k_pci_id_table[] __devinitdata = {
        { PCI_VDEVICE(ATHEROS, 0x0207), .driver_data = AR5K_AR5210 }, /* 5210 early */
        { PCI_VDEVICE(ATHEROS, 0x0007), .driver_data = AR5K_AR5210 }, /* 5210 */
        { PCI_VDEVICE(ATHEROS, 0x0011), .driver_data = AR5K_AR5211 }, /* 5311 - this is on AHB bus !*/
        { PCI_VDEVICE(ATHEROS, 0x0012), .driver_data = AR5K_AR5211 }, /* 5211 */
        { PCI_VDEVICE(ATHEROS, 0x0013), .driver_data = AR5K_AR5212 }, /* 5212 */
        { PCI_VDEVICE(3COM_2,  0x0013), .driver_data = AR5K_AR5212 }, /* 3com 5212 */
        { PCI_VDEVICE(3COM,    0x0013), .driver_data = AR5K_AR5212 }, /* 3com 3CRDAG675 5212 */
        { PCI_VDEVICE(ATHEROS, 0x1014), .driver_data = AR5K_AR5212 }, /* IBM minipci 5212 */
        { PCI_VDEVICE(ATHEROS, 0x0014), .driver_data = AR5K_AR5212 }, /* 5212 combatible */
        { PCI_VDEVICE(ATHEROS, 0x0015), .driver_data = AR5K_AR5212 }, /* 5212 combatible */
        { PCI_VDEVICE(ATHEROS, 0x0016), .driver_data = AR5K_AR5212 }, /* 5212 combatible */
        { PCI_VDEVICE(ATHEROS, 0x0017), .driver_data = AR5K_AR5212 }, /* 5212 combatible */
        { PCI_VDEVICE(ATHEROS, 0x0018), .driver_data = AR5K_AR5212 }, /* 5212 combatible */
        { PCI_VDEVICE(ATHEROS, 0x0019), .driver_data = AR5K_AR5212 }, /* 5212 combatible */
        { PCI_VDEVICE(ATHEROS, 0x001a), .driver_data = AR5K_AR5212 }, /* 2413 Griffin-lite */
        { PCI_VDEVICE(ATHEROS, 0x001b), .driver_data = AR5K_AR5212 }, /* 5413 Eagle */
        { PCI_VDEVICE(ATHEROS, 0x001c), .driver_data = AR5K_AR5212 }, /* PCI-E cards */
        { PCI_VDEVICE(ATHEROS, 0x001d), .driver_data = AR5K_AR5212 }, /* 2417 Nala */
        { 0 }
};
MODULE_DEVICE_TABLE(pci, ath5k_pci_id_table);

/* Known SREVs */
static 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 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 */
};

/*
 * Prototypes - PCI stack related functions
 */
static int __devinit    ath5k_pci_probe(struct pci_dev *pdev,
                                const struct pci_device_id *id);
static void __devexit   ath5k_pci_remove(struct pci_dev *pdev);
#ifdef CONFIG_PM
static int              ath5k_pci_suspend(struct pci_dev *pdev,
                                        pm_message_t state);
static int              ath5k_pci_resume(struct pci_dev *pdev);
#else
#define ath5k_pci_suspend NULL
#define ath5k_pci_resume NULL
#endif /* CONFIG_PM */

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),
        .suspend        = ath5k_pci_suspend,
        .resume         = ath5k_pci_resume,
};



/*
 * Prototypes - MAC 802.11 stack related functions
 */
static int ath5k_tx(struct ieee80211_hw *hw, struct sk_buff *skb);
static int ath5k_reset(struct ath5k_softc *sc, bool stop, bool change_channel);
static int ath5k_reset_wake(struct ath5k_softc *sc);
static int ath5k_start(struct ieee80211_hw *hw);
static void ath5k_stop(struct ieee80211_hw *hw);
static int ath5k_add_interface(struct ieee80211_hw *hw,
                struct ieee80211_if_init_conf *conf);
static void ath5k_remove_interface(struct ieee80211_hw *hw,
                struct ieee80211_if_init_conf *conf);
static int ath5k_config(struct ieee80211_hw *hw, u32 changed);
static int ath5k_config_interface(struct ieee80211_hw *hw,
                struct ieee80211_vif *vif,
                struct ieee80211_if_conf *conf);
static void ath5k_configure_filter(struct ieee80211_hw *hw,
                unsigned int changed_flags,
                unsigned int *new_flags,
                int mc_count, struct dev_mc_list *mclist);
static int ath5k_set_key(struct ieee80211_hw *hw,
                enum set_key_cmd cmd,
                const u8 *local_addr, const u8 *addr,
                struct ieee80211_key_conf *key);
static int ath5k_get_stats(struct ieee80211_hw *hw,
                struct ieee80211_low_level_stats *stats);
static int ath5k_get_tx_stats(struct ieee80211_hw *hw,
                struct ieee80211_tx_queue_stats *stats);
static u64 ath5k_get_tsf(struct ieee80211_hw *hw);
static void ath5k_reset_tsf(struct ieee80211_hw *hw);
static int ath5k_beacon_update(struct ath5k_softc *sc,
                struct sk_buff *skb);
static void ath5k_bss_info_changed(struct ieee80211_hw *hw,
                struct ieee80211_vif *vif,
                struct ieee80211_bss_conf *bss_conf,
                u32 changes);

static 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,
        .config_interface = ath5k_config_interface,
        .configure_filter = ath5k_configure_filter,
        .set_key        = ath5k_set_key,
        .get_stats      = ath5k_get_stats,
        .conf_tx        = NULL,
        .get_tx_stats   = ath5k_get_tx_stats,
        .get_tsf        = ath5k_get_tsf,
        .reset_tsf      = ath5k_reset_tsf,
        .bss_info_changed = ath5k_bss_info_changed,
};

