File content as of revision 189:f392fc9709a3:

/**
  ******************************************************************************
  * @file    stm32f0xx_ll_utils.c
  * @author  MCD Application Team
  * @brief   UTILS LL module driver.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT(c) 2016 STMicroelectronics</center></h2>
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *   1. Redistributions of source code must retain the above copyright notice,
  *      this list of conditions and the following disclaimer.
  *   2. Redistributions in binary form must reproduce the above copyright notice,
  *      this list of conditions and the following disclaimer in the documentation
  *      and/or other materials provided with the distribution.
  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
  *      without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  */
/* Includes ------------------------------------------------------------------*/
#include "stm32f0xx_ll_rcc.h"
#include "stm32f0xx_ll_utils.h"
#include "stm32f0xx_ll_system.h"
#ifdef  USE_FULL_ASSERT
#include "stm32_assert.h"
#else
#define assert_param(expr) ((void)0U)
#endif

/** @addtogroup STM32F0xx_LL_Driver
  * @{
  */

/** @addtogroup UTILS_LL
  * @{
  */

/* Private types -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private constants ---------------------------------------------------------*/
/** @addtogroup UTILS_LL_Private_Constants
  * @{
  */

/* Defines used for PLL range */
#define UTILS_PLL_OUTPUT_MIN        16000000U           /*!< Frequency min for PLL output, in Hz  */
#define UTILS_PLL_OUTPUT_MAX        48000000U    /*!< Frequency max for PLL output, in Hz  */

/* Defines used for HSE range */
#define UTILS_HSE_FREQUENCY_MIN      4000000U       /*!< Frequency min for HSE frequency, in Hz   */
#define UTILS_HSE_FREQUENCY_MAX     32000000U       /*!< Frequency max for HSE frequency, in Hz   */

/* Defines used for FLASH latency according to SYSCLK Frequency */
#define UTILS_LATENCY1_FREQ         24000000U        /*!< SYSCLK frequency to set FLASH latency 1 */
/**
  * @}
  */
/* Private macros ------------------------------------------------------------*/
/** @addtogroup UTILS_LL_Private_Macros
  * @{
  */
#define IS_LL_UTILS_SYSCLK_DIV(__VALUE__) (((__VALUE__) == LL_RCC_SYSCLK_DIV_1)   \
                                        || ((__VALUE__) == LL_RCC_SYSCLK_DIV_2)   \
                                        || ((__VALUE__) == LL_RCC_SYSCLK_DIV_4)   \
                                        || ((__VALUE__) == LL_RCC_SYSCLK_DIV_8)   \
                                        || ((__VALUE__) == LL_RCC_SYSCLK_DIV_16)  \
                                        || ((__VALUE__) == LL_RCC_SYSCLK_DIV_64)  \
                                        || ((__VALUE__) == LL_RCC_SYSCLK_DIV_128) \
                                        || ((__VALUE__) == LL_RCC_SYSCLK_DIV_256) \
                                        || ((__VALUE__) == LL_RCC_SYSCLK_DIV_512))

#define IS_LL_UTILS_APB1_DIV(__VALUE__) (((__VALUE__) == LL_RCC_APB1_DIV_1) \
                                      || ((__VALUE__) == LL_RCC_APB1_DIV_2) \
                                      || ((__VALUE__) == LL_RCC_APB1_DIV_4) \
                                      || ((__VALUE__) == LL_RCC_APB1_DIV_8) \
                                      || ((__VALUE__) == LL_RCC_APB1_DIV_16))

#define IS_LL_UTILS_PLLMUL_VALUE(__VALUE__) (((__VALUE__) == LL_RCC_PLL_MUL_2) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_3) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_4) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_5) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_6) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_7) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_8) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_9) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_10) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_11) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_12) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_13) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_14) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_15) \
                                          || ((__VALUE__) == LL_RCC_PLL_MUL_16))

