/*	$OpenBSD: if_athn_usb.c,v 1.36 2015/07/09 16:33:42 stsp Exp $	*/

/*-
 * Copyright (c) 2011 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.
 */

/*
 * USB front-end for Atheros AR9271 and AR7010 chipsets.
 */

#include "bpfilter.h"

#include <sys/param.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/systm.h>
#include <sys/timeout.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/endian.h>

#include <machine/bus.h>
#include <machine/intr.h>

#if NBPFILTER > 0
#include <net/bpf.h>
#endif
#include <net/if.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/if_ether.h>

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_amrr.h>
#include <net80211/ieee80211_radiotap.h>

#include <dev/ic/athnreg.h>
#include <dev/ic/athnvar.h>

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

#include <dev/usb/if_athn_usb.h>

static const struct athn_usb_type {
	struct usb_devno	devno;
	u_int			flags;
} athn_usb_devs[] = {
	{{ USB_VENDOR_ACCTON, USB_PRODUCT_ACCTON_AR9280 },
	   ATHN_USB_FLAG_AR7010 },
	{{ USB_VENDOR_ACTIONTEC, USB_PRODUCT_ACTIONTEC_AR9287 },
	   ATHN_USB_FLAG_AR7010 },
	{{ USB_VENDOR_ATHEROS2, USB_PRODUCT_ATHEROS2_AR9271_1 }},
	{{ USB_VENDOR_ATHEROS2, USB_PRODUCT_ATHEROS2_AR9271_2 }},
	{{ USB_VENDOR_ATHEROS2, USB_PRODUCT_ATHEROS2_AR9271_3 }},
	{{ USB_VENDOR_ATHEROS2, USB_PRODUCT_ATHEROS2_AR9280 },
	   ATHN_USB_FLAG_AR7010 },
	{{ USB_VENDOR_ATHEROS2, USB_PRODUCT_ATHEROS2_AR9287 },
	   ATHN_USB_FLAG_AR7010 },
	{{ USB_VENDOR_AZUREWAVE, USB_PRODUCT_AZUREWAVE_AR9271_1 }},
	{{ USB_VENDOR_AZUREWAVE, USB_PRODUCT_AZUREWAVE_AR9271_2 }},
	{{ USB_VENDOR_AZUREWAVE, USB_PRODUCT_AZUREWAVE_AR9271_3 }},
	{{ USB_VENDOR_AZUREWAVE, USB_PRODUCT_AZUREWAVE_AR9271_4 }},
	{{ USB_VENDOR_AZUREWAVE, USB_PRODUCT_AZUREWAVE_AR9271_5 }},
	{{ USB_VENDOR_AZUREWAVE, USB_PRODUCT_AZUREWAVE_AR9271_6 }},
	{{ USB_VENDOR_DLINK2, USB_PRODUCT_DLINK2_AR9271 }},
	{{ USB_VENDOR_LITEON, USB_PRODUCT_LITEON_AR9271 }},
	{{ USB_VENDOR_NETGEAR, USB_PRODUCT_NETGEAR_WNA1100 }},
	{{ USB_VENDOR_NETGEAR, USB_PRODUCT_NETGEAR_WNDA3200 },
	   ATHN_USB_FLAG_AR7010 },
	{{ USB_VENDOR_PANASONIC, USB_PRODUCT_PANASONIC_N5HBZ0000055 },
	   ATHN_USB_FLAG_AR7010 },
	{{ USB_VENDOR_VIA, USB_PRODUCT_VIA_AR9271 }}
};
#define athn_usb_lookup(v, p)	\
	((const struct athn_usb_type *)usb_lookup(athn_usb_devs, v, p))

int		athn_usb_match(struct device *, void *, void *);
void		athn_usb_attach(struct device *, struct device *, void *);
int		athn_usb_detach(struct device *, int);
void		athn_usb_attachhook(void *);
int		athn_usb_open_pipes(struct athn_usb_softc *);
void		athn_usb_close_pipes(struct athn_usb_softc *);
int		athn_usb_alloc_rx_list(struct athn_usb_softc *);
void		athn_usb_free_rx_list(struct athn_usb_softc *);
int		athn_usb_alloc_tx_list(struct athn_usb_softc *);
void		athn_usb_free_tx_list(struct athn_usb_softc *);
int		athn_usb_alloc_tx_cmd(struct athn_usb_softc *);
void		athn_usb_free_tx_cmd(struct athn_usb_softc *);
void		athn_usb_task(void *);
void		athn_usb_do_async(struct athn_usb_softc *,
		    void (*)(struct athn_usb_softc *, void *), void *, int);
void		athn_usb_wait_async(struct athn_usb_softc *);
int		athn_usb_load_firmware(struct athn_usb_softc *);
int		athn_usb_htc_msg(struct athn_usb_softc *, uint16_t, void *,
		    int);
int		athn_usb_htc_setup(struct athn_usb_softc *);
int		athn_usb_htc_connect_svc(struct athn_usb_softc *, uint16_t,
		    uint8_t, uint8_t, uint8_t *);
int		athn_usb_wmi_xcmd(struct athn_usb_softc *, uint16_t, void *,
		    int, void *);
int		athn_usb_read_rom(struct athn_softc *);
uint32_t	athn_usb_read(struct athn_softc *, uint32_t);
void		athn_usb_write(struct athn_softc *, uint32_t, uint32_t);
void		athn_usb_write_barrier(struct athn_softc *);
int		athn_usb_media_change(struct ifnet *);
void		athn_usb_next_scan(void *);
int		athn_usb_newstate(struct ieee80211com *, enum ieee80211_state,
		    int);
void		athn_usb_newstate_cb(struct athn_usb_softc *, void *);
void		athn_usb_newassoc(struct ieee80211com *,
		    struct ieee80211_node *, int);
void		athn_usb_newassoc_cb(struct athn_usb_softc *, void *);
void		athn_usb_node_leave(struct ieee80211com *,
		    struct ieee80211_node *);
void		athn_usb_node_leave_cb(struct athn_usb_softc *, void *);
int		athn_usb_ampdu_tx_start(struct ieee80211com *,
		    struct ieee80211_node *, uint8_t);
void		athn_usb_ampdu_tx_start_cb(struct athn_usb_softc *, void *);
void		athn_usb_ampdu_tx_stop(struct ieee80211com *,
		    struct ieee80211_node *, uint8_t);
void		athn_usb_ampdu_tx_stop_cb(struct athn_usb_softc *, void *);
int		athn_usb_create_node(struct athn_usb_softc *,
		    struct ieee80211_node *);
void		athn_usb_rx_enable(struct athn_softc *);
int		athn_set_chan(struct athn_softc *, struct ieee80211_channel *,
		    struct ieee80211_channel *);
int		athn_usb_switch_chan(struct athn_softc *,
		    struct ieee80211_channel *, struct ieee80211_channel *);
void		athn_usb_updateedca(struct ieee80211com *);
void		athn_usb_updateedca_cb(struct athn_usb_softc *, void *);
void		athn_usb_updateslot(struct ieee80211com *);
void		athn_usb_updateslot_cb(struct athn_usb_softc *, void *);
int		athn_usb_set_key(struct ieee80211com *,
		    struct ieee80211_node *, struct ieee80211_key *);
void		athn_usb_set_key_cb(struct athn_usb_softc *, void *);
void		athn_usb_delete_key(struct ieee80211com *,
		    struct ieee80211_node *, struct ieee80211_key *);
void		athn_usb_delete_key_cb(struct athn_usb_softc *, void *);
void		athn_usb_bcneof(struct usbd_xfer *, void *,
		    usbd_status);
void		athn_usb_swba(struct athn_usb_softc *);
void		athn_usb_rx_wmi_ctrl(struct athn_usb_softc *, uint8_t *, int);
void		athn_usb_intr(struct usbd_xfer *, void *,
		    usbd_status);
void		athn_usb_rx_radiotap(struct athn_softc *, struct mbuf *,
		    struct ar_rx_status *);
void		athn_usb_rx_frame(struct athn_usb_softc *, struct mbuf *);
void		athn_usb_rxeof(struct usbd_xfer *, void *,
		    usbd_status);
void		athn_usb_txeof(struct usbd_xfer *, void *,
		    usbd_status);
int		athn_usb_tx(struct athn_softc *, struct mbuf *,
		    struct ieee80211_node *);
void		athn_usb_start(struct ifnet *);
void		athn_usb_watchdog(struct ifnet *);
int		athn_usb_ioctl(struct ifnet *, u_long, caddr_t);
int		athn_usb_init(struct ifnet *);
void		athn_usb_stop(struct ifnet *);
void		ar9271_load_ani(struct athn_softc *);

/* Shortcut. */
#define athn_usb_wmi_cmd(sc, cmd_id)	\
	athn_usb_wmi_xcmd(sc, cmd_id, NULL, 0, NULL)

/* Extern functions. */
void		athn_led_init(struct athn_softc *);
void		athn_set_led(struct athn_softc *, int);
void		athn_btcoex_init(struct athn_softc *);
void		athn_set_rxfilter(struct athn_softc *, uint32_t);
int		athn_reset(struct athn_softc *, int);
void		athn_init_pll(struct athn_softc *,
		    const struct ieee80211_channel *);
int		athn_set_power_awake(struct athn_softc *);
void		athn_set_power_sleep(struct athn_softc *);
void		athn_reset_key(struct athn_softc *, int);
int		athn_set_key(struct ieee80211com *, struct ieee80211_node *,
		    struct ieee80211_key *);
void		athn_delete_key(struct ieee80211com *, struct ieee80211_node *,
		    struct ieee80211_key *);
void		athn_rx_start(struct athn_softc *);
void		athn_set_sta_timers(struct athn_softc *);
void		athn_set_hostap_timers(struct athn_softc *);
void		athn_set_opmode(struct athn_softc *);
void		athn_set_bss(struct athn_softc *, struct ieee80211_node *);
int		athn_hw_reset(struct athn_softc *, struct ieee80211_channel *,
		    struct ieee80211_channel *, int);
void		athn_updateedca(struct ieee80211com *);
void		athn_updateslot(struct ieee80211com *);

const struct cfattach athn_usb_ca = {
	sizeof(struct athn_usb_softc),
	athn_usb_match,
	athn_usb_attach,
	athn_usb_detach
};

int
athn_usb_match(struct device *parent, void *match, void *aux)
{
	struct usb_attach_arg *uaa = aux;

	if (uaa->iface == NULL || uaa->configno != 1)
		return (UMATCH_NONE);

	return ((athn_usb_lookup(uaa->vendor, uaa->product) != NULL) ?
	    UMATCH_VENDOR_PRODUCT_CONF_IFACE : UMATCH_NONE);
}

void
athn_usb_attach(struct device *parent, struct device *self, void *aux)
{
	struct athn_usb_softc *usc = (struct athn_usb_softc *)self;
	struct athn_softc *sc = &usc->sc_sc;
	struct usb_attach_arg *uaa = aux;

	usc->sc_udev = uaa->device;
	usc->sc_iface = uaa->iface;

	usc->flags = athn_usb_lookup(uaa->vendor, uaa->product)->flags;
	sc->flags |= ATHN_FLAG_USB;
#ifdef notyet
	/* Check if it is a combo WiFi+Bluetooth (WB193) device. */
	if (strncmp(product, "wb193", 5) == 0)
		sc->flags |= ATHN_FLAG_BTCOEX3WIRE;
#endif

	sc->ops.read = athn_usb_read;
	sc->ops.write = athn_usb_write;
	sc->ops.write_barrier = athn_usb_write_barrier;

	usb_init_task(&usc->sc_task, athn_usb_task, sc, USB_TASK_TYPE_GENERIC);

	if (athn_usb_open_pipes(usc) != 0)
		return;

