/*      $OpenBSD: if_upgt.c,v 1.35 2008/04/16 18:32:15 damien Exp $ */

/*
 * Copyright (c) 2007 Marcus Glocker <mglocker@openbsd.org>
 *
 * 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 "opt_wlan.h"

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

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_phy.h>
#include <net80211/ieee80211_radiotap.h>
#include <net80211/ieee80211_regdomain.h>

#include <net/bpf.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include "usbdevs.h"

#include <dev/usb/wlan/if_upgtvar.h>

/*
 * Driver for the USB PrismGT devices.
 *
 * For now just USB 2.0 devices with the GW3887 chipset are supported.
 * The driver has been written based on the firmware version 2.13.1.0_LM87.
 *
 * TODO's:
 * - MONITOR mode test.
 * - Add HOSTAP mode.
 * - Add IBSS mode.
 * - Support the USB 1.0 devices (NET2280, ISL3880, ISL3886 chipsets).
 *
 * Parts of this driver has been influenced by reading the p54u driver
 * written by Jean-Baptiste Note <jean-baptiste.note@m4x.org> and
 * Sebastien Bourdeauducq <lekernel@prism54.org>.
 */

static SYSCTL_NODE(_hw, OID_AUTO, upgt, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
    "USB PrismGT GW3887 driver parameters");

#ifdef UPGT_DEBUG
int upgt_debug = 0;
SYSCTL_INT(_hw_upgt, OID_AUTO, debug, CTLFLAG_RWTUN, &upgt_debug,
            0, "control debugging printfs");
enum {
        UPGT_DEBUG_XMIT         = 0x00000001,   /* basic xmit operation */
        UPGT_DEBUG_RECV         = 0x00000002,   /* basic recv operation */
        UPGT_DEBUG_RESET        = 0x00000004,   /* reset processing */
        UPGT_DEBUG_INTR         = 0x00000008,   /* INTR */
        UPGT_DEBUG_TX_PROC      = 0x00000010,   /* tx ISR proc */
        UPGT_DEBUG_RX_PROC      = 0x00000020,   /* rx ISR proc */
        UPGT_DEBUG_STATE        = 0x00000040,   /* 802.11 state transitions */
        UPGT_DEBUG_STAT         = 0x00000080,   /* statistic */
        UPGT_DEBUG_FW           = 0x00000100,   /* firmware */
        UPGT_DEBUG_ANY          = 0xffffffff
};
#define DPRINTF(sc, m, fmt, ...) do {                           \
        if (sc->sc_debug & (m))                                 \
                printf(fmt, __VA_ARGS__);                       \
} while (0)
#else
#define DPRINTF(sc, m, fmt, ...) do {                           \
        (void) sc;                                              \
} while (0)
#endif

/*
 * Prototypes.
 */
static device_probe_t upgt_match;
static device_attach_t upgt_attach;
static device_detach_t upgt_detach;
static int      upgt_alloc_tx(struct upgt_softc *);
static int      upgt_alloc_rx(struct upgt_softc *);
static int      upgt_device_reset(struct upgt_softc *);
static void     upgt_bulk_tx(struct upgt_softc *, struct upgt_data *);
static int      upgt_fw_verify(struct upgt_softc *);
static int      upgt_mem_init(struct upgt_softc *);
static int      upgt_fw_load(struct upgt_softc *);
static int      upgt_fw_copy(const uint8_t *, char *, int);
static uint32_t upgt_crc32_le(const void *, size_t);
static struct mbuf *
                upgt_rxeof(struct usb_xfer *, struct upgt_data *, int *);
static struct mbuf *
                upgt_rx(struct upgt_softc *, uint8_t *, int, int *);
static void     upgt_txeof(struct usb_xfer *, struct upgt_data *);
static int      upgt_eeprom_read(struct upgt_softc *);
static int      upgt_eeprom_parse(struct upgt_softc *);
static void     upgt_eeprom_parse_hwrx(struct upgt_softc *, uint8_t *);
static void     upgt_eeprom_parse_freq3(struct upgt_softc *, uint8_t *, int);
static void     upgt_eeprom_parse_freq4(struct upgt_softc *, uint8_t *, int);
static void     upgt_eeprom_parse_freq6(struct upgt_softc *, uint8_t *, int);
static uint32_t upgt_chksum_le(const uint32_t *, size_t);
static void     upgt_tx_done(struct upgt_softc *, uint8_t *);
static void     upgt_init(struct upgt_softc *);
static void     upgt_parent(struct ieee80211com *);
static int      upgt_transmit(struct ieee80211com *, struct mbuf *);
static void     upgt_start(struct upgt_softc *);
static int      upgt_raw_xmit(struct ieee80211_node *, struct mbuf *,
                    const struct ieee80211_bpf_params *);
static void     upgt_scan_start(struct ieee80211com *);
static void     upgt_scan_end(struct ieee80211com *);
static void     upgt_set_channel(struct ieee80211com *);
static struct ieee80211vap *upgt_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     upgt_vap_delete(struct ieee80211vap *);
static void     upgt_update_mcast(struct ieee80211com *);
static uint8_t  upgt_rx_rate(struct upgt_softc *, const int);
static void     upgt_set_multi(void *);
static void     upgt_stop(struct upgt_softc *);
static void     upgt_setup_rates(struct ieee80211vap *, struct ieee80211com *);
static int      upgt_set_macfilter(struct upgt_softc *, uint8_t);
static int      upgt_newstate(struct ieee80211vap *, enum ieee80211_state, int);
static void     upgt_set_chan(struct upgt_softc *, struct ieee80211_channel *);
static void     upgt_set_led(struct upgt_softc *, int);
static void     upgt_set_led_blink(void *);
static void     upgt_get_stats(struct upgt_softc *);
static void     upgt_mem_free(struct upgt_softc *, uint32_t);
static uint32_t upgt_mem_alloc(struct upgt_softc *);
static void     upgt_free_tx(struct upgt_softc *);
static void     upgt_free_rx(struct upgt_softc *);
static void     upgt_watchdog(void *);
static void     upgt_abort_xfers(struct upgt_softc *);
static void     upgt_abort_xfers_locked(struct upgt_softc *);
static void     upgt_sysctl_node(struct upgt_softc *);
static struct upgt_data *
                upgt_getbuf(struct upgt_softc *);
static struct upgt_data *
                upgt_gettxbuf(struct upgt_softc *);
static int      upgt_tx_start(struct upgt_softc *, struct mbuf *,
                    struct ieee80211_node *, struct upgt_data *);

static const char *upgt_fwname = "upgt-gw3887";

static const STRUCT_USB_HOST_ID upgt_devs[] = {
#define UPGT_DEV(v,p) { USB_VP(USB_VENDOR_##v, USB_PRODUCT_##v##_##p) }
        /* version 2 devices */
        UPGT_DEV(ACCTON,        PRISM_GT),
        UPGT_DEV(BELKIN,        F5D7050),
        UPGT_DEV(CISCOLINKSYS,  WUSB54AG),
        UPGT_DEV(CONCEPTRONIC,  PRISM_GT),
        UPGT_DEV(DELL,          PRISM_GT_1),
        UPGT_DEV(DELL,          PRISM_GT_2),
        UPGT_DEV(FSC,           E5400),
        UPGT_DEV(GLOBESPAN,     PRISM_GT_1),
        UPGT_DEV(GLOBESPAN,     PRISM_GT_2),
        UPGT_DEV(NETGEAR,       WG111V1_2),
        UPGT_DEV(INTERSIL,      PRISM_GT),
        UPGT_DEV(SMC,           2862WG),
        UPGT_DEV(USR,           USR5422),
        UPGT_DEV(WISTRONNEWEB,  UR045G),
        UPGT_DEV(XYRATEX,       PRISM_GT_1),
        UPGT_DEV(XYRATEX,       PRISM_GT_2),
        UPGT_DEV(ZCOM,          XG703A),
        UPGT_DEV(ZCOM,          XM142)
};

static usb_callback_t upgt_bulk_rx_callback;
static usb_callback_t upgt_bulk_tx_callback;

static const struct usb_config upgt_config[UPGT_N_XFERS] = {
        [UPGT_BULK_TX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_OUT,
                .bufsize = MCLBYTES * UPGT_TX_MAXCOUNT,
                .flags = {
                        .force_short_xfer = 1,
                        .pipe_bof = 1
                },
                .callback = upgt_bulk_tx_callback,
                .timeout = UPGT_USB_TIMEOUT,    /* ms */
        },
        [UPGT_BULK_RX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .bufsize = MCLBYTES * UPGT_RX_MAXCOUNT,
                .flags = {
                        .pipe_bof = 1,
                        .short_xfer_ok = 1
                },
                .callback = upgt_bulk_rx_callback,
        },
};

static int
upgt_match(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);

        if (uaa->usb_mode != USB_MODE_HOST)
                return (ENXIO);
        if (uaa->info.bConfigIndex != UPGT_CONFIG_INDEX)
                return (ENXIO);
        if (uaa->info.bIfaceIndex != UPGT_IFACE_INDEX)
                return (ENXIO);

        return (usbd_lookup_id_by_uaa(upgt_devs, sizeof(upgt_devs), uaa));
}

static int
upgt_attach(device_t dev)
{
        struct upgt_softc *sc = device_get_softc(dev);
        struct ieee80211com *ic = &sc->sc_ic;
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        uint8_t bands[IEEE80211_MODE_BYTES];
        uint8_t iface_index = UPGT_IFACE_INDEX;
        int error;

        sc->sc_dev = dev;
        sc->sc_udev = uaa->device;
#ifdef UPGT_DEBUG
        sc->sc_debug = upgt_debug;
#endif
        device_set_usb_desc(dev);

        mtx_init(&sc->sc_mtx, device_get_nameunit(sc->sc_dev), MTX_NETWORK_LOCK,
            MTX_DEF);
        callout_init(&sc->sc_led_ch, 0);
        callout_init(&sc->sc_watchdog_ch, 0);
        mbufq_init(&sc->sc_snd, ifqmaxlen);

        error = usbd_transfer_setup(uaa->device, &iface_index, sc->sc_xfer,
            upgt_config, UPGT_N_XFERS, sc, &sc->sc_mtx);
        if (error) {
                device_printf(dev, "could not allocate USB transfers, "
                    "err=%s\n", usbd_errstr(error));
                goto fail1;
        }

        sc->sc_rx_dma_buf = usbd_xfer_get_frame_buffer(
            sc->sc_xfer[UPGT_BULK_RX], 0);
        sc->sc_tx_dma_buf = usbd_xfer_get_frame_buffer(
            sc->sc_xfer[UPGT_BULK_TX], 0);

