/*
 * File:   si5351a.c
 * Author: www.henteko.org
 *
 * Created on 2016/12/26, 14:19
 */
 
#include <xc.h>
#include <stdio.h>
#include <plib/i2c.h>
#include "si5351a.h"

void i2c_init()
{
	OpenI2C(MASTER, SLEW_ON);	// i2c master mode, clock 400khz
	SSPADD = 9;					// _XTAL_FREQ / (SSPADD + 1) * 4 = 400khz
}

void si5351_write(unsigned char reg, unsigned char data)
{
	StartI2C();
	WriteI2C(SI5351_I2C_ADDR);
	WriteI2C(reg);
	WriteI2C(data);
	StopI2C();
}

void si5351_init(void)
{
	si5351_write(SI5351_XTAL_LOAD, 0x80);   // 8pF
}

void si5351_setpll(unsigned char pll, unsigned char mult, unsigned long num, unsigned long denom)
{
	unsigned long P1;
	unsigned long P2;
	unsigned long P3;

	P1 = 128 * mult + (128 * (double)num / denom) - 512;
	P2 = 128 * num - denom * (unsigned long)(128 * (double)num / denom);
	P3 = denom;
	
	si5351_write(pll,	 (P3 & 0x0000FF00) >> 8);
	si5351_write(pll + 1, (P3 & 0x000000FF));
	si5351_write(pll + 2, (P1 & 0x00030000) >> 16);
	si5351_write(pll + 3, (P1 & 0x0000FF00) >> 8);
	si5351_write(pll + 4, (P1 & 0x000000FF));
	si5351_write(pll + 5, ((P3 & 0x000F0000) >> 12) | ((P2 & 0x000F0000) >> 16));
	si5351_write(pll + 6, (P2 & 0x0000FF00) >> 8);
	si5351_write(pll + 7, (P2 & 0x000000FF));
}

void si5351_setms(unsigned char synth, unsigned long div)
{
	unsigned long P1;
	unsigned long P2;
	unsigned long P3;

	P1 = 128 * div - 512;
	P2 = 0;
	P3 = 1;

	si5351_write(synth,	 (P3 & 0x0000FF00) >> 8);
	si5351_write(synth + 1, (P3 & 0x000000FF));
	si5351_write(synth + 2, ((P1 & 0x00030000) >> 16));
	si5351_write(synth + 3, (P1 & 0x0000FF00) >> 8);
	si5351_write(synth + 4, (P1 & 0x000000FF));
	si5351_write(synth + 5, ((P3 & 0x000F0000) >> 12) | ((P2 & 0x000F0000) >> 16));
	si5351_write(synth + 6, (P2 & 0x0000FF00) >> 8);
	si5351_write(synth + 7, (P2 & 0x000000FF));
}

void si5351_setfreq(unsigned char channel, unsigned long freq)
{
	unsigned long div;		// synth divider value
	unsigned long pllfreq;	// target PLL frequency
	unsigned char mult;		// multisynth a
	unsigned long num;		// multisynth b
	unsigned long denom;	// multisynth c
	unsigned long lltmp;	// temporary value

	div = SI5351_PLL_FREQ / freq;	 
	div = div>>1<<1;				// synth divider value is even integer
	pllfreq = div * freq;			
	denom = 0xfffff;				// 20bit denominator max value 
	mult = pllfreq / SI5351_XTAL_FREQ;	
	lltmp = pllfreq % SI5351_XTAL_FREQ;
	num  = lltmp * ((double)denom / SI5351_XTAL_FREQ);
  
	si5351_write(SI5351_OUTPUT_CTRL, 0xff);
	
	if(channel == 0) {
		si5351_write(SI5351_CLK0_CTRL, 0x80);
		si5351_setpll(SI5351_PLL_A, mult, num, denom);
		si5351_setms(SI5351_MS_0, div);
		si5351_write(SI5351_PLL_RESET, 0xa0);	
		si5351_write(SI5351_CLK0_CTRL, 0x4f);
	} else {
		si5351_write(SI5351_CLK1_CTRL, 0x80);
 		si5351_setpll(SI5351_PLL_B, mult, num, denom);
		si5351_setms(SI5351_MS_1, div);
		si5351_write(SI5351_PLL_RESET, 0xa0);	
		si5351_write(SI5351_CLK1_CTRL, 0x6f);
	}
	si5351_write(SI5351_OUTPUT_CTRL, 0x00);
}