	/* Allocate xfer for firmware commands. */
	if (athn_usb_alloc_tx_cmd(usc) != 0)
		return;

	if (rootvp == NULL)
		mountroothook_establish(athn_usb_attachhook, usc);
	else
		athn_usb_attachhook(usc);
}

int
athn_usb_detach(struct device *self, int flags)
{
	struct athn_usb_softc *usc = (struct athn_usb_softc *)self;
	struct athn_softc *sc = &usc->sc_sc;

	if (usc->sc_athn_attached)
		athn_detach(sc);

	/* Wait for all async commands to complete. */
	athn_usb_wait_async(usc);

	usbd_ref_wait(usc->sc_udev);

	/* Abort and close Tx/Rx pipes. */
	athn_usb_close_pipes(usc);

	/* Free Tx/Rx buffers. */
	athn_usb_free_tx_cmd(usc);
	athn_usb_free_tx_list(usc);
	athn_usb_free_rx_list(usc);

	return (0);
}

void
athn_usb_attachhook(void *xsc)
{
	struct athn_usb_softc *usc = xsc;
	struct athn_softc *sc = &usc->sc_sc;
	struct athn_ops *ops = &sc->ops;
	struct ieee80211com *ic = &sc->sc_ic;
	struct ifnet *ifp = &ic->ic_if;
	int s, i, error;

	/* Load firmware. */
	error = athn_usb_load_firmware(usc);
	if (error != 0) {
		printf("%s: could not load firmware\n", sc->sc_dev.dv_xname);
		return;
	}

	/* Setup the host transport communication interface. */
	error = athn_usb_htc_setup(usc);
	if (error != 0)
		return;

	/* We're now ready to attach the bus agnostic driver. */
	s = splnet();
	error = athn_attach(sc);
	if (error != 0) {
		splx(s);
		return;
	}
	usc->sc_athn_attached = 1;
	/* Override some operations for USB. */
	ifp->if_ioctl = athn_usb_ioctl;
	ifp->if_start = athn_usb_start;
	ifp->if_watchdog = athn_usb_watchdog;
	ic->ic_newassoc = athn_usb_newassoc;
	ic->ic_node_leave = athn_usb_node_leave;
	ic->ic_updateslot = athn_usb_updateslot;
	ic->ic_updateedca = athn_usb_updateedca;
#ifdef notyet
	ic->ic_set_key = athn_usb_set_key;
	ic->ic_delete_key = athn_usb_delete_key;
	ic->ic_ampdu_tx_start = athn_usb_ampdu_tx_start;
	ic->ic_ampdu_tx_stop = athn_usb_ampdu_tx_stop;
#endif
	ic->ic_newstate = athn_usb_newstate;
	ic->ic_media.ifm_change = athn_usb_media_change;
	timeout_set(&sc->scan_to, athn_usb_next_scan, usc);

	ops->rx_enable = athn_usb_rx_enable;
	splx(s);

	/* Reset HW key cache entries. */
	for (i = 0; i < sc->kc_entries; i++)
		athn_reset_key(sc, i);

	ops->enable_antenna_diversity(sc);

#ifdef ATHN_BT_COEXISTENCE
	/* Configure bluetooth coexistence for combo chips. */
	if (sc->flags & ATHN_FLAG_BTCOEX)
		athn_btcoex_init(sc);
#endif
	/* Configure LED. */
	athn_led_init(sc);
}

int
athn_usb_open_pipes(struct athn_usb_softc *usc)
{
	usb_endpoint_descriptor_t *ed;
	int isize, error;

	error = usbd_open_pipe(usc->sc_iface, AR_PIPE_TX_DATA, 0,
	    &usc->tx_data_pipe);
	if (error != 0) {
		printf("%s: could not open Tx bulk pipe\n",
		    usc->usb_dev.dv_xname);
		goto fail;
	}

	error = usbd_open_pipe(usc->sc_iface, AR_PIPE_RX_DATA, 0,
	    &usc->rx_data_pipe);
	if (error != 0) {
		printf("%s: could not open Rx bulk pipe\n",
		    usc->usb_dev.dv_xname);
		goto fail;
	}

	ed = usbd_get_endpoint_descriptor(usc->sc_iface, AR_PIPE_RX_INTR);
	if (ed == NULL) {
		printf("%s: could not retrieve Rx intr pipe descriptor\n",
		    usc->usb_dev.dv_xname);
		goto fail;
	}
	isize = UGETW(ed->wMaxPacketSize);
	if (isize == 0) {
		printf("%s: invalid Rx intr pipe descriptor\n",
		    usc->usb_dev.dv_xname);
		goto fail;
	}
	usc->ibuf = malloc(isize, M_USBDEV, M_NOWAIT);
	if (usc->ibuf == NULL) {
		printf("%s: could not allocate Rx intr buffer\n",
		    usc->usb_dev.dv_xname);
		goto fail;
	}
	error = usbd_open_pipe_intr(usc->sc_iface, AR_PIPE_RX_INTR,
	    USBD_SHORT_XFER_OK, &usc->rx_intr_pipe, usc, usc->ibuf, isize,
	    athn_usb_intr, USBD_DEFAULT_INTERVAL);
	if (error != 0) {
		printf("%s: could not open Rx intr pipe\n",
		    usc->usb_dev.dv_xname);
		goto fail;
	}

	error = usbd_open_pipe(usc->sc_iface, AR_PIPE_TX_INTR, 0,
	    &usc->tx_intr_pipe);
	if (error != 0) {
		printf("%s: could not open Tx intr pipe\n",
		    usc->usb_dev.dv_xname);
		goto fail;
	}
 fail:
	if (error != 0)
		athn_usb_close_pipes(usc);
	return (error);
}

void
athn_usb_close_pipes(struct athn_usb_softc *usc)
{
	if (usc->tx_data_pipe != NULL) {
		usbd_close_pipe(usc->tx_data_pipe);
		usc->tx_data_pipe = NULL;
	}
	if (usc->rx_data_pipe != NULL) {
		usbd_close_pipe(usc->rx_data_pipe);
		usc->rx_data_pipe = NULL;
	}
	if (usc->tx_intr_pipe != NULL) {
		usbd_close_pipe(usc->tx_intr_pipe);
		usc->tx_intr_pipe = NULL;
	}
	if (usc->rx_intr_pipe != NULL) {
		usbd_close_pipe(usc->rx_intr_pipe);
		usc->rx_intr_pipe = NULL;
	}
	if (usc->ibuf != NULL) {
		free(usc->ibuf, M_USBDEV, 0);
		usc->ibuf = NULL;
	}
}

int
athn_usb_alloc_rx_list(struct athn_usb_softc *usc)
{
	struct athn_usb_rx_data *data;
	int i, error = 0;

	for (i = 0; i < ATHN_USB_RX_LIST_COUNT; i++) {
		data = &usc->rx_data[i];

		data->sc = usc;	/* Backpointer for callbacks. */

		data->xfer = usbd_alloc_xfer(usc->sc_udev);
		if (data->xfer == NULL) {
			printf("%s: could not allocate xfer\n",
			    usc->usb_dev.dv_xname);
			error = ENOMEM;
			break;
		}
		data->buf = usbd_alloc_buffer(data->xfer, ATHN_USB_RXBUFSZ);
		if (data->buf == NULL) {
			printf("%s: could not allocate xfer buffer\n",
			    usc->usb_dev.dv_xname);
			error = ENOMEM;
			break;
		}
	}
	if (error != 0)
		athn_usb_free_rx_list(usc);
	return (error);
}

void
athn_usb_free_rx_list(struct athn_usb_softc *usc)
{
	int i;

	/* NB: Caller must abort pipe first. */
	for (i = 0; i < ATHN_USB_RX_LIST_COUNT; i++) {
		if (usc->rx_data[i].xfer != NULL)
			usbd_free_xfer(usc->rx_data[i].xfer);
		usc->rx_data[i].xfer = NULL;
	}
}

int
athn_usb_alloc_tx_list(struct athn_usb_softc *usc)
{
	struct athn_usb_tx_data *data;
	int i, error = 0;

	TAILQ_INIT(&usc->tx_free_list);
	for (i = 0; i < ATHN_USB_TX_LIST_COUNT; i++) {
		data = &usc->tx_data[i];

		data->sc = usc;	/* Backpointer for callbacks. */

		data->xfer = usbd_alloc_xfer(usc->sc_udev);
		if (data->xfer == NULL) {
			printf("%s: could not allocate xfer\n",
			    usc->usb_dev.dv_xname);
			error = ENOMEM;
			break;
		}
		data->buf = usbd_alloc_buffer(data->xfer, ATHN_USB_TXBUFSZ);
		if (data->buf == NULL) {
			printf("%s: could not allocate xfer buffer\n",
			    usc->usb_dev.dv_xname);
			error = ENOMEM;
			break;
		}
		/* Append this Tx buffer to our free list. */
		TAILQ_INSERT_TAIL(&usc->tx_free_list, data, next);
	}
	if (error != 0)
		athn_usb_free_tx_list(usc);
	return (error);
}

void
athn_usb_free_tx_list(struct athn_usb_softc *usc)
{
	int i;

	/* NB: Caller must abort pipe first. */
	for (i = 0; i < ATHN_USB_TX_LIST_COUNT; i++) {
		if (usc->tx_data[i].xfer != NULL)
			usbd_free_xfer(usc->tx_data[i].xfer);
		usc->tx_data[i].xfer = NULL;
	}
}

int
athn_usb_alloc_tx_cmd(struct athn_usb_softc *usc)
{
	struct athn_usb_tx_data *data = &usc->tx_cmd;

	data->sc = usc;	/* Backpointer for callbacks. */

	data->xfer = usbd_alloc_xfer(usc->sc_udev);
	if (data->xfer == NULL) {
		printf("%s: could not allocate xfer\n",
		    usc->usb_dev.dv_xname);
		return (ENOMEM);
	}
	data->buf = usbd_alloc_buffer(data->xfer, ATHN_USB_TXCMDSZ);
	if (data->buf == NULL) {
		printf("%s: could not allocate xfer buffer\n",
		    usc->usb_dev.dv_xname);
		return (ENOMEM);
	}
	return (0);
}

void
athn_usb_free_tx_cmd(struct athn_usb_softc *usc)
{
	if (usc->tx_cmd.xfer != NULL)
		usbd_free_xfer(usc->tx_cmd.xfer);
	usc->tx_cmd.xfer = NULL;
}

void
athn_usb_task(void *arg)
{
	struct athn_usb_softc *usc = arg;
	struct athn_usb_host_cmd_ring *ring = &usc->cmdq;
	struct athn_usb_host_cmd *cmd;
	int s;