        /* Setup TX and RX buffers */
        error = upgt_alloc_tx(sc);
        if (error)
                goto fail2;
        error = upgt_alloc_rx(sc);
        if (error)
                goto fail3;

        /* Initialize the device.  */
        error = upgt_device_reset(sc);
        if (error)
                goto fail4;
        /* Verify the firmware.  */
        error = upgt_fw_verify(sc);
        if (error)
                goto fail4;
        /* Calculate device memory space.  */
        if (sc->sc_memaddr_frame_start == 0 || sc->sc_memaddr_frame_end == 0) {
                device_printf(dev,
                    "could not find memory space addresses on FW\n");
                error = EIO;
                goto fail4;
        }
        sc->sc_memaddr_frame_end -= UPGT_MEMSIZE_RX + 1;
        sc->sc_memaddr_rx_start = sc->sc_memaddr_frame_end + 1;

        DPRINTF(sc, UPGT_DEBUG_FW, "memory address frame start=0x%08x\n",
            sc->sc_memaddr_frame_start);
        DPRINTF(sc, UPGT_DEBUG_FW, "memory address frame end=0x%08x\n",
            sc->sc_memaddr_frame_end);
        DPRINTF(sc, UPGT_DEBUG_FW, "memory address rx start=0x%08x\n",
            sc->sc_memaddr_rx_start);

        upgt_mem_init(sc);

        /* Load the firmware.  */
        error = upgt_fw_load(sc);
        if (error)
                goto fail4;

        /* Read the whole EEPROM content and parse it.  */
        error = upgt_eeprom_read(sc);
        if (error)
                goto fail4;
        error = upgt_eeprom_parse(sc);
        if (error)
                goto fail4;

        /* all works related with the device have done here. */
        upgt_abort_xfers(sc);

        ic->ic_softc = sc;
        ic->ic_name = device_get_nameunit(dev);
        ic->ic_phytype = IEEE80211_T_OFDM;      /* not only, but not used */
        ic->ic_opmode = IEEE80211_M_STA;
        /* set device capabilities */
        ic->ic_caps =
                  IEEE80211_C_STA               /* station mode */
                | IEEE80211_C_MONITOR           /* monitor mode */
                | IEEE80211_C_SHPREAMBLE        /* short preamble supported */
                | IEEE80211_C_SHSLOT            /* short slot time supported */
                | IEEE80211_C_BGSCAN            /* capable of bg scanning */
                | IEEE80211_C_WPA               /* 802.11i */
                ;

        memset(bands, 0, sizeof(bands));
        setbit(bands, IEEE80211_MODE_11B);
        setbit(bands, IEEE80211_MODE_11G);
        ieee80211_init_channels(ic, NULL, bands);

        ieee80211_ifattach(ic);
        ic->ic_raw_xmit = upgt_raw_xmit;
        ic->ic_scan_start = upgt_scan_start;
        ic->ic_scan_end = upgt_scan_end;
        ic->ic_set_channel = upgt_set_channel;
        ic->ic_vap_create = upgt_vap_create;
        ic->ic_vap_delete = upgt_vap_delete;
        ic->ic_update_mcast = upgt_update_mcast;
        ic->ic_transmit = upgt_transmit;
        ic->ic_parent = upgt_parent;

        ic->ic_flags_ext |= IEEE80211_FEXT_SEQNO_OFFLOAD;

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

        upgt_sysctl_node(sc);

        if (bootverbose)
                ieee80211_announce(ic);

        return (0);

fail4:  upgt_free_rx(sc);
fail3:  upgt_free_tx(sc);
fail2:  usbd_transfer_unsetup(sc->sc_xfer, UPGT_N_XFERS);
fail1:  mtx_destroy(&sc->sc_mtx);

        return (error);
}

static void
upgt_txeof(struct usb_xfer *xfer, struct upgt_data *data)
{

        if (data->m) {
                /* XXX status? */
                ieee80211_tx_complete(data->ni, data->m, 0);
                data->m = NULL;
                data->ni = NULL;
        }
}

static void
upgt_get_stats(struct upgt_softc *sc)
{
        struct upgt_data *data_cmd;
        struct upgt_lmac_mem *mem;
        struct upgt_lmac_stats *stats;

        data_cmd = upgt_getbuf(sc);
        if (data_cmd == NULL) {
                device_printf(sc->sc_dev, "%s: out of buffers.\n", __func__);
                return;
        }

        /*
         * Transmit the URB containing the CMD data.
         */
        memset(data_cmd->buf, 0, MCLBYTES);

        mem = (struct upgt_lmac_mem *)data_cmd->buf;
        mem->addr = htole32(sc->sc_memaddr_frame_start +
            UPGT_MEMSIZE_FRAME_HEAD);

        stats = (struct upgt_lmac_stats *)(mem + 1);

        stats->header1.flags = 0;
        stats->header1.type = UPGT_H1_TYPE_CTRL;
        stats->header1.len = htole16(
            sizeof(struct upgt_lmac_stats) - sizeof(struct upgt_lmac_header));

        stats->header2.reqid = htole32(sc->sc_memaddr_frame_start);
        stats->header2.type = htole16(UPGT_H2_TYPE_STATS);
        stats->header2.flags = 0;

        data_cmd->buflen = sizeof(*mem) + sizeof(*stats);

        mem->chksum = upgt_chksum_le((uint32_t *)stats,
            data_cmd->buflen - sizeof(*mem));

        upgt_bulk_tx(sc, data_cmd);
}

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

        UPGT_LOCK(sc);
        if (sc->sc_flags & UPGT_FLAG_DETACHED) {
                UPGT_UNLOCK(sc);
                return;
        }
        if (ic->ic_nrunning > 0) {
                if (sc->sc_flags & UPGT_FLAG_INITDONE) {
                        if (ic->ic_allmulti > 0 || ic->ic_promisc > 0)
                                upgt_set_multi(sc);
                } else {
                        upgt_init(sc);
                        startall = 1;
                }
        } else if (sc->sc_flags & UPGT_FLAG_INITDONE)
                upgt_stop(sc);
        UPGT_UNLOCK(sc);
        if (startall)
                ieee80211_start_all(ic);
}

static void
upgt_stop(struct upgt_softc *sc)
{

        UPGT_ASSERT_LOCKED(sc);

        if (sc->sc_flags & UPGT_FLAG_INITDONE)
                upgt_set_macfilter(sc, IEEE80211_S_INIT);
        upgt_abort_xfers_locked(sc);
        /* device down */
        sc->sc_tx_timer = 0;
        sc->sc_flags &= ~UPGT_FLAG_INITDONE;
}

static void
upgt_set_led(struct upgt_softc *sc, int action)
{
        struct upgt_data *data_cmd;
        struct upgt_lmac_mem *mem;
        struct upgt_lmac_led *led;

        data_cmd = upgt_getbuf(sc);
        if (data_cmd == NULL) {
                device_printf(sc->sc_dev, "%s: out of buffers.\n", __func__);
                return;
        }

        /*
         * Transmit the URB containing the CMD data.
         */
        memset(data_cmd->buf, 0, MCLBYTES);

        mem = (struct upgt_lmac_mem *)data_cmd->buf;
        mem->addr = htole32(sc->sc_memaddr_frame_start +
            UPGT_MEMSIZE_FRAME_HEAD);

        led = (struct upgt_lmac_led *)(mem + 1);

        led->header1.flags = UPGT_H1_FLAGS_TX_NO_CALLBACK;
        led->header1.type = UPGT_H1_TYPE_CTRL;
        led->header1.len = htole16(
            sizeof(struct upgt_lmac_led) -
            sizeof(struct upgt_lmac_header));

        led->header2.reqid = htole32(sc->sc_memaddr_frame_start);
        led->header2.type = htole16(UPGT_H2_TYPE_LED);
        led->header2.flags = 0;

        switch (action) {
        case UPGT_LED_OFF:
                led->mode = htole16(UPGT_LED_MODE_SET);
                led->action_fix = 0;
                led->action_tmp = htole16(UPGT_LED_ACTION_OFF);
                led->action_tmp_dur = 0;
                break;
        case UPGT_LED_ON:
                led->mode = htole16(UPGT_LED_MODE_SET);
                led->action_fix = 0;
                led->action_tmp = htole16(UPGT_LED_ACTION_ON);
                led->action_tmp_dur = 0;
                break;
        case UPGT_LED_BLINK:
                if (sc->sc_state != IEEE80211_S_RUN) {
                        STAILQ_INSERT_TAIL(&sc->sc_tx_inactive, data_cmd, next);
                        return;
                }
                if (sc->sc_led_blink) {
                        /* previous blink was not finished */
                        STAILQ_INSERT_TAIL(&sc->sc_tx_inactive, data_cmd, next);
                        return;
                }
                led->mode = htole16(UPGT_LED_MODE_SET);
                led->action_fix = htole16(UPGT_LED_ACTION_OFF);
                led->action_tmp = htole16(UPGT_LED_ACTION_ON);
                led->action_tmp_dur = htole16(UPGT_LED_ACTION_TMP_DUR);
                /* lock blink */
                sc->sc_led_blink = 1;
                callout_reset(&sc->sc_led_ch, hz, upgt_set_led_blink, sc);
                break;
        default:
                STAILQ_INSERT_TAIL(&sc->sc_tx_inactive, data_cmd, next);
                return;
        }

        data_cmd->buflen = sizeof(*mem) + sizeof(*led);

        mem->chksum = upgt_chksum_le((uint32_t *)led,
            data_cmd->buflen - sizeof(*mem));

        upgt_bulk_tx(sc, data_cmd);
}

static void
upgt_set_led_blink(void *arg)
{
        struct upgt_softc *sc = arg;

        /* blink finished, we are ready for a next one */
        sc->sc_led_blink = 0;
}

static void
upgt_init(struct upgt_softc *sc)
{

        UPGT_ASSERT_LOCKED(sc);

        if (sc->sc_flags & UPGT_FLAG_INITDONE)
                upgt_stop(sc);

        usbd_transfer_start(sc->sc_xfer[UPGT_BULK_RX]);

