smsc95xx.c

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 /***************************************************************************
 *
 * Copyright (C) 2007-2008 SMSC
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 *****************************************************************************/

#include <linux/module.h>
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/crc32.h>
#include <linux/usb/usbnet.h>
#include <linux/slab.h>
#include "smsc95xx.h"

#define SMSC_CHIPNAME           "smsc95xx"
#define SMSC_DRIVER_VERSION     "1.0.4"
#define HS_USB_PKT_SIZE         (512)
#define FS_USB_PKT_SIZE         (64)
#define DEFAULT_HS_BURST_CAP_SIZE   (16 * 1024 + 5 * HS_USB_PKT_SIZE)
#define DEFAULT_FS_BURST_CAP_SIZE   (6 * 1024 + 33 * FS_USB_PKT_SIZE)
#define DEFAULT_BULK_IN_DELAY       (0x00002000)
#define MAX_SINGLE_PACKET_SIZE      (2048)
#define LAN95XX_EEPROM_MAGIC        (0x9500)
#define EEPROM_MAC_OFFSET       (0x01)
#define DEFAULT_TX_CSUM_ENABLE      (true)
#define DEFAULT_RX_CSUM_ENABLE      (true)
#define SMSC95XX_INTERNAL_PHY_ID    (1)
#define SMSC95XX_TX_OVERHEAD        (8)
#define SMSC95XX_TX_OVERHEAD_CSUM   (12)
#define SUPPORTED_WAKE          (WAKE_MAGIC)

#define check_warn(ret, fmt, args...) \
    ({ if (ret < 0) netdev_warn(dev->net, fmt, ##args); })

#define check_warn_return(ret, fmt, args...) \
    ({ if (ret < 0) { netdev_warn(dev->net, fmt, ##args); return ret; } })

#define check_warn_goto_done(ret, fmt, args...) \
    ({ if (ret < 0) { netdev_warn(dev->net, fmt, ##args); goto done; } })

struct smsc95xx_priv {
    u32 mac_cr;
    u32 hash_hi;
    u32 hash_lo;
    u32 wolopts;
    spinlock_t mac_cr_lock;
};

struct usb_context {
    struct usb_ctrlrequest req;
    struct usbnet *dev;
};

static bool turbo_mode = true;
module_param(turbo_mode, bool, 0644);
MODULE_PARM_DESC(turbo_mode, "Enable multiple frames per Rx transaction");

static int __must_check smsc95xx_read_reg(struct usbnet *dev, u32 index,
                      u32 *data)
{
    u32 *buf = kmalloc(4, GFP_KERNEL);
    int ret;

    BUG_ON(!dev);

    if (!buf)
        return -ENOMEM;

    ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
        USB_VENDOR_REQUEST_READ_REGISTER,
        USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
        00, index, buf, 4, USB_CTRL_GET_TIMEOUT);

    if (unlikely(ret < 0))
        netdev_warn(dev->net, "Failed to read register index 0x%08x\n", index);

    le32_to_cpus(buf);
    *data = *buf;
    kfree(buf);

    return ret;
}

static int __must_check smsc95xx_write_reg(struct usbnet *dev, u32 index,
                       u32 data)
{
    u32 *buf = kmalloc(4, GFP_KERNEL);
    int ret;

    BUG_ON(!dev);

    if (!buf)
        return -ENOMEM;

    *buf = data;
    cpu_to_le32s(buf);

    ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
        USB_VENDOR_REQUEST_WRITE_REGISTER,
        USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
        00, index, buf, 4, USB_CTRL_SET_TIMEOUT);

    if (unlikely(ret < 0))
        netdev_warn(dev->net, "Failed to write register index 0x%08x\n", index);

    kfree(buf);

    return ret;
}

static int smsc95xx_set_feature(struct usbnet *dev, u32 feature)
{
    if (WARN_ON_ONCE(!dev))
        return -EINVAL;

    cpu_to_le32s(&feature);

    return usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
        USB_REQ_SET_FEATURE, USB_RECIP_DEVICE, feature, 0, NULL, 0,
        USB_CTRL_SET_TIMEOUT);
}

static int smsc95xx_clear_feature(struct usbnet *dev, u32 feature)
{
    if (WARN_ON_ONCE(!dev))
        return -EINVAL;

    cpu_to_le32s(&feature);

    return usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
        USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE, feature, 0, NULL, 0,
        USB_CTRL_SET_TIMEOUT);
}

/* Loop until the read is completed with timeout
 * called with phy_mutex held */
static int __must_check smsc95xx_phy_wait_not_busy(struct usbnet *dev)
{
    unsigned long start_time = jiffies;
    u32 val;
    int ret;

    do {
        ret = smsc95xx_read_reg(dev, MII_ADDR, &val);
        check_warn_return(ret, "Error reading MII_ACCESS");
        if (!(val & MII_BUSY_))
            return 0;
    } while (!time_after(jiffies, start_time + HZ));

    return -EIO;
}

static int smsc95xx_mdio_read(struct net_device *netdev, int phy_id, int idx)
{
    struct usbnet *dev = netdev_priv(netdev);
    u32 val, addr;
    int ret;

    mutex_lock(&dev->phy_mutex);

    /* confirm MII not busy */
    ret = smsc95xx_phy_wait_not_busy(dev);
    check_warn_goto_done(ret, "MII is busy in smsc95xx_mdio_read");

    /* set the address, index & direction (read from PHY) */
    phy_id &= dev->mii.phy_id_mask;
    idx &= dev->mii.reg_num_mask;
    addr = (phy_id << 11) | (idx << 6) | MII_READ_ | MII_BUSY_;
    ret = smsc95xx_write_reg(dev, MII_ADDR, addr);
    check_warn_goto_done(ret, "Error writing MII_ADDR");

    ret = smsc95xx_phy_wait_not_busy(dev);
    check_warn_goto_done(ret, "Timed out reading MII reg %02X", idx);

    ret = smsc95xx_read_reg(dev, MII_DATA, &val);
    check_warn_goto_done(ret, "Error reading MII_DATA");

    ret = (u16)(val & 0xFFFF);

done:
    mutex_unlock(&dev->phy_mutex);
    return ret;
}

static void smsc95xx_mdio_write(struct net_device *netdev, int phy_id, int idx,
                int regval)
{
    struct usbnet *dev = netdev_priv(netdev);
    u32 val, addr;
    int ret;

    mutex_lock(&dev->phy_mutex);

    /* confirm MII not busy */
    ret = smsc95xx_phy_wait_not_busy(dev);
    check_warn_goto_done(ret, "MII is busy in smsc95xx_mdio_write");

    val = regval;
    ret = smsc95xx_write_reg(dev, MII_DATA, val);
    check_warn_goto_done(ret, "Error writing MII_DATA");

