#include <msp430g2553.h>
#include <stdint.h>

//Define Base Registers
#define W5500_COMMON_BASE     0x0000
#define W5500_SOCKET0_BASE    0x4000
#define W5500_TXBUF_BASE      0x8000

//W5500 Commands
#define W5500_WRITE           0x04
#define W5500_READ            0x00

//Function Definition
void spi_init(void);
void spi_write(uint8_t data);
uint8_t spi_read(void);
uint8_t w5500_read(uint16_t addr, uint8_t ctrl_byte);
void w5500_write(uint16_t addr, uint8_t ctrl_byte, uint8_t data);

//Variable Definitions
int counter = 0;
uint8_t data[]   = "XYZ";
uint16_t len     = sizeof(data) - 1;

void main(void) {
      WDTCTL = WDTPW + WDTHOLD;

      spi_init();
      
      spi_write(5);
      
      //W5500: Software Reset
      w5500_write(0x0000, 0x04, 0x80); //Software Reset
      for(counter=0; counter<1000; counter++);

      //W5500: MAC Address-00.08.DC.AB.CD.EF
      w5500_write(0x0009, 0x04, 0x00);
      w5500_write(0x000A, 0x04, 0x08);
      w5500_write(0x000B, 0x04, 0xDC);
      w5500_write(0x000C, 0x04, 0xAB);
      w5500_write(0x000D, 0x04, 0xCD);
      w5500_write(0x000E, 0x04, 0xEF);
      
      //W5500: IP Address-192.168.0.10
      w5500_write(0x000F, 0x04, 192);
      w5500_write(0x0010, 0x04, 168);
      w5500_write(0x0011, 0x04, 0);
      w5500_write(0x0012, 0x04, 10);

      //W5500: Subnetzmask-255.255.255.0
      w5500_write(0x0005, 0x04, 255);
      w5500_write(0x0006, 0x04, 255);
      w5500_write(0x0007, 0x04, 255);
      w5500_write(0x0008, 0x04, 0);

      //W5500: Gateway-192.168.0.1
      w5500_write(0x0001, 0x04, 192);
      w5500_write(0x0002, 0x04, 168);
      w5500_write(0x0003, 0x04, 0);
      w5500_write(0x0004, 0x04, 1);

      //W5500: Socket UDP
      w5500_write(0x4000, 0x0C, 0x02);

      //W5500: PORT 5000
      w5500_write(0x4004, 0x0C, 0x13);
      w5500_write(0x4005, 0x0C, 0x88);

      //W5500: OPEN Socket
      w5500_write(0x4001, 0x0C, 0x01); 

      //W5500: Data Pointer
      uint8_t tx_wr0 = w5500_read(0x0024, 0x0C);
      uint8_t tx_wr1 = w5500_read(0x0025, 0x0C);

      //W5500: Transfer Data
      for (uint16_t i = 0; i < len; i++) {
        w5500_write(W5500_TXBUF_BASE + i, 0x14, data[i]);
    }

      //W5500: Data length
      w5500_write(W5500_SOCKET0_BASE + 0x20, 0x0C, (len >> 8) & 0xFF);
      w5500_write(W5500_SOCKET0_BASE + 0x21, 0x0C, len & 0xFF);

      //W5500: Send Command
      w5500_write(W5500_SOCKET0_BASE + 0x01, 0x0C, 0x20);

      //W5500: Wait
      while (!(w5500_read(W5500_SOCKET0_BASE + 0x02, 0x0C) & 0x10));

      //W5500: Clear
      w5500_write(W5500_SOCKET0_BASE + 0x02, 0x0C, 0x10);
      
      //I/O PIN
      P1OUT |= BIT0;
      P1DIR |= BIT0;

      while (1)
      {
        P1OUT ^= BIT0;
      }
}


//Function Declarations
//----------------------------------------------spi_init
void spi_init(void) {
    BCSCTL1 = CALBC1_1MHZ;
    DCOCTL = CALDCO_1MHZ;

    P1SEL |= BIT5 + BIT6 + BIT7;
    P1SEL2 |= BIT5 + BIT6 + BIT7;

    UCB0CTL1 = UCSWRST;
    UCB0CTL0 = UCCKPH | UCMSB | UCMST | UCSYNC;
    UCB0CTL1 = UCSSEL_2 | UCSWRST;
    UCB0BR0 = 2;
    UCB0BR1 = 0;
    UCB0CTL1 &= ~UCSWRST;
}
//----------------------------------------------END


//----------------------------------------------spi_write
void spi_write(uint8_t data) {
    while (!(IFG2 & UCB0TXIFG));
    UCB0TXBUF = data;
    while (!(IFG2 & UCB0RXIFG));
    volatile uint8_t dummy = UCB0RXBUF;
}
//----------------------------------------------END


//----------------------------------------------spi_read
uint8_t spi_read(void) {
    while (!(IFG2 & UCB0TXIFG));
    UCB0TXBUF = 0x00;
    while (!(IFG2 & UCB0RXIFG));
    return UCB0RXBUF;
}
//----------------------------------------------END


//----------------------------------------------w5500_write
void w5500_write(uint16_t addr, uint8_t ctrl_byte, uint8_t data) {
    spi_write((addr >> 8) & 0xFF);    // Address high byte
    spi_write(addr & 0xFF);           // Address low byte
    spi_write(ctrl_byte | W5500_WRITE);
    spi_write(data);
}
//----------------------------------------------END


//----------------------------------------------w5500_read
uint8_t w5500_read(uint16_t addr, uint8_t ctrl_byte) {
    spi_write((addr >> 8) & 0xFF);
    spi_write(addr & 0xFF);
    spi_write(ctrl_byte | W5500_READ);
    return spi_read();
}
//----------------------------------------------END