/*
 * Copyright 2020 Koen Zandberg
 *           2023 Gunar Schorcht
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

/**
 * @ingroup     cpu_gd32v
 * @{
 *
 * @brief       Implementation of the CPU power management for Gigadevice GD32V
 *
 * @author      Koen Zandberg <koen@bergzand.net>
 * @author      Gunar Schorcht <gunar@schorcht.net>
 * @}
 */

#include <stdint.h>
#include <stdio.h>
#include "periph/pm.h"
#include "periph/wdt.h"

#undef MCAUSE_CAUSE /* redefined in NMSIS header */

#include "core_feature_base.h"

void pm_set(unsigned mode)
{
    bool csr_deepsleep = false; /* RISC-V sleep mode */

    switch (mode) {
        case GD32V_PM_STANDBY:
            csr_deepsleep = true;
            /* set the STANDBY mode flag */
            PMU->CTL |= PMU_CTL_WURST_Msk;
            /* reset the wake up flag */
            PMU->CTL |= PMU_CTL_STBMOD_Msk;
            break;
        case GD32V_PM_DEEPSLEEP:
            csr_deepsleep = true;
            /* reset the STANDBY mode flag */
            PMU->CTL &= ~PMU_CTL_STBMOD_Msk;
            /* use LDO low powered in deep sleep mode */
            PMU->CTL |= PMU_CTL_LDOLP_Msk;
            break;
        case GD32V_PM_IDLE:
            csr_deepsleep = false;
            break;
        default:
            break;
    }

    if (csr_deepsleep) {
        /* Enable WKUP pin if used */
        PMU->CS &= ~PMU_CS_WUPEN_Msk;
        PMU->CS |= (CONFIG_PM_EWUP_USED) ? PMU_CS_WUPEN_Msk : 0;
        /* set CSR_SLEEPVALUE bit in RISC-V system control register */
        __set_wfi_sleepmode(WFI_DEEP_SLEEP);
    }
    else {
        /* clear CSR_SLEEPVALUE bit in RISC-V system control register */
        __set_wfi_sleepmode(WFI_SHALLOW_SLEEP);
    }

    /* trigger sleeping, TODO wait for wake up event (__WFE) implementation */
    __WFI();

    if (csr_deepsleep) {
        /* clear CSR_SLEEPVALUE bit in RISC-V system control register */
        __set_wfi_sleepmode(WFI_SHALLOW_SLEEP);
        /* after deep sleep, the IRC8M is used as clock so that a clock
         * reinitialization is required */
        gd32vf103_clock_init();
    }
}

void pm_reboot(void)
{
    wdt_setup_reboot(0, 1);
    wdt_start();
    wdt_kick();
    while (1) {}
}