/**
 *
 * @file        main.c
 *
 * @brief       Main program body
 *
 * @version     V1.0.0
 *
 * @date        2025-10-30
 *
 * @attention
 *
 *  Copyright (C) 2025 Geehy Semiconductor
 *
 *  You may not use this file except in compliance with the
 *  GEEHY COPYRIGHT NOTICE (GEEHY SOFTWARE PACKAGE LICENSE).
 *
 *  The program is only for reference, which is distributed in the hope
 *  that it will be useful and instructional for customers to develop
 *  their software. Unless required by applicable law or agreed to in
 *  writing, the program is distributed on an "AS IS" BASIS, WITHOUT
 *  ANY WARRANTY OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the GEEHY SOFTWARE PACKAGE LICENSE for the governing permissions
 *  and limitations under the License.
 */

/* Includes ***************************************************************/
#include "main.h"

/* Private includes *******************************************************/
#include <stdio.h>

/* Private macro **********************************************************/
#define DEBUG_USART COM2_PORT

/* Private typedef ********************************************************/

/* Private variables ******************************************************/

/* Private function prototypes ********************************************/
void DDL_SysClkConfig(void);
void GPIO_Init(void);
void PMU_Init(void);
void EINT1_Isr(void);

/* External variables *****************************************************/

/* External functions *****************************************************/


/**
 * @brief     Main program
 *
 * @param     None
 *
 * @retval    None
 *
 */
int main(void)
{
    /* USART init structure */
    DDL_USART_InitTypeDef USART_InitStruct = {0U};

    /* Configure system clock */
    DDL_SysClkConfig();

    /* Configure interrupt group 4: 4-bit preemptive priority, 0-bit subpriority */
    DDL_NVIC_ConfigPriorityGroup(DDL_NVIC_PRIORITY_GROUP_4);

    /* USART Init */
    USART_InitStruct.BaudRate            = 115200U;
    USART_InitStruct.DataWidth           = DDL_USART_DATAWIDTH_8B;
    USART_InitStruct.StopBits            = DDL_USART_STOPBITS_1;
    USART_InitStruct.Parity              = DDL_USART_PARITY_NONE ;
    USART_InitStruct.TransferDirection   = DDL_USART_DIRECTION_TX_RX;
    USART_InitStruct.HardwareFlowControl = DDL_USART_HWCONTROL_NONE;
    USART_InitStruct.OverSampling        = DDL_USART_OVERSAMPLING_16;
    BOARD_COMInit(COM2, &USART_InitStruct);

    /* Initialize GPIO */
    GPIO_Init();

    /* Initialize PMU */
    PMU_Init();

    while (1)
    {

        printf("Enter Low Power Mode!\r\n");
        printf("Please give PC1 a falling edge to exit low power mode.\r\n");

        DDL_PMU_EnterStopModeWFI();

        /* Configure system clock */
        DDL_SysClkConfig();

        printf("Exit Low Mode!\r\n");
    }
}

/**
 * @brief   System clock configuration
 *
 * @param   None
 *
 * @retval  None
 */
void DDL_SysClkConfig(void)
{
    /* Unlock clock control registers */
    /* Wait until the registers are unlocked */
    DDL_RCM_Unlock();
    while ((RCM->KEY & RCM_KEY_KEYST) != RCM_KEY_KEYST) 
    { 
    }

    /* Enable HSE and wait for ready */
    /* Enable HSE input clock */
    DDL_RCM_HSE_Enable();
    /* Wait until HSE is ready */
    while (DDL_RCM_HSE_IsReady() != 1) 
    {
        /* wait for HSERDY */
    }

    /* Configure Flash wait states appropriate for 120 MHz */
    /* Set Flash wait period to accommodate higher frequency */
    DDL_FLASH_SetWaitPeriod(FLASH_DDL_WAIT_PERIOD_3);
    /* Set Flash erase time base to 120 MHz (use 119 to represent 120 MHz) */
    DDL_FLASH_SetEraseTimeBase(119);

    /* Configure PLL */
    /* Ensure PLL is disabled prior to configuration */
    DDL_RCM_PLL_Disable();

    /* Configure PLL settings: multiplier, prescaler, and clock source */
    /* PLL multiplier set to 15 (x15), prescaler no division, clock source from HSE */
    DDL_RCM_PLL_SetMultiplier(15);
    DDL_RCM_PLL_SetPrescaler(DDL_RCM_PLL_DIV1);
    DDL_RCM_PLL_SetClkSource(DDL_RCM_PLL_CLKSOURCE_HSE);

    /* Enable PLL and wait for ready */
    DDL_RCM_PLL_Enable();
    while (DDL_RCM_PLL_IsReady() != 1)
    {
        /* wait for PLL Ready */
    }

    /* Switch system clock to PLL output */
    DDL_RCM_SetSysClkSource(DDL_RCM_SYS_CLKSOURCE_PLL);

    /* Enable clock switch and wait for completion */
    DDL_RCM_EnableSysClkSwitch();
    while (DDL_RCM_IsActiveFlag_SWDONE() != 1)
    {
    }

    /* Set AHB, APB prescalers */
    DDL_RCM_SetAHBPrescaler(DDL_RCM_AHB_DIV_1);
    DDL_RCM_SetAPBPrescaler(DDL_RCM_APB_DIV_1);
    
    /* Disable temporary clock switch controls (if applicable) */
    DDL_RCM_DisableSysClkSwitch();
    
    /* Lock clock control registers */
    DDL_RCM_Unlock();

    /* Update SystemCoreClock if used by the project */
    SystemCoreClockUpdate();
}