    /* set the address, index & direction (write to PHY) */
    phy_id &= dev->mii.phy_id_mask;
    idx &= dev->mii.reg_num_mask;
    addr = (phy_id << 11) | (idx << 6) | MII_WRITE_ | MII_BUSY_;
    ret = smsc95xx_write_reg(dev, MII_ADDR, addr);
    check_warn_goto_done(ret, "Error writing MII_ADDR");

    ret = smsc95xx_phy_wait_not_busy(dev);
    check_warn_goto_done(ret, "Timed out writing MII reg %02X", idx);

done:
    mutex_unlock(&dev->phy_mutex);
}

static int __must_check smsc95xx_wait_eeprom(struct usbnet *dev)
{
    unsigned long start_time = jiffies;
    u32 val;
    int ret;

    do {
        ret = smsc95xx_read_reg(dev, E2P_CMD, &val);
        check_warn_return(ret, "Error reading E2P_CMD");
        if (!(val & E2P_CMD_BUSY_) || (val & E2P_CMD_TIMEOUT_))
            break;
        udelay(40);
    } while (!time_after(jiffies, start_time + HZ));

    if (val & (E2P_CMD_TIMEOUT_ | E2P_CMD_BUSY_)) {
        netdev_warn(dev->net, "EEPROM read operation timeout\n");
        return -EIO;
    }

    return 0;
}

static int __must_check smsc95xx_eeprom_confirm_not_busy(struct usbnet *dev)
{
    unsigned long start_time = jiffies;
    u32 val;
    int ret;

    do {
        ret = smsc95xx_read_reg(dev, E2P_CMD, &val);
        check_warn_return(ret, "Error reading E2P_CMD");

        if (!(val & E2P_CMD_BUSY_))
            return 0;

        udelay(40);
    } while (!time_after(jiffies, start_time + HZ));

    netdev_warn(dev->net, "EEPROM is busy\n");
    return -EIO;
}

static int smsc95xx_read_eeprom(struct usbnet *dev, u32 offset, u32 length,
                u8 *data)
{
    u32 val;
    int i, ret;

    BUG_ON(!dev);
    BUG_ON(!data);

    ret = smsc95xx_eeprom_confirm_not_busy(dev);
    if (ret)
        return ret;

    for (i = 0; i < length; i++) {
        val = E2P_CMD_BUSY_ | E2P_CMD_READ_ | (offset & E2P_CMD_ADDR_);
        ret = smsc95xx_write_reg(dev, E2P_CMD, val);
        check_warn_return(ret, "Error writing E2P_CMD");

        ret = smsc95xx_wait_eeprom(dev);
        if (ret < 0)
            return ret;

        ret = smsc95xx_read_reg(dev, E2P_DATA, &val);
        check_warn_return(ret, "Error reading E2P_DATA");

        data[i] = val & 0xFF;
        offset++;
    }

    return 0;
}

static int smsc95xx_write_eeprom(struct usbnet *dev, u32 offset, u32 length,
                 u8 *data)
{
    u32 val;
    int i, ret;

    BUG_ON(!dev);
    BUG_ON(!data);

    ret = smsc95xx_eeprom_confirm_not_busy(dev);
    if (ret)
        return ret;

    /* Issue write/erase enable command */
    val = E2P_CMD_BUSY_ | E2P_CMD_EWEN_;
    ret = smsc95xx_write_reg(dev, E2P_CMD, val);
    check_warn_return(ret, "Error writing E2P_DATA");

    ret = smsc95xx_wait_eeprom(dev);
    if (ret < 0)
        return ret;

    for (i = 0; i < length; i++) {

        /* Fill data register */
        val = data[i];
        ret = smsc95xx_write_reg(dev, E2P_DATA, val);
        check_warn_return(ret, "Error writing E2P_DATA");

        /* Send "write" command */
        val = E2P_CMD_BUSY_ | E2P_CMD_WRITE_ | (offset & E2P_CMD_ADDR_);
        ret = smsc95xx_write_reg(dev, E2P_CMD, val);
        check_warn_return(ret, "Error writing E2P_CMD");

        ret = smsc95xx_wait_eeprom(dev);
        if (ret < 0)
            return ret;

        offset++;
    }

    return 0;
}

static void smsc95xx_async_cmd_callback(struct urb *urb)
{
    struct usb_context *usb_context = urb->context;
    struct usbnet *dev = usb_context->dev;
    int status = urb->status;

    check_warn(status, "async callback failed with %d\n", status);

    kfree(usb_context);
    usb_free_urb(urb);
}

static int __must_check smsc95xx_write_reg_async(struct usbnet *dev, u16 index,
                         u32 *data)
{
    struct usb_context *usb_context;
    int status;
    struct urb *urb;
    const u16 size = 4;

    urb = usb_alloc_urb(0, GFP_ATOMIC);
    if (!urb) {
        netdev_warn(dev->net, "Error allocating URB\n");
        return -ENOMEM;
    }

    usb_context = kmalloc(sizeof(struct usb_context), GFP_ATOMIC);
    if (usb_context == NULL) {
        netdev_warn(dev->net, "Error allocating control msg\n");
        usb_free_urb(urb);
        return -ENOMEM;
    }

    usb_context->req.bRequestType =
        USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE;
    usb_context->req.bRequest = USB_VENDOR_REQUEST_WRITE_REGISTER;
    usb_context->req.wValue = 00;
    usb_context->req.wIndex = cpu_to_le16(index);
    usb_context->req.wLength = cpu_to_le16(size);

    usb_fill_control_urb(urb, dev->udev, usb_sndctrlpipe(dev->udev, 0),
        (void *)&usb_context->req, data, size,
        smsc95xx_async_cmd_callback,
        (void *)usb_context);

    status = usb_submit_urb(urb, GFP_ATOMIC);
    if (status < 0) {
        netdev_warn(dev->net, "Error submitting control msg, sts=%d\n",
                status);
        kfree(usb_context);
        usb_free_urb(urb);
    }

    return status;
}

/* returns hash bit number for given MAC address
 * example:
 * 01 00 5E 00 00 01 -> returns bit number 31 */
static unsigned int smsc95xx_hash(char addr[ETH_ALEN])
{
    return (ether_crc(ETH_ALEN, addr) >> 26) & 0x3f;
}

static void smsc95xx_set_multicast(struct net_device *netdev)
{
    struct usbnet *dev = netdev_priv(netdev);
    struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
    unsigned long flags;
    int ret;

    pdata->hash_hi = 0;
    pdata->hash_lo = 0;

    spin_lock_irqsave(&pdata->mac_cr_lock, flags);

