avr/base/base.h

#ifndef __BASE_H__
#define __BASE_H__

#include <avr/io.h>
#include <avr/delay.h>

#define LINE_OUT 1
#define LINE_IN  0

typedef struct GPIO {
    volatile uint8_t *ddr;
    volatile uint8_t *port;
    volatile uint8_t *pin;
    uint8_t addr;
} gpio_t;

/*
#define GPIOA(addr) (gpio_t){ .ddr = &DDRA, .port = &PORTA, .addr = addr }
#define GPIOB(addr) (gpio_t){ .ddr = &DDRB, .port = &PORTB, .addr = addr }
#define GPIOC(addr) (gpio_t){ .ddr = &DDRC, .port = &PORTC, .addr = addr }
#define GPIOD(addr) (gpio_t){ .ddr = &DDRD, .port = &PORTD, .addr = addr }
*/

inline void set_line_direction(gpio_t *line, int direction) {
    if (direction == LINE_OUT) {
        *(line->ddr) |= _BV(line->addr);
    } else {
        *(line->ddr) &= ~(_BV(line->addr));
    }
}

inline void set_line(gpio_t *line) {
    *(line->port) |= _BV(line->addr);
}

inline void clear_line(gpio_t *line) {
    *(line->port) &= ~(_BV(line->addr));
}

inline int read_line(gpio_t *line) {
    return (*(line->port) & _BV(line->addr)) > 0;
}

typedef struct RNG {
    uint8_t mod;
    int8_t a;
    int8_t c;
    uint8_t seed;
} rng_t;

rng_t rng_new(uint8_t seed);

uint8_t rng_sample(rng_t *state);

#endif