/*
 * Prototypes - Internal functions
 */
/* Attach detach */
static int      ath5k_attach(struct pci_dev *pdev,
                        struct ieee80211_hw *hw);
static void     ath5k_detach(struct pci_dev *pdev,
                        struct ieee80211_hw *hw);
/* Channel/mode setup */
static inline short ath5k_ieee2mhz(short chan);
static unsigned int ath5k_copy_channels(struct ath5k_hw *ah,
                                struct ieee80211_channel *channels,
                                unsigned int mode,
                                unsigned int max);
static int      ath5k_setup_bands(struct ieee80211_hw *hw);
static int      ath5k_chan_set(struct ath5k_softc *sc,
                                struct ieee80211_channel *chan);
static void     ath5k_setcurmode(struct ath5k_softc *sc,
                                unsigned int mode);
static void     ath5k_mode_setup(struct ath5k_softc *sc);

/* Descriptor setup */
static int      ath5k_desc_alloc(struct ath5k_softc *sc,
                                struct pci_dev *pdev);
static void     ath5k_desc_free(struct ath5k_softc *sc,
                                struct pci_dev *pdev);
/* Buffers setup */
static int      ath5k_rxbuf_setup(struct ath5k_softc *sc,
                                struct ath5k_buf *bf);
static int      ath5k_txbuf_setup(struct ath5k_softc *sc,
                                struct ath5k_buf *bf);
static inline void ath5k_txbuf_free(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;
}

/* Queues setup */
static struct   ath5k_txq *ath5k_txq_setup(struct ath5k_softc *sc,
                                int qtype, int subtype);
static int      ath5k_beaconq_setup(struct ath5k_hw *ah);
static int      ath5k_beaconq_config(struct ath5k_softc *sc);
static void     ath5k_txq_drainq(struct ath5k_softc *sc,
                                struct ath5k_txq *txq);
static void     ath5k_txq_cleanup(struct ath5k_softc *sc);
static void     ath5k_txq_release(struct ath5k_softc *sc);
/* Rx handling */
static int      ath5k_rx_start(struct ath5k_softc *sc);
static void     ath5k_rx_stop(struct ath5k_softc *sc);
static unsigned int ath5k_rx_decrypted(struct ath5k_softc *sc,
                                        struct ath5k_desc *ds,
                                        struct sk_buff *skb,
                                        struct ath5k_rx_status *rs);
static void     ath5k_tasklet_rx(unsigned long data);
/* Tx handling */
static void     ath5k_tx_processq(struct ath5k_softc *sc,
                                struct ath5k_txq *txq);
static void     ath5k_tasklet_tx(unsigned long data);
/* Beacon handling */
static int      ath5k_beacon_setup(struct ath5k_softc *sc,
                                        struct ath5k_buf *bf);
static void     ath5k_beacon_send(struct ath5k_softc *sc);
static void     ath5k_beacon_config(struct ath5k_softc *sc);
static void     ath5k_beacon_update_timers(struct ath5k_softc *sc, u64 bc_tsf);

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;
}

/* Interrupt handling */
static int      ath5k_init(struct ath5k_softc *sc, bool is_resume);
static int      ath5k_stop_locked(struct ath5k_softc *sc);
static int      ath5k_stop_hw(struct ath5k_softc *sc, bool is_suspend);
static irqreturn_t ath5k_intr(int irq, void *dev_id);
static void     ath5k_tasklet_reset(unsigned long data);

static void     ath5k_calibrate(unsigned long data);
/* LED functions */
static int      ath5k_init_leds(struct ath5k_softc *sc);
static void     ath5k_led_enable(struct ath5k_softc *sc);
static void     ath5k_led_off(struct ath5k_softc *sc);
static void     ath5k_unregister_leds(struct ath5k_softc *sc);

/*
 * 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);


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

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

        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_32BIT_MASK);
        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 / sizeof(u32);
                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_SIGNAL_DBM |
                    IEEE80211_HW_NOISE_DBM;

        hw->wiphy->interface_modes =
                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->cachelsz = csz * sizeof(u32); /* convert to bytes */
        sc->opmode = NL80211_IFTYPE_STATION;
        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, hw);

        /* 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;
        }

        /* Initialize device */
        sc->ah = ath5k_hw_attach(sc, id->driver_data);
        if (IS_ERR(sc->ah)) {
                ret = PTR_ERR(sc->ah);
                goto err_irq;
        }

        /* 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_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 ieee80211_hw *hw = pci_get_drvdata(pdev);
        struct ath5k_softc *sc = hw->priv;

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

#ifdef CONFIG_PM
static int
ath5k_pci_suspend(struct pci_dev *pdev, pm_message_t state)
{
        struct ieee80211_hw *hw = pci_get_drvdata(pdev);
        struct ath5k_softc *sc = hw->priv;

        ath5k_led_off(sc);

        ath5k_stop_hw(sc, true);

        free_irq(pdev->irq, sc);
        pci_save_state(pdev);
        pci_disable_device(pdev);
        pci_set_power_state(pdev, PCI_D3hot);

        return 0;
}

static int
ath5k_pci_resume(struct pci_dev *pdev)
{
        struct ieee80211_hw *hw = pci_get_drvdata(pdev);
        struct ath5k_softc *sc = hw->priv;
        int err;

        pci_restore_state(pdev);

        err = pci_enable_device(pdev);
        if (err)
                return err;

