// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Copyright (c) 2002 Petko Manolov (petkan@users.sourceforge.net)
 */

#include <linux/signal.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/usb.h>
#include <linux/uaccess.h>

#define DRIVER_AUTHOR "Petko Manolov <petkan@users.sourceforge.net>"
#define DRIVER_DESC "rtl8150 based usb-ethernet driver"

#define IDR                     0x0120
#define MAR                     0x0126
#define CR                      0x012e
#define TCR                     0x012f
#define RCR                     0x0130
#define TSR                     0x0132
#define RSR                     0x0133
#define CON0                    0x0135
#define CON1                    0x0136
#define MSR                     0x0137
#define PHYADD                  0x0138
#define PHYDAT                  0x0139
#define PHYCNT                  0x013b
#define GPPC                    0x013d
#define BMCR                    0x0140
#define BMSR                    0x0142
#define ANAR                    0x0144
#define ANLP                    0x0146
#define AER                     0x0148
#define CSCR                    0x014C  /* This one has the link status */
#define CSCR_LINK_STATUS        (1 << 3)

#define IDR_EEPROM              0x1202

#define PHY_READ                0
#define PHY_WRITE               0x20
#define PHY_GO                  0x40

#define MII_TIMEOUT             10
#define INTBUFSIZE              8

#define RTL8150_REQT_READ       0xc0
#define RTL8150_REQT_WRITE      0x40
#define RTL8150_REQ_GET_REGS    0x05
#define RTL8150_REQ_SET_REGS    0x05


/* Transmit status register errors */
#define TSR_ECOL                (1<<5)
#define TSR_LCOL                (1<<4)
#define TSR_LOSS_CRS            (1<<3)
#define TSR_JBR                 (1<<2)
#define TSR_ERRORS              (TSR_ECOL | TSR_LCOL | TSR_LOSS_CRS | TSR_JBR)
/* Receive status register errors */
#define RSR_CRC                 (1<<2)
#define RSR_FAE                 (1<<1)
#define RSR_ERRORS              (RSR_CRC | RSR_FAE)

/* Media status register definitions */
#define MSR_DUPLEX              (1<<4)
#define MSR_SPEED               (1<<3)
#define MSR_LINK                (1<<2)

/* USB endpoints */
enum rtl8150_usb_ep {
        RTL8150_USB_EP_CONTROL = 0,
        RTL8150_USB_EP_BULK_IN = 1,
        RTL8150_USB_EP_BULK_OUT = 2,
        RTL8150_USB_EP_INT_IN = 3,
};

/* Interrupt pipe data */
#define INT_TSR                 0x00
#define INT_RSR                 0x01
#define INT_MSR                 0x02
#define INT_WAKSR               0x03
#define INT_TXOK_CNT            0x04
#define INT_RXLOST_CNT          0x05
#define INT_CRERR_CNT           0x06
#define INT_COL_CNT             0x07


#define RTL8150_MTU             1540
#define RTL8150_TX_TIMEOUT      (HZ)
#define RX_SKB_POOL_SIZE        4

/* rtl8150 flags */
#define RTL8150_HW_CRC          0
#define RX_REG_SET              1
#define RTL8150_UNPLUG          2
#define RX_URB_FAIL             3

/* Define these values to match your device */
#define VENDOR_ID_REALTEK               0x0bda
#define VENDOR_ID_MELCO                 0x0411
#define VENDOR_ID_MICRONET              0x3980
#define VENDOR_ID_LONGSHINE             0x07b8
#define VENDOR_ID_OQO                   0x1557
#define VENDOR_ID_ZYXEL                 0x0586

#define PRODUCT_ID_RTL8150              0x8150
#define PRODUCT_ID_LUAKTX               0x0012
#define PRODUCT_ID_LCS8138TX            0x401a
#define PRODUCT_ID_SP128AR              0x0003
#define PRODUCT_ID_PRESTIGE             0x401a

