drivers/net/xilinx_emaclite.c - u-boot - Git at Google

 /******************************************************************************
  *
  * XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
  * AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
  * SOLUTIONS FOR XILINX DEVICES. BY PROVIDING THIS DESIGN, CODE,
  * OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
  * APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
  * THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
  * AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
  * FOR YOUR IMPLEMENTATION. XILINX EXPRESSLY DISCLAIMS ANY
  * WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
  * IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
  * REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
  * INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE.
  *
  * (C) Copyright 2007-2008 Michal Simek
  * Michal SIMEK <monstr@monstr.eu>
  *
  * (c) Copyright 2003 Xilinx Inc.
  * All rights reserved.
  *
  ******************************************************************************/

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

 #undef DEBUG

 #define ENET_MAX_MTU		PKTSIZE
 #define ENET_MAX_MTU_ALIGNED	PKTSIZE_ALIGN
 #define ENET_ADDR_LENGTH	6

 /* EmacLite constants */
 #define XEL_BUFFER_OFFSET	0x0800	/* Next buffer's offset */
 #define XEL_TPLR_OFFSET		0x07F4	/* Tx packet length */
 #define XEL_TSR_OFFSET		0x07FC	/* Tx status */
 #define XEL_RSR_OFFSET		0x17FC	/* Rx status */
 #define XEL_RXBUFF_OFFSET	0x1000	/* Receive Buffer */

 /* Xmit complete */
 #define XEL_TSR_XMIT_BUSY_MASK		0x00000001UL
 /* Xmit interrupt enable bit */
 #define XEL_TSR_XMIT_IE_MASK		0x00000008UL
 /* Buffer is active, SW bit only */
 #define XEL_TSR_XMIT_ACTIVE_MASK	0x80000000UL
 /* Program the MAC address */
 #define XEL_TSR_PROGRAM_MASK		0x00000002UL
 /* define for programming the MAC address into the EMAC Lite */
 #define XEL_TSR_PROG_MAC_ADDR	(XEL_TSR_XMIT_BUSY_MASK | XEL_TSR_PROGRAM_MASK)

 /* Transmit packet length upper byte */
 #define XEL_TPLR_LENGTH_MASK_HI		0x0000FF00UL
 /* Transmit packet length lower byte */
 #define XEL_TPLR_LENGTH_MASK_LO		0x000000FFUL

 /* Recv complete */
 #define XEL_RSR_RECV_DONE_MASK		0x00000001UL
 /* Recv interrupt enable bit */
 #define XEL_RSR_RECV_IE_MASK		0x00000008UL

 typedef struct {
 	unsigned int baseaddress;	/* Base address for device (IPIF) */
 	unsigned int nexttxbuffertouse;	/* Next TX buffer to write to */
 	unsigned int nextrxbuffertouse;	/* Next RX buffer to read from */
 	unsigned char deviceid;		/* Unique ID of device - for future */
 } xemaclite;

 static xemaclite emaclite;

 static char etherrxbuff[PKTSIZE_ALIGN/4]; /* Receive buffer */

 /* hardcoded MAC address for the Xilinx EMAC Core when env is nowhere*/
 #ifdef CONFIG_ENV_IS_NOWHERE
 static u8 emacaddr[ENET_ADDR_LENGTH] = { 0x00, 0x0a, 0x35, 0x00, 0x22, 0x01 };
 #else
 static u8 emacaddr[ENET_ADDR_LENGTH];
 #endif

 void xemaclite_alignedread (u32 * srcptr, void *destptr, unsigned bytecount)
 {
 	unsigned int i;
 	u32 alignbuffer;
 	u32 *to32ptr;
 	u32 *from32ptr;
 	u8 *to8ptr;
 	u8 *from8ptr;

 	from32ptr = (u32 *) srcptr;

