Initial revision

1 files changed, 881 insertions, 0 deletions

diff --git a/drivers/natsemi.c b/drivers/natsemi.c
new file mode 100644
index 0000000..5a8c5b4
--- /dev/null
+++ b/drivers/natsemi.c
@@ -0,0 +1,881 @@
+/*
+   natsemi.c: A U-Boot driver for the NatSemi DP8381x series.
+   Author: Mark A. Rakes (mark_rakes@vivato.net)
+
+   Adapted from an Etherboot driver written by:
+
+   Copyright (C) 2001 Entity Cyber, Inc.
+
+   This development of this Etherboot driver was funded by
+
+      Sicom Systems: http://www.sicompos.com/
+
+   Author: Marty Connor (mdc@thinguin.org)
+   Adapted from a Linux driver which was written by Donald Becker
+
+   This software may be used and distributed according to the terms
+   of the GNU Public License (GPL), incorporated herein by reference.
+
+   Original Copyright Notice:
+
+   Written/copyright 1999-2001 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
+   410 Severn Ave., Suite 210
+   Annapolis MD 21403
+
+   Support information and updates available at
+   http://www.scyld.com/network/netsemi.html
+
+   References:
+   http://www.scyld.com/expert/100mbps.html
+   http://www.scyld.com/expert/NWay.html
+   Datasheet is available from:
+   http://www.national.com/pf/DP/DP83815.html
+*/
+
+/* Revision History
+ * October 2002 mar	1.0
+ *   Initial U-Boot Release.  Tested with Netgear FA311 board
+ *   and dp83815 chipset on custom board
+*/
+
+/* Includes */
+#include <common.h>
+#include <malloc.h>
+#include <net.h>
+#include <asm/io.h>
+#include <pci.h>
+
+#if (CONFIG_COMMANDS & CFG_CMD_NET) && defined(CONFIG_NET_MULTI) && \
+	defined(CONFIG_NATSEMI)
+
+/* defines */
+#define EEPROM_SIZE 0xb /*12 16-bit chunks, or 24 bytes*/
+
+#define DSIZE     0x00000FFF
+#define ETH_ALEN	6
+#define CRC_SIZE  4
+#define TOUT_LOOP   500000
+#define TX_BUF_SIZE    1536
+#define RX_BUF_SIZE    1536
+#define NUM_RX_DESC    4	/* Number of Rx descriptor registers. */
+
+/* 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.  */
+enum register_offsets {
+	ChipCmd 	= 0x00,
+	ChipConfig 	= 0x04,
+	EECtrl 		= 0x08,
+	IntrMask 	= 0x14,
+	IntrEnable 	= 0x18,
+	TxRingPtr 	= 0x20,
+	TxConfig 	= 0x24,
+	RxRingPtr 	= 0x30,
+	RxConfig 	= 0x34,
+	ClkRun 		= 0x3C,
+	RxFilterAddr 	= 0x48,
+	RxFilterData 	= 0x4C,
+	SiliconRev 	= 0x58,
+	PCIPM 		= 0x44,
+	BasicControl	= 0x80,
+	BasicStatus	= 0x84,
+	/* These are from the spec, around page 78... on a separate table. */
+	PGSEL 		= 0xCC,
+	PMDCSR 		= 0xE4,
+	TSTDAT 		= 0xFC,
+	DSPCFG 		= 0xF4,
+	SDCFG 		= 0x8C
+};
+
+/* Bit in ChipCmd. */
+enum ChipCmdBits {
+	ChipReset 	= 0x100,
+	RxReset 	= 0x20,
+	TxReset 	= 0x10,
