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 EVM5509 board.
 */

#include <std.h>

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

#include <aic23.h>      

/* The I2C slave address of the AIC23 */
#define AIC23_I2CADDR        0x1A

/* a flag indicating whether the codec has been initialized */
static Bool codecInitialized = FALSE;

/* function for writing a control word to the AIC23 thru I2C */
static Void i2cWriteCtrl( Uns regaddr, Uns data );


/*
 *  ======== AIC23_init ========
 *
 *  Initializes codec module variables, if any. (There are none.)
 */
#pragma CODE_SECTION(AIC23_init, ".text:init")
Void AIC23_init()
{
}    

/*
 *  ======== 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.
 *  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.
 */
Int AIC23_setParams( AIC23_Params *params )
{
    Uns i;

    /* 
     * I2C structure which will be used to send the data */
    I2C_Init i2cInit = {
        0,      /* 7 bit address mode */
        0x007F,         /* own address - dont care if master */
        120,            /* clkout value (Mhz) */
        400,            /* a number between 10 and 400 */
        0,              /* num of bits/bytes to be received/transmitted (8) */
        0,              /* DLB mode off */
        0               /* FREE mode of operation off */
    };

    if (codecInitialized == FALSE) {
        codecInitialized = TRUE;
        
        /* setup config for I2C */
        I2C_init(&i2cInit);

        i2cWriteCtrl(15, 0);
    }
    
    for (i = 0; i < AIC23_NUMREGS; i++) {        
        i2cWriteCtrl(i, (params->regs[i] & 0x1ff));
    }
    return TRUE;
}

/*
 *  ======== i2cWriteCtrl ========
 *
 *  This function writes a control word to AIC23 reg thru I2C port 
 */
static Void i2cWriteCtrl(Uns regaddr, Uns data)
{
    Uint16 buf[2];
    buf[0] = (Uint16)((regaddr<<1)+(data>>8));
    buf[1] = (Uint16)(data & 0x00FF);
    I2C_write(buf, 2, 1, AIC23_I2CADDR, 1, 100);
}