    if (dev->net->flags & IFF_PROMISC) {
        netif_dbg(dev, drv, dev->net, "promiscuous mode enabled\n");
        pdata->mac_cr |= MAC_CR_PRMS_;
        pdata->mac_cr &= ~(MAC_CR_MCPAS_ | MAC_CR_HPFILT_);
    } else if (dev->net->flags & IFF_ALLMULTI) {
        netif_dbg(dev, drv, dev->net, "receive all multicast enabled\n");
        pdata->mac_cr |= MAC_CR_MCPAS_;
        pdata->mac_cr &= ~(MAC_CR_PRMS_ | MAC_CR_HPFILT_);
    } else if (!netdev_mc_empty(dev->net)) {
        struct netdev_hw_addr *ha;

        pdata->mac_cr |= MAC_CR_HPFILT_;
        pdata->mac_cr &= ~(MAC_CR_PRMS_ | MAC_CR_MCPAS_);

        netdev_for_each_mc_addr(ha, netdev) {
            u32 bitnum = smsc95xx_hash(ha->addr);
            u32 mask = 0x01 << (bitnum & 0x1F);
            if (bitnum & 0x20)
                pdata->hash_hi |= mask;
            else
                pdata->hash_lo |= mask;
        }

        netif_dbg(dev, drv, dev->net, "HASHH=0x%08X, HASHL=0x%08X\n",
                   pdata->hash_hi, pdata->hash_lo);
    } else {
        netif_dbg(dev, drv, dev->net, "receive own packets only\n");
        pdata->mac_cr &=
            ~(MAC_CR_PRMS_ | MAC_CR_MCPAS_ | MAC_CR_HPFILT_);
    }

    spin_unlock_irqrestore(&pdata->mac_cr_lock, flags);

    /* Initiate async writes, as we can't wait for completion here */
    ret = smsc95xx_write_reg_async(dev, HASHH, &pdata->hash_hi);
    check_warn(ret, "failed to initiate async write to HASHH");

    ret = smsc95xx_write_reg_async(dev, HASHL, &pdata->hash_lo);
    check_warn(ret, "failed to initiate async write to HASHL");

    ret = smsc95xx_write_reg_async(dev, MAC_CR, &pdata->mac_cr);
    check_warn(ret, "failed to initiate async write to MAC_CR");
}

static int smsc95xx_phy_update_flowcontrol(struct usbnet *dev, u8 duplex,
                       u16 lcladv, u16 rmtadv)
{
    u32 flow, afc_cfg = 0;

    int ret = smsc95xx_read_reg(dev, AFC_CFG, &afc_cfg);
    check_warn_return(ret, "Error reading AFC_CFG");

    if (duplex == DUPLEX_FULL) {
        u8 cap = mii_resolve_flowctrl_fdx(lcladv, rmtadv);

        if (cap & FLOW_CTRL_RX)
            flow = 0xFFFF0002;
        else
            flow = 0;

        if (cap & FLOW_CTRL_TX)
            afc_cfg |= 0xF;
        else
            afc_cfg &= ~0xF;

        netif_dbg(dev, link, dev->net, "rx pause %s, tx pause %s\n",
                   cap & FLOW_CTRL_RX ? "enabled" : "disabled",
                   cap & FLOW_CTRL_TX ? "enabled" : "disabled");
    } else {
        netif_dbg(dev, link, dev->net, "half duplex\n");
        flow = 0;
        afc_cfg |= 0xF;
    }

    ret = smsc95xx_write_reg(dev, FLOW, flow);
    check_warn_return(ret, "Error writing FLOW");

    ret = smsc95xx_write_reg(dev, AFC_CFG, afc_cfg);
    check_warn_return(ret, "Error writing AFC_CFG");

    return 0;
}

static int smsc95xx_link_reset(struct usbnet *dev)
{
    struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
    struct mii_if_info *mii = &dev->mii;
    struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET };
    unsigned long flags;
    u16 lcladv, rmtadv;
    int ret;

    /* clear interrupt status */
    ret = smsc95xx_mdio_read(dev->net, mii->phy_id, PHY_INT_SRC);
    check_warn_return(ret, "Error reading PHY_INT_SRC");

    ret = smsc95xx_write_reg(dev, INT_STS, INT_STS_CLEAR_ALL_);
    check_warn_return(ret, "Error writing INT_STS");

    mii_check_media(mii, 1, 1);
    mii_ethtool_gset(&dev->mii, &ecmd);
    lcladv = smsc95xx_mdio_read(dev->net, mii->phy_id, MII_ADVERTISE);
    rmtadv = smsc95xx_mdio_read(dev->net, mii->phy_id, MII_LPA);

    netif_dbg(dev, link, dev->net,
          "speed: %u duplex: %d lcladv: %04x rmtadv: %04x\n",
          ethtool_cmd_speed(&ecmd), ecmd.duplex, lcladv, rmtadv);

    spin_lock_irqsave(&pdata->mac_cr_lock, flags);
    if (ecmd.duplex != DUPLEX_FULL) {
        pdata->mac_cr &= ~MAC_CR_FDPX_;
        pdata->mac_cr |= MAC_CR_RCVOWN_;
    } else {
        pdata->mac_cr &= ~MAC_CR_RCVOWN_;
        pdata->mac_cr |= MAC_CR_FDPX_;
    }
    spin_unlock_irqrestore(&pdata->mac_cr_lock, flags);

    ret = smsc95xx_write_reg(dev, MAC_CR, pdata->mac_cr);
    check_warn_return(ret, "Error writing MAC_CR");

    ret = smsc95xx_phy_update_flowcontrol(dev, ecmd.duplex, lcladv, rmtadv);
    check_warn_return(ret, "Error updating PHY flow control");

    return 0;
}

static void smsc95xx_status(struct usbnet *dev, struct urb *urb)
{
    u32 intdata;

    if (urb->actual_length != 4) {
        netdev_warn(dev->net, "unexpected urb length %d\n",
                urb->actual_length);
        return;
    }

    memcpy(&intdata, urb->transfer_buffer, 4);
    le32_to_cpus(&intdata);

    netif_dbg(dev, link, dev->net, "intdata: 0x%08X\n", intdata);

    if (intdata & INT_ENP_PHY_INT_)
        usbnet_defer_kevent(dev, EVENT_LINK_RESET);
    else
        netdev_warn(dev->net, "unexpected interrupt, intdata=0x%08X\n",
                intdata);
}