        /*
         * 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);

        err = request_irq(pdev->irq, ath5k_intr, IRQF_SHARED, "ath", sc);
        if (err) {
                ATH5K_ERR(sc, "request_irq failed\n");
                goto err_no_irq;
        }

        err = ath5k_init(sc, true);
        if (err)
                goto err_irq;
        ath5k_led_enable(sc);

        return 0;
err_irq:
        free_irq(pdev->irq, sc);
err_no_irq:
        pci_disable_device(pdev);
        return err;
}
#endif /* CONFIG_PM */


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

static int
ath5k_attach(struct pci_dev *pdev, struct ieee80211_hw *hw)
{
        struct ath5k_softc *sc = hw->priv;
        struct ath5k_hw *ah = sc->ah;
        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.  MAC's that don't have support will
         * return false w/o doing anything.  MAC's that do
         * support it will return true w/o doing anything.
         */
        ret = ah->ah_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 reseting
         * 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->txq = ath5k_txq_setup(sc, AR5K_TX_QUEUE_DATA, AR5K_WME_AC_BK);
        if (IS_ERR(sc->txq)) {
                ATH5K_ERR(sc, "can't setup xmit queue\n");
                ret = PTR_ERR(sc->txq);
                goto err_bhal;
        }

        tasklet_init(&sc->rxtq, ath5k_tasklet_rx, (unsigned long)sc);
        tasklet_init(&sc->txtq, ath5k_tasklet_tx, (unsigned long)sc);
        tasklet_init(&sc->restq, ath5k_tasklet_reset, (unsigned long)sc);
        setup_timer(&sc->calib_tim, ath5k_calibrate, (unsigned long)sc);

        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 */
        memset(sc->bssidmask, 0xff, ETH_ALEN);
        ath5k_hw_set_bssid_mask(sc->ah, sc->bssidmask);

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

        ath5k_init_leds(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
         *   insure 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);

        /*
         * 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.
         */
}




/********************\
* 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;
}

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;

                /* 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.  If the channel is really being changed,
 * it's done by reseting the chip.  To accomplish this we must
 * first cleanup any pending DMA, then restart stuff 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, "(%u MHz) -> (%u MHz)\n",
                sc->curchan->center_freq, chan->center_freq);

        if (chan->center_freq != sc->curchan->center_freq ||
                chan->hw_value != sc->curchan->hw_value) {

                sc->curchan = chan;
                sc->curband = &sc->sbands[chan->band];

                /*
                 * 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, true, true);
        }

        return 0;
}

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);

        ath5k_hw_set_mcast_filter(ah, 0, 0);
        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)
{
        WARN_ON(hw_rix < 0 || hw_rix > AR5K_MAX_RATES);
        return sc->rate_idx[sc->curband->band][hw_rix];
}

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

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;

        if (likely(skb == NULL)) {
                unsigned int off;

                /*
                 * Allocate buffer with headroom_needed space for the
                 * fake physical layer header at the start.
                 */
                skb = dev_alloc_skb(sc->rxbufsize + sc->cachelsz - 1);
                if (unlikely(skb == NULL)) {
                        ATH5K_ERR(sc, "can't alloc skbuff of size %u\n",
                                        sc->rxbufsize + sc->cachelsz - 1);
                        return -ENOMEM;
                }
                /*
                 * Cache-line-align.  This is important (for the
                 * 5210 at least) as not doing so causes bogus data
                 * in rx'd frames.
                 */
                off = ((unsigned long)skb->data) % sc->cachelsz;
                if (off != 0)
                        skb_reserve(skb, sc->cachelsz - off);

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

        /*
         * 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 insure 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 insures 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;
        ah->ah_setup_rx_desc(ah, ds,
                skb_tailroom(skb),      /* buffer size */
                0);

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

static int
ath5k_txbuf_setup(struct ath5k_softc *sc, struct ath5k_buf *bf)
{
        struct ath5k_hw *ah = sc->ah;
        struct ath5k_txq *txq = sc->txq;
        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;

        flags = AR5K_TXDESC_INTREQ | AR5K_TXDESC_CLRDMASK;

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

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

        pktlen = skb->len;

        if (info->control.hw_key) {
                keyidx = info->control.hw_key->hw_key_idx;
                pktlen += info->control.hw_key->icv_len;
        }
        ret = ah->ah_setup_tx_desc(ah, ds, pktlen,
                ieee80211_get_hdrlen_from_skb(skb), AR5K_PKT_TYPE_NORMAL,
                (sc->power_level * 2),
                ieee80211_get_tx_rate(sc->hw, info)->hw_value,
                info->control.rates[0].count, keyidx, 0, flags, 0, 0);
        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;
        }

        ah->ah_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);
        sc->tx_stats[txq->qnum].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(sc, sc->bbuf);
        list_for_each_entry(bf, &sc->txbuf, list)
                ath5k_txbuf_free(sc, bf);
        list_for_each_entry(bf, &sc->rxbuf, list)
                ath5k_txbuf_free(sc, bf);

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

        kfree(sc->bufptr);
        sc->bufptr = 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 waiting 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;
        }
        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)
                return ret;
        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__);
                return ret;
        }

        return ath5k_hw_reset_tx_queue(ah, sc->bhalq); /* push to h/w */;
}

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(sc, bf);

                spin_lock_bh(&sc->txbuflock);
                sc->tx_stats[txq->qnum].len--;
                list_move_tail(&bf->list, &sc->txbuf);
                sc->txbuf_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);
                        }
        }
        ieee80211_wake_queues(sc->hw); /* XXX move to callers */

