// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Copyright (c) 1999-2021 Petko Manolov (petkan@nucleusys.com)
 *
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/module.h>
#include <asm/byteorder.h>
#include <linux/uaccess.h>
#include "pegasus.h"

/*
 * Version Information
 */
#define DRIVER_AUTHOR "Petko Manolov <petkan@nucleusys.com>"
#define DRIVER_DESC "Pegasus/Pegasus II USB Ethernet driver"

static const char driver_name[] = "pegasus";

#undef  PEGASUS_WRITE_EEPROM
#define BMSR_MEDIA      (BMSR_10HALF | BMSR_10FULL | BMSR_100HALF | \
                        BMSR_100FULL | BMSR_ANEGCAPABLE)
#define CARRIER_CHECK_DELAY (2 * HZ)

static bool loopback;
static bool mii_mode;
static char *devid;

static struct usb_eth_dev usb_dev_id[] = {
#define PEGASUS_DEV(pn, vid, pid, flags)        \
        {.name = pn, .vendor = vid, .device = pid, .private = flags},
#define PEGASUS_DEV_CLASS(pn, vid, pid, dclass, flags) \
        PEGASUS_DEV(pn, vid, pid, flags)
#include "pegasus.h"
#undef  PEGASUS_DEV
#undef  PEGASUS_DEV_CLASS
        {NULL, 0, 0, 0},
        {NULL, 0, 0, 0}
};

static struct usb_device_id pegasus_ids[] = {
#define PEGASUS_DEV(pn, vid, pid, flags) \
        {.match_flags = USB_DEVICE_ID_MATCH_DEVICE, .idVendor = vid, .idProduct = pid},
/*
 * The Belkin F8T012xx1 bluetooth adaptor has the same vendor and product
 * IDs as the Belkin F5D5050, so we need to teach the pegasus driver to
 * ignore adaptors belonging to the "Wireless" class 0xE0. For this one
 * case anyway, seeing as the pegasus is for "Wired" adaptors.
 */
#define PEGASUS_DEV_CLASS(pn, vid, pid, dclass, flags) \
        {.match_flags = (USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_DEV_CLASS), \
        .idVendor = vid, .idProduct = pid, .bDeviceClass = dclass},
#include "pegasus.h"
#undef  PEGASUS_DEV
#undef  PEGASUS_DEV_CLASS
        {},
        {}
};

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
module_param(loopback, bool, 0);
module_param(mii_mode, bool, 0);
module_param(devid, charp, 0);
MODULE_PARM_DESC(loopback, "Enable MAC loopback mode (bit 0)");
MODULE_PARM_DESC(mii_mode, "Enable HomePNA mode (bit 0),default=MII mode = 0");
MODULE_PARM_DESC(devid, "The format is: 'DEV_name:VendorID:DeviceID:Flags'");

/* use ethtool to change the level for any given device */
static int msg_level = -1;
module_param(msg_level, int, 0);
MODULE_PARM_DESC(msg_level, "Override default message level");

MODULE_DEVICE_TABLE(usb, pegasus_ids);
static const struct net_device_ops pegasus_netdev_ops;

/*****/

static void async_ctrl_callback(struct urb *urb)
{
        struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)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 get_registers(pegasus_t *pegasus, __u16 indx, __u16 size, void *data)
{
        return usb_control_msg_recv(pegasus->usb, 0, PEGASUS_REQ_GET_REGS,
                                   PEGASUS_REQT_READ, 0, indx, data, size,
                                   1000, GFP_NOIO);
}

static int set_registers(pegasus_t *pegasus, __u16 indx, __u16 size,
                         const void *data)
{
        int ret;

        ret = usb_control_msg_send(pegasus->usb, 0, PEGASUS_REQ_SET_REGS,
                                    PEGASUS_REQT_WRITE, 0, indx, data, size,
                                    1000, GFP_NOIO);
        if (ret < 0)
                netif_dbg(pegasus, drv, pegasus->net, "%s failed with %d\n", __func__, ret);

        return ret;
}

/*
 * There is only one way to write to a single ADM8511 register and this is via
 * specific control request.  'data' is ignored by the device, but it is here to
 * not break the API.
 */
static int set_register(pegasus_t *pegasus, __u16 indx, __u8 data)
{
        void *buf = &data;
        int ret;

        ret = usb_control_msg_send(pegasus->usb, 0, PEGASUS_REQ_SET_REG,
                                    PEGASUS_REQT_WRITE, data, indx, buf, 1,
                                    1000, GFP_NOIO);
        if (ret < 0)
                netif_dbg(pegasus, drv, pegasus->net, "%s failed with %d\n", __func__, ret);

        return ret;
}

static int update_eth_regs_async(pegasus_t *pegasus)
{
        int ret = -ENOMEM;
        struct urb *async_urb;
        struct usb_ctrlrequest *req;

        req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
        if (req == NULL)
                return ret;

        async_urb = usb_alloc_urb(0, GFP_ATOMIC);
        if (async_urb == NULL) {
                kfree(req);
                return ret;
        }
        req->bRequestType = PEGASUS_REQT_WRITE;
        req->bRequest = PEGASUS_REQ_SET_REGS;
        req->wValue = cpu_to_le16(0);
        req->wIndex = cpu_to_le16(EthCtrl0);
        req->wLength = cpu_to_le16(3);

        usb_fill_control_urb(async_urb, pegasus->usb,
                             usb_sndctrlpipe(pegasus->usb, 0), (void *)req,
                             pegasus->eth_regs, 3, async_ctrl_callback, req);