/* Enable or disable Tx & Rx checksum offload engines */
static int smsc95xx_set_features(struct net_device *netdev,
    netdev_features_t features)
{
    struct usbnet *dev = netdev_priv(netdev);
    u32 read_buf;
    int ret;

    ret = smsc95xx_read_reg(dev, COE_CR, &read_buf);
    check_warn_return(ret, "Failed to read COE_CR: %d\n", ret);

    if (features & NETIF_F_HW_CSUM)
        read_buf |= Tx_COE_EN_;
    else
        read_buf &= ~Tx_COE_EN_;

    if (features & NETIF_F_RXCSUM)
        read_buf |= Rx_COE_EN_;
    else
        read_buf &= ~Rx_COE_EN_;

    ret = smsc95xx_write_reg(dev, COE_CR, read_buf);
    check_warn_return(ret, "Failed to write COE_CR: %d\n", ret);

    netif_dbg(dev, hw, dev->net, "COE_CR = 0x%08x\n", read_buf);
    return 0;
}

static int smsc95xx_ethtool_get_eeprom_len(struct net_device *net)
{
    return MAX_EEPROM_SIZE;
}

static int smsc95xx_ethtool_get_eeprom(struct net_device *netdev,
                       struct ethtool_eeprom *ee, u8 *data)
{
    struct usbnet *dev = netdev_priv(netdev);

    ee->magic = LAN95XX_EEPROM_MAGIC;

    return smsc95xx_read_eeprom(dev, ee->offset, ee->len, data);
}

static int smsc95xx_ethtool_set_eeprom(struct net_device *netdev,
                       struct ethtool_eeprom *ee, u8 *data)
{
    struct usbnet *dev = netdev_priv(netdev);

    if (ee->magic != LAN95XX_EEPROM_MAGIC) {
        netdev_warn(dev->net, "EEPROM: magic value mismatch, magic = 0x%x\n",
                ee->magic);
        return -EINVAL;
    }

    return smsc95xx_write_eeprom(dev, ee->offset, ee->len, data);
}

static int smsc95xx_ethtool_getregslen(struct net_device *netdev)
{
    /* all smsc95xx registers */
    return COE_CR - ID_REV + 1;
}

static void
smsc95xx_ethtool_getregs(struct net_device *netdev, struct ethtool_regs *regs,
             void *buf)
{
    struct usbnet *dev = netdev_priv(netdev);
    unsigned int i, j;
    int retval;
    u32 *data = buf;

    retval = smsc95xx_read_reg(dev, ID_REV, &regs->version);
    if (retval < 0) {
        netdev_warn(netdev, "REGS: cannot read ID_REV\n");
        return;
    }

    for (i = ID_REV, j = 0; i <= COE_CR; i += (sizeof(u32)), j++) {
        retval = smsc95xx_read_reg(dev, i, &data[j]);
        if (retval < 0) {
            netdev_warn(netdev, "REGS: cannot read reg[%x]\n", i);
            return;
        }
    }
}

static void smsc95xx_ethtool_get_wol(struct net_device *net,
                     struct ethtool_wolinfo *wolinfo)
{
    struct usbnet *dev = netdev_priv(net);
    struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);

    wolinfo->supported = SUPPORTED_WAKE;
    wolinfo->wolopts = pdata->wolopts;
}

static int smsc95xx_ethtool_set_wol(struct net_device *net,
                    struct ethtool_wolinfo *wolinfo)
{
    struct usbnet *dev = netdev_priv(net);
    struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);

    pdata->wolopts = wolinfo->wolopts & SUPPORTED_WAKE;
    return 0;
}

static const struct ethtool_ops smsc95xx_ethtool_ops = {
    .get_link   = usbnet_get_link,
    .nway_reset = usbnet_nway_reset,
    .get_drvinfo    = usbnet_get_drvinfo,
    .get_msglevel   = usbnet_get_msglevel,
    .set_msglevel   = usbnet_set_msglevel,
    .get_settings   = usbnet_get_settings,
    .set_settings   = usbnet_set_settings,
    .get_eeprom_len = smsc95xx_ethtool_get_eeprom_len,
    .get_eeprom = smsc95xx_ethtool_get_eeprom,
    .set_eeprom = smsc95xx_ethtool_set_eeprom,
    .get_regs_len   = smsc95xx_ethtool_getregslen,
    .get_regs   = smsc95xx_ethtool_getregs,
    .get_wol    = smsc95xx_ethtool_get_wol,
    .set_wol    = smsc95xx_ethtool_set_wol,
};

static int smsc95xx_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
{
    struct usbnet *dev = netdev_priv(netdev);

    if (!netif_running(netdev))
        return -EINVAL;

    return generic_mii_ioctl(&dev->mii, if_mii(rq), cmd, NULL);
}

static void smsc95xx_init_mac_address(struct usbnet *dev)
{
    /* try reading mac address from EEPROM */
    if (smsc95xx_read_eeprom(dev, EEPROM_MAC_OFFSET, ETH_ALEN,
            dev->net->dev_addr) == 0) {
        if (is_valid_ether_addr(dev->net->dev_addr)) {
            /* eeprom values are valid so use them */
            netif_dbg(dev, ifup, dev->net, "MAC address read from EEPROM\n");
            return;
        }
    }

    /* no eeprom, or eeprom values are invalid. generate random MAC */
    eth_hw_addr_random(dev->net);
    netif_dbg(dev, ifup, dev->net, "MAC address set to eth_random_addr\n");
}

static int smsc95xx_set_mac_address(struct usbnet *dev)
{
    u32 addr_lo = dev->net->dev_addr[0] | dev->net->dev_addr[1] << 8 |
        dev->net->dev_addr[2] << 16 | dev->net->dev_addr[3] << 24;
    u32 addr_hi = dev->net->dev_addr[4] | dev->net->dev_addr[5] << 8;
    int ret;

    ret = smsc95xx_write_reg(dev, ADDRL, addr_lo);
    check_warn_return(ret, "Failed to write ADDRL: %d\n", ret);

    ret = smsc95xx_write_reg(dev, ADDRH, addr_hi);
    check_warn_return(ret, "Failed to write ADDRH: %d\n", ret);

    return 0;
}

/* starts the TX path */
static int smsc95xx_start_tx_path(struct usbnet *dev)
{
    struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
    unsigned long flags;
    int ret;

    /* Enable Tx at MAC */
    spin_lock_irqsave(&pdata->mac_cr_lock, flags);
    pdata->mac_cr |= MAC_CR_TXEN_;
    spin_unlock_irqrestore(&pdata->mac_cr_lock, flags);

    ret = smsc95xx_write_reg(dev, MAC_CR, pdata->mac_cr);
    check_warn_return(ret, "Failed to write MAC_CR: %d\n", ret);

    /* Enable Tx at SCSRs */
    ret = smsc95xx_write_reg(dev, TX_CFG, TX_CFG_ON_);
    check_warn_return(ret, "Failed to write TX_CFG: %d\n", ret);

    return 0;
}

/* Starts the Receive path */
static int smsc95xx_start_rx_path(struct usbnet *dev)
{
    struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
    unsigned long flags;
    int ret;

    spin_lock_irqsave(&pdata->mac_cr_lock, flags);
    pdata->mac_cr |= MAC_CR_RXEN_;
    spin_unlock_irqrestore(&pdata->mac_cr_lock, flags);

    ret = smsc95xx_write_reg(dev, MAC_CR, pdata->mac_cr);
    check_warn_return(ret, "Failed to write MAC_CR: %d\n", ret);

    return 0;
}

static int smsc95xx_phy_initialize(struct usbnet *dev)
{
    int bmcr, ret, timeout = 0;

