xref: /openbmc/u-boot/drivers/net/dm9000x.c (revision 850ba755)

/*
  dm9000.c: Version 1.2 12/15/2003

	A Davicom DM9000 ISA NIC fast Ethernet driver for Linux.
	Copyright (C) 1997  Sten Wang

	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

  (C)Copyright 1997-1998 DAVICOM Semiconductor,Inc. All Rights Reserved.

V0.11	06/20/2001	REG_0A bit3=1, default enable BP with DA match
	06/22/2001	Support DM9801 progrmming
			E3: R25 = ((R24 + NF) & 0x00ff) | 0xf000
			E4: R25 = ((R24 + NF) & 0x00ff) | 0xc200
		R17 = (R17 & 0xfff0) | NF + 3
			E5: R25 = ((R24 + NF - 3) & 0x00ff) | 0xc200
		R17 = (R17 & 0xfff0) | NF

v1.00			modify by simon 2001.9.5
	                change for kernel 2.4.x

v1.1   11/09/2001	fix force mode bug

v1.2   03/18/2003       Weilun Huang <weilun_huang@davicom.com.tw>:
			Fixed phy reset.
			Added tx/rx 32 bit mode.
			Cleaned up for kernel merge.

--------------------------------------

       12/15/2003       Initial port to u-boot by
       			Sascha Hauer <saschahauer@web.de>

       06/03/2008	Remy Bohmer <linux@bohmer.net>
			- Fixed the driver to work with DM9000A.
			  (check on ISR receive status bit before reading the
			  FIFO as described in DM9000 programming guide and
			  application notes)
			- Added autodetect of databus width.
			- Made debug code compile again.
			- Adapt eth_send such that it matches the DM9000*
			  application notes. Needed to make it work properly
			  for DM9000A.
			- Adapted reset procedure to match DM9000 application
			  notes (i.e. double reset)
			These changes are tested with DM9000{A,EP,E} together
			with a 200MHz Atmel AT91SAM92161 core

TODO: Homerun NIC and longrun NIC are not functional, only internal at the
      moment.
*/

#include <common.h>
#include <command.h>
#include <net.h>
#include <asm/io.h>

#ifdef CONFIG_DRIVER_DM9000

#include "dm9000x.h"

/* Board/System/Debug information/definition ---------------- */

#define DM9801_NOISE_FLOOR	0x08
#define DM9802_NOISE_FLOOR	0x05

/* #define CONFIG_DM9000_DEBUG */

#ifdef CONFIG_DM9000_DEBUG
#define DM9000_DBG(fmt,args...) printf(fmt, ##args)
#define DM9000_DMP_PACKET(func,packet,length)  \
	do { \
		int i; 							\
		printf(func ": length: %d\n", length);			\
		for (i = 0; i < length; i++) {				\
			if (i % 8 == 0)					\
				printf("\n%s: %02x: ", func, i);	\
			printf("%02x ", ((unsigned char *) packet)[i]);	\
		} printf("\n");						\
	} while(0)
#else
#define DM9000_DBG(fmt,args...)
#define DM9000_DMP_PACKET(func,packet,length)
#endif

enum DM9000_PHY_mode { DM9000_10MHD = 0, DM9000_100MHD =
	    1, DM9000_10MFD = 4, DM9000_100MFD = 5, DM9000_AUTO =
	    8, DM9000_1M_HPNA = 0x10
};
enum DM9000_NIC_TYPE { FASTETHER_NIC = 0, HOMERUN_NIC = 1, LONGRUN_NIC = 2
};