        (void)upgt_set_macfilter(sc, IEEE80211_S_SCAN);

        sc->sc_flags |= UPGT_FLAG_INITDONE;

        callout_reset(&sc->sc_watchdog_ch, hz, upgt_watchdog, sc);
}

static int
upgt_set_macfilter(struct upgt_softc *sc, uint8_t state)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211vap *vap = TAILQ_FIRST(&ic->ic_vaps);
        struct ieee80211_node *ni;
        struct upgt_data *data_cmd;
        struct upgt_lmac_mem *mem;
        struct upgt_lmac_filter *filter;

        UPGT_ASSERT_LOCKED(sc);

        data_cmd = upgt_getbuf(sc);
        if (data_cmd == NULL) {
                device_printf(sc->sc_dev, "out of TX buffers.\n");
                return (ENOBUFS);
        }

        /*
         * Transmit the URB containing the CMD data.
         */
        memset(data_cmd->buf, 0, MCLBYTES);

        mem = (struct upgt_lmac_mem *)data_cmd->buf;
        mem->addr = htole32(sc->sc_memaddr_frame_start +
            UPGT_MEMSIZE_FRAME_HEAD);

        filter = (struct upgt_lmac_filter *)(mem + 1);

        filter->header1.flags = UPGT_H1_FLAGS_TX_NO_CALLBACK;
        filter->header1.type = UPGT_H1_TYPE_CTRL;
        filter->header1.len = htole16(
            sizeof(struct upgt_lmac_filter) -
            sizeof(struct upgt_lmac_header));

        filter->header2.reqid = htole32(sc->sc_memaddr_frame_start);
        filter->header2.type = htole16(UPGT_H2_TYPE_MACFILTER);
        filter->header2.flags = 0;

        switch (state) {
        case IEEE80211_S_INIT:
                DPRINTF(sc, UPGT_DEBUG_STATE, "%s: set MAC filter to INIT\n",
                    __func__);
                filter->type = htole16(UPGT_FILTER_TYPE_RESET);
                break;
        case IEEE80211_S_SCAN:
                DPRINTF(sc, UPGT_DEBUG_STATE,
                    "set MAC filter to SCAN (bssid %s)\n",
                    ether_sprintf(ieee80211broadcastaddr));
                filter->type = htole16(UPGT_FILTER_TYPE_NONE);
                IEEE80211_ADDR_COPY(filter->dst,
                    vap ? vap->iv_myaddr : ic->ic_macaddr);
                IEEE80211_ADDR_COPY(filter->src, ieee80211broadcastaddr);
                filter->unknown1 = htole16(UPGT_FILTER_UNKNOWN1);
                filter->rxaddr = htole32(sc->sc_memaddr_rx_start);
                filter->unknown2 = htole16(UPGT_FILTER_UNKNOWN2);
                filter->rxhw = htole32(sc->sc_eeprom_hwrx);
                filter->unknown3 = htole16(UPGT_FILTER_UNKNOWN3);
                break;
        case IEEE80211_S_RUN:
                ni = ieee80211_ref_node(vap->iv_bss);
                /* XXX monitor mode isn't tested yet.  */
                if (vap->iv_opmode == IEEE80211_M_MONITOR) {
                        filter->type = htole16(UPGT_FILTER_TYPE_MONITOR);
                        IEEE80211_ADDR_COPY(filter->dst,
                            vap ? vap->iv_myaddr : ic->ic_macaddr);
                        IEEE80211_ADDR_COPY(filter->src, ni->ni_bssid);
                        filter->unknown1 = htole16(UPGT_FILTER_MONITOR_UNKNOWN1);
                        filter->rxaddr = htole32(sc->sc_memaddr_rx_start);
                        filter->unknown2 = htole16(UPGT_FILTER_MONITOR_UNKNOWN2);
                        filter->rxhw = htole32(sc->sc_eeprom_hwrx);
                        filter->unknown3 = htole16(UPGT_FILTER_MONITOR_UNKNOWN3);
                } else {
                        DPRINTF(sc, UPGT_DEBUG_STATE,
                            "set MAC filter to RUN (bssid %s)\n",
                            ether_sprintf(ni->ni_bssid));
                        filter->type = htole16(UPGT_FILTER_TYPE_STA);
                        IEEE80211_ADDR_COPY(filter->dst,
                            vap ? vap->iv_myaddr : ic->ic_macaddr);
                        IEEE80211_ADDR_COPY(filter->src, ni->ni_bssid);
                        filter->unknown1 = htole16(UPGT_FILTER_UNKNOWN1);
                        filter->rxaddr = htole32(sc->sc_memaddr_rx_start);
                        filter->unknown2 = htole16(UPGT_FILTER_UNKNOWN2);
                        filter->rxhw = htole32(sc->sc_eeprom_hwrx);
                        filter->unknown3 = htole16(UPGT_FILTER_UNKNOWN3);
                }
                ieee80211_free_node(ni);
                break;
        default:
                device_printf(sc->sc_dev,
                    "MAC filter does not know that state\n");
                break;
        }

        data_cmd->buflen = sizeof(*mem) + sizeof(*filter);

        mem->chksum = upgt_chksum_le((uint32_t *)filter,
            data_cmd->buflen - sizeof(*mem));

        upgt_bulk_tx(sc, data_cmd);

        return (0);
}

static void
upgt_setup_rates(struct ieee80211vap *vap, struct ieee80211com *ic)
{
        struct upgt_softc *sc = ic->ic_softc;
        const struct ieee80211_txparam *tp;

        /*
         * 0x01 = OFMD6   0x10 = DS1
         * 0x04 = OFDM9   0x11 = DS2
         * 0x06 = OFDM12  0x12 = DS5
         * 0x07 = OFDM18  0x13 = DS11
         * 0x08 = OFDM24
         * 0x09 = OFDM36
         * 0x0a = OFDM48
         * 0x0b = OFDM54
         */
        const uint8_t rateset_auto_11b[] =
            { 0x13, 0x13, 0x12, 0x11, 0x11, 0x10, 0x10, 0x10 };
        const uint8_t rateset_auto_11g[] =
            { 0x0b, 0x0a, 0x09, 0x08, 0x07, 0x06, 0x04, 0x01 };
        const uint8_t rateset_fix_11bg[] =
            { 0x10, 0x11, 0x12, 0x13, 0x01, 0x04, 0x06, 0x07,
              0x08, 0x09, 0x0a, 0x0b };

        tp = &vap->iv_txparms[ieee80211_chan2mode(ic->ic_curchan)];

        /* XXX */
        if (tp->ucastrate == IEEE80211_FIXED_RATE_NONE) {
                /*
                 * Automatic rate control is done by the device.
                 * We just pass the rateset from which the device
                 * will pickup a rate.
                 */
                if (ic->ic_curmode == IEEE80211_MODE_11B)
                        memcpy(sc->sc_cur_rateset, rateset_auto_11b,
                            sizeof(sc->sc_cur_rateset));
                if (ic->ic_curmode == IEEE80211_MODE_11G ||
                    ic->ic_curmode == IEEE80211_MODE_AUTO)
                        memcpy(sc->sc_cur_rateset, rateset_auto_11g,
                            sizeof(sc->sc_cur_rateset));
        } else {
                /* set a fixed rate */
                memset(sc->sc_cur_rateset, rateset_fix_11bg[tp->ucastrate],
                    sizeof(sc->sc_cur_rateset));
        }
}

static void
upgt_set_multi(void *arg)
{

        /* XXX don't know how to set a device.  Lack of docs. */
}

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

        UPGT_LOCK(sc);
        if ((sc->sc_flags & UPGT_FLAG_INITDONE) == 0) {
                UPGT_UNLOCK(sc);
                return (ENXIO);
        }
        error = mbufq_enqueue(&sc->sc_snd, m);
        if (error) {
                UPGT_UNLOCK(sc);
                return (error);
        }
        upgt_start(sc);
        UPGT_UNLOCK(sc);

        return (0);
}

static void
upgt_start(struct upgt_softc *sc)
{
        struct upgt_data *data_tx;
        struct ieee80211_node *ni;
        struct mbuf *m;

        UPGT_ASSERT_LOCKED(sc);

        if ((sc->sc_flags & UPGT_FLAG_INITDONE) == 0)
                return;

        while ((m = mbufq_dequeue(&sc->sc_snd)) != NULL) {
                data_tx = upgt_gettxbuf(sc);
                if (data_tx == NULL) {
                        mbufq_prepend(&sc->sc_snd, m);
                        break;
                }

                ni = (struct ieee80211_node *)m->m_pkthdr.rcvif;
                m->m_pkthdr.rcvif = NULL;

                if (upgt_tx_start(sc, m, ni, data_tx) != 0) {
                        if_inc_counter(ni->ni_vap->iv_ifp,
                            IFCOUNTER_OERRORS, 1);
                        STAILQ_INSERT_HEAD(&sc->sc_tx_inactive, data_tx, next);
                        UPGT_STAT_INC(sc, st_tx_inactive);
                        ieee80211_free_node(ni);
                        continue;
                }
                sc->sc_tx_timer = 5;
        }
}

static int
upgt_raw_xmit(struct ieee80211_node *ni, struct mbuf *m,
        const struct ieee80211_bpf_params *params)
{
        struct ieee80211com *ic = ni->ni_ic;
        struct upgt_softc *sc = ic->ic_softc;
        struct upgt_data *data_tx = NULL;

        UPGT_LOCK(sc);
        /* prevent management frames from being sent if we're not ready */
        if (!(sc->sc_flags & UPGT_FLAG_INITDONE)) {
                m_freem(m);
                UPGT_UNLOCK(sc);
                return ENETDOWN;
        }

        data_tx = upgt_gettxbuf(sc);
        if (data_tx == NULL) {
                m_freem(m);
                UPGT_UNLOCK(sc);
                return (ENOBUFS);
        }

        if (upgt_tx_start(sc, m, ni, data_tx) != 0) {
                STAILQ_INSERT_HEAD(&sc->sc_tx_inactive, data_tx, next);
                UPGT_STAT_INC(sc, st_tx_inactive);
                UPGT_UNLOCK(sc);
                return (EIO);
        }
        UPGT_UNLOCK(sc);

        sc->sc_tx_timer = 5;
        return (0);
}

static void
upgt_watchdog(void *arg)
{
        struct upgt_softc *sc = arg;
        struct ieee80211com *ic = &sc->sc_ic;

        if (sc->sc_tx_timer > 0) {
                if (--sc->sc_tx_timer == 0) {
                        device_printf(sc->sc_dev, "watchdog timeout\n");
                        /* upgt_init(sc); XXX needs a process context ? */
                        counter_u64_add(ic->ic_oerrors, 1);
                        return;
                }
                callout_reset(&sc->sc_watchdog_ch, hz, upgt_watchdog, sc);
        }
}

static uint32_t
upgt_mem_alloc(struct upgt_softc *sc)
{
        int i;

        for (i = 0; i < sc->sc_memory.pages; i++) {
                if (sc->sc_memory.page[i].used == 0) {
                        sc->sc_memory.page[i].used = 1;
                        return (sc->sc_memory.page[i].addr);
                }
        }

        return (0);
}

static void
upgt_scan_start(struct ieee80211com *ic)
{
        /* do nothing.  */
}

static void
upgt_scan_end(struct ieee80211com *ic)
{
        /* do nothing.  */
}

static void
upgt_set_channel(struct ieee80211com *ic)
{
        struct upgt_softc *sc = ic->ic_softc;

