path: root/linux/src/drivers/net/natsemi.c

/* natsemi.c: A Linux PCI Ethernet driver for the NatSemi DP83810 series. */
/*
	Written/copyright 1999-2003 by Donald Becker.

	This software may be used and distributed according to the terms of
	the GNU General Public License (GPL), incorporated herein by reference.
	Drivers based on or derived from this code fall under the GPL and must
	retain the authorship, copyright and license notice.  This file is not
	a complete program and may only be used when the entire operating
	system is licensed under the GPL.  License for under other terms may be
	available.  Contact the original author for details.

	The original author may be reached as becker@scyld.com, or at
	Scyld Computing Corporation
	914 Bay Ridge Road, Suite 220
	Annapolis MD 21403

	Support information and updates available at
		http://www.scyld.com/network/natsemi.html
	The information and support mailing lists are based at
		http://www.scyld.com/mailman/listinfo/
*/

/* These identify the driver base version and may not be removed. */
static const char version1[] =
"natsemi.c:v1.17a 8/09/2003  Written by Donald Becker <becker@scyld.com>\n";
static const char version2[] =
"  http://www.scyld.com/network/natsemi.html\n";
/* Updated to recommendations in pci-skeleton v2.11. */

/* Automatically extracted configuration info:
probe-func: natsemi_probe
config-in: tristate 'National Semiconductor DP8381x series PCI Ethernet support' CONFIG_NATSEMI

c-help-name: National Semiconductor DP8381x series PCI Ethernet support
c-help-symbol: CONFIG_NATSEMI
c-help: This driver is for the National Semiconductor DP83810 series,
c-help: including the 83815 chip.
c-help: Usage information and updates are available from
c-help: http://www.scyld.com/network/natsemi.html
*/

/* The user-configurable values.
   These may be modified when a driver module is loaded.*/

/* Message enable level: 0..31 = no..all messages.  See NETIF_MSG docs. */
static int debug = 2;

/* Maximum events (Rx packets, etc.) to handle at each interrupt. */
static int max_interrupt_work = 20;

/* Maximum number of multicast addresses to filter (vs. rx-all-multicast).
   This chip uses a 512 element hash table based on the Ethernet CRC.
   Some chip versions are reported to have unreliable multicast filter
   circuitry.  To work around an observed problem set this value to '0',
   which will immediately switch to Rx-all-multicast.
*/
static int multicast_filter_limit = 100;

/* Set the copy breakpoint for the copy-only-tiny-frames scheme.
   Setting to > 1518 effectively disables this feature.
   This chip can only receive into aligned buffers, so architectures such
   as the Alpha AXP might benefit from a copy-align.
*/
static int rx_copybreak = 0;

/* Used to pass the media type, etc.
   Both 'options[]' and 'full_duplex[]' should exist for driver
   interoperability, however setting full_duplex[] is deprecated.
   The media type is usually passed in 'options[]'.
	The default is autonegotation for speed and duplex.
	This should rarely be overridden.
	Use option values 0x10/0x20 for 10Mbps, 0x100,0x200 for 100Mbps.
	Use option values 0x10 and 0x100 for forcing half duplex fixed speed.
	Use option values 0x20 and 0x200 for forcing full duplex operation.
*/
#define MAX_UNITS 8		/* More are supported, limit only on options */
static int options[MAX_UNITS] = {-1, -1, -1, -1, -1, -1, -1, -1};
static int full_duplex[MAX_UNITS] = {-1, -1, -1, -1, -1, -1, -1, -1};

/* Operational parameters that are set at compile time. */

/* Keep the ring sizes a power of two for compile efficiency.
   Understand the implications before changing these settings!
   The compiler will convert <unsigned>'%'<2^N> into a bit mask.
   Making the Tx ring too large decreases the effectiveness of channel
   bonding and packet priority.
   Too-large receive rings waste memory and confound network buffer limits. */
#define TX_RING_SIZE	16
#define TX_QUEUE_LEN	10		/* Limit ring entries actually used, min 4. */
#define RX_RING_SIZE	32

/* Operational parameters that usually are not changed. */
/* Time in jiffies before concluding the transmitter is hung.
   Re-autonegotiation may take up to 3 seconds.
 */
#define TX_TIMEOUT  (6*HZ)

/* Allocation size of Rx buffers with normal sized Ethernet frames.
   Do not change this value without good reason.  This is not a limit,
   but a way to keep a consistent allocation size among drivers.
 */
#define PKT_BUF_SZ		1536

#ifndef __KERNEL__
#define __KERNEL__
#endif
#if !defined(__OPTIMIZE__)
#warning  You must compile this file with the correct options!
#warning  See the last lines of the source file.
#error You must compile this driver with "-O".
#endif

/* Include files, designed to support most kernel versions 2.0.0 and later. */
#include <linux/config.h>
#if defined(CONFIG_SMP) && ! defined(__SMP__)
#define __SMP__
#endif
#if defined(MODULE) && defined(CONFIG_MODVERSIONS) && ! defined(MODVERSIONS)
#define MODVERSIONS
#endif

#include <linux/version.h>
#if defined(MODVERSIONS)
#include <linux/modversions.h>
#endif
#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#if LINUX_VERSION_CODE >= 0x20400
#include <linux/slab.h>
#else
#include <linux/malloc.h>
#endif
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <asm/processor.h>		/* Processor type for cache alignment. */
#include <asm/bitops.h>
#include <asm/io.h>

#ifdef INLINE_PCISCAN
#include "k_compat.h"
#else
#include "pci-scan.h"
#include "kern_compat.h"
#endif

/* Condensed operations for readability. */
#define virt_to_le32desc(addr)  cpu_to_le32(virt_to_bus(addr))
#define le32desc_to_virt(addr)  bus_to_virt(le32_to_cpu(addr))

#if (LINUX_VERSION_CODE >= 0x20100)  &&  defined(MODULE)
char kernel_version[] = UTS_RELEASE;
#endif

MODULE_AUTHOR("Donald Becker <becker@scyld.com>");
MODULE_DESCRIPTION("National Semiconductor DP83810 series PCI Ethernet driver");
MODULE_LICENSE("GPL");
MODULE_PARM(debug, "i");
MODULE_PARM(options, "1-" __MODULE_STRING(MAX_UNITS) "i");
MODULE_PARM(rx_copybreak, "i");
MODULE_PARM(full_duplex, "1-" __MODULE_STRING(MAX_UNITS) "i");
MODULE_PARM(multicast_filter_limit, "i");
MODULE_PARM(max_interrupt_work, "i");
MODULE_PARM_DESC(debug, "Driver message level (0-31)");
MODULE_PARM_DESC(options, "Force transceiver type or fixed speed+duplex");
MODULE_PARM_DESC(max_interrupt_work,
				 "Driver maximum events handled per interrupt");
MODULE_PARM_DESC(full_duplex,
				 "Non-zero to force full duplex, non-negotiated link "
				 "(deprecated).");
MODULE_PARM_DESC(rx_copybreak,
				 "Breakpoint in bytes for copy-only-tiny-frames");
MODULE_PARM_DESC(multicast_filter_limit,
				 "Multicast addresses before switching to Rx-all-multicast");

/*
				Theory of Operation

I. Board Compatibility

This driver is designed for National Semiconductor DP83815 PCI Ethernet NIC.
It also works with other chips in in the DP83810 series.
The most common board is the Netgear FA311 using the 83815.

