root/sys/dev/usb/wlan/if_rsu.c
/*      $OpenBSD: if_rsu.c,v 1.17 2013/04/15 09:23:01 mglocker Exp $    */

/*-
 * Copyright (c) 2010 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.
 */
/*
 * Driver for Realtek RTL8188SU/RTL8191SU/RTL8192SU.
 *
 * TODO:
 *   o tx a-mpdu
 *   o hostap / ibss / mesh
 *   o power-save operation
 */

#include "opt_wlan.h"

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

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

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

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

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

#include <dev/rtwn/if_rtwn_ridx.h>      /* XXX */
#include <dev/usb/wlan/if_rsureg.h>

#define RSU_RATE_IS_CCK RTWN_RATE_IS_CCK

#ifdef USB_DEBUG
static int rsu_debug = 0;
SYSCTL_NODE(_hw_usb, OID_AUTO, rsu, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "USB rsu");
SYSCTL_INT(_hw_usb_rsu, OID_AUTO, debug, CTLFLAG_RWTUN, &rsu_debug, 0,
    "Debug level");
#define RSU_DPRINTF(_sc, _flg, ...)                                     \
        do                                                              \
                if (((_flg) == (RSU_DEBUG_ANY)) || (rsu_debug & (_flg))) \
                        device_printf((_sc)->sc_dev, __VA_ARGS__);      \
        while (0)
#else
#define RSU_DPRINTF(_sc, _flg, ...)
#endif

static int rsu_enable_11n = 1;
TUNABLE_INT("hw.usb.rsu.enable_11n", &rsu_enable_11n);

#define RSU_DEBUG_ANY           0xffffffff
#define RSU_DEBUG_TX            0x00000001
#define RSU_DEBUG_RX            0x00000002
#define RSU_DEBUG_RESET         0x00000004
#define RSU_DEBUG_CALIB         0x00000008
#define RSU_DEBUG_STATE         0x00000010
#define RSU_DEBUG_SCAN          0x00000020
#define RSU_DEBUG_FWCMD         0x00000040
#define RSU_DEBUG_TXDONE        0x00000080
#define RSU_DEBUG_FW            0x00000100
#define RSU_DEBUG_FWDBG         0x00000200
#define RSU_DEBUG_AMPDU         0x00000400
#define RSU_DEBUG_KEY           0x00000800
#define RSU_DEBUG_USB           0x00001000

static const STRUCT_USB_HOST_ID rsu_devs[] = {
#define RSU_HT_NOT_SUPPORTED 0
#define RSU_HT_SUPPORTED 1
#define RSU_DEV_HT(v,p)  { USB_VPI(USB_VENDOR_##v, USB_PRODUCT_##v##_##p, \
                                   RSU_HT_SUPPORTED) }
#define RSU_DEV(v,p)     { USB_VPI(USB_VENDOR_##v, USB_PRODUCT_##v##_##p, \
                                   RSU_HT_NOT_SUPPORTED) }
        RSU_DEV(ASUS,                   RTL8192SU),
        RSU_DEV(AZUREWAVE,              RTL8192SU_4),
        RSU_DEV(SITECOMEU,              WLA1000),
        RSU_DEV_HT(ACCTON,              RTL8192SU),
        RSU_DEV_HT(ASUS,                USBN10),
        RSU_DEV_HT(AZUREWAVE,           RTL8192SU_1),
        RSU_DEV_HT(AZUREWAVE,           RTL8192SU_2),
        RSU_DEV_HT(AZUREWAVE,           RTL8192SU_3),
        RSU_DEV_HT(AZUREWAVE,           RTL8192SU_5),
        RSU_DEV_HT(BELKIN,              RTL8192SU_1),
        RSU_DEV_HT(BELKIN,              RTL8192SU_2),
        RSU_DEV_HT(BELKIN,              RTL8192SU_3),
        RSU_DEV_HT(CONCEPTRONIC2,       RTL8192SU_1),
        RSU_DEV_HT(CONCEPTRONIC2,       RTL8192SU_2),
        RSU_DEV_HT(CONCEPTRONIC2,       RTL8192SU_3),
        RSU_DEV_HT(COREGA,              RTL8192SU),
        RSU_DEV_HT(DLINK2,              DWA131A1),
        RSU_DEV_HT(DLINK2,              RTL8192SU_1),
        RSU_DEV_HT(DLINK2,              RTL8192SU_2),
        RSU_DEV_HT(EDIMAX,              RTL8192SU_1),
        RSU_DEV_HT(EDIMAX,              RTL8192SU_2),
        RSU_DEV_HT(EDIMAX,              EW7622UMN),
        RSU_DEV_HT(GUILLEMOT,           HWGUN54),
        RSU_DEV_HT(GUILLEMOT,           HWNUM300),
        RSU_DEV_HT(HAWKING,             RTL8192SU_1),
        RSU_DEV_HT(HAWKING,             RTL8192SU_2),
        RSU_DEV_HT(PLANEX2,             GWUSNANO),
        RSU_DEV_HT(REALTEK,             RTL8171),
        RSU_DEV_HT(REALTEK,             RTL8172),
        RSU_DEV_HT(REALTEK,             RTL8173),
        RSU_DEV_HT(REALTEK,             RTL8174),
        RSU_DEV_HT(REALTEK,             RTL8192SU),
        RSU_DEV_HT(REALTEK,             RTL8712),
        RSU_DEV_HT(REALTEK,             RTL8713),
        RSU_DEV_HT(SENAO,               RTL8192SU_1),
        RSU_DEV_HT(SENAO,               RTL8192SU_2),
        RSU_DEV_HT(SITECOMEU,           WL349V1),
        RSU_DEV_HT(SITECOMEU,           WL353),
        RSU_DEV_HT(SITECOMEU,           RTL8188S),
        RSU_DEV_HT(SWEEX2,              LW154),
        RSU_DEV_HT(TRENDNET,            TEW646UBH),
#undef RSU_DEV_HT
#undef RSU_DEV
};

static device_probe_t   rsu_match;
static device_attach_t  rsu_attach;
static device_detach_t  rsu_detach;
static usb_callback_t   rsu_bulk_tx_callback_be_bk;
static usb_callback_t   rsu_bulk_tx_callback_vi_vo;
static usb_callback_t   rsu_bulk_tx_callback_h2c;
static usb_callback_t   rsu_bulk_rx_callback;
static usb_error_t      rsu_do_request(struct rsu_softc *,
                            struct usb_device_request *, void *);
static struct ieee80211vap *
                rsu_vap_create(struct ieee80211com *, const char name[IFNAMSIZ],
                    int, enum ieee80211_opmode, int,
                    const uint8_t bssid[IEEE80211_ADDR_LEN],
                    const uint8_t mac[IEEE80211_ADDR_LEN]);
static void     rsu_vap_delete(struct ieee80211vap *);
static void     rsu_scan_start(struct ieee80211com *);
static void     rsu_scan_end(struct ieee80211com *);
static void     rsu_getradiocaps(struct ieee80211com *, int, int *,
                    struct ieee80211_channel[]);
static void     rsu_set_channel(struct ieee80211com *);
static void     rsu_scan_curchan(struct ieee80211_scan_state *, unsigned long);
static void     rsu_scan_mindwell(struct ieee80211_scan_state *);
static void     rsu_update_promisc(struct ieee80211com *);
static uint8_t  rsu_get_multi_pos(const uint8_t[]);
static void     rsu_set_multi(struct rsu_softc *);
static void     rsu_update_mcast(struct ieee80211com *);
static int      rsu_alloc_rx_list(struct rsu_softc *);
static void     rsu_free_rx_list(struct rsu_softc *);
static int      rsu_alloc_tx_list(struct rsu_softc *);
static void     rsu_free_tx_list(struct rsu_softc *);
static void     rsu_free_list(struct rsu_softc *, struct rsu_data [], int);
static struct rsu_data *_rsu_getbuf(struct rsu_softc *);
static struct rsu_data *rsu_getbuf(struct rsu_softc *);
static void     rsu_freebuf(struct rsu_softc *, struct rsu_data *);
static int      rsu_write_region_1(struct rsu_softc *, uint16_t, uint8_t *,
                    int);
static void     rsu_write_1(struct rsu_softc *, uint16_t, uint8_t);
static void     rsu_write_2(struct rsu_softc *, uint16_t, uint16_t);
static void     rsu_write_4(struct rsu_softc *, uint16_t, uint32_t);
static int      rsu_read_region_1(struct rsu_softc *, uint16_t, uint8_t *,
                    int);
static uint8_t  rsu_read_1(struct rsu_softc *, uint16_t);
static uint16_t rsu_read_2(struct rsu_softc *, uint16_t);
static uint32_t rsu_read_4(struct rsu_softc *, uint16_t);
static int      rsu_fw_iocmd(struct rsu_softc *, uint32_t);
static uint8_t  rsu_efuse_read_1(struct rsu_softc *, uint16_t);
static int      rsu_read_rom(struct rsu_softc *);
static int      rsu_fw_cmd(struct rsu_softc *, uint8_t, void *, int);
static void     rsu_calib_task(void *, int);
static void     rsu_tx_task(void *, int);
static void     rsu_set_led(struct rsu_softc *, int);
static int      rsu_monitor_newstate(struct ieee80211vap *,
                    enum ieee80211_state, int);
static int      rsu_newstate(struct ieee80211vap *, enum ieee80211_state, int);
static int      rsu_key_alloc(struct ieee80211vap *, struct ieee80211_key *,
                    ieee80211_keyix *, ieee80211_keyix *);
static int      rsu_process_key(struct ieee80211vap *,
                    const struct ieee80211_key *, int);
static int      rsu_key_set(struct ieee80211vap *,
                    const struct ieee80211_key *);
static int      rsu_key_delete(struct ieee80211vap *,
                    const struct ieee80211_key *);
static int      rsu_cam_read(struct rsu_softc *, uint8_t, uint32_t *);
static void     rsu_cam_write(struct rsu_softc *, uint8_t, uint32_t);
static int      rsu_key_check(struct rsu_softc *, ieee80211_keyix, int);
static uint8_t  rsu_crypto_mode(struct rsu_softc *, u_int, int);
static int      rsu_set_key_group(struct rsu_softc *,
                    const struct ieee80211_key *);
static int      rsu_set_key_pair(struct rsu_softc *,
                    const struct ieee80211_key *);
static int      rsu_reinit_static_keys(struct rsu_softc *);
static int      rsu_delete_key(struct rsu_softc *sc, ieee80211_keyix);
static void     rsu_delete_key_pair_cb(void *, int);
static int      rsu_site_survey(struct rsu_softc *,
                    struct ieee80211_scan_ssid *);
static int      rsu_join_bss(struct rsu_softc *, struct ieee80211_node *);
static int      rsu_disconnect(struct rsu_softc *);
static int      rsu_hwrssi_to_rssi(struct rsu_softc *, int hw_rssi);
static void     rsu_event_survey(struct rsu_softc *, uint8_t *, int);
static void     rsu_event_join_bss(struct rsu_softc *, uint8_t *, int);
static void     rsu_rx_event(struct rsu_softc *, uint8_t, uint8_t *, int);
static void     rsu_rx_multi_event(struct rsu_softc *, uint8_t *, int);
static int8_t   rsu_get_rssi(struct rsu_softc *, int, void *);
static struct mbuf * rsu_rx_copy_to_mbuf(struct rsu_softc *,
                    struct r92s_rx_stat *, int);
static uint32_t rsu_get_tsf_low(struct rsu_softc *);
static uint32_t rsu_get_tsf_high(struct rsu_softc *);
static struct ieee80211_node * rsu_rx_frame(struct rsu_softc *, struct mbuf *);
static struct mbuf * rsu_rx_multi_frame(struct rsu_softc *, uint8_t *, int);
static struct mbuf *
                rsu_rxeof(struct usb_xfer *, struct rsu_data *);
static void     rsu_txeof(struct usb_xfer *, struct rsu_data *);
static int      rsu_raw_xmit(struct ieee80211_node *, struct mbuf *, 
                    const struct ieee80211_bpf_params *);
static void     rsu_rxfilter_init(struct rsu_softc *);
static void     rsu_rxfilter_set(struct rsu_softc *, uint32_t, uint32_t);
static void     rsu_rxfilter_refresh(struct rsu_softc *);
static int      rsu_init(struct rsu_softc *);
static int      rsu_tx_start(struct rsu_softc *, struct ieee80211_node *, 
                    struct mbuf *, struct rsu_data *);
static int      rsu_transmit(struct ieee80211com *, struct mbuf *);
static void     rsu_start(struct rsu_softc *);
static void     _rsu_start(struct rsu_softc *);
static int      rsu_ioctl_net(struct ieee80211com *, u_long, void *);
static void     rsu_parent(struct ieee80211com *);
static void     rsu_stop(struct rsu_softc *);
static void     rsu_ms_delay(struct rsu_softc *, int);

static device_method_t rsu_methods[] = {
        DEVMETHOD(device_probe,         rsu_match),
        DEVMETHOD(device_attach,        rsu_attach),
        DEVMETHOD(device_detach,        rsu_detach),

        DEVMETHOD_END
};

static driver_t rsu_driver = {
        .name = "rsu",
        .methods = rsu_methods,
        .size = sizeof(struct rsu_softc)
};

DRIVER_MODULE(rsu, uhub, rsu_driver, NULL, NULL);
MODULE_DEPEND(rsu, wlan, 1, 1, 1);
MODULE_DEPEND(rsu, usb, 1, 1, 1);
MODULE_DEPEND(rsu, firmware, 1, 1, 1);
MODULE_VERSION(rsu, 1);
USB_PNP_HOST_INFO(rsu_devs);

static uint8_t rsu_wme_ac_xfer_map[4] = {
        [WME_AC_BE] = RSU_BULK_TX_BE_BK,
        [WME_AC_BK] = RSU_BULK_TX_BE_BK,
        [WME_AC_VI] = RSU_BULK_TX_VI_VO,
        [WME_AC_VO] = RSU_BULK_TX_VI_VO,
};

/* XXX hard-coded */
#define RSU_H2C_ENDPOINT        3

static const struct usb_config rsu_config[RSU_N_TRANSFER] = {
        [RSU_BULK_RX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .bufsize = RSU_RXBUFSZ,
                .flags = {
                        .pipe_bof = 1,
                        .short_xfer_ok = 1
                },
                .callback = rsu_bulk_rx_callback
        },
        [RSU_BULK_TX_BE_BK] = {
                .type = UE_BULK,
                .endpoint = 0x06,
                .direction = UE_DIR_OUT,
                .bufsize = RSU_TXBUFSZ,
                .flags = {
                        .ext_buffer = 1,
                        .pipe_bof = 1,
                        .force_short_xfer = 1
                },
                .callback = rsu_bulk_tx_callback_be_bk,
                .timeout = RSU_TX_TIMEOUT
        },
        [RSU_BULK_TX_VI_VO] = {
                .type = UE_BULK,
                .endpoint = 0x04,
                .direction = UE_DIR_OUT,
                .bufsize = RSU_TXBUFSZ,
                .flags = {
                        .ext_buffer = 1,
                        .pipe_bof = 1,
                        .force_short_xfer = 1
                },
                .callback = rsu_bulk_tx_callback_vi_vo,
                .timeout = RSU_TX_TIMEOUT
        },
        [RSU_BULK_TX_H2C] = {
                .type = UE_BULK,
                .endpoint = 0x0d,
                .direction = UE_DIR_OUT,
                .bufsize = RSU_TXBUFSZ,
                .flags = {
                        .ext_buffer = 1,
                        .pipe_bof = 1,
                        .short_xfer_ok = 1
                },
                .callback = rsu_bulk_tx_callback_h2c,
                .timeout = RSU_TX_TIMEOUT
        },
};

static int
rsu_match(device_t self)
{
        struct usb_attach_arg *uaa = device_get_ivars(self);

        if (uaa->usb_mode != USB_MODE_HOST ||
            uaa->info.bIfaceIndex != 0 ||
            uaa->info.bConfigIndex != 0)
                return (ENXIO);

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

static int
rsu_send_mgmt(struct ieee80211_node *ni, int type, int arg)
{

        return (ENOTSUP);
}

static void
rsu_update_chw(struct ieee80211com *ic)
{

}

/*
 * notification from net80211 that it'd like to do A-MPDU on the given TID.
 */
static int
rsu_ampdu_enable(struct ieee80211_node *ni, struct ieee80211_tx_ampdu *tap)
{
        struct rsu_softc *sc = ni->ni_ic->ic_softc;
        struct r92s_add_ba_req req;

        RSU_DPRINTF(sc, RSU_DEBUG_AMPDU, "%s: called, tid=%d\n",
            __func__, tap->txa_tid);

        /* Don't enable if it's requested or running */
        if (IEEE80211_AMPDU_REQUESTED(tap))
                return (0);
        if (IEEE80211_AMPDU_RUNNING(tap))
                return (0);

        /* We've decided to send addba; so send it */
        req.tid = htole32(tap->txa_tid);

        /* Attempt net80211 state */
        if (ieee80211_ampdu_tx_request_ext(ni, tap->txa_tid) != 1)
                return (0);

        /* Send the firmware command */
        RSU_DPRINTF(sc, RSU_DEBUG_AMPDU,
            "%s: establishing AMPDU TX for TID %d\n",
            __func__,
            tap->txa_tid);