    /* Initialize MII structure */
    dev->mii.dev = dev->net;
    dev->mii.mdio_read = smsc95xx_mdio_read;
    dev->mii.mdio_write = smsc95xx_mdio_write;
    dev->mii.phy_id_mask = 0x1f;
    dev->mii.reg_num_mask = 0x1f;
    dev->mii.phy_id = SMSC95XX_INTERNAL_PHY_ID;

    /* reset phy and wait for reset to complete */
    smsc95xx_mdio_write(dev->net, dev->mii.phy_id, MII_BMCR, BMCR_RESET);

    do {
        msleep(10);
        bmcr = smsc95xx_mdio_read(dev->net, dev->mii.phy_id, MII_BMCR);
        timeout++;
    } while ((bmcr & BMCR_RESET) && (timeout < 100));

    if (timeout >= 100) {
        netdev_warn(dev->net, "timeout on PHY Reset");
        return -EIO;
    }

    smsc95xx_mdio_write(dev->net, dev->mii.phy_id, MII_ADVERTISE,
        ADVERTISE_ALL | ADVERTISE_CSMA | ADVERTISE_PAUSE_CAP |
        ADVERTISE_PAUSE_ASYM);

    /* read to clear */
    ret = smsc95xx_mdio_read(dev->net, dev->mii.phy_id, PHY_INT_SRC);
    check_warn_return(ret, "Failed to read PHY_INT_SRC during init");

    smsc95xx_mdio_write(dev->net, dev->mii.phy_id, PHY_INT_MASK,
        PHY_INT_MASK_DEFAULT_);
    mii_nway_restart(&dev->mii);

    netif_dbg(dev, ifup, dev->net, "phy initialised successfully\n");
    return 0;
}

static int smsc95xx_reset(struct usbnet *dev)
{
    struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
    u32 read_buf, write_buf, burst_cap;
    int ret = 0, timeout;

    netif_dbg(dev, ifup, dev->net, "entering smsc95xx_reset\n");

    ret = smsc95xx_write_reg(dev, HW_CFG, HW_CFG_LRST_);
    check_warn_return(ret, "Failed to write HW_CFG_LRST_ bit in HW_CFG\n");

    timeout = 0;
    do {
        msleep(10);
        ret = smsc95xx_read_reg(dev, HW_CFG, &read_buf);
        check_warn_return(ret, "Failed to read HW_CFG: %d\n", ret);
        timeout++;
    } while ((read_buf & HW_CFG_LRST_) && (timeout < 100));

    if (timeout >= 100) {
        netdev_warn(dev->net, "timeout waiting for completion of Lite Reset\n");
        return ret;
    }

    ret = smsc95xx_write_reg(dev, PM_CTRL, PM_CTL_PHY_RST_);
    check_warn_return(ret, "Failed to write PM_CTRL: %d\n", ret);

    timeout = 0;
    do {
        msleep(10);
        ret = smsc95xx_read_reg(dev, PM_CTRL, &read_buf);
        check_warn_return(ret, "Failed to read PM_CTRL: %d\n", ret);
        timeout++;
    } while ((read_buf & PM_CTL_PHY_RST_) && (timeout < 100));

    if (timeout >= 100) {
        netdev_warn(dev->net, "timeout waiting for PHY Reset\n");
        return ret;
    }

    ret = smsc95xx_set_mac_address(dev);
    if (ret < 0)
        return ret;

    netif_dbg(dev, ifup, dev->net,
          "MAC Address: %pM\n", dev->net->dev_addr);

    ret = smsc95xx_read_reg(dev, HW_CFG, &read_buf);
    check_warn_return(ret, "Failed to read HW_CFG: %d\n", ret);

    netif_dbg(dev, ifup, dev->net,
          "Read Value from HW_CFG : 0x%08x\n", read_buf);

    read_buf |= HW_CFG_BIR_;

    ret = smsc95xx_write_reg(dev, HW_CFG, read_buf);
    check_warn_return(ret, "Failed to write HW_CFG_BIR_ bit in HW_CFG\n");

    ret = smsc95xx_read_reg(dev, HW_CFG, &read_buf);
    check_warn_return(ret, "Failed to read HW_CFG: %d\n", ret);
    netif_dbg(dev, ifup, dev->net,
          "Read Value from HW_CFG after writing HW_CFG_BIR_: 0x%08x\n",
          read_buf);

    if (!turbo_mode) {
        burst_cap = 0;
        dev->rx_urb_size = MAX_SINGLE_PACKET_SIZE;
    } else if (dev->udev->speed == USB_SPEED_HIGH) {
        burst_cap = DEFAULT_HS_BURST_CAP_SIZE / HS_USB_PKT_SIZE;
        dev->rx_urb_size = DEFAULT_HS_BURST_CAP_SIZE;
    } else {
        burst_cap = DEFAULT_FS_BURST_CAP_SIZE / FS_USB_PKT_SIZE;
        dev->rx_urb_size = DEFAULT_FS_BURST_CAP_SIZE;
    }

    netif_dbg(dev, ifup, dev->net,
          "rx_urb_size=%ld\n", (ulong)dev->rx_urb_size);

    ret = smsc95xx_write_reg(dev, BURST_CAP, burst_cap);
    check_warn_return(ret, "Failed to write BURST_CAP: %d\n", ret);

    ret = smsc95xx_read_reg(dev, BURST_CAP, &read_buf);
    check_warn_return(ret, "Failed to read BURST_CAP: %d\n", ret);

    netif_dbg(dev, ifup, dev->net,
          "Read Value from BURST_CAP after writing: 0x%08x\n",
          read_buf);

    ret = smsc95xx_write_reg(dev, BULK_IN_DLY, DEFAULT_BULK_IN_DELAY);
    check_warn_return(ret, "Failed to write BULK_IN_DLY: %d\n", ret);

    ret = smsc95xx_read_reg(dev, BULK_IN_DLY, &read_buf);
    check_warn_return(ret, "Failed to read BULK_IN_DLY: %d\n", ret);

    netif_dbg(dev, ifup, dev->net,
          "Read Value from BULK_IN_DLY after writing: 0x%08x\n",
          read_buf);

    ret = smsc95xx_read_reg(dev, HW_CFG, &read_buf);
    check_warn_return(ret, "Failed to read HW_CFG: %d\n", ret);

    netif_dbg(dev, ifup, dev->net,
          "Read Value from HW_CFG: 0x%08x\n", read_buf);

    if (turbo_mode)
        read_buf |= (HW_CFG_MEF_ | HW_CFG_BCE_);

    read_buf &= ~HW_CFG_RXDOFF_;

