/** @file power.c
 *  @brief Power management implementation.
 */
#include "power.h"
#include "regs.h"
#include <nrf52840.h>
#include <cmsis_gcc.h>

/* P0.02 on XIAO BLE  -  adjust to match your schematic */
#define BUTTON_PIN 2u

void power_init(void)
{
    /* DC/DC converter has lower quiescent current than the LDO */
    NRF_POWER->DCDCEN = 1u;

    NRF_GPIOTE->CONFIG[0] = (gpiote_config_t){
        .bit = {
            .MODE = GPIOTE_MODE_EVENT,
            .PSEL = BUTTON_PIN,
            .PORT = 0u,
            .POLARITY = GPIOTE_POL_LOTOHI,
        }}.reg;

    NRF_GPIOTE->INTENSET = (gpiote_inten_t){.bit.IN0 = 1u}.reg;

    NVIC_EnableIRQ(GPIOTE_IRQn);
}

void power_sleep_until_button(void)
{
    NRF_POWER->TASKS_LOWPWR = 1u;
    __WFI();
}

void GPIOTE_IRQHandler(void)
{
    NRF_GPIOTE->EVENTS_IN[0] = 0u;
}