	/* Process host commands. */
	s = splusb();
	while (ring->next != ring->cur) {
		cmd = &ring->cmd[ring->next];
		splx(s);
		/* Invoke callback. */
		cmd->cb(usc, cmd->data);
		s = splusb();
		ring->queued--;
		ring->next = (ring->next + 1) % ATHN_USB_HOST_CMD_RING_COUNT;
	}
	splx(s);
}

void
athn_usb_do_async(struct athn_usb_softc *usc,
    void (*cb)(struct athn_usb_softc *, void *), void *arg, int len)
{
	struct athn_usb_host_cmd_ring *ring = &usc->cmdq;
	struct athn_usb_host_cmd *cmd;
	int s;

	if (ring->queued == ATHN_USB_HOST_CMD_RING_COUNT) {
		printf("%s: host cmd queue overrun\n", usc->usb_dev.dv_xname);
		return;	/* XXX */
	}
	
	s = splusb();
	cmd = &ring->cmd[ring->cur];
	cmd->cb = cb;
	KASSERT(len <= sizeof(cmd->data));
	memcpy(cmd->data, arg, len);
	ring->cur = (ring->cur + 1) % ATHN_USB_HOST_CMD_RING_COUNT;

	/* If there is no pending command already, schedule a task. */
	if (++ring->queued == 1)
		usb_add_task(usc->sc_udev, &usc->sc_task);
	splx(s);
}

void
athn_usb_wait_async(struct athn_usb_softc *usc)
{
	/* Wait for all queued asynchronous commands to complete. */
	usb_wait_task(usc->sc_udev, &usc->sc_task);
}

int
athn_usb_load_firmware(struct athn_usb_softc *usc)
{
	usb_device_descriptor_t *dd;
	usb_device_request_t req;
	const char *name;
	u_char *fw, *ptr;
	size_t size;
	uint32_t addr;
	int s, mlen, error;

	/* Determine which firmware image to load. */
	if (usc->flags & ATHN_USB_FLAG_AR7010) {
		dd = usbd_get_device_descriptor(usc->sc_udev);
		if (UGETW(dd->bcdDevice) == 0x0202)
			name = "athn-ar7010-11";
		else
			name = "athn-ar7010";
	} else
		name = "athn-ar9271";
	/* Read firmware image from the filesystem. */
	if ((error = loadfirmware(name, &fw, &size)) != 0) {
		printf("%s: failed loadfirmware of file %s (error %d)\n",
		    usc->usb_dev.dv_xname, name, error);
		return (error);
	}
	/* Load firmware image. */
	ptr = fw;
	addr = AR9271_FIRMWARE >> 8;
	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
	req.bRequest = AR_FW_DOWNLOAD;
	USETW(req.wIndex, 0);
	while (size > 0) {
		mlen = MIN(size, 4096);

		USETW(req.wValue, addr);
		USETW(req.wLength, mlen);
		error = usbd_do_request(usc->sc_udev, &req, ptr);
		if (error != 0) {
			free(fw, M_DEVBUF, 0);
			return (error);
		}
		addr += mlen >> 8;
		ptr  += mlen;
		size -= mlen;
	}
	free(fw, M_DEVBUF, 0);

	/* Start firmware. */
	if (usc->flags & ATHN_USB_FLAG_AR7010)
		addr = AR7010_FIRMWARE_TEXT >> 8;
	else
		addr = AR9271_FIRMWARE_TEXT >> 8;
	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
	req.bRequest = AR_FW_DOWNLOAD_COMP;
	USETW(req.wIndex, 0);
	USETW(req.wValue, addr);
	USETW(req.wLength, 0);
	s = splusb();
	usc->wait_msg_id = AR_HTC_MSG_READY;
	error = usbd_do_request(usc->sc_udev, &req, NULL);
	/* Wait at most 1 second for firmware to boot. */
	if (error == 0 && usc->wait_msg_id != 0)
		error = tsleep(&usc->wait_msg_id, 0, "athnfw", hz);
	usc->wait_msg_id = 0;
	splx(s);
	return (error);
}

int
athn_usb_htc_msg(struct athn_usb_softc *usc, uint16_t msg_id, void *buf,
    int len)
{
	struct athn_usb_tx_data *data = &usc->tx_cmd;
	struct ar_htc_frame_hdr *htc;
	struct ar_htc_msg_hdr *msg;

	htc = (struct ar_htc_frame_hdr *)data->buf;
	memset(htc, 0, sizeof(*htc));
	htc->endpoint_id = 0;
	htc->payload_len = htobe16(sizeof(*msg) + len);

	msg = (struct ar_htc_msg_hdr *)&htc[1];
	msg->msg_id = htobe16(msg_id);

	memcpy(&msg[1], buf, len);

	usbd_setup_xfer(data->xfer, usc->tx_intr_pipe, NULL, data->buf,
	    sizeof(*htc) + sizeof(*msg) + len,
	    USBD_SHORT_XFER_OK | USBD_NO_COPY | USBD_SYNCHRONOUS,
	    ATHN_USB_CMD_TIMEOUT, NULL);
	return (usbd_transfer(data->xfer));
}

int
athn_usb_htc_setup(struct athn_usb_softc *usc)
{
	struct ar_htc_msg_config_pipe cfg;
	int s, error;

	/*
	 * Connect WMI services to USB pipes.
	 */
	error = athn_usb_htc_connect_svc(usc, AR_SVC_WMI_CONTROL,
	    AR_PIPE_TX_INTR, AR_PIPE_RX_INTR, &usc->ep_ctrl);
	if (error != 0)
		return (error);
	error = athn_usb_htc_connect_svc(usc, AR_SVC_WMI_BEACON,
	    AR_PIPE_TX_DATA, AR_PIPE_RX_DATA, &usc->ep_bcn);
	if (error != 0)
		return (error);
	error = athn_usb_htc_connect_svc(usc, AR_SVC_WMI_CAB,
	    AR_PIPE_TX_DATA, AR_PIPE_RX_DATA, &usc->ep_cab);
	if (error != 0)
		return (error);
	error = athn_usb_htc_connect_svc(usc, AR_SVC_WMI_UAPSD,
	    AR_PIPE_TX_DATA, AR_PIPE_RX_DATA, &usc->ep_uapsd);
	if (error != 0)
		return (error);
	error = athn_usb_htc_connect_svc(usc, AR_SVC_WMI_MGMT,
	    AR_PIPE_TX_DATA, AR_PIPE_RX_DATA, &usc->ep_mgmt);
	if (error != 0)
		return (error);
	error = athn_usb_htc_connect_svc(usc, AR_SVC_WMI_DATA_BE,
	    AR_PIPE_TX_DATA, AR_PIPE_RX_DATA, &usc->ep_data[EDCA_AC_BE]);
	if (error != 0)
		return (error);
	error = athn_usb_htc_connect_svc(usc, AR_SVC_WMI_DATA_BK,
	    AR_PIPE_TX_DATA, AR_PIPE_RX_DATA, &usc->ep_data[EDCA_AC_BK]);
	if (error != 0)
		return (error);
	error = athn_usb_htc_connect_svc(usc, AR_SVC_WMI_DATA_VI,
	    AR_PIPE_TX_DATA, AR_PIPE_RX_DATA, &usc->ep_data[EDCA_AC_VI]);
	if (error != 0)
		return (error);
	error = athn_usb_htc_connect_svc(usc, AR_SVC_WMI_DATA_VO,
	    AR_PIPE_TX_DATA, AR_PIPE_RX_DATA, &usc->ep_data[EDCA_AC_VO]);
	if (error != 0)
		return (error);

	/* Set credits for WLAN Tx pipe. */
	memset(&cfg, 0, sizeof(cfg));
	cfg.pipe_id = UE_GET_ADDR(AR_PIPE_TX_DATA);
	cfg.credits = (usc->flags & ATHN_USB_FLAG_AR7010) ? 45 : 33;
	s = splusb();
	usc->wait_msg_id = AR_HTC_MSG_CONF_PIPE_RSP;
	error = athn_usb_htc_msg(usc, AR_HTC_MSG_CONF_PIPE, &cfg, sizeof(cfg));
	if (error == 0 && usc->wait_msg_id != 0)
		error = tsleep(&usc->wait_msg_id, 0, "athnhtc", hz);
	usc->wait_msg_id = 0;
	splx(s);
	if (error != 0) {
		printf("%s: could not configure pipe\n",
		    usc->usb_dev.dv_xname);
		return (error);
	}

	error = athn_usb_htc_msg(usc, AR_HTC_MSG_SETUP_COMPLETE, NULL, 0);
	if (error != 0) {
		printf("%s: could not complete setup\n",
		    usc->usb_dev.dv_xname);
		return (error);
	}
	return (0);
}

int
athn_usb_htc_connect_svc(struct athn_usb_softc *usc, uint16_t svc_id,
    uint8_t ul_pipe, uint8_t dl_pipe, uint8_t *endpoint_id)
{
	struct ar_htc_msg_conn_svc msg;
	struct ar_htc_msg_conn_svc_rsp rsp;
	int s, error;

	memset(&msg, 0, sizeof(msg));
	msg.svc_id = htobe16(svc_id);
	msg.dl_pipeid = UE_GET_ADDR(dl_pipe);
	msg.ul_pipeid = UE_GET_ADDR(ul_pipe);
	s = splusb();
	usc->msg_conn_svc_rsp = &rsp;
	usc->wait_msg_id = AR_HTC_MSG_CONN_SVC_RSP;
	error = athn_usb_htc_msg(usc, AR_HTC_MSG_CONN_SVC, &msg, sizeof(msg));
	/* Wait at most 1 second for response. */
	if (error == 0 && usc->wait_msg_id != 0)
		error = tsleep(&usc->wait_msg_id, 0, "athnhtc", hz);
	usc->wait_msg_id = 0;
	splx(s);
	if (error != 0) {
		printf("%s: error waiting for service %d connection\n",
		    usc->usb_dev.dv_xname, svc_id);
		return (error);
	}
	if (rsp.status != AR_HTC_SVC_SUCCESS) {
		printf("%s: service %d connection failed, error %d\n",
		    usc->usb_dev.dv_xname, svc_id, rsp.status);
		return (EIO);
	}
	DPRINTF(("service %d successfully connected to endpoint %d\n",
	    svc_id, rsp.endpoint_id));

	/* Return endpoint id. */
	*endpoint_id = rsp.endpoint_id;
	return (0);
}

int
athn_usb_wmi_xcmd(struct athn_usb_softc *usc, uint16_t cmd_id, void *ibuf,
    int ilen, void *obuf)
{
	struct athn_usb_tx_data *data = &usc->tx_cmd;
	struct ar_htc_frame_hdr *htc;
	struct ar_wmi_cmd_hdr *wmi;
	int s, error;

	if (usbd_is_dying(usc->sc_udev))
		return ENXIO;

	s = splusb();
	while (usc->wait_cmd_id) {
		/* 
		 * The previous USB transfer is not done yet. We can't use
		 * data->xfer until it is done or we'll cause major confusion
		 * in the USB stack.
		 */
		tsleep(&usc->wait_cmd_id, 0, "athnwmx", ATHN_USB_CMD_TIMEOUT);
		if (usbd_is_dying(usc->sc_udev)) {
			splx(s);
			return ENXIO;
		}
	}
	splx(s);

	htc = (struct ar_htc_frame_hdr *)data->buf;
	memset(htc, 0, sizeof(*htc));
	htc->endpoint_id = usc->ep_ctrl;
	htc->payload_len = htobe16(sizeof(*wmi) + ilen);

	wmi = (struct ar_wmi_cmd_hdr *)&htc[1];
	wmi->cmd_id = htobe16(cmd_id);
	usc->wmi_seq_no++;
	wmi->seq_no = htobe16(usc->wmi_seq_no);

	memcpy(&wmi[1], ibuf, ilen);

	usbd_setup_xfer(data->xfer, usc->tx_intr_pipe, NULL, data->buf,
	    sizeof(*htc) + sizeof(*wmi) + ilen,
	    USBD_SHORT_XFER_OK | USBD_NO_COPY, ATHN_USB_CMD_TIMEOUT,
	    NULL);
	s = splusb();
	error = usbd_transfer(data->xfer);
	if (__predict_false(error != USBD_IN_PROGRESS && error != 0)) {
		splx(s);
		return (error);
	}
	usc->obuf = obuf;
	usc->wait_cmd_id = cmd_id;
	/* 
	 * Wait for WMI command complete interrupt. In case it does not fire
	 * wait until the USB transfer times out to avoid racing the transfer.
	 */
	error = tsleep(&usc->wait_cmd_id, 0, "athnwmi", ATHN_USB_CMD_TIMEOUT);
	if (error) {
		if (error == EWOULDBLOCK) {
			printf("%s: firmware command 0x%x timed out\n",
			    usc->usb_dev.dv_xname, cmd_id);
			error = ETIMEDOUT;
		}
	}

