rt-thread/bsp/stm32/libraries/HAL_Drivers/drv_usart.c

/*
 * Copyright (c) 2006-2018, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2018-10-30     SummerGift   change to new framework
 */
 
#include "board.h"
#include "drv_usart.h"
#include "drv_config.h"

#ifdef RT_USING_SERIAL

//#define DRV_DEBUG
#define LOG_TAG             "drv.usart"
#include <drv_log.h>

#if !defined(BSP_USING_UART1) && !defined(BSP_USING_UART2) && !defined(BSP_USING_UART3) && !defined(BSP_USING_UART4) && !defined(BSP_USING_UART5)
#error "Please define at least one BSP_USING_UARTx"
/* this driver can be disabled at menuconfig → RT-Thread Components → Device Drivers */
#endif

#if defined(SOC_SERIES_STM32F1) || defined(SOC_SERIES_STM32L4) || defined(SOC_SERIES_STM32F4)
#define UART_INSTANCE_CLEAR_FUNCTION    __HAL_UART_CLEAR_FLAG
#elif defined(SOC_SERIES_STM32F7)
#define UART_INSTANCE_CLEAR_FUNCTION    __HAL_UART_CLEAR_IT
#endif

#ifdef BSP_UART_USING_DMA_RX
static void stm32_dma_config(struct rt_serial_device *serial);
#endif

enum
{
#ifdef BSP_USING_UART1
    UART1_INDEX,
#endif
#ifdef BSP_USING_UART2
    UART2_INDEX,
#endif
#ifdef BSP_USING_UART3
    UART3_INDEX,
#endif
#ifdef BSP_USING_UART4
    UART4_INDEX,
#endif
#ifdef BSP_USING_UART5
    UART5_INDEX,
#endif
};

static const struct stm32_uart_config uart_config[] =
{
#ifdef BSP_USING_UART1
        UART1_CONFIG,
#endif
#ifdef BSP_USING_UART2
        UART2_CONFIG,
#endif
#ifdef BSP_USING_UART3
        UART3_CONFIG,
#endif
#ifdef BSP_USING_UART4
        UART4_CONFIG,
#endif
#ifdef BSP_USING_UART5
        UART5_CONFIG,
#endif
};

static struct stm32_uart uart_obj[sizeof(uart_config) / sizeof(uart_config[0])];

static rt_err_t stm32_configure(struct rt_serial_device *serial, struct serial_configure *cfg)
{
    struct stm32_uart *uart;
    RT_ASSERT(serial != RT_NULL);
    RT_ASSERT(cfg != RT_NULL);
    uart = (struct stm32_uart *)serial->parent.user_data;
    RT_ASSERT(uart != RT_NULL);

    uart->handle.Instance          = uart->config->Instance;
    uart->handle.Init.BaudRate     = cfg->baud_rate;
    uart->handle.Init.HwFlowCtl    = UART_HWCONTROL_NONE;
    uart->handle.Init.Mode         = UART_MODE_TX_RX;
    uart->handle.Init.OverSampling = UART_OVERSAMPLING_16;
    switch (cfg->data_bits)
    {
    case DATA_BITS_8:
        uart->handle.Init.WordLength = UART_WORDLENGTH_8B;
        break;
    case DATA_BITS_9:
        uart->handle.Init.WordLength = UART_WORDLENGTH_9B;
        break;
    default:
        uart->handle.Init.WordLength = UART_WORDLENGTH_8B;
        break;
    }
    switch (cfg->stop_bits)
    {
    case STOP_BITS_1:
        uart->handle.Init.StopBits   = UART_STOPBITS_1;
        break;
    case STOP_BITS_2:
        uart->handle.Init.StopBits   = UART_STOPBITS_2;
        break;
    default:
        uart->handle.Init.StopBits   = UART_STOPBITS_1;
        break;
    }
    switch (cfg->parity)
    {
    case PARITY_NONE:
        uart->handle.Init.Parity     = UART_PARITY_NONE;
        break;
    case PARITY_ODD:
        uart->handle.Init.Parity     = UART_PARITY_ODD;
        break;
    case PARITY_EVEN:
        uart->handle.Init.Parity     = UART_PARITY_EVEN;
        break;
    default:
        uart->handle.Init.Parity     = UART_PARITY_NONE;
        break;
    }

    if (HAL_UART_Init(&uart->handle) != HAL_OK)
    {
        return -RT_ERROR;
    }

    return RT_EOK;
}

static rt_err_t stm32_control(struct rt_serial_device *serial, int cmd, void *arg)
{
    struct stm32_uart *uart;
#ifdef BSP_UART_USING_DMA_RX
    rt_ubase_t ctrl_arg = (rt_ubase_t)arg;
#endif
    