/* Structure/enum declaration ------------------------------- */
typedef struct board_info {
	u32 runt_length_counter;	/* counter: RX length < 64byte */
	u32 long_length_counter;	/* counter: RX length > 1514byte */
	u32 reset_counter;	/* counter: RESET */
	u32 reset_tx_timeout;	/* RESET caused by TX Timeout */
	u32 reset_rx_status;	/* RESET caused by RX Statsus wrong */
	u16 tx_pkt_cnt;
	u16 queue_start_addr;
	u16 dbug_cnt;
	u8 phy_addr;
	u8 device_wait_reset;	/* device state */
	u8 nic_type;		/* NIC type */
	unsigned char srom[128];
	void (*outblk)(void *data_ptr, int count);
	void (*inblk)(void *data_ptr, int count);
	void (*rx_status)(u16 *RxStatus, u16 *RxLen);
 } board_info_t;
static board_info_t dm9000_info;

/* For module input parameter */
static int media_mode = DM9000_AUTO;
static u8 nfloor = 0;

/* function declaration ------------------------------------- */
int eth_init(bd_t * bd);
int eth_send(volatile void *, int);
int eth_rx(void);
void eth_halt(void);
static int dm9000_probe(void);
static u16 phy_read(int);
static void phy_write(int, u16);
u16 read_srom_word(int);
static u8 DM9000_ior(int);
static void DM9000_iow(int reg, u8 value);

/* DM9000 network board routine ---------------------------- */

#define DM9000_outb(d,r) ( *(volatile u8 *)r = d )
#define DM9000_outw(d,r) ( *(volatile u16 *)r = d )
#define DM9000_outl(d,r) ( *(volatile u32 *)r = d )
#define DM9000_inb(r) (*(volatile u8 *)r)
#define DM9000_inw(r) (*(volatile u16 *)r)
#define DM9000_inl(r) (*(volatile u32 *)r)

#ifdef CONFIG_DM9000_DEBUG
static void
dump_regs(void)
{
	DM9000_DBG("\n");
	DM9000_DBG("NCR   (0x00): %02x\n", DM9000_ior(0));
	DM9000_DBG("NSR   (0x01): %02x\n", DM9000_ior(1));
	DM9000_DBG("TCR   (0x02): %02x\n", DM9000_ior(2));
	DM9000_DBG("TSRI  (0x03): %02x\n", DM9000_ior(3));
	DM9000_DBG("TSRII (0x04): %02x\n", DM9000_ior(4));
	DM9000_DBG("RCR   (0x05): %02x\n", DM9000_ior(5));
	DM9000_DBG("RSR   (0x06): %02x\n", DM9000_ior(6));
	DM9000_DBG("ISR   (0xFE): %02x\n", DM9000_ior(DM9000_ISR));
	DM9000_DBG("\n");
}
#endif

static void dm9000_outblk_8bit(void *data_ptr, int count)
{
	int i;
	for (i = 0; i < count; i++)
		DM9000_outb((((u8 *) data_ptr)[i] & 0xff), DM9000_DATA);
}

static void dm9000_outblk_16bit(void *data_ptr, int count)
{
	int i;
	u32 tmplen = (count + 1) / 2;

	for (i = 0; i < tmplen; i++)
		DM9000_outw(((u16 *) data_ptr)[i], DM9000_DATA);
}
static void dm9000_outblk_32bit(void *data_ptr, int count)
{
	int i;
	u32 tmplen = (count + 3) / 4;

	for (i = 0; i < tmplen; i++)
		DM9000_outl(((u32 *) data_ptr)[i], DM9000_DATA);
}

static void dm9000_inblk_8bit(void *data_ptr, int count)
{
	int i;
	for (i = 0; i < count; i++)
		((u8 *) data_ptr)[i] = DM9000_inb(DM9000_DATA);
}

static void dm9000_inblk_16bit(void *data_ptr, int count)
{
	int i;
	u32 tmplen = (count + 1) / 2;

	for (i = 0; i < tmplen; i++)
		((u16 *) data_ptr)[i] = DM9000_inw(DM9000_DATA);
}
static void dm9000_inblk_32bit(void *data_ptr, int count)
{
	int i;
	u32 tmplen = (count + 3) / 4;

	for (i = 0; i < tmplen; i++)
		((u32 *) data_ptr)[i] = DM9000_inl(DM9000_DATA);
}

static void dm9000_rx_status_32bit(u16 *RxStatus, u16 *RxLen)
{
	u32 tmpdata = DM9000_inl(DM9000_DATA);

