#include <stdio.h>
#include <stdlib.h> 
#include <ctype.h>
#include "LPC17xx.h"

// SP0SPCR  Bit-Definitions
#define BitEn   2
#define CPHA    3
#define CPOL    4
#define MSTR    5
// SP0SPSR  Bit-Definitions
#define SPIF    7

// Defines for LPC1768
#define SPI_IODIR            LPC_GPIO0->FIODIR
#define SPI_SCK_PIN         15        /* Clock        P0.15 out            (PINSEL0) */
#define SPI_SSEL_PIN        16        /* Digital I/O Select P0.16 GPIO out (PINSEL1) */
#define SPI_MISO_PIN        17        /* from Card    P0.17 in             (PINSEL1) */
#define SPI_MOSI_PIN        18        /* to Card        P0.18 out          (PINSEL1) */
#define SPI_ASEL_PIN        19        /* Analog Out Select P0.19 GPIO out  (PINSEL1) */

#define SPI_PINSEL            LPC_PINCON->PINSEL1
#define SPI_SCK_FUNCMASK    0xC0000000 //(3 << 30)  // P0.15 - PINSEL0 [31:30]
#define SPI_SSEL_FUNCMASK   0x00000003 // (3 << 0)  // P0.16 - PINSEL1 [1:0]
#define SPI_MISO_FUNCMASK   0x0000000C // (3 << 2)  // P0.17 - PINSEL1 [3:2]
#define SPI_MOSI_FUNCMASK   0x00000030 // (3 << 4)  // P0.18 - PINSEL1 [5:4]

#define SPI_SCK_FUNCBIT     (3 << 30)
#define SPI_SSEL_FUNCBIT    (0 << 0) // Note - SSEL needed as GPIO
#define SPI_MISO_FUNCBIT    (3 << 2)
#define SPI_MOSI_FUNCBIT    (3 << 4)

#define SPI_PRESCALE_REG    LPC_SPI->SPCCR
//#define SCK_WAIT            100     // 3MHz PCLK
//#define SCK_WAIT            50      // 6MHz PCLK
#define SCK_WAIT            25      // 12MHz PCLK

extern uint8_t Data[];

// SPI Slave 8-bit Initialize

void SSPI1_Init8(void)
{
    uint8_t i,tmp;
     
    LPC_SC->PCONP        |=  (1UL << 10);   // Enable the SSP1 peripheral.
    LPC_SC->PCLKSEL0     &= ~(3UL << 20);   // Select the clock required for SSP1...
    LPC_SC->PCLKSEL0     |=  (1UL << 20);   // ... must be at least 12x faster then slave clk coming in.
    LPC_PINCON->PINSEL0  &= ~(3UL << 14);   // Connect pin SCK1
    LPC_PINCON->PINSEL0  |=  (2UL << 14);
    LPC_PINCON->PINSEL0  &= ~(3UL << 16);   // Connect pin MISO1
    LPC_PINCON->PINSEL0  |=  (2UL << 16);
    LPC_PINCON->PINSEL0  &= ~(3UL << 12);   // Connect pin SSEL1
    LPC_PINCON->PINSEL0  |=  (2UL << 12);        
    LPC_PINCON->PINSEL0  &= ~(3UL << 18);   // Connect pin MOSI1 
    LPC_PINCON->PINSEL0  |=  (2UL << 18);
     
    // enable SPI mode with 8-bit transfers,  CPOL = 0, CPHA = 0, No Prescale 
    LPC_SSP1->CR0 = 0x707;     

    LPC_SSP1->CPSR = 0;    

    // enable SSP, Slave Mode, MISO Disabled   
    LPC_SSP1->CR1 = 0x00E;  
    for(i=0;i<=8;i++) tmp = (uint8_t)LPC_SSP1->DR;    // Flush Buffer  
    // Note Enable MISO before each transmission   
}

// Slave Recieve four bytes
void SPIRecv4(void) // Data In
{
    uint8_t i, j;
    
    i = LPC_SPI->SPDR;
    for (i = 0; i < 4; i++) {
        for(j=0;j<SCK_WAIT;j++);
        LPC_SPI->SPDR = 0xFF;
        while (!(LPC_SPI->SPSR & (1 << SPIF)));
        Data[3 - i] = LPC_SPI->SPDR;
    }
}

// SPI Master Initialize

void SPIInit8(void)
{
     
    // Turn on the power
    LPC_SC->PCONP |= (1<<8); // PCSPI

    // setup clock
//    LPC_SC->PCLKSEL0 &= ~(3<<16);    // PCLK_SPI(00) = CCLK/4 = 3MHz
    LPC_SC->PCLKSEL0 |=  (1<<16);  // PCLK_SPI(01) = CCLK = = 12MHz
//    LPC_SC->PCLKSEL0 |=  (1<<17);  // PCLK_SPI(10) = CCLK/2 = 6MHz
//    LPC_SC->PCLKSEL0 |=  (3<<16);  // PCLK_SPI(11) = CCLK/8 = 1.5MHz

    // setup GPIO
    SPI_IODIR |= (1 << SPI_SCK_PIN) | (1 << SPI_MOSI_PIN);
    SPI_IODIR &= ~(1 << SPI_MISO_PIN);

    //// reset Pin-Functions
    // P0.15 set to SCK
    LPC_PINCON->PINSEL0 &= ~SPI_SCK_FUNCMASK;
    LPC_PINCON->PINSEL0 |=  SPI_SCK_FUNCBIT;    
    // P0.17, P0.18 set to MISI, MOSI
    SPI_PINSEL &= ~(SPI_MOSI_FUNCMASK | SPI_MISO_FUNCMASK);
    SPI_PINSEL |=  (SPI_MOSI_FUNCBIT | SPI_MISO_FUNCBIT);
    
    // enable SPI-Master    
    LPC_SPI->SPCR = (1 << MSTR) | (1 << CPOL) | (1 << CPHA);         
//    LPC_SPI->SPCR = (1 << MSTR) | (0 << CPOL);    // TODO: check CPOL     
}

// Master Send (8-bit)

uint8_t SPISend(uint8_t outgoing)
{
    uint8_t incoming;
    
    LPC_SPI->SPDR = outgoing;
    while (!(LPC_SPI->SPSR & (1 << SPIF)));
    incoming = LPC_SPI->SPDR;
    return incoming;
}