 	/* Word aligned buffer, no correction needed. */
 	to32ptr = (u32 *) destptr;
 	while (bytecount > 3) {
 		*to32ptr++ = *from32ptr++;
 		bytecount -= 4;
 	}
 	to8ptr = (u8 *) to32ptr;

 	alignbuffer = *from32ptr++;
 	from8ptr = (u8 *) & alignbuffer;

 	for (i = 0; i < bytecount; i++) {
 		*to8ptr++ = *from8ptr++;
 	}
 }

 void xemaclite_alignedwrite (void *srcptr, u32 destptr, unsigned bytecount)
 {
 	unsigned i;
 	u32 alignbuffer;
 	u32 *to32ptr = (u32 *) destptr;
 	u32 *from32ptr;
 	u8 *to8ptr;
 	u8 *from8ptr;

 	from32ptr = (u32 *) srcptr;
 	while (bytecount > 3) {

 		*to32ptr++ = *from32ptr++;
 		bytecount -= 4;
 	}

 	alignbuffer = 0;
 	to8ptr = (u8 *) & alignbuffer;
 	from8ptr = (u8 *) from32ptr;

 	for (i = 0; i < bytecount; i++) {
 		*to8ptr++ = *from8ptr++;
 	}

 	*to32ptr++ = alignbuffer;
 }

 void eth_halt (void)
 {
 	debug ("eth_halt\n");
 }

 int eth_init (bd_t * bis)
 {
 	debug ("EmacLite Initialization Started\n");
 	memset (&emaclite, 0, sizeof (xemaclite));
 	emaclite.baseaddress = XILINX_EMACLITE_BASEADDR;

 	if (!getenv("ethaddr")) {
 		memcpy(bis->bi_enetaddr, emacaddr, ENET_ADDR_LENGTH);
 	}

 /*
  * TX - TX_PING & TX_PONG initialization
  */
 	/* Restart PING TX */
 	out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET, 0);
 	/* Copy MAC address */
 	xemaclite_alignedwrite (bis->bi_enetaddr,
 		emaclite.baseaddress, ENET_ADDR_LENGTH);
 	/* Set the length */
 	out_be32 (emaclite.baseaddress + XEL_TPLR_OFFSET, ENET_ADDR_LENGTH);
 	/* Update the MAC address in the EMAC Lite */
 	out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET, XEL_TSR_PROG_MAC_ADDR);
 	/* Wait for EMAC Lite to finish with the MAC address update */
 	while ((in_be32 (emaclite.baseaddress + XEL_TSR_OFFSET) &
 		XEL_TSR_PROG_MAC_ADDR) != 0) ;

 #ifdef CONFIG_XILINX_EMACLITE_TX_PING_PONG
 	/* The same operation with PONG TX */
 	out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET + XEL_BUFFER_OFFSET, 0);
 	xemaclite_alignedwrite (bis->bi_enetaddr, emaclite.baseaddress +
 		XEL_BUFFER_OFFSET, ENET_ADDR_LENGTH);
 	out_be32 (emaclite.baseaddress + XEL_TPLR_OFFSET, ENET_ADDR_LENGTH);
 	out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET + XEL_BUFFER_OFFSET,
 		XEL_TSR_PROG_MAC_ADDR);
 	while ((in_be32 (emaclite.baseaddress + XEL_TSR_OFFSET +
 		XEL_BUFFER_OFFSET) & XEL_TSR_PROG_MAC_ADDR) != 0) ;
 #endif

 /*
  * RX - RX_PING & RX_PONG initialization
  */
 	/* Write out the value to flush the RX buffer */
 	out_be32 (emaclite.baseaddress + XEL_RSR_OFFSET, XEL_RSR_RECV_IE_MASK);
 #ifdef CONFIG_XILINX_EMACLITE_RX_PING_PONG
 	out_be32 (emaclite.baseaddress + XEL_RSR_OFFSET + XEL_BUFFER_OFFSET,
 		XEL_RSR_RECV_IE_MASK);
 #endif

 	debug ("EmacLite Initialization complete\n");
 	return 0;
 }

 int xemaclite_txbufferavailable (xemaclite * instanceptr)
 {
 	u32 reg;
 	u32 txpingbusy;
 	u32 txpongbusy;
 	/*
 	 * Read the other buffer register
 	 * and determine if the other buffer is available
 	 */
 	reg = in_be32 (instanceptr->baseaddress +
 			instanceptr->nexttxbuffertouse + 0);
 	txpingbusy = ((reg & XEL_TSR_XMIT_BUSY_MASK) ==
 			XEL_TSR_XMIT_BUSY_MASK);