	DM9000_outb(DM9000_MRCMD, DM9000_IO);

	*RxStatus = tmpdata;
	*RxLen = tmpdata >> 16;
}

static void dm9000_rx_status_16bit(u16 *RxStatus, u16 *RxLen)
{
	DM9000_outb(DM9000_MRCMD, DM9000_IO);

	*RxStatus = DM9000_inw(DM9000_DATA);
	*RxLen = DM9000_inw(DM9000_DATA);
}

static void dm9000_rx_status_8bit(u16 *RxStatus, u16 *RxLen)
{
	DM9000_outb(DM9000_MRCMD, DM9000_IO);

	*RxStatus = DM9000_inb(DM9000_DATA) + (DM9000_inb(DM9000_DATA) << 8);
	*RxLen = DM9000_inb(DM9000_DATA) + (DM9000_inb(DM9000_DATA) << 8);
}

/*
  Search DM9000 board, allocate space and register it
*/
int
dm9000_probe(void)
{
	u32 id_val;
	id_val = DM9000_ior(DM9000_VIDL);
	id_val |= DM9000_ior(DM9000_VIDH) << 8;
	id_val |= DM9000_ior(DM9000_PIDL) << 16;
	id_val |= DM9000_ior(DM9000_PIDH) << 24;
	if (id_val == DM9000_ID) {
		printf("dm9000 i/o: 0x%x, id: 0x%x \n", CONFIG_DM9000_BASE,
		       id_val);
		return 0;
	} else {
		printf("dm9000 not found at 0x%08x id: 0x%08x\n",
		       CONFIG_DM9000_BASE, id_val);
		return -1;
	}
}

/* Set PHY operationg mode
*/
static void
set_PHY_mode(void)
{
	u16 phy_reg4 = 0x01e1, phy_reg0 = 0x1000;
	if (!(media_mode & DM9000_AUTO)) {
		switch (media_mode) {
		case DM9000_10MHD:
			phy_reg4 = 0x21;
			phy_reg0 = 0x0000;
			break;
		case DM9000_10MFD:
			phy_reg4 = 0x41;
			phy_reg0 = 0x1100;
			break;
		case DM9000_100MHD:
			phy_reg4 = 0x81;
			phy_reg0 = 0x2000;
			break;
		case DM9000_100MFD:
			phy_reg4 = 0x101;
			phy_reg0 = 0x3100;
			break;
		}
		phy_write(4, phy_reg4);	/* Set PHY media mode */
		phy_write(0, phy_reg0);	/*  Tmp */
	}
	DM9000_iow(DM9000_GPCR, 0x01);	/* Let GPIO0 output */
	DM9000_iow(DM9000_GPR, 0x00);	/* Enable PHY */
}

/*
	Init HomeRun DM9801
*/
static void
program_dm9801(u16 HPNA_rev)
{
	__u16 reg16, reg17, reg24, reg25;
	if (!nfloor)
		nfloor = DM9801_NOISE_FLOOR;
	reg16 = phy_read(16);
	reg17 = phy_read(17);
	reg24 = phy_read(24);
	reg25 = phy_read(25);
	switch (HPNA_rev) {
	case 0xb900:		/* DM9801 E3 */
		reg16 |= 0x1000;
		reg25 = ((reg24 + nfloor) & 0x00ff) | 0xf000;
		break;
	case 0xb901:		/* DM9801 E4 */
		reg25 = ((reg24 + nfloor) & 0x00ff) | 0xc200;
		reg17 = (reg17 & 0xfff0) + nfloor + 3;
		break;
	case 0xb902:		/* DM9801 E5 */
	case 0xb903:		/* DM9801 E6 */
	default:
		reg16 |= 0x1000;
		reg25 = ((reg24 + nfloor - 3) & 0x00ff) | 0xc200;
		reg17 = (reg17 & 0xfff0) + nfloor;
	}
	phy_write(16, reg16);
	phy_write(17, reg17);
	phy_write(25, reg25);
}