        ret = usb_submit_urb(async_urb, GFP_ATOMIC);
        if (ret) {
                if (ret == -ENODEV)
                        netif_device_detach(pegasus->net);
                netif_err(pegasus, drv, pegasus->net,
                          "%s returned %d\n", __func__, ret);
        }
        return ret;
}

static int __mii_op(pegasus_t *p, __u8 phy, __u8 indx, __u16 *regd, __u8 cmd)
{
        int i, ret;
        __le16 regdi;
        __u8 data[4] = { phy, 0, 0, indx };

        if (cmd & PHY_WRITE) {
                __le16 *t = (__le16 *) & data[1];
                *t = cpu_to_le16(*regd);
        }
        set_register(p, PhyCtrl, 0);
        set_registers(p, PhyAddr, sizeof(data), data);
        set_register(p, PhyCtrl, (indx | cmd));
        for (i = 0; i < REG_TIMEOUT; i++) {
                ret = get_registers(p, PhyCtrl, 1, data);
                if (ret < 0)
                        goto fail;
                if (data[0] & PHY_DONE)
                        break;
        }
        if (i >= REG_TIMEOUT) {
                ret = -ETIMEDOUT;
                goto fail;
        }
        if (cmd & PHY_READ) {
                ret = get_registers(p, PhyData, 2, &regdi);
                if (ret < 0)
                        goto fail;
                *regd = le16_to_cpu(regdi);
        }
        return 0;
fail:
        netif_dbg(p, drv, p->net, "%s failed\n", __func__);
        return ret;
}

/* Returns non-negative int on success, error on failure */
static int read_mii_word(pegasus_t *pegasus, __u8 phy, __u8 indx, __u16 *regd)
{
        return __mii_op(pegasus, phy, indx, regd, PHY_READ);
}

/* Returns zero on success, error on failure */
static int write_mii_word(pegasus_t *pegasus, __u8 phy, __u8 indx, __u16 *regd)
{
        return __mii_op(pegasus, phy, indx, regd, PHY_WRITE);
}

static int mdio_read(struct net_device *dev, int phy_id, int loc)
{
        pegasus_t *pegasus = netdev_priv(dev);
        int ret;
        u16 res;

        ret = read_mii_word(pegasus, phy_id, loc, &res);
        if (ret < 0)
                return ret;

        return (int)res;
}

static void mdio_write(struct net_device *dev, int phy_id, int loc, int val)
{
        pegasus_t *pegasus = netdev_priv(dev);
        u16 data = val;

        write_mii_word(pegasus, phy_id, loc, &data);
}

static int read_eprom_word(pegasus_t *pegasus, __u8 index, __u16 *retdata)
{
        int ret, i;
        __le16 retdatai;
        __u8 tmp = 0;

        set_register(pegasus, EpromCtrl, 0);
        set_register(pegasus, EpromOffset, index);
        set_register(pegasus, EpromCtrl, EPROM_READ);

        for (i = 0; i < REG_TIMEOUT; i++) {
                ret = get_registers(pegasus, EpromCtrl, 1, &tmp);
                if (ret < 0)
                        goto fail;
                if (tmp & EPROM_DONE)
                        break;
        }
        if (i >= REG_TIMEOUT) {
                ret = -ETIMEDOUT;
                goto fail;
        }

        ret = get_registers(pegasus, EpromData, 2, &retdatai);
        if (ret < 0)
                goto fail;
        *retdata = le16_to_cpu(retdatai);
        return ret;

fail:
        netif_dbg(pegasus, drv, pegasus->net, "%s failed\n", __func__);
        return ret;
}

#ifdef  PEGASUS_WRITE_EEPROM
static inline void enable_eprom_write(pegasus_t *pegasus)
{
        __u8 tmp;

        get_registers(pegasus, EthCtrl2, 1, &tmp);
        set_register(pegasus, EthCtrl2, tmp | EPROM_WR_ENABLE);
}

static inline void disable_eprom_write(pegasus_t *pegasus)
{
        __u8 tmp;

        get_registers(pegasus, EthCtrl2, 1, &tmp);
        set_register(pegasus, EpromCtrl, 0);
        set_register(pegasus, EthCtrl2, tmp & ~EPROM_WR_ENABLE);
}

static int write_eprom_word(pegasus_t *pegasus, __u8 index, __u16 data)
{
        int i;
        __u8 tmp, d[4] = { 0x3f, 0, 0, EPROM_WRITE };
        int ret;
        __le16 le_data = cpu_to_le16(data);

        set_registers(pegasus, EpromOffset, 4, d);
        enable_eprom_write(pegasus);
        set_register(pegasus, EpromOffset, index);
        set_registers(pegasus, EpromData, 2, &le_data);
        set_register(pegasus, EpromCtrl, EPROM_WRITE);

        for (i = 0; i < REG_TIMEOUT; i++) {
                ret = get_registers(pegasus, EpromCtrl, 1, &tmp);
                if (ret == -ESHUTDOWN)
                        goto fail;
                if (tmp & EPROM_DONE)
                        break;
        }
        disable_eprom_write(pegasus);
        if (i >= REG_TIMEOUT)
                goto fail;

        return ret;

fail:
        netif_dbg(pegasus, drv, pegasus->net, "%s failed\n", __func__);
        return -ETIMEDOUT;
}
#endif  /* PEGASUS_WRITE_EEPROM */

static inline int get_node_id(pegasus_t *pegasus, u8 *id)
{
        int i, ret;
        u16 w16;

        for (i = 0; i < 3; i++) {
                ret = read_eprom_word(pegasus, i, &w16);
                if (ret < 0)
                        return ret;
                ((__le16 *) id)[i] = cpu_to_le16(w16);
        }