        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 ath5k_buf *bf;
        int ret;

        sc->rxbufsize = roundup(IEEE80211_MAX_LEN, sc->cachelsz);

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

        sc->rxlink = NULL;

        spin_lock_bh(&sc->rxbuflock);
        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);
        spin_unlock_bh(&sc->rxbuflock);

        ath5k_hw_set_rxdp(ah, bf->daddr);
        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);

        sc->rxlink = NULL;              /* just in case */
}

static unsigned int
ath5k_rx_decrypted(struct ath5k_softc *sc, struct ath5k_desc *ds,
                struct sk_buff *skb, struct ath5k_rx_status *rs)
{
        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, sc->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)
{
        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, sc->ah->ah_bssid, 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_tasklet_rx(unsigned long data)
{
        struct ieee80211_rx_status rxs = {};
        struct ath5k_rx_status rs = {};
        struct sk_buff *skb;
        struct ath5k_softc *sc = (void *)data;
        struct ath5k_buf *bf, *bf_last;
        struct ath5k_desc *ds;
        int ret;
        int hdrlen;
        int padsize;

        spin_lock(&sc->rxbuflock);
        if (list_empty(&sc->rxbuf)) {
                ATH5K_WARN(sc, "empty rx buf pool\n");
                goto unlock;
        }
        bf_last = list_entry(sc->rxbuf.prev, struct ath5k_buf, list);
        do {
                rxs.flag = 0;

                bf = list_first_entry(&sc->rxbuf, struct ath5k_buf, list);
                BUG_ON(bf->skb == NULL);
                skb = bf->skb;
                ds = bf->desc;

                /*
                 * last buffer must not be freed to ensure proper hardware
                 * function. When the hardware finishes also a packet next to
                 * it, we are sure, it doesn't use it anymore and we can go on.
                 */
                if (bf_last == bf)
                        bf->flags |= 1;
                if (bf->flags) {
                        struct ath5k_buf *bf_next = list_entry(bf->list.next,
                                        struct ath5k_buf, list);
                        ret = sc->ah->ah_proc_rx_desc(sc->ah, bf_next->desc,
                                        &rs);
                        if (ret)
                                break;
                        bf->flags &= ~1;
                        /* skip the overwritten one (even status is martian) */
                        goto next;
                }

                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");
                        spin_unlock(&sc->rxbuflock);
                        return;
                }

                if (unlikely(rs.rs_more)) {
                        ATH5K_WARN(sc, "unsupported jumbo\n");
                        goto next;
                }

                if (unlikely(rs.rs_status)) {
                        if (rs.rs_status & AR5K_RXERR_PHY)
                                goto next;
                        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
                                 */
                                if (rs.rs_keyix == AR5K_RXKEYIX_INVALID &&
                                    !(rs.rs_status & AR5K_RXERR_CRC))
                                        goto accept;
                        }
                        if (rs.rs_status & AR5K_RXERR_MIC) {
                                rxs.flag |= RX_FLAG_MMIC_ERROR;
                                goto accept;
                        }

                        /* let crypto-error packets fall through in MNTR */
                        if ((rs.rs_status &
                                ~(AR5K_RXERR_DECRYPT|AR5K_RXERR_MIC)) ||
                                        sc->opmode != NL80211_IFTYPE_MONITOR)
                                goto next;
                }
accept:
                pci_unmap_single(sc->pdev, bf->skbaddr, sc->rxbufsize,
                                PCI_DMA_FROMDEVICE);
                bf->skb = NULL;

                skb_put(skb, rs.rs_datalen);

                /* 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 % 4) % 4; However, since only
                 * even-length headers are used, padding can only be 0 or 2
                 * bytes and we can optimize this a bit. In addition, we must
                 * not try to remove padding from short control frames that do
                 * not have payload. */
                hdrlen = ieee80211_get_hdrlen_from_skb(skb);
                padsize = ath5k_pad_size(hdrlen);
                if (padsize) {
                        memmove(skb->data + padsize, skb->data, hdrlen);
                        skb_pull(skb, padsize);
                }

                /*
                 * 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.noise = sc->ah->ah_noise_floor;
                rxs.signal = rxs.noise + rs.rs_rssi;

                /* An rssi of 35 indicates you should be able use
                 * 54 Mbps reliably. A more elaborate scheme can be used
                 * here but it requires a map of SNR/throughput for each
                 * possible mode used */
                rxs.qual = rs.rs_rssi * 100 / 35;

                /* rssi can be more than 35 though, anything above that
                 * should be considered at 100% */
                if (rxs.qual > 100)
                        rxs.qual = 100;

                rxs.antenna = rs.rs_antenna;
                rxs.rate_idx = ath5k_hw_to_driver_rix(sc, rs.rs_rate);
                rxs.flag |= ath5k_rx_decrypted(sc, ds, 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);

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

                __ieee80211_rx(sc->hw, skb, &rxs);
next:
                list_move_tail(&bf->list, &sc->rxbuf);
        } while (ath5k_rxbuf_setup(sc, bf) == 0);
unlock:
        spin_unlock(&sc->rxbuflock);
}




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

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;

                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;
                }

                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->ll_stats.dot11ACKFailureCount++;
                        if (ts.ts_status & AR5K_TXERR_FILT)
                                info->flags |= IEEE80211_TX_STAT_TX_FILTERED;
                } else {
                        info->flags |= IEEE80211_TX_STAT_ACK;
                        info->status.ack_signal = ts.ts_rssi;
                }

                ieee80211_tx_status(sc->hw, skb);
                sc->tx_stats[txq->qnum].count++;

                spin_lock(&sc->txbuflock);
                sc->tx_stats[txq->qnum].len--;
                list_move_tail(&bf->list, &sc->txbuf);
                sc->txbuf_len++;
                spin_unlock(&sc->txbuflock);
        }
        if (likely(list_empty(&txq->q)))
                txq->link = NULL;
        spin_unlock(&txq->lock);
        if (sc->txbuf_len > ATH_TXBUF / 5)
                ieee80211_wake_queues(sc->hw);
}

