/**
******************************************************************************
* @file stm32l1xx_ll_usart.c
* @author MCD Application Team
* @brief USART LL module driver.
******************************************************************************
* @attention
*
* Copyright (c) 2016 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_usart.h"
#include "stm32l1xx_ll_rcc.h"
#include "stm32l1xx_ll_bus.h"
#ifdef USE_FULL_ASSERT
#include "stm32_assert.h"
#else
#define assert_param(expr) ((void)0U)
#endif
/** @addtogroup STM32L1xx_LL_Driver
* @{
*/
#if defined (USART1) || defined (USART2) || defined (USART3) || defined (UART4) || defined (UART5)
/** @addtogroup USART_LL
* @{
*/
/* Private types -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private constants ---------------------------------------------------------*/
/** @addtogroup USART_LL_Private_Constants
* @{
*/
/**
* @}
*/
/* Private macros ------------------------------------------------------------*/
/** @addtogroup USART_LL_Private_Macros
* @{
*/
/* __BAUDRATE__ The maximum Baud Rate is derived from the maximum clock available
* divided by the smallest oversampling used on the USART (i.e. 8) */
#define IS_LL_USART_BAUDRATE(__BAUDRATE__) ((__BAUDRATE__) <= 4000000U)
/* __VALUE__ In case of oversampling by 16 and 8, BRR content must be greater than or equal to 16d. */
#define IS_LL_USART_BRR_MIN(__VALUE__) ((__VALUE__) >= 16U)
#define IS_LL_USART_DIRECTION(__VALUE__) (((__VALUE__) == LL_USART_DIRECTION_NONE) \
|| ((__VALUE__) == LL_USART_DIRECTION_RX) \
|| ((__VALUE__) == LL_USART_DIRECTION_TX) \
|| ((__VALUE__) == LL_USART_DIRECTION_TX_RX))
#define IS_LL_USART_PARITY(__VALUE__) (((__VALUE__) == LL_USART_PARITY_NONE) \
|| ((__VALUE__) == LL_USART_PARITY_EVEN) \
|| ((__VALUE__) == LL_USART_PARITY_ODD))
#define IS_LL_USART_DATAWIDTH(__VALUE__) (((__VALUE__) == LL_USART_DATAWIDTH_8B) \
|| ((__VALUE__) == LL_USART_DATAWIDTH_9B))
#define IS_LL_USART_OVERSAMPLING(__VALUE__) (((__VALUE__) == LL_USART_OVERSAMPLING_16) \
|| ((__VALUE__) == LL_USART_OVERSAMPLING_8))
#define IS_LL_USART_LASTBITCLKOUTPUT(__VALUE__) (((__VALUE__) == LL_USART_LASTCLKPULSE_NO_OUTPUT) \
|| ((__VALUE__) == LL_USART_LASTCLKPULSE_OUTPUT))
#define IS_LL_USART_CLOCKPHASE(__VALUE__) (((__VALUE__) == LL_USART_PHASE_1EDGE) \
|| ((__VALUE__) == LL_USART_PHASE_2EDGE))
#define IS_LL_USART_CLOCKPOLARITY(__VALUE__) (((__VALUE__) == LL_USART_POLARITY_LOW) \
|| ((__VALUE__) == LL_USART_POLARITY_HIGH))
#define IS_LL_USART_CLOCKOUTPUT(__VALUE__) (((__VALUE__) == LL_USART_CLOCK_DISABLE) \
|| ((__VALUE__) == LL_USART_CLOCK_ENABLE))
#define IS_LL_USART_STOPBITS(__VALUE__) (((__VALUE__) == LL_USART_STOPBITS_0_5) \
|| ((__VALUE__) == LL_USART_STOPBITS_1) \
|| ((__VALUE__) == LL_USART_STOPBITS_1_5) \
|| ((__VALUE__) == LL_USART_STOPBITS_2))
#define IS_LL_USART_HWCONTROL(__VALUE__) (((__VALUE__) == LL_USART_HWCONTROL_NONE) \
|| ((__VALUE__) == LL_USART_HWCONTROL_RTS) \
|| ((__VALUE__) == LL_USART_HWCONTROL_CTS) \
|| ((__VALUE__) == LL_USART_HWCONTROL_RTS_CTS))
/**
* @}
*/
/* Private function prototypes -----------------------------------------------*/
/* Exported functions --------------------------------------------------------*/
/** @addtogroup USART_LL_Exported_Functions
* @{
*/
/** @addtogroup USART_LL_EF_Init
* @{
*/
/**
* @brief De-initialize USART registers (Registers restored to their default values).