 	reg = in_be32 (instanceptr->baseaddress +
 			(instanceptr->nexttxbuffertouse ^ XEL_TSR_OFFSET) + 0);
 	txpongbusy = ((reg & XEL_TSR_XMIT_BUSY_MASK) ==
 			XEL_TSR_XMIT_BUSY_MASK);

 	return (!(txpingbusy && txpongbusy));
 }

 int eth_send (volatile void *ptr, int len) {

 	unsigned int reg;
 	unsigned int baseaddress;

 	unsigned maxtry = 1000;

 	if (len > ENET_MAX_MTU)
 		len = ENET_MAX_MTU;

 	while (!xemaclite_txbufferavailable (&emaclite) && maxtry) {
 		udelay (10);
 		maxtry--;
 	}

 	if (!maxtry) {
 		printf ("Error: Timeout waiting for ethernet TX buffer\n");
 		/* Restart PING TX */
 		out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET, 0);
 #ifdef CONFIG_XILINX_EMACLITE_TX_PING_PONG
 		out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET +
 		XEL_BUFFER_OFFSET, 0);
 #endif
 		return 0;
 	}

 	/* Determine the expected TX buffer address */
 	baseaddress = (emaclite.baseaddress + emaclite.nexttxbuffertouse);

 	/* Determine if the expected buffer address is empty */
 	reg = in_be32 (baseaddress + XEL_TSR_OFFSET);
 	if (((reg & XEL_TSR_XMIT_BUSY_MASK) == 0)
 		&& ((in_be32 ((baseaddress) + XEL_TSR_OFFSET)
 			& XEL_TSR_XMIT_ACTIVE_MASK) == 0)) {

 #ifdef CONFIG_XILINX_EMACLITE_TX_PING_PONG
 		emaclite.nexttxbuffertouse ^= XEL_BUFFER_OFFSET;
 #endif
 		debug ("Send packet from 0x%x\n", baseaddress);
 		/* Write the frame to the buffer */
 		xemaclite_alignedwrite ((void *) ptr, baseaddress, len);
 		out_be32 (baseaddress + XEL_TPLR_OFFSET,(len &
 			(XEL_TPLR_LENGTH_MASK_HI | XEL_TPLR_LENGTH_MASK_LO)));
 		reg = in_be32 (baseaddress + XEL_TSR_OFFSET);
 		reg |= XEL_TSR_XMIT_BUSY_MASK;
 		if ((reg & XEL_TSR_XMIT_IE_MASK) != 0) {
 			reg |= XEL_TSR_XMIT_ACTIVE_MASK;
 		}
 		out_be32 (baseaddress + XEL_TSR_OFFSET, reg);
 		return 1;
 	}
 #ifdef CONFIG_XILINX_EMACLITE_TX_PING_PONG
 	/* Switch to second buffer */
 	baseaddress ^= XEL_BUFFER_OFFSET;
 	/* Determine if the expected buffer address is empty */
 	reg = in_be32 (baseaddress + XEL_TSR_OFFSET);
 	if (((reg & XEL_TSR_XMIT_BUSY_MASK) == 0)
 		&& ((in_be32 ((baseaddress) + XEL_TSR_OFFSET)
 			& XEL_TSR_XMIT_ACTIVE_MASK) == 0)) {
 		debug ("Send packet from 0x%x\n", baseaddress);
 		/* Write the frame to the buffer */
 		xemaclite_alignedwrite ((void *) ptr, baseaddress, len);
 		out_be32 (baseaddress + XEL_TPLR_OFFSET,(len &
 			(XEL_TPLR_LENGTH_MASK_HI | XEL_TPLR_LENGTH_MASK_LO)));
 		reg = in_be32 (baseaddress + XEL_TSR_OFFSET);
 		reg |= XEL_TSR_XMIT_BUSY_MASK;
 		if ((reg & XEL_TSR_XMIT_IE_MASK) != 0) {
 			reg |= XEL_TSR_XMIT_ACTIVE_MASK;
 		}
 		out_be32 (baseaddress + XEL_TSR_OFFSET, reg);
 		return 1;
 	}
 #endif
 	puts ("Error while sending frame\n");
 	return 0;
 }

 int eth_rx (void)
 {
 	unsigned int length;
 	unsigned int reg;
 	unsigned int baseaddress;

