dna.c

#include "board.h"
#include "syscon.h"

#define DNA_DATA 1
#define DNA_CLK 4
#define DNA_SHIFT 3
#define DNA_READ 2

void dna_read(uint32_t * lo, uint32_t * hi)
{
	uint64_t dna = 0;
	int i;

	gpio_out(DNA_DATA, 0);
	delay(10);
	gpio_out(DNA_CLK, 0);
	delay(10);
	gpio_out(DNA_READ, 1);
	delay(10);
	gpio_out(DNA_SHIFT, 0);
	delay(10);

	delay(10);
	gpio_out(DNA_CLK, 1);
	delay(10);
	if (gpio_in(DNA_DATA))
		dna |= 1;
	delay(10);
	gpio_out(DNA_CLK, 0);
	delay(10);
	gpio_out(DNA_READ, 0);
	gpio_out(DNA_SHIFT, 1);
	delay(10);

	for (i = 0; i < 57; i++) {
		dna <<= 1;
		delay(10);
		delay(10);
		gpio_out(DNA_CLK, 1);
		delay(10);
		if (gpio_in(DNA_DATA))
			dna |= 1;
		delay(10);
		gpio_out(DNA_CLK, 0);
		delay(10);
	}

	*hi = (uint32_t) (dna >> 32);
	*lo = (uint32_t) dna;
}