II. Board-specific settings

This driver requires the PCI interrupt line to be valid.
It honors the EEPROM-set values.

III. Driver operation

IIIa. Ring buffers

This driver uses two statically allocated fixed-size descriptor lists
formed into rings by a branch from the final descriptor to the beginning of
the list.  The ring sizes are set at compile time by RX/TX_RING_SIZE.
The NatSemi design uses a 'next descriptor' pointer that the driver forms
into a list, thus rings can be arbitrarily sized.  Before changing the
ring sizes you should understand the flow and cache effects of the
full/available/empty hysteresis.

IIIb/c. Transmit/Receive Structure

This driver uses a zero-copy receive and transmit scheme.
The driver allocates full frame size skbuffs for the Rx ring buffers at
open() time and passes the skb->data field to the chip as receive data
buffers.  When an incoming frame is less than RX_COPYBREAK bytes long,
a fresh skbuff is allocated and the frame is copied to the new skbuff.
When the incoming frame is larger, the skbuff is passed directly up the
protocol stack.  Buffers consumed this way are replaced by newly allocated
skbuffs in a later phase of receives.

The RX_COPYBREAK value is chosen to trade-off the memory wasted by
using a full-sized skbuff for small frames vs. the copying costs of larger
frames.  New boards are typically used in generously configured machines
and the underfilled buffers have negligible impact compared to the benefit of
a single allocation size, so the default value of zero results in never
copying packets.  When copying is done, the cost is usually mitigated by using
a combined copy/checksum routine.  Copying also preloads the cache, which is
most useful with small frames.

A subtle aspect of the operation is that unaligned buffers are not permitted
by the hardware.  Thus the IP header at offset 14 in an ethernet frame isn't
longword aligned for further processing.  On copies frames are put into the
skbuff at an offset of "+2", 16-byte aligning the IP header.

IIId. Synchronization

The driver runs as two independent, single-threaded flows of control.  One
is the send-packet routine, which enforces single-threaded use by the
dev->tbusy flag.  The other thread is the interrupt handler, which is single
threaded by the hardware and interrupt handling software.

The send packet thread has partial control over the Tx ring and 'dev->tbusy'
flag.  It sets the tbusy flag whenever it's queuing a Tx packet. If the next
queue slot is empty, it clears the tbusy flag when finished otherwise it sets
the 'lp->tx_full' flag.

The interrupt handler has exclusive control over the Rx ring and records stats
from the Tx ring.  After reaping the stats, it marks the Tx queue entry as
empty by incrementing the dirty_tx mark. Iff the 'lp->tx_full' flag is set, it
clears both the tx_full and tbusy flags.

IV. Notes

The older dp83810 chips are so uncommon that support is not relevant.
No NatSemi datasheet was publically available at the initial release date,
but the dp83815 has now been published.

IVb. References

http://www.scyld.com/expert/100mbps.html
http://www.scyld.com/expert/NWay.html


IVc. Errata

Qustionable multicast filter implementation.
The EEPROM format is obviously the result of a chip bug.
*/



static void *natsemi_probe1(struct pci_dev *pdev, void *init_dev,
							long ioaddr, int irq, int chip_idx, int find_cnt);
static int power_event(void *dev_instance, int event);
#ifdef USE_IO_OPS
#define PCI_IOTYPE (PCI_USES_MASTER | PCI_USES_IO  | PCI_ADDR0)
#else
#define PCI_IOTYPE (PCI_USES_MASTER | PCI_USES_MEM | PCI_ADDR1)
#endif

static struct pci_id_info pci_id_tbl[] = {
	{"Netgear FA311 (NatSemi DP83815)",
	 { 0x0020100B, 0xffffffff, 0xf3111385, 0xffffffff, },
	 PCI_IOTYPE, 256, 0},
	{"NatSemi DP83815", { 0x0020100B, 0xffffffff },
	 PCI_IOTYPE, 256, 0},
	{0,},						/* 0 terminated list. */
};

struct drv_id_info natsemi_drv_id = {
	"natsemi", PCI_HOTSWAP, PCI_CLASS_NETWORK_ETHERNET<<8, pci_id_tbl,
	natsemi_probe1, power_event };

/* Offsets to the device registers.
   Unlike software-only systems, device drivers interact with complex hardware.
   It's not useful to define symbolic names for every register bit in the
   device.  Please do not change these names without good reason.
*/
enum register_offsets {
	ChipCmd=0x00, ChipConfig=0x04, EECtrl=0x08, PCIBusCfg=0x0C,
	IntrStatus=0x10, IntrMask=0x14, IntrEnable=0x18,
	TxRingPtr=0x20, TxConfig=0x24,
	RxRingPtr=0x30, RxConfig=0x34, ClkRunCtrl=0x3C,
	WOLCmd=0x40, PauseCmd=0x44, RxFilterAddr=0x48, RxFilterData=0x4C,
	BootRomAddr=0x50, BootRomData=0x54, ChipRevReg=0x58,
	StatsCtrl=0x5C, StatsData=0x60,
	RxPktErrs=0x60, RxMissed=0x68, RxCRCErrs=0x64,
	NS_Xcvr_Mgmt = 0x80, NS_MII_BMCR=0x80, NS_MII_BMSR=0x84,
	NS_MII_Advert=0x90, NS_MIILinkPartner=0x94,
};

/* Bits in ChipCmd. */
enum ChipCmdBits {
	ChipReset=0x100, SoftIntr=0x80, RxReset=0x20, TxReset=0x10,
	RxOff=0x08, RxOn=0x04, TxOff=0x02, TxOn=0x01,
};

/* Bits in ChipConfig. */
enum ChipConfigBits {
	CfgLinkGood=0x80000000, CfgFDX=0x20000000,
};

/* Bits in the interrupt status/mask registers. */
enum intr_status_bits {
	IntrRxDone=0x0001, IntrRxIntr=0x0002, IntrRxErr=0x0004, IntrRxEarly=0x0008,
	IntrRxIdle=0x0010, IntrRxOverrun=0x0020,
	IntrTxDone=0x0040, IntrTxIntr=0x0080, IntrTxErr=0x0100,
	IntrTxIdle=0x0200, IntrTxUnderrun=0x0400,
	StatsMax=0x0800, IntrDrv=0x1000, WOLPkt=0x2000, LinkChange=0x4000,
	RxStatusOverrun=0x10000,
	RxResetDone=0x1000000, TxResetDone=0x2000000,
	IntrPCIErr=0x00f00000,
	IntrNormalSummary=0x0251, IntrAbnormalSummary=0xED20,
};

/* Bits in the RxMode register. */
enum rx_mode_bits {
	AcceptErr=0x20, AcceptRunt=0x10,
	AcceptBroadcast=0xC0000000,
	AcceptMulticast=0x00200000, AcceptAllMulticast=0x20000000,
	AcceptAllPhys=0x10000000, AcceptMyPhys=0x08000000,
};