 	baseaddress = emaclite.baseaddress + emaclite.nextrxbuffertouse;
 	reg = in_be32 (baseaddress + XEL_RSR_OFFSET);
 	debug ("Testing data at address 0x%x\n", baseaddress);
 	if ((reg & XEL_RSR_RECV_DONE_MASK) == XEL_RSR_RECV_DONE_MASK) {
 #ifdef CONFIG_XILINX_EMACLITE_RX_PING_PONG
 		emaclite.nextrxbuffertouse ^= XEL_BUFFER_OFFSET;
 #endif
 	} else {
 #ifndef CONFIG_XILINX_EMACLITE_RX_PING_PONG
 		debug ("No data was available - address 0x%x\n", baseaddress);
 		return 0;
 #else
 		baseaddress ^= XEL_BUFFER_OFFSET;
 		reg = in_be32 (baseaddress + XEL_RSR_OFFSET);
 		if ((reg & XEL_RSR_RECV_DONE_MASK) !=
 					XEL_RSR_RECV_DONE_MASK) {
 			debug ("No data was available - address 0x%x\n",
 					baseaddress);
 			return 0;
 		}
 #endif
 	}
 	/* Get the length of the frame that arrived */
 	switch(((in_be32 (baseaddress + XEL_RXBUFF_OFFSET + 0xC)) &
 			0xFFFF0000 ) >> 16) {
 		case 0x806:
 			length = 42 + 20; /* FIXME size of ARP */
 			debug ("ARP Packet\n");
 			break;
 		case 0x800:
 			length = 14 + 14 +
 			(((in_be32 (baseaddress + XEL_RXBUFF_OFFSET + 0x10)) &
 			0xFFFF0000) >> 16); /* FIXME size of IP packet */
 			debug ("IP Packet\n");
 			break;
 		default:
 			debug ("Other Packet\n");
 			length = ENET_MAX_MTU;
 			break;
 	}

 	xemaclite_alignedread ((u32 *) (baseaddress + XEL_RXBUFF_OFFSET),
 			etherrxbuff, length);

 	/* Acknowledge the frame */
 	reg = in_be32 (baseaddress + XEL_RSR_OFFSET);
 	reg &= ~XEL_RSR_RECV_DONE_MASK;
 	out_be32 (baseaddress + XEL_RSR_OFFSET, reg);

 	debug ("Packet receive from 0x%x, length %dB\n", baseaddress, length);
 	NetReceive ((uchar *) etherrxbuff, length);
 	return 1;

 }
	/******************************************************************************
	*
	* XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
	* AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
	* SOLUTIONS FOR XILINX DEVICES. BY PROVIDING THIS DESIGN, CODE,
	* OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
	* APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
	* THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
	* AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
	* FOR YOUR IMPLEMENTATION. XILINX EXPRESSLY DISCLAIMS ANY
	* WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
	* IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
	* REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
	* INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	* FOR A PARTICULAR PURPOSE.
	*
	* (C) Copyright 2007-2008 Michal Simek
	* Michal SIMEK <monstr@monstr.eu>
	*
	* (c) Copyright 2003 Xilinx Inc.
	* All rights reserved.
	*
	******************************************************************************/

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

	#undef DEBUG

	#define ENET_MAX_MTU PKTSIZE
	#define ENET_MAX_MTU_ALIGNED PKTSIZE_ALIGN
	#define ENET_ADDR_LENGTH 6

	/* EmacLite constants */
	#define XEL_BUFFER_OFFSET 0x0800 /* Next buffer's offset */
	#define XEL_TPLR_OFFSET 0x07F4 /* Tx packet length */
	#define XEL_TSR_OFFSET 0x07FC /* Tx status */
	#define XEL_RSR_OFFSET 0x17FC /* Rx status */
	#define XEL_RXBUFF_OFFSET 0x1000 /* Receive Buffer */

	/* Xmit complete */
	#define XEL_TSR_XMIT_BUSY_MASK 0x00000001UL
	/* Xmit interrupt enable bit */
	#define XEL_TSR_XMIT_IE_MASK 0x00000008UL
	/* Buffer is active, SW bit only */
	#define XEL_TSR_XMIT_ACTIVE_MASK 0x80000000UL
	/* Program the MAC address */
	#define XEL_TSR_PROGRAM_MASK 0x00000002UL
	/* define for programming the MAC address into the EMAC Lite */
	#define XEL_TSR_PROG_MAC_ADDR (XEL_TSR_XMIT_BUSY_MASK \| XEL_TSR_PROGRAM_MASK)

