/*-
 * Copyright (c) 2006
 *      Damien Bergamini <damien.bergamini@free.fr>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/cdefs.h>
/*-
 * Ralink Technology RT2561, RT2561S and RT2661 chipset driver
 * http://www.ralinktech.com/
 */

#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/firmware.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>

#include <net/bpf.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/if_types.h>

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_radiotap.h>
#include <net80211/ieee80211_regdomain.h>
#include <net80211/ieee80211_ratectl.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/if_ether.h>

#include <dev/ral/rt2661reg.h>
#include <dev/ral/rt2661var.h>

#define RAL_DEBUG
#ifdef RAL_DEBUG
#define DPRINTF(sc, fmt, ...) do {                              \
        if (sc->sc_debug > 0)                                   \
                printf(fmt, __VA_ARGS__);                       \
} while (0)
#define DPRINTFN(sc, n, fmt, ...) do {                          \
        if (sc->sc_debug >= (n))                                \
                printf(fmt, __VA_ARGS__);                       \
} while (0)
#else
#define DPRINTF(sc, fmt, ...)
#define DPRINTFN(sc, n, fmt, ...)
#endif

static struct ieee80211vap *rt2661_vap_create(struct ieee80211com *,
                            const char [IFNAMSIZ], int, enum ieee80211_opmode,
                            int, const uint8_t [IEEE80211_ADDR_LEN],
                            const uint8_t [IEEE80211_ADDR_LEN]);
static void             rt2661_vap_delete(struct ieee80211vap *);
static void             rt2661_dma_map_addr(void *, bus_dma_segment_t *, int,
                            int);
static int              rt2661_alloc_tx_ring(struct rt2661_softc *,
                            struct rt2661_tx_ring *, int);
static void             rt2661_reset_tx_ring(struct rt2661_softc *,
                            struct rt2661_tx_ring *);
static void             rt2661_free_tx_ring(struct rt2661_softc *,
                            struct rt2661_tx_ring *);
static int              rt2661_alloc_rx_ring(struct rt2661_softc *,
                            struct rt2661_rx_ring *, int);
static void             rt2661_reset_rx_ring(struct rt2661_softc *,
                            struct rt2661_rx_ring *);
static void             rt2661_free_rx_ring(struct rt2661_softc *,
                            struct rt2661_rx_ring *);
static int              rt2661_newstate(struct ieee80211vap *,
                            enum ieee80211_state, int);
static uint16_t         rt2661_eeprom_read(struct rt2661_softc *, uint8_t);
static void             rt2661_rx_intr(struct rt2661_softc *);
static void             rt2661_tx_intr(struct rt2661_softc *);
static void             rt2661_tx_dma_intr(struct rt2661_softc *,
                            struct rt2661_tx_ring *);
static void             rt2661_mcu_beacon_expire(struct rt2661_softc *);
static void             rt2661_mcu_wakeup(struct rt2661_softc *);
static void             rt2661_mcu_cmd_intr(struct rt2661_softc *);
static void             rt2661_scan_start(struct ieee80211com *);
static void             rt2661_scan_end(struct ieee80211com *);
static void             rt2661_getradiocaps(struct ieee80211com *, int, int *,
                            struct ieee80211_channel[]);
static void             rt2661_set_channel(struct ieee80211com *);
static void             rt2661_setup_tx_desc(struct rt2661_softc *,
                            struct rt2661_tx_desc *, uint32_t, uint16_t, int,
                            int, const bus_dma_segment_t *, int, int);
static int              rt2661_tx_data(struct rt2661_softc *, struct mbuf *,
                            struct ieee80211_node *, int);
static int              rt2661_tx_mgt(struct rt2661_softc *, struct mbuf *,
                            struct ieee80211_node *);
static int              rt2661_transmit(struct ieee80211com *, struct mbuf *);
static void             rt2661_start(struct rt2661_softc *);
static int              rt2661_raw_xmit(struct ieee80211_node *, struct mbuf *,
                            const struct ieee80211_bpf_params *);
static void             rt2661_watchdog(void *);
static void             rt2661_parent(struct ieee80211com *);
static void             rt2661_bbp_write(struct rt2661_softc *, uint8_t,
                            uint8_t);
static uint8_t          rt2661_bbp_read(struct rt2661_softc *, uint8_t);
static void             rt2661_rf_write(struct rt2661_softc *, uint8_t,
                            uint32_t);
static int              rt2661_tx_cmd(struct rt2661_softc *, uint8_t,
                            uint16_t);
static void             rt2661_select_antenna(struct rt2661_softc *);
static void             rt2661_enable_mrr(struct rt2661_softc *);
static void             rt2661_set_txpreamble(struct rt2661_softc *);
static void             rt2661_set_basicrates(struct rt2661_softc *,
                            const struct ieee80211_rateset *);
static void             rt2661_select_band(struct rt2661_softc *,
                            struct ieee80211_channel *);
static void             rt2661_set_chan(struct rt2661_softc *,
                            struct ieee80211_channel *);
static void             rt2661_set_bssid(struct rt2661_softc *,
                            const uint8_t *);
static void             rt2661_set_macaddr(struct rt2661_softc *,
                           const uint8_t *);
static void             rt2661_update_promisc(struct ieee80211com *);
static int              rt2661_wme_update(struct ieee80211com *) __unused;
static void             rt2661_update_slot(struct ieee80211com *);
static const char       *rt2661_get_rf(int);
static void             rt2661_read_eeprom(struct rt2661_softc *,
                            uint8_t macaddr[IEEE80211_ADDR_LEN]);
static int              rt2661_bbp_init(struct rt2661_softc *);
static void             rt2661_init_locked(struct rt2661_softc *);
static void             rt2661_init(void *);
static void             rt2661_stop_locked(struct rt2661_softc *);
static void             rt2661_stop(void *);
static int              rt2661_load_microcode(struct rt2661_softc *);
#ifdef notyet
static void             rt2661_rx_tune(struct rt2661_softc *);
static void             rt2661_radar_start(struct rt2661_softc *);
static int              rt2661_radar_stop(struct rt2661_softc *);
#endif
static int              rt2661_prepare_beacon(struct rt2661_softc *,
                            struct ieee80211vap *);
static void             rt2661_enable_tsf_sync(struct rt2661_softc *);
static void             rt2661_enable_tsf(struct rt2661_softc *);
static int              rt2661_get_rssi(struct rt2661_softc *, uint8_t);

static const struct {
        uint32_t        reg;
        uint32_t        val;
} rt2661_def_mac[] = {
        RT2661_DEF_MAC
};

static const struct {
        uint8_t reg;
        uint8_t val;
} rt2661_def_bbp[] = {
        RT2661_DEF_BBP
};

static const struct rfprog {
        uint8_t         chan;
        uint32_t        r1, r2, r3, r4;
}  rt2661_rf5225_1[] = {
        RT2661_RF5225_1
}, rt2661_rf5225_2[] = {
        RT2661_RF5225_2
};

static const uint8_t rt2661_chan_5ghz[] =
        { 36, 40, 44, 48, 52, 56, 60, 64,
          100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140,
          149, 153, 157, 161, 165 };

int
rt2661_attach(device_t dev, int id)
{
        struct rt2661_softc *sc = device_get_softc(dev);
        struct ieee80211com *ic = &sc->sc_ic;
        uint32_t val;
        int error, ac, ntries;

        sc->sc_id = id;
        sc->sc_dev = dev;

        mtx_init(&sc->sc_mtx, device_get_nameunit(dev), MTX_NETWORK_LOCK,
            MTX_DEF | MTX_RECURSE);

        callout_init_mtx(&sc->watchdog_ch, &sc->sc_mtx, 0);
        mbufq_init(&sc->sc_snd, ifqmaxlen);

        /* wait for NIC to initialize */
        for (ntries = 0; ntries < 1000; ntries++) {
                if ((val = RAL_READ(sc, RT2661_MAC_CSR0)) != 0)
                        break;
                DELAY(1000);
        }
        if (ntries == 1000) {
                device_printf(sc->sc_dev,
                    "timeout waiting for NIC to initialize\n");
                error = EIO;
                goto fail1;
        }

        /* retrieve RF rev. no and various other things from EEPROM */
        rt2661_read_eeprom(sc, ic->ic_macaddr);

        device_printf(dev, "MAC/BBP RT%X, RF %s\n", val,
            rt2661_get_rf(sc->rf_rev));

        /*
         * Allocate Tx and Rx rings.
         */
        for (ac = 0; ac < 4; ac++) {
                error = rt2661_alloc_tx_ring(sc, &sc->txq[ac],
                    RT2661_TX_RING_COUNT);
                if (error != 0) {
                        device_printf(sc->sc_dev,
                            "could not allocate Tx ring %d\n", ac);
                        goto fail2;
                }
        }

        error = rt2661_alloc_tx_ring(sc, &sc->mgtq, RT2661_MGT_RING_COUNT);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not allocate Mgt ring\n");
                goto fail2;
        }

        error = rt2661_alloc_rx_ring(sc, &sc->rxq, RT2661_RX_RING_COUNT);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not allocate Rx ring\n");
                goto fail3;
        }

        ic->ic_softc = sc;
        ic->ic_name = device_get_nameunit(dev);
        ic->ic_opmode = IEEE80211_M_STA;
        ic->ic_phytype = IEEE80211_T_OFDM; /* not only, but not used */

        /* set device capabilities */
        ic->ic_caps =
                  IEEE80211_C_STA               /* station mode */
                | IEEE80211_C_IBSS              /* ibss, nee adhoc, mode */
                | IEEE80211_C_HOSTAP            /* hostap mode */
                | IEEE80211_C_MONITOR           /* monitor mode */
                | IEEE80211_C_AHDEMO            /* adhoc demo mode */
                | IEEE80211_C_WDS               /* 4-address traffic works */
                | IEEE80211_C_MBSS              /* mesh point link mode */
                | IEEE80211_C_SHPREAMBLE        /* short preamble supported */
                | IEEE80211_C_SHSLOT            /* short slot time supported */
                | IEEE80211_C_WPA               /* capable of WPA1+WPA2 */
                | IEEE80211_C_BGSCAN            /* capable of bg scanning */
#ifdef notyet
                | IEEE80211_C_TXFRAG            /* handle tx frags */
                | IEEE80211_C_WME               /* 802.11e */
#endif
                ;

        ic->ic_flags_ext |= IEEE80211_FEXT_SEQNO_OFFLOAD;

        rt2661_getradiocaps(ic, IEEE80211_CHAN_MAX, &ic->ic_nchans,
            ic->ic_channels);

        ieee80211_ifattach(ic);
#if 0
        ic->ic_wme.wme_update = rt2661_wme_update;
#endif
        ic->ic_scan_start = rt2661_scan_start;
        ic->ic_scan_end = rt2661_scan_end;
        ic->ic_getradiocaps = rt2661_getradiocaps;
        ic->ic_set_channel = rt2661_set_channel;
        ic->ic_updateslot = rt2661_update_slot;
        ic->ic_update_promisc = rt2661_update_promisc;
        ic->ic_raw_xmit = rt2661_raw_xmit;
        ic->ic_transmit = rt2661_transmit;
        ic->ic_parent = rt2661_parent;
        ic->ic_vap_create = rt2661_vap_create;
        ic->ic_vap_delete = rt2661_vap_delete;

        ieee80211_radiotap_attach(ic,
            &sc->sc_txtap.wt_ihdr, sizeof(sc->sc_txtap),
                RT2661_TX_RADIOTAP_PRESENT,
            &sc->sc_rxtap.wr_ihdr, sizeof(sc->sc_rxtap),
                RT2661_RX_RADIOTAP_PRESENT);

#ifdef RAL_DEBUG
        SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
            SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
            "debug", CTLFLAG_RW, &sc->sc_debug, 0, "debug msgs");
#endif
        if (bootverbose)
                ieee80211_announce(ic);

        return 0;

fail3:  rt2661_free_tx_ring(sc, &sc->mgtq);
fail2:  while (--ac >= 0)
                rt2661_free_tx_ring(sc, &sc->txq[ac]);
fail1:  mtx_destroy(&sc->sc_mtx);
        return error;
}

int
rt2661_detach(void *xsc)
{
        struct rt2661_softc *sc = xsc;
        struct ieee80211com *ic = &sc->sc_ic;