+	RxOff 		= 0x08,
+	RxOn 		= 0x04,
+	TxOff 		= 0x02,
+	TxOn 		= 0x01
+};
+
+enum ChipConfigBits {
+	LinkSts 	= 0x80000000,
+	HundSpeed 	= 0x40000000,
+	FullDuplex 	= 0x20000000,
+	TenPolarity	= 0x10000000,
+	AnegDone	= 0x08000000,
+	AnegEnBothBoth	= 0x0000E000,
+	AnegDis100Full	= 0x0000C000,
+	AnegEn100Both	= 0x0000A000,
+	AnegDis100Half	= 0x00008000,
+	AnegEnBothHalf	= 0x00006000,
+	AnegDis10Full	= 0x00004000,
+	AnegEn10Both	= 0x00002000,
+	DuplexMask	= 0x00008000,
+	SpeedMask	= 0x00004000,
+	AnegMask	= 0x00002000,
+	AnegDis10Half	= 0x00000000,
+	ExtPhy 		= 0x00001000,
+	PhyRst 		= 0x00000400,
+	PhyDis 		= 0x00000200,
+	BootRomDisable	= 0x00000004,
+	BEMode 		= 0x00000001,
+};
+
+enum TxConfig_bits {
+	TxDrthMask 	= 0x3f,
+	TxFlthMask 	= 0x3f00,
+	TxMxdmaMask	= 0x700000,
+	TxMxdma_512 	= 0x0,
+	TxMxdma_4 	= 0x100000,
+	TxMxdma_8 	= 0x200000,
+	TxMxdma_16 	= 0x300000,
+	TxMxdma_32 	= 0x400000,
+	TxMxdma_64 	= 0x500000,
+	TxMxdma_128 	= 0x600000,
+	TxMxdma_256 	= 0x700000,
+	TxCollRetry 	= 0x800000,
+	TxAutoPad 	= 0x10000000,
+	TxMacLoop 	= 0x20000000,
+	TxHeartIgn 	= 0x40000000,
+	TxCarrierIgn 	= 0x80000000
+};
+
+enum RxConfig_bits {
+	RxDrthMask 	= 0x3e,
+	RxMxdmaMask 	= 0x700000,
+	RxMxdma_512 	= 0x0,
+	RxMxdma_4 	= 0x100000,
+	RxMxdma_8 	= 0x200000,
+	RxMxdma_16 	= 0x300000,
+	RxMxdma_32 	= 0x400000,
+	RxMxdma_64 	= 0x500000,
+	RxMxdma_128 	= 0x600000,
+	RxMxdma_256 	= 0x700000,
+	RxAcceptLong 	= 0x8000000,
+	RxAcceptTx 	= 0x10000000,
+	RxAcceptRunt 	= 0x40000000,
+	RxAcceptErr 	= 0x80000000
+};
+
+/* Bits in the RxMode register. */
+enum rx_mode_bits {
+	AcceptErr 		= 0x20,
+	AcceptRunt 		= 0x10,
+	AcceptBroadcast 	= 0xC0000000,
+	AcceptMulticast 	= 0x00200000,
+	AcceptAllMulticast 	= 0x20000000,
+	AcceptAllPhys 		= 0x10000000,
+	AcceptMyPhys 		= 0x08000000
+};
+
+typedef struct _BufferDesc {
+	u32 link;
+	vu_long cmdsts;
+	u32 bufptr;
+	u32 software_use;
+} BufferDesc;
+
+/* Bits in network_desc.status */
+enum desc_status_bits {
+	DescOwn = 0x80000000, DescMore = 0x40000000, DescIntr = 0x20000000,
+	DescNoCRC = 0x10000000, DescPktOK = 0x08000000,
+	DescSizeMask = 0xfff,
+
+	DescTxAbort = 0x04000000, DescTxFIFO = 0x02000000,
+	DescTxCarrier = 0x01000000, DescTxDefer = 0x00800000,
+	DescTxExcDefer = 0x00400000, DescTxOOWCol = 0x00200000,
+	DescTxExcColl = 0x00100000, DescTxCollCount = 0x000f0000,
+
+	DescRxAbort = 0x04000000, DescRxOver = 0x02000000,
+	DescRxDest = 0x01800000, DescRxLong = 0x00400000,
+	DescRxRunt = 0x00200000, DescRxInvalid = 0x00100000,
+	DescRxCRC = 0x00080000, DescRxAlign = 0x00040000,
+	DescRxLoop = 0x00020000, DesRxColl = 0x00010000,
+};
+
+/* Globals */
