csl_pwmopen.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_pwmOpen.c
 *  
 *  @brief    File for functional layer of CSL API @a CSL_pwmOpen()
 *
 *  Path: \\(CSLPATH)\\ipmodules\\pwm\\src
 *
 *  Description
 *    - The @a CSL_pwmOpen() function definition & it's associated functions
 *
 *  @date 27 April, 2004
 *  @author Pratheesh Gangadhar
 */
 
/* =============================================================================
 *  Revision History
 *  ===============
 *  03-Oct-2004 brn Updated for the new CSL architecture.
 *  11-Oct_2004 brn File updated with the review comments
 * =============================================================================
 */


#include <csl_pwm.h>

/** ============================================================================
 *   @n@b CSL_pwmOpen
 *
 *   @b Description
 *   @n This function populates the peripheral dpwm object for the instance
 *      and returns a handle to the instance.
 *      The open call sets up the dpwm structures for the particular instance
 *      of PWM device. The device can be re-opened anytime after it has been
 *      normally closed if so required. PWM Hardware setup will be performed
 *      at the end of the open call only if the HwSetup Pointer supplied was
 *      non- NULL. The handle returned by this call is input as an essential
 *      argument for rest of the APIs described for this module.
 *
 *   @b Arguments
 *   @verbatim
              pPwmObj      Pointer to the PWM instance object
 
              pwmNum       Instance of the PWM to be opened
 
              pPwmParam    Pointer to module specific parameters
 
              pStatus      pointer for returning status of the function call
     @endverbatim
 *
 *   <b> Return Value </b>  CSL_PwmHandle
 *   @n                     Valid PWM instance handle will be returned if status
                            value is equal to CSL_SOK.
 *
 *   <b> Pre Condition </b>
 *   @n  None
 *
 *   <b> Post Condition </b>
 *   @n   1.    PWM object structure is populated
 *   @n   2.    The status is returned in the status variable. If status
 *              returned is
 *   @li            CSL_SOK             Valid pwm handle is returned
 *   @li            CSL_ESYS_FAIL       The pwm instance is invalid
 *   @li            CSL_ESYS_INVPARAMS  Invalid parameter
 *
 *   @b Modifies
 *   @n    1. The status variable
 *   @n    2. PWM object structure
 *
 *   @b Example
 *   @verbatim
            CSL_status              status;
            CSL_PwmObj              pwmObj;
            CSL_PwmHandle           hPwm;
            ...
                
            hPwm = CSL_pwmOpen (&pwmObj, CSL_PWM_PER_CNT, NULL, &status);
            ...
    @endverbatim
 * =============================================================================
 */
#pragma CODE_SECTION (CSL_pwmOpen, ".text:csl_section:pwm");
CSL_PwmHandle   CSL_pwmOpen (
    CSL_PwmObj           *pPwmObj,   
    CSL_InstNum          pwmNum,     
    CSL_PwmParam         *pPwmParam, 
    CSL_Status           *pStatus
)   
{    
    CSL_Status           status;
    CSL_PwmHandle        hPwm;
    CSL_PwmBaseAddress   baseAddress;
    
    /* Mistral: BRN updated the code according to the code review*/
    *pPwmParam         = *pPwmParam;
    
    /* Added the following code according to the code review comments*/
    if (pPwmObj == NULL) {
        *pStatus = CSL_ESYS_INVPARAMS;
        return NULL;
    }
    
    status = CSL_pwmGetBaseAddress(pwmNum, pPwmParam, &baseAddress);
    
    if (status == CSL_SOK) {
        pPwmObj->regs = baseAddress.regs;
        pPwmObj->perNum = (CSL_InstNum)pwmNum;
        hPwm = (CSL_PwmHandle)pPwmObj;
    } 
    else {
        pPwmObj->regs = (CSL_PwmRegsOvly)NULL;
        pPwmObj->perNum = (CSL_InstNum)-1;
        hPwm = (CSL_PwmHandle)NULL;
    }
    
    if (pStatus) {
        *pStatus = status;
    }
    
    return hPwm;
}