usb.c

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/*
 * Marvell Wireless LAN device driver: USB specific handling
 *
 * Copyright (C) 2012, Marvell International Ltd.
 *
 * This software file (the "File") is distributed by Marvell International
 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
 * (the "License").  You may use, redistribute and/or modify this File in
 * accordance with the terms and conditions of the License, a copy of which
 * is available by writing to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
 * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
 * this warranty disclaimer.
 */

#include "main.h"
#include "usb.h"

#define USB_VERSION "1.0"

static const char usbdriver_name[] = "usb8797";

static u8 user_rmmod;
static struct mwifiex_if_ops usb_ops;
static struct semaphore add_remove_card_sem;

static struct usb_device_id mwifiex_usb_table[] = {
    {USB_DEVICE(USB8797_VID, USB8797_PID_1)},
    {USB_DEVICE_AND_INTERFACE_INFO(USB8797_VID, USB8797_PID_2,
                       USB_CLASS_VENDOR_SPEC,
                       USB_SUBCLASS_VENDOR_SPEC, 0xff)},
    { } /* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, mwifiex_usb_table);

static int mwifiex_usb_submit_rx_urb(struct urb_context *ctx, int size);

/* This function handles received packet. Necessary action is taken based on
 * cmd/event/data.
 */
static int mwifiex_usb_recv(struct mwifiex_adapter *adapter,
                struct sk_buff *skb, u8 ep)
{
    struct device *dev = adapter->dev;
    u32 recv_type;
    __le32 tmp;
    int ret;

    if (adapter->hs_activated)
        mwifiex_process_hs_config(adapter);

    if (skb->len < INTF_HEADER_LEN) {
        dev_err(dev, "%s: invalid skb->len\n", __func__);
        return -1;
    }

    switch (ep) {
    case MWIFIEX_USB_EP_CMD_EVENT:
        dev_dbg(dev, "%s: EP_CMD_EVENT\n", __func__);
        skb_copy_from_linear_data(skb, &tmp, INTF_HEADER_LEN);
        recv_type = le32_to_cpu(tmp);
        skb_pull(skb, INTF_HEADER_LEN);

        switch (recv_type) {
        case MWIFIEX_USB_TYPE_CMD:
            if (skb->len > MWIFIEX_SIZE_OF_CMD_BUFFER) {
                dev_err(dev, "CMD: skb->len too large\n");
                ret = -1;
                goto exit_restore_skb;
            } else if (!adapter->curr_cmd) {
                dev_dbg(dev, "CMD: no curr_cmd\n");
                if (adapter->ps_state == PS_STATE_SLEEP_CFM) {
                    mwifiex_process_sleep_confirm_resp(
                            adapter, skb->data,
                            skb->len);
                    ret = 0;
                    goto exit_restore_skb;
                }
                ret = -1;
                goto exit_restore_skb;
            }

            adapter->curr_cmd->resp_skb = skb;
            adapter->cmd_resp_received = true;
            break;
        case MWIFIEX_USB_TYPE_EVENT:
            if (skb->len < sizeof(u32)) {
                dev_err(dev, "EVENT: skb->len too small\n");
                ret = -1;
                goto exit_restore_skb;
            }
            skb_copy_from_linear_data(skb, &tmp, sizeof(u32));
            adapter->event_cause = le32_to_cpu(tmp);
            dev_dbg(dev, "event_cause %#x\n", adapter->event_cause);

            if (skb->len > MAX_EVENT_SIZE) {
                dev_err(dev, "EVENT: event body too large\n");
                ret = -1;
                goto exit_restore_skb;
            }

            memcpy(adapter->event_body, skb->data +
                   MWIFIEX_EVENT_HEADER_LEN, skb->len);

            adapter->event_received = true;
            adapter->event_skb = skb;
            break;
        default:
            dev_err(dev, "unknown recv_type %#x\n", recv_type);
            return -1;
        }
        break;
    case MWIFIEX_USB_EP_DATA:
        dev_dbg(dev, "%s: EP_DATA\n", __func__);
        if (skb->len > MWIFIEX_RX_DATA_BUF_SIZE) {
            dev_err(dev, "DATA: skb->len too large\n");
            return -1;
        }
        skb_queue_tail(&adapter->usb_rx_data_q, skb);
        adapter->data_received = true;
        break;
    default:
        dev_err(dev, "%s: unknown endport %#x\n", __func__, ep);
        return -1;
    }

    return -EINPROGRESS;

exit_restore_skb:
    /* The buffer will be reused for further cmds/events */
    skb_push(skb, INTF_HEADER_LEN);

