static usb_callback_t	ubt_probe_intr_callback;

	/* Intel Wireless 8260/8265 and successors */

	{ USB_VPI(USB_VENDOR_INTEL2, 0x0a2b, UBT_INTEL8265) },

	{ USB_VPI(USB_VENDOR_INTEL2, 0x0aaa, UBT_INTEL8265) },

	{ USB_VPI(USB_VENDOR_INTEL2, 0x0025, UBT_INTEL8265) },

	{ USB_VPI(USB_VENDOR_INTEL2, 0x0026, UBT_INTEL8265) },

	{ USB_VPI(USB_VENDOR_INTEL2, 0x0029, UBT_INTEL8265) },

/*

 * Does a synchronous (waits for completion event) execution of HCI command.

 * Size of both command and response buffers are passed in length field of

 * corresponding structures in "Parameter Total Length" format i.e.

 * not including HCI packet headers.

 *

 * Must not be used after USB transfers have been configured in attach routine.

 */

static usb_error_t

ubt_do_hci_request(struct usb_device *udev, struct ubt_hci_cmd *cmd,

    struct ubt_hci_event *evt, usb_timeout_t timeout)

{

	static const struct usb_config ubt_probe_config = {

		.type = UE_INTERRUPT,

		.endpoint = UE_ADDR_ANY,

		.direction = UE_DIR_IN,

		.flags = { .pipe_bof = 1, .short_xfer_ok = 1 },

		.bufsize = UBT_INTR_BUFFER_SIZE,

		.callback = &ubt_probe_intr_callback,

	};

	struct usb_device_request req;

	struct usb_xfer *xfer[1];

	struct mtx mtx;

	usb_error_t error = USB_ERR_NORMAL_COMPLETION;

	uint8_t iface_index = 0;

	/* Initialize a USB control request and then do it */

	bzero(&req, sizeof(req));

	req.bmRequestType = UBT_HCI_REQUEST;

	req.wIndex[0] = iface_index;

	USETW(req.wLength, UBT_HCI_CMD_SIZE(cmd));

	error = usbd_do_request(udev, NULL, &req, cmd);

	if (error != USB_ERR_NORMAL_COMPLETION) {

		printf("ng_ubt: usbd_do_request error=%s\n",

			usbd_errstr(error));

		return (error);

	}

	if (evt == NULL)

		return (USB_ERR_NORMAL_COMPLETION);

	/* Initialize INTR endpoint xfer and wait for response */

	mtx_init(&mtx, "ubt pb", NULL, MTX_DEF);

	error = usbd_transfer_setup(udev, &iface_index, xfer,

	    &ubt_probe_config, 1, evt, &mtx);

	if (error == USB_ERR_NORMAL_COMPLETION) {

		mtx_lock(&mtx);

		usbd_transfer_start(*xfer);

		if (msleep_sbt(evt, &mtx, 0, "ubt pb", SBT_1MS * timeout,

				0, C_HARDCLOCK) == EWOULDBLOCK) {

			printf("ng_ubt: HCI command 0x%04x timed out\n",

				le16toh(cmd->opcode));

			error = USB_ERR_TIMEOUT;

		}

		usbd_transfer_stop(*xfer);

		mtx_unlock(&mtx);

		usbd_transfer_unsetup(xfer, 1);

	} else

		printf("ng_ubt: usbd_transfer_setup error=%s\n",

			usbd_errstr(error));

	mtx_destroy(&mtx);

	return (error);

}

/*

 * Find if the Intel Wireless 8260/8265 device is in bootloader mode or is

 * running operational firmware with checking of 7-th byte "Intel version"

 * HCI command response. The value 0x23 identifies the operational firmware.

 * Attempt to initialize bluetooth stack while device is in bootloader mode

 * (7-th byte is 0x06) locks the adapter hardly and requires power on/off

 * cycle to restore.

 */

static bool

ubt_check_intel8265_firmware_state(struct usb_device *udev)

{

#define	UBT_INTEL_VER_LEN		13

#define UBT_INTEL_HCICMD_TIMEOUT	2000	/* ms */

	struct ubt_hci_event *evt;

	uint8_t buf[offsetof(struct ubt_hci_event, data) + UBT_INTEL_VER_LEN];

	static struct ubt_hci_cmd cmd = {

		.opcode = htole16(NG_HCI_OPCODE(NG_HCI_OGF_VENDOR, 0x05)),

		.length = 0,

	};

	usb_error_t error;

	bzero(buf, sizeof(buf));

	evt = (struct ubt_hci_event *)buf;

	evt->length = UBT_INTEL_VER_LEN;

	error = ubt_do_hci_request(udev, &cmd, evt, UBT_INTEL_HCICMD_TIMEOUT);

	if (error != USB_ERR_NORMAL_COMPLETION)

		return false;

	return (evt->event == NG_HCI_EVENT_COMMAND_COMPL &&

		evt->length == UBT_INTEL_VER_LEN &&

		evt->data[7] == 0x23);

}

/*

 * Called when incoming interrupt transfer (HCI event) has completed, i.e.

 * HCI event was received from the device during device probe stage.

 * USB context.

 */

static void

ubt_probe_intr_callback(struct usb_xfer *xfer, usb_error_t error)

{

	struct ubt_hci_event	*evt = usbd_xfer_softc(xfer);

	struct usb_page_cache	*pc;

	int			actlen;

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

	switch (USB_GET_STATE(xfer)) {

	case USB_ST_TRANSFERRED:

		if (actlen > UBT_HCI_EVENT_SIZE(evt))

			actlen = UBT_HCI_EVENT_SIZE(evt);

		pc = usbd_xfer_get_frame(xfer, 0);

		usbd_copy_out(pc, 0, evt, actlen);

		/* OneShot mode */

		wakeup(evt);

		break;

	case USB_ST_SETUP:

submit_next:

		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));

		usbd_transfer_submit(xfer);

		break;

	default:

		if (error != USB_ERR_CANCELLED) {

			printf("ng_ubt: interrupt transfer failed: %s\n",

				usbd_errstr(error));

			/* Try clear stall first */

			usbd_xfer_set_stall(xfer);

			goto submit_next;

		}

		break;

	}

} /* ubt_probe_intr_callback */

/* USB driver info flags */

#define	UBT_INTEL8265	(1 << 0)

/* USB control request (HCI command) structure */

struct ubt_hci_cmd {

	uint16_t	opcode;

	uint8_t		length;

	uint8_t		data[];

} __attribute__ ((packed));

#define	UBT_HCI_CMD_SIZE(cmd) \

	((cmd)->length + offsetof(struct ubt_hci_cmd, data))

/* USB interrupt transfer (HCI event) structure */

struct ubt_hci_event {

	uint8_t		event;

	uint8_t		length;

	uint8_t		data[];

} __attribute__ ((packed));

#define	UBT_HCI_EVENT_SIZE(evt) \

	((evt)->length + offsetof(struct ubt_hci_event, data))