	/* Transmit packet length upper byte */
	#define XEL_TPLR_LENGTH_MASK_HI 0x0000FF00UL
	/* Transmit packet length lower byte */
	#define XEL_TPLR_LENGTH_MASK_LO 0x000000FFUL

	/* Recv complete */
	#define XEL_RSR_RECV_DONE_MASK 0x00000001UL
	/* Recv interrupt enable bit */
	#define XEL_RSR_RECV_IE_MASK 0x00000008UL

	typedef struct {
	unsigned int baseaddress; /* Base address for device (IPIF) */
	unsigned int nexttxbuffertouse; /* Next TX buffer to write to */
	unsigned int nextrxbuffertouse; /* Next RX buffer to read from */
	unsigned char deviceid; /* Unique ID of device - for future */
	} xemaclite;

	static xemaclite emaclite;

	static char etherrxbuff[PKTSIZE_ALIGN/4]; /* Receive buffer */

	/* hardcoded MAC address for the Xilinx EMAC Core when env is nowhere*/
	#ifdef CONFIG_ENV_IS_NOWHERE
	static u8 emacaddr[ENET_ADDR_LENGTH] = { 0x00, 0x0a, 0x35, 0x00, 0x22, 0x01 };
	#else
	static u8 emacaddr[ENET_ADDR_LENGTH];
	#endif

	void xemaclite_alignedread (u32 * srcptr, void *destptr, unsigned bytecount)
	{
	unsigned int i;
	u32 alignbuffer;
	u32 *to32ptr;
	u32 *from32ptr;
	u8 *to8ptr;
	u8 *from8ptr;

	from32ptr = (u32 *) srcptr;

	/* Word aligned buffer, no correction needed. */
	to32ptr = (u32 *) destptr;
	while (bytecount > 3) {
	to32ptr++ = from32ptr++;
	bytecount -= 4;
	}
	to8ptr = (u8 *) to32ptr;

	alignbuffer = *from32ptr++;
	from8ptr = (u8 *) & alignbuffer;

	for (i = 0; i < bytecount; i++) {
	to8ptr++ = from8ptr++;
	}
	}

	void xemaclite_alignedwrite (void *srcptr, u32 destptr, unsigned bytecount)
	{
	unsigned i;
	u32 alignbuffer;
	u32 to32ptr = (u32 ) destptr;
	u32 *from32ptr;
	u8 *to8ptr;
	u8 *from8ptr;

	from32ptr = (u32 *) srcptr;
	while (bytecount > 3) {

	to32ptr++ = from32ptr++;
	bytecount -= 4;
	}

	alignbuffer = 0;
	to8ptr = (u8 *) & alignbuffer;
	from8ptr = (u8 *) from32ptr;

	for (i = 0; i < bytecount; i++) {
	to8ptr++ = from8ptr++;
	}

	*to32ptr++ = alignbuffer;
	}

	void eth_halt (void)
	{
	debug ("eth_halt\n");
	}

	int eth_init (bd_t * bis)
	{
	debug ("EmacLite Initialization Started\n");
	memset (&emaclite, 0, sizeof (xemaclite));
	emaclite.baseaddress = XILINX_EMACLITE_BASEADDR;

	if (!getenv("ethaddr")) {
	memcpy(bis->bi_enetaddr, emacaddr, ENET_ADDR_LENGTH);
	}

	/*
	* TX - TX_PING & TX_PONG initialization
	*/
	/* Restart PING TX */
	out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET, 0);
	/* Copy MAC address */
	xemaclite_alignedwrite (bis->bi_enetaddr,
	emaclite.baseaddress, ENET_ADDR_LENGTH);
	/* Set the length */
	out_be32 (emaclite.baseaddress + XEL_TPLR_OFFSET, ENET_ADDR_LENGTH);
	/* Update the MAC address in the EMAC Lite */
	out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET, XEL_TSR_PROG_MAC_ADDR);
	/* Wait for EMAC Lite to finish with the MAC address update */
	while ((in_be32 (emaclite.baseaddress + XEL_TSR_OFFSET) &
	XEL_TSR_PROG_MAC_ADDR) != 0) ;