#undef  EEPROM_WRITE

/* table of devices that work with this driver */
static const struct usb_device_id rtl8150_table[] = {
        {USB_DEVICE(VENDOR_ID_REALTEK, PRODUCT_ID_RTL8150)},
        {USB_DEVICE(VENDOR_ID_MELCO, PRODUCT_ID_LUAKTX)},
        {USB_DEVICE(VENDOR_ID_MICRONET, PRODUCT_ID_SP128AR)},
        {USB_DEVICE(VENDOR_ID_LONGSHINE, PRODUCT_ID_LCS8138TX)},
        {USB_DEVICE(VENDOR_ID_OQO, PRODUCT_ID_RTL8150)},
        {USB_DEVICE(VENDOR_ID_ZYXEL, PRODUCT_ID_PRESTIGE)},
        {}
};

MODULE_DEVICE_TABLE(usb, rtl8150_table);

struct rtl8150 {
        unsigned long flags;
        struct usb_device *udev;
        struct tasklet_struct tl;
        struct net_device *netdev;
        struct urb *rx_urb, *tx_urb, *intr_urb;
        struct sk_buff *tx_skb, *rx_skb;
        struct sk_buff *rx_skb_pool[RX_SKB_POOL_SIZE];
        spinlock_t rx_pool_lock;
        struct usb_ctrlrequest dr;
        int intr_interval;
        u8 *intr_buff;
        u8 phy;
};

typedef struct rtl8150 rtl8150_t;

struct async_req {
        struct usb_ctrlrequest dr;
        u16 rx_creg;
};

static const char driver_name [] = "rtl8150";

/*
**
**      device related part of the code
**
*/
static int get_registers(rtl8150_t * dev, u16 indx, u16 size, void *data)
{
        return usb_control_msg_recv(dev->udev, 0, RTL8150_REQ_GET_REGS,
                                    RTL8150_REQT_READ, indx, 0, data, size,
                                    1000, GFP_NOIO);
}

static int set_registers(rtl8150_t * dev, u16 indx, u16 size, const void *data)
{
        return usb_control_msg_send(dev->udev, 0, RTL8150_REQ_SET_REGS,
                                    RTL8150_REQT_WRITE, indx, 0, data, size,
                                    1000, GFP_NOIO);
}

static void async_set_reg_cb(struct urb *urb)
{
        struct async_req *req = (struct async_req *)urb->context;
        int status = urb->status;

        if (status < 0)
                dev_dbg(&urb->dev->dev, "%s failed with %d", __func__, status);
        kfree(req);
        usb_free_urb(urb);
}

static int async_set_registers(rtl8150_t *dev, u16 indx, u16 size, u16 reg)
{
        int res = -ENOMEM;
        struct urb *async_urb;
        struct async_req *req;

        req = kmalloc_obj(struct async_req, GFP_ATOMIC);
        if (req == NULL)
                return res;
        async_urb = usb_alloc_urb(0, GFP_ATOMIC);
        if (async_urb == NULL) {
                kfree(req);
                return res;
        }
        req->rx_creg = cpu_to_le16(reg);
        req->dr.bRequestType = RTL8150_REQT_WRITE;
        req->dr.bRequest = RTL8150_REQ_SET_REGS;
        req->dr.wIndex = 0;
        req->dr.wValue = cpu_to_le16(indx);
        req->dr.wLength = cpu_to_le16(size);
        usb_fill_control_urb(async_urb, dev->udev,
                             usb_sndctrlpipe(dev->udev, 0), (void *)&req->dr,
                             &req->rx_creg, size, async_set_reg_cb, req);
        res = usb_submit_urb(async_urb, GFP_ATOMIC);
        if (res) {
                if (res == -ENODEV)
                        netif_device_detach(dev->netdev);
                dev_err(&dev->udev->dev, "%s failed with %d\n", __func__, res);
                kfree(req);
                usb_free_urb(async_urb);
        }
        return res;
}

static int read_mii_word(rtl8150_t * dev, u8 phy, __u8 indx, u16 * reg)
{
        int i;
        u8 data[3], tmp;

        data[0] = phy;
        data[1] = data[2] = 0;
        tmp = indx | PHY_READ | PHY_GO;
        i = 0;

        set_registers(dev, PHYADD, sizeof(data), data);
        set_registers(dev, PHYCNT, 1, &tmp);
        do {
                get_registers(dev, PHYCNT, 1, data);
        } while ((data[0] & PHY_GO) && (i++ < MII_TIMEOUT));