/* The Rx and Tx buffer descriptors. */
/* Note that using only 32 bit fields simplifies conversion to big-endian
   architectures. */
struct netdev_desc {
	u32 next_desc;
	s32 cmd_status;
	u32 buf_addr;
	u32 software_use;
};

/* Bits in network_desc.status */
enum desc_status_bits {
	DescOwn=0x80000000, DescMore=0x40000000, DescIntr=0x20000000,
	DescNoCRC=0x10000000,
	DescPktOK=0x08000000, RxTooLong=0x00400000,
};

#define PRIV_ALIGN	15	/* Required alignment mask */
struct netdev_private {
	/* Descriptor rings first for alignment. */
	struct netdev_desc rx_ring[RX_RING_SIZE];
	struct netdev_desc tx_ring[TX_RING_SIZE];
	struct net_device *next_module;		/* Link for devices of this type. */
	void *priv_addr;					/* Unaligned address for kfree */
	const char *product_name;
	/* The addresses of receive-in-place skbuffs. */
	struct sk_buff* rx_skbuff[RX_RING_SIZE];
	/* The saved address of a sent-in-place packet/buffer, for later free(). */
	struct sk_buff* tx_skbuff[TX_RING_SIZE];
	struct net_device_stats stats;
	struct timer_list timer;	/* Media monitoring timer. */
	/* Frequently used values: keep some adjacent for cache effect. */
	int msg_level;
	int chip_id, drv_flags;
	struct pci_dev *pci_dev;
	long in_interrupt;			/* Word-long for SMP locks. */
	int max_interrupt_work;
	int intr_enable;
	unsigned int restore_intr_enable:1;	/* Set if temporarily masked.  */
	unsigned int rx_q_empty:1;			/* Set out-of-skbuffs.  */

	struct netdev_desc *rx_head_desc;
	unsigned int cur_rx, dirty_rx;		/* Producer/consumer ring indices */
	unsigned int rx_buf_sz;				/* Based on MTU+slack. */
	int rx_copybreak;

	unsigned int cur_tx, dirty_tx;
	unsigned int tx_full:1;				/* The Tx queue is full. */
	/* These values keep track of the transceiver/media in use. */
	unsigned int full_duplex:1;			/* Full-duplex operation requested. */
	unsigned int duplex_lock:1;
	unsigned int medialock:1;			/* Do not sense media. */
	unsigned int default_port;			/* Last dev->if_port value. */
	/* Rx filter. */
	u32 cur_rx_mode;
	u16 rx_filter[32];
	int multicast_filter_limit;
	/* FIFO and PCI burst thresholds. */
	int tx_config, rx_config;
	/* MII transceiver section. */
	u16 advertising;					/* NWay media advertisement */
};

static int  eeprom_read(long ioaddr, int location);
static int  mdio_read(struct net_device *dev, int phy_id, int location);
static void mdio_write(struct net_device *dev, int phy_id, int location,
					   int value);
static int  netdev_open(struct net_device *dev);
static void check_duplex(struct net_device *dev);
static void netdev_timer(unsigned long data);
static void tx_timeout(struct net_device *dev);
static int  rx_ring_fill(struct net_device *dev);
static void init_ring(struct net_device *dev);
static int  start_tx(struct sk_buff *skb, struct net_device *dev);
static void intr_handler(int irq, void *dev_instance, struct pt_regs *regs);
static void netdev_error(struct net_device *dev, int intr_status);
static int  netdev_rx(struct net_device *dev);
static void netdev_error(struct net_device *dev, int intr_status);
static void set_rx_mode(struct net_device *dev);
static struct net_device_stats *get_stats(struct net_device *dev);
static int mii_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
static int  netdev_close(struct net_device *dev);



/* A list of our installed devices, for removing the driver module. */
static struct net_device *root_net_dev = NULL;

#ifndef MODULE
int natsemi_probe(struct net_device *dev)
{
	if (pci_drv_register(&natsemi_drv_id, dev) < 0)
		return -ENODEV;
	printk(KERN_INFO "%s" KERN_INFO "%s", version1, version2);
	return 0;
}
#endif

static void *natsemi_probe1(struct pci_dev *pdev, void *init_dev,
							long ioaddr, int irq, int chip_idx, int card_idx)
{
	struct net_device *dev;
	struct netdev_private *np;
	void *priv_mem;
	int i, option = card_idx < MAX_UNITS ? options[card_idx] : 0;
	int prev_eedata;

	dev = init_etherdev(init_dev, 0);
	if (!dev)
		return NULL;

	/* Perhaps NETIF_MSG_PROBE */
	printk(KERN_INFO "%s: %s at 0x%lx, ",
		   dev->name, pci_id_tbl[chip_idx].name, ioaddr);

	/* Work around the dropped serial bit. */
	prev_eedata = eeprom_read(ioaddr, 6);
	for (i = 0; i < 3; i++) {
		int eedata = eeprom_read(ioaddr, i + 7);
		dev->dev_addr[i*2] = (eedata << 1) + (prev_eedata >> 15);
		dev->dev_addr[i*2+1] = eedata >> 7;
		prev_eedata = eedata;
	}
	for (i = 0; i < 5; i++)
		printk("%2.2x:", dev->dev_addr[i]);
	printk("%2.2x, IRQ %d.\n", dev->dev_addr[i], irq);

	/* Reset the chip to erase previous misconfiguration. */
	writel(ChipReset, ioaddr + ChipCmd);

	/* Make certain elements e.g. descriptor lists are aligned. */
	priv_mem = kmalloc(sizeof(*np) + PRIV_ALIGN, GFP_KERNEL);
	/* Check for the very unlikely case of no memory. */
	if (priv_mem == NULL)
		return NULL;

	dev->base_addr = ioaddr;
	dev->irq = irq;

	dev->priv = np = (void *)(((long)priv_mem + PRIV_ALIGN) & ~PRIV_ALIGN);
	memset(np, 0, sizeof(*np));
	np->priv_addr = priv_mem;

	np->next_module = root_net_dev;
	root_net_dev = dev;

	np->pci_dev = pdev;
	np->chip_id = chip_idx;
	np->drv_flags = pci_id_tbl[chip_idx].drv_flags;
	np->msg_level = (1 << debug) - 1;
	np->rx_copybreak = rx_copybreak;
	np->max_interrupt_work = max_interrupt_work;
	np->multicast_filter_limit = multicast_filter_limit;

	if (dev->mem_start)
		option = dev->mem_start;

	/* 0x10/0x20/0x100/0x200 set forced speed&duplex modes. */
	if (option > 0) {
		if (option & 0x220)
			np->full_duplex = 1;
		np->default_port = option & 0x3ff;
		if (np->default_port & 0x330) {
			np->medialock = 1;
			if (np->msg_level & NETIF_MSG_PROBE)
				printk(KERN_INFO "  Forcing %dMbs %s-duplex operation.\n",
					   (option & 0x300 ? 100 : 10),
					   (np->full_duplex ? "full" : "half"));
			writew(((option & 0x300) ? 0x2000 : 0) |	/* 100mbps? */
				   (np->full_duplex ? 0x0100 : 0), /* Full duplex? */
				   ioaddr + NS_MII_BMCR);
		}
	}
	if (card_idx < MAX_UNITS  &&  full_duplex[card_idx] > 0)
		np->full_duplex = 1;

	if (np->full_duplex) {
		if (np->msg_level & NETIF_MSG_PROBE)
			printk(KERN_INFO "%s: Set to forced full duplex, autonegotiation"
				   " disabled.\n", dev->name);
		np->duplex_lock = 1;
	}