        RSU_LOCK(sc);
        if (rsu_fw_cmd(sc, R92S_CMD_ADDBA_REQ, &req, sizeof(req)) != 0) {
                RSU_UNLOCK(sc);
                RSU_DPRINTF(sc, RSU_DEBUG_AMPDU, "%s: AMPDU TX cmd failure\n",
                    __func__);
                /* Mark failure */
                ieee80211_ampdu_tx_request_active_ext(ni, tap->txa_tid, 0);
                /* Return 0, we've been driving this ourselves */
                return (0);
        }
        RSU_UNLOCK(sc);

        RSU_DPRINTF(sc, RSU_DEBUG_AMPDU, "%s: AMPDU TX cmd success\n",
            __func__);

        /* Mark success; we don't get any further notifications */
        ieee80211_ampdu_tx_request_active_ext(ni, tap->txa_tid, 1);

        /* Return 0, we've been driving this ourselves */
        return (0);
}

static int
rsu_wme_update(struct ieee80211com *ic)
{

        /* Firmware handles this; not our problem */
        return (0);
}

static int
rsu_attach(device_t self)
{
        struct usb_attach_arg *uaa = device_get_ivars(self);
        struct rsu_softc *sc = device_get_softc(self);
        struct ieee80211com *ic = &sc->sc_ic;
        int error;
        uint8_t iface_index;
        struct usb_interface *iface;
        const char *rft;

        device_set_usb_desc(self);
        sc->sc_udev = uaa->device;
        sc->sc_dev = self;
        sc->sc_rx_checksum_enable = 1;
        if (rsu_enable_11n)
                sc->sc_ht = !! (USB_GET_DRIVER_INFO(uaa) & RSU_HT_SUPPORTED);

        /* Get number of endpoints */
        iface = usbd_get_iface(sc->sc_udev, 0);
        sc->sc_nendpoints = iface->idesc->bNumEndpoints;

        /* Endpoints are hard-coded for now, so enforce 4-endpoint only */
        if (sc->sc_nendpoints != 4) {
                device_printf(sc->sc_dev,
                    "the driver currently only supports 4-endpoint devices\n");
                return (ENXIO);
        }

        mtx_init(&sc->sc_mtx, device_get_nameunit(self), MTX_NETWORK_LOCK,
            MTX_DEF);
        RSU_DELKEY_BMAP_LOCK_INIT(sc);
        TIMEOUT_TASK_INIT(taskqueue_thread, &sc->calib_task, 0, 
            rsu_calib_task, sc);
        TASK_INIT(&sc->del_key_task, 0, rsu_delete_key_pair_cb, sc);
        TASK_INIT(&sc->tx_task, 0, rsu_tx_task, sc);
        mbufq_init(&sc->sc_snd, ifqmaxlen);

        /* Allocate Tx/Rx buffers. */
        error = rsu_alloc_rx_list(sc);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not allocate Rx buffers\n");
                goto fail_usb;
        }

        error = rsu_alloc_tx_list(sc);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not allocate Tx buffers\n");
                rsu_free_rx_list(sc);
                goto fail_usb;
        }

        iface_index = 0;
        error = usbd_transfer_setup(uaa->device, &iface_index, sc->sc_xfer,
            rsu_config, RSU_N_TRANSFER, sc, &sc->sc_mtx);
        if (error) {
                device_printf(sc->sc_dev,
                    "could not allocate USB transfers, err=%s\n", 
                    usbd_errstr(error));
                goto fail_usb;
        }
        RSU_LOCK(sc);
        /* Read chip revision. */
        sc->cut = MS(rsu_read_4(sc, R92S_PMC_FSM), R92S_PMC_FSM_CUT);
        if (sc->cut != 3)
                sc->cut = (sc->cut >> 1) + 1;
        error = rsu_read_rom(sc);
        RSU_UNLOCK(sc);
        if (error != 0) {
                device_printf(self, "could not read ROM\n");
                goto fail_rom;
        }

        /* Figure out TX/RX streams */
        switch (sc->rom[84]) {
        case 0x0:
                sc->sc_rftype = RTL8712_RFCONFIG_1T1R;
                sc->sc_nrxstream = 1;
                sc->sc_ntxstream = 1;
                rft = "1T1R";
                break;
        case 0x1:
                sc->sc_rftype = RTL8712_RFCONFIG_1T2R;
                sc->sc_nrxstream = 2;
                sc->sc_ntxstream = 1;
                rft = "1T2R";
                break;
        case 0x2:
                sc->sc_rftype = RTL8712_RFCONFIG_2T2R;
                sc->sc_nrxstream = 2;
                sc->sc_ntxstream = 2;
                rft = "2T2R";
                break;
        case 0x3:       /* "green" NIC */
                sc->sc_rftype = RTL8712_RFCONFIG_1T2R;
                sc->sc_nrxstream = 2;
                sc->sc_ntxstream = 1;
                rft = "1T2R ('green')";
                break;
        default:
                device_printf(sc->sc_dev,
                    "%s: unknown board type (rfconfig=0x%02x)\n",
                    __func__,
                    sc->rom[84]);
                goto fail_rom;
        }

        IEEE80211_ADDR_COPY(ic->ic_macaddr, &sc->rom[0x12]);
        device_printf(self, "MAC/BB RTL8712 cut %d %s\n", sc->cut, rft);

        ic->ic_softc = sc;
        ic->ic_name = device_get_nameunit(self);
        ic->ic_phytype = IEEE80211_T_OFDM;      /* Not only, but not used. */
        ic->ic_opmode = IEEE80211_M_STA;        /* Default to BSS mode. */

        /* Set device capabilities. */
        ic->ic_caps =
            IEEE80211_C_STA |           /* station mode */
            IEEE80211_C_MONITOR |       /* monitor mode supported */
#if 0
            IEEE80211_C_BGSCAN |        /* Background scan. */
#endif
            IEEE80211_C_SHPREAMBLE |    /* Short preamble supported. */
            IEEE80211_C_WME |           /* WME/QoS */
            IEEE80211_C_SHSLOT |        /* Short slot time supported. */
            IEEE80211_C_WPA;            /* WPA/RSN. */

        ic->ic_cryptocaps =
            IEEE80211_CRYPTO_WEP |
            IEEE80211_CRYPTO_TKIP |
            IEEE80211_CRYPTO_AES_CCM;

        /* Check if HT support is present. */
        if (sc->sc_ht) {
                device_printf(sc->sc_dev, "%s: enabling 11n\n", __func__);

                /* Enable basic HT */
                ic->ic_htcaps = IEEE80211_HTC_HT |
                    IEEE80211_HTC_AMPDU |
                    IEEE80211_HTC_AMSDU |
                    IEEE80211_HTCAP_MAXAMSDU_3839 |
                    IEEE80211_HTCAP_SMPS_OFF;
                ic->ic_htcaps |= IEEE80211_HTCAP_CHWIDTH40;

                /* set number of spatial streams */
                ic->ic_txstream = sc->sc_ntxstream;
                ic->ic_rxstream = sc->sc_nrxstream;
        }
        ic->ic_flags_ext |= IEEE80211_FEXT_SCAN_OFFLOAD;
        ic->ic_flags_ext |= IEEE80211_FEXT_SEQNO_OFFLOAD;

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

        ieee80211_ifattach(ic);
        ic->ic_raw_xmit = rsu_raw_xmit;
        ic->ic_scan_start = rsu_scan_start;
        ic->ic_scan_end = rsu_scan_end;
        ic->ic_getradiocaps = rsu_getradiocaps;
        ic->ic_set_channel = rsu_set_channel;
        ic->ic_scan_curchan = rsu_scan_curchan;
        ic->ic_scan_mindwell = rsu_scan_mindwell;
        ic->ic_vap_create = rsu_vap_create;
        ic->ic_vap_delete = rsu_vap_delete;
        ic->ic_update_promisc = rsu_update_promisc;
        ic->ic_update_mcast = rsu_update_mcast;
        ic->ic_ioctl = rsu_ioctl_net;
        ic->ic_parent = rsu_parent;
        ic->ic_transmit = rsu_transmit;
        ic->ic_send_mgmt = rsu_send_mgmt;
        ic->ic_update_chw = rsu_update_chw;
        ic->ic_ampdu_enable = rsu_ampdu_enable;
        ic->ic_wme.wme_update = rsu_wme_update;

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

        if (bootverbose)
                ieee80211_announce(ic);

        return (0);

fail_rom:
        usbd_transfer_unsetup(sc->sc_xfer, RSU_N_TRANSFER);
fail_usb:
        mtx_destroy(&sc->sc_mtx);
        return (ENXIO);
}

static int
rsu_detach(device_t self)
{
        struct rsu_softc *sc = device_get_softc(self);
        struct ieee80211com *ic = &sc->sc_ic;

        rsu_stop(sc);

        usbd_transfer_unsetup(sc->sc_xfer, RSU_N_TRANSFER);

        /*
         * Free buffers /before/ we detach from net80211, else node
         * references to destroyed vaps will lead to a panic.
         */
        /* Free Tx/Rx buffers. */
        RSU_LOCK(sc);
        rsu_free_tx_list(sc);
        rsu_free_rx_list(sc);
        RSU_UNLOCK(sc);

        /* Frames are freed; detach from net80211 */
        ieee80211_ifdetach(ic);

        taskqueue_drain_timeout(taskqueue_thread, &sc->calib_task);
        taskqueue_drain(taskqueue_thread, &sc->del_key_task);
        taskqueue_drain(taskqueue_thread, &sc->tx_task);

        RSU_DELKEY_BMAP_LOCK_DESTROY(sc);
        mtx_destroy(&sc->sc_mtx);

        return (0);
}

static usb_error_t
rsu_do_request(struct rsu_softc *sc, struct usb_device_request *req,
    void *data)
{
        usb_error_t err;
        int ntries = 10;

        RSU_ASSERT_LOCKED(sc);

        while (ntries--) {
                err = usbd_do_request_flags(sc->sc_udev, &sc->sc_mtx,
                    req, data, 0, NULL, 250 /* ms */);
                if (err == 0 || err == USB_ERR_NOT_CONFIGURED)
                        break;
                RSU_DPRINTF(sc, RSU_DEBUG_USB,
                    "Control request failed, %s (retries left: %d)\n",
                    usbd_errstr(err), ntries);
                rsu_ms_delay(sc, 10);
        }

        return (err);
}

static struct ieee80211vap *
rsu_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 rsu_softc *sc = ic->ic_softc;
        struct rsu_vap *uvp;
        struct ieee80211vap *vap;
        if_t ifp;

        if (!TAILQ_EMPTY(&ic->ic_vaps))         /* only one at a time */
                return (NULL);

        uvp =  malloc(sizeof(struct rsu_vap), M_80211_VAP, M_WAITOK | M_ZERO);
        vap = &uvp->vap;

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

        ifp = vap->iv_ifp;
        if_setcapabilities(ifp, IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6);
        RSU_LOCK(sc);
        if (sc->sc_rx_checksum_enable)
                if_setcapenablebit(ifp, IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6, 0);
        RSU_UNLOCK(sc);

        /* override state transition machine */
        uvp->newstate = vap->iv_newstate;
        if (opmode == IEEE80211_M_MONITOR)
                vap->iv_newstate = rsu_monitor_newstate;
        else
                vap->iv_newstate = rsu_newstate;
        vap->iv_key_alloc = rsu_key_alloc;
        vap->iv_key_set = rsu_key_set;
        vap->iv_key_delete = rsu_key_delete;

        /* Limits from the r92su driver */
        vap->iv_ampdu_density = IEEE80211_HTCAP_MPDUDENSITY_16;
        vap->iv_ampdu_rxmax = IEEE80211_HTCAP_MAXRXAMPDU_32K;

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

        return (vap);
}

static void
rsu_vap_delete(struct ieee80211vap *vap)
{
        struct rsu_vap *uvp = RSU_VAP(vap);

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

static void
rsu_scan_start(struct ieee80211com *ic)
{
        struct rsu_softc *sc = ic->ic_softc;
        struct ieee80211_scan_state *ss = ic->ic_scan;
        struct ieee80211vap *vap = TAILQ_FIRST(&ic->ic_vaps);
        int error;

        /* Scanning is done by the firmware. */
        RSU_LOCK(sc);
        sc->sc_active_scan = !!(ss->ss_flags & IEEE80211_SCAN_ACTIVE);
        /* XXX TODO: force awake if in network-sleep? */
        error = rsu_site_survey(sc, ss->ss_nssid > 0 ? &ss->ss_ssid[0] : NULL);
        RSU_UNLOCK(sc);
        if (error != 0) {
                device_printf(sc->sc_dev,
                    "could not send site survey command\n");
                ieee80211_cancel_scan(vap);
        }
}

static void
rsu_scan_end(struct ieee80211com *ic)
{
        /* Nothing to do here. */
}

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

        /* Set supported .11b and .11g rates. */
        memset(bands, 0, sizeof(bands));
        setbit(bands, IEEE80211_MODE_11B);
        setbit(bands, IEEE80211_MODE_11G);
        if (sc->sc_ht)
                setbit(bands, IEEE80211_MODE_11NG);
        ieee80211_add_channels_default_2ghz(chans, maxchans, nchans,
            bands, (ic->ic_htcaps & IEEE80211_HTCAP_CHWIDTH40) ?
                NET80211_CBW_FLAG_HT40 : 0);
}

static void
rsu_set_channel(struct ieee80211com *ic)
{
        struct rsu_softc *sc = ic->ic_softc;

        /*
         * Only need to set the channel in Monitor mode. AP scanning and auth
         * are already taken care of by their respective firmware commands.
         */     
        if (ic->ic_opmode == IEEE80211_M_MONITOR) {
                struct r92s_set_channel cmd;
                int error;

                cmd.channel = IEEE80211_CHAN2IEEE(ic->ic_curchan);

                RSU_LOCK(sc);
                error = rsu_fw_cmd(sc, R92S_CMD_SET_CHANNEL, &cmd,
                    sizeof(cmd));
                if (error != 0) {
                        device_printf(sc->sc_dev,
                            "%s: error %d setting channel\n", __func__,
                            error);
                }
                RSU_UNLOCK(sc);
        }
}

static void
rsu_scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
{
        /* Scan is done in rsu_scan_start(). */
}

/**
 * Called by the net80211 framework to indicate
 * the minimum dwell time has been met, terminate the scan.
 * We don't actually terminate the scan as the firmware will notify
 * us when it's finished and we have no way to interrupt it.
 */
static void
rsu_scan_mindwell(struct ieee80211_scan_state *ss)
{
        /* NB: don't try to abort scan; wait for firmware to finish */
}

static void
rsu_update_promisc(struct ieee80211com *ic)
{
        struct rsu_softc *sc = ic->ic_softc;

        RSU_LOCK(sc);
        if (sc->sc_running)
                rsu_rxfilter_refresh(sc);
        RSU_UNLOCK(sc);
}

/*
 * The same as rtwn_get_multi_pos() / rtwn_set_multi().
 */
static uint8_t
rsu_get_multi_pos(const uint8_t maddr[])
{
        uint64_t mask = 0x00004d101df481b4;
        uint8_t pos = 0x27;     /* initial value */
        int i, j;

        for (i = 0; i < IEEE80211_ADDR_LEN; i++)
                for (j = (i == 0) ? 1 : 0; j < 8; j++)
                        if ((maddr[i] >> j) & 1)
                                pos ^= (mask >> (i * 8 + j - 1));

        pos &= 0x3f;

        return (pos);
}

static u_int
rsu_hash_maddr(void *arg, struct sockaddr_dl *sdl, u_int cnt)
{
        uint32_t *mfilt = arg;
        uint8_t pos;

        pos = rsu_get_multi_pos(LLADDR(sdl));
        mfilt[pos / 32] |= (1 << (pos % 32));

        return (1);
}

static void
rsu_set_multi(struct rsu_softc *sc)
{
        struct ieee80211com *ic = &sc->sc_ic;
        uint32_t mfilt[2];

        RSU_ASSERT_LOCKED(sc);

        /* general structure was copied from ath(4). */
        if (ic->ic_allmulti == 0) {
                struct ieee80211vap *vap;

                /*
                 * Merge multicast addresses to form the hardware filter.
                 */
                mfilt[0] = mfilt[1] = 0;
                TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next)
                        if_foreach_llmaddr(vap->iv_ifp, rsu_hash_maddr, &mfilt);
        } else
                mfilt[0] = mfilt[1] = ~0;

        rsu_write_4(sc, R92S_MAR + 0, mfilt[0]);
        rsu_write_4(sc, R92S_MAR + 4, mfilt[1]);

        RSU_DPRINTF(sc, RSU_DEBUG_STATE, "%s: MC filter %08x:%08x\n",
            __func__, mfilt[0], mfilt[1]);
}

static void
rsu_update_mcast(struct ieee80211com *ic)
{
        struct rsu_softc *sc = ic->ic_softc;