	/* 
	 * Both the WMI command and transfer are done or have timed out.
	 * Allow other threads to enter this function and use data->xfer.
	 */
	usc->wait_cmd_id = 0;
	wakeup(&usc->wait_cmd_id);

	splx(s);
	return (error);
}

int
athn_usb_read_rom(struct athn_softc *sc)
{
	struct athn_usb_softc *usc = (struct athn_usb_softc *)sc;
	uint32_t addrs[8], vals[8], addr;
	uint16_t *eep;
	int i, j, error;

	/* Read EEPROM by blocks of 16 bytes. */
	eep = sc->eep;
	addr = AR_EEPROM_OFFSET(sc->eep_base);
	for (i = 0; i < sc->eep_size / 16; i++) {
		for (j = 0; j < 8; j++, addr += 4)
			addrs[j] = htobe32(addr);
		error = athn_usb_wmi_xcmd(usc, AR_WMI_CMD_REG_READ,
		    addrs, sizeof(addrs), vals);
		if (error != 0)
			break;
		for (j = 0; j < 8; j++)
			*eep++ = betoh32(vals[j]);
	}
	return (error);
}

uint32_t
athn_usb_read(struct athn_softc *sc, uint32_t addr)
{
	struct athn_usb_softc *usc = (struct athn_usb_softc *)sc;
	uint32_t val;
	int error;

	/* Flush pending writes for strict consistency. */
	athn_usb_write_barrier(sc);

	addr = htobe32(addr);
	error = athn_usb_wmi_xcmd(usc, AR_WMI_CMD_REG_READ,
	    &addr, sizeof(addr), &val);
	if (error != 0)
		return (0xdeadbeef);
	return (betoh32(val));
}

void
athn_usb_write(struct athn_softc *sc, uint32_t addr, uint32_t val)
{
	struct athn_usb_softc *usc = (struct athn_usb_softc *)sc;

	usc->wbuf[usc->wcount].addr = htobe32(addr);
	usc->wbuf[usc->wcount].val  = htobe32(val);
	if (++usc->wcount == AR_MAX_WRITE_COUNT)
		athn_usb_write_barrier(sc);
}

void
athn_usb_write_barrier(struct athn_softc *sc)
{
	struct athn_usb_softc *usc = (struct athn_usb_softc *)sc;

	if (usc->wcount == 0)
		return;	/* Nothing to write. */

	(void)athn_usb_wmi_xcmd(usc, AR_WMI_CMD_REG_WRITE,
	    usc->wbuf, usc->wcount * sizeof(usc->wbuf[0]), NULL);
	usc->wcount = 0;	/* Always flush buffer. */
}

int
athn_usb_media_change(struct ifnet *ifp)
{
	struct athn_usb_softc *usc = (struct athn_usb_softc *)ifp->if_softc;
	int error;

	if (usbd_is_dying(usc->sc_udev))
		return ENXIO;

	error = ieee80211_media_change(ifp);
	if (error != ENETRESET)
		return (error);

	if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) ==
	    (IFF_UP | IFF_RUNNING)) {
		athn_usb_stop(ifp);
		error = athn_usb_init(ifp);
	}
	return (error);
}

void
athn_usb_next_scan(void *arg)
{
	struct athn_usb_softc *usc = arg;
	struct athn_softc *sc = &usc->sc_sc;
	struct ieee80211com *ic = &sc->sc_ic;
	int s;

	if (usbd_is_dying(usc->sc_udev))
		return;

	usbd_ref_incr(usc->sc_udev);

	s = splnet();
	if (ic->ic_state == IEEE80211_S_SCAN)
		ieee80211_next_scan(&ic->ic_if);
	splx(s);

	usbd_ref_decr(usc->sc_udev);
}

int
athn_usb_newstate(struct ieee80211com *ic, enum ieee80211_state nstate,
    int arg)
{
	struct athn_usb_softc *usc = ic->ic_softc;
	struct athn_usb_cmd_newstate cmd;

	/* Do it in a process context. */
	cmd.state = nstate;
	cmd.arg = arg;
	athn_usb_do_async(usc, athn_usb_newstate_cb, &cmd, sizeof(cmd));
	return (0);
}

void
athn_usb_newstate_cb(struct athn_usb_softc *usc, void *arg)
{
	struct athn_usb_cmd_newstate *cmd = arg;
	struct athn_softc *sc = &usc->sc_sc;
	struct ieee80211com *ic = &sc->sc_ic;
	enum ieee80211_state ostate;
	uint32_t reg, imask;
#ifndef IEEE80211_STA_ONLY
	uint8_t sta_index;
#endif
	int s, error;

	timeout_del(&sc->calib_to);

	s = splnet();
	ostate = ic->ic_state;
	DPRINTF(("newstate %d -> %d\n", ostate, cmd->state));

	if (ostate == IEEE80211_S_RUN) {
#ifndef IEEE80211_STA_ONLY
		if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
			/* XXX really needed? */
			sta_index = ((struct athn_node *)ic->ic_bss)->sta_index;
			(void)athn_usb_wmi_xcmd(usc, AR_WMI_CMD_NODE_REMOVE,
			    &sta_index, sizeof(sta_index), NULL);
		}
#endif
		reg = AR_READ(sc, AR_RX_FILTER);
		reg = (reg & ~AR_RX_FILTER_MYBEACON) |
		    AR_RX_FILTER_BEACON;
		AR_WRITE(sc, AR_RX_FILTER, reg);
		AR_WRITE_BARRIER(sc);
	}
	switch (cmd->state) {
	case IEEE80211_S_INIT:
		athn_set_led(sc, 0);
		break;
	case IEEE80211_S_SCAN:
		/* Make the LED blink while scanning. */
		athn_set_led(sc, !sc->led_state);
		(void)athn_usb_switch_chan(sc, ic->ic_bss->ni_chan, NULL);
		if (!usbd_is_dying(usc->sc_udev))
			timeout_add_msec(&sc->scan_to, 200);
		break;
	case IEEE80211_S_AUTH:
		athn_set_led(sc, 0);
		error = athn_usb_switch_chan(sc, ic->ic_bss->ni_chan, NULL);
		break;
	case IEEE80211_S_ASSOC:
		break;
	case IEEE80211_S_RUN:
		athn_set_led(sc, 1);

		if (ic->ic_opmode == IEEE80211_M_MONITOR)
			break;

#ifndef IEEE80211_STA_ONLY
		if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
			/* Create node entry for our BSS */
			/* XXX really needed? breaks station mode on down/up */
			error = athn_usb_create_node(usc, ic->ic_bss);
		}
#endif

		athn_set_bss(sc, ic->ic_bss);
		athn_usb_wmi_cmd(usc, AR_WMI_CMD_DISABLE_INTR);
#ifndef IEEE80211_STA_ONLY
		if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
			athn_set_hostap_timers(sc);
			/* Enable software beacon alert interrupts. */
			imask = htobe32(AR_IMR_SWBA);
		} else
#endif
		{
			athn_set_sta_timers(sc);
			/* Enable beacon miss interrupts. */
			imask = htobe32(AR_IMR_BMISS);

			/* Stop receiving beacons from other BSS. */
			reg = AR_READ(sc, AR_RX_FILTER);
			reg = (reg & ~AR_RX_FILTER_BEACON) |
			    AR_RX_FILTER_MYBEACON;
			AR_WRITE(sc, AR_RX_FILTER, reg);
			AR_WRITE_BARRIER(sc);
		}
		athn_usb_wmi_xcmd(usc, AR_WMI_CMD_ENABLE_INTR,
		    &imask, sizeof(imask), NULL);
		break;
	}
	(void)sc->sc_newstate(ic, cmd->state, cmd->arg);
	splx(s);
}

void
athn_usb_newassoc(struct ieee80211com *ic, struct ieee80211_node *ni,
    int isnew)
{
#ifndef IEEE80211_STA_ONLY
	struct athn_usb_softc *usc = ic->ic_softc;

	if (ic->ic_opmode != IEEE80211_M_HOSTAP || !isnew)
		return;
	/* Do it in a process context. */
	ieee80211_ref_node(ni);
	athn_usb_do_async(usc, athn_usb_newassoc_cb, &ni, sizeof(ni));
}

void
athn_usb_newassoc_cb(struct athn_usb_softc *usc, void *arg)
{
	struct ieee80211com *ic = &usc->sc_sc.sc_ic;
	struct ieee80211_node *ni = *(void **)arg;
	int s;

	s = splnet();
	/* NB: Node may have left before we got scheduled. */
	if (ni->ni_associd != 0)
		(void)athn_usb_create_node(usc, ni);
	ieee80211_release_node(ic, ni);
	splx(s);
#endif
}

void
athn_usb_node_leave(struct ieee80211com *ic, struct ieee80211_node *ni)
{
	struct athn_usb_softc *usc = ic->ic_softc;
	uint8_t sta_index;

	/* Do it in a process context. */
	sta_index = ((struct athn_node *)ni)->sta_index;
	athn_usb_do_async(usc, athn_usb_node_leave_cb,
	    &sta_index, sizeof(sta_index));
}

void
athn_usb_node_leave_cb(struct athn_usb_softc *usc, void *arg)
{
	uint8_t sta_index = *(uint8_t *)arg;

	(void)athn_usb_wmi_xcmd(usc, AR_WMI_CMD_NODE_REMOVE,
	    &sta_index, sizeof(sta_index), NULL);
	usc->nnodes--;
}

int
athn_usb_ampdu_tx_start(struct ieee80211com *ic, struct ieee80211_node *ni,
    uint8_t tid)
{
	struct athn_usb_softc *usc = ic->ic_softc;
	struct athn_node *an = (struct athn_node *)ni;
	struct athn_usb_aggr_cmd cmd;

	/* Do it in a process context. */
	cmd.sta_index = an->sta_index;
	cmd.tid = tid;
	athn_usb_do_async(usc, athn_usb_ampdu_tx_start_cb, &cmd, sizeof(cmd));
	return (0);
}

void
athn_usb_ampdu_tx_start_cb(struct athn_usb_softc *usc, void *arg)
{
	struct athn_usb_aggr_cmd *cmd = arg;
	struct ar_htc_target_aggr aggr;

	memset(&aggr, 0, sizeof(aggr));
	aggr.sta_index = cmd->sta_index;
	aggr.tidno = cmd->tid;
	aggr.aggr_enable = 1;
	(void)athn_usb_wmi_xcmd(usc, AR_WMI_CMD_TX_AGGR_ENABLE,
	    &aggr, sizeof(aggr), NULL);
}

void
athn_usb_ampdu_tx_stop(struct ieee80211com *ic, struct ieee80211_node *ni,
    uint8_t tid)
{
	struct athn_usb_softc *usc = ic->ic_softc;
	struct athn_node *an = (struct athn_node *)ni;
	struct athn_usb_aggr_cmd cmd;