        if (i <= MII_TIMEOUT) {
                get_registers(dev, PHYDAT, 2, data);
                *reg = data[0] | (data[1] << 8);
                return 0;
        } else
                return 1;
}

static int write_mii_word(rtl8150_t * dev, u8 phy, __u8 indx, u16 reg)
{
        int i;
        u8 data[3], tmp;

        data[0] = phy;
        data[1] = reg & 0xff;
        data[2] = (reg >> 8) & 0xff;
        tmp = indx | PHY_WRITE | PHY_GO;
        i = 0;

        set_registers(dev, PHYADD, sizeof(data), data);
        set_registers(dev, PHYCNT, 1, &tmp);
        do {
                get_registers(dev, PHYCNT, 1, data);
        } while ((data[0] & PHY_GO) && (i++ < MII_TIMEOUT));

        if (i <= MII_TIMEOUT)
                return 0;
        else
                return 1;
}

static void set_ethernet_addr(rtl8150_t *dev)
{
        u8 node_id[ETH_ALEN];
        int ret;

        ret = get_registers(dev, IDR, sizeof(node_id), node_id);

        if (!ret) {
                eth_hw_addr_set(dev->netdev, node_id);
        } else {
                eth_hw_addr_random(dev->netdev);
                netdev_notice(dev->netdev, "Assigned a random MAC address: %pM\n",
                              dev->netdev->dev_addr);
        }
}

static int rtl8150_set_mac_address(struct net_device *netdev, void *p)
{
        struct sockaddr *addr = p;
        rtl8150_t *dev = netdev_priv(netdev);

        if (netif_running(netdev))
                return -EBUSY;

        eth_hw_addr_set(netdev, addr->sa_data);
        netdev_dbg(netdev, "Setting MAC address to %pM\n", netdev->dev_addr);
        /* Set the IDR registers. */
        set_registers(dev, IDR, netdev->addr_len, netdev->dev_addr);
#ifdef EEPROM_WRITE
        {
        int i;
        u8 cr;
        /* Get the CR contents. */
        get_registers(dev, CR, 1, &cr);
        /* Set the WEPROM bit (eeprom write enable). */
        cr |= 0x20;
        set_registers(dev, CR, 1, &cr);
        /* Write the MAC address into eeprom. Eeprom writes must be word-sized,
           so we need to split them up. */
        for (i = 0; i * 2 < netdev->addr_len; i++) {
                set_registers(dev, IDR_EEPROM + (i * 2), 2,
                netdev->dev_addr + (i * 2));
        }
        /* Clear the WEPROM bit (preventing accidental eeprom writes). */
        cr &= 0xdf;
        set_registers(dev, CR, 1, &cr);
        }
#endif
        return 0;
}

static int rtl8150_reset(rtl8150_t * dev)
{
        u8 data = 0x10;
        int i = HZ;

        set_registers(dev, CR, 1, &data);
        do {
                get_registers(dev, CR, 1, &data);
        } while ((data & 0x10) && --i);

        return (i > 0) ? 1 : 0;
}

static int alloc_all_urbs(rtl8150_t * dev)
{
        dev->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!dev->rx_urb)
                return 0;
        dev->tx_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!dev->tx_urb) {
                usb_free_urb(dev->rx_urb);
                return 0;
        }
        dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!dev->intr_urb) {
                usb_free_urb(dev->rx_urb);
                usb_free_urb(dev->tx_urb);
                return 0;
        }

        return 1;
}

static void free_all_urbs(rtl8150_t * dev)
{
        usb_free_urb(dev->rx_urb);
        usb_free_urb(dev->tx_urb);
        usb_free_urb(dev->intr_urb);
}

static void unlink_all_urbs(rtl8150_t * dev)
{
        usb_kill_urb(dev->rx_urb);
        usb_kill_urb(dev->tx_urb);
        usb_kill_urb(dev->intr_urb);
}

static inline struct sk_buff *pull_skb(rtl8150_t *dev)
{
        struct sk_buff *skb;
        int i;

        for (i = 0; i < RX_SKB_POOL_SIZE; i++) {
                if (dev->rx_skb_pool[i]) {
                        skb = dev->rx_skb_pool[i];
                        dev->rx_skb_pool[i] = NULL;
                        return skb;
                }
        }
        return NULL;
}