    /* set Rx data offset=2, Make IP header aligns on word boundary. */
    read_buf |= NET_IP_ALIGN << 9;

    ret = smsc95xx_write_reg(dev, HW_CFG, read_buf);
    check_warn_return(ret, "Failed to write HW_CFG: %d\n", ret);

    ret = smsc95xx_read_reg(dev, HW_CFG, &read_buf);
    check_warn_return(ret, "Failed to read HW_CFG: %d\n", ret);

    netif_dbg(dev, ifup, dev->net,
          "Read Value from HW_CFG after writing: 0x%08x\n", read_buf);

    ret = smsc95xx_write_reg(dev, INT_STS, INT_STS_CLEAR_ALL_);
    check_warn_return(ret, "Failed to write INT_STS: %d\n", ret);

    ret = smsc95xx_read_reg(dev, ID_REV, &read_buf);
    check_warn_return(ret, "Failed to read ID_REV: %d\n", ret);
    netif_dbg(dev, ifup, dev->net, "ID_REV = 0x%08x\n", read_buf);

    /* Configure GPIO pins as LED outputs */
    write_buf = LED_GPIO_CFG_SPD_LED | LED_GPIO_CFG_LNK_LED |
        LED_GPIO_CFG_FDX_LED;
    ret = smsc95xx_write_reg(dev, LED_GPIO_CFG, write_buf);
    check_warn_return(ret, "Failed to write LED_GPIO_CFG: %d\n", ret);

    /* Init Tx */
    ret = smsc95xx_write_reg(dev, FLOW, 0);
    check_warn_return(ret, "Failed to write FLOW: %d\n", ret);

    ret = smsc95xx_write_reg(dev, AFC_CFG, AFC_CFG_DEFAULT);
    check_warn_return(ret, "Failed to write AFC_CFG: %d\n", ret);

    /* Don't need mac_cr_lock during initialisation */
    ret = smsc95xx_read_reg(dev, MAC_CR, &pdata->mac_cr);
    check_warn_return(ret, "Failed to read MAC_CR: %d\n", ret);

    /* Init Rx */
    /* Set Vlan */
    ret = smsc95xx_write_reg(dev, VLAN1, (u32)ETH_P_8021Q);
    check_warn_return(ret, "Failed to write VLAN1: %d\n", ret);

    /* Enable or disable checksum offload engines */
    ret = smsc95xx_set_features(dev->net, dev->net->features);
    check_warn_return(ret, "Failed to set checksum offload features");

    smsc95xx_set_multicast(dev->net);

    ret = smsc95xx_phy_initialize(dev);
    check_warn_return(ret, "Failed to init PHY");

    ret = smsc95xx_read_reg(dev, INT_EP_CTL, &read_buf);
    check_warn_return(ret, "Failed to read INT_EP_CTL: %d\n", ret);

    /* enable PHY interrupts */
    read_buf |= INT_EP_CTL_PHY_INT_;

    ret = smsc95xx_write_reg(dev, INT_EP_CTL, read_buf);
    check_warn_return(ret, "Failed to write INT_EP_CTL: %d\n", ret);

    ret = smsc95xx_start_tx_path(dev);
    check_warn_return(ret, "Failed to start TX path");

    ret = smsc95xx_start_rx_path(dev);
    check_warn_return(ret, "Failed to start RX path");

    netif_dbg(dev, ifup, dev->net, "smsc95xx_reset, return 0\n");
    return 0;
}

static const struct net_device_ops smsc95xx_netdev_ops = {
    .ndo_open       = usbnet_open,
    .ndo_stop       = usbnet_stop,
    .ndo_start_xmit     = usbnet_start_xmit,
    .ndo_tx_timeout     = usbnet_tx_timeout,
    .ndo_change_mtu     = usbnet_change_mtu,
    .ndo_set_mac_address    = eth_mac_addr,
    .ndo_validate_addr  = eth_validate_addr,
    .ndo_do_ioctl       = smsc95xx_ioctl,
    .ndo_set_rx_mode    = smsc95xx_set_multicast,
    .ndo_set_features   = smsc95xx_set_features,
};

static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
{
    struct smsc95xx_priv *pdata = NULL;
    int ret;

    printk(KERN_INFO SMSC_CHIPNAME " v" SMSC_DRIVER_VERSION "\n");

    ret = usbnet_get_endpoints(dev, intf);
    check_warn_return(ret, "usbnet_get_endpoints failed: %d\n", ret);

    dev->data[0] = (unsigned long)kzalloc(sizeof(struct smsc95xx_priv),
        GFP_KERNEL);

    pdata = (struct smsc95xx_priv *)(dev->data[0]);
    if (!pdata) {
        netdev_warn(dev->net, "Unable to allocate struct smsc95xx_priv\n");
        return -ENOMEM;
    }

    spin_lock_init(&pdata->mac_cr_lock);

    if (DEFAULT_TX_CSUM_ENABLE)
        dev->net->features |= NETIF_F_HW_CSUM;
    if (DEFAULT_RX_CSUM_ENABLE)
        dev->net->features |= NETIF_F_RXCSUM;

    dev->net->hw_features = NETIF_F_HW_CSUM | NETIF_F_RXCSUM;

    smsc95xx_init_mac_address(dev);

    /* Init all registers */
    ret = smsc95xx_reset(dev);

    dev->net->netdev_ops = &smsc95xx_netdev_ops;
    dev->net->ethtool_ops = &smsc95xx_ethtool_ops;
    dev->net->flags |= IFF_MULTICAST;
    dev->net->hard_header_len += SMSC95XX_TX_OVERHEAD_CSUM;
    dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;
    return 0;
}

static void smsc95xx_unbind(struct usbnet *dev, struct usb_interface *intf)
{
    struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
    if (pdata) {
        netif_dbg(dev, ifdown, dev->net, "free pdata\n");
        kfree(pdata);
        pdata = NULL;
        dev->data[0] = 0;
    }
}

static int smsc95xx_suspend(struct usb_interface *intf, pm_message_t message)
{
    struct usbnet *dev = usb_get_intfdata(intf);
    struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
    int ret;
    u32 val;

    ret = usbnet_suspend(intf, message);
    check_warn_return(ret, "usbnet_suspend error");

    /* if no wol options set, enter lowest power SUSPEND2 mode */
    if (!(pdata->wolopts & SUPPORTED_WAKE)) {
        netdev_info(dev->net, "entering SUSPEND2 mode");

