csl_spiopen.c

TI达芬奇dm644x各硬件模块测试代码

/*  ============================================================================
 *   Copyright (c) Texas Instruments Inc 2002, 2003, 2004, 2005
 *
 *   Use of this software is controlled by the terms and conditions found in the
 *   license agreement under which this software has been supplied.
 *   ===========================================================================
 */

/** @file csl_spiOpen.c
 *
 *  @brief    File for functional layer of CSL API @a CSL_spiOpen()
 *
 *  Description
 *    - The @a CSL_spiOpen() function definition & it's associated functions
 *
 *  Path: \\(CSLPATH)\\ipmodules\\spi\\src
 *
 *  Modification 1
 *    - modified on: 15/12/2003
 *    - reason: created the sources
 *
 *  Modification 2
 *    - modified on: 19/12/2003
 *    - reason: created better documentation
 *
 *  Modification 3
 *    - modified on: 01/03/2004
 *    - reason: modified according to review comments
 *
 *  Modification 4
 *    - modified on: 10/05/2004
 *    - reason: removed MIB from code & documentation
 *
 *  Date 15th Dec, 2003
 *    Author Sumant S. NaikKhanvte
 */

/* =============================================================================
 *  Revision History
 *  ===============
 *  11-oct-2004 Hs Updated code review comments
 *  10-sep-2004 Hs Updated function and documentation for CSL_spiOpen.
 *                 - Removed the include file, csl_resource.h.
 * =============================================================================
 */

#include <csl_spi.h>

/** ============================================================================
 *   @n@b CSL_spiOpen
 *
 *   @b Description
 *   @n This function populates the peripheral data object for the SPI instance
 *        and returns a handle to the instance.
 *        The open call sets up the data structures for the particular instance
 *      of SPI device. The device can be re-opened anytime after it has been
 *      normally closed if so required. The handle returned by this call is
 *      input as an essential argument for rest of the APIs described
 *      for this module.
 *
 *   @b Arguments
 *   @verbatim
            spiObj          Pointer to SPI object.

            spiNum          Instance of SPI CSL to be opened.

            pSpiParam       Module specific parameters.

            status          Status of the function call
     @endverbatim
 *
 *   <b> Return Value </b>  CSL_SpiHandle
 *   @n                         Valid SPI handle will be returned if
 *                              status value is equal to CSL_SOK.
 *
 *   <b> Pre Condition </b>
 *   @n  None
 *
 *   <b> Post Condition </b>
 *   @n   1.    The status is returned in the status variable. If status
 *              returned is
 *   @li            CSL_SOK             Valid SPI handle is returned
 *   @li            CSL_ESYS_FAIL       The SPI instance is invalid
 *
 *        2.    SPI object structure is populated
 *
 *   @b Modifies
 *   @n    1. The status variable
 *
 *         2. SPI object structure
 *
 *   @b Example
 *   @verbatim
            CSL_status              status;
       CSL_SpiObj     spiObj;
            CSL_SpiHandle           hSpi;

            hSpi = CSL_spiOpen (&spiObj, CSL_SPI, NULL, &status);
       ...
       @endverbatim
 * =============================================================================
 */
#pragma CODE_SECTION (CSL_spiOpen, ".text:csl_section:spi");
CSL_SpiHandle CSL_spiOpen (
    CSL_SpiObj              *pSpiObj,
    CSL_InstNum              spiNum,
    CSL_SpiParam            *pSpiParam,
    CSL_Status              *pStatus
)
{
    CSL_Status            status;
    CSL_SpiHandle hSpi    = (CSL_SpiHandle) NULL;
    CSL_SpiBaseAddress    baseAddress;

    if ((pSpiObj == NULL) || (spiNum < CSL_SPI)) {
        *pStatus = CSL_ESYS_INVPARAMS;
        return NULL;
    }

    if (pStatus == NULL) {
        return NULL;
    }

    *pSpiParam = *pSpiParam;

    status = CSL_spiGetBaseAddress(spiNum, pSpiParam, &baseAddress);

    if (status == CSL_SOK) {
        pSpiObj->regs   = baseAddress.regs;
        pSpiObj->perNum = (CSL_InstNum)spiNum;
        hSpi            = (CSL_SpiHandle)pSpiObj;
    }
    else {
        pSpiObj->regs   = (CSL_SpiRegsOvly)NULL;
        pSpiObj->perNum = (CSL_InstNum)-1;
        hSpi            = (CSL_SpiHandle)NULL;
    }

    if (pStatus) {
        *pStatus = status;
    }

    return (hSpi);
}