svc_spi.c

AT91SAM7S64 SPI Slave mode with PDC sample code from Konrad.Wei

/************************************************************************************
* File : svc_spi.c		 															*
* Programmer: Konrad Wei (Taiwan)													*
* November 2006															 			*
*************************************************************************************

	- 2006 November. Add Slave Mode

*************************************************************************************/

#include "svc_spi.h"

/*
*********************************************************************************************************
*                                            Defintion
*********************************************************************************************************
*/
#define SPI_INTERRUPT_LEVEL		1

/*
*********************************************************************************************************
*                                            Global Variable
*********************************************************************************************************
*/
/* AT91SAN7S64 Component Offset */
AT91PS_SPI s_pSpi = AT91C_BASE_SPI;
AT91PS_PIO s_pPio = AT91C_BASE_PIOA;
AT91PS_PMC s_pPMC = AT91C_BASE_PMC;
AT91PS_PDC s_pPDC = AT91C_BASE_PDC_SPI;

static char buff_spi_rx0[100];		///< SPI RX Buffer 1
static char buff_spi_rx1[100];		///< SPI RX Buffer 2
static U8 gbSpiRxBufIndex =0;		///< Ping-Pong Buffer Index

/*
*********************************************************************************************************
*                                            Local Function Prototype
*********************************************************************************************************
*/

void spi_c_interrupt_handler(void);

/*
*********************************************************************************************************
*                                            Interrupt ISR
*********************************************************************************************************
*/

/**
	\breif spi_interrupt_handler SPI interrupt handler.
	\date 2006.11.20
*/
void spi_c_interrupt_handler(void)
{  	
	unsigned int status;
	
	status = s_pSpi->SPI_SR;
	
	if ( status & AT91C_SPI_RXBUFF ) {			
	
		if (gbSpiRxBufIndex == 0) {		
			s_pSpi->SPI_RPR = (unsigned int) buff_spi_rx1;
			s_pSpi->SPI_RCR = 100;
			gbSpiRxBufIndex = 1;		
			
			//* TODO: Do some procedure for processing data.
			
		} else{
			s_pSpi->SPI_RPR = (unsigned int) buff_spi_rx0;
			s_pSpi->SPI_RCR = 100;			
			gbSpiRxBufIndex = 0;		
			
			//* TODO: Do some procedure for processing data.
		}
	}
	
	if( status & AT91C_SPI_NSSR ) {
	
	  	//* TODO: Do some procedure for processing data.
	}	
}

/*
*********************************************************************************************************
*                                            FUNCTION
*********************************************************************************************************
*/


// setup usart1 in spi mode
/**
  \brief svc_spi_init Initiate SPI
  \param[in] bMaster 0:Slave >1:Master
  \param[in] bBaudRate SPI Baud Rate
  \param[in] bClkMode ClockPhase & Polarity
  \return ERROR CODE
*/
void spi_init (void)
{
	//set functionalite to pins:
	//port0.11 -> NPCS0
	//port0.12 -> MISO
	//port0.13 -> MOSI
	//port0.14 -> SPCK
	s_pPio->PIO_PDR = SPI_CS0 | SPI_MISO | SPI_MOSI | SPI_SPCK;
	s_pPio->PIO_ASR = SPI_CS0 | SPI_MISO | SPI_MOSI | SPI_SPCK;
	s_pPio->PIO_BSR = 0;

	//s_pPMC->PMC_PCER = AT91C_ID_SPI;        //enable the clock of SPI
	s_pPMC->PMC_PCER = 1 << AT91C_ID_SPI;

	/****  Fixed mode ****/
	s_pSpi->SPI_CR      = 0x81;              //SPI Enable, Sowtware reset
	s_pSpi->SPI_CR      = 0x01;              //SPI Enable

#ifdef SPI_MASTER	
	s_pSpi->SPI_MR      = 0xE0011;          //Master mode, fixed select, disable decoder, FDIV=0 (MCK), PCS=1110
#else
	s_pSpi->SPI_MR      = 0xE0010;          //Slave mode, fixed select, disable decoder, FDIV=0 (MCK), PCS=1110
#endif 	
	
	s_pSpi->SPI_CSR[0]  = 0x4A02;           //8bit, CPOL=0, ClockPhase=1, SCLK = 200kHz

	//* PDC DMA enable
	s_pPDC->PDC_PTCR = AT91C_PDC_TXTEN | AT91C_PDC_RXTEN;
	s_pSpi->SPI_PTCR = AT91C_PDC_TXTEN | AT91C_PDC_RXTEN;

    /* Konrad Test 2006.10.11 */
    s_pSpi->SPI_CSR[0] |= AT91C_SPI_CSAAT;

	/* AIC Setting */
    //* open SPI Interrupt
    AT91F_AIC_ConfigureIt (AT91C_BASE_AIC, AT91C_ID_SPI, SPI_INTERRUPT_LEVEL,
                           AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL, spi_c_interrupt_handler);		
	AT91F_AIC_EnableIt (AT91C_BASE_AIC, AT91C_ID_SPI);
	
	//* Set the PDC
	AT91F_PDC_Open(AT91C_BASE_PDC_SPI);
	s_pSpi->SPI_RPR = (unsigned int) buff_spi_rx0;
	s_pSpi->SPI_RCR = 100;							///< DMA Buffer length setting
	gbSpiRxBufIndex = 0;							///< Buf Ping-Pong Index
	
	AT91F_SPI_EnableIt(s_pSpi, AT91C_SPI_RXBUFF|AT91C_SPI_NSSR);
}

/**
  \brief svc_spi_SendByte Send Byte and Read Byte is same function. SPI's Specific
  \param[in] data byte data
  \return Get the Receive Data
*/
__ramfunc U8 svc_spi_SendByte(const U8 sendData)
{
  	int i=0;
	unsigned int spib;

	while((s_pSpi->SPI_SR & AT91C_SPI_TDRE) == 0);      // Wait for the transfer to complete
	  s_pSpi->SPI_TDR = (sendData & 0xFFFF);                  // Send the data

	while((s_pSpi->SPI_SR & AT91C_SPI_RDRF) == 0);      // Wait until the character can be sent
	  spib = ((s_pSpi->SPI_RDR) & 0xFFFF);                // Get the data received

     return (U8)spib;
}