#include "battery_adc.h"
#include <zephyr/drivers/adc.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/sys/printk.h>

#define USER_NODE DT_PATH(zephyr_user)
static const struct gpio_dt_spec btt_meas_en = GPIO_DT_SPEC_GET(USER_NODE, btt_meas_en_gpios);
static const struct adc_dt_spec adc_channel = ADC_DT_SPEC_GET(USER_NODE);

static uint32_t sample_buffer;

struct adc_sequence sequence = {
    .buffer = &sample_buffer,
    .buffer_size = sizeof(sample_buffer),
    //.calibrate = true
};

int battery_adc_init(void) {
    if (!adc_is_ready_dt(&adc_channel)) {
        printk("ADC not ready\n");
        return -ENODEV;
    }
    gpio_pin_configure_dt(&btt_meas_en, GPIO_OUTPUT_INACTIVE);
    int ret = 0;
    ret = adc_channel_setup_dt(&adc_channel);
    if(ret){
        return ret;
    }
    ret = adc_sequence_init_dt(&adc_channel, &sequence);
    if(ret){
        return ret;
    }
    return 0;
}

int battery_measure_mv(int32_t *mv_out) {
    int ret = 0;
    gpio_pin_set_dt(&btt_meas_en, 1);  // enable measurement
    k_sleep(K_MSEC(5));


    ret = adc_read(adc_channel.dev, &sequence);
    if (ret) return ret;

    ret = adc_raw_to_millivolts_dt(&adc_channel, &sample_buffer);
    *mv_out = (int)((float)sample_buffer*((270.0f+110.0f)/110.0f));

    gpio_pin_set_dt(&btt_meas_en, 0);  // disable measurement

    return ret;
}