        RAL_LOCK(sc);
        rt2661_stop_locked(sc);
        RAL_UNLOCK(sc);

        ieee80211_ifdetach(ic);
        mbufq_drain(&sc->sc_snd);

        rt2661_free_tx_ring(sc, &sc->txq[0]);
        rt2661_free_tx_ring(sc, &sc->txq[1]);
        rt2661_free_tx_ring(sc, &sc->txq[2]);
        rt2661_free_tx_ring(sc, &sc->txq[3]);
        rt2661_free_tx_ring(sc, &sc->mgtq);
        rt2661_free_rx_ring(sc, &sc->rxq);

        mtx_destroy(&sc->sc_mtx);

        return 0;
}

static struct ieee80211vap *
rt2661_vap_create(struct ieee80211com *ic, const char name[IFNAMSIZ], int unit,
    enum ieee80211_opmode opmode, int flags,
    const uint8_t bssid[IEEE80211_ADDR_LEN],
    const uint8_t mac[IEEE80211_ADDR_LEN])
{
        struct rt2661_softc *sc = ic->ic_softc;
        struct rt2661_vap *rvp;
        struct ieee80211vap *vap;

        switch (opmode) {
        case IEEE80211_M_STA:
        case IEEE80211_M_IBSS:
        case IEEE80211_M_AHDEMO:
        case IEEE80211_M_MONITOR:
        case IEEE80211_M_HOSTAP:
        case IEEE80211_M_MBSS:
                /* XXXRP: TBD */
                if (!TAILQ_EMPTY(&ic->ic_vaps)) {
                        device_printf(sc->sc_dev, "only 1 vap supported\n");
                        return NULL;
                }
                if (opmode == IEEE80211_M_STA)
                        flags |= IEEE80211_CLONE_NOBEACONS;
                break;
        case IEEE80211_M_WDS:
                if (TAILQ_EMPTY(&ic->ic_vaps) ||
                    ic->ic_opmode != IEEE80211_M_HOSTAP) {
                        device_printf(sc->sc_dev,
                            "wds only supported in ap mode\n");
                        return NULL;
                }
                /*
                 * Silently remove any request for a unique
                 * bssid; WDS vap's always share the local
                 * mac address.
                 */
                flags &= ~IEEE80211_CLONE_BSSID;
                break;
        default:
                device_printf(sc->sc_dev, "unknown opmode %d\n", opmode);
                return NULL;
        }
        rvp = malloc(sizeof(struct rt2661_vap), M_80211_VAP, M_WAITOK | M_ZERO);
        vap = &rvp->ral_vap;
        ieee80211_vap_setup(ic, vap, name, unit, opmode, flags, bssid);

        /* override state transition machine */
        rvp->ral_newstate = vap->iv_newstate;
        vap->iv_newstate = rt2661_newstate;
#if 0
        vap->iv_update_beacon = rt2661_beacon_update;
#endif

        ieee80211_ratectl_init(vap);
        /* complete setup */
        ieee80211_vap_attach(vap, ieee80211_media_change,
            ieee80211_media_status, mac);
        if (TAILQ_FIRST(&ic->ic_vaps) == vap)
                ic->ic_opmode = opmode;
        return vap;
}

static void
rt2661_vap_delete(struct ieee80211vap *vap)
{
        struct rt2661_vap *rvp = RT2661_VAP(vap);

        ieee80211_ratectl_deinit(vap);
        ieee80211_vap_detach(vap);
        free(rvp, M_80211_VAP);
}

void
rt2661_shutdown(void *xsc)
{
        struct rt2661_softc *sc = xsc;

        rt2661_stop(sc);
}

void
rt2661_suspend(void *xsc)
{
        struct rt2661_softc *sc = xsc;

        rt2661_stop(sc);
}

void
rt2661_resume(void *xsc)
{
        struct rt2661_softc *sc = xsc;

        if (sc->sc_ic.ic_nrunning > 0)
                rt2661_init(sc);
}

static void
rt2661_dma_map_addr(void *arg, bus_dma_segment_t *segs, int nseg, int error)
{
        if (error != 0)
                return;

        KASSERT(nseg == 1, ("too many DMA segments, %d should be 1", nseg));

        *(bus_addr_t *)arg = segs[0].ds_addr;
}

static int
rt2661_alloc_tx_ring(struct rt2661_softc *sc, struct rt2661_tx_ring *ring,
    int count)
{
        int i, error;

        ring->count = count;
        ring->queued = 0;
        ring->cur = ring->next = ring->stat = 0;

        error = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev), 4, 0, 
            BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
            count * RT2661_TX_DESC_SIZE, 1, count * RT2661_TX_DESC_SIZE,
            0, NULL, NULL, &ring->desc_dmat);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not create desc DMA tag\n");
                goto fail;
        }

        error = bus_dmamem_alloc(ring->desc_dmat, (void **)&ring->desc,
            BUS_DMA_NOWAIT | BUS_DMA_ZERO, &ring->desc_map);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not allocate DMA memory\n");
                goto fail;
        }

        error = bus_dmamap_load(ring->desc_dmat, ring->desc_map, ring->desc,
            count * RT2661_TX_DESC_SIZE, rt2661_dma_map_addr, &ring->physaddr,
            0);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not load desc DMA map\n");
                goto fail;
        }

        ring->data = malloc(count * sizeof (struct rt2661_tx_data), M_DEVBUF,
            M_NOWAIT | M_ZERO);
        if (ring->data == NULL) {
                device_printf(sc->sc_dev, "could not allocate soft data\n");
                error = ENOMEM;
                goto fail;
        }

        error = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev), 1, 0, 
            BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL, MCLBYTES,
            RT2661_MAX_SCATTER, MCLBYTES, 0, NULL, NULL, &ring->data_dmat);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not create data DMA tag\n");
                goto fail;
        }

        for (i = 0; i < count; i++) {
                error = bus_dmamap_create(ring->data_dmat, 0,
                    &ring->data[i].map);
                if (error != 0) {
                        device_printf(sc->sc_dev, "could not create DMA map\n");
                        goto fail;
                }
        }

        return 0;

fail:   rt2661_free_tx_ring(sc, ring);
        return error;
}

static void
rt2661_reset_tx_ring(struct rt2661_softc *sc, struct rt2661_tx_ring *ring)
{
        struct rt2661_tx_desc *desc;
        struct rt2661_tx_data *data;
        int i;

        for (i = 0; i < ring->count; i++) {
                desc = &ring->desc[i];
                data = &ring->data[i];

                if (data->m != NULL) {
                        bus_dmamap_sync(ring->data_dmat, data->map,
                            BUS_DMASYNC_POSTWRITE);
                        bus_dmamap_unload(ring->data_dmat, data->map);
                        m_freem(data->m);
                        data->m = NULL;
                }

                if (data->ni != NULL) {
                        ieee80211_free_node(data->ni);
                        data->ni = NULL;
                }

                desc->flags = 0;
        }

        bus_dmamap_sync(ring->desc_dmat, ring->desc_map, BUS_DMASYNC_PREWRITE);

        ring->queued = 0;
        ring->cur = ring->next = ring->stat = 0;
}

static void
rt2661_free_tx_ring(struct rt2661_softc *sc, struct rt2661_tx_ring *ring)
{
        struct rt2661_tx_data *data;
        int i;

        if (ring->desc != NULL) {
                bus_dmamap_sync(ring->desc_dmat, ring->desc_map,
                    BUS_DMASYNC_POSTWRITE);
                bus_dmamap_unload(ring->desc_dmat, ring->desc_map);
                bus_dmamem_free(ring->desc_dmat, ring->desc, ring->desc_map);
        }

        if (ring->desc_dmat != NULL)
                bus_dma_tag_destroy(ring->desc_dmat);

        if (ring->data != NULL) {
                for (i = 0; i < ring->count; i++) {
                        data = &ring->data[i];

                        if (data->m != NULL) {
                                bus_dmamap_sync(ring->data_dmat, data->map,
                                    BUS_DMASYNC_POSTWRITE);
                                bus_dmamap_unload(ring->data_dmat, data->map);
                                m_freem(data->m);
                        }

                        if (data->ni != NULL)
                                ieee80211_free_node(data->ni);

                        if (data->map != NULL)
                                bus_dmamap_destroy(ring->data_dmat, data->map);
                }

                free(ring->data, M_DEVBUF);
        }

        if (ring->data_dmat != NULL)
                bus_dma_tag_destroy(ring->data_dmat);
}

static int
rt2661_alloc_rx_ring(struct rt2661_softc *sc, struct rt2661_rx_ring *ring,
    int count)
{
        struct rt2661_rx_desc *desc;
        struct rt2661_rx_data *data;
        bus_addr_t physaddr;
        int i, error;

        ring->count = count;
        ring->cur = ring->next = 0;

        error = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev), 4, 0, 
            BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
            count * RT2661_RX_DESC_SIZE, 1, count * RT2661_RX_DESC_SIZE,
            0, NULL, NULL, &ring->desc_dmat);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not create desc DMA tag\n");
                goto fail;
        }

        error = bus_dmamem_alloc(ring->desc_dmat, (void **)&ring->desc,
            BUS_DMA_NOWAIT | BUS_DMA_ZERO, &ring->desc_map);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not allocate DMA memory\n");
                goto fail;
        }

        error = bus_dmamap_load(ring->desc_dmat, ring->desc_map, ring->desc,
            count * RT2661_RX_DESC_SIZE, rt2661_dma_map_addr, &ring->physaddr,
            0);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not load desc DMA map\n");
                goto fail;
        }

        ring->data = malloc(count * sizeof (struct rt2661_rx_data), M_DEVBUF,
            M_NOWAIT | M_ZERO);
        if (ring->data == NULL) {
                device_printf(sc->sc_dev, "could not allocate soft data\n");
                error = ENOMEM;
                goto fail;
        }

        /*
         * Pre-allocate Rx buffers and populate Rx ring.
         */
        error = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev), 1, 0, 
            BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL, MCLBYTES,
            1, MCLBYTES, 0, NULL, NULL, &ring->data_dmat);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not create data DMA tag\n");
                goto fail;
        }

        for (i = 0; i < count; i++) {
                desc = &sc->rxq.desc[i];
                data = &sc->rxq.data[i];

                error = bus_dmamap_create(ring->data_dmat, 0, &data->map);
                if (error != 0) {
                        device_printf(sc->sc_dev, "could not create DMA map\n");
                        goto fail;
                }

                data->m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
                if (data->m == NULL) {
                        device_printf(sc->sc_dev,
                            "could not allocate rx mbuf\n");
                        error = ENOMEM;
                        goto fail;
                }

                error = bus_dmamap_load(ring->data_dmat, data->map,
                    mtod(data->m, void *), MCLBYTES, rt2661_dma_map_addr,
                    &physaddr, 0);
                if (error != 0) {
                        device_printf(sc->sc_dev,
                            "could not load rx buf DMA map");
                        goto fail;
                }

                desc->flags = htole32(RT2661_RX_BUSY);
                desc->physaddr = htole32(physaddr);
        }

        bus_dmamap_sync(ring->desc_dmat, ring->desc_map, BUS_DMASYNC_PREWRITE);

        return 0;

fail:   rt2661_free_rx_ring(sc, ring);
        return error;
}

static void
rt2661_reset_rx_ring(struct rt2661_softc *sc, struct rt2661_rx_ring *ring)
{
        int i;

        for (i = 0; i < ring->count; i++)
                ring->desc[i].flags = htole32(RT2661_RX_BUSY);

        bus_dmamap_sync(ring->desc_dmat, ring->desc_map, BUS_DMASYNC_PREWRITE);

        ring->cur = ring->next = 0;
}

static void
rt2661_free_rx_ring(struct rt2661_softc *sc, struct rt2661_rx_ring *ring)
{
        struct rt2661_rx_data *data;
        int i;

        if (ring->desc != NULL) {
                bus_dmamap_sync(ring->desc_dmat, ring->desc_map,
                    BUS_DMASYNC_POSTWRITE);
                bus_dmamap_unload(ring->desc_dmat, ring->desc_map);
                bus_dmamem_free(ring->desc_dmat, ring->desc, ring->desc_map);
        }

        if (ring->desc_dmat != NULL)
                bus_dma_tag_destroy(ring->desc_dmat);

        if (ring->data != NULL) {
                for (i = 0; i < ring->count; i++) {
                        data = &ring->data[i];

                        if (data->m != NULL) {
                                bus_dmamap_sync(ring->data_dmat, data->map,
                                    BUS_DMASYNC_POSTREAD);
                                bus_dmamap_unload(ring->data_dmat, data->map);
                                m_freem(data->m);
                        }

                        if (data->map != NULL)
                                bus_dmamap_destroy(ring->data_dmat, data->map);
                }

                free(ring->data, M_DEVBUF);
        }

        if (ring->data_dmat != NULL)
                bus_dma_tag_destroy(ring->data_dmat);
}

static int
rt2661_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
{
        struct rt2661_vap *rvp = RT2661_VAP(vap);
        struct ieee80211com *ic = vap->iv_ic;
        struct rt2661_softc *sc = ic->ic_softc;
        int error;

        if (nstate == IEEE80211_S_INIT && vap->iv_state == IEEE80211_S_RUN) {
                uint32_t tmp;

