lt8920_test/modules/debug/usart.c

#include "stm32l0xx_hal.h"
#include "usart.h"
#include <stdio.h>
#include <string.h>

#ifdef __GNUC__    
  #define PUTCHAR_PROTOTYPE int __io_putchar(int ch)    
#else    
  #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)    
#endif  


UART_HandleTypeDef UartHandle;


PUTCHAR_PROTOTYPE   
{   
    UartHandle.Instance->TDR = ch & 0x01FF;
    //USART2->TDR = ch & 0x01FF;
    while (__HAL_USART_GET_FLAG(&UartHandle, USART_FLAG_TC) == RESET) {}
    //while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET) {}   
    return ch; 
}  


//
void usart_init(void)
{
    GPIO_InitTypeDef  GPIO_InitStruct;
    
    HAL_UART_DeInit(&UartHandle);
    
    __HAL_RCC_GPIOA_CLK_ENABLE();
    __HAL_RCC_USART2_CLK_ENABLE();
    
    GPIO_InitStruct.Pin       = GPIO_PIN_2;
    GPIO_InitStruct.Mode      = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull      = GPIO_PULLUP;
    GPIO_InitStruct.Speed     = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF4_USART2;
    
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
    
    GPIO_InitStruct.Pin = GPIO_PIN_3;
    GPIO_InitStruct.Alternate = GPIO_AF4_USART2;
    
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
    
    UartHandle.Instance        = USART2;

    UartHandle.Init.BaudRate   = 115200;
    UartHandle.Init.WordLength = UART_WORDLENGTH_8B;
    UartHandle.Init.StopBits   = UART_STOPBITS_1;
    UartHandle.Init.Parity     = UART_PARITY_NONE;
    UartHandle.Init.HwFlowCtl  = UART_HWCONTROL_NONE;
    UartHandle.Init.Mode       = UART_MODE_TX_RX;
    
    
    HAL_UART_Init(&UartHandle);
}

//
void HAL_UART_MspDeInit(UART_HandleTypeDef *huart)
{
    if (huart->Instance == USART2)
    {
        __HAL_RCC_USART2_FORCE_RESET();
        __HAL_RCC_USART2_RELEASE_RESET();
  
        HAL_GPIO_DeInit(GPIOA, GPIO_PIN_2);
        HAL_GPIO_DeInit(GPIOA, GPIO_PIN_3);
    }
}