ESP-Ventilation/lpc_chip_15xx/src/adc_15xx.c

/*
 * @brief LPC15xx ADC driver
 *
 * @note
 * Copyright(C) NXP Semiconductors, 2013
 * All rights reserved.
 *
 * @par
 * Software that is described herein is for illustrative purposes only
 * which provides customers with programming information regarding the
 * LPC products.  This software is supplied "AS IS" without any warranties of
 * any kind, and NXP Semiconductors and its licensor disclaim any and
 * all warranties, express or implied, including all implied warranties of
 * merchantability, fitness for a particular purpose and non-infringement of
 * intellectual property rights.  NXP Semiconductors assumes no responsibility
 * or liability for the use of the software, conveys no license or rights under any
 * patent, copyright, mask work right, or any other intellectual property rights in
 * or to any products. NXP Semiconductors reserves the right to make changes
 * in the software without notification. NXP Semiconductors also makes no
 * representation or warranty that such application will be suitable for the
 * specified use without further testing or modification.
 *
 * @par
 * Permission to use, copy, modify, and distribute this software and its
 * documentation is hereby granted, under NXP Semiconductors' and its
 * licensor's relevant copyrights in the software, without fee, provided that it
 * is used in conjunction with NXP Semiconductors microcontrollers.  This
 * copyright, permission, and disclaimer notice must appear in all copies of
 * this code.
 */

#include "chip.h"

/*****************************************************************************
 * Private types/enumerations/variables
 ****************************************************************************/

/*****************************************************************************
 * Public types/enumerations/variables
 ****************************************************************************/

/*****************************************************************************
 * Private functions
 ****************************************************************************/

/* Set ADC interrupt bits (safe) */
void Chip_ADC_SetIntBits(LPC_ADC_T *pADC, uint32_t intMask)
{
	uint32_t temp;

	/* Read and write values may not be the same, write 0 to
	   undefined bits */
	temp = pADC->INTEN & 0x07FFFFFF;

	pADC->INTEN = temp | intMask;
}

/* Clear ADC interrupt bits (safe) */
void Chip_ADC_ClearIntBits(LPC_ADC_T *pADC, uint32_t intMask)
{
	uint32_t temp;

	/* Read and write values may not be the same, write 0 to
	   undefined bits */
	temp = pADC->INTEN & 0x07FFFFFF;

	pADC->INTEN = temp & ~intMask;
}

/* Set ADC threshold selection bits (safe) */
void Chip_ADC_SetTHRSELBits(LPC_ADC_T *pADC, uint32_t mask)
{
	uint32_t temp;

	/* Read and write values may not be the same, write 0 to
	   undefined bits */
	temp = pADC->CHAN_THRSEL & 0x00000FFF;

	pADC->CHAN_THRSEL = temp | mask;
}

/* Clear ADC threshold selection bits (safe) */
void Chip_ADC_ClearTHRSELBits(LPC_ADC_T *pADC, uint32_t mask)
{
	uint32_t temp;

	/* Read and write values may not be the same, write 0 to
	   undefined bits */
	temp = pADC->CHAN_THRSEL & 0x00000FFF;

	pADC->CHAN_THRSEL = temp & ~mask;
}

/*****************************************************************************
 * Public functions
 ****************************************************************************/

/* Initialize the ADC peripheral */
void Chip_ADC_Init(LPC_ADC_T *pADC, uint32_t flags)
{
	/* Power up ADC and enable ADC base clock */
	if (pADC == LPC_ADC0) {
		Chip_SYSCTL_PowerUp(SYSCTL_POWERDOWN_ADC0_PD);
		Chip_Clock_EnablePeriphClock(SYSCTL_CLOCK_ADC0);
		Chip_SYSCTL_PeriphReset(RESET_ADC0);
	}
	else {
		Chip_SYSCTL_PowerUp(SYSCTL_POWERDOWN_ADC1_PD);
		Chip_Clock_EnablePeriphClock(SYSCTL_CLOCK_ADC1);
		Chip_SYSCTL_PeriphReset(RESET_ADC1);
	}

	/* Disable ADC interrupts */
	pADC->INTEN = 0;

	/* Set ADC control options */
	pADC->CTRL = flags;
}

/* Shutdown ADC */
void Chip_ADC_DeInit(LPC_ADC_T *pADC)
{
	pADC->INTEN = 0;
	pADC->CTRL = 0;