	#ifdef CONFIG_XILINX_EMACLITE_TX_PING_PONG
	/* The same operation with PONG TX */
	out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET + XEL_BUFFER_OFFSET, 0);
	xemaclite_alignedwrite (bis->bi_enetaddr, emaclite.baseaddress +
	XEL_BUFFER_OFFSET, ENET_ADDR_LENGTH);
	out_be32 (emaclite.baseaddress + XEL_TPLR_OFFSET, ENET_ADDR_LENGTH);
	out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET + XEL_BUFFER_OFFSET,
	XEL_TSR_PROG_MAC_ADDR);
	while ((in_be32 (emaclite.baseaddress + XEL_TSR_OFFSET +
	XEL_BUFFER_OFFSET) & XEL_TSR_PROG_MAC_ADDR) != 0) ;
	#endif

	/*
	* RX - RX_PING & RX_PONG initialization
	*/
	/* Write out the value to flush the RX buffer */
	out_be32 (emaclite.baseaddress + XEL_RSR_OFFSET, XEL_RSR_RECV_IE_MASK);
	#ifdef CONFIG_XILINX_EMACLITE_RX_PING_PONG
	out_be32 (emaclite.baseaddress + XEL_RSR_OFFSET + XEL_BUFFER_OFFSET,
	XEL_RSR_RECV_IE_MASK);
	#endif

	debug ("EmacLite Initialization complete\n");
	return 0;
	}

	int xemaclite_txbufferavailable (xemaclite * instanceptr)
	{
	u32 reg;
	u32 txpingbusy;
	u32 txpongbusy;
	/*
	* Read the other buffer register
	* and determine if the other buffer is available
	*/
	reg = in_be32 (instanceptr->baseaddress +
	instanceptr->nexttxbuffertouse + 0);
	txpingbusy = ((reg & XEL_TSR_XMIT_BUSY_MASK) ==
	XEL_TSR_XMIT_BUSY_MASK);

	reg = in_be32 (instanceptr->baseaddress +
	(instanceptr->nexttxbuffertouse ^ XEL_TSR_OFFSET) + 0);
	txpongbusy = ((reg & XEL_TSR_XMIT_BUSY_MASK) ==
	XEL_TSR_XMIT_BUSY_MASK);

	return (!(txpingbusy && txpongbusy));
	}

	int eth_send (volatile void *ptr, int len) {

	unsigned int reg;
	unsigned int baseaddress;

	unsigned maxtry = 1000;

	if (len > ENET_MAX_MTU)
	len = ENET_MAX_MTU;

	while (!xemaclite_txbufferavailable (&emaclite) && maxtry) {
	udelay (10);
	maxtry--;
	}

	if (!maxtry) {
	printf ("Error: Timeout waiting for ethernet TX buffer\n");
	/* Restart PING TX */
	out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET, 0);
	#ifdef CONFIG_XILINX_EMACLITE_TX_PING_PONG
	out_be32 (emaclite.baseaddress + XEL_TSR_OFFSET +
	XEL_BUFFER_OFFSET, 0);
	#endif
	return 0;
	}

	/* Determine the expected TX buffer address */
	baseaddress = (emaclite.baseaddress + emaclite.nexttxbuffertouse);

	/* Determine if the expected buffer address is empty */
	reg = in_be32 (baseaddress + XEL_TSR_OFFSET);
	if (((reg & XEL_TSR_XMIT_BUSY_MASK) == 0)
	&& ((in_be32 ((baseaddress) + XEL_TSR_OFFSET)
	& XEL_TSR_XMIT_ACTIVE_MASK) == 0)) {