    RT_ASSERT(serial != RT_NULL);
    uart = (struct stm32_uart *)serial->parent.user_data;
    RT_ASSERT(uart != RT_NULL);

    switch (cmd)
    {
    /* disable interrupt */
    case RT_DEVICE_CTRL_CLR_INT:
        /* disable rx irq */
        NVIC_DisableIRQ(uart->config->irq_type);
        /* disable interrupt */
        __HAL_UART_DISABLE_IT(&(uart->handle), UART_IT_RXNE);
        break;
    /* enable interrupt */
    case RT_DEVICE_CTRL_SET_INT:
        /* enable rx irq */
        NVIC_EnableIRQ(uart->config->irq_type);
        /* enable interrupt */
        __HAL_UART_ENABLE_IT(&(uart->handle), UART_IT_RXNE);
        break;

#ifdef BSP_UART_USING_DMA_RX
    case RT_DEVICE_CTRL_CONFIG:
        if (ctrl_arg == RT_DEVICE_FLAG_DMA_RX)
        {
            stm32_dma_config(serial);
        }
        break;
#endif
    }
    return RT_EOK;
}

static int stm32_putc(struct rt_serial_device *serial, char c)
{
    struct stm32_uart *uart;
    RT_ASSERT(serial != RT_NULL);

    uart = (struct stm32_uart *)serial->parent.user_data;
    UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_TC);
#if defined(SOC_SERIES_STM32L4) || defined(SOC_SERIES_STM32F7)
    uart->handle.Instance->TDR = c;
#else
    uart->handle.Instance->DR = c;
#endif
    while (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_TC) == RESET);
    return 1;
}

static int stm32_getc(struct rt_serial_device *serial)
{
    int ch;
    struct stm32_uart *uart;
    RT_ASSERT(serial != RT_NULL);
    uart = (struct stm32_uart *)serial->parent.user_data;
    RT_ASSERT(uart != RT_NULL);

    ch = -1;
    if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_RXNE) != RESET)
    {
#if defined(SOC_SERIES_STM32L4) || defined(SOC_SERIES_STM32F7)
        ch = uart->handle.Instance->RDR & 0xff;
#else
        ch = uart->handle.Instance->DR & 0xff;
#endif
    }
    return ch;
}

static const struct rt_uart_ops stm32_uart_ops =
{
    .configure = stm32_configure,
    .control = stm32_control,
    .putc = stm32_putc,
    .getc = stm32_getc,
};

/**
 * Uart common interrupt process. This need add to uart ISR.
 *
 * @param serial serial device
 */
static void uart_isr(struct rt_serial_device *serial)
{
    struct stm32_uart *uart;
#ifdef BSP_UART_USING_DMA_RX
    rt_size_t recv_total_index, recv_len;
    rt_base_t level;
#endif
    
    RT_ASSERT(serial != RT_NULL);

    uart = (struct stm32_uart *) serial->parent.user_data;
    RT_ASSERT(uart != RT_NULL);

    /* UART in mode Receiver -------------------------------------------------*/
    if ((__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_RXNE) != RESET) &&
        (__HAL_UART_GET_IT_SOURCE(&(uart->handle), UART_IT_RXNE) != RESET))
    {
        rt_hw_serial_isr(serial, RT_SERIAL_EVENT_RX_IND);
        /* Clear RXNE interrupt flag */
        UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_RXNE);
    }
#ifdef BSP_UART_USING_DMA_RX
    else if ((__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_IDLE) != RESET) &&
             (__HAL_UART_GET_IT_SOURCE(&(uart->handle), UART_IT_IDLE) != RESET))
    {
        level = rt_hw_interrupt_disable();
        recv_total_index = serial->config.bufsz - __HAL_DMA_GET_COUNTER(&(uart->dma.handle));
        recv_len = recv_total_index - uart->dma.last_index;
        uart->dma.last_index = recv_total_index;
        rt_hw_interrupt_enable(level);

        if (recv_len)
        {
            rt_hw_serial_isr(serial, RT_SERIAL_EVENT_RX_DMADONE | (recv_len << 8));
        }

        UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_IDLE);
        rt_uint32_t ch;
#if defined(SOC_SERIES_STM32L4) || defined(SOC_SERIES_STM32F7)
        ch = uart->handle.Instance->RDR;
#else
        ch = uart->handle.Instance->DR;
#endif
        ch = ch;
    }
#endif
    else
    {
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_ORE) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_ORE);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_NE) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_NE);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_FE) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_FE);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_PE) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_PE);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_CTS) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_CTS);
        }
#if defined(SOC_SERIES_STM32F1) || defined(SOC_SERIES_STM32F4)
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_LBD) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_LBD);
        }
#elif defined(SOC_SERIES_STM32F7) || defined(SOC_SERIES_STM32L4)
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_LBDF) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_LBDF);
        }
#endif
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_TXE) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_TXE);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_TC) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_TC);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_RXNE) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_RXNE);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_IDLE) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_IDLE);
        }
#if defined(SOC_SERIES_STM32F7) || defined(SOC_SERIES_STM32L4)
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_TEACK) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_TEACK);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_SBKF) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_SBKF);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_CMF) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_CMF);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_BUSY) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_BUSY);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_ABRF) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_ABRF);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_ABRE) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_ABRE);
        }
        if (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_CTSIF) != RESET)
        {
            UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_CTSIF);
        }
#endif         
    }
}

#if defined(BSP_USING_UART1)
void USART1_IRQHandler(void)
{
    /* enter interrupt */
    rt_interrupt_enter();

    uart_isr(&(uart_obj[UART1_INDEX].serial));
    
    /* leave interrupt */
    rt_interrupt_leave();
}
#if defined(BSP_UART_USING_DMA_RX) && defined(USART1_RX_DMA_ISR)
void USART1_RX_DMA_ISR(void)
{
    /* enter interrupt */
    rt_interrupt_enter();

    HAL_DMA_IRQHandler(&uart_obj[UART1_INDEX].dma.handle);

    /* leave interrupt */
    rt_interrupt_leave();
}
#endif /* defined(BSP_UART_USING_DMA_RX) && defined(USART1_RX_DMA_ISR) */
#endif /* BSP_USING_UART1 */

#if defined(BSP_USING_UART2)
void USART2_IRQHandler(void)
{
    /* enter interrupt */
    rt_interrupt_enter();

    uart_isr(&(uart_obj[UART2_INDEX].serial));

    /* leave interrupt */
    rt_interrupt_leave();
}
#if defined(BSP_UART_USING_DMA_RX) && defined(USART2_RX_DMA_ISR)
void USART2_RX_DMA_ISR(void)
{
    /* enter interrupt */
    rt_interrupt_enter();

    HAL_DMA_IRQHandler(&uart_obj[UART2_INDEX].dma.handle);

    /* leave interrupt */
    rt_interrupt_leave();
}
#endif /* defined(BSP_UART_USING_DMA_RX) && defined(USART2_RX_DMA_ISR) */
#endif /* BSP_USING_UART2 */

#if defined(BSP_USING_UART3)
void USART3_IRQHandler(void)
{
    /* enter interrupt */
    rt_interrupt_enter();

    uart_isr(&(uart_obj[UART3_INDEX].serial));
    
    /* leave interrupt */
    rt_interrupt_leave();
}
#if defined(BSP_UART_USING_DMA_RX) && defined(USART3_RX_DMA_ISR)
void USART3_RX_DMA_ISR(void)
{
    /* enter interrupt */
    rt_interrupt_enter();

    HAL_DMA_IRQHandler(&uart_obj[UART3_INDEX].dma.handle);

    /* leave interrupt */
    rt_interrupt_leave();
}
#endif /* defined(BSP_UART_USING_DMA_RX) && defined(USART3_RX_DMA_ISR) */
#endif /* BSP_USING_UART3*/