                /* abort TSF synchronization */
                tmp = RAL_READ(sc, RT2661_TXRX_CSR9);
                RAL_WRITE(sc, RT2661_TXRX_CSR9, tmp & ~0x00ffffff);
        }

        error = rvp->ral_newstate(vap, nstate, arg);

        if (error == 0 && nstate == IEEE80211_S_RUN) {
                struct ieee80211_node *ni = vap->iv_bss;

                if (vap->iv_opmode != IEEE80211_M_MONITOR) {
                        rt2661_enable_mrr(sc);
                        rt2661_set_txpreamble(sc);
                        rt2661_set_basicrates(sc, &ni->ni_rates);
                        rt2661_set_bssid(sc, ni->ni_bssid);
                }

                if (vap->iv_opmode == IEEE80211_M_HOSTAP ||
                    vap->iv_opmode == IEEE80211_M_IBSS ||
                    vap->iv_opmode == IEEE80211_M_MBSS) {
                        error = rt2661_prepare_beacon(sc, vap);
                        if (error != 0)
                                return error;
                }
                if (vap->iv_opmode != IEEE80211_M_MONITOR)
                        rt2661_enable_tsf_sync(sc);
                else
                        rt2661_enable_tsf(sc);
        }
        return error;
}

/*
 * Read 16 bits at address 'addr' from the serial EEPROM (either 93C46 or
 * 93C66).
 */
static uint16_t
rt2661_eeprom_read(struct rt2661_softc *sc, uint8_t addr)
{
        uint32_t tmp;
        uint16_t val;
        int n;

        /* clock C once before the first command */
        RT2661_EEPROM_CTL(sc, 0);

        RT2661_EEPROM_CTL(sc, RT2661_S);
        RT2661_EEPROM_CTL(sc, RT2661_S | RT2661_C);
        RT2661_EEPROM_CTL(sc, RT2661_S);

        /* write start bit (1) */
        RT2661_EEPROM_CTL(sc, RT2661_S | RT2661_D);
        RT2661_EEPROM_CTL(sc, RT2661_S | RT2661_D | RT2661_C);

        /* write READ opcode (10) */
        RT2661_EEPROM_CTL(sc, RT2661_S | RT2661_D);
        RT2661_EEPROM_CTL(sc, RT2661_S | RT2661_D | RT2661_C);
        RT2661_EEPROM_CTL(sc, RT2661_S);
        RT2661_EEPROM_CTL(sc, RT2661_S | RT2661_C);

        /* write address (A5-A0 or A7-A0) */
        n = (RAL_READ(sc, RT2661_E2PROM_CSR) & RT2661_93C46) ? 5 : 7;
        for (; n >= 0; n--) {
                RT2661_EEPROM_CTL(sc, RT2661_S |
                    (((addr >> n) & 1) << RT2661_SHIFT_D));
                RT2661_EEPROM_CTL(sc, RT2661_S |
                    (((addr >> n) & 1) << RT2661_SHIFT_D) | RT2661_C);
        }

        RT2661_EEPROM_CTL(sc, RT2661_S);

        /* read data Q15-Q0 */
        val = 0;
        for (n = 15; n >= 0; n--) {
                RT2661_EEPROM_CTL(sc, RT2661_S | RT2661_C);
                tmp = RAL_READ(sc, RT2661_E2PROM_CSR);
                val |= ((tmp & RT2661_Q) >> RT2661_SHIFT_Q) << n;
                RT2661_EEPROM_CTL(sc, RT2661_S);
        }

        RT2661_EEPROM_CTL(sc, 0);

        /* clear Chip Select and clock C */
        RT2661_EEPROM_CTL(sc, RT2661_S);
        RT2661_EEPROM_CTL(sc, 0);
        RT2661_EEPROM_CTL(sc, RT2661_C);

        return val;
}

static void
rt2661_tx_intr(struct rt2661_softc *sc)
{
        struct ieee80211_ratectl_tx_status *txs = &sc->sc_txs;
        struct rt2661_tx_ring *txq;
        struct rt2661_tx_data *data;
        uint32_t val;
        int error, qid;

        txs->flags = IEEE80211_RATECTL_TX_FAIL_LONG;
        for (;;) {
                struct ieee80211_node *ni;
                struct mbuf *m;

                val = RAL_READ(sc, RT2661_STA_CSR4);
                if (!(val & RT2661_TX_STAT_VALID))
                        break;

                /* retrieve the queue in which this frame was sent */
                qid = RT2661_TX_QID(val);
                txq = (qid <= 3) ? &sc->txq[qid] : &sc->mgtq;

                /* retrieve rate control algorithm context */
                data = &txq->data[txq->stat];
                m = data->m;
                data->m = NULL;
                ni = data->ni;
                data->ni = NULL;

                /* if no frame has been sent, ignore */
                if (ni == NULL)
                        continue;

                switch (RT2661_TX_RESULT(val)) {
                case RT2661_TX_SUCCESS:
                        txs->status = IEEE80211_RATECTL_TX_SUCCESS;
                        txs->long_retries = RT2661_TX_RETRYCNT(val);

                        DPRINTFN(sc, 10, "data frame sent successfully after "
                            "%d retries\n", txs->long_retries);
                        if (data->rix != IEEE80211_FIXED_RATE_NONE)
                                ieee80211_ratectl_tx_complete(ni, txs);
                        error = 0;
                        break;

                case RT2661_TX_RETRY_FAIL:
                        txs->status = IEEE80211_RATECTL_TX_FAIL_LONG;
                        txs->long_retries = RT2661_TX_RETRYCNT(val);

                        DPRINTFN(sc, 9, "%s\n",
                            "sending data frame failed (too much retries)");
                        if (data->rix != IEEE80211_FIXED_RATE_NONE)
                                ieee80211_ratectl_tx_complete(ni, txs);
                        error = 1;
                        break;

                default:
                        /* other failure */
                        device_printf(sc->sc_dev,
                            "sending data frame failed 0x%08x\n", val);
                        error = 1;
                }

                DPRINTFN(sc, 15, "tx done q=%d idx=%u\n", qid, txq->stat);

                txq->queued--;
                if (++txq->stat >= txq->count)  /* faster than % count */
                        txq->stat = 0;

                ieee80211_tx_complete(ni, m, error);
        }

        sc->sc_tx_timer = 0;

        rt2661_start(sc);
}

static void
rt2661_tx_dma_intr(struct rt2661_softc *sc, struct rt2661_tx_ring *txq)
{
        struct rt2661_tx_desc *desc;
        struct rt2661_tx_data *data;

        bus_dmamap_sync(txq->desc_dmat, txq->desc_map, BUS_DMASYNC_POSTREAD);

        for (;;) {
                desc = &txq->desc[txq->next];
                data = &txq->data[txq->next];

                if ((le32toh(desc->flags) & RT2661_TX_BUSY) ||
                    !(le32toh(desc->flags) & RT2661_TX_VALID))
                        break;

                bus_dmamap_sync(txq->data_dmat, data->map,
                    BUS_DMASYNC_POSTWRITE);
                bus_dmamap_unload(txq->data_dmat, data->map);

                /* descriptor is no longer valid */
                desc->flags &= ~htole32(RT2661_TX_VALID);

                DPRINTFN(sc, 15, "tx dma done q=%p idx=%u\n", txq, txq->next);

                if (++txq->next >= txq->count)  /* faster than % count */
                        txq->next = 0;
        }

        bus_dmamap_sync(txq->desc_dmat, txq->desc_map, BUS_DMASYNC_PREWRITE);
}

static void
rt2661_rx_intr(struct rt2661_softc *sc)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct rt2661_rx_desc *desc;
        struct rt2661_rx_data *data;
        bus_addr_t physaddr;
        struct ieee80211_frame *wh;
        struct ieee80211_node *ni;
        struct mbuf *mnew, *m;
        int error;

        bus_dmamap_sync(sc->rxq.desc_dmat, sc->rxq.desc_map,
            BUS_DMASYNC_POSTREAD);

        for (;;) {
                int8_t rssi, nf;

                desc = &sc->rxq.desc[sc->rxq.cur];
                data = &sc->rxq.data[sc->rxq.cur];

                if (le32toh(desc->flags) & RT2661_RX_BUSY)
                        break;

                if ((le32toh(desc->flags) & RT2661_RX_PHY_ERROR) ||
                    (le32toh(desc->flags) & RT2661_RX_CRC_ERROR)) {
                        /*
                         * This should not happen since we did not request
                         * to receive those frames when we filled TXRX_CSR0.
                         */
                        DPRINTFN(sc, 5, "PHY or CRC error flags 0x%08x\n",
                            le32toh(desc->flags));
                        counter_u64_add(ic->ic_ierrors, 1);
                        goto skip;
                }

                if ((le32toh(desc->flags) & RT2661_RX_CIPHER_MASK) != 0) {
                        counter_u64_add(ic->ic_ierrors, 1);
                        goto skip;
                }

                /*
                 * Try to allocate a new mbuf for this ring element and load it
                 * before processing the current mbuf. If the ring element
                 * cannot be loaded, drop the received packet and reuse the old
                 * mbuf. In the unlikely case that the old mbuf can't be
                 * reloaded either, explicitly panic.
                 */
                mnew = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
                if (mnew == NULL) {
                        counter_u64_add(ic->ic_ierrors, 1);
                        goto skip;
                }

                bus_dmamap_sync(sc->rxq.data_dmat, data->map,
                    BUS_DMASYNC_POSTREAD);
                bus_dmamap_unload(sc->rxq.data_dmat, data->map);

                error = bus_dmamap_load(sc->rxq.data_dmat, data->map,
                    mtod(mnew, void *), MCLBYTES, rt2661_dma_map_addr,
                    &physaddr, 0);
                if (error != 0) {
                        m_freem(mnew);

                        /* try to reload the old mbuf */
                        error = bus_dmamap_load(sc->rxq.data_dmat, data->map,
                            mtod(data->m, void *), MCLBYTES,
                            rt2661_dma_map_addr, &physaddr, 0);
                        if (error != 0) {
                                /* very unlikely that it will fail... */
                                panic("%s: could not load old rx mbuf",
                                    device_get_name(sc->sc_dev));
                        }
                        counter_u64_add(ic->ic_ierrors, 1);
                        goto skip;
                }

                /*
                 * New mbuf successfully loaded, update Rx ring and continue
                 * processing.
                 */
                m = data->m;
                data->m = mnew;
                desc->physaddr = htole32(physaddr);

                /* finalize mbuf */
                m->m_pkthdr.len = m->m_len =
                    (le32toh(desc->flags) >> 16) & 0xfff;

                rssi = rt2661_get_rssi(sc, desc->rssi);
                /* Error happened during RSSI conversion. */
                if (rssi < 0)
                        rssi = -30;     /* XXX ignored by net80211 */
                nf = RT2661_NOISE_FLOOR;

                if (ieee80211_radiotap_active(ic)) {
                        struct rt2661_rx_radiotap_header *tap = &sc->sc_rxtap;
                        uint32_t tsf_lo, tsf_hi;

                        /* get timestamp (low and high 32 bits) */
                        tsf_hi = RAL_READ(sc, RT2661_TXRX_CSR13);
                        tsf_lo = RAL_READ(sc, RT2661_TXRX_CSR12);

                        tap->wr_tsf =
                            htole64(((uint64_t)tsf_hi << 32) | tsf_lo);
                        tap->wr_flags = 0;
                        tap->wr_rate = ieee80211_plcp2rate(desc->rate,
                            (desc->flags & htole32(RT2661_RX_OFDM)) ?
                                IEEE80211_T_OFDM : IEEE80211_T_CCK);
                        tap->wr_antsignal = nf + rssi;
                        tap->wr_antnoise = nf;
                }
                sc->sc_flags |= RAL_INPUT_RUNNING;
                RAL_UNLOCK(sc);
                wh = mtod(m, struct ieee80211_frame *);

                /* send the frame to the 802.11 layer */
                ni = ieee80211_find_rxnode(ic,
                    (struct ieee80211_frame_min *)wh);
                if (ni != NULL) {
                        (void) ieee80211_input(ni, m, rssi, nf);
                        ieee80211_free_node(ni);
                } else
                        (void) ieee80211_input_all(ic, m, rssi, nf);

                RAL_LOCK(sc);
                sc->sc_flags &= ~RAL_INPUT_RUNNING;

skip:           desc->flags |= htole32(RT2661_RX_BUSY);

                DPRINTFN(sc, 15, "rx intr idx=%u\n", sc->rxq.cur);

                sc->rxq.cur = (sc->rxq.cur + 1) % RT2661_RX_RING_COUNT;
        }

        bus_dmamap_sync(sc->rxq.desc_dmat, sc->rxq.desc_map,
            BUS_DMASYNC_PREWRITE);
}