+#ifdef NATSEMI_DEBUG
+static int natsemi_debug = 0;	/* 1 verbose debugging, 0 normal */
+#endif
+static u32 SavedClkRun;
+static unsigned int cur_rx;
+static unsigned int advertising;
+static unsigned int rx_config;
+static unsigned int tx_config;
+
+/* Note: transmit and receive buffers and descriptors must be
+   longword aligned */
+static BufferDesc txd __attribute__ ((aligned(4)));
+static BufferDesc rxd[NUM_RX_DESC] __attribute__ ((aligned(4)));
+
+static unsigned char txb[TX_BUF_SIZE] __attribute__ ((aligned(4)));
+static unsigned char rxb[NUM_RX_DESC * RX_BUF_SIZE]
+    __attribute__ ((aligned(4)));
+
+/* Function Prototypes */
+#if 0
+static void write_eeprom(struct eth_device *dev, long addr, int location,
+			 short value);
+#endif
+static int read_eeprom(struct eth_device *dev, long addr, int location);
+static int mdio_read(struct eth_device *dev, int phy_id, int location);
+static int natsemi_init(struct eth_device *dev, bd_t * bis);
+static void natsemi_reset(struct eth_device *dev);
+static void natsemi_init_rxfilter(struct eth_device *dev);
+static void natsemi_init_txd(struct eth_device *dev);
+static void natsemi_init_rxd(struct eth_device *dev);
+static void natsemi_set_rx_mode(struct eth_device *dev);
+static void natsemi_check_duplex(struct eth_device *dev);
+static int natsemi_send(struct eth_device *dev, volatile void *packet,
+			int length);
+static int natsemi_poll(struct eth_device *dev);
+static void natsemi_disable(struct eth_device *dev);
+
+static struct pci_device_id supported[] = {
+	{PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_83815},
+	{}
+};
+
+#define bus_to_phys(a)	pci_mem_to_phys((pci_dev_t)dev->priv, a)
+#define phys_to_bus(a)	pci_phys_to_mem((pci_dev_t)dev->priv, a)
+
+static inline int
+INW(struct eth_device *dev, u_long addr)
+{
+	return le16_to_cpu(*(vu_short *) (addr + dev->iobase));
+}
+
+static int
+INL(struct eth_device *dev, u_long addr)
+{
+	return le32_to_cpu(*(vu_long *) (addr + dev->iobase));
+}
+
+static inline void
+OUTW(struct eth_device *dev, int command, u_long addr)
+{
+	*(vu_short *) ((addr + dev->iobase)) = cpu_to_le16(command);
+}
+
+static inline void
+OUTL(struct eth_device *dev, int command, u_long addr)
+{
+	*(vu_long *) ((addr + dev->iobase)) = cpu_to_le32(command);
+}
+
+/*
+ * Function: natsemi_initialize
+ *
+ * Description: Retrieves the MAC address of the card, and sets up some
+ * globals required by other routines,  and initializes the NIC, making it
+ * ready to send and receive packets.
+ *
+ * Side effects:
+ *            leaves the natsemi initialized, and ready to recieve packets.