#if defined(BSP_USING_UART4)
void UART4_IRQHandler(void)
{
    /* enter interrupt */
    rt_interrupt_enter();

    uart_isr(&(uart_obj[UART4_INDEX].serial));
    
    /* leave interrupt */
    rt_interrupt_leave();
}
#if defined(BSP_UART_USING_DMA_RX) && defined(USART1_RX_DMA_ISR)
void USART4_RX_DMA_ISR(void)
{
    /* enter interrupt */
    rt_interrupt_enter();

    HAL_DMA_IRQHandler(&uart_obj[UART4_INDEX].dma.handle);

    /* leave interrupt */
    rt_interrupt_leave();
}
#endif /* defined(BSP_UART_USING_DMA_RX) && defined(USART4_RX_DMA_ISR) */
#endif /* BSP_USING_UART4*/

#if defined(BSP_USING_UART5)
void UART5_IRQHandler(void)
{
    /* enter interrupt */
    rt_interrupt_enter();

    uart_isr(&(uart_obj[UART5_INDEX].serial));
    
    /* leave interrupt */
    rt_interrupt_leave();
}
#if defined(BSP_UART_USING_DMA_RX) && defined(USART5_RX_DMA_ISR)
void USART5_RX_DMA_ISR(void)
{
    /* enter interrupt */
    rt_interrupt_enter();

    HAL_DMA_IRQHandler(&uart_obj[UART5_INDEX].dma.handle);

    /* leave interrupt */
    rt_interrupt_leave();
}
#endif /* defined(BSP_UART_USING_DMA_RX) && defined(USART5_RX_DMA_ISR) */
#endif /* BSP_USING_UART5*/

#ifdef BSP_UART_USING_DMA_RX
static void stm32_dma_config(struct rt_serial_device *serial)
{
    RT_ASSERT(serial != RT_NULL);
    struct stm32_uart *uart = (struct stm32_uart *)serial->parent.user_data;
    RT_ASSERT(uart != RT_NULL);
    struct rt_serial_rx_fifo *rx_fifo;
    
    LOG_D("%s dma config start", uart->config->name);

    {
        rt_uint32_t tmpreg= 0x00U;
#if defined(SOC_SERIES_STM32F1)
        /* enable DMA clock && Delay after an RCC peripheral clock enabling*/
        SET_BIT(RCC->AHBENR, uart->config->dma_rcc);
        tmpreg = READ_BIT(RCC->AHBENR, uart->config->dma_rcc);
#elif defined(SOC_SERIES_STM32F4) || defined(SOC_SERIES_STM32F7) || defined(SOC_SERIES_STM32L4)
        /* enable DMA clock && Delay after an RCC peripheral clock enabling*/
        SET_BIT(RCC->AHB1ENR, uart->config->dma_rcc);
        tmpreg = READ_BIT(RCC->AHB1ENR, uart->config->dma_rcc);
#endif  
        UNUSED(tmpreg);   /* To avoid compiler warnings */
    }
    
    __HAL_LINKDMA(&(uart->handle), hdmarx, uart->dma.handle);

#if defined(SOC_SERIES_STM32F1) 
    uart->dma.handle.Instance                 = uart->config->dma.Instance;
#elif defined(SOC_SERIES_STM32F4) || defined(SOC_SERIES_STM32F7)
    uart->dma.handle.Instance                 = uart->config->dma.Instance;
    uart->dma.handle.Init.Channel             = uart->config->dma.stream_channel.channel;
#elif defined(SOC_SERIES_STM32L4) 
    uart->dma.handle.Instance                 = uart->config->dma.Instance;
    uart->dma.handle.Init.Request             = uart->config->dma.channel_request.request;
#endif
    uart->dma.handle.Init.Direction           = DMA_PERIPH_TO_MEMORY;
    uart->dma.handle.Init.PeriphInc           = DMA_PINC_DISABLE;
    uart->dma.handle.Init.MemInc              = DMA_MINC_ENABLE;
    uart->dma.handle.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
    uart->dma.handle.Init.MemDataAlignment    = DMA_MDATAALIGN_BYTE;
    uart->dma.handle.Init.Mode                = DMA_CIRCULAR;
    uart->dma.handle.Init.Priority            = DMA_PRIORITY_MEDIUM;
#if defined(SOC_SERIES_STM32F4) || defined(SOC_SERIES_STM32F7)
    uart->dma.handle.Init.FIFOMode            = DMA_FIFOMODE_DISABLE;
#endif
    if (HAL_DMA_DeInit(&(uart->dma.handle)) != HAL_OK)
    {
        RT_ASSERT(0);
    }

    if (HAL_DMA_Init(&(uart->dma.handle)) != HAL_OK)
    {
        RT_ASSERT(0);
    }

    rx_fifo = (struct rt_serial_rx_fifo *)serial->serial_rx;
    
