i2s.c

i2s usb audio demo lpc2138

/*****************************************************************************
 *   i2s.c:  - for NXP LPC23xx/24xx Family Microprocessors
 *                                I2S Audio demo with UDA1341
 *             this file contains configuration and control files for i2s interface
 *             on LPC23xx                 
 *
 *   Copyright(C) 2007, NXP Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2007.02.20  ver 1.00    Prelimnary version, first Release
 *
******************************************************************************/

#include "LPC23xx.h"        /* LPC23xx/24xx definitions */
#include "type.h"           /* LPC23xx/24xx definitions */
#include "irq.h"            /* LPC23xx/24xx definitions */
#include "timer.h"          /* LPC23xx/24xx definitions */


extern void IRQ_I2S_service(void);

/* functions in this file - table of contents/prototypes */
int  i2s_init(void);
void i2s_start_clock(void);
void i2s_stop_clock(void);
int  i2s_config_rxrate(unsigned int bitrate, unsigned int pclk_i2s_freq);
int  i2s_config_txrate(unsigned int bitrate, unsigned int pclk_i2s_freq);

void i2s_enable_tx_irq(int flag);
void i2s_enable_rx_irq(int flag);

void i2s_set_tx_depth_irq(int depth);
void i2s_set_rx_depth_irq(int depth);

void I2S_Enable_DAIO(int flag);
void I2S_Enable_DAI(int flag);
void I2S_Enable_DAO(int flag);
void I2S_Mute_DAO(int flag);

void I2S_Config_DAI(unsigned int wordwidth, unsigned int mono,
                    unsigned int ws_sel, unsigned int ws_halfperiod);
void I2S_Config_DAO(unsigned int wordwidth, unsigned int mono,
                    unsigned int ws_sel, unsigned int ws_halfperiod);
__irq void IRQ_I2S_Handler(void);


/*******************************************************************************
* Function: init_i2s
*
*******************************************************************************/
int i2s_init(void)
{
  /*set (pclk_i2s  pclk = cclk) = 32.7619Mhz */
  PCLKSEL1 &=  ~(0x03 << 22);  /* clear I2S clock register */
  PCLKSEL1 |=   (0x01 << 22);  /* set I2S clock register */

  /*enable I2S in the PCONP register. I2S is disabled on reset*/
  PCONP |= (1 << 27);

  /*connect the I2S sigals to port pins(P0.4-P0.9)*/
//  PINSEL0 &=  ~0x00055500;   /* clear port pins */
  PINSEL0 |=   0x00055500;     /* set port pins */

  return(1);

}

/*******************************************************************************
* Function: i2s_start_clock
*
*******************************************************************************/
void i2s_start_clock(void)
{
  /*enable I2S in the PCONP register. I2S is disabled on reset*/
  PCONP |= (1 << 27);
}
/*******************************************************************************
* Function: i2s_stop_clock
*
*******************************************************************************/
void i2s_stop_clock(void)
{
  /*enable I2S in the PCONP register. I2S is disabled on reset*/
  PCONP &= ~(1 << 27);
}

/*******************************************************************************
* Function: i2s_config_rxrate
*
*******************************************************************************/
int i2s_config_rxrate(unsigned int bitrate, unsigned int pclk_i2s_freq)
{
  if(pclk_i2s_freq <= bitrate)
  {
    I2S_RXRATE = 0;
  }
  else
  {
    I2S_RXRATE = (pclk_i2s_freq / bitrate)-1 ;
//    I2S_RXRATE = (pclk_i2s_freq / bitrate) ;
  }
  return (1);
}

/*******************************************************************************
* Function: i2s_config_txrate
*
*******************************************************************************/
int i2s_config_txrate(unsigned int bitrate, unsigned int pclk_i2s_freq)
{
  if(pclk_i2s_freq <= bitrate)
  {
    I2S_TXRATE = 0;
  }
  else
  {
    I2S_TXRATE = (pclk_i2s_freq / bitrate) -1;
  }

  return (1);
}

/*******************************************************************************
* Function: i2s_enable_tx_irq
*
*******************************************************************************/
void i2s_enable_tx_irq(int flag)
{
  if(flag == 0)
  {
    I2S_IRQ &= ~2;
  }
  else
  {
    I2S_IRQ |= 2;
  }
}

