/*
 *  Copyright (c) 2002 Petko Manolov (petkan@users.sourceforge.net)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

#include <linux/init.h>
#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 <asm/uaccess.h>

/* Version Information */
#define DRIVER_VERSION "v0.6.2 (2004/08/27)"
#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)

/* 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

/* 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)

/* 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 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, *ctrl_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;
	__le16 rx_creg;
	u8 *intr_buff;
	u8 phy;
};

typedef struct rtl8150 rtl8150_t;

static void fill_skb_pool(rtl8150_t *);
static void free_skb_pool(rtl8150_t *);
static inline struct sk_buff *pull_skb(rtl8150_t *);
static void rtl8150_disconnect(struct usb_interface *intf);
static int rtl8150_probe(struct usb_interface *intf,
			   const struct usb_device_id *id);
static int rtl8150_suspend(struct usb_interface *intf, pm_message_t message);
static int rtl8150_resume(struct usb_interface *intf);

static const char driver_name [] = "rtl8150";

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
};

/*
**
**	device related part of the code
**
*/
static int get_registers(rtl8150_t * dev, u16 indx, u16 size, void *data)
{
	return usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
			       RTL8150_REQ_GET_REGS, RTL8150_REQT_READ,
			       indx, 0, data, size, 500);
}

static int set_registers(rtl8150_t * dev, u16 indx, u16 size, void *data)
{
	return usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
			       RTL8150_REQ_SET_REGS, RTL8150_REQT_WRITE,
			       indx, 0, data, size, 500);
}

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

	switch (status) {
	case 0:
		break;
	case -EINPROGRESS:
		break;
	case -ENOENT:
		break;
	default:
		if (printk_ratelimit())
			dev_warn(&urb->dev->dev, "ctrl urb status %d\n", status);
	}
	dev = urb->context;
	clear_bit(RX_REG_SET, &dev->flags);
}

static int async_set_registers(rtl8150_t * dev, u16 indx, u16 size)
{
	int ret;

	if (test_bit(RX_REG_SET, &dev->flags))
		return -EAGAIN;

	dev->dr.bRequestType = RTL8150_REQT_WRITE;
	dev->dr.bRequest = RTL8150_REQ_SET_REGS;
	dev->dr.wValue = cpu_to_le16(indx);
	dev->dr.wIndex = 0;
	dev->dr.wLength = cpu_to_le16(size);
	dev->ctrl_urb->transfer_buffer_length = size;
	usb_fill_control_urb(dev->ctrl_urb, dev->udev,
			 usb_sndctrlpipe(dev->udev, 0), (char *) &dev->dr,
			 &dev->rx_creg, size, ctrl_callback, dev);
	if ((ret = usb_submit_urb(dev->ctrl_urb, GFP_ATOMIC))) {
		if (ret == -ENODEV)
			netif_device_detach(dev->netdev);
		err("control request submission failed: %d", ret);
	} else
		set_bit(RX_REG_SET, &dev->flags);

	return ret;
}

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 inline void set_ethernet_addr(rtl8150_t * dev)
{
	u8 node_id[6];

	get_registers(dev, IDR, sizeof(node_id), node_id);
	memcpy(dev->netdev->dev_addr, node_id, sizeof(node_id));
}

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;

	memcpy(netdev->dev_addr, addr->sa_data, netdev->addr_len);
	dbg("%s: Setting MAC address to %pM\n", netdev->name, 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;
	}
	dev->ctrl_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!dev->ctrl_urb) {
		usb_free_urb(dev->rx_urb);
		usb_free_urb(dev->tx_urb);
		usb_free_urb(dev->intr_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);
	usb_free_urb(dev->ctrl_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);
	usb_kill_urb(dev->ctrl_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;
	u16 rx_stat;
	int status = urb->status;
	int result;

	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;
	rx_stat = le16_to_cpu(*(__le16 *)(urb->transfer_buffer + res - 4));
	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(&dev->rx_pool_lock);
	skb = pull_skb(dev);
	spin_unlock(&dev->rx_pool_lock);
	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 rx_fixup(unsigned long data)
{
	rtl8150_t *dev;
	struct sk_buff *skb;
	int status;

	dev = (rtl8150_t *)data;

	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 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);
	dev->netdev->trans_start = jiffies;
	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);
			dbg("%s: LINK LOST\n", __func__);
		}
	} else {
		if (!netif_carrier_ok(dev->netdev)) {
			netif_carrier_on(dev->netdev);
			dbg("%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)
		err ("can't resubmit intr, %s-%s/input0, status %d",
				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++)
		if (dev->rx_skb_pool[i])
			dev_kfree_skb(dev->rx_skb_pool[i]);
}