	/* Stop ADC clock and then power down ADC */
	if (pADC == LPC_ADC0) {
		Chip_Clock_DisablePeriphClock(SYSCTL_CLOCK_ADC0);
		Chip_SYSCTL_PowerDown(SYSCTL_POWERDOWN_ADC0_PD);
	}
	else {
		Chip_Clock_DisablePeriphClock(SYSCTL_CLOCK_ADC1);
		Chip_SYSCTL_PowerDown(SYSCTL_POWERDOWN_ADC1_PD);
	}
}

/* Set ADC clock rate */
void Chip_ADC_SetClockRate(LPC_ADC_T *pADC, uint32_t rate)
{
	uint32_t div;

	/* Get ADC clock source to determine base ADC rate. IN sychronous mode,
	   the ADC base clock comes from the system clock. In ASYNC mode, it
	   comes from the ASYNC ADC clock and this function doesn't work. */
	div = Chip_Clock_GetSystemClockRate() / rate;
	if (div == 0) {
		div = 1;
	}

	Chip_ADC_SetDivider(pADC, (uint8_t) div - 1);
}

/* Start ADC calibration */
void Chip_ADC_StartCalibration(LPC_ADC_T *pADC)
{
	/* Set calibration mode */
	pADC->CTRL |= ADC_CR_CALMODEBIT;

	/* Clear ASYNC bit */
	pADC->CTRL &= ~ADC_CR_ASYNMODE;

	/* Setup ADC for about 500KHz (per UM) */
	Chip_ADC_SetClockRate(pADC, 500000);

	/* Clearn low power bit */
	pADC->CTRL &= ~ADC_CR_LPWRMODEBIT;

	/* Calibration is only complete when ADC_CR_CALMODEBIT bit has cleared */
}

/* Helper function for safely setting ADC sequencer register bits */
void Chip_ADC_SetSequencerBits(LPC_ADC_T *pADC, ADC_SEQ_IDX_T seqIndex, uint32_t bits)
{
	uint32_t temp;

	/* Read sequencer register and mask off bits 20..25 */
	temp = pADC->SEQ_CTRL[seqIndex] & ~(0x3F << 20);

	/* OR in passed bits */
	pADC->SEQ_CTRL[seqIndex] = temp | bits;
}

/* Helper function for safely clearing ADC sequencer register bits */
void Chip_ADC_ClearSequencerBits(LPC_ADC_T *pADC, ADC_SEQ_IDX_T seqIndex, uint32_t bits)
{
	uint32_t temp;

	/* Read sequencer register and mask off bits 20..25 */
	temp = pADC->SEQ_CTRL[seqIndex] & ~(0x3F << 20);

	/* OR in passed bits */
	pADC->SEQ_CTRL[seqIndex] = temp & ~bits;
}

/* Enable interrupts in ADC (sequencers A/B and overrun) */
void Chip_ADC_EnableInt(LPC_ADC_T *pADC, uint32_t intMask)
{
	Chip_ADC_SetIntBits(pADC, intMask);
}

/* Disable interrupts in ADC (sequencers A/B and overrun) */
void Chip_ADC_DisableInt(LPC_ADC_T *pADC, uint32_t intMask)
{
	Chip_ADC_ClearIntBits(pADC, intMask);
}

/* Enable a threshold event interrupt in ADC */
void Chip_ADC_SetThresholdInt(LPC_ADC_T *pADC, uint8_t ch, ADC_INTEN_THCMP_T thInt)
{
	int shiftIndex = 3 + (ch * 2);

	/* Clear current bits first */
	Chip_ADC_ClearIntBits(pADC, (ADC_INTEN_CMP_MASK << shiftIndex));

	/* Set new threshold interrupt type */
	Chip_ADC_SetIntBits(pADC, ((uint32_t) thInt << shiftIndex));
}

/* Select threshold 0 values for comparison for selected channels */
void Chip_ADC_SelectTH0Channels(LPC_ADC_T *pADC, uint32_t channels)
{
	Chip_ADC_ClearTHRSELBits(pADC, channels);
}

/* Select threshold 1 value for comparison for selected channels */
void Chip_ADC_SelectTH1Channels(LPC_ADC_T *pADC, uint32_t channels)
{
	Chip_ADC_SetTHRSELBits(pADC, channels);
}