pca9539.c

IT projecotr reference design.

/****************************************************************************/
/*             TEXAS INSTRUMENTS PROPRIETARY INFORMATION                    */
/*                                                                          */
/*  (c) Copyright, Texas Instruments Incorporated, 2006.                    */
/*      All Rights Reserved.                                                */
/*                                                                          */
/*  Property of Texas Instruments Incorporated. Restricted Rights -         */
/*  Use, duplication, or disclosure is subject to restrictions set          */
/*  forth in TI's program license agreement and associated documentation.   */
/****************************************************************************/

/****************************************************************************/
/* pca9539.c                                                                */
/*                                                                          */
/* 16-Bit IO expander device driver.                                        */
/****************************************************************************/

#include "common.h"
#include "ddp2230_rtos_include.h"
#include "tmr.h"
#include "i2c.h"

#include "ioExpander.h"

                        /****************************************************/
                        /* Local constants and definitions.                 */
                        /****************************************************/

#define DEVBASE      0x74                   /* unshifted i2c device address */
#define PINPERCHIP     16                     /* number of IO pins per chip */
#define PINPERREG       8            /* number of IO pins per chip register */

#define CMD_INPORT      0x00                         /* read input register */
#define CMD_OUTPORT     0x02                  /* read/write output register */
#define CMD_POLARITY    0x04                /* read/write polarity register */
#define CMD_CONFIG      0x06           /* read/write configuration register */

                        /****************************************************/
                        /* Local data.                                      */
                        /****************************************************/

static int32   semTicks;                   /* semaphore acquisition timeout */
static uint32  semID;                       /* IO expander i2c semaphore ID */
static I2CPORT iPort;                           /* ASIC i2c controller port */

static IOXCC _ccTestRtn( int08 APIcc );



/****************************************************************************/
/* Open the IOX device driver.                                              */
/*                                                                          */
/* All pins are programmed to inputs. This is done to ensure the device is  */
/* in a known state during debug. This is not necessary in production code  */
/* since a power-up automatically configures the pins.                      */
/****************************************************************************/

IOXCC ioxdd_open( IOXINITSTRUCT *pInit )
{
    iPort    = pInit -> xPort;                           /* i2c port number */
    semTicks = TMR_ConvertMSToTicks(  pInit -> xTimeout );  /* tick timeout */
    I2C_GetSemaphoreID( iPort, &semID);                 /* i2c semaphore ID */
    
    return IOXCC_PASS;
}



/****************************************************************************/
/* Configure a pca9539 pin.                                                 */
/****************************************************************************/

IOXCC ioxdd_configPin( uint08 pinCfg )
{
    int08  cc = PASS;                                /* API completion code */
    
    int08 pin    = IOX_GETPIN( pinCfg );
    int08 chipNo = pin / PINPERCHIP;
    int08 regNo  = pin / PINPERREG;
    
    uint08 writeCmd[2];                           /* write command/register */
    uint32 numTran;

    if( RTA_SUCCESS != RTA_SemReserve( semID, semTicks ))
        return IOXCC_FAIL;

                        /****************************************************/
                        /* Update ioxDirection,                             */
                        /****************************************************/

    if( IOX_IN == IOX_GETDIR( pinCfg ))
        ioxDirection |= ( 0x00000001 << pin );   /* update global direction */
    else
        ioxDirection &= ~( 0x00000001 << IOX_GETPIN( pinCfg ));

                        /****************************************************/
                        /* Update ioxState,                                 */
                        /****************************************************/
    
    if( IOX_GETVAL( pinCfg ))
        ioxState |=  ( 0x00000001 << pin );
    else
        ioxState &= ~( 0x00000001 << pin );
        
                        /****************************************************/
                        /* Update state before direction to avoid glitching */
                        /* the output on direction change to output,        */
                        /****************************************************/

    if( IOX_OUT == IOX_GETDIR( pinCfg ))
    {
        writeCmd[0] = CMD_OUTPORT | ( regNo & 1 );
        writeCmd[1] = (uint08)( ioxState >> ( regNo * PINPERREG ));
        
        cc = I2C_MasterWrite( iPort, ( DEVBASE + chipNo ) << 1, 2,  
                writeCmd, 0, 0, &numTran ); 
    }

