#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(1);
  //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 void
write_reg (uint8_t reg, uint8_t data)
{

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

  spip_send_8 (reg);
  spip_send_8 (data);

  spip_send_8 (reg);
  spip_send_8 (data);

  spip_send_8 (reg);
  spip_send_8 (data);

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


static void
write_regs (uint8_t reg, uint8_t data1, uint8_t data2, uint8_t data3)
{

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

  spip_send_8 (reg);
  spip_send_8 (data3);

  spip_send_8 (reg);
  spip_send_8 (data2);

  spip_send_8 (reg);
  spip_send_8 (data1);

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

#define SDP 0x80
#define SA 0x40
#define SB 0x20
#define SC 0x10
#define SD 0x08
#define SE 0x04
#define SF 0x02
#define SG 0x01

static uint8_t hex (unsigned v)
{
  switch (v) {
  case 0:
  case '0':
    return SA | SF | SB | SE | SC | SD;

  case 1:
  case '1':
    return SB | SC;

  case 2:
  case '2':
  case 'z':
    return SA | SB | SG | SE | SD;

  case 3:
  case '3':
    return SA | SB | SG | SC | SD;

  case 4:
  case '4':
    return SF | SG | SB | SC;

  case 5:
  case '5':
  case 's':
    return SA | SF | SG | SC | SD;

  case 6:
  case '6':
    return SA | SF | SG | SE | SC | SD;

  case 7:
  case '7':
    return SA | SB | SC;

  case 8:
  case '8':
    return SA | SF | SB | SG | SE | SC | SD;

  case 9:
  case '9':
  case 'g':
    return SA | SF | SB | SG | SC | SD;

  case 0xa:
  case 'a':
    return SA | SF | SB | SG | SE | SC;

  case 0xb:
  case 'b':
    return SF | SG | SE | SC | SD;

  case 0xc:
  case 'c':
    return SG | SE | SD;

  case 0xd:
  case 'd':
    return SB | SG | SE | SC | SD;

  case 0xe:
  case 'e':
    return SA | SF | SG | SE | SD;

  case 0xf:
  case 'f':
    return SA | SF | SG | SE;

  case 'h':
    return SF | SG | SE | SC;

  case 'i':
    return SE;

  case 'j':
    return SB | SC | SD;

  case 'k':
  case 'x':
    return SF | SB | SG | SE | SC;

  case 'l':
    return SF | SE | SD;

  case 'm':
  case 'n':
    return SG | SE | SC;

  case 'o':
    return SG | SE | SC | SD;

  case 'p':
    return SA | SF | SB | SG | SE;

  case 'q':
    return SA | SF | SB | SG | SC;

  case 'r':
    return SG | SE;

  case 't':
    return SF | SG | SE | SD;

  case 'u':
  case 'w':
    return SE | SC | SD;

  case 'y':
    return SF | SB | SG | SC | SD;

  case '-':
    return SG;

  case '.':
    return SDP;

  }

  return 0;
}

void max7219_report_addr (uint32_t baseaddr)
{
  unsigned i;

  for (i = 1; i <= 8; ++i) {
    write_regs (i, hex (baseaddr & 0xf), 0, 0);
    baseaddr >>= 4;
  }
}



void
max7219 (const char *str)
{
  MAP_OUTPUT_PP (SCK);
  MAP_OUTPUT_PP (NCS);
  MAP_OUTPUT_PP (MOSI);
  unsigned reg;

  set (0, 1, 0);


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

  write_reg (0x9, 0x0); //No decode
  write_reg (0xb, 0x7); //8 digits
  write_regs (0xa, 15, 15, 15); //max brightness

  for (reg = 8; reg && *str; reg--, str++)
    write_regs (reg, hex (*str) | (!str[1] ? SDP : 0), 0, 0);

  for (; reg; reg--)
    write_reg (reg, 0);
}