/*
	Init LongRun DM9802
*/
static void
program_dm9802(void)
{
	__u16 reg25;
	if (!nfloor)
		nfloor = DM9802_NOISE_FLOOR;
	reg25 = phy_read(25);
	reg25 = (reg25 & 0xff00) + nfloor;
	phy_write(25, reg25);
}

/* Identify NIC type
*/
static void
identify_nic(void)
{
	struct board_info *db = &dm9000_info;
	u16 phy_reg3;
	DM9000_iow(DM9000_NCR, NCR_EXT_PHY);
	phy_reg3 = phy_read(3);
	switch (phy_reg3 & 0xfff0) {
	case 0xb900:
		if (phy_read(31) == 0x4404) {
			db->nic_type = HOMERUN_NIC;
			program_dm9801(phy_reg3);
			DM9000_DBG("found homerun NIC\n");
		} else {
			db->nic_type = LONGRUN_NIC;
			DM9000_DBG("found longrun NIC\n");
			program_dm9802();
		}
		break;
	default:
		db->nic_type = FASTETHER_NIC;
		break;
	}
	DM9000_iow(DM9000_NCR, 0);
}

/* General Purpose dm9000 reset routine */
static void
dm9000_reset(void)
{
	DM9000_DBG("resetting DM9000\n");

	/* Reset DM9000,
	   see DM9000 Application Notes V1.22 Jun 11, 2004 page 29 */

	/* DEBUG: Make all GPIO pins outputs */
	DM9000_iow(DM9000_GPCR, 0x0F);
	/* Step 1: Power internal PHY by writing 0 to GPIO0 pin */
	DM9000_iow(DM9000_GPR, 0);
	/* Step 2: Software reset */
	DM9000_iow(DM9000_NCR, 3);

	do {
		DM9000_DBG("resetting the DM9000, 1st reset\n");
		udelay(25); /* Wait at least 20 us */
	} while (DM9000_ior(DM9000_NCR) & 1);

	DM9000_iow(DM9000_NCR, 0);
	DM9000_iow(DM9000_NCR, 3); /* Issue a second reset */

	do {
		DM9000_DBG("resetting the DM9000, 2nd reset\n");
		udelay(25); /* Wait at least 20 us */
	} while (DM9000_ior(DM9000_NCR) & 1);

	/* Check whether the ethernet controller is present */
	if ((DM9000_ior(DM9000_PIDL) != 0x0) ||
	    (DM9000_ior(DM9000_PIDH) != 0x90))
		printf("ERROR: resetting DM9000 -> not responding\n");
}

/* Initilize dm9000 board
*/
int
eth_init(bd_t * bd)
{
	int i, oft, lnk;
	u8 io_mode;
	struct board_info *db = &dm9000_info;

	DM9000_DBG("eth_init()\n");

	/* RESET device */
	dm9000_reset();
	dm9000_probe();

	/* Auto-detect 8/16/32 bit mode, ISR Bit 6+7 indicate bus width */
	io_mode = DM9000_ior(DM9000_ISR) >> 6;

