usbstk5515_i2c.c

/*
 *  Copyright 2010 by Spectrum Digital Incorporated.
 *  All rights reserved. Property of Spectrum Digital Incorporated.
 */

/*
 *  I2C implementation
 *
 */

#include "usbstk5515_i2c.h"
#include "usbstk5515_gpio.h"
Int32 i2c_timeout = 0x0fff;

#define MDR_STT			0x2000
#define MDR_TRX			0x0200
#define MDR_MST			0x0400
#define MDR_IRS			0x0020
#define MDR_FREE		0x4000
#define STR_XRDY		0x0010
#define STR_RRDY		0x0008
#define MDR_STP 		0x0800


/* ------------------------------------------------------------------------ *
 *  _I2C_init( )                                                            *
 *      The I2C clk is set to run at 20 KHz                                 *
 * ------------------------------------------------------------------------ */
Int16 USBSTK5515_I2C_init( )
{
    I2C_MDR = 0x0400;             // Reset I2C
    I2C_PSC   = 15;               // Config prescaler for 100MHz
    I2C_CLKL  = 25;               // Config clk LOW for 100kHz
    I2C_CLKH  = 25;               // Config clk HIGH for 100kHz
    
    I2C_MDR   = 0x0420   ;        // Release from reset; Master, Transmitter, 7-bit address
    
    return 0;
}

/* ------------------------------------------------------------------------ *
 *  _I2C_close( )                                                           *
 * ------------------------------------------------------------------------ */
Int16 USBSTK5515_I2C_close( )
{
    I2C_MDR = 0;                      // Reset I2C
    return 0;
}

/* ------------------------------------------------------------------------ *
 *  _I2C_reset( )                                                           *
 * ------------------------------------------------------------------------ */
Int16 USBSTK5515_I2C_reset( )
{
    USBSTK5515_I2C_close( );
    USBSTK5515_I2C_init( );
    return 0;
}

/* ------------------------------------------------------------------------ *
 *  _I2C_write( i2c_addr, data, len )                                       *
 *      I2C write in Master mode                                            *
 * ------------------------------------------------------------------------ */
Int16 USBSTK5515_I2C_write( Uint16 i2c_addr, Uint8* data, Uint16 len )
{
    Int16 timeout, i;

		//I2C_IER = 0x0000;
        I2C_CNT = len;                    // Set length
        I2C_SAR = i2c_addr;               // Set I2C slave address
        I2C_MDR = MDR_STT                 // Set for Master Write
                  | MDR_TRX
                  | MDR_MST
                  | MDR_IRS
                  | MDR_FREE;

        USBSTK5515_wait(100);              // Short delay

        for ( i = 0 ; i < len ; i++ )
        {
           I2C_DXR = data[i];            // Write
            timeout = 0x510;             // I2C_timeout = 1ms;
            USBSTK5515_GPIO_setOutput( 17, 1);
            do
            {
                if ( timeout-- < 0  )
                {
                	USBSTK5515_GPIO_setOutput( 17, 0);
                    USBSTK5515_I2C_reset( );
                    return -1;
                }
            } while ( ( I2C_STR & STR_XRDY ) == 0 );// Wait for Tx Ready
        }

        I2C_MDR |= MDR_STP;             // Generate STOP

		USBSTK5515_waitusec(1000);

        return 0;

}

/* ------------------------------------------------------------------------ *
 *  _I2C_read( i2c_addr, data, len )                                        *
 *      I2C read in Master mode                                             *
 *      Returns:    0: PASS                                                 *
 *                 -1: FAIL Timeout                                         *
 * ------------------------------------------------------------------------ */
Int16 USBSTK5515_I2C_read( Uint16 i2c_addr, Uint8* data, Uint16 len )
{
    Int32 timeout, i;

    I2C_CNT = len;                    // Set length
    I2C_SAR = i2c_addr;               // Set I2C slave address
    I2C_MDR = MDR_STT                 // Set for Master Read
              | MDR_MST
              | MDR_IRS
              | MDR_FREE;

    USBSTK5515_wait( 10 );            // Short delay

    for ( i = 0 ; i < len ; i++ )
    {
        timeout = i2c_timeout;

        //Wait for Rx Ready 
        do
        {
            if ( timeout-- < 0 )
            {
                USBSTK5515_I2C_reset( );
                return -1;
            }
        } while ( ( I2C_STR & STR_RRDY ) == 0 );// Wait for Rx Ready

        data[i] = I2C_DRR;            // Read
    }

    I2C_MDR |= MDR_STP;               // Generate STOP

	USBSTK5515_waitusec(10);
    return 0;
}