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

#include "LS7366R.h"


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;

uint8_t spiChan = 0;


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

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

/* unused so far */
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
static uint8_t read8(uint8_t c) {
  uint8_t buf[2];
  buf[0] = c;
  wiringPiSPIDataRW(spiChan, buf, 2);
  return buf[1];
}
#pragma GCC diagnostic pop

static uint32_t read32(uint8_t c) {
  uint8_t buf[5];
  buf[0] = c;
  wiringPiSPIDataRW(spiChan, 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 ls7366rInit(uint8_t spiChanIn) {
  spiChan = spiChanIn;
  writeCmd(CMD_CLR | REG_STR);
  writeCmd(CMD_CLR | REG_CNTR);
  writeCmdData(CMD_WR | REG_MDR0, MDR0_ILO);
}

uint32_t ls7366rReadOTR() {
  return read32(CMD_RD | REG_OTR);
}