/**************************************************************************//**
 * @file     main.c
 * @version  V3.00
 * @brief    Demonstrate how to minimize power consumption when entering power down mode.
 *
 * @copyright SPDX-License-Identifier: Apache-2.0
 * @copyright Copyright (C) 2014 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "M0519.h"


#define PLLCON_SETTING  CLK_PLLCON_72MHz_HXT
#define PLL_CLOCK       72000000


/*
//-------- <<< Use Configuration Wizard in Context Menu >>> -----------------
*/

/*
// <o0> LVR
//      <0=> Disable
//      <1=> Enable
*/
#define SET_LVR       1

/*
// <o0> POR
//      <0=> Disable
//      <1=> Enable
*/
#define SET_POR       0

/*
// <o0> LIRC
//      <0=> Disable
//      <1=> Enable
*/
#define SET_LIRC      0

/*
// <o0> LXT
//      <0=> Disable
//      <1=> Enable
*/
#define SET_LXT       0


void PowerDownFunction(void);
void GPG0_IRQHandler(void);
void LvrSetting(void);
void PorSetting(void);
int32_t LircSetting(void);
void SYS_Init(void);
void UART0_Init(void);

/*---------------------------------------------------------------------------------------------------------*/
/*  Function for System Entry to Power Down Mode                                                           */
/*---------------------------------------------------------------------------------------------------------*/
void PowerDownFunction(void)
{
    uint32_t u32TimeOutCnt;

    /* Check if all the debug messages are finished */
    u32TimeOutCnt = SystemCoreClock; /* 1 second time-out */
    UART_WAIT_TX_EMPTY(DEBUG_PORT)
    if(--u32TimeOutCnt == 0) break;

    /* Set the processor uses deep sleep as its low power mode */
    SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk;

    /* Chip enter Power-down mode after CPU run WFI instruction */
    __WFI();

}

/**
 * @brief       GPIO group 0 (P0/P1/P2/P3/P4) IRQ
 *
 * @param       None
 *
 * @return      None
 *
 * @details     The GPIO group 0 (P0/P1/P2/P3/P4) default IRQ, declared in startup_M0519.s.
 */
void GPG0_IRQHandler(void)
{
    /* To check if P1.3 interrupt occurred */
    if(GPIO_GET_INT_FLAG(P1, BIT3))
    {
        GPIO_CLR_INT_FLAG(P1, BIT3);
        printf("P1.3 INT occurred.\n");
    }
    else
    {
        /* Un-expected interrupt. Just clear all P0, P1, P2, P3 and P4 interrupts */
        P0->ISF = P0->ISF;
        P1->ISF = P1->ISF;
        P2->ISF = P2->ISF;
        P3->ISF = P3->ISF;
        P4->ISF = P4->ISF;
        printf("Un-expected interrupts.\n");
    }
}


void LvrSetting(void)
{
    if(SET_LVR == 0)
    {
        /* Disable LVR */
        SYS_DISABLE_LVR();
        CLK_SysTickDelay(200);
    }
    else
    {
        /* Enable LVR */
        SYS_ENABLE_LVR();
        CLK_SysTickDelay(200);
    }
}

void PorSetting(void)
{
    if(SET_POR == 0)
    {
        /* Disable POR */
        SYS_DISABLE_POR();
    }
    else
    {
        /* Enable POR */
        SYS_ENABLE_POR();
    }
}

int32_t LircSetting(void)
{
    uint32_t u32TimeOutCnt;