static void read_bulk_callback(struct urb *urb)
{
        rtl8150_t *dev;
        unsigned pkt_len, res;
        struct sk_buff *skb;
        struct net_device *netdev;
        int status = urb->status;
        int result;
        unsigned long flags;

        dev = urb->context;
        if (!dev)
                return;
        if (test_bit(RTL8150_UNPLUG, &dev->flags))
                return;
        netdev = dev->netdev;
        if (!netif_device_present(netdev))
                return;

        switch (status) {
        case 0:
                break;
        case -ENOENT:
                return; /* the urb is in unlink state */
        case -ETIME:
                if (printk_ratelimit())
                        dev_warn(&urb->dev->dev, "may be reset is needed?..\n");
                goto goon;
        default:
                if (printk_ratelimit())
                        dev_warn(&urb->dev->dev, "Rx status %d\n", status);
                goto goon;
        }

        if (!dev->rx_skb)
                goto resched;
        /* protect against short packets (tell me why we got some?!?) */
        if (urb->actual_length < 4)
                goto goon;

        res = urb->actual_length;
        pkt_len = res - 4;

        skb_put(dev->rx_skb, pkt_len);
        dev->rx_skb->protocol = eth_type_trans(dev->rx_skb, netdev);
        netif_rx(dev->rx_skb);
        netdev->stats.rx_packets++;
        netdev->stats.rx_bytes += pkt_len;

        spin_lock_irqsave(&dev->rx_pool_lock, flags);
        skb = pull_skb(dev);
        spin_unlock_irqrestore(&dev->rx_pool_lock, flags);
        if (!skb)
                goto resched;

        dev->rx_skb = skb;
goon:
        usb_fill_bulk_urb(dev->rx_urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
                      dev->rx_skb->data, RTL8150_MTU, read_bulk_callback, dev);
        result = usb_submit_urb(dev->rx_urb, GFP_ATOMIC);
        if (result == -ENODEV)
                netif_device_detach(dev->netdev);
        else if (result) {
                set_bit(RX_URB_FAIL, &dev->flags);
                goto resched;
        } else {
                clear_bit(RX_URB_FAIL, &dev->flags);
        }

        return;
resched:
        tasklet_schedule(&dev->tl);
}

static void write_bulk_callback(struct urb *urb)
{
        rtl8150_t *dev;
        int status = urb->status;

        dev = urb->context;
        if (!dev)
                return;
        dev_kfree_skb_irq(dev->tx_skb);
        if (!netif_device_present(dev->netdev))
                return;
        if (status)
                dev_info(&urb->dev->dev, "%s: Tx status %d\n",
                         dev->netdev->name, status);
        netif_trans_update(dev->netdev);
        netif_wake_queue(dev->netdev);
}

static void intr_callback(struct urb *urb)
{
        rtl8150_t *dev;
        __u8 *d;
        int status = urb->status;
        int res;

        dev = urb->context;
        if (!dev)
                return;
        switch (status) {
        case 0:                 /* success */
                break;
        case -ECONNRESET:       /* unlink */
        case -ENOENT:
        case -ESHUTDOWN:
                return;
        /* -EPIPE:  should clear the halt */
        default:
                dev_info(&urb->dev->dev, "%s: intr status %d\n",
                         dev->netdev->name, status);
                goto resubmit;
        }

        d = urb->transfer_buffer;
        if (d[0] & TSR_ERRORS) {
                dev->netdev->stats.tx_errors++;
                if (d[INT_TSR] & (TSR_ECOL | TSR_JBR))
                        dev->netdev->stats.tx_aborted_errors++;
                if (d[INT_TSR] & TSR_LCOL)
                        dev->netdev->stats.tx_window_errors++;
                if (d[INT_TSR] & TSR_LOSS_CRS)
                        dev->netdev->stats.tx_carrier_errors++;
        }
        /* Report link status changes to the network stack */
        if ((d[INT_MSR] & MSR_LINK) == 0) {
                if (netif_carrier_ok(dev->netdev)) {
                        netif_carrier_off(dev->netdev);
                        netdev_dbg(dev->netdev, "%s: LINK LOST\n", __func__);
                }
        } else {
                if (!netif_carrier_ok(dev->netdev)) {
                        netif_carrier_on(dev->netdev);
                        netdev_dbg(dev->netdev, "%s: LINK CAME BACK\n", __func__);
                }
        }