        UPGT_LOCK(sc);
        upgt_set_chan(sc, ic->ic_curchan);
        UPGT_UNLOCK(sc);
}

static void
upgt_set_chan(struct upgt_softc *sc, struct ieee80211_channel *c)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct upgt_data *data_cmd;
        struct upgt_lmac_mem *mem;
        struct upgt_lmac_channel *chan;
        int channel;

        UPGT_ASSERT_LOCKED(sc);

        channel = ieee80211_chan2ieee(ic, c);
        if (channel == 0 || channel == IEEE80211_CHAN_ANY) {
                /* XXX should NEVER happen */
                device_printf(sc->sc_dev,
                    "%s: invalid channel %x\n", __func__, channel);
                return;
        }

        DPRINTF(sc, UPGT_DEBUG_STATE, "%s: channel %d\n", __func__, channel);

        data_cmd = upgt_getbuf(sc);
        if (data_cmd == NULL) {
                device_printf(sc->sc_dev, "%s: out of buffers.\n", __func__);
                return;
        }
        /*
         * Transmit the URB containing the CMD data.
         */
        memset(data_cmd->buf, 0, MCLBYTES);

        mem = (struct upgt_lmac_mem *)data_cmd->buf;
        mem->addr = htole32(sc->sc_memaddr_frame_start +
            UPGT_MEMSIZE_FRAME_HEAD);

        chan = (struct upgt_lmac_channel *)(mem + 1);

        chan->header1.flags = UPGT_H1_FLAGS_TX_NO_CALLBACK;
        chan->header1.type = UPGT_H1_TYPE_CTRL;
        chan->header1.len = htole16(
            sizeof(struct upgt_lmac_channel) - sizeof(struct upgt_lmac_header));

        chan->header2.reqid = htole32(sc->sc_memaddr_frame_start);
        chan->header2.type = htole16(UPGT_H2_TYPE_CHANNEL);
        chan->header2.flags = 0;

        chan->unknown1 = htole16(UPGT_CHANNEL_UNKNOWN1);
        chan->unknown2 = htole16(UPGT_CHANNEL_UNKNOWN2);
        chan->freq6 = sc->sc_eeprom_freq6[channel];
        chan->settings = sc->sc_eeprom_freq6_settings;
        chan->unknown3 = UPGT_CHANNEL_UNKNOWN3;

        memcpy(chan->freq3_1, &sc->sc_eeprom_freq3[channel].data,
            sizeof(chan->freq3_1));
        memcpy(chan->freq4, &sc->sc_eeprom_freq4[channel],
            sizeof(sc->sc_eeprom_freq4[channel]));
        memcpy(chan->freq3_2, &sc->sc_eeprom_freq3[channel].data,
            sizeof(chan->freq3_2));

        data_cmd->buflen = sizeof(*mem) + sizeof(*chan);

        mem->chksum = upgt_chksum_le((uint32_t *)chan,
            data_cmd->buflen - sizeof(*mem));

        upgt_bulk_tx(sc, data_cmd);
}

static struct ieee80211vap *
upgt_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 upgt_vap *uvp;
        struct ieee80211vap *vap;

        if (!TAILQ_EMPTY(&ic->ic_vaps))         /* only one at a time */
                return NULL;
        uvp = malloc(sizeof(struct upgt_vap), M_80211_VAP, M_WAITOK | M_ZERO);
        vap = &uvp->vap;
        /* enable s/w bmiss handling for sta mode */

        if (ieee80211_vap_setup(ic, vap, name, unit, opmode,
            flags | IEEE80211_CLONE_NOBEACONS, bssid) != 0) {
                /* out of memory */
                free(uvp, M_80211_VAP);
                return (NULL);
        }

        /* override state transition machine */
        uvp->newstate = vap->iv_newstate;
        vap->iv_newstate = upgt_newstate;

        /* setup device rates */
        upgt_setup_rates(vap, ic);

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

static int
upgt_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
{
        struct upgt_vap *uvp = UPGT_VAP(vap);
        struct ieee80211com *ic = vap->iv_ic;
        struct upgt_softc *sc = ic->ic_softc;

        /* do it in a process context */
        sc->sc_state = nstate;

        IEEE80211_UNLOCK(ic);
        UPGT_LOCK(sc);
        callout_stop(&sc->sc_led_ch);
        callout_stop(&sc->sc_watchdog_ch);

        switch (nstate) {
        case IEEE80211_S_INIT:
                /* do not accept any frames if the device is down */
                (void)upgt_set_macfilter(sc, sc->sc_state);
                upgt_set_led(sc, UPGT_LED_OFF);
                break;
        case IEEE80211_S_SCAN:
                upgt_set_chan(sc, ic->ic_curchan);
                break;
        case IEEE80211_S_AUTH:
                upgt_set_chan(sc, ic->ic_curchan);
                break;
        case IEEE80211_S_ASSOC:
                break;
        case IEEE80211_S_RUN:
                upgt_set_macfilter(sc, sc->sc_state);
                upgt_set_led(sc, UPGT_LED_ON);
                break;
        default:
                break;
        }
        UPGT_UNLOCK(sc);
        IEEE80211_LOCK(ic);
        return (uvp->newstate(vap, nstate, arg));
}

static void
upgt_vap_delete(struct ieee80211vap *vap)
{
        struct upgt_vap *uvp = UPGT_VAP(vap);

        ieee80211_vap_detach(vap);
        free(uvp, M_80211_VAP);
}

static void
upgt_update_mcast(struct ieee80211com *ic)
{
        struct upgt_softc *sc = ic->ic_softc;

        upgt_set_multi(sc);
}

static int
upgt_eeprom_parse(struct upgt_softc *sc)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct upgt_eeprom_header *eeprom_header;
        struct upgt_eeprom_option *eeprom_option;
        uint16_t option_len;
        uint16_t option_type;
        uint16_t preamble_len;
        int option_end = 0;

        /* calculate eeprom options start offset */
        eeprom_header = (struct upgt_eeprom_header *)sc->sc_eeprom;
        preamble_len = le16toh(eeprom_header->preamble_len);
        eeprom_option = (struct upgt_eeprom_option *)(sc->sc_eeprom +
            (sizeof(struct upgt_eeprom_header) + preamble_len));

        while (!option_end) {
                /* sanity check */
                if (eeprom_option >= (struct upgt_eeprom_option *)
                    (sc->sc_eeprom + UPGT_EEPROM_SIZE)) {
                        return (EINVAL);
                }

                /* the eeprom option length is stored in words */
                option_len =
                    (le16toh(eeprom_option->len) - 1) * sizeof(uint16_t);
                option_type =
                    le16toh(eeprom_option->type);

                /* sanity check */
                if (option_len == 0 || option_len >= UPGT_EEPROM_SIZE)
                        return (EINVAL);

                switch (option_type) {
                case UPGT_EEPROM_TYPE_NAME:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "EEPROM name len=%d\n", option_len);
                        break;
                case UPGT_EEPROM_TYPE_SERIAL:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "EEPROM serial len=%d\n", option_len);
                        break;
                case UPGT_EEPROM_TYPE_MAC:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "EEPROM mac len=%d\n", option_len);

                        IEEE80211_ADDR_COPY(ic->ic_macaddr,
                            eeprom_option->data);
                        break;
                case UPGT_EEPROM_TYPE_HWRX:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "EEPROM hwrx len=%d\n", option_len);

                        upgt_eeprom_parse_hwrx(sc, eeprom_option->data);
                        break;
                case UPGT_EEPROM_TYPE_CHIP:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "EEPROM chip len=%d\n", option_len);
                        break;
                case UPGT_EEPROM_TYPE_FREQ3:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "EEPROM freq3 len=%d\n", option_len);

                        upgt_eeprom_parse_freq3(sc, eeprom_option->data,
                            option_len);
                        break;
                case UPGT_EEPROM_TYPE_FREQ4:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "EEPROM freq4 len=%d\n", option_len);

                        upgt_eeprom_parse_freq4(sc, eeprom_option->data,
                            option_len);
                        break;
                case UPGT_EEPROM_TYPE_FREQ5:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "EEPROM freq5 len=%d\n", option_len);
                        break;
                case UPGT_EEPROM_TYPE_FREQ6:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "EEPROM freq6 len=%d\n", option_len);

                        upgt_eeprom_parse_freq6(sc, eeprom_option->data,
                            option_len);
                        break;
                case UPGT_EEPROM_TYPE_END:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "EEPROM end len=%d\n", option_len);
                        option_end = 1;
                        break;
                case UPGT_EEPROM_TYPE_OFF:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "%s: EEPROM off without end option\n", __func__);
                        return (EIO);
                default:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "EEPROM unknown type 0x%04x len=%d\n",
                            option_type, option_len);
                        break;
                }

                /* jump to next EEPROM option */
                eeprom_option = (struct upgt_eeprom_option *)
                    (eeprom_option->data + option_len);
        }
        return (0);
}

static void
upgt_eeprom_parse_freq3(struct upgt_softc *sc, uint8_t *data, int len)
{
        struct upgt_eeprom_freq3_header *freq3_header;
        struct upgt_lmac_freq3 *freq3;
        int i;
        int elements;
        unsigned channel;

        freq3_header = (struct upgt_eeprom_freq3_header *)data;
        freq3 = (struct upgt_lmac_freq3 *)(freq3_header + 1);

        elements = freq3_header->elements;