	/* Do it in a process context. */
	cmd.sta_index = an->sta_index;
	cmd.tid = tid;
	athn_usb_do_async(usc, athn_usb_ampdu_tx_stop_cb, &cmd, sizeof(cmd));
}

void
athn_usb_ampdu_tx_stop_cb(struct athn_usb_softc *usc, void *arg)
{
	struct athn_usb_aggr_cmd *cmd = arg;
	struct ar_htc_target_aggr aggr;

	memset(&aggr, 0, sizeof(aggr));
	aggr.sta_index = cmd->sta_index;
	aggr.tidno = cmd->tid;
	aggr.aggr_enable = 0;
	(void)athn_usb_wmi_xcmd(usc, AR_WMI_CMD_TX_AGGR_ENABLE,
	    &aggr, sizeof(aggr), NULL);
}

int
athn_usb_create_node(struct athn_usb_softc *usc, struct ieee80211_node *ni)
{
	struct athn_node *an = (struct athn_node *)ni;
	struct ar_htc_target_sta sta;
	struct ar_htc_target_rate rate;
	int error;

	/* Firmware cannot handle more than 8 STAs. */
	if (usc->nnodes > AR_USB_MAX_STA)
		return ENOBUFS;

	an->sta_index = IEEE80211_AID(ni->ni_associd);

	/* Create node entry on target. */
	memset(&sta, 0, sizeof(sta));
	IEEE80211_ADDR_COPY(sta.macaddr, ni->ni_macaddr);
	IEEE80211_ADDR_COPY(sta.bssid, ni->ni_bssid);
	sta.associd = htobe16(ni->ni_associd);
	sta.valid = 1;
	sta.sta_index = an->sta_index;
	sta.maxampdu = 0xffff;
	if (ni->ni_flags & IEEE80211_NODE_HT)
		sta.flags |= htobe16(AR_HTC_STA_HT);
	error = athn_usb_wmi_xcmd(usc, AR_WMI_CMD_NODE_CREATE,
	    &sta, sizeof(sta), NULL);
	if (error != 0)
		return (error);
	usc->nnodes++;

	/* Setup supported rates. */
	memset(&rate, 0, sizeof(rate));
	rate.sta_index = sta.sta_index;
	rate.isnew = 1;
	rate.lg_rates.rs_nrates = ni->ni_rates.rs_nrates;
	memcpy(rate.lg_rates.rs_rates, ni->ni_rates.rs_rates,
	    ni->ni_rates.rs_nrates);
	if (ni->ni_flags & IEEE80211_NODE_HT) {
		rate.capflags |= htobe32(AR_RC_HT_FLAG);
#ifdef notyet
		/* XXX setup HT rates */
		if (ni->ni_htcaps & IEEE80211_HTCAP_CBW20_40)
			rate.capflags |= htobe32(AR_RC_40_FLAG);
		if (ni->ni_htcaps & IEEE80211_HTCAP_SGI40)
			rate.capflags |= htobe32(AR_RC_SGI_FLAG);
		if (ni->ni_htcaps & IEEE80211_HTCAP_SGI20)
			rate.capflags |= htobe32(AR_RC_SGI_FLAG);
#endif
	}
	error = athn_usb_wmi_xcmd(usc, AR_WMI_CMD_RC_RATE_UPDATE,
	    &rate, sizeof(rate), NULL);
	return (error);
}

void
athn_usb_rx_enable(struct athn_softc *sc)
{
	AR_WRITE(sc, AR_CR, AR_CR_RXE);
	AR_WRITE_BARRIER(sc);
}

int
athn_usb_switch_chan(struct athn_softc *sc, struct ieee80211_channel *c,
    struct ieee80211_channel *extc)
{
	struct athn_usb_softc *usc = (struct athn_usb_softc *)sc;
	uint16_t mode;
	int error;

	/* Disable interrupts. */
	error = athn_usb_wmi_cmd(usc, AR_WMI_CMD_DISABLE_INTR);
	if (error != 0)
		goto reset;
	/* Stop all Tx queues. */
	error = athn_usb_wmi_cmd(usc, AR_WMI_CMD_DRAIN_TXQ_ALL);
	if (error != 0)
		goto reset;
	/* Stop Rx. */
	error = athn_usb_wmi_cmd(usc, AR_WMI_CMD_STOP_RECV);
	if (error != 0)
		goto reset;

	/* If band or bandwidth changes, we need to do a full reset. */
	if (c->ic_flags != sc->curchan->ic_flags ||
	    ((extc != NULL) ^ (sc->curchanext != NULL))) {
		DPRINTFN(2, ("channel band switch\n"));
		goto reset;
	}

	error = athn_set_chan(sc, c, extc);
	if (AR_SREV_9271(sc) && error == 0)
		ar9271_load_ani(sc);
	if (error != 0) {
 reset:		/* Error found, try a full reset. */
		DPRINTFN(3, ("needs a full reset\n"));
		error = athn_hw_reset(sc, c, extc, 0);
		if (error != 0)	/* Hopeless case. */
			return (error);
	}

	error = athn_usb_wmi_cmd(usc, AR_WMI_CMD_START_RECV);
	if (error != 0)
		return (error);
	athn_rx_start(sc);

	mode = htobe16(IEEE80211_IS_CHAN_2GHZ(c) ?
	    AR_HTC_MODE_11NG : AR_HTC_MODE_11NA);
	error = athn_usb_wmi_xcmd(usc, AR_WMI_CMD_SET_MODE,
	    &mode, sizeof(mode), NULL);
	if (error != 0)
		return (error);

	/* Re-enable interrupts. */
	error = athn_usb_wmi_cmd(usc, AR_WMI_CMD_ENABLE_INTR);
	return (error);
}

void
athn_usb_updateedca(struct ieee80211com *ic)
{
	struct athn_usb_softc *usc = ic->ic_softc;

	/* Do it in a process context. */
	athn_usb_do_async(usc, athn_usb_updateedca_cb, NULL, 0);
}

void
athn_usb_updateedca_cb(struct athn_usb_softc *usc, void *arg)
{
	int s;

	s = splnet();
	athn_updateedca(&usc->sc_sc.sc_ic);
	splx(s);
}

void
athn_usb_updateslot(struct ieee80211com *ic)
{
	struct athn_usb_softc *usc = ic->ic_softc;

	return;	/* XXX */
	/* Do it in a process context. */
	athn_usb_do_async(usc, athn_usb_updateslot_cb, NULL, 0);
}

void
athn_usb_updateslot_cb(struct athn_usb_softc *usc, void *arg)
{
	int s;

	s = splnet();
	athn_updateslot(&usc->sc_sc.sc_ic);
	splx(s);
}

int
athn_usb_set_key(struct ieee80211com *ic, struct ieee80211_node *ni,
    struct ieee80211_key *k)
{
	struct athn_usb_softc *usc = ic->ic_softc;
	struct athn_usb_cmd_key cmd;

	/* Defer setting of WEP keys until interface is brought up. */
	if ((ic->ic_if.if_flags & (IFF_UP | IFF_RUNNING)) !=
	    (IFF_UP | IFF_RUNNING))
		return (0);

	/* Do it in a process context. */
	cmd.ni = (ni != NULL) ? ieee80211_ref_node(ni) : NULL;
	cmd.key = k;
	athn_usb_do_async(usc, athn_usb_set_key_cb, &cmd, sizeof(cmd));
	return (0);
}

void
athn_usb_set_key_cb(struct athn_usb_softc *usc, void *arg)
{
	struct ieee80211com *ic = &usc->sc_sc.sc_ic;
	struct athn_usb_cmd_key *cmd = arg;
	int s;

	s = splnet();
	athn_set_key(ic, cmd->ni, cmd->key);
	if (cmd->ni != NULL)
		ieee80211_release_node(ic, cmd->ni);
	splx(s);
}

void
athn_usb_delete_key(struct ieee80211com *ic, struct ieee80211_node *ni,
    struct ieee80211_key *k)
{
	struct athn_usb_softc *usc = ic->ic_softc;
	struct athn_usb_cmd_key cmd;

	if (!(ic->ic_if.if_flags & IFF_RUNNING) ||
	    ic->ic_state != IEEE80211_S_RUN)
		return;	/* Nothing to do. */

	/* Do it in a process context. */
	cmd.ni = (ni != NULL) ? ieee80211_ref_node(ni) : NULL;
	cmd.key = k;
	athn_usb_do_async(usc, athn_usb_delete_key_cb, &cmd, sizeof(cmd));
}

void
athn_usb_delete_key_cb(struct athn_usb_softc *usc, void *arg)
{
	struct ieee80211com *ic = &usc->sc_sc.sc_ic;
	struct athn_usb_cmd_key *cmd = arg;
	int s;

	s = splnet();
	athn_delete_key(ic, cmd->ni, cmd->key);
	if (cmd->ni != NULL)
		ieee80211_release_node(ic, cmd->ni);
	splx(s);
}

#ifndef IEEE80211_STA_ONLY
void
athn_usb_bcneof(struct usbd_xfer *xfer, void *priv,
    usbd_status status)
{
	struct athn_usb_tx_data *data = priv;
	struct athn_usb_softc *usc = data->sc;

	if (__predict_false(status == USBD_STALLED))
		usbd_clear_endpoint_stall_async(usc->tx_data_pipe);
	usc->tx_bcn = data;
}

/*
 * Process Software Beacon Alert interrupts.
 */
void
athn_usb_swba(struct athn_usb_softc *usc)
{
	struct athn_softc *sc = &usc->sc_sc;
	struct ieee80211com *ic = &sc->sc_ic;
	struct athn_usb_tx_data *data;
	struct ieee80211_frame *wh;
	struct ar_stream_hdr *hdr;
	struct ar_htc_frame_hdr *htc;
	struct ar_tx_bcn *bcn;
	struct mbuf *m;
	int error;

	if (ic->ic_dtim_count == 0)
		ic->ic_dtim_count = ic->ic_dtim_period - 1;
	else
		ic->ic_dtim_count--;

	/* Make sure previous beacon has been sent. */
	if (usc->tx_bcn == NULL)
		return;
	data = usc->tx_bcn;

