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#include <xc.h>

#include <stdio.h>

#include <string.h>

#include "defines.h"

#include "spi.h"

#include "uart.h"

static SPI_DATA *spi_data_p;

void SPI2_Init(SPI_DATA *data, char speed) {

    spi_data_p = data;

    // Set up SPI2 with specified pins

    RPINR22 = PPS_SPI2_CLK_IN; // SPI2 CLK Input

    PPS_SPI2_CLK_OUT = 11; // SPI2 CLK Output

#ifndef SPI2_WRITE_ONLY

    RPINR21 = PPS_SPI2_MISO; // SPI2 Data Input

    SPI_MISO_TRIS = 1; // SPI2 data in pin (MISO)

#endif

    SPI_CLK_TRIS = 0; // SPI2 clock pin

    PPS_SPI2_MOSI = 10; // SPI2 Data Output (MOSI)

    SPI_MOSI_TRIS = 0; // SPI2 data out pin (MOSI)

    SPI_SLAVE_SELECT_TRIS = 0; // SPI2 slave select

    SPI_SLAVE_SELECT_LAT = 1; // SPI2 SS high (Idle)

    SPI_RESET_TRIS = 0; // SPI2 reset

    SPI_RESET_LAT = 1; // SPI2 reset active low

    SPI_DC_SELECT_TRIS = 0; // SPI2 D/C select

    SPI_DC_SELECT_LAT = 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

    SSP2CON1bits.SSPM = speed;

    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

#ifndef SPI2_WRITE_ONLY

    spi_data_p->buffer_in_len = 0;

    spi_data_p->buffer_in_read_ind = 0;

    spi_data_p->buffer_in_write_ind = 0;

#endif

    spi_data_p->buffer_out_ind = 0;

    spi_data_p->buffer_out_len = 0;

}

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

    unsigned int i = 0;

#ifdef SPI2_USE_INTERRUPT

    spi_data_p->buffer_out_len = length;

    spi_data_p->buffer_out_ind = 1;

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

        spi_data_p->buffer_out[i] = msg[i];

    }

    SPI_SLAVE_SELECT_LAT = 0; // Bring SS line low

    SSP2BUF = spi_data_p->buffer_out[0]; // Transmit first byte

#else

    SPI_SLAVE_SELECT_LAT = 0;

    while (i != length) {

        SSP2BUF = msg[i];

        i++;

        while (!SSP2STATbits.BF);

#ifndef SPI2_WRITE_ONLY

        spi_data_p->buffer_in[spi_data_p->buffer_in_write_ind] = SSP2BUF;

        if (spi_data_p->buffer_in_write_ind == MAXSPIBUF - 1) {

            spi_data_p->buffer_in_write_ind = 0;

        } else {

            spi_data_p->buffer_in_write_ind++;

        }

        spi_data_p->buffer_in_len++;

#else

        // Read data in buffer to clear it

        char tmp = SSP2BUF;

#endif

    }

    SPI_SLAVE_SELECT_LAT = 1;

#endif

}

void SPI2_Write_Repeat(char c, unsigned int length) {

#ifdef SPI2_USE_INTERRUPT

    // TODO Implement interrupts for SPI2

#else

    unsigned int i = 0;

    SPI_SLAVE_SELECT_LAT = 0;

    while (i != length) {

        SSP2BUF = c;

        i++;

        while (!SSP2STATbits.BF);

#ifndef SPI2_WRITE_ONLY

        spi_data_p->buffer_in[spi_data_p->buffer_in_write_ind] = SSP2BUF;

        if (spi_data_p->buffer_in_write_ind == MAXSPIBUF - 1) {

            spi_data_p->buffer_in_write_ind = 0;

        } else {

            spi_data_p->buffer_in_write_ind++;

        }

        spi_data_p->buffer_in_len++;

#else

        // Read data in buffer to clear it

        char tmp = SSP2BUF;

#endif

    }

    SPI_SLAVE_SELECT_LAT = 1;

#endif

}

#ifndef SPI2_WRITE_ONLY

void SPI2_Recv_Interrupt_Handler() {

    char c;

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

        if (spi_data_p->buffer_in_len == MAXSPIBUF - 1) {

            char output[64];

            sprintf(output, "SPI2: (ERROR) buffer overflow\r\n");

            DBG_PRINT_SPI(output, strlen(output));

            c = SSP2BUF; // Read SSP2BUF to clear it

        } else {

            // Save received data into buffer

            spi_data_p->buffer_in[spi_data_p->buffer_in_write_ind] = SSP2BUF;

            if (spi_data_p->buffer_in_write_ind == MAXSPIBUF - 1) {

                spi_data_p->buffer_in_write_ind = 0;

            } else {

                spi_data_p->buffer_in_write_ind++;

            }

            spi_data_p->buffer_in_len++;

            // Put next byte in SSP2BUF for transmit

            if (spi_data_p->buffer_out_ind != spi_data_p->buffer_out_len) {

                SSP2BUF = spi_data_p->buffer_out[spi_data_p->buffer_out_ind];

                spi_data_p->buffer_out_ind++;

            } else {

                SPI_SLAVE_SELECT_LAT = 1; // Bring SS line high

                spi_data_p->buffer_out_ind = 0;

                spi_data_p->buffer_out_len = 0;

            }

        }

    }

}

void SPI2_Read(char length) {

#ifdef SPI2_USE_INTERRUPT

    spi_data_p->buffer_out_len = length;

    spi_data_p->buffer_out_ind = 1;

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

        spi_data_p->buffer_out[i] = 0x0;

    }

    SPI_SLAVE_SELECT_LAT = 0; // Bring SS line low

    SSP2BUF = spi_data_p->buffer_out[0]; // Transmit first byte

#else

    SPI_SLAVE_SELECT_LAT = 0;

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

        SSP2BUF = 0x0;

        while (!SSP2STATbits.BF);

        spi_data_p->buffer_in[spi_data_p->buffer_in_write_ind] = SSP2BUF;

        if (spi_data_p->buffer_in_write_ind == MAXSPIBUF - 1) {

            spi_data_p->buffer_in_write_ind = 0;

        } else {

            spi_data_p->buffer_in_write_ind++;

        }

        spi_data_p->buffer_in_len++;

    }

    SPI_SLAVE_SELECT_LAT = 1;

#endif

}

char SPI2_Buffer_Len() {

    return spi_data_p->buffer_in_len;

}

char SPI2_Read_Buffer(char* buffer) {

    char i = 0;

    while (spi_data_p->buffer_in_len != 0) {

        buffer[i] = spi_data_p->buffer_in[spi_data_p->buffer_in_read_ind];

        i++;

        if (spi_data_p->buffer_in_read_ind == MAXSPIBUF - 1) {

            spi_data_p->buffer_in_read_ind = 0;

        } else {

            spi_data_p->buffer_in_read_ind++;

        }

        spi_data_p->buffer_in_len--;

    }

    return i;

}

#endif