/********************************************************************************     Author: Xilinx, Inc.***     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.***     XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" AS A*     COURTESY TO YOU. 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 THIRD PARTY 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.***     Xilinx hardware products are not intended for use in life support*     appliances, devices, or systems. Use in such applications is*     expressly prohibited.***     (c) Copyright 2002-2004 Xilinx Inc.*     All rights reserved.***     You should have received a copy of the GNU General Public License along*     with this program; if not, write to the Free Software Foundation, Inc.,*     675 Mass Ave, Cambridge, MA 02139, USA.*******************************************************************************//*****************************************************************************//**** @file xemac_polled.c** Contains functions used when the driver is in polled mode. Use the* XEmac_SetOptions() function to put the driver into polled mode.** <pre>* MODIFICATION HISTORY:** Ver   Who  Date     Changes* ----- ---- -------- -----------------------------------------------* 1.00a rpm  07/31/01 First release* 1.00b rpm  02/20/02 Repartitioned files and functions* 1.00c rpm  12/05/02 New version includes support for simple DMA* </pre>*******************************************************************************//***************************** Include Files *********************************/#include "xbasic_types.h"#include "xemac_i.h"#include "xio.h"#include "xipif_v1_23_b.h"	/* Uses v1.23b of the IPIF *//************************** Constant Definitions *****************************//**************************** Type Definitions *******************************//***************** Macros (Inline Functions) Definitions *********************//************************** Variable Definitions *****************************//************************** Function Prototypes ******************************//*****************************************************************************//**** Send an Ethernet frame in polled mode.  The device/driver must be in polled* mode before calling this function. The driver writes the frame directly to* the MAC's packet FIFO, then enters a loop checking the device status for* completion or error. Statistics are updated if an error occurs. The buffer* to be sent must be word-aligned.** It is assumed that the upper layer software supplies a correctly formatted* Ethernet frame, including the destination and source addresses, the* type/length field, and the data field.  It is also assumed that upper layer* software does not append FCS at the end of the frame.** @param InstancePtr is a pointer to the XEmac instance to be worked on.* @param BufPtr is a pointer to a word-aligned buffer containing the Ethernet*        frame to be sent.* @param ByteCount is the size of the Ethernet frame.** @return** - XST_SUCCESS if the frame was sent successfully* - XST_DEVICE_IS_STOPPED if the device has not yet been started* - XST_NOT_POLLED if the device is not in polled mode* - XST_FIFO_NO_ROOM if there is no room in the EMAC's length FIFO for this frame* - XST_FIFO_ERROR if the FIFO was overrun or underrun. This error is critical*   and requires the caller to reset the device.* - XST_EMAC_COLLISION if the send failed due to excess deferral or late*   collision** @note** There is the possibility that this function will not return if the hardware* is broken (i.e., it never sets the status bit indicating that transmission is* done). If this is of concern to the user, the user should provide protection* from this problem - perhaps by using a different timer thread to monitor the* PollSend thread. On a 10Mbps MAC, it takes about 1.21 msecs to transmit a* maximum size Ethernet frame (1518 bytes). On a 100Mbps MAC, it takes about* 121 usecs to transmit a maximum size Ethernet frame.