#define IS_LL_UTILS_PREDIV_VALUE(__VALUE__) (((__VALUE__) == LL_RCC_PREDIV_DIV_1)  || ((__VALUE__) == LL_RCC_PREDIV_DIV_2)   || \
                                             ((__VALUE__) == LL_RCC_PREDIV_DIV_3)  || ((__VALUE__) == LL_RCC_PREDIV_DIV_4)   || \
                                             ((__VALUE__) == LL_RCC_PREDIV_DIV_5)  || ((__VALUE__) == LL_RCC_PREDIV_DIV_6)   || \
                                             ((__VALUE__) == LL_RCC_PREDIV_DIV_7)  || ((__VALUE__) == LL_RCC_PREDIV_DIV_8)   || \
                                             ((__VALUE__) == LL_RCC_PREDIV_DIV_9)  || ((__VALUE__) == LL_RCC_PREDIV_DIV_10)  || \
                                             ((__VALUE__) == LL_RCC_PREDIV_DIV_11) || ((__VALUE__) == LL_RCC_PREDIV_DIV_12)  || \
                                             ((__VALUE__) == LL_RCC_PREDIV_DIV_13) || ((__VALUE__) == LL_RCC_PREDIV_DIV_14)  || \
                                             ((__VALUE__) == LL_RCC_PREDIV_DIV_15) || ((__VALUE__) == LL_RCC_PREDIV_DIV_16))

#define IS_LL_UTILS_PLL_FREQUENCY(__VALUE__) ((UTILS_PLL_OUTPUT_MIN <= (__VALUE__)) && ((__VALUE__) <= UTILS_PLL_OUTPUT_MAX))


#define IS_LL_UTILS_HSE_BYPASS(__STATE__) (((__STATE__) == LL_UTILS_HSEBYPASS_ON) \
                                        || ((__STATE__) == LL_UTILS_HSEBYPASS_OFF))

#define IS_LL_UTILS_HSE_FREQUENCY(__FREQUENCY__) (((__FREQUENCY__) >= UTILS_HSE_FREQUENCY_MIN) && ((__FREQUENCY__) <= UTILS_HSE_FREQUENCY_MAX))
/**
  * @}
  */
/* Private function prototypes -----------------------------------------------*/
/** @defgroup UTILS_LL_Private_Functions UTILS Private functions
  * @{
  */
static uint32_t    UTILS_GetPLLOutputFrequency(uint32_t PLL_InputFrequency,
                                               LL_UTILS_PLLInitTypeDef *UTILS_PLLInitStruct);
#if defined(FLASH_ACR_LATENCY)
static ErrorStatus UTILS_SetFlashLatency(uint32_t Frequency);
#endif /* FLASH_ACR_LATENCY */
static ErrorStatus UTILS_EnablePLLAndSwitchSystem(uint32_t SYSCLK_Frequency, LL_UTILS_ClkInitTypeDef *UTILS_ClkInitStruct);
static ErrorStatus UTILS_PLL_IsBusy(void);
/**
  * @}
  */

/* Exported functions --------------------------------------------------------*/
/** @addtogroup UTILS_LL_Exported_Functions
  * @{
  */

/** @addtogroup UTILS_LL_EF_DELAY
  * @{
  */

/**
  * @brief  This function configures the Cortex-M SysTick source to have 1ms time base.
  * @note   When a RTOS is used, it is recommended to avoid changing the Systick
  *         configuration by calling this function, for a delay use rather osDelay RTOS service.
  * @param  HCLKFrequency HCLK frequency in Hz
  * @note   HCLK frequency can be calculated thanks to RCC helper macro or function @ref LL_RCC_GetSystemClocksFreq
  * @retval None
  */
void LL_Init1msTick(uint32_t HCLKFrequency)
{
  /* Use frequency provided in argument */
  LL_InitTick(HCLKFrequency, 1000U);
}

/**
  * @brief  This function provides accurate delay (in milliseconds) based
  *         on SysTick counter flag
  * @note   When a RTOS is used, it is recommended to avoid using blocking delay
  *         and use rather osDelay service.
  * @note   To respect 1ms timebase, user should call @ref LL_Init1msTick function which
  *         will configure Systick to 1ms
  * @param  Delay specifies the delay time length, in milliseconds.
  * @retval None
  */
void LL_mDelay(uint32_t Delay)
{
  __IO uint32_t  tmp = SysTick->CTRL;  /* Clear the COUNTFLAG first */
  /* Add this code to indicate that local variable is not used */
  ((void)tmp);

  /* Add a period to guaranty minimum wait */
  if (Delay < LL_MAX_DELAY)
  {
    Delay++;
  }

  while (Delay)
  {
    if ((SysTick->CTRL & SysTick_CTRL_COUNTFLAG_Msk) != 0U)
    {
      Delay--;
    }
  }
}