+ *
+ * Returns:   struct eth_device *:          pointer to NIC data structure
+ */
+
+int
+natsemi_initialize(bd_t * bis)
+{
+	pci_dev_t devno;
+	int card_number = 0;
+	struct eth_device *dev;
+	u32 iobase, status, chip_config;
+	int i, idx = 0;
+	int prev_eedata;
+	u32 tmp;
+
+	while (1) {
+		/* Find PCI device(s) */
+		if ((devno = pci_find_devices(supported, idx++)) < 0) {
+			break;
+		}
+
+		pci_read_config_dword(devno, PCI_BASE_ADDRESS_0, &iobase);
+		iobase &= ~0x3;	/* 1: unused and 0:I/O Space Indicator */
+
+		pci_write_config_dword(devno, PCI_COMMAND,
+				       PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
+
+		/* Check if I/O accesses and Bus Mastering are enabled. */
+		pci_read_config_dword(devno, PCI_COMMAND, &status);
+		if (!(status & PCI_COMMAND_MEMORY)) {
+			printf("Error: Can not enable MEM access.\n");
+			continue;
+		} else if (!(status & PCI_COMMAND_MASTER)) {
+			printf("Error: Can not enable Bus Mastering.\n");
+			continue;
+		}
+
+		dev = (struct eth_device *) malloc(sizeof *dev);
+
+		sprintf(dev->name, "dp83815#%d", card_number);
+		dev->iobase = bus_to_phys(iobase);
+#ifdef NATSEMI_DEBUG
+		printf("natsemi: NatSemi ns8381[56] @ %#x\n", dev->iobase);
+#endif
+		dev->priv = (void *) devno;
+		dev->init = natsemi_init;
+		dev->halt = natsemi_disable;
+		dev->send = natsemi_send;
+		dev->recv = natsemi_poll;
+
+		eth_register(dev);
+
+		card_number++;
+
+		/* Set the latency timer for value. */
+		pci_write_config_byte(devno, PCI_LATENCY_TIMER, 0x20);
+
+		udelay(10 * 1000);
+
+		/* natsemi has a non-standard PM control register
+		 * in PCI config space.  Some boards apparently need
+		 * to be brought to D0 in this manner.  */
+		pci_read_config_dword(devno, PCIPM, &tmp);
+		if (tmp & (0x03 | 0x100)) {
+			/* D0 state, disable PME assertion */
+			u32 newtmp = tmp & ~(0x03 | 0x100);
+			pci_write_config_dword(devno, PCIPM, newtmp);
+		}
+
+		printf("natsemi: EEPROM contents:\n");
+		for (i = 0; i <= EEPROM_SIZE; i++) {
+			short eedata = read_eeprom(dev, EECtrl, i);
+			printf(" %04hx", eedata);
+		}
+		printf("\n");
+
+		/* get MAC address */
+		prev_eedata = read_eeprom(dev, EECtrl, 6);
+		for (i = 0; i < 3; i++) {
+			int eedata = read_eeprom(dev, EECtrl, i + 7);
+			dev->enetaddr[i*2] = (eedata << 1) + (prev_eedata >> 15);
+			dev->enetaddr[i*2+1] = eedata >> 7;
+			prev_eedata = eedata;
+		}
+
+		/* Reset the chip to erase any previous misconfiguration. */
+		OUTL(dev, ChipReset, ChipCmd);
+
+		advertising = mdio_read(dev, 1, 4);
+		chip_config = INL(dev, ChipConfig);
+#ifdef NATSEMI_DEBUG
+		printf("%s: Transceiver status %#08X advertising %#08X\n",
+		       	dev->name, (int) INL(dev, BasicStatus), advertising);
+		printf("%s: Transceiver default autoneg. %s 10%s %s duplex.\n",
+			dev->name, chip_config & AnegMask ? "enabled, advertise" :
+			"disabled, force", chip_config & SpeedMask ? "0" : "",
+			chip_config & DuplexMask ? "full" : "half");
+#endif
+		chip_config |= AnegEnBothBoth;
+#ifdef NATSEMI_DEBUG
+		printf("%s: changed to autoneg. %s 10%s %s duplex.\n",
+			dev->name, chip_config & AnegMask ? "enabled, advertise" :
+			"disabled, force", chip_config & SpeedMask ? "0" : "",
+			chip_config & DuplexMask ? "full" : "half");
+#endif
+		/*write new autoneg bits, reset phy*/
+		OUTL(dev, (chip_config | PhyRst), ChipConfig);
+		/*un-reset phy*/
+		OUTL(dev, chip_config, ChipConfig);
+
+		/* Disable PME:
+		 * The PME bit is initialized from the EEPROM contents.
+		 * PCI cards probably have PME disabled, but motherboard
+		 * implementations may have PME set to enable WakeOnLan.
+		 * With PME set the chip will scan incoming packets but
+		 * nothing will be written to memory. */
+		SavedClkRun = INL(dev, ClkRun);
+		OUTL(dev, SavedClkRun & ~0x100, ClkRun);
+	}
+	return card_number;
+}
+
+/* Read the EEPROM and MII Management Data I/O (MDIO) interfaces.
+   The EEPROM code is for common 93c06/46 EEPROMs w/ 6bit addresses.  */
+
+/* Delay between EEPROM clock transitions.