    /* Start DMA transfer */
    if (HAL_UART_Receive_DMA(&(uart->handle), rx_fifo->buffer, serial->config.bufsz) != HAL_OK)
    {
        /* Transfer error in reception process */
        RT_ASSERT(0);
    }

    /* enable interrupt */
    __HAL_UART_ENABLE_IT(&(uart->handle), UART_IT_IDLE);
    
    /* enable rx irq */
    HAL_NVIC_SetPriority(uart->config->dma_irq, 1, 0);
    HAL_NVIC_EnableIRQ(uart->config->dma_irq);
    
    HAL_NVIC_SetPriority(uart->config->irq_type, 0, 0);
    HAL_NVIC_EnableIRQ(uart->config->irq_type);
    
    LOG_D("%s dma RX instance: %x", uart->config->name, uart->dma.handle.Instance);
    LOG_D("%s dma config done", uart->config->name);
}

/**
  * @brief  UART error callbacks
  * @param  huart: UART handle
  * @note   This example shows a simple way to report transfer error, and you can
  *         add your own implementation.
  * @retval None
  */
void HAL_UART_ErrorCallback(UART_HandleTypeDef *huart)
{
    RT_ASSERT(huart != NULL);
    struct stm32_uart *uart = (struct stm32_uart *)huart;
    LOG_D("%s: %s %d\n", __FUNCTION__, uart->config->name, huart->ErrorCode);
    UNUSED(uart);
}

/**
  * @brief  Rx Transfer completed callback
  * @param  huart: UART handle
  * @note   This example shows a simple way to report end of DMA Rx transfer, and
  *         you can add your own implementation.
  * @retval None
  */
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
    struct rt_serial_device *serial;
    struct stm32_uart *uart;
    rt_size_t recv_len;
    rt_base_t level;

    RT_ASSERT(huart != NULL);
    uart = (struct stm32_uart *)huart;
    serial = &uart->serial;

    level = rt_hw_interrupt_disable();

    recv_len = serial->config.bufsz - uart->dma.last_index;
    uart->dma.last_index = 0;

    rt_hw_interrupt_enable(level);
    if (recv_len)
    {
        rt_hw_serial_isr(serial, RT_SERIAL_EVENT_RX_DMADONE | (recv_len << 8));
    }
}
#endif  /* BSP_UART_USING_DMA_RX */

int rt_hw_usart_init(void)
{
    rt_size_t obj_num = sizeof(uart_obj) / sizeof(struct stm32_uart);
    struct serial_configure config = RT_SERIAL_CONFIG_DEFAULT;
    
    rt_err_t result = 0;
    
    for (int i = 0; i < obj_num; i++)
    {
        uart_obj[i].config = &uart_config[i];
        uart_obj[i].serial.ops    = &stm32_uart_ops;
        uart_obj[i].serial.config = config;
        
        /* Determines whether a serial instance supports DMA */
        if(uart_obj[i].config->dma.Instance != DMA_NOT_AVAILABLE) 
        {
            /* register UART device */
            result = rt_hw_serial_register(&uart_obj[i].serial,uart_obj[i].config->name,
                                           RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX
#if defined(BSP_UART_USING_DMA_RX)
                                           | RT_DEVICE_FLAG_DMA_RX 
#endif
                                           ,&uart_obj[i]);
        }
        else
        {
            /* register UART device */
            result = rt_hw_serial_register(&uart_obj[i].serial,uart_obj[i].config->name,
                                           RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX
                                           ,&uart_obj[i]);
        }
        RT_ASSERT(result == RT_EOK);
    }

    return result;
}

#endif /* RT_USING_SERIAL */