/**
  * @}
  */

/** @addtogroup UTILS_EF_SYSTEM
  *  @brief    System Configuration functions
  *
  @verbatim
 ===============================================================================
           ##### System Configuration functions #####
 ===============================================================================
    [..]
         System, AHB and APB buses clocks configuration

         (+) The maximum frequency of the SYSCLK, HCLK, PCLK1 and PCLK2 is 48000000 Hz.
  @endverbatim
  @internal
             Depending on the SYSCLK frequency, the flash latency should be adapted accordingly:
             (++) +-----------------------------------------------+
             (++) | Latency       | SYSCLK clock frequency (MHz)  |
             (++) |---------------|-------------------------------|
             (++) |0WS(1CPU cycle)|       0 < SYSCLK <= 24        |
             (++) |---------------|-------------------------------|
             (++) |1WS(2CPU cycle)|      24 < SYSCLK <= 48        |
             (++) +-----------------------------------------------+
  @endinternal
  * @{
  */

/**
  * @brief  This function sets directly SystemCoreClock CMSIS variable.
  * @note   Variable can be calculated also through SystemCoreClockUpdate function.
  * @param  HCLKFrequency HCLK frequency in Hz (can be calculated thanks to RCC helper macro)
  * @retval None
  */
void LL_SetSystemCoreClock(uint32_t HCLKFrequency)
{
  /* HCLK clock frequency */
  SystemCoreClock = HCLKFrequency;
}

/**
  * @brief  This function configures system clock with HSI as clock source of the PLL
  * @note   The application need to ensure that PLL is disabled.
  * @note   Function is based on the following formula:
  *         - PLL output frequency = ((HSI frequency / PREDIV) * PLLMUL)
  *         - PREDIV: Set to 2 for few devices
  *         - PLLMUL: The application software must set correctly the PLL multiplication factor to 
  *                   be in the range 16-48MHz
  * @note   FLASH latency can be modified through this function. 
  * @param  UTILS_PLLInitStruct pointer to a @ref LL_UTILS_PLLInitTypeDef structure that contains
  *                             the configuration information for the PLL.
  * @param  UTILS_ClkInitStruct pointer to a @ref LL_UTILS_ClkInitTypeDef structure that contains
  *                             the configuration information for the BUS prescalers.
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: Max frequency configuration done
  *          - ERROR: Max frequency configuration not done
  */
ErrorStatus LL_PLL_ConfigSystemClock_HSI(LL_UTILS_PLLInitTypeDef *UTILS_PLLInitStruct,
                                         LL_UTILS_ClkInitTypeDef *UTILS_ClkInitStruct)
{
  ErrorStatus status = SUCCESS;
  uint32_t pllfreq = 0U;

  /* Check if one of the PLL is enabled */
  if (UTILS_PLL_IsBusy() == SUCCESS)
  {
#if defined(RCC_PLLSRC_PREDIV1_SUPPORT)
    /* Check PREDIV value */
    assert_param(IS_LL_UTILS_PREDIV_VALUE(UTILS_PLLInitStruct->PLLDiv));
#else
    /* Force PREDIV value to 2 */
    UTILS_PLLInitStruct->Prediv = LL_RCC_PREDIV_DIV_2;
#endif /*RCC_PLLSRC_PREDIV1_SUPPORT*/
    /* Calculate the new PLL output frequency */
    pllfreq = UTILS_GetPLLOutputFrequency(HSI_VALUE, UTILS_PLLInitStruct);

    /* Enable HSI if not enabled */
    if (LL_RCC_HSI_IsReady() != 1U)
    {
      LL_RCC_HSI_Enable();
      while (LL_RCC_HSI_IsReady() != 1U)
      {
        /* Wait for HSI ready */
      }
    }

    /* Configure PLL */
#if defined(RCC_PLLSRC_PREDIV1_SUPPORT)
    LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSI, UTILS_PLLInitStruct->PLLMul, UTILS_PLLInitStruct->PLLDiv);
#else
    LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSI_DIV_2, UTILS_PLLInitStruct->PLLMul);
#endif /*RCC_PLLSRC_PREDIV1_SUPPORT*/

