key_inc.c

 #include"key_inc.h"
 void key1_it_config()
 {
    //使能GPIOF外设时钟
    RCC->MP_AHB4ENSETR |= (0x1<<5);
    //将PF9设置为输入模式
    GPIOF->MODER &= (~(0x3<<18));
    //设置由PF9管脚产生EXTI9事件
    EXTI->EXTICR3 &= (~(0XFF<<8));
    EXTI->EXTICR3|= (0X05<<8);
    //通过下降沿检测EXTI9事件是否产生
    EXTI->FTSR1 |= (0x1<<9);
    //取消EXTI9中断屏蔽
    EXTI->C1IMR1 |= (0x1<<9);
    //设置EXTI9中断全局使能
    GICD->ISENABLER[3] |= (0x1<<3);
    //设置中断优先级
    GICD->IPRIORITYR[24] &= (~(0x1f<<27));
      //设置CPU0处理当前中断
    GICD->ITARGETSR[24] |= (0x1<<24);
    //设置组0中断可以被转发到GICC层
    GICD->CTRL |=0X1;
    //设置中断优先级掩码
    GICC->PMR |= (0x1f<<3);
    //设置组0中断交给指定处理器处理
    GICC->CTRL |= 0x1;
 }
 
  void key2_it_config()
 {
     //使能GPIOF外设时钟
    RCC->MP_AHB4ENSETR |= (0x1<<5);
    //将PF7设置为输入模式
    GPIOF->MODER &= (~(0x3<<14));
    //设置由PF7脚产生EXTI9事件
    EXTI->EXTICR2 &= (~(0XFF<<24));
    EXTI->EXTICR2|= (0X05<<24);
    //通过下降沿检测EXTI7事件是否产生
    EXTI->FTSR1 |= (0x1<<7);
    //取消EXTI7中断屏蔽
    EXTI->C1IMR1 |= (0x1<<7);
    //设置EXTI7中断全局使能
    GICD->ISENABLER[3] |= (0x1<<1);
    //设置中断优先级
    GICD->IPRIORITYR[24] &= (~(0x1f<<11));
      //设置CPU0处理当前中断
    GICD->ITARGETSR[24] |= (0x1<<8);
    //设置组0中断可以被转发到GICC层
    GICD->CTRL |=0X1;
    //设置中断优先级掩码
    GICC->PMR |= (0x1f<<3);
    //设置组0中断交给指定处理器处理
    GICC->CTRL |= 0x1;
 }

   void key3_it_config()
 {
     //使能GPIOF外设时钟
    RCC->MP_AHB4ENSETR |= (0x1<<5);
    //将PF8设置为输入模式
    GPIOF->MODER &= (~(0x3<<16));
    //设置由PF7脚产生EXTI8事件
    EXTI->EXTICR3 &= (~(0XFF));
    EXTI->EXTICR3|= (0X05);
    //通过下降沿检测EXTI8事件是否产生
    EXTI->FTSR1 |= (0x1<<8);
    //取消EXTI8中断屏蔽
    EXTI->C1IMR1 |= (0x1<<8);
    //设置EXTI8中断全局使能
    GICD->ISENABLER[3] |= (0x1<<2);
    //设置中断优先级
    GICD->IPRIORITYR[24] &= (~(0x1f<<19));
      //设置CPU0处理当前中断
    GICD->ITARGETSR[24] |= (0x1<<16);
    //设置组0中断可以被转发到GICC层
    GICD->CTRL |=0X1;
    //设置中断优先级掩码
    GICC->PMR |= (0x1f<<3);
    //设置组0中断交给指定处理器处理
    GICC->CTRL |= 0x1;
 }

do_irq.c

#include "stm32mp1xx_gic.h"
#include "stm32mp1xx_exti.h"
extern void printf(const char *fmt, ...);
unsigned int i = 0;
void do_irq(void) 
{
    //获取要处理的中断的中断号
    unsigned int irqno=GICC->IAR&0x3ff;
    switch (irqno)
    {
    case 99:
        printf("key1_intc\n");
        //清除GICD中断排队标志
        GICD->ICPENDR[3] |= (0X1<<3);
        //清除EXTI中断触发标志
        EXTI->FPR1 |= (0X1<<9);
        break;

        case 97:
        printf("key2_intc\n");
        //清除GICD中断排队标志
         GICD->ICPENDR[3] |= (0X1<<1);
        //清除EXTI中断触发标志
        EXTI->FPR1 |= (0X1<<7);
        break;

        case 98:
        printf("key3_intc\n");
        //清除GICD中断排队标志
         GICD->ICPENDR[3] |= (0X1<<8);
        //清除EXTI中断触发标志
        EXTI->FPR1 |= (0X1<<8);
        break;
    
    default:
        break;
    }
    //清除IAR寄存器中的中断号
    GICC->EOIR |= irqno;
}