/**
 ***************************************************************************************
  * File Name          : stm32_lpm_if.c
  * Description        : Low layer function to enter/exit low power modes (stop, sleep).
 ***************************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2019 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the 
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */
  
/* Includes ------------------------------------------------------------------*/  
#include "stm32_lpm_if.h"
#include "app_conf.h"

#include "stm32wbxx_ll_hsem.h"
#include "stm32wbxx_ll_cortex.h"


/* Exported variables --------------------------------------------------------*/

/* Private function prototypes -----------------------------------------------*/
static void Switch_On_HSI( void );

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

/* Private define ------------------------------------------------------------*/

/* Private macro -------------------------------------------------------------*/

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


/* Functions Definition ------------------------------------------------------*/
/**
  * @brief Enters Low Power Off Mode
  * @param none
  * @retval none
  */
void PWR_EnterOffMode( void )
{
  /************************************************************************************
   * ENTER OFF MODE
   ***********************************************************************************/
  /*
   * There is no risk to clear all the WUF here because in the current implementation, this API is called
   * in critical section. If an interrupt occurs while in that critical section before that point,
   * the flag is set and will be cleared here but the system will not enter Off Mode
   * because an interrupt is pending in the NVIC. The ISR will be executed when moving out
   * of this critical section
   */
  LL_PWR_ClearFlag_WU( );

  LL_PWR_SetPowerMode( LL_PWR_MODE_STANDBY );

  LL_LPM_EnableDeepSleep( ); /**< Set SLEEPDEEP bit of Cortex System Control Register */

  /**
   * This option is used to ensure that store operations are completed
   */
#if defined ( __CC_ARM)
  __force_stores( );
#endif

  __WFI( );
}

/**
  * @brief Exits Low Power Off Mode
  * @param none
  * @retval none
  */
void PWR_ExitOffMode( void )
{

}

/**
  * @brief Enters Low Power Stop Mode
  * @note ARM exists the function when waking up
  * @param none
  * @retval none
  */
void PWR_EnterStopMode( void )
{
  /**
   * This function is called from CRITICAL SECTION
   */
  while( LL_HSEM_1StepLock( HSEM, CFG_HW_RCC_SEMID ) );

  if ( ! LL_HSEM_1StepLock( HSEM, CFG_HW_ENTRY_STOP_MODE_SEMID ) )
  {
    if( LL_PWR_IsActiveFlag_C2DS( ) )
    {
      /* Release ENTRY_STOP_MODE semaphore */
      LL_HSEM_ReleaseLock( HSEM, CFG_HW_ENTRY_STOP_MODE_SEMID, 0 );

      /**
       * The switch on HSI before entering Stop Mode is required 
       */
      Switch_On_HSI( );
    }
  }
  else
  {
    /**
     * The switch on HSI before entering Stop Mode is required 
     */
    Switch_On_HSI( );
  }

  /* Release RCC semaphore */
  LL_HSEM_ReleaseLock( HSEM, CFG_HW_RCC_SEMID, 0 );

  /************************************************************************************
   * ENTER STOP MODE
   ***********************************************************************************/
#if defined(PWR_SUPPORT_STOP2)
  LL_PWR_SetPowerMode( LL_PWR_MODE_STOP2 );
#else
  LL_PWR_SetPowerMode( LL_PWR_MODE_STOP1 );
#endif

  LL_LPM_EnableDeepSleep( ); /**< Set SLEEPDEEP bit of Cortex System Control Register */

  /**
   * This option is used to ensure that store operations are completed
   */
#if defined ( __CC_ARM)
  __force_stores( );
#endif

  __WFI();
}

/**
  * @brief Exits Low Power Stop Mode
  * @note Enable the pll at 32MHz
  * @param none
  * @retval none
  */
void PWR_ExitStopMode( void )
{
  /**
   * This function is called from CRITICAL SECTION
   */

  /* Release ENTRY_STOP_MODE semaphore */
  LL_HSEM_ReleaseLock( HSEM, CFG_HW_ENTRY_STOP_MODE_SEMID, 0 );

  while( LL_HSEM_1StepLock( HSEM, CFG_HW_RCC_SEMID ) );

  if(LL_RCC_GetSysClkSource( ) == LL_RCC_SYS_CLKSOURCE_STATUS_HSI)
  {
    LL_RCC_HSE_Enable( );
    while(!LL_RCC_HSE_IsReady( ));
    LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_HSE);
    while (LL_RCC_GetSysClkSource( ) != LL_RCC_SYS_CLKSOURCE_STATUS_HSE);
  }
  else
  {
    /**
     * As long as the current application is fine with HSE as system clock source,
     * there is nothing to do here
     */
  }

  /* Release RCC semaphore */
  LL_HSEM_ReleaseLock( HSEM, CFG_HW_RCC_SEMID, 0 );
}

/**
  * @brief Enters Low Power Sleep Mode
  * @note ARM exits the function when waking up
  * @param none
  * @retval none
  */
void PWR_EnterSleepMode( void )
{

  HAL_SuspendTick();

  /************************************************************************************
   * ENTER SLEEP MODE
   ***********************************************************************************/
  LL_LPM_EnableSleep( ); /**< Clear SLEEPDEEP bit of Cortex System Control Register */

  /**
   * This option is used to ensure that store operations are completed
   */
#if defined ( __CC_ARM)
  __force_stores();
#endif

  __WFI( );
}

/**
  * @brief Exits Low Power Sleep Mode
  * @note ARM exits the function when waking up
  * @param none
  * @retval none
  */
void PWR_ExitSleepMode( void )
{

  HAL_ResumeTick();

}

/*************************************************************
 *
 * LOCAL FUNCTIONS
 *
 *************************************************************/
/**
  * @brief Switch the system clock on HSI
  * @param none
  * @retval none
  */
static void Switch_On_HSI( void )
{
  LL_RCC_HSI_Enable( );
  while(!LL_RCC_HSI_IsReady( ));
  LL_RCC_SetSysClkSource( LL_RCC_SYS_CLKSOURCE_HSI );
  LL_RCC_SetSMPSClockSource(LL_RCC_SMPS_CLKSOURCE_HSI);
  while (LL_RCC_GetSysClkSource( ) != LL_RCC_SYS_CLKSOURCE_STATUS_HSI);
}



/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/