gex-nrf-dongle/Src/usart.c

/**
  ******************************************************************************
  * File Name          : USART.c
  * Description        : This file provides code for the configuration
  *                      of the USART instances.
  ******************************************************************************
  * This notice applies to any and all portions of this file
  * that are not between comment pairs USER CODE BEGIN and
  * USER CODE END. Other portions of this file, whether 
  * inserted by the user or by software development tools
  * are owned by their respective copyright owners.
  *
  * Copyright (c) 2018 STMicroelectronics International N.V. 
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without 
  * modification, are permitted, provided that the following conditions are met:
  *
  * 1. Redistribution of source code must retain the above copyright notice, 
  *    this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright notice,
  *    this list of conditions and the following disclaimer in the documentation
  *    and/or other materials provided with the distribution.
  * 3. Neither the name of STMicroelectronics nor the names of other 
  *    contributors to this software may be used to endorse or promote products 
  *    derived from this software without specific written permission.
  * 4. This software, including modifications and/or derivative works of this 
  *    software, must execute solely and exclusively on microcontroller or
  *    microprocessor devices manufactured by or for STMicroelectronics.
  * 5. Redistribution and use of this software other than as permitted under 
  *    this license is void and will automatically terminate your rights under 
  *    this license. 
  *
  * THIS SOFTWARE IS PROVIDED BY STMICROELECTRONICS AND CONTRIBUTORS "AS IS" 
  * AND ANY EXPRESS, IMPLIED OR STATUTORY WARRANTIES, INCLUDING, BUT NOT 
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 
  * PARTICULAR PURPOSE AND NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY
  * RIGHTS ARE DISCLAIMED TO THE FULLEST EXTENT PERMITTED BY LAW. IN NO EVENT 
  * SHALL STMICROELECTRONICS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
  * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "usart.h"
#include <stdbool.h>

#include "gpio.h"
#include "dma.h"

/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/* USART1 init function */

void MX_USART1_UART_Init(void)
{
  LL_USART_InitTypeDef USART_InitStruct;

  LL_GPIO_InitTypeDef GPIO_InitStruct;
  /* Peripheral clock enable */
  LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_USART1);
  
  /**USART1 GPIO Configuration  
  PA9   ------> USART1_TX
  PA10   ------> USART1_RX 
  */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_9;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_HIGH;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  // we don't use Rx
//  GPIO_InitStruct.Pin = LL_GPIO_PIN_10;
//  GPIO_InitStruct.Mode = LL_GPIO_MODE_FLOATING;
//  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* USART1 DMA Init */

  /* USART1_TX Init */
  LL_DMA_SetDataTransferDirection(DMA1, LL_DMA_CHANNEL_4, LL_DMA_DIRECTION_MEMORY_TO_PERIPH);

  LL_DMA_SetChannelPriorityLevel(DMA1, LL_DMA_CHANNEL_4, LL_DMA_PRIORITY_LOW);

  LL_DMA_SetMode(DMA1, LL_DMA_CHANNEL_4, LL_DMA_MODE_NORMAL);

  LL_DMA_SetPeriphIncMode(DMA1, LL_DMA_CHANNEL_4, LL_DMA_PERIPH_NOINCREMENT);

  LL_DMA_SetMemoryIncMode(DMA1, LL_DMA_CHANNEL_4, LL_DMA_MEMORY_INCREMENT);

  LL_DMA_SetPeriphSize(DMA1, LL_DMA_CHANNEL_4, LL_DMA_PDATAALIGN_BYTE);

  LL_DMA_SetMemorySize(DMA1, LL_DMA_CHANNEL_4, LL_DMA_MDATAALIGN_BYTE);

  // the USART address
  LL_DMA_SetPeriphAddress(DMA1, LL_DMA_CHANNEL_4, LL_USART_DMA_GetRegAddr(USART1));

  USART_InitStruct.BaudRate = 115200;
  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;
  USART_InitStruct.HardwareFlowControl = LL_USART_HWCONTROL_NONE;
  LL_USART_Init(USART1, &USART_InitStruct);

  LL_USART_ConfigAsyncMode(USART1);

  LL_USART_Enable(USART1);
}


/* USER CODE BEGIN 1 */
static volatile bool usart_dma_first = true;
/** Wait for the last DMA request to finish - so the buffer can be re-filled with new content */
void MX_USART_DmaWaitReady(void)
{
    if (!usart_dma_first) {
        // wait for the last transfer to finish
        while (!LL_DMA_IsActiveFlag_TC4(DMA1));
    }

    LL_USART_DisableDMAReq_TX(USART1);
}

/** Send new content using DMA */
void MX_USART_DmaSend(uint8_t *buffer, uint32_t length)
{
    usart_dma_first = false;

    LL_USART_EnableDMAReq_TX(USART1);

    LL_DMA_DisableChannel(DMA1, LL_DMA_CHANNEL_4);
    LL_DMA_ClearFlag_TC4(DMA1);
    LL_DMA_SetMemoryAddress(DMA1, LL_DMA_CHANNEL_4, (uint32_t) buffer);
    LL_DMA_SetDataLength(DMA1, LL_DMA_CHANNEL_4, length);
    LL_DMA_EnableChannel(DMA1, LL_DMA_CHANNEL_4);
}

/* USER CODE END 1 */

/**
  * @}
  */

/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/