/**
 * @brief     PMU Init
 *
 * @param     None
 *
 * @retval    None
 *
 */
void PMU_Init(void)
{
    /* Enable LSI Clock */
    DDL_RCM_Unlock();
    DDL_RCM_EnableAPBPeripheral(DDL_RCM_APB_PERIPHERAL_BKP);
    DDL_RCM_DisableBackupWriteProtect();
    DDL_RCM_EnableBackupDomainReset();
    DDL_RCM_DisableBackupDomainReset();
    DDL_RCM_LSI_Enable();
    while (DDL_RCM_LSI_IsReady() == RESET);

    /* Config PMU */
    DDL_PMU_SetWakeUpPinPolarity(DDL_PMU_WAKEUP_PIN1, DDL_PMU_WAKEUP_PIN_POLARITY_FALLING);
    DDL_PMU_EnableWakeUpPin(DDL_PMU_WAKEUP_PIN1);
    DDL_PMU_SetPinModeInStandby(DDL_PMU_WAKEUP_PIN1, DDL_PMU_STANDBY_PINMODE_PU);
}

/**
 * @brief     GPIO Init
 *
 * @param     None
 *
 * @retval    None
 *
 */
void GPIO_Init(void)
{
    DDL_GPIO_InitTypeDef GPIO_InitStruct = {0U};
    DDL_EINT_InitTypeDef EINT_InitStruct = {0U};

    /* Config Clock */
    DDL_RCM_Unlock();
    DDL_RCM_EnableAHBPeripheral(DDL_RCM_AHB_PERIPHERAL_GPIO);
    DDL_RCM_EnableAPBPeripheral(DDL_RCM_APB_PERIPHERAL_EINT);
    DDL_RCM_Lock();

    /* PC1 Init */
    GPIO_InitStruct.Pin        = DDL_GPIO_PIN_1;
    GPIO_InitStruct.Mode       = DDL_GPIO_MODE_INPUT;
    GPIO_InitStruct.Speed      = DDL_GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.OutputType = DDL_GPIO_OUTPUT_PUSHPULL;
    GPIO_InitStruct.Pull       = DDL_GPIO_PULL_NO;
    GPIO_InitStruct.Alternate  = DDL_GPIO_AF_0;
    DDL_GPIO_Init(GPIOC, &GPIO_InitStruct);

    /* Enable EINT1 */
    EINT_InitStruct.Line           = DDL_EINT_LINE_1;
    EINT_InitStruct.LineCommand    = ENABLE;
    EINT_InitStruct.Mode           = DDL_EINT_MODE_IT;
    EINT_InitStruct.Trigger        = DDL_EINT_TRIGGER_FALLING;
    DDL_EINT_Init(&EINT_InitStruct);
    
    DDL_EINT_SetLineSource(DDL_EINT_LINE_1, DDL_EINT_LINE_SOURCE_GPIOC);

    DDL_Interrupt_Register(EINT1_IRQn, EINT1_Isr);
    DDL_NVIC_EnableIRQRequest(EINT1_IRQn, 0, 0);
}

/**
 * @brief     EINT0 Isr
 *
 * @param     None
 *
 * @retval    None
 *
 */
void EINT1_Isr(void)
{
    if (DDL_EINT_ReadFlag(DDL_EINT_LINE_1))
    {
        DDL_EINT_ClearFlag(DDL_EINT_LINE_1);
    }
}


#if defined(__CC_ARM) || defined(__ARMCC_VERSION)
/*!
* @brief       Redirect C Library function printf to serial port.
*              After Redirection, you can use printf function.
*
* @param       ch:  The characters that need to be send.
*
* @param       *f:  pointer to a FILE that can recording all information
*              needed to control a stream
*
* @retval      The characters that need to be send.
*
* @note
*/
int fputc(int ch, FILE* f)
{
    /* send a byte of data to the serial port */
    DDL_USART_TransmitData8(DEBUG_USART, (uint8_t)ch);
    
    /* wait for the data to be send */
    while (DDL_USART_IsActiveFlag_TC(DEBUG_USART) == RESET);

    return (ch);
}
#elif defined(__ICCARM__)

/*!
* @brief       Redirect C Library function printf to serial port.
*              After Redirection, you can use printf function.
*
* @param       ch:  The characters that need to be send.
*
* @retval      The characters that need to be send.
*
* @note
*/
int __io_putchar(int ch)
{
    /* send a byte of data to the serial port */
    DDL_USART_TransmitData8(DEBUG_USART, (uint8_t)ch);
    
    /* wait for the data to be send */
    while (DDL_USART_IsActiveFlag_TC(DEBUG_USART) == RESET);

    return (ch);
}

/*!
* @brief       Redirect C Library function printf to serial port.
*              After Redirection, you can use printf function.
*
* @param       file:  Meaningless in this function.
*
* @param       *ptr:  Buffer pointer for data to be sent.
*
* @param       len:  Length of data to be sent.
*
* @retval      The characters that need to be send.
*
* @note
*/
int __write(int file, char* ptr, int len)
{
    int i;
    for (i = 0; i < len; i++)
    {
        __io_putchar(*ptr++);
    }

    return len;
}
#elif defined (__clang__) && !defined (__ARMCC_VERSION)

int uart_putc(char ch, FILE *file)
{
    /* send a byte of data to the serial port */
    DDL_USART_TransmitData8(DEBUG_USART, (uint8_t)ch);
    
    /* wait for the data to be send */
    while (DDL_USART_IsActiveFlag_TC(DEBUG_USART) == RESET);

    return (ch);
}

static FILE __stdio = FDEV_SETUP_STREAM(uart_putc, NULL, NULL, _FDEV_SETUP_WRITE);
FILE *const stdin = &__stdio;

__strong_reference(stdin, stdout);
__strong_reference(stdin, stderr);

#else

#warning Not supported compiler type
#endif