/* ARGSUSED */
static void
rt2661_mcu_beacon_expire(struct rt2661_softc *sc)
{
        /* do nothing */
}

static void
rt2661_mcu_wakeup(struct rt2661_softc *sc)
{
        RAL_WRITE(sc, RT2661_MAC_CSR11, 5 << 16);

        RAL_WRITE(sc, RT2661_SOFT_RESET_CSR, 0x7);
        RAL_WRITE(sc, RT2661_IO_CNTL_CSR, 0x18);
        RAL_WRITE(sc, RT2661_PCI_USEC_CSR, 0x20);

        /* send wakeup command to MCU */
        rt2661_tx_cmd(sc, RT2661_MCU_CMD_WAKEUP, 0);
}

static void
rt2661_mcu_cmd_intr(struct rt2661_softc *sc)
{
        RAL_READ(sc, RT2661_M2H_CMD_DONE_CSR);
        RAL_WRITE(sc, RT2661_M2H_CMD_DONE_CSR, 0xffffffff);
}

void
rt2661_intr(void *arg)
{
        struct rt2661_softc *sc = arg;
        uint32_t r1, r2;

        RAL_LOCK(sc);

        /* disable MAC and MCU interrupts */
        RAL_WRITE(sc, RT2661_INT_MASK_CSR, 0xffffff7f);
        RAL_WRITE(sc, RT2661_MCU_INT_MASK_CSR, 0xffffffff);

        /* don't re-enable interrupts if we're shutting down */
        if (!(sc->sc_flags & RAL_RUNNING)) {
                RAL_UNLOCK(sc);
                return;
        }

        r1 = RAL_READ(sc, RT2661_INT_SOURCE_CSR);
        RAL_WRITE(sc, RT2661_INT_SOURCE_CSR, r1);

        r2 = RAL_READ(sc, RT2661_MCU_INT_SOURCE_CSR);
        RAL_WRITE(sc, RT2661_MCU_INT_SOURCE_CSR, r2);

        if (r1 & RT2661_MGT_DONE)
                rt2661_tx_dma_intr(sc, &sc->mgtq);

        if (r1 & RT2661_RX_DONE)
                rt2661_rx_intr(sc);

        if (r1 & RT2661_TX0_DMA_DONE)
                rt2661_tx_dma_intr(sc, &sc->txq[0]);

        if (r1 & RT2661_TX1_DMA_DONE)
                rt2661_tx_dma_intr(sc, &sc->txq[1]);

        if (r1 & RT2661_TX2_DMA_DONE)
                rt2661_tx_dma_intr(sc, &sc->txq[2]);

        if (r1 & RT2661_TX3_DMA_DONE)
                rt2661_tx_dma_intr(sc, &sc->txq[3]);

        if (r1 & RT2661_TX_DONE)
                rt2661_tx_intr(sc);

        if (r2 & RT2661_MCU_CMD_DONE)
                rt2661_mcu_cmd_intr(sc);

        if (r2 & RT2661_MCU_BEACON_EXPIRE)
                rt2661_mcu_beacon_expire(sc);

        if (r2 & RT2661_MCU_WAKEUP)
                rt2661_mcu_wakeup(sc);

        /* re-enable MAC and MCU interrupts */
        RAL_WRITE(sc, RT2661_INT_MASK_CSR, 0x0000ff10);
        RAL_WRITE(sc, RT2661_MCU_INT_MASK_CSR, 0);

        RAL_UNLOCK(sc);
}

static uint8_t
rt2661_plcp_signal(int rate)
{
        switch (rate) {
        /* OFDM rates (cf IEEE Std 802.11a-1999, pp. 14 Table 80) */
        case 12:        return 0xb;
        case 18:        return 0xf;
        case 24:        return 0xa;
        case 36:        return 0xe;
        case 48:        return 0x9;
        case 72:        return 0xd;
        case 96:        return 0x8;
        case 108:       return 0xc;

        /* CCK rates (NB: not IEEE std, device-specific) */
        case 2:         return 0x0;
        case 4:         return 0x1;
        case 11:        return 0x2;
        case 22:        return 0x3;
        }
        return 0xff;            /* XXX unsupported/unknown rate */
}

static void
rt2661_setup_tx_desc(struct rt2661_softc *sc, struct rt2661_tx_desc *desc,
    uint32_t flags, uint16_t xflags, int len, int rate,
    const bus_dma_segment_t *segs, int nsegs, int ac)
{
        struct ieee80211com *ic = &sc->sc_ic;
        uint16_t plcp_length;
        int i, remainder;

        desc->flags = htole32(flags);
        desc->flags |= htole32(len << 16);
        desc->flags |= htole32(RT2661_TX_BUSY | RT2661_TX_VALID);

        desc->xflags = htole16(xflags);
        desc->xflags |= htole16(nsegs << 13);

        desc->wme = htole16(
            RT2661_QID(ac) |
            RT2661_AIFSN(2) |
            RT2661_LOGCWMIN(4) |
            RT2661_LOGCWMAX(10));

        /*
         * Remember in which queue this frame was sent. This field is driver
         * private data only. It will be made available by the NIC in STA_CSR4
         * on Tx interrupts.
         */
        desc->qid = ac;

        /* setup PLCP fields */
        desc->plcp_signal  = rt2661_plcp_signal(rate);
        desc->plcp_service = 4;

        len += IEEE80211_CRC_LEN;
        if (ieee80211_rate2phytype(ic->ic_rt, rate) == IEEE80211_T_OFDM) {
                desc->flags |= htole32(RT2661_TX_OFDM);

                plcp_length = len & 0xfff;
                desc->plcp_length_hi = plcp_length >> 6;
                desc->plcp_length_lo = plcp_length & 0x3f;
        } else {
                plcp_length = howmany(16 * len, rate);
                if (rate == 22) {
                        remainder = (16 * len) % 22;
                        if (remainder != 0 && remainder < 7)
                                desc->plcp_service |= RT2661_PLCP_LENGEXT;
                }
                desc->plcp_length_hi = plcp_length >> 8;
                desc->plcp_length_lo = plcp_length & 0xff;

                if (rate != 2 && (ic->ic_flags & IEEE80211_F_SHPREAMBLE))
                        desc->plcp_signal |= 0x08;
        }

        /* RT2x61 supports scatter with up to 5 segments */
        for (i = 0; i < nsegs; i++) {
                desc->addr[i] = htole32(segs[i].ds_addr);
                desc->len [i] = htole16(segs[i].ds_len);
        }
}

static int
rt2661_tx_mgt(struct rt2661_softc *sc, struct mbuf *m0,
    struct ieee80211_node *ni)
{
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211com *ic = ni->ni_ic;
        struct rt2661_tx_desc *desc;
        struct rt2661_tx_data *data;
        struct ieee80211_frame *wh;
        struct ieee80211_key *k;
        bus_dma_segment_t segs[RT2661_MAX_SCATTER];
        uint16_t dur;
        uint32_t flags = 0;     /* XXX HWSEQ */
        int nsegs, rate, error;

        desc = &sc->mgtq.desc[sc->mgtq.cur];
        data = &sc->mgtq.data[sc->mgtq.cur];

        rate = ni->ni_txparms->mgmtrate;

        wh = mtod(m0, struct ieee80211_frame *);
        ieee80211_output_seqno_assign(ni, -1, m0);
        if (wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {
                k = ieee80211_crypto_encap(ni, m0);
                if (k == NULL) {
                        m_freem(m0);
                        return ENOBUFS;
                }
        }

        error = bus_dmamap_load_mbuf_sg(sc->mgtq.data_dmat, data->map, m0,
            segs, &nsegs, 0);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not map mbuf (error %d)\n",
                    error);
                m_freem(m0);
                return error;
        }

        if (ieee80211_radiotap_active_vap(vap)) {
                struct rt2661_tx_radiotap_header *tap = &sc->sc_txtap;

                tap->wt_flags = 0;
                tap->wt_rate = rate;

                ieee80211_radiotap_tx(vap, m0);
        }

        data->m = m0;
        data->ni = ni;
        /* management frames are not taken into account for amrr */
        data->rix = IEEE80211_FIXED_RATE_NONE;

        wh = mtod(m0, struct ieee80211_frame *);

        if (!IEEE80211_IS_MULTICAST(wh->i_addr1)) {
                flags |= RT2661_TX_NEED_ACK;

                dur = ieee80211_ack_duration(ic->ic_rt,
                    rate, ic->ic_flags & IEEE80211_F_SHPREAMBLE);
                *(uint16_t *)wh->i_dur = htole16(dur);

                /* tell hardware to add timestamp in probe responses */
                if (IEEE80211_IS_MGMT_PROBE_RESP(wh))
                        flags |= RT2661_TX_TIMESTAMP;
        }

        rt2661_setup_tx_desc(sc, desc, flags, 0 /* XXX HWSEQ */,
            m0->m_pkthdr.len, rate, segs, nsegs, RT2661_QID_MGT);

        bus_dmamap_sync(sc->mgtq.data_dmat, data->map, BUS_DMASYNC_PREWRITE);
        bus_dmamap_sync(sc->mgtq.desc_dmat, sc->mgtq.desc_map,
            BUS_DMASYNC_PREWRITE);

        DPRINTFN(sc, 10, "sending mgt frame len=%u idx=%u rate=%u\n",
            m0->m_pkthdr.len, sc->mgtq.cur, rate);

        /* kick mgt */
        sc->mgtq.queued++;
        sc->mgtq.cur = (sc->mgtq.cur + 1) % RT2661_MGT_RING_COUNT;
        RAL_WRITE(sc, RT2661_TX_CNTL_CSR, RT2661_KICK_MGT);

        return 0;
}

static int
rt2661_sendprot(struct rt2661_softc *sc, int ac,
    const struct mbuf *m, struct ieee80211_node *ni, int prot, int rate)
{
        struct ieee80211com *ic = ni->ni_ic;
        struct rt2661_tx_ring *txq = &sc->txq[ac];
        struct rt2661_tx_desc *desc;
        struct rt2661_tx_data *data;
        struct mbuf *mprot;
        int protrate, flags, error;
        bus_dma_segment_t segs[RT2661_MAX_SCATTER];
        int nsegs;

        mprot = ieee80211_alloc_prot(ni, m, rate, prot);
        if (mprot == NULL) {
                if_inc_counter(ni->ni_vap->iv_ifp, IFCOUNTER_OERRORS, 1);
                device_printf(sc->sc_dev,
                    "could not allocate mbuf for protection mode %d\n", prot);
                return ENOBUFS;
        }

        data = &txq->data[txq->cur];
        desc = &txq->desc[txq->cur];

        error = bus_dmamap_load_mbuf_sg(txq->data_dmat, data->map, mprot, segs,
            &nsegs, 0);
        if (error != 0) {
                device_printf(sc->sc_dev,
                    "could not map mbuf (error %d)\n", error);
                m_freem(mprot);
                return error;
        }

        data->m = mprot;
        data->ni = ieee80211_ref_node(ni);
        /* ctl frames are not taken into account for amrr */
        data->rix = IEEE80211_FIXED_RATE_NONE;

        protrate = ieee80211_ctl_rate(ic->ic_rt, rate);
        flags = RT2661_TX_MORE_FRAG;
        if (prot == IEEE80211_PROT_RTSCTS)
                flags |= RT2661_TX_NEED_ACK;

        rt2661_setup_tx_desc(sc, desc, flags, 0, mprot->m_pkthdr.len,
            protrate, segs, 1, ac);

        bus_dmamap_sync(txq->data_dmat, data->map, BUS_DMASYNC_PREWRITE);
        bus_dmamap_sync(txq->desc_dmat, txq->desc_map, BUS_DMASYNC_PREWRITE);

        txq->queued++;
        txq->cur = (txq->cur + 1) % RT2661_TX_RING_COUNT;

        return 0;
}

static int
rt2661_tx_data(struct rt2661_softc *sc, struct mbuf *m0,
    struct ieee80211_node *ni, int ac)
{
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211com *ic = &sc->sc_ic;
        struct rt2661_tx_ring *txq = &sc->txq[ac];
        struct rt2661_tx_desc *desc;
        struct rt2661_tx_data *data;
        struct ieee80211_frame *wh;
        const struct ieee80211_txparam *tp = ni->ni_txparms;
        struct ieee80211_key *k;
        struct mbuf *mnew;
        bus_dma_segment_t segs[RT2661_MAX_SCATTER];
        uint16_t dur;
        uint32_t flags;
        int error, nsegs, rate, noack = 0;

        wh = mtod(m0, struct ieee80211_frame *);

        if (m0->m_flags & M_EAPOL) {
                rate = tp->mgmtrate;
        } else if (IEEE80211_IS_MULTICAST(wh->i_addr1)) {
                rate = tp->mcastrate;
        } else if (tp->ucastrate != IEEE80211_FIXED_RATE_NONE) {
                rate = tp->ucastrate;
        } else {
                (void) ieee80211_ratectl_rate(ni, NULL, 0);
                rate = ieee80211_node_get_txrate_dot11rate(ni);
        }
        rate &= IEEE80211_RATE_VAL;

        if (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_QOS_DATA)
                noack = !! ieee80211_wme_vap_ac_is_noack(vap, ac);

        if (wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {
                k = ieee80211_crypto_encap(ni, m0);
                if (k == NULL) {
                        m_freem(m0);
                        return ENOBUFS;
                }