resubmit:
        res = usb_submit_urb (urb, GFP_ATOMIC);
        if (res == -ENODEV)
                netif_device_detach(dev->netdev);
        else if (res)
                dev_err(&dev->udev->dev,
                        "can't resubmit intr, %s-%s/input0, status %d\n",
                        dev->udev->bus->bus_name, dev->udev->devpath, res);
}

static int rtl8150_suspend(struct usb_interface *intf, pm_message_t message)
{
        rtl8150_t *dev = usb_get_intfdata(intf);

        netif_device_detach(dev->netdev);

        if (netif_running(dev->netdev)) {
                usb_kill_urb(dev->rx_urb);
                usb_kill_urb(dev->intr_urb);
        }
        return 0;
}

static int rtl8150_resume(struct usb_interface *intf)
{
        rtl8150_t *dev = usb_get_intfdata(intf);

        netif_device_attach(dev->netdev);
        if (netif_running(dev->netdev)) {
                dev->rx_urb->status = 0;
                dev->rx_urb->actual_length = 0;
                read_bulk_callback(dev->rx_urb);

                dev->intr_urb->status = 0;
                dev->intr_urb->actual_length = 0;
                intr_callback(dev->intr_urb);
        }
        return 0;
}

/*
**
**      network related part of the code
**
*/

static void fill_skb_pool(rtl8150_t *dev)
{
        struct sk_buff *skb;
        int i;

        for (i = 0; i < RX_SKB_POOL_SIZE; i++) {
                if (dev->rx_skb_pool[i])
                        continue;
                skb = dev_alloc_skb(RTL8150_MTU + 2);
                if (!skb) {
                        return;
                }
                skb_reserve(skb, 2);
                dev->rx_skb_pool[i] = skb;
        }
}

static void free_skb_pool(rtl8150_t *dev)
{
        int i;

        for (i = 0; i < RX_SKB_POOL_SIZE; i++)
                dev_kfree_skb(dev->rx_skb_pool[i]);
}

static void rx_fixup(struct tasklet_struct *t)
{
        struct rtl8150 *dev = from_tasklet(dev, t, tl);
        struct sk_buff *skb;
        int status;

        spin_lock_irq(&dev->rx_pool_lock);
        fill_skb_pool(dev);
        spin_unlock_irq(&dev->rx_pool_lock);
        if (test_bit(RX_URB_FAIL, &dev->flags))
                if (dev->rx_skb)
                        goto try_again;
        spin_lock_irq(&dev->rx_pool_lock);
        skb = pull_skb(dev);
        spin_unlock_irq(&dev->rx_pool_lock);
        if (skb == NULL)
                goto tlsched;
        dev->rx_skb = skb;
        usb_fill_bulk_urb(dev->rx_urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
                      dev->rx_skb->data, RTL8150_MTU, read_bulk_callback, dev);
try_again:
        status = usb_submit_urb(dev->rx_urb, GFP_ATOMIC);
        if (status == -ENODEV) {
                netif_device_detach(dev->netdev);
        } else if (status) {
                set_bit(RX_URB_FAIL, &dev->flags);
                goto tlsched;
        } else {
                clear_bit(RX_URB_FAIL, &dev->flags);
        }

        return;
tlsched:
        tasklet_schedule(&dev->tl);
}

static int enable_net_traffic(rtl8150_t * dev)
{
        u8 cr, tcr, rcr, msr;

        if (!rtl8150_reset(dev)) {
                dev_warn(&dev->udev->dev, "device reset failed\n");
        }
        /* RCR bit7=1 attach Rx info at the end;  =0 HW CRC (which is broken) */
        rcr = 0x9e;
        tcr = 0xd8;
        cr = 0x0c;
        if (!(rcr & 0x80))
                set_bit(RTL8150_HW_CRC, &dev->flags);
        set_registers(dev, RCR, 1, &rcr);
        set_registers(dev, TCR, 1, &tcr);
        set_registers(dev, CR, 1, &cr);
        get_registers(dev, MSR, 1, &msr);