	switch (io_mode) {
	case 0x0:  /* 16-bit mode */
		printf("DM9000: running in 16 bit mode\n");
		db->outblk    = dm9000_outblk_16bit;
		db->inblk     = dm9000_inblk_16bit;
		db->rx_status = dm9000_rx_status_16bit;
		break;
	case 0x01:  /* 32-bit mode */
		printf("DM9000: running in 32 bit mode\n");
		db->outblk    = dm9000_outblk_32bit;
		db->inblk     = dm9000_inblk_32bit;
		db->rx_status = dm9000_rx_status_32bit;
		break;
	case 0x02: /* 8 bit mode */
		printf("DM9000: running in 8 bit mode\n");
		db->outblk    = dm9000_outblk_8bit;
		db->inblk     = dm9000_inblk_8bit;
		db->rx_status = dm9000_rx_status_8bit;
		break;
	default:
		/* Assume 8 bit mode, will probably not work anyway */
		printf("DM9000: Undefined IO-mode:0x%x\n", io_mode);
		db->outblk    = dm9000_outblk_8bit;
		db->inblk     = dm9000_inblk_8bit;
		db->rx_status = dm9000_rx_status_8bit;
		break;
	}

	/* NIC Type: FASTETHER, HOMERUN, LONGRUN */
	identify_nic();

	/* GPIO0 on pre-activate PHY */
	DM9000_iow(DM9000_GPR, 0x00);	/*REG_1F bit0 activate phyxcer */

	/* Set PHY */
	set_PHY_mode();

	/* Program operating register */
	DM9000_iow(DM9000_NCR, 0x0);	/* only intern phy supported by now */
	DM9000_iow(DM9000_TCR, 0);	/* TX Polling clear */
	DM9000_iow(DM9000_BPTR, 0x3f);	/* Less 3Kb, 200us */
	DM9000_iow(DM9000_FCTR, FCTR_HWOT(3) | FCTR_LWOT(8));	/* Flow Control : High/Low Water */
	DM9000_iow(DM9000_FCR, 0x0);	/* SH FIXME: This looks strange! Flow Control */
	DM9000_iow(DM9000_SMCR, 0);	/* Special Mode */
	DM9000_iow(DM9000_NSR, NSR_WAKEST | NSR_TX2END | NSR_TX1END);	/* clear TX status */
	DM9000_iow(DM9000_ISR, 0x0f);	/* Clear interrupt status */

	/* Set Node address */
	for (i = 0; i < 6; i++)
		((u16 *) bd->bi_enetaddr)[i] = read_srom_word(i);

	if (is_zero_ether_addr(bd->bi_enetaddr) ||
	    is_multicast_ether_addr(bd->bi_enetaddr)) {
		/* try reading from environment */
		u8 i;
		char *s, *e;
		s = getenv ("ethaddr");
		for (i = 0; i < 6; ++i) {
			bd->bi_enetaddr[i] = s ?
				simple_strtoul (s, &e, 16) : 0;
			if (s)
				s = (*e) ? e + 1 : e;
		}
	}

	printf("MAC: %02x:%02x:%02x:%02x:%02x:%02x\n", bd->bi_enetaddr[0],
	       bd->bi_enetaddr[1], bd->bi_enetaddr[2], bd->bi_enetaddr[3],
	       bd->bi_enetaddr[4], bd->bi_enetaddr[5]);
	for (i = 0, oft = 0x10; i < 6; i++, oft++)
		DM9000_iow(oft, bd->bi_enetaddr[i]);
	for (i = 0, oft = 0x16; i < 8; i++, oft++)
		DM9000_iow(oft, 0xff);

	/* read back mac, just to be sure */
	for (i = 0, oft = 0x10; i < 6; i++, oft++)
		DM9000_DBG("%02x:", DM9000_ior(oft));
	DM9000_DBG("\n");

	/* Activate DM9000 */
	DM9000_iow(DM9000_RCR, RCR_DIS_LONG | RCR_DIS_CRC | RCR_RXEN);	/* RX enable */
	DM9000_iow(DM9000_IMR, IMR_PAR);	/* Enable TX/RX interrupt mask */
	i = 0;
	while (!(phy_read(1) & 0x20)) {	/* autonegation complete bit */
		udelay(1000);
		i++;
		if (i == 10000) {
			printf("could not establish link\n");
			return 0;
		}
	}