        RSU_LOCK(sc);
        if (sc->sc_running)
                rsu_set_multi(sc);
        RSU_UNLOCK(sc);
}

static int
rsu_alloc_list(struct rsu_softc *sc, struct rsu_data data[],
    int ndata, int maxsz)
{
        int i, error;

        for (i = 0; i < ndata; i++) {
                struct rsu_data *dp = &data[i];
                dp->sc = sc;
                dp->m = NULL;
                dp->buf = malloc(maxsz, M_USBDEV, M_NOWAIT);
                if (dp->buf == NULL) {
                        device_printf(sc->sc_dev,
                            "could not allocate buffer\n");
                        error = ENOMEM;
                        goto fail;
                }
                dp->ni = NULL;
        }

        return (0);
fail:
        rsu_free_list(sc, data, ndata);
        return (error);
}

static int
rsu_alloc_rx_list(struct rsu_softc *sc)
{
        int error, i;

        error = rsu_alloc_list(sc, sc->sc_rx, RSU_RX_LIST_COUNT,
            RSU_RXBUFSZ);
        if (error != 0)
                return (error);

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

        for (i = 0; i < RSU_RX_LIST_COUNT; i++)
                STAILQ_INSERT_HEAD(&sc->sc_rx_inactive, &sc->sc_rx[i], next);

        return (0);
}

static int
rsu_alloc_tx_list(struct rsu_softc *sc)
{
        int error, i;

        error = rsu_alloc_list(sc, sc->sc_tx, RSU_TX_LIST_COUNT,
            RSU_TXBUFSZ);
        if (error != 0)
                return (error);

        STAILQ_INIT(&sc->sc_tx_inactive);

        for (i = 0; i != RSU_N_TRANSFER; i++) {
                STAILQ_INIT(&sc->sc_tx_active[i]);
                STAILQ_INIT(&sc->sc_tx_pending[i]);
        }

        for (i = 0; i < RSU_TX_LIST_COUNT; i++) {
                STAILQ_INSERT_HEAD(&sc->sc_tx_inactive, &sc->sc_tx[i], next);
        }

        return (0);
}

static void
rsu_free_tx_list(struct rsu_softc *sc)
{
        int i;

        /* prevent further allocations from TX list(s) */
        STAILQ_INIT(&sc->sc_tx_inactive);

        for (i = 0; i != RSU_N_TRANSFER; i++) {
                STAILQ_INIT(&sc->sc_tx_active[i]);
                STAILQ_INIT(&sc->sc_tx_pending[i]);
        }

        rsu_free_list(sc, sc->sc_tx, RSU_TX_LIST_COUNT);
}

static void
rsu_free_rx_list(struct rsu_softc *sc)
{
        /* prevent further allocations from RX list(s) */
        STAILQ_INIT(&sc->sc_rx_inactive);
        STAILQ_INIT(&sc->sc_rx_active);

        rsu_free_list(sc, sc->sc_rx, RSU_RX_LIST_COUNT);
}

static void
rsu_free_list(struct rsu_softc *sc, struct rsu_data data[], int ndata)
{
        int i;

        for (i = 0; i < ndata; i++) {
                struct rsu_data *dp = &data[i];

                if (dp->buf != NULL) {
                        free(dp->buf, M_USBDEV);
                        dp->buf = NULL;
                }
                if (dp->ni != NULL) {
                        ieee80211_free_node(dp->ni);
                        dp->ni = NULL;
                }
        }
}

static struct rsu_data *
_rsu_getbuf(struct rsu_softc *sc)
{
        struct rsu_data *bf;

        bf = STAILQ_FIRST(&sc->sc_tx_inactive);
        if (bf != NULL)
                STAILQ_REMOVE_HEAD(&sc->sc_tx_inactive, next);
        else
                bf = NULL;
        return (bf);
}

static struct rsu_data *
rsu_getbuf(struct rsu_softc *sc)
{
        struct rsu_data *bf;

        RSU_ASSERT_LOCKED(sc);

        bf = _rsu_getbuf(sc);
        if (bf == NULL) {
                RSU_DPRINTF(sc, RSU_DEBUG_TX, "%s: no buffers\n", __func__);
        }
        return (bf);
}

static void
rsu_freebuf(struct rsu_softc *sc, struct rsu_data *bf)
{

        RSU_ASSERT_LOCKED(sc);
        STAILQ_INSERT_TAIL(&sc->sc_tx_inactive, bf, next);
}

static int
rsu_write_region_1(struct rsu_softc *sc, uint16_t addr, uint8_t *buf,
    int len)
{
        usb_device_request_t req;

        req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
        req.bRequest = R92S_REQ_REGS;
        USETW(req.wValue, addr);
        USETW(req.wIndex, 0);
        USETW(req.wLength, len);

        return (rsu_do_request(sc, &req, buf));
}

static void
rsu_write_1(struct rsu_softc *sc, uint16_t addr, uint8_t val)
{
        rsu_write_region_1(sc, addr, &val, 1);
}

static void
rsu_write_2(struct rsu_softc *sc, uint16_t addr, uint16_t val)
{
        val = htole16(val);
        rsu_write_region_1(sc, addr, (uint8_t *)&val, 2);
}

static void
rsu_write_4(struct rsu_softc *sc, uint16_t addr, uint32_t val)
{
        val = htole32(val);
        rsu_write_region_1(sc, addr, (uint8_t *)&val, 4);
}

static int
rsu_read_region_1(struct rsu_softc *sc, uint16_t addr, uint8_t *buf,
    int len)
{
        usb_device_request_t req;

        req.bmRequestType = UT_READ_VENDOR_DEVICE;
        req.bRequest = R92S_REQ_REGS;
        USETW(req.wValue, addr);
        USETW(req.wIndex, 0);
        USETW(req.wLength, len);

        return (rsu_do_request(sc, &req, buf));
}

static uint8_t
rsu_read_1(struct rsu_softc *sc, uint16_t addr)
{
        uint8_t val;

        if (rsu_read_region_1(sc, addr, &val, 1) != 0)
                return (0xff);
        return (val);
}

static uint16_t
rsu_read_2(struct rsu_softc *sc, uint16_t addr)
{
        uint16_t val;

        if (rsu_read_region_1(sc, addr, (uint8_t *)&val, 2) != 0)
                return (0xffff);
        return (le16toh(val));
}

static uint32_t
rsu_read_4(struct rsu_softc *sc, uint16_t addr)
{
        uint32_t val;

        if (rsu_read_region_1(sc, addr, (uint8_t *)&val, 4) != 0)
                return (0xffffffff);
        return (le32toh(val));
}

static int
rsu_fw_iocmd(struct rsu_softc *sc, uint32_t iocmd)
{
        int ntries;

        rsu_write_4(sc, R92S_IOCMD_CTRL, iocmd);
        rsu_ms_delay(sc, 1);
        for (ntries = 0; ntries < 50; ntries++) {
                if (rsu_read_4(sc, R92S_IOCMD_CTRL) == 0)
                        return (0);
                rsu_ms_delay(sc, 1);
        }
        return (ETIMEDOUT);
}

static uint8_t
rsu_efuse_read_1(struct rsu_softc *sc, uint16_t addr)
{
        uint32_t reg;
        int ntries;

        reg = rsu_read_4(sc, R92S_EFUSE_CTRL);
        reg = RW(reg, R92S_EFUSE_CTRL_ADDR, addr);
        reg &= ~R92S_EFUSE_CTRL_VALID;
        rsu_write_4(sc, R92S_EFUSE_CTRL, reg);
        /* Wait for read operation to complete. */
        for (ntries = 0; ntries < 100; ntries++) {
                reg = rsu_read_4(sc, R92S_EFUSE_CTRL);
                if (reg & R92S_EFUSE_CTRL_VALID)
                        return (MS(reg, R92S_EFUSE_CTRL_DATA));
                rsu_ms_delay(sc, 1);
        }
        device_printf(sc->sc_dev,
            "could not read efuse byte at address 0x%x\n", addr);
        return (0xff);
}

static int
rsu_read_rom(struct rsu_softc *sc)
{
        uint8_t *rom = sc->rom;
        uint16_t addr = 0;
        uint32_t reg;
        uint8_t off, msk;
        int i;

        /* Make sure that ROM type is eFuse and that autoload succeeded. */
        reg = rsu_read_1(sc, R92S_EE_9346CR);
        if ((reg & (R92S_9356SEL | R92S_EEPROM_EN)) != R92S_EEPROM_EN)
                return (EIO);

        /* Turn on 2.5V to prevent eFuse leakage. */
        reg = rsu_read_1(sc, R92S_EFUSE_TEST + 3);
        rsu_write_1(sc, R92S_EFUSE_TEST + 3, reg | 0x80);
        rsu_ms_delay(sc, 1);
        rsu_write_1(sc, R92S_EFUSE_TEST + 3, reg & ~0x80);

        /* Read full ROM image. */
        memset(&sc->rom, 0xff, sizeof(sc->rom));
        while (addr < 512) {
                reg = rsu_efuse_read_1(sc, addr);
                if (reg == 0xff)
                        break;
                addr++;
                off = reg >> 4;
                msk = reg & 0xf;
                for (i = 0; i < 4; i++) {
                        if (msk & (1 << i))
                                continue;
                        rom[off * 8 + i * 2 + 0] =
                            rsu_efuse_read_1(sc, addr);
                        addr++;
                        rom[off * 8 + i * 2 + 1] =
                            rsu_efuse_read_1(sc, addr);
                        addr++;
                }
        }
#ifdef USB_DEBUG
        if (rsu_debug & RSU_DEBUG_RESET) {
                /* Dump ROM content. */
                printf("\n");
                for (i = 0; i < sizeof(sc->rom); i++)
                        printf("%02x:", rom[i]);
                printf("\n");
        }
#endif
        return (0);
}

static int
rsu_fw_cmd(struct rsu_softc *sc, uint8_t code, void *buf, int len)
{
        const uint8_t which = RSU_H2C_ENDPOINT;
        struct rsu_data *data;
        struct r92s_tx_desc *txd;
        struct r92s_fw_cmd_hdr *cmd;
        int cmdsz;
        int xferlen;

        RSU_ASSERT_LOCKED(sc);

        data = rsu_getbuf(sc);
        if (data == NULL)
                return (ENOMEM);

        /* Blank the entire payload, just to be safe */
        memset(data->buf, '\0', RSU_TXBUFSZ);

        /* Round-up command length to a multiple of 8 bytes. */
        /* XXX TODO: is this required? */
        cmdsz = (len + 7) & ~7;

        xferlen = sizeof(*txd) + sizeof(*cmd) + cmdsz;
        KASSERT(xferlen <= RSU_TXBUFSZ, ("%s: invalid length", __func__));
        memset(data->buf, 0, xferlen);

        /* Setup Tx descriptor. */
        txd = (struct r92s_tx_desc *)data->buf;
        txd->txdw0 = htole32(
            SM(R92S_TXDW0_OFFSET, sizeof(*txd)) |
            SM(R92S_TXDW0_PKTLEN, sizeof(*cmd) + cmdsz) |
            R92S_TXDW0_OWN | R92S_TXDW0_FSG | R92S_TXDW0_LSG);
        txd->txdw1 = htole32(SM(R92S_TXDW1_QSEL, R92S_TXDW1_QSEL_H2C));

        /* Setup command header. */
        cmd = (struct r92s_fw_cmd_hdr *)&txd[1];
        cmd->len = htole16(cmdsz);
        cmd->code = code;
        cmd->seq = sc->cmd_seq;
        sc->cmd_seq = (sc->cmd_seq + 1) & 0x7f;

        /* Copy command payload. */
        memcpy(&cmd[1], buf, len);

        RSU_DPRINTF(sc, RSU_DEBUG_TX | RSU_DEBUG_FWCMD,
            "%s: Tx cmd code=0x%x len=0x%x\n",
            __func__, code, cmdsz);
        data->buflen = xferlen;
        STAILQ_INSERT_TAIL(&sc->sc_tx_pending[which], data, next);
        usbd_transfer_start(sc->sc_xfer[which]);

        return (0);
}

/* ARGSUSED */
static void
rsu_calib_task(void *arg, int pending __unused)
{
        struct rsu_softc *sc = arg;
#ifdef notyet
        uint32_t reg;
#endif

        RSU_DPRINTF(sc, RSU_DEBUG_CALIB, "%s: running calibration task\n",
            __func__);

        RSU_LOCK(sc);
#ifdef notyet
        /* Read WPS PBC status. */
        rsu_write_1(sc, R92S_MAC_PINMUX_CTRL,
            R92S_GPIOMUX_EN | SM(R92S_GPIOSEL_GPIO, R92S_GPIOSEL_GPIO_JTAG));
        rsu_write_1(sc, R92S_GPIO_IO_SEL,
            rsu_read_1(sc, R92S_GPIO_IO_SEL) & ~R92S_GPIO_WPS);
        reg = rsu_read_1(sc, R92S_GPIO_CTRL);
        if (reg != 0xff && (reg & R92S_GPIO_WPS))
                RSU_DPRINTF(sc, RSU_DEBUG_CALIB, "WPS PBC is pushed\n");
#endif
        /* Read current signal level. */
        if (rsu_fw_iocmd(sc, 0xf4000001) == 0) {
                sc->sc_currssi = rsu_read_4(sc, R92S_IOCMD_DATA);
                RSU_DPRINTF(sc, RSU_DEBUG_CALIB, "%s: RSSI=%d (%d)\n",
                    __func__, sc->sc_currssi,
                    rsu_hwrssi_to_rssi(sc, sc->sc_currssi));
        }
        if (sc->sc_calibrating)
                taskqueue_enqueue_timeout(taskqueue_thread, &sc->calib_task, hz);
        RSU_UNLOCK(sc);
}

static void
rsu_tx_task(void *arg, int pending __unused)
{
        struct rsu_softc *sc = arg;

        RSU_LOCK(sc);
        _rsu_start(sc);
        RSU_UNLOCK(sc);
}

#define RSU_PWR_UNKNOWN         0x0
#define RSU_PWR_ACTIVE          0x1
#define RSU_PWR_OFF             0x2
#define RSU_PWR_SLEEP           0x3

/*
 * Set the current power state.
 *
 * The rtlwifi code doesn't do this so aggressively; it
 * waits for an idle period after association with
 * no traffic before doing this.
 *
 * For now - it's on in all states except RUN, and
 * in RUN it'll transition to allow sleep.
 */

struct r92s_pwr_cmd {
        uint8_t mode;
        uint8_t smart_ps;
        uint8_t bcn_pass_time;
};

static int
rsu_set_fw_power_state(struct rsu_softc *sc, int state)
{
        struct r92s_set_pwr_mode cmd;
        //struct r92s_pwr_cmd cmd;
        int error;

        RSU_ASSERT_LOCKED(sc);

        /* only change state if required */
        if (sc->sc_curpwrstate == state)
                return (0);

        memset(&cmd, 0, sizeof(cmd));

        switch (state) {
        case RSU_PWR_ACTIVE:
                /* Force the hardware awake */
                rsu_write_1(sc, R92S_USB_HRPWM,
                    R92S_USB_HRPWM_PS_ST_ACTIVE | R92S_USB_HRPWM_PS_ALL_ON);
                cmd.mode = R92S_PS_MODE_ACTIVE;
                break;
        case RSU_PWR_SLEEP:
                cmd.mode = R92S_PS_MODE_DTIM;   /* XXX configurable? */
                cmd.smart_ps = 1; /* XXX 2 if doing p2p */
                cmd.bcn_pass_time = 5; /* in 100mS usb.c, linux/rtlwifi */
                break;
        case RSU_PWR_OFF:
                cmd.mode = R92S_PS_MODE_RADIOOFF;
                break;
        default:
                device_printf(sc->sc_dev, "%s: unknown ps mode (%d)\n",
                    __func__,
                    state);
                return (ENXIO);
        }

        RSU_DPRINTF(sc, RSU_DEBUG_RESET,
            "%s: setting ps mode to %d (mode %d)\n",
            __func__, state, cmd.mode);
        error = rsu_fw_cmd(sc, R92S_CMD_SET_PWR_MODE, &cmd, sizeof(cmd));
        if (error == 0)
                sc->sc_curpwrstate = state;

        return (error);
}

static void
rsu_set_led(struct rsu_softc *sc, int on)
{
        rsu_write_1(sc, R92S_LEDCFG,
            (rsu_read_1(sc, R92S_LEDCFG) & 0xf0) | (!on << 3));
}

static int
rsu_monitor_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate,
    int arg)
{
        struct ieee80211com *ic = vap->iv_ic;
        struct rsu_softc *sc = ic->ic_softc;
        struct rsu_vap *uvp = RSU_VAP(vap);

        if (vap->iv_state != nstate) {
                IEEE80211_UNLOCK(ic);
                RSU_LOCK(sc);

                switch (nstate) {
                case IEEE80211_S_INIT:
                        sc->sc_vap_is_running = 0;
                        rsu_set_led(sc, 0);
                        break;
                case IEEE80211_S_RUN:
                        sc->sc_vap_is_running = 1;
                        rsu_set_led(sc, 1);
                        break;
                default:
                        /* NOTREACHED */
                        break;
                }
                rsu_rxfilter_refresh(sc);

                RSU_UNLOCK(sc);
                IEEE80211_LOCK(ic);
        }

        return (uvp->newstate(vap, nstate, arg));
}

static int
rsu_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
{
        struct rsu_vap *uvp = RSU_VAP(vap);
        struct ieee80211com *ic = vap->iv_ic;
        struct rsu_softc *sc = ic->ic_softc;
        struct ieee80211_node *ni;
        struct ieee80211_rateset *rs;
        enum ieee80211_state ostate;
        int error, startcal = 0;

        ostate = vap->iv_state;
        RSU_DPRINTF(sc, RSU_DEBUG_STATE, "%s: %s -> %s\n",
            __func__,
            ieee80211_state_name[ostate],
            ieee80211_state_name[nstate]);