        return 0;
}

static void disable_net_traffic(rtl8150_t * dev)
{
        u8 cr;

        get_registers(dev, CR, 1, &cr);
        cr &= 0xf3;
        set_registers(dev, CR, 1, &cr);
}

static void rtl8150_tx_timeout(struct net_device *netdev, unsigned int txqueue)
{
        rtl8150_t *dev = netdev_priv(netdev);
        dev_warn(&netdev->dev, "Tx timeout.\n");
        usb_unlink_urb(dev->tx_urb);
        netdev->stats.tx_errors++;
}

static void rtl8150_set_multicast(struct net_device *netdev)
{
        rtl8150_t *dev = netdev_priv(netdev);
        u16 rx_creg = 0x9e;

        if (netdev->flags & IFF_PROMISC) {
                rx_creg |= 0x0001;
                dev_info(&netdev->dev, "%s: promiscuous mode\n", netdev->name);
        } else if (!netdev_mc_empty(netdev) ||
                   (netdev->flags & IFF_ALLMULTI)) {
                rx_creg &= 0xfffe;
                rx_creg |= 0x0002;
                dev_dbg(&netdev->dev, "%s: allmulti set\n", netdev->name);
        } else {
                /* ~RX_MULTICAST, ~RX_PROMISCUOUS */
                rx_creg &= 0x00fc;
        }
        async_set_registers(dev, RCR, sizeof(rx_creg), rx_creg);
}

static netdev_tx_t rtl8150_start_xmit(struct sk_buff *skb,
                                            struct net_device *netdev)
{
        rtl8150_t *dev = netdev_priv(netdev);
        int count, res;

        /* pad the frame and ensure terminating USB packet, datasheet 9.2.3 */
        count = max(skb->len, ETH_ZLEN);
        if (count % 64 == 0)
                count++;
        if (skb_padto(skb, count)) {
                netdev->stats.tx_dropped++;
                return NETDEV_TX_OK;
        }

        netif_stop_queue(netdev);
        dev->tx_skb = skb;
        usb_fill_bulk_urb(dev->tx_urb, dev->udev, usb_sndbulkpipe(dev->udev, 2),
                      skb->data, count, write_bulk_callback, dev);
        if ((res = usb_submit_urb(dev->tx_urb, GFP_ATOMIC))) {
                /* Can we get/handle EPIPE here? */
                if (res == -ENODEV)
                        netif_device_detach(dev->netdev);
                else {
                        dev_warn(&netdev->dev, "failed tx_urb %d\n", res);
                        netdev->stats.tx_errors++;
                        netif_start_queue(netdev);
                }
        } else {
                netdev->stats.tx_packets++;
                netdev->stats.tx_bytes += skb->len;
                netif_trans_update(netdev);
        }

        return NETDEV_TX_OK;
}


static void set_carrier(struct net_device *netdev)
{
        rtl8150_t *dev = netdev_priv(netdev);
        short tmp;

        get_registers(dev, CSCR, 2, &tmp);
        if (tmp & CSCR_LINK_STATUS)
                netif_carrier_on(netdev);
        else
                netif_carrier_off(netdev);
}

static int rtl8150_open(struct net_device *netdev)
{
        rtl8150_t *dev = netdev_priv(netdev);
        int res;

        if (dev->rx_skb == NULL)
                dev->rx_skb = pull_skb(dev);
        if (!dev->rx_skb)
                return -ENOMEM;

        set_registers(dev, IDR, 6, netdev->dev_addr);