/*******************************************************************************
* Function: i2s_enable_rx_irq
*
*******************************************************************************/
void i2s_enable_rx_irq(int flag)
{
  if(flag == 0)
  {
    I2S_IRQ &= ~1;
  }
  else
  {
    I2S_IRQ |= 1;
  }
}

/*******************************************************************************
* Function: i2s_set_tx_depth_irq
*
*******************************************************************************/
void i2s_set_tx_depth_irq(int depth)
{
  I2S_IRQ &= ~(0xFF << 16);
  I2S_IRQ |= (depth << 16);
}

/*******************************************************************************
* Function: i2s_set_rx_depth_irq
*
*******************************************************************************/
void i2s_set_rx_depth_irq(int depth)
{
  depth &= 0xFF;
  I2S_IRQ &= ~(0xFF << 8);
  I2S_IRQ |= (depth << 8);
}

/*******************************************************************************
* Function: I2S_Enable_DAIO
*
*******************************************************************************/
void I2S_Enable_DAIO(int flag)
{
  if(flag == 0)
  {
    I2S_DAI |= 0x18;	/* stop and reset */
    I2S_DAO |= 0x18;
    I2S_DAO &= ~0x10;
    I2S_DAI &= ~0x10;   /* release reset */
  }
  else
  {
    I2S_DAO &= ~0x18;
    I2S_DAI &= ~0x18;   /* go and release reset */
  }
}
/*******************************************************************************
* Function: I2S_Enable_DAI
*
*******************************************************************************/
void I2S_Enable_DAI(int flag)
{
  if(flag == 0)
  {
    I2S_DAI |= 0x18;	   /* stop and reset */
    I2S_DAI &= ~0x10;   /* release reset */
  }
  else
  {
    I2S_DAI &= ~0x18;   /* go and release reset */
  }
}

/*******************************************************************************
* Function: I2S_Enable_DAO
*
*******************************************************************************/
void I2S_Enable_DAO(int flag)
{
  if(flag == 0)
  {
    I2S_DAO |= 0x18;	   /* stop and reset */
    I2S_DAO &= ~0x10;   /* release reset */
  }
  else
  {
    I2S_DAO &= ~0x18;	 /* go and release reset */
  }
}

/*******************************************************************************
* Function: I2S_Mute_DAO
*
*******************************************************************************/
void I2S_Mute_DAO(int flag)
{
  if(flag == 0)
  {
    I2S_DAO &= ~(0x8000);
  }
  else
  {
    I2S_DAO |= 0x8000;
  }
}

/*******************************************************************************
* Function: config_i2s_dai
*
*******************************************************************************/
void I2S_Config_DAI(unsigned int wordwidth, unsigned int mono,
                    unsigned int ws_sel, unsigned int ws_halfperiod)
{

  I2S_DAI = 0x18 | wordwidth | (mono << 2) | (ws_sel << 5) | (ws_halfperiod << 6);
   /* 0x18 = stop and reset(async) Rx channel & FIFO */
   /* ws_sel determines master/slave operation */
}

/*******************************************************************************
* Function: I2S_Config_DAO
*
*******************************************************************************/
void I2S_Config_DAO(unsigned int wordwidth, unsigned int mono,
                    unsigned int ws_sel, unsigned int ws_halfperiod)
{
  I2S_DAO = 0x18 | wordwidth | (mono << 2) | (ws_sel << 5) | (ws_halfperiod << 6);
   /* 0x18 = stop and reset(async) Tx channel & FIFO */
   /* ws_sel determines master/slave operation */
}


/*******************************************************************************
* Function: i2s_IRQ_Handler
*
*******************************************************************************/
__irq void IRQ_I2S_Handler(void)
{
  IRQ_I2S_service();
}