                /* packet header may have moved, reset our local pointer */
                wh = mtod(m0, struct ieee80211_frame *);
        }

        flags = 0;
        if (!IEEE80211_IS_MULTICAST(wh->i_addr1)) {
                int prot = IEEE80211_PROT_NONE;
                if (m0->m_pkthdr.len + IEEE80211_CRC_LEN > vap->iv_rtsthreshold)
                        prot = IEEE80211_PROT_RTSCTS;
                else if ((ic->ic_flags & IEEE80211_F_USEPROT) &&
                    ieee80211_rate2phytype(ic->ic_rt, rate) == IEEE80211_T_OFDM)
                        prot = ic->ic_protmode;
                if (prot != IEEE80211_PROT_NONE) {
                        error = rt2661_sendprot(sc, ac, m0, ni, prot, rate);
                        if (error) {
                                m_freem(m0);
                                return error;
                        }
                        flags |= RT2661_TX_LONG_RETRY | RT2661_TX_IFS;
                }
        }

        data = &txq->data[txq->cur];
        desc = &txq->desc[txq->cur];

        error = bus_dmamap_load_mbuf_sg(txq->data_dmat, data->map, m0, segs,
            &nsegs, 0);
        if (error != 0 && error != EFBIG) {
                device_printf(sc->sc_dev, "could not map mbuf (error %d)\n",
                    error);
                m_freem(m0);
                return error;
        }
        if (error != 0) {
                mnew = m_defrag(m0, M_NOWAIT);
                if (mnew == NULL) {
                        device_printf(sc->sc_dev,
                            "could not defragment mbuf\n");
                        m_freem(m0);
                        return ENOBUFS;
                }
                m0 = mnew;

                error = bus_dmamap_load_mbuf_sg(txq->data_dmat, data->map, m0,
                    segs, &nsegs, 0);
                if (error != 0) {
                        device_printf(sc->sc_dev,
                            "could not map mbuf (error %d)\n", error);
                        m_freem(m0);
                        return error;
                }

                /* packet header have moved, reset our local pointer */
                wh = mtod(m0, struct ieee80211_frame *);
        }

        if (ieee80211_radiotap_active_vap(vap)) {
                struct rt2661_tx_radiotap_header *tap = &sc->sc_txtap;

                tap->wt_flags = 0;
                tap->wt_rate = rate;

                ieee80211_radiotap_tx(vap, m0);
        }

        data->m = m0;
        data->ni = ni;

        /* remember link conditions for rate adaptation algorithm */
        if (tp->ucastrate == IEEE80211_FIXED_RATE_NONE) {
                data->rix = ieee80211_node_get_txrate_dot11rate(ni);
                /* XXX probably need last rssi value and not avg */
                data->rssi = ic->ic_node_getrssi(ni);
        } else
                data->rix = IEEE80211_FIXED_RATE_NONE;

        if (!noack && !IEEE80211_IS_MULTICAST(wh->i_addr1)) {
                flags |= RT2661_TX_NEED_ACK;

                dur = ieee80211_ack_duration(ic->ic_rt,
                    rate, ic->ic_flags & IEEE80211_F_SHPREAMBLE);
                *(uint16_t *)wh->i_dur = htole16(dur);
        }

        rt2661_setup_tx_desc(sc, desc, flags, 0, m0->m_pkthdr.len, rate, segs,
            nsegs, ac);

        bus_dmamap_sync(txq->data_dmat, data->map, BUS_DMASYNC_PREWRITE);
        bus_dmamap_sync(txq->desc_dmat, txq->desc_map, BUS_DMASYNC_PREWRITE);

        DPRINTFN(sc, 10, "sending data frame len=%u idx=%u rate=%u\n",
            m0->m_pkthdr.len, txq->cur, rate);

        /* kick Tx */
        txq->queued++;
        txq->cur = (txq->cur + 1) % RT2661_TX_RING_COUNT;
        RAL_WRITE(sc, RT2661_TX_CNTL_CSR, 1 << ac);

        return 0;
}

static int
rt2661_transmit(struct ieee80211com *ic, struct mbuf *m)   
{
        struct rt2661_softc *sc = ic->ic_softc;
        int error;

        RAL_LOCK(sc);
        if ((sc->sc_flags & RAL_RUNNING) == 0) {
                RAL_UNLOCK(sc);
                return (ENXIO);
        }
        error = mbufq_enqueue(&sc->sc_snd, m);
        if (error) {
                RAL_UNLOCK(sc);
                return (error);
        }
        rt2661_start(sc);
        RAL_UNLOCK(sc);

        return (0);
}

static void
rt2661_start(struct rt2661_softc *sc)
{
        struct mbuf *m;
        struct ieee80211_node *ni;
        int ac;

        RAL_LOCK_ASSERT(sc);

        /* prevent management frames from being sent if we're not ready */
        if (!(sc->sc_flags & RAL_RUNNING) || sc->sc_invalid)
                return;

        while ((m = mbufq_dequeue(&sc->sc_snd)) != NULL) {
                ac = M_WME_GETAC(m);
                if (sc->txq[ac].queued >= RT2661_TX_RING_COUNT - 1) {
                        /* there is no place left in this ring */
                        mbufq_prepend(&sc->sc_snd, m);
                        break;
                }
                ni = (struct ieee80211_node *) m->m_pkthdr.rcvif;
                if (rt2661_tx_data(sc, m, ni, ac) != 0) {
                        if_inc_counter(ni->ni_vap->iv_ifp,
                            IFCOUNTER_OERRORS, 1);
                        ieee80211_free_node(ni);
                        break;
                }
                sc->sc_tx_timer = 5;
        }
}

static int
rt2661_raw_xmit(struct ieee80211_node *ni, struct mbuf *m,
        const struct ieee80211_bpf_params *params)
{
        struct ieee80211com *ic = ni->ni_ic;
        struct rt2661_softc *sc = ic->ic_softc;

        RAL_LOCK(sc);

        /* prevent management frames from being sent if we're not ready */
        if (!(sc->sc_flags & RAL_RUNNING)) {
                RAL_UNLOCK(sc);
                m_freem(m);
                return ENETDOWN;
        }
        if (sc->mgtq.queued >= RT2661_MGT_RING_COUNT) {
                RAL_UNLOCK(sc);
                m_freem(m);
                return ENOBUFS;         /* XXX */
        }

        /*
         * Legacy path; interpret frame contents to decide
         * precisely how to send the frame.
         * XXX raw path
         */
        if (rt2661_tx_mgt(sc, m, ni) != 0)
                goto bad;
        sc->sc_tx_timer = 5;

        RAL_UNLOCK(sc);

        return 0;
bad:
        RAL_UNLOCK(sc);
        return EIO;             /* XXX */
}

static void
rt2661_watchdog(void *arg)
{
        struct rt2661_softc *sc = (struct rt2661_softc *)arg;

        RAL_LOCK_ASSERT(sc);

        KASSERT(sc->sc_flags & RAL_RUNNING, ("not running"));

        if (sc->sc_invalid)             /* card ejected */
                return;

        if (sc->sc_tx_timer > 0 && --sc->sc_tx_timer == 0) {
                device_printf(sc->sc_dev, "device timeout\n");
                rt2661_init_locked(sc);
                counter_u64_add(sc->sc_ic.ic_oerrors, 1);
                /* NB: callout is reset in rt2661_init() */
                return;
        }
        callout_reset(&sc->watchdog_ch, hz, rt2661_watchdog, sc);
}

static void
rt2661_parent(struct ieee80211com *ic)
{
        struct rt2661_softc *sc = ic->ic_softc;
        int startall = 0;

        RAL_LOCK(sc);
        if (ic->ic_nrunning > 0) {
                if ((sc->sc_flags & RAL_RUNNING) == 0) {
                        rt2661_init_locked(sc);
                        startall = 1;
                } else
                        rt2661_update_promisc(ic);
        } else if (sc->sc_flags & RAL_RUNNING)
                rt2661_stop_locked(sc);
        RAL_UNLOCK(sc);
        if (startall)
                ieee80211_start_all(ic);
}

static void
rt2661_bbp_write(struct rt2661_softc *sc, uint8_t reg, uint8_t val)
{
        uint32_t tmp;
        int ntries;

        for (ntries = 0; ntries < 100; ntries++) {
                if (!(RAL_READ(sc, RT2661_PHY_CSR3) & RT2661_BBP_BUSY))
                        break;
                DELAY(1);
        }
        if (ntries == 100) {
                device_printf(sc->sc_dev, "could not write to BBP\n");
                return;
        }

        tmp = RT2661_BBP_BUSY | (reg & 0x7f) << 8 | val;
        RAL_WRITE(sc, RT2661_PHY_CSR3, tmp);

        DPRINTFN(sc, 15, "BBP R%u <- 0x%02x\n", reg, val);
}

static uint8_t
rt2661_bbp_read(struct rt2661_softc *sc, uint8_t reg)
{
        uint32_t val;
        int ntries;

        for (ntries = 0; ntries < 100; ntries++) {
                if (!(RAL_READ(sc, RT2661_PHY_CSR3) & RT2661_BBP_BUSY))
                        break;
                DELAY(1);
        }
        if (ntries == 100) {
                device_printf(sc->sc_dev, "could not read from BBP\n");
                return 0;
        }

        val = RT2661_BBP_BUSY | RT2661_BBP_READ | reg << 8;
        RAL_WRITE(sc, RT2661_PHY_CSR3, val);

        for (ntries = 0; ntries < 100; ntries++) {
                val = RAL_READ(sc, RT2661_PHY_CSR3);
                if (!(val & RT2661_BBP_BUSY))
                        return val & 0xff;
                DELAY(1);
        }

        device_printf(sc->sc_dev, "could not read from BBP\n");
        return 0;
}

static void
rt2661_rf_write(struct rt2661_softc *sc, uint8_t reg, uint32_t val)
{
        uint32_t tmp;
        int ntries;

        for (ntries = 0; ntries < 100; ntries++) {
                if (!(RAL_READ(sc, RT2661_PHY_CSR4) & RT2661_RF_BUSY))
                        break;
                DELAY(1);
        }
        if (ntries == 100) {
                device_printf(sc->sc_dev, "could not write to RF\n");
                return;
        }

        tmp = RT2661_RF_BUSY | RT2661_RF_21BIT | (val & 0x1fffff) << 2 |
            (reg & 3);
        RAL_WRITE(sc, RT2661_PHY_CSR4, tmp);

        /* remember last written value in sc */
        sc->rf_regs[reg] = val;

        DPRINTFN(sc, 15, "RF R[%u] <- 0x%05x\n", reg & 3, val & 0x1fffff);
}

static int
rt2661_tx_cmd(struct rt2661_softc *sc, uint8_t cmd, uint16_t arg)
{
        if (RAL_READ(sc, RT2661_H2M_MAILBOX_CSR) & RT2661_H2M_BUSY)
                return EIO;     /* there is already a command pending */

        RAL_WRITE(sc, RT2661_H2M_MAILBOX_CSR,
            RT2661_H2M_BUSY | RT2661_TOKEN_NO_INTR << 16 | arg);

        RAL_WRITE(sc, RT2661_HOST_CMD_CSR, RT2661_KICK_CMD | cmd);

        return 0;
}

static void
rt2661_select_antenna(struct rt2661_softc *sc)
{
        uint8_t bbp4, bbp77;
        uint32_t tmp;

        bbp4  = rt2661_bbp_read(sc,  4);
        bbp77 = rt2661_bbp_read(sc, 77);

        /* TBD */

        /* make sure Rx is disabled before switching antenna */
        tmp = RAL_READ(sc, RT2661_TXRX_CSR0);
        RAL_WRITE(sc, RT2661_TXRX_CSR0, tmp | RT2661_DISABLE_RX);

        rt2661_bbp_write(sc,  4, bbp4);
        rt2661_bbp_write(sc, 77, bbp77);