** @internal** The EMAC uses FIFOs behind its length and status registers. For this reason,* it is important to keep the length, status, and data FIFOs in sync when* reading or writing to them.*******************************************************************************/XStatusXEmac_PollSend(XEmac * InstancePtr, u8 * BufPtr, u32 ByteCount){	u32 IntrStatus;	u32 XmitStatus;	XStatus Result;	XASSERT_NONVOID(InstancePtr != NULL);	XASSERT_NONVOID(BufPtr != NULL);	XASSERT_NONVOID(ByteCount > XEM_HDR_SIZE);	/* send at least 1 byte */	XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);	/*	 * Be sure the device is configured for polled mode and it is started	 */	if (!InstancePtr->IsPolled) {		return XST_NOT_POLLED;	}	if (InstancePtr->IsStarted != XCOMPONENT_IS_STARTED) {		return XST_DEVICE_IS_STOPPED;	}	/*	 * Check for overruns and underruns for the transmit status and length	 * FIFOs and make sure the send packet FIFO is not deadlocked. Any of these	 * conditions is bad enough that we do not want to continue. The upper layer	 * software should reset the device to resolve the error.	 */	IntrStatus = XIIF_V123B_READ_IISR(InstancePtr->BaseAddress);	/*	 * Overrun errors	 */	if (IntrStatus & (XEM_EIR_XMIT_SFIFO_OVER_MASK |			  XEM_EIR_XMIT_LFIFO_OVER_MASK)) {		InstancePtr->Stats.XmitOverrunErrors++;		InstancePtr->Stats.FifoErrors++;		return XST_FIFO_ERROR;	}	/*	 * Underrun errors	 */	if (IntrStatus & (XEM_EIR_XMIT_SFIFO_UNDER_MASK |			  XEM_EIR_XMIT_LFIFO_UNDER_MASK)) {		InstancePtr->Stats.XmitUnderrunErrors++;		InstancePtr->Stats.FifoErrors++;		return XST_FIFO_ERROR;	}	if (XPF_V100B_IS_DEADLOCKED(&InstancePtr->SendFifo)) {		InstancePtr->Stats.FifoErrors++;		return XST_FIFO_ERROR;	}	/*	 * Before writing to the data FIFO, make sure the length FIFO is not	 * full.  The data FIFO might not be full yet even though the length FIFO	 * is. This avoids an overrun condition on the length FIFO and keeps the	 * FIFOs in sync.	 */	if (IntrStatus & XEM_EIR_XMIT_LFIFO_FULL_MASK) {		/*		 * Clear the latched LFIFO_FULL bit so next time around the most		 * current status is represented		 */		XIIF_V123B_WRITE_IISR(InstancePtr->BaseAddress,				      XEM_EIR_XMIT_LFIFO_FULL_MASK);		return XST_FIFO_NO_ROOM;	}	/*	 * This is a non-blocking write. The packet FIFO returns an error if there	 * is not enough room in the FIFO for this frame.	 */	Result =	    XPacketFifoV100b_Write(&InstancePtr->SendFifo, BufPtr, ByteCount);	if (Result != XST_SUCCESS) {		return Result;	}	/*	 * Loop on the MAC's status to wait for any pause to complete.	 */	IntrStatus = XIIF_V123B_READ_IISR(InstancePtr->BaseAddress);	while ((IntrStatus & XEM_EIR_XMIT_PAUSE_MASK) != 0) {		IntrStatus = XIIF_V123B_READ_IISR(InstancePtr->BaseAddress);		/*		   * Clear the pause status from the transmit status register		 */		XIIF_V123B_WRITE_IISR(InstancePtr->BaseAddress,				      IntrStatus & XEM_EIR_XMIT_PAUSE_MASK);	}	/*	 * Set the MAC's transmit packet length register to tell it to transmit	 */	XIo_Out32(InstancePtr->BaseAddress + XEM_TPLR_OFFSET, ByteCount);	/*	 * Loop on the MAC's status to wait for the transmit to complete. The	 * transmit status is in the FIFO when the XMIT_DONE bit is set.	 */	do {		IntrStatus = XIIF_V123B_READ_IISR(InstancePtr->BaseAddress);	}	while ((IntrStatus & XEM_EIR_XMIT_DONE_MASK) == 0);	XmitStatus = XIo_In32(InstancePtr->BaseAddress + XEM_TSR_OFFSET);	InstancePtr->Stats.XmitFrames++;	InstancePtr->Stats.XmitBytes += ByteCount;	/*	 * Check for various errors, bump statistics, and return an error status.	 */	/*