	/* see what we've got */
	lnk = phy_read(17) >> 12;
	printf("operating at ");
	switch (lnk) {
	case 1:
		printf("10M half duplex ");
		break;
	case 2:
		printf("10M full duplex ");
		break;
	case 4:
		printf("100M half duplex ");
		break;
	case 8:
		printf("100M full duplex ");
		break;
	default:
		printf("unknown: %d ", lnk);
		break;
	}
	printf("mode\n");
	return 0;
}

/*
  Hardware start transmission.
  Send a packet to media from the upper layer.
*/
int
eth_send(volatile void *packet, int length)
{
	char *data_ptr;
	int tmo;
	struct board_info *db = &dm9000_info;

	DM9000_DMP_PACKET("eth_send", packet, length);

	DM9000_iow(DM9000_ISR, IMR_PTM); /* Clear Tx bit in ISR */

	/* Move data to DM9000 TX RAM */
	data_ptr = (char *) packet;
	DM9000_outb(DM9000_MWCMD, DM9000_IO); /* Prepare for TX-data */

	/* push the data to the TX-fifo */
	(db->outblk)(data_ptr, length);

	/* Set TX length to DM9000 */
	DM9000_iow(DM9000_TXPLL, length & 0xff);
	DM9000_iow(DM9000_TXPLH, (length >> 8) & 0xff);

	/* Issue TX polling command */
	DM9000_iow(DM9000_TCR, TCR_TXREQ); /* Cleared after TX complete */

	/* wait for end of transmission */
	tmo = get_timer(0) + 5 * CFG_HZ;
	while ( !(DM9000_ior(DM9000_NSR) & (NSR_TX1END | NSR_TX2END)) ||
		!(DM9000_ior(DM9000_ISR) & IMR_PTM) ) {
		if (get_timer(0) >= tmo) {
			printf("transmission timeout\n");
			break;
		}
	}
	DM9000_iow(DM9000_ISR, IMR_PTM); /* Clear Tx bit in ISR */

	DM9000_DBG("transmit done\n\n");
	return 0;
}

/*
  Stop the interface.
  The interface is stopped when it is brought.
*/
void
eth_halt(void)
{
	DM9000_DBG("eth_halt\n");

	/* RESET devie */
	phy_write(0, 0x8000);	/* PHY RESET */
	DM9000_iow(DM9000_GPR, 0x01);	/* Power-Down PHY */
	DM9000_iow(DM9000_IMR, 0x80);	/* Disable all interrupt */
	DM9000_iow(DM9000_RCR, 0x00);	/* Disable RX */
}

/*
  Received a packet and pass to upper layer
*/
int
eth_rx(void)
{
	u8 rxbyte, *rdptr = (u8 *) NetRxPackets[0];
	u16 RxStatus, RxLen = 0;
	struct board_info *db = &dm9000_info;

	/* Check packet ready or not, we must check
	   the ISR status first for DM9000A */
	if (!(DM9000_ior(DM9000_ISR) & 0x01)) /* Rx-ISR bit must be set. */
		return 0;

	DM9000_iow(DM9000_ISR, 0x01); /* clear PR status latched in bit 0 */

	/* There is _at least_ 1 package in the fifo, read them all */
	for (;;) {
		DM9000_ior(DM9000_MRCMDX);	/* Dummy read */

		/* Get most updated data */
		rxbyte = DM9000_inb(DM9000_DATA);

		/* Status check: this byte must be 0 or 1 */
		if (rxbyte > DM9000_PKT_RDY) {
			DM9000_iow(DM9000_RCR, 0x00);	/* Stop Device */
			DM9000_iow(DM9000_ISR, 0x80);	/* Stop INT request */
			printf("DM9000 error: status check fail: 0x%x\n",
				rxbyte);
			return 0;
		}

		if (rxbyte != DM9000_PKT_RDY)
			return 0; /* No packet received, ignore */

		DM9000_DBG("receiving packet\n");

		/* A packet ready now  & Get status/length */
		(db->rx_status)(&RxStatus, &RxLen);