	/* Get new beacon. */
	m = ieee80211_beacon_alloc(ic, ic->ic_bss);
	if (__predict_false(m == NULL))
		return;
	/* Assign sequence number. */
	wh = mtod(m, struct ieee80211_frame *);
	*(uint16_t *)&wh->i_seq[0] =
	    htole16(ic->ic_bss->ni_txseq << IEEE80211_SEQ_SEQ_SHIFT);
	ic->ic_bss->ni_txseq++;

	hdr = (struct ar_stream_hdr *)data->buf;
	hdr->tag = htole16(AR_USB_TX_STREAM_TAG);
	hdr->len = htole16(sizeof(*htc) + sizeof(*bcn) + m->m_pkthdr.len);

	htc = (struct ar_htc_frame_hdr *)&hdr[1];
	memset(htc, 0, sizeof(*htc));
	htc->endpoint_id = usc->ep_bcn;
	htc->payload_len = htobe16(sizeof(*bcn) + m->m_pkthdr.len);

	bcn = (struct ar_tx_bcn *)&htc[1];
	memset(bcn, 0, sizeof(*bcn));
	bcn->vif_idx = 0;

	m_copydata(m, 0, m->m_pkthdr.len, (caddr_t)&bcn[1]);

	usbd_setup_xfer(data->xfer, usc->tx_data_pipe, data, data->buf,
	    sizeof(*hdr) + sizeof(*htc) + sizeof(*bcn) + m->m_pkthdr.len,
	    USBD_SHORT_XFER_OK | USBD_NO_COPY, ATHN_USB_TX_TIMEOUT,
	    athn_usb_bcneof);

	m_freem(m);
	usc->tx_bcn = NULL;
	error = usbd_transfer(data->xfer);
	if (__predict_false(error != USBD_IN_PROGRESS && error != 0))
		usc->tx_bcn = data;
}
#endif

void
athn_usb_rx_wmi_ctrl(struct athn_usb_softc *usc, uint8_t *buf, int len)
{
	struct ar_wmi_cmd_hdr *wmi;
	struct ar_wmi_evt_txrate *txrate;
	uint16_t cmd_id;

	if (__predict_false(len < sizeof(*wmi)))
		return;
	wmi = (struct ar_wmi_cmd_hdr *)buf;
	cmd_id = betoh16(wmi->cmd_id);

	if (!(cmd_id & AR_WMI_EVT_FLAG)) {
		if (usc->wait_cmd_id != cmd_id)
			return;	/* Unexpected reply. */
		if (usc->obuf != NULL) {
			/* Copy answer into caller supplied buffer. */
			memcpy(usc->obuf, &wmi[1], len - sizeof(*wmi));
		}
		/* Notify caller of completion. */
		wakeup(&usc->wait_cmd_id);
		return;
	}
	switch (cmd_id & 0xfff) {
#ifndef IEEE80211_STA_ONLY
	case AR_WMI_EVT_SWBA:
		athn_usb_swba(usc);
		break;
#endif
	case AR_WMI_EVT_TXRATE:
		txrate = (struct ar_wmi_evt_txrate *)&wmi[1];
		DPRINTF(("txrate=%d\n", betoh32(txrate->txrate)));
		break;
	case AR_WMI_EVT_FATAL:
		printf("%s: fatal firmware error\n", usc->usb_dev.dv_xname);
		break;
	default:
		DPRINTF(("WMI event %d ignored\n", cmd_id));
		break;
	}
}

void
athn_usb_intr(struct usbd_xfer *xfer, void *priv,
    usbd_status status)
{
	struct athn_usb_softc *usc = priv;
	struct ar_htc_frame_hdr *htc;
	struct ar_htc_msg_hdr *msg;
	uint8_t *buf = usc->ibuf;
	uint16_t msg_id;
	int len;

	if (__predict_false(status != USBD_NORMAL_COMPLETION)) {
		DPRINTF(("intr status=%d\n", status));
		if (status == USBD_STALLED)
			usbd_clear_endpoint_stall_async(usc->rx_intr_pipe);
		else if (status == USBD_IOERROR) {
			/*
			 * The device has gone away. If async commands are
			 * pending or running ensure the device dies ASAP
			 * and any blocked processes are woken up.
			 */
			if (usc->cmdq.queued > 0)
				usbd_deactivate(usc->sc_udev);
		}
		return;
	}
	usbd_get_xfer_status(xfer, NULL, NULL, &len, NULL);

	/* Skip watchdog pattern if present. */
	if (len >= 4 && *(uint32_t *)buf == htobe32(0x00c60000)) {
		buf += 4;
		len -= 4;
	}
	if (__predict_false(len < sizeof(*htc)))
		return;
	htc = (struct ar_htc_frame_hdr *)buf;
	/* Skip HTC header. */
	buf += sizeof(*htc);
	len -= sizeof(*htc);

	if (htc->endpoint_id != 0) {
		if (__predict_false(htc->endpoint_id != usc->ep_ctrl))
			return;
		/* Remove trailer if present. */
		if (htc->flags & AR_HTC_FLAG_TRAILER) {
			if (__predict_false(len < htc->control[0]))
				return;
			len -= htc->control[0];
		}
		athn_usb_rx_wmi_ctrl(usc, buf, len);
		return;
	}
	/* Endpoint 0 carries HTC messages. */
	if (__predict_false(len < sizeof(*msg)))
		return;
	msg = (struct ar_htc_msg_hdr *)buf;
	msg_id = betoh16(msg->msg_id);
	DPRINTF(("Rx HTC message %d\n", msg_id));
	switch (msg_id) {
	case AR_HTC_MSG_READY:
		if (usc->wait_msg_id != msg_id)
			break;
		usc->wait_msg_id = 0;
		wakeup(&usc->wait_msg_id);
		break;
	case AR_HTC_MSG_CONN_SVC_RSP:
		if (usc->wait_msg_id != msg_id)
			break;
		if (usc->msg_conn_svc_rsp != NULL) {
			memcpy(usc->msg_conn_svc_rsp, &msg[1],
			    sizeof(struct ar_htc_msg_conn_svc_rsp));
		}
		usc->wait_msg_id = 0;
		wakeup(&usc->wait_msg_id);
		break;
	case AR_HTC_MSG_CONF_PIPE_RSP:
		if (usc->wait_msg_id != msg_id)
			break;
		usc->wait_msg_id = 0;
		wakeup(&usc->wait_msg_id);
		break;
	default:
		DPRINTF(("HTC message %d ignored\n", msg_id));
		break;
	}
}

#if NBPFILTER > 0
void
athn_usb_rx_radiotap(struct athn_softc *sc, struct mbuf *m,
    struct ar_rx_status *rs)
{
#define IEEE80211_RADIOTAP_F_SHORTGI	0x80	/* XXX from FBSD */

	struct athn_rx_radiotap_header *tap = &sc->sc_rxtap;
	struct ieee80211com *ic = &sc->sc_ic;
	struct mbuf mb;
	uint8_t rate;

	tap->wr_flags = IEEE80211_RADIOTAP_F_FCS;
	tap->wr_tsft = htole64(betoh64(rs->rs_tstamp));
	tap->wr_chan_freq = htole16(ic->ic_bss->ni_chan->ic_freq);
	tap->wr_chan_flags = htole16(ic->ic_bss->ni_chan->ic_flags);
	tap->wr_dbm_antsignal = rs->rs_rssi;
	/* XXX noise. */
	tap->wr_antenna = rs->rs_antenna;
	tap->wr_rate = 0;	/* In case it can't be found below. */
	rate = rs->rs_rate;
	if (rate & 0x80) {		/* HT. */
		/* Bit 7 set means HT MCS instead of rate. */
		tap->wr_rate = rate;
		if (!(rs->rs_flags & AR_RXS_FLAG_GI))
			tap->wr_flags |= IEEE80211_RADIOTAP_F_SHORTGI;

	} else if (rate & 0x10) {	/* CCK. */
		if (rate & 0x04)
			tap->wr_flags |= IEEE80211_RADIOTAP_F_SHORTPRE;
		switch (rate & ~0x14) {
		case 0xb: tap->wr_rate =   2; break;
		case 0xa: tap->wr_rate =   4; break;
		case 0x9: tap->wr_rate =  11; break;
		case 0x8: tap->wr_rate =  22; break;
		}
	} else {			/* OFDM. */
		switch (rate) {
		case 0xb: tap->wr_rate =  12; break;
		case 0xf: tap->wr_rate =  18; break;
		case 0xa: tap->wr_rate =  24; break;
		case 0xe: tap->wr_rate =  36; break;
		case 0x9: tap->wr_rate =  48; break;
		case 0xd: tap->wr_rate =  72; break;
		case 0x8: tap->wr_rate =  96; break;
		case 0xc: tap->wr_rate = 108; break;
		}
	}
	mb.m_data = (caddr_t)tap;
	mb.m_len = sc->sc_rxtap_len;
	mb.m_next = m;
	mb.m_nextpkt = NULL;
	mb.m_type = 0;
	mb.m_flags = 0;
	bpf_mtap(sc->sc_drvbpf, &mb, BPF_DIRECTION_IN);
}
#endif

void
athn_usb_rx_frame(struct athn_usb_softc *usc, struct mbuf *m)
{
	struct athn_softc *sc = &usc->sc_sc;
	struct ieee80211com *ic = &sc->sc_ic;
	struct ifnet *ifp = &ic->ic_if;
	struct ieee80211_frame *wh;
	struct ieee80211_node *ni;
	struct ieee80211_rxinfo rxi;
	struct ar_htc_frame_hdr *htc;
	struct ar_rx_status *rs;
	uint16_t datalen;
	int s;

	if (__predict_false(m->m_len < sizeof(*htc)))
		goto skip;
	htc = mtod(m, struct ar_htc_frame_hdr *);
	if (__predict_false(htc->endpoint_id == 0)) {
		DPRINTF(("bad endpoint %d\n", htc->endpoint_id));
		goto skip;
	}
	if (htc->flags & AR_HTC_FLAG_TRAILER) {
		if (m->m_len < htc->control[0])
			goto skip;
		m_adj(m, -(int)htc->control[0]);
	}
	m_adj(m, sizeof(*htc));	/* Strip HTC header. */

	if (__predict_false(m->m_len < sizeof(*rs)))
		goto skip;
	rs = mtod(m, struct ar_rx_status *);

	/* Make sure that payload fits. */
	datalen = betoh16(rs->rs_datalen);
	if (__predict_false(m->m_len < sizeof(*rs) + datalen))
		goto skip;

	if (__predict_false(datalen < sizeof(*wh) + IEEE80211_CRC_LEN))
		goto skip;

	m_adj(m, sizeof(*rs));	/* Strip Rx status. */

	s = splnet();

	/* Grab a reference to the source node. */
	wh = mtod(m, struct ieee80211_frame *);
	ni = ieee80211_find_rxnode(ic, wh);

	/* Remove any HW padding after the 802.11 header. */
	if (!(wh->i_fc[0] & IEEE80211_FC0_TYPE_CTL)) {
		u_int hdrlen = ieee80211_get_hdrlen(wh);
		if (hdrlen & 3) {
			memmove((caddr_t)wh + 2, wh, hdrlen);
			m_adj(m, 2);
		}
	}
#if NBPFILTER > 0
	if (__predict_false(sc->sc_drvbpf != NULL))
		athn_usb_rx_radiotap(sc, m, rs);
#endif
	/* Trim 802.11 FCS after radiotap. */
	m_adj(m, -IEEE80211_CRC_LEN);

	/* Send the frame to the 802.11 layer. */
	rxi.rxi_flags = 0;
	rxi.rxi_rssi = rs->rs_rssi + AR_USB_DEFAULT_NF;
	rxi.rxi_tstamp = betoh64(rs->rs_tstamp);
	ieee80211_input(ifp, m, ni, &rxi);