    return ret;
}

static void mwifiex_usb_rx_complete(struct urb *urb)
{
    struct urb_context *context = (struct urb_context *)urb->context;
    struct mwifiex_adapter *adapter = context->adapter;
    struct sk_buff *skb = context->skb;
    struct usb_card_rec *card;
    int recv_length = urb->actual_length;
    int size, status;

    if (!adapter || !adapter->card) {
        pr_err("mwifiex adapter or card structure is not valid\n");
        return;
    }

    card = (struct usb_card_rec *)adapter->card;
    if (card->rx_cmd_ep == context->ep)
        atomic_dec(&card->rx_cmd_urb_pending);
    else
        atomic_dec(&card->rx_data_urb_pending);

    if (recv_length) {
        if (urb->status || (adapter->surprise_removed)) {
            dev_err(adapter->dev,
                "URB status is failed: %d\n", urb->status);
            /* Do not free skb in case of command ep */
            if (card->rx_cmd_ep != context->ep)
                dev_kfree_skb_any(skb);
            goto setup_for_next;
        }
        if (skb->len > recv_length)
            skb_trim(skb, recv_length);
        else
            skb_put(skb, recv_length - skb->len);

        atomic_inc(&adapter->rx_pending);
        status = mwifiex_usb_recv(adapter, skb, context->ep);

        dev_dbg(adapter->dev, "info: recv_length=%d, status=%d\n",
            recv_length, status);
        if (status == -EINPROGRESS) {
            queue_work(adapter->workqueue, &adapter->main_work);

            /* urb for data_ep is re-submitted now;
             * urb for cmd_ep will be re-submitted in callback
             * mwifiex_usb_recv_complete
             */
            if (card->rx_cmd_ep == context->ep)
                return;
        } else {
            atomic_dec(&adapter->rx_pending);
            if (status == -1)
                dev_err(adapter->dev,
                    "received data processing failed!\n");

            /* Do not free skb in case of command ep */
            if (card->rx_cmd_ep != context->ep)
                dev_kfree_skb_any(skb);
        }
    } else if (urb->status) {
        if (!adapter->is_suspended) {
            dev_warn(adapter->dev,
                 "Card is removed: %d\n", urb->status);
            adapter->surprise_removed = true;
        }
        dev_kfree_skb_any(skb);
        return;
    } else {
        /* Do not free skb in case of command ep */
        if (card->rx_cmd_ep != context->ep)
            dev_kfree_skb_any(skb);

        /* fall through setup_for_next */
    }

setup_for_next:
    if (card->rx_cmd_ep == context->ep)
        size = MWIFIEX_RX_CMD_BUF_SIZE;
    else
        size = MWIFIEX_RX_DATA_BUF_SIZE;

    mwifiex_usb_submit_rx_urb(context, size);

    return;
}

static void mwifiex_usb_tx_complete(struct urb *urb)
{
    struct urb_context *context = (struct urb_context *)(urb->context);
    struct mwifiex_adapter *adapter = context->adapter;
    struct usb_card_rec *card = adapter->card;

    dev_dbg(adapter->dev, "%s: status: %d\n", __func__, urb->status);

    if (context->ep == card->tx_cmd_ep) {
        dev_dbg(adapter->dev, "%s: CMD\n", __func__);
        atomic_dec(&card->tx_cmd_urb_pending);
        adapter->cmd_sent = false;
    } else {
        dev_dbg(adapter->dev, "%s: DATA\n", __func__);
        atomic_dec(&card->tx_data_urb_pending);
        mwifiex_write_data_complete(adapter, context->skb,
                        urb->status ? -1 : 0);
    }

    queue_work(adapter->workqueue, &adapter->main_work);

    return;
}

static int mwifiex_usb_submit_rx_urb(struct urb_context *ctx, int size)
{
    struct mwifiex_adapter *adapter = ctx->adapter;
    struct usb_card_rec *card = (struct usb_card_rec *)adapter->card;

    if (card->rx_cmd_ep != ctx->ep) {
        ctx->skb = dev_alloc_skb(size);
        if (!ctx->skb) {
            dev_err(adapter->dev,
                "%s: dev_alloc_skb failed\n", __func__);
            return -ENOMEM;
        }
    }

    usb_fill_bulk_urb(ctx->urb, card->udev,
              usb_rcvbulkpipe(card->udev, ctx->ep), ctx->skb->data,
              size, mwifiex_usb_rx_complete, (void *)ctx);

    if (card->rx_cmd_ep == ctx->ep)
        atomic_inc(&card->rx_cmd_urb_pending);
    else
        atomic_inc(&card->rx_data_urb_pending);

