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#include <avr/io.h>

#include "ssc.h"

//-------------------------------------- Hardware specific definitions --------------------------------------

#define PORTR_SPI                       PINB

#define PORTW_SPI                       PORTB           //Port to which the sd-card is connected (SPI Port)

#define PORT_MISO                       PORTB6          //Port Pin that is connected to the DO of the MMC/SD-card

#define PORT_MOSI                       PORTB5          //Port Pin that is connected to  DI of the MMC/SD-card

#define PORT_SCK                        PORTB7          //Port Pin that is connected the CLK of the MMC/SD-card

#define PORT_SS                         PORTB4          //Slave Select is not used in SPI Master Mode, but must be defined

#define PORT_CS                         PORTB4          //Port Pin that is connected to /CS of the MMC/SD-Karte

#ifdef USE_SDLOGGER

#define __SD_INTERFACE_INVERTED         // the interface between the controller and the SD-card uses an inverting leveltranslator (transistorinverter)

#endif                                                          // and therefore the signals to or from the memorycard have to be inverted.

#ifdef USE_FOLLOWME                                     // uses resitors, therefore its not inverted

//#define       __SD_INTERFACE_INVERTED // the interface between the controller and the MMC/SD-card uses an inverting leveltranslator (transistorinverter)

#endif

#define DDR_SPI                         DDRB

#define DD_MISO                         DDB6            //Port Pin that is connected to the DO of the MMC/SD-card

#define DD_MOSI                         DDB5            //Port Pin that is connected to  DI of the MMC/SD-card

#define DD_SCK                          DDB7            //Port Pin that is connected the CLK of the MMC/SD-card

#define DD_SS                           DDB4            //Slave Select is not used in SPI Master Mode, but must be defined

#define DD_CS                           DDB4            //Port Pin that is connected to /CS of the MMC/SD-Karte

// for compatibility reasons gcc3.x <-> gcc4.x

#ifndef SPCR

#define SPCR   SPCR0

#endif

#ifndef SPIE

#define SPIE   SPIE0

#endif

#ifndef SPE

#define SPE    SPE0

#endif

#ifndef DORD

#define DORD   DORD0

#endif

#ifndef MSTR

#define MSTR   MSTR0

#endif

#ifndef CPOL

#define CPOL   CPOL0

#endif

#ifndef CPHA

#define CPHA   CPHA0

#endif

#ifndef SPR1

#define SPR1   SPR01

#endif

#ifndef SPR0

#define SPR0   SPR00

#endif

#ifndef SPDR

#define SPDR   SPDR0

#endif

#ifndef SPSR

#define SPSR   SPSR0

#endif

#ifndef SPIF

#define SPIF   SPIF0

#endif

#ifndef WCOL

#define WCOL   WCOL0

#endif

#ifndef SPI2X

#define SPI2X  SPI2X0

#endif

//________________________________________________________________________________________________________________________________________

// Function:    SSC_Init(void);

//

// Description: This function initialises the synchronus serial channel to the sdcard.

//

//

// Returnvalue: none

//________________________________________________________________________________________________________________________________________

void SSC_Init(void)

{

        // Set MOSI,SCK and CS as output

        DDR_SPI |= (1<<DD_MOSI)|(1<<DD_SCK)|(1<<DD_CS);

        // set MISO as input

        DDR_SPI &= ~(1<<DD_MISO);

        SSC_Disable();

        // 20MHz / 32 = 625 kHz

        #ifdef __SD_INTERFACE_INVERTED

        SPCR = (1<<SPE)|(1<<MSTR)|(0<<DORD)|(1<<CPOL)|(0<<CPHA)|(1<<SPR1)|(0<<SPR0);    // Enable SSC in mastermode, inverted clockpolarity (idle high)

        #else

        SPCR = (1<<SPE)|(1<<MSTR)|(0<<DORD)|(0<<CPOL)|(0<<CPHA)|(1<<SPR1)|(0<<SPR0);    // Enable SSC in mastermode, noninverted clockpolarity (idle low)

        #endif

        SPSR |= (1<<SPI2X);

        // set port pin as input pullup for SD-Card switch

        #ifdef USE_FOLLOWME

        PORTB |= (1 << PORTB2);

        DDRB &= ~(1 << DDB2);

        #endif

        #ifdef USE_SDLOGGER

        PORTB |= (1 << PORTB3);

        DDRB &= ~(1 << DDB3);

        #endif

}

void    SSC_Deinit(void)

{

        SSC_Disable();

        SPCR = 0;

        SPSR = 0;

}

//________________________________________________________________________________________________________________________________________

// Function:    SSC_GetChar(void);

//

// Description: This function reads one byte from the SSC

//

//

// Returnvalue: the byte received.

//________________________________________________________________________________________________________________________________________

uint8_t SSC_GetChar (void)

{

        uint8_t Byte = 0;

        #ifdef __SD_INTERFACE_INVERTED

        SPDR = 0x00;                                                                            // send dummy byte to initiate the reading

        #else

        SPDR = 0xFF;                                                                            // send dummy byte to initiate the reading

        #endif

        while(!(SPSR & (1<<SPIF)))

        {

                // wait until the data has been read.

        }

        Byte = SPDR;

        #ifdef __SD_INTERFACE_INVERTED

        Byte = ~Byte;

        #endif

        return(Byte);

}

//________________________________________________________________________________________________________________________________________

// Function:    SSC_PutChar(u8 Byte);

//

// Description: This function writes one byte to the SSC

//

//

// Returnvalue: none

//________________________________________________________________________________________________________________________________________

void SSC_PutChar (uint8_t Byte)

{

        #ifdef __SD_INTERFACE_INVERTED

        SPDR = ~Byte;                                                                           // send one byte of data to the SSC

        #else

        SPDR =  Byte;                                                                           // send one byte of data to the SSC

        #endif

        while(!(SPSR & (1<<SPIF)))

        {

                // wait until the data has been sent.

        }

}

//________________________________________________________________________________________________________________________________________

// Function:    SSC_Disable(void);

//

// Description: This function enables chipselect of the sdcard (active low)

//

//

// Returnvalue: none

//________________________________________________________________________________________________________________________________________

void SSC_Disable(void)

{

        #ifdef __SD_INTERFACE_INVERTED

        PORTW_SPI &= ~(1<<PORT_CS);                                     // disable chipselect of the sdcard (active low).

        #else

        PORTW_SPI |= (1<<PORT_CS);                                      // disable chipselect of the sdcard (active low).

        #endif

}

//________________________________________________________________________________________________________________________________________

// Function:    SSC_Enable(void);

//

// Description: This function disables chipselect of the sdcard (active low)

//

//

// Returnvalue: none

//________________________________________________________________________________________________________________________________________

void SSC_Enable(void)

{

        #ifdef __SD_INTERFACE_INVERTED

        PORTW_SPI |= (1<<PORT_CS);                                      // enable chipselect of the sdcard (active low).

        #else

        PORTW_SPI &= ~(1<<PORT_CS);                                     // enable chipselect of the sdcard (active low).

        #endif

}