xpacket_fifo_v1_00_b.c

uboot在arm处理器s3c2410的移植代码

/******************************************************************************
*
*     Author: Xilinx, Inc.
*
*
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******************************************************************************/
/*****************************************************************************/
/*
*
* @file xpacket_fifo_v1_00_b.c
*
* Contains functions for the XPacketFifoV100b component. See xpacket_fifo_v1_00_b.h
* for more information about the component.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver   Who  Date     Changes
* ----- ---- -------- -----------------------------------------------
* 1.00b rpm 03/26/02  First release
* </pre>
*
*****************************************************************************/

/***************************** Include Files *********************************/

#include "xbasic_types.h"
#include "xio.h"
#include "xstatus.h"
#include "xpacket_fifo_v1_00_b.h"

/************************** Constant Definitions *****************************/

/* width of a FIFO word */

#define XPF_FIFO_WIDTH_BYTE_COUNT       4UL

/**************************** Type Definitions *******************************/

/***************** Macros (Inline Functions) Definitions *********************/

/************************* Variable Definitions ******************************/

/************************** Function Prototypes ******************************/

/*****************************************************************************/
/*
*
* This function initializes a packet FIFO.  Initialization resets the
* FIFO such that it's empty and ready to use.
*
* @param InstancePtr contains a pointer to the FIFO to operate on.
* @param RegBaseAddress contains the base address of the registers for
*        the packet FIFO.
* @param DataBaseAddress contains the base address of the data for
*        the packet FIFO.
*
* @return
*
* Always returns XST_SUCCESS.
*
* @note
*
* None.
*
******************************************************************************/
XStatus
XPacketFifoV100b_Initialize(XPacketFifoV100b * InstancePtr,
			    u32 RegBaseAddress, u32 DataBaseAddress)
{
	/* assert to verify input argument are valid */

	XASSERT_NONVOID(InstancePtr != NULL);

	/* initialize the component variables to the specified state */

	InstancePtr->RegBaseAddress = RegBaseAddress;
	InstancePtr->DataBaseAddress = DataBaseAddress;
	InstancePtr->IsReady = XCOMPONENT_IS_READY;

	/* reset the FIFO such that it's empty and ready to use and indicate the
	 * initialization was successful, note that the is ready variable must be
	 * set prior to calling the reset function to prevent an assert
	 */
	XPF_V100B_RESET(InstancePtr);

	return XST_SUCCESS;
}

/*****************************************************************************/
/*
*
* This function performs a self-test on the specified packet FIFO.  The self
* test resets the FIFO and reads a register to determine if it is the correct
* reset value.  This test is destructive in that any data in the FIFO will
* be lost.
*
* @param InstancePtr is a pointer to the packet FIFO to be operated on.
*
* @param FifoType specifies the type of FIFO, read or write, for the self test.
*        The FIFO type is specified by the values XPF_READ_FIFO_TYPE or
*        XPF_WRITE_FIFO_TYPE.
*
* @return
*
* XST_SUCCESS is returned if the selftest is successful, or
* XST_PFIFO_BAD_REG_VALUE indicating that the value readback from the
* occupancy/vacancy count register after a reset does not match the
* specified reset value.
*
* @note
*
* None.
*
******************************************************************************/
XStatus
XPacketFifoV100b_SelfTest(XPacketFifoV100b * InstancePtr, u32 FifoType)
{
	u32 Register;

	/* assert to verify valid input arguments */

	XASSERT_NONVOID(InstancePtr != NULL);
	XASSERT_NONVOID((FifoType == XPF_READ_FIFO_TYPE) ||
			(FifoType == XPF_WRITE_FIFO_TYPE));
	XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);

	/* reset the fifo and then check to make sure the occupancy/vacancy
	 * register contents are correct for a reset condition
	 */
	XPF_V100B_RESET(InstancePtr);

	Register = XIo_In32(InstancePtr->RegBaseAddress +
			    XPF_COUNT_STATUS_REG_OFFSET);

	/* check the value of the register to ensure that it's correct for the
	 * specified FIFO type since both FIFO types reset to empty, but a bit
	 * in the register changes definition based upon FIFO type
	 */

	if (FifoType == XPF_READ_FIFO_TYPE) {
		/* check the regiser value for a read FIFO which should be empty */

		if (Register != XPF_EMPTY_FULL_MASK) {
			return XST_PFIFO_BAD_REG_VALUE;
		}
	} else {
		/* check the register value for a write FIFO which should not be full
		 * on reset
		 */
		if ((Register & XPF_EMPTY_FULL_MASK) != 0) {
			return XST_PFIFO_BAD_REG_VALUE;
		}
	}

	/* the test was successful */

	return XST_SUCCESS;
}

/*****************************************************************************/
/*
*
* Read data from a FIFO and puts it into a specified buffer. The packet FIFO is
* currently 32 bits wide such that an input buffer which is a series of bytes
* is filled from the FIFO a word at a time. If the requested byte count is not
* a multiple of 32 bit words, it is necessary for this function to format the
* remaining 32 bit word from the FIFO into a series of bytes in the buffer.
* There may be up to 3 extra bytes which must be extracted from the last word
* of the FIFO and put into the buffer.
*
* @param InstancePtr contains a pointer to the FIFO to operate on.
* @param BufferPtr points to the memory buffer to write the data into. This
*        buffer must be 32 bit aligned or an alignment exception could be
*        generated. Since this buffer is a byte buffer, the data is assumed to
*        be endian independent.
* @param ByteCount contains the number of bytes to read from the FIFO. This
*        number of bytes must be present in the FIFO or an error will be
*        returned.
*
* @return
*
* XST_SUCCESS indicates the operation was successful.  If the number of
* bytes specified by the byte count is not present in the FIFO
* XST_PFIFO_LACK_OF_DATA is returned.
*
* If the function was successful, the specified buffer is modified to contain
* the bytes which were removed from the FIFO.
*
* @note
*
* Note that the exact number of bytes which are present in the FIFO is
* not known by this function.  It can only check for a number of 32 bit