    if (usb_submit_urb(ctx->urb, GFP_ATOMIC)) {
        dev_err(adapter->dev, "usb_submit_urb failed\n");
        dev_kfree_skb_any(ctx->skb);
        ctx->skb = NULL;

        if (card->rx_cmd_ep == ctx->ep)
            atomic_dec(&card->rx_cmd_urb_pending);
        else
            atomic_dec(&card->rx_data_urb_pending);

        return -1;
    }

    return 0;
}

static void mwifiex_usb_free(struct usb_card_rec *card)
{
    int i;

    if (atomic_read(&card->rx_cmd_urb_pending) && card->rx_cmd.urb)
        usb_kill_urb(card->rx_cmd.urb);

    usb_free_urb(card->rx_cmd.urb);
    card->rx_cmd.urb = NULL;

    if (atomic_read(&card->rx_data_urb_pending))
        for (i = 0; i < MWIFIEX_RX_DATA_URB; i++)
            if (card->rx_data_list[i].urb)
                usb_kill_urb(card->rx_data_list[i].urb);

    for (i = 0; i < MWIFIEX_RX_DATA_URB; i++) {
        usb_free_urb(card->rx_data_list[i].urb);
        card->rx_data_list[i].urb = NULL;
    }

    for (i = 0; i < MWIFIEX_TX_DATA_URB; i++) {
        usb_free_urb(card->tx_data_list[i].urb);
        card->tx_data_list[i].urb = NULL;
    }

    usb_free_urb(card->tx_cmd.urb);
    card->tx_cmd.urb = NULL;

    return;
}

/* This function probes an mwifiex device and registers it. It allocates
 * the card structure, initiates the device registration and initialization
 * procedure by adding a logical interface.
 */
static int mwifiex_usb_probe(struct usb_interface *intf,
                 const struct usb_device_id *id)
{
    struct usb_device *udev = interface_to_usbdev(intf);
    struct usb_host_interface *iface_desc = intf->cur_altsetting;
    struct usb_endpoint_descriptor *epd;
    int ret, i;
    struct usb_card_rec *card;
    u16 id_vendor, id_product, bcd_device, bcd_usb;

    card = kzalloc(sizeof(struct usb_card_rec), GFP_KERNEL);
    if (!card)
        return -ENOMEM;

    id_vendor = le16_to_cpu(udev->descriptor.idVendor);
    id_product = le16_to_cpu(udev->descriptor.idProduct);
    bcd_device = le16_to_cpu(udev->descriptor.bcdDevice);
    bcd_usb = le16_to_cpu(udev->descriptor.bcdUSB);
    pr_debug("info: VID/PID = %X/%X, Boot2 version = %X\n",
         id_vendor, id_product, bcd_device);

    /* PID_1 is used for firmware downloading only */
    if (id_product == USB8797_PID_1)
        card->usb_boot_state = USB8797_FW_DNLD;
    else
        card->usb_boot_state = USB8797_FW_READY;

    card->udev = udev;
    card->intf = intf;

    pr_debug("info: bcdUSB=%#x Device Class=%#x SubClass=%#x Protocl=%#x\n",
         udev->descriptor.bcdUSB, udev->descriptor.bDeviceClass,
         udev->descriptor.bDeviceSubClass,
         udev->descriptor.bDeviceProtocol);

    for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
        epd = &iface_desc->endpoint[i].desc;
        if (usb_endpoint_dir_in(epd) &&
            usb_endpoint_num(epd) == MWIFIEX_USB_EP_CMD_EVENT &&
            usb_endpoint_xfer_bulk(epd)) {
            pr_debug("info: bulk IN: max pkt size: %d, addr: %d\n",
                 le16_to_cpu(epd->wMaxPacketSize),
                 epd->bEndpointAddress);
            card->rx_cmd_ep = usb_endpoint_num(epd);
            atomic_set(&card->rx_cmd_urb_pending, 0);
        }
        if (usb_endpoint_dir_in(epd) &&
            usb_endpoint_num(epd) == MWIFIEX_USB_EP_DATA &&
            usb_endpoint_xfer_bulk(epd)) {
            pr_debug("info: bulk IN: max pkt size: %d, addr: %d\n",
                 le16_to_cpu(epd->wMaxPacketSize),
                 epd->bEndpointAddress);
            card->rx_data_ep = usb_endpoint_num(epd);
            atomic_set(&card->rx_data_urb_pending, 0);
        }
        if (usb_endpoint_dir_out(epd) &&
            usb_endpoint_num(epd) == MWIFIEX_USB_EP_DATA &&
            usb_endpoint_xfer_bulk(epd)) {
            pr_debug("info: bulk OUT: max pkt size: %d, addr: %d\n",
                 le16_to_cpu(epd->wMaxPacketSize),
                 epd->bEndpointAddress);
            card->tx_data_ep = usb_endpoint_num(epd);
            atomic_set(&card->tx_data_urb_pending, 0);
        }
        if (usb_endpoint_dir_out(epd) &&
            usb_endpoint_num(epd) == MWIFIEX_USB_EP_CMD_EVENT &&
            usb_endpoint_xfer_bulk(epd)) {
            pr_debug("info: bulk OUT: max pkt size: %d, addr: %d\n",
                 le16_to_cpu(epd->wMaxPacketSize),
                 epd->bEndpointAddress);
            card->tx_cmd_ep = usb_endpoint_num(epd);
            atomic_set(&card->tx_cmd_urb_pending, 0);
            card->bulk_out_maxpktsize =
                    le16_to_cpu(epd->wMaxPacketSize);
        }
    }