        usb_fill_bulk_urb(dev->rx_urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1),
                      dev->rx_skb->data, RTL8150_MTU, read_bulk_callback, dev);
        if ((res = usb_submit_urb(dev->rx_urb, GFP_KERNEL))) {
                if (res == -ENODEV)
                        netif_device_detach(dev->netdev);
                dev_warn(&netdev->dev, "rx_urb submit failed: %d\n", res);
                return res;
        }
        usb_fill_int_urb(dev->intr_urb, dev->udev, usb_rcvintpipe(dev->udev, 3),
                     dev->intr_buff, INTBUFSIZE, intr_callback,
                     dev, dev->intr_interval);
        if ((res = usb_submit_urb(dev->intr_urb, GFP_KERNEL))) {
                if (res == -ENODEV)
                        netif_device_detach(dev->netdev);
                dev_warn(&netdev->dev, "intr_urb submit failed: %d\n", res);
                usb_kill_urb(dev->rx_urb);
                return res;
        }
        enable_net_traffic(dev);
        set_carrier(netdev);
        netif_start_queue(netdev);

        return res;
}

static int rtl8150_close(struct net_device *netdev)
{
        rtl8150_t *dev = netdev_priv(netdev);

        netif_stop_queue(netdev);
        if (!test_bit(RTL8150_UNPLUG, &dev->flags))
                disable_net_traffic(dev);
        unlink_all_urbs(dev);

        return 0;
}

static void rtl8150_get_drvinfo(struct net_device *netdev, struct ethtool_drvinfo *info)
{
        rtl8150_t *dev = netdev_priv(netdev);

        strscpy(info->driver, driver_name, sizeof(info->driver));
        usb_make_path(dev->udev, info->bus_info, sizeof(info->bus_info));
}

static int rtl8150_get_link_ksettings(struct net_device *netdev,
                                      struct ethtool_link_ksettings *ecmd)
{
        rtl8150_t *dev = netdev_priv(netdev);
        short lpa = 0;
        short bmcr = 0;
        u32 supported;

        supported = (SUPPORTED_10baseT_Half |
                          SUPPORTED_10baseT_Full |
                          SUPPORTED_100baseT_Half |
                          SUPPORTED_100baseT_Full |
                          SUPPORTED_Autoneg |
                          SUPPORTED_TP | SUPPORTED_MII);
        ecmd->base.port = PORT_TP;
        ecmd->base.phy_address = dev->phy;
        get_registers(dev, BMCR, 2, &bmcr);
        get_registers(dev, ANLP, 2, &lpa);
        if (bmcr & BMCR_ANENABLE) {
                u32 speed = ((lpa & (LPA_100HALF | LPA_100FULL)) ?
                             SPEED_100 : SPEED_10);
                ecmd->base.speed = speed;
                ecmd->base.autoneg = AUTONEG_ENABLE;
                if (speed == SPEED_100)
                        ecmd->base.duplex = (lpa & LPA_100FULL) ?
                            DUPLEX_FULL : DUPLEX_HALF;
                else
                        ecmd->base.duplex = (lpa & LPA_10FULL) ?
                            DUPLEX_FULL : DUPLEX_HALF;
        } else {
                ecmd->base.autoneg = AUTONEG_DISABLE;
                ecmd->base.speed = ((bmcr & BMCR_SPEED100) ?
                                             SPEED_100 : SPEED_10);
                ecmd->base.duplex = (bmcr & BMCR_FULLDPLX) ?
                    DUPLEX_FULL : DUPLEX_HALF;
        }

        ethtool_convert_legacy_u32_to_link_mode(ecmd->link_modes.supported,
                                                supported);

        return 0;
}

static const struct ethtool_ops ops = {
        .get_drvinfo = rtl8150_get_drvinfo,
        .get_link = ethtool_op_get_link,
        .get_link_ksettings = rtl8150_get_link_ksettings,
};

static int rtl8150_siocdevprivate(struct net_device *netdev, struct ifreq *rq,
                                  void __user *udata, int cmd)
{
        rtl8150_t *dev = netdev_priv(netdev);
        u16 *data = (u16 *) & rq->ifr_ifru;
        int res = 0;

        switch (cmd) {
        case SIOCDEVPRIVATE:
                data[0] = dev->phy;
                fallthrough;
        case SIOCDEVPRIVATE + 1:
                read_mii_word(dev, dev->phy, (data[1] & 0x1f), &data[3]);
                break;
        case SIOCDEVPRIVATE + 2:
                if (!capable(CAP_NET_ADMIN))
                        return -EPERM;
                write_mii_word(dev, dev->phy, (data[1] & 0x1f), data[2]);
                break;
        default:
                res = -EOPNOTSUPP;
        }

        return res;
}

static const struct net_device_ops rtl8150_netdev_ops = {
        .ndo_open               = rtl8150_open,
        .ndo_stop               = rtl8150_close,
        .ndo_siocdevprivate     = rtl8150_siocdevprivate,
        .ndo_start_xmit         = rtl8150_start_xmit,
        .ndo_tx_timeout         = rtl8150_tx_timeout,
        .ndo_set_rx_mode        = rtl8150_set_multicast,
        .ndo_set_mac_address    = rtl8150_set_mac_address,

