按键1实现小灯亮灭，按键2实现蜂鸣器，安静3实现风扇

src/key_it.c

#include"key_it.h"

void key3_it_config()
{
    //RCC使能GPIOF时钟
    RCC->MP_AHB4ENSETR |= (0x1<<5);
    GPIOF->MODER &= (~(0x3<<16));
    EXTI->EXTICR3 &=(~(0xFF<<0));
    EXTI->EXTICR3 |= (0x5<<0);
    EXTI->FTSR1 |= (0x1<<8);
    EXTI->C1IMR1 |= (0x1<<8);
    GICD->ISENABLER[3] |= (0X1<<2); 
    GICD->IPRIORITYR[24] &= (~(0X1F<<19)); 
    GICD->ITARGETSR[24]  &= (~(0X3<<16));
    GICD->ITARGETSR[24] |= (0X1<<16);
}
void key_it_config()
{
    //RCC使能GPIOF时钟
    RCC->MP_AHB4ENSETR |= (0x1<<5);
    //设置PF9 PF7 PF8GPIO输入
    //PF9
    GPIOF->MODER &= (~(0x3<<18));
    //PF8
    // GPIOF->MODER &= (~(0x3<<16));
    //pf7
    GPIOF->MODER &= (~(0x3<<14));
    //设置PF9 PF7 PF8产生EXTI事件 EXTI_EXTICRx
    //pf7
    EXTI->EXTICR2 &=(~(0xFF<<24));
    EXTI->EXTICR2 |= (0x5<<24);
    //pf8
    // EXTI->EXTICR3 &=(~(0xFF<<0));
    // EXTI->EXTICR3 |= (0x5<<0);
    //pf9
    EXTI->EXTICR3 &=(~(0xFF<<8));
    EXTI->EXTICR3 |= (0x5<<8);
    //设置事件触发方式为下降沿触发EXTI_FTSR1
    //pf7
    EXTI->FTSR1 |= (0x1<<7);
    //pf8
    // EXTI->FTSR1 |= (0x1<<8);
    //pf9
    EXTI->FTSR1 |= (0x1<<9);
    //设置EXTI事件触发不屏蔽EXTI_IMR1
    //PF7
    EXTI->C1IMR1 |= (0x1<<7);
    //PF8
    // EXTI->C1IMR1 |= (0x1<<8);
    //PF9
    EXTI->C1IMR1 |= (0x1<<9);
    //使能中断能转发到特定的CPU接口层GICD_ISENABLERx
    //PF7 97号中断
    GICD->ISENABLER[3] |= (0X1<<1); 
    //PF78 98号中断
    // GICD->ISENABLER[3] |= (0X1<<2); 
    //PF9 99号中断
    GICD->ISENABLER[3] |= (0X1<<3); 
    // GICD_ISENABLERx设置中断优先级
    //PF7
    GICD->IPRIORITYR[24] &= (~(0X1F<<11)); 
    //PF8
    // GICD->IPRIORITYR[24] &= (~(0X1F<<19)); 
    //PF9
    GICD->IPRIORITYR[24] &= (~(0X1F<<27)); 
    //设置当前中断被转发到哪一个CPU处理GICD_ITARGETSRx
    //pf7 97中断
    GICD->ITARGETSR[24]  &= (~(0X3<<8));
    GICD->ITARGETSR[24] |= (0X1<<8);
    //pf8 98中断
    // GICD->ITARGETSR[24]  &= (~(0X3<<16));
    // GICD->ITARGETSR[24] |= (0X1<<16);
    //pf9 99中断
    GICD->ITARGETSR[24]  &= (~(0X3<<24));
    GICD->ITARGETSR[24] |= (0X1<<24);
    //使能组0转发中断GICD_CTLR
    GICD->CTRL |= 0X1;
    //设置中断优先级掩码GICC_PMR
    GICC->PMR |= (0x1F<<3);

    //使能CPU可以处理组0转发的中断GICC_CTLR
    GICC->CTRL |= 0X1;