        /* restore Rx filter */
        RAL_WRITE(sc, RT2661_TXRX_CSR0, tmp);
}

/*
 * Enable multi-rate retries for frames sent at OFDM rates.
 * In 802.11b/g mode, allow fallback to CCK rates.
 */
static void
rt2661_enable_mrr(struct rt2661_softc *sc)
{
        struct ieee80211com *ic = &sc->sc_ic;
        uint32_t tmp;

        tmp = RAL_READ(sc, RT2661_TXRX_CSR4);

        tmp &= ~RT2661_MRR_CCK_FALLBACK;
        if (!IEEE80211_IS_CHAN_5GHZ(ic->ic_bsschan))
                tmp |= RT2661_MRR_CCK_FALLBACK;
        tmp |= RT2661_MRR_ENABLED;

        RAL_WRITE(sc, RT2661_TXRX_CSR4, tmp);
}

static void
rt2661_set_txpreamble(struct rt2661_softc *sc)
{
        struct ieee80211com *ic = &sc->sc_ic;
        uint32_t tmp;

        tmp = RAL_READ(sc, RT2661_TXRX_CSR4);

        tmp &= ~RT2661_SHORT_PREAMBLE;
        if (ic->ic_flags & IEEE80211_F_SHPREAMBLE)
                tmp |= RT2661_SHORT_PREAMBLE;

        RAL_WRITE(sc, RT2661_TXRX_CSR4, tmp);
}

static void
rt2661_set_basicrates(struct rt2661_softc *sc,
    const struct ieee80211_rateset *rs)
{
        struct ieee80211com *ic = &sc->sc_ic;
        uint32_t mask = 0;
        uint8_t rate;
        int i;

        for (i = 0; i < rs->rs_nrates; i++) {
                rate = rs->rs_rates[i];

                if (!(rate & IEEE80211_RATE_BASIC))
                        continue;

                mask |= 1 << ieee80211_legacy_rate_lookup(ic->ic_rt,
                    IEEE80211_RV(rate));
        }

        RAL_WRITE(sc, RT2661_TXRX_CSR5, mask);

        DPRINTF(sc, "Setting basic rate mask to 0x%x\n", mask);
}

/*
 * Reprogram MAC/BBP to switch to a new band.  Values taken from the reference
 * driver.
 */
static void
rt2661_select_band(struct rt2661_softc *sc, struct ieee80211_channel *c)
{
        uint8_t bbp17, bbp35, bbp96, bbp97, bbp98, bbp104;
        uint32_t tmp;

        /* update all BBP registers that depend on the band */
        bbp17 = 0x20; bbp96 = 0x48; bbp104 = 0x2c;
        bbp35 = 0x50; bbp97 = 0x48; bbp98  = 0x48;
        if (IEEE80211_IS_CHAN_5GHZ(c)) {
                bbp17 += 0x08; bbp96 += 0x10; bbp104 += 0x0c;
                bbp35 += 0x10; bbp97 += 0x10; bbp98  += 0x10;
        }
        if ((IEEE80211_IS_CHAN_2GHZ(c) && sc->ext_2ghz_lna) ||
            (IEEE80211_IS_CHAN_5GHZ(c) && sc->ext_5ghz_lna)) {
                bbp17 += 0x10; bbp96 += 0x10; bbp104 += 0x10;
        }

        rt2661_bbp_write(sc,  17, bbp17);
        rt2661_bbp_write(sc,  96, bbp96);
        rt2661_bbp_write(sc, 104, bbp104);

        if ((IEEE80211_IS_CHAN_2GHZ(c) && sc->ext_2ghz_lna) ||
            (IEEE80211_IS_CHAN_5GHZ(c) && sc->ext_5ghz_lna)) {
                rt2661_bbp_write(sc, 75, 0x80);
                rt2661_bbp_write(sc, 86, 0x80);
                rt2661_bbp_write(sc, 88, 0x80);
        }

        rt2661_bbp_write(sc, 35, bbp35);
        rt2661_bbp_write(sc, 97, bbp97);
        rt2661_bbp_write(sc, 98, bbp98);

        tmp = RAL_READ(sc, RT2661_PHY_CSR0);
        tmp &= ~(RT2661_PA_PE_2GHZ | RT2661_PA_PE_5GHZ);
        if (IEEE80211_IS_CHAN_2GHZ(c))
                tmp |= RT2661_PA_PE_2GHZ;
        else
                tmp |= RT2661_PA_PE_5GHZ;
        RAL_WRITE(sc, RT2661_PHY_CSR0, tmp);
}

static void
rt2661_set_chan(struct rt2661_softc *sc, struct ieee80211_channel *c)
{
        struct ieee80211com *ic = &sc->sc_ic;
        const struct rfprog *rfprog;
        uint8_t bbp3, bbp94 = RT2661_BBPR94_DEFAULT;
        int8_t power;
        u_int i, chan;

        chan = ieee80211_chan2ieee(ic, c);
        KASSERT(chan != 0 && chan != IEEE80211_CHAN_ANY, ("chan 0x%x", chan));

        /* select the appropriate RF settings based on what EEPROM says */
        rfprog = (sc->rfprog == 0) ? rt2661_rf5225_1 : rt2661_rf5225_2;

        /* find the settings for this channel (we know it exists) */
        for (i = 0; rfprog[i].chan != chan; i++);

        power = sc->txpow[i];
        if (power < 0) {
                bbp94 += power;
                power = 0;
        } else if (power > 31) {
                bbp94 += power - 31;
                power = 31;
        }

        /*
         * If we are switching from the 2GHz band to the 5GHz band or
         * vice-versa, BBP registers need to be reprogrammed.
         */
        if (c->ic_flags != sc->sc_curchan->ic_flags) {
                rt2661_select_band(sc, c);
                rt2661_select_antenna(sc);
        }
        sc->sc_curchan = c;

        rt2661_rf_write(sc, RAL_RF1, rfprog[i].r1);
        rt2661_rf_write(sc, RAL_RF2, rfprog[i].r2);
        rt2661_rf_write(sc, RAL_RF3, rfprog[i].r3 | power << 7);
        rt2661_rf_write(sc, RAL_RF4, rfprog[i].r4 | sc->rffreq << 10);

        DELAY(200);

        rt2661_rf_write(sc, RAL_RF1, rfprog[i].r1);
        rt2661_rf_write(sc, RAL_RF2, rfprog[i].r2);
        rt2661_rf_write(sc, RAL_RF3, rfprog[i].r3 | power << 7 | 1);
        rt2661_rf_write(sc, RAL_RF4, rfprog[i].r4 | sc->rffreq << 10);

        DELAY(200);

        rt2661_rf_write(sc, RAL_RF1, rfprog[i].r1);
        rt2661_rf_write(sc, RAL_RF2, rfprog[i].r2);
        rt2661_rf_write(sc, RAL_RF3, rfprog[i].r3 | power << 7);
        rt2661_rf_write(sc, RAL_RF4, rfprog[i].r4 | sc->rffreq << 10);

        /* enable smart mode for MIMO-capable RFs */
        bbp3 = rt2661_bbp_read(sc, 3);

        bbp3 &= ~RT2661_SMART_MODE;
        if (sc->rf_rev == RT2661_RF_5325 || sc->rf_rev == RT2661_RF_2529)
                bbp3 |= RT2661_SMART_MODE;

        rt2661_bbp_write(sc, 3, bbp3);

        if (bbp94 != RT2661_BBPR94_DEFAULT)
                rt2661_bbp_write(sc, 94, bbp94);

        /* 5GHz radio needs a 1ms delay here */
        if (IEEE80211_IS_CHAN_5GHZ(c))
                DELAY(1000);
}

static void
rt2661_set_bssid(struct rt2661_softc *sc, const uint8_t *bssid)
{
        uint32_t tmp;

        tmp = bssid[0] | bssid[1] << 8 | bssid[2] << 16 | bssid[3] << 24;
        RAL_WRITE(sc, RT2661_MAC_CSR4, tmp);

        tmp = bssid[4] | bssid[5] << 8 | RT2661_ONE_BSSID << 16;
        RAL_WRITE(sc, RT2661_MAC_CSR5, tmp);
}

static void
rt2661_set_macaddr(struct rt2661_softc *sc, const uint8_t *addr)
{
        uint32_t tmp;

        tmp = addr[0] | addr[1] << 8 | addr[2] << 16 | addr[3] << 24;
        RAL_WRITE(sc, RT2661_MAC_CSR2, tmp);

        tmp = addr[4] | addr[5] << 8;
        RAL_WRITE(sc, RT2661_MAC_CSR3, tmp);
}

static void
rt2661_update_promisc(struct ieee80211com *ic)
{
        struct rt2661_softc *sc = ic->ic_softc;
        uint32_t tmp;

        tmp = RAL_READ(sc, RT2661_TXRX_CSR0);

        tmp &= ~RT2661_DROP_NOT_TO_ME;
        if (ic->ic_promisc == 0)
                tmp |= RT2661_DROP_NOT_TO_ME;

        RAL_WRITE(sc, RT2661_TXRX_CSR0, tmp);

        DPRINTF(sc, "%s promiscuous mode\n",
            (ic->ic_promisc > 0) ?  "entering" : "leaving");
}

/*
 * Update QoS (802.11e) settings for each h/w Tx ring.
 */
static int
rt2661_wme_update(struct ieee80211com *ic)
{
        struct rt2661_softc *sc = ic->ic_softc;
        struct chanAccParams chp;
        const struct wmeParams *wmep;

        ieee80211_wme_ic_getparams(ic, &chp);

        wmep = chp.cap_wmeParams;

        /* XXX: not sure about shifts. */
        /* XXX: the reference driver plays with AC_VI settings too. */

        /* update TxOp */
        RAL_WRITE(sc, RT2661_AC_TXOP_CSR0,
            wmep[WME_AC_BE].wmep_txopLimit << 16 |
            wmep[WME_AC_BK].wmep_txopLimit);
        RAL_WRITE(sc, RT2661_AC_TXOP_CSR1,
            wmep[WME_AC_VI].wmep_txopLimit << 16 |
            wmep[WME_AC_VO].wmep_txopLimit);

        /* update CWmin */
        RAL_WRITE(sc, RT2661_CWMIN_CSR,
            wmep[WME_AC_BE].wmep_logcwmin << 12 |
            wmep[WME_AC_BK].wmep_logcwmin <<  8 |
            wmep[WME_AC_VI].wmep_logcwmin <<  4 |
            wmep[WME_AC_VO].wmep_logcwmin);

        /* update CWmax */
        RAL_WRITE(sc, RT2661_CWMAX_CSR,
            wmep[WME_AC_BE].wmep_logcwmax << 12 |
            wmep[WME_AC_BK].wmep_logcwmax <<  8 |
            wmep[WME_AC_VI].wmep_logcwmax <<  4 |
            wmep[WME_AC_VO].wmep_logcwmax);

        /* update Aifsn */
        RAL_WRITE(sc, RT2661_AIFSN_CSR,
            wmep[WME_AC_BE].wmep_aifsn << 12 |
            wmep[WME_AC_BK].wmep_aifsn <<  8 |
            wmep[WME_AC_VI].wmep_aifsn <<  4 |
            wmep[WME_AC_VO].wmep_aifsn);

        return 0;
}

static void
rt2661_update_slot(struct ieee80211com *ic)
{
        struct rt2661_softc *sc = ic->ic_softc;
        uint8_t slottime;
        uint32_t tmp;

        slottime = IEEE80211_GET_SLOTTIME(ic);

        tmp = RAL_READ(sc, RT2661_MAC_CSR9);
        tmp = (tmp & ~0xff) | slottime;
        RAL_WRITE(sc, RT2661_MAC_CSR9, tmp);
}

static const char *
rt2661_get_rf(int rev)
{
        switch (rev) {
        case RT2661_RF_5225:    return "RT5225";
        case RT2661_RF_5325:    return "RT5325 (MIMO XR)";
        case RT2661_RF_2527:    return "RT2527";
        case RT2661_RF_2529:    return "RT2529 (MIMO XR)";
        default:                return "unknown";
        }
}

static void
rt2661_read_eeprom(struct rt2661_softc *sc, uint8_t macaddr[IEEE80211_ADDR_LEN])
{
        uint16_t val;
        int i;

        /* read MAC address */
        val = rt2661_eeprom_read(sc, RT2661_EEPROM_MAC01);
        macaddr[0] = val & 0xff;
        macaddr[1] = val >> 8;

        val = rt2661_eeprom_read(sc, RT2661_EEPROM_MAC23);
        macaddr[2] = val & 0xff;
        macaddr[3] = val >> 8;

        val = rt2661_eeprom_read(sc, RT2661_EEPROM_MAC45);
        macaddr[4] = val & 0xff;
        macaddr[5] = val >> 8;

        val = rt2661_eeprom_read(sc, RT2661_EEPROM_ANTENNA);
        /* XXX: test if different from 0xffff? */
        sc->rf_rev   = (val >> 11) & 0x1f;
        sc->hw_radio = (val >> 10) & 0x1;
        sc->rx_ant   = (val >> 4)  & 0x3;
        sc->tx_ant   = (val >> 2)  & 0x3;
        sc->nb_ant   = val & 0x3;