    usb_set_intfdata(intf, card);

    ret = mwifiex_add_card(card, &add_remove_card_sem, &usb_ops,
                   MWIFIEX_USB);
    if (ret) {
        pr_err("%s: mwifiex_add_card failed: %d\n", __func__, ret);
        usb_reset_device(udev);
        kfree(card);
        return ret;
    }

    usb_get_dev(udev);

    return 0;
}

/* Kernel needs to suspend all functions separately. Therefore all
 * registered functions must have drivers with suspend and resume
 * methods. Failing that the kernel simply removes the whole card.
 *
 * If already not suspended, this function allocates and sends a
 * 'host sleep activate' request to the firmware and turns off the traffic.
 */
static int mwifiex_usb_suspend(struct usb_interface *intf, pm_message_t message)
{
    struct usb_card_rec *card = usb_get_intfdata(intf);
    struct mwifiex_adapter *adapter;
    int i;

    if (!card || !card->adapter) {
        pr_err("%s: card or card->adapter is NULL\n", __func__);
        return 0;
    }
    adapter = card->adapter;

    if (unlikely(adapter->is_suspended))
        dev_warn(adapter->dev, "Device already suspended\n");

    mwifiex_enable_hs(adapter);

    /* 'is_suspended' flag indicates device is suspended.
     * It must be set here before the usb_kill_urb() calls. Reason
     * is in the complete handlers, urb->status(= -ENOENT) and
     * this flag is used in combination to distinguish between a
     * 'suspended' state and a 'disconnect' one.
     */
    adapter->is_suspended = true;

    for (i = 0; i < adapter->priv_num; i++)
        netif_carrier_off(adapter->priv[i]->netdev);

    if (atomic_read(&card->rx_cmd_urb_pending) && card->rx_cmd.urb)
        usb_kill_urb(card->rx_cmd.urb);

    if (atomic_read(&card->rx_data_urb_pending))
        for (i = 0; i < MWIFIEX_RX_DATA_URB; i++)
            if (card->rx_data_list[i].urb)
                usb_kill_urb(card->rx_data_list[i].urb);

    for (i = 0; i < MWIFIEX_TX_DATA_URB; i++)
        if (card->tx_data_list[i].urb)
            usb_kill_urb(card->tx_data_list[i].urb);

    if (card->tx_cmd.urb)
        usb_kill_urb(card->tx_cmd.urb);

    return 0;
}

/* Kernel needs to suspend all functions separately. Therefore all
 * registered functions must have drivers with suspend and resume
 * methods. Failing that the kernel simply removes the whole card.
 *
 * If already not resumed, this function turns on the traffic and
 * sends a 'host sleep cancel' request to the firmware.
 */
static int mwifiex_usb_resume(struct usb_interface *intf)
{
    struct usb_card_rec *card = usb_get_intfdata(intf);
    struct mwifiex_adapter *adapter;
    int i;

    if (!card || !card->adapter) {
        pr_err("%s: card or card->adapter is NULL\n", __func__);
        return 0;
    }
    adapter = card->adapter;

    if (unlikely(!adapter->is_suspended)) {
        dev_warn(adapter->dev, "Device already resumed\n");
        return 0;
    }

    /* Indicate device resumed. The netdev queue will be resumed only
     * after the urbs have been re-submitted
     */
    adapter->is_suspended = false;

    if (!atomic_read(&card->rx_data_urb_pending))
        for (i = 0; i < MWIFIEX_RX_DATA_URB; i++)
            mwifiex_usb_submit_rx_urb(&card->rx_data_list[i],
                          MWIFIEX_RX_DATA_BUF_SIZE);

    if (!atomic_read(&card->rx_cmd_urb_pending)) {
        card->rx_cmd.skb = dev_alloc_skb(MWIFIEX_RX_CMD_BUF_SIZE);
        if (card->rx_cmd.skb)
            mwifiex_usb_submit_rx_urb(&card->rx_cmd,
                          MWIFIEX_RX_CMD_BUF_SIZE);
    }

    for (i = 0; i < adapter->priv_num; i++)
        if (adapter->priv[i]->media_connected)
            netif_carrier_on(adapter->priv[i]->netdev);

