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#include "maindefs.h"

#include "spi.h"

static SPI_DATA spi_data;

void SPI2_Init(unsigned char speed) {

    // Set up SPI2 with specified pins

    RPINR22 = 7; // SPI2 CLK Input  (Pin RB4)

    RPOR7 = 11; // SPI2 CLK Output (Pin RB4)

#ifndef SPI2_WRITE_ONLY

    RPINR21 = 6; // SPI2 Data Input (Pin RB3)

#endif

    RPOR5 = 10; // SPI2 Data Output   (MOSI) (Pin RB2)

    TRISBbits.TRISB4 = 0; // SPI2 clock pin       (Pin RB4)

#ifndef SPI2_WRITE_ONLY

    TRISBbits.TRISB3 = 1; // SPI2 data in pin     (Pin RB3)(MISO)

#endif

    TRISBbits.TRISB2 = 0; // SPI2 data out pin    (Pin RB2)(MOSI)

    TRISBbits.TRISB7 = 0; // SPI2 slave select    (Pin RB7)

    LATBbits.LATB7 = 1; // SPI2 SS high (Idle)

    TRISBbits.TRISB6 = 0; // SPI2 reset   (Pin RB6)

    LATBbits.LATB6 = 1; // SPI2 reset active low

    TRISBbits.TRISB5 = 0; // SPI2 D/C select (Pin RB5)

    LATBbits.LATB5 = 0;

    SSP2STATbits.SMP = 0; // Input is sampled in the middle of data output time

    SSP2STATbits.CKE = 0; // Transmit occurs on transition from Idle to active clock state

    if (speed == SPI2_FOSC_4)

        SSP2CON1bits.SSPM = 0b0000; // Clock = FOSC/4

    else if (speed == SPI2_FOSC_8)

        SSP2CON1bits.SSPM = 0b1010; // Clock = FOSC/8

    else if (speed == SPI2_FOSC_16)

        SSP2CON1bits.SSPM = 0b0001; // Clock = FOSC/16

    else

        SSP2CON1bits.SSPM = 0b0010; // Clock = FOSC/64

    SSP2CON1bits.CKP = 1; // Idle state for clock is a high level

    SSP2CON1bits.SSPEN = 1; // Enable MSSP module

#ifdef SPI2_USE_INTERRUPT

    PIE3bits.SSP2IE = 1; // Enable MSSP2 interrupt

#else

    PIE3bits.SSP2IE = 0;

#endif

    spi_data.buffer_in_len = 0;

    spi_data.buffer_in_read_ind = 0;

    spi_data.buffer_in_write_ind = 0;

    spi_data.buffer_out_ind = 0;

    spi_data.buffer_out_len = 0;

}

void SPI2_Recv_Interrupt_Handler() {

    unsigned char c;

    if (SSP2STATbits.BF) { // Check if data receive flag is set

        if (spi_data.buffer_in_len == MAXSPIBUF - 1) {

            DBG_PRINT_SPI("SPI2: buffer overflow\r\n");

            c = SSP2BUF; // Read SSP2BUF to clear it

        } else {

            // Save received data into buffer

            spi_data.buffer_in[spi_data.buffer_in_write_ind] = SSP2BUF;

            if (spi_data.buffer_in_write_ind == MAXSPIBUF - 1) {

                spi_data.buffer_in_write_ind = 0;

            } else {

                spi_data.buffer_in_write_ind++;

            }

            spi_data.buffer_in_len++;

            // Put next byte in SSP2BUF for transmit

            if (spi_data.buffer_out_ind != spi_data.buffer_out_len) {

                SSP2BUF = spi_data.buffer_out[spi_data.buffer_out_ind];

                spi_data.buffer_out_ind++;

            } else {

                LATBbits.LATB2 = 1; // Bring SS line high

                spi_data.buffer_out_ind = 0;

                spi_data.buffer_out_len = 0;

