/****************************************************************************
 *   $Id:: adc.c 3633 2010-06-01 23:03:16Z usb00423                         $
 *   Project: NXP LPC13xx ADC example
 *
 *   Description:
 *     This file contains ADC code example which include ADC 
 *     initialization, ADC interrupt handler, and APIs for ADC
 *     reading.
 *
 ****************************************************************************
 * Software that is described herein is for illustrative purposes only
 * which provides customers with programming information regarding the
 * products. This software is supplied "AS IS" without any warranties.
 * NXP Semiconductors assumes no responsibility or liability for the
 * use of the software, conveys no license or title under any patent,
 * copyright, or mask work right to the product. NXP Semiconductors
 * reserves the right to make changes in the software without
 * notification. NXP Semiconductors also make no representation or
 * warranty that such application will be suitable for the specified
 * use without further testing or modification.
****************************************************************************/
#include "LPC13xx.h"			/* LPC13xx Peripheral Registers */
#include "adc.h"

volatile uint32_t ADCValue[ADC_NUM];
volatile uint32_t ADCIntDone = 0;

#if BURST_MODE
volatile uint32_t channel_flag; 
#endif

#if ADC_INTERRUPT_FLAG
/******************************************************************************
** Function name:		ADC_IRQHandler
**
** Descriptions:		ADC interrupt handler
**
** parameters:			None
** Returned value:		None
** 
******************************************************************************/
void ADC_IRQHandler (void) 
{
  uint32_t regVal;
  
  regVal = LPC_ADC->STAT;		/* Read ADC will clear the interrupt */
  if ( regVal & 0x0000FF00 )	/* check OVERRUN error first */
  {
	regVal = (regVal & 0x0000FF00) >> 0x08;
	/* if overrun, just read ADDR to clear */
	/* regVal variable has been reused. */
	switch ( regVal )
	{
	  case 0x01:
		regVal = LPC_ADC->DR0;
		break;
	  case 0x02:
		regVal = LPC_ADC->DR1;
		break;
	  case 0x04:
		regVal = LPC_ADC->DR2;
		break;
	  case 0x08:
		regVal = LPC_ADC->DR3;
		break;
	  case 0x10:
		regVal = LPC_ADC->DR4;
		break;
	  case 0x20:
		regVal = LPC_ADC->DR5;
		break;
	  case 0x40:
		regVal = LPC_ADC->DR6;
		break;
	  case 0x80:
		regVal = LPC_ADC->DR7;
		break;
	  default:
		break;
	}
	LPC_ADC->CR &= 0xF8FFFFFF;	/* stop ADC now */ 
	ADCIntDone = 1;
	return;	
  }

  if ( regVal & ADC_ADINT )
  {
	switch ( regVal & 0xFF )	/* check DONE bit */
	{
	  case 0x01:
		ADCValue[0] = ( LPC_ADC->DR0 >> 6 ) & 0x3FF;
	    break;
	  case 0x02:
		ADCValue[1] = ( LPC_ADC->DR1 >> 6 ) & 0x3FF;
	    break;
	  case 0x04:
		ADCValue[2] = ( LPC_ADC->DR2 >> 6 ) & 0x3FF;
	    break;
	  case 0x08:
		ADCValue[3] = ( LPC_ADC->DR3 >> 6 ) & 0x3FF;
	    break;
	  case 0x10:
		ADCValue[4] = ( LPC_ADC->DR4 >> 6 ) & 0x3FF;
	    break;
	  case 0x20:
		ADCValue[5] = ( LPC_ADC->DR5 >> 6 ) & 0x3FF;
	    break;
	  case 0x40:
		ADCValue[6] = ( LPC_ADC->DR6 >> 6 ) & 0x3FF;
	    break;
	  case 0x80:
		ADCValue[7] = ( LPC_ADC->DR7 >> 6 ) & 0x3FF;
	    break;		
	  default:
	    break;
	}
#if BURST_MODE
	channel_flag |= (regVal & 0xFF);
	if ( (channel_flag & 0xFF) == 0xFF )
	{
	  /* All the bits in have been set, it indicates all the ADC 
	  channels have been converted. */
	  LPC_ADC->CR &= 0xF8FFFFFF;	/* stop ADC now */ 
	  ADCIntDone = 1;
	}
#else
	LPC_ADC->CR &= 0xF8FFFFFF;	/* stop ADC now */ 
	ADCIntDone = 1;
#endif
  }
  return;
}
#endif

/*****************************************************************************
** Function name:		ADCInit
**
** Descriptions:		initialize ADC channel
**
** parameters:			ADC clock rate
** Returned value:		None
** 
*****************************************************************************/
void ADCInit( uint32_t ADC_Clk )
{
  uint32_t i;

  /* Disable Power down bit to the ADC block. */  
  LPC_SYSCON->PDRUNCFG &= ~(0x1<<4);

  /* Enable AHB clock to the ADC. */
  LPC_SYSCON->SYSAHBCLKCTRL |= (1<<13);

  for ( i = 0; i < ADC_NUM; i++ )
  {
	ADCValue[i] = 0x0;
  }
  /* Unlike some other pings, for ADC test, all the pins need
  to set to analog mode. Bit 7 needs to be cleared according 
  to design team. */
  LPC_IOCON->PIO0_11 &= ~0x8F; /*  ADC I/O config */
  LPC_IOCON->PIO0_11 |= 0x02;  /* ADC IN0 */