+   No extra delay is needed with 33Mhz PCI, but future 66Mhz
+   access may need a delay. */
+#define eeprom_delay(ee_addr)	INL(dev, 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 alway-set leading bit. */
+enum EEPROM_Cmds {
+	EE_WrEnCmd = (4 << 6), EE_WriteCmd = (5 << 6),
+	EE_ReadCmd = (6 << 6), EE_EraseCmd = (7 << 6),
+};
+
+#if 0
+static void
+write_eeprom(struct eth_device *dev, long addr, int location, short value)
+{
+	int i;
+	int ee_addr = (typeof(ee_addr))addr;
+	short wren_cmd = EE_WrEnCmd | 0x30; /*wren is 100 + 11XXXX*/
+	short write_cmd = location | EE_WriteCmd;
+
+#ifdef NATSEMI_DEBUG
+	printf("write_eeprom: %08x, %04hx, %04hx\n",
+		dev->iobase + ee_addr, write_cmd, value);
+#endif
+	/* Shift the write enable command bits out. */
+	for (i = 9; i >= 0; i--) {
+		short cmdval = (wren_cmd & (1 << i)) ? EE_Write1 : EE_Write0;
+		OUTL(dev, cmdval, ee_addr);
+		eeprom_delay(ee_addr);
+		OUTL(dev, cmdval | EE_ShiftClk, ee_addr);
+		eeprom_delay(ee_addr);
+	}
+
+	OUTL(dev, 0, ee_addr); /*bring chip select low*/
+	OUTL(dev, EE_ShiftClk, ee_addr);
+	eeprom_delay(ee_addr);
+
+	/* Shift the write command bits out. */
+	for (i = 9; i >= 0; i--) {
+		short cmdval = (write_cmd & (1 << i)) ? EE_Write1 : EE_Write0;
+		OUTL(dev, cmdval, ee_addr);
+		eeprom_delay(ee_addr);
+		OUTL(dev, cmdval | EE_ShiftClk, ee_addr);
+		eeprom_delay(ee_addr);
+	}
+
+	for (i = 0; i < 16; i++) {
+		short cmdval = (value & (1 << i)) ? EE_Write1 : EE_Write0;
+		OUTL(dev, cmdval, ee_addr);
+		eeprom_delay(ee_addr);
+		OUTL(dev, cmdval | EE_ShiftClk, ee_addr);
+		eeprom_delay(ee_addr);
+	}
+
+	OUTL(dev, 0, ee_addr); /*bring chip select low*/
+	OUTL(dev, EE_ShiftClk, ee_addr);
+	for (i = 0; i < 200000; i++) {
+		OUTL(dev, EE_Write0, ee_addr); /*poll for done*/
+		if (INL(dev, ee_addr) & EE_DataOut) {
+		    break; /*finished*/
+		}
+	}
+	eeprom_delay(ee_addr);
+
+	/* Terminate the EEPROM access. */
+	OUTL(dev, EE_Write0, ee_addr);
+	OUTL(dev, 0, ee_addr);
+	return;
+}
+#endif
+
+static int
+read_eeprom(struct eth_device *dev, long addr, int location)
+{
+	int i;
+	int retval = 0;
+	int ee_addr = (typeof(ee_addr))addr;
+	int read_cmd = location | EE_ReadCmd;
+
+	OUTL(dev, 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;
+		OUTL(dev, dataval, ee_addr);
+		eeprom_delay(ee_addr);
+		OUTL(dev, dataval | EE_ShiftClk, ee_addr);
+		eeprom_delay(ee_addr);
+	}
+	OUTL(dev, EE_ChipSelect, ee_addr);
+	eeprom_delay(ee_addr);
+
+	for (i = 0; i < 16; i++) {
+		OUTL(dev, EE_ChipSelect | EE_ShiftClk, ee_addr);
+		eeprom_delay(ee_addr);
+		retval |= (INL(dev, ee_addr) & EE_DataOut) ? 1 << i : 0;
+		OUTL(dev, EE_ChipSelect, ee_addr);
+		eeprom_delay(ee_addr);
+	}
+
+	/* Terminate the EEPROM access. */
+	OUTL(dev, EE_Write0, ee_addr);
+	OUTL(dev, 0, ee_addr);
+#ifdef NATSEMI_DEBUG
+	if (natsemi_debug)
+		printf("read_eeprom: %08x, %08x, retval %08x\n",
+			dev->iobase + ee_addr, read_cmd, retval);
+#endif
+	return retval;
+}
+
+/*  MII transceiver control section.