        return 0;
}

static void set_ethernet_addr(pegasus_t *pegasus)
{
        int ret;
        u8 node_id[6];

        if (pegasus->features & PEGASUS_II) {
                ret = get_registers(pegasus, 0x10, sizeof(node_id), node_id);
                if (ret < 0)
                        goto err;
        } else {
                ret = get_node_id(pegasus, node_id);
                if (ret < 0)
                        goto err;
                ret = set_registers(pegasus, EthID, sizeof(node_id), node_id);
                if (ret < 0)
                        goto err;
        }

        memcpy(pegasus->net->dev_addr, node_id, sizeof(node_id));

        return;
err:
        eth_hw_addr_random(pegasus->net);
        netif_dbg(pegasus, drv, pegasus->net, "software assigned MAC address.\n");

        return;
}

static inline int reset_mac(pegasus_t *pegasus)
{
        int ret, i;
        __u8 data = 0x8;

        set_register(pegasus, EthCtrl1, data);
        for (i = 0; i < REG_TIMEOUT; i++) {
                ret = get_registers(pegasus, EthCtrl1, 1, &data);
                if (ret < 0)
                        goto fail;
                if (~data & 0x08) {
                        if (loopback)
                                break;
                        if (mii_mode && (pegasus->features & HAS_HOME_PNA))
                                set_register(pegasus, Gpio1, 0x34);
                        else
                                set_register(pegasus, Gpio1, 0x26);
                        set_register(pegasus, Gpio0, pegasus->features);
                        set_register(pegasus, Gpio0, DEFAULT_GPIO_SET);
                        break;
                }
        }
        if (i == REG_TIMEOUT)
                return -ETIMEDOUT;

        if (usb_dev_id[pegasus->dev_index].vendor == VENDOR_LINKSYS ||
            usb_dev_id[pegasus->dev_index].vendor == VENDOR_DLINK) {
                set_register(pegasus, Gpio0, 0x24);
                set_register(pegasus, Gpio0, 0x26);
        }
        if (usb_dev_id[pegasus->dev_index].vendor == VENDOR_ELCON) {
                __u16 auxmode;
                ret = read_mii_word(pegasus, 3, 0x1b, &auxmode);
                if (ret < 0)
                        goto fail;
                auxmode |= 4;
                write_mii_word(pegasus, 3, 0x1b, &auxmode);
        }

        return 0;
fail:
        netif_dbg(pegasus, drv, pegasus->net, "%s failed\n", __func__);
        return ret;
}

static int enable_net_traffic(struct net_device *dev, struct usb_device *usb)
{
        pegasus_t *pegasus = netdev_priv(dev);
        int ret;
        __u16 linkpart;
        __u8 data[4];

        ret = read_mii_word(pegasus, pegasus->phy, MII_LPA, &linkpart);
        if (ret < 0)
                goto fail;
        data[0] = 0xc8; /* TX & RX enable, append status, no CRC */
        data[1] = 0;
        if (linkpart & (ADVERTISE_100FULL | ADVERTISE_10FULL))
                data[1] |= 0x20;        /* set full duplex */
        if (linkpart & (ADVERTISE_100FULL | ADVERTISE_100HALF))
                data[1] |= 0x10;        /* set 100 Mbps */
        if (mii_mode)
                data[1] = 0;
        data[2] = loopback ? 0x09 : 0x01;

        memcpy(pegasus->eth_regs, data, sizeof(data));
        ret = set_registers(pegasus, EthCtrl0, 3, data);

        if (usb_dev_id[pegasus->dev_index].vendor == VENDOR_LINKSYS ||
            usb_dev_id[pegasus->dev_index].vendor == VENDOR_LINKSYS2 ||
            usb_dev_id[pegasus->dev_index].vendor == VENDOR_DLINK) {
                u16 auxmode;
                ret = read_mii_word(pegasus, 0, 0x1b, &auxmode);
                if (ret < 0)
                        goto fail;
                auxmode |= 4;
                write_mii_word(pegasus, 0, 0x1b, &auxmode);
        }

        return ret;
fail:
        netif_dbg(pegasus, drv, pegasus->net, "%s failed\n", __func__);
        return ret;
}

static void read_bulk_callback(struct urb *urb)
{
        pegasus_t *pegasus = urb->context;
        struct net_device *net;
        u8 *buf = urb->transfer_buffer;
        int rx_status, count = urb->actual_length;
        int status = urb->status;
        __u16 pkt_len;

        if (!pegasus)
                return;

        net = pegasus->net;
        if (!netif_device_present(net) || !netif_running(net))
                return;

        switch (status) {
        case 0:
                break;
        case -ETIME:
                netif_dbg(pegasus, rx_err, net, "reset MAC\n");
                pegasus->flags &= ~PEGASUS_RX_BUSY;
                break;
        case -EPIPE:            /* stall, or disconnect from TT */
                /* FIXME schedule work to clear the halt */
                netif_warn(pegasus, rx_err, net, "no rx stall recovery\n");
                return;
        case -ENOENT:
        case -ECONNRESET:
        case -ESHUTDOWN:
                netif_dbg(pegasus, ifdown, net, "rx unlink, %d\n", status);
                return;
        default:
                netif_dbg(pegasus, rx_err, net, "RX status %d\n", status);
                goto goon;
        }

        if (count < 4)
                goto goon;

        rx_status = buf[count - 2];
        if (rx_status & 0x1e) {
                netif_dbg(pegasus, rx_err, net,
                          "RX packet error %x\n", rx_status);
                net->stats.rx_errors++;
                if (rx_status & 0x06)   /* long or runt */
                        net->stats.rx_length_errors++;
                if (rx_status & 0x08)
                        net->stats.rx_crc_errors++;
                if (rx_status & 0x10)   /* extra bits   */
                        net->stats.rx_frame_errors++;
                goto goon;
        }
        if (pegasus->chip == 0x8513) {
                pkt_len = le32_to_cpu(*(__le32 *)urb->transfer_buffer);
                pkt_len &= 0x0fff;
                pegasus->rx_skb->data += 2;
        } else {
                pkt_len = buf[count - 3] << 8;
                pkt_len += buf[count - 4];
                pkt_len &= 0xfff;
                pkt_len -= 4;
        }

