#include <stdint.h>

#define SPI0_BASE       0xFFF01000UL
#define GPI0_BASE       0xFF709000UL

#define CTRLR0_OFFSET   0x00
#define CTRLR1_OFFSET   0x04
#define SSIENR_OFFSET   0x08
#define SER_OFFSET      0x10
#define BAUDR_OFFSET    0x14
#define SR_OFFSET       0x28
#define DR_OFFSET       0x60   // primo registro dati

#define SR_BUSY         (1 << 0)
#define SR_TFNF         (1 << 1)
#define SR_TFE          (1 << 2)

#define TMOD_TX_ONLY    (1 << 8)
#define DFS_8BIT        (0x07)   // 8-bit frame size
#define DFS_16BIT       (0x0F)   // 16-bit
#define SPI_MODE0       (0 << 5) | (0 << 6) /// forse 6 e 7 ??

#define GPIO_DR			0x00
#define GPIO_DDR		0x04 

#define GPIO_LED		(1<<24)
#define GPIO_SWITCH		(1<<11)

volatile uint32_t * const SPI0 = (volatile uint32_t *)SPI0_BASE;
volatile uint32_t * const GPI0 = (volatile uint32_t *)GPI0_BASE;

// tabella di 16 valori a 16 bit (esadecimali)
static const uint16_t spi_data_table[16] = {
    0x0000, 0x013C, 0x0242, 0x03A5,
    0x0481, 0x05A5, 0x0699, 0x0742,
    0x083C, 0x0900, 0x0A03, 0x0B07,
    0x0C01, 0x0D01, 0x0E01, 0x0F00
};


void spi0_init(void) {
    // 1. Disabilita SPI per configurarlo
    SPI0[SSIENR_OFFSET/4] = 0;
    // 2. Configura CTRLR0: 8-bit, CPOL=0, CPHA=0, TX only
    SPI0[CTRLR0_OFFSET/4] = DFS_16BIT | TMOD_TX_ONLY | SPI_MODE0;
    // 3. Imposta baud rate (divisore)
    SPI0[BAUDR_OFFSET/4] = 500; // fSPI = fPCLK / 50 (≈ 1 MHz se PCLK=50 MHz)
    // 4. Seleziona slave 0
    SPI0[SER_OFFSET/4] = 0x1; // bit0 = CS0 attivo
    // 5. Abilita SPI
    SPI0[SSIENR_OFFSET/4] = 1;
}

 void gpi0_init(void) {
     GPI0[GPIO_DDR/4] = GPIO_LED | GPIO_SWITCH; // Configuro i GPIO come uscite
     GPI0[GPIO_DR/4] = GPIO_LED ; 				// accendo il led e lo switch a 0
 }

void spi0_send16(uint16_t data) {
    // Attende spazio nel TX FIFO
    while (!(SPI0[SR_OFFSET/4] & SR_TFNF));
    // Scrive nel registro dati (avvia trasmissione)
    SPI0[DR_OFFSET/4] = data;
    // Attende fine trasmissione
    while (SPI0[SR_OFFSET/4] & SR_BUSY);
}




int main(void) 
	{
	int i,j;
	printf("INIT SPI\n");
	spi0_init();
	printf("INIT GPIO\n");
	gpi0_init();
    while(1){
    // Invio dei 16 valori a 16 bit
    for (i = 0; i < 16; i++) {
        spi0_send16(spi_data_table[i]);
		//printf("%d\n",i);
        //for (j = 0; j < 10000; j++); // piccolo delay opzionale
		}
    }

    // Disabilita SPI (opzionale)
    SPI0[SSIENR_OFFSET/4] = 0;

    return 0;
}