	/* The chip-specific entries in the device structure. */
	dev->open = &netdev_open;
	dev->hard_start_xmit = &start_tx;
	dev->stop = &netdev_close;
	dev->get_stats = &get_stats;
	dev->set_multicast_list = &set_rx_mode;
	dev->do_ioctl = &mii_ioctl;

	/* Override the PME enable from the EEPROM. */
	writel(0x8000, ioaddr + ClkRunCtrl);

	if ((readl(ioaddr + ChipConfig) & 0xe000) != 0xe000) {
		u32 chip_config = readl(ioaddr + ChipConfig);
		if (np->msg_level & NETIF_MSG_PROBE)
			printk(KERN_INFO "%s: Transceiver default autonegotiation %s "
				   "10%s %s duplex.\n",
				   dev->name, chip_config & 0x2000 ? "enabled, advertise"
				   : "disabled, force", chip_config & 0x4000 ? "0" : "",
				   chip_config & 0x8000 ? "full" : "half");
	}
	if (np->msg_level & NETIF_MSG_PROBE)
		printk(KERN_INFO "%s: Transceiver status 0x%4.4x partner %4.4x.\n",
			   dev->name, (int)readl(ioaddr + NS_MII_BMSR),
			   (int)readl(ioaddr + NS_MIILinkPartner));

	return dev;
}


/* Read the EEPROM and MII Management Data I/O (MDIO) interfaces.
   The EEPROM code is for the common 93c06/46 EEPROMs with 6 bit addresses.
   Update to the code in other drivers for 8/10 bit addresses.
*/

/* Delay between EEPROM clock transitions.
   This "delay" forces out buffered PCI writes, which is sufficient to meet
   the timing requirements of most EEPROMs.
*/
#define eeprom_delay(ee_addr)	readl(ee_addr)

enum EEPROM_Ctrl_Bits {
	EE_ShiftClk=0x04, EE_DataIn=0x01, EE_ChipSelect=0x08, EE_DataOut=0x02,
};
#define EE_Write0 (EE_ChipSelect)
#define EE_Write1 (EE_ChipSelect | EE_DataIn)

/* The EEPROM commands include the preamble. */
enum EEPROM_Cmds {
	EE_WriteCmd=(5 << 6), EE_ReadCmd=(6 << 6), EE_EraseCmd=(7 << 6),
};

static int eeprom_read(long addr, int location)
{
	int i;
	int retval = 0;
	long ee_addr = addr + EECtrl;
	int read_cmd = location | EE_ReadCmd;
	writel(EE_Write0, ee_addr);

	/* Shift the read command bits out. */
	for (i = 10; i >= 0; i--) {
		short dataval = (read_cmd & (1 << i)) ? EE_Write1 : EE_Write0;
		writel(dataval, ee_addr);
		eeprom_delay(ee_addr);
		writel(dataval | EE_ShiftClk, ee_addr);
		eeprom_delay(ee_addr);
	}
	writel(EE_ChipSelect, ee_addr);
	eeprom_delay(ee_addr);

	for (i = 0; i < 16; i++) {
		writel(EE_ChipSelect | EE_ShiftClk, ee_addr);
		eeprom_delay(ee_addr);
		retval |= (readl(ee_addr) & EE_DataOut) ? 1 << i : 0;
		writel(EE_ChipSelect, ee_addr);
		eeprom_delay(ee_addr);
	}

	/* Terminate the EEPROM access. */
	writel(EE_Write0, ee_addr);
	writel(0, ee_addr);
	return retval;
}

/*  MII transceiver control section.
	The 83815 series has an internal, directly accessable transceiver.
	We present the management registers as if they were MII connected. */

static int mdio_read(struct net_device *dev, int phy_id, int location)
{
	if (phy_id == 1 && location < 32)
		return readw(dev->base_addr + NS_Xcvr_Mgmt + (location<<2));
	else
		return 0xffff;
}

static void mdio_write(struct net_device *dev, int phy_id, int location,
					   int value)
{
	if (phy_id == 1 && location < 32)
		writew(value, dev->base_addr + NS_Xcvr_Mgmt + (location<<2));
}


static int netdev_open(struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	long ioaddr = dev->base_addr;
	int i;

	/* We do not need to reset the '815 chip. */

	MOD_INC_USE_COUNT;

	if (request_irq(dev->irq, &intr_handler, SA_SHIRQ, dev->name, dev)) {
		MOD_DEC_USE_COUNT;
		return -EAGAIN;
	}

	if (np->msg_level & NETIF_MSG_IFUP)
		printk(KERN_DEBUG "%s: netdev_open() irq %d.\n",
			   dev->name, dev->irq);

	init_ring(dev);

	writel(virt_to_bus(np->rx_ring), ioaddr + RxRingPtr);
	writel(virt_to_bus(np->tx_ring), ioaddr + TxRingPtr);

	for (i = 0; i < 6; i += 2) {
		writel(i, ioaddr + RxFilterAddr);
		writel(dev->dev_addr[i] + (dev->dev_addr[i+1] << 8),
			   ioaddr + RxFilterData);
	}

	/* Initialize other registers. */
	/* See the datasheet for this correction. */
	if (readl(ioaddr + ChipRevReg) == 0x0203) {
		writew(0x0001, ioaddr + 0xCC);
		writew(0x18C9, ioaddr + 0xE4);
		writew(0x0000, ioaddr + 0xFC);
		writew(0x5040, ioaddr + 0xF4);
		writew(0x008C, ioaddr + 0xF8);
	}

	/* Configure the PCI bus bursts and FIFO thresholds. */
	/* Configure for standard, in-spec Ethernet. */

	if (readl(ioaddr + ChipConfig) & CfgFDX) {	/* Full duplex */
		np->tx_config = 0xD0801002;
		np->rx_config = 0x10000020;
	} else {
		np->tx_config = 0x10801002;
		np->rx_config = 0x0020;
	}
	if (dev->mtu > 1500)
		np->rx_config |= 0x08000000;
	writel(np->tx_config, ioaddr + TxConfig);
	writel(np->rx_config, ioaddr + RxConfig);

	if (dev->if_port == 0)
		dev->if_port = np->default_port;

	np->in_interrupt = 0;

	check_duplex(dev);
	set_rx_mode(dev);
	netif_start_tx_queue(dev);

	/* Enable interrupts by setting the interrupt mask. */
	np->intr_enable = IntrNormalSummary | IntrAbnormalSummary | 0x1f;
	writel(np->intr_enable, ioaddr + IntrMask);
	writel(1, ioaddr + IntrEnable);

	writel(RxOn | TxOn, ioaddr + ChipCmd);
	writel(4, ioaddr + StatsCtrl);					/* Clear Stats */

	if (np->msg_level & NETIF_MSG_IFUP)
		printk(KERN_DEBUG "%s: Done netdev_open(), status: %x.\n",
			   dev->name, (int)readl(ioaddr + ChipCmd));