        IEEE80211_UNLOCK(ic);
        if (ostate == IEEE80211_S_RUN) {
                RSU_LOCK(sc);
                /* Stop calibration. */
                sc->sc_calibrating = 0;

                /* Pause Tx for AC queues. */
                rsu_write_1(sc, R92S_TXPAUSE, R92S_TXPAUSE_AC);
                usb_pause_mtx(&sc->sc_mtx, USB_MS_TO_TICKS(10));

                RSU_UNLOCK(sc);
                taskqueue_drain_timeout(taskqueue_thread, &sc->calib_task);
                taskqueue_drain(taskqueue_thread, &sc->tx_task);
                RSU_LOCK(sc);
                /* Disassociate from our current BSS. */
                rsu_disconnect(sc);
                usb_pause_mtx(&sc->sc_mtx, USB_MS_TO_TICKS(10));

                /* Refresh Rx filter (may be modified by firmware). */
                sc->sc_vap_is_running = 0;
                rsu_rxfilter_refresh(sc);

                /* Reinstall static keys. */
                if (sc->sc_running)
                        rsu_reinit_static_keys(sc);
        } else
                RSU_LOCK(sc);
        switch (nstate) {
        case IEEE80211_S_INIT:
                (void) rsu_set_fw_power_state(sc, RSU_PWR_ACTIVE);
                break;
        case IEEE80211_S_AUTH:
                ni = ieee80211_ref_node(vap->iv_bss);
                (void) rsu_set_fw_power_state(sc, RSU_PWR_ACTIVE);
                error = rsu_join_bss(sc, ni);
                ieee80211_free_node(ni);
                if (error != 0) {
                        device_printf(sc->sc_dev,
                            "could not send join command\n");
                }
                break;
        case IEEE80211_S_RUN:
                /* Flush all AC queues. */
                rsu_write_1(sc, R92S_TXPAUSE, 0);

                ni = ieee80211_ref_node(vap->iv_bss);
                rs = &ni->ni_rates;
                /* Indicate highest supported rate. */
                ieee80211_node_set_txrate_dot11rate(ni,
                    rs->rs_rates[rs->rs_nrates - 1]);
                (void) rsu_set_fw_power_state(sc, RSU_PWR_SLEEP);
                ieee80211_free_node(ni);
                startcal = 1;
                break;
        default:
                break;
        }
        if (startcal != 0) {
                sc->sc_calibrating = 1;
                /* Start periodic calibration. */
                taskqueue_enqueue_timeout(taskqueue_thread, &sc->calib_task,
                    hz);
        }
        RSU_UNLOCK(sc);
        IEEE80211_LOCK(ic);
        return (uvp->newstate(vap, nstate, arg));
}

static int
rsu_key_alloc(struct ieee80211vap *vap, struct ieee80211_key *k,
    ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
{
        struct rsu_softc *sc = vap->iv_ic->ic_softc;
        int is_checked = 0;

        if (ieee80211_is_key_global(vap, k)) {
                *keyix = ieee80211_crypto_get_key_wepidx(vap, k);
        } else {
                /* Note: assumes this is a pairwise key */
                if (vap->iv_opmode != IEEE80211_M_STA) {
                        *keyix = 0;
                        /* TODO: obtain keyix from node id */
                        is_checked = 1;
                        k->wk_flags |= IEEE80211_KEY_SWCRYPT;
                } else
                        /*
                         * TODO: should allocate these from the CAM space;
                         * skipping over the fixed slots and _BC / _BSS.
                         */
                        *keyix = R92S_MACID_BSS;
        }

        if (!is_checked) {
                RSU_LOCK(sc);
                if (isset(sc->keys_bmap, *keyix)) {
                        device_printf(sc->sc_dev,
                            "%s: key slot %d is already used!\n",
                            __func__, *keyix);
                        RSU_UNLOCK(sc);
                        return (0);
                }
                setbit(sc->keys_bmap, *keyix);
                RSU_UNLOCK(sc);
        }

        *rxkeyix = *keyix;

        return (1);
}

static int
rsu_process_key(struct ieee80211vap *vap, const struct ieee80211_key *k,
    int set)
{
        struct rsu_softc *sc = vap->iv_ic->ic_softc;
        int ret;

        if (k->wk_flags & IEEE80211_KEY_SWCRYPT) {
                /* Not for us. */
                return (1);
        }

        /* Handle group keys. */
        if (ieee80211_is_key_global(vap, k)) {
                KASSERT(k->wk_keyix < nitems(sc->group_keys),
                    ("keyix %u > %zu\n", k->wk_keyix, nitems(sc->group_keys)));

                RSU_LOCK(sc);
                sc->group_keys[k->wk_keyix] = (set ? k : NULL);
                if (!sc->sc_running) {
                        /* Static keys will be set during device startup. */
                        RSU_UNLOCK(sc);
                        return (1);
                }

                if (set)
                        ret = rsu_set_key_group(sc, k);
                else
                        ret = rsu_delete_key(sc, k->wk_keyix);
                RSU_UNLOCK(sc);

                return (!ret);
        }

        if (set) {
                /* wait for pending key removal */
                taskqueue_drain(taskqueue_thread, &sc->del_key_task);

                RSU_LOCK(sc);
                ret = rsu_set_key_pair(sc, k);
                RSU_UNLOCK(sc);
        } else {
                RSU_DELKEY_BMAP_LOCK(sc);
                setbit(sc->free_keys_bmap, k->wk_keyix);
                RSU_DELKEY_BMAP_UNLOCK(sc);

                /* workaround ieee80211_node_delucastkey() locking */
                taskqueue_enqueue(taskqueue_thread, &sc->del_key_task);
                ret = 0;        /* fake success */
        }

        return (!ret);
}

static int
rsu_key_set(struct ieee80211vap *vap, const struct ieee80211_key *k)
{
        return (rsu_process_key(vap, k, 1));
}

static int
rsu_key_delete(struct ieee80211vap *vap, const struct ieee80211_key *k)
{
        return (rsu_process_key(vap, k, 0));
}

static int
rsu_cam_read(struct rsu_softc *sc, uint8_t addr, uint32_t *val)
{
        int ntries;

        rsu_write_4(sc, R92S_CAMCMD,
            R92S_CAMCMD_POLLING | SM(R92S_CAMCMD_ADDR, addr));
        for (ntries = 0; ntries < 10; ntries++) {
                if (!(rsu_read_4(sc, R92S_CAMCMD) & R92S_CAMCMD_POLLING))
                        break;

                usb_pause_mtx(&sc->sc_mtx, USB_MS_TO_TICKS(1));
        }
        if (ntries == 10) {
                device_printf(sc->sc_dev,
                    "%s: cannot read CAM entry at address %02X\n",
                    __func__, addr);
                return (ETIMEDOUT);
        }

        *val = rsu_read_4(sc, R92S_CAMREAD);

        return (0);
}

static void
rsu_cam_write(struct rsu_softc *sc, uint8_t addr, uint32_t data)
{

        rsu_write_4(sc, R92S_CAMWRITE, data);
        rsu_write_4(sc, R92S_CAMCMD,
            R92S_CAMCMD_POLLING | R92S_CAMCMD_WRITE |
            SM(R92S_CAMCMD_ADDR, addr));
}

static int
rsu_key_check(struct rsu_softc *sc, ieee80211_keyix keyix, int is_valid)
{
        uint32_t val;
        int error, ntries;

        for (ntries = 0; ntries < 20; ntries++) {
                usb_pause_mtx(&sc->sc_mtx, USB_MS_TO_TICKS(1));

                error = rsu_cam_read(sc, R92S_CAM_CTL0(keyix), &val);
                if (error != 0) {
                        device_printf(sc->sc_dev,
                            "%s: cannot check key status!\n", __func__);
                        return (error);
                }
                if (((val & R92S_CAM_VALID) == 0) ^ is_valid)
                        break;
        }
        if (ntries == 20) {
                device_printf(sc->sc_dev,
                    "%s: key %d is %s marked as valid, rejecting request\n",
                    __func__, keyix, is_valid ? "not" : "still");
                return (EIO);
        }

        return (0);
}

/*
 * Map net80211 cipher to RTL8712 security mode.
 */
static uint8_t
rsu_crypto_mode(struct rsu_softc *sc, u_int cipher, int keylen)
{
        switch (cipher) {
        case IEEE80211_CIPHER_WEP:
                return keylen < 8 ? R92S_KEY_ALGO_WEP40 : R92S_KEY_ALGO_WEP104;
        case IEEE80211_CIPHER_TKIP:
                return R92S_KEY_ALGO_TKIP;
        case IEEE80211_CIPHER_AES_CCM:
                return R92S_KEY_ALGO_AES;
        default:
                device_printf(sc->sc_dev, "unknown cipher %d\n", cipher);
                return R92S_KEY_ALGO_INVALID;
        }
}

static int
rsu_set_key_group(struct rsu_softc *sc, const struct ieee80211_key *k)
{
        struct r92s_fw_cmd_set_key key;
        uint8_t algo;
        int error;

        RSU_ASSERT_LOCKED(sc);

        /* Map net80211 cipher to HW crypto algorithm. */
        algo = rsu_crypto_mode(sc, k->wk_cipher->ic_cipher,
            ieee80211_crypto_get_key_len(k));
        if (algo == R92S_KEY_ALGO_INVALID)
                return (EINVAL);

        memset(&key, 0, sizeof(key));
        key.algo = algo;
        key.cam_id = k->wk_keyix;
        key.grpkey = (k->wk_flags & IEEE80211_KEY_GROUP) != 0;
        memcpy(key.key, ieee80211_crypto_get_key_data(k),
            MIN(ieee80211_crypto_get_key_len(k), sizeof(key.key)));

        RSU_DPRINTF(sc, RSU_DEBUG_KEY | RSU_DEBUG_FWCMD,
            "%s: keyix %u, group %u, algo %u/%u, flags %04X, len %u, "
            "macaddr %s\n", __func__, key.cam_id, key.grpkey,
            k->wk_cipher->ic_cipher, key.algo, k->wk_flags,
            ieee80211_crypto_get_key_len(k), ether_sprintf(k->wk_macaddr));

        error = rsu_fw_cmd(sc, R92S_CMD_SET_KEY, &key, sizeof(key));
        if (error != 0) {
                device_printf(sc->sc_dev,
                    "%s: cannot send firmware command, error %d\n",
                    __func__, error);
                return (error);
        }

        return (rsu_key_check(sc, k->wk_keyix, 1));
}

static int
rsu_set_key_pair(struct rsu_softc *sc, const struct ieee80211_key *k)
{
        struct r92s_fw_cmd_set_key_mac key;
        uint8_t algo;
        int error;

        RSU_ASSERT_LOCKED(sc);

        if (!sc->sc_running)
                return (ESHUTDOWN);

        /* Map net80211 cipher to HW crypto algorithm. */
        algo = rsu_crypto_mode(sc, k->wk_cipher->ic_cipher,
            ieee80211_crypto_get_key_len(k));
        if (algo == R92S_KEY_ALGO_INVALID)
                return (EINVAL);

        memset(&key, 0, sizeof(key));
        key.algo = algo;
        memcpy(key.macaddr, k->wk_macaddr, sizeof(key.macaddr));
        memcpy(key.key, ieee80211_crypto_get_key_data(k),
            MIN(ieee80211_crypto_get_key_len(k), sizeof(key.key)));

        RSU_DPRINTF(sc, RSU_DEBUG_KEY | RSU_DEBUG_FWCMD,
            "%s: keyix %u, algo %u/%u, flags %04X, len %u, macaddr %s\n",
            __func__, k->wk_keyix, k->wk_cipher->ic_cipher, key.algo,
            k->wk_flags, ieee80211_crypto_get_key_len(k),
            ether_sprintf(key.macaddr));

        error = rsu_fw_cmd(sc, R92S_CMD_SET_STA_KEY, &key, sizeof(key));
        if (error != 0) {
                device_printf(sc->sc_dev,
                    "%s: cannot send firmware command, error %d\n",
                    __func__, error);
                return (error);
        }

        return (rsu_key_check(sc, k->wk_keyix, 1));
}

static int
rsu_reinit_static_keys(struct rsu_softc *sc)
{
        int i, error;

        for (i = 0; i < nitems(sc->group_keys); i++) {
                if (sc->group_keys[i] != NULL) {
                        error = rsu_set_key_group(sc, sc->group_keys[i]);
                        if (error != 0) {
                                device_printf(sc->sc_dev,
                                    "%s: failed to set static key %d, "
                                    "error %d\n", __func__, i, error);
                                return (error);
                        }
                }
        }

        return (0);
}

static int
rsu_delete_key(struct rsu_softc *sc, ieee80211_keyix keyix)
{
        struct r92s_fw_cmd_set_key key;
        uint32_t val;
        int error;

        RSU_ASSERT_LOCKED(sc);

        if (!sc->sc_running)
                return (0);

        /* check if it was automatically removed by firmware */
        error = rsu_cam_read(sc, R92S_CAM_CTL0(keyix), &val);
        if (error == 0 && (val & R92S_CAM_VALID) == 0) {
                RSU_DPRINTF(sc, RSU_DEBUG_KEY,
                    "%s: key %u does not exist\n", __func__, keyix);
                clrbit(sc->keys_bmap, keyix);
                return (0);
        }

        memset(&key, 0, sizeof(key));
        key.cam_id = keyix;

        RSU_DPRINTF(sc, RSU_DEBUG_KEY | RSU_DEBUG_FWCMD,
            "%s: removing key %u\n", __func__, key.cam_id);

        error = rsu_fw_cmd(sc, R92S_CMD_SET_KEY, &key, sizeof(key));
        if (error != 0) {
                device_printf(sc->sc_dev,
                    "%s: cannot send firmware command, error %d\n",
                    __func__, error);
                goto finish;
        }

        usb_pause_mtx(&sc->sc_mtx, USB_MS_TO_TICKS(5));

        /*
         * Clear 'valid' bit manually (cannot be done via firmware command).
         * Used for key check + when firmware command cannot be sent.
         */
finish:
        rsu_cam_write(sc, R92S_CAM_CTL0(keyix), 0);

        clrbit(sc->keys_bmap, keyix);

        return (rsu_key_check(sc, keyix, 0));
}

static void
rsu_delete_key_pair_cb(void *arg, int pending __unused)
{
        struct rsu_softc *sc = arg;
        int i;

        RSU_DELKEY_BMAP_LOCK(sc);
        for (i = IEEE80211_WEP_NKID; i < R92S_CAM_ENTRY_LIMIT; i++) {
                if (isset(sc->free_keys_bmap, i)) {
                        RSU_DELKEY_BMAP_UNLOCK(sc);

                        RSU_LOCK(sc);
                        RSU_DPRINTF(sc, RSU_DEBUG_KEY,
                            "%s: calling rsu_delete_key() with keyix = %d\n",
                            __func__, i);
                        (void) rsu_delete_key(sc, i);
                        RSU_UNLOCK(sc);

                        RSU_DELKEY_BMAP_LOCK(sc);
                        clrbit(sc->free_keys_bmap, i);

                        /* bmap can be changed */
                        i = IEEE80211_WEP_NKID - 1;
                        continue;
                }
        }
        RSU_DELKEY_BMAP_UNLOCK(sc);
}

static int
rsu_site_survey(struct rsu_softc *sc, struct ieee80211_scan_ssid *ssid)
{
        struct r92s_fw_cmd_sitesurvey cmd;

        RSU_ASSERT_LOCKED(sc);

        memset(&cmd, 0, sizeof(cmd));
        /* TODO: passive channels? */
        if (sc->sc_active_scan)
                cmd.active = htole32(1);
        cmd.limit = htole32(48);

        if (ssid != NULL) {
                sc->sc_extra_scan = 1;
                cmd.ssidlen = htole32(ssid->len);
                memcpy(cmd.ssid, ssid->ssid, ssid->len);
        }
#ifdef USB_DEBUG
        if (rsu_debug & (RSU_DEBUG_SCAN | RSU_DEBUG_FWCMD)) {
                device_printf(sc->sc_dev,
                    "sending site survey command, active %d",
                    le32toh(cmd.active));
                if (ssid != NULL) {
                        printf(", ssid: ");
                        ieee80211_print_essid(cmd.ssid, le32toh(cmd.ssidlen));
                }
                printf("\n");
        }
#endif
        return (rsu_fw_cmd(sc, R92S_CMD_SITE_SURVEY, &cmd, sizeof(cmd)));
}

static int
rsu_join_bss(struct rsu_softc *sc, struct ieee80211_node *ni)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211vap *vap = ni->ni_vap;
        struct ndis_wlan_bssid_ex *bss;
        struct ndis_802_11_fixed_ies *fixed;
        struct r92s_fw_cmd_auth auth;
        uint8_t buf[sizeof(*bss) + 128] __aligned(4);
        uint8_t *frm;
        uint8_t opmode;
        int error;

        RSU_ASSERT_LOCKED(sc);