* @param USARTx USART Instance
* @retval An ErrorStatus enumeration value:
* - SUCCESS: USART registers are de-initialized
* - ERROR: USART registers are not de-initialized
*/
ErrorStatus LL_USART_DeInit(const USART_TypeDef *USARTx)
{
ErrorStatus status = SUCCESS;
/* Check the parameters */
assert_param(IS_UART_INSTANCE(USARTx));
if (USARTx == USART1)
{
/* Force reset of USART clock */
LL_APB2_GRP1_ForceReset(LL_APB2_GRP1_PERIPH_USART1);
/* Release reset of USART clock */
LL_APB2_GRP1_ReleaseReset(LL_APB2_GRP1_PERIPH_USART1);
}
else if (USARTx == USART2)
{
/* Force reset of USART clock */
LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_USART2);
/* Release reset of USART clock */
LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_USART2);
}
else if (USARTx == USART3)
{
/* Force reset of USART clock */
LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_USART3);
/* Release reset of USART clock */
LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_USART3);
}
#if defined(UART4)
else if (USARTx == UART4)
{
/* Force reset of UART clock */
LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_UART4);
/* Release reset of UART clock */
LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_UART4);
}
#endif /* UART4 */
#if defined(UART5)
else if (USARTx == UART5)
{
/* Force reset of UART clock */
LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_UART5);
/* Release reset of UART clock */
LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_UART5);
}
#endif /* UART5 */
else
{
status = ERROR;
}
return (status);
}
/**
* @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, const LL_USART_InitTypeDef *USART_InitStruct)
{
ErrorStatus status = ERROR;
uint32_t periphclk = LL_RCC_PERIPH_FREQUENCY_NO;
LL_RCC_ClocksTypeDef rcc_clocks;
/* 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
*/
LL_RCC_GetSystemClocksFreq(&rcc_clocks);
if (USARTx == USART1)
{
periphclk = rcc_clocks.PCLK2_Frequency;
}
else if (USARTx == USART2)
{
periphclk = rcc_clocks.PCLK1_Frequency;
}
else if (USARTx == USART3)
{
periphclk = rcc_clocks.PCLK1_Frequency;
}
#if defined(UART4)
else if (USARTx == UART4)
{
periphclk = rcc_clocks.PCLK1_Frequency;
}
#endif /* UART4 */
#if defined(UART5)
else if (USARTx == UART5)
{
periphclk = rcc_clocks.PCLK1_Frequency;
}
#endif /* UART5 */
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);
/* Check BRR is greater than or equal to 16d */
assert_param(IS_LL_USART_BRR_MIN(USARTx->BRR));
}
}
/* Endif (=> USART not in Disabled state => return ERROR) */
return (status);
}
/**
* @brief Set each @ref LL_USART_InitTypeDef field to default value.
* @param USART_InitStruct Pointer to a @ref LL_USART_InitTypeDef structure
* whose fields will be set to default values.
* @retval None
*/
void LL_USART_StructInit(LL_USART_InitTypeDef *USART_InitStruct)
{
/* Set USART_InitStruct fields to default values */
USART_InitStruct->BaudRate = 9600U;
USART_InitStruct->DataWidth = LL_USART_DATAWIDTH_8B;
USART_InitStruct->StopBits = LL_USART_STOPBITS_1;
USART_InitStruct->Parity = LL_USART_PARITY_NONE ;
USART_InitStruct->TransferDirection = LL_USART_DIRECTION_TX_RX;
USART_InitStruct->HardwareFlowControl = LL_USART_HWCONTROL_NONE;
USART_InitStruct->OverSampling = LL_USART_OVERSAMPLING_16;
}
/**
* @brief Initialize USART Clock related settings according to the
* specified parameters in the USART_ClockInitStruct.