        DPRINTF(sc, "RF revision=%d\n", sc->rf_rev);

        val = rt2661_eeprom_read(sc, RT2661_EEPROM_CONFIG2);
        sc->ext_5ghz_lna = (val >> 6) & 0x1;
        sc->ext_2ghz_lna = (val >> 4) & 0x1;

        DPRINTF(sc, "External 2GHz LNA=%d\nExternal 5GHz LNA=%d\n",
            sc->ext_2ghz_lna, sc->ext_5ghz_lna);

        val = rt2661_eeprom_read(sc, RT2661_EEPROM_RSSI_2GHZ_OFFSET);
        if ((val & 0xff) != 0xff)
                sc->rssi_2ghz_corr = (int8_t)(val & 0xff);      /* signed */

        /* Only [-10, 10] is valid */
        if (sc->rssi_2ghz_corr < -10 || sc->rssi_2ghz_corr > 10)
                sc->rssi_2ghz_corr = 0;

        val = rt2661_eeprom_read(sc, RT2661_EEPROM_RSSI_5GHZ_OFFSET);
        if ((val & 0xff) != 0xff)
                sc->rssi_5ghz_corr = (int8_t)(val & 0xff);      /* signed */

        /* Only [-10, 10] is valid */
        if (sc->rssi_5ghz_corr < -10 || sc->rssi_5ghz_corr > 10)
                sc->rssi_5ghz_corr = 0;

        /* adjust RSSI correction for external low-noise amplifier */
        if (sc->ext_2ghz_lna)
                sc->rssi_2ghz_corr -= 14;
        if (sc->ext_5ghz_lna)
                sc->rssi_5ghz_corr -= 14;

        DPRINTF(sc, "RSSI 2GHz corr=%d\nRSSI 5GHz corr=%d\n",
            sc->rssi_2ghz_corr, sc->rssi_5ghz_corr);

        val = rt2661_eeprom_read(sc, RT2661_EEPROM_FREQ_OFFSET);
        if ((val >> 8) != 0xff)
                sc->rfprog = (val >> 8) & 0x3;
        if ((val & 0xff) != 0xff)
                sc->rffreq = val & 0xff;

        DPRINTF(sc, "RF prog=%d\nRF freq=%d\n", sc->rfprog, sc->rffreq);

        /* read Tx power for all a/b/g channels */
        for (i = 0; i < 19; i++) {
                val = rt2661_eeprom_read(sc, RT2661_EEPROM_TXPOWER + i);
                sc->txpow[i * 2] = (int8_t)(val >> 8);          /* signed */
                DPRINTF(sc, "Channel=%d Tx power=%d\n",
                    rt2661_rf5225_1[i * 2].chan, sc->txpow[i * 2]);
                sc->txpow[i * 2 + 1] = (int8_t)(val & 0xff);    /* signed */
                DPRINTF(sc, "Channel=%d Tx power=%d\n",
                    rt2661_rf5225_1[i * 2 + 1].chan, sc->txpow[i * 2 + 1]);
        }

        /* read vendor-specific BBP values */
        for (i = 0; i < 16; i++) {
                val = rt2661_eeprom_read(sc, RT2661_EEPROM_BBP_BASE + i);
                if (val == 0 || val == 0xffff)
                        continue;       /* skip invalid entries */
                sc->bbp_prom[i].reg = val >> 8;
                sc->bbp_prom[i].val = val & 0xff;
                DPRINTF(sc, "BBP R%d=%02x\n", sc->bbp_prom[i].reg,
                    sc->bbp_prom[i].val);
        }
}

static int
rt2661_bbp_init(struct rt2661_softc *sc)
{
        int i, ntries;
        uint8_t val;

        /* wait for BBP to be ready */
        for (ntries = 0; ntries < 100; ntries++) {
                val = rt2661_bbp_read(sc, 0);
                if (val != 0 && val != 0xff)
                        break;
                DELAY(100);
        }
        if (ntries == 100) {
                device_printf(sc->sc_dev, "timeout waiting for BBP\n");
                return EIO;
        }

        /* initialize BBP registers to default values */
        for (i = 0; i < nitems(rt2661_def_bbp); i++) {
                rt2661_bbp_write(sc, rt2661_def_bbp[i].reg,
                    rt2661_def_bbp[i].val);
        }

        /* write vendor-specific BBP values (from EEPROM) */
        for (i = 0; i < 16; i++) {
                if (sc->bbp_prom[i].reg == 0)
                        continue;
                rt2661_bbp_write(sc, sc->bbp_prom[i].reg, sc->bbp_prom[i].val);
        }

        return 0;
}

static void
rt2661_init_locked(struct rt2661_softc *sc)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211vap *vap = TAILQ_FIRST(&ic->ic_vaps);
        uint32_t tmp, sta[3];
        int i, error, ntries;

        RAL_LOCK_ASSERT(sc);

        if ((sc->sc_flags & RAL_FW_LOADED) == 0) {
                error = rt2661_load_microcode(sc);
                if (error != 0) {
                        device_printf(sc->sc_dev,
                            "%s: could not load 8051 microcode, error %d\n",
                            __func__, error);
                        return;
                }
                sc->sc_flags |= RAL_FW_LOADED;
        }

        rt2661_stop_locked(sc);

        /* initialize Tx rings */
        RAL_WRITE(sc, RT2661_AC1_BASE_CSR, sc->txq[1].physaddr);
        RAL_WRITE(sc, RT2661_AC0_BASE_CSR, sc->txq[0].physaddr);
        RAL_WRITE(sc, RT2661_AC2_BASE_CSR, sc->txq[2].physaddr);
        RAL_WRITE(sc, RT2661_AC3_BASE_CSR, sc->txq[3].physaddr);

        /* initialize Mgt ring */
        RAL_WRITE(sc, RT2661_MGT_BASE_CSR, sc->mgtq.physaddr);

        /* initialize Rx ring */
        RAL_WRITE(sc, RT2661_RX_BASE_CSR, sc->rxq.physaddr);

        /* initialize Tx rings sizes */
        RAL_WRITE(sc, RT2661_TX_RING_CSR0,
            RT2661_TX_RING_COUNT << 24 |
            RT2661_TX_RING_COUNT << 16 |
            RT2661_TX_RING_COUNT <<  8 |
            RT2661_TX_RING_COUNT);

        RAL_WRITE(sc, RT2661_TX_RING_CSR1,
            RT2661_TX_DESC_WSIZE << 16 |
            RT2661_TX_RING_COUNT <<  8 |        /* XXX: HCCA ring unused */
            RT2661_MGT_RING_COUNT);

        /* initialize Rx rings */
        RAL_WRITE(sc, RT2661_RX_RING_CSR,
            RT2661_RX_DESC_BACK  << 16 |
            RT2661_RX_DESC_WSIZE <<  8 |
            RT2661_RX_RING_COUNT);

        /* XXX: some magic here */
        RAL_WRITE(sc, RT2661_TX_DMA_DST_CSR, 0xaa);

        /* load base addresses of all 5 Tx rings (4 data + 1 mgt) */
        RAL_WRITE(sc, RT2661_LOAD_TX_RING_CSR, 0x1f);

        /* load base address of Rx ring */
        RAL_WRITE(sc, RT2661_RX_CNTL_CSR, 2);

        /* initialize MAC registers to default values */
        for (i = 0; i < nitems(rt2661_def_mac); i++)
                RAL_WRITE(sc, rt2661_def_mac[i].reg, rt2661_def_mac[i].val);

        rt2661_set_macaddr(sc, vap ? vap->iv_myaddr : ic->ic_macaddr);

        /* set host ready */
        RAL_WRITE(sc, RT2661_MAC_CSR1, 3);
        RAL_WRITE(sc, RT2661_MAC_CSR1, 0);

        /* wait for BBP/RF to wakeup */
        for (ntries = 0; ntries < 1000; ntries++) {
                if (RAL_READ(sc, RT2661_MAC_CSR12) & 8)
                        break;
                DELAY(1000);
        }
        if (ntries == 1000) {
                printf("timeout waiting for BBP/RF to wakeup\n");
                rt2661_stop_locked(sc);
                return;
        }

        if (rt2661_bbp_init(sc) != 0) {
                rt2661_stop_locked(sc);
                return;
        }

        /* select default channel */
        sc->sc_curchan = ic->ic_curchan;
        rt2661_select_band(sc, sc->sc_curchan);
        rt2661_select_antenna(sc);
        rt2661_set_chan(sc, sc->sc_curchan);

        /* update Rx filter */
        tmp = RAL_READ(sc, RT2661_TXRX_CSR0) & 0xffff;

        tmp |= RT2661_DROP_PHY_ERROR | RT2661_DROP_CRC_ERROR;
        if (ic->ic_opmode != IEEE80211_M_MONITOR) {
                tmp |= RT2661_DROP_CTL | RT2661_DROP_VER_ERROR |
                       RT2661_DROP_ACKCTS;
                if (ic->ic_opmode != IEEE80211_M_HOSTAP &&
                    ic->ic_opmode != IEEE80211_M_MBSS)
                        tmp |= RT2661_DROP_TODS;
                if (ic->ic_promisc == 0)
                        tmp |= RT2661_DROP_NOT_TO_ME;
        }

        RAL_WRITE(sc, RT2661_TXRX_CSR0, tmp);

        /* clear STA registers */
        RAL_READ_REGION_4(sc, RT2661_STA_CSR0, sta, nitems(sta));

        /* initialize ASIC */
        RAL_WRITE(sc, RT2661_MAC_CSR1, 4);

        /* clear any pending interrupt */
        RAL_WRITE(sc, RT2661_INT_SOURCE_CSR, 0xffffffff);

        /* enable interrupts */
        RAL_WRITE(sc, RT2661_INT_MASK_CSR, 0x0000ff10);
        RAL_WRITE(sc, RT2661_MCU_INT_MASK_CSR, 0);

        /* kick Rx */
        RAL_WRITE(sc, RT2661_RX_CNTL_CSR, 1);

        sc->sc_flags |= RAL_RUNNING;

        callout_reset(&sc->watchdog_ch, hz, rt2661_watchdog, sc);
}

static void
rt2661_init(void *priv)
{
        struct rt2661_softc *sc = priv;
        struct ieee80211com *ic = &sc->sc_ic;

        RAL_LOCK(sc);
        rt2661_init_locked(sc);
        RAL_UNLOCK(sc);

        if (sc->sc_flags & RAL_RUNNING)
                ieee80211_start_all(ic);                /* start all vap's */
}

void
rt2661_stop_locked(struct rt2661_softc *sc)
{
        volatile int *flags = &sc->sc_flags;
        uint32_t tmp;

        while (*flags & RAL_INPUT_RUNNING)
                msleep(sc, &sc->sc_mtx, 0, "ralrunning", hz/10);

        callout_stop(&sc->watchdog_ch);
        sc->sc_tx_timer = 0;

        if (sc->sc_flags & RAL_RUNNING) {
                sc->sc_flags &= ~RAL_RUNNING;

                /* abort Tx (for all 5 Tx rings) */
                RAL_WRITE(sc, RT2661_TX_CNTL_CSR, 0x1f << 16);
                
                /* disable Rx (value remains after reset!) */
                tmp = RAL_READ(sc, RT2661_TXRX_CSR0);
                RAL_WRITE(sc, RT2661_TXRX_CSR0, tmp | RT2661_DISABLE_RX);
                
                /* reset ASIC */
                RAL_WRITE(sc, RT2661_MAC_CSR1, 3);
                RAL_WRITE(sc, RT2661_MAC_CSR1, 0);
                
                /* disable interrupts */
                RAL_WRITE(sc, RT2661_INT_MASK_CSR, 0xffffffff);
                RAL_WRITE(sc, RT2661_MCU_INT_MASK_CSR, 0xffffffff);
                
                /* clear any pending interrupt */
                RAL_WRITE(sc, RT2661_INT_SOURCE_CSR, 0xffffffff);
                RAL_WRITE(sc, RT2661_MCU_INT_SOURCE_CSR, 0xffffffff);
                
                /* reset Tx and Rx rings */
                rt2661_reset_tx_ring(sc, &sc->txq[0]);
                rt2661_reset_tx_ring(sc, &sc->txq[1]);
                rt2661_reset_tx_ring(sc, &sc->txq[2]);
                rt2661_reset_tx_ring(sc, &sc->txq[3]);
                rt2661_reset_tx_ring(sc, &sc->mgtq);
                rt2661_reset_rx_ring(sc, &sc->rxq);
        }
}

void
rt2661_stop(void *priv)
{
        struct rt2661_softc *sc = priv;