    /* Disable Host Sleep */
    if (adapter->hs_activated)
        mwifiex_cancel_hs(mwifiex_get_priv(adapter,
                           MWIFIEX_BSS_ROLE_ANY),
                  MWIFIEX_ASYNC_CMD);

#ifdef CONFIG_PM
    /* Resume handler may be called due to remote wakeup,
     * force to exit suspend anyway
     */
    usb_disable_autosuspend(card->udev);
#endif /* CONFIG_PM */

    return 0;
}

static void mwifiex_usb_disconnect(struct usb_interface *intf)
{
    struct usb_card_rec *card = usb_get_intfdata(intf);
    struct mwifiex_adapter *adapter;
    int i;

    if (!card || !card->adapter) {
        pr_err("%s: card or card->adapter is NULL\n", __func__);
        return;
    }

    adapter = card->adapter;
    if (!adapter->priv_num)
        return;

    /* In case driver is removed when asynchronous FW downloading is
     * in progress
     */
    wait_for_completion(&adapter->fw_load);

    if (user_rmmod) {
#ifdef CONFIG_PM
        if (adapter->is_suspended)
            mwifiex_usb_resume(intf);
#endif
        for (i = 0; i < adapter->priv_num; i++)
            if ((GET_BSS_ROLE(adapter->priv[i]) ==
                 MWIFIEX_BSS_ROLE_STA) &&
                adapter->priv[i]->media_connected)
                mwifiex_deauthenticate(adapter->priv[i], NULL);

        mwifiex_init_shutdown_fw(mwifiex_get_priv(adapter,
                              MWIFIEX_BSS_ROLE_ANY),
                     MWIFIEX_FUNC_SHUTDOWN);
    }

    mwifiex_usb_free(card);

    dev_dbg(adapter->dev, "%s: removing card\n", __func__);
    mwifiex_remove_card(adapter, &add_remove_card_sem);

    usb_set_intfdata(intf, NULL);
    usb_put_dev(interface_to_usbdev(intf));
    kfree(card);

    return;
}

static struct usb_driver mwifiex_usb_driver = {
    .name = usbdriver_name,
    .probe = mwifiex_usb_probe,
    .disconnect = mwifiex_usb_disconnect,
    .id_table = mwifiex_usb_table,
    .suspend = mwifiex_usb_suspend,
    .resume = mwifiex_usb_resume,
    .supports_autosuspend = 1,
};

static int mwifiex_usb_tx_init(struct mwifiex_adapter *adapter)
{
    struct usb_card_rec *card = (struct usb_card_rec *)adapter->card;
    int i;

    card->tx_cmd.adapter = adapter;
    card->tx_cmd.ep = card->tx_cmd_ep;

    card->tx_cmd.urb = usb_alloc_urb(0, GFP_KERNEL);
    if (!card->tx_cmd.urb) {
        dev_err(adapter->dev, "tx_cmd.urb allocation failed\n");
        return -ENOMEM;
    }

    card->tx_data_ix = 0;

    for (i = 0; i < MWIFIEX_TX_DATA_URB; i++) {
        card->tx_data_list[i].adapter = adapter;
        card->tx_data_list[i].ep = card->tx_data_ep;

        card->tx_data_list[i].urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!card->tx_data_list[i].urb) {
            dev_err(adapter->dev,
                "tx_data_list[] urb allocation failed\n");
            return -ENOMEM;
        }
    }

    return 0;
}

static int mwifiex_usb_rx_init(struct mwifiex_adapter *adapter)
{
    struct usb_card_rec *card = (struct usb_card_rec *)adapter->card;
    int i;

    card->rx_cmd.adapter = adapter;
    card->rx_cmd.ep = card->rx_cmd_ep;

    card->rx_cmd.urb = usb_alloc_urb(0, GFP_KERNEL);
    if (!card->rx_cmd.urb) {
        dev_err(adapter->dev, "rx_cmd.urb allocation failed\n");
        return -ENOMEM;
    }

    card->rx_cmd.skb = dev_alloc_skb(MWIFIEX_RX_CMD_BUF_SIZE);
    if (!card->rx_cmd.skb) {
        dev_err(adapter->dev, "rx_cmd.skb allocation failed\n");
        return -ENOMEM;
    }