    /* Enable PLL and switch system clock to PLL */
    status = UTILS_EnablePLLAndSwitchSystem(pllfreq, UTILS_ClkInitStruct);
  }
  else
  {
    /* Current PLL configuration cannot be modified */
    status = ERROR;
  }

  return status;
}

#if defined(RCC_CFGR_SW_HSI48)
/**
  * @brief  This function configures system clock with HSI48 as clock source of the PLL
  * @note   The application need to ensure that PLL is disabled.
  * @note   Function is based on the following formula:
  *         - PLL output frequency = ((HSI48 frequency / PREDIV) * PLLMUL)
  *         - PLLMUL: The application software must set correctly the PLL multiplication factor to 
  *                   be in the range 16-48MHz
  * @param  UTILS_PLLInitStruct pointer to a @ref LL_UTILS_PLLInitTypeDef structure that contains
  *                             the configuration information for the PLL.
  * @param  UTILS_ClkInitStruct pointer to a @ref LL_UTILS_ClkInitTypeDef structure that contains
  *                             the configuration information for the BUS prescalers.
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: Max frequency configuration done
  *          - ERROR: Max frequency configuration not done
  */
ErrorStatus LL_PLL_ConfigSystemClock_HSI48(LL_UTILS_PLLInitTypeDef *UTILS_PLLInitStruct,
                                         LL_UTILS_ClkInitTypeDef *UTILS_ClkInitStruct)
{
  ErrorStatus status = SUCCESS;
  uint32_t pllfreq = 0U;

  /* Check if one of the PLL is enabled */
  if (UTILS_PLL_IsBusy() == SUCCESS)
  {
    /* Check PREDIV value */
    assert_param(IS_LL_UTILS_PREDIV_VALUE(UTILS_PLLInitStruct->PLLDiv));

    /* Calculate the new PLL output frequency */
    pllfreq = UTILS_GetPLLOutputFrequency(HSI48_VALUE, UTILS_PLLInitStruct);

    /* Enable HSI48 if not enabled */
    if (LL_RCC_HSI48_IsReady() != 1U)
    {
      LL_RCC_HSI48_Enable();
      while (LL_RCC_HSI48_IsReady() != 1U)
      {
        /* Wait for HSI48 ready */
      }
    }

    /* Configure PLL */
    LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSI48, UTILS_PLLInitStruct->PLLMul, UTILS_PLLInitStruct->PLLDiv);

    /* Enable PLL and switch system clock to PLL */
    status = UTILS_EnablePLLAndSwitchSystem(pllfreq, UTILS_ClkInitStruct);
  }
  else
  {
    /* Current PLL configuration cannot be modified */
    status = ERROR;
  }

  return status;
}

#endif /*RCC_CFGR_SW_HSI48*/
/**
  * @brief  This function configures system clock with HSE as clock source of the PLL
  * @note   The application need to ensure that PLL is disabled.
  * @note   Function is based on the following formula:
  *         - PLL output frequency = ((HSE frequency / PREDIV) * PLLMUL)
  *         - PLLMUL: The application software must set correctly the PLL multiplication factor to 
  *                   be in the range 16-48MHz
  * @note   FLASH latency can be modified through this function. 
  * @param  HSEFrequency Value between Min_Data = 4000000 and Max_Data = 32000000
  * @param  HSEBypass This parameter can be one of the following values:
  *         @arg @ref LL_UTILS_HSEBYPASS_ON
  *         @arg @ref LL_UTILS_HSEBYPASS_OFF
  * @param  UTILS_PLLInitStruct pointer to a @ref LL_UTILS_PLLInitTypeDef structure that contains
  *                             the configuration information for the PLL.
  * @param  UTILS_ClkInitStruct pointer to a @ref LL_UTILS_ClkInitTypeDef structure that contains
  *                             the configuration information for the BUS prescalers.
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: Max frequency configuration done
  *          - ERROR: Max frequency configuration not done
  */
ErrorStatus LL_PLL_ConfigSystemClock_HSE(uint32_t HSEFrequency, uint32_t HSEBypass,
                                         LL_UTILS_PLLInitTypeDef *UTILS_PLLInitStruct, LL_UTILS_ClkInitTypeDef *UTILS_ClkInitStruct)
{
  ErrorStatus status = SUCCESS;
  uint32_t pllfreq = 0U;

