#include "project.h"

#define NCS     (GPIO7)
#define NCS_PORT  GPIOG

#define SCK   (GPIO3)
#define SCK_PORT  GPIOB

#define MOSI    (GPIO5)
#define MOSI_PORT GPIOB


static void
set (int sck, int ncs, int mosi)
{
  if (sck)
    SET (SCK);
  else
    CLEAR (SCK);


  if (ncs)
    SET (NCS);
  else
    CLEAR (NCS);


  if (mosi)
    SET (MOSI);
  else
    CLEAR (MOSI);

  //delay_us(10);

}

static void
spip_send_8 (uint8_t wot)
{
  int i;

  for (i = 0; i < 8; ++i) {
    set (0, 0, wot & 0x80);
    set (1, 0, wot & 0x80);
    set (0, 0, wot & 0x80);
    wot <<= 1;
  }
}


static int mutex = 0;

static int
lock (void)
{
  if (__sync_add_and_fetch (&mutex, 1) != 1) {
    __sync_sub_and_fetch (&mutex, 1);
    return -1;
  }

  return 0;
}


static void
unlock (void)
{
  __sync_sub_and_fetch (&mutex, 1);
}


static void
write_reg (uint8_t reg, uint8_t data)
{
  while (lock());

  set (0, 1, 0);
  set (0, 0, 0);

  spip_send_8 (reg);
  spip_send_8 (data);

  set (0, 0, 0);
  set (0, 1, 0);
  unlock();
}

static void write_pair (uint8_t reg, int d)
{
  write_reg (reg, d / 10);
  write_reg (reg - 1, (d % 10) | 0x80);
}

void max7219_write (int d, int h, int m, int s)
{

  write_pair (8, d);
  write_pair (6, h);
  write_pair (4, m);
  write_pair (2, s);

}

void max7219_dispatch (void)
{
  uint32_t now = HW_CLOCK_REG;
  uint64_t abs =  abs_extend (now);
  EPOCH e = pll_decompose (abs);
  UTC u = time_epoch_to_utc (e);


  max7219_write (u.mday, u.hour, u.minute, u.second);
}

void
max7219_init (int on)
{
  MAP_OUTPUT_PP (SCK);
  MAP_OUTPUT_PP (NCS);
  MAP_OUTPUT_PP (MOSI);

  set (0, 1, 0);


  if (on) {

    write_reg (0xc, 0x1); //Power up
    write_reg (0xf, 0x0); //normal mode

    write_reg (0x9, 0xff); //BCD decode
    write_reg (0xb, 0x7); //8 digits
    write_reg (0xa, 0x8); //intensity
  } else {
    write_reg (0xc, 0x0); //Power up
  }



}