csl_mcbspopen.c

TI达芬奇dm644x各硬件模块测试代码

/** \file csl_mcbspOpen.c
 *
 *  \brief    File for functional layer of CSL API \a CSL_mcbspOpen()
 *
 *  Description
 *    - The \a CSL_mcbspOpen() function contains definition of the 
 *      functional layer API
 *
 *  Path: \\(CSLPATH)\\ipmodules\\mcbsp\\src
 *
 */
 
/* =============================================================================
 *  Revision History
 *  ================
 *  15-Feb-2005 NSR Updated function and documentation for CSL_i2cOpen.
 *                 - Removed the include file, csl_resource.h.
 *
 * =============================================================================
 */

#include <csl_mcbsp.h>

/** 
 * Reserves the specified MCBSP for use. The device can be re-opened anytime
 * after it has been normally closed, if so required. 
 * The MCBSP handle returned by this call is input as an essential argument for
 * the rest of the APIs in MCBSP module.
 * If @a hwSetup parameter is non-NULL, it configures MCBSP depending on the 
 * paramters passed in this structure, after successful open
 * 
 * <b> Usage Constraints: </b>
 * The CSL system as well as MCBSP must be succesfully initialized via
 * @a CSL_sysInit() and @a CSL_mcbspInit() before calling this function. Memory
 * for the @a CSL_McbspObj must be allocated outside this call. This object must
 * be retained while using this peripheral instance.
 * 
 * @b Example:
 * @verbatim

   CSL_McbspHandle  hMcbsp;
   CSL_McbspObj     mcbspObj;
   CSL_McbspHwSetup mcbspSetup;
   CSL_Status       status;
   ...
   hMcbsp = CSL_mcbspOpen(&mcbspObj,
                          CSL_MCBSP_PER_CNT,
                          NULL,
                          &status);
   @endverbatim
 * 
 * @return @a CSL_McbspHandle to the requested instance of MCBSP if the
 * call is successful, otherwise @a NULL is returned.
 * 
 */
#pragma CODE_SECTION (CSL_mcbspOpen, ".text:csl_section:mcbsp");
CSL_McbspHandle  CSL_mcbspOpen(
    /** Pointer to MCBSP object that holds the context.
     *  Memory for this object should be allocated by the user */  
    CSL_McbspObj                            *pMcbspObj,
    /** The instance of MCBSP to be opened */
    CSL_InstNum                            mcbspNum,
    /** Parameter for McBSP */
    CSL_McbspParam                         *pMcbspParam,
    /** Pointer to the variable that holds the status of the open call */
    CSL_Status                              *pStatus
)
{
     CSL_Status            status;
    CSL_McbspHandle         hMcbsp;
    CSL_McbspBaseAddress    baseAddress;

    if ((pMcbspObj == NULL) || (mcbspNum < CSL_MCBSP)) {
        *pStatus = CSL_ESYS_INVPARAMS;
        return NULL;
    }

    /* Added according to review comment 1. */
    if (pStatus == NULL) {
        return NULL;
    }

    *pMcbspParam = *pMcbspParam; /* To remove compiler warning/remark.*/

    status = CSL_mcbspGetBaseAddress(mcbspNum, pMcbspParam, &baseAddress);

    if (status == CSL_SOK) {
        pMcbspObj->regs = baseAddress.regs;
        pMcbspObj->perNum = (CSL_InstNum)mcbspNum;
        hMcbsp = (CSL_McbspHandle)pMcbspObj;
    }
    else {
        pMcbspObj->regs = (CSL_McbspRegsOvly)NULL;
        pMcbspObj->perNum = (CSL_InstNum)-1;
        hMcbsp = (CSL_McbspHandle)NULL;
    }

    if (pStatus) {
        *pStatus = status;
    }

    return hMcbsp;
}