        /*
         * If the packet is unreasonably long, quietly drop it rather than
         * kernel panicing by calling skb_put.
         */
        if (pkt_len > PEGASUS_MTU)
                goto goon;

        /*
         * at this point we are sure pegasus->rx_skb != NULL
         * so we go ahead and pass up the packet.
         */
        skb_put(pegasus->rx_skb, pkt_len);
        pegasus->rx_skb->protocol = eth_type_trans(pegasus->rx_skb, net);
        netif_rx(pegasus->rx_skb);
        net->stats.rx_packets++;
        net->stats.rx_bytes += pkt_len;

        if (pegasus->flags & PEGASUS_UNPLUG)
                return;

        pegasus->rx_skb = __netdev_alloc_skb_ip_align(pegasus->net, PEGASUS_MTU,
                                                      GFP_ATOMIC);

        if (pegasus->rx_skb == NULL)
                goto tl_sched;
goon:
        usb_fill_bulk_urb(pegasus->rx_urb, pegasus->usb,
                          usb_rcvbulkpipe(pegasus->usb, 1),
                          pegasus->rx_skb->data, PEGASUS_MTU,
                          read_bulk_callback, pegasus);
        rx_status = usb_submit_urb(pegasus->rx_urb, GFP_ATOMIC);
        if (rx_status == -ENODEV)
                netif_device_detach(pegasus->net);
        else if (rx_status) {
                pegasus->flags |= PEGASUS_RX_URB_FAIL;
                goto tl_sched;
        } else {
                pegasus->flags &= ~PEGASUS_RX_URB_FAIL;
        }

        return;

tl_sched:
        tasklet_schedule(&pegasus->rx_tl);
}

static void rx_fixup(struct tasklet_struct *t)
{
        pegasus_t *pegasus = from_tasklet(pegasus, t, rx_tl);
        int status;

        if (pegasus->flags & PEGASUS_UNPLUG)
                return;

        if (pegasus->flags & PEGASUS_RX_URB_FAIL)
                if (pegasus->rx_skb)
                        goto try_again;
        if (pegasus->rx_skb == NULL)
                pegasus->rx_skb = __netdev_alloc_skb_ip_align(pegasus->net,
                                                              PEGASUS_MTU,
                                                              GFP_ATOMIC);
        if (pegasus->rx_skb == NULL) {
                netif_warn(pegasus, rx_err, pegasus->net, "low on memory\n");
                tasklet_schedule(&pegasus->rx_tl);
                return;
        }
        usb_fill_bulk_urb(pegasus->rx_urb, pegasus->usb,
                          usb_rcvbulkpipe(pegasus->usb, 1),
                          pegasus->rx_skb->data, PEGASUS_MTU,
                          read_bulk_callback, pegasus);
try_again:
        status = usb_submit_urb(pegasus->rx_urb, GFP_ATOMIC);
        if (status == -ENODEV)
                netif_device_detach(pegasus->net);
        else if (status) {
                pegasus->flags |= PEGASUS_RX_URB_FAIL;
                tasklet_schedule(&pegasus->rx_tl);
        } else {
                pegasus->flags &= ~PEGASUS_RX_URB_FAIL;
        }
}

static void write_bulk_callback(struct urb *urb)
{
        pegasus_t *pegasus = urb->context;
        struct net_device *net;
        int status = urb->status;

        if (!pegasus)
                return;

        net = pegasus->net;

        if (!netif_device_present(net) || !netif_running(net))
                return;

        switch (status) {
        case -EPIPE:
                /* FIXME schedule_work() to clear the tx halt */
                netif_stop_queue(net);
                netif_warn(pegasus, tx_err, net, "no tx stall recovery\n");
                return;
        case -ENOENT:
        case -ECONNRESET:
        case -ESHUTDOWN:
                netif_dbg(pegasus, ifdown, net, "tx unlink, %d\n", status);
                return;
        default:
                netif_info(pegasus, tx_err, net, "TX status %d\n", status);
                fallthrough;
        case 0:
                break;
        }

        netif_trans_update(net); /* prevent tx timeout */
        netif_wake_queue(net);
}

static void intr_callback(struct urb *urb)
{
        pegasus_t *pegasus = urb->context;
        struct net_device *net;
        int res, status = urb->status;

        if (!pegasus)
                return;
        net = pegasus->net;

        switch (status) {
        case 0:
                break;
        case -ECONNRESET:       /* unlink */
        case -ENOENT:
        case -ESHUTDOWN:
                return;
        default:
                /* some Pegasus-I products report LOTS of data
                 * toggle errors... avoid log spamming
                 */
                netif_dbg(pegasus, timer, net, "intr status %d\n", status);
        }

        if (urb->actual_length >= 6) {
                u8 *d = urb->transfer_buffer;

