/*!
 * \file      xc_drv_systick.c
 *
 * \brief     Target xinchip systick driver implementation
 *
 * \copyright Revised BSD License, see section \ref LICENSE.
 *
 * \code
 *
 *            _  __ _       ________    _
 *           | |/ /(_)___  / ____/ /_  (_)___
 *           |   // / __ \/ /   / __ \/ / __ \
 *          /   |/ / / / / /___/ / / / / /_/ /
 *         /_/|_/_/_/ /_/\____/_/ /_/_/ .___/
 *                                   /_/
 *           (C) 2022-2025 XinChip
 *
 * \endcode
 *
 * \author     ( XinChip ) Alex-J
 *
 * \author     ( XinChip )
 */

/*-----------------------------------------------------------------------------------
                                       INCLUDE HEADE FILES
 ------------------------------------------------------------------------------------*/
#include "xc_drv_systick.h"
#include "xc_drv_clock.h"

/*------------------------------------------------------------------------------------
                                            Functions
 -------------------------------------------------------------------------------------*/

void SysTick_Handler(void) { systick_callback(); }

void delay_us(uint32_t nus)
{
    if (nus == 0)
        return;

    uint32_t unit = xc_systick_unit_get();

    uint32_t temp;

    SysTick->CTRL = 0x00; // 关闭计数器
    SysTick->LOAD = unit * nus - unit + 1;

    SysTick->VAL  = 0;
    SysTick->CTRL = 0x05;

    do {
        temp = SysTick->CTRL; // 读取当前倒计数值
    } while ((temp & 0x01) && (!(temp & (1 << 16))));
}

void delay_ms(uint32_t nms)
{
    if (nms == 0) {
        return;
    }

    do {
        delay_us(1000);
    } while (--nms);
}

__WEAK void systick_callback(void) {}