        DPRINTF(sc, UPGT_DEBUG_FW, "flags=0x%02x elements=%d\n",
            freq3_header->flags, elements);

        if (elements >= (int)(UPGT_EEPROM_SIZE / sizeof(freq3[0])))
                return;

        for (i = 0; i < elements; i++) {
                channel = ieee80211_mhz2ieee(le16toh(freq3[i].freq), 0);
                if (channel >= IEEE80211_CHAN_MAX)
                        continue;

                sc->sc_eeprom_freq3[channel] = freq3[i];

                DPRINTF(sc, UPGT_DEBUG_FW, "frequency=%d, channel=%d\n",
                    le16toh(sc->sc_eeprom_freq3[channel].freq), channel);
        }
}

void
upgt_eeprom_parse_freq4(struct upgt_softc *sc, uint8_t *data, int len)
{
        struct upgt_eeprom_freq4_header *freq4_header;
        struct upgt_eeprom_freq4_1 *freq4_1;
        struct upgt_eeprom_freq4_2 *freq4_2;
        int i;
        int j;
        int elements;
        int settings;
        unsigned channel;

        freq4_header = (struct upgt_eeprom_freq4_header *)data;
        freq4_1 = (struct upgt_eeprom_freq4_1 *)(freq4_header + 1);
        elements = freq4_header->elements;
        settings = freq4_header->settings;

        /* we need this value later */
        sc->sc_eeprom_freq6_settings = freq4_header->settings;

        DPRINTF(sc, UPGT_DEBUG_FW, "flags=0x%02x elements=%d settings=%d\n",
            freq4_header->flags, elements, settings);

        if (elements >= (int)(UPGT_EEPROM_SIZE / sizeof(freq4_1[0])))
                return;

        for (i = 0; i < elements; i++) {
                channel = ieee80211_mhz2ieee(le16toh(freq4_1[i].freq), 0);
                if (channel >= IEEE80211_CHAN_MAX)
                        continue;

                freq4_2 = (struct upgt_eeprom_freq4_2 *)freq4_1[i].data;
                for (j = 0; j < settings; j++) {
                        sc->sc_eeprom_freq4[channel][j].cmd = freq4_2[j];
                        sc->sc_eeprom_freq4[channel][j].pad = 0;
                }

                DPRINTF(sc, UPGT_DEBUG_FW, "frequency=%d, channel=%d\n",
                    le16toh(freq4_1[i].freq), channel);
        }
}

void
upgt_eeprom_parse_freq6(struct upgt_softc *sc, uint8_t *data, int len)
{
        struct upgt_lmac_freq6 *freq6;
        int i;
        int elements;
        unsigned channel;

        freq6 = (struct upgt_lmac_freq6 *)data;
        elements = len / sizeof(struct upgt_lmac_freq6);

        DPRINTF(sc, UPGT_DEBUG_FW, "elements=%d\n", elements);

        if (elements >= (int)(UPGT_EEPROM_SIZE / sizeof(freq6[0])))
                return;

        for (i = 0; i < elements; i++) {
                channel = ieee80211_mhz2ieee(le16toh(freq6[i].freq), 0);
                if (channel >= IEEE80211_CHAN_MAX)
                        continue;

                sc->sc_eeprom_freq6[channel] = freq6[i];

                DPRINTF(sc, UPGT_DEBUG_FW, "frequency=%d, channel=%d\n",
                    le16toh(sc->sc_eeprom_freq6[channel].freq), channel);
        }
}

static void
upgt_eeprom_parse_hwrx(struct upgt_softc *sc, uint8_t *data)
{
        struct upgt_eeprom_option_hwrx *option_hwrx;

        option_hwrx = (struct upgt_eeprom_option_hwrx *)data;

        sc->sc_eeprom_hwrx = option_hwrx->rxfilter - UPGT_EEPROM_RX_CONST;

        DPRINTF(sc, UPGT_DEBUG_FW, "hwrx option value=0x%04x\n",
            sc->sc_eeprom_hwrx);
}

static int
upgt_eeprom_read(struct upgt_softc *sc)
{
        struct upgt_data *data_cmd;
        struct upgt_lmac_mem *mem;
        struct upgt_lmac_eeprom *eeprom;
        int block, error, offset;

        UPGT_LOCK(sc);
        usb_pause_mtx(&sc->sc_mtx, USB_MS_TO_TICKS(100));

        offset = 0;
        block = UPGT_EEPROM_BLOCK_SIZE;
        while (offset < UPGT_EEPROM_SIZE) {
                DPRINTF(sc, UPGT_DEBUG_FW,
                    "request EEPROM block (offset=%d, len=%d)\n", offset, block);

                data_cmd = upgt_getbuf(sc);
                if (data_cmd == NULL) {
                        UPGT_UNLOCK(sc);
                        return (ENOBUFS);
                }

                /*
                 * Transmit the URB containing the CMD data.
                 */
                memset(data_cmd->buf, 0, MCLBYTES);

                mem = (struct upgt_lmac_mem *)data_cmd->buf;
                mem->addr = htole32(sc->sc_memaddr_frame_start +
                    UPGT_MEMSIZE_FRAME_HEAD);

                eeprom = (struct upgt_lmac_eeprom *)(mem + 1);
                eeprom->header1.flags = 0;
                eeprom->header1.type = UPGT_H1_TYPE_CTRL;
                eeprom->header1.len = htole16((
                    sizeof(struct upgt_lmac_eeprom) -
                    sizeof(struct upgt_lmac_header)) + block);

                eeprom->header2.reqid = htole32(sc->sc_memaddr_frame_start);
                eeprom->header2.type = htole16(UPGT_H2_TYPE_EEPROM);
                eeprom->header2.flags = 0;

                eeprom->offset = htole16(offset);
                eeprom->len = htole16(block);

                data_cmd->buflen = sizeof(*mem) + sizeof(*eeprom) + block;

                mem->chksum = upgt_chksum_le((uint32_t *)eeprom,
                    data_cmd->buflen - sizeof(*mem));
                upgt_bulk_tx(sc, data_cmd);

                error = mtx_sleep(sc, &sc->sc_mtx, 0, "eeprom_request", hz);
                if (error != 0) {
                        device_printf(sc->sc_dev,
                            "timeout while waiting for EEPROM data\n");
                        UPGT_UNLOCK(sc);
                        return (EIO);
                }

                offset += block;
                if (UPGT_EEPROM_SIZE - offset < block)
                        block = UPGT_EEPROM_SIZE - offset;
        }

        UPGT_UNLOCK(sc);
        return (0);
}

/*
 * When a rx data came in the function returns a mbuf and a rssi values.
 */
static struct mbuf *
upgt_rxeof(struct usb_xfer *xfer, struct upgt_data *data, int *rssi)
{
        struct mbuf *m = NULL;
        struct upgt_softc *sc = usbd_xfer_softc(xfer);
        struct upgt_lmac_header *header;
        struct upgt_lmac_eeprom *eeprom;
        uint8_t h1_type;
        uint16_t h2_type;
        int actlen, sumlen;

        usbd_xfer_status(xfer, &actlen, &sumlen, NULL, NULL);

        UPGT_ASSERT_LOCKED(sc);

        if (actlen < 1)
                return (NULL);

        /* Check only at the very beginning.  */
        if (!(sc->sc_flags & UPGT_FLAG_FWLOADED) &&
            (memcmp(data->buf, "OK", 2) == 0)) {
                sc->sc_flags |= UPGT_FLAG_FWLOADED;
                wakeup_one(sc);
                return (NULL);
        }

        if (actlen < (int)UPGT_RX_MINSZ)
                return (NULL);

        /*
         * Check what type of frame came in.
         */
        header = (struct upgt_lmac_header *)(data->buf + 4);

        h1_type = header->header1.type;
        h2_type = le16toh(header->header2.type);

        if (h1_type == UPGT_H1_TYPE_CTRL && h2_type == UPGT_H2_TYPE_EEPROM) {
                eeprom = (struct upgt_lmac_eeprom *)(data->buf + 4);
                uint16_t eeprom_offset = le16toh(eeprom->offset);
                uint16_t eeprom_len = le16toh(eeprom->len);

                DPRINTF(sc, UPGT_DEBUG_FW,
                    "received EEPROM block (offset=%d, len=%d)\n",
                    eeprom_offset, eeprom_len);

                memcpy(sc->sc_eeprom + eeprom_offset,
                    data->buf + sizeof(struct upgt_lmac_eeprom) + 4,
                    eeprom_len);

                /* EEPROM data has arrived in time, wakeup.  */
                wakeup(sc);
        } else if (h1_type == UPGT_H1_TYPE_CTRL &&
            h2_type == UPGT_H2_TYPE_TX_DONE) {
                DPRINTF(sc, UPGT_DEBUG_XMIT, "%s: received 802.11 TX done\n",
                    __func__);
                upgt_tx_done(sc, data->buf + 4);
        } else if (h1_type == UPGT_H1_TYPE_RX_DATA ||
            h1_type == UPGT_H1_TYPE_RX_DATA_MGMT) {
                DPRINTF(sc, UPGT_DEBUG_RECV, "%s: received 802.11 RX data\n",
                    __func__);
                m = upgt_rx(sc, data->buf + 4, le16toh(header->header1.len),
                    rssi);
        } else if (h1_type == UPGT_H1_TYPE_CTRL &&
            h2_type == UPGT_H2_TYPE_STATS) {
                DPRINTF(sc, UPGT_DEBUG_STAT, "%s: received statistic data\n",
                    __func__);
                /* TODO: what could we do with the statistic data? */
        } else {
                /* ignore unknown frame types */
                DPRINTF(sc, UPGT_DEBUG_INTR,
                    "received unknown frame type 0x%02x\n",
                    header->header1.type);
        }
        return (m);
}

/*
 * The firmware awaits a checksum for each frame we send to it.
 * The algorithm used therefor is uncommon but somehow similar to CRC32.
 */
static uint32_t
upgt_chksum_le(const uint32_t *buf, size_t size)
{
        size_t i;
        uint32_t crc = 0;

        for (i = 0; i < size; i += sizeof(uint32_t)) {
                crc = htole32(crc ^ *buf++);
                crc = htole32((crc >> 5) ^ (crc << 3));
        }

        return (crc);
}

static struct mbuf *
upgt_rx(struct upgt_softc *sc, uint8_t *data, int pkglen, int *rssi)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct upgt_lmac_rx_desc *rxdesc;
        struct mbuf *m;

        /*
         * don't pass packets to the ieee80211 framework if the driver isn't
         * RUNNING.
         */
        if (!(sc->sc_flags & UPGT_FLAG_INITDONE))
                return (NULL);

