csl_i2copen.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_i2cOpen.c
 *
 *  @brief    File for functional layer of CSL API @a CSL_i2cOpen()
 *
 *  Description
 *    - The @a CSL_i2cOpen() function definition & it's associated functions
 *
 *  PATH  \\(CSLPATH)\\ipmodules\\i2c\\src
 *
 *  Modification 1
 *    - Created on: 28/05/2004
 *
 *  Date 28th May, 2004
 *  Author Santosh Narayanan.
 */

/* =============================================================================
 *  Revision History
 *  ===============
 *  11-oct-2004 Hs updated code according to code review comments.
 *  31-aug-2004 Hs Updated function and documentation for CSL_i2cOpen.
 *                 - Removed the include file, csl_resource.h.
 * =============================================================================
 */

#include <csl_i2c.h>

/** ============================================================================
 *   @n@b CSL_i2cOpen
 *
 *   @b Description
 *   @n This function populates the peripheral data object for the instance
 *        and returns a handle to the instance.
 *        The open call sets up the data structures for the particular instance
 *        of I2C 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

            pI2cObj      Pointer to the object that holds reference to the
                         instance of I2C requested after the call

            i2cNum       Instance of I2C to which a handle is requested

            pI2cParam    Specifies if I2C should be opened with exclusive or
                         shared access to the associate pins

            pStatus      This returns the status (success/errors) of the call

     @endverbatim
 *
 *   <b> Return Value </b>
 *      CSL_I2cHandle
 *        Valid I2C instance handle will be returned if status value is
 *        equal to CSL_SOK.
 *
 *   <b> Pre Condition </b>
 *   @n  @a CSL_i2cInit() must be called successfully.
 *
 *   <b> Post Condition </b>
 *   @n  None
 *
 *   @b  Modifies
 *   @n  None
 *
 *   @b Example:
 *   @verbatim
         CSL_status        status;
         CSL_I2cObj        i2cObj;
         CSL_I2cHandle     hI2c;

         hI2c = CSL_I2cOpen (&i2cObj,
                             CSL_I2C,
                             NULL,
                             &status
                             );
     @endverbatim
 *  ============================================================================
 */
#pragma CODE_SECTION (CSL_i2cOpen, ".text:csl_section:i2c");
CSL_I2cHandle CSL_i2cOpen (
    CSL_I2cObj              *pI2cObj,
    CSL_InstNum              i2cNum,
    CSL_I2cParam            *pI2cParam,
    CSL_Status              *pStatus
)
{
    CSL_Status            status;
    CSL_I2cHandle         hI2c;
    CSL_I2cBaseAddress    baseAddress;

    if ((pI2cObj == NULL) || (i2cNum < CSL_I2C)) {
        *pStatus = CSL_ESYS_INVPARAMS;
        return NULL;
    }

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

    *pI2cParam = *pI2cParam; /* To remove compiler warning/remark.*/

    status = CSL_i2cGetBaseAddress (i2cNum, pI2cParam, &baseAddress);

    if (status == CSL_SOK) {
        pI2cObj->regs   = baseAddress.regs;
        pI2cObj->perNum = (CSL_InstNum)i2cNum;
        hI2c            = (CSL_I2cHandle)pI2cObj;
    }
    else {
        pI2cObj->regs   = (CSL_I2cRegsOvly)NULL;
        pI2cObj->perNum = (CSL_InstNum)-1;
        hI2c            = (CSL_I2cHandle)NULL;
    }

    if (pStatus) {
        *pStatus = status;
    }

    return hI2c;
}