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;
	dev->rx_creg = cpu_to_le16(rcr);
	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)
{
	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);
	netif_stop_queue(netdev);
	if (netdev->flags & IFF_PROMISC) {
		dev->rx_creg |= cpu_to_le16(0x0001);
		dev_info(&netdev->dev, "%s: promiscuous mode\n", netdev->name);
	} else if (netdev->mc_count ||
		   (netdev->flags & IFF_ALLMULTI)) {
		dev->rx_creg &= cpu_to_le16(0xfffe);
		dev->rx_creg |= cpu_to_le16(0x0002);
		dev_info(&netdev->dev, "%s: allmulti set\n", netdev->name);
	} else {
		/* ~RX_MULTICAST, ~RX_PROMISCUOUS */
		dev->rx_creg &= cpu_to_le16(0x00fc);
	}
	async_set_registers(dev, RCR, 2);
	netif_wake_queue(netdev);
}

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

	netif_stop_queue(netdev);
	count = (skb->len < 60) ? 60 : skb->len;
	count = (count & 0x3f) ? count : count + 1;
	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;
		netdev->trans_start = jiffies;
	}

	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);
	int res = 0;

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

	return res;
}

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

	strncpy(info->driver, driver_name, ETHTOOL_BUSINFO_LEN);
	strncpy(info->version, DRIVER_VERSION, ETHTOOL_BUSINFO_LEN);
	usb_make_path(dev->udev, info->bus_info, sizeof info->bus_info);
}

static int rtl8150_get_settings(struct net_device *netdev, struct ethtool_cmd *ecmd)
{
	rtl8150_t *dev = netdev_priv(netdev);
	short lpa, bmcr;

	ecmd->supported = (SUPPORTED_10baseT_Half |
			  SUPPORTED_10baseT_Full |
			  SUPPORTED_100baseT_Half |
			  SUPPORTED_100baseT_Full |
			  SUPPORTED_Autoneg |
			  SUPPORTED_TP | SUPPORTED_MII);
	ecmd->port = PORT_TP;
	ecmd->transceiver = XCVR_INTERNAL;
	ecmd->phy_address = dev->phy;
	get_registers(dev, BMCR, 2, &bmcr);
	get_registers(dev, ANLP, 2, &lpa);
	if (bmcr & BMCR_ANENABLE) {
		ecmd->autoneg = AUTONEG_ENABLE;
		ecmd->speed = (lpa & (LPA_100HALF | LPA_100FULL)) ?
			     SPEED_100 : SPEED_10;
		if (ecmd->speed == SPEED_100)
			ecmd->duplex = (lpa & LPA_100FULL) ?
			    DUPLEX_FULL : DUPLEX_HALF;
		else
			ecmd->duplex = (lpa & LPA_10FULL) ?
			    DUPLEX_FULL : DUPLEX_HALF;
	} else {
		ecmd->autoneg = AUTONEG_DISABLE;
		ecmd->speed = (bmcr & BMCR_SPEED100) ?
		    SPEED_100 : SPEED_10;
		ecmd->duplex = (bmcr & BMCR_FULLDPLX) ?
		    DUPLEX_FULL : DUPLEX_HALF;
	}
	return 0;
}

static const struct ethtool_ops ops = {
	.get_drvinfo = rtl8150_get_drvinfo,
	.get_settings = rtl8150_get_settings,
	.get_link = ethtool_op_get_link
};

static int rtl8150_ioctl(struct net_device *netdev, struct ifreq *rq, 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;
	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_do_ioctl		= rtl8150_ioctl,
	.ndo_start_xmit		= rtl8150_start_xmit,
	.ndo_tx_timeout 	= rtl8150_tx_timeout,
	.ndo_set_multicast_list = rtl8150_set_multicast,
	.ndo_set_mac_address	= rtl8150_set_mac_address,

	.ndo_change_mtu		= eth_change_mtu,
	.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;

	netdev = alloc_etherdev(sizeof(rtl8150_t));
	if (!netdev) {
		err("Out of memory");
		return -ENOMEM;
	}

	dev = netdev_priv(netdev);

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

	tasklet_init(&dev->tl, rx_fixup, (unsigned long)dev);
	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;
	SET_ETHTOOL_OPS(netdev, &ops);
	dev->intr_interval = 100;	/* 100ms */

	if (!alloc_all_urbs(dev)) {
		err("out of memory");
		goto out;
	}
	if (!rtl8150_reset(dev)) {
		err("couldn't reset the device");
		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) {
		err("couldn't register the device");
		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_disable(&dev->tl);
		tasklet_kill(&dev->tl);
		unregister_netdev(dev->netdev);
		unlink_all_urbs(dev);
		free_all_urbs(dev);
		free_skb_pool(dev);
		if (dev->rx_skb)
			dev_kfree_skb(dev->rx_skb);
		kfree(dev->intr_buff);
		free_netdev(dev->netdev);
	}
}

static int __init usb_rtl8150_init(void)
{
	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
	       DRIVER_DESC "\n");
	return usb_register(&rtl8150_driver);
}

static void __exit usb_rtl8150_exit(void)
{
	usb_deregister(&rtl8150_driver);
}

module_init(usb_rtl8150_init);
module_exit(usb_rtl8150_exit);

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