        RAL_LOCK(sc);
        rt2661_stop_locked(sc);
        RAL_UNLOCK(sc);
}

static int
rt2661_load_microcode(struct rt2661_softc *sc)
{
        const struct firmware *fp;
        const char *imagename;
        int ntries, error;

        RAL_LOCK_ASSERT(sc);

        switch (sc->sc_id) {
        case 0x0301: imagename = "rt2561sfw"; break;
        case 0x0302: imagename = "rt2561fw"; break;
        case 0x0401: imagename = "rt2661fw"; break;
        default:
                device_printf(sc->sc_dev, "%s: unexpected pci device id 0x%x, "
                    "don't know how to retrieve firmware\n",
                    __func__, sc->sc_id);
                return EINVAL;
        }
        RAL_UNLOCK(sc);
        fp = firmware_get(imagename);
        RAL_LOCK(sc);
        if (fp == NULL) {
                device_printf(sc->sc_dev,
                    "%s: unable to retrieve firmware image %s\n",
                    __func__, imagename);
                return EINVAL;
        }

        /*
         * Load 8051 microcode into NIC.
         */
        /* reset 8051 */
        RAL_WRITE(sc, RT2661_MCU_CNTL_CSR, RT2661_MCU_RESET);

        /* cancel any pending Host to MCU command */
        RAL_WRITE(sc, RT2661_H2M_MAILBOX_CSR, 0);
        RAL_WRITE(sc, RT2661_M2H_CMD_DONE_CSR, 0xffffffff);
        RAL_WRITE(sc, RT2661_HOST_CMD_CSR, 0);

        /* write 8051's microcode */
        RAL_WRITE(sc, RT2661_MCU_CNTL_CSR, RT2661_MCU_RESET | RT2661_MCU_SEL);
        RAL_WRITE_REGION_1(sc, RT2661_MCU_CODE_BASE, fp->data, fp->datasize);
        RAL_WRITE(sc, RT2661_MCU_CNTL_CSR, RT2661_MCU_RESET);

        /* kick 8051's ass */
        RAL_WRITE(sc, RT2661_MCU_CNTL_CSR, 0);

        /* wait for 8051 to initialize */
        for (ntries = 0; ntries < 500; ntries++) {
                if (RAL_READ(sc, RT2661_MCU_CNTL_CSR) & RT2661_MCU_READY)
                        break;
                DELAY(100);
        }
        if (ntries == 500) {
                device_printf(sc->sc_dev,
                    "%s: timeout waiting for MCU to initialize\n", __func__);
                error = EIO;
        } else
                error = 0;

        firmware_put(fp, FIRMWARE_UNLOAD);
        return error;
}

#ifdef notyet
/*
 * Dynamically tune Rx sensitivity (BBP register 17) based on average RSSI and
 * false CCA count.  This function is called periodically (every seconds) when
 * in the RUN state.  Values taken from the reference driver.
 */
static void
rt2661_rx_tune(struct rt2661_softc *sc)
{
        uint8_t bbp17;
        uint16_t cca;
        int lo, hi, dbm;

        /*
         * Tuning range depends on operating band and on the presence of an
         * external low-noise amplifier.
         */
        lo = 0x20;
        if (IEEE80211_IS_CHAN_5GHZ(sc->sc_curchan))
                lo += 0x08;
        if ((IEEE80211_IS_CHAN_2GHZ(sc->sc_curchan) && sc->ext_2ghz_lna) ||
            (IEEE80211_IS_CHAN_5GHZ(sc->sc_curchan) && sc->ext_5ghz_lna))
                lo += 0x10;
        hi = lo + 0x20;

        /* retrieve false CCA count since last call (clear on read) */
        cca = RAL_READ(sc, RT2661_STA_CSR1) & 0xffff;

        if (dbm >= -35) {
                bbp17 = 0x60;
        } else if (dbm >= -58) {
                bbp17 = hi;
        } else if (dbm >= -66) {
                bbp17 = lo + 0x10;
        } else if (dbm >= -74) {
                bbp17 = lo + 0x08;
        } else {
                /* RSSI < -74dBm, tune using false CCA count */

                bbp17 = sc->bbp17; /* current value */

                hi -= 2 * (-74 - dbm);
                if (hi < lo)
                        hi = lo;

                if (bbp17 > hi) {
                        bbp17 = hi;

                } else if (cca > 512) {
                        if (++bbp17 > hi)
                                bbp17 = hi;
                } else if (cca < 100) {
                        if (--bbp17 < lo)
                                bbp17 = lo;
                }
        }

        if (bbp17 != sc->bbp17) {
                rt2661_bbp_write(sc, 17, bbp17);
                sc->bbp17 = bbp17;
        }
}

/*
 * Enter/Leave radar detection mode.
 * This is for 802.11h additional regulatory domains.
 */
static void
rt2661_radar_start(struct rt2661_softc *sc)
{
        uint32_t tmp;

        /* disable Rx */
        tmp = RAL_READ(sc, RT2661_TXRX_CSR0);
        RAL_WRITE(sc, RT2661_TXRX_CSR0, tmp | RT2661_DISABLE_RX);

        rt2661_bbp_write(sc, 82, 0x20);
        rt2661_bbp_write(sc, 83, 0x00);
        rt2661_bbp_write(sc, 84, 0x40);

        /* save current BBP registers values */
        sc->bbp18 = rt2661_bbp_read(sc, 18);
        sc->bbp21 = rt2661_bbp_read(sc, 21);
        sc->bbp22 = rt2661_bbp_read(sc, 22);
        sc->bbp16 = rt2661_bbp_read(sc, 16);
        sc->bbp17 = rt2661_bbp_read(sc, 17);
        sc->bbp64 = rt2661_bbp_read(sc, 64);

        rt2661_bbp_write(sc, 18, 0xff);
        rt2661_bbp_write(sc, 21, 0x3f);
        rt2661_bbp_write(sc, 22, 0x3f);
        rt2661_bbp_write(sc, 16, 0xbd);
        rt2661_bbp_write(sc, 17, sc->ext_5ghz_lna ? 0x44 : 0x34);
        rt2661_bbp_write(sc, 64, 0x21);

        /* restore Rx filter */
        RAL_WRITE(sc, RT2661_TXRX_CSR0, tmp);
}

static int
rt2661_radar_stop(struct rt2661_softc *sc)
{
        uint8_t bbp66;

        /* read radar detection result */
        bbp66 = rt2661_bbp_read(sc, 66);

        /* restore BBP registers values */
        rt2661_bbp_write(sc, 16, sc->bbp16);
        rt2661_bbp_write(sc, 17, sc->bbp17);
        rt2661_bbp_write(sc, 18, sc->bbp18);
        rt2661_bbp_write(sc, 21, sc->bbp21);
        rt2661_bbp_write(sc, 22, sc->bbp22);
        rt2661_bbp_write(sc, 64, sc->bbp64);

        return bbp66 == 1;
}
#endif

static int
rt2661_prepare_beacon(struct rt2661_softc *sc, struct ieee80211vap *vap)
{
        struct ieee80211com *ic = vap->iv_ic;
        struct rt2661_tx_desc desc;
        struct mbuf *m0;
        int rate;

        if ((m0 = ieee80211_beacon_alloc(vap->iv_bss))== NULL) {
                device_printf(sc->sc_dev, "could not allocate beacon frame\n");
                return ENOBUFS;
        }

        /* send beacons at the lowest available rate */
        rate = IEEE80211_IS_CHAN_5GHZ(ic->ic_bsschan) ? 12 : 2;

        rt2661_setup_tx_desc(sc, &desc, RT2661_TX_TIMESTAMP, RT2661_TX_HWSEQ,
            m0->m_pkthdr.len, rate, NULL, 0, RT2661_QID_MGT);

        /* copy the first 24 bytes of Tx descriptor into NIC memory */
        RAL_WRITE_REGION_1(sc, RT2661_HW_BEACON_BASE0, (uint8_t *)&desc, 24);

        /* copy beacon header and payload into NIC memory */
        RAL_WRITE_REGION_1(sc, RT2661_HW_BEACON_BASE0 + 24,
            mtod(m0, uint8_t *), m0->m_pkthdr.len);

        m_freem(m0);

        return 0;
}

/*
 * Enable TSF synchronization and tell h/w to start sending beacons for IBSS
 * and HostAP operating modes.
 */
static void
rt2661_enable_tsf_sync(struct rt2661_softc *sc)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211vap *vap = TAILQ_FIRST(&ic->ic_vaps);
        uint32_t tmp;

        if (vap->iv_opmode != IEEE80211_M_STA) {
                /*
                 * Change default 16ms TBTT adjustment to 8ms.
                 * Must be done before enabling beacon generation.
                 */
                RAL_WRITE(sc, RT2661_TXRX_CSR10, 1 << 12 | 8);
        }

        tmp = RAL_READ(sc, RT2661_TXRX_CSR9) & 0xff000000;

        /* set beacon interval (in 1/16ms unit) */
        tmp |= vap->iv_bss->ni_intval * 16;

        tmp |= RT2661_TSF_TICKING | RT2661_ENABLE_TBTT;
        if (vap->iv_opmode == IEEE80211_M_STA)
                tmp |= RT2661_TSF_MODE(1);
        else
                tmp |= RT2661_TSF_MODE(2) | RT2661_GENERATE_BEACON;

        RAL_WRITE(sc, RT2661_TXRX_CSR9, tmp);
}

static void
rt2661_enable_tsf(struct rt2661_softc *sc)
{
        RAL_WRITE(sc, RT2661_TXRX_CSR9, 
              (RAL_READ(sc, RT2661_TXRX_CSR9) & 0xff000000)
            | RT2661_TSF_TICKING | RT2661_TSF_MODE(2));
}

/*
 * Retrieve the "Received Signal Strength Indicator" from the raw values
 * contained in Rx descriptors.  The computation depends on which band the
 * frame was received.  Correction values taken from the reference driver.
 */
static int
rt2661_get_rssi(struct rt2661_softc *sc, uint8_t raw)
{
        int lna, agc, rssi;

        lna = (raw >> 5) & 0x3;
        agc = raw & 0x1f;

        if (lna == 0) {
                /*
                 * No mapping available.
                 *
                 * NB: Since RSSI is relative to noise floor, -1 is
                 *     adequate for caller to know error happened.
                 */
                return -1;
        }

        rssi = (2 * agc) - RT2661_NOISE_FLOOR;

        if (IEEE80211_IS_CHAN_2GHZ(sc->sc_curchan)) {
                rssi += sc->rssi_2ghz_corr;

                if (lna == 1)
                        rssi -= 64;
                else if (lna == 2)
                        rssi -= 74;
                else if (lna == 3)
                        rssi -= 90;
        } else {
                rssi += sc->rssi_5ghz_corr;

                if (lna == 1)
                        rssi -= 64;
                else if (lna == 2)
                        rssi -= 86;
                else if (lna == 3)
                        rssi -= 100;
        }
        return rssi;
}

static void
rt2661_scan_start(struct ieee80211com *ic)
{
        struct rt2661_softc *sc = ic->ic_softc;
        uint32_t tmp;

        /* abort TSF synchronization */
        tmp = RAL_READ(sc, RT2661_TXRX_CSR9);
        RAL_WRITE(sc, RT2661_TXRX_CSR9, tmp & ~0xffffff);
        rt2661_set_bssid(sc, ieee80211broadcastaddr);
}

static void
rt2661_scan_end(struct ieee80211com *ic)
{
        struct rt2661_softc *sc = ic->ic_softc;
        struct ieee80211vap *vap = TAILQ_FIRST(&ic->ic_vaps);

        rt2661_enable_tsf_sync(sc);
        /* XXX keep local copy */
        rt2661_set_bssid(sc, vap->iv_bss->ni_bssid);
}

static void
rt2661_getradiocaps(struct ieee80211com *ic,
    int maxchans, int *nchans, struct ieee80211_channel chans[])
{
        struct rt2661_softc *sc = ic->ic_softc;
        uint8_t bands[IEEE80211_MODE_BYTES];

        memset(bands, 0, sizeof(bands));
        setbit(bands, IEEE80211_MODE_11B);
        setbit(bands, IEEE80211_MODE_11G);
        ieee80211_add_channels_default_2ghz(chans, maxchans, nchans, bands, 0);

        if (sc->rf_rev == RT2661_RF_5225 || sc->rf_rev == RT2661_RF_5325) {
                setbit(bands, IEEE80211_MODE_11A);
                ieee80211_add_channel_list_5ghz(chans, maxchans, nchans,
                    rt2661_chan_5ghz, nitems(rt2661_chan_5ghz), bands, 0);
        }
}

static void
rt2661_set_channel(struct ieee80211com *ic)
{
        struct rt2661_softc *sc = ic->ic_softc;

        RAL_LOCK(sc);
        rt2661_set_chan(sc, ic->ic_curchan);
        RAL_UNLOCK(sc);

}