ATY_LIB/NoPublic/ad7124_support.c

/*!
 *****************************************************************************
  @file:  ad7124_support.c

  @brief: Provides useful support functions for the AD7124 NoOS driver

  @details:
 -----------------------------------------------------------------------------
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20180927-7CBSD SLA

*****************************************************************************/

#include <stdbool.h>
#include "ad7124_support.h"

// Public Functions
/*
 * @brief helper function get the setup setting for an ADC channel
 *
 * @param dev The device structure.
 *
 * @param channel ADC channel to get Setup for.
 *
 * @return value of setup field in channel configuration.
 */
uint8_t ad7124_get_channel_setup(struct ad7124_dev *dev, uint8_t channel)
{
	return (dev->regs[AD7124_Channel_0 + channel].value >> 12) & 0x7;
}


/*
 * @brief helper function get the PGA setting for an ADC channel
 *
 * @param dev The device structure.
 *
 * @param channel ADC channel to get Setup for.
 *
 * @return value of PGA field in the setup for an ADC channel.
 */
uint8_t ad7124_get_channel_pga(struct ad7124_dev *dev, uint8_t channel)
{
	uint8_t setup = ad7124_get_channel_setup(dev, channel);

	return (dev->regs[AD7124_Config_0 + setup].value) & 0x07;
}


/*
 * @brief helper function get the bipolar setting for an ADC channel
 *
 * @param dev The device structure.
 *
 * @param channel ADC channel to get bipolar mode for.
 *
 * @return value of bipolar field in the setup for an ADC channel.
 */
bool ad7124_get_channel_bipolar(struct ad7124_dev *dev, uint8_t channel)
{
	uint8_t setup = ad7124_get_channel_setup(dev, channel);

	return ((dev->regs[AD7124_Config_0 + setup].value >> 11) & 0x1) ? true : false;
}


/*
 * @brief converts ADC sample value to voltage based on gain setting
 *
 * @param dev The device structure.
 *
 * @param channel ADC channel to get Setup for.
 *
 * @param sample Raw ADC sample
 *
 * @return Sample ADC value converted to voltage.
 *
 * @note The conversion equation is implemented for simplicity,
 *       not for accuracy or performance
 *
 */
float ad7124_convert_sample_to_voltage(struct ad7124_dev *dev, uint8_t channel, uint32_t sample)
{
	bool isBipolar = ad7124_get_channel_bipolar(dev, channel);
	uint8_t channelPGA = ad7124_get_channel_pga(dev, channel);

	float convertedValue;

	if (isBipolar) {
        convertedValue = ( ((float)sample / (1 << (AD7124_ADC_N_BITS -1))) -1 ) * \
        		              (AD7124_REF_VOLTAGE / AD7124_PGA_GAIN(channelPGA));
	} else {
		convertedValue = ((float)sample * AD7124_REF_VOLTAGE)/(AD7124_PGA_GAIN(channelPGA) * \
								                              (1 << AD7124_ADC_N_BITS));
	}

    return (convertedValue);
}