#include <stdio.h>
#include <stdlib.h>
#include <xc.h>
#include <stdint.h>

void i2c_init(void)
{
    SSPSTATbits.SMP = 1; // FIXME: needed?
    SSPCON1bits.SSPM = 0b1000;
    SSPCON1bits.SSPEN = 1;
    //SSPADD = 0x4; // ~400 kHz, see table 17-3 of the DS39631E manual.
    SSPADD = 0x13; // ~100 kHz, see table 17-3 of the DS39631E manual.
}


inline void i2c_busy_wait(void)
{
    // SSPCON has various flags that are cleared by hardware when the operation
    // has completed. SSPSTATbots.R_NOT_W tells whether a transmit is in progress.
    while(SSPCON2 & 0b00011111  || SSPSTATbits.R_NOT_W);
}

inline void i2c_start(void)
{
    i2c_busy_wait();
    SSPCON2bits.SEN = 1;
}

inline void i2c_stop(void)
{
    i2c_busy_wait();
    SSPCON2bits.PEN = 1;
}

inline void i2c_send(uint8_t byte)
{
    i2c_busy_wait();
    SSPBUF = byte;
}

void i2c_send_byte(uint8_t addr, uint8_t data)
{
    i2c_start();
    i2c_send(addr);
    i2c_send(data);
    i2c_stop();
}

int main(int argc, char** argv) {
    i2c_init();
    while(1)
    {
        i2c_send_byte(0x80, 0x80);
    }


    return (EXIT_SUCCESS);
}