aic23.c

用DSP5410实现对音乐文件音量的限制性调节

/*
 *  Copyright 2003 by Texas Instruments Incorporated.
 *  All rights reserved. Property of Texas Instruments Incorporated.
 *  Restricted rights to use, duplicate or disclose this code are
 *  granted through contract.
 *  
 */
/* "@(#) DDK 1.11.00.00 11-04-03 (ddk-b13)" */
/* 
 *  ======== aic23.c ======== 
 *
 *  AIC23 codec driver implementation specific to the 
 *  Spectrum Digital DM642 EVM board.
 */

#include <std.h>

#include <csl.h>
#include <csl_i2c.h>

#include <aic23.h>      
#include <evmdm642_edma_aic23.h>

extern I2C_Handle EVMDM642_I2C_hI2C;

static void aic23Rset(Uint16 regnum, Uint16 regval);
                                                                   
static AIC23_Params codecstate = AIC23_DEFAULTPARAMS_EVMDM642;


static I2C_Config aic23XmtCfg = {
    0x0000007f, /* I2COAR -    Not used if master */
    0x00000000, /* I2CIER -    Disable interrupts, use polling */
    0x0000001b, /* I2CCLKL -   Low period for 100KHz operation */
    0x0000001b, /* I2CCLKH -   High period for 100KHz operation */
    0x00000002, /* I2CCNT -    Data words per transmission */
    0x0000001a, /* I2CSAR -    Slave address */
    0x00004ea0, /* I2CMDR -    Mode */
    0x00000019  /* I2CPSC -    Prescale 300MHz to 12MHz */
};

/*
 *  ======== AIC23_setParams ========
 *
 *  This function takes a pointer to the object of type AIC23_Params,
 *  and writes all 11 control words found in it to the codec. Prior
 *  to that it initializes the codec if this is the first time the
 *  function is ever called.  Return TRUE for successful completion,
 *  FALSE if errors.
 */
Int AIC23_setParams(AIC23_Params *paramsp)
{
    Int i;
    AIC23_Params *params = paramsp;
   
    /*  set to AIC23_DEFAULTPARAMS_EVMDM642 if NULL */
    if (params == NULL) {
        params = &codecstate;
    }
    
    /* Reset the AIC23 */
    aic23Rset(AIC23_RESET, 0);
    
    /* Assign each register */
    for (i = 0; i < AIC23_NUMREGS; i++) {
        aic23Rset(i, params->regs[i]);
    }
    
    return TRUE;
}


/*
 *  ======== aic23Rset ========
 *  Set codec register regnum to value regval.  The 16-bit word is composed
 *  of register address in the upper 7 bits and the 9-bit register value
 *  stored in the parameters structure.
 */
static Void aic23Rset(Uint16 regnum, Uint16 regval)
{
    Uint16 data;
    I2C_Config prevI2CCfg;
    
    /* Mask off lower 9 bits */
    regval &= 0x1ff;
    
    /* Set transmit data */
    data = (regnum << 9) | regval;
    
    /* Wait until bus is free */
    while (I2C_bb(EVMDM642_I2C_hI2C));
    
    /* Save old settings */
    I2C_getConfig(EVMDM642_I2C_hI2C, &prevI2CCfg);
    
    /* Restore settings for AIC23 */
    I2C_config(EVMDM642_I2C_hI2C, &aic23XmtCfg);

    /* Submit the MSB for transmit */
    I2C_writeByte(EVMDM642_I2C_hI2C, (data >> 8) & 0xff);
    
    /* Generate start condition, starts transmission */
    I2C_start(EVMDM642_I2C_hI2C);
    
    /* Wait until MSB transmit is done */
    while(!I2C_xrdy(EVMDM642_I2C_hI2C));

    /* Submit the LSB for transmit */ 
    I2C_writeByte(EVMDM642_I2C_hI2C, data & 0xff);
        
    /* Generate stop condition */
    I2C_sendStop(EVMDM642_I2C_hI2C);  

    /* Wait until bus is free */
    while (I2C_bb(EVMDM642_I2C_hI2C));
    
    /* Save register value if regnum is in range */
    if (regnum < AIC23_NUMREGS)
        codecstate.regs[regnum] = regval;

    /* Short delay for AIC23 to accept command */        
    EVMDM642_waitusec(20);

    /* Reconfigure I2C with old settings */
    I2C_config(EVMDM642_I2C_hI2C, &prevI2CCfg);  
}