    if(SET_LIRC == 0)
    {
        /* Disable LIRC and wait for LIRC stable flag is cleared */
        CLK->PWRCON &= ~CLK_PWRCON_OSC10K_EN_Msk;
        u32TimeOutCnt = SystemCoreClock; /* 1 second time-out */
        while(CLK->CLKSTATUS & CLK_CLKSTATUS_IRC10K_STB_Msk)
        {
            if(--u32TimeOutCnt == 0)
            {
                printf("Wait for LIRC disable time-out!\n");
                return -1;
            }
        }
    }
    else
    {
        /* Enable LIRC and wait for LIRC stable flag is set */
        CLK->PWRCON |= CLK_PWRCON_OSC10K_EN_Msk;
        u32TimeOutCnt = SystemCoreClock; /* 1 second time-out */
        while((CLK->CLKSTATUS & CLK_CLKSTATUS_IRC10K_STB_Msk) == 0)
        {
            if(--u32TimeOutCnt == 0)
            {
                printf("Wait for LIRC enable time-out!\n");
                return -1;
            }
        }
    }

    return 0;
}

void SYS_Init(void)
{
    uint32_t u32TimeOutCnt;

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init System Clock                                                                                       */
    /*---------------------------------------------------------------------------------------------------------*/

    /* Enable Internal RC 22.1184MHz clock */
    CLK->PWRCON |= CLK_PWRCON_OSC22M_EN_Msk;

    /* Waiting for Internal RC clock ready */
    u32TimeOutCnt = __HIRC;
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_OSC22M_STB_Msk))
		if(--u32TimeOutCnt == 0) break;

    /* Switch HCLK clock source to Internal RC and HCLK source divide 1 */
    CLK->CLKSEL0 = (CLK->CLKSEL0 & (~CLK_CLKSEL0_HCLK_S_Msk)) | CLK_CLKSEL0_HCLK_S_HIRC;
    CLK->CLKDIV = (CLK->CLKDIV & (~CLK_CLKDIV_HCLK_N_Msk)) | CLK_CLKDIV_HCLK(1);

    /* Set PLL to Power-down mode */
    CLK->PLLCON |= CLK_PLLCON_PD_Msk;

    /* Enable external XTAL 12MHz clock */
    CLK->PWRCON |= CLK_PWRCON_XTL12M_EN_Msk;

    /* Waiting for external XTAL clock ready */
    u32TimeOutCnt = __HIRC;
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_XTL12M_STB_Msk))
		if(--u32TimeOutCnt == 0) break;

    /* Set core clock as PLL_CLOCK from PLL */
    CLK->PLLCON = PLLCON_SETTING;
    u32TimeOutCnt = __HIRC;
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_PLL_STB_Msk))
		if(--u32TimeOutCnt == 0) break;
    CLK->CLKSEL0 = (CLK->CLKSEL0 & (~CLK_CLKSEL0_HCLK_S_Msk)) | CLK_CLKSEL0_HCLK_S_PLL;

    /* Update System Core Clock */
    /* User can use SystemCoreClockUpdate() to calculate PllClock, SystemCoreClock and CyclesPerUs automatically. */
    //SystemCoreClockUpdate();
    PllClock        = PLL_CLOCK;            // PLL
    SystemCoreClock = PLL_CLOCK / 1;        // HCLK
    CyclesPerUs     = PLL_CLOCK / 1000000;  // For CLK_SysTickDelay()

    /* Enable UART module clock */
    CLK->APBCLK |= CLK_APBCLK_UART0_EN_Msk;

    /* Select UART module clock source */
    CLK->CLKSEL1 = (CLK->CLKSEL1 & (~CLK_CLKSEL1_UART_S_Msk)) | CLK_CLKSEL1_UART_S_HXT;

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/

    /* Set P3 multi-function pins for UART0 RXD and TXD */
    SYS->P3_MFP &= ~(SYS_MFP_P30_Msk | SYS_MFP_P31_Msk);
    SYS->P3_MFP |= (SYS_MFP_P30_UART0_RXD | SYS_MFP_P31_UART0_TXD);

}

void UART0_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART0 */
    SYS->IPRSTC2 |=  SYS_IPRSTC2_UART0_RST_Msk;
    SYS->IPRSTC2 &= ~SYS_IPRSTC2_UART0_RST_Msk;