	/* Set the timer to check for link beat. */
	init_timer(&np->timer);
	np->timer.expires = jiffies + 3*HZ;
	np->timer.data = (unsigned long)dev;
	np->timer.function = &netdev_timer;				/* timer handler */
	add_timer(&np->timer);

	return 0;
}

static void check_duplex(struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	long ioaddr = dev->base_addr;
	int duplex;

	if (np->duplex_lock)
		return;
	duplex = readl(ioaddr + ChipConfig) & 0x20000000 ? 1 : 0;
	if (np->full_duplex != duplex) {
		np->full_duplex = duplex;
		if (np->msg_level & NETIF_MSG_LINK)
			printk(KERN_INFO "%s: Setting %s-duplex based on negotiated link"
				   " capability.\n", dev->name,
				   duplex ? "full" : "half");
		if (duplex) {
			np->rx_config |= 0x10000000;
			np->tx_config |= 0xC0000000;
		} else {
			np->rx_config &= ~0x10000000;
			np->tx_config &= ~0xC0000000;
		}
		writel(np->tx_config, ioaddr + TxConfig);
		writel(np->rx_config, ioaddr + RxConfig);
	}
}

static void netdev_timer(unsigned long data)
{
	struct net_device *dev = (struct net_device *)data;
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	long ioaddr = dev->base_addr;
	int next_tick = 10*HZ;

	if (np->msg_level & NETIF_MSG_TIMER)
		printk(KERN_DEBUG "%s: Driver monitor timer tick, status %8.8x.\n",
			   dev->name, (int)readl(ioaddr + IntrStatus));
	if (np->rx_q_empty) {
		/* Trigger an interrupt to refill. */
		writel(SoftIntr, ioaddr + ChipCmd);
	}
	/* This will either have a small false-trigger window or will not catch
	   tbusy incorrectly set when the queue is empty. */
	if (netif_queue_paused(dev)  &&
		np->cur_tx - np->dirty_tx > 1  &&
		(jiffies - dev->trans_start) > TX_TIMEOUT) {
		tx_timeout(dev);
	}
	check_duplex(dev);
	np->timer.expires = jiffies + next_tick;
	add_timer(&np->timer);
}

static void tx_timeout(struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	long ioaddr = dev->base_addr;

	printk(KERN_WARNING "%s: Transmit timed out, status %8.8x,"
		   " resetting...\n", dev->name, (int)readl(ioaddr + TxRingPtr));

	if (np->msg_level & NETIF_MSG_TX_ERR) {
		int i;
		printk(KERN_DEBUG "  Rx ring %p: ", np->rx_ring);
		for (i = 0; i < RX_RING_SIZE; i++)
			printk(" %8.8x", (unsigned int)np->rx_ring[i].cmd_status);
		printk("\n"KERN_DEBUG"  Tx ring %p: ", np->tx_ring);
		for (i = 0; i < TX_RING_SIZE; i++)
			printk(" %4.4x", np->tx_ring[i].cmd_status);
		printk("\n");
	}

	/* Reinitialize the hardware here. */
	/* Stop and restart the chip's Tx processes . */

	/* Trigger an immediate transmit demand. */

	dev->trans_start = jiffies;
	np->stats.tx_errors++;
	return;
}

/* Refill the Rx ring buffers, returning non-zero if not full. */
static int rx_ring_fill(struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	unsigned int entry;

	for (; np->cur_rx - np->dirty_rx > 0; np->dirty_rx++) {
		entry = np->dirty_rx % RX_RING_SIZE;
		if (np->rx_skbuff[entry] == NULL) {
			struct sk_buff *skb = dev_alloc_skb(np->rx_buf_sz);
			np->rx_skbuff[entry] = skb;
			if (skb == NULL)
				return 1;				/* Better luck next time. */
			skb->dev = dev;			/* Mark as being used by this device. */
			np->rx_ring[entry].buf_addr = virt_to_le32desc(skb->tail);
		}
		np->rx_ring[entry].cmd_status = cpu_to_le32(DescIntr | np->rx_buf_sz);
	}
	return 0;
}

/* Initialize the Rx and Tx rings, along with various 'dev' bits. */
static void init_ring(struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	int i;

	np->tx_full = 0;
	np->cur_rx = np->cur_tx = 0;
	np->dirty_rx = np->dirty_tx = 0;

	/* MAX(PKT_BUF_SZ, dev->mtu + 8); */
	/* I know you _want_ to change this without understanding it.  Don't. */
	np->rx_buf_sz = (dev->mtu <= 1532 ? PKT_BUF_SZ : dev->mtu + 8);
	np->rx_head_desc = &np->rx_ring[0];

	/* Initialize all Rx descriptors. */
	for (i = 0; i < RX_RING_SIZE; i++) {
		np->rx_ring[i].next_desc = virt_to_le32desc(&np->rx_ring[i+1]);
		np->rx_ring[i].cmd_status = cpu_to_le32(DescOwn);
		np->rx_skbuff[i] = 0;
	}
	/* Mark the last entry as wrapping the ring. */
	np->rx_ring[i-1].next_desc = virt_to_le32desc(&np->rx_ring[0]);

	for (i = 0; i < TX_RING_SIZE; i++) {
		np->tx_skbuff[i] = 0;
		np->tx_ring[i].next_desc = virt_to_le32desc(&np->tx_ring[i+1]);
		np->tx_ring[i].cmd_status = 0;
	}
	np->tx_ring[i-1].next_desc = virt_to_le32desc(&np->tx_ring[0]);

	/* Fill in the Rx buffers.
	   Allocation failure just leaves a "negative" np->dirty_rx. */
	np->dirty_rx = (unsigned int)(0 - RX_RING_SIZE);
	rx_ring_fill(dev);

	return;
}

static int start_tx(struct sk_buff *skb, struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	unsigned int entry;

	/* Block a timer-based transmit from overlapping.  This happens when
	   packets are presumed lost, and we use this check the Tx status. */
	if (netif_pause_tx_queue(dev) != 0) {
		/* This watchdog code is redundant with the media monitor timer. */
		if (jiffies - dev->trans_start > TX_TIMEOUT)
			tx_timeout(dev);
		return 1;
	}

	/* Note: Ordering is important here, set the field with the
	   "ownership" bit last, and only then increment cur_tx.
	   No spinlock is needed for either Tx or Rx.
	*/

	/* Calculate the next Tx descriptor entry. */
	entry = np->cur_tx % TX_RING_SIZE;

	np->tx_skbuff[entry] = skb;

	np->tx_ring[entry].buf_addr = virt_to_le32desc(skb->data);
	np->tx_ring[entry].cmd_status = cpu_to_le32(DescOwn|DescIntr | skb->len);
	np->cur_tx++;

