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/*******************************************
  USART interrupt hander
   Ver 0.01 2024/07/15 by skyriver
 *******************************************/

/*
 * usard receive interrupt routine
 * USART2:Tx(PA2),Rx(PA3)
 */

#define	RiSIO	USART2
#define	RiPORT	GPIOA
#define	RiSIOTx	GPIO_Pin_2
#define	RiSIORx	GPIO_Pin_3

#define RXBUFSIZE	128	// receive buffer size
#define BUFIDXMASK	(RXBUFSIZE - 1)


void InitSio( void );
uint8_t SioGetc( void );

extern volatile uint8_t RxCnt;

/*******************************************
  USART interrupt hander
   Ver 0.01 2024/07/15 by skyriver
 *******************************************/


#include "debug.h"
#include <stdint.h>

#include "serial.h"


voratile uint8_t RxBuf[ RXBUFSIZE ] = {0};
volatile uint8_t RxCnt = 0, RxWrIdx = 0;
volatile uint8_t RxRdIdx = 0; 

void USART2_IRQHandler(void) __attribute__((interrupt("WCH-Interrupt-fast")));


/*
 * configlate USARTn
 *  return : none
 */
void InitSio( void )
{
	GPIO_InitTypeDef  GPIO_InitStructure = {0};
	USART_InitTypeDef USART_InitStructure = {0};
	NVIC_InitTypeDef  NVIC_InitStructure = {0};

	RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);	// uart name
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);	// port name

	/* USART TX   Rx */
	GPIO_InitStructure.GPIO_Pin = RiSIOTx;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
	GPIO_Init(RiPORT, &GPIO_InitStructure);

	GPIO_InitStructure.GPIO_Pin = RiSIORx;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
	GPIO_Init(RiPORT, &GPIO_InitStructure);

	USART_InitStructure.USART_BaudRate = 115200;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;
	USART_InitStructure.USART_StopBits = USART_StopBits_1;
	USART_InitStructure.USART_Parity = USART_Parity_No;
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
	USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;

	USART_Init(RiSIO, &USART_InitStructure);
	USART_ITConfig(RiSIO, USART_IT_RXNE, ENABLE);

	NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;		// uart name
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);

	USART_Cmd(RiSIO, ENABLE);
}


/*
 * Rx interrupt handler
 */
void USART2_IRQHandler( void )
{
	if( USART_GetITStatus( RiSIO, USART_IT_RXNE ) != RESET ) {
		if( RxCnt < (RXBUFSIZE - 1) ) {	// not buffer full
			RxCnt++;
			RxBuf[RxWrIdx++] = USART_ReceiveData(RiSIO);
			RxWrIdx &= BUFIDXMASK;
		} else {
			USART_ReceiveData(RiSIO);
		}
	}
}


/*
 * get character from Rx buffer
 *  return -> data
 */
uint8_t SioGetc( void )
{
	uint8_t data;

	while( RxCnt == 0 ) {}
	USART_ITConfig(RiSIO, USART_IT_RXNE, DISABLE);		// disable Rx interrupt
	data = RxBuf[ RxRdIdx++ ];
	RxRdIdx &= BUFIDXMASK;
	RxCnt--;
	USART_ITConfig(RiSIO, USART_IT_RXNE, ENABLE);		// enable Rx interrupt
	return( data );
}