+	The 83815 series has an internal transceiver, and we present the
+	management registers as if they were MII connected. */
+
+static int
+mdio_read(struct eth_device *dev, int phy_id, int location)
+{
+	if (phy_id == 1 && location < 32)
+		return INL(dev, BasicControl+(location<<2))&0xffff;
+	else
+		return 0xffff;
+}
+
+/* Function: natsemi_init
+ *
+ * Description: resets the ethernet controller chip and configures
+ *    registers and data structures required for sending and receiving packets.
+ *
+ * Arguments: struct eth_device *dev:          NIC data structure
+ *
+ * returns:  	int.
+ */
+
+static int
+natsemi_init(struct eth_device *dev, bd_t * bis)
+{
+
+	natsemi_reset(dev);
+
+	/* Disable PME:
+	 * The PME bit is initialized from the EEPROM contents.
+	 * PCI cards probably have PME disabled, but motherboard
+	 * implementations may have PME set to enable WakeOnLan.
+	 * With PME set the chip will scan incoming packets but
+	 * nothing will be written to memory. */
+	OUTL(dev, SavedClkRun & ~0x100, ClkRun);
+
+	natsemi_init_rxfilter(dev);
+	natsemi_init_txd(dev);
+	natsemi_init_rxd(dev);
+
+	/* Configure the PCI bus bursts and FIFO thresholds. */
+	tx_config = TxAutoPad | TxCollRetry | TxMxdma_256 | (0x1002);
+	rx_config = RxMxdma_256 | 0x20;
+
+#ifdef NATSEMI_DEBUG
+	printf("%s: Setting TxConfig Register %#08X\n", dev->name, tx_config);
+	printf("%s: Setting RxConfig Register %#08X\n", dev->name, rx_config);
+#endif
+	OUTL(dev, tx_config, TxConfig);
+	OUTL(dev, rx_config, RxConfig);
+
+	natsemi_check_duplex(dev);
+	natsemi_set_rx_mode(dev);
+
+	OUTL(dev, (RxOn | TxOn), ChipCmd);
+	return 1;
+}
+
+/*
+ * Function: natsemi_reset
+ *
+ * Description: soft resets the controller chip
+ *
+ * Arguments: struct eth_device *dev:          NIC data structure
+ *
+ * Returns:   void.
+ */
+static void
+natsemi_reset(struct eth_device *dev)
+{
+	OUTL(dev, ChipReset, ChipCmd);
+
+	/* On page 78 of the spec, they recommend some settings for "optimum
+	   performance" to be done in sequence.  These settings optimize some
+	   of the 100Mbit autodetection circuitry.  Also, we only want to do
+	   this for rev C of the chip.  */
+	if (INL(dev, SiliconRev) == 0x302) {
+		OUTW(dev, 0x0001, PGSEL);
+		OUTW(dev, 0x189C, PMDCSR);
+		OUTW(dev, 0x0000, TSTDAT);
+		OUTW(dev, 0x5040, DSPCFG);
+		OUTW(dev, 0x008C, SDCFG);
+	}
+	/* Disable interrupts using the mask. */
+	OUTL(dev, 0, IntrMask);
+	OUTL(dev, 0, IntrEnable);
+}
+
+/* Function: natsemi_init_rxfilter
+ *
+ * Description: sets receive filter address to our MAC address
+ *
+ * Arguments: struct eth_device *dev:          NIC data structure
+ *
+ * returns:   void.
+ */
+
+static void
+natsemi_init_rxfilter(struct eth_device *dev)
+{
+	int i;
+
+	for (i = 0; i < ETH_ALEN; i += 2) {
+		OUTL(dev, i, RxFilterAddr);
+		OUTW(dev, dev->enetaddr[i] + (dev->enetaddr[i + 1] << 8),
+		     RxFilterData);
+	}
+}
+
+/*
+ * Function: natsemi_init_txd
+ *
+ * Description: initializes the Tx descriptor
+ *
+ * Arguments: struct eth_device *dev:          NIC data structure
+ *
+ * returns:   void.
