text: /**
    ******************************************************************************
    * @file    stm32l0xx_ll_lpuart.c
    * @author  MCD Application Team
    * @brief   LPUART LL module driver.
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; Copyright (c) 2016 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
    *
    ******************************************************************************
    */
  #if defined(USE_FULL_LL_DRIVER)
  
  /* Includes ------------------------------------------------------------------*/
  #include "stm32l0xx_ll_lpuart.h"
  #include "stm32l0xx_ll_rcc.h"
  #include "stm32l0xx_ll_bus.h"
  #ifdef  USE_FULL_ASSERT
      #include "stm32_assert.h"
  #else
      #define assert_param(expr) ((void)0U)
  #endif
  
  /** @addtogroup STM32L0xx_LL_Driver
    * @{
    */
  
  #if defined (LPUART1)
  
  /** @addtogroup LPUART_LL
    * @{
    */
  
  /* Private types -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  /* Private constants ---------------------------------------------------------*/
  /** @addtogroup LPUART_LL_Private_Constants
    * @{
    */
  
  /**
    * @}
    */
  
  
  /* Private macros ------------------------------------------------------------*/
  /** @addtogroup LPUART_LL_Private_Macros
    * @{
    */
  
  /* Check of parameters for configuration of LPUART registers                  */
  
  /* __BAUDRATE__ Depending on constraints applicable for LPUART BRR register   */
  /*              value :                                                       */
  /*                - fck must be in the range [3 x baudrate, 4096 x baudrate]  */
  /*                - LPUART_BRR register value should be >= 0x300              */
  /*                - LPUART_BRR register value should be <= 0xFFFFF (20 bits)  */
  /*              Baudrate specified by the user should belong to [8, 10600000].*/
  #define IS_LL_LPUART_BAUDRATE(__BAUDRATE__) (((__BAUDRATE__) <= 10600000U) && ((__BAUDRATE__) >= 8U))
  
  /* __VALUE__ BRR content must be greater than or equal to 0x300. */
  #define IS_LL_LPUART_BRR_MIN(__VALUE__)   ((__VALUE__) >= 0x300U)
  
  /* __VALUE__ BRR content must be lower than or equal to 0xFFFFF. */
  #define IS_LL_LPUART_BRR_MAX(__VALUE__)   ((__VALUE__) <= 0x000FFFFFU)
  
  #define IS_LL_LPUART_DIRECTION(__VALUE__) (((__VALUE__) == LL_LPUART_DIRECTION_NONE) \
                                          || ((__VALUE__) == LL_LPUART_DIRECTION_RX) \
                                          || ((__VALUE__) == LL_LPUART_DIRECTION_TX) \
                                          || ((__VALUE__) == LL_LPUART_DIRECTION_TX_RX))
  
  #define IS_LL_LPUART_PARITY(__VALUE__) (((__VALUE__) == LL_LPUART_PARITY_NONE) \
                                       || ((__VALUE__) == LL_LPUART_PARITY_EVEN) \
                                       || ((__VALUE__) == LL_LPUART_PARITY_ODD))
  
  #define IS_LL_LPUART_DATAWIDTH(__VALUE__) (((__VALUE__) == LL_LPUART_DATAWIDTH_7B) \
                                          || ((__VALUE__) == LL_LPUART_DATAWIDTH_8B) \
                                          || ((__VALUE__) == LL_LPUART_DATAWIDTH_9B))
  
  #define IS_LL_LPUART_STOPBITS(__VALUE__) (((__VALUE__) == LL_LPUART_STOPBITS_1) \
                                         || ((__VALUE__) == LL_LPUART_STOPBITS_2))
  
  #define IS_LL_LPUART_HWCONTROL(__VALUE__) (((__VALUE__) == LL_LPUART_HWCONTROL_NONE) \
                                         || ((__VALUE__) == LL_LPUART_HWCONTROL_RTS) \
                                         || ((__VALUE__) == LL_LPUART_HWCONTROL_CTS) \
                                         || ((__VALUE__) == LL_LPUART_HWCONTROL_RTS_CTS))
  