    if (mwifiex_usb_submit_rx_urb(&card->rx_cmd, MWIFIEX_RX_CMD_BUF_SIZE))
        return -1;

    for (i = 0; i < MWIFIEX_RX_DATA_URB; i++) {
        card->rx_data_list[i].adapter = adapter;
        card->rx_data_list[i].ep = card->rx_data_ep;

        card->rx_data_list[i].urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!card->rx_data_list[i].urb) {
            dev_err(adapter->dev,
                "rx_data_list[] urb allocation failed\n");
            return -1;
        }
        if (mwifiex_usb_submit_rx_urb(&card->rx_data_list[i],
                          MWIFIEX_RX_DATA_BUF_SIZE))
            return -1;
    }

    return 0;
}

static int mwifiex_write_data_sync(struct mwifiex_adapter *adapter, u8 *pbuf,
                   u32 *len, u8 ep, u32 timeout)
{
    struct usb_card_rec *card = adapter->card;
    int actual_length, ret;

    if (!(*len % card->bulk_out_maxpktsize))
        (*len)++;

    /* Send the data block */
    ret = usb_bulk_msg(card->udev, usb_sndbulkpipe(card->udev, ep), pbuf,
               *len, &actual_length, timeout);
    if (ret) {
        dev_err(adapter->dev, "usb_bulk_msg for tx failed: %d\n", ret);
        ret = -1;
    }

    *len = actual_length;

    return ret;
}

static int mwifiex_read_data_sync(struct mwifiex_adapter *adapter, u8 *pbuf,
                  u32 *len, u8 ep, u32 timeout)
{
    struct usb_card_rec *card = adapter->card;
    int actual_length, ret;

    /* Receive the data response */
    ret = usb_bulk_msg(card->udev, usb_rcvbulkpipe(card->udev, ep), pbuf,
               *len, &actual_length, timeout);
    if (ret) {
        dev_err(adapter->dev, "usb_bulk_msg for rx failed: %d\n", ret);
        ret = -1;
    }

    *len = actual_length;

    return ret;
}

/* This function write a command/data packet to card. */
static int mwifiex_usb_host_to_card(struct mwifiex_adapter *adapter, u8 ep,
                    struct sk_buff *skb,
                    struct mwifiex_tx_param *tx_param)
{
    struct usb_card_rec *card = adapter->card;
    struct urb_context *context;
    u8 *data = (u8 *)skb->data;
    struct urb *tx_urb;

    if (adapter->is_suspended) {
        dev_err(adapter->dev,
            "%s: not allowed while suspended\n", __func__);
        return -1;
    }

    if (adapter->surprise_removed) {
        dev_err(adapter->dev, "%s: device removed\n", __func__);
        return -1;
    }

    if (ep == card->tx_data_ep &&
        atomic_read(&card->tx_data_urb_pending) >= MWIFIEX_TX_DATA_URB) {
        return -EBUSY;
    }

    dev_dbg(adapter->dev, "%s: ep=%d\n", __func__, ep);

    if (ep == card->tx_cmd_ep) {
        context = &card->tx_cmd;
    } else {
        if (card->tx_data_ix >= MWIFIEX_TX_DATA_URB)
            card->tx_data_ix = 0;
        context = &card->tx_data_list[card->tx_data_ix++];
    }

    context->adapter = adapter;
    context->ep = ep;
    context->skb = skb;
    tx_urb = context->urb;

    usb_fill_bulk_urb(tx_urb, card->udev, usb_sndbulkpipe(card->udev, ep),
              data, skb->len, mwifiex_usb_tx_complete,
              (void *)context);

    tx_urb->transfer_flags |= URB_ZERO_PACKET;

    if (ep == card->tx_cmd_ep)
        atomic_inc(&card->tx_cmd_urb_pending);
    else
        atomic_inc(&card->tx_data_urb_pending);

    if (usb_submit_urb(tx_urb, GFP_ATOMIC)) {
        dev_err(adapter->dev, "%s: usb_submit_urb failed\n", __func__);
        if (ep == card->tx_cmd_ep) {
            atomic_dec(&card->tx_cmd_urb_pending);
        } else {
            atomic_dec(&card->tx_data_urb_pending);
            if (card->tx_data_ix)
                card->tx_data_ix--;
            else
                card->tx_data_ix = MWIFIEX_TX_DATA_URB;
        }

        return -1;
    } else {
        if (ep == card->tx_data_ep &&
            atomic_read(&card->tx_data_urb_pending) ==
                            MWIFIEX_TX_DATA_URB)
            return -ENOSR;
    }