        /* access RX packet descriptor */
        rxdesc = (struct upgt_lmac_rx_desc *)data;

        /* create mbuf which is suitable for strict alignment archs */
        KASSERT((pkglen + ETHER_ALIGN) < MCLBYTES,
            ("A current mbuf storage is small (%d)", pkglen + ETHER_ALIGN));
        m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
        if (m == NULL) {
                device_printf(sc->sc_dev, "could not create RX mbuf\n");
                return (NULL);
        }
        m_adj(m, ETHER_ALIGN);
        memcpy(mtod(m, char *), rxdesc->data, pkglen);
        /* trim FCS */
        m->m_len = m->m_pkthdr.len = pkglen - IEEE80211_CRC_LEN;

        if (ieee80211_radiotap_active(ic)) {
                struct upgt_rx_radiotap_header *tap = &sc->sc_rxtap;

                tap->wr_flags = 0;
                tap->wr_rate = upgt_rx_rate(sc, rxdesc->rate);
                tap->wr_antsignal = rxdesc->rssi;
        }

        DPRINTF(sc, UPGT_DEBUG_RX_PROC, "%s: RX done\n", __func__);
        *rssi = rxdesc->rssi;
        return (m);
}

static uint8_t
upgt_rx_rate(struct upgt_softc *sc, const int rate)
{
        struct ieee80211com *ic = &sc->sc_ic;
        static const uint8_t cck_upgt2rate[4] = { 2, 4, 11, 22 };
        static const uint8_t ofdm_upgt2rate[12] =
            { 2, 4, 11, 22, 12, 18, 24, 36, 48, 72, 96, 108 };

        if (ic->ic_curmode == IEEE80211_MODE_11B &&
            !(rate < 0 || rate > 3))
                return cck_upgt2rate[rate & 0xf];

        if (ic->ic_curmode == IEEE80211_MODE_11G &&
            !(rate < 0 || rate > 11))
                return ofdm_upgt2rate[rate & 0xf];

        return (0);
}

static void
upgt_tx_done(struct upgt_softc *sc, uint8_t *data)
{
        struct upgt_lmac_tx_done_desc *desc;
        int i, freed = 0;

        UPGT_ASSERT_LOCKED(sc);

        desc = (struct upgt_lmac_tx_done_desc *)data;

        for (i = 0; i < UPGT_TX_MAXCOUNT; i++) {
                struct upgt_data *data_tx = &sc->sc_tx_data[i];

                if (data_tx->addr == le32toh(desc->header2.reqid)) {
                        upgt_mem_free(sc, data_tx->addr);
                        data_tx->ni = NULL;
                        data_tx->addr = 0;
                        data_tx->m = NULL;

                        DPRINTF(sc, UPGT_DEBUG_TX_PROC,
                            "TX done: memaddr=0x%08x, status=0x%04x, rssi=%d, ",
                            le32toh(desc->header2.reqid),
                            le16toh(desc->status), le16toh(desc->rssi));
                        DPRINTF(sc, UPGT_DEBUG_TX_PROC, "seq=%d\n",
                            le16toh(desc->seq));

                        freed++;
                }
        }

        if (freed != 0) {
                UPGT_UNLOCK(sc);
                sc->sc_tx_timer = 0;
                upgt_start(sc);
                UPGT_LOCK(sc);
        }
}

static void
upgt_mem_free(struct upgt_softc *sc, uint32_t addr)
{
        int i;

        for (i = 0; i < sc->sc_memory.pages; i++) {
                if (sc->sc_memory.page[i].addr == addr) {
                        sc->sc_memory.page[i].used = 0;
                        return;
                }
        }

        device_printf(sc->sc_dev,
            "could not free memory address 0x%08x\n", addr);
}

static int
upgt_fw_load(struct upgt_softc *sc)
{
        const struct firmware *fw;
        struct upgt_data *data_cmd;
        struct upgt_fw_x2_header *x2;
        char start_fwload_cmd[] = { 0x3c, 0x0d };
        int error = 0;
        size_t offset;
        int bsize;
        int n;
        uint32_t crc32;

        fw = firmware_get(upgt_fwname);
        if (fw == NULL) {
                device_printf(sc->sc_dev, "could not read microcode %s\n",
                    upgt_fwname);
                return (EIO);
        }

        UPGT_LOCK(sc);

        /* send firmware start load command */
        data_cmd = upgt_getbuf(sc);
        if (data_cmd == NULL) {
                error = ENOBUFS;
                goto fail;
        }
        data_cmd->buflen = sizeof(start_fwload_cmd);
        memcpy(data_cmd->buf, start_fwload_cmd, data_cmd->buflen);
        upgt_bulk_tx(sc, data_cmd);

        /* send X2 header */
        data_cmd = upgt_getbuf(sc);
        if (data_cmd == NULL) {
                error = ENOBUFS;
                goto fail;
        }
        data_cmd->buflen = sizeof(struct upgt_fw_x2_header);
        x2 = (struct upgt_fw_x2_header *)data_cmd->buf;
        memcpy(x2->signature, UPGT_X2_SIGNATURE, UPGT_X2_SIGNATURE_SIZE);
        x2->startaddr = htole32(UPGT_MEMADDR_FIRMWARE_START);
        x2->len = htole32(fw->datasize);
        x2->crc = upgt_crc32_le((uint8_t *)data_cmd->buf +
            UPGT_X2_SIGNATURE_SIZE,
            sizeof(struct upgt_fw_x2_header) - UPGT_X2_SIGNATURE_SIZE -
            sizeof(uint32_t));
        upgt_bulk_tx(sc, data_cmd);

        /* download firmware */
        for (offset = 0; offset < fw->datasize; offset += bsize) {
                if (fw->datasize - offset > UPGT_FW_BLOCK_SIZE)
                        bsize = UPGT_FW_BLOCK_SIZE;
                else
                        bsize = fw->datasize - offset;

                data_cmd = upgt_getbuf(sc);
                if (data_cmd == NULL) {
                        error = ENOBUFS;
                        goto fail;
                }
                n = upgt_fw_copy((const uint8_t *)fw->data + offset,
                    data_cmd->buf, bsize);
                data_cmd->buflen = bsize;
                upgt_bulk_tx(sc, data_cmd);

                DPRINTF(sc, UPGT_DEBUG_FW, "FW offset=%zu, read=%d, sent=%d\n",
                    offset, n, bsize);
                bsize = n;
        }
        DPRINTF(sc, UPGT_DEBUG_FW, "%s: firmware downloaded\n", __func__);

        /* load firmware */
        data_cmd = upgt_getbuf(sc);
        if (data_cmd == NULL) {
                error = ENOBUFS;
                goto fail;
        }
        crc32 = upgt_crc32_le(fw->data, fw->datasize);
        *((uint32_t *)(data_cmd->buf)    ) = crc32;
        *((uint8_t  *)(data_cmd->buf) + 4) = 'g';
        *((uint8_t  *)(data_cmd->buf) + 5) = '\r';
        data_cmd->buflen = 6;
        upgt_bulk_tx(sc, data_cmd);

        /* waiting 'OK' response.  */
        usbd_transfer_start(sc->sc_xfer[UPGT_BULK_RX]);
        error = mtx_sleep(sc, &sc->sc_mtx, 0, "upgtfw", 2 * hz);
        if (error != 0) {
                device_printf(sc->sc_dev, "firmware load failed\n");
                error = EIO;
        }

        DPRINTF(sc, UPGT_DEBUG_FW, "%s: firmware loaded\n", __func__);
fail:
        UPGT_UNLOCK(sc);
        firmware_put(fw, FIRMWARE_UNLOAD);
        return (error);
}

static uint32_t
upgt_crc32_le(const void *buf, size_t size)
{
        uint32_t crc;

        crc = ether_crc32_le(buf, size);

        /* apply final XOR value as common for CRC-32 */
        crc = htole32(crc ^ 0xffffffffU);

        return (crc);
}

/*
 * While copying the version 2 firmware, we need to replace two characters:
 *
 * 0x7e -> 0x7d 0x5e
 * 0x7d -> 0x7d 0x5d
 */
static int
upgt_fw_copy(const uint8_t *src, char *dst, int size)
{
        int i, j;

        for (i = 0, j = 0; i < size && j < size; i++) {
                switch (src[i]) {
                case 0x7e:
                        dst[j] = 0x7d;
                        j++;
                        dst[j] = 0x5e;
                        j++;
                        break;
                case 0x7d:
                        dst[j] = 0x7d;
                        j++;
                        dst[j] = 0x5d;
                        j++;
                        break;
                default:
                        dst[j] = src[i];
                        j++;
                        break;
                }
        }

        return (i);
}

static int
upgt_mem_init(struct upgt_softc *sc)
{
        int i;

        for (i = 0; i < UPGT_MEMORY_MAX_PAGES; i++) {
                sc->sc_memory.page[i].used = 0;

                if (i == 0) {
                        /*
                         * The first memory page is always reserved for
                         * command data.
                         */
                        sc->sc_memory.page[i].addr =
                            sc->sc_memaddr_frame_start + MCLBYTES;
                } else {
                        sc->sc_memory.page[i].addr =
                            sc->sc_memory.page[i - 1].addr + MCLBYTES;
                }

                if (sc->sc_memory.page[i].addr + MCLBYTES >=
                    sc->sc_memaddr_frame_end)
                        break;

                DPRINTF(sc, UPGT_DEBUG_FW, "memory address page %d=0x%08x\n",
                    i, sc->sc_memory.page[i].addr);
        }

        sc->sc_memory.pages = i;

        DPRINTF(sc, UPGT_DEBUG_FW, "memory pages=%d\n", sc->sc_memory.pages);
        return (0);
}

static int
upgt_fw_verify(struct upgt_softc *sc)
{
        const struct firmware *fw;
        const struct upgt_fw_bra_option *bra_opt;
        const struct upgt_fw_bra_descr *descr;
        const uint8_t *p;
        const uint32_t *uc;
        uint32_t bra_option_type, bra_option_len;
        size_t offset;
        int bra_end = 0;
        int error = 0;

        fw = firmware_get(upgt_fwname);
        if (fw == NULL) {
                device_printf(sc->sc_dev, "could not read microcode %s\n",
                    upgt_fwname);
                return EIO;
        }