	/* Node is no longer needed. */
	ieee80211_release_node(ic, ni);
	splx(s);
	return;
 skip:
	m_freem(m);
}

void
athn_usb_rxeof(struct usbd_xfer *xfer, void *priv,
    usbd_status status)
{
	struct athn_usb_rx_data *data = priv;
	struct athn_usb_softc *usc = data->sc;
	struct athn_softc *sc = &usc->sc_sc;
	struct ifnet *ifp = &sc->sc_ic.ic_if;
	struct athn_usb_rx_stream *stream = &usc->rx_stream;
	uint8_t *buf = data->buf;
	struct ar_stream_hdr *hdr;
	struct mbuf *m;
	uint16_t pktlen;
	int off, len;

	if (__predict_false(status != USBD_NORMAL_COMPLETION)) {
		DPRINTF(("RX status=%d\n", status));
		if (status == USBD_STALLED)
			usbd_clear_endpoint_stall_async(usc->rx_data_pipe);
		if (status != USBD_CANCELLED)
			goto resubmit;
		return;
	}
	usbd_get_xfer_status(xfer, NULL, NULL, &len, NULL);

	if (stream->left > 0) {
		if (len >= stream->left) {
			/* We have all our pktlen bytes now. */
			if (__predict_true(stream->m != NULL)) {
				memcpy(mtod(stream->m, uint8_t *) +
				    stream->moff, buf, stream->left);
				athn_usb_rx_frame(usc, stream->m);
				stream->m = NULL;
			}
			/* Next header is 32-bit aligned. */
			off = (stream->left + 3) & ~3;
			buf += off;
			len -= off;
			stream->left = 0;
		} else {
			/* Still need more bytes, save what we have. */
			if (__predict_true(stream->m != NULL)) {
				memcpy(mtod(stream->m, uint8_t *) +
				    stream->moff, buf, len);
				stream->moff += len;
			}
			stream->left -= len;
			goto resubmit;
		}
	}
	KASSERT(stream->left == 0);
	while (len >= sizeof(*hdr)) {
		hdr = (struct ar_stream_hdr *)buf;
		if (hdr->tag != htole16(AR_USB_RX_STREAM_TAG)) {
			DPRINTF(("invalid tag 0x%x\n", hdr->tag));
			break;
		}
		pktlen = letoh16(hdr->len);
		buf += sizeof(*hdr);
		len -= sizeof(*hdr);

		if (__predict_true(pktlen <= MCLBYTES)) {
			/* Allocate an mbuf to store the next pktlen bytes. */
			MGETHDR(m, M_DONTWAIT, MT_DATA);
			if (__predict_true(m != NULL)) {
				m->m_pkthdr.len = m->m_len = pktlen;
				if (pktlen > MHLEN) {
					MCLGET(m, M_DONTWAIT);
					if (!(m->m_flags & M_EXT)) {
						m_free(m);
						m = NULL;
					}
				}
			}
		} else	/* Drop frames larger than MCLBYTES. */
			m = NULL;

		if (m == NULL)
			ifp->if_ierrors++;

		/*
		 * NB: m can be NULL, in which case the next pktlen bytes
		 * will be discarded from the Rx stream.
		 */
		if (pktlen > len) {
			/* Need more bytes, save what we have. */
			stream->m = m;	/* NB: m can be NULL. */
			if (__predict_true(stream->m != NULL)) {
				memcpy(mtod(stream->m, uint8_t *), buf, len);
				stream->moff = len;
			}
			stream->left = pktlen - len;
			goto resubmit;
		}
		if (__predict_true(m != NULL)) {
			/* We have all the pktlen bytes in this xfer. */
			memcpy(mtod(m, uint8_t *), buf, pktlen);
			athn_usb_rx_frame(usc, m);
		}

		/* Next header is 32-bit aligned. */
		off = (pktlen + 3) & ~3;
		buf += off;
		len -= off;
	}

 resubmit:
	/* Setup a new transfer. */
	usbd_setup_xfer(xfer, usc->rx_data_pipe, data, data->buf,
	    ATHN_USB_RXBUFSZ, USBD_SHORT_XFER_OK | USBD_NO_COPY,
	    USBD_NO_TIMEOUT, athn_usb_rxeof);
	(void)usbd_transfer(xfer);
}

void
athn_usb_txeof(struct usbd_xfer *xfer, void *priv,
    usbd_status status)
{
	struct athn_usb_tx_data *data = priv;
	struct athn_usb_softc *usc = data->sc;
	struct athn_softc *sc = &usc->sc_sc;
	struct ifnet *ifp = &sc->sc_ic.ic_if;
	int s;

	s = splnet();
	/* Put this Tx buffer back to our free list. */
	TAILQ_INSERT_TAIL(&usc->tx_free_list, data, next);

	if (__predict_false(status != USBD_NORMAL_COMPLETION)) {
		DPRINTF(("TX status=%d\n", status));
		if (status == USBD_STALLED)
			usbd_clear_endpoint_stall_async(usc->tx_data_pipe);
		ifp->if_oerrors++;
		splx(s);
		/* XXX Why return? */
		return;
	}
	sc->sc_tx_timer = 0;
	ifp->if_opackets++;

	/* We just released a Tx buffer, notify Tx. */
	if (ifp->if_flags & IFF_OACTIVE) {
		ifp->if_flags &= ~IFF_OACTIVE;
		ifp->if_start(ifp);
	}
	splx(s);
}

int
athn_usb_tx(struct athn_softc *sc, struct mbuf *m, struct ieee80211_node *ni)
{
	struct athn_usb_softc *usc = (struct athn_usb_softc *)sc;
	struct athn_node *an = (struct athn_node *)ni;
	struct ieee80211com *ic = &sc->sc_ic;
	struct ieee80211_frame *wh;
	struct ieee80211_key *k = NULL;
	struct athn_usb_tx_data *data;
	struct ar_stream_hdr *hdr;
	struct ar_htc_frame_hdr *htc;
	struct ar_tx_frame *txf;
	struct ar_tx_mgmt *txm;
	uint8_t *frm;
	uint16_t qos;
	uint8_t sta_index, qid, tid = 0;
	int hasqos, xferlen, error;

	wh = mtod(m, struct ieee80211_frame *);
	if (wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {
		k = ieee80211_get_txkey(ic, wh, ni);
		if ((m = ieee80211_encrypt(ic, m, k)) == NULL)
			return (ENOBUFS);
		wh = mtod(m, struct ieee80211_frame *);
	}
	if ((hasqos = ieee80211_has_qos(wh))) {
		qos = ieee80211_get_qos(wh);
		tid = qos & IEEE80211_QOS_TID;
		qid = ieee80211_up_to_ac(ic, tid);
	} else
		qid = EDCA_AC_BE;

	/* Grab a Tx buffer from our free list. */
	data = TAILQ_FIRST(&usc->tx_free_list);
	TAILQ_REMOVE(&usc->tx_free_list, data, next);

#if NBPFILTER > 0
	/* XXX Change radiotap Tx header for USB (no txrate). */
	if (__predict_false(sc->sc_drvbpf != NULL)) {
		struct athn_tx_radiotap_header *tap = &sc->sc_txtap;
		struct mbuf mb;

		tap->wt_flags = 0;
		tap->wt_chan_freq = htole16(ic->ic_bss->ni_chan->ic_freq);
		tap->wt_chan_flags = htole16(ic->ic_bss->ni_chan->ic_flags);
		mb.m_data = (caddr_t)tap;
		mb.m_len = sc->sc_txtap_len;
		mb.m_next = m;
		mb.m_nextpkt = NULL;
		mb.m_type = 0;
		mb.m_flags = 0;
		bpf_mtap(sc->sc_drvbpf, &mb, BPF_DIRECTION_OUT);
	}
#endif
	sta_index = an->sta_index;

	/* NB: We don't take advantage of USB Tx stream mode for now. */
	hdr = (struct ar_stream_hdr *)data->buf;
	hdr->tag = htole16(AR_USB_TX_STREAM_TAG);

	htc = (struct ar_htc_frame_hdr *)&hdr[1];
	memset(htc, 0, sizeof(*htc));
	if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) ==
	    IEEE80211_FC0_TYPE_DATA) {
		htc->endpoint_id = usc->ep_data[qid];

		txf = (struct ar_tx_frame *)&htc[1];
		memset(txf, 0, sizeof(*txf));
		txf->data_type = AR_HTC_NORMAL;
		txf->node_idx = sta_index;
		txf->vif_idx = 0;
		txf->tid = tid;
		if (m->m_pkthdr.len + IEEE80211_CRC_LEN > ic->ic_rtsthreshold)
			txf->flags |= htobe32(AR_HTC_TX_RTSCTS);
		else if (ic->ic_flags & IEEE80211_F_USEPROT) {
			if (ic->ic_protmode == IEEE80211_PROT_CTSONLY)
				txf->flags |= htobe32(AR_HTC_TX_CTSONLY);
			else if (ic->ic_protmode == IEEE80211_PROT_RTSCTS)
				txf->flags |= htobe32(AR_HTC_TX_RTSCTS);
		}
		txf->key_idx = 0xff;
		frm = (uint8_t *)&txf[1];
	} else {
		htc->endpoint_id = usc->ep_mgmt;

		txm = (struct ar_tx_mgmt *)&htc[1];
		memset(txm, 0, sizeof(*txm));
		txm->node_idx = sta_index;
		txm->vif_idx = 0;
		txm->key_idx = 0xff;
		frm = (uint8_t *)&txm[1];
	}
	/* Copy payload. */
	m_copydata(m, 0, m->m_pkthdr.len, (caddr_t)frm);
	frm += m->m_pkthdr.len;
	m_freem(m);

	/* Finalize headers. */
	htc->payload_len = htobe16(frm - (uint8_t *)&htc[1]);
	hdr->len = htole16(frm - (uint8_t *)&hdr[1]);
	xferlen = frm - data->buf;

	usbd_setup_xfer(data->xfer, usc->tx_data_pipe, data, data->buf,
	    xferlen, USBD_FORCE_SHORT_XFER | USBD_NO_COPY, ATHN_USB_TX_TIMEOUT,
	    athn_usb_txeof);
	error = usbd_transfer(data->xfer);
	if (__predict_false(error != USBD_IN_PROGRESS && error != 0)) {
		/* Put this Tx buffer back to our free list. */
		TAILQ_INSERT_TAIL(&usc->tx_free_list, data, next);
		return (error);
	}
	ieee80211_release_node(ic, ni);
	return (0);
}

void
athn_usb_start(struct ifnet *ifp)
{
	struct athn_softc *sc = ifp->if_softc;
	struct athn_usb_softc *usc = (struct athn_usb_softc *)sc;
	struct ieee80211com *ic = &sc->sc_ic;
	struct ieee80211_node *ni;
	struct mbuf *m;

	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
		return;

	for (;;) {
		if (TAILQ_EMPTY(&usc->tx_free_list)) {
			ifp->if_flags |= IFF_OACTIVE;
			break;
		}
		/* Send pending management frames first. */
		IF_DEQUEUE(&ic->ic_mgtq, m);
		if (m != NULL) {
			ni = m->m_pkthdr.ph_cookie;
			goto sendit;
		}
		if (ic->ic_state != IEEE80211_S_RUN)
			break;