    return -EINPROGRESS;
}

/* This function register usb device and initialize parameter. */
static int mwifiex_register_dev(struct mwifiex_adapter *adapter)
{
    struct usb_card_rec *card = (struct usb_card_rec *)adapter->card;

    card->adapter = adapter;
    adapter->dev = &card->udev->dev;
    strcpy(adapter->fw_name, USB8797_DEFAULT_FW_NAME);

    return 0;
}

/* This function reads one block of firmware data. */
static int mwifiex_get_fw_data(struct mwifiex_adapter *adapter,
                   u32 offset, u32 len, u8 *buf)
{
    if (!buf || !len)
        return -1;

    if (offset + len > adapter->firmware->size)
        return -1;

    memcpy(buf, adapter->firmware->data + offset, len);

    return 0;
}

static int mwifiex_prog_fw_w_helper(struct mwifiex_adapter *adapter,
                    struct mwifiex_fw_image *fw)
{
    int ret = 0;
    u8 *firmware = fw->fw_buf, *recv_buff;
    u32 retries = USB8797_FW_MAX_RETRY, dlen;
    u32 fw_seqnum = 0, tlen = 0, dnld_cmd = 0;
    struct fw_data *fwdata;
    struct fw_sync_header sync_fw;
    u8 check_winner = 1;

    if (!firmware) {
        dev_err(adapter->dev,
            "No firmware image found! Terminating download\n");
        ret = -1;
        goto fw_exit;
    }

    /* Allocate memory for transmit */
    fwdata = kzalloc(FW_DNLD_TX_BUF_SIZE, GFP_KERNEL);
    if (!fwdata)
        goto fw_exit;

    /* Allocate memory for receive */
    recv_buff = kzalloc(FW_DNLD_RX_BUF_SIZE, GFP_KERNEL);
    if (!recv_buff)
        goto cleanup;

    do {
        /* Send pseudo data to check winner status first */
        if (check_winner) {
            memset(&fwdata->fw_hdr, 0, sizeof(struct fw_header));
            dlen = 0;
        } else {
            /* copy the header of the fw_data to get the length */
            if (firmware)
                memcpy(&fwdata->fw_hdr, &firmware[tlen],
                       sizeof(struct fw_header));
            else
                mwifiex_get_fw_data(adapter, tlen,
                            sizeof(struct fw_header),
                            (u8 *)&fwdata->fw_hdr);

            dlen = le32_to_cpu(fwdata->fw_hdr.data_len);
            dnld_cmd = le32_to_cpu(fwdata->fw_hdr.dnld_cmd);
            tlen += sizeof(struct fw_header);

            if (firmware)
                memcpy(fwdata->data, &firmware[tlen], dlen);
            else
                mwifiex_get_fw_data(adapter, tlen, dlen,
                            (u8 *)fwdata->data);

            fwdata->seq_num = cpu_to_le32(fw_seqnum);
            tlen += dlen;
        }

        /* If the send/receive fails or CRC occurs then retry */
        while (retries--) {
            u8 *buf = (u8 *)fwdata;
            u32 len = FW_DATA_XMIT_SIZE;

            /* send the firmware block */
            ret = mwifiex_write_data_sync(adapter, buf, &len,
                        MWIFIEX_USB_EP_CMD_EVENT,
                        MWIFIEX_USB_TIMEOUT);
            if (ret) {
                dev_err(adapter->dev,
                    "write_data_sync: failed: %d\n", ret);
                continue;
            }

            buf = recv_buff;
            len = FW_DNLD_RX_BUF_SIZE;

            /* Receive the firmware block response */
            ret = mwifiex_read_data_sync(adapter, buf, &len,
                        MWIFIEX_USB_EP_CMD_EVENT,
                        MWIFIEX_USB_TIMEOUT);
            if (ret) {
                dev_err(adapter->dev,
                    "read_data_sync: failed: %d\n", ret);
                continue;
            }

            memcpy(&sync_fw, recv_buff,
                   sizeof(struct fw_sync_header));

            /* check 1st firmware block resp for highest bit set */
            if (check_winner) {
                if (le32_to_cpu(sync_fw.cmd) & 0x80000000) {
                    dev_warn(adapter->dev,
                         "USB is not the winner %#x\n",
                         sync_fw.cmd);