                /* byte 0 == tx_status1, reg 2B */
                if (d[0] & (TX_UNDERRUN|EXCESSIVE_COL
                                        |LATE_COL|JABBER_TIMEOUT)) {
                        net->stats.tx_errors++;
                        if (d[0] & TX_UNDERRUN)
                                net->stats.tx_fifo_errors++;
                        if (d[0] & (EXCESSIVE_COL | JABBER_TIMEOUT))
                                net->stats.tx_aborted_errors++;
                        if (d[0] & LATE_COL)
                                net->stats.tx_window_errors++;
                }

                /* d[5].LINK_STATUS lies on some adapters.
                 * d[0].NO_CARRIER kicks in only with failed TX.
                 * ... so monitoring with MII may be safest.
                 */

                /* bytes 3-4 == rx_lostpkt, reg 2E/2F */
                net->stats.rx_missed_errors += ((d[3] & 0x7f) << 8) | d[4];
        }

        res = usb_submit_urb(urb, GFP_ATOMIC);
        if (res == -ENODEV)
                netif_device_detach(pegasus->net);
        if (res)
                netif_err(pegasus, timer, net,
                          "can't resubmit interrupt urb, %d\n", res);
}

static void pegasus_tx_timeout(struct net_device *net, unsigned int txqueue)
{
        pegasus_t *pegasus = netdev_priv(net);
        netif_warn(pegasus, timer, net, "tx timeout\n");
        usb_unlink_urb(pegasus->tx_urb);
        net->stats.tx_errors++;
}

static netdev_tx_t pegasus_start_xmit(struct sk_buff *skb,
                                            struct net_device *net)
{
        pegasus_t *pegasus = netdev_priv(net);
        int count = ((skb->len + 2) & 0x3f) ? skb->len + 2 : skb->len + 3;
        int res;
        __u16 l16 = skb->len;

        netif_stop_queue(net);

        ((__le16 *) pegasus->tx_buff)[0] = cpu_to_le16(l16);
        skb_copy_from_linear_data(skb, pegasus->tx_buff + 2, skb->len);
        usb_fill_bulk_urb(pegasus->tx_urb, pegasus->usb,
                          usb_sndbulkpipe(pegasus->usb, 2),
                          pegasus->tx_buff, count,
                          write_bulk_callback, pegasus);
        if ((res = usb_submit_urb(pegasus->tx_urb, GFP_ATOMIC))) {
                netif_warn(pegasus, tx_err, net, "fail tx, %d\n", res);
                switch (res) {
                case -EPIPE:            /* stall, or disconnect from TT */
                        /* cleanup should already have been scheduled */
                        break;
                case -ENODEV:           /* disconnect() upcoming */
                case -EPERM:
                        netif_device_detach(pegasus->net);
                        break;
                default:
                        net->stats.tx_errors++;
                        netif_start_queue(net);
                }
        } else {
                net->stats.tx_packets++;
                net->stats.tx_bytes += skb->len;
        }
        dev_kfree_skb(skb);

        return NETDEV_TX_OK;
}

static inline void disable_net_traffic(pegasus_t *pegasus)
{
        __le16 tmp = cpu_to_le16(0);

        set_registers(pegasus, EthCtrl0, sizeof(tmp), &tmp);
}

static inline int get_interrupt_interval(pegasus_t *pegasus)
{
        u16 data;
        u8 interval;
        int ret;

        ret = read_eprom_word(pegasus, 4, &data);
        if (ret < 0)
                return ret;

        interval = data >> 8;
        if (pegasus->usb->speed != USB_SPEED_HIGH) {
                if (interval < 0x80) {
                        netif_info(pegasus, timer, pegasus->net,
                                   "intr interval changed from %ums to %ums\n",
                                   interval, 0x80);
                        interval = 0x80;
                        data = (data & 0x00FF) | ((u16)interval << 8);
#ifdef PEGASUS_WRITE_EEPROM
                        write_eprom_word(pegasus, 4, data);
#endif
                }
        }
        pegasus->intr_interval = interval;

        return 0;
}

static void set_carrier(struct net_device *net)
{
        pegasus_t *pegasus = netdev_priv(net);
        u16 tmp;

        if (read_mii_word(pegasus, pegasus->phy, MII_BMSR, &tmp))
                return;

        if (tmp & BMSR_LSTATUS)
                netif_carrier_on(net);
        else
                netif_carrier_off(net);
}

static void free_all_urbs(pegasus_t *pegasus)
{
        usb_free_urb(pegasus->intr_urb);
        usb_free_urb(pegasus->tx_urb);
        usb_free_urb(pegasus->rx_urb);
}

static void unlink_all_urbs(pegasus_t *pegasus)
{
        usb_kill_urb(pegasus->intr_urb);
        usb_kill_urb(pegasus->tx_urb);
        usb_kill_urb(pegasus->rx_urb);
}

static int alloc_urbs(pegasus_t *pegasus)
{
        int res = -ENOMEM;

        pegasus->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!pegasus->rx_urb) {
                return res;
        }
        pegasus->tx_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!pegasus->tx_urb) {
                usb_free_urb(pegasus->rx_urb);
                return res;
        }
        pegasus->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!pegasus->intr_urb) {
                usb_free_urb(pegasus->tx_urb);
                usb_free_urb(pegasus->rx_urb);
                return res;
        }

        return 0;
}

static int pegasus_open(struct net_device *net)
{
        pegasus_t *pegasus = netdev_priv(net);
        int res=-ENOMEM;

        if (pegasus->rx_skb == NULL)
                pegasus->rx_skb = __netdev_alloc_skb_ip_align(pegasus->net,
                                                              PEGASUS_MTU,
                                                              GFP_KERNEL);
        if (!pegasus->rx_skb)
                goto exit;

        set_registers(pegasus, EthID, 6, net->dev_addr);