        /*
         * Seek to beginning of Boot Record Area (BRA).
         */
        for (offset = 0; offset < fw->datasize; offset += sizeof(*uc)) {
                uc = (const uint32_t *)((const uint8_t *)fw->data + offset);
                if (*uc == 0)
                        break;
        }
        for (; offset < fw->datasize; offset += sizeof(*uc)) {
                uc = (const uint32_t *)((const uint8_t *)fw->data + offset);
                if (*uc != 0)
                        break;
        }
        if (offset == fw->datasize) { 
                device_printf(sc->sc_dev,
                    "firmware Boot Record Area not found\n");
                error = EIO;
                goto fail;
        }

        DPRINTF(sc, UPGT_DEBUG_FW,
            "firmware Boot Record Area found at offset %zu\n", offset);

        /*
         * Parse Boot Record Area (BRA) options.
         */
        while (offset < fw->datasize && bra_end == 0) {
                /* get current BRA option */
                p = (const uint8_t *)fw->data + offset;
                bra_opt = (const struct upgt_fw_bra_option *)p;
                bra_option_type = le32toh(bra_opt->type);
                bra_option_len = le32toh(bra_opt->len) * sizeof(*uc);

                switch (bra_option_type) {
                case UPGT_BRA_TYPE_FW:
                        DPRINTF(sc, UPGT_DEBUG_FW, "UPGT_BRA_TYPE_FW len=%d\n",
                            bra_option_len);

                        if (bra_option_len != UPGT_BRA_FWTYPE_SIZE) {
                                device_printf(sc->sc_dev,
                                    "wrong UPGT_BRA_TYPE_FW len\n");
                                error = EIO;
                                goto fail;
                        }
                        if (memcmp(UPGT_BRA_FWTYPE_LM86, bra_opt->data,
                            bra_option_len) == 0) {
                                sc->sc_fw_type = UPGT_FWTYPE_LM86;
                                break;
                        }
                        if (memcmp(UPGT_BRA_FWTYPE_LM87, bra_opt->data,
                            bra_option_len) == 0) {
                                sc->sc_fw_type = UPGT_FWTYPE_LM87;
                                break;
                        }
                        device_printf(sc->sc_dev,
                            "unsupported firmware type\n");
                        error = EIO;
                        goto fail;
                case UPGT_BRA_TYPE_VERSION:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "UPGT_BRA_TYPE_VERSION len=%d\n", bra_option_len);
                        break;
                case UPGT_BRA_TYPE_DEPIF:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "UPGT_BRA_TYPE_DEPIF len=%d\n", bra_option_len);
                        break;
                case UPGT_BRA_TYPE_EXPIF:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "UPGT_BRA_TYPE_EXPIF len=%d\n", bra_option_len);
                        break;
                case UPGT_BRA_TYPE_DESCR:
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "UPGT_BRA_TYPE_DESCR len=%d\n", bra_option_len);

                        descr = (const struct upgt_fw_bra_descr *)bra_opt->data;

                        sc->sc_memaddr_frame_start =
                            le32toh(descr->memaddr_space_start);
                        sc->sc_memaddr_frame_end =
                            le32toh(descr->memaddr_space_end);

                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "memory address space start=0x%08x\n",
                            sc->sc_memaddr_frame_start);
                        DPRINTF(sc, UPGT_DEBUG_FW,
                            "memory address space end=0x%08x\n",
                            sc->sc_memaddr_frame_end);
                        break;
                case UPGT_BRA_TYPE_END:
                        DPRINTF(sc, UPGT_DEBUG_FW, "UPGT_BRA_TYPE_END len=%d\n",
                            bra_option_len);
                        bra_end = 1;
                        break;
                default:
                        DPRINTF(sc, UPGT_DEBUG_FW, "unknown BRA option len=%d\n",
                            bra_option_len);
                        error = EIO;
                        goto fail;
                }

                /* jump to next BRA option */
                offset += sizeof(struct upgt_fw_bra_option) + bra_option_len;
        }

        DPRINTF(sc, UPGT_DEBUG_FW, "%s: firmware verified", __func__);
fail:
        firmware_put(fw, FIRMWARE_UNLOAD);
        return (error);
}

static void
upgt_bulk_tx(struct upgt_softc *sc, struct upgt_data *data)
{

        UPGT_ASSERT_LOCKED(sc);

        STAILQ_INSERT_TAIL(&sc->sc_tx_pending, data, next);
        UPGT_STAT_INC(sc, st_tx_pending);
        usbd_transfer_start(sc->sc_xfer[UPGT_BULK_TX]);
}

static int
upgt_device_reset(struct upgt_softc *sc)
{
        struct upgt_data *data;
        char init_cmd[] = { 0x7e, 0x7e, 0x7e, 0x7e };

        UPGT_LOCK(sc);

        data = upgt_getbuf(sc);
        if (data == NULL) {
                UPGT_UNLOCK(sc);
                return (ENOBUFS);
        }
        memcpy(data->buf, init_cmd, sizeof(init_cmd));
        data->buflen = sizeof(init_cmd);
        upgt_bulk_tx(sc, data);
        usb_pause_mtx(&sc->sc_mtx, USB_MS_TO_TICKS(100));

        UPGT_UNLOCK(sc);
        DPRINTF(sc, UPGT_DEBUG_FW, "%s: device initialized\n", __func__);
        return (0);
}

static int
upgt_alloc_tx(struct upgt_softc *sc)
{
        int i;

        STAILQ_INIT(&sc->sc_tx_active);
        STAILQ_INIT(&sc->sc_tx_inactive);
        STAILQ_INIT(&sc->sc_tx_pending);

        for (i = 0; i < UPGT_TX_MAXCOUNT; i++) {
                struct upgt_data *data = &sc->sc_tx_data[i];
                data->buf = ((uint8_t *)sc->sc_tx_dma_buf) + (i * MCLBYTES);
                STAILQ_INSERT_TAIL(&sc->sc_tx_inactive, data, next);
                UPGT_STAT_INC(sc, st_tx_inactive);
        }

        return (0);
}

static int
upgt_alloc_rx(struct upgt_softc *sc)
{
        int i;

        STAILQ_INIT(&sc->sc_rx_active);
        STAILQ_INIT(&sc->sc_rx_inactive);

        for (i = 0; i < UPGT_RX_MAXCOUNT; i++) {
                struct upgt_data *data = &sc->sc_rx_data[i];
                data->buf = ((uint8_t *)sc->sc_rx_dma_buf) + (i * MCLBYTES);
                STAILQ_INSERT_TAIL(&sc->sc_rx_inactive, data, next);
        }
        return (0);
}

static int
upgt_detach(device_t dev)
{
        struct upgt_softc *sc = device_get_softc(dev);
        struct ieee80211com *ic = &sc->sc_ic;
        unsigned x;

        /*
         * Prevent further allocations from RX/TX/CMD
         * data lists and ioctls
         */
        UPGT_LOCK(sc);
        sc->sc_flags |= UPGT_FLAG_DETACHED;

        STAILQ_INIT(&sc->sc_tx_active);
        STAILQ_INIT(&sc->sc_tx_inactive);
        STAILQ_INIT(&sc->sc_tx_pending);

        STAILQ_INIT(&sc->sc_rx_active);
        STAILQ_INIT(&sc->sc_rx_inactive);

        upgt_stop(sc);
        UPGT_UNLOCK(sc);

        callout_drain(&sc->sc_led_ch);
        callout_drain(&sc->sc_watchdog_ch);

        /* drain USB transfers */
        for (x = 0; x != UPGT_N_XFERS; x++)
                usbd_transfer_drain(sc->sc_xfer[x]);

        /* free data buffers */
        UPGT_LOCK(sc);
        upgt_free_rx(sc);
        upgt_free_tx(sc);
        UPGT_UNLOCK(sc);

        /* free USB transfers and some data buffers */
        usbd_transfer_unsetup(sc->sc_xfer, UPGT_N_XFERS);

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

        return (0);
}

static void
upgt_free_rx(struct upgt_softc *sc)
{
        int i;

        for (i = 0; i < UPGT_RX_MAXCOUNT; i++) {
                struct upgt_data *data = &sc->sc_rx_data[i];

                data->buf = NULL;
                data->ni = NULL;
        }
}

static void
upgt_free_tx(struct upgt_softc *sc)
{
        int i;

        for (i = 0; i < UPGT_TX_MAXCOUNT; i++) {
                struct upgt_data *data = &sc->sc_tx_data[i];

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

                data->buf = NULL;
                data->ni = NULL;
        }
}

static void
upgt_abort_xfers_locked(struct upgt_softc *sc)
{
        int i;

        UPGT_ASSERT_LOCKED(sc);
        /* abort any pending transfers */
        for (i = 0; i < UPGT_N_XFERS; i++)
                usbd_transfer_stop(sc->sc_xfer[i]);
}

static void
upgt_abort_xfers(struct upgt_softc *sc)
{

        UPGT_LOCK(sc);
        upgt_abort_xfers_locked(sc);
        UPGT_UNLOCK(sc);
}

#define UPGT_SYSCTL_STAT_ADD32(c, h, n, p, d)   \
            SYSCTL_ADD_UINT(c, h, OID_AUTO, n, CTLFLAG_RD, p, 0, d)

static void
upgt_sysctl_node(struct upgt_softc *sc)
{
        struct sysctl_ctx_list *ctx;
        struct sysctl_oid_list *child;
        struct sysctl_oid *tree;
        struct upgt_stat *stats;

        stats = &sc->sc_stat;
        ctx = device_get_sysctl_ctx(sc->sc_dev);
        child = SYSCTL_CHILDREN(device_get_sysctl_tree(sc->sc_dev));

        tree = SYSCTL_ADD_NODE(ctx, child, OID_AUTO, "stats",
            CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "UPGT statistics");
        child = SYSCTL_CHILDREN(tree);
        UPGT_SYSCTL_STAT_ADD32(ctx, child, "tx_active",
            &stats->st_tx_active, "Active numbers in TX queue");
        UPGT_SYSCTL_STAT_ADD32(ctx, child, "tx_inactive",
            &stats->st_tx_inactive, "Inactive numbers in TX queue");
        UPGT_SYSCTL_STAT_ADD32(ctx, child, "tx_pending",
            &stats->st_tx_pending, "Pending numbers in TX queue");
}