+ */
+
+static void
+natsemi_init_txd(struct eth_device *dev)
+{
+	txd.link = (u32) 0;
+	txd.cmdsts = (u32) 0;
+	txd.bufptr = (u32) & txb[0];
+
+	/* load Transmit Descriptor Register */
+	OUTL(dev, (u32) & txd, TxRingPtr);
+#ifdef NATSEMI_DEBUG
+	printf("natsemi_init_txd: TX descriptor reg loaded with: %#08X\n",
+	       INL(dev, TxRingPtr));
+#endif
+}
+
+/* Function: natsemi_init_rxd
+ *
+ * Description: initializes the Rx descriptor ring
+ *
+ * Arguments: struct eth_device *dev:          NIC data structure
+ *
+ * Returns:   void.
+ */
+
+static void
+natsemi_init_rxd(struct eth_device *dev)
+{
+	int i;
+
+	cur_rx = 0;
+
+	/* init RX descriptor */
+	for (i = 0; i < NUM_RX_DESC; i++) {
+		rxd[i].link =
+		    cpu_to_le32((i + 1 <
+				 NUM_RX_DESC) ? (u32) & rxd[i +
+							    1] : (u32) &
+				rxd[0]);
+		rxd[i].cmdsts = cpu_to_le32((u32) RX_BUF_SIZE);
+		rxd[i].bufptr = cpu_to_le32((u32) & rxb[i * RX_BUF_SIZE]);
+#ifdef NATSEMI_DEBUG
+		printf
+		    ("natsemi_init_rxd: rxd[%d]=%p link=%X cmdsts=%lX bufptr=%X\n",
+		     	i, &rxd[i], le32_to_cpu(rxd[i].link),
+		     		rxd[i].cmdsts, rxd[i].bufptr);
+#endif
+	}
+
+	/* load Receive Descriptor Register */
+	OUTL(dev, (u32) & rxd[0], RxRingPtr);
+
+#ifdef NATSEMI_DEBUG
+	printf("natsemi_init_rxd: RX descriptor register loaded with: %X\n",
+	       INL(dev, RxRingPtr));
+#endif
+}
+
+/* Function: natsemi_set_rx_mode
+ *
+ * Description:
+ *    sets the receive mode to accept all broadcast packets and packets
+ *    with our MAC address, and reject all multicast packets.
+ *
+ * Arguments: struct eth_device *dev:          NIC data structure
+ *
+ * Returns:   void.
+ */
+
+static void
+natsemi_set_rx_mode(struct eth_device *dev)
+{
+	u32 rx_mode = AcceptBroadcast | AcceptMyPhys;
+
+	OUTL(dev, rx_mode, RxFilterAddr);
+}
+
+static void
+natsemi_check_duplex(struct eth_device *dev)
+{
+	int duplex = INL(dev, ChipConfig) & FullDuplex ? 1 : 0;
+
+#ifdef NATSEMI_DEBUG
+	printf("%s: Setting %s-duplex based on negotiated link"
+	       " capability.\n", dev->name, duplex ? "full" : "half");
+#endif
+	if (duplex) {
+		rx_config |= RxAcceptTx;
+		tx_config |= (TxCarrierIgn | TxHeartIgn);
+	} else {
+		rx_config &= ~RxAcceptTx;
+		tx_config &= ~(TxCarrierIgn | TxHeartIgn);
+	}
+	OUTL(dev, tx_config, TxConfig);
+	OUTL(dev, rx_config, RxConfig);
+}
+
+/* Function: natsemi_send
+ *
+ * Description: transmits a packet and waits for completion or timeout.