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

        ath5k_tx_processq(sc, sc->txq);
}


/*****************\
* 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, antenna = 0;
        u32 flags;

        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;

        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;
                /*
                 * Let hardware handle antenna switching if txantenna is not set
                 */
        } else {
                ds->ds_link = 0;
                /*
                 * Switch antenna every 4 beacons if txantenna is not set
                 * XXX assumes two antennas
                 */
                if (antenna == 0)
                        antenna = sc->bsent & 4 ? 2 : 1;
        }

        ds->ds_data = bf->skbaddr;
        ret = ah->ah_setup_tx_desc(ah, ds, skb->len,
                        ieee80211_get_hdrlen_from_skb(skb),
                        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;
}

/*
 * 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 usually called from interrupt context (ath5k_intr())
 * but also from ath5k_beacon_config() in IBSS mode which in turn
 * can be called from a tasklet and user context
 */
static void
ath5k_beacon_send(struct ath5k_softc *sc)
{
        struct ath5k_buf *bf = sc->bbuf;
        struct ath5k_hw *ah = sc->ah;

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

        if (unlikely(bf->skb == NULL || sc->opmode == NL80211_IFTYPE_STATION ||
                        sc->opmode == NL80211_IFTYPE_MONITOR)) {
                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 > 3) {               /* NB: 3 is a guess */
                        ATH5K_DBG(sc, ATH5K_DEBUG_BEACON,
                                "stuck beacon time (%u missed)\n",
                                sc->bmisscount);
                        tasklet_schedule(&sc->restq);
                }
                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 stop?\n", sc->bhalq);
                /* NB: hw still stops DMA, so proceed */
        }

        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);

        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
 *
 * When operating in station mode we want to receive a BMISS interrupt when we
 * stop seeing beacons from the AP we've associated with so we can look for
 * another AP to associate with.
 *
 * 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;

        ath5k_hw_set_imr(ah, 0);
        sc->bmisscount = 0;
        sc->imask &= ~(AR5K_INT_BMISS | AR5K_INT_SWBA);

        if (sc->opmode == NL80211_IFTYPE_STATION) {
                sc->imask |= AR5K_INT_BMISS;
        } else if (sc->opmode == NL80211_IFTYPE_ADHOC ||
                        sc->opmode == NL80211_IFTYPE_MESH_POINT ||
                        sc->opmode == NL80211_IFTYPE_AP) {
                /*
                 * 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)) {
                                spin_lock(&sc->block);
                                ath5k_beacon_send(sc);
                                spin_unlock(&sc->block);
                        }
                } else
                        ath5k_beacon_update_timers(sc, -1);
        }

        ath5k_hw_set_imr(ah, sc->imask);
}


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

static int
ath5k_init(struct ath5k_softc *sc, bool is_resume)
{
        struct ath5k_hw *ah = sc->ah;
        int ret, i;

        mutex_lock(&sc->lock);

        if (is_resume && !test_bit(ATH_STAT_STARTED, sc->status))
                goto out_ok;

        __clear_bit(ATH_STAT_STARTED, sc->status);

        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, false, false);
        if (ret)
                goto done;

        /*
         * Reset the key cache since some parts do not reset the
         * contents on initial power up or resume from suspend.
         */
        for (i = 0; i < AR5K_KEYTABLE_SIZE; i++)
                ath5k_hw_reset_key(ah, i);

        __set_bit(ATH_STAT_STARTED, sc->status);

        /* Set ack to be sent at low bit-rates */
        ath5k_hw_set_ack_bitrate_high(ah, false);

        mod_timer(&sc->calib_tim, round_jiffies(jiffies +
                        msecs_to_jiffies(ath5k_calinterval * 1000)));

out_ok:
        ret = 0;
done:
        mmiowb();
        mutex_unlock(&sc->lock);
        return ret;
}

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);
        } else
                sc->rxlink = NULL;

        return 0;
}

/*
 * 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, bool is_suspend)
{
        int ret;

        mutex_lock(&sc->lock);
        ret = ath5k_stop_locked(sc);
        if (ret == 0 && !test_bit(ATH_STAT_INVALID, sc->status)) {
                /*
                 * Set the chip in full sleep mode.  Note that we are
                 * careful to do this only when bringing the interface
                 * completely to a stop.  When the chip 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 that go to sleep more quickly.
                 */
                if (sc->ah->ah_mac_srev >= 0x78) {
                        /*
                         * XXX
                         * don't put newer MAC revisions > 7.8 to sleep because
                         * of the above mentioned problems
                         */
                        ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "mac version > 7.8, "
                                "not putting device to sleep\n");
                } else {
                        ATH5K_DBG(sc, ATH5K_DEBUG_RESET,
                                "putting device to full sleep\n");
                        ath5k_hw_set_power(sc->ah, AR5K_PM_FULL_SLEEP, true, 0);
                }
        }
        ath5k_txbuf_free(sc, sc->bbuf);
        if (!is_suspend)
                __clear_bit(ATH_STAT_STARTED, sc->status);

