/********************************** (C) COPYRIGHT  *******************************
 * File Name          : debug.c
 * Author             : WCH
 * Version            : V1.0.0
 * Date               : 2022/08/08
 * Description        : This file contains all the functions prototypes for UART
 *                      Printf , Delay functions.
 * Copyright (c) 2021 Nanjing Qinheng Microelectronics Co., Ltd.
 * SPDX-License-Identifier: Apache-2.0
 *******************************************************************************/
#include <debug.h>

static uint8_t  p_us = 0;
static uint16_t p_ms = 0;

/*********************************************************************
 * @fn      Delay_Init
 *
 * @brief   Initializes Delay Funcation.
 *
 * @return  none
 */
void Delay_Init(void)
{
    p_us = SystemCoreClock / 8000000;
    p_ms = (uint16_t)p_us * 1000;
}

/*********************************************************************
 * @fn      Delay_Us
 *
 * @brief   Microsecond Delay Time.
 *
 * @param   n - Microsecond number.
 *
 * @return  None
 */
void Delay_Us(uint32_t n)
{
    uint32_t i;

    SysTick->SR &= ~(1 << 0);
    i = (uint32_t)n * p_us;

    SysTick->CMP = i;
    SysTick->CNT = 0;
    SysTick->CTLR |= (1 << 5) | (1 << 0);

    while((SysTick->SR & (1 << 0)) != (1 << 0));
    SysTick->CTLR &= ~(1 << 0);
}

/*********************************************************************
 * @fn      Delay_Ms
 *
 * @brief   Millisecond Delay Time.
 *
 * @param   n - Millisecond number.
 *
 * @return  None
 */
void Delay_Ms(uint32_t n)
{
    uint32_t i;

    SysTick->SR &= ~(1 << 0);
    i = (uint32_t)n * p_ms;

    SysTick->CMP = i;
    SysTick->CNT = 0;
    SysTick->CTLR |= (1 << 5) | (1 << 0);

    while((SysTick->SR & (1 << 0)) != (1 << 0));
    SysTick->CTLR &= ~(1 << 0);
}

/*********************************************************************
 * @fn      USART_Printf_Init
 *
 * @brief   Initializes the USARTx peripheral.
 *
 * @param   baudrate - USART communication baud rate.
 *
 * @return  None
 */
void USART_Printf_Init(uint32_t baudrate)
{
    GPIO_InitTypeDef  GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD | RCC_APB2Periph_USART1, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOD, &GPIO_InitStructure);

    USART_InitStructure.USART_BaudRate = baudrate;
    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_Init(USART1, &USART_InitStructure);
    USART_Cmd(USART1, ENABLE);
}

/*********************************************************************
 * @fn      _write
 *
 * @brief   Support Printf Function
 *
 * @param   *buf - UART send Data.
 *          size - Data length.
 *
 * @return  size - Data length
 */
__attribute__((used)) 
int _write(int fd, char *buf, int size)
{
    int i;

    for(i = 0; i < size; i++){
        while(USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET);
        USART_SendData(USART1, *buf++);
    }

    return size;
}

/*********************************************************************
 * @fn      _sbrk
 *
 * @brief   Change the spatial position of data segment.
 *
 * @return  size: Data length
 */
void *_sbrk(ptrdiff_t incr)
{
    extern char _end[];
    extern char _heap_end[];
    static char *curbrk = _end;

    if ((curbrk + incr < _end) || (curbrk + incr > _heap_end))
    return NULL - 1;

    curbrk += incr;
    return curbrk - incr;
}