		/* Encapsulate and send data frames. */
		IFQ_DEQUEUE(&ifp->if_snd, m);
		if (m == NULL)
			break;
#if NBPFILTER > 0
		if (ifp->if_bpf != NULL)
			bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_OUT);
#endif
		if ((m = ieee80211_encap(ifp, m, &ni)) == NULL)
			continue;
 sendit:
#if NBPFILTER > 0
		if (ic->ic_rawbpf != NULL)
			bpf_mtap(ic->ic_rawbpf, m, BPF_DIRECTION_OUT);
#endif
		if (athn_usb_tx(sc, m, ni) != 0) {
			ieee80211_release_node(ic, ni);
			ifp->if_oerrors++;
			continue;
		}

		sc->sc_tx_timer = 5;
		ifp->if_timer = 1;
	}
}

void
athn_usb_watchdog(struct ifnet *ifp)
{
	struct athn_softc *sc = ifp->if_softc;

	ifp->if_timer = 0;

	if (sc->sc_tx_timer > 0) {
		if (--sc->sc_tx_timer == 0) {
			printf("%s: device timeout\n", sc->sc_dev.dv_xname);
			/* athn_usb_init(ifp); XXX needs a process context! */
			ifp->if_oerrors++;
			return;
		}
		ifp->if_timer = 1;
	}
	ieee80211_watchdog(ifp);
}

int
athn_usb_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
	struct athn_softc *sc = ifp->if_softc;
	struct athn_usb_softc *usc = (struct athn_usb_softc *)sc;
	struct ieee80211com *ic = &sc->sc_ic;
	struct ifaddr *ifa;
	struct ifreq *ifr;
	int s, error = 0;

	if (usbd_is_dying(usc->sc_udev))
		return ENXIO;

	usbd_ref_incr(usc->sc_udev);

	s = splnet();

	switch (cmd) {
	case SIOCSIFADDR:
		ifa = (struct ifaddr *)data;
		ifp->if_flags |= IFF_UP;
		if (ifa->ifa_addr->sa_family == AF_INET)
			arp_ifinit(&ic->ic_ac, ifa);
		/* FALLTHROUGH */
	case SIOCSIFFLAGS:
		if (ifp->if_flags & IFF_UP) {
			if (!(ifp->if_flags & IFF_RUNNING))
				error = athn_usb_init(ifp);
		} else {
			if (ifp->if_flags & IFF_RUNNING)
				athn_usb_stop(ifp);
		}
		break;
	case SIOCADDMULTI:
	case SIOCDELMULTI:
		ifr = (struct ifreq *)data;
		error = (cmd == SIOCADDMULTI) ?
		    ether_addmulti(ifr, &ic->ic_ac) :
		    ether_delmulti(ifr, &ic->ic_ac);
		if (error == ENETRESET)
			error = 0;
		break;
	case SIOCS80211CHANNEL:
		error = ieee80211_ioctl(ifp, cmd, data);
		if (error == ENETRESET &&
		    ic->ic_opmode == IEEE80211_M_MONITOR) {
			if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) ==
			    (IFF_UP | IFF_RUNNING)) {
				athn_usb_switch_chan(sc, ic->ic_ibss_chan,
				    NULL);
			}
			error = 0;
		}
		break;
	default:
		error = ieee80211_ioctl(ifp, cmd, data);
	}

	if (error == ENETRESET) {
		error = 0;
		if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) ==
		    (IFF_UP | IFF_RUNNING)) {
			athn_usb_stop(ifp);
			error = athn_usb_init(ifp);
		}
	}
	splx(s);

	usbd_ref_decr(usc->sc_udev);

	return (error);
}

int
athn_usb_init(struct ifnet *ifp)
{
	struct athn_softc *sc = ifp->if_softc;
	struct athn_usb_softc *usc = (struct athn_usb_softc *)sc;
	struct athn_ops *ops = &sc->ops;
	struct ieee80211com *ic = &sc->sc_ic;
	struct ieee80211_channel *c, *extc;
	struct athn_usb_rx_data *data;
	struct ar_htc_target_vif hvif;
	struct ar_htc_target_sta sta;
	struct ar_htc_cap_target hic;
	uint16_t mode;
	int i, error;

	/* Init host async commands ring. */
	usc->cmdq.cur = usc->cmdq.next = usc->cmdq.queued = 0;

	/* Allocate Tx/Rx buffers. */
	error = athn_usb_alloc_rx_list(usc);
	if (error != 0)
		goto fail;
	error = athn_usb_alloc_tx_list(usc);
	if (error != 0)
		goto fail;
	/* Steal one buffer for beacons. */
	usc->tx_bcn = TAILQ_FIRST(&usc->tx_free_list);
	TAILQ_REMOVE(&usc->tx_free_list, usc->tx_bcn, next);

	c = ic->ic_bss->ni_chan = ic->ic_ibss_chan;
	extc = NULL;

	/* In case a new MAC address has been configured. */
	IEEE80211_ADDR_COPY(ic->ic_myaddr, LLADDR(ifp->if_sadl));

	error = athn_set_power_awake(sc);
	if (error != 0)
		goto fail;

	error = athn_usb_wmi_cmd(usc, AR_WMI_CMD_FLUSH_RECV);
	if (error != 0)
		goto fail;

	error = athn_hw_reset(sc, c, extc, 1);
	if (error != 0)
		goto fail;

	ops->set_txpower(sc, c, extc);

	mode = htobe16(IEEE80211_IS_CHAN_2GHZ(c) ?
	    AR_HTC_MODE_11NG : AR_HTC_MODE_11NA);
	error = athn_usb_wmi_xcmd(usc, AR_WMI_CMD_SET_MODE,
	    &mode, sizeof(mode), NULL);
	if (error != 0)
		goto fail;

	error = athn_usb_wmi_cmd(usc, AR_WMI_CMD_ATH_INIT);
	if (error != 0)
		goto fail;

	error = athn_usb_wmi_cmd(usc, AR_WMI_CMD_START_RECV);
	if (error != 0)
		goto fail;

	athn_rx_start(sc);

	/* Create main interface on target. */
	memset(&hvif, 0, sizeof(hvif));
	hvif.index = 0;
	IEEE80211_ADDR_COPY(hvif.myaddr, ic->ic_myaddr);
	switch (ic->ic_opmode) {
	case IEEE80211_M_STA:
		hvif.opmode = htobe32(AR_HTC_M_STA);
		break;
	case IEEE80211_M_MONITOR:
		hvif.opmode = htobe32(AR_HTC_M_MONITOR);
		break;
#ifndef IEEE80211_STA_ONLY
	case IEEE80211_M_IBSS:
		hvif.opmode = htobe32(AR_HTC_M_IBSS);
		break;
	case IEEE80211_M_AHDEMO:
		hvif.opmode = htobe32(AR_HTC_M_AHDEMO);
		break;
	case IEEE80211_M_HOSTAP:
		hvif.opmode = htobe32(AR_HTC_M_HOSTAP);
		break;
#endif
	}
	hvif.rtsthreshold = htobe16(ic->ic_rtsthreshold);
	DPRINTF(("creating VAP\n"));
	error = athn_usb_wmi_xcmd(usc, AR_WMI_CMD_VAP_CREATE,
	    &hvif, sizeof(hvif), NULL);
	if (error != 0)
		goto fail;

	/* Create a fake node to send management frames before assoc. */
	memset(&sta, 0, sizeof(sta));
	IEEE80211_ADDR_COPY(sta.macaddr, ic->ic_myaddr);
	sta.sta_index = 0;
	sta.is_vif_sta = 1;
	sta.vif_index = hvif.index;
	sta.maxampdu = 0xffff;
	DPRINTF(("creating default node\n"));
	error = athn_usb_wmi_xcmd(usc, AR_WMI_CMD_NODE_CREATE,
	    &sta, sizeof(sta), NULL);
	if (error != 0)
		goto fail;
	usc->nnodes++;

	/* Update target capabilities. */
	memset(&hic, 0, sizeof(hic));
	hic.flags = htobe32(0x400c2400);
	hic.flags_ext = htobe32(0x00106080);
	hic.ampdu_limit = htobe32(0x0000ffff);
	hic.ampdu_subframes = 20;
	hic.protmode = 1;	/* XXX */
	hic.lg_txchainmask = sc->txchainmask;
	hic.ht_txchainmask = sc->txchainmask;
	DPRINTF(("updating target configuration\n"));
	error = athn_usb_wmi_xcmd(usc, AR_WMI_CMD_TARGET_IC_UPDATE,
	    &hic, sizeof(hic), NULL);
	if (error != 0)
		goto fail;

	/* Queue Rx xfers. */
	for (i = 0; i < ATHN_USB_RX_LIST_COUNT; i++) {
		data = &usc->rx_data[i];

		usbd_setup_xfer(data->xfer, usc->rx_data_pipe, data, data->buf,
		    ATHN_USB_RXBUFSZ, USBD_SHORT_XFER_OK | USBD_NO_COPY,
		    USBD_NO_TIMEOUT, athn_usb_rxeof);
		error = usbd_transfer(data->xfer);
		if (error != 0 && error != USBD_IN_PROGRESS)
			goto fail;
	}
	/* We're ready to go. */
	ifp->if_flags &= ~IFF_OACTIVE;
	ifp->if_flags |= IFF_RUNNING;

#ifdef notyet
	if (ic->ic_flags & IEEE80211_F_WEPON) {
		/* Install WEP keys. */
		for (i = 0; i < IEEE80211_WEP_NKID; i++)
			athn_usb_set_key(ic, NULL, &ic->ic_nw_keys[i]);
	}
#endif
	if (ic->ic_opmode == IEEE80211_M_MONITOR)
		ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
	else
		ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
	athn_usb_wait_async(usc);
	return (0);
 fail:
	athn_usb_stop(ifp);
	return (error);
}

void
athn_usb_stop(struct ifnet *ifp)
{
	struct athn_softc *sc = ifp->if_softc;
	struct athn_usb_softc *usc = (struct athn_usb_softc *)sc;
	struct ieee80211com *ic = &sc->sc_ic;
	struct ar_htc_target_vif hvif;
	uint8_t sta_index;
	int s;

	sc->sc_tx_timer = 0;
	ifp->if_timer = 0;
	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);

	s = splusb();
	ieee80211_new_state(ic, IEEE80211_S_INIT, -1);

	/* Wait for all async commands to complete. */
	athn_usb_wait_async(usc);

	timeout_del(&sc->scan_to);
	timeout_del(&sc->calib_to);

	/* Remove main interface. */
	memset(&hvif, 0, sizeof(hvif));
	hvif.index = 0;
	IEEE80211_ADDR_COPY(hvif.myaddr, ic->ic_myaddr);
	(void)athn_usb_wmi_xcmd(usc, AR_WMI_CMD_VAP_REMOVE,
	    &hvif, sizeof(hvif), NULL);
	/* Remove default node. */
	sta_index = 0;
	(void)athn_usb_wmi_xcmd(usc, AR_WMI_CMD_NODE_REMOVE,
	    &sta_index, sizeof(sta_index), NULL);
	usc->nnodes--;

	(void)athn_usb_wmi_cmd(usc, AR_WMI_CMD_DISABLE_INTR);
	(void)athn_usb_wmi_cmd(usc, AR_WMI_CMD_DRAIN_TXQ_ALL);
	(void)athn_usb_wmi_cmd(usc, AR_WMI_CMD_STOP_RECV);

	athn_reset(sc, 0);
	athn_init_pll(sc, NULL);
	athn_set_power_awake(sc);
	athn_reset(sc, 1);
	athn_init_pll(sc, NULL);
	athn_set_power_sleep(sc);

	/* Abort Tx/Rx. */
	usbd_abort_pipe(usc->tx_data_pipe);
	usbd_abort_pipe(usc->rx_data_pipe);

	/* Free Tx/Rx buffers. */
	athn_usb_free_tx_list(usc);
	athn_usb_free_rx_list(usc);
	splx(s);

	/* Flush Rx stream. */
	if (usc->rx_stream.m != NULL)
		m_freem(usc->rx_stream.m);
	usc->rx_stream.m = NULL;
	usc->rx_stream.left = 0;
}
