Src/stm32l1xx_ll_rcc.c

/**
  ******************************************************************************
  * @file    stm32l1xx_ll_rcc.c
  * @author  MCD Application Team
  * @brief   RCC LL module driver.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2017 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file in
  * the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  ******************************************************************************
  */
#if defined(USE_FULL_LL_DRIVER)

/* Includes ------------------------------------------------------------------*/
#include "stm32l1xx_ll_rcc.h"
/** @addtogroup STM32L1xx_LL_Driver
  * @{
  */

#if defined(RCC)

/** @defgroup RCC_LL RCC
  * @{
  */

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

/* Private constants ---------------------------------------------------------*/
/* Private macros ------------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/** @defgroup RCC_LL_Private_Functions RCC Private functions
  * @{
  */
static uint32_t RCC_GetSystemClockFreq(void);
static uint32_t RCC_GetHCLKClockFreq(uint32_t SYSCLK_Frequency);
static uint32_t RCC_GetPCLK1ClockFreq(uint32_t HCLK_Frequency);
static uint32_t RCC_GetPCLK2ClockFreq(uint32_t HCLK_Frequency);
static uint32_t RCC_PLL_GetFreqDomain_SYS(void);
/**
  * @}
  */


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

/** @addtogroup RCC_LL_EF_Init
  * @{
  */

/**
  * @brief  Reset the RCC clock configuration to the default reset state.
  * @note   The default reset state of the clock configuration is given below:
  *         - MSI  ON and used as system clock source
  *         - HSE, HSI and PLL OFF
  *         - AHB, APB1 and APB2 prescaler set to 1.
  *         - CSS, MCO OFF
  *         - All interrupts disabled
  * @note   This function doesn't modify the configuration of the
  *         - Peripheral clocks
  *         - LSI, LSE and RTC clocks
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: RCC registers are de-initialized
  *          - ERROR: not applicable
  */
ErrorStatus LL_RCC_DeInit(void)
{
  __IO uint32_t vl_mask;

  /* Set MSION bit */
  LL_RCC_MSI_Enable();

  /* Insure MSIRDY bit is set before writing default MSIRANGE value */
  while (LL_RCC_MSI_IsReady() == 0U)
  {
    __NOP();
  }

  /* Set MSIRANGE default value */
  LL_RCC_MSI_SetRange(LL_RCC_MSIRANGE_5);
  /* Set MSITRIM bits to the reset value*/
  LL_RCC_MSI_SetCalibTrimming(0U);

  /* Set HSITRIM bits to the reset value*/
  LL_RCC_HSI_SetCalibTrimming(0x10U);

  /* Reset SW, HPRE, PPRE and MCOSEL bits */
  vl_mask = 0xFFFFFFFFU;
  CLEAR_BIT(vl_mask, (RCC_CFGR_SW | RCC_CFGR_HPRE | RCC_CFGR_PPRE1 | RCC_CFGR_PPRE2 | RCC_CFGR_MCOSEL));
  LL_RCC_WriteReg(CFGR, vl_mask);

  /* Read CR register */
  vl_mask = LL_RCC_ReadReg(CR);

  /* Reset HSION, HSEON, CSSON, PLLON bits */
  CLEAR_BIT(vl_mask, (RCC_CR_PLLON | RCC_CR_CSSON | RCC_CR_HSEON | RCC_CR_HSION));
  LL_RCC_WriteReg(CR, vl_mask);

  /* Reset HSEBYP bit */
  LL_RCC_HSE_DisableBypass();

  /* Insure PLL is disabled before to reset PLLSRC/PLLMUL/PLLDIV in CFGR register */
  while(LL_RCC_PLL_IsReady() != 0U) {};

  /* Reset CFGR register */
  LL_RCC_WriteReg(CFGR, 0x00000000U);

  /* Disable all interrupts */
  LL_RCC_WriteReg(CIR, 0x00000000U);

  /* Clear pending flags */
#if defined(RCC_LSECSS_SUPPORT)
  vl_mask = (LL_RCC_CIR_LSIRDYC | LL_RCC_CIR_LSERDYC | LL_RCC_CIR_HSIRDYC | LL_RCC_CIR_HSERDYC | \
             LL_RCC_CIR_PLLRDYC | LL_RCC_CIR_MSIRDYC | LL_RCC_CIR_LSECSSC | LL_RCC_CIR_CSSC);
#else
  vl_mask = (LL_RCC_CIR_LSIRDYC | LL_RCC_CIR_LSERDYC | LL_RCC_CIR_HSIRDYC | LL_RCC_CIR_HSERDYC | \
             LL_RCC_CIR_PLLRDYC | LL_RCC_CIR_MSIRDYC | LL_RCC_CIR_CSSC);
#endif /* RCC_LSECSS_SUPPORT */
  LL_RCC_WriteReg(CIR, vl_mask);

  /* Clear reset flags */
  LL_RCC_ClearResetFlags();

  return SUCCESS;
}

/**
  * @}
  */

/** @addtogroup RCC_LL_EF_Get_Freq
  * @brief  Return the frequencies of different on chip clocks;  System, AHB, APB1 and APB2 buses clocks
  *         and different peripheral clocks available on the device.
  * @note   If SYSCLK source is MSI, function returns values based on MSI clock(*)
  * @note   If SYSCLK source is HSI, function returns values based on HSI_VALUE(**)
  * @note   If SYSCLK source is HSE, function returns values based on HSE_VALUE(***)
  * @note   If SYSCLK source is PLL, function returns values based on
  *         HSI_VALUE(**) or HSE_VALUE(***) multiplied/divided by the PLL factors.
  * @note   (*) MSI clock depends on the selected MSI range but the real value
  *             may vary depending on the variations in voltage and temperature.
  * @note   (**) HSI_VALUE is a defined constant but the real value may vary
  *              depending on the variations in voltage and temperature.
  * @note   (***) HSE_VALUE is a defined constant, user has to ensure that
  *               HSE_VALUE is same as the real frequency of the crystal used.
  *               Otherwise, this function may have wrong result.
  * @note   The result of this function could be incorrect when using fractional
  *         value for HSE crystal.
  * @note   This function can be used by the user application to compute the
  *         baud-rate for the communication peripherals or configure other parameters.
  * @{
  */

