#ifndef ADC_H
#define ADC_H

#include <avr/io.h>
#include "lib/mystd.h"

typedef enum e_adc_ref {
	ADC_AREF	  = 0,
	ADC_AVCC	  = BV(REFS0),
	ADC_INT		  = BV(REFS0) | BV(REFS1),

	_ADC_REF_MASK = BV(REFS0) | BV(REFS1),
} e_adc_ref;

typedef enum e_adc_size {
	ADC_10BIT	   = 0,
	ADC_8BIT	   = BV(ADLAR),
	_ADC_SIZE_MASK = BV(ADLAR),
} e_adc_size;

typedef enum e_adc_prescaler {
	ADC_PRESCALER_2		= BV(ADPS0),
	ADC_PRESCALER_4		= BV(ADPS1),
	ADC_PRESCALER_8		= BV(ADPS1) | BV(ADPS0),
	ADC_PRESCALER_16	= BV(ADPS2),
	ADC_PRESCALER_32	= BV(ADPS2) | BV(ADPS0),
	ADC_PRESCALER_64	= BV(ADPS2) | BV(ADPS1),
	ADC_PRESCALER_128	= BV(ADPS2) | BV(ADPS1) | BV(ADPS0),

	_ADC_PRESCALER_MASK = BV(ADPS2) | BV(ADPS1) | BV(ADPS0),

} e_adc_prescaler;

typedef enum e_adc_input {
	ADC_ADC0		= 0,
	ADC_ADC1		= BV(MUX0),
	ADC_ADC2		= BV(MUX1),
	ADC_ADC3		= BV(MUX0) | BV(MUX1),
	ADC_ADC4		= BV(MUX2),
	ADC_ADC5		= BV(MUX2) | BV(MUX0),
	ADC_ADC6		= BV(MUX2) | BV(MUX1),
	ADC_ADC7		= BV(MUX2) | BV(MUX1) | BV(MUX0),
	ADC_TEMP		= BV(MUX3),
	ADC_11V			= BV(MUX3) | BV(MUX2) | BV(MUX1),
	ADC_0V			= BV(MUX3) | BV(MUX2) | BV(MUX1) | BV(MUX0),
	_ADC_INPUT_MASK = BV(MUX0) | BV(MUX1) | BV(MUX2) | BV(MUX3),
} e_adc_input;

static inline uint8_t adc_read_pin(e_adc_input input) {
	ADMUX	= (ADMUX & ~(_ADC_INPUT_MASK | _ADC_SIZE_MASK)) | input | BV(ADLAR);
	ADCSRA |= BV(ADSC);

	while (ADCSRA & BV(ADSC))
		;
	return ADCH;
}

static inline uint16_t adc_read_pin_10bit(e_adc_input input) {
	ADMUX	= (ADMUX & ~(_ADC_SIZE_MASK | _ADC_INPUT_MASK)) | (input & _ADC_INPUT_MASK);
	ADCSRA |= BV(ADSC);

	while (ADCSRA & BV(ADSC))
		;
	return ADC;
}

static inline void adc_init(e_adc_ref v_ref, e_adc_prescaler prescaler) {
	ADMUX  = (ADMUX & ~(_ADC_REF_MASK)) | v_ref;

	ADCSRA = BV(ADEN) | (prescaler & _ADC_PRESCALER_MASK);

	(void)adc_read_pin(0);
}
#endif /* ADC_H */