                        /****************************************************/
                        /* Set pin direction,                               */
                        /****************************************************/

    if( PASS )
    {
        writeCmd[0] = CMD_CONFIG | ( regNo & 1 );
        writeCmd[1] = (uint08)( ioxDirection >> ( regNo * PINPERREG ));
        
        cc = I2C_MasterWrite( iPort, ( DEVBASE + chipNo ) << 1, 2,  
                writeCmd, 0, 0, &numTran );
    }

    return _ccTestRtn( cc );
}



/****************************************************************************/
/* Drive a pca9539 pin to the indicated state.                              */
/****************************************************************************/

IOXCC ioxdd_drivePin( int08 pin, BOOL state )
{
    int08  cc;                                       /* API completion code */
    
    int08 chipNo = pin / PINPERCHIP;
    int08 regNo  = pin / PINPERREG;
    
    uint08 writeCmd[2];                           /* write command/register */
    uint32 numTran;

    if( RTA_SUCCESS != RTA_SemReserve( semID, semTicks ))
        return IOXCC_FAIL;

                        /****************************************************/
                        /* Update ioxState,                                 */
                        /****************************************************/
    
    if( state )
        ioxState |=  ( 0x00000001 << pin );
    else
        ioxState &= ~( 0x00000001 << pin );
        
                        /****************************************************/
                        /* Update state,                                    */
                        /****************************************************/

    writeCmd[0] = CMD_OUTPORT | ( regNo & 1 );
    writeCmd[1] = (uint08)( ioxState >> ( regNo * PINPERREG ));
    
    cc = I2C_MasterWrite( iPort, ( DEVBASE + chipNo ) << 1, 2,  
            writeCmd, 0, 0, &numTran ); 

    return _ccTestRtn( cc );
}



/****************************************************************************/
/* Read a pca9539 pin.                                                      */
/****************************************************************************/

IOXCC ioxdd_readPin( int08 pin, BOOL *state )
{
    int08  cc;                                       /* API completion code */
    
    int08  chipNo = pin / PINPERCHIP;
    int08  regNo  = pin / PINPERREG;
    uint08 mask   = 0x01 << ( pin % PINPERREG );
    
    uint08 writeCmd[2];                           /* write command/register */
    uint08 readState;                                         /* read state */
    uint32 numTran;

    if( RTA_SUCCESS != RTA_SemReserve( semID, semTicks ))
        return IOXCC_FAIL;

    writeCmd[0] = CMD_INPORT | ( regNo & 1 );
    
    cc = I2C_MasterWriteRestartRead( iPort, ( DEVBASE + chipNo ) << 1,  
            1, writeCmd, 0, 1, &readState, 0, &numTran, &numTran );

   *state = ( mask == ( readState & mask ));
   
    return _ccTestRtn( cc );
}



/****************************************************************************/
/* Return device type.                                                      */
/****************************************************************************/

IOXTYPE ioxdd_type( void )
{
    return IOXTYPE_PCA9539;
}



/****************************************************************************/
/* Test completion code and reset i2c configuration on error.               */
/*                                                                          */
/* This function is called when exiting any function that has reserved the  */
/* i2c semaphore. An API completion code is passed in and examined for      */
/* error. If an error is seen, the port is reset.                           */
/****************************************************************************/

static IOXCC _ccTestRtn( int08 APIcc )
{
    I2CINIT saveConfig;                           /*saved i2c configuration */

    if( PASS != APIcc )                         /* if an API error occurred */
    {
        I2C_GetConfig( iPort, &saveConfig );
        I2C_Reset( iPort );
        I2C_SetConfig( iPort, &saveConfig );
    }

    RTA_SemRelease( semID );
    
    return ( PASS == APIcc ) ? IOXCC_PASS : IOXCC_APIERROR;
}