        /* disable energy detect (link up) & wake up events */
        ret = smsc95xx_read_reg(dev, WUCSR, &val);
        check_warn_return(ret, "Error reading WUCSR");

        val &= ~(WUCSR_MPEN_ | WUCSR_WAKE_EN_);

        ret = smsc95xx_write_reg(dev, WUCSR, val);
        check_warn_return(ret, "Error writing WUCSR");

        ret = smsc95xx_read_reg(dev, PM_CTRL, &val);
        check_warn_return(ret, "Error reading PM_CTRL");

        val &= ~(PM_CTL_ED_EN_ | PM_CTL_WOL_EN_);

        ret = smsc95xx_write_reg(dev, PM_CTRL, val);
        check_warn_return(ret, "Error writing PM_CTRL");

        /* enter suspend2 mode */
        ret = smsc95xx_read_reg(dev, PM_CTRL, &val);
        check_warn_return(ret, "Error reading PM_CTRL");

        val &= ~(PM_CTL_SUS_MODE_ | PM_CTL_WUPS_ | PM_CTL_PHY_RST_);
        val |= PM_CTL_SUS_MODE_2;

        ret = smsc95xx_write_reg(dev, PM_CTRL, val);
        check_warn_return(ret, "Error writing PM_CTRL");

        return 0;
    }

    if (pdata->wolopts & WAKE_MAGIC) {
        /* clear any pending magic packet status */
        ret = smsc95xx_read_reg(dev, WUCSR, &val);
        check_warn_return(ret, "Error reading WUCSR");

        val |= WUCSR_MPR_;

        ret = smsc95xx_write_reg(dev, WUCSR, val);
        check_warn_return(ret, "Error writing WUCSR");
    }

    /* enable/disable magic packup wake */
    ret = smsc95xx_read_reg(dev, WUCSR, &val);
    check_warn_return(ret, "Error reading WUCSR");

    if (pdata->wolopts & WAKE_MAGIC) {
        netdev_info(dev->net, "enabling magic packet wakeup");
        val |= WUCSR_MPEN_;
    } else {
        netdev_info(dev->net, "disabling magic packet wakeup");
        val &= ~WUCSR_MPEN_;
    }

    ret = smsc95xx_write_reg(dev, WUCSR, val);
    check_warn_return(ret, "Error writing WUCSR");

    /* enable wol wakeup source */
    ret = smsc95xx_read_reg(dev, PM_CTRL, &val);
    check_warn_return(ret, "Error reading PM_CTRL");

    val |= PM_CTL_WOL_EN_;

    ret = smsc95xx_write_reg(dev, PM_CTRL, val);
    check_warn_return(ret, "Error writing PM_CTRL");

    /* enable receiver */
    smsc95xx_start_rx_path(dev);

    /* some wol options are enabled, so enter SUSPEND0 */
    netdev_info(dev->net, "entering SUSPEND0 mode");

    ret = smsc95xx_read_reg(dev, PM_CTRL, &val);
    check_warn_return(ret, "Error reading PM_CTRL");

    val &= (~(PM_CTL_SUS_MODE_ | PM_CTL_WUPS_ | PM_CTL_PHY_RST_));
    val |= PM_CTL_SUS_MODE_0;

    ret = smsc95xx_write_reg(dev, PM_CTRL, val);
    check_warn_return(ret, "Error writing PM_CTRL");

    /* clear wol status */
    val &= ~PM_CTL_WUPS_;
    val |= PM_CTL_WUPS_WOL_;
    ret = smsc95xx_write_reg(dev, PM_CTRL, val);
    check_warn_return(ret, "Error writing PM_CTRL");

    /* read back PM_CTRL */
    ret = smsc95xx_read_reg(dev, PM_CTRL, &val);
    check_warn_return(ret, "Error reading PM_CTRL");

    smsc95xx_set_feature(dev, USB_DEVICE_REMOTE_WAKEUP);

    return 0;
}

static int smsc95xx_resume(struct usb_interface *intf)
{
    struct usbnet *dev = usb_get_intfdata(intf);
    struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
    int ret;
    u32 val;

    BUG_ON(!dev);

    if (pdata->wolopts & WAKE_MAGIC) {
        smsc95xx_clear_feature(dev, USB_DEVICE_REMOTE_WAKEUP);

        /* Disable magic packup wake */
        ret = smsc95xx_read_reg(dev, WUCSR, &val);
        check_warn_return(ret, "Error reading WUCSR");

        val &= ~WUCSR_MPEN_;

        ret = smsc95xx_write_reg(dev, WUCSR, val);
        check_warn_return(ret, "Error writing WUCSR");

        /* clear wake-up status */
        ret = smsc95xx_read_reg(dev, PM_CTRL, &val);
        check_warn_return(ret, "Error reading PM_CTRL");

        val &= ~PM_CTL_WOL_EN_;
        val |= PM_CTL_WUPS_;

        ret = smsc95xx_write_reg(dev, PM_CTRL, val);
        check_warn_return(ret, "Error writing PM_CTRL");
    }

    return usbnet_resume(intf);
    check_warn_return(ret, "usbnet_resume error");

    return 0;
}

static void smsc95xx_rx_csum_offload(struct sk_buff *skb)
{
    skb->csum = *(u16 *)(skb_tail_pointer(skb) - 2);
    skb->ip_summed = CHECKSUM_COMPLETE;
    skb_trim(skb, skb->len - 2);
}

static int smsc95xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
    while (skb->len > 0) {
        u32 header, align_count;
        struct sk_buff *ax_skb;
        unsigned char *packet;
        u16 size;

        memcpy(&header, skb->data, sizeof(header));
        le32_to_cpus(&header);
        skb_pull(skb, 4 + NET_IP_ALIGN);
        packet = skb->data;

        /* get the packet length */
        size = (u16)((header & RX_STS_FL_) >> 16);
        align_count = (4 - ((size + NET_IP_ALIGN) % 4)) % 4;

        if (unlikely(header & RX_STS_ES_)) {
            netif_dbg(dev, rx_err, dev->net,
                  "Error header=0x%08x\n", header);
            dev->net->stats.rx_errors++;
            dev->net->stats.rx_dropped++;

            if (header & RX_STS_CRC_) {
                dev->net->stats.rx_crc_errors++;
            } else {
                if (header & (RX_STS_TL_ | RX_STS_RF_))
                    dev->net->stats.rx_frame_errors++;

                if ((header & RX_STS_LE_) &&
                    (!(header & RX_STS_FT_)))
                    dev->net->stats.rx_length_errors++;
            }
        } else {
            /* ETH_FRAME_LEN + 4(CRC) + 2(COE) + 4(Vlan) */
            if (unlikely(size > (ETH_FRAME_LEN + 12))) {
                netif_dbg(dev, rx_err, dev->net,
                      "size err header=0x%08x\n", header);
                return 0;
            }

