// This wants to be a "generic" library for ad9833, ad9850 and ad9851.
// currently, only ad9851 is supported
#include <stdint.h>
#include <libopencm3/stm32/gpio.h>
#include "lib/ad98xx.h"
#include "lib/gpio_utils.h"


/* ad98_init will initialize pins, not the whole port.
 * That is, you'll need to
 * rcc_periph_clock_enable(RCC_${dds.gpioport})
 * */
void ad98_init(ad98_dds dds) {
	gpio_set_mode(dds.gpioport, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL,
            dds.reset | dds.clock | dds.load | dds.data);
    gpio_pulseHigh(dds.gpioport, dds.reset);
    gpio_pulseHigh(dds.gpioport, dds.clock);
    gpio_pulseHigh(dds.gpioport, dds.load);
}

static void _send_byte(ad98_dds dds, unsigned char byte) {
    for(int i=0; i<8; i++) { // every bit
        char bit = ((byte >> i) & 1);
        if(bit) {
            gpio_set(dds.gpioport, dds.data);
        } else {
            gpio_clear(dds.gpioport, dds.data);
        }
        gpio_pulseHigh(dds.gpioport, dds.clock);
    }
}

const float tunings[AD98_MODELS_NUM] = {AD98_AD9833_TUNING,
    AD98_AD9850_TUNING,
    AD98_AD9851_TUNING};

void ad98_set_frequency(ad98_dds dds, double frequency) {  // requires dds_init to be called before it
    // support AD98_MODEL_AD9850
    uint32_t freqWord;
    freqWord = frequency * tunings[dds.model];
    for(char i=0; i<4; i++) {
       _send_byte(dds, freqWord & 0xFF);
       freqWord >>= 8;
    }
    _send_byte(dds, 0x01);
    gpio_pulseHigh(dds.gpioport, dds.load);
}