#include <wiringPi.h>
#include <wiringPiSPI.h>
#include <stdint.h>
#include <stdio.h>
#include <unistd.h>


const int CTRL_OUT = 16;
const int INTR_IN  = 19;
const int SPI_CHAN = 0;
const int SPI_SPEED = 1000000;

const uint8_t REG_MDR0 = 0b00001000;
const uint8_t REG_MDR1 = 0b00010000;
const uint8_t REG_DTR  = 0b00011000;
const uint8_t REG_CNTR = 0b00100000;
const uint8_t REG_OTR  = 0b00101000;
const uint8_t REG_STR  = 0b00110000;

const uint8_t CMD_CLR  = 0b00000000;
const uint8_t CMD_RD   = 0b01000000;
const uint8_t CMD_WR   = 0b10000000;
const uint8_t CMD_LOAD = 0b11000000;

const uint8_t STR_CY   = 0b10000000;
const uint8_t STR_BW   = 0b01000000;
const uint8_t STR_CMP  = 0b00100000;
const uint8_t STR_IDX  = 0b00010000;
const uint8_t STR_CEN  = 0b00001000;
const uint8_t STR_PLS  = 0b00000100;
const uint8_t STR_UD   = 0b00000010;
const uint8_t STR_S    = 0b00000001;

const uint8_t MDR0_NOQ = 0b00000000;
const uint8_t MDR0_Q1  = 0b00000001;
const uint8_t MDR0_Q2  = 0b00000010;
const uint8_t MDR0_Q4  = 0b00000011;
const uint8_t MDR0_FRC = 0b00000000;
const uint8_t MDR0_SCC = 0b00000100;
const uint8_t MDR0_RLC = 0b00001000;
const uint8_t MDR0_MNC = 0b00001100;
const uint8_t MDR0_DI  = 0b00000000;
const uint8_t MDR0_ILC = 0b00010000;
const uint8_t MDR0_IRC = 0b00100000;
const uint8_t MDR0_ILO = 0b00110000;
const uint8_t MDR0_AI  = 0b00000000;
const uint8_t MDR0_SI  = 0b01000000;
const uint8_t MDR0_FC1 = 0b00000000;
const uint8_t MDR0_FC2 = 0b10000000;

const uint8_t MDR1_4CM = 0b00000000;
const uint8_t MDR1_3CM = 0b00000001;
const uint8_t MDR1_2CM = 0b00000010;
const uint8_t MDR1_1CM = 0b00000011;
const uint8_t MDR1_EC  = 0b00000000;
const uint8_t MDR1_DC  = 0b00000100;
const uint8_t MDR1_F_IDX = 0b00010000;
const uint8_t MDR1_F_CMP = 0b00100000;
const uint8_t MDR1_F_BW  = 0b01000000;
const uint8_t MDR1_F_CY  = 0b10000000;


volatile uint32_t ec = 0;

void isr() {
	ec++;
}

void writeCmd(uint8_t c) {
	uint8_t buf[1];
	buf[0] = c;
	wiringPiSPIDataRW(SPI_CHAN, buf, 1);
}

void writeCmdData(uint8_t c, uint8_t d) {
	uint8_t buf[2];
	buf[0] = c;
	buf[1] = d;
	wiringPiSPIDataRW(SPI_CHAN, buf, 2);
}

uint8_t read8(uint8_t c) {
  uint8_t buf[2];
	buf[0] = c;
  wiringPiSPIDataRW(SPI_CHAN, buf, 2);
	return buf[1];
}

uint32_t read32(uint8_t c) {
	uint8_t buf[5];
	buf[0] = c;
	wiringPiSPIDataRW(SPI_CHAN, buf, 5);
	uint32_t r = ((uint32_t)buf[1] << 24) | ((uint32_t)buf[2] << 16) | ((uint32_t)buf[3] << 8) | ((uint32_t)buf[4]);
	return r;
}

void init() {
	wiringPiSetupGpio();

	wiringPiSPISetup(SPI_CHAN, SPI_SPEED);

	pinMode(CTRL_OUT, OUTPUT);
	digitalWrite(CTRL_OUT, 0);

	pinMode(INTR_IN, INPUT);
	wiringPiISR(INTR_IN, INT_EDGE_FALLING, isr);
}

void initCounter() {
	writeCmd(CMD_CLR | REG_STR);
	writeCmd(CMD_CLR | REG_CNTR);
}

int main (void) {
	init();
	initCounter();

	while (1) {
		uint8_t str = read8(CMD_RD | REG_STR);
		uint32_t cntr = read32(CMD_RD | REG_CNTR);

		printf("%02x %d %d\n", str, ec, cntr);

		sleep(1);
	}
}