#ifdef __JTAG_DISABLED

  LPC_IOCON->R_PIO1_0  &= ~0x8F;	
  LPC_IOCON->R_PIO1_0  |= 0x02;  /* ADC IN1 */
  LPC_IOCON->R_PIO1_1  &= ~0x8F;	
  LPC_IOCON->R_PIO1_1  |= 0x02;  /* ADC IN2 */
  LPC_IOCON->R_PIO1_2  &= ~0x8F;	
  LPC_IOCON->R_PIO1_2  |= 0x02;  /* ADC IN3 */
#ifdef __SWD_DISABLED
  LPC_IOCON->SWDIO_PIO1_3   &= ~0x8F;	
  LPC_IOCON->SWDIO_PIO1_3   |= 0x02;  /* ADC IN4 */
#endif
#endif
  LPC_IOCON->PIO1_4    &= ~0x8F; /* Clear bit7, change to analog mode. */	
  LPC_IOCON->PIO1_4    |= 0x01;  /* ADC IN5 */
  LPC_IOCON->PIO1_10   &= ~0x8F; /* Clear bit7, change to analog mode. */	
  LPC_IOCON->PIO1_10   |= 0x01;  /* ADC IN6 */
  LPC_IOCON->PIO1_11   &= ~0x8F; /* Clear bit7, change to analog mode. */	
  LPC_IOCON->PIO1_11   |= 0x01;  /* ADC IN7 */

  LPC_ADC->CR = ( 0x01 << 0 ) |  /* SEL=1,select channel 0~7 on ADC0 */
	(((SystemCoreClock/LPC_SYSCON->SYSAHBCLKDIV)/ADC_Clk-1)<<8) |  /* CLKDIV = Fpclk / 1000000 - 1 */
	( 0 << 16 ) | 		/* BURST = 0, no BURST, software controlled */
	( 3 << 17 ) |  		/* CLKS = 0, 11 clocks/10 bits */
	( 0 << 24 ) |  		/* START = 0 A/D conversion stops */
	( 0 << 27 );		/* EDGE = 0 (CAP/MAT singal falling,trigger A/D conversion) */

  /* If POLLING, no need to do the following */
#if ADC_INTERRUPT_FLAG
  NVIC_EnableIRQ(ADC_IRQn);
  LPC_ADC->INTEN = 0x1FF;		/* Enable all interrupts */
#endif
  return;
}

/*****************************************************************************
** Function name:		ADCRead
**
** Descriptions:		Read ADC channel
**
** parameters:			Channel number
** Returned value:		Value read, if interrupt driven, return channel #
** 
*****************************************************************************/
uint32_t ADCRead( uint8_t channelNum )
{
#if !ADC_INTERRUPT_FLAG
  uint32_t regVal, ADC_Data;
#endif

  /* channel number is 0 through 7 */
  if ( channelNum >= ADC_NUM )
  {
	channelNum = 0;		/* reset channel number to 0 */
  }
  LPC_ADC->CR &= 0xFFFFFF00;
  LPC_ADC->CR |= (1 << 24) | (1 << channelNum);	
				/* switch channel,start A/D convert */
#if !ADC_INTERRUPT_FLAG
  while ( 1 )			/* wait until end of A/D convert */
  {
	regVal = *(volatile unsigned long *)(LPC_ADC_BASE 
			+ ADC_OFFSET + ADC_INDEX * channelNum);
	/* read result of A/D conversion */
	if ( regVal & ADC_DONE )
	{
	  break;
	}
  }	
        
  LPC_ADC->CR &= 0xF8FFFFFF;	/* stop ADC now */    
  if ( regVal & ADC_OVERRUN )	/* save data when it's not overrun, otherwise, return zero */
  {
	return ( 0 );
  }
  ADC_Data = ( regVal >> 6 ) & 0x3FF;
  return ( ADC_Data );	/* return A/D conversion value */
#else
  return ( channelNum );	/* if it's interrupt driven, the ADC reading is 
							done inside the handler. so, return channel number */
#endif
}

/*****************************************************************************
** Function name:		ADC0BurstRead
**
** Descriptions:		Use burst mode to convert multiple channels once.
**
** parameters:			None
** Returned value:		None
** 
*****************************************************************************/
void ADCBurstRead( void )
{
  if ( LPC_ADC->CR & (0x7<<24) )
  {
	LPC_ADC->CR &= ~(0x7<<24);
  }
  /* Test channel 5,6,7 using burst mode because they are not shared
  with the JTAG pins. */
  LPC_ADC->CR &= ~0xFF;
  /* Read all channels, 0 through 7. */
  LPC_ADC->CR |= (0xFF);
  LPC_ADC->CR |= (0x1<<16);		/* Set burst mode and start A/D convert */
  return;						/* the ADC reading is done inside the 
								handler, return 0. */
}

/*********************************************************************************
**                            End Of File
*********************************************************************************/