* @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.
* @param USARTx USART Instance
* @param USART_ClockInitStruct Pointer to a @ref LL_USART_ClockInitTypeDef structure
* that contains the Clock configuration information for the specified USART peripheral.
* @retval An ErrorStatus enumeration value:
* - SUCCESS: USART registers related to Clock settings are initialized according to USART_ClockInitStruct content
* - ERROR: Problem occurred during USART Registers initialization
*/
ErrorStatus LL_USART_ClockInit(USART_TypeDef *USARTx, const LL_USART_ClockInitTypeDef *USART_ClockInitStruct)
{
ErrorStatus status = SUCCESS;
/* Check USART Instance and Clock signal output parameters */
assert_param(IS_UART_INSTANCE(USARTx));
assert_param(IS_LL_USART_CLOCKOUTPUT(USART_ClockInitStruct->ClockOutput));
/* 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 CR2 Configuration -----------------------*/
/* If Clock signal has to be output */
if (USART_ClockInitStruct->ClockOutput == LL_USART_CLOCK_DISABLE)
{
/* Deactivate Clock signal delivery :
* - Disable Clock Output: USART_CR2_CLKEN cleared
*/
LL_USART_DisableSCLKOutput(USARTx);
}
else
{
/* Ensure USART instance is USART capable */
assert_param(IS_USART_INSTANCE(USARTx));
/* Check clock related parameters */
assert_param(IS_LL_USART_CLOCKPOLARITY(USART_ClockInitStruct->ClockPolarity));
assert_param(IS_LL_USART_CLOCKPHASE(USART_ClockInitStruct->ClockPhase));
assert_param(IS_LL_USART_LASTBITCLKOUTPUT(USART_ClockInitStruct->LastBitClockPulse));
/*---------------------------- USART CR2 Configuration -----------------------
* Configure USARTx CR2 (Clock signal related bits) with parameters:
* - Enable Clock Output: USART_CR2_CLKEN set
* - Clock Polarity: USART_CR2_CPOL bit according to USART_ClockInitStruct->ClockPolarity value
* - Clock Phase: USART_CR2_CPHA bit according to USART_ClockInitStruct->ClockPhase value
* - Last Bit Clock Pulse Output: USART_CR2_LBCL bit according to USART_ClockInitStruct->LastBitClockPulse value.
*/
MODIFY_REG(USARTx->CR2,
USART_CR2_CLKEN | USART_CR2_CPHA | USART_CR2_CPOL | USART_CR2_LBCL,
USART_CR2_CLKEN | USART_ClockInitStruct->ClockPolarity |
USART_ClockInitStruct->ClockPhase | USART_ClockInitStruct->LastBitClockPulse);
}
}
/* Else (USART not in Disabled state => return ERROR */
else
{
status = ERROR;
}
return (status);
}
/**
* @brief Set each field of a @ref LL_USART_ClockInitTypeDef type structure to default value.
* @param USART_ClockInitStruct Pointer to a @ref LL_USART_ClockInitTypeDef structure
* whose fields will be set to default values.
* @retval None
*/
void LL_USART_ClockStructInit(LL_USART_ClockInitTypeDef *USART_ClockInitStruct)
{
/* Set LL_USART_ClockInitStruct fields with default values */
USART_ClockInitStruct->ClockOutput = LL_USART_CLOCK_DISABLE;
USART_ClockInitStruct->ClockPolarity = LL_USART_POLARITY_LOW; /* Not relevant when ClockOutput = LL_USART_CLOCK_DISABLE */
USART_ClockInitStruct->ClockPhase = LL_USART_PHASE_1EDGE; /* Not relevant when ClockOutput = LL_USART_CLOCK_DISABLE */
USART_ClockInitStruct->LastBitClockPulse = LL_USART_LASTCLKPULSE_NO_OUTPUT; /* Not relevant when ClockOutput = LL_USART_CLOCK_DISABLE */
}
/**
* @}
*/
/**
* @}
*/
/**
* @}
*/
#endif /* USART1 || USART2|| USART3 || UART4 || UART5 */
/**
* @}
*/
#endif /* USE_FULL_LL_DRIVER */