  /* Check the parameters */
  assert_param(IS_LL_UTILS_HSE_FREQUENCY(HSEFrequency));
  assert_param(IS_LL_UTILS_HSE_BYPASS(HSEBypass));

  /* Check if one of the PLL is enabled */
  if (UTILS_PLL_IsBusy() == SUCCESS)
  {
    /* Check PREDIV value */
#if defined(RCC_PLLSRC_PREDIV1_SUPPORT)
    assert_param(IS_LL_UTILS_PREDIV_VALUE(UTILS_PLLInitStruct->PLLDiv));
#else
    assert_param(IS_LL_UTILS_PREDIV_VALUE(UTILS_PLLInitStruct->Prediv));
#endif /*RCC_PLLSRC_PREDIV1_SUPPORT*/

    /* Calculate the new PLL output frequency */
    pllfreq = UTILS_GetPLLOutputFrequency(HSEFrequency, UTILS_PLLInitStruct);

    /* Enable HSE if not enabled */
    if (LL_RCC_HSE_IsReady() != 1U)
    {
      /* Check if need to enable HSE bypass feature or not */
      if (HSEBypass == LL_UTILS_HSEBYPASS_ON)
      {
        LL_RCC_HSE_EnableBypass();
      }
      else
      {
        LL_RCC_HSE_DisableBypass();
      }

      /* Enable HSE */
      LL_RCC_HSE_Enable();
      while (LL_RCC_HSE_IsReady() != 1U)
      {
        /* Wait for HSE ready */
      }
    }

      /* Configure PLL */
#if defined(RCC_PLLSRC_PREDIV1_SUPPORT)
      LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSE, UTILS_PLLInitStruct->PLLMul, UTILS_PLLInitStruct->PLLDiv);
#else
    LL_RCC_PLL_ConfigDomain_SYS((RCC_CFGR_PLLSRC_HSE_PREDIV | UTILS_PLLInitStruct->Prediv), UTILS_PLLInitStruct->PLLMul);
#endif /*RCC_PLLSRC_PREDIV1_SUPPORT*/

    /* Enable PLL and switch system clock to PLL */
    status = UTILS_EnablePLLAndSwitchSystem(pllfreq, UTILS_ClkInitStruct);
  }
  else
  {
    /* Current PLL configuration cannot be modified */
    status = ERROR;
  }

  return status;
}

/**
  * @}
  */

/**
  * @}
  */

/** @addtogroup UTILS_LL_Private_Functions
  * @{
  */
/**
  * @brief  Update number of Flash wait states in line with new frequency and current
            voltage range.
  * @param  Frequency  SYSCLK frequency
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: Latency has been modified
  *          - ERROR: Latency cannot be modified
  */
#if defined(FLASH_ACR_LATENCY)
static ErrorStatus UTILS_SetFlashLatency(uint32_t Frequency)
{
  ErrorStatus status = SUCCESS;

  uint32_t latency = LL_FLASH_LATENCY_0;  /* default value 0WS */

  /* Frequency cannot be equal to 0 */
  if (Frequency == 0U)
  {
    status = ERROR;
  }
  else
  {
    if (Frequency > UTILS_LATENCY1_FREQ)
    {
      /* 24 < SYSCLK <= 48 => 1WS (2 CPU cycles) */
      latency = LL_FLASH_LATENCY_1;
    }
    /* else SYSCLK < 24MHz default LL_FLASH_LATENCY_0 0WS */

    LL_FLASH_SetLatency(latency);

    /* Check that the new number of wait states is taken into account to access the Flash
       memory by reading the FLASH_ACR register */
    if (LL_FLASH_GetLatency() != latency)
    {
      status = ERROR;
    }
  }
  return status;
}
#endif /* FLASH_ACR_LATENCY */

/**
  * @brief  Function to check that PLL can be modified
  * @param  PLL_InputFrequency  PLL input frequency (in Hz)
  * @param  UTILS_PLLInitStruct pointer to a @ref LL_UTILS_PLLInitTypeDef structure that contains
  *                             the configuration information for the PLL.
  * @retval PLL output frequency (in Hz)
  */
static uint32_t UTILS_GetPLLOutputFrequency(uint32_t PLL_InputFrequency, LL_UTILS_PLLInitTypeDef *UTILS_PLLInitStruct)
{
  uint32_t pllfreq = 0U;