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

        del_timer_sync(&sc->calib_tim);
        tasklet_kill(&sc->rxtq);
        tasklet_kill(&sc->txtq);
        tasklet_kill(&sc->restq);

        return ret;
}

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 {
                /*
                 * Figure out the reason(s) for the interrupt.  Note
                 * that get_isr returns a pseudo-ISR that may include
                 * bits we haven't explicitly enabled so we mask the
                 * value to insure we only process bits we requested.
                 */
                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);
                status &= sc->imask; /* discard unasked for bits */
                if (unlikely(status & AR5K_INT_FATAL)) {
                        /*
                         * Fatal errors are unrecoverable.
                         * Typically these are caused by DMA errors.
                         */
                        tasklet_schedule(&sc->restq);
                } else if (unlikely(status & AR5K_INT_RXORN)) {
                        tasklet_schedule(&sc->restq);
                } else {
                        if (status & AR5K_INT_SWBA) {
                                /*
                                * Software beacon alert--time to send a beacon.
                                * Handle beacon transmission directly; deferring
                                * this is too slow to meet timing constraints
                                * under load.
                                *
                                * 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(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);
                                }
                        }
                        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->rxlink = NULL;
                        }
                        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) {
                        }
                        if (status & AR5K_INT_MIB) {
                                /*
                                 * These stats are also used for ANI i think
                                 * so how about updating them more often ?
                                 */
                                ath5k_hw_update_mib_counters(ah, &sc->ll_stats);
                        }
                }
        } while (ath5k_hw_is_intr_pending(ah) && counter-- > 0);

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

        return IRQ_HANDLED;
}

static void
ath5k_tasklet_reset(unsigned long data)
{
        struct ath5k_softc *sc = (void *)data;

        ath5k_reset_wake(sc);
}

/*
 * Periodically recalibrate the PHY to account
 * for temperature/environment changes.
 */
static void
ath5k_calibrate(unsigned long data)
{
        struct ath5k_softc *sc = (void *)data;
        struct ath5k_hw *ah = sc->ah;

        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_get_rf_gain(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");
                ath5k_reset_wake(sc);
        }
        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));

        mod_timer(&sc->calib_tim, round_jiffies(jiffies +
                        msecs_to_jiffies(ath5k_calinterval * 1000)));
}



/***************\
* LED functions *
\***************/

static void
ath5k_led_enable(struct ath5k_softc *sc)
{
        if (test_bit(ATH_STAT_LEDSOFT, sc->status)) {
                ath5k_hw_set_gpio_output(sc->ah, sc->led_pin);
                ath5k_led_off(sc);
        }
}

static void
ath5k_led_on(struct ath5k_softc *sc)
{
        if (!test_bit(ATH_STAT_LEDSOFT, sc->status))
                return;
        ath5k_hw_set_gpio(sc->ah, sc->led_pin, sc->led_on);
}

static void
ath5k_led_off(struct ath5k_softc *sc)
{
        if (!test_bit(ATH_STAT_LEDSOFT, sc->status))
                return;
        ath5k_hw_set_gpio(sc->ah, sc->led_pin, !sc->led_on);
}

static void
ath5k_led_brightness_set(struct led_classdev *led_dev,
        enum led_brightness brightness)
{
        struct ath5k_led *led = container_of(led_dev, struct ath5k_led,
                led_dev);

        if (brightness == LED_OFF)
                ath5k_led_off(led->sc);
        else
                ath5k_led_on(led->sc);
}

static int
ath5k_register_led(struct ath5k_softc *sc, struct ath5k_led *led,
                   const char *name, char *trigger)
{
        int err;

        led->sc = sc;
        strncpy(led->name, name, sizeof(led->name));
        led->led_dev.name = led->name;
        led->led_dev.default_trigger = trigger;
        led->led_dev.brightness_set = ath5k_led_brightness_set;

        err = led_classdev_register(&sc->pdev->dev, &led->led_dev);
        if (err) {
                ATH5K_WARN(sc, "could not register LED %s\n", name);
                led->sc = NULL;
        }
        return err;
}

static void
ath5k_unregister_led(struct ath5k_led *led)
{
        if (!led->sc)
                return;
        led_classdev_unregister(&led->led_dev);
        ath5k_led_off(led->sc);
        led->sc = NULL;
}

static void
ath5k_unregister_leds(struct ath5k_softc *sc)
{
        ath5k_unregister_led(&sc->rx_led);
        ath5k_unregister_led(&sc->tx_led);
}


static int
ath5k_init_leds(struct ath5k_softc *sc)
{
        int ret = 0;
        struct ieee80211_hw *hw = sc->hw;
        struct pci_dev *pdev = sc->pdev;
        char name[ATH5K_LED_MAX_NAME_LEN + 1];

        /*
         * Auto-enable soft led processing for IBM cards and for
         * 5211 minipci cards.
         */
        if (pdev->device == PCI_DEVICE_ID_ATHEROS_AR5212_IBM ||
            pdev->device == PCI_DEVICE_ID_ATHEROS_AR5211) {
                __set_bit(ATH_STAT_LEDSOFT, sc->status);
                sc->led_pin = 0;
                sc->led_on = 0;  /* active low */
        }
        /* Enable softled on PIN1 on HP Compaq nc6xx, nc4000 & nx5000 laptops */
        if (pdev->subsystem_vendor == PCI_VENDOR_ID_COMPAQ) {
                __set_bit(ATH_STAT_LEDSOFT, sc->status);
                sc->led_pin = 1;
                sc->led_on = 1;  /* active high */
        }
        if (!test_bit(ATH_STAT_LEDSOFT, sc->status))
                goto out;

        ath5k_led_enable(sc);

        snprintf(name, sizeof(name), "ath5k-%s::rx", wiphy_name(hw->wiphy));
        ret = ath5k_register_led(sc, &sc->rx_led, name,
                ieee80211_get_rx_led_name(hw));
        if (ret)
                goto out;

        snprintf(name, sizeof(name), "ath5k-%s::tx", wiphy_name(hw->wiphy));
        ret = ath5k_register_led(sc, &sc->tx_led, name,
                ieee80211_get_tx_led_name(hw));
out:
        return ret;
}


