/** * @brief Initialize USART registers according to the specified * parameters in USART_InitStruct. * @note As some bits in USART configuration registers can only be written when the USART is disabled (USART_CR1_UE bit =0), * USART IP should be in disabled state prior calling this function. Otherwise, ERROR result will be returned. * @note Baud rate value stored in USART_InitStruct BaudRate field, should be valid (different from 0). * @param USARTx USART Instance * @param USART_InitStruct: pointer to a LL_USART_InitTypeDef structure * that contains the configuration information for the specified USART peripheral. * @retval An ErrorStatus enumeration value: * - SUCCESS: USART registers are initialized according to USART_InitStruct content * - ERROR: Problem occurred during USART Registers initialization */ ErrorStatus LL_USART_Init(USART_TypeDef *USARTx, LL_USART_InitTypeDef *USART_InitStruct) { ErrorStatus status = ERROR; uint32_t periphclk = LL_RCC_PERIPH_FREQUENCY_NO; #if (defined(USART4) || defined(USART5)) LL_RCC_ClocksTypeDef RCC_Clocks; #endif /* Check the parameters */ assert_param(IS_UART_INSTANCE(USARTx)); assert_param(IS_LL_USART_BAUDRATE(USART_InitStruct->BaudRate)); assert_param(IS_LL_USART_DATAWIDTH(USART_InitStruct->DataWidth)); assert_param(IS_LL_USART_STOPBITS(USART_InitStruct->StopBits)); assert_param(IS_LL_USART_PARITY(USART_InitStruct->Parity)); assert_param(IS_LL_USART_DIRECTION(USART_InitStruct->TransferDirection)); assert_param(IS_LL_USART_HWCONTROL(USART_InitStruct->HardwareFlowControl)); assert_param(IS_LL_USART_OVERSAMPLING(USART_InitStruct->OverSampling)); /* USART needs to be in disabled state, in order to be able to configure some bits in CRx registers */ if (LL_USART_IsEnabled(USARTx) == 0U) { /*---------------------------- USART CR1 Configuration ----------------------- * Configure USARTx CR1 (USART Word Length, Parity, Mode and Oversampling bits) with parameters: * - DataWidth: USART_CR1_M bits according to USART_InitStruct->DataWidth value * - Parity: USART_CR1_PCE, USART_CR1_PS bits according to USART_InitStruct->Parity value * - TransferDirection: USART_CR1_TE, USART_CR1_RE bits according to USART_InitStruct->TransferDirection value * - Oversampling: USART_CR1_OVER8 bit according to USART_InitStruct->OverSampling value. */ MODIFY_REG(USARTx->CR1, (USART_CR1_M | USART_CR1_PCE | USART_CR1_PS | USART_CR1_TE | USART_CR1_RE | USART_CR1_OVER8), (USART_InitStruct->DataWidth | USART_InitStruct->Parity | USART_InitStruct->TransferDirection | USART_InitStruct->OverSampling)); /*---------------------------- USART CR2 Configuration ----------------------- * Configure USARTx CR2 (Stop bits) with parameters: * - Stop Bits: USART_CR2_STOP bits according to USART_InitStruct->StopBits value. * - CLKEN, CPOL, CPHA and LBCL bits are to be configured using LL_USART_ClockInit(). */ LL_USART_SetStopBitsLength(USARTx, USART_InitStruct->StopBits); /*---------------------------- USART CR3 Configuration ----------------------- * Configure USARTx CR3 (Hardware Flow Control) with parameters: * - HardwareFlowControl: USART_CR3_RTSE, USART_CR3_CTSE bits according to USART_InitStruct->HardwareFlowControl value. */ LL_USART_SetHWFlowCtrl(USARTx, USART_InitStruct->HardwareFlowControl); /*---------------------------- USART BRR Configuration ----------------------- * Retrieve Clock frequency used for USART Peripheral */ #if defined(USART1) if (USARTx == USART1) { periphclk = LL_RCC_GetUSARTClockFreq(LL_RCC_USART1_CLKSOURCE); } #endif /* USART1 */ #if defined(USART1) else if (USARTx == USART2) #else if (USARTx == USART2) #endif { periphclk = LL_RCC_GetUSARTClockFreq(LL_RCC_USART2_CLKSOURCE); } #if defined(USART4) else if (USARTx == USART4) { /* USART4 clock is PCLK1 */ LL_RCC_GetSystemClocksFreq(&RCC_Clocks); periphclk = RCC_Clocks.PCLK1_Frequency; } #endif /* USART4 */ #if defined(USART5) else if (USARTx == USART5) { /* USART5 clock is PCLK1 */ LL_RCC_GetSystemClocksFreq(&RCC_Clocks); periphclk = RCC_Clocks.PCLK1_Frequency; } #endif /* USART5 */ else { /* Nothing to do, as error code is already assigned to ERROR value */ } /* Configure the USART 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) && (USART_InitStruct->BaudRate != 0U)) { status = SUCCESS; LL_USART_SetBaudRate(USARTx, periphclk, USART_InitStruct->OverSampling, USART_InitStruct->BaudRate); } } /* Endif (=> USART not in Disabled state => return ERROR) */ return (status); }
static inline void uart_stm32_set_hwctrl(struct device *dev, u32_t hwctrl) { USART_TypeDef *UartInstance = UART_STRUCT(dev); LL_USART_SetHWFlowCtrl(UartInstance, hwctrl); }