        usb_fill_bulk_urb(pegasus->rx_urb, pegasus->usb,
                          usb_rcvbulkpipe(pegasus->usb, 1),
                          pegasus->rx_skb->data, PEGASUS_MTU,
                          read_bulk_callback, pegasus);
        if ((res = usb_submit_urb(pegasus->rx_urb, GFP_KERNEL))) {
                if (res == -ENODEV)
                        netif_device_detach(pegasus->net);
                netif_dbg(pegasus, ifup, net, "failed rx_urb, %d\n", res);
                goto exit;
        }

        usb_fill_int_urb(pegasus->intr_urb, pegasus->usb,
                         usb_rcvintpipe(pegasus->usb, 3),
                         pegasus->intr_buff, sizeof(pegasus->intr_buff),
                         intr_callback, pegasus, pegasus->intr_interval);
        if ((res = usb_submit_urb(pegasus->intr_urb, GFP_KERNEL))) {
                if (res == -ENODEV)
                        netif_device_detach(pegasus->net);
                netif_dbg(pegasus, ifup, net, "failed intr_urb, %d\n", res);
                usb_kill_urb(pegasus->rx_urb);
                goto exit;
        }
        res = enable_net_traffic(net, pegasus->usb);
        if (res < 0) {
                netif_dbg(pegasus, ifup, net,
                          "can't enable_net_traffic() - %d\n", res);
                res = -EIO;
                usb_kill_urb(pegasus->rx_urb);
                usb_kill_urb(pegasus->intr_urb);
                goto exit;
        }
        set_carrier(net);
        netif_start_queue(net);
        netif_dbg(pegasus, ifup, net, "open\n");
        res = 0;
exit:
        return res;
}

static int pegasus_close(struct net_device *net)
{
        pegasus_t *pegasus = netdev_priv(net);

        netif_stop_queue(net);
        if (!(pegasus->flags & PEGASUS_UNPLUG))
                disable_net_traffic(pegasus);
        tasklet_kill(&pegasus->rx_tl);
        unlink_all_urbs(pegasus);

        return 0;
}

static void pegasus_get_drvinfo(struct net_device *dev,
                                struct ethtool_drvinfo *info)
{
        pegasus_t *pegasus = netdev_priv(dev);

        strlcpy(info->driver, driver_name, sizeof(info->driver));
        usb_make_path(pegasus->usb, info->bus_info, sizeof(info->bus_info));
}

/* also handles three patterns of some kind in hardware */
#define WOL_SUPPORTED   (WAKE_MAGIC|WAKE_PHY)

static void
pegasus_get_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
{
        pegasus_t       *pegasus = netdev_priv(dev);

        wol->supported = WAKE_MAGIC | WAKE_PHY;
        wol->wolopts = pegasus->wolopts;
}

static int
pegasus_set_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
{
        pegasus_t       *pegasus = netdev_priv(dev);
        u8              reg78 = 0x04;
        int             ret;

        if (wol->wolopts & ~WOL_SUPPORTED)
                return -EINVAL;

        if (wol->wolopts & WAKE_MAGIC)
                reg78 |= 0x80;
        if (wol->wolopts & WAKE_PHY)
                reg78 |= 0x40;
        /* FIXME this 0x10 bit still needs to get set in the chip... */
        if (wol->wolopts)
                pegasus->eth_regs[0] |= 0x10;
        else
                pegasus->eth_regs[0] &= ~0x10;
        pegasus->wolopts = wol->wolopts;

        ret = set_register(pegasus, WakeupControl, reg78);
        if (!ret)
                ret = device_set_wakeup_enable(&pegasus->usb->dev,
                                                wol->wolopts);
        return ret;
}

static inline void pegasus_reset_wol(struct net_device *dev)
{
        struct ethtool_wolinfo wol;

        memset(&wol, 0, sizeof wol);
        (void) pegasus_set_wol(dev, &wol);
}

static int
pegasus_get_link_ksettings(struct net_device *dev,
                           struct ethtool_link_ksettings *ecmd)
{
        pegasus_t *pegasus;

        pegasus = netdev_priv(dev);
        mii_ethtool_get_link_ksettings(&pegasus->mii, ecmd);
        return 0;
}

static int
pegasus_set_link_ksettings(struct net_device *dev,
                           const struct ethtool_link_ksettings *ecmd)
{
        pegasus_t *pegasus = netdev_priv(dev);
        return mii_ethtool_set_link_ksettings(&pegasus->mii, ecmd);
}

static int pegasus_nway_reset(struct net_device *dev)
{
        pegasus_t *pegasus = netdev_priv(dev);
        return mii_nway_restart(&pegasus->mii);
}

static u32 pegasus_get_link(struct net_device *dev)
{
        pegasus_t *pegasus = netdev_priv(dev);
        return mii_link_ok(&pegasus->mii);
}

static u32 pegasus_get_msglevel(struct net_device *dev)
{
        pegasus_t *pegasus = netdev_priv(dev);
        return pegasus->msg_enable;
}

static void pegasus_set_msglevel(struct net_device *dev, u32 v)
{
        pegasus_t *pegasus = netdev_priv(dev);
        pegasus->msg_enable = v;
}

static const struct ethtool_ops ops = {
        .get_drvinfo = pegasus_get_drvinfo,
        .nway_reset = pegasus_nway_reset,
        .get_link = pegasus_get_link,
        .get_msglevel = pegasus_get_msglevel,
        .set_msglevel = pegasus_set_msglevel,
        .get_wol = pegasus_get_wol,
        .set_wol = pegasus_set_wol,
        .get_link_ksettings = pegasus_get_link_ksettings,

