/*
 * Serial communication for STM32F042 boards.
 *
 *  Copyright (C) 2019 Eug Krashtan <eug.krashtan@gmail.com>
 *  This file may be distributed under the terms of the GNU GPLv3 license.
 *
 */

#include "stm32f0xx_hal.h"
#include <string.h>
#include "autoconf.h" // CONFIG_SERIAL_BAUD
#include "board/serial_irq.h" // serial_rx_byte
#include "sched.h" // DECL_INIT

UART_HandleTypeDef huart2;
static uint8_t rxbuf, txbuf;

void USART2_IRQHandler(void)
{
  HAL_UART_IRQHandler(&huart2);
}

/**
  * @brief USART2 Initialization Function
  * @param None
  * @retval None
  */
void UartInit(void)
{
    huart2.Instance = USART2;
    huart2.Init.BaudRate = CONFIG_SERIAL_BAUD;
    huart2.Init.WordLength = UART_WORDLENGTH_8B;
    huart2.Init.StopBits = UART_STOPBITS_1;
    huart2.Init.Parity = UART_PARITY_NONE;
    huart2.Init.Mode = UART_MODE_TX_RX;
    huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
    huart2.Init.OverSampling = UART_OVERSAMPLING_16;
    huart2.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
    huart2.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
    HAL_UART_Init(&huart2);

    HAL_UART_Receive_IT(&huart2,&rxbuf,(uint16_t)1);
}
DECL_INIT(UartInit);

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
    if (huart == &huart2) {
        serial_rx_byte(rxbuf);
        HAL_UART_Receive_IT(&huart2,&rxbuf,(uint16_t)1);
    }
}

void serial_enable_tx_irq(void)
{
    while(huart2.gState != HAL_UART_STATE_READY);
    if(serial_get_tx_byte(&txbuf) == 0) {
        HAL_UART_Transmit_IT(&huart2,&txbuf,(uint16_t)1);
    }
}

void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
{
    if (huart == &huart2)
        serial_enable_tx_irq();
}

/**
* @brief UART MSP Initialization
* @param huart: UART handle pointer
* @retval None
*/
void HAL_UART_MspInit(UART_HandleTypeDef* huart)
{

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(huart->Instance==USART2)
  {
    /* Peripheral clock enable */
    __HAL_RCC_USART2_CLK_ENABLE();

    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**USART2 GPIO Configuration
    PA2     ------> USART2_TX
    PA3     ------> USART2_RX
    */
    GPIO_InitStruct.Pin = GPIO_PIN_2|GPIO_PIN_3;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF1_USART2;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* USART2 interrupt Init */
    HAL_NVIC_SetPriority(USART2_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(USART2_IRQn);
  }
}