	/* For some architectures explicitly flushing np->tx_ring,sizeof(tx_ring)
	   and skb->data,skb->len improves performance. */

	if (np->cur_tx - np->dirty_tx >= TX_QUEUE_LEN - 1) {
		np->tx_full = 1;
		/* Check for a just-cleared queue. */
		if (np->cur_tx - (volatile unsigned int)np->dirty_tx
			< TX_QUEUE_LEN - 4) {
			np->tx_full = 0;
			netif_unpause_tx_queue(dev);
		} else
			netif_stop_tx_queue(dev);
	} else
		netif_unpause_tx_queue(dev);		/* Typical path */
	/* Wake the potentially-idle transmit channel. */
	writel(TxOn, dev->base_addr + ChipCmd);

	dev->trans_start = jiffies;

	if (np->msg_level & NETIF_MSG_TX_QUEUED) {
		printk(KERN_DEBUG "%s: Transmit frame #%d queued in slot %d.\n",
			   dev->name, np->cur_tx, entry);
	}
	return 0;
}

/* The interrupt handler does all of the Rx thread work and cleans up
   after the Tx thread. */
static void intr_handler(int irq, void *dev_instance, struct pt_regs *rgs)
{
	struct net_device *dev = (struct net_device *)dev_instance;
	struct netdev_private *np;
	long ioaddr;
	int boguscnt;

#ifndef final_version			/* Can never occur. */
	if (dev == NULL) {
		printk (KERN_ERR "Netdev interrupt handler(): IRQ %d for unknown "
				"device.\n", irq);
		return;
	}
#endif

	ioaddr = dev->base_addr;
	np = (struct netdev_private *)dev->priv;
	boguscnt = np->max_interrupt_work;

	do {
		u32 intr_status = readl(ioaddr + IntrStatus);

		if (intr_status == 0 || intr_status == 0xffffffff)
			break;

		/* Acknowledge all of the current interrupt sources ASAP.
		   Nominally the read above accomplishes this, but... */
		writel(intr_status & 0x001ffff, ioaddr + IntrStatus);

		if (np->msg_level & NETIF_MSG_INTR)
			printk(KERN_DEBUG "%s: Interrupt, status %8.8x.\n",
				   dev->name, intr_status);

		if (intr_status & (IntrRxDone | IntrRxIntr)) {
			netdev_rx(dev);
			np->rx_q_empty = rx_ring_fill(dev);
		}

		if (intr_status & (IntrRxIdle | IntrDrv)) {
			unsigned int old_dirty_rx = np->dirty_rx;
			if (rx_ring_fill(dev) == 0)
				np->rx_q_empty = 0;
			/* Restart Rx engine iff we did add a buffer. */
			if (np->dirty_rx != old_dirty_rx)
				writel(RxOn, dev->base_addr + ChipCmd);
		}

		for (; np->cur_tx - np->dirty_tx > 0; np->dirty_tx++) {
			int entry = np->dirty_tx % TX_RING_SIZE;
			int tx_status = le32_to_cpu(np->tx_ring[entry].cmd_status);
			if (tx_status & DescOwn)
				break;
			if (np->msg_level & NETIF_MSG_TX_DONE)
				printk(KERN_DEBUG "%s: Transmit done, Tx status %8.8x.\n",
					   dev->name, tx_status);
			if (tx_status & 0x08000000) {
				np->stats.tx_packets++;
#if LINUX_VERSION_CODE > 0x20127
				np->stats.tx_bytes += np->tx_skbuff[entry]->len;
#endif
			} else {			/* Various Tx errors */
				if (np->msg_level & NETIF_MSG_TX_ERR)
					printk(KERN_DEBUG "%s: Transmit error, Tx status %8.8x.\n",
						   dev->name, tx_status);
				if (tx_status & 0x04010000) np->stats.tx_aborted_errors++;
				if (tx_status & 0x02000000) np->stats.tx_fifo_errors++;
				if (tx_status & 0x01000000) np->stats.tx_carrier_errors++;
				if (tx_status & 0x00200000) np->stats.tx_window_errors++;
				np->stats.tx_errors++;
			}
			/* Free the original skb. */
			dev_free_skb_irq(np->tx_skbuff[entry]);
			np->tx_skbuff[entry] = 0;
		}
		/* Note the 4 slot hysteresis to mark the queue non-full. */
		if (np->tx_full
			&& np->cur_tx - np->dirty_tx < TX_QUEUE_LEN - 4) {
			/* The ring is no longer full, allow new TX entries. */
			np->tx_full = 0;
			netif_resume_tx_queue(dev);
		}

		/* Abnormal error summary/uncommon events handlers. */
		if (intr_status & IntrAbnormalSummary)
			netdev_error(dev, intr_status);

		if (--boguscnt < 0) {
			printk(KERN_WARNING "%s: Too much work at interrupt, "
				   "status=0x%4.4x.\n",
				   dev->name, intr_status);
			np->restore_intr_enable = 1;
			break;
		}
	} while (1);

	if (np->msg_level & NETIF_MSG_INTR)
		printk(KERN_DEBUG "%s: exiting interrupt, status=%#4.4x.\n",
			   dev->name, (int)readl(ioaddr + IntrStatus));

	return;
}

/* This routine is logically part of the interrupt handler, but separated
   for clarity and better register allocation. */
static int netdev_rx(struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	int entry = np->cur_rx % RX_RING_SIZE;
	int boguscnt = np->dirty_rx + RX_RING_SIZE - np->cur_rx;
	s32 desc_status = le32_to_cpu(np->rx_head_desc->cmd_status);

	/* If the driver owns the next entry it's a new packet. Send it up. */
	while (desc_status < 0) {		/* e.g. & DescOwn */
		if (np->msg_level & NETIF_MSG_RX_STATUS)
			printk(KERN_DEBUG "  In netdev_rx() entry %d status was %8.8x.\n",
				   entry, desc_status);
		if (--boguscnt < 0)
			break;
		if ((desc_status & (DescMore|DescPktOK|RxTooLong)) != DescPktOK) {
			if (desc_status & DescMore) {
				printk(KERN_WARNING "%s: Oversized(?) Ethernet frame spanned "
					   "multiple buffers, entry %#x status %x.\n",
					   dev->name, np->cur_rx, desc_status);
				np->stats.rx_length_errors++;
			} else {
				/* There was a error. */
				if (np->msg_level & NETIF_MSG_RX_ERR)
					printk(KERN_DEBUG "  netdev_rx() Rx error was %8.8x.\n",
						   desc_status);
				np->stats.rx_errors++;
				if (desc_status & 0x06000000) np->stats.rx_over_errors++;
				if (desc_status & 0x00600000) np->stats.rx_length_errors++;
				if (desc_status & 0x00140000) np->stats.rx_frame_errors++;
				if (desc_status & 0x00080000) np->stats.rx_crc_errors++;
			}
		} else {
			struct sk_buff *skb;
			int pkt_len = (desc_status & 0x0fff) - 4;	/* Omit CRC size. */
			/* Check if the packet is long enough to accept without copying
			   to a minimally-sized skbuff. */
			if (pkt_len < np->rx_copybreak
				&& (skb = dev_alloc_skb(pkt_len + 2)) != NULL) {
				skb->dev = dev;
				skb_reserve(skb, 2);	/* 16 byte align the IP header */
#if defined(HAS_IP_COPYSUM)  ||  (LINUX_VERSION_CODE >= 0x20100)
				eth_copy_and_sum(skb, np->rx_skbuff[entry]->tail, pkt_len, 0);
				skb_put(skb, pkt_len);
#else
				memcpy(skb_put(skb, pkt_len), np->rx_skbuff[entry]->tail,
					   pkt_len);
#endif
			} else {
				skb_put(skb = np->rx_skbuff[entry], pkt_len);
				np->rx_skbuff[entry] = NULL;
			}
			skb->protocol = eth_type_trans(skb, dev);
			/* W/ hardware checksum: skb->ip_summed = CHECKSUM_UNNECESSARY; */
			netif_rx(skb);
			dev->last_rx = jiffies;
			np->stats.rx_packets++;
#if LINUX_VERSION_CODE > 0x20127
			np->stats.rx_bytes += pkt_len;
#endif
		}
		entry = (++np->cur_rx) % RX_RING_SIZE;
		np->rx_head_desc = &np->rx_ring[entry];
		desc_status = le32_to_cpu(np->rx_head_desc->cmd_status);
	}