        .set_link_ksettings = pegasus_set_link_ksettings,
};

static int pegasus_siocdevprivate(struct net_device *net, struct ifreq *rq,
                                  void __user *udata, int cmd)
{
        __u16 *data = (__u16 *) &rq->ifr_ifru;
        pegasus_t *pegasus = netdev_priv(net);
        int res;

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

static void pegasus_set_multicast(struct net_device *net)
{
        pegasus_t *pegasus = netdev_priv(net);

        if (net->flags & IFF_PROMISC) {
                pegasus->eth_regs[EthCtrl2] |= RX_PROMISCUOUS;
                netif_info(pegasus, link, net, "Promiscuous mode enabled\n");
        } else if (!netdev_mc_empty(net) || (net->flags & IFF_ALLMULTI)) {
                pegasus->eth_regs[EthCtrl0] |= RX_MULTICAST;
                pegasus->eth_regs[EthCtrl2] &= ~RX_PROMISCUOUS;
                netif_dbg(pegasus, link, net, "set allmulti\n");
        } else {
                pegasus->eth_regs[EthCtrl0] &= ~RX_MULTICAST;
                pegasus->eth_regs[EthCtrl2] &= ~RX_PROMISCUOUS;
        }
        update_eth_regs_async(pegasus);
}

static __u8 mii_phy_probe(pegasus_t *pegasus)
{
        int i, ret;
        __u16 tmp;

        for (i = 0; i < 32; i++) {
                ret = read_mii_word(pegasus, i, MII_BMSR, &tmp);
                if (ret < 0)
                        goto fail;
                if (tmp == 0 || tmp == 0xffff || (tmp & BMSR_MEDIA) == 0)
                        continue;
                else
                        return i;
        }
fail:
        return 0xff;
}

static inline void setup_pegasus_II(pegasus_t *pegasus)
{
        int ret;
        __u8 data = 0xa5;

        set_register(pegasus, Reg1d, 0);
        set_register(pegasus, Reg7b, 1);
        msleep(100);
        if ((pegasus->features & HAS_HOME_PNA) && mii_mode)
                set_register(pegasus, Reg7b, 0);
        else
                set_register(pegasus, Reg7b, 2);

        set_register(pegasus, 0x83, data);
        ret = get_registers(pegasus, 0x83, 1, &data);
        if (ret < 0)
                goto fail;

        if (data == 0xa5)
                pegasus->chip = 0x8513;
        else
                pegasus->chip = 0;

        set_register(pegasus, 0x80, 0xc0);
        set_register(pegasus, 0x83, 0xff);
        set_register(pegasus, 0x84, 0x01);

        if (pegasus->features & HAS_HOME_PNA && mii_mode)
                set_register(pegasus, Reg81, 6);
        else
                set_register(pegasus, Reg81, 2);

        return;
fail:
        netif_dbg(pegasus, drv, pegasus->net, "%s failed\n", __func__);
}

static void check_carrier(struct work_struct *work)
{
        pegasus_t *pegasus = container_of(work, pegasus_t, carrier_check.work);
        set_carrier(pegasus->net);
        if (!(pegasus->flags & PEGASUS_UNPLUG)) {
                queue_delayed_work(system_long_wq, &pegasus->carrier_check,
                        CARRIER_CHECK_DELAY);
        }
}

static int pegasus_blacklisted(struct usb_device *udev)
{
        struct usb_device_descriptor *udd = &udev->descriptor;

        /* Special quirk to keep the driver from handling the Belkin Bluetooth
         * dongle which happens to have the same ID.
         */
        if ((udd->idVendor == cpu_to_le16(VENDOR_BELKIN)) &&
            (udd->idProduct == cpu_to_le16(0x0121)) &&
            (udd->bDeviceClass == USB_CLASS_WIRELESS_CONTROLLER) &&
            (udd->bDeviceProtocol == 1))
                return 1;

        return 0;
}

static int pegasus_probe(struct usb_interface *intf,
                         const struct usb_device_id *id)
{
        struct usb_device *dev = interface_to_usbdev(intf);
        struct net_device *net;
        pegasus_t *pegasus;
        int dev_index = id - pegasus_ids;
        int res = -ENOMEM;

        if (pegasus_blacklisted(dev))
                return -ENODEV;

        net = alloc_etherdev(sizeof(struct pegasus));
        if (!net)
                goto out;

        pegasus = netdev_priv(net);
        pegasus->dev_index = dev_index;

        res = alloc_urbs(pegasus);
        if (res < 0) {
                dev_err(&intf->dev, "can't allocate %s\n", "urbs");
                goto out1;
        }

        tasklet_setup(&pegasus->rx_tl, rx_fixup);

        INIT_DELAYED_WORK(&pegasus->carrier_check, check_carrier);

        pegasus->intf = intf;
        pegasus->usb = dev;
        pegasus->net = net;


        net->watchdog_timeo = PEGASUS_TX_TIMEOUT;
        net->netdev_ops = &pegasus_netdev_ops;
        net->ethtool_ops = &ops;
        pegasus->mii.dev = net;
        pegasus->mii.mdio_read = mdio_read;
        pegasus->mii.mdio_write = mdio_write;
        pegasus->mii.phy_id_mask = 0x1f;
        pegasus->mii.reg_num_mask = 0x1f;
        pegasus->msg_enable = netif_msg_init(msg_level, NETIF_MSG_DRV
                                | NETIF_MSG_PROBE | NETIF_MSG_LINK);

