#include "project.h"

// P0.20 => ginatop pin 8 MISO
// P0.19 => ginatop pin 7 CS
// P0.18 => ginatop pin 4 SCLK
// P0.17 => ginatop pin 3 MOSI

#define MOSI   17
#define SCLK   18
#define NCS    19
#define MISO   20

#define READ 0x3
#define FAST_READ 0xb


static inline void d(void)
{
nrf_delay_us(1);
}

void
gt_init (void)
{
  NRF_GPIO->PIN_CNF[SCLK] =
    (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos) |
    (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos) |
    (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos) |
    (GPIO_PIN_CNF_INPUT_Disconnect << GPIO_PIN_CNF_INPUT_Pos) |
    (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos);

  NRF_GPIO->PIN_CNF[MOSI] =
    (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos) |
    (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos) |
    (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos) |
    (GPIO_PIN_CNF_INPUT_Disconnect << GPIO_PIN_CNF_INPUT_Pos) |
    (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos);


  NRF_GPIO->PIN_CNF[NCS] =
    (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos) |
    (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos) |
    (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos) |
    (GPIO_PIN_CNF_INPUT_Disconnect << GPIO_PIN_CNF_INPUT_Pos) |
    (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos);



  NRF_GPIO->PIN_CNF[MISO] =
    (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos) |
    (GPIO_PIN_CNF_DRIVE_S0D1 << GPIO_PIN_CNF_DRIVE_Pos) |
    (GPIO_PIN_CNF_PULL_Pulldown << GPIO_PIN_CNF_PULL_Pos) |
    (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) |
    (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos);


  NRF_GPIO->DIRSET = (1 << MOSI) | (1 << NCS) | (1<<SCLK);
  NRF_GPIO->DIRCLR = (1 << MISO);

  NRF_GPIO->OUTSET = (1 << NCS) | (1<<MISO);
}

static void gt_read(uint32_t a,uint8_t * buf,size_t len)
{
  uint32_t c;
  uint8_t v;
  
  NRF_GPIO->OUTCLR = (1 << SCLK);
  d();
  NRF_GPIO->OUTCLR = (1 << NCS);
  //NRF_GPIO->OUTSET = (1 << NCS);
  d();
  
 a |= READ << 24;

  for (c=0x80000000;c;c>>=1) {
	if (c&a) 
		  NRF_GPIO->OUTSET = (1 << MOSI);
	else
		  NRF_GPIO->OUTCLR = (1 << MOSI);
  d();

  NRF_GPIO->OUTSET = (1 << SCLK);
  d();
  NRF_GPIO->OUTCLR = (1 << SCLK);
  d();
  }

  while (len--) {
	v=0;
	for (c=0x80;c;c>>=1) {
	if (NRF_GPIO->IN & (1<<MISO)) v|=c;
	


  NRF_GPIO->OUTSET = (1 << SCLK);
  d();
  NRF_GPIO->OUTCLR = (1 << SCLK);
  d();
	}
	*(buf++)=v;
  }

  d();
	
  NRF_GPIO->OUTSET = (1 << NCS);
  d();
	

}

void gt_read_8x8(uint32_t c,uint8_t *d,size_t l)
{
if (c<0x20) c=0x20;
if (c>0x7e) c=0x20;

c-=0x20;

c*=8;
c+=768;

gt_read(c,d,l);
}