  /**
    * @}
    */
  
  /* Private function prototypes -----------------------------------------------*/
  
  /* Exported functions --------------------------------------------------------*/
  /** @addtogroup LPUART_LL_Exported_Functions
    * @{
    */
  
  /** @addtogroup LPUART_LL_EF_Init
    * @{
    */
  
  /**
    * @brief  De-initialize LPUART registers (Registers restored to their default values).
    * @param  LPUARTx LPUART Instance
    * @retval An ErrorStatus enumeration value:
    *          - SUCCESS: LPUART registers are de-initialized
    *          - ERROR: not applicable
    */
  ErrorStatus LL_LPUART_DeInit( USART_TypeDef *LPUARTx )
  {
      ErrorStatus status = SUCCESS;
  
      /* Check the parameters */
      assert_param( IS_LPUART_INSTANCE( LPUARTx ) );
  
      if( LPUARTx == LPUART1 )
      {
          /* Force reset of LPUART peripheral */
          LL_APB1_GRP1_ForceReset( LL_APB1_GRP1_PERIPH_LPUART1 );
  
          /* Release reset of LPUART peripheral */
          LL_APB1_GRP1_ReleaseReset( LL_APB1_GRP1_PERIPH_LPUART1 );
      }
      else
      {
          status = ERROR;
      }
  
      return ( status );
  }
  
  /**
    * @brief  Initialize LPUART registers according to the specified
    *         parameters in LPUART_InitStruct.
    * @note   As some bits in LPUART configuration registers can only be written when the LPUART is disabled (USART_CR1_UE bit =0),
    *         LPUART Peripheral should be in disabled state prior calling this function. Otherwise, ERROR result will be returned.
    * @note   Baud rate value stored in LPUART_InitStruct BaudRate field, should be valid (different from 0).
    * @param  LPUARTx LPUART Instance
    * @param  LPUART_InitStruct pointer to a @ref LL_LPUART_InitTypeDef structure
    *         that contains the configuration information for the specified LPUART peripheral.
    * @retval An ErrorStatus enumeration value:
    *          - SUCCESS: LPUART registers are initialized according to LPUART_InitStruct content
    *          - ERROR: Problem occurred during LPUART Registers initialization
    */
  ErrorStatus LL_LPUART_Init( USART_TypeDef *LPUARTx, LL_LPUART_InitTypeDef *LPUART_InitStruct )
  {
      ErrorStatus status = ERROR;
      uint32_t periphclk = LL_RCC_PERIPH_FREQUENCY_NO;
  
      /* Check the parameters */
      assert_param( IS_LPUART_INSTANCE( LPUARTx ) );
      assert_param( IS_LL_LPUART_BAUDRATE( LPUART_InitStruct->BaudRate ) );
      assert_param( IS_LL_LPUART_DATAWIDTH( LPUART_InitStruct->DataWidth ) );
      assert_param( IS_LL_LPUART_STOPBITS( LPUART_InitStruct->StopBits ) );
      assert_param( IS_LL_LPUART_PARITY( LPUART_InitStruct->Parity ) );
      assert_param( IS_LL_LPUART_DIRECTION( LPUART_InitStruct->TransferDirection ) );
      assert_param( IS_LL_LPUART_HWCONTROL( LPUART_InitStruct->HardwareFlowControl ) );
  