#undef UPGT_SYSCTL_STAT_ADD32

static struct upgt_data *
_upgt_getbuf(struct upgt_softc *sc)
{
        struct upgt_data *bf;

        bf = STAILQ_FIRST(&sc->sc_tx_inactive);
        if (bf != NULL) {
                STAILQ_REMOVE_HEAD(&sc->sc_tx_inactive, next);
                UPGT_STAT_DEC(sc, st_tx_inactive);
        } else
                bf = NULL;
        if (bf == NULL)
                DPRINTF(sc, UPGT_DEBUG_XMIT, "%s: %s\n", __func__,
                    "out of xmit buffers");
        return (bf);
}

static struct upgt_data *
upgt_getbuf(struct upgt_softc *sc)
{
        struct upgt_data *bf;

        UPGT_ASSERT_LOCKED(sc);

        bf = _upgt_getbuf(sc);
        if (bf == NULL)
                DPRINTF(sc, UPGT_DEBUG_XMIT, "%s: stop queue\n", __func__);

        return (bf);
}

static struct upgt_data *
upgt_gettxbuf(struct upgt_softc *sc)
{
        struct upgt_data *bf;

        UPGT_ASSERT_LOCKED(sc);

        bf = upgt_getbuf(sc);
        if (bf == NULL)
                return (NULL);

        bf->addr = upgt_mem_alloc(sc);
        if (bf->addr == 0) {
                DPRINTF(sc, UPGT_DEBUG_XMIT, "%s: no free prism memory!\n",
                    __func__);
                STAILQ_INSERT_HEAD(&sc->sc_tx_inactive, bf, next);
                UPGT_STAT_INC(sc, st_tx_inactive);
                return (NULL);
        }
        return (bf);
}

static int
upgt_tx_start(struct upgt_softc *sc, struct mbuf *m, struct ieee80211_node *ni,
    struct upgt_data *data)
{
        struct ieee80211vap *vap = ni->ni_vap;
        int error = 0, len;
        struct ieee80211_frame *wh;
        struct ieee80211_key *k;
        struct upgt_lmac_mem *mem;
        struct upgt_lmac_tx_desc *txdesc;

        UPGT_ASSERT_LOCKED(sc);

        upgt_set_led(sc, UPGT_LED_BLINK);

        /* Assign sequence number */
        ieee80211_output_seqno_assign(ni, -1, m);

        /*
         * Software crypto.
         */
        wh = mtod(m, struct ieee80211_frame *);
        if (wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {
                k = ieee80211_crypto_encap(ni, m);
                if (k == NULL) {
                        device_printf(sc->sc_dev,
                            "ieee80211_crypto_encap returns NULL.\n");
                        error = EIO;
                        goto done;
                }

                /* in case packet header moved, reset pointer */
                wh = mtod(m, struct ieee80211_frame *);
        }

        /* Transmit the URB containing the TX data.  */
        memset(data->buf, 0, MCLBYTES);
        mem = (struct upgt_lmac_mem *)data->buf;
        mem->addr = htole32(data->addr);
        txdesc = (struct upgt_lmac_tx_desc *)(mem + 1);

        if (IEEE80211_IS_MGMT(wh)) {
                /* mgmt frames  */
                txdesc->header1.flags = UPGT_H1_FLAGS_TX_MGMT;
                /* always send mgmt frames at lowest rate (DS1) */
                memset(txdesc->rates, 0x10, sizeof(txdesc->rates));
        } else {
                /* data frames  */
                txdesc->header1.flags = UPGT_H1_FLAGS_TX_DATA;
                memcpy(txdesc->rates, sc->sc_cur_rateset, sizeof(txdesc->rates));
        }
        txdesc->header1.type = UPGT_H1_TYPE_TX_DATA;
        txdesc->header1.len = htole16(m->m_pkthdr.len);
        txdesc->header2.reqid = htole32(data->addr);
        txdesc->header2.type = htole16(UPGT_H2_TYPE_TX_ACK_YES);
        txdesc->header2.flags = htole16(UPGT_H2_FLAGS_TX_ACK_YES);
        txdesc->type = htole32(UPGT_TX_DESC_TYPE_DATA);
        txdesc->pad3[0] = UPGT_TX_DESC_PAD3_SIZE;

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

                tap->wt_flags = 0;
                tap->wt_rate = 0;       /* XXX where to get from? */

                ieee80211_radiotap_tx(vap, m);
        }

        /* copy frame below our TX descriptor header */
        m_copydata(m, 0, m->m_pkthdr.len,
            data->buf + (sizeof(*mem) + sizeof(*txdesc)));
        /* calculate frame size */
        len = sizeof(*mem) + sizeof(*txdesc) + m->m_pkthdr.len;
        /* we need to align the frame to a 4 byte boundary */
        len = (len + 3) & ~3;
        /* calculate frame checksum */
        mem->chksum = upgt_chksum_le((uint32_t *)txdesc, len - sizeof(*mem));
        data->ni = ni;
        data->m = m;
        data->buflen = len;

        DPRINTF(sc, UPGT_DEBUG_XMIT, "%s: TX start data sending (%d bytes)\n",
            __func__, len);
        KASSERT(len <= MCLBYTES, ("mbuf is small for saving data"));

        upgt_bulk_tx(sc, data);
done:
        /*
         * If we don't regulary read the device statistics, the RX queue
         * will stall.  It's strange, but it works, so we keep reading
         * the statistics here.  *shrug*
         */
        if (!(if_getcounter(vap->iv_ifp, IFCOUNTER_OPACKETS) %
            UPGT_TX_STAT_INTERVAL))
                upgt_get_stats(sc);

        return (error);
}

static void
upgt_bulk_rx_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct upgt_softc *sc = usbd_xfer_softc(xfer);
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211_frame *wh;
        struct ieee80211_node *ni;
        struct mbuf *m = NULL;
        struct upgt_data *data;
        int8_t nf;
        int rssi = -1;

        UPGT_ASSERT_LOCKED(sc);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                data = STAILQ_FIRST(&sc->sc_rx_active);
                if (data == NULL)
                        goto setup;
                STAILQ_REMOVE_HEAD(&sc->sc_rx_active, next);
                m = upgt_rxeof(xfer, data, &rssi);
                STAILQ_INSERT_TAIL(&sc->sc_rx_inactive, data, next);
                /* FALLTHROUGH */
        case USB_ST_SETUP:
setup:
                data = STAILQ_FIRST(&sc->sc_rx_inactive);
                if (data == NULL)
                        return;
                STAILQ_REMOVE_HEAD(&sc->sc_rx_inactive, next);
                STAILQ_INSERT_TAIL(&sc->sc_rx_active, data, next);
                usbd_xfer_set_frame_data(xfer, 0, data->buf, MCLBYTES);
                usbd_transfer_submit(xfer);

                /*
                 * To avoid LOR we should unlock our private mutex here to call
                 * ieee80211_input() because here is at the end of a USB
                 * callback and safe to unlock.
                 */
                UPGT_UNLOCK(sc);
                if (m != NULL) {
                        wh = mtod(m, struct ieee80211_frame *);
                        ni = ieee80211_find_rxnode(ic,
                            (struct ieee80211_frame_min *)wh);
                        nf = -95;       /* XXX */
                        if (ni != NULL) {
                                (void) ieee80211_input(ni, m, rssi, nf);
                                /* node is no longer needed */
                                ieee80211_free_node(ni);
                        } else
                                (void) ieee80211_input_all(ic, m, rssi, nf);
                        m = NULL;
                }
                UPGT_LOCK(sc);
                upgt_start(sc);
                break;
        default:
                /* needs it to the inactive queue due to a error.  */
                data = STAILQ_FIRST(&sc->sc_rx_active);
                if (data != NULL) {
                        STAILQ_REMOVE_HEAD(&sc->sc_rx_active, next);
                        STAILQ_INSERT_TAIL(&sc->sc_rx_inactive, data, next);
                }
                if (error != USB_ERR_CANCELLED) {
                        usbd_xfer_set_stall(xfer);
                        counter_u64_add(ic->ic_ierrors, 1);
                        goto setup;
                }
                break;
        }
}

static void
upgt_bulk_tx_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct upgt_softc *sc = usbd_xfer_softc(xfer);
        struct upgt_data *data;

        UPGT_ASSERT_LOCKED(sc);
        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                data = STAILQ_FIRST(&sc->sc_tx_active);
                if (data == NULL)
                        goto setup;
                STAILQ_REMOVE_HEAD(&sc->sc_tx_active, next);
                UPGT_STAT_DEC(sc, st_tx_active);
                upgt_txeof(xfer, data);
                STAILQ_INSERT_TAIL(&sc->sc_tx_inactive, data, next);
                UPGT_STAT_INC(sc, st_tx_inactive);
                /* FALLTHROUGH */
        case USB_ST_SETUP:
setup:
                data = STAILQ_FIRST(&sc->sc_tx_pending);
                if (data == NULL) {
                        DPRINTF(sc, UPGT_DEBUG_XMIT, "%s: empty pending queue\n",
                            __func__);
                        return;
                }
                STAILQ_REMOVE_HEAD(&sc->sc_tx_pending, next);
                UPGT_STAT_DEC(sc, st_tx_pending);
                STAILQ_INSERT_TAIL(&sc->sc_tx_active, data, next);
                UPGT_STAT_INC(sc, st_tx_active);

                usbd_xfer_set_frame_data(xfer, 0, data->buf, data->buflen);
                usbd_transfer_submit(xfer);
                upgt_start(sc);
                break;
        default:
                data = STAILQ_FIRST(&sc->sc_tx_active);
                if (data == NULL)
                        goto setup;
                if (data->ni != NULL) {
                        if_inc_counter(data->ni->ni_vap->iv_ifp,
                            IFCOUNTER_OERRORS, 1);
                        ieee80211_free_node(data->ni);
                        data->ni = NULL;
                }
                if (error != USB_ERR_CANCELLED) {
                        usbd_xfer_set_stall(xfer);
                        goto setup;
                }
                break;
        }
}

static device_method_t upgt_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe, upgt_match),
        DEVMETHOD(device_attach, upgt_attach),
        DEVMETHOD(device_detach, upgt_detach),
        DEVMETHOD_END
};

static driver_t upgt_driver = {
        .name = "upgt",
        .methods = upgt_methods,
        .size = sizeof(struct upgt_softc)
};

DRIVER_MODULE(if_upgt, uhub, upgt_driver, NULL, NULL);
MODULE_VERSION(if_upgt, 1);
MODULE_DEPEND(if_upgt, usb, 1, 1, 1);
MODULE_DEPEND(if_upgt, wlan, 1, 1, 1);
MODULE_DEPEND(if_upgt, upgtfw_fw, 1, 1, 1);
USB_PNP_HOST_INFO(upgt_devs);