+ *
+ * Returns:   void.  */
+static int
+natsemi_send(struct eth_device *dev, volatile void *packet, int length)
+{
+	u32 i, status = 0;
+	u32 tx_status = 0;
+
+	/* Stop the transmitter */
+	OUTL(dev, TxOff, ChipCmd);
+
+#ifdef NATSEMI_DEBUG
+	if (natsemi_debug)
+		printf("natsemi_send: sending %d bytes\n", (int) length);
+#endif
+
+	/* set the transmit buffer descriptor and enable Transmit State Machine */
+	txd.link = cpu_to_le32(0);
+	txd.bufptr = cpu_to_le32(phys_to_bus((u32) packet));
+	txd.cmdsts = cpu_to_le32(DescOwn | length);
+
+	/* load Transmit Descriptor Register */
+	OUTL(dev, phys_to_bus((u32) & txd), TxRingPtr);
+#ifdef NATSEMI_DEBUG
+	if (natsemi_debug)
+	    printf("natsemi_send: TX descriptor register loaded with: %#08X\n",
+	     INL(dev, TxRingPtr));
+#endif
+	/* restart the transmitter */
+	OUTL(dev, TxOn, ChipCmd);
+
+	for (i = 0;
+	     ((vu_long)tx_status = le32_to_cpu(txd.cmdsts)) & DescOwn;
+	     i++) {
+		if (i >= TOUT_LOOP) {
+			printf
+			    ("%s: tx error buffer not ready: txd.cmdsts == %#X\n",
+			     dev->name, tx_status);
+			goto Done;
+		}
+	}
+
+	if (!(tx_status & DescPktOK)) {
+		printf("natsemi_send: Transmit error, Tx status %X.\n",
+		       tx_status);
+		goto Done;
+	}
+
+	status = 1;
+      Done:
+	return status;
+}
+
+/* Function: natsemi_poll
+ *
+ * Description: checks for a received packet and returns it if found.
+ *
+ * Arguments: struct eth_device *dev:          NIC data structure
+ *
+ * Returns:   1 if    packet was received.
+ *            0 if no packet was received.
+ *
+ * Side effects:
+ *            Returns (copies) the packet to the array dev->packet.
+ *            Returns the length of the packet.
+ */
+
+static int
+natsemi_poll(struct eth_device *dev)
+{
+	int retstat = 0;
+	int length = 0;
+	u32 rx_status = le32_to_cpu(rxd[cur_rx].cmdsts);
+
+	if (!(rx_status & (u32) DescOwn))
+		return retstat;
+#ifdef NATSEMI_DEBUG
+	if (natsemi_debug)
+		printf("natsemi_poll: got a packet: cur_rx:%d, status:%X\n",
+		       cur_rx, rx_status);
+#endif
+	length = (rx_status & DSIZE) - CRC_SIZE;
+
+	if ((rx_status & (DescMore | DescPktOK | DescRxLong)) != DescPktOK) {
+		printf
+		    ("natsemi_poll: Corrupted packet received, buffer status = %X\n",
+		     rx_status);
+		retstat = 0;
+	} else {		/* give packet to higher level routine */
+		NetReceive((rxb + cur_rx * RX_BUF_SIZE), length);
+		retstat = 1;
+	}
+
+	/* return the descriptor and buffer to receive ring */
+	rxd[cur_rx].cmdsts = cpu_to_le32(RX_BUF_SIZE);
+	rxd[cur_rx].bufptr = cpu_to_le32((u32) & rxb[cur_rx * RX_BUF_SIZE]);
+
+	if (++cur_rx == NUM_RX_DESC)
+		cur_rx = 0;
+
+	/* re-enable the potentially idle receive state machine */
+	OUTL(dev, RxOn, ChipCmd);
+
+	return retstat;
+}
+
+/* Function: natsemi_disable
+ *
+ * Description: Turns off interrupts and stops Tx and Rx engines
+ *
+ * Arguments: struct eth_device *dev:          NIC data structure
+ *
+ * Returns:   void.
+ */
+
+static void
+natsemi_disable(struct eth_device *dev)
+{
+	/* Disable interrupts using the mask. */
+	OUTL(dev, 0, IntrMask);
+	OUTL(dev, 0, IntrEnable);
+
+	/* Stop the chip's Tx and Rx processes. */
+	OUTL(dev, RxOff | TxOff, ChipCmd);
+
+	/* Restore PME enable bit */
+	OUTL(dev, SavedClkRun, ClkRun);
+}
+
+#endif