bspcspi.c

Microsoft WinCE 6.0 BSP FINAL release source code for use with the i.MX27ADS TO2 WCE600_FINAL_MX27_S

//
// Copyright (C) 2004, Motorola Inc. All Rights Reserved
//
//-----------------------------------------------------------------------------
//
// Copyright (C) 2004-2006, Freescale Semiconductor, Inc. All Rights Reserved.
// THIS SOURCE CODE, AND ITS USE AND DISTRIBUTION, IS SUBJECT TO THE TERMS
// AND CONDITIONS OF THE APPLICABLE LICENSE AGREEMENT
//
//------------------------------------------------------------------------------
//
// File: bspcspi.c
//
// Provides BSP-specific configuration routines for the CSPI peripheral.
//
//------------------------------------------------------------------------------
#include <windows.h>
#include "bsp.h"

//-----------------------------------------------------------------------------
// External Functions

//-----------------------------------------------------------------------------
// External Variables

//-----------------------------------------------------------------------------
// Defines

//-----------------------------------------------------------------------------
// Types

//-----------------------------------------------------------------------------
// Global Variables

//-----------------------------------------------------------------------------
// Local Variables

//-----------------------------------------------------------------------------
//
// Function: CalculateDivRate
//
// This is a private function to calculate the data
// rate divider from input frequency.
//
// Parameters:
//      dwFrequency
//          [in] Frequency requested.
//
// Returns:
//      Data rate divisor for requested frequency.
//
//-----------------------------------------------------------------------------
UINT32 BSPCSPICalculateDivRate(UINT32 dwFrequency)
{
    UINT32 n;
	UINT32 dwDivisor;
    UINT32 dwCspiClk;

    DDKClockGetFreq(DDK_CLOCK_SIGNAL_PERDIV2, &dwCspiClk);

    for (n = CSPI_CONTROLREG_DATARATE_DIV4; 
        n < CSPI_CONTROLREG_DATARATE_DIV512; n++) {
        if (n % 2)
            dwDivisor = 3 * (2 << (((n-1)/2 - 1))); // odd
        else
            dwDivisor = 2 * (2 << ((n/2) - 1));     // even
        
        if ((dwCspiClk / dwDivisor) <= dwFrequency) break;
    }
    
    return dwDivisor;
}

//-----------------------------------------------------------------------------
//
// Function: SetIOMux
//
// This is a private function which request IOMUX for 
// the corresponding CSPI Bus.
//
// Parameters:
//      dwIndex
//          [in] CSPI port to be configured.
//
// Returns:
//      TRUE if successful, FALSE otherwise.
//
//-----------------------------------------------------------------------------
BOOL BSPCSPISetIOMux(UINT32 dwIndex)
{
	DDK_GPIO_CFG cfg;

    if (dwIndex == 1)
    	DDK_GPIO_SET_CONFIG(cfg, CSPI1);
    else if(dwIndex == 2)
        DDK_GPIO_SET_CONFIG(cfg, CSPI2);
    else if(dwIndex == 3)
        DDK_GPIO_SET_CONFIG(cfg, CSPI3);
    
    return DDKGpioEnable(&cfg);
}

//-----------------------------------------------------------------------------
//
// Function: ReleaseIOMux
//
// This is a private function which releases the 
// IOMUX pins selected for the CSPI bus.
//
// Parameters:
//      dwIndex
//          [in] CSPI port to be released.
//
// Returns:
//      TRUE if successful, FALSE otherwise.
//
//-----------------------------------------------------------------------------
BOOL BSPCSPIReleaseIOMux(UINT32 dwIndex)
{
	DDK_GPIO_CFG cfg;

    if (dwIndex == 1)
    	DDK_GPIO_SET_CONFIG(cfg, CSPI1);
    else if(dwIndex == 2)
        DDK_GPIO_SET_CONFIG(cfg, CSPI2);
    else if(dwIndex == 3)
        DDK_GPIO_SET_CONFIG(cfg, CSPI3);
    
    return DDKGpioDisable(&cfg);
}

//-----------------------------------------------------------------------------
//
// Function: EnableClock
//
// Provides the platform-specific CSPI clock gating control to enable/disable 
// module clocks.
//
// Parameters:
//      dwIndex
//          [in] CSPI port to be configured.
//      bEnable
//          [in] Set to TRUE to enable CSPI clocks, set to FALSE to disable
//          CSPI clocks.
//
// Returns:
//      TRUE if successful, FALSE otherwise.
//
//-----------------------------------------------------------------------------
BOOL BSPCSPIEnableClock(UINT32 dwIndex, BOOL bEnable)
{
    DDK_CLOCK_GATE_INDEX index;
    DDK_CLOCK_GATE_MODE mode = bEnable ? 
        DDK_CLOCK_GATE_MODE_ENABLE : DDK_CLOCK_GATE_MODE_DISABLE;

    if (dwIndex == 1)
    	index = DDK_CLOCK_GATE_INDEX_CSPI1;
    else if(dwIndex == 2)
        index = DDK_CLOCK_GATE_INDEX_CSPI2;
    else if(dwIndex == 3)
        index = DDK_CLOCK_GATE_INDEX_CSPI3;

    return DDKClockSetGatingMode(index, mode);
}