        /* Let the FW decide the opmode based on the capinfo field. */
        opmode = NDIS802_11AUTOUNKNOWN;
        RSU_DPRINTF(sc, RSU_DEBUG_RESET,
            "%s: setting operating mode to %d\n",
            __func__, opmode);
        error = rsu_fw_cmd(sc, R92S_CMD_SET_OPMODE, &opmode, sizeof(opmode));
        if (error != 0)
                return (error);

        memset(&auth, 0, sizeof(auth));
        if (vap->iv_flags & IEEE80211_F_WPA) {
                auth.mode = R92S_AUTHMODE_WPA;
                auth.dot1x = (ni->ni_authmode == IEEE80211_AUTH_8021X);
        } else
                auth.mode = R92S_AUTHMODE_OPEN;
        RSU_DPRINTF(sc, RSU_DEBUG_RESET,
            "%s: setting auth mode to %d\n",
            __func__, auth.mode);
        error = rsu_fw_cmd(sc, R92S_CMD_SET_AUTH, &auth, sizeof(auth));
        if (error != 0)
                return (error);

        memset(buf, 0, sizeof(buf));
        bss = (struct ndis_wlan_bssid_ex *)buf;
        IEEE80211_ADDR_COPY(bss->macaddr, ni->ni_bssid);
        bss->ssid.ssidlen = htole32(ni->ni_esslen);
        memcpy(bss->ssid.ssid, ni->ni_essid, ni->ni_esslen);
        if (vap->iv_flags & (IEEE80211_F_PRIVACY | IEEE80211_F_WPA))
                bss->privacy = htole32(1);
        bss->rssi = htole32(ni->ni_avgrssi);
        if (ic->ic_curmode == IEEE80211_MODE_11B)
                bss->networktype = htole32(NDIS802_11DS);
        else
                bss->networktype = htole32(NDIS802_11OFDM24);
        bss->config.len = htole32(sizeof(bss->config));
        bss->config.bintval = htole32(ni->ni_intval);
        bss->config.dsconfig = htole32(ieee80211_chan2ieee(ic, ni->ni_chan));
        bss->inframode = htole32(NDIS802_11INFRASTRUCTURE);
        /* XXX verify how this is supposed to look! */
        memcpy(bss->supprates, ni->ni_rates.rs_rates,
            ni->ni_rates.rs_nrates);
        /* Write the fixed fields of the beacon frame. */
        fixed = (struct ndis_802_11_fixed_ies *)&bss[1];
        memcpy(&fixed->tstamp, ni->ni_tstamp.data, 8);
        fixed->bintval = htole16(ni->ni_intval);
        fixed->capabilities = htole16(ni->ni_capinfo);
        /* Write IEs to be included in the association request. */
        frm = (uint8_t *)&fixed[1];
        frm = ieee80211_add_rsn(frm, vap);
        frm = ieee80211_add_wpa(frm, vap);
        frm = ieee80211_add_qos(frm, ni);
        if ((ic->ic_flags & IEEE80211_F_WME) &&
            (ni->ni_ies.wme_ie != NULL))
                frm = ieee80211_add_wme_info(frm, &ic->ic_wme, ni);
        if (ni->ni_flags & IEEE80211_NODE_HT) {
                frm = ieee80211_add_htcap(frm, ni);
                frm = ieee80211_add_htinfo(frm, ni);
        }
        bss->ieslen = htole32(frm - (uint8_t *)fixed);
        bss->len = htole32(((frm - buf) + 3) & ~3);
        RSU_DPRINTF(sc, RSU_DEBUG_RESET | RSU_DEBUG_FWCMD,
            "%s: sending join bss command to %s chan %d\n",
            __func__,
            ether_sprintf(bss->macaddr), le32toh(bss->config.dsconfig));
        return (rsu_fw_cmd(sc, R92S_CMD_JOIN_BSS, buf, sizeof(buf)));
}

static int
rsu_disconnect(struct rsu_softc *sc)
{
        uint32_t zero = 0;      /* :-) */

        /* Disassociate from our current BSS. */
        RSU_DPRINTF(sc, RSU_DEBUG_STATE | RSU_DEBUG_FWCMD,
            "%s: sending disconnect command\n", __func__);
        return (rsu_fw_cmd(sc, R92S_CMD_DISCONNECT, &zero, sizeof(zero)));
}

/*
 * Map the hardware provided RSSI value to a signal level.
 * For the most part it's just something we divide by and cap
 * so it doesn't overflow the representation by net80211.
 */
static int
rsu_hwrssi_to_rssi(struct rsu_softc *sc, int hw_rssi)
{
        int v;

        if (hw_rssi == 0)
                return (0);
        v = hw_rssi >> 4;
        if (v > 80)
                v = 80;
        return (v);
}

CTASSERT(MCLBYTES > sizeof(struct ieee80211_frame));

static void
rsu_event_survey(struct rsu_softc *sc, uint8_t *buf, int len)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211_frame *wh;
        struct ndis_wlan_bssid_ex *bss;
        struct ieee80211_rx_stats rxs;
        struct mbuf *m;
        uint32_t ieslen;
        uint32_t pktlen;

        if (__predict_false(len < sizeof(*bss)))
                return;
        bss = (struct ndis_wlan_bssid_ex *)buf;
        ieslen = le32toh(bss->ieslen);
        /* range check length of information element */
        if (__predict_false(ieslen > (uint32_t)(len - sizeof(*bss))))
                return;

        RSU_DPRINTF(sc, RSU_DEBUG_SCAN,
            "%s: found BSS %s: len=%d chan=%d inframode=%d "
            "networktype=%d privacy=%d, RSSI=%d\n",
            __func__,
            ether_sprintf(bss->macaddr), ieslen,
            le32toh(bss->config.dsconfig), le32toh(bss->inframode),
            le32toh(bss->networktype), le32toh(bss->privacy),
            le32toh(bss->rssi));

        /* Build a fake beacon frame to let net80211 do all the parsing. */
        /* XXX TODO: just call the new scan API methods! */
        if (__predict_false(ieslen > (size_t)(MCLBYTES - sizeof(*wh))))
                return;
        pktlen = sizeof(*wh) + ieslen;
        m = m_get2(pktlen, M_NOWAIT, MT_DATA, M_PKTHDR);
        if (__predict_false(m == NULL))
                return;
        wh = mtod(m, struct ieee80211_frame *);
        wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_MGT |
            IEEE80211_FC0_SUBTYPE_BEACON;
        wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
        USETW(wh->i_dur, 0);
        IEEE80211_ADDR_COPY(wh->i_addr1, ieee80211broadcastaddr);
        IEEE80211_ADDR_COPY(wh->i_addr2, bss->macaddr);
        IEEE80211_ADDR_COPY(wh->i_addr3, bss->macaddr);
        *(uint16_t *)wh->i_seq = 0;
        memcpy(&wh[1], (uint8_t *)&bss[1], ieslen);

        /* Finalize mbuf. */
        m->m_pkthdr.len = m->m_len = pktlen;

        /* Set channel flags for input path */
        bzero(&rxs, sizeof(rxs));
        rxs.r_flags |= IEEE80211_R_IEEE | IEEE80211_R_FREQ;
        rxs.r_flags |= IEEE80211_R_BAND;
        rxs.r_flags |= IEEE80211_R_NF | IEEE80211_R_RSSI;
        rxs.c_ieee = le32toh(bss->config.dsconfig);
        rxs.c_freq = ieee80211_ieee2mhz(rxs.c_ieee, IEEE80211_CHAN_2GHZ);
        rxs.c_band = IEEE80211_CHAN_2GHZ;
        /* This is a number from 0..100; so let's just divide it down a bit */
        rxs.c_rssi = le32toh(bss->rssi) / 2;
        rxs.c_nf = -96;
        if (ieee80211_add_rx_params(m, &rxs) == 0)
                return;

        /* XXX avoid a LOR */
        RSU_UNLOCK(sc);
        ieee80211_input_mimo_all(ic, m);
        RSU_LOCK(sc);
}

static void
rsu_event_join_bss(struct rsu_softc *sc, uint8_t *buf, int len)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211vap *vap = TAILQ_FIRST(&ic->ic_vaps);
        struct ieee80211_node *ni = vap->iv_bss;
        struct r92s_event_join_bss *rsp;
        uint32_t tmp;
        int res;

        if (__predict_false(len < sizeof(*rsp)))
                return;
        rsp = (struct r92s_event_join_bss *)buf;
        res = (int)le32toh(rsp->join_res);

        RSU_DPRINTF(sc, RSU_DEBUG_STATE | RSU_DEBUG_FWCMD,
            "%s: Rx join BSS event len=%d res=%d\n",
            __func__, len, res);

        /*
         * XXX Don't do this; there's likely a better way to tell
         * the caller we failed.
         */
        if (res <= 0) {
                RSU_UNLOCK(sc);
                ieee80211_new_state(vap, IEEE80211_S_SCAN, -1);
                RSU_LOCK(sc);
                return;
        }

        tmp = le32toh(rsp->associd);
        if (tmp >= vap->iv_max_aid) {
                RSU_DPRINTF(sc, RSU_DEBUG_ANY, "Assoc ID overflow\n");
                tmp = 1;
        }
        RSU_DPRINTF(sc, RSU_DEBUG_STATE | RSU_DEBUG_FWCMD,
            "%s: associated with %s associd=%d\n",
            __func__, ether_sprintf(rsp->bss.macaddr), tmp);
        /* XXX is this required? What's the top two bits for again? */
        ni->ni_associd = tmp | 0xc000;

        /* Refresh Rx filter (was changed by firmware). */
        sc->sc_vap_is_running = 1;
        rsu_rxfilter_refresh(sc);

        RSU_UNLOCK(sc);
        ieee80211_new_state(vap, IEEE80211_S_RUN,
            IEEE80211_FC0_SUBTYPE_ASSOC_RESP);
        RSU_LOCK(sc);
}

static void
rsu_event_addba_req_report(struct rsu_softc *sc, uint8_t *buf, int len)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211vap *vap = TAILQ_FIRST(&ic->ic_vaps);
        struct r92s_add_ba_event *ba = (void *) buf;
        struct ieee80211_node *ni;

        if (len < sizeof(*ba)) {
                device_printf(sc->sc_dev, "%s: short read (%d)\n", __func__, len);
                return;
        }

        if (vap == NULL)
                return;

        RSU_DPRINTF(sc, RSU_DEBUG_AMPDU, "%s: mac=%s, tid=%d, ssn=%d\n",
            __func__,
            ether_sprintf(ba->mac_addr),
            (int) ba->tid,
            (int) le16toh(ba->ssn) >> 4);

        /* XXX do node lookup; this is STA specific */

        ni = ieee80211_ref_node(vap->iv_bss);
        ieee80211_ampdu_rx_start_ext(ni, ba->tid, le16toh(ba->ssn) >> 4, 32);
        ieee80211_free_node(ni);
}

static void
rsu_rx_event(struct rsu_softc *sc, uint8_t code, uint8_t *buf, int len)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211vap *vap = TAILQ_FIRST(&ic->ic_vaps);

        RSU_DPRINTF(sc, RSU_DEBUG_RX | RSU_DEBUG_FWCMD,
            "%s: Rx event code=%d len=%d\n", __func__, code, len);
        switch (code) {
        case R92S_EVT_SURVEY:
                rsu_event_survey(sc, buf, len);
                break;
        case R92S_EVT_SURVEY_DONE:
                RSU_DPRINTF(sc, RSU_DEBUG_SCAN,
                    "%s: %s scan done, found %d BSS\n",
                    __func__, sc->sc_extra_scan ? "direct" : "broadcast",
                    le32toh(*(uint32_t *)buf));
                if (sc->sc_extra_scan == 1) {
                        /* Send broadcast probe request. */
                        sc->sc_extra_scan = 0;
                        if (vap != NULL && rsu_site_survey(sc, NULL) != 0) {
                                RSU_UNLOCK(sc);
                                ieee80211_cancel_scan(vap);
                                RSU_LOCK(sc);
                        }
                        break;
                }
                if (vap != NULL) {
                        RSU_UNLOCK(sc);
                        ieee80211_scan_done(vap);
                        RSU_LOCK(sc);
                }
                break;
        case R92S_EVT_JOIN_BSS:
                if (vap->iv_state == IEEE80211_S_AUTH)
                        rsu_event_join_bss(sc, buf, len);
                break;

        /* TODO: what about R92S_EVT_ADD_STA? and decoding macid? */
        /* It likely is required for IBSS/AP mode */

        /* TODO: should I be doing this transition in AP mode? */
        case R92S_EVT_DEL_STA:
                RSU_DPRINTF(sc, RSU_DEBUG_FWCMD | RSU_DEBUG_STATE,
                    "%s: disassociated from %s\n", __func__,
                    ether_sprintf(buf));
                if (vap->iv_state == IEEE80211_S_RUN &&
                    IEEE80211_ADDR_EQ(vap->iv_bss->ni_bssid, buf)) {
                        RSU_UNLOCK(sc);
                        ieee80211_new_state(vap, IEEE80211_S_SCAN, -1);
                        RSU_LOCK(sc);
                }
                break;
        case R92S_EVT_WPS_PBC:
                RSU_DPRINTF(sc, RSU_DEBUG_RX | RSU_DEBUG_FWCMD,
                    "%s: WPS PBC pushed.\n", __func__);
                break;
        case R92S_EVT_FWDBG:
                buf[60] = '\0';
                /* TODO: some are \n terminated, some aren't, sigh */
                RSU_DPRINTF(sc, RSU_DEBUG_FWDBG, "FWDBG: %s\n", (char *)buf);
                break;
        case R92S_EVT_ADDBA_REQ_REPORT:
                rsu_event_addba_req_report(sc, buf, len);
                break;
        default:
                device_printf(sc->sc_dev, "%s: unhandled code (%d)\n", __func__, code);
                break;
        }
}

static void
rsu_rx_multi_event(struct rsu_softc *sc, uint8_t *buf, int len)
{
        struct r92s_fw_cmd_hdr *cmd;
        int cmdsz;

        RSU_DPRINTF(sc, RSU_DEBUG_RX, "%s: Rx events len=%d\n", __func__, len);

        /* Skip Rx status. */
        buf += sizeof(struct r92s_rx_stat);
        len -= sizeof(struct r92s_rx_stat);

        /* Process all events. */
        for (;;) {
                /* Check that command header fits. */
                if (__predict_false(len < sizeof(*cmd)))
                        break;
                cmd = (struct r92s_fw_cmd_hdr *)buf;
                /* Check that command payload fits. */
                cmdsz = le16toh(cmd->len);
                if (__predict_false(len < sizeof(*cmd) + cmdsz))
                        break;

                /* Process firmware event. */
                rsu_rx_event(sc, cmd->code, (uint8_t *)&cmd[1], cmdsz);

                if (!(cmd->seq & R92S_FW_CMD_MORE))
                        break;
                buf += sizeof(*cmd) + cmdsz;
                len -= sizeof(*cmd) + cmdsz;
        }
}

static int8_t
rsu_get_rssi(struct rsu_softc *sc, int rate, void *physt)
{
        static const int8_t cckoff[] = { 14, -2, -20, -40 };
        struct r92s_rx_phystat *phy;
        struct r92s_rx_cck *cck;
        uint8_t rpt;
        int8_t rssi;

        if (rate <= 3) {
                cck = (struct r92s_rx_cck *)physt;
                rpt = (cck->agc_rpt >> 6) & 0x3;
                rssi = cck->agc_rpt & 0x3e;
                rssi = cckoff[rpt] - rssi;
        } else {        /* OFDM/HT. */
                phy = (struct r92s_rx_phystat *)physt;
                rssi = ((le32toh(phy->phydw1) >> 1) & 0x7f) - 106;
        }
        return (rssi);
}

static struct mbuf *
rsu_rx_copy_to_mbuf(struct rsu_softc *sc, struct r92s_rx_stat *stat,
    int totlen)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct mbuf *m;
        uint32_t rxdw0;
        int pktlen;

        rxdw0 = le32toh(stat->rxdw0);
        if (__predict_false(rxdw0 & (R92S_RXDW0_CRCERR | R92S_RXDW0_ICVERR))) {
                RSU_DPRINTF(sc, RSU_DEBUG_RX,
                    "%s: RX flags error (%s)\n", __func__,
                    rxdw0 & R92S_RXDW0_CRCERR ? "CRC" : "ICV");
                goto fail;
        }

        pktlen = MS(rxdw0, R92S_RXDW0_PKTLEN);
        if (__predict_false(pktlen < sizeof (struct ieee80211_frame_ack))) {
                RSU_DPRINTF(sc, RSU_DEBUG_RX,
                    "%s: frame is too short: %d\n", __func__, pktlen);
                goto fail;
        }

        m = m_get2(totlen, M_NOWAIT, MT_DATA, M_PKTHDR);
        if (__predict_false(m == NULL)) {
                device_printf(sc->sc_dev,
                    "%s: could not allocate RX mbuf, totlen %d\n",
                    __func__, totlen);
                goto fail;
        }

        /* Finalize mbuf. */
        memcpy(mtod(m, uint8_t *), (uint8_t *)stat, totlen);
        m->m_pkthdr.len = m->m_len = totlen;

        return (m);
fail:
        counter_u64_add(ic->ic_ierrors, 1);
        return (NULL);
}

static uint32_t
rsu_get_tsf_low(struct rsu_softc *sc)
{
        return (rsu_read_4(sc, R92S_TSFTR));
}

static uint32_t
rsu_get_tsf_high(struct rsu_softc *sc)
{
        return (rsu_read_4(sc, R92S_TSFTR + 4));
}

static struct ieee80211_node *
rsu_rx_frame(struct rsu_softc *sc, struct mbuf *m)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211_frame_min *wh;
        struct ieee80211_rx_stats rxs;
        struct r92s_rx_stat *stat;
        uint32_t rxdw0, rxdw3;
        uint8_t cipher, rate;
        int infosz;
        int rssi;

        stat = mtod(m, struct r92s_rx_stat *);
        rxdw0 = le32toh(stat->rxdw0);
        rxdw3 = le32toh(stat->rxdw3);

        rate = MS(rxdw3, R92S_RXDW3_RATE);
        cipher = MS(rxdw0, R92S_RXDW0_CIPHER);
        infosz = MS(rxdw0, R92S_RXDW0_INFOSZ) * 8;

