stm32g4xx_hal_usart_ex.c

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/**
  ******************************************************************************
  * @file    stm32g4xx_hal_usart_ex.c
  * @author  MCD Application Team
  * @brief   Extended USART HAL module driver.
  *          This file provides firmware functions to manage the following extended
  *          functionalities of the Universal Synchronous Receiver Transmitter Peripheral (USART).
  *           + Peripheral Control functions
  *
  *
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2019 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.
  *
  ******************************************************************************
  @verbatim
  ==============================================================================
               ##### USART peripheral extended features  #####
  ==============================================================================

    (#) FIFO mode enabling/disabling and RX/TX FIFO threshold programming.

        -@- When USART operates in FIFO mode, FIFO mode must be enabled prior
            starting RX/TX transfers. Also RX/TX FIFO thresholds must be
            configured prior starting RX/TX transfers.

    (#) Slave mode enabling/disabling and NSS pin configuration.

        -@- When USART operates in Slave mode, Slave mode must be enabled prior
            starting RX/TX transfers.

  @endverbatim
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "stm32g4xx_hal.h"

/** @addtogroup STM32G4xx_HAL_Driver
  * @{
  */

/** @defgroup USARTEx USARTEx
  * @brief USART Extended HAL module driver
  * @{
  */

#ifdef HAL_USART_MODULE_ENABLED

/* Private typedef -----------------------------------------------------------*/
/** @defgroup USARTEx_Private_Constants USARTEx Private Constants
  * @{
  */
/* USART RX FIFO depth */
#define RX_FIFO_DEPTH 8U

/* USART TX FIFO depth */
#define TX_FIFO_DEPTH 8U
/**
  * @}
  */

/* Private define ------------------------------------------------------------*/
/* Private macros ------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/** @defgroup USARTEx_Private_Functions USARTEx Private Functions
  * @{
  */
static void USARTEx_SetNbDataToProcess(USART_HandleTypeDef *husart);
/**
  * @}
  */

/* Exported functions --------------------------------------------------------*/

/** @defgroup USARTEx_Exported_Functions  USARTEx Exported Functions
  * @{
  */

/** @defgroup USARTEx_Exported_Functions_Group1 IO operation functions
  * @brief Extended USART Transmit/Receive functions
  *
@verbatim
 ===============================================================================
                      ##### IO operation functions #####
 ===============================================================================
    This subsection provides a set of FIFO mode related callback functions.

    (#) TX/RX Fifos Callbacks:
        (+) HAL_USARTEx_RxFifoFullCallback()
        (+) HAL_USARTEx_TxFifoEmptyCallback()

@endverbatim
  * @{
  */

/**
  * @brief  USART RX Fifo full callback.
  * @param  husart USART handle.
  * @retval None
  */
__weak void HAL_USARTEx_RxFifoFullCallback(USART_HandleTypeDef *husart)
{
/* Prevent unused argument(s) compilation warning */
  UNUSED(husart);

/* NOTE : This function should not be modified, when the callback is needed,
            the HAL_USARTEx_RxFifoFullCallback can be implemented in the user file.
   */
}

/**
  * @brief  USART TX Fifo empty callback.
  * @param  husart USART handle.
  * @retval None
  */
__weak void HAL_USARTEx_TxFifoEmptyCallback(USART_HandleTypeDef *husart)
{
/* Prevent unused argument(s) compilation warning */
  UNUSED(husart);

/* NOTE : This function should not be modified, when the callback is needed,
            the HAL_USARTEx_TxFifoEmptyCallback can be implemented in the user file.
   */
}

/**
  * @}
  */

/** @defgroup USARTEx_Exported_Functions_Group2 Peripheral Control functions
  * @brief    Extended Peripheral Control functions
  *
@verbatim
 ===============================================================================
                      ##### Peripheral Control functions #####
 ===============================================================================
    [..] This section provides the following functions:
     (+) HAL_USARTEx_EnableSPISlaveMode() API enables the SPI slave mode
     (+) HAL_USARTEx_DisableSPISlaveMode() API disables the SPI slave mode
     (+) HAL_USARTEx_ConfigNSS API configures the Slave Select input pin (NSS)
     (+) HAL_USARTEx_EnableFifoMode() API enables the FIFO mode
     (+) HAL_USARTEx_DisableFifoMode() API disables the FIFO mode
     (+) HAL_USARTEx_SetTxFifoThreshold() API sets the TX FIFO threshold
     (+) HAL_USARTEx_SetRxFifoThreshold() API sets the RX FIFO threshold


@endverbatim
  * @{
  */

/**
  * @brief  Enable the SPI slave mode.
  * @note When the USART operates in SPI slave mode, it handles data flow using
  *       the serial interface clock derived from the external SCLK signal
  *       provided by the external master SPI device.
  * @note In SPI slave mode, the USART must be enabled before starting the master
  *       communications (or between frames while the clock is stable). Otherwise,
  *       if the USART slave is enabled while the master is in the middle of a
  *       frame, it will become desynchronized with the master.
  * @note The data register of the slave needs to be ready before the first edge
  *       of the communication clock or before the end of the ongoing communication,
  *       otherwise the SPI slave will transmit zeros.
  * @param husart      USART handle.
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_USARTEx_EnableSlaveMode(USART_HandleTypeDef *husart)
{
  uint32_t tmpcr1;

  /* Check parameters */
  assert_param(IS_UART_SPI_SLAVE_INSTANCE(husart->Instance));

  /* Process Locked */
  __HAL_LOCK(husart);

  husart->State = HAL_USART_STATE_BUSY;

  /* Save actual USART configuration */
  tmpcr1 = READ_REG(husart->Instance->CR1);

  /* Disable USART */
  __HAL_USART_DISABLE(husart);

  /* In SPI slave mode mode, the following bits must be kept cleared:
  - LINEN and CLKEN bit in the USART_CR2 register
  - HDSEL, SCEN and IREN bits in the USART_CR3 register.*/
  CLEAR_BIT(husart->Instance->CR2, (USART_CR2_LINEN | USART_CR2_CLKEN));
  CLEAR_BIT(husart->Instance->CR3, (USART_CR3_SCEN | USART_CR3_HDSEL | USART_CR3_IREN));

  /* Enable SPI slave mode */
  SET_BIT(husart->Instance->CR2, USART_CR2_SLVEN);

  /* Restore USART configuration */
  WRITE_REG(husart->Instance->CR1, tmpcr1);

  husart->SlaveMode = USART_SLAVEMODE_ENABLE;

  husart->State = HAL_USART_STATE_READY;

  /* Enable USART */
  __HAL_USART_ENABLE(husart);

  /* Process Unlocked */
  __HAL_UNLOCK(husart);

  return HAL_OK;
}

/**
  * @brief  Disable the SPI slave mode.
  * @param husart      USART handle.