                    /* returning success */
                    ret = 0;
                    goto cleanup;
                }

                dev_dbg(adapter->dev,
                    "USB is the winner, start to download FW\n");

                check_winner = 0;
                break;
            }

            /* check the firmware block response for CRC errors */
            if (sync_fw.cmd) {
                dev_err(adapter->dev,
                    "FW received block with CRC %#x\n",
                    sync_fw.cmd);
                ret = -1;
                continue;
            }

            retries = USB8797_FW_MAX_RETRY;
            break;
        }
        fw_seqnum++;
    } while ((dnld_cmd != FW_HAS_LAST_BLOCK) && retries);

cleanup:
    dev_dbg(adapter->dev, "%s: %d bytes downloaded\n", __func__, tlen);

    kfree(recv_buff);
    kfree(fwdata);

    if (retries)
        ret = 0;
fw_exit:
    return ret;
}

static int mwifiex_usb_dnld_fw(struct mwifiex_adapter *adapter,
            struct mwifiex_fw_image *fw)
{
    int ret;
    struct usb_card_rec *card = (struct usb_card_rec *)adapter->card;

    if (card->usb_boot_state == USB8797_FW_DNLD) {
        ret = mwifiex_prog_fw_w_helper(adapter, fw);
        if (ret)
            return -1;

        /* Boot state changes after successful firmware download */
        if (card->usb_boot_state == USB8797_FW_DNLD)
            return -1;
    }

    ret = mwifiex_usb_rx_init(adapter);
    if (!ret)
        ret = mwifiex_usb_tx_init(adapter);

    return ret;
}

static void mwifiex_submit_rx_urb(struct mwifiex_adapter *adapter, u8 ep)
{
    struct usb_card_rec *card = (struct usb_card_rec *)adapter->card;

    skb_push(card->rx_cmd.skb, INTF_HEADER_LEN);
    if ((ep == card->rx_cmd_ep) &&
        (!atomic_read(&card->rx_cmd_urb_pending)))
        mwifiex_usb_submit_rx_urb(&card->rx_cmd,
                      MWIFIEX_RX_CMD_BUF_SIZE);

    return;
}

static int mwifiex_usb_cmd_event_complete(struct mwifiex_adapter *adapter,
                       struct sk_buff *skb)
{
    atomic_dec(&adapter->rx_pending);
    mwifiex_submit_rx_urb(adapter, MWIFIEX_USB_EP_CMD_EVENT);

    return 0;
}

static int mwifiex_usb_data_complete(struct mwifiex_adapter *adapter,
                     struct sk_buff *skb)
{
    atomic_dec(&adapter->rx_pending);
    dev_kfree_skb_any(skb);

    return 0;
}

/* This function wakes up the card. */
static int mwifiex_pm_wakeup_card(struct mwifiex_adapter *adapter)
{
    /* Simulation of HS_AWAKE event */
    adapter->pm_wakeup_fw_try = false;
    adapter->pm_wakeup_card_req = false;
    adapter->ps_state = PS_STATE_AWAKE;

    return 0;
}

static struct mwifiex_if_ops usb_ops = {
    .register_dev =     mwifiex_register_dev,
    .wakeup =       mwifiex_pm_wakeup_card,
    .wakeup_complete =  mwifiex_pm_wakeup_card_complete,

    /* USB specific */
    .dnld_fw =      mwifiex_usb_dnld_fw,
    .cmdrsp_complete =  mwifiex_usb_cmd_event_complete,
    .event_complete =   mwifiex_usb_cmd_event_complete,
    .data_complete =    mwifiex_usb_data_complete,
    .host_to_card =     mwifiex_usb_host_to_card,
};

/* This function initializes the USB driver module.
 *
 * This initiates the semaphore and registers the device with
 * USB bus.
 */
static int mwifiex_usb_init_module(void)
{
    int ret;

    pr_debug("Marvell USB8797 Driver\n");

    sema_init(&add_remove_card_sem, 1);

    ret = usb_register(&mwifiex_usb_driver);
    if (ret)
        pr_err("Driver register failed!\n");
    else
        pr_debug("info: Driver registered successfully!\n");

    return ret;
}

/* This function cleans up the USB driver.
 *
 * The following major steps are followed in .disconnect for cleanup:
 *      - Resume the device if its suspended
 *      - Disconnect the device if connected
 *      - Shutdown the firmware
 *      - Unregister the device from USB bus.
 */
static void mwifiex_usb_cleanup_module(void)
{
    if (!down_interruptible(&add_remove_card_sem))
        up(&add_remove_card_sem);

    /* set the flag as user is removing this module */
    user_rmmod = 1;

    usb_deregister(&mwifiex_usb_driver);
}

module_init(mwifiex_usb_init_module);
module_exit(mwifiex_usb_cleanup_module);

MODULE_AUTHOR("Marvell International Ltd.");
MODULE_DESCRIPTION("Marvell WiFi-Ex USB Driver version" USB_VERSION);
MODULE_VERSION(USB_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_FIRMWARE("mrvl/usb8797_uapsta.bin");