	#ifdef CONFIG_XILINX_EMACLITE_TX_PING_PONG
	emaclite.nexttxbuffertouse ^= XEL_BUFFER_OFFSET;
	#endif
	debug ("Send packet from 0x%x\n", baseaddress);
	/* Write the frame to the buffer */
	xemaclite_alignedwrite ((void *) ptr, baseaddress, len);
	out_be32 (baseaddress + XEL_TPLR_OFFSET,(len &
	(XEL_TPLR_LENGTH_MASK_HI \| XEL_TPLR_LENGTH_MASK_LO)));
	reg = in_be32 (baseaddress + XEL_TSR_OFFSET);
	reg \|= XEL_TSR_XMIT_BUSY_MASK;
	if ((reg & XEL_TSR_XMIT_IE_MASK) != 0) {
	reg \|= XEL_TSR_XMIT_ACTIVE_MASK;
	}
	out_be32 (baseaddress + XEL_TSR_OFFSET, reg);
	return 1;
	}
	#ifdef CONFIG_XILINX_EMACLITE_TX_PING_PONG
	/* Switch to second buffer */
	baseaddress ^= XEL_BUFFER_OFFSET;
	/* Determine if the expected buffer address is empty */
	reg = in_be32 (baseaddress + XEL_TSR_OFFSET);
	if (((reg & XEL_TSR_XMIT_BUSY_MASK) == 0)
	&& ((in_be32 ((baseaddress) + XEL_TSR_OFFSET)
	& XEL_TSR_XMIT_ACTIVE_MASK) == 0)) {
	debug ("Send packet from 0x%x\n", baseaddress);
	/* Write the frame to the buffer */
	xemaclite_alignedwrite ((void *) ptr, baseaddress, len);
	out_be32 (baseaddress + XEL_TPLR_OFFSET,(len &
	(XEL_TPLR_LENGTH_MASK_HI \| XEL_TPLR_LENGTH_MASK_LO)));
	reg = in_be32 (baseaddress + XEL_TSR_OFFSET);
	reg \|= XEL_TSR_XMIT_BUSY_MASK;
	if ((reg & XEL_TSR_XMIT_IE_MASK) != 0) {
	reg \|= XEL_TSR_XMIT_ACTIVE_MASK;
	}
	out_be32 (baseaddress + XEL_TSR_OFFSET, reg);
	return 1;
	}
	#endif
	puts ("Error while sending frame\n");
	return 0;
	}

	int eth_rx (void)
	{
	unsigned int length;
	unsigned int reg;
	unsigned int baseaddress;

	baseaddress = emaclite.baseaddress + emaclite.nextrxbuffertouse;
	reg = in_be32 (baseaddress + XEL_RSR_OFFSET);
	debug ("Testing data at address 0x%x\n", baseaddress);
	if ((reg & XEL_RSR_RECV_DONE_MASK) == XEL_RSR_RECV_DONE_MASK) {
	#ifdef CONFIG_XILINX_EMACLITE_RX_PING_PONG
	emaclite.nextrxbuffertouse ^= XEL_BUFFER_OFFSET;
	#endif
	} else {
	#ifndef CONFIG_XILINX_EMACLITE_RX_PING_PONG
	debug ("No data was available - address 0x%x\n", baseaddress);
	return 0;
	#else
	baseaddress ^= XEL_BUFFER_OFFSET;
	reg = in_be32 (baseaddress + XEL_RSR_OFFSET);
	if ((reg & XEL_RSR_RECV_DONE_MASK) !=
	XEL_RSR_RECV_DONE_MASK) {
	debug ("No data was available - address 0x%x\n",
	baseaddress);
	return 0;
	}
	#endif
	}
	/* Get the length of the frame that arrived */
	switch(((in_be32 (baseaddress + XEL_RXBUFF_OFFSET + 0xC)) &
	0xFFFF0000 ) >> 16) {
	case 0x806:
	length = 42 + 20; /* FIXME size of ARP */
	debug ("ARP Packet\n");
	break;
	case 0x800:
	length = 14 + 14 +
	(((in_be32 (baseaddress + XEL_RXBUFF_OFFSET + 0x10)) &
	0xFFFF0000) >> 16); /* FIXME size of IP packet */
	debug ("IP Packet\n");
	break;
	default:
	debug ("Other Packet\n");
	length = ENET_MAX_MTU;
	break;
	}

	xemaclite_alignedread ((u32 *) (baseaddress + XEL_RXBUFF_OFFSET),
	etherrxbuff, length);

	/* Acknowledge the frame */
	reg = in_be32 (baseaddress + XEL_RSR_OFFSET);
	reg &= ~XEL_RSR_RECV_DONE_MASK;
	out_be32 (baseaddress + XEL_RSR_OFFSET, reg);

	debug ("Packet receive from 0x%x, length %dB\n", baseaddress, length);
	NetReceive ((uchar *) etherrxbuff, length);
	return 1;

	}