  /* Check the parameters */
  assert_param(IS_LL_UTILS_PLLMUL_VALUE(UTILS_PLLInitStruct->PLLMul));

  /* Check different PLL parameters according to RM                          */
  /* The application software must set correctly the PLL multiplication factor to 
     be in the range 16-48MHz */
#if defined(RCC_PLLSRC_PREDIV1_SUPPORT)
  pllfreq = __LL_RCC_CALC_PLLCLK_FREQ(PLL_InputFrequency, UTILS_PLLInitStruct->PLLMul, UTILS_PLLInitStruct->PLLDiv);
#else
  pllfreq = __LL_RCC_CALC_PLLCLK_FREQ(PLL_InputFrequency / (UTILS_PLLInitStruct->Prediv + 1U), UTILS_PLLInitStruct->PLLMul);
#endif /*RCC_PLLSRC_PREDIV1_SUPPORT*/
  assert_param(IS_LL_UTILS_PLL_FREQUENCY(pllfreq));

  return pllfreq;
}

/**
  * @brief  Function to check that PLL can be modified
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: PLL modification can be done
  *          - ERROR: PLL is busy
  */
static ErrorStatus UTILS_PLL_IsBusy(void)
{
  ErrorStatus status = SUCCESS;

  /* Check if PLL is busy*/
  if (LL_RCC_PLL_IsReady() != 0U)
  {
    /* PLL configuration cannot be modified */
    status = ERROR;
  }

  return status;
}

/**
  * @brief  Function to enable PLL and switch system clock to PLL
  * @param  SYSCLK_Frequency SYSCLK frequency
  * @param  UTILS_ClkInitStruct pointer to a @ref LL_UTILS_ClkInitTypeDef structure that contains
  *                             the configuration information for the BUS prescalers.
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: No problem to switch system to PLL
  *          - ERROR: Problem to switch system to PLL
  */
static ErrorStatus UTILS_EnablePLLAndSwitchSystem(uint32_t SYSCLK_Frequency, LL_UTILS_ClkInitTypeDef *UTILS_ClkInitStruct)
{
  ErrorStatus status = SUCCESS;
  uint32_t sysclk_frequency_current = 0U;

  assert_param(IS_LL_UTILS_SYSCLK_DIV(UTILS_ClkInitStruct->AHBCLKDivider));
  assert_param(IS_LL_UTILS_APB1_DIV(UTILS_ClkInitStruct->APB1CLKDivider));

  /* Calculate current SYSCLK frequency */
  sysclk_frequency_current = (SystemCoreClock << AHBPrescTable[LL_RCC_GetAHBPrescaler() >> RCC_POSITION_HPRE]);

  /* Increasing the number of wait states because of higher CPU frequency */
  if (sysclk_frequency_current < SYSCLK_Frequency)
  {
    /* Set FLASH latency to highest latency */
    status = UTILS_SetFlashLatency(SYSCLK_Frequency);
  }

  /* Update system clock configuration */
  if (status == SUCCESS)
  {
    /* Enable PLL */
    LL_RCC_PLL_Enable();
    while (LL_RCC_PLL_IsReady() != 1U)
    {
      /* Wait for PLL ready */
    }

    /* Sysclk activation on the main PLL */
    LL_RCC_SetAHBPrescaler(UTILS_ClkInitStruct->AHBCLKDivider);
    LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);
    while (LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL)
    {
      /* Wait for system clock switch to PLL */
    }

    /* Set APB1 & APB2 prescaler*/
    LL_RCC_SetAPB1Prescaler(UTILS_ClkInitStruct->APB1CLKDivider);
  }

  /* Decreasing the number of wait states because of lower CPU frequency */
  if (sysclk_frequency_current > SYSCLK_Frequency)
  {
    /* Set FLASH latency to lowest latency */
    status = UTILS_SetFlashLatency(SYSCLK_Frequency);
  }

  /* Update SystemCoreClock variable */
  if (status == SUCCESS)
  {
    LL_SetSystemCoreClock(__LL_RCC_CALC_HCLK_FREQ(SYSCLK_Frequency, UTILS_ClkInitStruct->AHBCLKDivider));
  }

  return status;
}

/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */

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