        .ndo_validate_addr      = eth_validate_addr,
};

static int rtl8150_probe(struct usb_interface *intf,
                         const struct usb_device_id *id)
{
        struct usb_device *udev = interface_to_usbdev(intf);
        rtl8150_t *dev;
        struct net_device *netdev;
        static const u8 bulk_ep_addr[] = {
                RTL8150_USB_EP_BULK_IN | USB_DIR_IN,
                RTL8150_USB_EP_BULK_OUT | USB_DIR_OUT,
                0};
        static const u8 int_ep_addr[] = {
                RTL8150_USB_EP_INT_IN | USB_DIR_IN,
                0};

        netdev = alloc_etherdev(sizeof(rtl8150_t));
        if (!netdev)
                return -ENOMEM;

        dev = netdev_priv(netdev);

        dev->intr_buff = kmalloc(INTBUFSIZE, GFP_KERNEL);
        if (!dev->intr_buff) {
                free_netdev(netdev);
                return -ENOMEM;
        }

        /* Verify that all required endpoints are present */
        if (!usb_check_bulk_endpoints(intf, bulk_ep_addr) ||
            !usb_check_int_endpoints(intf, int_ep_addr)) {
                dev_err(&intf->dev, "couldn't find required endpoints\n");
                goto out;
        }

        tasklet_setup(&dev->tl, rx_fixup);
        spin_lock_init(&dev->rx_pool_lock);

        dev->udev = udev;
        dev->netdev = netdev;
        netdev->netdev_ops = &rtl8150_netdev_ops;
        netdev->watchdog_timeo = RTL8150_TX_TIMEOUT;
        netdev->ethtool_ops = &ops;
        dev->intr_interval = 100;       /* 100ms */

        if (!alloc_all_urbs(dev)) {
                dev_err(&intf->dev, "out of memory\n");
                goto out;
        }
        if (!rtl8150_reset(dev)) {
                dev_err(&intf->dev, "couldn't reset the device\n");
                goto out1;
        }
        fill_skb_pool(dev);
        set_ethernet_addr(dev);

        usb_set_intfdata(intf, dev);
        SET_NETDEV_DEV(netdev, &intf->dev);
        if (register_netdev(netdev) != 0) {
                dev_err(&intf->dev, "couldn't register the device\n");
                goto out2;
        }

        dev_info(&intf->dev, "%s: rtl8150 is detected\n", netdev->name);

        return 0;

out2:
        usb_set_intfdata(intf, NULL);
        free_skb_pool(dev);
out1:
        free_all_urbs(dev);
out:
        kfree(dev->intr_buff);
        free_netdev(netdev);
        return -EIO;
}

static void rtl8150_disconnect(struct usb_interface *intf)
{
        rtl8150_t *dev = usb_get_intfdata(intf);

        usb_set_intfdata(intf, NULL);
        if (dev) {
                set_bit(RTL8150_UNPLUG, &dev->flags);
                tasklet_kill(&dev->tl);
                unregister_netdev(dev->netdev);
                unlink_all_urbs(dev);
                free_all_urbs(dev);
                free_skb_pool(dev);
                dev_kfree_skb(dev->rx_skb);
                kfree(dev->intr_buff);
                free_netdev(dev->netdev);
        }
}

static struct usb_driver rtl8150_driver = {
        .name           = driver_name,
        .probe          = rtl8150_probe,
        .disconnect     = rtl8150_disconnect,
        .id_table       = rtl8150_table,
        .suspend        = rtl8150_suspend,
        .resume         = rtl8150_resume,
        .disable_hub_initiated_lpm = 1,
};

module_usb_driver(rtl8150_driver);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");