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

static int
ath5k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
{
        struct ath5k_softc *sc = hw->priv;
        struct ath5k_buf *bf;
        unsigned long flags;
        int hdrlen;
        int padsize;

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

        if (sc->opmode == NL80211_IFTYPE_MONITOR)
                ATH5K_DBG(sc, ATH5K_DEBUG_XMIT, "tx in monitor (scan?)\n");

        /*
         * the hardware expects the header padded to 4 byte boundaries
         * if this is not the case we add the padding after the header
         */
        hdrlen = ieee80211_get_hdrlen_from_skb(skb);
        padsize = ath5k_pad_size(hdrlen);
        if (padsize) {

                if (skb_headroom(skb) < padsize) {
                        ATH5K_ERR(sc, "tx hdrlen not %%4: %d not enough"
                                  " headroom to pad %d\n", hdrlen, padsize);
                        return NETDEV_TX_BUSY;
                }
                skb_push(skb, padsize);
                memmove(skb->data, skb->data+padsize, hdrlen);
        }

        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_queue(hw, skb_get_queue_mapping(skb));
                return NETDEV_TX_BUSY;
        }
        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)) {
                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);
                dev_kfree_skb_any(skb);
                return NETDEV_TX_OK;
        }

        return NETDEV_TX_OK;
}

static int
ath5k_reset(struct ath5k_softc *sc, bool stop, bool change_channel)
{
        struct ath5k_hw *ah = sc->ah;
        int ret;

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

        if (stop) {
                ath5k_hw_set_imr(ah, 0);
                ath5k_txq_cleanup(sc);
                ath5k_rx_stop(sc);
        }
        ret = ath5k_hw_reset(ah, sc->opmode, sc->curchan, true);
        if (ret) {
                ATH5K_ERR(sc, "can't reset hardware (%d)\n", ret);
                goto err;
        }

        /*
         * This is needed only to setup initial state
         * but it's best done after a reset.
         */
        ath5k_hw_set_txpower_limit(sc->ah, 0);

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

        /*
         * 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 */

        return 0;
err:
        return ret;
}

static int
ath5k_reset_wake(struct ath5k_softc *sc)
{
        int ret;

        ret = ath5k_reset(sc, true, true);
        if (!ret)
                ieee80211_wake_queues(sc->hw);

        return ret;
}

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

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

static int ath5k_add_interface(struct ieee80211_hw *hw,
                struct ieee80211_if_init_conf *conf)
{
        struct ath5k_softc *sc = hw->priv;
        int ret;

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

        sc->vif = conf->vif;

        switch (conf->type) {
        case NL80211_IFTYPE_AP:
        case NL80211_IFTYPE_STATION:
        case NL80211_IFTYPE_ADHOC:
        case NL80211_IFTYPE_MESH_POINT:
        case NL80211_IFTYPE_MONITOR:
                sc->opmode = conf->type;
                break;
        default:
                ret = -EOPNOTSUPP;
                goto end;
        }

        /* Set to a reasonable value. Note that this will
         * be set to mac80211's value at ath5k_config(). */
        sc->bintval = 1000;
        ath5k_hw_set_lladdr(sc->ah, conf->mac_addr);

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

static void
ath5k_remove_interface(struct ieee80211_hw *hw,
                        struct ieee80211_if_init_conf *conf)
{
        struct ath5k_softc *sc = hw->priv;
        u8 mac[ETH_ALEN] = {};

        mutex_lock(&sc->lock);
        if (sc->vif != conf->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 ieee80211_conf *conf = &hw->conf;
        int ret;

        mutex_lock(&sc->lock);

        sc->bintval = conf->beacon_int;
        sc->power_level = conf->power_level;

        ret = ath5k_chan_set(sc, conf->channel);

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

static int
ath5k_config_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
                        struct ieee80211_if_conf *conf)
{
        struct ath5k_softc *sc = hw->priv;
        struct ath5k_hw *ah = sc->ah;
        int ret;

        mutex_lock(&sc->lock);
        if (sc->vif != vif) {
                ret = -EIO;
                goto unlock;
        }
        if (conf->changed & IEEE80211_IFCC_BSSID && conf->bssid) {
                /* Cache for later use during resets */
                memcpy(ah->ah_bssid, conf->bssid, ETH_ALEN);
                /* XXX: assoc id is set to 0 for now, mac80211 doesn't have
                 * a clean way of letting us retrieve this yet. */
                ath5k_hw_set_associd(ah, ah->ah_bssid, 0);
                mmiowb();
        }
        if (conf->changed & IEEE80211_IFCC_BEACON &&
                        (vif->type == NL80211_IFTYPE_ADHOC ||
                         vif->type == NL80211_IFTYPE_MESH_POINT ||
                         vif->type == NL80211_IFTYPE_AP)) {
                struct sk_buff *beacon = ieee80211_beacon_get(hw, vif);
                if (!beacon) {
                        ret = -ENOMEM;
                        goto unlock;
                }
                ath5k_beacon_update(sc, beacon);
        }
        mutex_unlock(&sc->lock);

        return ath5k_reset_wake(sc);
unlock:
        mutex_unlock(&sc->lock);
        return ret;
}

