#include "dds.h"
#include "io.h"

static void sendCommand(dds_t *dds, uint16_t reg, uint8_t *data, uint16_t len)
{
    uint8_t tmp[2];
    tmp[0] = (uint8_t)(reg >> 8); // Reset bit held
    tmp[1] = (uint8_t)(reg & 0x00ff);

    SPI0_SendBytes(tmp, 2, dds->mode);

    if (data != NULL)
    {
        SPI0_SendBytes(data, len, dds->mode);
    }
}

static uint32_t calculateDDSValue(uint32_t frequency)  // Calculate frequency word for DDS
{
    // FREG = (Frequency * 2^28)/fclk = 12MHz normally
	return (uint32_t)((frequency * 268435456.0) / DDS_CLK + 0.5);

}

void dds_setFrequency(dds_t *dds, uint32_t frequency)
{
    uint16_t freq_hi = FREQ0_REG;
    uint16_t freq_lo = FREQ0_REG;

    dds->frequency = frequency;

    uint8_t data[4];

    // set signal DDS
	if (frequency > 0)
    {
        uint32_t freqValue = calculateDDSValue(dds->frequency);

        freq_hi = FREQ0_REG;
        freq_lo = FREQ0_REG;

        freq_lo |= (freqValue & 0x3fff);
        freqValue >>= 14;
        freq_hi |= (freqValue & 0x3fff);

        data[0] = (uint8_t)(freq_lo >> 8);		//LS 16-bit word, MSB
        data[1] = (uint8_t)(freq_lo & 0x00ff);	//LS 16-bit word, LSB
        data[2] = (uint8_t)(freq_hi >> 8);
        data[3] = (uint8_t)(freq_hi & 0x00ff);

        // send Control word to hold setup
        sendCommand(dds, FRQ_CTRL_WORD1, data, sizeof(data));

        // send Control word to release setup
        sendCommand(dds, FRQ_CTRL_WORD2, NULL, 0);

    }
    else
    {
        dds_sleep(dds, true, false);
    }

}

void dds_init(dds_t *dds, SPI_MODE_t mode, gpio_pin_t resetPin)
{
    dds->mode = mode;
    dds->resetPin = resetPin;

    dds_reset(dds, true);
}

void dds_reset(dds_t *dds, bool reset)
{
    GPIO_PinWrite(GPIO, dds->resetPin.port, dds->resetPin.pin, (reset ? 1 : 0) );
}

void dds_sleep(dds_t *dds, bool sleep, bool disableDAC)
{
    if (sleep)
    {
        if (disableDAC)
        {
            sendCommand(dds, SLP_CTRL_WRD2, NULL, 0);
        }
        else
        {
            sendCommand(dds, SLP_CTRL_WRD, NULL, 0);
        }
    }
}