xemac_polled.c

powerpc405开发板的linux网口驱动程序

/* $Id: xemac_polled.c,v 1.1 2005/10/26 15:44:52 meinelte Exp $ */
/******************************************************************************
*
*       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 2003 Xilinx Inc.
*       All rights reserved.
*
******************************************************************************/
/*****************************************************************************/
/**
*
* @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
* 1.00d rpm  09/26/03 New version includes support PLB Ethernet and v2.00a of
*                     the packet fifo driver.
* </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 32-bit 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 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.
*
******************************************************************************/
XStatus XEmac_PollSend(XEmac *InstancePtr, Xuint8 *BufPtr, Xuint32 ByteCount)
{
    Xuint32 IntrStatus;
    Xuint32 XmitStatus;
    XStatus Result;

    XASSERT_NONVOID(InstancePtr != XNULL);
    XASSERT_NONVOID(BufPtr != XNULL);
    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_V200A_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 = XPacketFifoV200a_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.
     */

    /*
     * 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;
    }