#include "Spi.h"
#include "deca_device_api.h"

void Spi_Init(void)
{
	SPI_InitTypeDef SPI_InitStructure;
    GPIO_InitTypeDef GPIO_InitStructure;
	
	/* Enable GPIO clock */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
	/* Enable SPI clock */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
	
	/* SPI GPIO setup */
	// SPIx SCK, MISO and MOSI pin setup
    GPIO_InitStructure.GPIO_Pin = SPIx_SCK | SPIx_MOSI | SPIx_MISO;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(SPIx_GPIO, &GPIO_InitStructure);

    // SPIx CS pin setup
    GPIO_InitStructure.GPIO_Pin = SPIx_CS;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(SPIx_CS_GPIO, &GPIO_InitStructure);
	
	// Set CS high
    GPIO_SetBits(SPIx_CS_GPIO, SPIx_CS);

    SPI_I2S_DeInit(SPIx);

    // SPIx Mode setup
    SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
    SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
    SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
    SPI_InitStructure.SPI_CPOL = SPIx_CPOL;	 
    SPI_InitStructure.SPI_CPHA = SPIx_CPHA;
    SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
    SPI_InitStructure.SPI_BaudRatePrescaler = SPIx_PRESCALER_SLOW;
    SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
    SPI_InitStructure.SPI_CRCPolynomial = 7;

    SPI_Init(SPIx, &SPI_InitStructure);

    // Disable SPIx SS Output
    SPI_SSOutputCmd(SPIx, DISABLE);

    // Enable SPIx
    SPI_Cmd(SPIx, ENABLE);
}


void Spi_ChangePrescaler(uint16_t scaling_factor)
{
    uint16_t tmpreg = 0;

    /* Get the SPIx CR1 value */
    tmpreg = SPIx->CR1;

    /*clear the scaling bits*/
    tmpreg &= 0xFFC7;

    /*set the scaling bits*/
    tmpreg |= scaling_factor;

    /* Write to SPIx CR1 */
    SPIx->CR1 = tmpreg;
}

/*! ------------------------------------------------------------------------------------------------------------------
 * Function: writetospi()
 *
 * Low level abstract function to write to the SPI
 * Takes two separate byte buffers for write header and write data
 * returns 0 for success, or -1 for error
 */
int writetospi
(
    uint16_t       headerLength,
    const uint8_t *headerBuffer,
    uint32_t       bodylength,
    const uint8_t *bodyBuffer
)
{

    int i = 0;

    decaIrqStatus_t  stat ;

    stat = decamutexon() ;

    SPIx_CS_GPIO->BRR = SPIx_CS;

    for(i = 0; i < headerLength; i++)
    {
        SPIx->DR = headerBuffer[i];

        while ((SPIx->SR & SPI_I2S_FLAG_RXNE) == (uint16_t)RESET);

        SPIx->DR ;
    }

    for(i = 0; i < bodylength; i++)
    {
        SPIx->DR = bodyBuffer[i];

        while((SPIx->SR & SPI_I2S_FLAG_RXNE) == (uint16_t)RESET);

        SPIx->DR ;
    }

    SPIx_CS_GPIO->BSRR = SPIx_CS;

    decamutexoff(stat) ;

    return 0;
} // end writetospi()


/*! ------------------------------------------------------------------------------------------------------------------
 * Function: readfromspi()
 *
 * Low level abstract function to read from the SPI
 * Takes two separate byte buffers for write header and read data
 * returns the offset into read buffer where first byte of read data may be found,
 * or returns -1 if there was an error
 */
int readfromspi
(
    uint16_t       headerLength,
    const uint8_t *headerBuffer,
    uint32_t       readlength,
    uint8_t       *readBuffer
)
{

    int i = 0;

    decaIrqStatus_t  stat ;

    stat = decamutexon() ;

    /* Wait for SPIx Tx buffer empty */
    //while (port_SPIx_busy_sending());

    SPIx_CS_GPIO->BRR = SPIx_CS;

    for(i = 0; i < headerLength; i++)
    {
        SPIx->DR = headerBuffer[i];

        while((SPIx->SR & SPI_I2S_FLAG_RXNE) == (uint16_t)RESET);

        readBuffer[0] = SPIx->DR ; // Dummy read as we write the header
    }

    for(i = 0; i < readlength; i++)
    {
        SPIx->DR = 0;  // Dummy write as we read the message body

        while((SPIx->SR & SPI_I2S_FLAG_RXNE) == (uint16_t)RESET);

        readBuffer[i] = SPIx->DR ;//port_SPIx_receive_data(); //this clears RXNE bit
    }

    SPIx_CS_GPIO->BSRR = SPIx_CS;

    decamutexoff(stat) ;

    return 0;
} // end readfromspi()