    /* Configure UART0 and set UART0 Baudrate */
    UART0->BAUD = UART_BAUD_MODE2 | UART_BAUD_MODE2_DIVIDER(__HXT, 115200);
    UART0->LCR = UART_WORD_LEN_8 | UART_PARITY_NONE | UART_STOP_BIT_1;
}

/*---------------------------------------------------------------------------------------------------------*/
/* MAIN function                                                                                           */
/*---------------------------------------------------------------------------------------------------------*/
int32_t main(void)
{
    /* Unlock protected registers */
    SYS_UnlockReg();

    /* Init System, peripheral clock and multi-function I/O */
    SYS_Init();

    /* Lock protected registers */
    SYS_LockReg();

    /* Init UART0 for printf */
    UART0_Init();

    printf("\n\nCPU @ %d Hz\n", SystemCoreClock);
    printf("+-------------------------------------------------------------------+\n");
    printf("|  SYS_PowerDown_MinCurrent and Wake-up by P1.3 Sample Code         |\n");
    printf("+-------------------------------------------------------------------+\n\n");

    printf("+-------------------------------------------------------------------+\n");
    printf("| Operating sequence                                                |\n");
    printf("|  1. Remove all continuous load, e.g. LED.                         |\n");
    printf("|  2. Configure all GPIO as Quasi-bidirectional Mode                |\n");
    printf("|  3. Disable analog function, e.g. POR module                      |\n");
    printf("|  4. Disable unused clock, e.g. LIRC                               |\n");
    printf("|  5. Enter to Power-Down                                           |\n");
    printf("|  6. Wait for P1.3 falling-edge interrupt event to wake-up the MCU |\n");
    printf("+-------------------------------------------------------------------+\n\n");

    /*
        To measure Power-down current:
        On NuTiny-SDK-M0519 V1.0 board, remove components, e.g. Nu-Link-Me, R9 and R10.
    */

    /* Set the driving type of PWM output ports which are controlled by GPIO mode register */
    GPIO->PWMPOEN = 0;

    /* Set function pin to GPIO mode except UART pin to print message */
    SYS->P0_MFP = 0;
    SYS->P1_MFP = 0;
    SYS->P2_MFP = 0;
    SYS->P3_MFP = SYS_MFP_P31_UART0_TXD;
    SYS->P4_MFP = 0;
    SYS->P5_MFP = 0;
    SYS->P6_MFP = 0;
    SYS->P7_MFP = 0;
    SYS->P9_MFP = 0;
    SYS->PA_MFP = 0;

    /* Configure all GPIO as Quasi-bidirectional Mode. They are default output high. */
    P0->PMD = 0xFFFF;
    P1->PMD = 0xFFFF;
    P2->PMD = 0xFFFF;
    P3->PMD = 0xFFFF;
    P4->PMD = 0xFFFF;
    P5->PMD = 0xFFFF;
    P6->PMD = 0xFFFF;
    P7->PMD = 0xFFFF;
    P8->PMD = 0xFFFF;
    P9->PMD = 0xFFFF;
    PA->PMD = 0xFFFF;

    /* Unlock protected registers for Power-down setting */
    SYS_UnlockReg();

    /* LVR setting */
    LvrSetting();

    /* POR setting */
    PorSetting();

    /* LIRC setting */
    if(LircSetting() < 0) goto lexit;

    /* Wake-up source configuration */
    /* Configure P1.3 as Quasi mode and enable interrupt by falling edge trigger */
    P1->PMD = (P1->PMD & (~GPIO_PMD_PMD3_Msk)) | (GPIO_PMD_QUASI << GPIO_PMD_PMD3_Pos);
    P1->IMD |= (GPIO_IMD_EDGE << 3);
    P1->IEN |= (BIT3 << GPIO_IEN_IF_EN_Pos);
    NVIC_EnableIRQ(GPG0_IRQn);

    /* Enter to Power-down mode */
    printf("Enter to Power-Down ......\n");
    PowerDownFunction();

    /* Waiting for P1.3 falling-edge interrupt event */
    printf("System waken-up done.\n\n");

lexit:

    while(1);
}