        pegasus->features = usb_dev_id[dev_index].private;
        res = get_interrupt_interval(pegasus);
        if (res)
                goto out2;
        if (reset_mac(pegasus)) {
                dev_err(&intf->dev, "can't reset MAC\n");
                res = -EIO;
                goto out2;
        }
        set_ethernet_addr(pegasus);
        if (pegasus->features & PEGASUS_II) {
                dev_info(&intf->dev, "setup Pegasus II specific registers\n");
                setup_pegasus_II(pegasus);
        }
        pegasus->phy = mii_phy_probe(pegasus);
        if (pegasus->phy == 0xff) {
                dev_warn(&intf->dev, "can't locate MII phy, using default\n");
                pegasus->phy = 1;
        }
        pegasus->mii.phy_id = pegasus->phy;
        usb_set_intfdata(intf, pegasus);
        SET_NETDEV_DEV(net, &intf->dev);
        pegasus_reset_wol(net);
        res = register_netdev(net);
        if (res)
                goto out3;
        queue_delayed_work(system_long_wq, &pegasus->carrier_check,
                           CARRIER_CHECK_DELAY);
        dev_info(&intf->dev, "%s, %s, %pM\n", net->name,
                 usb_dev_id[dev_index].name, net->dev_addr);
        return 0;

out3:
        usb_set_intfdata(intf, NULL);
out2:
        free_all_urbs(pegasus);
out1:
        free_netdev(net);
out:
        return res;
}

static void pegasus_disconnect(struct usb_interface *intf)
{
        struct pegasus *pegasus = usb_get_intfdata(intf);

        usb_set_intfdata(intf, NULL);
        if (!pegasus) {
                dev_dbg(&intf->dev, "unregistering non-bound device?\n");
                return;
        }

        pegasus->flags |= PEGASUS_UNPLUG;
        cancel_delayed_work_sync(&pegasus->carrier_check);
        unregister_netdev(pegasus->net);
        unlink_all_urbs(pegasus);
        free_all_urbs(pegasus);
        if (pegasus->rx_skb != NULL) {
                dev_kfree_skb(pegasus->rx_skb);
                pegasus->rx_skb = NULL;
        }
        free_netdev(pegasus->net);
}

static int pegasus_suspend(struct usb_interface *intf, pm_message_t message)
{
        struct pegasus *pegasus = usb_get_intfdata(intf);

        netif_device_detach(pegasus->net);
        cancel_delayed_work_sync(&pegasus->carrier_check);
        if (netif_running(pegasus->net)) {
                usb_kill_urb(pegasus->rx_urb);
                usb_kill_urb(pegasus->intr_urb);
        }
        return 0;
}

static int pegasus_resume(struct usb_interface *intf)
{
        struct pegasus *pegasus = usb_get_intfdata(intf);

        netif_device_attach(pegasus->net);
        if (netif_running(pegasus->net)) {
                pegasus->rx_urb->status = 0;
                pegasus->rx_urb->actual_length = 0;
                read_bulk_callback(pegasus->rx_urb);

                pegasus->intr_urb->status = 0;
                pegasus->intr_urb->actual_length = 0;
                intr_callback(pegasus->intr_urb);
        }
        queue_delayed_work(system_long_wq, &pegasus->carrier_check,
                                CARRIER_CHECK_DELAY);
        return 0;
}

static const struct net_device_ops pegasus_netdev_ops = {
        .ndo_open =                     pegasus_open,
        .ndo_stop =                     pegasus_close,
        .ndo_siocdevprivate =           pegasus_siocdevprivate,
        .ndo_start_xmit =               pegasus_start_xmit,
        .ndo_set_rx_mode =              pegasus_set_multicast,
        .ndo_tx_timeout =               pegasus_tx_timeout,
        .ndo_set_mac_address =          eth_mac_addr,
        .ndo_validate_addr =            eth_validate_addr,
};

static struct usb_driver pegasus_driver = {
        .name = driver_name,
        .probe = pegasus_probe,
        .disconnect = pegasus_disconnect,
        .id_table = pegasus_ids,
        .suspend = pegasus_suspend,
        .resume = pegasus_resume,
        .disable_hub_initiated_lpm = 1,
};

static void __init parse_id(char *id)
{
        unsigned int vendor_id = 0, device_id = 0, flags = 0, i = 0;
        char *token, *name = NULL;

        if ((token = strsep(&id, ":")) != NULL)
                name = token;
        /* name now points to a null terminated string*/
        if ((token = strsep(&id, ":")) != NULL)
                vendor_id = simple_strtoul(token, NULL, 16);
        if ((token = strsep(&id, ":")) != NULL)
                device_id = simple_strtoul(token, NULL, 16);
        flags = simple_strtoul(id, NULL, 16);
        pr_info("%s: new device %s, vendor ID 0x%04x, device ID 0x%04x, flags: 0x%x\n",
                driver_name, name, vendor_id, device_id, flags);

        if (vendor_id > 0x10000 || vendor_id == 0)
                return;
        if (device_id > 0x10000 || device_id == 0)
                return;

        for (i = 0; usb_dev_id[i].name; i++);
        usb_dev_id[i].name = name;
        usb_dev_id[i].vendor = vendor_id;
        usb_dev_id[i].device = device_id;
        usb_dev_id[i].private = flags;
        pegasus_ids[i].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
        pegasus_ids[i].idVendor = vendor_id;
        pegasus_ids[i].idProduct = device_id;
}

static int __init pegasus_init(void)
{
        pr_info("%s: " DRIVER_DESC "\n", driver_name);
        if (devid)
                parse_id(devid);
        return usb_register(&pegasus_driver);
}

static void __exit pegasus_exit(void)
{
        usb_deregister(&pegasus_driver);
}

module_init(pegasus_init);
module_exit(pegasus_exit);