        /* Get RSSI from PHY status descriptor if present. */
        if (infosz != 0 && (rxdw0 & R92S_RXDW0_PHYST))
                rssi = rsu_get_rssi(sc, rate, &stat[1]);
        else {
                /* Cheat and get the last calibrated RSSI */
                rssi = rsu_hwrssi_to_rssi(sc, sc->sc_currssi);
        }

        /* Hardware does Rx TCP checksum offload. */
        /*
         * This flag can be set for some other
         * (e.g., EAPOL) frame types, so don't rely on it.
         */
        if (rxdw3 & R92S_RXDW3_TCPCHKVALID) {
                RSU_DPRINTF(sc, RSU_DEBUG_RX,
                    "%s: TCP/IP checksums: %schecked / %schecked\n",
                    __func__,
                    (rxdw3 & R92S_RXDW3_TCPCHKRPT) ? "" : "not ",
                    (rxdw3 & R92S_RXDW3_IPCHKRPT) ? "" : "not ");

                /*
                 * 'IP header checksum valid' bit will not be set if
                 * the frame was not checked / has incorrect checksum /
                 * does not have checksum (IPv6).
                 *
                 * NB: if DF bit is not set then frame will not be checked.
                 */
                if (rxdw3 & R92S_RXDW3_IPCHKRPT) {
                        m->m_pkthdr.csum_flags = CSUM_IP_CHECKED;
                        m->m_pkthdr.csum_flags |= CSUM_IP_VALID;
                }

                /*
                 * This is independent of the above check.
                 */
                if (rxdw3 & R92S_RXDW3_TCPCHKRPT) {
                        m->m_pkthdr.csum_flags |= CSUM_DATA_VALID;
                        m->m_pkthdr.csum_flags |= CSUM_PSEUDO_HDR;
                        m->m_pkthdr.csum_data = 0xffff;
                }
        }

        /* RX flags */

        /* Set channel flags for input path */
        bzero(&rxs, sizeof(rxs));

        /* normal RSSI */
        rxs.r_flags |= IEEE80211_R_NF | IEEE80211_R_RSSI;
        rxs.c_rssi = rssi;
        rxs.c_nf = -96;

        /* Rate */
        if (rate < 12) {
                rxs.c_rate = ridx2rate[rate];
                if (RSU_RATE_IS_CCK(rate))
                        rxs.c_pktflags |= IEEE80211_RX_F_CCK;
                else
                        rxs.c_pktflags |= IEEE80211_RX_F_OFDM;
        } else {
                rxs.c_rate = IEEE80211_RATE_MCS | (rate - 12);
                rxs.c_pktflags |= IEEE80211_RX_F_HT;
        }

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

                /* Map HW rate index to 802.11 rate. */
                tap->wr_flags = 0;              /* TODO */
                tap->wr_tsft = rsu_get_tsf_high(sc);
                if (le32toh(stat->tsf_low) > rsu_get_tsf_low(sc))
                        tap->wr_tsft--;
                tap->wr_tsft = (uint64_t)htole32(tap->wr_tsft) << 32;
                tap->wr_tsft += stat->tsf_low;

                tap->wr_rate = rxs.c_rate;
                tap->wr_dbm_antsignal = rssi;
        };

        (void) ieee80211_add_rx_params(m, &rxs);

        /* Drop descriptor. */
        m_adj(m, sizeof(*stat) + infosz);
        wh = mtod(m, struct ieee80211_frame_min *);
        if ((wh->i_fc[1] & IEEE80211_FC1_PROTECTED) &&
            cipher != R92S_KEY_ALGO_NONE) {
                m->m_flags |= M_WEP;
        }

        RSU_DPRINTF(sc, RSU_DEBUG_RX,
            "%s: Rx frame len %d, rate %d, infosz %d\n",
            __func__, m->m_len, rate, infosz);

        if (m->m_len >= sizeof(*wh))
                return (ieee80211_find_rxnode(ic, wh));

        return (NULL);
}

static struct mbuf *
rsu_rx_multi_frame(struct rsu_softc *sc, uint8_t *buf, int len)
{
        struct r92s_rx_stat *stat;
        uint32_t rxdw0;
        int totlen, pktlen, infosz, npkts;
        struct mbuf *m, *m0 = NULL, *prevm = NULL;

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

        /* Get the number of encapsulated frames. */
        stat = (struct r92s_rx_stat *)buf;
        npkts = MS(le32toh(stat->rxdw2), R92S_RXDW2_PKTCNT);
        RSU_DPRINTF(sc, RSU_DEBUG_RX,
            "%s: Rx %d frames in one chunk\n", __func__, npkts);

        /* Process all of them. */
        while (npkts-- > 0) {
                if (__predict_false(len < sizeof(*stat)))
                        break;
                stat = (struct r92s_rx_stat *)buf;
                rxdw0 = le32toh(stat->rxdw0);

                pktlen = MS(rxdw0, R92S_RXDW0_PKTLEN);
                if (__predict_false(pktlen == 0))
                        break;

                infosz = MS(rxdw0, R92S_RXDW0_INFOSZ) * 8;

                /* Make sure everything fits in xfer. */
                totlen = sizeof(*stat) + infosz + pktlen;
                if (__predict_false(totlen > len))
                        break;

                /* Process 802.11 frame. */
                m = rsu_rx_copy_to_mbuf(sc, stat, totlen);
                if (m0 == NULL)
                        m0 = m;
                if (prevm == NULL)
                        prevm = m;
                else {
                        prevm->m_next = m;
                        prevm = m;
                }
                /* Next chunk is 128-byte aligned. */
                totlen = (totlen + 127) & ~127;
                buf += totlen;
                len -= totlen;
        }

        return (m0);
}

static struct mbuf *
rsu_rxeof(struct usb_xfer *xfer, struct rsu_data *data)
{
        struct rsu_softc *sc = data->sc;
        struct ieee80211com *ic = &sc->sc_ic;
        struct r92s_rx_stat *stat;
        int len;

        usbd_xfer_status(xfer, &len, NULL, NULL, NULL);

        if (__predict_false(len < sizeof(*stat))) {
                RSU_DPRINTF(sc, RSU_DEBUG_RX, "xfer too short %d\n", len);
                counter_u64_add(ic->ic_ierrors, 1);
                return (NULL);
        }
        /* Determine if it is a firmware C2H event or an 802.11 frame. */
        stat = (struct r92s_rx_stat *)data->buf;
        if ((le32toh(stat->rxdw1) & 0x1ff) == 0x1ff) {
                rsu_rx_multi_event(sc, data->buf, len);
                /* No packets to process. */
                return (NULL);
        } else
                return (rsu_rx_multi_frame(sc, data->buf, len));
}

static void
rsu_bulk_rx_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct rsu_softc *sc = usbd_xfer_softc(xfer);
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211_node *ni;
        struct mbuf *m = NULL, *next;
        struct rsu_data *data;

        RSU_ASSERT_LOCKED(sc);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                data = STAILQ_FIRST(&sc->sc_rx_active);
                if (data == NULL)
                        goto tr_setup;
                STAILQ_REMOVE_HEAD(&sc->sc_rx_active, next);
                m = rsu_rxeof(xfer, data);
                STAILQ_INSERT_TAIL(&sc->sc_rx_inactive, data, next);
                /* FALLTHROUGH */
        case USB_ST_SETUP:
tr_setup:
                data = STAILQ_FIRST(&sc->sc_rx_inactive);
                if (data == NULL) {
                        KASSERT(m == NULL, ("mbuf isn't 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,
                    usbd_xfer_max_len(xfer));
                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.
                 */
                while (m != NULL) {
                        next = m->m_next;
                        m->m_next = NULL;

                        ni = rsu_rx_frame(sc, m);
                        RSU_UNLOCK(sc);

                        if (ni != NULL) {
                                if (ni->ni_flags & IEEE80211_NODE_HT)
                                        m->m_flags |= M_AMPDU;
                                (void)ieee80211_input_mimo(ni, m);
                                ieee80211_free_node(ni);
                        } else
                                (void)ieee80211_input_mimo_all(ic, m);

                        RSU_LOCK(sc);
                        m = next;
                }
                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 tr_setup;
                }
                break;
        }

}

static void
rsu_txeof(struct usb_xfer *xfer, struct rsu_data *data)
{
#ifdef  USB_DEBUG
        struct rsu_softc *sc = usbd_xfer_softc(xfer);
#endif

        RSU_DPRINTF(sc, RSU_DEBUG_TXDONE, "%s: called; data=%p\n",
            __func__,
            data);

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

static void
rsu_bulk_tx_callback_sub(struct usb_xfer *xfer, usb_error_t error,
    uint8_t which)
{
        struct rsu_softc *sc = usbd_xfer_softc(xfer);
        struct ieee80211com *ic = &sc->sc_ic;
        struct rsu_data *data;

        RSU_ASSERT_LOCKED(sc);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                data = STAILQ_FIRST(&sc->sc_tx_active[which]);
                if (data == NULL)
                        goto tr_setup;
                RSU_DPRINTF(sc, RSU_DEBUG_TXDONE, "%s: transfer done %p\n",
                    __func__, data);
                STAILQ_REMOVE_HEAD(&sc->sc_tx_active[which], next);
                rsu_txeof(xfer, data);
                rsu_freebuf(sc, data);
                /* FALLTHROUGH */
        case USB_ST_SETUP:
tr_setup:
                data = STAILQ_FIRST(&sc->sc_tx_pending[which]);
                if (data == NULL) {
                        RSU_DPRINTF(sc, RSU_DEBUG_TXDONE,
                            "%s: empty pending queue sc %p\n", __func__, sc);
                        return;
                }
                STAILQ_REMOVE_HEAD(&sc->sc_tx_pending[which], next);
                STAILQ_INSERT_TAIL(&sc->sc_tx_active[which], data, next);
                usbd_xfer_set_frame_data(xfer, 0, data->buf, data->buflen);
                RSU_DPRINTF(sc, RSU_DEBUG_TXDONE,
                    "%s: submitting transfer %p\n",
                    __func__,
                    data);
                usbd_transfer_submit(xfer);
                break;
        default:
                data = STAILQ_FIRST(&sc->sc_tx_active[which]);
                if (data != NULL) {
                        STAILQ_REMOVE_HEAD(&sc->sc_tx_active[which], next);
                        rsu_txeof(xfer, data);
                        rsu_freebuf(sc, data);
                }
                counter_u64_add(ic->ic_oerrors, 1);

                if (error != USB_ERR_CANCELLED) {
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                break;
        }

        /*
         * XXX TODO: if the queue is low, flush out FF TX frames.
         * Remember to unlock the driver for now; net80211 doesn't
         * defer it for us.
         */
}

static void
rsu_bulk_tx_callback_be_bk(struct usb_xfer *xfer, usb_error_t error)
{
        struct rsu_softc *sc = usbd_xfer_softc(xfer);

        rsu_bulk_tx_callback_sub(xfer, error, RSU_BULK_TX_BE_BK);

        /* This kicks the TX taskqueue */
        rsu_start(sc);
}

static void
rsu_bulk_tx_callback_vi_vo(struct usb_xfer *xfer, usb_error_t error)
{
        struct rsu_softc *sc = usbd_xfer_softc(xfer);

        rsu_bulk_tx_callback_sub(xfer, error, RSU_BULK_TX_VI_VO);

        /* This kicks the TX taskqueue */
        rsu_start(sc);
}

static void
rsu_bulk_tx_callback_h2c(struct usb_xfer *xfer, usb_error_t error)
{
        struct rsu_softc *sc = usbd_xfer_softc(xfer);

        rsu_bulk_tx_callback_sub(xfer, error, RSU_BULK_TX_H2C);

        /* This kicks the TX taskqueue */
        rsu_start(sc);
}

/*
 * Transmit the given frame.
 *
 * This doesn't free the node or mbuf upon failure.
 */
static int
rsu_tx_start(struct rsu_softc *sc, struct ieee80211_node *ni, 
    struct mbuf *m0, struct rsu_data *data)
{
        const struct ieee80211_txparam *tp = ni->ni_txparms;
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211_frame *wh;
        struct ieee80211_key *k = NULL;
        struct r92s_tx_desc *txd;
        uint8_t rate, ridx, type, cipher, qos;
        int prio = 0;
        uint8_t which;
        int hasqos;
        int ismcast;
        int xferlen;
        int qid;

        RSU_ASSERT_LOCKED(sc);

        wh = mtod(m0, struct ieee80211_frame *);
        type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
        ismcast = IEEE80211_IS_MULTICAST(wh->i_addr1);

        RSU_DPRINTF(sc, RSU_DEBUG_TX, "%s: data=%p, m=%p\n",
            __func__, data, m0);

        /* Choose a TX rate index. */
        if (type == IEEE80211_FC0_TYPE_MGT ||
            type == IEEE80211_FC0_TYPE_CTL ||
            (m0->m_flags & M_EAPOL) != 0)
                rate = tp->mgmtrate;
        else if (ismcast)
                rate = tp->mcastrate;
        else if (tp->ucastrate != IEEE80211_FIXED_RATE_NONE)
                rate = tp->ucastrate;
        else
                rate = 0;

        if (rate != 0)
                ridx = rate2ridx(rate);

        /* Assign sequence number, A-MPDU or otherwise */
        ieee80211_output_seqno_assign(ni, -1, m0);

        if (wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {
                k = ieee80211_crypto_encap(ni, m0);
                if (k == NULL) {
                        device_printf(sc->sc_dev,
                            "ieee80211_crypto_encap returns NULL.\n");
                        /* XXX we don't expect the fragmented frames */
                        return (ENOBUFS);
                }
                wh = mtod(m0, struct ieee80211_frame *);
        }
        /* If we have QoS then use it */
        /* XXX TODO: mbuf WME/PRI versus TID? */
        if (IEEE80211_QOS_HAS_SEQ(wh)) {
                /* Has QoS */
                prio = M_WME_GETAC(m0);
                which = rsu_wme_ac_xfer_map[prio];
                hasqos = 1;
                qos = ((const struct ieee80211_qosframe *)wh)->i_qos[0];
        } else {
                /* Non-QoS TID */
                /* XXX TODO: tid=0 for non-qos TID? */
                which = rsu_wme_ac_xfer_map[WME_AC_BE];
                hasqos = 0;
                prio = 0;
                qos = 0;
        }

        qid = rsu_ac2qid[prio];
#if 0
        switch (type) {
        case IEEE80211_FC0_TYPE_CTL:
        case IEEE80211_FC0_TYPE_MGT:
                which = rsu_wme_ac_xfer_map[WME_AC_VO];
                break;
        default:
                which = rsu_wme_ac_xfer_map[M_WME_GETAC(m0)];
                break;
        }
        hasqos = 0;
#endif

        RSU_DPRINTF(sc, RSU_DEBUG_TX, "%s: pri=%d, which=%d, hasqos=%d\n",
            __func__,
            prio,
            which,
            hasqos);

        /* Fill Tx descriptor. */
        txd = (struct r92s_tx_desc *)data->buf;
        memset(txd, 0, sizeof(*txd));

        txd->txdw0 |= htole32(
            SM(R92S_TXDW0_PKTLEN, m0->m_pkthdr.len) |
            SM(R92S_TXDW0_OFFSET, sizeof(*txd)) |
            R92S_TXDW0_OWN | R92S_TXDW0_FSG | R92S_TXDW0_LSG);

        /* TODO: correct macid here? It should be in the node */
        txd->txdw1 |= htole32(
            SM(R92S_TXDW1_MACID, R92S_MACID_BSS) | SM(R92S_TXDW1_QSEL, qid));

        if (!hasqos)
                txd->txdw1 |= htole32(R92S_TXDW1_NONQOS);
        if (k != NULL && !(k->wk_flags & IEEE80211_KEY_SWENCRYPT)) {
                switch (k->wk_cipher->ic_cipher) {
                case IEEE80211_CIPHER_WEP:
                        cipher = R92S_TXDW1_CIPHER_WEP;
                        break;
                case IEEE80211_CIPHER_TKIP:
                        cipher = R92S_TXDW1_CIPHER_TKIP;
                        break;
                case IEEE80211_CIPHER_AES_CCM:
                        cipher = R92S_TXDW1_CIPHER_AES;
                        break;
                default:
                        cipher = R92S_TXDW1_CIPHER_NONE;
                }
                txd->txdw1 |= htole32(
                    SM(R92S_TXDW1_CIPHER, cipher) |
                    SM(R92S_TXDW1_KEYIDX, k->wk_keyix));
        }

