/**
* @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);
}