qei.c

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//*****************************************************************************
//
// qei.c - Driver for the Quadrature Encoder with Index.
//
// Copyright (c) 2005-2014 Texas Instruments Incorporated.  All rights reserved.
// Software License Agreement
// 
//   Redistribution and use in source and binary forms, with or without
//   modification, are permitted provided that the following conditions
//   are met:
// 
//   Redistributions of source code must retain the above copyright
//   notice, this list of conditions and the following disclaimer.
// 
//   Redistributions in binary form must reproduce the above copyright
//   notice, this list of conditions and the following disclaimer in the
//   documentation and/or other materials provided with the  
//   distribution.
// 
//   Neither the name of Texas Instruments Incorporated nor the names of
//   its contributors may be used to endorse or promote products derived
//   from this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 
// This is part of revision 2.1.0.12573 of the Tiva Peripheral Driver Library.
//
//*****************************************************************************

//*****************************************************************************
//
//
//*****************************************************************************

#include <stdbool.h>
#include <stdint.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_qei.h"
#include "inc/hw_types.h"
#include "inc/hw_sysctl.h"
#include "driverlib/debug.h"
#include "driverlib/interrupt.h"
#include "driverlib/qei.h"

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIEnable(uint32_t ui32Base)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Enable the QEI module.
    //
    HWREG(ui32Base + QEI_O_CTL) |= QEI_CTL_ENABLE;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIDisable(uint32_t ui32Base)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Disable the QEI module.
    //
    HWREG(ui32Base + QEI_O_CTL) &= ~(QEI_CTL_ENABLE);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIConfigure(uint32_t ui32Base, uint32_t ui32Config,
             uint32_t ui32MaxPosition)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Write the new configuration to the hardware.
    //
    HWREG(ui32Base + QEI_O_CTL) = ((HWREG(ui32Base + QEI_O_CTL) &
                                    ~(QEI_CTL_CAPMODE | QEI_CTL_RESMODE |
                                      QEI_CTL_SIGMODE | QEI_CTL_SWAP)) |
                                   ui32Config);

    //
    // Set the maximum position.
    //
    HWREG(ui32Base + QEI_O_MAXPOS) = ui32MaxPosition;
}

//*****************************************************************************
//
//
//*****************************************************************************
uint32_t
QEIPositionGet(uint32_t ui32Base)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Return the current position counter.
    //
    return(HWREG(ui32Base + QEI_O_POS));
}

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIPositionSet(uint32_t ui32Base, uint32_t ui32Position)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Set the position counter.
    //
    HWREG(ui32Base + QEI_O_POS) = ui32Position;
}

//*****************************************************************************
//
//
//*****************************************************************************
int32_t
QEIDirectionGet(uint32_t ui32Base)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Return the direction of rotation.
    //
    return((HWREG(ui32Base + QEI_O_STAT) & QEI_STAT_DIRECTION) ? -1 : 1);
}

//*****************************************************************************
//
//
//*****************************************************************************
bool
QEIErrorGet(uint32_t ui32Base)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Return the error indicator.
    //
    return((HWREG(ui32Base + QEI_O_STAT) & QEI_STAT_ERROR) ? true : false);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIVelocityEnable(uint32_t ui32Base)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Enable the velocity capture.
    //
    HWREG(ui32Base + QEI_O_CTL) |= QEI_CTL_VELEN;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIVelocityDisable(uint32_t ui32Base)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Disable the velocity capture.
    //
    HWREG(ui32Base + QEI_O_CTL) &= ~(QEI_CTL_VELEN);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIVelocityConfigure(uint32_t ui32Base, uint32_t ui32PreDiv,
                     uint32_t ui32Period)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));
    ASSERT(!(ui32PreDiv & ~(QEI_CTL_VELDIV_M)));
    ASSERT(ui32Period != 0);

    //
    // Set the velocity predivider.
    //
    HWREG(ui32Base + QEI_O_CTL) = ((HWREG(ui32Base + QEI_O_CTL) &
                                    ~(QEI_CTL_VELDIV_M)) | ui32PreDiv);

    //
    // Set the timer period.
    //
    HWREG(ui32Base + QEI_O_LOAD) = ui32Period - 1;
}

//*****************************************************************************
//
//
//*****************************************************************************
uint32_t
QEIVelocityGet(uint32_t ui32Base)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Return the speed capture value.
    //
    return(HWREG(ui32Base + QEI_O_SPEED));
}

//*****************************************************************************
//
//
//*****************************************************************************
static uint32_t
_QEIIntNumberGet(uint32_t ui32Base)
{
    uint32_t ui32Int;

    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Find the valid interrupt number for this quadrature encoder.
    //
    if(CLASS_IS_TM4C123)
    {
        if(ui32Base == QEI0_BASE)
        {
            ui32Int = INT_QEI0_TM4C123;
        }
        else
        {
            ui32Int = INT_QEI1_TM4C123;
        }
    }
    else if(CLASS_IS_TM4C129)
    {
        if(ui32Base == QEI0_BASE)
        {
            ui32Int = INT_QEI0_TM4C129;
        }
        else
        {
            ui32Int = 0;
        }
    }
    else
    {
        ui32Int = 0;
    }

    return(ui32Int);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIIntRegister(uint32_t ui32Base, void (*pfnHandler)(void))
{
    uint32_t ui32Int;

    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Determine the interrupt number based on the QEI module.
    //
    ui32Int = _QEIIntNumberGet(ui32Base);

    ASSERT(ui32Int != 0);

    //
    // Register the interrupt handler, returning an error if an error occurs.
    //
    IntRegister(ui32Int, pfnHandler);

    //
    // Enable the quadrature encoder interrupt.
    //
    IntEnable(ui32Int);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIIntUnregister(uint32_t ui32Base)
{
    uint32_t ui32Int;

    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Determine the interrupt number based on the QEI module.
    //
    ui32Int = _QEIIntNumberGet(ui32Base);

    ASSERT(ui32Int != 0);

    //
    // Disable the interrupt.
    //
    IntDisable(ui32Int);

    //
    // Unregister the interrupt handler.
    //
    IntUnregister(ui32Int);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIIntEnable(uint32_t ui32Base, uint32_t ui32IntFlags)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Enable the specified interrupts.
    //
    HWREG(ui32Base + QEI_O_INTEN) |= ui32IntFlags;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIIntDisable(uint32_t ui32Base, uint32_t ui32IntFlags)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Disable the specified interrupts.
    //
    HWREG(ui32Base + QEI_O_INTEN) &= ~(ui32IntFlags);
}

//*****************************************************************************
//
//
//*****************************************************************************
uint32_t
QEIIntStatus(uint32_t ui32Base, bool bMasked)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Return either the interrupt status or the raw interrupt status as
    // requested.
    //
    if(bMasked)
    {
        return(HWREG(ui32Base + QEI_O_ISC));
    }
    else
    {
        return(HWREG(ui32Base + QEI_O_RIS));
    }
}

//*****************************************************************************
//
//
//*****************************************************************************
void
QEIIntClear(uint32_t ui32Base, uint32_t ui32IntFlags)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Base == QEI0_BASE) || (ui32Base == QEI1_BASE));

    //
    // Clear the requested interrupt sources.
    //
    HWREG(ui32Base + QEI_O_ISC) = ui32IntFlags;
}

//*****************************************************************************
//
// Close the Doxygen group.
//
//*****************************************************************************