      /* LPUART needs to be in disabled state, in order to be able to configure some bits in
         CRx registers. Otherwise (LPUART not in Disabled state) => return ERROR */
      if( LL_LPUART_IsEnabled( LPUARTx ) == 0U )
      {
          /*---------------------------- LPUART CR1 Configuration -----------------------
           * Configure LPUARTx CR1 (LPUART Word Length, Parity and Transfer Direction bits) with parameters:
           * - DataWidth:          USART_CR1_M bits according to LPUART_InitStruct->DataWidth value
           * - Parity:             USART_CR1_PCE, USART_CR1_PS bits according to LPUART_InitStruct->Parity value
           * - TransferDirection:  USART_CR1_TE, USART_CR1_RE bits according to LPUART_InitStruct->TransferDirection value
           */
          MODIFY_REG( LPUARTx->CR1,
                      ( USART_CR1_M | USART_CR1_PCE | USART_CR1_PS | USART_CR1_TE | USART_CR1_RE ),
                      ( LPUART_InitStruct->DataWidth | LPUART_InitStruct->Parity | LPUART_InitStruct->TransferDirection ) );
  
          /*---------------------------- LPUART CR2 Configuration -----------------------
           * Configure LPUARTx CR2 (Stop bits) with parameters:
           * - Stop Bits:          USART_CR2_STOP bits according to LPUART_InitStruct->StopBits value.
           */
          LL_LPUART_SetStopBitsLength( LPUARTx, LPUART_InitStruct->StopBits );
  
          /*---------------------------- LPUART CR3 Configuration -----------------------
           * Configure LPUARTx CR3 (Hardware Flow Control) with parameters:
           * - HardwareFlowControl: USART_CR3_RTSE, USART_CR3_CTSE bits according to LPUART_InitStruct->HardwareFlowControl value.
           */
          LL_LPUART_SetHWFlowCtrl( LPUARTx, LPUART_InitStruct->HardwareFlowControl );
  
          /*---------------------------- LPUART BRR Configuration -----------------------
           * Retrieve Clock frequency used for LPUART Peripheral
           */
          periphclk = LL_RCC_GetLPUARTClockFreq( LL_RCC_LPUART1_CLKSOURCE );
  
          /* Configure the LPUART Baud Rate :
             - valid baud rate value (different from 0) is required
             - Peripheral clock as returned by RCC service, should be valid (different from 0).
          */
          if( ( periphclk != LL_RCC_PERIPH_FREQUENCY_NO )
                  && ( LPUART_InitStruct->BaudRate != 0U ) )
          {
              status = SUCCESS;
              LL_LPUART_SetBaudRate( LPUARTx,
                                     periphclk,
                                     LPUART_InitStruct->BaudRate );
  
              /* Check BRR is greater than or equal to 0x300 */
              assert_param( IS_LL_LPUART_BRR_MIN( LPUARTx->BRR ) );
  
              /* Check BRR is lower than or equal to 0xFFFFF */
              assert_param( IS_LL_LPUART_BRR_MAX( LPUARTx->BRR ) );
          }
  
      }
  
      return ( status );
  }
  
  /**
    * @brief Set each @ref LL_LPUART_InitTypeDef field to default value.
    * @param LPUART_InitStruct pointer to a @ref LL_LPUART_InitTypeDef structure
    *                          whose fields will be set to default values.
    * @retval None
    */
  
  void LL_LPUART_StructInit( LL_LPUART_InitTypeDef *LPUART_InitStruct )
  {
      /* Set LPUART_InitStruct fields to default values */
      LPUART_InitStruct->BaudRate            = 9600U;
      LPUART_InitStruct->DataWidth           = LL_LPUART_DATAWIDTH_8B;
      LPUART_InitStruct->StopBits            = LL_LPUART_STOPBITS_1;
      LPUART_InitStruct->Parity              = LL_LPUART_PARITY_NONE ;
      LPUART_InitStruct->TransferDirection   = LL_LPUART_DIRECTION_TX_RX;
      LPUART_InitStruct->HardwareFlowControl = LL_LPUART_HWCONTROL_NONE;
  }
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  #endif /* defined (LPUART1) */
  
  /**
    * @}
    */
  
  #endif /* USE_FULL_LL_DRIVER */
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
  
  