	/* Refill is now done in the main interrupt loop. */
	return 0;
}

static void netdev_error(struct net_device *dev, int intr_status)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	long ioaddr = dev->base_addr;

	if (intr_status & LinkChange) {
		int chip_config = readl(ioaddr + ChipConfig);
		if (np->msg_level & NETIF_MSG_LINK)
			printk(KERN_NOTICE "%s: Link changed: Autonegotiation advertising"
				   " %4.4x  partner %4.4x.\n", dev->name,
				   (int)readw(ioaddr + NS_MII_Advert),
				   (int)readw(ioaddr + NS_MIILinkPartner));
		if (chip_config & CfgLinkGood)
			netif_link_up(dev);
		else
			netif_link_down(dev);
		check_duplex(dev);
	}
	if (intr_status & StatsMax) {
		get_stats(dev);
	}
	if (intr_status & IntrTxUnderrun) {
		/* Increase the Tx threshold, 32 byte units. */
		if ((np->tx_config & 0x3f) < 62)
			np->tx_config += 2;			/* +64 bytes */
		writel(np->tx_config, ioaddr + TxConfig);
	}
	if (intr_status & WOLPkt) {
		int wol_status = readl(ioaddr + WOLCmd);
		printk(KERN_NOTICE "%s: Link wake-up event %8.8x",
			   dev->name, wol_status);
	}
	if (intr_status & (RxStatusOverrun | IntrRxOverrun)) {
		if (np->msg_level & NETIF_MSG_DRV)
			printk(KERN_ERR "%s: Rx overflow! ns815 %8.8x.\n",
				   dev->name, intr_status);
		np->stats.rx_fifo_errors++;
	}
	if (intr_status & ~(LinkChange|StatsMax|RxResetDone|TxResetDone|
						RxStatusOverrun|0xA7ff)) {
		if (np->msg_level & NETIF_MSG_DRV)
			printk(KERN_ERR "%s: Something Wicked happened! natsemi %8.8x.\n",
				   dev->name, intr_status);
	}
	/* Hmmmmm, it's not clear how to recover from PCI faults. */
	if (intr_status & IntrPCIErr) {
		np->stats.tx_fifo_errors++;
		np->stats.rx_fifo_errors++;
	}
}

static struct net_device_stats *get_stats(struct net_device *dev)
{
	long ioaddr = dev->base_addr;
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	int crc_errs = readl(ioaddr + RxCRCErrs);

	if (crc_errs != 0xffffffff) {
		/* We need not lock this segment of code for SMP.
		   There is no atomic-add vulnerability for most CPUs,
		   and statistics are non-critical. */
		/* The chip only need report frame silently dropped. */
		np->stats.rx_crc_errors	+= crc_errs;
		np->stats.rx_missed_errors += readl(ioaddr + RxMissed);
	}

	return &np->stats;
}

/* The big-endian AUTODIN II ethernet CRC calculations.
   See ns820.c for how to fill the table on new chips.
 */
static unsigned const ethernet_polynomial = 0x04c11db7U;
static inline u32 ether_crc(int length, unsigned char *data)
{
	int crc = -1;

	while(--length >= 0) {
		unsigned char current_octet = *data++;
		int bit;
		for (bit = 0; bit < 8; bit++, current_octet >>= 1)
			crc = (crc << 1) ^
				((crc < 0) ^ (current_octet & 1) ? ethernet_polynomial : 0);
	}
	return crc;
}

static void set_rx_mode(struct net_device *dev)
{
	long ioaddr = dev->base_addr;
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	u8 mc_filter[64];			/* Multicast hash filter */
	u32 rx_mode;

	if (dev->flags & IFF_PROMISC) {			/* Set promiscuous. */
		/* Unconditionally log net taps. */
		printk(KERN_NOTICE "%s: Promiscuous mode enabled.\n", dev->name);
		rx_mode = AcceptBroadcast | AcceptAllMulticast | AcceptAllPhys
			| AcceptMyPhys;
	} else if ((dev->mc_count > np->multicast_filter_limit)
			   ||  (dev->flags & IFF_ALLMULTI)) {
		rx_mode = AcceptBroadcast | AcceptAllMulticast | AcceptMyPhys;
	} else {
		struct dev_mc_list *mclist;
		int i;
		memset(mc_filter, 0, sizeof(mc_filter));
		for (i = 0, mclist = dev->mc_list; mclist && i < dev->mc_count;
			 i++, mclist = mclist->next) {
			int filterbit = ether_crc(ETH_ALEN, mclist->dmi_addr);
			set_bit(filterbit & 0x1ff, mc_filter);
			if (np->msg_level & NETIF_MSG_RXFILTER)
				printk(KERN_INFO "%s: Added filter for %2.2x:%2.2x:%2.2x:"
					   "%2.2x:%2.2x:%2.2x  crc %8.8x bit %d.\n", dev->name,
					   mclist->dmi_addr[0], mclist->dmi_addr[1],
					   mclist->dmi_addr[2], mclist->dmi_addr[3],
					   mclist->dmi_addr[4], mclist->dmi_addr[5],
					   filterbit, filterbit & 0x1ff);
		}
		rx_mode = AcceptBroadcast | AcceptMulticast | AcceptMyPhys;
		for (i = 0; i < 64; i += 2) {
			u16 filterword = (mc_filter[i+1]<<8) + mc_filter[i];
			if (filterword != np->rx_filter[i>>2]) {
				writel(0x200 + i, ioaddr + RxFilterAddr);
				writel(filterword, ioaddr + RxFilterData);
				np->rx_filter[i>>2] = filterword;
			}
		}
	}
	writel(rx_mode, ioaddr + RxFilterAddr);
	np->cur_rx_mode = rx_mode;
}

static int mii_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	u16 *data = (u16 *)&rq->ifr_data;
	u32 *data32 = (void *)&rq->ifr_data;