            }

        }

    }

}

void SPI2_Write(unsigned char *msg, unsigned int length) {

#ifdef SPI2_USE_INTERRUPT

    unsigned char i;

    spi_data.buffer_out_len = length;

    spi_data.buffer_out_ind = 1;

    for (i = 0; i < length; i++) {

        spi_data.buffer_out[i] = msg[i];

    }

    LATBbits.LATB7 = 0; // Bring SS line low

    SSP2BUF = spi_data.buffer_out[0]; // Transmit first byte

#else

    unsigned int i = 0;

    unsigned char tmp = 0;

    LATBbits.LATB7 = 0;

    while (i != length) {

        SSP2BUF = msg[i];

        i++;

        while (!SSP2STATbits.BF);

#ifndef SPI2_WRITE_ONLY

        spi_data.buffer_in[spi_data.buffer_in_write_ind] = SSP2BUF;

        if (spi_data.buffer_in_write_ind == MAXSPIBUF - 1) {

            spi_data.buffer_in_write_ind = 0;

        } else {

            spi_data.buffer_in_write_ind++;

        }

        spi_data.buffer_in_len++;

#else

        // Read data in buffer to clear it

        tmp = SSP2BUF;

#endif

    }

    LATBbits.LATB7 = 1;

#endif

}

void SPI2_Write_Repeat(unsigned char c, unsigned int length) {

#ifdef SPI2_USE_INTERRUPT

    // TODO

#else

    unsigned int i = 0;

    unsigned char tmp = 0;

    LATBbits.LATB7 = 0;

    while (i != length) {

        SSP2BUF = c;

        i++;

        while (!SSP2STATbits.BF);

#ifndef SPI2_WRITE_ONLY

        spi_data.buffer_in[spi_data.buffer_in_write_ind] = SSP2BUF;

        if (spi_data.buffer_in_write_ind == MAXSPIBUF - 1) {

            spi_data.buffer_in_write_ind = 0;

        } else {

            spi_data.buffer_in_write_ind++;

        }

        spi_data.buffer_in_len++;

#else

        // Read data in buffer to clear it

        tmp = SSP2BUF;

#endif

    }

    LATBbits.LATB7 = 1;

#endif

}

void SPI2_Read(unsigned char length) {

#ifdef SPI2_USE_INTERRUPT

    unsigned char i;

    spi_data.buffer_out_len = length;

    spi_data.buffer_out_ind = 1;

    for (i = 0; i < length; i++) {

        spi_data.buffer_out[i] = 0x0;

    }

    LATBbits.LATB7 = 0; // Bring SS line low

    SSP2BUF = spi_data.buffer_out[0]; // Transmit first byte

#else

    unsigned char i = 0;

    LATBbits.LATB7 = 0;

    for (i = 0; i < length; i++) {

        SSP2BUF = 0x0;

        while (!SSP2STATbits.BF);

        spi_data.buffer_in[spi_data.buffer_in_write_ind] = SSP2BUF;

        if (spi_data.buffer_in_write_ind == MAXSPIBUF - 1) {

            spi_data.buffer_in_write_ind = 0;

        } else {

            spi_data.buffer_in_write_ind++;

        }

        spi_data.buffer_in_len++;

    }

    LATBbits.LATB7 = 1;

#endif

}

unsigned char SPI2_Buffer_Len() {

    return spi_data.buffer_in_len;

}

unsigned char SPI2_Buffer_Read(unsigned char* buffer) {

    unsigned char i = 0;

    while (spi_data.buffer_in_len != 0) {

        buffer[i] = spi_data.buffer_in[spi_data.buffer_in_read_ind];

        i++;

        if (spi_data.buffer_in_read_ind == MAXSPIBUF - 1) {

            spi_data.buffer_in_read_ind = 0;

        } else {

            spi_data.buffer_in_read_ind++;

        }

        spi_data.buffer_in_len--;

    }

    return i;

}