    
}
void all_led_init()
{
    //RCC使能
    RCC->MP_AHB4ENSETR |= (0x3<<4);
    //设置PE10 PF10 PE8为输出
    GPIOE->MODER &= (~(0X3<<20));
    GPIOE->MODER |= (0X1<<20);
    GPIOF->MODER &= (~(0X3<<20));
    GPIOF->MODER |= (0X1<<20);
    GPIOE->MODER &= (~(0X3<<16));
    GPIOE->MODER |= (0X1<<16);
    //设置推挽输出
    GPIOE->OTYPER &= (~(0X1<<10));
    GPIOF->OTYPER &= (~(0X1<<10));
    GPIOE->OTYPER &= (~(0X1<<8));
    //设置三个管脚低速输出
    GPIOE->OSPEEDR &= (~(0X3<<20));
    GPIOF->OSPEEDR &= (~(0X3<<20));
    GPIOE->OSPEEDR &= (~(0X3<<16));
    //设置三个管脚输出时无上拉电阻和下拉电阻
    GPIOE->PUPDR &= (~(0X3<<20));
    GPIOF->PUPDR &= (~(0X3<<20));
    GPIOE->PUPDR &= (~(0X3<<16));

}
void all_fmq_init()
{
	RCC->MP_AHB4ENSETR |=(0x1<<1);
	GPIOB->MODER &=(~(0x3<<12));
	GPIOB->MODER |=(0x1<<12);
	GPIOB->OTYPER &=(~(0x1<<6));
	GPIOB->OSPEEDR &=(~(0x3<<12));
	GPIOB->PUPDR &=(~(0x3<<12));
}
void all_fun_init()
{

	GPIOE->MODER &=(~(0x3<<18));
	GPIOE->MODER |=(0x1<<18);
	GPIOE->OTYPER &=(~(0x1<<9));
	GPIOE->OSPEEDR &=(~(0x3<<18));
	GPIOE->PUPDR &=(~(0x3<<18));

}

src/do_irq.c

#include "key_it.h"
extern void printf(const char *fmt, ...);
unsigned int i = 0;
void do_irq(void)
{
    int irqno; // 保存中断号
    irqno = GICC->IAR & 0X3FF;
    switch (irqno)
    {
    case 99: // key1
        // 按键1中断处理
		if(GPIOE->ODR&(1<<10))
		{
			GPIOE->ODR&=(~(1<<10));
		}else
		{
			GPIOE->ODR |=(1<<10);
		}
        printf("KEY1 INT\n");
		// 清除挂起中断标志位GICD_ICPENDRx
        GICD->ICPENDR[3] |= (0x1 << 3);
        // 清除中断触发标志位EXTI_FPR1
        EXTI->FPR1 |= (0x1 << 9);
        break;
    case 97: // KEY2
		if(GPIOB->ODR & (1<<6)){
                GPIOB->ODR &= (~(1<<6));
            }else{
                GPIOB->ODR |= (1<<6);
            }

        // 按键2中断处理
        printf("KEY2 INT\n");
        // 清除挂起中断标志位GICD_ICPENDRx
        GICD->ICPENDR[3] |= (0x1 << 1);
        // 清除中断触发标志位EXTI_FPR1
        EXTI->FPR1 |= (0x1 << 7);
        break;
    case 98: // key3
        // 按键3中断处理
		if(GPIOE->ODR & (1<<9)){
                GPIOE->ODR &= (~(1<<9));
            }else{
                GPIOE->ODR |= (1<<9);
            }

        printf("KEY3 INT\n");
        // 清除挂起中断标志位GICD_ICPENDRx
        GICD->ICPENDR[3] |= (0x1 << 2);
        // 清除中断触发标志位EXTI_FPR1
        EXTI->FPR1 |= (0x1 << 8);
        break;
    }
    // 清除处理完的中断号GICC_EOIR
    GICC->EOIR = irqno;
}

include/key_it.h

#ifndef _KEY_IT_H
#define _KEY_IT_H
#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_exti.h"
#include "stm32mp1xx_gic.h"
void key_it_config();
void all_led_init();
void all_fmg_init();
void all_fun_init();
#endif

main.c

#include"uart.h"
#include"key_it.h"
int main()
{
	char c;
	char *s;
	uart4_init();//串口初始化
	key_it_config();
	key3_it_config();
	all_led_init();
	all_fmq_init();
	all_fun_init();
	while(1)
	{
		//串口数据收发
		//接受一个字符
		//c=getchar();
		//发送一个字符
		//putchar(c+1);
	//	s=getchars();
	//	putchars(s);
		//LED1亮
        
		
		
	}
	
	return 0;
}