	switch(cmd) {
	case 0x8947: case 0x89F0:
		/* SIOCGMIIPHY: Get the address of the PHY in use. */
		data[0] = 1;
		/* Fall Through */
	case 0x8948: case 0x89F1:
		/* SIOCGMIIREG: Read the specified MII register. */
		data[3] = mdio_read(dev, data[0] & 0x1f, data[1] & 0x1f);
		return 0;
	case 0x8949: case 0x89F2:
		/* SIOCSMIIREG: Write the specified MII register */
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		if (data[0] == 1) {
			u16 miireg = data[1] & 0x1f;
			u16 value = data[2];
			mdio_write(dev, 1, miireg, value);
			switch (miireg) {
			case 0:
				/* Check for autonegotiation on or reset. */
				np->duplex_lock = (value & 0x9000) ? 0 : 1;
				if (np->duplex_lock)
					np->full_duplex = (value & 0x0100) ? 1 : 0;
				break;
			case 4: np->advertising = value; break;
			}
		}
		return 0;
	case SIOCGPARAMS:
		data32[0] = np->msg_level;
		data32[1] = np->multicast_filter_limit;
		data32[2] = np->max_interrupt_work;
		data32[3] = np->rx_copybreak;
		return 0;
	case SIOCSPARAMS:
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		np->msg_level = data32[0];
		np->multicast_filter_limit = data32[1];
		np->max_interrupt_work = data32[2];
		np->rx_copybreak = data32[3];
		return 0;
	default:
		return -EOPNOTSUPP;
	}
}

static int netdev_close(struct net_device *dev)
{
	long ioaddr = dev->base_addr;
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	int i;

	netif_stop_tx_queue(dev);

	if (np->msg_level & NETIF_MSG_IFDOWN) {
		printk(KERN_DEBUG "%s: Shutting down ethercard, status was %4.4x "
			   "Int %2.2x.\n",
			   dev->name, (int)readl(ioaddr + ChipCmd),
			   (int)readl(ioaddr + IntrStatus));
		printk(KERN_DEBUG "%s: Queue pointers were Tx %d / %d,  Rx %d / %d.\n",
			   dev->name, np->cur_tx, np->dirty_tx, np->cur_rx, np->dirty_rx);
	}

	/* We don't want the timer to re-start anything. */
	del_timer(&np->timer);

	/* Disable interrupts using the mask. */
	writel(0, ioaddr + IntrMask);
	writel(0, ioaddr + IntrEnable);
	writel(2, ioaddr + StatsCtrl);					/* Freeze Stats */

	/* Stop the chip's Tx and Rx processes. */
	writel(RxOff | TxOff, ioaddr + ChipCmd);

	get_stats(dev);

#ifdef __i386__
	if (np->msg_level & NETIF_MSG_IFDOWN) {
		printk("\n"KERN_DEBUG"  Tx ring at %8.8x:\n",
			   (int)virt_to_bus(np->tx_ring));
		for (i = 0; i < TX_RING_SIZE; i++)
			printk(" #%d desc. %8.8x %8.8x.\n",
				   i, np->tx_ring[i].cmd_status, (u32)np->tx_ring[i].buf_addr);
		printk("\n"KERN_DEBUG "  Rx ring %8.8x:\n",
			   (int)virt_to_bus(np->rx_ring));
		for (i = 0; i < RX_RING_SIZE; i++) {
			printk(KERN_DEBUG " #%d desc. %8.8x %8.8x\n",
				   i, np->rx_ring[i].cmd_status, (u32)np->rx_ring[i].buf_addr);
		}
	}
#endif /* __i386__ debugging only */

	free_irq(dev->irq, dev);

	/* Free all the skbuffs in the Rx queue. */
	for (i = 0; i < RX_RING_SIZE; i++) {
		np->rx_ring[i].cmd_status = 0;
		np->rx_ring[i].buf_addr = 0xBADF00D0; /* An invalid address. */
		if (np->rx_skbuff[i]) {
#if LINUX_VERSION_CODE < 0x20100
			np->rx_skbuff[i]->free = 1;
#endif
			dev_free_skb(np->rx_skbuff[i]);
		}
		np->rx_skbuff[i] = 0;
	}
	for (i = 0; i < TX_RING_SIZE; i++) {
		if (np->tx_skbuff[i])
			dev_free_skb(np->tx_skbuff[i]);
		np->tx_skbuff[i] = 0;
	}

#if 0
	writel(0x0200, ioaddr + ChipConfig); /* Power down Xcvr. */
#endif

	MOD_DEC_USE_COUNT;

	return 0;
}

static int power_event(void *dev_instance, int event)
{
	struct net_device *dev = dev_instance;
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	long ioaddr = dev->base_addr;

	if (np->msg_level & NETIF_MSG_LINK)
		printk(KERN_DEBUG "%s: Handling power event %d.\n", dev->name, event);
	switch(event) {
	case DRV_ATTACH:
		MOD_INC_USE_COUNT;
		break;
	case DRV_SUSPEND:
		/* Disable interrupts, freeze stats, stop Tx and Rx. */
		writel(0, ioaddr + IntrEnable);
		writel(2, ioaddr + StatsCtrl);
		writel(RxOff | TxOff, ioaddr + ChipCmd);
		break;
	case DRV_RESUME:
		/* This is incomplete: the open() actions should be repeated. */
		set_rx_mode(dev);
		writel(np->intr_enable, ioaddr + IntrEnable);
		writel(1, ioaddr + IntrEnable);
		writel(RxOn | TxOn, ioaddr + ChipCmd);
		break;
	case DRV_DETACH: {
		struct net_device **devp, **next;
		if (dev->flags & IFF_UP) {
			/* Some, but not all, kernel versions close automatically. */
			dev_close(dev);
			dev->flags &= ~(IFF_UP|IFF_RUNNING);
		}
		unregister_netdev(dev);
		release_region(dev->base_addr, pci_id_tbl[np->chip_id].io_size);
		for (devp = &root_net_dev; *devp; devp = next) {
			next = &((struct netdev_private *)(*devp)->priv)->next_module;
			if (*devp == dev) {
				*devp = *next;
				break;
			}
		}
		if (np->priv_addr)
			kfree(np->priv_addr);
		kfree(dev);
		MOD_DEC_USE_COUNT;
		break;
	}
	}

	return 0;
}


#ifdef MODULE
int init_module(void)
{
	if (debug >= NETIF_MSG_DRV)	/* Emit version even if no cards detected. */
		printk(KERN_INFO "%s" KERN_INFO "%s", version1, version2);
#ifdef CARDBUS
	register_driver(&etherdev_ops);
	return 0;
#else
	return pci_drv_register(&natsemi_drv_id, NULL);
#endif
}

void cleanup_module(void)
{
	struct net_device *next_dev;

#ifdef CARDBUS
	unregister_driver(&etherdev_ops);
#else
	pci_drv_unregister(&natsemi_drv_id);
#endif

	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
	while (root_net_dev) {
		struct netdev_private *np = (void *)(root_net_dev->priv);
		unregister_netdev(root_net_dev);
		iounmap((char *)root_net_dev->base_addr);
		next_dev = np->next_module;
		if (np->priv_addr)
			kfree(np->priv_addr);
		kfree(root_net_dev);
		root_net_dev = next_dev;
	}
}

#endif  /* MODULE */

/*
 * Local variables:
 *  compile-command: "make KERNVER=`uname -r` natsemi.o"
 *  compile-cmd: "gcc -DMODULE -Wall -Wstrict-prototypes -O6 -c natsemi.c"
 *  simple-compile-command: "gcc -DMODULE -O6 -c natsemi.c"
 *  c-indent-level: 4
 *  c-basic-offset: 4
 *  tab-width: 4
 * End:
 */