        /*
         * Note: no need to set TXDW2_AGGEN/TXDW2_BK to mark
         * A-MPDU and non-AMPDU candidates; the firmware will
         * handle this for us.
         */

        if (ismcast)
                txd->txdw2 |= htole32(R92S_TXDW2_BMCAST);

        if (!ismcast && (!qos || (qos & IEEE80211_QOS_ACKPOLICY) !=
            IEEE80211_QOS_ACKPOLICY_NOACK)) {
                txd->txdw2 |= htole32(R92S_TXDW2_RTY_LMT_ENA);
                txd->txdw2 |= htole32(SM(R92S_TXDW2_RTY_LMT, tp->maxretry));
        }

        /* Force mgmt / mcast / ucast rate if needed. */
        if (rate != 0) {
                /* Data rate fallback limit (max). */
                txd->txdw5 |= htole32(SM(R92S_TXDW5_DATARATE_FB_LMT, 0x1f));
                txd->txdw5 |= htole32(SM(R92S_TXDW5_DATARATE, ridx));
                txd->txdw4 |= htole32(R92S_TXDW4_DRVRATE);
        }

        /*
         * Pass in prio here, NOT the sequence number.
         *
         * The hardware is in theory incrementing sequence numbers
         * for us, but I haven't yet figured out exactly when/how
         * it's supposed to work.
         */
        txd->txdw3 |= htole32(SM(R92S_TXDW3_SEQ, prio));

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

                tap->wt_flags = 0;
                ieee80211_radiotap_tx(vap, m0);
        }

        xferlen = sizeof(*txd) + m0->m_pkthdr.len;
        KASSERT(xferlen <= RSU_TXBUFSZ, ("%s: invalid length", __func__));
        m_copydata(m0, 0, m0->m_pkthdr.len, (caddr_t)&txd[1]);

        data->buflen = xferlen;
        data->ni = ni;
        data->m = m0;
        STAILQ_INSERT_TAIL(&sc->sc_tx_pending[which], data, next);

        /* start transfer, if any */
        usbd_transfer_start(sc->sc_xfer[which]);
        return (0);
}

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

        RSU_LOCK(sc);
        if (!sc->sc_running) {
                RSU_UNLOCK(sc);
                return (ENXIO);
        }

        /*
         * XXX TODO: ensure that we treat 'm' as a list of frames
         * to transmit!
         */
        error = mbufq_enqueue(&sc->sc_snd, m);
        if (error) {
                RSU_DPRINTF(sc, RSU_DEBUG_TX,
                    "%s: mbufq_enable: failed (%d)\n",
                    __func__,
                    error);
                RSU_UNLOCK(sc);
                return (error);
        }
        RSU_UNLOCK(sc);

        /* This kicks the TX taskqueue */
        rsu_start(sc);

        return (0);
}

static void
rsu_drain_mbufq(struct rsu_softc *sc)
{
        struct mbuf *m;
        struct ieee80211_node *ni;

        RSU_ASSERT_LOCKED(sc);
        while ((m = mbufq_dequeue(&sc->sc_snd)) != NULL) {
                ni = (struct ieee80211_node *)m->m_pkthdr.rcvif;
                m->m_pkthdr.rcvif = NULL;
                ieee80211_free_node(ni);
                m_freem(m);
        }
}

static void
_rsu_start(struct rsu_softc *sc)
{
        struct ieee80211_node *ni;
        struct rsu_data *bf;
        struct mbuf *m;

        RSU_ASSERT_LOCKED(sc);

        while ((m = mbufq_dequeue(&sc->sc_snd)) != NULL) {
                bf = rsu_getbuf(sc);
                if (bf == NULL) {
                        RSU_DPRINTF(sc, RSU_DEBUG_TX,
                            "%s: failed to get buffer\n", __func__);
                        mbufq_prepend(&sc->sc_snd, m);
                        break;
                }

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

                if (rsu_tx_start(sc, ni, m, bf) != 0) {
                        RSU_DPRINTF(sc, RSU_DEBUG_TX,
                            "%s: failed to transmit\n", __func__);
                        if_inc_counter(ni->ni_vap->iv_ifp,
                            IFCOUNTER_OERRORS, 1);
                        rsu_freebuf(sc, bf);
                        ieee80211_free_node(ni);
                        m_freem(m);
                        break;
                }
        }
}

static void
rsu_start(struct rsu_softc *sc)
{

        taskqueue_enqueue(taskqueue_thread, &sc->tx_task);
}

static int
rsu_ioctl_net(struct ieee80211com *ic, u_long cmd, void *data)
{
        struct rsu_softc *sc = ic->ic_softc;
        struct ifreq *ifr = (struct ifreq *)data;
        int error;

        error = 0;
        switch (cmd) {
        case SIOCSIFCAP:
        {
                struct ieee80211vap *vap;
                int rxmask;

                rxmask = ifr->ifr_reqcap & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6);

                RSU_LOCK(sc);
                /* Both RXCSUM bits must be set (or unset). */
                if (sc->sc_rx_checksum_enable &&
                    rxmask != (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6)) {
                        rxmask = 0;
                        sc->sc_rx_checksum_enable = 0;
                        rsu_rxfilter_set(sc, R92S_RCR_TCP_OFFLD_EN, 0);
                } else if (!sc->sc_rx_checksum_enable && rxmask != 0) {
                        rxmask = IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6;
                        sc->sc_rx_checksum_enable = 1;
                        rsu_rxfilter_set(sc, 0, R92S_RCR_TCP_OFFLD_EN);
                } else {
                        /* Nothing to do. */
                        RSU_UNLOCK(sc);
                        break;
                }
                RSU_UNLOCK(sc);

                IEEE80211_LOCK(ic);     /* XXX */
                TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
                        if_t ifp = vap->iv_ifp;

                        if_setcapenablebit(ifp, 0,
                            IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6);
                        if_setcapenablebit(ifp, rxmask, 0);
                }
                IEEE80211_UNLOCK(ic);
                break;
        }
        default:
                error = ENOTTY;         /* for net80211 */
                break;
        }

        return (error);
}

static void
rsu_parent(struct ieee80211com *ic)
{
        struct rsu_softc *sc = ic->ic_softc;

        if (ic->ic_nrunning > 0) {
                if (rsu_init(sc) == 0)
                        ieee80211_start_all(ic);
                else {
                        struct ieee80211vap *vap = TAILQ_FIRST(&ic->ic_vaps);
                        if (vap != NULL)
                                ieee80211_stop(vap);
                }
        } else
                rsu_stop(sc);
}

/*
 * Power on sequence for A-cut adapters.
 */
static void
rsu_power_on_acut(struct rsu_softc *sc)
{
        uint32_t reg;

        rsu_write_1(sc, R92S_SPS0_CTRL + 1, 0x53);
        rsu_write_1(sc, R92S_SPS0_CTRL + 0, 0x57);

        /* Enable AFE macro block's bandgap and Mbias. */
        rsu_write_1(sc, R92S_AFE_MISC,
            rsu_read_1(sc, R92S_AFE_MISC) |
            R92S_AFE_MISC_BGEN | R92S_AFE_MISC_MBEN);
        /* Enable LDOA15 block. */
        rsu_write_1(sc, R92S_LDOA15_CTRL,
            rsu_read_1(sc, R92S_LDOA15_CTRL) | R92S_LDA15_EN);

        rsu_write_1(sc, R92S_SPS1_CTRL,
            rsu_read_1(sc, R92S_SPS1_CTRL) | R92S_SPS1_LDEN);
        rsu_ms_delay(sc, 2000);
        /* Enable switch regulator block. */
        rsu_write_1(sc, R92S_SPS1_CTRL,
            rsu_read_1(sc, R92S_SPS1_CTRL) | R92S_SPS1_SWEN);

        rsu_write_4(sc, R92S_SPS1_CTRL, 0x00a7b267);

        rsu_write_1(sc, R92S_SYS_ISO_CTRL + 1,
            rsu_read_1(sc, R92S_SYS_ISO_CTRL + 1) | 0x08);

        rsu_write_1(sc, R92S_SYS_FUNC_EN + 1,
            rsu_read_1(sc, R92S_SYS_FUNC_EN + 1) | 0x20);

        rsu_write_1(sc, R92S_SYS_ISO_CTRL + 1,
            rsu_read_1(sc, R92S_SYS_ISO_CTRL + 1) & ~0x90);

        /* Enable AFE clock. */
        rsu_write_1(sc, R92S_AFE_XTAL_CTRL + 1,
            rsu_read_1(sc, R92S_AFE_XTAL_CTRL + 1) & ~0x04);
        /* Enable AFE PLL macro block. */
        rsu_write_1(sc, R92S_AFE_PLL_CTRL,
            rsu_read_1(sc, R92S_AFE_PLL_CTRL) | 0x11);
        /* Attach AFE PLL to MACTOP/BB. */
        rsu_write_1(sc, R92S_SYS_ISO_CTRL,
            rsu_read_1(sc, R92S_SYS_ISO_CTRL) & ~0x11);

        /* Switch to 40MHz clock instead of 80MHz. */
        rsu_write_2(sc, R92S_SYS_CLKR,
            rsu_read_2(sc, R92S_SYS_CLKR) & ~R92S_SYS_CLKSEL);

        /* Enable MAC clock. */
        rsu_write_2(sc, R92S_SYS_CLKR,
            rsu_read_2(sc, R92S_SYS_CLKR) |
            R92S_MAC_CLK_EN | R92S_SYS_CLK_EN);

        rsu_write_1(sc, R92S_PMC_FSM, 0x02);

        /* Enable digital core and IOREG R/W. */
        rsu_write_1(sc, R92S_SYS_FUNC_EN + 1,
            rsu_read_1(sc, R92S_SYS_FUNC_EN + 1) | 0x08);

        rsu_write_1(sc, R92S_SYS_FUNC_EN + 1,
            rsu_read_1(sc, R92S_SYS_FUNC_EN + 1) | 0x80);

        /* Switch the control path to firmware. */
        reg = rsu_read_2(sc, R92S_SYS_CLKR);
        reg = (reg & ~R92S_SWHW_SEL) | R92S_FWHW_SEL;
        rsu_write_2(sc, R92S_SYS_CLKR, reg);

        rsu_write_2(sc, R92S_CR, 0x37fc);

        /* Fix USB RX FIFO issue. */
        rsu_write_1(sc, 0xfe5c,
            rsu_read_1(sc, 0xfe5c) | 0x80);
        rsu_write_1(sc, 0x00ab,
            rsu_read_1(sc, 0x00ab) | 0xc0);

        rsu_write_1(sc, R92S_SYS_CLKR,
            rsu_read_1(sc, R92S_SYS_CLKR) & ~R92S_SYS_CPU_CLKSEL);
}

/*
 * Power on sequence for B-cut and C-cut adapters.
 */
static void
rsu_power_on_bcut(struct rsu_softc *sc)
{
        uint32_t reg;
        int ntries;

        /* Prevent eFuse leakage. */
        rsu_write_1(sc, 0x37, 0xb0);
        rsu_ms_delay(sc, 10);
        rsu_write_1(sc, 0x37, 0x30);

        /* Switch the control path to hardware. */
        reg = rsu_read_2(sc, R92S_SYS_CLKR);
        if (reg & R92S_FWHW_SEL) {
                rsu_write_2(sc, R92S_SYS_CLKR,
                    reg & ~(R92S_SWHW_SEL | R92S_FWHW_SEL));
        }
        rsu_write_1(sc, R92S_SYS_FUNC_EN + 1,
            rsu_read_1(sc, R92S_SYS_FUNC_EN + 1) & ~0x8c);
        rsu_ms_delay(sc, 1);

        rsu_write_1(sc, R92S_SPS0_CTRL + 1, 0x53);
        rsu_write_1(sc, R92S_SPS0_CTRL + 0, 0x57);

        reg = rsu_read_1(sc, R92S_AFE_MISC);
        rsu_write_1(sc, R92S_AFE_MISC, reg | R92S_AFE_MISC_BGEN);
        rsu_write_1(sc, R92S_AFE_MISC, reg | R92S_AFE_MISC_BGEN |
            R92S_AFE_MISC_MBEN | R92S_AFE_MISC_I32_EN);

        /* Enable PLL. */
        rsu_write_1(sc, R92S_LDOA15_CTRL,
            rsu_read_1(sc, R92S_LDOA15_CTRL) | R92S_LDA15_EN);

        rsu_write_1(sc, R92S_LDOV12D_CTRL,
            rsu_read_1(sc, R92S_LDOV12D_CTRL) | R92S_LDV12_EN);

        rsu_write_1(sc, R92S_SYS_ISO_CTRL + 1,
            rsu_read_1(sc, R92S_SYS_ISO_CTRL + 1) | 0x08);

        rsu_write_1(sc, R92S_SYS_FUNC_EN + 1,
            rsu_read_1(sc, R92S_SYS_FUNC_EN + 1) | 0x20);

        /* Support 64KB IMEM. */
        rsu_write_1(sc, R92S_SYS_ISO_CTRL + 1,
            rsu_read_1(sc, R92S_SYS_ISO_CTRL + 1) & ~0x97);

        /* Enable AFE clock. */
        rsu_write_1(sc, R92S_AFE_XTAL_CTRL + 1,
            rsu_read_1(sc, R92S_AFE_XTAL_CTRL + 1) & ~0x04);
        /* Enable AFE PLL macro block. */
        reg = rsu_read_1(sc, R92S_AFE_PLL_CTRL);
        rsu_write_1(sc, R92S_AFE_PLL_CTRL, reg | 0x11);
        rsu_ms_delay(sc, 1);
        rsu_write_1(sc, R92S_AFE_PLL_CTRL, reg | 0x51);
        rsu_ms_delay(sc, 1);
        rsu_write_1(sc, R92S_AFE_PLL_CTRL, reg | 0x11);
        rsu_ms_delay(sc, 1);

        /* Attach AFE PLL to MACTOP/BB. */
        rsu_write_1(sc, R92S_SYS_ISO_CTRL,
            rsu_read_1(sc, R92S_SYS_ISO_CTRL) & ~0x11);

        /* Switch to 40MHz clock. */
        rsu_write_1(sc, R92S_SYS_CLKR, 0x00);
        /* Disable CPU clock and 80MHz SSC. */
        rsu_write_1(sc, R92S_SYS_CLKR,
            rsu_read_1(sc, R92S_SYS_CLKR) | 0xa0);
        /* Enable MAC clock. */
        rsu_write_2(sc, R92S_SYS_CLKR,
            rsu_read_2(sc, R92S_SYS_CLKR) |
            R92S_MAC_CLK_EN | R92S_SYS_CLK_EN);

        rsu_write_1(sc, R92S_PMC_FSM, 0x02);

        /* Enable digital core and IOREG R/W. */
        rsu_write_1(sc, R92S_SYS_FUNC_EN + 1,
            rsu_read_1(sc, R92S_SYS_FUNC_EN + 1) | 0x08);

        rsu_write_1(sc, R92S_SYS_FUNC_EN + 1,
            rsu_read_1(sc, R92S_SYS_FUNC_EN + 1) | 0x80);

        /* Switch the control path to firmware. */
        reg = rsu_read_2(sc, R92S_SYS_CLKR);
        reg = (reg & ~R92S_SWHW_SEL) | R92S_FWHW_SEL;
        rsu_write_2(sc, R92S_SYS_CLKR, reg);

        rsu_write_2(sc, R92S_CR, 0x37fc);

        /* Fix USB RX FIFO issue. */
        rsu_write_1(sc, 0xfe5c,
            rsu_read_1(sc, 0xfe5c) | 0x80);

        rsu_write_1(sc, R92S_SYS_CLKR,
            rsu_read_1(sc, R92S_SYS_CLKR) & ~R92S_SYS_CPU_CLKSEL);

        rsu_write_1(sc, 0xfe1c, 0x80);

        /* Make sure TxDMA is ready to download firmware. */
        for (ntries = 0; ntries < 20; ntries++) {
                reg = rsu_read_1(sc, R92S_TCR);
                if ((reg & (R92S_TCR_IMEM_CHK_RPT | R92S_TCR_EMEM_CHK_RPT)) ==
                    (R92S_TCR_IMEM_CHK_RPT | R92S_TCR_EMEM_CHK_RPT))
                        break;
                rsu_ms_delay(sc, 1);
        }
        if (ntries == 20) {
                RSU_DPRINTF(sc, RSU_DEBUG_RESET | RSU_DEBUG_TX,
                    "%s: TxDMA is not ready\n",
                    __func__);
                /* Reset TxDMA. */
                reg = rsu_read_1(sc, R92S_CR);
                rsu_write_1(sc, R92S_CR, reg & ~R92S_CR_TXDMA_EN);
                rsu_ms_delay(sc, 1);
                rsu_write_1(sc, R92S_CR, reg | R92S_CR_TXDMA_EN);
        }
}

static void
rsu_power_off(struct rsu_softc *sc)
{
        /* Turn RF off. */
        rsu_write_1(sc, R92S_RF_CTRL, 0x00);
        rsu_ms_delay(sc, 5);

        /* Turn MAC off. */
        /* Switch control path. */
        rsu_write_1(sc, R92S_SYS_CLKR + 1, 0x38);
        /* Reset MACTOP. */
        rsu_write_1(sc, R92S_SYS_FUNC_EN + 1, 0x70);
        rsu_write_1(sc, R92S_PMC_FSM, 0x06);
        rsu_write_1(sc, R92S_SYS_ISO_CTRL + 0, 0xf9);
        rsu_write_1(sc, R92S_SYS_ISO_CTRL + 1, 0xe8);

