/****************************************************************************
 * @file     main.c
 * @version  V3.00
 * $Revision: 4 $
 * $Date: 15/07/15 10:05a $
 * @brief
 *           Show how to wake up system form Power-down mode by UART interrupt.
 *
 * @note
 * @copyright SPDX-License-Identifier: Apache-2.0
 *
 * @copyright Copyright (C) 2014~2015 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "NUC123.h"


#define PLLCON_SETTING  CLK_PLLCON_72MHz_HXT
#define PLL_CLOCK       72000000


/*---------------------------------------------------------------------------------------------------------*/
/* Define functions prototype                                                                              */
/*---------------------------------------------------------------------------------------------------------*/
int32_t main(void);
void UART_CTSWakeUpTest(void);


/*---------------------------------------------------------------------------------------------------------*/
/* ISR to handle UART Channel 1 interrupt event                                                            */
/*---------------------------------------------------------------------------------------------------------*/
void UART1_IRQHandler(void)
{
    uint32_t u32IntSts = UART1->ISR;

    if(u32IntSts & UART_ISR_MODEM_IF_Msk)   /* UART Modem Status interrupt flag */
    {
        printf("UART Modem Status interrupt happen.");
        UART1->MSR |= UART_MSR_DCTSF_Msk;   /* Clear UART Modem Status interrupt flag */
    }
}

/*---------------------------------------------------------------------------------------------------------*/
/*  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(UART0)
        if(--u32TimeOutCnt == 0) break;

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

    /* Set system Power-down enabled and Power-down entry condition */
    CLK->PWRCON |= (CLK_PWRCON_PWR_DOWN_EN_Msk | CLK_PWRCON_PD_WAIT_CPU_Msk);

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

/*---------------------------------------------------------------------------------------------------------*/
/*  UART nCTS Wake-up Function                                                                             */
/*---------------------------------------------------------------------------------------------------------*/
void UART_CTSWakeUpTest(void)
{

    printf("+----------------------------------------------------------+\n");
    printf("|   Power-Down and Wake-up by UART interrupt Sample Code   |\n");
    printf("+----------------------------------------------------------+\n\n");

    /* Clear Modem Status interrupt before entering Power-down mode */
    UART1->MSR |= UART_MSR_DCTSF_Msk;

    /* Enable UART Wake-up function and Modem Status interrupt */
    UART1->IER |= (UART_IER_WAKE_EN_Msk|UART_IER_MODEM_IEN_Msk);
    NVIC_EnableIRQ(UART1_IRQn);

    printf("System enter to Power-down mode.\n");
    printf("Toggle nCTS of UART1 to wake-up system.\n\n");

    /* Unlock protected registers before entering Power-down mode */
    SYS_UnlockReg();

    /* Enter to Power-down mode */
    PowerDownFunction();

    /* Lock protected registers after entering Power-down mode */
    SYS_LockReg();

    /* Disable UART Wake-up function and Modem Status interrupt */
    UART1->IER &= ~(UART_IER_WAKE_EN_Msk|UART_IER_MODEM_IEN_Msk);
    NVIC_DisableIRQ(UART1_IRQn);

    printf("\nSystem waken-up done.\n");
    printf("\nUART Sample Program End.\n");

}

void SYS_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init System Clock                                                                                       */
    /*---------------------------------------------------------------------------------------------------------*/

    /* Enable XT1_OUT(PF0) and XT1_IN(PF1) */
    SYS->GPF_MFP &= ~(SYS_GPF_MFP_PF0_Msk | SYS_GPF_MFP_PF1_Msk);
    SYS->GPF_MFP |= SYS_GPF_MFP_PF0_XT1_OUT | SYS_GPF_MFP_PF1_XT1_IN;

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

    /* Waiting for Internal RC clock ready */
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_OSC22M_STB_Msk));

    /* 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 and PLL_STB bit in CLKSTATUS register will be cleared by hardware */
    CLK->PLLCON |= CLK_PLLCON_PD_Msk;

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

    /* Waiting for external XTAL clock ready */
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_XTL12M_STB_Msk));

    /* Set core clock as PLL_CLOCK from PLL */
    CLK->PLLCON = PLLCON_SETTING;
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_PLL_STB_Msk));
    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 | CLK_APBCLK_UART1_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 GPB multi-function pins for UART0 RXD(PB.0) and TXD(PB.1) */
    /* Set GPB multi-function pins for UART1 RXD(PB.4), TXD(PB.5) and nCTS(PB.7) */

    SYS->GPB_MFP &= ~(SYS_GPB_MFP_PB0_Msk | SYS_GPB_MFP_PB1_Msk |
                      SYS_GPB_MFP_PB4_Msk | SYS_GPB_MFP_PB5_Msk | SYS_GPB_MFP_PB7_Msk);
    SYS->GPB_MFP |= (SYS_GPB_MFP_PB0_UART0_RXD | SYS_GPB_MFP_PB1_UART0_TXD |
                     SYS_GPB_MFP_PB4_UART1_RXD | SYS_GPB_MFP_PB5_UART1_TXD | SYS_GPB_MFP_PB7_UART1_nCTS);

    SYS->ALT_MFP &= ~(SYS_ALT_MFP_PB4_Msk | SYS_ALT_MFP_PB5_Msk | SYS_ALT_MFP_PB7_Msk);
    SYS->ALT_MFP |= (SYS_ALT_MFP_PB4_UART1_RXD | SYS_ALT_MFP_PB5_UART1_TXD | SYS_ALT_MFP_PB7_UART1_nCTS);

}

void UART0_Init()
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* 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;
}

void UART1_Init()
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART1 */
    SYS->IPRSTC2 |=  SYS_IPRSTC2_UART1_RST_Msk;
    SYS->IPRSTC2 &= ~SYS_IPRSTC2_UART1_RST_Msk;

    /* Configure UART1 and set UART1 Baudrate */
    UART1->BAUD = UART_BAUD_MODE2 | UART_BAUD_MODE2_DIVIDER(__HXT, 115200);
    UART1->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();

    /* Init UART1 for testing */
    UART1_Init();

    /*---------------------------------------------------------------------------------------------------------*/
    /* SAMPLE CODE                                                                                             */
    /*---------------------------------------------------------------------------------------------------------*/

    printf("\n\nCPU @ %dHz\n", SystemCoreClock);

    printf("\n\nUART Sample Program.\n");

    /* UART wake-up sample function */
    UART_CTSWakeUpTest();

    while(1);
}