/**
  * @brief  Return the frequencies of different on chip clocks;  System, AHB, APB1 and APB2 buses clocks
  * @note   Each time SYSCLK, HCLK, PCLK1 and/or PCLK2 clock changes, this function
  *         must be called to update structure fields. Otherwise, any
  *         configuration based on this function will be incorrect.
  * @param  RCC_Clocks pointer to a @ref LL_RCC_ClocksTypeDef structure which will hold the clocks frequencies
  * @retval None
  */
void LL_RCC_GetSystemClocksFreq(LL_RCC_ClocksTypeDef *RCC_Clocks)
{
  /* Get SYSCLK frequency */
  RCC_Clocks->SYSCLK_Frequency = RCC_GetSystemClockFreq();

  /* HCLK clock frequency */
  RCC_Clocks->HCLK_Frequency   = RCC_GetHCLKClockFreq(RCC_Clocks->SYSCLK_Frequency);

  /* PCLK1 clock frequency */
  RCC_Clocks->PCLK1_Frequency  = RCC_GetPCLK1ClockFreq(RCC_Clocks->HCLK_Frequency);

  /* PCLK2 clock frequency */
  RCC_Clocks->PCLK2_Frequency  = RCC_GetPCLK2ClockFreq(RCC_Clocks->HCLK_Frequency);
}

/**
  * @}
  */

/**
  * @}
  */

/** @addtogroup RCC_LL_Private_Functions
  * @{
  */

/**
  * @brief  Return SYSTEM clock frequency
  * @retval SYSTEM clock frequency (in Hz)
  */
static uint32_t RCC_GetSystemClockFreq(void)
{
  uint32_t frequency;

  /* Get SYSCLK source -------------------------------------------------------*/
  switch (LL_RCC_GetSysClkSource())
  {
    case LL_RCC_SYS_CLKSOURCE_STATUS_MSI:  /* MSI used as system clock source */
      frequency = __LL_RCC_CALC_MSI_FREQ(LL_RCC_MSI_GetRange());
      break;

    case LL_RCC_SYS_CLKSOURCE_STATUS_HSI:  /* HSI used as system clock  source */
      frequency = HSI_VALUE;
      break;

    case LL_RCC_SYS_CLKSOURCE_STATUS_HSE:  /* HSE used as system clock  source */
      frequency = HSE_VALUE;
      break;

    case LL_RCC_SYS_CLKSOURCE_STATUS_PLL:  /* PLL used as system clock  source */
      frequency = RCC_PLL_GetFreqDomain_SYS();
      break;

    default:
      frequency = __LL_RCC_CALC_MSI_FREQ(LL_RCC_MSI_GetRange());
      break;
  }

  return frequency;
}

/**
  * @brief  Return HCLK clock frequency
  * @param  SYSCLK_Frequency SYSCLK clock frequency
  * @retval HCLK clock frequency (in Hz)
  */
static uint32_t RCC_GetHCLKClockFreq(uint32_t SYSCLK_Frequency)
{
  /* HCLK clock frequency */
  return __LL_RCC_CALC_HCLK_FREQ(SYSCLK_Frequency, LL_RCC_GetAHBPrescaler());
}

/**
  * @brief  Return PCLK1 clock frequency
  * @param  HCLK_Frequency HCLK clock frequency
  * @retval PCLK1 clock frequency (in Hz)
  */
static uint32_t RCC_GetPCLK1ClockFreq(uint32_t HCLK_Frequency)
{
  /* PCLK1 clock frequency */
  return __LL_RCC_CALC_PCLK1_FREQ(HCLK_Frequency, LL_RCC_GetAPB1Prescaler());
}

/**
  * @brief  Return PCLK2 clock frequency
  * @param  HCLK_Frequency HCLK clock frequency
  * @retval PCLK2 clock frequency (in Hz)
  */
static uint32_t RCC_GetPCLK2ClockFreq(uint32_t HCLK_Frequency)
{
  /* PCLK2 clock frequency */
  return __LL_RCC_CALC_PCLK2_FREQ(HCLK_Frequency, LL_RCC_GetAPB2Prescaler());
}

/**
  * @brief  Return PLL clock frequency used for system domain
  * @retval PLL clock frequency (in Hz)
  */
static uint32_t RCC_PLL_GetFreqDomain_SYS(void)
{
  uint32_t pllsource, pllinputfreq;

  /* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL divider) * PLL Multiplicator */

  /* Get PLL source */
  pllsource = LL_RCC_PLL_GetMainSource();

  switch (pllsource)
  {
    case LL_RCC_PLLSOURCE_HSI:       /* HSI used as PLL clock source */
      pllinputfreq = HSI_VALUE;
      break;

    case LL_RCC_PLLSOURCE_HSE:       /* HSE used as PLL clock source */
      pllinputfreq = HSE_VALUE;
      break;

    default:
      pllinputfreq = HSI_VALUE;
      break;
  }
  return __LL_RCC_CALC_PLLCLK_FREQ(pllinputfreq, LL_RCC_PLL_GetMultiplicator(), LL_RCC_PLL_GetDivider());
}
/**
  * @}
  */

/**
  * @}
  */

#endif /* defined(RCC) */

/**
  * @}
  */

#endif /* USE_FULL_LL_DRIVER */