		DM9000_DBG("rx status: 0x%04x rx len: %d\n", RxStatus, RxLen);

		/* Move data from DM9000 */
		/* Read received packet from RX SRAM */
		(db->inblk)(rdptr, RxLen);

		if ((RxStatus & 0xbf00) || (RxLen < 0x40)
			|| (RxLen > DM9000_PKT_MAX)) {
			if (RxStatus & 0x100) {
				printf("rx fifo error\n");
			}
			if (RxStatus & 0x200) {
				printf("rx crc error\n");
			}
			if (RxStatus & 0x8000) {
				printf("rx length error\n");
			}
			if (RxLen > DM9000_PKT_MAX) {
				printf("rx length too big\n");
				dm9000_reset();
			}
		} else {
			DM9000_DMP_PACKET("eth_rx", rdptr, RxLen);

			DM9000_DBG("passing packet to upper layer\n");
			NetReceive(NetRxPackets[0], RxLen);
		}
	}
	return 0;
}

/*
  Read a word data from SROM
*/
u16
read_srom_word(int offset)
{
	DM9000_iow(DM9000_EPAR, offset);
	DM9000_iow(DM9000_EPCR, 0x4);
	udelay(8000);
	DM9000_iow(DM9000_EPCR, 0x0);
	return (DM9000_ior(DM9000_EPDRL) + (DM9000_ior(DM9000_EPDRH) << 8));
}

void
write_srom_word(int offset, u16 val)
{
	DM9000_iow(DM9000_EPAR, offset);
	DM9000_iow(DM9000_EPDRH, ((val >> 8) & 0xff));
	DM9000_iow(DM9000_EPDRL, (val & 0xff));
	DM9000_iow(DM9000_EPCR, 0x12);
	udelay(8000);
	DM9000_iow(DM9000_EPCR, 0);
}


/*
   Read a byte from I/O port
*/
static u8
DM9000_ior(int reg)
{
	DM9000_outb(reg, DM9000_IO);
	return DM9000_inb(DM9000_DATA);
}

/*
   Write a byte to I/O port
*/
static void
DM9000_iow(int reg, u8 value)
{
	DM9000_outb(reg, DM9000_IO);
	DM9000_outb(value, DM9000_DATA);
}

/*
   Read a word from phyxcer
*/
static u16
phy_read(int reg)
{
	u16 val;

	/* Fill the phyxcer register into REG_0C */
	DM9000_iow(DM9000_EPAR, DM9000_PHY | reg);
	DM9000_iow(DM9000_EPCR, 0xc);	/* Issue phyxcer read command */
	udelay(100);		/* Wait read complete */
	DM9000_iow(DM9000_EPCR, 0x0);	/* Clear phyxcer read command */
	val = (DM9000_ior(DM9000_EPDRH) << 8) | DM9000_ior(DM9000_EPDRL);

	/* The read data keeps on REG_0D & REG_0E */
	DM9000_DBG("phy_read(0x%x): 0x%x\n", reg, val);
	return val;
}

/*
   Write a word to phyxcer
*/
static void
phy_write(int reg, u16 value)
{

	/* Fill the phyxcer register into REG_0C */
	DM9000_iow(DM9000_EPAR, DM9000_PHY | reg);

	/* Fill the written data into REG_0D & REG_0E */
	DM9000_iow(DM9000_EPDRL, (value & 0xff));
	DM9000_iow(DM9000_EPDRH, ((value >> 8) & 0xff));
	DM9000_iow(DM9000_EPCR, 0xa);	/* Issue phyxcer write command */
	udelay(500);		/* Wait write complete */
	DM9000_iow(DM9000_EPCR, 0x0);	/* Clear phyxcer write command */
	DM9000_DBG("phy_write(reg:0x%x, value:0x%x)\n", reg, value);
}
#endif				/* CONFIG_DRIVER_DM9000 */