#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,
                int mc_count, struct dev_mc_list *mclist)
{
        struct ath5k_softc *sc = hw->priv;
        struct ath5k_hw *ah = sc->ah;
        u32 mfilt[2], val, rfilt;
        u8 pos;
        int i;

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

        /* 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) {
                        rfilt |= AR5K_RX_FILTER_PROM;
                        __set_bit(ATH_STAT_PROMISC, sc->status);
                } else {
                        __clear_bit(ATH_STAT_PROMISC, sc->status);
                }
        }

        /* Note, AR5K_RX_FILTER_MCAST is already enabled */
        if (*new_flags & FIF_ALLMULTI) {
                mfilt[0] =  ~0;
                mfilt[1] =  ~0;
        } else {
                for (i = 0; i < mc_count; i++) {
                        if (!mclist)
                                break;
                        /* calculate XOR of eight 6-bit values */
                        val = get_unaligned_le32(mclist->dmi_addr + 0);
                        pos = (val >> 18) ^ (val >> 12) ^ (val >> 6) ^ val;
                        val = get_unaligned_le32(mclist->dmi_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,
                         *      mclist->dmi_addr[5]); */
                        mclist = mclist->next;
                }
        }

        /* 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, this needs testing */
        if (*new_flags & FIF_BCN_PRBRESP_PROMISC)
                rfilt |= AR5K_RX_FILTER_BEACON | AR5K_RX_FILTER_PROBEREQ;

        /* 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 */

        if (sc->opmode == NL80211_IFTYPE_MONITOR)
                rfilt |= AR5K_RX_FILTER_CONTROL | AR5K_RX_FILTER_BEACON |
                        AR5K_RX_FILTER_PROBEREQ | AR5K_RX_FILTER_PROM;
        if (sc->opmode != NL80211_IFTYPE_STATION)
                rfilt |= AR5K_RX_FILTER_PROBEREQ;
        if (sc->opmode != NL80211_IFTYPE_AP &&
                sc->opmode != NL80211_IFTYPE_MESH_POINT &&
                test_bit(ATH_STAT_PROMISC, sc->status))
                rfilt |= AR5K_RX_FILTER_PROM;
        if ((sc->opmode == NL80211_IFTYPE_STATION && sc->assoc) ||
                sc->opmode == NL80211_IFTYPE_ADHOC ||
                sc->opmode == NL80211_IFTYPE_AP)
                rfilt |= AR5K_RX_FILTER_BEACON;
        if (sc->opmode == NL80211_IFTYPE_MESH_POINT)
                rfilt |= AR5K_RX_FILTER_CONTROL | AR5K_RX_FILTER_BEACON |
                        AR5K_RX_FILTER_PROBEREQ | AR5K_RX_FILTER_PROM;

        /* 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 alter actually
         * be set in HW */
        sc->filter_flags = rfilt;
}

static int
ath5k_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
                const u8 *local_addr, const u8 *addr,
                struct ieee80211_key_conf *key)
{
        struct ath5k_softc *sc = hw->priv;
        int ret = 0;

        if (modparam_nohwcrypt)
                return -EOPNOTSUPP;

        switch (key->alg) {
        case ALG_WEP:
        case ALG_TKIP:
                break;
        case ALG_CCMP:
                return -EOPNOTSUPP;
        default:
                WARN_ON(1);
                return -EINVAL;
        }

        mutex_lock(&sc->lock);

        switch (cmd) {
        case SET_KEY:
                ret = ath5k_hw_set_key(sc->ah, key->keyidx, key, addr);
                if (ret) {
                        ATH5K_ERR(sc, "can't set the key\n");
                        goto unlock;
                }
                __set_bit(key->keyidx, sc->keymap);
                key->hw_key_idx = key->keyidx;
                key->flags |= (IEEE80211_KEY_FLAG_GENERATE_IV |
                               IEEE80211_KEY_FLAG_GENERATE_MMIC);
                break;
        case DISABLE_KEY:
                ath5k_hw_reset_key(sc->ah, key->keyidx);
                __clear_bit(key->keyidx, sc->keymap);
                break;
        default:
                ret = -EINVAL;
                goto unlock;
        }

unlock:
        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;
        struct ath5k_hw *ah = sc->ah;

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

        memcpy(stats, &sc->ll_stats, sizeof(sc->ll_stats));

        return 0;
}

static int
ath5k_get_tx_stats(struct ieee80211_hw *hw,
                struct ieee80211_tx_queue_stats *stats)
{
        struct ath5k_softc *sc = hw->priv;

        memcpy(stats, &sc->tx_stats, sizeof(sc->tx_stats));

        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_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 int
ath5k_beacon_update(struct ath5k_softc *sc, struct sk_buff *skb)
{
        unsigned long flags;
        int ret;

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

        spin_lock_irqsave(&sc->block, flags);
        ath5k_txbuf_free(sc, sc->bbuf);
        sc->bbuf->skb = skb;
        ret = ath5k_beacon_setup(sc, sc->bbuf);
        if (ret)
                sc->bbuf->skb = NULL;
        spin_unlock_irqrestore(&sc->block, flags);
        if (!ret) {
                ath5k_beacon_config(sc);
                mmiowb();
        }

        return ret;
}
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;
        if (changes & BSS_CHANGED_ASSOC) {
                mutex_lock(&sc->lock);
                sc->assoc = bss_conf->assoc;
                if (sc->opmode == NL80211_IFTYPE_STATION)
                        set_beacon_filter(hw, sc->assoc);
                mutex_unlock(&sc->lock);
        }
}