        /* Disable AFE PLL. */
        rsu_write_1(sc, R92S_AFE_PLL_CTRL, 0x00);
        /* Disable A15V. */
        rsu_write_1(sc, R92S_LDOA15_CTRL, 0x54);
        /* Disable eFuse 1.2V. */
        rsu_write_1(sc, R92S_SYS_FUNC_EN + 1, 0x50);
        rsu_write_1(sc, R92S_LDOV12D_CTRL, 0x24);
        /* Enable AFE macro block's bandgap and Mbias. */
        rsu_write_1(sc, R92S_AFE_MISC, 0x30);
        /* Disable 1.6V LDO. */
        rsu_write_1(sc, R92S_SPS0_CTRL + 0, 0x56);
        rsu_write_1(sc, R92S_SPS0_CTRL + 1, 0x43);

        /* Firmware - tell it to switch things off */
        (void) rsu_set_fw_power_state(sc, RSU_PWR_OFF);
}

static int
rsu_fw_loadsection(struct rsu_softc *sc, const uint8_t *buf, int len)
{
        const uint8_t which = rsu_wme_ac_xfer_map[WME_AC_VO];
        struct rsu_data *data;
        struct r92s_tx_desc *txd;
        int mlen;

        while (len > 0) {
                data = rsu_getbuf(sc);
                if (data == NULL)
                        return (ENOMEM);
                txd = (struct r92s_tx_desc *)data->buf;
                memset(txd, 0, sizeof(*txd));
                if (len <= RSU_TXBUFSZ - sizeof(*txd)) {
                        /* Last chunk. */
                        txd->txdw0 |= htole32(R92S_TXDW0_LINIP);
                        mlen = len;
                } else
                        mlen = RSU_TXBUFSZ - sizeof(*txd);
                txd->txdw0 |= htole32(SM(R92S_TXDW0_PKTLEN, mlen));
                memcpy(&txd[1], buf, mlen);
                data->buflen = sizeof(*txd) + mlen;
                RSU_DPRINTF(sc, RSU_DEBUG_TX | RSU_DEBUG_FW | RSU_DEBUG_RESET,
                    "%s: starting transfer %p\n",
                    __func__, data);
                STAILQ_INSERT_TAIL(&sc->sc_tx_pending[which], data, next);
                buf += mlen;
                len -= mlen;
        }
        usbd_transfer_start(sc->sc_xfer[which]);
        return (0);
}

CTASSERT(sizeof(size_t) >= sizeof(uint32_t));

static int
rsu_load_firmware(struct rsu_softc *sc)
{
        const struct r92s_fw_hdr *hdr;
        struct r92s_fw_priv dmem;
        struct ieee80211com *ic = &sc->sc_ic;
        const uint8_t *imem, *emem;
        uint32_t imemsz, ememsz;
        const struct firmware *fw;
        size_t size;
        uint32_t reg;
        int ntries, error;

        if (rsu_read_1(sc, R92S_TCR) & R92S_TCR_FWRDY) {
                RSU_DPRINTF(sc, RSU_DEBUG_ANY,
                    "%s: Firmware already loaded\n",
                    __func__);
                return (0);
        }

        RSU_UNLOCK(sc);
        /* Read firmware image from the filesystem. */
        if ((fw = firmware_get("rsu-rtl8712fw")) == NULL) {
                device_printf(sc->sc_dev, 
                    "%s: failed load firmware of file rsu-rtl8712fw\n",
                    __func__);
                RSU_LOCK(sc);
                return (ENXIO);
        }
        RSU_LOCK(sc);
        size = fw->datasize;
        if (size < sizeof(*hdr)) {
                device_printf(sc->sc_dev, "firmware too short\n");
                error = EINVAL;
                goto fail;
        }
        hdr = (const struct r92s_fw_hdr *)fw->data;
        if (hdr->signature != htole16(0x8712) &&
            hdr->signature != htole16(0x8192)) {
                device_printf(sc->sc_dev,
                    "invalid firmware signature 0x%x\n",
                    le16toh(hdr->signature));
                error = EINVAL;
                goto fail;
        }
        RSU_DPRINTF(sc, RSU_DEBUG_FW, "FW V%d %02x-%02x %02x:%02x\n",
            le16toh(hdr->version), hdr->month, hdr->day, hdr->hour,
            hdr->minute);

        /* Make sure that driver and firmware are in sync. */
        if (hdr->privsz != htole32(sizeof(dmem))) {
                device_printf(sc->sc_dev, "unsupported firmware image\n");
                error = EINVAL;
                goto fail;
        }
        /* Get FW sections sizes. */
        imemsz = le32toh(hdr->imemsz);
        ememsz = le32toh(hdr->sramsz);
        /* Check that all FW sections fit in image. */
        if (imemsz > (size_t)(size - sizeof(*hdr)) ||
            ememsz > (size_t)(size - sizeof(*hdr) - imemsz)) {
                device_printf(sc->sc_dev, "firmware too short\n");
                error = EINVAL;
                goto fail;
        }
        imem = (const uint8_t *)&hdr[1];
        emem = imem + imemsz;

        /* Load IMEM section. */
        error = rsu_fw_loadsection(sc, imem, imemsz);
        if (error != 0) {
                device_printf(sc->sc_dev,
                    "could not load firmware section %s\n", "IMEM");
                goto fail;
        }
        /* Wait for load to complete. */
        for (ntries = 0; ntries != 50; ntries++) {
                rsu_ms_delay(sc, 10);
                reg = rsu_read_1(sc, R92S_TCR);
                if (reg & R92S_TCR_IMEM_CODE_DONE)
                        break;
        }
        if (ntries == 50) {
                device_printf(sc->sc_dev, "timeout waiting for IMEM transfer\n");
                error = ETIMEDOUT;
                goto fail;
        }
        /* Load EMEM section. */
        error = rsu_fw_loadsection(sc, emem, ememsz);
        if (error != 0) {
                device_printf(sc->sc_dev,
                    "could not load firmware section %s\n", "EMEM");
                goto fail;
        }
        /* Wait for load to complete. */
        for (ntries = 0; ntries != 50; ntries++) {
                rsu_ms_delay(sc, 10);
                reg = rsu_read_2(sc, R92S_TCR);
                if (reg & R92S_TCR_EMEM_CODE_DONE)
                        break;
        }
        if (ntries == 50) {
                device_printf(sc->sc_dev, "timeout waiting for EMEM transfer\n");
                error = ETIMEDOUT;
                goto fail;
        }
        /* Enable CPU. */
        rsu_write_1(sc, R92S_SYS_CLKR,
            rsu_read_1(sc, R92S_SYS_CLKR) | R92S_SYS_CPU_CLKSEL);
        if (!(rsu_read_1(sc, R92S_SYS_CLKR) & R92S_SYS_CPU_CLKSEL)) {
                device_printf(sc->sc_dev, "could not enable system clock\n");
                error = EIO;
                goto fail;
        }
        rsu_write_2(sc, R92S_SYS_FUNC_EN,
            rsu_read_2(sc, R92S_SYS_FUNC_EN) | R92S_FEN_CPUEN);
        if (!(rsu_read_2(sc, R92S_SYS_FUNC_EN) & R92S_FEN_CPUEN)) {
                device_printf(sc->sc_dev, 
                    "could not enable microcontroller\n");
                error = EIO;
                goto fail;
        }
        /* Wait for CPU to initialize. */
        for (ntries = 0; ntries < 100; ntries++) {
                if (rsu_read_1(sc, R92S_TCR) & R92S_TCR_IMEM_RDY)
                        break;
                rsu_ms_delay(sc, 1);
        }
        if (ntries == 100) {
                device_printf(sc->sc_dev,
                    "timeout waiting for microcontroller\n");
                error = ETIMEDOUT;
                goto fail;
        }

        /* Update DMEM section before loading. */
        memset(&dmem, 0, sizeof(dmem));
        dmem.hci_sel = R92S_HCI_SEL_USB | R92S_HCI_SEL_8172;
        dmem.nendpoints = sc->sc_nendpoints;
        dmem.chip_version = sc->cut;
        dmem.rf_config = sc->sc_rftype;
        dmem.vcs_type = R92S_VCS_TYPE_AUTO;
        dmem.vcs_mode = R92S_VCS_MODE_RTS_CTS;
        dmem.turbo_mode = 0;
        dmem.bw40_en = !! (ic->ic_htcaps & IEEE80211_HTCAP_CHWIDTH40);
        /* net80211 handles AMSDUs just fine */
        dmem.amsdu2ampdu_en = 0;
        dmem.ampdu_en = !! (sc->sc_ht);
        dmem.agg_offload = !! (sc->sc_ht);
        dmem.qos_en = 1;
        dmem.ps_offload = 1;
        dmem.lowpower_mode = 1; /* XXX TODO: configurable? */
        /* Load DMEM section. */
        error = rsu_fw_loadsection(sc, (uint8_t *)&dmem, sizeof(dmem));
        if (error != 0) {
                device_printf(sc->sc_dev,
                    "could not load firmware section %s\n", "DMEM");
                goto fail;
        }
        /* Wait for load to complete. */
        for (ntries = 0; ntries < 100; ntries++) {
                if (rsu_read_1(sc, R92S_TCR) & R92S_TCR_DMEM_CODE_DONE)
                        break;
                rsu_ms_delay(sc, 1);
        }
        if (ntries == 100) {
                device_printf(sc->sc_dev, "timeout waiting for %s transfer\n",
                    "DMEM");
                error = ETIMEDOUT;
                goto fail;
        }
        /* Wait for firmware readiness. */
        for (ntries = 0; ntries < 60; ntries++) {
                if (!(rsu_read_1(sc, R92S_TCR) & R92S_TCR_FWRDY))
                        break;
                rsu_ms_delay(sc, 1);
        }
        if (ntries == 60) {
                device_printf(sc->sc_dev, 
                    "timeout waiting for firmware readiness\n");
                error = ETIMEDOUT;
                goto fail;
        }
 fail:
        firmware_put(fw, FIRMWARE_UNLOAD);
        return (error);
}

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

        /* prevent management frames from being sent if we're not ready */
        if (!sc->sc_running) {
                m_freem(m);
                return (ENETDOWN);
        }
        RSU_LOCK(sc);
        bf = rsu_getbuf(sc);
        if (bf == NULL) {
                m_freem(m);
                RSU_UNLOCK(sc);
                return (ENOBUFS);
        }
        if (rsu_tx_start(sc, ni, m, bf) != 0) {
                m_freem(m);
                rsu_freebuf(sc, bf);
                RSU_UNLOCK(sc);
                return (EIO);
        }
        RSU_UNLOCK(sc);

        return (0);
}

static void
rsu_rxfilter_init(struct rsu_softc *sc)
{
        uint32_t reg;

        RSU_ASSERT_LOCKED(sc);

        /* Setup multicast filter. */
        rsu_set_multi(sc);

        /* Adjust Rx filter. */
        reg = rsu_read_4(sc, R92S_RCR);
        reg &= ~R92S_RCR_AICV;
        reg |= R92S_RCR_APP_PHYSTS;
        if (sc->sc_rx_checksum_enable)
                reg |= R92S_RCR_TCP_OFFLD_EN;
        rsu_write_4(sc, R92S_RCR, reg);

        /* Update dynamic Rx filter parts. */
        rsu_rxfilter_refresh(sc);
}

static void
rsu_rxfilter_set(struct rsu_softc *sc, uint32_t clear, uint32_t set)
{
        /* NB: firmware can touch this register too. */
        rsu_write_4(sc, R92S_RCR,
           (rsu_read_4(sc, R92S_RCR) & ~clear) | set);
}

static void
rsu_rxfilter_refresh(struct rsu_softc *sc)
{
        struct ieee80211com *ic = &sc->sc_ic;
        uint32_t mask_all, mask_min;

        RSU_ASSERT_LOCKED(sc);

        /* NB: RCR_AMF / RXFLTMAP_MGT are used by firmware. */
        mask_all = R92S_RCR_ACF | R92S_RCR_AAP;
        mask_min = R92S_RCR_APM;
        if (sc->sc_vap_is_running)
                mask_min |= R92S_RCR_CBSSID;
        else
                mask_all |= R92S_RCR_ADF;

        if (ic->ic_opmode == IEEE80211_M_MONITOR) {
                uint16_t rxfltmap;
                if (sc->sc_vap_is_running)
                        rxfltmap = 0;
                else
                        rxfltmap = R92S_RXFLTMAP_MGT_DEF;
                rsu_write_2(sc, R92S_RXFLTMAP_MGT, rxfltmap);
        }

        if (ic->ic_promisc == 0 && ic->ic_opmode != IEEE80211_M_MONITOR)
                rsu_rxfilter_set(sc, mask_all, mask_min);
        else
                rsu_rxfilter_set(sc, mask_min, mask_all);
}

static int
rsu_init(struct rsu_softc *sc)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211vap *vap = TAILQ_FIRST(&ic->ic_vaps);
        uint8_t macaddr[IEEE80211_ADDR_LEN];
        int error;
        int i;

        RSU_LOCK(sc);

        if (sc->sc_running) {
                RSU_UNLOCK(sc);
                return (0);
        }

        /* Ensure the mbuf queue is drained */
        rsu_drain_mbufq(sc);

        /* Reset power management state. */
        rsu_write_1(sc, R92S_USB_HRPWM, 0);

        /* Power on adapter. */
        if (sc->cut == 1)
                rsu_power_on_acut(sc);
        else
                rsu_power_on_bcut(sc);

        /* Load firmware. */
        error = rsu_load_firmware(sc);
        if (error != 0)
                goto fail;

        rsu_write_4(sc, R92S_CR,
            rsu_read_4(sc, R92S_CR) & ~0xff000000);

        /* Use 128 bytes pages. */
        rsu_write_1(sc, 0x00b5,
            rsu_read_1(sc, 0x00b5) | 0x01);
        /* Enable USB Rx aggregation. */
        rsu_write_1(sc, 0x00bd,
            rsu_read_1(sc, 0x00bd) | 0x80);
        /* Set USB Rx aggregation threshold. */
        rsu_write_1(sc, 0x00d9, 0x01);
        /* Set USB Rx aggregation timeout (1.7ms/4). */
        rsu_write_1(sc, 0xfe5b, 0x04);
        /* Fix USB Rx FIFO issue. */
        rsu_write_1(sc, 0xfe5c,
            rsu_read_1(sc, 0xfe5c) | 0x80);

        /* Set MAC address. */
        IEEE80211_ADDR_COPY(macaddr, vap ? vap->iv_myaddr : ic->ic_macaddr);
        rsu_write_region_1(sc, R92S_MACID, macaddr, IEEE80211_ADDR_LEN);

        /* It really takes 1.5 seconds for the firmware to boot: */
        usb_pause_mtx(&sc->sc_mtx, USB_MS_TO_TICKS(2000));

        RSU_DPRINTF(sc, RSU_DEBUG_RESET, "%s: setting MAC address to %s\n",
            __func__,
            ether_sprintf(macaddr));
        error = rsu_fw_cmd(sc, R92S_CMD_SET_MAC_ADDRESS, macaddr,
            IEEE80211_ADDR_LEN);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not set MAC address\n");
                goto fail;
        }

        /* Initialize Rx filter. */
        rsu_rxfilter_init(sc);

        /* Set PS mode fully active */
        error = rsu_set_fw_power_state(sc, RSU_PWR_ACTIVE);
        if (error != 0) {
                device_printf(sc->sc_dev, "could not set PS mode\n");
                goto fail;
        }

        /* Install static keys (if any). */
        error = rsu_reinit_static_keys(sc);
        if (error != 0)
                goto fail;

        sc->sc_extra_scan = 0;
        usbd_transfer_start(sc->sc_xfer[RSU_BULK_RX]);

        /* We're ready to go. */
        sc->sc_running = 1;
        RSU_UNLOCK(sc);

        return (0);
fail:
        /* Need to stop all failed transfers, if any */
        for (i = 0; i != RSU_N_TRANSFER; i++)
                usbd_transfer_stop(sc->sc_xfer[i]);
        RSU_UNLOCK(sc);

        return (error);
}

static void
rsu_stop(struct rsu_softc *sc)
{
        int i;

        RSU_LOCK(sc);
        if (!sc->sc_running) {
                RSU_UNLOCK(sc);
                return;
        }

        sc->sc_running = 0;
        sc->sc_vap_is_running = 0;
        sc->sc_calibrating = 0;
        taskqueue_cancel_timeout(taskqueue_thread, &sc->calib_task, NULL);
        taskqueue_cancel(taskqueue_thread, &sc->tx_task, NULL);

        /* Power off adapter. */
        rsu_power_off(sc);

        /*
         * CAM is not accessible after shutdown;
         * all entries are marked (by firmware?) as invalid.
         */
        memset(sc->free_keys_bmap, 0, sizeof(sc->free_keys_bmap));
        memset(sc->keys_bmap, 0, sizeof(sc->keys_bmap));

        for (i = 0; i < RSU_N_TRANSFER; i++)
                usbd_transfer_stop(sc->sc_xfer[i]);

        /* Ensure the mbuf queue is drained */
        rsu_drain_mbufq(sc);
        RSU_UNLOCK(sc);
}

/*
 * Note: usb_pause_mtx() actually releases the mutex before calling pause(),
 * which breaks any kind of driver serialisation.
 */
static void
rsu_ms_delay(struct rsu_softc *sc, int ms)
{

        //usb_pause_mtx(&sc->sc_mtx, hz / 1000);
        DELAY(ms * 1000);
}