            /* last frame in this batch */
            if (skb->len == size) {
                if (dev->net->features & NETIF_F_RXCSUM)
                    smsc95xx_rx_csum_offload(skb);
                skb_trim(skb, skb->len - 4); /* remove fcs */
                skb->truesize = size + sizeof(struct sk_buff);

                return 1;
            }

            ax_skb = skb_clone(skb, GFP_ATOMIC);
            if (unlikely(!ax_skb)) {
                netdev_warn(dev->net, "Error allocating skb\n");
                return 0;
            }

            ax_skb->len = size;
            ax_skb->data = packet;
            skb_set_tail_pointer(ax_skb, size);

            if (dev->net->features & NETIF_F_RXCSUM)
                smsc95xx_rx_csum_offload(ax_skb);
            skb_trim(ax_skb, ax_skb->len - 4); /* remove fcs */
            ax_skb->truesize = size + sizeof(struct sk_buff);

            usbnet_skb_return(dev, ax_skb);
        }

        skb_pull(skb, size);

        /* padding bytes before the next frame starts */
        if (skb->len)
            skb_pull(skb, align_count);
    }

    if (unlikely(skb->len < 0)) {
        netdev_warn(dev->net, "invalid rx length<0 %d\n", skb->len);
        return 0;
    }

    return 1;
}

static u32 smsc95xx_calc_csum_preamble(struct sk_buff *skb)
{
    u16 low_16 = (u16)skb_checksum_start_offset(skb);
    u16 high_16 = low_16 + skb->csum_offset;
    return (high_16 << 16) | low_16;
}

static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev,
                     struct sk_buff *skb, gfp_t flags)
{
    bool csum = skb->ip_summed == CHECKSUM_PARTIAL;
    int overhead = csum ? SMSC95XX_TX_OVERHEAD_CSUM : SMSC95XX_TX_OVERHEAD;
    u32 tx_cmd_a, tx_cmd_b;

    /* We do not advertise SG, so skbs should be already linearized */
    BUG_ON(skb_shinfo(skb)->nr_frags);

    if (skb_headroom(skb) < overhead) {
        struct sk_buff *skb2 = skb_copy_expand(skb,
            overhead, 0, flags);
        dev_kfree_skb_any(skb);
        skb = skb2;
        if (!skb)
            return NULL;
    }

    if (csum) {
        if (skb->len <= 45) {
            /* workaround - hardware tx checksum does not work
             * properly with extremely small packets */
            long csstart = skb_checksum_start_offset(skb);
            __wsum calc = csum_partial(skb->data + csstart,
                skb->len - csstart, 0);
            *((__sum16 *)(skb->data + csstart
                + skb->csum_offset)) = csum_fold(calc);

            csum = false;
        } else {
            u32 csum_preamble = smsc95xx_calc_csum_preamble(skb);
            skb_push(skb, 4);
            cpu_to_le32s(&csum_preamble);
            memcpy(skb->data, &csum_preamble, 4);
        }
    }

    skb_push(skb, 4);
    tx_cmd_b = (u32)(skb->len - 4);
    if (csum)
        tx_cmd_b |= TX_CMD_B_CSUM_ENABLE;
    cpu_to_le32s(&tx_cmd_b);
    memcpy(skb->data, &tx_cmd_b, 4);

    skb_push(skb, 4);
    tx_cmd_a = (u32)(skb->len - 8) | TX_CMD_A_FIRST_SEG_ |
        TX_CMD_A_LAST_SEG_;
    cpu_to_le32s(&tx_cmd_a);
    memcpy(skb->data, &tx_cmd_a, 4);

    return skb;
}

static const struct driver_info smsc95xx_info = {
    .description    = "smsc95xx USB 2.0 Ethernet",
    .bind       = smsc95xx_bind,
    .unbind     = smsc95xx_unbind,
    .link_reset = smsc95xx_link_reset,
    .reset      = smsc95xx_reset,
    .rx_fixup   = smsc95xx_rx_fixup,
    .tx_fixup   = smsc95xx_tx_fixup,
    .status     = smsc95xx_status,
    .flags      = FLAG_ETHER | FLAG_SEND_ZLP | FLAG_LINK_INTR,
};

static const struct usb_device_id products[] = {
    {
        /* SMSC9500 USB Ethernet Device */
        USB_DEVICE(0x0424, 0x9500),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9505 USB Ethernet Device */
        USB_DEVICE(0x0424, 0x9505),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9500A USB Ethernet Device */
        USB_DEVICE(0x0424, 0x9E00),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9505A USB Ethernet Device */
        USB_DEVICE(0x0424, 0x9E01),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9512/9514 USB Hub & Ethernet Device */
        USB_DEVICE(0x0424, 0xec00),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9500 USB Ethernet Device (SAL10) */
        USB_DEVICE(0x0424, 0x9900),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9505 USB Ethernet Device (SAL10) */
        USB_DEVICE(0x0424, 0x9901),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9500A USB Ethernet Device (SAL10) */
        USB_DEVICE(0x0424, 0x9902),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9505A USB Ethernet Device (SAL10) */
        USB_DEVICE(0x0424, 0x9903),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9512/9514 USB Hub & Ethernet Device (SAL10) */
        USB_DEVICE(0x0424, 0x9904),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9500A USB Ethernet Device (HAL) */
        USB_DEVICE(0x0424, 0x9905),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9505A USB Ethernet Device (HAL) */
        USB_DEVICE(0x0424, 0x9906),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9500 USB Ethernet Device (Alternate ID) */
        USB_DEVICE(0x0424, 0x9907),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9500A USB Ethernet Device (Alternate ID) */
        USB_DEVICE(0x0424, 0x9908),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC9512/9514 USB Hub & Ethernet Device (Alternate ID) */
        USB_DEVICE(0x0424, 0x9909),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC LAN9530 USB Ethernet Device */
        USB_DEVICE(0x0424, 0x9530),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC LAN9730 USB Ethernet Device */
        USB_DEVICE(0x0424, 0x9730),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    {
        /* SMSC LAN89530 USB Ethernet Device */
        USB_DEVICE(0x0424, 0x9E08),
        .driver_info = (unsigned long) &smsc95xx_info,
    },
    { },        /* END */
};
MODULE_DEVICE_TABLE(usb, products);

static struct usb_driver smsc95xx_driver = {
    .name       = "smsc95xx",
    .id_table   = products,
    .probe      = usbnet_probe,
    .suspend    = smsc95xx_suspend,
    .resume     = smsc95xx_resume,
    .reset_resume   = smsc95xx_resume,
    .disconnect = usbnet_disconnect,
    .disable_hub_initiated_lpm = 1,
};

module_usb_driver(smsc95xx_driver);

MODULE_AUTHOR("Nancy Lin");
MODULE_AUTHOR("Steve Glendinning <[email protected]>");
MODULE_DESCRIPTION("SMSC95XX USB 2.0 Ethernet Devices");
MODULE_LICENSE("GPL");